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What is the function of the AIRE gene at the embryonic stage?

Aire regulates the expression of differentiation-associated genes and self-renewal of embryonic stem cells. Aire and Deaf1 help regulate the ectopic expression of diverse tissue-specific antigens to establish self-immune tolerance. Knockdown of Aire in mouse ESCs resulted in significantly decreased clone-forming efficiency as well as attenuated cell cycle, suggesting Aire plays a role in ESC self-renewal. Aire promotes the expression of the pluripotent factor Lin28 and the self-renewal of ES cells.

[19008896, 21952165, 22540148, 20226168, 19302042]

The negative selection of T cells in the thymus is necessary for the maintenance of self tolerance. Medullary thymic epithelial cells have a key function in this process as they express a large number of tissue-specific self antigens that are presented to developing T cells. Mutations in the autoimmune regulator (AIRE) protein cause a breakdown of central tolerance that is associated with decreased expression of self antigens in the thymus. In this Review, we discuss the role of AIRE in the thymus and recent advances in our understanding of how AIRE might function at the molecular level to regulate gene expression. Mesenchymal stem cells (MSCs) are emerging as a promising immunotherapeutic, based largely on their overt suppression of T lymphocytes under inflammatory and autoimmune conditions. While paracrine cross-talk between MSCs and T cells has been well-studied, an intrinsic transcriptional switch that programs MSCs for immunomodulation has remained undefined. Here we show that bone marrow-derived MSCs require the transcriptional regulator Aire to suppress T cell-mediated pathogenesis in a mouse model of chronic colitis. Surprisingly, Aire did not control MSC suppression of T cell proliferation in vitro. Instead, Aire reduced T cell mitochondrial reductase by negatively regulating a proinflammatory cytokine, early T cell activation factor (Eta)-1. Neutralization of Eta-1 enabled Aire(-/-) MSCs to ameliorate colitis, reducing the number of infiltrating effector T cells in the colon, and normalizing T cell reductase levels. We propose that Aire represents an early molecular switch imposing a suppressive MSC phenotype via regulation of Eta-1. Monitoring Aire expression in MSCs may thus be a critical parameter for clinical use. Embryonic stem cells (ESCs) are pluripotent stem cells from early embryos. It has been well recognized that ESC genomes are maintained in a globally transcriptional hyperactive state, which genetically poised ESCs to the high differentiation potential. However, the transcription factors regulating the global transcription activities in ESCs are not well defined. We show here that mouse and human ESCs express two transcription factors, Aire and Deaf1. Previously known to function in the thymus stromal cells and peripheral lymphoid organs respectively, Aire and Deaf1 help regulate the ectopic expression of diverse tissue-specific antigens to establish self-immune tolerance. Differentiation of ESCs greatly reduced Aire and Deaf1 expression, in a pattern similar to the pluripotent factors, Oct4 and Nanog. Knockdown of Aire in mouse ESCs resulted in significantly decreased clone-forming efficiency as well as attenuated cell cycle, suggesting Aire plays a role in ESC self-renewal. In addition, some differentiation-associated genes that are sporadically expressed in ESCs were reduced in expression upon Aire knockdown. These results suggest that transcription factors such as Aire and Deaf1, which exert global transcriptional regulatory functions, may play important roles in self-renewal of ESCs and maintaining ESC in a transcriptionally hyperactive state. Mutations in the transcriptional regulator, Aire, cause APECED, a polyglandular autoimmune disease with monogenic transmission. Animal models of APECED have revealed that Aire plays an important role in T cell tolerance induction in the thymus, mainly by promoting ectopic expression of a large repertoire of transcripts encoding proteins normally restricted to differentiated organs residing in the periphery. The absence of Aire results in impaired clonal deletion of self-reactive thymocytes, which escape into the periphery and attack a variety of organs. In addition, Aire is a proapoptotic factor, expressed at the final maturation stage of thymic medullary epithelial cells, a function that may promote cross-presentation of the antigens encoded by Aire-induced transcripts in these cells. Transcriptional regulation by Aire is unusual in being very broad, context-dependent, probabilistic, and noisy. Structure/function analyses and identification of its interaction partners suggest that Aire may impact transcription at several levels, including nucleosome displacement during elongation and transcript splicing or other aspects of maturation.

What is the principle of the PAR-CLIP methodology?

In particular, PAR-CLIP utilizes a photoactivatable nucleoside for more efficient crosslinking. A recent method, PAR-CLIP, uses photoreactive nucleosides to crosslink RBPs to target RNAs in cells prior to immunoprecipitation. One characteristic feature of cDNA libraries prepared by PAR-CliP is that the precise position of crosslinking can be identified by mutations residing in the sequenced cDNA.

[21559008, 23706177, 22213601, 24297251, 22152485, 22844102, 21851591, 21816340, 20371350, 21572407, 22885304, 20644507, 23368412, 22926237]

The unique composition and spatial arrangement of RNA-binding proteins (RBPs) on a transcript guide the diverse aspects of post-transcriptional regulation. Therefore, an essential step towards understanding transcript regulation at the molecular level is to gain positional information on the binding sites of RBPs. Protein-RNA interactions can be studied using biochemical methods, but these approaches do not address RNA binding in its native cellular context. Initial attempts to study protein-RNA complexes in their cellular environment employed affinity purification or immunoprecipitation combined with differential display or microarray analysis (RIP-CHIP). These approaches were prone to identifying indirect or non-physiological interactions. In order to increase the specificity and positional resolution, a strategy referred to as CLIP (UV cross-linking and immunoprecipitation) was introduced. CLIP combines UV cross-linking of proteins and RNA molecules with rigorous purification schemes including denaturing polyacrylamide gel electrophoresis. In combination with high-throughput sequencing technologies, CLIP has proven as a powerful tool to study protein-RNA interactions on a genome-wide scale (referred to as HITS-CLIP or CLIP-seq). Recently, PAR-CLIP was introduced that uses photoreactive ribonucleoside analogs for cross-linking. Despite the high specificity of the obtained data, CLIP experiments often generate cDNA libraries of limited sequence complexity. This is partly due to the restricted amount of co-purified RNA and the two inefficient RNA ligation reactions required for library preparation. In addition, primer extension assays indicated that many cDNAs truncate prematurely at the crosslinked nucleotide. Such truncated cDNAs are lost during the standard CLIP library preparation protocol. We recently developed iCLIP (individual-nucleotide resolution CLIP), which captures the truncated cDNAs by replacing one of the inefficient intermolecular RNA ligation steps with a more efficient intramolecular cDNA circularization (Figure 1). Importantly, sequencing the truncated cDNAs provides insights into the position of the cross-link site at nucleotide resolution. We successfully applied iCLIP to study hnRNP C particle organization on a genome-wide scale and assess its role in splicing regulation. All mRNA molecules are subject to some degree of post-transcriptional gene regulation (PTGR) involving sequence-dependent modulation of splicing, cleavage and polyadenylation, editing, transport, stability, and translation. The recent introduction of deep-sequencing technologies enabled the development of new methods for broadly mapping interaction sites between RNA-binding proteins (RBPs) and their RNA target sites. In this article, we review crosslinking and immunoprecipitation (CLIP) methods adapted for large-scale identification of target RNA-binding sites and the respective RNA recognition elements. CLIP methods have the potential to detect hundreds of thousands of binding sites in single experiments although the separation of signal from noise can be challenging. As a consequence, each CLIP method has developed different strategies to distinguish true targets from background. We focus on photoactivatable ribonucleoside-enhanced CLIP, which relies on the intracellular incorporation of photoactivatable ribonucleoside analogs into nascent transcripts, and yields characteristic sequence changes upon crosslinking that facilitate the separation of signal from noise. The precise knowledge of the position and distribution of binding sites across mature and primary mRNA transcripts allows critical insights into cellular localization and regulatory function of the examined RBP. When coupled with other systems-wide approaches measuring transcript and protein abundance, the generation of high-resolution RBP-binding site maps across the transcriptome will broaden our understanding of PTGR and thereby lead to new strategies for therapeutic treatment of genetic diseases perturbing these processes. Although microRNAs (miRNAs), other non-coding RNAs (ncRNAs) (e.g. lncRNAs, pseudogenes and circRNAs) and competing endogenous RNAs (ceRNAs) have been implicated in cell-fate determination and in various human diseases, surprisingly little is known about the regulatory interaction networks among the multiple classes of RNAs. In this study, we developed starBase v2.0 (http://starbase.sysu.edu.cn/) to systematically identify the RNA-RNA and protein-RNA interaction networks from 108 CLIP-Seq (PAR-CLIP, HITS-CLIP, iCLIP, CLASH) data sets generated by 37 independent studies. By analyzing millions of RNA-binding protein binding sites, we identified ∼9000 miRNA-circRNA, 16 000 miRNA-pseudogene and 285,000 protein-RNA regulatory relationships. Moreover, starBase v2.0 has been updated to provide the most comprehensive CLIP-Seq experimentally supported miRNA-mRNA and miRNA-lncRNA interaction networks to date. We identified ∼10,000 ceRNA pairs from CLIP-supported miRNA target sites. By combining 13 functional genomic annotations, we developed miRFunction and ceRNAFunction web servers to predict the function of miRNAs and other ncRNAs from the miRNA-mediated regulatory networks. Finally, we developed interactive web implementations to provide visualization, analysis and downloading of the aforementioned large-scale data sets. This study will greatly expand our understanding of ncRNA functions and their coordinated regulatory networks. Animal mRNAs are regulated by hundreds of RNA binding proteins (RBPs). The identification of RBP targets is crucial for understanding their function. A recent method, PAR-CLIP, uses photoreactive nucleosides to crosslink RBPs to target RNAs in cells prior to immunoprecipitation. Here, we establish iPAR-CLIP (in vivo PAR-CLIP) to determine, at nucleotide resolution, transcriptome-wide binding sites of GLD-1, a conserved, germline-specific translational repressor in C. elegans. We identified 439 reproducible target mRNAs and demonstrate an excellent dynamic range of target detection by iPAR-CLIP. Upon GLD-1 knockdown, protein but not mRNA expression of the 439 targets was specifically upregulated, demonstrating functionality. Finally, we discovered strongly conserved GLD-1 binding sites near the start codon of target genes. These sites are functional in vitro and likely confer strong repression in vivo. We propose that GLD-1 interacts with the translation machinery near the start codon, a so-far-unknown mode of gene regulation in eukaryotes. The Photo-Activatable Ribonucleoside-enhanced CrossLinking and ImmunoPrecipitation (PAR-CLIP) method was recently developed for global identification of RNAs interacting with proteins. The strength of this versatile method results from induction of specific T to C transitions at sites of interaction. However, current analytical tools do not distinguish between non-experimentally and experimentally induced transitions. Furthermore, geometric properties at potential binding sites are not taken into account. To surmount these shortcomings, we developed a two-step algorithm consisting of a non-parametric two-component mixture model and a wavelet-based peak calling procedure. Our algorithm can reduce the number of false positives up to 24% thereby identifying high confidence interaction sites. We successfully employed this approach in conjunction with a modified PAR-CLIP protocol to study the functional role of nuclear Moloney leukemia virus 10, a putative RNA helicase interacting with Argonaute2 and Polycomb. Our method, available as the R package wavClusteR, is generally applicable to any substitution-based inference problem in genomics. The RNA-binding protein HuR, while known to stabilize cytoplasmic mRNAs, is largely nuclear. In this issue of Molecular Cell, Mukherjee et al. (2011) and Lebedeva et al. (2011) identify transcriptome-wide HuR-RNA interactions using PAR-CLIP, unveiling HuR's nuclear role in pre-mRNA processing. RNA transcripts are subject to posttranscriptional gene regulation involving hundreds of RNA-binding proteins (RBPs) and microRNA-containing ribonucleoprotein complexes (miRNPs) expressed in a cell-type dependent fashion. We developed a cell-based crosslinking approach to determine at high resolution and transcriptome-wide the binding sites of cellular RBPs and miRNPs. The crosslinked sites are revealed by thymidine to cytidine transitions in the cDNAs prepared from immunopurified RNPs of 4-thiouridine-treated cells. We determined the binding sites and regulatory consequences for several intensely studied RBPs and miRNPs, including PUM2, QKI, IGF2BP1-3, AGO/EIF2C1-4 and TNRC6A-C. Our study revealed that these factors bind thousands of sites containing defined sequence motifs and have distinct preferences for exonic versus intronic or coding versus untranslated transcript regions. The precise mapping of binding sites across the transcriptome will be critical to the interpretation of the rapidly emerging data on genetic variation between individuals and how these variations contribute to complex genetic diseases. Cross-linking and immunoprecipitation (CLIP) is increasingly used to map transcriptome-wide binding sites of RNA-binding proteins. We developed a method for CLIP data analysis, and applied it to compare CLIP with photoactivatable ribonucleoside-enhanced CLIP (PAR-CLIP) and to uncover how differences in cross-linking and ribonuclease digestion affect the identified sites. We found only small differences in accuracies of these methods in identifying binding sites of HuR, which binds low-complexity sequences, and Argonaute 2, which has a complex binding specificity. We found that cross-link-induced mutations led to single-nucleotide resolution for both PAR-CLIP and CLIP. Our results confirm the expectation from original CLIP publications that RNA-binding proteins do not protect their binding sites sufficiently under the denaturing conditions used during the CLIP procedure, and we show that extensive digestion with sequence-specific RNases strongly biases the recovered binding sites. This bias can be substantially reduced by milder nuclease digestion conditions. Systematic analysis of the RNA-protein interactome requires robust and scalable methods. We here show the combination of two completely orthogonal, generic techniques to identify RNA-protein interactions: PAR-CLIP reveals a collection of RNAs bound to a protein whereas SILAC-based RNA pull-downs identify a group of proteins bound to an RNA. We investigated binding sites for five different proteins (IGF2BP1-3, QKI and PUM2) exhibiting different binding patterns. We report near perfect agreement between the two approaches. Nevertheless, they are non-redundant, and ideally complement each other to map the RNA-protein interaction network. RNA transcripts are subjected to post-transcriptional gene regulation by interacting with hundreds of RNA-binding proteins (RBPs) and microRNA-containing ribonucleoprotein complexes (miRNPs) that are often expressed in a cell-type dependently. To understand how the interplay of these RNA-binding factors affects the regulation of individual transcripts, high resolution maps of in vivo protein-RNA interactions are necessary. A combination of genetic, biochemical and computational approaches are typically applied to identify RNA-RBP or RNA-RNP interactions. Microarray profiling of RNAs associated with immunopurified RBPs (RIP-Chip) defines targets at a transcriptome level, but its application is limited to the characterization of kinetically stable interactions and only in rare cases allows to identify the RBP recognition element (RRE) within the long target RNA. More direct RBP target site information is obtained by combining in vivo UV crosslinking with immunoprecipitation followed by the isolation of crosslinked RNA segments and cDNA sequencing (CLIP). CLIP was used to identify targets of a number of RBPs. However, CLIP is limited by the low efficiency of UV 254 nm RNA-protein crosslinking, and the location of the crosslink is not readily identifiable within the sequenced crosslinked fragments, making it difficult to separate UV-crosslinked target RNA segments from background non-crosslinked RNA fragments also present in the sample. We developed a powerful cell-based crosslinking approach to determine at high resolution and transcriptome-wide the binding sites of cellular RBPs and miRNPs that we term PAR-CliP (Photoactivatable-Ribonucleoside-Enhanced Crosslinking and Immunoprecipitation) (see Fig. 1A for an outline of the method). The method relies on the incorporation of photoreactive ribonucleoside analogs, such as 4-thiouridine (4-SU) and 6-thioguanosine (6-SG) into nascent RNA transcripts by living cells. Irradiation of the cells by UV light of 365 nm induces efficient crosslinking of photoreactive nucleoside-labeled cellular RNAs to interacting RBPs. Immunoprecipitation of the RBP of interest is followed by isolation of the crosslinked and coimmunoprecipitated RNA. The isolated RNA is converted into a cDNA library and deep sequenced using Solexa technology. One characteristic feature of cDNA libraries prepared by PAR-CliP is that the precise position of crosslinking can be identified by mutations residing in the sequenced cDNA. When using 4-SU, crosslinked sequences thymidine to cytidine transition, whereas using 6-SG results in guanosine to adenosine mutations. The presence of the mutations in crosslinked sequences makes it possible to separate them from the background of sequences derived from abundant cellular RNAs. Application of the method to a number of diverse RNA binding proteins was reported in Hafner et al. BACKGROUND: MicroRNAs (miRNAs) play a critical role in down-regulating gene expression. By coupling with Argonaute family proteins, miRNAs bind to target sites on mRNAs and employ translational repression. A large amount of miRNA-target interactions (MTIs) have been identified by the crosslinking and immunoprecipitation (CLIP) and the photoactivatable-ribonucleoside-enhanced CLIP (PAR-CLIP) along with the next-generation sequencing (NGS). PAR-CLIP shows high efficiency of RNA co-immunoprecipitation, but it also lead to T to C conversion in miRNA-RNA-protein crosslinking regions. This artificial error obviously reduces the mappability of reads. However, a specific tool to analyze CLIP and PAR-CLIP data that takes T to C conversion into account is still in need. RESULTS: We herein propose the first CLIP and PAR-CLIP sequencing analysis platform specifically for miRNA target analysis, namely miRTarCLIP. From scratch, it automatically removes adaptor sequences from raw reads, filters low quality reads, reverts C to T, aligns reads to 3'UTRs, scans for read clusters, identifies high confidence miRNA target sites, and provides annotations from external databases. With multi-threading techniques and our novel C to T reversion procedure, miRTarCLIP greatly reduces the running time comparing to conventional approaches. In addition, miRTarCLIP serves with a web-based interface to provide better user experiences in browsing and searching targets of interested miRNAs. To demonstrate the superior functionality of miRTarCLIP, we applied miRTarCLIP to two public available CLIP and PAR-CLIP sequencing datasets. miRTarCLIP not only shows comparable results to that of other existing tools in a much faster speed, but also reveals interesting features among these putative target sites. Specifically, we used miRTarCLIP to disclose that T to C conversion within position 1-7 and that within position 8-14 of miRNA target sites are significantly different (p value = 0.02), and even more significant when focusing on sites targeted by top 102 highly expressed miRNAs only (p value = 0.01). These results comply with previous findings and further suggest that combining miRNA expression and PAR-CLIP data can improve accuracy of the miRNA target prediction. CONCLUSION: To sum up, we devised a systematic approach for mining miRNA-target sites from CLIP-seq and PAR-CLIP sequencing data, and integrated the workflow with a graphical web-based browser, which provides a user friendly interface and detailed annotations of MTIs. We also showed through real-life examples that miRTarCLIP is a powerful tool for understanding miRNAs. Our integrated tool can be accessed online freely at http://miRTarCLIP.mbc.nctu.edu.tw.

Which drugs are utilized to treat amiodarone-induced thyroitoxicosis?

Amiodarone-induced thyrotoxicosis treatment includes anti-thyroid drugs and steroid therapy Radio Iodine Treatment (RIT) may be a safe and useful method of AIT therapy in patients with low RAIU, in whom other treatment methods are contraindicated. Lithium is a useful and safe medication for treatment of iodine-induced thyrotoxicosis caused by amiodarone. Thyrodectomy may be necessary in presence of unresponsiveness to standard medical treatments

[2781955, 12727944, 21135419, 9217642, 11901034, 16910349, 7946779, 16544025, 19675515]

Treatment of amiodarone-induced thyrotoxicosis (AIT) with thionamide, lithium or radioactive iodine is ineffective. This particular form of hyperthyroidism is long-lasting because of the slow elimination of amiodarone. Therefore, an alternative therapy is necessary, especially for patients who need to continue permanent administration of the drug. We report 2 cases of AIT: in one case, amiodarone was interrupted; in the other case, amiodarone was continued because of recurrent ventricular tachycardia resistant to classical antiarrhythmic drugs. Both patients were successfully treated with propylthiouracil (PTU) and dexamethasone (DXT). Amiodarone-induced thyrotoxicosis (AIT) may occur either in the presence of underlying thyroid disease (type I AIT) or in apparently normal thyroid glands (type II AIT). Type II AIT, a destructive thyroiditis, often favorably responds to glucocorticoids. Iopanoic acid (IopAc) is an iodinated cholecystographic agent that inhibits deiodinase activity and reduces the conversion of T(4) toT(3). It has recently been reported that cholecystographic agents restore euthyroidism in patients with type II AIT. We describe the results of a prospective randomized study conducted in 12 patients with type II AIT treated with either iopanoic acid (group A, n = 6) or glucocorticoids (group B, n = 6). Serum free T(3) levels normalized rapidly in both groups after 7 d, from 0.75 +/- 0.20 ng/dl (11.5 +/- 3.1 pmol/liter) to 0.46 +/- 0.10 ng/d (7.1 +/- 1.7 pmol/liter), P < 0.01, and from 0.58 +/- 0.10 ng/dl (9.0 +/- 1.2 pmol/liter) to 0.34 +/- 0.03 ng/dl (5.2 +/- 0.5 pmol/liter), P < 0.003, in groups A and B, respectively (P = NS). Serum free T(4) levels reduced at 6 months in group B [from 2.70 +/- 0.32 ng/dl (35.1 +/- 4.1 pmol/liter) to 1.0 +/- 0.04 ng/dl (13.4 +/- 0.6 pmol/liter), P < 0.0001] but not in group A (from 2.90 +/- 0.6 ng/dl (38.0 +/- 7.5 pmol/liter) to 2.30 +/- 0.4 ng/dl (35.6 +/- 6.1 pmol/liter, P = 0.39; P = 0.005 group B vs. group A). All patients in both groups became euthyroid and had their amiodarone-induced destructive thyroiditis cured as defined by normalization of both serum free T(4) and free T(3) levels, during both drugs therapy. However, patients in group B were cured more rapidly than patients in group A (43 +/- 34 d vs. 221 +/- 111 d, respectively, P < 0.002). This study shows that, albeit both drugs are effective, glucocorticoids are probably the drug of choice for more rapidly curing type II AIT. OBJECTIVE: To determine the frequency, risk factors, clinical features, and management of amiodarone-induced thyroid dysfunctions. DESIGN: Retrospective study. SETTING: A regional hospital in Hong Kong. PATIENTS: Patients who had been prescribed amiodarone for at least 6 months from 1 October 2005 to 30 September 2007. RESULTS: A total of 390 patients (mean age, 70 years; standard deviation, 9 years; 54% male) with a median follow-up of 43 (interquartile range, 25-69) months were studied. Hypothyroidism developed in 87 (22%) of the patients (mean age, 72 years; standard deviation, 7 years; 56% male) and thyrotoxicosis in 24 (6%) of the patients (65 years; 11 years; 54% male). Increased baseline thyrotropin (thyroid-stimulating hormone) level appeared to be predictive of amiodarone-induced hypothyroidism, in which a thyroid-stimulating hormone level of 4 mIU/L or above was associated with a 4.7-fold increase in the risk (95% confidence interval, 1.9-11.7; P<0.001). Compared with those who remained euthyroid on amiodarone, thyrotoxicosis developed in younger patients. In these patients, the classical symptoms of thyroid dysfunction were frequently absent, although worsening of underlying arrhythmias, their cardiac condition, weight loss, and over-warfarinisation were suggestive of amiodarone-induced thyrotoxicosis. In both amiodarone-induced thyrotoxicosis and hypothyroidism, the disease course was benign. Patients with the former showed a good response to anti-thyroid drugs and steroid therapy. CONCLUSIONS: Amiodarone-induced thyroid dysfunction is common among our population. As the clinical presentations are usually vague and atypical, regular biochemical monitoring of thyroid function is warranted, particularly in patients with elevated baseline thyroid-stimulating hormone level. The disease course of amiodarone-induced thyrotoxicosis is usually benign and remits with timely administration of anti-thyroid medications, with or without corticosteroids. PURPOSE: Amiodarone hydrochloride is an iodine-rich drug effective in the control of various tachyarrhythmias. It is known to cause refractory to thyrotoxicosis, which usually does not respond to regular antithyroid drugs. Lithium bicarbonate is a medication used to treat psychiatric disorders; it also influences thyroid production and release of hormones. We tried it in combination with propylthiouracil (PTU) for the treatment of amiodarone-induced thyrotoxicosis. PATIENTS AND METHODS: Twenty-one patients were studied. The first group (n = 5) was treated by amiodarone withdrawal only. The second group (n = 7) received PTU (300 to 600 mg), and the third (n = 9) PTU (300 mg) and lithium (900 to 1350 mg) daily. Patient selection was not randomized. The PTU + lithium group had more severe symptoms and signs of thyrotoxicosis, as well as thyroxine levels at least 50% above the upper limit of normal. They also had been on a longer course of amiodarone treatment (34.3 +/- 11.9 months) than the PTU-only (11.4 +/- 7.5) and the no-treatment (7.8 +/- 4.2) groups. RESULTS: While there was no difference between the first two groups in time until recovery (10.6 +/- 4.0 versus 11.6 +/- 0.5 weeks, respectively), the group receiving lithium normalized their thyroid function tests in only 4.3 +/- 0.5 weeks (P < 0.01 versus both other groups). T3 levels normalized even earlier-by 3 weeks of lithium treatment. No adverse effects of lithium were encountered, and the medication was stopped 4 to 6 weeks after achieving a normal clinical and biochemical state. CONCLUSIONS: We conclude that lithium is a useful and safe medication for treatment of iodine-induced thyrotoxicosis caused by amiodarone. We would reserve this treatment for severe cases only. Further studies are needed to find out whether in patients with this troublesome complication lithium therapy could permit continuation of amiodarone treatment. A female patient was admitted to our Department for total thyroidectomy in amiodarone-induced thyrotoxicosis. The drug was prescribed for ventricular arrhythmia and atrial paroxysmal fibrillation in dilated cardiomyopathy due to chronic aortic regurgitation with left ventricular dysfunction (ejection fraction 35%; Class Functional NYHA III) and moderate-severe respiratory insufficiency. The cardiologist-anesthetist team has allowed to evaluate the surgical-cardiovascular-anesthesiologic risks and the balance between the improvement by the amiodarone administration for the arrhythmia, and the discontinuation of this treatment in order to prevent aggravation of the thyrotoxicosis. These hypotheses were subsequently discharged for the two reasons listed below: - several other antiarrhytmic drugs (that didn't show equivalent efficacy as amiodarone in preventing or converting such ventricular and atrial arrhythmias) may be proposed in the place of amiodarone. However, this could expose the patient to an arrhythmia; - a clear proof that the suspension of amiodarone can allow restoring normalization of the thyroid function doesn't exist. Therefore, the patient has been successfully submitted to the surgical intervention and in the follow-up we brought her back to a state of normalized thyroid function and cardiovascular conditions. In patients that cannot safely discontinue amiodarone or when medical therapy is ineffective in controlling thyrotoxicosis, thyroidectomy is the treatment of choice. Two patients with amiodarone-induced thyrotoxicosis were treated successfully with potassium perchlorate and carbimazole while treatment with amiodarone was continued. These antithyroid drugs were stopped after the patients had became clinically and biochemically euthyroid. During follow up, when treatment with amiodarone continued, thyrotoxicosis did not recur. Amiodarone-induced thyrotoxicosis seems to be a transient condition that can be treated successfully with a short course of antithyroid drugs without stopping amiodarone treatment. Among the amiodarone-induced thyroid dysfunctions, thyrotoxicosis is the most troublesome and with the highest rate of morbidity and mortality. Treatment consists in the use of a high dose of anti-thyroid drugs and steroids in an isolated form or in combination. Association of several other drugs have been proposed for the treatment of refractory cases. In this study we report the case of a 40 y.o. patient, with a history of idiopatic dilated miocardiopathy, who developed severe amioradone-induced thyrotoxicosis after heart transplantation. Since the patient did not respond to an initial treatment consisting of a high dose of anti-thyroid drugs combined with steroids, a low dose of lithium carbonate was added for a short period of time, which resulted in normalization of the thyroid function. In this case, the addition of lithium carbonate to the two other drugs resulted in a successful and safety therapy in controlling amiodarone-induced thyrotoxicosis. INTRODUCTION: Amiodarone (AM) is frequently used in the therapy of patients with cardiac disorders. However, due to high iodine content, it has side effects on thyroid function. The use of radioiodine therapy (RIT) in amiodarone-induced thyrotoxicosis (AIT) with low radioactive iodine uptake (RAIU) is still controversial. In these patients therapeutic choices for refractory disease include surgery, antithyroid drugs, or glu ocorticosteriods. AIM: The aim of the study was to evaluate the efficacy of RIT in patients presenting AIT and low RAIU in two-year follow-up. PATIENTS AND METHODS: 40 patients (25 men and 15 women) aged from 63 to 83 years (x +/- SD: 66.2 +/- 5.0 years; median: 65 years) treated with RIT were included into the study. In these patients AM therapy was essential for the underlying heart disorder, while surgery, antithyroid drugs or glucocorticosteroids, were contraindicated. Forty seven patients with toxic multinodular goiter (TMNG) (39 women and 8 men), matched for age (67 +/- 12 yr; range 54-89 yr), were enrolled into the study as a comparative group. The diagnostic procedures included baseline thyroid function tests (thyrothropin - TSH, free triiodothyronine - fT3 and free thyroxine - fT4 levels), thyroid autoantibodies measurement (antithyroglobulin autoantibodies - TgAb, antithyroid peroxidase autoantibodies - TPOAb, anti-TSH receptor autoantibodies - TRAb), thyroid ultrasonography, thyroid scintiscan and RAIU assessment. RESULTS: Serum values of TSH, TgAb, TPOAb and TRAb were undetectable in both groups. In patients with AIT fT4 level was 18.7 to 38.7 pmol/l (mean: 27.1 +/- 5.8) and fT3 concentration was 3.9 to 5.6 pmo/l (mean: 5.7 +/- 1.4), while in TMNG patients level of fT4 was 31.5 to 22.2 pmol/l (mean: 25,3 +/- 5,8) and fT3 concentration was 3.8 to 4,2 pmo/l (mean: 4,2 +/- 0,2). Mean RAIU values after 5h and 24h in AIT patients were 2.3 +/- 0.5 and 3.1 +/- 0.9%, while in TMNG patients were 18,0 +/- 3,8 and 35,7 +/- 9,1%, respectively. A significant difference (p<0.001) between 5h and 24h RAIU in AIT compared to TMNG was noted. In all patients with AIT, a dose of 800 MBq of 131I was administered. During two-year-observation recurrence of hyperthyroidism was observed in two patients (5%) with TMNG. These patients received a second radioiodine dose 16.2 +/- 15 months later (the mean re-treatment dose was 735.93 +/- 196.1 MBq). In comparison, none of the patients with AIT required a second 131I dose and only one patient (2.5%) 6 months after ablative 131I dose needed anti-thyroid medication. Transient hypothyroidism was observed in only two patients (5%) with AIH, though was not observed in TMNG. During follow-up time, no sudden deaths in AIT patients were observed; one patient was diagnosed with prostate cancer, and in one patient acute toxic hepatitis after AM occurred. CONCLUSION: RIT may be a safe and useful method of AIT therapy in patients with low RAIU, in whom other treatment methods are contraindicated.

How is spastic diplegia diagnosed?

Diagnosis of spastic diplegia is mainly carried out with through clinical gait analysis (CGA), with variations such as 1-minute walk, LSU, and 10-meter walk tests, or Gross Motor Function Measure-88 (GMFM-88). Other methods used for evaluation of patients include brain magnetic resonance imaging (MRI) and motor function, presence of epileptic episodes, and IQ or developmental quotient.

[24901761, 21310339, 25276040, 24239880, 17826455, 20829081, 10427678, 1743414, 23085499, 25700542, 24409030, 24182356, 16344032, 2816867, 15157997, 23121133, 2600179, 7270517, 12549749, 17509240]

Argininemia is caused by a deficiency of arginase 1, which catalyzes the final step in the urea cycle, i.e., the cytosolic hydrolysis of arginine to ornithine and urea. In contrast to other urea cycle disorders, hyperammonemic encephalopathy is rarely observed in patients with argininemia. Rather, most exhibit an insidious onset and progression of neurologic manifestations, including spastic diplegia. We describe the first Korean patient with argininemia, manifesting as slowly progressive spastic diplegia. Our patient carries c.[32T>C]+[913G>A] (p.[Ile11Thr]+[Gly305Arg]) mutations in the ARG1 gene. The latter mutation was not previously reported. Although argininemia is a very rare disease, it is recognized as a pan-ethnic disorder. We conclude that argininemia should be considered more frequently in the differential diagnosis of a patient with slowly progressive neurologic manifestations, especially progressive spastic diplegia, even in a population where argininemia was previously unknown. OBJECTIVE: To determine the relationships between spasticity, strength, and the functional measures of gait and gross motor function in persons with spastic diplegia cerebral palsy (CP). DESIGN: Retrospective, cross-sectional study. SETTING: Hospital clinic. PARTICIPANTS: Ninety-seven participants (49 boys, 48 girls; mean age+/-standard deviation, 9.11+/-4.8 y) with spastic diplegia CP were tested once. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: A KinCom dynamometer was used to objectively measure spasticity (ankle plantarflexors, knee flexors, hip adductors) and maximum strength (ankle dorsiflexors and plantarflexors, knee flexors and extensors, hip abductors and adductors). A gait analysis was conducted to evaluate linear variables (gait speed, stride length, cadence) and kinematic variables (ankle dorsiflexion, foot progression, knee and hip flexion, pelvic tilt at initial contact and ankle dorsiflexion, knee and hip flexion, pelvic tilt, trunk rotation range of motion) during gait. Gross motor function was measured using the Gross Motor Function Measure (GMFM-66) and separately, the GMFM walking, running & jumping dimension. Multiple linear regression analysis was used to determine the relationships between spasticity, strength, gait, and the GMFM (P<.05). RESULTS: Spasticity did not account for a substantial amount of explained variance in gait and gross motor function (up to 8% for the GMFM walking, running & jumping dimension). Moderate to high correlations existed between strength and gait linear data and function, accounting for up to 69% of the explained variance (strength and GMFM-66, r2=.69). CONCLUSIONS: For this cohort of participants with spastic diplegia CP who ambulated with or without an assistive device, strength was highly related to function and explained far more of the variance than spasticity. The results may not be generalized to those with more severe forms of CP. OBJECTIVE: This study examined the construct validity of the In-Hand Manipulation Test (IMT) by assessing the test's ability to discriminate between samples of children with and without known fine motor problems. METHOD: The IMT was administered to 55 children without known fine motor problems and 24 children with spastic diplegia who had mild to moderate fine motor problems. Construct validity was estimated by evaluating how accurately the IMT classified the children as having or not having fine motor problems on the basis of total score. RESULTS: A discriminant analysis indicated that IMT total score correctly classified 83.33% of the participants as having or not having fine motor problems. CONCLUSION: The IMT has adequate construct validity to classify the participants of this study and for continued use as a research instrument to assess children's in-hand manipulation skills. Additional validity studies of the IMT are needed with other samples of children before its use for clinical purposes. Leg movements in the supine position of 49 infants with spastic diplegia (three to 11 months corrected age) were examined. Only simultaneous flexion and extension of the hips and knees were seen, with exceptional isolated hip movements; the simultaneous movements had synergic features. When the knees were flexed, the hips were flexed, abducted and externally rotated, and the ankles were dorsiflexed. When the knees were extended, the hips were extended, adducted and internally rotated and the ankles were plantar-flexed. Hip flexion combined with knee extension (leg elevation) and isolated knee movements were not seen in diplegic infants, but were seen in all control preterm infants with a good prognosis, after five and six months corrected age, respectively. The absence of these movements is a useful diagnostic item for spastic diplegia. Hereditary spastic paraplegia (HSP) and spastic diplegia (SD) patients share a strong clinical resemblance. Thus, HSP patients are frequently misdiagnosed with a mild form of SD. Clinical gait analysis (CGA) has been highlighted as a possible tool to support the differential diagnosis of HSP and SD. Previous analysis has focused on the lower-body but not the upper-body, where numerous compensations during walking occur. The aim of this study was to compare the full-body movements of HSP and SD groups and, in particular, the movement of the upper limbs. Ten HSP and 12 SD patients were evaluated through a CGA (VICON 460 and Mx3+; ViconPeak(®), Oxford, UK) between 2008 and 2012. The kinematic parameters were computed using the ViconPeak(®) software (Plug-In-Gait). In addition, the mean amplitude of normalised (by the patient's height) arm swing was calculated. All patients were asked to walk at a self-selected speed along a 10-m walkway. The mean kinematic parameters for the two populations were analysed with Mann-Whitney comparison tests, with a significant P-value set at 0.05. The results demonstrated that HSP patients used more spine movement to compensate for lower limb movement alterations, whereas SD patients used their arms for compensation. SD patients had increased shoulder movements in the sagittal plane (Flexion/extension angle) and frontal plane (elevation angle) compared to HSP patients. These arm postures are similar to the description of the guard position that toddlers exhibit during the first weeks of walking. To increase speed, SD patients have larger arm swings in the sagittal, frontal and transversal planes. Upper-body kinematics, and more specifically arm movements and spine movements, may support the differential diagnosis of HSP and SD. Author information: (1)Division of Pediatric Neurology, Department of Pediatrics, University of Saskatchewan, Saskatoon, Saskatchewan, Canada. (2)Division of Medical Genetics, Department of Pediatrics, University of Saskatchewan, Saskatoon, Saskatchewan, Canada. (3)Division of Neurosurgery, Department of Surgery, University of Saskatchewan, Saskatoon, Saskatchewan, Canada. (4)Division of Pediatric Orthopedics, Department of Surgery, University of Saskatchewan, Saskatoon, Saskatchewan, Canada. (5)Division of Developmental Pediatrics, Department of Pediatrics, University of Saskatchewan, Saskatoon, Saskatchewan, Canada. [Purpose] This study aimed to investigate the effects of Vojta therapy on spatiotemporal gait parameters in children with spastic diplegia. [Methods] The study population consisted of 3 children diagnosed with spastic diplegia. The subjects were treated with Vojta therapy for 8 weeks and followed up for 8 weeks after completion of the therapy. Vicon motion analysis was used to determine the subjects' spatiotemporal gait parameters. [Results] The following results were noted in the changes of each joint angle in the sagittal plane after Vojta therapy. Subject 1 remained in phase throughout the entire gait cycle and did not show any noticeable improvement, even demonstrating a negative range of motion when compared to the baseline. Subject 2 showed a normal anti-phase in heel strike, and the mid-stance, and swing phases. Subject 3 showed a normal anti-phase in heel strike and mid-stance, but the anti-phase during the swing phase was not significantly different from the baseline. For subjects 2 and 3, compared to the baseline, the range of motion of the hip and knee increased but the range of motion of the ankle decreased. [Conclusion] The findings of this study indicate that Vojta therapy can do a good role in improve the spatiotemporal gait parameters of children with spastic diplegia. AIM: The aim of this study was to explore the physical status and gait patterns of children with spastic diplegia secondary to human immunodeficiency virus encephalopathy (HIVE). METHOD: A cross-sectional study was conducted on children diagnosed with HIVE and spastic diplegia. Sociodemographic and clinical background information was obtained, followed by three-dimensional gait analysis (3DGA) and a physical examination including assessments of muscle tone, strength, motor control, contractures, and bony deformities of the lower extremities. RESULTS: Fourteen children (eight males, six females; mean age 5 y 8 mo [SD 9 mo], range 4 y 4 mo-6 y 10 mo) were studied. The cohort was divided into two groups based on distinctive gait patterns. Nine participants in group I showed only limited abnormalities. Group II displayed a more pathological gait pattern including stiff knee and equinus ankle abnormalities. Results of 3DGA, as with the physical examination outcomes, showed increased impairments from proximal to distal (except for hip extension). INTERPRETATION: This study provides a first description of distinctive gait patterns and related physical characteristics of children with HIVE and spastic diplegia. Further research is necessary. OBJECTIVE: To assess the reliability and validity of a newly described classification of sagittal plane alignment in spastic diplegic gait. DESIGN: Twenty split-screen videos of children with spastic diplegia, Gross Motor Function Classification System levels I to III, were viewed on 2 occasions, 6 weeks apart, by 5 raters. The sagittal plane alignments of the right and left lower limbs in gait were classified separately as true equinus, jump knee, apparent equinus, or crouch, based on the published classification. A fifth category, nonclassifiable, was used if classification was not possible. We then used sagittal plane kinematic data to confirm the classification for each subject and these were compared with rater classification scores, which used the video information only. SETTING: Tertiary-level children's hospital. PARTICIPANTS: Three pediatric orthopedic surgeons and 2 pediatric orthopedic residents. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Gait classification scores derived from visual observation were compared among and within raters. The gait classification scores derived from visual observation were compared with the scores derived from sagittal plane kinematic data to assess validity. RESULTS: A moderate correlation was found among the 5 raters within each session, with an interrater weighted kappa score of .45 in session 1 and .49 in session 2. The intrarater, weighted kappa scores showed a moderate to substantial level of agreement between sessions, ranging from .50 to .68. The classification scores of individual raters had moderate validity when compared with classifications derived from the sagittal plane kinematic data. However, there was a substantial level of agreement between the consensus opinion and the classification obtained using the kinematic data as well as the video recordings (weighted kappa=0.8). CONCLUSIONS: This classification has only moderate reliability and validity when a single experienced rater views the 2-dimensional gait videos. However, the consensus opinion derived from the scores of 5 raters considerably improves the validity of the assessment. A retrospective study examined early neurodevelopmental behaviors of children with spastic diplegia, spastic hemiplegia, and quadriplegia (spastic, athetoid, or mixed) who had been followed up longitudinally in a high-risk infant follow-up clinic. Compared with peers with normal outcomes, children with all three types of cerebral palsy had significantly lower scores on the Bayley Mental Scale at 4 months of age; children with hemiplegia and quadriplegia also scored significantly lower on the Bayley Motor Scale. On the Movement Assessment of Infants at 4 months of age, the children with hemiplegia and quadriplegia showed significantly higher risk scores than the nonhandicapped group. The Movement Assessment of Infants was more than three times as sensitive as the Bayley Motor Scale in detecting motor abnormalities in 4-month-old infants with diplegia and more than twice as sensitive in detecting early abnormalities of hemiplegia. At 1 year of age, however, the Bayley Motor Scale was extremely sensitive in picking up motor deficits in children with all three types of cerebral palsy. The objective of this prospective study was the application of proton magnetic resonance spectroscopy in children with spastic diplegia (SD) to determine the metabolite profile of SD children in the left basal ganglia, and to assess the relationship of this profile with motor and mental development. Patients with SD showed reduced ratios of N-acetylaspartate (NAA)/creatine (Cr), NAA/choline (Cho), NAA/myo-inositol (mI), Cho/NAA, Cho/Cr and Cho/mI in the basal ganglia compared to a well-matched control group. On the other hand, we noted increased Cr/NAA, Cr/Cho and mI/NAA ratios in the SD patients as compared with controls. NAA/mI ratios were positively correlated with the severity scale of cerebral palsy in SD children. There was also a significant correlation between Cr/NAA and mental retardation. Increased Cr/NAA, Cr/Cho and mI/NAA ratios in SD children may suggest the existence of the compensatory mechanisms in these patients. The NAA/mI ratio could be used as an additional marker of SD severity and Cr/NAA as a marker of the mental retardation. AIM: To investigate the association between magnetic resonance imaging (MRI) patterns and motor function, epileptic episodes, and IQ or developmental quotient in patients born at term with spastic diplegia. METHOD: Eighty-six patients born at term with cerebral palsy (CP) and spastic diplegia (54 males, 32 females; median age 20 y, range 7-42 y) among 829 patients with CP underwent brain MRI between 1990 and 2008. The MRI and clinical findings were analysed retrospectively. Intellectual disability was classified according to the Enjoji developmental test or the Wechsler Intelligence Scale for Children (3rd edition). RESULTS: The median ages at diagnosis of CP, assignment of Gross Motor Function Classification System (GMFCS) level, cognitive assessment, and MRI were 2 years (range 5 mo-8 y), 6 years (2 y 8 mo-19 y), 6 years (1 y 4 mo-19 y), and 7 years (10 mo-30 y) respectively. MRI included normal findings (41.9%), periventricular leukomalacia, hypomyelination, and porencephaly/periventricular venous infarction. The frequency of patients in GMFCS levels III to V and intellectual disability did not differ between those with normal and abnormal MRI findings. Patients with normal MRI findings had significantly fewer epileptic episodes than those with abnormal ones (p=0.001). INTERPRETATION: Varied MRI findings, as well as the presence of severe motor dysfunction and intellectual disability (despite normal MRI), suggest that patients born at term with spastic diplegia had heterogeneous and unidentified pathophysiology. To investigate the etiology of spastic diplegia (SD) of prematurity, we compared the prenatal, perinatal, and neonatal course of 18 preterm infants with SD to that of a control group of preterm infants without SD. No significant differences between the group with SD and the control group were found in most of the perinatal and neonatal factors analyzed. Significant differences were found in birth weight, birth head circumference, and the one-minute Apgar score. Controlling for gestational age, infants with SD weighed less at birth, had smaller heads, and were more often briefly neurologically depressed. Intracranial hemorrhage and neonatal seizures occurred significantly more often in infants with SD. Fifteen infants with SD were believed to be neurologically normal at the time of nursery discharge. These findings suggest the importance of prenatal factors in optimally treated preterm infants in whom SD develops. Patients with hereditary spastic paraplegia (HSP) often resemble patients with mild spastic diplegia (SD), although their motor limitations differ. The aim of this study was to analyse quantitatively the gait of HSP and SD subjects in order to define the gait pattern in HSP and the differences between the two conditions. Fifteen subjects with HSP, 40 patients with SD and 20 healthy subjects underwent gait analysis (GA). The spatio-temporal and kinematic parameters at the proximal joints were found to be similar in HSP and SD, whereas the most significant differences were found at the knee and ankle joints. Both groups displayed a tendency for knee hyperextension in the midstance phase, but the duration of this hyperextension was longer in the HSP patients. This study shows that GA complements traditional clinical evaluations, making it possible to distinguish, clearly, between motor ability in HSP and in SD patients; the duration of the knee hyperextension during midstance was found to discriminate between the two gait patterns.

Which is the genetic defect causing Neurofibromatosis type 1?

Neurofibromatosis type 1 (NF1) is due to all types of mutations in the neurofibromin (NF1) gene.

[14722917, 2129297, 16323217, 21567923, 16835897]

One of the main features of neurofibromatosis type 1 (NF1) is benign neurofibromas, 10-20% of which become transformed into malignant peripheral nerve sheath tumors (MPNSTs). The molecular basis of NF1 tumorigenesis is, however, still unclear. Ninety-one tumors from 31 NF1 patients were screened for gross changes in the NF1 gene using microsatellite/restriction fragment length polymorphism (RFLP) markers; loss of heterozygosity (LOH) was found in 17 out of 91 (19%) tumors (including two out of seven MPNSTs). Denaturing high performance liquid chromatography (DHPLC) was then used to screen 43 LOH-negative and 10 LOH-positive tumors for NF1 microlesions at both RNA and DNA levels. Thirteen germline and 12 somatic mutations were identified, of which three germline (IVS7-2A>G, 3731delT, 6117delG) and eight somatic (1888delG, 4374-4375delCC, R2129S, 2088delG, 2341del18, IVS27b-5C>T, 4083insT, Q519P) were novel. A mosaic mutation (R2429X) was also identified in a neurofibroma by DHPLC analysis and cloning/sequencing. The observed somatic and germline mutational spectra were similar in terms of mutation type, relative frequency of occurrence, and putative underlying mechanisms of mutagenesis. Tumors lacking mutations were screened for NF1 gene promoter hypermethylation but none were found. Microsatellite instability (MSI) analysis revealed MSI in five out of 11 MPNSTs as compared to none out of 70 neurofibromas (p=1.8 x 10(-5)). The screening of seven MPNSTs for subtle mutations in the CDKN2A and TP53 genes proved negative, although the screening of 11 MPNSTs detected LOH involving either the TP53 or the CDKN2A gene in a total of four tumors. These findings are consistent with the view that NF1 tumorigenesis is a complex multistep process involving a variety of different types of genetic defect at multiple loci. The locus for the gene causing neurofibromatosis type 1 (NF1) was bracketed to a region on the long arm of chromosome 17 by means of genetic linkage analysis. When the limits of resolution for genetic mapping were reached physical mapping methods were used to map the NF1 gene precisely, with reference to translocation breakpoints in NF1 affected individuals who harboured constitutional chromosomal translocations on chromosome 17. The region of DNA located between two translocation breakpoints has been cloned and a DNA sequence encoding a 11-13 kb mRNA identified. That this sequence shows deletions and point mutations in NF1 affected individuals and not in normal controls provides strong evidence that it is indeed the NF1 gene. The genetic defect in NF2 has been mapped to chromosome 22 by studies of chromosomal loss in tumours associated with this disease. Subsequent linkage analysis of NF2 pedigrees has confirmed this location. DNA markers that bracket the NF2 locus to a region of 5-10 Mb have been identified. Neurofibromatosis type 1 (NF1) is a common tumor predisposition syndrome affecting approximately 1 in 4,000 persons. It is an autosomal-dominant disorder with half of the cases resulting from spontaneous mutations. This genetic defect leads to the formation of benign tumors or neurofibromas of the peripheral nervous system. Dermal neurofibromas may cause local discomfort and itching but are rarely associated with neurological deficit and do not undergo malignant change. The more extensive plexiform neurofibromas produce neurological complications in 27%-43% of patients with NF1 and may undergo malignant degeneration in 5% of cases. Patients with NF1 who develop pain or new neurological symptoms should have a rapid and thorough assessment for malignancy. In this report, we illustrate this point by presenting a patient who developed acute shoulder pain and weakness due to malignant degeneration of a plexiform neurofibroma involving the left brachial plexus, and review the literature on this subject. Neurofibromatosis type 1 and Noonan syndrome are both common genetic disorders with autosomal dominant inheritance. Similarities between neurofibromatosis type 1 and Noonan syndrome have been noted for over 20 years and patients who share symptoms of both conditions are often given the diagnosis of neurofibromatosis-Noonan syndrome (NFNS). The molecular basis of these combined phenotypes was poorly understood and controversially discussed over several decades until the discovery that the syndromes are related through disturbances of the Ras pathway. We present an infant male with coarse facial features, severe supravalvar pulmonic stenosis, automated atrial tachycardia, hypertrophic cardiomyopathy, airway compression, severe neurological involvement, and multiple complications that lead to death during early infancy. The severity of clinical presentation and significant dysmorphic features suggested the possibility of a double genetic disorder in the Ras pathway instead of NFNS. Molecular analysis showed a missense mutation in exon 25 of the NF1 gene (4288A>G, p.N1430D) and a pathogenic mutation on exon 8 (922A>G, p.N308D) of the PTPN11 gene. Cardiovascular disease has been well described in patients with Noonan syndrome with PTPN11 mutations but the role of haploinsufficiency for neurofibromin in the heart development and function is not yet well understood. Our case suggests that a double genetic defect resulting in the hypersignaling of the Ras pathway may lead to complex cardiovascular abnormalities, cardiomyopathy, refractory arrhythmia, severe neurological phenotype, and early death. Neurofibromatosis type 1 (NF1), characterized by skin neurofibromas and an excess of café-au-lait spots, is due to mutations in the neurofibromin (NF1) gene. Identifying the genetic defect in individuals with the disease represents a significant challenge because the gene is extremely large with a high incidence of sporadic mutations across the entire gene ranging from single nucleotide substitutes to large deletions. In the present study, we have used a combination of techniques (heteroduplex analysis, sequencing, loss of heterozygosity and quantification of gene dosage) to define the genetic defect in 68 individuals from a cohort of 107 NF1 Taiwanese patients of Chinese origin. Fifty-eight were initially identified using heteroduplex analytical techniques and confirmed by sequence analysis. A further five were identified by direct sequence analysis alone. The reminders were shown to carry large deletions in the NF1 gene by demonstrating loss of heterozygosity that was confirmed by gene dosage measurements using quantitative-PCR techniques. Mis-sense, non-sense, frame-shift or splice-site mutations were identified across the entire gene of which the majority (45/68) were novel in nature. The detection rate with the various analytical techniques and the types of mutation detected are consistent with published data involving both individuals and large cohort studies from other ethnic backgrounds.

Which is the human selenoprotein that contains several Se-Cys residues?

Selenoprotein P, that contains 10 selenocysteines.

[19345254, 11122377, 10692426, 7637580, 20417644, 15104205, 9288402, 17000762, 15777501]

Selenoprotein P (Sepp1) is a secreted protein that is made up of 2 domains. The larger N-terminal domain contains 1 selenocysteine residue in a redox motif and the smaller C-terminal domain contains the other 9 selenocysteines. Sepp1 isoforms of varying lengths occur but quantitation of them has not been achieved. Hepatic synthesis of Sepp1 affects whole-body selenium content and the liver is the source of most plasma Sepp1. ApoER2, a member of the lipoprotein receptor family, binds Sepp1 and facilitates its uptake into the testis and retention of its selenium by the brain. Megalin, another lipoprotein receptor, facilitates uptake of filtered Sepp1 into proximal tubule cells of the kidney. Thus, Sepp1 serves in homeostasis and distribution of selenium. Mice with deletion of Sepp1 suffer greater morbidity and mortality from infection with Trypanosoma congolense than do wild-type mice. Mice that express only the N-terminal domain of Sepp1 have the same severity of illness as wild-type mice, indicating that the protective function of Sepp1 against the infection resides in the N-terminal (redox) domain. Thus, Sepp1 has several functions. In addition, plasma Sepp1 concentration falls in selenium deficiency and, therefore, it can be used as an index of selenium nutritional status. Most selenoproteins contain a single selenocysteine residue per polypeptide chain, encoded by an in-frame UGA codon. Selenoprotein P is unique in that its mRNA encodes 10-12 selenocysteine residues, depending on species. In addition to the high number of selenocysteines, the protein is cysteine- and histidine-rich. The function of selenoprotein P has remained elusive, in part due to the inability to express the recombinant protein. This has been attributed to presumed inefficient translation through the selenocysteine/stop codons. Herein, we report for the first time the expression of recombinant rat selenoprotein P in a transiently transfected human epithelial kidney cell line, as well as the endogenously expressed protein from HepG2 and Chinese hamster ovary cells. The majority of the expressed protein migrates with the predicted 57-kDa size of full-length glycosylated selenoprotein P. Based on the histidine-rich nature of selenoprotein P, we have purified the recombinant and endogenously expressed proteins using nickel-agarose affinity chromatography. We show that the recombinant rat and endogenous human proteins react in Western blotting and immunoprecipitation assays with commercial anti-histidine antibodies. The ability to express, purify, and immunochemically detect the recombinant protein provides a foundation for investigating the functions and efficiency of expression of this intriguing protein. When cDNA containing proteins enriched in the bovine cerebellar cortex were cloned, a clone which seemed to encode a selenoprotein P-like protein was isolated. The coding nucleotide sequence of its cDNA insert displayed high homology to rat and human selenoprotein P cDNA but contained 12 rather than 10 TGAs (12 rather than 10 selenocysteines in deduced amino acids), a tandem repeat of one CACTCC (His-Ser) and seven CATCCCs (His-Pro), and a 3' untranslated region approximately 890 bases shorter than that of rat liver selenoprotein P. RT-PCR using a set of primers flanking to the repeat displayed the existence of mRNA without the repeat. The tandem repeat and its adjacent region consisted of a similar motif of CAC/TCC/AC/T. Thus, these proteins included a (His-Pro) rich domain with a slightly negative free energy change irrespective of having the tandem repeat or not. Such His-Pro repeats reportedly exist in the segmentation gene paired or homeobox protein Om(1D) of Drosophila. Moreover, both this selenoprotein P-like protein mRNA and selenoprotein P mRNA were expressed in all the areas of the brain but most prominently in the cerebellar cortex, hippocampus, and olfactory bulb. These findings suggest the possibility that these selenoproteins are major selenium carriers in the brain and play a role in the morphological response of nerve or glial cells. Selenoprotein P (SeP) is an extracellular glycoprotein with 8-10 selenocysteines per molecule, containing approximately 50% of total selenium in human serum. An antioxidant function of SeP has been postulated. In the present study, we show that SeP protects low-density lipoproteins (LDL) against oxidation in a cell-free in-vitro system. LDL were isolated from human blood plasma and oxidized with CuCl2, 2,2'-azobis(2-amidinopropane) (AAPH) or peroxynitrite in the presence or absence of SeP, using the formation of conjugated dienes as parameter for lipid peroxidation. SeP delayed the CuCl2- and AAPH-induced LDL oxidation significantly and more efficiently than bovine serum albumin used as control. In contrast, SeP was not capable of inhibiting peroxynitrite-induced LDL oxidation. The protection of LDL against CuCl2- and AAPH-induced oxidation provides evidence for the antioxidant capacity of SeP. Because SeP associates with endothelial membranes, it may act in vivo as a protective factor inhibiting the oxidation of LDL by reactive oxygen species. OBJECTIVE: Human selenoprotein P (HSelP) is unique protein that contains 10 selenocysteines encoded by 10 inframe UGA, which typically function as stop codon. The function of HSelP remains unclear, in part due to the inability to express it by gene recombinant technique. This study is to investigate expression and purification of recombinant HSelP in prokaryotic expression system, and its activity to induce apoptosis in vitro. METHODS: The shorter HSelP isoform was cloned. After the selenocysteine (SeCys) at 40th position from N terminus of the HSelP shorter isoform was mutated into cysteine by PCR, it was expressed in E. coli. The expressed product was purified with DEAE column and identified by Western blot. Subsequently, its function on induction of mitochondrial apoptotic activity was studied. RESULTS: The mutant HSelP shorter isoform expressed in prokaryotic system was purified by DEAE column to 90% homogeneity. The purified product, HSelP280m, induced the opening of mitochondrial permeability transition pore (PTP) and decreased the transmembrane potential in a dose-dependent manner. These events could be abolished by PTP specific inhibitors. CONCLUSION: HSelP280m can induce the opening of mitochondrial PTP, which provides a basis for investigating the structure and function of recombinant HSelP.

Which package is available for analysing genomic interactions in R/Bioconductor?

r3Cseq is an R/Bioconductor package designed to perform 3C-seq data analysis in a number of different experimental designs. The package reads a common aligned read input format, provides data normalization, allows the visualization of candidate interaction regions and detects statistically significant chromatin interactions, thus greatly facilitating hypothesis generation and the interpretation of experimental results.

[23671339]

The coupling of chromosome conformation capture (3C) with next-generation sequencing technologies enables the high-throughput detection of long-range genomic interactions, via the generation of ligation products between DNA sequences, which are closely juxtaposed in vivo. These interactions involve promoter regions, enhancers and other regulatory and structural elements of chromosomes and can reveal key details of the regulation of gene expression. 3C-seq is a variant of the method for the detection of interactions between one chosen genomic element (viewpoint) and the rest of the genome. We present r3Cseq, an R/Bioconductor package designed to perform 3C-seq data analysis in a number of different experimental designs. The package reads a common aligned read input format, provides data normalization, allows the visualization of candidate interaction regions and detects statistically significant chromatin interactions, thus greatly facilitating hypothesis generation and the interpretation of experimental results. We further demonstrate its use on a series of real-world applications.

Are stress granules involved in the pathogenesis of Amyotrophic Lateral Sclerosis?

Stress granules are cytoplasmic inclusions that repress translation of a subset of RNAs in times of cellular stress, and several proteins implicated in neurodegeneration (i.e. Ataxin-2 and SMN) interact with stress granules. Mutant FUS proteins that cause amyotrophic lateral sclerosis incorporate into stress granules. ALS-linked mutations in profilin 1 alter stress granule dynamics, providing further evidence for the potential role of stress granules in ALS pathogenesis. ALS mutations in FUS NLS can impair FUS nuclear localization, induce cytoplasmic inclusions and stress granules, and potentially perturb RNA metabolism.

[26557057, 23474818, 23629963, 25888396, 25429138, 24297750, 24090136, 20606625, 24920614, 21173160, 24336168, 20674093, 20699327, 19765185, 23257289, 25216585, 24312274, 22405725, 24013423, 23152885]

Stress granules (SGs) are RNA-containing cytoplasmic foci formed in response to stress exposure. Since their discovery in 1999, over 120 proteins have been described to be localized to these structures (in 154 publications). Most of these components are RNA binding proteins (RBPs) or are involved in RNA metabolism and translation. SGs have been linked to several pathologies including inflammatory diseases, cancer, viral infection, and neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). In ALS and FTD, the majority of cases have no known etiology and exposure to external stress is frequently proposed as a contributor to either disease initiation or the rate of disease progression. Of note, both ALS and FTD are characterized by pathological inclusions, where some well-known SG markers localize with the ALS related proteins TDP-43 and FUS. We propose that TDP-43 and FUS serve as an interface between genetic susceptibility and environmental stress exposure in disease pathogenesis. Here, we will discuss the role of TDP-43 and FUS in SG dynamics and how disease-linked mutations affect this process. Mutations in the gene encoding Fused in Sarcoma (FUS) cause amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disorder. FUS is a predominantly nuclear DNA- and RNA-binding protein that is involved in RNA processing. Large FUS-immunoreactive inclusions fill the perikaryon of surviving motor neurons of ALS patients carrying mutations at post-mortem. This sequestration of FUS is predicted to disrupt RNA processing and initiate neurodegeneration. Here, we demonstrate that C-terminal ALS mutations disrupt the nuclear localizing signal (NLS) of FUS resulting in cytoplasmic accumulation in transfected cells and patient fibroblasts. FUS mislocalization is rescued by the addition of the wild-type FUS NLS to mutant proteins. We also show that oxidative stress recruits mutant FUS to cytoplasmic stress granules where it is able to bind and sequester wild-type FUS. While FUS interacts with itself directly by protein-protein interaction, the recruitment of FUS to stress granules and interaction with PABP are RNA dependent. These findings support a two-hit hypothesis, whereby cytoplasmic mislocalization of FUS protein, followed by cellular stress, contributes to the formation of cytoplasmic aggregates that may sequester FUS, disrupt RNA processing and initiate motor neuron degeneration. Amyotrophic lateral sclerosis (ALS) is a fatal human neurodegenerative disease affecting primarily motor neurons. Two RNA-binding proteins, TDP-43 and FUS, aggregate in the degenerating motor neurons of ALS patients, and mutations in the genes encoding these proteins cause some forms of ALS. TDP-43 and FUS and several related RNA-binding proteins harbor aggregation-promoting prion-like domains that allow them to rapidly self-associate. This property is critical for the formation and dynamics of cellular ribonucleoprotein granules, the crucibles of RNA metabolism and homeostasis. Recent work connecting TDP-43 and FUS to stress granules has suggested how this cellular pathway, which involves protein aggregation as part of its normal function, might be coopted during disease pathogenesis. BACKGROUND: Mutations in calcium-responsive transactivator (CREST) encoding gene have been recently linked to ALS. Similar to several proteins implicated in ALS, CREST contains a prion-like domain and was reported to be a component of paraspeckles. RESULTS: We demonstrate that CREST is prone to aggregation and co-aggregates with FUS but not with other two ALS-linked proteins, TDP-43 and TAF15, in cultured cells. Aggregation of CREST affects paraspeckle integrity, probably by trapping other paraspeckle proteins within aggregates. Like several other ALS-associated proteins, CREST is recruited to induced stress granules. Neither of the CREST mutations described in ALS alters its subcellular localization, stress granule recruitment or detergent solubility; however Q388stop mutation results in elevated steady-state levels and more frequent nuclear aggregation of the protein. Both wild-type protein and its mutants negatively affect neurite network complexity of unstimulated cultured neurons when overexpressed, with Q388stop mutation being the most deleterious. When overexpressed in the fly eye, wild-type CREST or its mutants lead to severe retinal degeneration without obvious differences between the variants. CONCLUSIONS: Our data indicate that CREST and certain other ALS-linked proteins share several features implicated in ALS pathogenesis, namely the ability to aggregate, be recruited to stress granules and alter paraspeckle integrity. A change in CREST levels in neurons which might occur under pathological conditions would have a profound negative effect on neuronal homeostasis. TDP-43 is an RNA-binding protein linked to amyotrophic lateral sclerosis (ALS) that is known to regulate the splicing, transport, and storage of specific mRNAs into stress granules. Although TDP-43 has been shown to interact with translation factors, its role in protein synthesis remains unclear, and no in vivo translation targets have been reported to date. Here we provide evidence that TDP-43 associates with futsch mRNA in a complex and regulates its expression at the neuromuscular junction (NMJ) in Drosophila. In the context of TDP-43-induced proteinopathy, there is a significant reduction of futsch mRNA at the NMJ compared with motor neuron cell bodies where we find higher levels of transcript compared with controls. TDP-43 also leads to a significant reduction in Futsch protein expression at the NMJ. Polysome fractionations coupled with quantitative PCR experiments indicate that TDP-43 leads to a futsch mRNA shift from actively translating polysomes to nontranslating ribonuclear protein particles, suggesting that in addition to its effect on localization, TDP-43 also regulates the translation of futsch mRNA. We also show that futsch overexpression is neuroprotective by extending life span, reducing TDP-43 aggregation, and suppressing ALS-like locomotor dysfunction as well as NMJ abnormalities linked to microtubule and synaptic stabilization. Furthermore, the localization of MAP1B, the mammalian homolog of Futsch, is altered in ALS spinal cords in a manner similar to our observations in Drosophila motor neurons. Together, our results suggest a microtubule-dependent mechanism in motor neuron disease caused by TDP-43-dependent alterations in futsch mRNA localization and translation in vivo. RNA localization pathways direct numerous mRNAs to distinct subcellular regions and affect many physiological processes. In one such pathway the tumor-suppressor protein adenomatous polyposis coli (APC) targets RNAs to cell protrusions, forming APC-containing ribonucleoprotein complexes (APC-RNPs). Here, we show that APC-RNPs associate with the RNA-binding protein Fus/TLS (fused in sarcoma/translocated in liposarcoma). Fus is not required for APC-RNP localization but is required for efficient translation of associated transcripts. Labeling of newly synthesized proteins revealed that Fus promotes translation preferentially within protrusions. Mutations in Fus cause amyotrophic lateral sclerosis (ALS) and the mutant protein forms inclusions that appear to correspond to stress granules. We show that overexpression or mutation of Fus results in formation of granules, which preferentially recruit APC-RNPs. Remarkably, these granules are not translationally silent. Instead, APC-RNP transcripts are translated within cytoplasmic Fus granules. These results unexpectedly show that translation can occur within stress-like granules. Importantly, they identify a new local function for cytoplasmic Fus with implications for ALS pathology. Mutations in fused in sarcoma (FUS) are a cause of familial amyotrophic lateral sclerosis (fALS). Patients carrying point mutations in the C-terminus of FUS show neuronal cytoplasmic FUS-positive inclusions, whereas in healthy controls, FUS is predominantly nuclear. Cytoplasmic FUS inclusions have also been identified in a subset of frontotemporal lobar degeneration (FTLD-FUS). We show that a non-classical PY nuclear localization signal (NLS) in the C-terminus of FUS is necessary for nuclear import. The majority of fALS-associated mutations occur within the NLS and impair nuclear import to a degree that correlates with the age of disease onset. This presents the first case of disease-causing mutations within a PY-NLS. Nuclear import of FUS is dependent on Transportin, and interference with this transport pathway leads to cytoplasmic redistribution and recruitment of FUS into stress granules. Moreover, proteins known to be stress granule markers co-deposit with inclusions in fALS and FTLD-FUS patients, implicating stress granule formation in the pathogenesis of these diseases. We propose that two pathological hits, namely nuclear import defects and cellular stress, are involved in the pathogenesis of FUS-opathies. Mutations in the PFN1 gene encoding profilin 1 are a rare cause of familial amyotrophic lateral sclerosis (ALS). Profilin 1 is a well studied actin-binding protein but how PFN1 mutations cause ALS is unknown. The budding yeast, Saccharomyces cerevisiae, has one PFN1 ortholog. We expressed the ALS-linked profilin 1 mutant proteins in yeast, demonstrating a loss of protein stability and failure to restore growth to profilin mutant cells, without exhibiting gain-of-function toxicity. This model provides for simple and rapid screening of novel ALS-linked PFN1 variants. To gain insight into potential novel roles for profilin 1, we performed an unbiased, genome-wide synthetic lethal screen with yeast cells lacking profilin (pfy1Δ). Unexpectedly, deletion of several stress granule and processing body genes, including pbp1Δ, were found to be synthetic lethal with pfy1Δ. Mutations in ATXN2, the human ortholog of PBP1, are a known ALS genetic risk factor and ataxin 2 is a stress granule component in mammalian cells. Given this genetic interaction and recent evidence linking stress granule dynamics to ALS pathogenesis, we hypothesized that profilin 1 might also associate with stress granules. Here we report that profilin 1 and related protein profilin 2 are novel stress granule-associated proteins in mouse primary cortical neurons and in human cell lines and that ALS-linked mutations in profilin 1 alter stress granule dynamics, providing further evidence for the potential role of stress granules in ALS pathogenesis. TDP-43, or TAR DNA-binding protein 43, is a pathological marker of a spectrum of neurodegenerative disorders, including amyotrophic lateral sclerosis and frontotemporal lobar degeneration with ubiquitin-positive inclusions. TDP-43 is an RNA/DNA-binding protein implicated in transcriptional and posttranscriptional regulation. Recent work also suggests that TDP-43 associates with cytoplasmic stress granules, which are transient structures that form in response to stress. In this study, we establish sorbitol as a novel physiological stressor that directs TDP-43 to stress granules in Hek293T cells and primary cultured glia. We quantify the association of TDP-43 with stress granules over time and show that stress granule association and size are dependent on the glycine-rich region of TDP-43, which harbors the majority of pathogenic mutations. Moreover, we establish that cells harboring wild-type and mutant TDP-43 have distinct stress responses: mutant TDP-43 forms significantly larger stress granules, and is incorporated into stress granules earlier, than wild-type TDP-43; in striking contrast, wild-type TDP-43 forms more stress granules over time, but the granule size remains relatively unchanged. We propose that mutant TDP-43 alters stress granule dynamics, which may contribute to the progression of TDP-43 proteinopathies. Amyotrophic lateral sclerosis (ALS) is a fatal, late-onset neurodegenerative disease primarily affecting motor neurons. A unifying feature of many proteins associated with ALS, including TDP-43 and ataxin-2, is that they localize to stress granules. Unexpectedly, we found that genes that modulate stress granules are strong modifiers of TDP-43 toxicity in Saccharomyces cerevisiae and Drosophila melanogaster. eIF2α phosphorylation is upregulated by TDP-43 toxicity in flies, and TDP-43 interacts with a central stress granule component, polyA-binding protein (PABP). In human ALS spinal cord neurons, PABP accumulates abnormally, suggesting that prolonged stress granule dysfunction may contribute to pathogenesis. We investigated the efficacy of a small molecule inhibitor of eIF2α phosphorylation in ALS models. Treatment with this inhibitor mitigated TDP-43 toxicity in flies and mammalian neurons. These findings indicate that the dysfunction induced by prolonged stress granule formation might contribute directly to ALS and that compounds that mitigate this process may represent a novel therapeutic approach. Amyotrophic lateral sclerosis (ALS) is an uncommon neurodegenerative disease caused by degeneration of upper and lower motor neurons. Several genes, including SOD1, TDP-43, FUS, Ubiquilin 2, C9orf72 and Profilin 1, have been linked with the sporadic and familiar forms of ALS. FUS is a DNA/RNA-binding protein (RBP) that forms cytoplasmic inclusions in ALS and frontotemporal lobular degeneration (FTLD) patients' brains and spinal cords. However, it is unknown whether the RNA-binding ability of FUS is required for causing ALS pathogenesis. Here, we exploited a Drosophila model of ALS and neuronal cell lines to elucidate the role of the RNA-binding ability of FUS in regulating FUS-mediated toxicity, cytoplasmic mislocalization and incorporation into stress granules (SGs). To determine the role of the RNA-binding ability of FUS in ALS, we mutated FUS RNA-binding sites (F305L, F341L, F359L, F368L) and generated RNA-binding-incompetent FUS mutants with and without ALS-causing mutations (R518K or R521C). We found that mutating the aforementioned four phenylalanine (F) amino acids to leucines (L) (4F-L) eliminates FUS RNA binding. We observed that these RNA-binding mutations block neurodegenerative phenotypes seen in the fly brains, eyes and motor neurons compared with the expression of RNA-binding-competent FUS carrying ALS-causing mutations. Interestingly, RNA-binding-deficient FUS strongly localized to the nucleus of Drosophila motor neurons and mammalian neuronal cells, whereas FUS carrying ALS-linked mutations was distributed to the nucleus and cytoplasm. Importantly, we determined that incorporation of mutant FUS into the SG compartment is dependent on the RNA-binding ability of FUS. In summary, we demonstrate that the RNA-binding ability of FUS is essential for the neurodegenerative phenotype in vivo of mutant FUS (either through direct contact with RNA or through interactions with other RBPs). Mutations in fused in sarcoma (FUS), a DNA/RNA binding protein, have been associated with familial amyotrophic lateral sclerosis (fALS), which is a fatal neurodegenerative disease that causes progressive muscular weakness and has overlapping clinical and pathologic characteristics with frontotemporal lobar degeneration. However, the role of autophagy in regulation of FUS-positive stress granules (SGs) and aggregates remains unclear. We found that the ALS-linked FUS(R521C) mutation causes accumulation of FUS-positive SGs under oxidative stress, leading to a disruption in the release of FUS from SGs in cultured neurons. Autophagy controls the quality of proteins or organelles; therefore, we checked whether autophagy regulates FUS(R521C)-positive SGs. Interestingly, FUS(R521C)-positive SGs were colocalized to RFP-LC3-positive autophagosomes. Furthermore, FUS-positive SGs accumulated in atg5(-/-) mouse embryonic fibroblasts (MEFs) and in autophagy-deficient neurons. However, FUS(R521C) expression did not significantly impair autophagic degradation. Moreover, autophagy activation with rapamycin reduced the accumulation of FUS-positive SGs in an autophagy-dependent manner. Rapamycin further reduced neurite fragmentation and cell death in neurons expressing mutant FUS under oxidative stress. Overall, we provide a novel pathogenic mechanism of ALS associated with a FUS mutation under oxidative stress, as well as therapeutic insight regarding FUS pathology associated with excessive SGs. In amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration, TAR DNA binding protein 43 (TDP-43) accumulates in the cytoplasm of affected neurons and glia, where it associates with stress granules (SGs) and forms large inclusions. SGs form in response to cellular stress, including endoplasmic reticulum (ER) stress, which is induced in both familial and sporadic forms of ALS. Here we demonstrate that pharmacological induction of ER stress causes TDP-43 to accumulate in the cytoplasm, where TDP-43 also associates with SGs. Furthermore, treatment with salubrinal, an inhibitor of dephosphorylation of eukaryotic initiation factor 2-α, a key modulator of ER stress, potentiates ER stress-mediated SG formation. Inclusions of C-terminal fragment TDP-43, reminiscent of disease-pathology, form in close association with ER and Golgi compartments, further indicating the involvement of ER dysfunction in TDP-43-associated disease. Consistent with this notion, over-expression of ALS-linked mutant TDP-43, and to a lesser extent wildtype TDP-43, triggers several ER stress pathways in neuroblastoma cells. Similarly, we found an interaction between the ER chaperone protein disulphide isomerase and TDP-43 in transfected cell lysates and in the spinal cords of mutant A315T TDP-43 transgenic mice. This study provides evidence for ER stress as a pathogenic pathway in TDP-43-mediated disease. Fused in sarcoma (FUS) belongs to the group of RNA-binding proteins implicated as underlying factors in amyotrophic lateral sclerosis (ALS) and certain other neurodegenerative diseases. Multiple FUS gene mutations have been linked to hereditary forms, and aggregation of FUS protein is believed to play an important role in pathogenesis of these diseases. In cultured cells, FUS variants with disease-associated amino acid substitutions or short deletions affecting nuclear localization signal (NLS) and causing cytoplasmic mislocalization can be sequestered into stress granules (SGs). We demonstrated that disruption of motifs responsible for RNA recognition and binding not only prevents SG recruitment, but also dramatically increases the protein propensity to aggregate in the cell cytoplasm with formation of juxtanuclear structures displaying typical features of aggresomes. Functional RNA-binding domains from TAR DNA-binding protein of 43 kDa (TDP-43) fused to highly aggregation-prone C-terminally truncated FUS protein restored the ability to enter SGs and prevented aggregation of the chimeric protein. Truncated FUS was also able to trap endogenous FUS molecules in the cytoplasmic aggregates. Our data indicate that RNA binding and recruitment to SGs protect cytoplasmic FUS from aggregation, and loss of this protection may trigger its pathological aggregation in vivo. Fused in sarcoma/translocated in liposarcoma (FUS/TLS) is one of causative genes for familial amyotrophic lateral sclerosis (ALS). In order to identify binding partners for FUS/TLS, we performed a yeast two-hybrid screening and found that protein arginine methyltransferase 1 (PRMT1) is one of binding partners primarily in the nucleus. In vitro and in vivo methylation assays showed that FUS/TLS could be methylated by PRMT1. The modulation of arginine methylation levels by a general methyltransferase inhibitor or conditional over-expression of PRMT1 altered slightly the nucleus-cytoplasmic ratio of FUS/TLS in cell fractionation assays. Although co-localized primarily in the nucleus in normal condition, FUS/TLS and PRMT1 were partially recruited to the cytoplasmic granules under oxidative stress, which were merged with stress granules (SGs) markers in SH-SY5Y cell. C-terminal truncated form of FUS/TLS (FUS-dC), which lacks C-terminal nuclear localization signal (NLS), formed cytoplasmic inclusions like ALS-linked FUS mutants and was partially co-localized with PRMT1. Furthermore, conditional over-expression of PRMT1 reduced the FUS-dC-mediated SGs formation and the detergent-insoluble aggregates in HEK293 cells. These findings indicate that PRMT1-mediated arginine methylation could be implicated in the nucleus-cytoplasmic shuttling of FUS/TLS and in the SGs formation and the detergent-insoluble inclusions of ALS-linked FUS/TLS mutants.

Does TGF-beta play a role in cardiac regeneration after myocardial infarction?

TGFβ signaling orchestrates the beneficial interplay between scar-based repair and cardiomyocyte-based regeneration to achieve complete heart regeneration.

[18985280, 17322368, 19966054, 15883211, 23293297, 10198196, 16842199, 12374778, 22513374]

Macrophages have been suggested to be beneficial for myocardial wound healing. We investigated the role of macrophages in myocardial wound healing by inhibition of macrophage infiltration after myocardial injury. We used a murine cryoinjury model to induce left ventricular damage. Infiltrating macrophages were depleted during the 1st week after cryoinjury by serial intravenous injections of clodronate-containing liposomes. After injury, the presence of macrophages, which secreted high levels of transforming growth factor-beta and vascular endothelial growth factor-A, led to rapid removal of cell debris and replacement by granulation tissue containing inflammatory cells and blood vessels, followed by myofibroblast infiltration and collagen deposition. In macrophage-depleted hearts, nonresorbed cell debris was still observed 4 weeks after injury. Secretion of transforming growth factor-beta and vascular endothelial growth factor-A as well as neovascularization, myofibroblast infiltration, and collagen deposition decreased. Moreover, macrophage depletion resulted in a high mortality rate accompanied by increased left ventricular dilatation and wall thinning. In conclusion, infiltrating macrophage depletion markedly impairs wound healing and increases remodeling and mortality after myocardial injury, identifying the macrophage as a key player in myocardial wound healing. Based on these findings, we propose that increasing macrophage numbers early after myocardial infarction could be a clinically relevant option to promote myocardial wound healing and subsequently to reduce remodeling and heart failure. In addition to mediating cell-to-cell electrical coupling, gap junctions are important in tissue repair, wound healing, and scar formation. The expression and distribution of connexin43 (Cx43), the major gap junction protein expressed in the heart, are altered substantially after myocardial infarction (MI); however, the effects of Cx43 remodeling on wound healing and the attendant ventricular dysfunction are incompletely understood. Cx43-deficient and wild-type mice were subjected to proximal ligation of the anterior descending coronary artery and followed for 6 days or 4 wk to test the hypothesis that reduced expression of Cx43 influences wound healing, fibrosis, and ventricular remodeling after MI. We quantified the progression of infarct healing by measuring neutrophil expression, collagen content, and myofibroblast expression. We found significantly reduced transformation of fibroblasts to myofibroblasts at 6 days and significantly reduced collagen deposition both in the infarct at 6 days and at 4 wk in the noninfarcted region of Cx43-deficient mice. As expected, transforming growth factor (TGF)-beta, a profibrotic cytokine, was dramatically upregulated in MI hearts, but its phosphorylated comediator (pSmad) was significantly downregulated in the nuclei of Cx43-deficient hearts post-MI, suggesting that downstream signaling of TGF-beta is diminished substantially in Cx43-deficient hearts. This diminution in profibrotic TGF-beta signaling resulted in the attenuation of adverse structural remodeling as assessed by echocardiography. These findings suggest that efforts to enhance the expression of Cx43 to maintain intercellular coupling or reduce susceptibility to arrhythmias should be met with caution until the role of Cx43 in infarct healing is fully understood. BACKGROUND: Recent studies have shown that bone marrow-derived stem cells differentiate into the phenotype of cardiomyocytes in vivo and in vitro. We tried to regenerate infarcted myocardium by implanting ex vivo transforming growth factor (TGF)-beta-preprogrammed CD117 (c-kit)-positive (CD117+) stem cells intramyocardially. METHODS AND RESULTS: CD117+ cells were isolated from the bone marrow mononuclear cells of GFP-transgenic or normal C57/BL6 mice. The myogenic differentiation of CD117+ cells was achieved by cultivation with TGF-beta. Using an acute myocardial infarction model, we also tried to regenerate infarcted myocardium by implanting untreated (newly isolated) or preprogrammed (24 hours of cultivation with 5 ng/mL TGF-beta1) CD117+ cells intramyocardially. TGF-beta increased the cellular expression of myosin, troponins, connexin-43, GATA-4, and NKx-2.5, which suggested that it induced the myogenic differentiation of CD117+ cells. Compared with the effects of PBS injection only, the microvessel density in the infarcted myocardium was increased significantly 3 months after the implantation of either TGF-beta-preprogrammed or untreated CD117+ cells. Moreover, many of the TGF-beta-preprogrammed CD117+ cells were stained positively for myosin, whereas few of the untreated CD117+ cells were. Histological analysis revealed newly regenerated myocardium in the left ventricular anterior wall after the implantation of TGF-beta-preprogrammed cells but not untreated cells. Furthermore, the left ventricular percent fraction shortening was significantly higher after the implantation of TGF-beta-preprogrammed cells than after the implantation of untreated CD117+ cells. CONCLUSIONS: TGF-beta conducted the myogenic differentiation of CD117+ stem cells by upregulating GATA-4 and NKx-2.5 expression. Therefore, the intramyocardial implantation of TGF-beta-preprogrammed CD117+ cells effectively assisted the myocardial regeneration and induced therapeutic angiogenesis, contributing to functional cardiac regeneration. Healing of myocardial infarcts depends on an inflammatory cascade that ultimately results in clearance of dead cells and matrix debris and formation of a scar. Myocardial necrosis activates complement, Nuclear Factor (NF)-kappaB and Toll-like Receptor (TLR)-dependent pathways, and generates free radicals, triggering an inflammatory response. Chemokines and cytokines are markedly induced in the infarct and mediate recruitment and activation of neutrophils and mononuclear cells. Extravasation of platelets and plasma proteins, such as fibrinogen and fibronectin, results in formation of a clot, consisting of platelets embedded in a mesh of crosslinked fibrin. This provisional matrix provides a scaffold for migration of cells into the infarct. Monocytes differentiate into macrophages and secrete fibrogenic and angiogenic growth factors inducing formation of granulation tissue, containing myofibroblasts and neovessels. Repression of proinflammatory cytokine and chemokine synthesis, mediated in part through Transforming Growth Factor (TGF)-beta and Interleukin (IL)-10, is critical for resolution of the inflammatory infiltrate and transition to fibrous tissue deposition. Infarct myofibroblasts deposit extracellular matrix proteins and a collagen-based scar is formed. As the wound matures, fibroblasts undergo apoptosis and neovessels regress, resulting in formation of a scar with a low cellular content containing dense, cross-linked collagen. The pathologic and structural changes associated with infarct healing directly influence ventricular remodeling and affect prognosis in patients with myocardial infarction. Understanding the mechanisms involved in the regulation of the post-infarction inflammatory response, and the spatial and temporal parameters of wound healing is necessary in order to identify specific molecular targets for therapeutic intervention. Members of the transforming growth factor beta1 (TGF-beta) superfamily--namely, TGF-beta and BMP2--applied to undifferentiated murine embryonic stem cells up-regulated mRNA of mesodermal (Brachyury) and cardiac specific transcription factors (Nkx2.5, MEF2C). Embryoid bodies generated from stem cells primed with these growth factors demonstrated an increased potential for cardiac differentiation with a significant increase in beating areas and enhanced myofibrillogenesis. In an environment of postmitotic cardiomyocytes, stem cells engineered to express a fluorescent protein under the control of a cardiac promoter differentiated into fluorescent ventricular myocytes beating in synchrony with host cells, a process significantly enhanced by TGF-beta or BMP2. In vitro, disruption of the TGF-beta/BMP signaling pathways by latency-associated peptide and/or noggin prevented differentiation of stem cells. In fact, only host cells that secrete a TGF-beta family member induced a cardiac phenotype in stem cells. In vivo, transplantation of stem cells into heart also resulted in cardiac differentiation provided that TGF-beta/BMP2 signaling was intact. In infarcted myocardium, grafted stem cells differentiated into functional cardiomyocytes integrated with surrounding tissue, improving contractile performance. Thus, embryonic stem cells are directed to differentiate into cardiomyocytes by signaling mediated through TGF-beta/BMP2, a cardiac paracrine pathway required for therapeutic benefit of stem cell transplantation in diseased heart.

Is there a genetic component for happiness?

Results of studies on genetic factors indicated an average effectiveness of genetic about 35 -50 percent on happiness. The MAOA gene predicts happiness in women. The heritability of happiness was estimated at 22% for males and 41% in females.

[20440640, 19728071, 26060713, 20981772, 20397744, 23769682, 24690898, 22885141, 19569406]

Subjective Wellbeing (SWB) can be assessed with distinct measures that have been hypothesized to represent different domains of SWB. The current study assessed SWB with four different measures in a genetically informative sample of adolescent twins and their siblings aged 13-28 years (N = 5,024 subjects from 2,157 families). Multivariate genetic modeling was applied to the data to explore the etiology of individual differences in SWB measures and the association among them. Developmental trends and sex differences were examined for mean levels and the variance-covariance structure. Mean SWB levels were equal in men and women. A small negative effect of age on mean levels of SWB was found. Individual differences in SWB were accounted for by additive and non-additive genetic influences, and non-shared environment. The broad-sense heritabilities were estimated between 40 and 50%. The clustering of the four different measures (quality of life in general, satisfaction with life, quality of life at present, and subjective happiness) was explained by an underlying additive genetic factor and an underlying non-additive genetic factor. The effect of these latent genetic factors on the phenotypes was not moderated by either age or sex. The Angelman syndrome is clinically delineated by the combination of seizures, absent speech, hypermotoric and ataxic movements and certain remarkable behaviors. Those with the syndrome have a predisposition toward apparent happiness and paroxysms of laughter, and this finding helps distinguish Angelman syndrome from other ones involving severe developmental handicap. In this review the core neurological features of the syndrome are discussed with a focus on those behaviors that make Angelman syndrome a prototypical genetic disorder expressing a behavioral phenotype. Causes of individual differences in happiness, as assessed with the Subjective Happiness Scale, are investigated in a large of sample twins and siblings from the Netherlands Twin Register. Over 12,000 twins and siblings, average age 24.7 years (range 12 to 88), took part in the study. A genetic model with an age by sex design was fitted to the data with structural equation modeling in Mx. The heritability of happiness was estimated at 22% for males and 41% in females. No effect of age was observed. To identify the genomic regions contributing to this heritability, a genome-wide linkage study for happiness was conducted in sibling pairs. A subsample of 1157 offspring from 441 families was genotyped with an average of 371 micro-satellite markers per individual. Phenotype and genotype data were analyzed in MERLIN with multipoint variance component linkage analysis and age and sex as covariates. A linkage signal (logarithm of odds score 2.73, empirical p value 0.095) was obtained at the end of the long arm of chromosome 19 for marker D19S254 at 110 cM. A second suggestive linkage peak was found at the short arm of chromosome 1 (LOD of 2.37) at 153 cM, marker D1S534 (empirical p value of .209). These two regions of interest are not overlapping with the regions found for contrasting phenotypes (such as depression, which is negatively associated with happiness). Further linkage and future association studies are warranted. BACKGROUND: Investigating genetic modulation of emotion processing may contribute to the understanding of heritable mechanisms of emotional disorders. The aim of the present study was to test the effects of catechol-O-methyltransferase (COMT) val158met and serotonin-transporter-linked promoter region (5-HTTLPR) polymorphisms on facial emotion processing in healthy individuals. METHODS: Two hundred and seventy five (167 female) participants were asked to complete a computerized facial affect recognition task, which involved four experimental conditions, each containing one type of emotional face (fearful, angry, sad or happy) intermixed with neutral faces. Participants were asked to indicate whether the face displayed an emotion or was neutral. The COMT-val158met and 5-HTTLPR polymorphisms were genotyped. RESULTS: Met homozygotes (COMT) showed a stronger bias to perceive neutral faces as expressions of anger, compared with val homozygotes. However, the S-homozygotes (5-HTTLPR) showed a reduced bias to perceive neutral faces as expressions of happiness, compared to L-homozygotes. No interaction between 5-HTTLPR and COMT was found. CONCLUSIONS: These results add to the knowledge of individual differences in social cognition that are modulated via serotonergic and dopaminergic systems. This potentially could contribute to the understanding of the mechanisms of susceptibility to emotional disorders. Happiness has been viewed as a temporary emotional state (e.g., pleasure) and a relatively stable state of being happy (subjective happiness level). As previous studies demonstrated that individuals with high subjective happiness level rated their current affective states more positively when they experience positive events, these two aspects of happiness are interrelated. According to a recent neuroimaging study, the cytosine to thymine single-nucleotide polymorphism of the human cannabinoid receptor 1 gene is associated with sensitivity to positive emotional stimuli. Thus, we hypothesized that our genetic traits, such as the human cannabinoid receptor 1 genotypes, are closely related to the two aspects of happiness. In Experiment 1, 198 healthy volunteers were used to compare the subjective happiness level between cytosine allele carriers and thymine-thymine carriers of the human cannabinoid receptor 1 gene. In Experiment 2, we used positron emission tomography with 20 healthy participants to compare the brain responses to positive emotional stimuli of cytosine allele carriers to that of thymine-thymine carriers. Compared to thymine-thymine carriers, cytosine allele carriers have a higher subjective happiness level. Regression analysis indicated that the cytosine allele is significantly associated with subjective happiness level. The positive mood after watching a positive film was significantly higher for the cytosine allele carriers compared to the thymine-thymine carriers. Positive emotion-related brain region such as the medial prefrontal cortex was significantly activated when the cytosine allele carriers watched the positive film compared to the thymine-thymine carriers. Thus, the human cannabinoid receptor 1 genotypes are closely related to two aspects of happiness. Compared to thymine-thymine carriers, the cytosine allele carriers of the human cannabinoid receptor 1 gene, who are sensitive to positive emotional stimuli, exhibited greater magnitude positive emotions when they experienced positive events and had a higher subjective happiness level. Psychologists, quality of life and well-being researchers have grown increasingly interested in understanding the factors that are associated with human happiness. Although twin studies estimate that genetic factors account for 35-50% of the variance in human happiness, knowledge of specific genes is limited. However, recent advances in molecular genetics can now provide a window into neurobiological markers of human happiness. This investigation examines association between happiness and monoamine oxidase A (MAOA) genotype. Data were drawn from a longitudinal study of a population-based cohort, followed for three decades. In women, low expression of MAOA (MAOA-L) was related significantly to greater happiness (0.261 SD increase with one L-allele, 0.522 SD with two L-alleles, P=0.002) after adjusting for the potential effects of age, education, household income, marital status, employment status, mental disorder, physical health, relationship quality, religiosity, abuse history, recent negative life events and self-esteem use in linear regression models. In contrast, no such association was found in men. This new finding may help explain the gender difference on happiness and provide a link between MAOA and human happiness. Although there is considerable evidence linking success -- including wealth, marriage, and friendships -- to happiness, this relationship might not reflect, as is often assumed, the effects of the proximate environment on well-being. Such an interpretation is contravened by evidence that both happiness and the environment are influenced by genetic factors and family upbringing. Using the National Survey of Midlife Development in the United States, which includes a subsample of twins, this study evaluates the relationship between happiness and various features of success before and after eliminating the influence of endowments. The results suggest that many putative indicators of the environment are highly heritable and, indeed, that the same genes that affect the environment may affect happiness as well. Yet the results also suggest that the role of genetic endowments varies considerably across different features of success, suggesting complex patterns of selection, reinforcement, and causation among genes and the environment.

What enzyme is inhibied by Opicapone?

Opicapone is a novel catechol-O-methyltransferase (COMT) inhibitor to be used as adjunctive therapy in levodopa-treated patients with Parkinson's disease

[24925090, 23248072, 24148813, 23336248, 24271646]

BACKGROUND AND OBJECTIVES: Opicapone is a novel third generation catechol-O-methyltransferase (COMT) inhibitor. The purpose of this study was to compare the levodopa pharmacokinetic profile throughout a day driven by the COMT inhibition either following repeated doses of opicapone or concomitant administration with entacapone. METHODS: A randomized, double-blind, gender-balanced, parallel-group study was performed in 4 groups of 20 healthy subjects each. Four subjects in each group received placebo during the entire study. Sixteen subjects in one group received placebo once daily for 11 days and on day 12, 200 mg entacapone concomitantly with each levodopa/carbidopa dose (three times separated by a 5-h interval). Sixteen subjects in each of the remaining three groups received respectively 25, 50, and 75 mg opicapone once daily for 11 days and on day 12, placebo concomitantly with each levodopa/carbidopa dose. RESULTS: Levodopa minimum plasma concentration (Cmin) for each levodopa/carbidopa dose and for the mean of all levodopa/carbidopa doses increased substantially with all active treatments (entacapone and opicapone) when compared to the control group (placebo), with values ranging from 1.7-fold (200 mg entacapone) to 3.3-fold (75 mg opicapone). No statistical difference was found for levodopa peak of systemic exposure (as assessed by maximum observed plasma concentration (Cmax)) between all active treatments and placebo. A significant increase in the levodopa extent of systemic exposure (as assessed by concentration-time curve (AUC)) occurred with all opicapone treatments in relation to placebo. No statistical difference was found for levodopa AUC when entacapone was compared to placebo. When compared to entacapone, both 50 and 75 mg opicapone presented a significant increase for the levodopa AUC. All active treatments significantly inhibited both peak (as assessed by Emax) and extent (as assessed by effect-time curve (AUEC)) of the COMT activity in relation to placebo. When compared to entacapone, all opicapone treatments significantly decreased the extent (AUEC) of the COMT activity due to a long-lasting and sustained effect. The tolerability profile was favorable for all active treatments. CONCLUSION: Opicapone, a novel third generation COMT inhibitor, when compared to entacapone, provides a superior response upon the bioavailability of levodopa associated to more pronounced, long-lasting, and sustained COMT inhibition. The tolerability profile was favorable. On the basis of the results presented in this study and along with the earlier pharmacology studies, it is anticipated that opicapone adjunct therapy at the dosages of 25 and 50 mg will provide an enhancement in levodopa availability that will translate into clinical benefit for Parkinson's disease patients. BACKGROUND AND OBJECTIVES: Opicapone is a novel catechol-O-methyltransferase (COMT) inhibitor. The purpose of this study was to evaluate the tolerability, pharmacokinetics (including the effect of food) and pharmacodynamics (effect on COMT activity) following single oral doses of opicapone in young healthy male volunteers. METHODS: Single rising oral doses of opicapone (10, 25, 50, 100, 200, 400, 800 and 1,200 mg) were administered to eight groups of eight subjects per group (two subjects randomized to placebo and six subjects to opicapone), under a double-blind, randomized, placebo-controlled design. In an additional group of 12 subjects, a 50 mg single dose of opicapone was administered on two occasions, once having fasted overnight and once with a high-fat high-calorie meal. RESULTS: Opicapone was well tolerated at all doses tested. The extent of systemic exposure (area under the plasma concentration-time curve and maximum plasma concentration) to opicapone and metabolites increased in an approximately dose-proportional manner and showed a decrease following concomitant ingestion of a high-fat high-calorie meal. The apparent terminal elimination half-life of opicapone was 0.8-3.2 h. Sulphation appeared to be the main metabolic pathway for opicapone, and both opicapone and the main sulphated metabolite are likely excreted by the biliary route. Maximum COMT inhibition by opicapone was dose dependent, ranged from 36.1% (10 mg) to 100% (200 mg and above), and reached statistical significance at all doses tested. The long duration of COMT inhibition by opicapone, however, tended to be independent from the dose taken. The observed half-life of opicapone-induced COMT inhibition in human erythrocytes was 61.6 h (standard deviation [SD] = 37.6 h), which reflects an underlying dissociative process with a kinetic rate constant of 3.1 × 10(-6) s(-1) (SD = 1.9 × 10(-6) s(-1)). Such a process compares well to the estimated dissociation rate constant (k(off)) of the COMT-opicapone molecular complex (k(off) = 1.9 × 10(-6) s(-1)). CONCLUSIONS: Opicapone was well-tolerated and presented dose-proportional kinetics. Opicapone demonstrated marked and sustained inhibition of erythrocyte soluble COMT activity. Based on the observation that the half-life of COMT inhibition is independent of the dose and that it reflects an underlying kinetic process that is consistent with the k(off) value of the COMT-opicapone complex, we propose that the sustained COMT inhibition, far beyond the observable point of clearance of circulating drug, is due to the long residence time of the reversible complex formed between COMT and opicapone. Globally, these promising results provide a basis for further clinical development of opicapone. OBJECTIVE: The present study aimed at evaluating the effect of opicapone, a third generation nitrocatechol catechol-O-methyltransferase (COMT) inhibitor, on the systemic and central bioavailability of 3,4-dihydroxy-l-phenylalanine (levodopa) and related metabolites in the cynomolgus monkey. METHODS: Four monkeys, implanted with guiding cannulas for microdialysis probes, in the substantia nigra, dorsal striatum and prefrontal cortex, were randomized in two groups that received, in a crossover design, vehicle or 100 mg/kg opicapone for 14 days. Twenty-three hours after last administration of vehicle or opicapone, animals were challenged with levodopa/benserazide (12/3 mg/kg). Extracellular dialysate and blood samples were collected over 360 min (at 30 min intervals) for the assays of catecholamine and COMT activity. RESULTS: Opicapone increased levodopa systemic exposure by 2-fold not changing Cmax values and reduced both 3-O-methyldopa (3-OMD) exposure and Cmax values by 5-fold. These changes were accompanied by ∼76-84% reduction in erythrocyte COMT activity. In dorsal striatum and substantia nigra, opicapone increased levodopa exposure by 1.7- and 1.4-fold, respectively, reducing 3-OMD exposure by 5- and 7-fold respectively. DOPAC exposure was increased by 4-fold in the substantia nigra. In the prefrontal cortex, opicapone increased levodopa exposure and reduced 3-OMD levels by 2.3- and 2.4-fold, respectively. CONCLUSIONS: Opicapone behaved as long-acting COMT inhibitor that markedly increased systemic and central levodopa bioavailability. Opicapone is a strong candidate to fill the unmet need for COMT inhibitors that lead to more sustained levodopa levels in Parkinson's disease patients. AIMS: The aim of this study was to assess the tolerability, pharmacokinetics and inhibitory effect on erythrocyte soluble catechol-O-methyltransferase (S-COMT) activity following repeated doses of opicapone. METHODS: This randomized, placebo-controlled, double-blind study enrolled healthy male subjects who received either once daily placebo or opicapone 5, 10, 20 or 30 mg for 8 days. RESULTS: Opicapone was well tolerated. Its systemic exposure increased in an approximately dose-proportional manner with an apparent terminal half-life of 1.0 to 1.4 h. Sulphation was the main metabolic pathway. Opicapone metabolites recovered in urine accounted for less than 3% of the amount of opicapone administered suggesting that bile is likely the main route of excretion. Maximum S-COMT inhibition (Emax ) ranged from 69.9% to 98.0% following the last dose of opicapone. The opicapone-induced S-COMT inhibition showed a half-life in excess of 100 h, which was dose-independent and much longer than plasma drug exposure. Such a half-life translates into a putative underlying rate constant that is comparable with the estimated dissociation rate constant of the COMT-opicapone complex. CONCLUSION: Despite its short elimination half-life, opicapone markedly and sustainably inhibited erythrocyte S-COMT activity making it suitable for a once daily regimen. PURPOSE: Opicapone (OPC) is a novel catechol-O-methyltransferase (COMT) inhibitor to be used as adjunctive therapy in levodopa-treated patients with Parkinson's disease. The purpose of this study was to evaluate the effect of moderate liver impairment on the pharmacokinetics (PK) and pharmacodynamics (PD; effect on COMT activity) of OPC. METHODS: An open-label, parallel-group study in patients (n = 8) with moderate liver impairment (Child-Pugh category B, score of 7 to 9) and matched healthy subjects (n = 8, control) with normal liver function. All subjects received a single 50-mg oral dose of OPC, with plasma and urine concentrations of opicapone and its metabolites measured up to 72 h post-dose, including soluble COMT (S-COMT) activity. A one-way analysis of variance (ANOVA) was used to compare the main PK and PD parameters between groups. Point estimates (PE) of geometric mean ratios (GMR) and corresponding 90 % confidence intervals (90%CI) for the ratio hepatic/control subjects of each parameter were calculated and compared with the reference interval (80-125 %). RESULTS: Exposure to opicapone (AUC and Cmax) increased significantly in patients with moderate hepatic impairment (PE [90%CI]: AUC0-∞, 184 % [135-250 %]; Cmax, 189 % [144-249 %]). Although apparent total clearance (CL/F) of opicapone was decreased by ∼35 %, similar elimination half-life and unbound/bound fractions of opicapone were observed between the two groups. Both rate and extent of exposure to BIA 9-1103 were higher in the hepatically impaired group, but not statistically significant compared with the control group. Similar to the parent (opicapone), the observed increase in exposure to BIA 9-1106 was statistically significant in the hepatically impaired group over the control group. BIA 9-1106 was the only metabolite detected in urine and its urine PK parameters were in accordance with plasma data. Maximum S-COMT inhibition (Emax) occurred earlier for the hepatically impaired group with values of 100 % and 91.2 % for the hepatically impaired and control groups respectively. Both Emax and AUEC for the hepatically impaired group reached statistical significance over the control group. OPC was well tolerated in both hepatically impaired and control groups. CONCLUSION: The bioavailability of an orally administered single dose of 50 mg OPC was significantly higher in patients with moderate chronic hepatic impairment, perhaps by a reduced first-pass effect. As the tolerability profile of OPC was favourable under the conditions of this study and its exposure is completely purged from systemic circulation before the subsequent dose administration, no OPC dose adjustment is needed in patients with mild to moderate chronic hepatic impairment. However, as OPC is under clinical development for use as adjunctive therapy in levodopa-treated patients with Parkinson's disease, an adjustment of levodopa and/or OPC regimens in patients should be carefully considered based on a potentially enhanced levodopa dopaminergic response and the associated tolerability.

What kind of affinity purification would you use in order to isolate soluble lysosomal proteins?

The rationale for purification of the soluble lysosomal proteins resides in their characteristic sugar, the mannose-6-phosphate (M6P), which allows an easy purification by affinity chromatography on immobilized M6P receptors.

[15789345, 17258946, 18370023, 18507433, 11079561, 16145712, 16399764, 22158965, 18977398, 19383612, 16709564]

The lysosome is a membrane delimited cytoplasmic organelle that contains at least 50 hydrolytic enzymes and associated cofactors. The biomedical importance of these enzymes is highlighted by the many lysosomal storage disorders that are associated with mutations in genes encoding lysosomal proteins, and there is also evidence that lysosomal activities may be involved in more widespread human diseases. The aim of this study was to characterize the human brain lysosomal proteome with the goal of establishing a reference map to investigate human diseases of unknown etiology and to gain insights into the cellular function of the lysosome. Proteins containing mannose 6-phosphate (Man6-P), a carbohydrate modification used for targeting resident soluble lysosomal proteins to the lysosome, were affinity-purified using immobilized Man6-P receptor. Fractionation by two-dimensional electrophoresis resolved a complex mixture comprising approximately 800 spots. Constituent proteins in each spot were identified using a combination of matrix-assisted laser desorption/ionization-time of flight mass spectrometry (both peptide mass fingerprinting and tandem mass spectrometry) [corrected] on in-gel tryptic digests and N-terminal sequencing. In a complementary analysis, we also analyzed a tryptic digest of the unfractionated mixture by liquid chromatography MS/MS. In total, 61 different proteins were identified. Seven were likely contaminants associated with true Man6-P glycoproteins. Forty-one were known lysosomal proteins of which 11 have not previously been reported to contain Man6-P. An additional nine proteins were either uncharacterized or proteins not previously reported to have lysosomal function. We found that the human brain Man6-P-containing lysosomal proteome is highly complex and contains more proteins with a much greater number of individual isoforms than found in previous studies of Man6-P glycoproteomes. Glycoproteins containing the mannose 6-phosphate (Man-6-P) modification represent a class of proteins of considerable biomedical importance. They include over sixty different soluble lysosomal hydrolases and accessory proteins, deficiencies of which result in over forty different known human genetic diseases. In addition, there are patients with lysosomal storage diseases of unknown etiology and lysosomal proteins have been implicated in pathophysiological processes associated with Alzheimer disease, arthritis, and cancer. The aim of this study was to explore urine as a source for the proteomic investigation of lysosomal storage disorders as well as for biomarker studies on the role of Man-6-P containing proteins in other human diseases. To this end, urinary proteins were affinity purified on immobilized Man-6-P receptors, digested with trypsin, and analyzed using nanospray LC/MS/MS. This resulted in identification of 67 proteins, including 48 known lysosomal proteins and 9 proteins that may be lysosomal. The identification of a large proportion of the known set of soluble lysosomal proteins with relatively few contaminants suggests that urine represents a promising substrate for the development of comparative proteomic methods for the investigation of lysosomal disorders and other diseases involving Man-6-P glycoproteins. This chapter describes the process of production, purification, separation, and mass spectrometry identification of soluble lysosomal proteins. The rationale for purification of these proteins resides in their characteristic sugar, the mannose-6-phosphate (M6P), which allows an easy purification by affinity chromatography on immobilized M6P receptor (MPR). The secretion of M6P proteins (essentially soluble lysosomal proteins) from cells in culture is induced by adding a weak base in the culture medium. Secreted proteins are ammonium sulfate precipitated, dialyzed, and loaded onto the immobilized MPR column. After specific elution and collection of the M6P proteins, these are resolved by either bidimensional or monodimensional gel electrophoresis (designated as 2-DE or 1-DE, respectively). Mass spectrometry analysis is performed on spots excised from the 2-DE gel, or on discrete bands covering altogether the whole length of the 1-DE gel lane: these spots or bands are in-gel digested with trypsin and protein identification is obtained, thanks to peptide mass fingerprints [provided by analysis of the digests by matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS)] or peptide amino acid sequences (provided by analysis of the digests by the coupling between liquid chromatography and tandem mass spectrometry, LC-MS/MS). Most luminal lysosomal proteins are synthesized as precursors containing mannose 6-phosphate (Man6-P) and a number of recent studies have conducted affinity purification of Man6-P containing proteins as a step toward defining the composition of the lysosome. Approximately 60 known lysosomal proteins have been found in such studies as well as many other Man-6-P glycoproteins, some of which represent new lysosomal proteins. The latter are of considerable interest from cell-biological and biomedical perspectives, but differentiating between them and other proteins remains a significant challenge. The aim of this study was to conduct a global analysis of the mammalian Man6-P glycoproteome, implementing technical and biostatistical methods to aid in the discovery and validation of lysosomal candidates. We purified Man6-P glycoproteins from 17 individual rat tissues. To distinguish nonspecific contaminants (i.e., abundant or "sticky" proteins that are not fully removed during purification) from specifically purified proteins, we conducted a semiquantitative mass spectrometric comparison of protein levels in nonspecific mock eluates versus specific affinity chromatography eluates to identify those proteins that are specifically purified. We identified 60 known lysosomal proteins, representing nearly all that are currently known to contain Man-6-P. We also find 136 other proteins that are specifically purified but which are not known to have lysosomal function. This approach provides a list of candidate lysosomal proteins and also provides insights into the relative distribution of Man6-P glycoproteins. The lysosomal compartment of human monocytic cells has never been investigated by a proteomic approach. By a combination of one-dimensional (1-D) and two-dimensional (2-D) gel electrophoresis, protein identification by N-terminal sequencing, matrix assisted laser desorption/ionization-mass spectrometry (MALDI-MS) peptide mass fingerprinting and tandem mass spectrometry (MS/MS) peptide sequence analysis, we initiated an exhaustive study of the human lyososomal proteome, which aims at establishing a 2-D reference map of human soluble lyososomal proteins. Human monocytic U937 cells were induced to secrete lysosomal soluble hydrolases by addition of NH4Cl in the culture medium. Since lysosomal soluble proteins are characterized by the presence of mannose-6-phosphate, they were purified on an affinity support bearing mannose-6-phosphate receptor. Analysis of the purified fraction led to the preliminary identification of fifteen proteins, among which twelve are well-known lysosomal hydrolases, one is assumed to be lysosomal on the basis of sequence homology to cysteine proteinases of the papain family, and two (leukocystatin and the human cellular repressor of E1A-stimulated genes) are described here for the first time as mannose-6-phosphate-containing proteins. The lysosomal matrix is estimated to contain about 50 different proteins. Most of the matrix proteins are acid hydrolases that depend on mannose 6-phosphate receptors (MPR) for targeting to lysosomes. Here, we describe a comprehensive proteome analysis of MPR-binding proteins from mouse. Mouse embryonic fibroblasts defective in both MPR (MPR 46-/- and MPR 300-/-) are known to secrete the lysosomal matrix proteins. Secretions of these cells were affinity purified using an affinity matrix derivatized with MPR46 and MPR300. In the protein fraction bound to the affinity matrix and eluted with mannose 6-phosphate, 34 known lysosomal matrix proteins, 4 candidate proteins of the lysosomal matrix and 4 non-lysosomal contaminants were identified by mass spectrometry after separation by two-dimensional gel electrophoresis or by multidimensional protein identification technology. For 3 of the candidate proteins, mammalian ependymin-related protein-2 (MERP-2), retinoid-inducible serine carboxypeptidase (RISC) and the hypothetical 66.3-kDa protein we could verify that C-terminally tagged forms bound in an M6P-dependent manner to an MPR-affinity matrix and were internalized via MPR-mediated endocytosis. Hence these 3 proteins are likely to represent hitherto unrecognized lysosomal matrix proteins. Most newly synthesized soluble lysosomal proteins contain mannose 6-phosphate (Man-6-P), a specific carbohydrate modification that is recognized by Man-6-P receptors (MPRs) that direct targeting to the lysosome. A number of proteomic studies have focused on lysosomal proteins, exploiting the fact that Man-6-P-containing forms can be purified by affinity chromatography on immobilized MPRs. These studies have identified many known lysosomal proteins as well as many proteins not previously classified as lysosomal. The latter are of considerable biological interest with potential implications for lysosomal function and as candidates for lysosomal storage diseases of unknown etiology. However, a significant problem in interpreting the biological relevance of such proteins has been in distinguishing true Man-6-P glycoproteins from simple contaminants and from proteins associated with true Man-6-P glycoproteins (e.g. protease inhibitors and lectins). In this report, we describe a mass spectrometric approach to the verification of Man-6-phosphorylation based upon LC-MS of MPR-purified proteolytic glycopeptides. This provided a useful tool in validating novel MPR-purified proteins as true Man-6-P glycoproteins and also allowed identification of low abundance components not observed in the analysis of the total Man-6-P glycoprotein mixture. In addition, this approach allowed the global mapping of 99 Man-6-phosphorylation sites from 44 known lysosomal proteins purified from mouse and human brain. This information is likely to provide useful insights into protein determinants for this modification and may be of significant value in protein engineering approaches designed to optimize protein delivery to the lysosome in therapeutic applications such as gene and enzyme replacement therapies. Mannose 6-phosphate (Man6P) residues represent a recognition signal required for efficient receptor-dependent transport of soluble lysosomal proteins to lysosomes. Upon arrival, the proteins are rapidly dephosphorylated. We used mice deficient for the lysosomal acid phosphatase Acp2 or Acp5 or lacking both phosphatases (Acp2/Acp5(-/-)) to examine their role in dephosphorylation of Man6P-containing proteins. Two-dimensional (2D) Man6P immunoblot analyses of tyloxapol-purified lysosomal fractions revealed an important role of Acp5 acting in concert with Acp2 for complete dephosphorylation of lysosomal proteins. The most abundant lysosomal substrates of Acp2 and Acp5 were identified by Man6P affinity chromatography and mass spectrometry. Depending on the presence of Acp2 or Acp5, the isoelectric point of the lysosomal cholesterol-binding protein Npc2 ranged between 7.0 and 5.4 and may thus regulate its interaction with negatively charged lysosomal membranes at acidic pH. Correspondingly, unesterified cholesterol was found to accumulate in lysosomes of cultured hepatocytes of Acp2/Acp5(-/-) mice. The data demonstrate that dephosphorylation of Man6P-containing lysosomal proteins requires the concerted action of Acp2 and Acp5 and is needed for hydrolysis and removal of degradation products. Acid hydrolase activities are normally confined within the cell to the lysosome, a membrane-delimited cytoplasmic organelle primarily responsible for the degradation of macromolecules. However, lysosomal proteins are also present in human plasma, and a proportion of these retain mannose 6-phosphate (Man-6-P), a modification on N-linked glycans that is recognized by Man-6-P receptors (MPRs) that normally direct the targeting of these proteins to the lysosome. In this study, we purified the Man-6-P glycoforms of proteins from human plasma by affinity chromatography on immobilized MPRs and characterized this subproteome by two-dimensional gel electrophoresis and by tandem mass spectrometry. As expected, we identified many known and potential candidate lysosomal proteins. In addition, we also identified a number of abundant classical plasma proteins that were retained even after two consecutive rounds of affinity purification. Given their abundance in plasma, we initially considered these proteins to be likely contaminants, but a mass spectrometric study of Man-6-phosphorylation sites using MPR-purified glycopeptides revealed that some proportion of these classical plasma proteins contained the Man-6-P modification. We propose that these glycoproteins are phosphorylated at low levels by the lysosomal enzyme phosphotransferase, but their high abundance results in detection of Man-6-P glycoforms in plasma. These results may provide useful insights into the molecular processes underlying Man-6-phosphorylation and highlight circumstances under which the presence of Man-6-P may not be indicative of lysosomal function. In addition, characterization of the plasma Man-6-P glycoproteome should facilitate development of mass spectrometry-based tools for the diagnosis of lysosomal storage diseases and for investigating the involvement of Man-6-P-containing glycoproteins in more widespread human diseases and their potential utility as biomarkers.

Which are the genes thought to be regulated by EWS/FLI?

The EWS/FLI translocation product is the causative oncogene in Ewing sarcoma and acts as an aberrant transcription factor. EWS/FLI dysregulates gene expression during tumorigenesis by abnormally activating or repressing genes. The expression levels of a significant number of genes are affected in Ewing sarcoma, some of which are known to be directly or indirectly regulated by EWS/FLI. Such genes are BCL11B, NRoB1, GSTM4, NKX2.2 and p53.

[23527175, 16697960, 17114343, 18927503, 15492248, 19920188, 19718047]

The EWS/FLI translocation product is the causative oncogene in Ewing sarcoma and acts as an aberrant transcription factor. EWS/FLI dysregulates gene expression during tumorigenesis by abnormally activating or repressing genes. The expression levels of thousands of genes are affected in Ewing sarcoma, however, it is unknown which of these genes contribute to the transformed phenotype. Here we characterize BCL11B as an up-regulated EWS/FLI target that is necessary for the maintenance of transformation in patient derived Ewing sarcoma cells lines. BCL11B, a zinc finger transcription factor, acts as a transcriptional repressor in Ewing's sarcoma and contributes to the EWS/FLI repressed gene signature. BCL11B repressive activity is mediated by the NuRD co-repressor complex. We further demonstrate that re-expression of SPRY1, a repressed target of BCL11B, limits the transformation capacity of Ewing sarcoma cells. These data define a new pathway downstream of EWS/FLI required for oncogenic maintenance in Ewing sarcoma. Our understanding of Ewing's sarcoma development mediated by the EWS/FLI fusion protein has been limited by a lack of knowledge regarding the tumor cell of origin. To circumvent this, we analyzed the function of EWS/FLI in Ewing's sarcoma itself. By combining retroviral-mediated RNA interference with reexpression studies, we show that ongoing EWS/FLI expression is required for the tumorigenic phenotype of Ewing's sarcoma. We used this system to define the full complement of EWS/FLI-regulated genes in Ewing's sarcoma. Functional analysis revealed that NKX2.2 is an EWS/FLI-regulated gene that is necessary for oncogenic transformation in this tumor. Thus, we developed a highly validated transcriptional profile for the EWS/FLI fusion protein and identified a critical target gene in Ewing's sarcoma development. A number of solid tumors, such as alveolar rhabdomyosarcoma, synovial sarcoma, and myxoid liposarcoma, are associated with recurrent translocation events that encode fusion proteins. Ewing's sarcoma is a pediatric tumor that serves as a prototype for this tumor class. Ewing's sarcomas usually harbor the (11;22)(q24;q12) translocation. The t(11;22) encodes the EWS/FLI fusion oncoprotein. EWS/FLI functions as an aberrant transcription factor, but the key target genes that are involved in oncogenesis are largely unknown. Although some target genes have been defined, many of these have been identified in heterologous model systems with uncertain relevance to the human disease. To understand the function of EWS/FLI and its targets in a more clinically relevant system, we used retroviral-mediated RNAi to "knock-down" the fusion protein in patient-derived Ewing's sarcoma cell lines. By combining transcriptional profiling data from three of these lines, we identified a conserved transcriptional response to EWS/FLI. The gene that was most reproducibly up-regulated by EWS/FLI was NR0B1. NR0B1 is a developmentally important orphan nuclear receptor with no previously defined role in oncogenesis. We validated NR0B1 as an EWS/FLI-dysregulated gene and confirmed its expression in primary human tumor samples. Functional studies revealed that ongoing NR0B1 expression is required for the transformed phenotype of Ewing's sarcoma. These studies define a new role for NR0B1 in oncogenic transformation and emphasize the utility of analyzing the function of EWS/FLI in Ewing's sarcoma cells. Ewing's sarcoma is a solid tumor of the bone that primarily occurs in children and young adults. Most cases harbor the (11;22) (q24;q12) chromosomal translocation that encodes the EWS/FLI oncoprotein. EWS/FLI is an aberrant ETS-type transcription factor that dysregulates a number of genes important in the development of Ewing's sarcoma. Because EWS/FLI is the key oncoprotein in this tumor and ETS proteins are often dysregulated in various human cancers, Ewing's sarcoma serves as a useful paradigm for ETS-mediated oncogenesis. We recently showed that EWS/FLI interacts with GGAA-microsatellites to regulate some of its target genes, including NR0B1, an EWS/FLI-regulated gene that is required for the oncogenic phenotype of Ewing's sarcoma. While microsatellites typically have no ascribed function, and are sometimes considered "junk" DNA, our findings provide a unique role for microsatellites in cancer development. Furthermore, these findings may indicate a novel mechanism for normal ETS protein function as well. Finally, it is tempting to speculate that microsatellite polymorphisms may confer differences in susceptibility to Ewing's sarcoma, both between individuals and between populations, and other diseases mediated by ETS transcription factors. The observation of microsatellites as transcriptional response elements for EWS/FLI suggest that these elements may not be "junk" after all. One hallmark of Ewing's sarcoma/peripheral neuroectodermal tumors is the presence of the Ews/Fli-1 chimeric oncogene. Interestingly, infection of neuroblastoma tumor cell lines with Ews/Fli-1 switches the differentiation program of neuroblastomas to Ewing's sarcoma/peripheral neuroectodermal tumors. Here we examined the status of cytoplasmically sequestered wt-p53 in neuroblastomas after stable expression of Ews/Fli-1. Immunofluorescence revealed that in the neuroblastoma-Ews/Fli-1 infectant cell lines, p53 went from a punctate-pattern of cytoplasmic sequestration to increased nuclear localization. Western blot analysis revealed that PARC was down-regulated in one neuroblastoma cell line but not expressed in the second. Therefore, decreased PARC expression could not fully account for relieving p53 sequestration in the neuroblastoma tumor cells. Neuroblastoma-Ews/Fli-1 infectant cell lines showed marked increases in p53 protein expression without transcriptional up-regulation. Interestingly, p53 was primarily phosphorylated, without activation of its downstream target p21(WAF1). Western blot analysis revealed that whereas MDM2 gene expression does not change, p14(ARF), a negative protein regulator of MDM2, increases. These observations suggest that the downstream p53 pathway may be inactivated as a result of abnormal p53. We also found that p53 has an extended half-life in the neuroblastoma-Ews/Fli-1 infectants despite the retention of a wild-type sequence in neuroblastoma-Ews/Fli-1 infectant cell lines. We then tested the p53 response pathway and observed that the neuroblastoma parent cells responded to genotoxic stress, whereas the neuroblastoma-Ews/Fli-1 infectants did not. These results suggest that Ews/Fli-1 can directly abrogate the p53 pathway to promote tumorigenesis. These studies also provide additional insight into the relationship among the p53 pathway proteins. Ewing's sarcoma is a malignant bone-associated tumor of children and young adults. Most cases of Ewing's sarcoma express the EWS/FLI fusion protein. EWS/FLI functions as an aberrant ETS-type transcription factor and serves as the master regulator of Ewing's sarcoma-transformed phenotype. We recently showed that EWS/FLI regulates one of its key targets, NR0B1, through a GGAA-microsatellite in its promoter. Whether other critical EWS/FLI targets are also regulated by GGAA-microsatellites was unknown. In this study, we combined transcriptional analysis, whole genome localization data, and RNA interference knockdown to identify glutathione S-transferase M4 (GSTM4) as a critical EWS/FLI target gene in Ewing's sarcoma. We found that EWS/FLI directly binds the GSTM4 promoter, and regulates GSTM4 expression through a GGAA-microsatellite in its promoter. Reduction of GSTM4 levels caused a loss of oncogenic transformation. Furthermore, reduction of GSTM4 resulted in an increased sensitivity of Ewing's sarcoma cells to chemotherapeutic agents, suggesting a role for this protein in drug resistance. Consistent with this hypothesis, patients with Ewing's sarcoma whose tumors had higher levels of GSTM4 expression had worse outcomes than those with lower expression levels. These data show that GSTM4 contributes to the cancerous behavior of Ewing's sarcoma and define a wider role for GGAA-microsatellites in EWS/FLI function than previously appreciated. These data also suggest a novel therapeutic resistance mechanism, in which the central oncogenic abnormality directly regulates a resistance gene.

Do archaeal genomes contain one or multiple origins of replication?

Some archaea replicate from single origins but most archaea and all eukaryotes replicate using multiple origins.

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Chromosomes with multiple DNA replication origins are a hallmark of Eukaryotes and some Archaea. All eukaryal nuclear replication origins are defined by the origin recognition complex (ORC) that recruits the replicative helicase MCM(2-7) via Cdc6 and Cdt1. We find that the three origins in the single chromosome of the archaeon Sulfolobus islandicus are specified by distinct initiation factors. While two origins are dependent on archaeal homologs of eukaryal Orc1 and Cdc6, the third origin is instead reliant on an archaeal Cdt1 homolog. We exploit the nonessential nature of the orc1-1 gene to investigate the role of ATP binding and hydrolysis in initiator function in vivo and in vitro. We find that the ATP-bound form of Orc1-1 is proficient for replication and implicates hydrolysis of ATP in downregulation of origin activity. Finally, we reveal that ATP and DNA binding by Orc1-1 remodels the protein's structure rather than that of the DNA template. Hyperthermus butylicus, a hyperthermophilic neutrophile and anaerobe, is a member of the archaeal kingdom Crenarchaeota. Its genome consists of a single circular chromosome of 1,667,163 bp with a 53.7% G+C content. A total of 1672 genes were annotated, of which 1602 are protein-coding, and up to a third are specific to H. butylicus. In contrast to some other crenarchaeal genomes, a high level of GUG and UUG start codons are predicted. Two cdc6 genes are present, but neither could be linked unambiguously to an origin of replication. Many of the predicted metabolic gene products are associated with the fermentation of peptide mixtures including several peptidases with diverse specificities, and there are many encoded transporters. Most of the sulfur-reducing enzymes, hydrogenases and electron-transfer proteins were identified which are associated with energy production by reducing sulfur to H(2)S. Two large clusters of regularly interspaced repeats (CRISPRs) are present, one of which is associated with a crenarchaeal-type cas gene superoperon; none of the spacer sequences yielded good sequence matches with known archaeal chromosomal elements. The genome carries no detectable transposable or integrated elements, no inteins, and introns are exclusive to tRNA genes. This suggests that the genome structure is quite stable, possibly reflecting a constant, and relatively uncompetitive, natural environment. The "baby machine" provides a means of generating synchronized cultures of minimally perturbed cells. We describe the use of this technique to establish the key cell-cycle parameters of hyperthermophilic archaea of the genus Sulfolobus. The 3 DNA replication origins of Sulfolobus acidocaldarius were mapped by 2D gel analysis to near 0 (oriC2), 579 (oriC1), and 1,197 kb (oriC3) on the 2,226-kb circular genome, and we present a direct demonstration of their activity within the first few minutes of a synchronous cell cycle. We also detected X-shaped DNA molecules at the origins in log-phase cells, but these were not directly associated with replication initiation or ongoing chromosome replication in synchronized cells. Whole-genome marker frequency analyses of both synchronous and log-phase cultures showed that origin utilization was close to 100% for all 3 origins per round of replication. However, oriC2 was activated slightly later on average compared with oriC1 and oriC3. The DNA replication forks moved bidirectionally away from each origin at approximately 88 bp per second in synchronous culture. Analysis of the 3 Orc1/Cdc6 initiator proteins showed a uniformity of cellular abundance and origin binding throughout the cell cycle. In contrast, although levels of the MCM helicase were constant across the cell cycle, its origin localization was regulated, because it was strongly enriched at all 3 origins in early S phase. BACKGROUND: While multiple replication origins have been observed in archaea, considerably less is known about their evolutionary processes. Here, we performed a comparative analysis of the predicted (proved in part) orc/cdc6-associated replication origins in 15 completely sequenced haloarchaeal genomes to investigate the diversity and evolution of replication origins in halophilic Archaea. RESULTS: Multiple orc/cdc6-associated replication origins were predicted in all of the analyzed haloarchaeal genomes following the identification of putative ORBs (origin recognition boxes) that are associated with orc/cdc6 genes. Five of these predicted replication origins in Haloarcula hispanica were experimentally confirmed via autonomous replication activities. Strikingly, several predicted replication origins in H. hispanica and Haloarcula marismortui are located in the distinct regions of their highly homologous chromosomes, suggesting that these replication origins might have been introduced as parts of new genomic content. A comparison of the origin-associated Orc/Cdc6 homologs and the corresponding predicted ORB elements revealed that the replication origins in a given haloarchaeon are quite diverse, while different haloarchaea can share a few conserved origins. Phylogenetic and genomic context analyses suggested that there is an original replication origin (oriC1) that was inherited from the ancestor of archaea, and several other origins were likely evolved and/or translocated within the haloarchaeal species. CONCLUSION: This study provides detailed information about the diversity of multiple orc/cdc6-associated replication origins in haloarchaeal genomes, and provides novel insight into the evolution of multiple replication origins in Archaea. Deviations from Chargaff's 2nd parity rule, according to which A approximately T and G approximately C in single stranded DNA, have been associated with replication as well as with transcription in prokaryotes. Based on observations regarding mainly the transcription-replication co-linearity in a large number of prokaryotic species, we formulate the hypothesis that the replication procedure may follow different modes between genomes throughout which the skews clearly follow different patterns. We draw the conclusion that multiple functional sites of origin of replication may exist in the genomes of most archaea and in some exceptional cases of eubacteria, while in the majority of eubacteria, replication occurs through a single fixed origin. In all three domains of life, DNA replication begins at specialized loci termed replication origins. In bacteria, replication initiates from a single, clearly defined site. In contrast, eukaryotic organisms exploit a multitude of replication origins, dividing their genomes into an array of short contiguous units. Recently, the multiple replication origin paradigm has also been demonstrated within the archaeal domain of life, with the discovery that the hyperthermophilic archaeon Sulfolobus has three replication origins. However, the evolutionary mechanism driving the progression from single to multiple origin usage remains unclear. Here, we demonstrate that Aeropyrum pernix, a distant relative of Sulfolobus, has two origins. Comparison with the Sulfolobus origins provides evidence for evolution of replicon complexity by capture of extrachromosomal genetic elements. We additionally identify a previously unrecognized candidate archaeal initiator protein that is distantly related to eukaryotic Cdt1. Our data thus provide evidence that horizontal gene transfer, in addition to its well-established role in contributing to the information content of chromosomes, may fundamentally alter the manner in which the host chromosome is replicated. DNA replication initiates at defined sites called origins, which serve as binding sites for initiator proteins that recruit the replicative machinery. Origins differ in number and structure across the three domains of life and their properties determine the dynamics of chromosome replication. Bacteria and some archaea replicate from single origins, whereas most archaea and all eukaryotes replicate using multiple origins. Initiation mechanisms that rely on homologous recombination operate in some viruses. Here we show that such mechanisms also operate in archaea. We use deep sequencing to study replication in Haloferax volcanii and identify four chromosomal origins of differing activity. Deletion of individual origins results in perturbed replication dynamics and reduced growth. However, a strain lacking all origins has no apparent defects and grows significantly faster than wild type. Origin-less cells initiate replication at dispersed sites rather than at discrete origins and have an absolute requirement for the recombinase RadA, unlike strains lacking individual origins. Our results demonstrate that homologous recombination alone can efficiently initiate the replication of an entire cellular genome. This raises the question of what purpose replication origins serve and why they have evolved. In bacterial chromosomes, the position of a gene relative to the single origin of replication generally reflects its replication timing, how often it is expressed, and consequently, its rate of evolution. However, because some archaeal genomes contain multiple origins of replication, bias in gene dosage caused by delayed replication should be minimized and hence the substitution rate of genes should associate less with chromosome position. To test this hypothesis, six archaeal genomes from the genus Sulfolobus containing three origins of replication were selected, conserved orthologs were identified, and the evolutionary rates (dN and dS) of these orthologs were quantified. Ortholog families were grouped by their consensus position and designated by their proximity to one of the three origins (O1, O2, O3). Conserved orthologs were concentrated near the origins and most variation in genome content occurred distant from the origins. Linear regressions of both synonymous and nonsynonymous substitution rates on distance from replication origins were significantly positive, the rates being greatest in the region furthest from any of the origins and slowest among genes near the origins. Genes near O1 also evolved faster than those near O2 and O3, which suggest that this origin may fire later in the cell cycle. Increased evolutionary rates and gene dispensability are strongly associated with reduced gene expression caused in part by reduced gene dosage during the cell cycle. Therefore, in this genus of Archaea as well as in many Bacteria, evolutionary rates and variation in genome content associate with replication timing. Halobacterium halobium contains two gas vacuole protein genes that are located in plasmid pHH1 (p-vac) and in the chromosomal DNA (c-vac). The mutation frequency for these genes is different: the constitutively expressed p-vac gene is mutated with a frequency of 10(-2), while the chromosomal gene expressed in the stationary phase of growth is mutated with a frequency of 10(-5). The difference in the mutation susceptibility is due to the dynamics of plasmid pHH1. p-vac gene mutations are caused (i) by the integration of an insertion element or (ii) by a deletion event encompassing the p-vac gene region. In contrast, c-vac mutants analyzed to date incurred neither insertion elements nor deletions. Deletion events within pHH1 occur at high frequencies during the development of a H. halobium culture. The investigation of the fusion regions resulting from deletion events indicates that insertion elements are involved. The analysis of pHH1 deletion variants led to a 4 kilobase pair DNA region containing the origin of replication of the pHH1 plasmid. Genome replication is a crucial and essential process for the continuity of life.In all organisms it starts at a specific region of the genome known as origin of replication (Ori) site. The number of Ori sites varies in prokaryotes and eukaryotes. Replication starts at a single Ori site in bacteria, but in eukaryotes multiple Ori sites are used for fast copying across all chromosomes. The situation becomes complex in archaea, where some groups have single and others have multiple origins of replication. Themococcales, are a hyperthermophilic order of archaea. They are anaerobes and heterotrophs-peptide fermenters, sulphate reducers, methanogens being some of the examples of metabolic types. In this paper we have applied a combination of multiple in silico approaches - Z curve, the cell division cycle (cdc6) gene location and location of consensus origin recognition box (ORB) sequences for location of origin of replication in Thermococcus onnurineus, Thermococcus gammatolerans and other Themococcales and compared the results to that of the well-documented case of Pyrococcus abyssi. The motivation behind this study is to find the number of Ori sites based on the data available for members of this order. Results from this in silico analysis show that the Themococcales have a single origin of replication. This report shows that isochore-like structures can be found not only in warm-blooded animals, some reptiles, fishes and yeast, but also in certain archaeal species. In perfectly shaped isochore-like structures (in "protoisochores") from Sulfolobus acidocaldarius and Thermofilum pendens genomes the difference in 3GC levels between genes from different "protoisochores" is about 30%. In these archaeal species GC-poor "protoisochores" are situated near the origin of replication, while GC-rich "protoisochores" are situated near the terminus of replication. There is a strong linear dependence between position of a gene and its 3GC level in S. acidocaldarius (an average difference in 3GC per 100,000 base pairs is equal to 3.6%). Detailed analyses of nucleotide usage biases in genes from leading and lagging strands led us to the suggestion that 3GC in genes situated near terminus of replication grows due to higher rates of thymine oxidation producing T to C transitions in lagging strands. Until recently, the only archaeon for which a bona fide origin of replication was reported was Pyrococcus abyssi, where a single origin was identified. Although several in silico analyses have suggested that some archaeal species might contain more than one origin, this has only been demonstrated recently. Two studies have shown that multiple origins of replication function in two archaeal species. One study identified two origins of replication in the archaeon Sulfolobus solfataricus, whereas a second study used a different technique to show that both S. solfataricus and Sulfolobus acidocaldarius have three functional origins. These are the first reports of archaea having multiple origins. This finding has implications for research on the mechanisms of DNA replication and evolution. We report the construction of a series of replicating shuttle vectors that consist of a low-copy-number cloning vector for Escherichia coli and functional components of the origin of replication (oriC) of the chromosome of the hyperthermophilic archaeon Pyrococcus furiosus. In the process of identifying the minimum replication origin sequence required for autonomous plasmid replication in P. furiosus, we discovered that several features of the origin predicted by bioinformatic analysis and in vitro binding studies were not essential for stable autonomous plasmid replication. A minimum region required to promote plasmid DNA replication was identified, and plasmids based on this sequence readily transformed P. furiosus. The plasmids replicated autonomously and existed in a single copy. In contrast to shuttle vectors based on a plasmid from the closely related hyperthermophile Pyrococcus abyssi for use in P. furiosus, plasmids based on the P. furiosus chromosomal origin were structurally unchanged after transformation and were stable without selection for more than 100 generations. The genomic sequence of the archaeon Methanosarcina mazei has been analyzed by the Z curve method. The Z curve is a three-dimensional curve that uniquely represents the given DNA sequence. The three-dimensional Z curve and its x and y components for the genome of M. mazei show a sharp peak and relatively broad peak, respectively. The cdc6 gene is located exactly at the position of the sharp peak. Based on the known behavior of the Z curves for the archaea whose replication origins have been identified, we hypothesize that the replication origin and termination sites correspond to the positions of the sharp peak and broad peak, respectively. We have located an intergenic region that is between the cdc6 gene (MM1314) and the gene for an adjacent protein (MM1315), which shows strong characteristics of the known replication origins. This region is highly rich in AT and contains multiple copies of consecutive repeats. Our results strongly suggest that the single replication origin of M. mazei is situated at the intergenic region between the cdc6 gene and the gene for the adjacent protein, from 1,564,657 to 1,566,241 bp of the genome. Different patterns of strand asymmetry have been documented in a variety of prokaryotic genomes as well as mitochondrial genomes. Because different replication mechanisms often lead to different patterns of strand asymmetry, much can be learned of replication mechanisms by examining strand asymmetry. Here I summarize the diverse patterns of strand asymmetry among different taxonomic groups to suggest that (1) the single-origin replication may not be universal among bacterial species as the endosymbionts Wigglesworthia glossinidia, Wolbachia species, cyanobacterium Synechocystis 6803 and Mycoplasma pulmonis genomes all exhibit strand asymmetry patterns consistent with the multiple origins of replication, (2) different replication origins in some archaeal genomes leave quite different patterns of strand asymmetry, suggesting that different replication origins in the same genome may be differentially used, (3) mitochondrial genomes from representative vertebrate species share one strand asymmetry pattern consistent with the strand-displacement replication documented in mammalian mtDNA, suggesting that the mtDNA replication mechanism in mammals may be shared among all vertebrate species, and (4) mitochondrial genomes from primitive forms of metazoans such as the sponge and hydra (representing Porifera and Cnidaria, respectively), as well as those from plants, have strand asymmetry patterns similar to single-origin or multi-origin replications observed in prokaryotes and are drastically different from mitochondrial genomes from other metazoans. This may explain why sponge and hydra mitochondrial genomes, as well as plant mitochondrial genomes, evolves much slower than those from other metazoans. The genomic sequence of the halophilic archaeon Halobacterium NRC-1 has been analyzed by the Z curve method. The Z curve is a three-dimensional curve that uniquely represents a given DNA sequence. Based on the known behaviors of the Z curves for the archaea whose replication origins have been identified, the analysis of the Z curve for the genome of Halobacterium NRC-1 strongly suggests that the large genome has two replication origins, oriC1 (921,863-922,014) and oriC2 (1,806,444-1,807,229), which are located at two sharp peaks of the Z curve. These two regions are next to the cdc6 genes and contain multiple copies of stretches of G and C, i.e., ggggtgggg and ccccacccc, which may also be regarded as direct and inverted repeats. Based on the above analysis, a model of replication of Halobacterium NRC-1 with two replication origins and two termini has been proposed. The experimental confirmation of this model would constitute the first example of multiple replication origins of archaea, which will finally provide much insight into the understanding of replication mechanisms of eukaryotic organisms, including human. In addition, the potential multiple replication origins of the archaeon Sulfolobus solfataricus are suggested by the analysis based on the Z curve method. The Z-curve is a three-dimensional curve that constitutes a unique representation of a DNA sequence, i.e., both the Z-curve and the given DNA sequence can be uniquely reconstructed from the other. We employed Z-curve analysis to identify one replication origin in the Methanocaldococcus jannaschii genome, two replication origins in the Halobacterium species NRC-1 genome and one replication origin in the Methanosarcina mazei genome. One of the predicted replication origins of Halobacterium species NRC-1 is the same as a replication origin later identified by in vivo experiments. The Z-curve analysis of the Sulfolobus solfataricus P2 genome suggested the existence of three replication origins, which is also consistent with later experimental results. This review aims to summarize applications of the Z-curve in identifying replication origins of archaeal genomes, and to provide clues about the locations of as yet unidentified replication origins of the Aeropyrum pernix K1, Methanococcus maripaludis S2, Picrophilus torridus DSM 9790 and Pyrobaculum aerophilum str. IM2 genomes. BACKGROUND: Species of the crenarchaeon Sulfolobus harbour three replication origins in their single circular chromosome that are synchronously initiated during replication. RESULTS: We demonstrate that global gene expression in two Sulfolobus species is highly biased, such that early replicating genome regions are more highly expressed at all three origins. The bias by far exceeds what would be anticipated by gene dosage effects alone. In addition, early replicating regions are denser in archaeal core genes (enriched in essential functions), display lower intergenic distances, and are devoid of mobile genetic elements. CONCLUSION: The strong replication-biased structuring of the Sulfolobus chromosome implies that the multiple replication origins serve purposes other than simply shortening the time required for replication. The higher-level chromosomal organisation could be of importance for minimizing the impact of DNA damage, and may also be linked to transcriptional regulation. The halophilic archaeon Haloferax volcanii has a multireplicon genome, consisting of a main chromosome, three secondary chromosomes, and a plasmid. Genes for the initiator protein Cdc6/Orc1, which are commonly located adjacent to archaeal origins of DNA replication, are found on all replicons except plasmid pHV2. However, prediction of DNA replication origins in H. volcanii is complicated by the fact that this species has no less than 14 cdc6/orc1 genes. We have used a combination of genetic, biochemical, and bioinformatic approaches to map DNA replication origins in H. volcanii. Five autonomously replicating sequences were found adjacent to cdc6/orc1 genes and replication initiation point mapping was used to confirm that these sequences function as bidirectional DNA replication origins in vivo. Pulsed field gel analyses revealed that cdc6/orc1-associated replication origins are distributed not only on the main chromosome (2.9 Mb) but also on pHV1 (86 kb), pHV3 (442 kb), and pHV4 (690 kb) replicons. Gene inactivation studies indicate that linkage of the initiator gene to the origin is not required for replication initiation, and genetic tests with autonomously replicating plasmids suggest that the origin located on pHV1 and pHV4 may be dominant to the principal chromosomal origin. The replication origins we have identified appear to show a functional hierarchy or differential usage, which might reflect the different replication requirements of their respective chromosomes. We propose that duplication of H. volcanii replication origins was a prerequisite for the multireplicon structure of this genome, and that this might provide a means for chromosome-specific replication control under certain growth conditions. Our observations also suggest that H. volcanii is an ideal organism for studying how replication of four replicons is regulated in the context of the archaeal cell cycle. HF2 is a haloarchaeal virus infecting two Halorubrum species (Family Halobacteriaceae). It is lytic, has a head-and-tail morphology and belongs to the Myoviridae (contractile tails). The linear double-stranded DNA genome was sequenced and found to be 77 670 bp in length, with a mol% G+C of 55.8. A total of 121 likely open reading frames (ORFs) were identified, of which 37 overlapped at start and stop codons. The predicted proteins were usually acidic (average pI of 4.8), and less than about 12% of them had homologues in the sequence databases. Four complete tRNA-like sequences (tRNA-Arg, -Asx, -Pro and -Tyr) and an incomplete tRNA-Thr were detected. A transcription map showed that most of the genome was transcribed and that the synthesis of transcripts occurred in a highly organized and reproducible pattern over a 5 h infection cycle. Transcripts often spanned multiple ORFs, suggesting that viral genes were organized into operons. The predicted ORF and observed transcript directions matched well and showed that transcription is mainly directed inwards from the genome termini, meeting at about 45-48 kb, and this was also a turning point in a cumulative GC-skew plot. The low point in cumulative GC-skew, near the left end, was a region rich in short repeats and lacking ORFs, which is likely to be an origin of replication. The HF2 genome is a mosaic of components from widely different sources, demonstrating clearly that viruses of haloarchaea, like their bacteriophage counterparts, are vectors for the exchange and transmission of genetic material between wide taxonomic distances, even across domains. We report here a comparative analysis of the genome sequence of Methanosarcina barkeri with those of Methanosarcina acetivorans and Methanosarcina mazei. The genome of M. barkeri is distinguished by having an organization that is well conserved with respect to the other Methanosarcina spp. in the region proximal to the origin of replication, with interspecies gene similarities as high as 95%. However, it is disordered and marked by increased transposase frequency and decreased gene synteny and gene density in the distal semigenome. Of the 3,680 open reading frames (ORFs) in M. barkeri, 746 had homologs with better than 80% identity to both M. acetivorans and M. mazei, while 128 nonhypothetical ORFs were unique (nonorthologous) among these species, including a complete formate dehydrogenase operon, genes required for N-acetylmuramic acid synthesis, a 14-gene gas vesicle cluster, and a bacterial-like P450-specific ferredoxin reductase cluster not previously observed or characterized for this genus. A cryptic 36-kbp plasmid sequence that contains an orc1 gene flanked by a presumptive origin of replication consisting of 38 tandem repeats of a 143-nucleotide motif was detected in M. barkeri. Three-way comparison of these genomes reveals differing mechanisms for the accrual of changes. Elongation of the relatively large M. acetivorans genome is the result of uniformly distributed multiple gene scale insertions and duplications, while the M. barkeri genome is characterized by localized inversions associated with the loss of gene content. In contrast, the short M. mazei genome most closely approximates the putative ancestral organizational state of these species. Replication origins were mapped in hyperthermophilic crenarchaea, using high-throughput sequencing-based marker frequency analysis. We confirm previous origin mapping in Sulfolobus acidocaldarius, and demonstrate that the single chromosome of Pyrobaculum calidifontis contains four replication origins, the highest number detected in a prokaryotic organism. The relative positions of the origins in both organisms coincided with regions enriched in highly conserved (core) archaeal genes. We show that core gene distribution provides a useful tool for origin identification in archaea, and predict multiple replication origins in a range of species. One of the P. calidifontis origins was mapped in detail, and electrophoretic mobility shift assays demonstrated binding of the Cdc6/Orc1 replication initiator protein to a repeated sequence element, denoted Orb-1, within the origin. The high-throughput sequencing approach also allowed for an annotation update of both genomes, resulting in the restoration of open reading frames encoding proteins involved in, e.g., sugar, nitrate and energy metabolism, as well as in glycosylation and DNA repair.

Which pathological conditions are caused by mutations in the CYLD gene?

Since loss of CYLD expression can be observed in different types of human cancer, it is now well established that CYLD acts as a tumor suppressor gene. Pathogenic mutations in CYLD can be identified in patients affected with Brooke-Spiegler syndrome, (Familial) Cylindromatosis or multiple familial trichoepithelioma. CYLD expression has also been reported to be dramatically downregulated in basal cell carcinoma (BCC), the most common cancer in humans.

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Multiple familial trichoepitheliomas (MFT) constitute an autosomally inherited syndrome possibly related to Brooke-Spiegler syndrome (BSS). Although some early studies suggested a role for the PTCH gene on chromosome 9q22.3 in the etiopathogenesis of MFT, recent studies of occasional patients with the MFT clinical phenotype identified mutations in the CYLD gene on chromosome 16q12-q13, a gene responsible for BSS. A systematic investigation of PTCH and CYLD mutations in patients with MFT has never been performed. Our main objective was to collect a reasonably large series of patients with MFT to (1) study the clinicopathological spectrum of the disease, (2) determine whether the PTCH gene is implicated in the pathogenesis of MFT, and if so (3) determine the relative frequency of CYLD and PTCH mutations, (4) establish if there may be any possible genotype-phenotype correlations, and (5) study the spectrum of somatic mutations. Clinical analysis including family histories, histopathological investigations, and molecular genetic studies were performed. There were 9 female and 7 male patients ranging in age from 11 to 63 years. They presented with multiple, small, discrete and sometimes confluent, skin-colored to pink, asymptomatic nodules preferentially located on the face, being especially prominent and confluent in the nasolabial folds and inner aspects of the eyebrows. A total of 66 conventional trichoepitheliomas (TEs) were studied microscopically. Aside from typical features of TE, some also exhibited variant morphological patterns including areas reminiscent of other benign adnexal neoplasms and melanocytic hyperplasia. In none of the 9 patients tested was a germline mutation of the PTCH gene identified. Germline CYLD mutations were detected in 6 of 13 patients tested (identical in 2 unrelated patients) including 2 novel mutations, whereas the remaining 7 individuals showed wild-type alleles. Two patients with germline wild-type CYLD showed, however, a somatic mutation in the gene (1 duplication, 1 substitution mutation). Neither CYLD nor PTCH germline mutations were found in the 5 patients in whom both genes were analyzed. MFT seems to be a phenotypic variant of BSS. The PTCH gene is rarely, if ever, involved in the pathogenesis of MFT. Absence of a germline mutation of the CYLD gene in cases harboring a somatic mutation may be explained by large deletions in the gene or by mutation in intronic sequences or in the promoter region. Considering our 5 patients with no mutation in either gene, the final possibility is that another, as yet undescribed gene (neither CYLD nor PTCH) is implicated in the pathogenesis of some patients with MFT. Familial cylindromatosis (turban tumor syndrome; Brooke-Spiegler syndrome) (OMIM numbers 123850, 132700, 313100, and 605041) is a rare autosomal dominantly inherited tumor syndrome. The disorder can present with cutaneous adnexal tumors such as cylindromas, trichoepitheliomas, and spiradenomas, and tumors preferably develop in hairy areas of the body such as head and neck. In affected families, mutations have been demonstrated in the CYLD gene located on chromosome 16q12-13 and reveal the characteristic attributes of a tumor suppressor. Here, we studied familial cylindromatosis in a multigeneration family of German origin. Clinically, some individuals only revealed discrete small skin-colored tumors localized in the nasolabial region whereas one family member showed expansion of multiple big tumors on the trunk and in a turban-like fashion on the scalp. Histologically, cylindromas as well as epithelioma adenoides cysticum were found. We detected a frameshift mutation in the CYLD gene, designated 2253delG, underlying the disorder and were able to show that a single mutation can result in distinct clinical and histologic expression in familial cylindromatosis. The reasons for different expression patterns of the same genetic defect in this disease remain elusive, however. Identification of mutations in the CYLD gene enable us to rapidly confirm putative diagnoses on the genetic level and to provide affected families with genetic counseling. Individuals with germline mutations in the tumour-suppressor gene CYLD are at high risk of developing disfiguring cutaneous appendageal tumours, the defining tumour being the highly organised cylindroma. Here, we analysed CYLD mutant tumour genomes by array comparative genomic hybridisation and gene expression microarray analysis. CYLD mutant tumours were characterised by an absence of copy-number aberrations apart from LOH chromosome 16q, the genomic location of the CYLD gene. Gene expression profiling of CYLD mutant tumours showed dysregulated tropomyosin kinase (TRK) signalling, with overexpression of TRKB and TRKC in tumours when compared with perilesional skin. Immunohistochemical analysis of a tumour microarray showed strong membranous TRKB and TRKC staining in cylindromas, as well as elevated levels of ERK phosphorylation and BCL2 expression. Membranous TRKC overexpression was also observed in 70% of sporadic BCCs. RNA interference-mediated silencing of TRKB and TRKC, as well as treatment with the small-molecule TRK inhibitor lestaurtinib, reduced colony formation and proliferation in 3D primary cell cultures established from CYLD mutant tumours. These results suggest that TRK inhibition could be used as a strategy to treat tumours with loss of functional CYLD. The pleiomorphic adenoma gene 1 (PLAG1) gene is activated in a subset of pleomorphic adenomas of the salivary gland by gene fusion. Germ‑line mutation in cylindromatosis (CYLD), a tumor suppressor gene, causes familial cylindromatosis and Brook‑Spiegler syndrome. In the present study, aberrations in PLAG1 and CYLD were investigated in adenoid cystic carcinoma (ACC) of the salivary gland. Reverse‑transcription PCR and PCR direct sequencing were performed to detect gene fusion of PLAG1 and mutation of CYLD in 34 ACC tissues. No PLAG1 fusion was detected in ACC. However, silent mutation of CYLD was detected in 2 cases of ACC, but no missense mutation was detected in ACC. These results suggest that PLAG1 and CYLD do not play a role in ACC tumorigenesis. We report a patient with multiple trichoepitheliomas whose biopsy material also demonstrated a range of other neoplasms with follicular differentiation, including small nodular trichoblastoma, small nodular basal cell carcinoma (BCC), and areas resembling infundibulocystic BCC/basaloid follicular hamartoma. These were all intimately associated with otherwise typical trichoepitheliomas that dominated the microscopic appearances. Peripheral blood and tumor tissues of the patient and his 2 daughters, who apparently had a milder phenotype, were studied for alterations in the CYLD and PTCH genes, but mutations or loss of heterozygosity was not found in either gene. The occurrence of multiple follicular neoplasms within a single lesion adds evidence that, although in most cases BCC and trichoblastoma are distinct lesions, the 2 neoplasms do encompass a morphological spectrum of follicular differentiation, which is probably more overtly expressed in syndromic patients. Multiple familial trichoepithelioma (MFT) is an autosomal dominant disease characterized by numerous skin-coloured papules on the central face. Mutations in the CYLD gene, which is also the gene responsible for familial cylindromatosis, have been reported recently. Recent studies indicate that CYLD is a tumour-suppressor gene. The CYLD protein is a negative regulator of the activation of transcription factor nuclear factor-kappaB, and loss of CYLD contributes to oncogenesis. We report a novel splicing mutation (IVS12 + 1 G-->A) in the CYLD gene in a Taiwanese pedigree with MFT, and discuss new developments in treatment options. Brooke-Spiegler syndrome, familial cylindromatosis, and familial trichoepithelioma are autosomal-dominant genetic predispositions for benign tumors of skin appendages caused by mutations in the CYLD gene localized on chromosome 16q12-q13. The encoded protein functions as ubiquitin-specific protease (UBP), which negatively regulates NF-kappaB and c-Jun N-terminal kinase (JNK) signaling. We investigated five families affected with these skin neoplasms and identified four premature stop codons and the novel missense mutation D681G in a family in which 11 of 12 investigated tumors were trichoepitheliomas. CYLD protein harboring this missense mutation had a significant reduced ability to inhibit TNF receptor-associated factor (TRAF)2- and TRAF6-mediated NF-kappaB activation, tumor necrosis factor-alpha (TNFalpha)-induced JNK signaling, and to deubiquitinate TRAF2. CYLD-D681G was coimmunoprecipitated by TRAF2, but was unable to cleave K63-linked polyubiquitin chains. Aspartic acid 681 is highly conserved in CYLD homologues and other members of the UBP family, but does not belong to the Cys and His boxes providing the CYLD catalytic triad (Cys601, His871, and Asp889). As reported previously, the homologous residue D295 of HAUSP/USP-7 forms a hydrogen bond with the C-terminal end of ubiquitin and is important for the enzymatic activity. These results underline that D681 in CYLD is required for cleavage of K63-linked polyubiquitin chains. The authors report a case of Brooke-Spiegler syndrome (BSS) with a novel germline CYLD mutation and various somatic mutations identified in the lesional tissues. The patient was a 46-year-old man with multiple lesions on the face. The available histopathological material included 24 trichoepitheliomas, 2 large nodular basal cell carcinomas (BCCs), 2 spiradenomas, 1 spiradenocylindroma and 1 trichoblastoma composed of large and small nodules with prominent clear cell differentiation. Whereas one of the two BCCs manifested a conventional morphology, the second neoplasm additionally showed foci with high grade cytological features characterized by marked pleomorphism and numerous mitotic figures. There were also numerous signet ring cells and cells containing intracytoplasmic eosinophilic inclusions. The germline mutation was a substitution mutation c.1684 + 1G> A. Somatic mutations were investigated in eight tissue blocks from which high quality genomic DNA had been successfully extracted. Somatic mutations included loss of heterozygosity (LOH) in four lesions and a single sequence mutation, namely a single base deletion c. 2322delA causing a frameshift mutation E774DfsX2. LOH occurred in both BCCs, one trichoepithelioma and one spiradenoma. In the remaining three lesions, the somatic event remained undetected. Brooke-Spiegler syndrome represents an autosomal dominant disease characterized by the occurrence of multiple cylindromas, trichoepitheliomas and (sporadically) spiroadenomas. Patients with Brooke-Spiegler syndrome are also at risk of developing tumors of the major and minor salivary glands. Patients with Brooke-Spiegler syndrome have various mutations in the CYLD gene, a tumor-suppressor gene located on chromosome 16q. To date, 68 unique CYLD mutations have been identified. We describe two families with Brooke-Spiegler syndrome, one with familial cylindromatosis and one with multiple familial trichoepithelioma, which showed wide inter-family phenotypic variability. Analysis of germline mutations of the CYLD and PTCH genes was performed using peripheral blood. In addition, formalin-fixed paraffin-embedded tumor samples were analyzed for PTCH somatic mutations and cylindroma cell cultures were obtained directly from patients for further growth and analysis. Clinically, the major features of Brooke-Spiegler syndrome include the presence of heterogeneous skin tumors and wide inter- and intra-familial phenotypic variability. Histopathologically, both cylindromas and trichoepitheliomas were found in affected individuals. Mutations or loss of heterozygosity was not found in CYLD and PTCH genes. In CYLD and PTCH mutation-negative patients, other genes may be affected and further studies are needed to clarify whether these patients may be affected by de novo germline mutations. Pathogenic mutations in CYLD can be identified in patients affected with Brooke-Spiegler syndrome, (Familial) Cylindromatosis or multiple familial trichoepithelioma. To date, only technologies which are able to identify small point mutations in CYLD, such as sequence and WAVE analysis, were used. Here we describe the identification of a larger rearrangement identified by Quantitative PCR analysis of CYLD, indicating that a combination of these technologies is necessary when searching for pathogenic mutations in CYLD. The authors report a case of basaloid carcinoma involving the anus and rectum of a 57-year-old woman. Microscopically, the tumor showed unusual morphologic features strongly resembling a spiradenocylindroma because it consisted, in most parts, of basaloid cell nodules arranged in a jigsaw-puzzle fashion containing or surrounded by eosinophilic basal membrane material; in addition, there were intratumoral lymphocytes. The overlying squamous epithelium manifested dysplastic changes compatible with in situ squamous carcinoma that gradually became invasive and blended with basaloid cell islands; additionally, there were koilocytes in the squamous epithelium. A molecular biology study identified HPV-16 in the lesional tissue. Analysis of the CYLD gene did not prove any mutation. Familial cylindromatosis is a rare dominantly inherited disease characterized by the development of multiple benign tumours of the skin appendages, including cylindromas, trichoepitheliomas and spiradenomas. The gene responsible was positionally cloned recently, and was designated CYLD. We describe a family with cylindromatosis, in which affected individuals have an inherited R758X nonsense mutation of CYLD. Affected members of this family manifest a relatively mild tumour phenotype; the largest tumour was only 30 mm in diameter. Thus far, there is no evident genotype-phenotype relationship in cylindromatosis, although the number of families reported with both phenotypic and genotypic data remains small. Brooke-Spiegler syndrome (BSS) is an autosomal dominant disease characterized by cylindromas, trichoepitheliomas and occasionally spiradenomas. The disease gene was mapped to 16q12-13, and mutations in the CYLD gene were identified in families with BSS. In the present report, we describe a large consanguineous Chinese family with BSS showing an intra-family phenotypic variability. Clinically, some affected individuals only revealed discrete small skin-coloured tumors whereas the proband showed an expansion of multiple large tumors on the back of nose and numerous dome-shaped papules on her scalp. Histologically, both trichoepitheliomas and cylindromas were found in the affected individuals. By sequence analysis, we identified a recurrent mutation 2272C>T (R758X) of the CYLD gene in the affected individuals of this family, which was previously identified in other ethnic families with familial cylindromatosis. Our result provided additional information for phenotype-genotype correlation in BSS. Brooke-Spiegler syndrome (BSS), familial cylindromatosis (FC), and multiple familial trichoepithelioma (MFT), originally described as distinct inherited disorders, are characterized by a variety of skin appendage neoplasms. Mutations in the CYLD gene are found in individuals with these syndromes. We describe a single family with affected members exhibiting either the FC or the MFT phenotypes associated with a mutation in the CYLD gene. These findings support the notion that BSS, FC, and MFT represent phenotypic variation of a single defect. Of interest, one of the affected individuals described in this report exhibits a severe phenotype illustrating the morbidity of the disorder. Multiple familial trichoepithelioma (MFT) and familial cylindromatosis are two clinically distinct cancer syndromes. MFT patients developed mostly trichoepithelioma in the face while cylindromatosis patients developed cylindromas predominantly (approximately 90%) on the head and neck. However, multiple familial trichoepithelioma is occasionally associated with familial cylindromatosis while cylindromatosis patients can also develop trichoepithelioma. This has led to the speculation that the 2 types of dermatoses may be caused by dysfunction of a common pathway. Previously, a candidate MTF locus has been mapped to 9p21 while disease gene for familial cylindromatosis, the CYLD gene located on 16q21-13 has been identified. Here, we show that mutations in the CYLD gene are also the genetic basis for three different Chinese families with MFT. Sequence analysis reveal a single nucleotide deletion, c.1462delA (P.Ile488fsX9) in exon 9, a nonsense mutation, c.2128C>T (p. Gln710X) in exon 17, and a missense mutation, c.2822A>T (p. Asp941Val) in exon 21 in each of the three families respectively. This provides direct evidence that the mutations in CYLD can cause two clinically distinct cancer syndromes. Survival of the malignant Hodgkin and Reed/Sternberg (HRS) cells in classical Hodgkin lymphoma (cHL) is dependent on constitutive activation of the nuclear factor kappaB (NF-kappaB) transcription factor. The deubiquitinating enzyme CYLD is a negative regulator of NF-kappaB and known to function as a tumor suppressor. To determine whether CYLD mutations play a role in cHL pathogenesis, we sequenced the gene in cHL cell lines and microdissected HRS cells obtained from lymph-node biopsies. A biallelic inactivation by mutations was found in the cHL cell-line KM-H2. However, the other seven cHL cell lines analyzed and HRS cells of 10 primary cHL cases did not show any mutations. By interphase cytogenetics, a (sub)clonal biallelic CYLD deletion was observed by interphase cytogenetics in 1 of 29 primary cHL, whereas signal patterns indicating decreased CYLD copy numbers were observed in a total of 10 of 29 primary cases. Our results suggest that biallelic CYLD mutations are rarely involved in cHL pathogenesis. Nevertheless, it is remarkable that KM-H2 cells, besides the CYLD mutations, also carry inactivating mutations in the genes of two other NF-kappaB inhibitors, that is, NFKBIA and TNFAIP3, exemplifying that multiple lesions in regulators of this signaling pathway can likely cooperatively contribute to the strong NF-kappaB activity of these cells. We present a case of Brooke-Spiegler syndrome with a germline deep intronic mutation in the CYLD gene leading to intronic exonization. Additionally, diverse somatic mutations were identified, namely loss of heterozygosity, a recurrent nonsense mutation, and a sequence mutation causing exon skipping. These somatic aberrations were identified in 4 different cylindromas that had been removed from the patient. Additionally, we microscopically studied a spiradenocylindroma that showed unusual histology, including foci of follicular differentiation. A deep intronic mutation resulting in exonization and a somatic sequence mutations causing exon skipping are hitherto unreported genetic mechanisms involving the CYLD gene in patients with Brooke-Spiegler syndrome. CYLD is a deubiquitination enzyme that regulates different cellular processes, such as cell proliferation and cell survival. Mutation and loss of heterozygosity of the CYLD gene causes development of cylindromatosis, a benign tumour originating from the skin. Our study shows that CYLD expression is dramatically downregulated in basal cell carcinoma (BCC), the most common cancer in humans. Reduced CYLD expression in basal cell carcinoma was mediated by GLI1-dependent activation of the transcriptional repressor Snail. Inhibition of GLI1 restored the CYLD expression-mediated Snail signaling pathway, and caused a significant delay in the G1 to S phase transition, as well as proliferation. Our data suggest that GLI1-mediated suppression of CYLD has a significant role in basal cell carcinoma progression. The authors report a 64-year-old female with Brooke-Spiegler syndrome who presented with multiple cutaneous nodules and tumors mostly involving the scalp. Histopathological examination of one of the lesions located in a periauricular area revealed a typical cylindroma. In some neoplastic nodules ductal differentiation and occasional bilayered glands composed of the dark abluminal basal/myoepithelial cells and luminal mucinous cells might be recognized. Apocrine secretion was focally noted. Molecular biologic study of the CYLD gene performed from the peripheral blood identified a novel splice site c.2041+1 G>T mutation. This new germline mutation in the CYLD gene of a Slovak patient with Brooke-Spiegler syndrome extends the catalogue of known CYLD germline mutations in this condition.

Which is the genetic basis of Spinal Muscular Atrophy (SMA)?

The molecular genetic basis of spinal muscular atrophy (SMA), an autosomal recessive neuromuscular disorder, is the loss of function of the survival motor neuron gene (SMN1). Mutations of the SMN1 gene are responsible for SMA. A single nucleotide in the SMN gene regulates splicing and is responsible for spinal muscular atrophy. A critical question is why only the homozygous loss of SMN1, and not SMN2, results in spinal muscular atrophy (SMA). H4F5 is also highly deleted in type I SMA chromosomes, and thus is a candidate phenotypic modifier for SMA. The molecular genetic basis of spinal muscular atrophy (SMA), an autosomal recessive neuromuscular disorder, is the loss of function of the survival motor neuron gene (SMN1).

[22323744, 19062530, 22628388, 9073029, 20225030, 12220455, 12115944, 17076267, 9731538, 19646678, 11442327, 10339583]

OBJECTIVE: We report the cases of 2 patients with late-onset spinal muscular atrophy (SMA) type III, who were hemizygous for SMN1 deletion and carriers of novel SMN1 intragenic missense mutations, and we investigate the genotype-phenotype relationship. METHODS: Patients were tested for SMN1 deletions with standard methodology. Sequencing of all exons, exon-intron junctions, and flanking sequences of SMN1 by nested PCR was used to detect intragenic point mutations. SMN1 and SMN2 quantification was undertaken to investigate the genotype-phenotype relationship. RESULTS: Two novel point mutations were identified in exon 3 of SMN1 (p.Tyr130Cys and p.Tyr130His) in the highly conserved Tudor domain of the Smn protein. CONCLUSIONS: The genetic basis of SMA in the rare cases of compound heterozygous carriers of SMN1 deletions is complex. Small intragenic SMN1 mutations often lead to severe SMA phenotypes, especially if the point mutations lie in exon 3 that codes for the highly conserved Tudor domain of the Smn protein. Although both our patients were carriers of intragenic SMN1 mutations in the coding region of the Tudor domain, they presented with a mild SMA phenotype despite a low SMN2 copy number. We discuss the possible determinant role of these novel missense mutations in the phenotypic outcome and compensatory mechanisms that may account for the genotype-phenotype discrepancy. The review considers the original and published data on the molecular genetic basis of proximal spinal muscular atrophy (SMA), the most common monogenic neuromuscular disease. The structures of the SMN1 gene and SMN2 pseudogene, mutations distorting the SMN1 function, the structure and functions of the Smn neurotrophic protein, its role in biogenesis of small nuclear ribonucleoproteins (snRNPs), and the principles and prdblems of molecular diagnosis in SMA are described. Special consideration is given to the current approaches and prospects of gene and cell therapy of SMA, pharmacogenetic methods to correct the SMN2 function, and original results of long-term treatment of SMA patients with valproic acid drugs. Autosomal dominant congenital spinal muscular atrophy is characterized by predominantly lower limb weakness and wasting, and congenital or early-onset contractures of the hip, knee and ankle. Mutations in TRPV4, encoding a cation channel, have recently been identified in one large dominant congenital spinal muscular atrophy kindred, but the genetic basis of dominant congenital spinal muscular atrophy in many families remains unknown. It has been hypothesized that differences in the timing and site of anterior horn cell loss in the central nervous system account for the variations in clinical phenotype between different forms of spinal muscular atrophy, but there has been a lack of neuropathological data to support this concept in dominant congenital spinal muscular atrophy. We report clinical, electrophysiology, muscle magnetic resonance imaging and histopathology findings in a four generation family with typical dominant congenital spinal muscular atrophy features, without mutations in TRPV4, and in whom linkage to other known dominant neuropathy and spinal muscular atrophy genes has been excluded. The autopsy findings in the proband, who died at 14 months of age from an unrelated illness, provided a rare opportunity to study the neuropathological basis of dominant congenital spinal muscular atrophy. There was a reduction in anterior horn cell number in the lumbar and, to a lesser degree, the cervical spinal cord, and atrophy of the ventral nerve roots at these levels, in the absence of additional peripheral nerve pathology or abnormalities elsewhere along the neuraxis. Despite the young age of the child at the time of autopsy, there was no pathological evidence of ongoing loss or degeneration of anterior horn cells suggesting that anterior horn cell loss in dominant congenital spinal muscular atrophy occurs in early life, and is largely complete by the end of infancy. These findings confirm that dominant congenital spinal muscular atrophy is a true form of spinal muscular atrophy caused by a loss of anterior horn cells localized to lumbar and cervical regions early in development. Amyotrophic lateral sclerosis (ALS) is found in a familial form in around 5-10% of cases. Of these familial cases around 20% are associated with mutations of SOD-1. The genetic basis of the disease in the remaining familial cases, and genetic risk factors in sporadic cases, are unknown. Recently, the common forms of spinal muscular atrophy (SMA) have been associated with mutations of the SMN and NAIP genes on chromosome 5, in the region q11.2-13.3. Some patients with both familial and sporadic motor neuron disease show only lower motor neuron signs, in common with SMA patients, and families containing individuals with phenotypes of both childhood SMA and adult motor neuron disease have been reported. We therefore examined the SMA locus as a candidate for ALS, in 54 patients with sporadic motor neuron disease, and 10 single-generation familial patients (with no evidence of SOD-1 mutations), and in a single patient with Brown-Vialetto-Van Laere syndrome. No mutations of the SMN or NAIP genes were detected. The difficulties of classification of lower motor neuron presentations of motor neuron diseases are discussed. The demonstration that mutations diagnostic of SMA are not found in ALS patients helps distinguish these conditions. Spinal muscular atrophies (SMA) are frequent autosomal recessive disorders characterized by degeneration of lower motor neurons. SMA are caused by mutations of the survival of motor neuron gene (SMN1) leading to a reduction of the SMN protein amount. The identification of SMN interacting proteins involved in the formation of the spliceosome and splicing changes in SMN-deficient tissues of mutant mice strongly support the view that SMN is involved in the splicing reaction. However, the molecular pathway linking SMN defect to the SMA phenotype remains unclear. From a better knowledge of the genetic basis of SMA and the defects resulting from the mutations of SMN1 in cellular or animal models, several therapeutics strategies have been selected aiming at targeting SMN2, a partially functional copy of SMN1 gene which remains present in patients, or to prevent neurons from death. Refined characterization of the degenerative process in SMA and the identification of the defective molecular pathway downstream from the SMN defect will provide further exciting insight into this disease in the near future. They should contribute to clarify the pathophysiology of SMA, the function of SMN and should help in designing potential targeted or non-targeted therapeutic molecules. Only one study has reported on the genetic basis of spinal muscular atrophy (SMA) in South African subjects. This was conducted in the Johannesburg region and has suggested that black South Africans only (indigenous Africans) differ from the norm. We have explored this further by DNA studies in 30 unrelated and racially diverse patients who reside in the Western Cape, and who were assessed as SMA subjects according to the internationally accepted inclusion criteria for SMA. These subjects were seen at the neurology clinic at Red Cross Children's Hospital in Cape Town during the period 1980-2001. Four had the type 1 form of SMA, 16 had type 2 and 10 had type 3. All patients were found to be homozygous for the loss of either exon 7 or exons 7 and 8 of the SMN1 gene. Six additional patients had anterior horn cell disease but were negative for the SMN1 gene deletion. All six had exclusion features listed in the international guidelines. This study shows that all patients from the Western Cape, which included 12 black South Africans, are no different genetically or phenotypically from the internationally recognized form of typical SMA. Spinal muscular atrophies (SMA) are characterized by degeneration of lower motor neurons associated with muscle paralysis and atrophy. Childhood SMA is a frequent recessive autosomal disorder and represents one of the most common genetic causes of death in childhood. Mutations of the SMN1 gene are responsible for SMA. The knowledge of the genetic basis of SMA, a better understanding of SMN function, and the recent generation of SMA mouse models represent major advances in the field of SMA. These are starting points towards understanding the pathophysiology of SMA and developing therapeutic strategies for this devastating neurodegenerative disease, for which no curative treatment is known so far. The molecular genetic basis of spinal muscular atrophy (SMA), an autosomal recessive neuromuscular disorder, is the loss of function of the survival motor neuron gene (SMN1). The SMN2 gene, a nearly identical copy of SMN1, has been detected as a promising target for SMA therapy. Both genes are ubiquitously expressed and encode identical proteins, but markedly differ in their splicing patterns: While SMN1 produces full-length (FL)-SMN transcripts only, the majority of SMN2 transcripts lacks exon 7. Transcriptional SMN2 activation or modulation of its splicing pattern to increase FL-SMN levels is believed to be clinically beneficial and therefore a crucial challenge in SMA research. Drugs such as valproic acid, phenylbutyrate, sodium butyrate, M344 and SAHA that mainly act as histone deacetylase inhibitors can mediate both: they stimulate the SMN2 gene transcription and/or restore the splicing pattern, thereby elevating the levels of FL-SMN2 protein. Preliminary phase II clinical trials and individual experimental curative approaches SMA patients show promising results. However, phase III double-blind placebo controlled clinical trials have to finally prove the efficacy of these drugs. Spinal muscular atrophy (SMA) is a common recessive disorder characterized by the loss of lower motor neurons in the spinal cord. The disease has been classified into three types based on age of onset and severity. SMA I-III all map to chromosome 5q13 (refs 2,3), and nearly all patients display deletions or gene conversions of the survival motor neuron (SMN1) gene. Some correlation has been established between SMN protein levels and disease course; nevertheless, the genetic basis for SMA phenotypic variability remains unclear, and it has been postulated that the loss of an additional modifying factor contributes to the severity of type I SMA. Using comparative genomics to screen for such a factor among evolutionarily conserved sequences between mouse and human, we have identified a novel transcript, H4F5, which lies closer to SMN1 than any previously identified gene in the region. A multi-copy microsatellite marker that is deleted in more than 90% of type I SMA chromosomes is embedded in an intron of this gene, indicating that H4F5 is also highly deleted in type I SMA chromosomes, and thus is a candidate phenotypic modifier for SMA. The spinal muscular atrophies are a group of mostly inherited disorders selectively affecting the lower motor neuron. There is a wide degree of clinical and genetic heterogeneity that must be taken into account when giving prognostic information. Autosomal recessive childhood proximal SMA is the commonest form and is due to mutations in a gene encoding a novel protein, SMN, that appears to play a critical role in RNA metabolism but has also been shown to interact with actin-binding proteins and mediators of programmed cell death. The identification of the genetic basis of SMA has resulted in advances for prenatal diagnosis and in new insights into motor neuron biology. The chromosomal location of two of the rarer dominant forms of SMA has been found. Identification of the molecular pathophysiology of lower motor neuron syndromes can be expected to aid in the development of therapy for these disabling disorders.

Which are the common symptoms of Cushing's syndrome?

Cushing syndrome is the constellation of signs and symptoms caused by protracted exposure to glucocorticoids. Presenting features commonly include weight gain, growth retardation, hirsutism, obesity, striae, acne and hypertension.

[17322955, 24062268]

CONTEXT: Carney complex (CNC), a familial multiple neoplasm syndrome with dominant autosomal transmission, is characterized by tumors of the heart, skin, endocrine and peripheral nervous system, and also cutaneous lentiginosis. This is a rare syndrome and its main endocrine manifestation, primary pigmented nodular adrenal disease (PPNAD), is an uncommon cause of adrenocorticotropic hormone-independent Cushing's syndrome. CASE REPORT: We report the case of a 20-year-old patient with a history of weight gain, hirsutism, acne, secondary amenorrhea and facial lentiginosis. Following the diagnosing of CNC and PPNAD, the patient underwent laparoscopic bilateral adrenalectomy, and she evolved with decreasing hypercortisolism. Screening was also performed for other tumors related to this syndrome. The diagnostic criteria, screening and follow-up for patients and affected family members are discussed. Cushing syndrome is the constellation of signs and symptoms caused by protracted exposure to glucocorticoids. The most common cause of Cushing syndrome in children and adolescents is exogenous administration of glucocorticoids. Presenting features commonly include weight gain, growth retardation, hirsutism, obesity, striae, acne and hypertension. Almost invariably, linear growth is severely diminished, a factor which may be useful in differentiating between childhood obesity and Cushing syndrome. Diagnostic approaches are based on distinguishing between adrenocorticotropic hormone (ACTH)-dependent and ACTH-independent etiologies, and consideration of the most likely diagnosis by age. Treatment modality is dependent upon etiology. After cure, important components of care include attention to linear growth, pubertal progression and body composition.

Which kinase is inhibited by the small molecule KN-93?

The calcium/calmodulin-dependent protein kinase-II (CaMK-II) is inhibited by the small molecule KN-93. KN-93 is a membrane-permeant calcium/calmodulin- dependent kinase II (CaMK-II)-selective inhibitor

[9596994, 15175389, 1662507, 21187407, 11827960, 11248432, 10712242, 8939965, 15569687, 16896952, 22290426, 17457979, 14749212, 9864285, 7690557, 11164895]

The calmodulin-dependent protein kinase-II (CaMK-II) inhibitor KN-93 has been shown to reversibly arrest mouse and human cells in the G1 phase of the cell cycle [Tombes, R. M., Westin, E., Grant. S., and Krystal, G. (1995) Cell Growth Differ. 6, 1073-1070; Rasmussen, G., and Rasmussen, C. (1995) Biochem. Cell Biol. 71, 201-207]. The stimulation of Ca(2+)-independent (autonomous) CaMK-II enzymatic activity, a barometer of in situ activated CaMK-II, was prevented by the same KN-93 concentrations that cause G1 phase arrest. KN-93 caused the retinoblastoma protein pRB to become dephosphorylated and the activity of both cdk2 and cdk4, two potential pRb kinases, to decrease. Neither the activity of p42MAP kinase, an early response G1 signaling molecule, nor the phosphorylation status or DNA-binding capability of the transcription factors serum response factor and cAMP responsive element-binding protein was altered during this G1 arrest. The protein levels of cyclin-dependent kinase 2 (cdk2) and cdk4 were unaffected during this G1 arrest and the total cellular levels of the cdk inhibitors p21cip1 and p27kip1 were not increased. Instead, the cdk4 activity decreases resulting from KN-93 were the result of a 75% decrease in cyclin D1 levels. In contrast, cyclin A and E levels were relatively constant. Cdk2 activity decreases were primarily the result of enhanced p27kip1 association with cdk2/cyclin E. All of these phenomena were unaffected by KN-93's inactive analog, KN-92, and were reversible upon KN-93 washout. The kinetics of recovery from cell cycle arrest were similar to those reported for other G1 phase blockers. These results suggest a mechanism by which G1 Ca2+ signals could be linked via calmodulin-dependent phosphorylations to the cell cycle-controlling machinery through cyclins and cdk inhibitors. We reported that one of the isoquinolinesulfonamide derivatives, KN-62, is a potent and specific inhibitor of Ca2+/calmodulin-dependent protein kinase II (CaMKII) (Tokumitsu, H., Chijiwa, T., Hagiwara, M., Mizutani, A., Terasawa, M. and Hidaka, H. (1990) J. Biol. Chem. 265, 4315-4320). We have now investigated the inhibitory property of a newly synthesized methoxybenzenesulfonamide, KN-93, on CaMKII activity in situ and in vitro. KN-93 elicited potent inhibitory effects on CaMKII phosphorylating activity with an inhibition constant of 0.37 microM but this compound had no significant effects on the catalytic activity of cAMP-dependent protein kinase, Ca2+/phospholipid dependent protein kinase, myosin light chain kinase and Ca(2+)-phosphodiesterase. KN-93 also inhibited the autophosphorylation of both the alpha- and beta-subunits of CaMKII. Kinetic analysis indicated that KN-93 inhibits CaMKII, in a competitive fashion against calmodulin. To evaluate the regulatory role of CaMKII on catecholamine metabolism, we examined the effect of KN-93 on dopamine (DA) levels in PC12h cells. The DA levels decreased in the presence of KN-93. Further, the tyrosine hydroxylase (TH) phosphorylation induced by KCl or acetylcholine was significantly suppressed by KN-93 in PC12h cells while events induced by forskolin or 8-Br-cAMP were not affected. These results suggest that KN-93 inhibits DA formation by modulating the reaction rate of TH to reduce the Ca(2+)-mediated phosphorylation levels of the TH molecule. Prolonged AMPA-receptor blockade in hippocampal neuron cultures leads to both an increased expression of GluA1 postsynaptically and an increase in vesicle pool size and turnover rate presynaptically, adaptive changes that extend beyond simple synaptic scaling. As a molecular correlate, expression of the β Ca(2+)/CaM-dependent kinase type II (βCaMKII) is increased in response to synaptic inactivity. Here we set out to clarify the role of βCaMKII in the various manifestations of adaptation. Knockdown of βCaMKII by lentiviral-mediated expression of shRNA prevented the synaptic inactivity-induced increase in GluA1, as did treatment with the CaM kinase inhibitor KN-93, but not the inactive analog KN-92. These results demonstrate that, spurred by AMPA-receptor blockade, up-regulation of βCaMKII promotes increased GluA1 expression. Indeed, transfection of βCaMKII, but not a kinase-dead mutant, increased GluA1 expression on dendrites and elevated vesicle turnover (Syt-Ab uptake), mimicking the effect of synaptic inactivity on both sides of the synapse. In cells with elevated βCaMKII, relief of synaptic-activity blockade uncovered an increase in the frequency of miniature excitatory postsynaptic currents that could be rapidly and fully suppressed by PhTx blockade of GluA1 receptors. This increased mini frequency involved a genuine presynaptic enhancement, not merely an increased abundance of synapses. This finding suggests that Ca(2+) flux through GluA1 receptors may trigger the acute release of a retrograde messenger. Taken together, our results indicate that synaptic inactivity-induced increases in βCaMKII expression set in motion a series of events that culminate in coordinated pre- and postsynaptic adaptations in synaptic transmission. Once ingested by mosquitoes, malaria parasites undergo complex cellular changes. These include zygote formation, transformation of zygote to ookinete, and differentiation from ookinete to oocyst. Within the oocyst, the parasite multiplies into numerous sporozoites. Modulators of intracellular calcium homeostasis, MAPTAM, and TMB-8 blocked ookinete development as did the calmodulin (CaM) antagonists W-7 and calmidazolium. Ca(2+)/CaM-dependent protein kinase inhibitor KN-93 also blocked zygote elongation, while its ineffective analog KN-92 did not have such effect. In vitro both zygote and ookinete extracts efficiently phosphorylated autocamtide-2, a classic CaM kinase substrate, which could be blocked by calmodulin antagonists W-7 and calmidazolium and CaM kinase inhibitor KN-93. These results demonstrated the presence of calmodulin-dependent CaM kinase activity in the parasite. KN-93-treated parasites, however, expressed the ookinete-specific enzyme chitinase and the ookinete surface antigen Pgs28 normally, suggesting that the morphologically untransformed parasites are biochemically mature ookinetes. In mosquitoes, KN-93-treated parasites did not develop as oocysts, while KN-92-treated parasites produced similar numbers of oocysts as controls. These data suggested that in Plasmodium gallinaceum morphological development of zygote to ookinete, but not its biochemical maturation, relies on Ca(2+)/CaM-dependent protein kinase activity and demonstrated that the morphological differentiation is essential for the further development of the parasite in infected blood-fed mosquitoes. We have investigated the contribution of Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) and mitogen-activated protein kinase (MAP kinase) in norepinephrine (NE)-induced arachidonic acid (AA) release in rabbit aortic vascular smooth muscle cells (VSMC). NE enhanced release of AA via activation of cytosolic phospholipase A2 (cPLA2) but not secretory PLA2 in VSMC prelabeled with [3H]AA. NE (10 microM) enhanced CaM kinase II and MAP kinase activity. In cells transiently transfected with antisense oligonucleotides complementary to the translation initiation sites of CaM kinase II and MAP kinase, NE-induced AA release was inhibited by 100 and 35% respectively. Treatment of cells with PD-098059, a MAP kinase kinase inhibitor, or with MAP kinase antisense oligonucleotide reduced NE-induced activation of MAP kinase and cPLA2. NE-induced MAP kinase and cPLA2 activation was also inhibited in cells treated with a CaM kinase II inhibitor, KN-93, or with CaM kinase II antisense oligonucleotide. On the other hand, inhibition of MAP kinase kinase with PD-098059 or of MAP kinase with antisense oligonucleotides did not alter the NE-induced increase in CaM kinase II activity. Phosphorylation of MAP kinase and CaM kinase II by NE, studied by 32P incorporation and immune complex kinase assays, was inhibited by KN-93. Collectively, these data suggest that CaM kinase II can activate MAP kinase, which in turn activates cPLA2 to release AA for prostacyclin synthesis in the rabbit VSMC. This novel pathway for activation of MAP kinase by CaM kinase II appears to be mediated through stimulation of MAP kinase kinase. Activation of adrenergic receptors with NE in VSMC caused translocation of CaM kinase II, MAP kinase, and cPLA2 to the nuclear envelope only in the presence of extracellular Ca2+. Okadaic acid, which increased phosphorylation and activity, did not translocate these enzymes. Therefore, it appears that in rabbit VSMC, NE, by promoting extracellular Ca2+ influx, increases CaM kinase II activity, leading to activation of MAP kinase and cPLA2 and translocation to the nuclear envelope, resulting in release of AA from the nuclear envelope for prostacyclin synthesis. KN-93, a membrane-permeant calcium/calmodulin- dependent kinase-selective inhibitor, induces apoptosis in some lines of human tumor cells. We investigated the effect of KN-93 in the choriocarcinoma cell line, BeWo. BeWo cells were treated with various concentrations of KN-93, and changes in cell growth, the cell cycle, apoptosis, and related parameters were examined. A WST-1 assay showed that BeWo cells were sensitive to the growth inhibitory effect of KN-93. Cell cycle analysis indicated that exposure to KN-93 decreased the proportion of cells in the S phase and increased the proportion in the G0/G1 phases of the cell cycle. Induction of apoptosis was confirmed by Annexin V staining of externalized phosphatidylserine, by the loss of mitochondrial transmembrane potential, and by antibodies directed against histones from fragmented DNA. This induction occurred in conjunction with the altered expression of genes related to cell growth, malignant phenotype, and apoptosis. These results suggest that KN-93 may serve as a therapeutic agent for the treatment of choriocarcinoma. AIM: To investigate the effects of KN-93, a CaMKII selective inhibitor on cell proliferation and the expression of p53 or p21 protein in human hepatic stellate cells. METHODS: Human hepatic stellate cells (LX-2) were incubated with various concentrations (0-50 micromol/L) of KN-93 or its inactive derivative, KN-92. Cell proliferation was measured by CCK-8 assay, and the expression of two cell cycle regulators, p53 and p21, was determined by SDS-PAGE and Western blotting. RESULTS: KN-93 (5-50 micromol/L) decreased the proliferation of human hepatic stellate cells in a dose-dependent manner from 81.76% (81.76% +/- 2.58% vs 96.63% +/- 2.69%, P < 0.05) to 27.15% (27.15% +/- 2.86% vs 96.59% +/- 2.44%, P < 0.01) after 24 h treatment. Incubation of 10 micromol/L KN-93 induced the cell growth reduction in a time-dependent manner from 78.27% at 8 h to 11.48% at 48 h. However, KN-92, an inactive derivative of KN-93, did not inhibit cell proliferation effectively. Moreover, analysis of cell cycle regulator expression revealed that KN-93 rather than KN-92 reduced the expression of p53 and p21. CONCLUSION: KN-93 has potent inhibitory effect on proliferation of LX-2 cells by modulating the expression of two special cell cycle regulators, p53 and p21. ATP, a purinergic receptor agonist, has been shown to be involved in vascular smooth muscle (VSM) cell DNA synthesis and cell proliferation during embryonic and postnatal development, after injury, and in atherosclerosis. One mechanism that ATP utilizes to regulate cellular function is through activation of ERK1/2. In the present study, we provide evidence that ATP-dependent activation of ERK1/2 in VSM cells utilizes specific isoforms of the multifunctional serine/threonine kinases, PKC, and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) as intermediates. Selective inhibition of PKC-delta activity with rottlerin, or adenoviral overexpression of kinase-negative PKC-delta, attenuated the ATP- and phorbol 12,13-dibutyrate (PDBu)-stimulated ERK1/2 activation. Inhibition of PKC-alpha activity with Gö-6976, or adenoviral overexpression of kinase-negative PKC-alpha, was ineffective. Alternatively, treatment with KN-93, a selective inhibitor of CaMKII activation, or adenoviral overexpression of kinase-negative CaMKII-delta(2), inhibited ATP-dependent activation of ERK1/2 but had no effect on PDBu- or PDGF-stimulated ERK1/2. In addition, adenoviral overexpression of dominant-negative ras (Ad.HA-Ras(N17)) partially inhibited the ATP- and PDBu-induced activation of ERK1/2 and blocked ionomycin- and EGF-stimulated ERK1/2, and inhibition of tyrosine kinases with AG-1478, an EGFR inhibitor, or the src family kinase inhibitor PP2 attenuated ATP-stimulated ERK1/2 activation. Taken together, these data indicate that PKC-delta and CaMKII-delta(2) coordinately mediate ATP-dependent transactivation of EGF receptor, resulting in increased ERK1/2 activity in VSM cells. The multifunctional Ca++/calmodulin-dependent protein kinase II (CaM kinase) mediates Ca++-induced augmentation of L-type Ca++ current (ICa); therefore it may act as a proarrhythmic signaling molecule during early afterdepolarizations (EADs) due to ICa. To investigate the hypothesis that ICa-dependent EADs are favored by CaM kinase activation EADs were induced with clofilium in isolated rabbit hearts. All EADs were rapidly terminated with ICa antagonists. Hearts were pretreated with the CaM kinase inhibitor KN-93 or the inactive analog KN-92 (0.5 microM) for 10 min before clofilium exposure. EADs were significantly suppressed by KN-93 (EADs present in 4/10 hearts) compared to KN-92 (EADs present in 10/11 hearts) (P =.024). There were no significant differences in parameters favoring EADs such as monophasic action potential duration or heart rate in KN-93- or KN-92-treated hearts. CaM kinase activity in situ increased 37% in hearts with EADs compared to hearts without EADs (P =.015). This increase in CaM kinase activity was prevented by pretreatment with KN-93. In vitro, KN-93 potently inhibited rabbit myocardial CaM kinase activity (calculated Ki </= 2.58 microM), but the inactive analog KN-92 did not (Ki > 100 microM). The actions of KN-93 and KN-92 on ICa and other repolarizing K+ currents did not explain preferential EAD suppression by KN-93. These data show a novel association between CaM kinase activation and EADs and are consistent with the hypothesis that the ICa and CaM kinase activation both contribute to EADs in this model. A novel Ca2+/calmodulin-dependent protein kinase II (CaM Kinase II) inhibitor, KN-93 potently inhibits gastric acid secretion from parietal cells. As previously reported (1), treatment of parietal cells with a selective inhibitor of CaM kinase II, KN-62 resulted in the inhibition of cholinergic-stimulated rabbit parietal cell secretion, whereas it failed to inhibit the histamine and forskolin response. In contrast effects of carbachol, histamine and forskolin were significantly inhibited by KN-93 with an IC50 of 0.15, 0.3 and 1 microM, respectively; these effects occurred without any changes in intracellular cyclic AMP and Ca2+ levels. In the present study we investigated the mechanism by which KN-93 acts upon the acid-secreting machinery of gastric parietal cells. Neither redistribution of the proton pump activity nor the morphological transformation were affected by KN-93. The drug only weakly inhibited the H+, K(+)-ATPase activity but strongly dissipated the proton gradient formed in the gastric membrane vesicles and reduced the volume of luminal space. Thus KN-93 acts at pH gradient formation whereas KN-62 acts only at CaM Kinase II. We previously demonstrated that stimulation of human T-lymphocytes with calcium ionophores induced the phosphorylation and enzymatic activation of ERK2. We now report on the mechanism by which calcium-ionophore-induced activation of ERK1 and 2 occurs in these cells. The activation of ERK1 and 2 by increases in intracellular calcium was inhibited by calmidazolium suggesting the involvement of calmodulin in this response. To further elucidate the mechanism by which calcium-induced ERK activation occurs, we used the CaM-kinase inhibitor KN-93 and an inactive analog of KN-93 (KN-92). KN-93, but not KN-92, blocked ionomycin-induced activation of ERK1 and 2 in human T lymphocytes. We previously demonstrated that stimulation of T lymphocytes with ionomycin or A23187 resulted in a CaM-kinase-dependent shift in the mobility of p56(Lck). To determine if p56(Lck) was involved in calcium-induced ERK activation, we stimulated the p56(Lck) negative Jurkat cell derivatives, J.CaM1.6 and J.CaM1/Rep3, with ionomycin. In these p56(Lck) negative cell lines, activation of ERK1 and 2 in response to ionomycin was only minimally detected. When J.CaM1 cells were reconstituted with p56(Lck), ionomycin induced ERK1 and 2 activation. Treatment of Jurkat cells with PP2, an inhibitor of p56(Lck), inhibited calcium-induced, but not PMA-induced, ERK1 and 2 activation. Treatment of Jurkat cells with the MEK inhibitor PD98059 blocked ionomycin-induced ERK activation, but not the shift in the mobility of p56(Lck). Our data suggests that increases in intracellular calcium induce the activation of ERK1 and 2 in human T lymphocytes via sequential activation of CaM-kinase and phosphorylation of p56(Lck).

What is the effect of Chk2 splice variants on wild-type Chk2 kinase activity?

Chk2 splice variants have been demonstrated to exert a dominant-negative effect on wild-type Chk2 kinase activity.

[20080130]

While the majority of RNA transcripts from protein-encoding genes in the human genome are subject to physiological splicing, pathological splicing is increasingly reported in cancer tissue. Previously, we identified >90 different splice variants of Chk2, a gene encoding a serine/threonine kinase propagating the DNA damage signal by phosphorylating and activating several downstream substrates like p53, Cdc25A, and Cdc25C involved in cell cycle arrest and apoptosis. While alternative splice forms of other genes have been reported to exert a dominant-negative effect on the wild-type molecules, the function of Chk2 splice protein variants is still unclear. Here we evaluated the function of four Chk2 splice proteins for which mRNA splice variants were identified in human breast carcinomas. These splice variants were stably expressed as nuclear proteins. Two splice forms (Chk2Delta4 and Chk2del(2-3)) expressed kinase activity while variants Chk2Delta11 and Chk2isoI were essentially kinase inactive. Independent of intrinsic kinase activity, each splice variant impaired wild-type Chk2 activity through heterodimerization. Based on our findings, we suggest alternative splicing as a possible novel mechanism for repression of the Chk2 wild-type function.

List genes that have been found mutated in CMT1A (Charcot-Marie-Tooth disease type 1 A).

PMP22 is the common gene found mutated through a duplication in CMT1A. Other genes are MPZ and SH3TC2

[25519680, 25150498, 25522693, 24819634, 25500726, 25400662, 25430934, 25385046, 25429913]

Charcot-Marie-Tooth (CMT) diseases include a group of clinically heterogeneous inherited neuropathies subdivided into demyelinating (CMT1), axonal (CMT2) and intermediate CMT forms. CMTs are associated with different genes, although mutations in some of these genes may cause both clinical pictures. To date, more than 50 CMT genes have been identified, but more than half of the cases are due to mutations in MFN2, MPZ, GJB1 and PMP22. The aim of this study was to estimate the frequency of disease mutations of these four genes in the axonal form of CMT in order to evaluate their effectiveness in the molecular diagnosis of CMT2 patients. A cohort of 38 CMT2 Italian subjects was screened for mutations in the MFN2, MPZ and GJB1 genes by direct sequencing and for PMP22 rearrangements using the MLPA technique. Overall, we identified 15 mutations, 8 of which were novel: 11 mutations (28.9 %) were in the MFN2 gene, 2 (5.3 %) in MPZ and 2 (5.3 %) in PMP22. No mutations were found in GJB1. Two patients showed rearrangements in the PMP22 gene, which is commonly associated with CMT1 or HNPP phenotypes thus usually not tested in CMT2 patients. By including this gene in the analysis, we reached a molecular diagnosis rate of 39.5 %, which is one of the highest reported in the literature. Our findings confirm the MFN2 gene as the most common cause of CMT2 and suggest that PMP22 rearrangements should be considered in the molecular diagnosis of CMT2 patients. Charcot-Marie-Tooth disease (CMT) is a genetically and clinically heterogeneous hereditary motor and sensory neuropathy signified by a distal symmetric polyneuropathy. The most frequent subtype is type 1A (CMT1A) caused by duplication in chromosome 17p12 that includes PMP22. This study reports a woman with a family history of CMT1A due to PMP22 duplication. However, she presented with a more severe phenotype than her sibling or ancestors and was found to have a PMP22 triplication instead of the duplication. This was caused by de novo mutation on her affected mother's duplication chromosome. Her lower limb magnetic resonance imaging revealed severe diffused atrophy and fatty replacement. However, her affected sister with typical PMP22 duplication showed almost intact lower limb. Triplication patient's median motor nerve conduction velocity was far lower compared with her sister. Her onset age was faster (8 years) than her sister (42 years). CMT1A triplication might be generated by a female-specific chromosomal rearrangement mechanism that is different from the frequent paternal-originated CMT1A duplication. It also suggests that the wide phenotypic variation of CMT1A might be partly caused by unstable genomic rearrangement, including PMP22 triplication. Author information: (1)Departments of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA. (2)University of South Florida Epidemiology Center, Tampa, Florida, USA. (3)MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, UK. (4)Departments of Neurology, IRCCS Foundation, Carlo Besta Neurological Institute, Milan, Italy. (5)Departments of Neurology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA. (6)Departments of Neurology, University of Sydney & Children's Hospital, Sydney, Australia. (7)Departments of Neurology, Stanford University, Stanford, California, USA. (8)Departments of Neurology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA Departments of Neurology, Wayne State University, Detroit, Michigan, USA. (9)Departments of Neurology, Nemours Children's Hospital, Orlando, Florida, USA. (10)Departments of Neurology, University of Rochester, Rochester, New York, USA. (11)Departments of Neurology, Vanderbilt University, Nashville, Tennessee, USA. (12)Departments of Neurology, John Hopkins University, Baltimore, Maryland, USA. (13)Departments of Neurology, UCL Institute of Child Health & Great Ormond Street Hospital, London, UK. (14)Departments of Neurology, Wayne State University, Detroit, Michigan, USA Departments of Neurology, University of Michigan, Ann Arbor, Michigan, USA. (15)Departments of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA Departments of Neurology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA. (16)Departments of Neurology, Center for Human Molecular Genomics, University of Miami, Miami, Florida, USA. (17)Departments of Neurology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA. Peripheral myelin protein 22 (PMP22) resides in the plasma membrane and is required for myelin formation in the peripheral nervous system. Many PMP22 mutants accumulate in excess in the endoplasmic reticulum (ER) and lead to the inherited neuropathies of Charcot-Marie-Tooth (CMT) disease. However, the mechanism through which PMP22 mutants accumulate in the ER is unknown. Here, we studied the quality control mechanisms for the PMP22 mutants L16P and G150D, which were originally identified in mice and patients with CMT. We found that the ER-localised ubiquitin ligase Hrd1/SYVN1 mediates ER-associated degradation (ERAD) of PMP22(L16P) and PMP22(G150D), and another ubiquitin ligase, gp78/AMFR, mediates ERAD of PMP22(G150D) as well. We also found that PMP22(L16P), but not PMP22(G150D), is partly released from the ER by loss of Rer1, which is a Golgi-localised sorting receptor for ER retrieval. Rer1 interacts with the wild-type and mutant forms of PMP22. Interestingly, release of PMP22(L16P) from the ER was more prominent with simultaneous knockdown of Rer1 and the ER-localised chaperone calnexin than with the knockdown of each gene. These results suggest that CMT disease-related PMP22(L16P) is trapped in the ER by calnexin-dependent ER retention and Rer1-mediated early Golgi retrieval systems and partly degraded by the Hrd1-mediated ERAD system. The objective of this study is to assess the genetic distribution of Charcot-Marie-Tooth (CMT) disease in Campania, a region of Southern Italy. We analyzed a cohort of 197 index cases and reported the type and frequency of mutations for the whole CMT population and for each electrophysiological group (CMT1, CMT2, and hereditary neuropathy with susceptibility to pressure palsies [HNPP]) and for familial and isolated CMT cases. Genetic diagnosis was achieved in 148 patients (75.1%) with a higher success rate in HNPP and CMT1 than CMT2. Only four genes (PMP22, GJB1, MPZ, and GDAP1) accounted for 92% of all genetically confirmed CMT cases. In CMT1, PMP22 duplication was the most common mutation while the second gene in order of frequency was MPZ in familial and SH3TC2 in isolated cases. In CMT2, GJB1 was the most frequent mutated gene and GJB1 with GDAP1 accounted for almost 3/4 of genetically defined CMT2 patients. The first gene in order of frequency was GJB1 in familial and GDAP1 in isolated cases. In HNPP, the majority of patients harbored the PMP22 gene deletion. The novelty of our data is the relatively high frequency of SH3TC2 and GDAP1 mutations in demyelinating and axonal forms, respectively. These epidemiological data can help in panel design for our patients' population.

Which viruses are best known to cause myocarditis?

The most frequent viruses causing myocarditis are Enterovirus, Adenovirus and Coxsackie B viruses.

[18039618, 8199011, 3889351, 18277927, 2641165, 14993139]

Enteroviruses have been considered to be the most common cause of acute myocarditis and possible consequence of dilated cardiomyopathy. Some publications shed light to the role of other viruses in this disease as well. Our molecular investigation has demonstrated that adeno- and herpes viruses might also frequently occur in dilated cardiomyopathy. AIM: The aim of our study was to screen virus genomes in heart tissues from heart-transplanted patients to prove their possible role in the pathogenesis of dilated cardiomyopathy. METHODS: DNA and RNA were isolated from five regions of the heart muscle. Amplification for Adenovirus Type 3, Human Herpes Virus Type 6 and Enterovirus genomes were performed by nested-Polymerase Chain Reaction. Finally the virus-positive samples were direct sequenced. RESULTS: In 2 patients Adenovirus Type 3 and in 1 patient both Adenovirus Type 3 and Human Herpes Virus Type 6 were detected. No enteroviruses were found in any heart tissue. CONCLUSIONS: In our study the adenovirus genome was found to be the most frequent virus genome in explanted heart tissues. The identified viral sequences proved previous viral infection, which could have played a role in the development of dilated cardiomyopathy. Detection of different viruses in the myocardium by molecular biological examinations might contribute to adequate treatment of these patients. A transfection-reactivated Coxsackievirus B3 (rCVB3), from a full-length cDNA clone of Nancy strain, has previously been shown to be as cardiovirulent as the wild-type virus. Myocarditis induced by this genetically defined virus was compared in SWR mice with the traditional Balb/c model. SWR mice inoculated with rCVB3 developed more severe myocarditis but less severe pancreatitis than Balb/c mice. In contrast to the poor general health and frequent mortality of Balb/c mice following CVB3 infection, the body weight of SWR mice was not affected by CVB3 inoculation and no mortality occurred at titres of 10(2)-10(7) plaque forming units (PFU). Typical myocarditis developed in SWR mice 7 days post infection. Myocarditic foci consisting of necrotic myocardial fibres and mononuclear cell infiltrates resolved by day 30, similar to that observed in Balb/c. However, SWR mice were more sensitive to rCVB3-induced myocarditis than were Balb/c mice: mild myocarditis was induced (4/4) by as low as 10(2) PFU of the virus (ID50 < 10(1.5) PFU), and more severe myocarditis was seen at higher PFU of virus in a dose-dependent manner. The SWR model was tested with attenuated variants derived from cardiovirulent rCVB3. The ID50 for myocarditis was 10(7) PFU for a large plaque-size attenuant and 10(6) PFU for a minute plaque-size attenuant, indicating loss of cardiovirulence by a factor of more than 10(4)-10(5). rCVB3-induced SWR mouse is a sensitive and reliable model for myocarditis. It is useful in assessing the cardiovirulence of different CVB3 variants and evaluating the efficacies of anti-viral therapies. It will allow follow-up study after high dose infection with cardiovirulent rCVB3. Coxsackie B viruses (types 1 to 5) are the most frequent reported cause of acute viral myocarditis. To study the pathogenesis of the disease at the cellular level, we simulated an infectious situation by infecting cultured human foetal heart cells with Coxsackie B3 (CB3) virus. Successful replication of this virus could be demonstrated by the presence of virus particles inside cultivated foetal myocytes together with high titres of progeny virus of 10(8) plaque-forming units (PFU) per millilitre culture medium. Within 9 h of infection networks of myocytes lost their ability to contract spontaneously followed by disintegration and replacement by overgrowing fibroblasts which survived the infection. These cells produced CB3 virus continuously over several months, indicating carrier state infection of human myocardial fibroblasts. Human fibroblasts interferon (IFN-beta) was found to act as a potent inhibitor of the replication of this virus. Virus yields could be reduced from 1.2 x 1.8 x 10(5) PFU/ml culture medium when human heart cells were incubated with IFN-beta 20 h prior to challenge with a high input multiplicity of 50 PFU of CB3 virus per cell, demonstrating the major protective role of IFN-beta in CB3 viral infection. It thus appear that IFN-beta might become useful as an antiviral agent in the treatment of Coxsackie myocarditis. BACKGROUND: Enteroviruses (EV) are an important cause of neonatal disease including hepatitis, meningoencephalitis, and myocarditis that can lead to death or severe long-term sequelae. Less is known about severe neonatal infection caused by the parechoviruses (PeV) of which type 1 (PeV1) and type 2 (PeV2) were previously known as echovirus 22 and echovirus 23. They belong to the same family of Picornaviridae as the EV. Of the PeV, so far only PeV3 has been associated in 2 recent reports with severe neonatal infection including involvement of central nervous system. METHODS: We compared the clinical signs, diagnosis, laboratory data, cerebral imaging, and neurodevelopmental outcome of 11 neonates with PeV infection with 21 infants with EV infection treated in our hospital between 1994 and 2006. The diagnosis of EV infection or PeV infection was confirmed by a positive EV and/or PeV real time-polymerase chain reaction on blood, cerebrospinal fluid, (CSF) or stool or a viral culture of stool, nasopharyngeal swab, and/or CSF. RESULTS: The 32 infants presented with sepsis-like illness and the most frequent signs were: fever, seizures, irritability, rash, and feeding problems. All patients received antibiotic treatment. Eleven of 21 infants infected with EV and 7 of 11 infants infected with PeV were full-term. Differentiation between the infants infected with EV and PeV on the basis of fever, irritability, rash, and seizures was not possible. Myocarditis was exclusively seen in 4 patients infected by EV. Eight of 11 patients with a PeV infection had meningoencephalitis of whom only 1 infant developed pleocytosis in the CSF. Serum C-reactive protein and CSF protein values were significantly higher in infants with EV infection than in those with PeV infection. Cerebral imaging of all infants with EV or PeV cerebral infection showed mild to severe white matter abnormalities. In 1 infant with EV infection and 3 infants with PeV infection, neurodevelopmental delay occurred. Mortality and long-term sequelae were mainly associated with myocarditis in the infants who were infected with EV (4 of 21). CONCLUSIONS: It is not possible to distinguish neonatal PeV from EV infection on the basis of clinical signs. Neonates with PeV or EV infection present with sepsis-like illness and the most frequent signs are fever, seizures, irritability, rash, and feeding problems. The results are presented of serological tests by the neutralization method for antigens of Coxsackie B group, and by the haemagglutination inhibition method for three types of parainfluenza and sporadic influenza virus in 529 patients with myocarditis. In 7 cases the virus was isolated from stools. Virus aetiology of the disease was confirmed in 23.4% of cases, on average. Raised levels of antibodies to Coxsackie B antigens were found more frequently than the levels of antibodies to parainfluenza viruses. Seroconversion was more frequent in infections by parainfluenza type 3 than type 2. During an influenza epidemic in 5 cases raised levels of antibodies to the epidemic-causing strain were observed. BACKGROUND: Myocarditis can occasionally lead to sudden death and may progress to dilated cardiomyopathy in up to 10% of patients. Because the initial onset is difficult to recognize clinically and the diagnostic tools available are unsatisfactory, new strategies to diagnose myocarditis are needed. METHODS AND RESULTS: Cardiovascular MR imaging (CMR) was performed in 32 patients who were diagnosed with myocarditis by clinical criteria. To determine whether CMR visualizes areas of active myocarditis, endomyocardial biopsy was taken from the region of contrast enhancement and submitted to histopathologic analysis. Follow-up was performed 3 month later. Contrast enhancement was present in 28 patients (88%) and was usually seen with one or several foci in the myocardium. Foci were most frequently located in the lateral free wall. In the 21 patients in whom biopsy was obtained from the region of contrast enhancement, histopathologic analysis revealed active myocarditis in 19 patients (parvovirus B19, n=12; human herpes virus type 6 [HHV 6], n=5). Conversely, in the remaining 11 patients, in whom biopsy could not be taken from the region of contrast enhancement, active myocarditis was found in one case only (HHV6). At follow-up, the area of contrast enhancement decreased from 9+/-11% to 3+/-4% of left ventricular mass as the left ventricular ejection fraction improved from 47+/-19% to 60+/-10%. CONCLUSIONS: Contrast enhancement is a frequent finding in the clinical setting of suspected myocarditis and is associated with active inflammation defined by histopathology. Myocarditis occurs predominantly in the lateral free wall. Contrast CMR is a valuable tool for the evaluation and monitoring of inflammatory heart disease.

Which genes have been associated with Cerebral Cavernous Malformation?

Loss-of-function mutations in genes encoding CCM1 (also known as KRIT1), CCM2 (also known as OSM and malcavernin) or CCM3 (also known as PDCD10) cause cerebral cavernous malformations (CCMs).

[25122144, 15543491, 25086949, 14697511, 24990152, 11310633, 12140362, 25451273, 12172908, 24287896, 16465592, 24481819, 26246098, 24466005, 20592472, 12877753, 16100539, 24251678]

PURPOSE: The phenotypic manifestations of cerebral cavernous malformation disease caused by rare PDCD10 mutations have not been systematically examined, and a mechanistic link to Rho kinase-mediated hyperpermeability, a potential therapeutic target, has not been established. METHODS: We analyzed PDCD10 small interfering RNA-treated endothelial cells for stress fibers, Rho kinase activity, and permeability. Rho kinase activity was assessed in cerebral cavernous malformation lesions. Brain permeability and cerebral cavernous malformation lesion burden were quantified, and clinical manifestations were assessed in prospectively enrolled subjects with PDCD10 mutations. RESULTS: We determined that PDCD10 protein suppresses endothelial stress fibers, Rho kinase activity, and permeability in vitro. Pdcd10 heterozygous mice have greater lesion burden than other Ccm genotypes. We demonstrated robust Rho kinase activity in murine and human cerebral cavernous malformation vasculature and increased brain vascular permeability in humans with PDCD10 mutation. Clinical phenotype is exceptionally aggressive compared with the more common KRIT1 and CCM2 familial and sporadic cerebral cavernous malformation, with greater lesion burden and more frequent hemorrhages earlier in life. We first report other phenotypic features, including scoliosis, cognitive disability, and skin lesions, unrelated to lesion burden or bleeding. CONCLUSION: These findings define a unique cerebral cavernous malformation disease with exceptional aggressiveness, and they inform preclinical therapeutic testing, clinical counseling, and the design of trials.Genet Med 17 3, 188-196. Cerebral cavernous malformations (CCMs) are hamartomatous vascular malformations characterized by abnormally enlarged capillary cavities without intervening brain parenchyma. They cause seizures and cerebral hemorrhages, which can result in focal neurological deficits. Three CCM loci have been mapped, and loss-of-function mutations were identified in the KRIT1 (CCM1) and MGC4607 (CCM2) genes. We report herein the identification of PDCD10 (programmed cell death 10) as the CCM3 gene. The CCM3 locus has been previously mapped to 3q26-27 within a 22-cM interval that is bracketed by D3S1763 and D3S1262. We hypothesized that genomic deletions might occur at the CCM3 locus, as reported previously to occur at the CCM2 locus. Through high-density microsatellite genotyping of 20 families, we identified, in one family, null alleles that resulted from a deletion within a 4-Mb interval flanked by markers D3S3668 and D3S1614. This de novo deletion encompassed D3S1763, which strongly suggests that the CCM3 gene lies within a 970-kb region bracketed by D3S1763 and D3S1614. Six additional distinct deleterious mutations within PDCD10, one of the five known genes mapped within this interval, were identified in seven families. Three of these mutations were nonsense mutations, and two led to an aberrant splicing of exon 9, with a frameshift and a longer open reading frame within exon 10. The last of the six mutations led to an aberrant splicing of exon 5, without frameshift. Three of these mutations occurred de novo. All of them cosegregated with the disease in the families and were not observed in 200 control chromosomes. PDCD10, also called "TFAR15," had been initially identified through a screening for genes differentially expressed during the induction of apoptosis in the TF-1 premyeloid cell line. It is highly conserved in both vertebrates and invertebrates. Its implication in cerebral cavernous malformations strongly suggests that it is a new player in vascular morphogenesis and/or remodeling. BACKGROUND: Cerebral cavernous malformations are relatively rare vascular disorders that may affect any part of the central nervous system. This presentation has been associated with heterozygous mutations in CCM1/KRIT1, CCM2/malcavernin and CCM3/PDCD10. We aimed to investigate the genetic defect underlying multiple cerebral and vertebral cavernous malformations in a multigenerational Italian family. CASE PRESENTATION: The proband is a 49-year-old man who underwent cerebral MRI in his thirties for persistent haeadache and tingling in his left arm and leg and was diagnosed with multiple supratentorial cavernous angiomas. A right frontal angioma with radiological evidence of a recent bleeding was surgically removed when he was 39 years old and he was thereafter asymptomatic. Magnetic resonance imaging revealed multiple cerebral cavernous malformations in seven members of his familily. Four subjects were asymptomatic. Other family mambers displayed heterogeneous clinical features including seizures and recurrent brain haemorrhages. Sequence analysis in the proband disclosed a novel heterozygous nucleotide substitution (c.263-10A > G) in intron 5 of CCM1. This variant is predicted to create an abnormal acceptor splice site and segregated in affected relatives available for molecular screening. The analysis of CCM1 transcript in proband's lymphocytes confirmed the partial retention of intron 3 resulting in a premature termination codon. CONCLUSIONS: Our findings demonstrate that c.263-10A > G mutation is associated with cerebral cavernous malformations. A better knowledge of the disease-associated phenotype may lead to an early diagnosis and to an appropriate clinical surveillance in affected patients. Cerebral cavernous malformations (CCM) are vascular malformations, mostly located in the central nervous system, which occur in 0.1-0.5% of the population. They are characterized by abnormally enlarged and often leaking capillary cavities without intervening neural parenchyma. Some are clinically silent, whereas others cause seizures, intracerebral haemorrhage or focal neurological deficits. These vascular malformations can arise sporadically or may be inherited as an autosomal dominant condition with incomplete penetrance. At least 45% of families affected with cerebral cavernous malformations harbour a mutation in Krev interaction trapped-1 (Krit1) gene (cerebral cavernous malformation gene-1, CCM1). This gene contains 16 coding exons which encode a 736-amino acid protein containing three ankyrin repeats and a FERM domain. Neither the CCM1 pathogenetic mechanisms nor the function of the Krit1 protein are understood so far, although several hypotheses have been inferred from the predicted consequences of Krit1 mutations as well as from the identification of Krit1 as a binding partner of Rap1A, ICAP1A and microtubules. Here, we report the identification of Krit1B, a novel Krit1 isoform characterized by the alternative splicing of the 15th coding exon. We show that the Krit1B splice isoform is widely expressed in mouse cell lines and tissues, whereas its expression is highly restricted in human. In addition, we developed a real-time PCR strategy to accurately quantify the relative ratio of the two Krit1 alternative transcripts in different tissues, demonstrating a Krit1B/Krit1A ratio up to 20% in mouse thymus, but significantly lower ratios in other tissues. Bioinformatic analysis using exon/gene-prediction, comparative alignment and structure analysis programs supported the existence of Krit1 alternative transcripts lacking the 15th coding exon and showed that the splicing out of this exon occurs outside of potentially important Krit1 structural domains but in a region required for association with Rap1A, suggesting a subtle, yet important effect on the protein function. Our results indicate that maintenance of a proper ratio between Krit1A and Krit1B could be functionally relevant and suggest that the novel Krit1B isoform might expand our understanding of the role of Krit1 in CCM1 pathogenesis. Author information: (1)Department of Molecular Medicine, Department of Oncological Sciences. (2)Flourescence Imaging Core. (3)Department of Molecular Medicine, Department of Bioengineering. (4)Department of Molecular Medicine, Department of Human Genetics. (5)Department of Molecular Medicine, Small Animal Ultrasound Core, University of Utah, Salt Lake City 84112, USA. (6)Department of Molecular Medicine. (7)Vascular Biology Laboratory, London Research Institute, Cancer Research UK, London WC2A 3LY, UK. (8)Vascular Patterning Laboratory, VIB3-Vesalius Research Center and CMVB, Department of Oncology, KU Leuven Campus Gasthuisberg O&N4, Herestraat 49 box 912, Leuven B-3000, Belgium. (9)Department of Molecular Medicine, Small Animal Ultrasound Core, University of Utah, Salt Lake City 84112, USA, Division of Cardiovascular Medicine, Salt Lake City 84132, USA and. (10)Department of Molecular Medicine, Department of Oncological Sciences, Division of Cardiovascular Medicine, Salt Lake City 84132, USA and The Key Laboratory for Human Disease Gene Study of Sichuan Province, Institute of Laboratory Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China [email protected] [email protected]. Mutations in the Kritl gene have been recently discovered as the cause of hereditary cerebral cavernous angioma. We sought the possibility that de novo, noninherited mutations of Kritl also cause cavernous angioma. A patient with two cerebral malformations carries a heterozygous deletion of two base pairs (741delTC) in exon VI of the Kritl gene. The deletion initiates a frameshift mutation that, 23 amino acids downstream, encodes a TAA stop triplet replacing a CAT triplet of histidine at exon VII (H271X). Magnetic resonance images of the parents were normal, neither parent carries the 741delTC mutation, and both bear the wild-type sequence of exon VI. These findings document a de novo germline mutation in Kritl gene that causes cerebral cavernous malformations. Mutations in Krev1 interaction trapped gene 1 (KRIT1) cause cerebral cavernous malformation, an autosomal dominant disease featuring malformation of cerebral capillaries resulting in cerebral hemorrhage, strokes, and seizures. The biological functions of KRIT1 are unknown. We have investigated KRIT1 expression in endothelial cells by using specific anti-KRIT1 antibodies. By both microscopy and coimmunoprecipitation, we show that KRIT1 colocalizes with microtubules. In interphase cells, KRIT1 is found along the length of microtubules. During metaphase, KRIT1 is located on spindle pole bodies and the mitotic spindle. During late phases of mitosis, KRIT1 localizes in a pattern indicative of association with microtubule plus ends. In anaphase, the plus ends of the interpolar microtubules show strong KRIT1 staining and, in late telophase, KRIT1 stains the midbody remnant most strongly; this is the site of cytokinesis where plus ends of microtubules from dividing cells overlap. These results establish that KRIT1 is a microtubule-associated protein; its location at plus ends in mitosis suggests a possible role in microtubule targeting. These findings, coupled with evidence of interaction of KRIT1 with Krev1 and integrin cytoplasmic domain-associated protein-1 alpha (ICAP1 alpha), suggest that KRIT1 may help determine endothelial cell shape and function in response to cell-cell and cell-matrix interactions by guiding cytoskeletal structure. We propose that the loss of this targeting function leads to abnormal endothelial tube formation, thereby explaining the mechanism of formation of cerebral cavernous malformation (CCM) lesions. The three cerebral cavernous malformations (CCMs) genes namely CCM1/KRIT1, CCM2/MGC4607 and CCM3/PDCD10 have been identified for which mutations cause cerebral cavernous malformations. However, the protein products of these genes involved in forming CCM signaling, are still poorly understood imposing an urgent need to understand these genes and their signaling processes in details. So far involvement of CCM3/PDCD10 in the cavernous angioma has been characterized from biochemical and biophysical analyses. However, there is no comprehensive study illustrating the phylogenetic history and comprehensive genetic variants of CCM3/PDCD10. Herein, we explored the phylogenetic history and genetic variants of CCM3/PDCD10 gene. Synteny analyses revealed that CCM3/PDCD10 gene shared same genomic loci from Drosophila to human and the gene structure of CCM3/PDCD10 is conserved from human to Branchiostoma floridae for about 500 MYs with some changes in sea urchin and in insects. The conserved CCM3/PDCD10 is characterized by presence of indels in the N-terminal dimerization domain. We identified 951 CCM3/PDCD10 variants by analysis of 1092 human genomes with top three variation classes belongs to 84% SNPs, 6.9% insertions and 6.2% deletions. We identified 22 missense mutations in the human CCM3/PDCD10 protein and out of which three mutations are deleterious. We also identified four stop-codon gaining mutations at the positions E34*, E68*, E97* and E140*, respectively. This study is the first comprehensive analysis of the CCM3/PDCD10 gene based on phylogenetic origin and genetic variants. This study corroborates that the evolution of CCM proteins with tubular organization evolvements by endothelial cells. Cerebral cavernous malformations (CCM) are neurovascular dysplasias that result in mulberry-shaped lesions predominantly located in brain and spinal tissues. Mutations in three genes are associated with CCM. These genes encode for the proteins KRIT1/CCM1 (krev interaction trapped 1/cerebral cavernous malformations 1), cerebral cavernous malformations 2, osmosensing scaffold for MEKK3 (CCM2/malcavernin/OSM), and cerebral cavernous malformations 3/programmed cell death 10 (CCM3/PDCD10). There have been many significant recent advances in our understanding of the structure and function of these proteins, as well as in their roles in cellular signaling. Here, we provide an update on the current knowledge of the structure of the CCM proteins and their functions within cellular signaling, particularly in cellular adhesion complexes and signaling cascades. We go on to discuss subcellular localization of the CCM proteins, the formation and regulation of the CCM complex signaling platform, and current progress towards targeted therapy for CCM disease. Recent structural studies have begun to shed new light on CCM protein function, and we focus here on how these studies have helped inform the current understanding of these roles and how they may aid future studies into both CCM-related biology and disease mechanisms. Cerebral cavernous malformations are vascular defects of the central nervous system consisting of clusters of dilated vessels that are subject to frequent hemorrhaging. The genes mutated in three forms of autosomal dominant cerebral cavernous malformations have been cloned, but it remains unclear which cell type is ultimately responsible for the lesion. In this article we describe mice with a gene trap insertion in the Ccm2 gene. Consistent with the human phenotype, heterozygous animals develop cerebral vascular malformations, although penetrance is low. Beta-galactosidase activity in heterozygous brain and in situ hybridization in wild-type brain revealed Ccm2 expression in neurons and choroid plexus but not in vascular endothelium of small vessels in the brain. The expression pattern of Ccm2 is similar to that of the Ccm1 gene and its interacting protein ICAP1 (Itgb1bp1). These data suggest that cerebral cavernous malformations arise as a result of defects in the neural parenchyma surrounding the vascular endothelial cells in the brain. Multiple familial meningiomas occur in rare genetic syndromes, particularly neurofibromatosis type 2. The association of meningiomas and cerebral cavernous malformations (CCMs) has been reported in few patients in the medical literature. The purpose of our study is to corroborate a preferential association of CCMs and multiple meningiomas in subjects harbouring mutations in the PDCD10 gene (also known as CCM3). Three members of an Italian family affected by seizures underwent conventional brain Magnetic Resonance Imaging (MRI) with gadolinium contrast agent including gradient echo (GRE) imaging. The three CCM-causative genes were sequenced by Sanger method. Literature data reporting patients with coexistence of CCMs and meningiomas were reviewed. MRI demonstrated dural-based meningioma-like lesions associated to multiple parenchymal CCMs in all affected individuals. A disease-causative mutation in the PDCD10 gene (p.Gln112PhefsX13) was identified. Based on neuroradiological and molecular data as well as on literature review, we outline a consistent association between PDCD10 mutations and a syndrome of CCMs with multiple meningiomas. This condition should be considered in the differential diagnosis of multiple/familial meningioma syndromes. In case of multiple/familial meningioma the use of appropriate MRI technique may include GRE and/or susceptibility-weighted imaging (SWI) to rule out CCM. By contrast, proper post-gadolinium scans may aid defining dural lesions in CCM patients and are indicated in PDCD10-mutated individuals. OBJECTIVE: To study the molecular genetic and clinical features of cerebral cavernous malformations (CCM) in a cohort of Spanish patients. METHODS: We analyzed the CCM1, CCM2, and CCM3 genes by MLPA and direct sequencing of exons and intronic boundaries in 94 familial forms and 41 sporadic cases of CCM patients of Spanish extraction. When available, RNA studies were performed seeking for alternative or cryptic splicing. RESULTS: A total of 26 pathogenic mutations, 22 of which predict truncated proteins, were identified in 29 familial forms and in three sporadic cases. The repertoire includes six novel non-sense and frameshift mutations in CCM1 and CCM3. We also found four missense mutations, one of them located at the third NPXY motif of CCM1 and another one that leads to cryptic splicing of CCM1 exon 6. We found four genomic deletions with the loss of the whole CCM2 gene in one patient and a partial loss of CCM1and CCM2 genes in three other patients. Four families had mutations in CCM3. The results include a high frequency of intronic variants, although most of them localize out of consensus splicing sequences. The main symptoms associated to clinical debut consisted of cerebral haemorrhage, migraines and epileptic seizures. The rare co-occurrence of CCM with Noonan and Chiari syndromes and delayed menarche is reported. CONCLUSIONS: Analysis of CCM genes by sequencing and MLPA has detected mutations in almost 35% of a Spanish cohort (36% of familial cases and 10% of sporadic patients). The results include 13 new mutations of CCM genes and the main clinical symptoms that deserves consideration in molecular diagnosis and genetic counselling of cerebral cavernous malformations. Cerebral cavernous malformation is a common human vascular disease that arises due to loss-of-function mutations in genes encoding three intracellular adaptor proteins, cerebral cavernous malformations 1 protein (CCM1), CCM2, and CCM3. CCM1, CCM2, and CCM3 interact biochemically in a pathway required in endothelial cells during cardiovascular development in mice and zebrafish. The downstream effectors by which this signaling pathway regulates endothelial function have not yet been identified. Here we have shown in zebrafish that expression of mutant ccm3 proteins (ccm3Delta) known to cause cerebral cavernous malformation in humans confers cardiovascular phenotypes identical to those associated with loss of ccm1 and ccm2. CCM3Delta proteins interacted with CCM1 and CCM2, but not with other proteins known to bind wild-type CCM3, serine/threonine protein kinase MST4 (MST4), sterile 20-like serine/threonine kinase 24 (STK24), and STK25, all of which have poorly defined biological functions. Cardiovascular phenotypes characteristic of CCM deficiency arose due to stk deficiency and combined low-level deficiency of stks and ccm3 in zebrafish embryos. In cultured human endothelial cells, CCM3 and STK25 regulated barrier function in a manner similar to CCM2, and STKs negatively regulated Rho by directly activating moesin. These studies identify STKs as essential downstream effectors of CCM signaling in development and disease that may regulate both endothelial and epithelial cell junctions. BACKGROUND: Cerebral cavernous malformations (CCM) present as either sporadic or autosomal dominant conditions with incomplete penetrance of symptoms. Differences in genetic and environmental factors might be minimized among first-degree relatives. We therefore studied clinical expression in a family with several affected members. METHODS: We studied a three-generation family with the onset of CCM as a cerebral haemorrhage in the younger (four-year-old) sibling. Identification and enumeration of CCMs were performed in T2-weighted or gradient-echo MRIs of the whole brains. Genetic analysis comprised SCCP, sequencing and restriction polymorphism of the Krit1 gene in the proband and at risk relatives. RESULTS: The phenotypes of cerebral cavernous malformations (CCMs) in carriers of Krit1 mutations were very variable. We identified a novel frameshift mutation caused by a 1902A insertion in exon 17 of the Krit1 gene, which leads to a premature TAA triplet and predicts the truncating phenotype Y634X. A very striking finding was the absence of both clinical symptoms and CCMs in the eldest sibling harbouring the 1902insA. CONCLUSIONS: Patients in this family, harbouring the same mutation, illustrate the very variable clinical and radiological expression of a Krit1 mutation. The early and critical onset in the proband contrasts with minor clinical findings in affected relatives. This consideration is important in genetic counselling. Loss-of-function mutations in CCM1/KRIT1, CCM2/MGC4607 and CCM3/PDCD10 genes are identified in the vast majority of familial cases with multiple cerebral cavernous malformations (CCMs). However, genomic DNA sequencing combined to large rearrangement screening fails to detect a mutation in 5% of those cases. We report a family in which CCM lesions were discovered fortuitously because of the investigation of a developmental delay in a boy. Three members of the family on three generations had typical multiple CCM lesions and no clinical signs related to CCM. No mutation was detected using genomic DNA sequencing and quantitative multiplex PCR of short fluorescent fragments (QMPSF). cDNA sequencing showed a 99-nucleotide insertion between exons 5 and 6 of CCM1, resulting from a mutation located deep into intron 5 (c.262+132_262+133del) that activates a cryptic splice site. This pseudoexon leads to a premature stop codon. These data highly suggest that deep intronic mutations explain part of the incomplete mutation detection rate in CCM patients and underline the importance of analyzing the cDNA to provide comprehensive CCM diagnostic tests. This kind of mutation may be responsible for apparent sporadic presentations due to a reduced penetrance.

Is DITPA a thyroid hormone analog utilized in experimental and clinical studies

There is very large body of evidence that DITPA is a true thyroid hormone analog, largely utilized in experimental and clinical studies.

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Thyroid hormone (T3 and T4) has many beneficial effects including enhancing cardiac function, promoting weight loss and reducing serum cholesterol. Excess thyroid hormone is, however, associated with unwanted effects on the heart, bone and skeletal muscle. We therefore need analogs that harness the beneficial effects of thyroid hormone without the untoward effects. Such work is largely based on understanding the cellular mechanisms of thyroid hormone action, specifically the crystal structure of the nuclear receptor proteins. In clinical studies, use of naturally occurring thyroid hormone analogs can suppress TSH levels in patients with thyroid cancer without producing tachycardia. Many thyromimetic compounds have been tested in animal models and shown to increase total body oxygen consumption, and to lower weight and serum cholesterol and triglyceride levels while having minor effects on heart rate. Alternatively, analogs that specifically enhance both systolic and diastolic function are potentially useful in the treatment of chronic congestive heart failure. In addition to analogs that are thyroid hormone receptor agonists, several compounds that are thyroid hormone receptor antagonists have been identified and tested. This Review discusses the potential application of thyroid hormone analogs (both agonists and antagonists) in a variety of human disease states. Previous studies have established that reductions in repolarizing currents occur in heart disease and can contribute to life-threatening arrhythmias in myocardium. In this study, we investigated whether the thyroid hormone analog 3, 5-diiodothyropropionic acid (DITPA) could restore repolarizing transient outward K(+) current (I(to)) density and gene expression in rat myocardium after myocardial infarction (MI). Our findings show that I(to) density was reduced after MI (14.0 +/- 1.0 vs. 10.2 +/- 0.9 pA/pF, sham vs. post-MI at +40 mV). mRNA levels of Kv4.2 and Kv4.3 genes were decreased but Kv1.4 mRNA levels were increased post-MI. Corresponding changes in Kv4.2 and Kv1.4 protein were also observed. Chronic treatment of post-MI rats with 10 mg/kg DITPA restored I(to) density (to 15.2 +/- 1.1 pA/pF at +40 mV) as well as Kv4.2 and Kv1.4 expression to levels observed in sham-operated controls. Other membrane currents (Na(+), L-type Ca(2+), sustained, and inward rectifier K(+) currents) were unaffected by DITPA treatment. Associated with the changes in I(to) expression, action potential durations (current-clamp recordings in isolated single right ventricular myocytes and monophasic action potential recordings from the right free wall in situ) were prolonged after MI and restored with DITPA treatment. Our results demonstrate that DITPA restores I(to) density in the setting of MI, which may be useful in preventing complications associated with I(to) downregulation. The patent application WO2008106213 describes the beneficial effects of thyroid hormone analogue 3,5 diiodothyropropionic acid (DITPA) such as stimulating weight loss in overweight mammals, lowering of triglyceride and treating metabolic syndrome in humans. The human population of the patients selected in the studies mentioned has a body mass index > 25. Two examples of the human clinical studies employing DITPA have been mentioned, namely, the body weight reduction and improvement in metabolic abnormalities in obese adults. CONTEXT: Monocarboxylate transporter 8 (MCT8) is a thyroid hormone-specific cell membrane transporter. MCT8 deficiency causes severe psychomotor retardation and abnormal thyroid tests. The great majority of affected children cannot walk or talk, and all have elevated serum T(3) levels, causing peripheral tissue hypermetabolism and inability to maintain weight. Treatment with thyroid hormone is ineffective. In Mct8-deficient mice, the thyroid hormone analog, diiodothyropropionic acid (DITPA), does not require MCT8 to enter tissues and could be an effective alternative to thyroid hormone treatment in humans. OBJECTIVE: The objective of the study was to evaluate the effect and efficacy of DITPA in children with MCT8 deficiency. METHODS: This was a multicenter report of four affected children given DITPA on compassionate grounds for 26-40 months. Treatment was initiated at ages 8.5-25 months, beginning with a small dose of 1.8 mg, increasing to a maximal 30 mg/d (2.1-2.4 mg/kg · d), given in three divided doses. RESULTS: DITPA normalized the elevated serum T(3) and TSH when the dose reached 1 mg/kg · d and T(4) and rT(3) increased to the lower normal range. The following significant changes were also observed: decline in SHBG (in all subjects), heart rate (in three of four), and ferritin (in one of four). Cholesterol increased in two subjects. There was no weight loss and weight gain occurred in two. None of the treated children required a gastric feeding tube or developed seizures. No adverse effects were observed. CONCLUSION: DITPA (1-2 mg/kg · d) almost completely normalizes thyroid tests and reduces the hypermetabolism and the tendency for weight loss. The effects of earlier commencement and long-term therapy remain to be determined. To determine the biochemical and related functional effects of the thyroid analog diiodothyroproprionic acid (DITPA) on primate myocardium, we examined, both before and after 23 days of DITPA (3.75 mg/kg): myosin heavy-chain (MHC) isoforms and sarcoplasmic reticulum (SR) calcium cycling proteins; left ventricular (LV) function; and the LV force-frequency relation in four baboons chronically instrumented with sonomicrometers and micromanometers. The force-frequency relation was measured as the response of isovolumic contraction (dP/dtmax) to incremental pacing and the critical heart rate (HRcrit) as the rate at which dP/dtmax reached its maximum. DITPA increased basal LV dPt/dtmax (3,300 +/- 378 versus 2,943 +/- 413 mm Hg/sec; p = .09), and velocity of circumferential shortening (1.13 +/- 0.30 versus 0.76 +/- 0.30 circ/sec; p < .01), decreased the basal time constant of isovolumic relaxation (24.2 +/- 1.6 versus 29.9 +/- 2.5 msec; p < .05), and increased the HRcrit (203 +/- 19 versus 168 +/- 20 bpm; p < .05), without effecting significant changes in either basal heart rate (119 +/- 14 versus 111 +/- 17 bpm) or systolic blood pressure (137 +/- 14 versus 126 +/- 8 mm Hg). Quantitative immunoblotting revealed significant decreases in both phospholamban and the ratio of phospholamban to SR Ca2+ adenosine triphosphatase in DITPA-treated animals when compared to four untreated controls. By contrast, alpha-MHC isoform was undetectable in both DITPA treated and control baboons. Thus, DITPA favorably alters the stoichiometry between the SR calcium pump and its inhibitor, phospholamban, and has positive inotropic and lusitropic effects in the normal primate left ventricle, which may be useful in the treatment of heart failure. Unlike thyroid hormone, these changes occur in the absence of detectable alpha-MHC isoform protein expression and without an increase in heart rate. Patients with hypothyroidism are at a higher risk for coronary vascular disease. Patients with diabetes and related vascular complications also have an increased incidence of low thyroid function. While thyroid hormones (THs) may be key regulators of a healthy vasculature, potential undesirable side effects hinder their use in the treatment of vascular disorders. TH analogs such as 3,5-diiodothyropropionic acid (DITPA) may provide a safer treatment option. However, the relative potency of DITPA on vascular growth, cardiac function, and metabolism is poorly understood. We hypothesized that the vascular growth-promoting effects of DITPA can be obtained with a minimum effect on cardiac function. Thyroidectomized Sprague-Dawley rats were given slow-release pellets with either thyroxine (T4, 2.7 or 5.2 mg) or DITPA (80 mg) for 6 wk and were compared with placebo. Heart mass, body mass, body temperature, serum THs, cardiac function (echocardiograms and hemodynamics), and myocardial arteriolar density were determined. Hypothyroidism led to reductions in cardiac function, heart mass, body temperature, and myocardial arterioles. High-dose T4 prevented arteriolar loss and the development of hypothyroidism. Low-dose T4 partially prevented the reduction in cardiac function but had minimal effects on arteriolar loss. In contrast, DITPA treatment prevented myocardial arteriolar loss but not the progression of hypothyroid-induced changes in cardiac function. The results suggested that DITPA can promote a healthy vasculature independently from its thyroid-related metabolic effects. Drugs in this class may provide new therapeutic options for patients with vascular disease. In view of the evidence that thyroid hormone administration has angiogenic effects on the hypertrophic myocardium, we tested the hypothesis that the capillary supply in the hypertrophic myocardium surviving infarction would be improved by administration of the thyroid hormone analog, diiodothyroproprionic acid (DITPA). We administered DITPA (MI-DITPA) or saline (MI-saline), s.c., to rats for 10 days following experimental infarction of the left ventricle (LV). Morphometric methods were used to assess capillarity and myocyte cross-sectional area in three regions of the left ventricle: (1) border (next to the scar of infarction); (2) adjacent (next to the border); and (3) remote (interventricular septum). Infarct size ranged from 20-85% of the LV free-wall, and both groups had similar mean infarct size. Capillary length density (LV) was significantly higher in the remote region of the treated group than in the MI-saline rats. LV in the border region, which experienced the most marked increase in cardiocyte cross-sectional area, was not significantly lower than in the other regions, indicating a more marked angiogenic response. In hearts with large infarcts (> or = 40%) LV in the border region was higher in the DITPA group than in the non-treated rats. In the MI-DITPA group, cardiocyte size in the border region was positively correlated with that of the other regions, which contrasts with the negative correlations noted for the MI-saline rats. These data suggest that DITPA therapy (1) may improve maximal perfusion potential of the hypertrophied myocardium surviving a myocardial infarction, and (2) is selectively effective in the border region of hearts with large infarcts. The heart is an important target of thyroid hormone actions. Only a limited number of cardiac target genes have been identified, and little is known about their regulation by T(3) (3,3',5-triiodothyronine) and thyroid hormone analogs. We used an oligonucleotide microarray to identify novel cardiac genes regulated by T(3) and two thyroid hormone analogs, 3,5-diidodothyropropionic acid (DITPA) and CGS 23425 [N-[3,5-dimethyl-4-(4'-hydroxy-3'-isopropylphenoxy)-phenyl]-oxamic acid]. DITPA binds with lower affinity than T(3) to thyroid hormone receptor alpha1 and beta1 isoforms, whereas CGS 23425 binds selectively to beta1. Fluorescent-labeled cDNA was prepared from cultured heart cells maintained in medium stripped of thyroid hormone ("hypothyroid" control) or treated with T(3), DITPA, and CGS 23425 at concentrations 5 times their respective K(d) values for 48 h. The arrays were scanned and analyzed using an analysis of variance program. Sixty-four genes were identified that were >1.5 times up- or down-regulated by one of the treatments with P < 0.05. The genes regulated by T(3) and DITPA were nearly identical. Thirteen genes were differentially regulated by CGS 23425. Genes encoding contractile proteins, Ca(2+)-ATPase of sarcoplasmic reticulum and several proteins of mitochondrial oxidative phosphorylation, were up-regulated by T(3) and DITPA but not by CGS 23425. These results indicate that some, but not all, of the actions of thyroid hormone analogs can be explained by differences in gene activation. CONTEXT: Widespread thyroid hormone actions offer the possibility of developing selective thyromimetic analogs with salutary metabolic properties. Consequently, effects of diiodothyropropionic acid (DITPA) on body weight, serum lipoproteins, and bone metabolism markers were studied in a prospective, controlled, double-blind 24-wk trial, which was primarily designed to assess treatment of stable chronic heart failure. DESIGN: Eighty-six patients (aged 66 +/- 11 yr, mean +/- sd) were randomized (1:2) to placebo or an escalating DITPA dose (90 to 180, 270, and 360 mg/d) over 8 wk until serum TSH was less than 0.02 mU/liter. Patients were studied at 2, 4, 6, 8, 16, and 24 wk and after 4 wk off study drug. Only 21 DITPA-treated and 27 placebo patients completed the full 24 wk of therapy. RESULTS: DITPA therapy lowered serum TSH levels and, to a lesser extent, serum T(3) and T(4), but there were no differences in clinical manifestations of thyrotoxicosis or hypothyroidism. Serum total and low-density lipoprotein cholesterol levels both decreased on DITPA; there was a transient decrease in triglycerides and no change in high-density lipoprotein cholesterol. DITPA therapy was associated with significant reduction in body weight, 12.5 lb at 24 wk. Increases in serum osteocalcin, N-telopeptide, and deoxypyridinoline levels were consistent with increased bone turnover on DITPA. CONCLUSION: This investigation of DITPA actions demonstrated its efficacy in reducing body weight and lowering total and low-density lipoprotein cholesterol levels. However, DITPA's adverse effects at doses used resulted in a high dropout rate and potentially dangerous skeletal actions were observed. After an initial safety study in 7 normal volunteers, a randomized double-blind comparison was made between 3,5-diiodothyropropionic acid (DITPA) and placebo in 19 patients with moderately severe congestive failure. In heart failure patients receiving the drug for 4 weeks, cardiac index was increased (p = 0.04) and systemic vascular resistance index was decreased (p = 0.02). Systolic cardiac function was unchanged but isovolumetric relaxation time was decreased significantly, suggesting improvement in diastolic function. Total serum cholesterol (p = 0.005) and triglycerides (p = 0.01) also were decreased significantly. DITPA could represent a useful new agent for treatment of congestive heart failure. There is emerging evidence that treatment with thyroid hormone (TH) can improve postischemic cardiac function. 3,5-Diiodothyropropionic acid (DITPA), a TH analog, has been proposed to be a safer therapeutic agent than TH because of its negligible effects on cardiac metabolism and heart rate. However, conflicting results have been reported for the cardiac effects of DITPA. Importantly, recent clinical trials demonstrated no symptomatic benefit in patients with DITPA despite some improved hemodynamic and metabolic parameters. To address these issues, dose-dependent effects of DITPA were investigated in mice for baseline cardiovascular effects and postischemic myocardial function and/or salvage. Mice were treated with subcutaneous DITPA at 0.937, 1.875, 3.75, or 7.5 mg·kg(-1)·day(-1) for 7 days, and the results were compared with untreated mice for ex vivo and/or in vivo myocardial ischemia-reperfusion (I/R). DITPA had no effects on baseline body temperature, body weight, or heart rate; however, it mildly increased blood pressure. In isolated hearts, baseline contractile function was significantly impaired in DITPA-pretreated mice; however, postischemic recovery was comparable between untreated and DITPA-treated groups. In vivo baseline cardiac parameters were significantly affected by DITPA, with increased ventricular dimensions and decreased contractile function. Importantly, DITPA-treated mice demonstrated high prevalence of fatal cardiac rhythm abnormalities during in vivo ischemia and/or reperfusion. There were no improvements in myocardial infarction and postischemic fractional shortening with DITPA. Myocardial sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA), phospholamban (PLB), and heat shock protein (HSP) levels remained unchanged with DITPA treatment. Thus DITPA administration impairs baseline cardiac parameters in mice and can be fatal during in vivo acute myocardial I/R. In hypothyroid patients, altered microvascular structure and function may affect mood and cognitive function. We hypothesized that adult male hypothyroid rats will have significantly lower forebrain blood vessel densities (BVD) than euthyroid rats and that treatment with 3,5-diiothyroprionic acid (DITPA) (a thyroid hormone analog) or thyroxine (T(4)) will normalize BVDs. The euthyroid group received no thyroidectomy or treatment. The other three groups received thyroidectomies and pellets. The hypothyroid group received a placebo pellet, the DITPA group received an 80-mg DITPA-containing pellet, and the T(4) group received a 5.2-mg T(4) slow-release pellet for 6 wk. Body weights, cardiac function, and body temperatures were measured. A monoclonal antiplatelet endothelial cell adhesion antibody was used to visualize blood vessels. The euthyroid group averaged body weights of 548 +/- 54 g, while the hypothyroid group averaged a body weight of 332 +/- 19 g (P value < 0.001). Relative to the euthyroid group, the DITPA-treated group was significantly lighter (P value < 0.05), while the T(4)-treated group was comparable in body weight to the euthyroid group. The same trends were seen with body temperature and cardiac function with the largest difference between the euthyroid and hypothyroid groups. BVD in the euthyroid group was 147 +/- 12 blood vessels/mm(2) and in hypothyroid group 69 +/- 5 blood vessels/mm(2) (P = 0.013) but similar among the euthyroid, DITPA, and T(4) groups. These results show that hypothyroidism decreased BVD in adult rat forebrain regions. Moreover, DITPA and T(4) were efficacious in preventing effects of hypothyroidism on cardiac function and BVD. We have recently described the proangiogenesis effects of thyroid hormone in the chick chorioallantoic membrane (CAM) model. Generation of new blood vessels from existing vessels was promoted 2- to 3-fold by either T(4) or T(3) at 10(-8)-10(-7) M total hormone concentrations. In the present studies, nanomolar concentrations of 3,5-diiodothyropropionic acid (DITPA), a thyroid hormone analog with inotropic but not chronotropic properties, exhibited potent proangiogenic activity that was comparable to that obtained with T(3) and T(4) in both the CAM model and in an in vitro three-dimensional human microvascular endothelial sprouting assay. The proangiogenesis effect of DITPA was inhibited by tetraiodothyroacetic acid, a thyroid hormone analog that competes with T(4) and T(3) for a novel cell surface hormone receptor site on integrin alphavbeta3. The thyroid hormone analogs DITPA, T(4), and T(4)-agarose, as well as basic fibroblast growth factor (b-FGF) and vascular endothelial cell growth factor, demonstrated comparable proangiogenic effects in the CAM model and in the three-dimensional human microvascular endothelial sprouting model. The proangiogenesis effect of either DITPA or b-FGF was blocked by PD 98059, an inhibitor of the ERK1/2 signal transduction cascade. Additionally, a specific integrin alphavbeta3 small molecule antagonist, XT199, effectively inhibited the proangiogenesis effect of DITPA and b-FGF. Thus, the proangiogenesis actions of thyroid hormone and its analog DITPA are initiated at the plasma membrane, apparently at integrin alphavbeta3, and are MAPK dependent. Diiodothyropropionic acid (DITPA) is a thyroid hormone analog that is currently in phase II clinical trials. However, there have not been any studies to comprehensively analyze its effect on myocyte morphology. In addition, long-term studies with DITPA have not been done. This study compares the effects of DITPA with L-thyroxine (T4) on chamber remodeling, cardiac function, cellular morphology, cardiac blood flow, and protein expression. Normal and cardiomyopathic hamsters were treated with T4 or DITPA for 2 months. At the end of the treatment, echos, hemodynamics, coronary blood flow, cell morphology, and protein expression data were collected. Both T4 and DITPA treatment reduced chamber diameter during diastole, suggesting attenuated chamber dilatation in cardiomyopathic hamsters. Wall thickness also tended to increase, which was supported by cell morphology data in which DITPA significantly increased cross-sectional growth of myocytes specifically in the minor dimension, which is oriented transmurally. T4 and DITPA also increased myocardial blood flow both at baseline and after maximal dilation. This suggests there was increased angiogenesis or reduced loss of arterioles. Both T4 and DITPA had beneficial effects on chamber remodeling, which was most likely due to beneficial changes in cell shape and improved vascular supply. Heart failure of diverse causes is associated with abnormalities of sarcoplasmic reticulum (SR) Ca(2+)transport. The purpose of this study was to determine whether the thyroid hormone analogue, 3,5-diiodothyropropionic acid (DITPA), prevents abnormal Ca(2+)transport and expression of SR proteins associated with post-infarction heart failure. New Zealand White rabbits were randomly assigned to circumflex artery ligation or sham operation, and to DITPA administration (3.75 mg/kg/day) or no treatment in a two-by-two factorial design. After 3 weeks, echo-Doppler and LV hemodynamic measurements were performed. From ventricular tissue, single myocyte shortening and relaxation were determined, and Ca(2+)transport was measured in homogenates and SR-enriched microsomes. Levels of mRNA and protein content were determined for the SR Ca(2+)-ATPase (SERCA2a), phospholamban (PLB), cardiac ryanodine receptor (RyR-2) and calsequestrin. The administration of DITPA improved LV contraction and relaxation and improved myocyte shortening in infarcted animals. The improvements in LV and myocyte function were associated with increases in V(max)for SR Ca(2+)transport in both homogenates and microsomes. Also, DITPA prevented the decrease in LV protein density for SERCA2a, PLB and RyR-2 post-infarction, without measurable changes in mRNA levels. The thyroid hormone analogue, DITPA, improves LV, myocyte and SR function in infarcted hearts and prevents the downregulation of SR proteins associated with post-infarction heart failure. The specific effects of DITPA on post-infarction SR Ca(2+)transport and the expression of SR proteins make this compound a potentially useful therapeutic agent for LV systolic and/or diastolic dysfunction. BACKGROUND: Thyroid hormone can have positive effects on the cardiovascular system but its therapeutic potential is limited secondary to its adverse effects. DITPA (3,5-diiodothyroproprionic acid) is a synthetic thyroid hormone analog with positive inotropic effects similar to thyroid hormone but with minimal systemic effects. DITPA has previously been shown to reduce pathologic remodeling and improve cardiac output following myocardial infarction; however, few studies have examined the role of DITPA in determining infarct size or the early inflammatory response following myocardial ischemia. We examined the role of DITPA in the acute phase following infarction. MATERIALS AND METHODS: Mice were subjected to surgical induction of myocardial infarction and were then randomized to receive daily injections of DITPA or vehicle control. After 3 d, animals were sacrificed and infarct size was determined by H and E staining. Myocardial macrophage and neutrophil accumulation was determined by immunofluorescent staining. Immunoblotting and enzyme-linked immunosorbent assay (ELISA) were used to examine the levels of intercellular adhesion molecule-1 (ICAM-1), keratinocyte-derived chemokine (KC), monocyte chemoattractant protein (MCP-1), and interleukin 6 (IL-6) in homogenates from the ischemic tissue. RESULTS: Compared with vehicle control, DITPA treated animals had smaller infarcts (52.1%±5.7% versus 37.3%±3.6%, P<0.05) and decreased macrophage (32±4 versus 14±1 cells/HPF, P<0.05, and neutrophil (14±2 versus 7±1 cells/HPF, P<0.05) accumulation. Myocardial ICAM-1, (2.37±0.4 versus 1.1±0.2, P<0.05), KC levels (33.32±12.4 pg/mg, versus 21.24±8.9 pg/mg, P<0.05), and IL-6 levels (112.3±78 pg/mg versus 37.3±25.9 pg/mg, P<0.05) were also reduced in the DITPA treated group, while MCP-1 levels were equivalent between groups. CONCLUSIONS: Treatment with DITPA attenuates the acute inflammatory response and reduces myocardial infarct size. The reduction in myocardial ICAM-1, KC, and IL-6 levels in the DITPA group was associated with a decrease in macrophage and neutrophil accumulation. Thyroid hormones [predominantly 3, 5, 3 -I- iodothyronine (T3)] regulate cholesterol and lipoprotein metabolism but cardiac effects restrict their use as hypolipidemic drugs. New molecules have been developped which target specifically the thyroid hormone receptor ss, predominant isoform in liver. The first thyroid hormone agonist, called GC1, has selective actions compared to T3. In animals, GC1 reduced serum cholesterol and serum triglycerides, probably by stimulation important steps in reverse cholesterol transport. Other selective thyromimetic, KB- 2115 and KB - 141 have similar effects. Another class of thyroid hormone analogs, the thyronamines have emerged recently but the basic biology of this new class of endogenous thyroid hormone remains to better understood. Therefore, these molecules may be a potentially treatment for obesity and reduction cholesterol, triglycerides and lipoprotein (a). To date the studies in human are preliminary. Tolerance and efficacy of these drugs are still under investigation. The possibility that thyroid hormone or a thyroid hormone analogue that improves cardiac performance might be useful in the treatment of heart failure has-been examined. In the rat postinfarction model of heart failure, treatment with low doses (1.5 micrograms/100 g) of thyroxine (T4) for 3 days produced a positive inotropic response, including an increase in left ventricular (LV) dP/dt and a decrease in LV end-diastolic pressure (LVEDP). When treatment with T4 was continued at the same or higher doses (3 to 15 micrograms/100 g) for 10-12 days, heart rate was increased and improvement in LVEDP was not sustained. To identify an analogue with a more favorable hemodynamic profile, single- and double-ring compounds related to T4 were screened for thyromimetic activity in heart cell cultures and for their ability to bind thyroid hormone receptors. One of the analogues selected, 3,5-diiodothyropropionic acid (DITPA), was found to have inotropic selectivity in hypothyroid rats. When administered (375 micrograms/100 g) to rats with ventricular dysfunction after myocardial infarction in combination with captopril, there was improvement of the resting and stressed cardiac index and LV filling pressure. Similar improvement in cardiac performance was obtained when DITPA was administered to rabbits after infarction. Thus a thyroid hormone analogue with inotropic selectivity may be a useful adjunct to other measures in the treatment of heart failure. We have used an oligonucleotide microarray to identify genes that are affected by congestive heart failure and those influenced by treatment with DITPA and DITPA in combination with captopril using a rat postinfarction model. The most striking result when comparing heart failure to sham operation was that all of the mitochondrial and metabolic enzymes affected were down regulated. When comparing heart failure with DITPA treatment, most of the down regulated metabolic genes were returned toward normal. When comparing heart failure with heart failure animals treated with DITPA and captopril, metabolic enzymes were no longer significantly downregulated. DITPA treatment and the combination of DITPA and captopril show that the metabolic enzymes were no longer down regulated. This represents a substantial improvement in the energy- generating capacity of the heart. These results indicate that the actions of DITPA and the combination of DITPA and captopril in heart failure can be partially explained by differences in gene activation.

What is Tarlov Cyst?

Tarlov or perineural cysts are nerve root cysts found most commonly at the sacral spine level arising between covering layers of the perineurium and the endoneurium near the dorsal root ganglion and are usually asymptomatic.

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We report the case of a 40-year-old man remitted to our department with a history of lower back pain and sciatica with no history of trauma. The laboratory analyses showed normal values whereas plain radiographs showed a sacrum rarefaction area. A 99mTc-MDP bone scintigraphy was performed to evaluate the lumbosacral area. Planar images did not show any abnormality. SPECT images revealed photopenic abnormality in the second sacral vertebral right hemibody, with no peripherally increased radiotracer accumulation. Subsequent MRI and CT myelography demonstrated the nature of the photopenic area as secondary to vertebral erosion by sacral perineurial cyst (Tarlov cyst). We describe a case of sacral perineural cyst presenting with complaints of low back pain with neurological claudication. The patient was treated by laminectomy and excision of the cyst. Tarlov cysts (sacral perineural cysts) are nerve root cysts found most commonly in the sacral roots, arising between the covering layer of the perineurium and the endoneurium near the dorsal root ganglion. The incidence of Tarlov cysts is 5% and most of them are asymptomatic, usually detected as incidental findings on MRI. Symptomatic Tarlov cysts are extremely rare, commonly presenting as sacral or lumbar pain syndromes, sciatica or rarely as cauda equina syndrome. Tarlov cysts should be considered in the differential diagnosis of patients presenting with these complaints. Perineural (Tarlov) cysts are most often found in the sacral region and are rare in the cervical spine. Although they are usually asymptomatic, a small number of those at the lumbosacral level have been known to produce localized or radicular pain. Few reports are available on symptomatic perineural cysts in the cervical spine and it has not been discussed how they should be managed. We present here a case of cervical perineural cysts with persistent radicular pain where the pain was adequately managed with repetitive transforaminal epidural steroid injection (TFESI). The patient had experienced intractable pain in the posterior neck and left upper extremity for more than 7 years. The nature of the pain was cramping and a tingling sensation, which was aggravated in the supine position. Magnetic resonance imaging revealed a perineural cyst in the neural foramen of left C7 root. The patient underwent three repetitive TFESIs targeted at the root. Each injection provided incremental relief, which lasted more than 6 months. Follow-up image revealed shrinkage of the cyst. This case illustrates in detail the clinical manifestation of a rare symptomatic perineural cyst in the cervical region and to our knowledge is the first to report the beneficial effect of repetitive TFESI. With technological advancements and wider availability of multimodality imaging, incidental lesions are frequently identified in patients undergoing various imaging studies. We report here a case of multiloculated disseminated perineural or Tarlov cysts (TCs). The primary aim of our study was to (1) provide a comprehensive review of the clinical, imaging and histopathological features of TCs (2) to draw attention to the fact that multiple lumbo-sacral and dorsal TCs can produce nerve injuries and serious movement disturbances (3) to document the usefulness of the magnetic resonance imaging (MRI) and bone scan in noninvasive diagnosis and guiding management in such cases. These cysts are clearly identified by MR and computerized tomography imaging of the lumbosacral spine. However, there are no reports on the scintigraphic findings of TCs in literature. TCs are typically benign, asymptomatic lesions that can simply be monitored. Until date, no consensus exists about the best surgical strategy to be followed for their management. Tarlov cyst syndrome is a rare, often asymptomatic disorder, characterised by isolated or multiple nerve-root cysts, usually occurring in the sacral spine, near the dorsal root ganglion, between the perineurium and endoneurium. The cysts may cause lower back pain, sacral radiculopathy, dyspareunia and urinary incontinence. There is little data in the literature on the relationship between Tarlov cysts and symptoms. Here, we report further details on the clinical impact of Tarlov cysts and investigate their pathogenesis and role as a cause of lumbosacral symptoms. We examined 157 patients with MRI evidence of symptomatic Tarlov cysts. Patients underwent complete neurological examination and were scored by the Hamilton Depression Rating Scale and the Visual Analogue Scale. Complete lower limb electromyography was performed in 32 patients. Clinical picture was correlated with size and number of cysts detected by MRI. Family history was recorded for signs of genetic inheritance. Almost all patients suffered perineal or lower back pain; 34 complained of sphincter and 46 of sexual disorders. Hamilton scores were abnormal, and family history was positive in a few cases. The scanty literature on Tarlov cysts mainly regards therapy by a neurosurgical approach. Our results provide new data on clinical impact and possible pathogenetic mechanisms. Patients with Marfan syndrome used to succumb early in life from cardiovascular complications. With the current rapid advance in medical and surgical care, such patients may now have near-normal longevities. Consequently, rare late-life complications are emerging in these patients and represent challenges to clinicians for their diagnoses and treatments. The authors report a rare case of pelvic pain and genital prolapse from a giant presacral Tarlov cyst in a 67-year-old patient with Marfan syndrome. This 67-year-old Caucasian female presented with progressively severe pelvic pain, intermittent explosive diarrhea, and dysuria. Physical and bimanual examination demonstrated genital prolapse and a nontender, cyst-like mass fixed in the midline. She underwent ultrasound, CT, and eventually MRI evaluations that led to the diagnosis of a giant (6.7 × 6.4 × 6.6 cm) Tarlov cyst originating from the right S-2 nerve root sleeve/sacral foramen with intrapelvic extension. She underwent S1-S2 and S2-S3 laminectomy with obliteration of the Tarlov cyst using aneurysm clips. Postoperatively, her pelvic pain and bowel symptoms resolved and the bladder symptoms improved. The 3-month follow-up CT of abdomen/pelvis demonstrated resolution of the cyst. The present case illustrates that clinicians caring for elderly patients with Marfan syndrome need to increasingly recognize such unusual late-life complications. Also, these large Tarlov cysts can be simply and effectively obliterated with aneurysm clips. OBJECT: Tarlov or perineurial cysts are lesions of the nerve root most often found in the sacral region. Although there is agreement that asymptomatic Tarlov cysts should be followed, it is still debated whether patients with symptomatic Tarlov cysts should be treated surgically. The authors assessed the outcome and efficacy of cyst wall resection in 10 patients with symptomatic Tarlov cysts. The medical literature is reviewed, theories of origin are evaluated, and suggestions as to their cause and pathogenesis are offered. METHODS: Ten consecutive patients harboring symptomatic Tarlov cysts were treated by the senior author between 1989 and 1999. All patients were assessed for neurological deficits and pain by neurological examination and visual analog scale, respectively. Computerized tomography myelography was performed in all patients to diagnose delayed filling of the cysts. A sacral laminectomy with resection of the sacral cyst or cysts was performed in all patients. Resected material from eight of 10 patients was submitted for histopathological evaluation. Seven (70%) of 10 patients obtained complete or substantial resolution of their symptoms, with an average follow up of 31.7 months. All of these patients had Tarlov cysts larger than 1.5 cm in diameter, producing radicular pain or bladder and bowel dysfunction. Three (30%) of 10 patients experienced no significant improvement. All three patients harbored Tarlov cysts smaller than 1.5 cm in diameter, producing nonradicular pain. Histopathological examination was performed on specimens from eight of 10 patients, which demonstrated nerve fibers in 75% of cases, ganglion cells in 25% of cases, and evidence of old hemorrhage in half. CONCLUSIONS: Large cysts (> 1.5 cm) and the presence of associated radicular symptoms strongly correlate with excellent outcome. Tarlov cysts may result from increased hydrostatic pressure and trauma. Sacral perineurial (Tarlov) cysts are rare lesions. Over a seven year period 4000 patients underwent surgery for lumbar disk herniation. In three patients neurological symptoms were caused by large sacral perineurial cysts. Methods of choice for diagnosis of Tarlov cysts are lumbosacral magnetic resonance imaging and computerized tomography myelography. The majority of Tarlov cysts are asymptomatic. In case of large (> or = 1.5 cm) and symptomatic perineurial cyst, as in three patients reported in this article, microsurgical treatment was successful. Although rare, perineurial (Tarlov) cysts must be taken into consideration when approaching to patient with low back and radicular pain. Authors review the medical literature, pathological and pathophysiological features and treatment options of sacral perineurial cysts. BACKGROUND: Acute low back pain is a very common symptom and reason for many medical consultations. In some unusual circumstances it could be linked to a rare aetiology. CASE PRESENTATION: We report a 70-year-old man with an 8-month history of left posterior thigh and leg pain who had sudden confusion after a fall from standing. It was due to cerebral fat embolism suspected by computed tomography scan, later confirmed by brain magnetic resonance imaging (MRI). A spinal MRI scan was then performed and revealed a sacral fracture which drained into an unknown perineurial cyst (Tarlov cyst). Under medical observation the patient fully recovered within three weeks. CONCLUSIONS: Sacral perineurial cysts are rare, however they remain a potential cause of lumbosacral radiculopathy. BACKGROUND/OBJECTIVE: Tarlov cysts or spinal perineurial cysts are uncommon lesions. These are mostly incidental findings on magnetic resonance imaging or myelograms. The objectives of this study were to describe Tarlov cysts of the sacral region as a potential cause for retrograde ejaculations and review available management options. METHODS: Case report and literature review. RESULTS: A 28-year-old man presented with back pain and retrograde ejaculations resulting in infertility. After microsurgical excision of large perineurial cysts, back pain resolved, but semen quality showed only marginal improvement. Later, the couple successfully conceived by intrauterine insemination. To the best of our knowledge, this is the first reported case of Tarlov cyst associated with retrograde ejaculation and infertility. CONCLUSIONS: Despite being mostly asymptomatic and an incidental finding, Tarlov cyst is an important clinical entity because of its tendency to increase in size with time. Tarlov cysts of the sacral and cauda equina region may be a rare underlying cause in otherwise unexplained retrograde ejaculations and infertility. Microsurgical excision may be a good option in a select group of patients.

What are 'vildagliptin', 'sitagliptin', 'saxagliptin', 'alogliptin', 'linagliptin', and 'dutogliptin'?

"Sitagliptin," "vildagliptin," "saxagliptin," "alogliptin," "linagliptin," and "dutogliptin" are dipeptidyl peptidase-4 (DPP-4) inhibitors.

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BACKGROUND: In studying the therapeutic evidence of innovative drug treatments, increasing attention is being devoted to differentiating between results that indicate no significant differences among the treatments under examination ("no proof of difference") and results that demonstrate the therapeutic equivalence among the treatments ("proof of no difference"). AIM: Our analysis was aimed at evaluating the degree of therapeutic equivalence for dipeptidylpeptidase-4 (DPP-4) inhibitors given in type 2 diabetes as monotherapy or in combination with metformin. METHODS: Equivalence was determined by developing a standard Forest plot that incorporated the information on margins previously reported in randomized trials on these agents. The end point was HbA1c change from baseline; the equivalence margin was set at ±0.25% change in HbA1c. The clinical material was obtained from a systematic review on this topic. RESULTS: Given as monotherapy, linagliptin, sitagliptin, and vildagliptin (but not saxagliptin) met the equivalence criterion when compared with one another. Given in combination with metformin, linagliptin, saxagliptin, sitagliptin, and vildagliptin showed an equivalent effect whereas alogliptin did not satisfy the equivalence criterion. CONCLUSIONS: Considering the most recent therapeutic guidelines, our results are of interest particularly as regards the information on DPP-4 inhibitors in combination with metformin. Four of the five DPP-4 inhibitors under examination clearly showed to have the same effectiveness; the fifth agent-alogliptin-failed to meet the equivalence criterion, but only because its superiority could not be excluded. AIMS: This meta-analysis was performed to provide an update on the efficacy and safety of dipeptidyl peptidase-4 (DPP-4) inhibitors and metformin as initial combination therapy and as monotherapy in patients with type 2 diabetes mellitus (T2DM). METHODS: We conducted a search on MEDLINE, Embase and Cochrane Collaborative database for randomized controlled trials (RCTs) of DPP-4 inhibitors and metformin as initial combination therapy or as monotherapy in patients with T2DM by the end of December 2012, using the key words 'alogliptin', 'dutogliptin', 'linagliptin', 'saxagliptin', 'sitagliptin', 'vildagliptin' and 'metformin'. RCTs were selected for meta-analysis if (1) they were RCTs comparing DPP-4 inhibitors plus metformin as initial combination therapy or DPP-4 inhibitor monotherapy to metformin monotherapy, (2) duration of treatment was ≥12 weeks and (3) reported data on haemoglobin A1c (HbA1c) change, fasting plasma glucose (FPG) change, weight change, adverse cardiovascular (CV) events, hypoglycaemia or gastrointestinal adverse events (AEs). RESULTS: A total of eight RCTs were included. Compared with metformin monotherapy, DPP-4 inhibitors monotherapy was associated with lower reduction in HbA1c level [weighted mean differences (MD) = 0.28, 95% confidence intervals (CIs) (0.17, 0.40), p < 0.00001], lower reduction in FPG level [MD = 0.81, 95% CI(0.60, 1.02), p <0.00001], lower weight loss [MD = 1.51, 95% CI (0.89, 2.13), p < 0.00001], but lower risk of adverse CV events [risk ratio (RR) = 0.36, 95% CI (0.15, 0.85), p = 0.02], lower risk of hypoglycaemia [RR = 0.44, 95% CI (0.27, 0.72), p = 0.001] and lower risk of gastrointestinal AEs [RR = 0.63, 95% CI(0.55, 0.70), p <0.00001]. Compared with metformin monotherapy, DPP-4 inhibitors plus metformin as initial combination therapy was associated with higher reduction in HbA1c level [MD = -0.49, 95% CI (-0.57, -0.40), p < 0.00001], higher reduction in FPG level [MD = -0.80, 95% CI (-0.87, -0.74), p < 0.00001], lower weight loss [MD = 0.44, 95% CI (0.22, 0.67), p = 0.0001]; but was not associated with a further reduction in adverse CV events [RR=0.54, 95% CI (0.25, 1.19), p = 0.13], nor the higher risk of hypoglycaemia [RR = 1.04, 95% CI (0.72, 1.50), p = 0.82], nor the prolonged risk of gastrointestinal AEs [RR = 0.98, 95% CI (0.88, 1.10), p = 0.77]. CONCLUSIONS: DPP-4 inhibitors, which are safe and effective in controlling the blood glucose, may possibly decrease the risk of CV events in patients with T2DM. It could be a credible alternative for T2DM patients who, for some reason, cannot use metformin, or are in high risk of CV exposure. High-quality, large sample and long-term follow-up clinical trails are needed to confirm the long-term conclusions. The dipeptidyl peptidase-4 (DPP-4) inhibitors linagliptin, sitagliptin, saxagliptin, vildagliptin and alogliptin are being developed and have been approved for the treatment of type-2 diabetes. These agents may be used either as monotherapy for the treatment of type-2 diabetes or in combination with other anti-diabetic drugs. The present review highlights the use of linagliptin and other new (DPP-4) inhibitors in the management of type-2 diabetes. The review also highlights advantages, comparative pharmacokinetic, safety profile and other potential uses including potential newer indications of DPP-4 inhibitors and relevant patents. The other potential uses that are not restricted to diabetes include obesity, cardiovascular disease, neurological disease, hepatobiliary disease, wound healing, and other inflammatory illnesses. INTRODUCTION: A recent treatment advance for type 2 diabetes is the oral therapy with DPP IV inhibitors. New substances of this class are in development in order to increase alternatives for treating this important metabolic disease. The reader will gain detailed pharmacological and clinical information on alogliptin, dutogliptin and linagliptin and will learn how these DPP IV inhibitors may widen the whole drug class. Possible special indications for the various DPP IV inhibitors are discussed. AREAS COVERED: The DPP IV inhibitors and their current role in type 2 diabetes are highlighted. Preclinical and clinical studies of the novel DPP IV inhibitors alogliptin, dutogliptin and linagliptin, including published data since 2007, are presented and a comparison of these compounds is made. EXPERT OPINION: The efficacy and safety profile of DPP IV inhibitors are promising and advantageous so far. In contrast to sulfonylureas, DPP IV inhibitors do not have an intrinsic risk for causing hypoglycemia and they are body weight neutral. Their tolerability profile is good and no specific adverse reactions have been reported. Experience so far suggests that there are no safety issues associated with inhibition of DPP IV activity by itself. Novel DPP IV inhibitors with distinct properties may offer alternative choices within this drug class. BACKGROUND: Vildagliptin is a dipeptidyl peptidase IV inhibitor (DPP4i). Its efficacy and safety of DPP4i in Chilean real life type 2 diabetic (T2D) patients is not well known. AIM: To assess the safety profile and effectiveness of 12 weeks of treatment with Vildagliptin for glycemic control in T2D Chilean patients with a poor glycemic control. PATIENTS AND METHODS: Retrospective assessment of the effects of Vildagliptin treatment during 12 weeks in 103 T2D patients aged 29 to 92 years (47% males). The main outcomes were changes in glycosylated hemoglobin and the occurrence of adverse effects. RESULTS: After 12 weeks of Vildagliptin use, glycosylated hemoglobin decreased from 8.3 ± 1.4 to 7.2 ± 1.1% (p < 0.01). Fasting plasma glucose and the number of hypoglycemic events also decreased significantly. No significant weight change was observed. The treatment had good compliance, tolerance and patient satisfaction. CONCLUSIONS: Vildagliptin treatment reduced glycosylated hemoglobin by 1.1% and was well tolerated in this group of diabetic patients. In recent years, various dipeptidyl peptidase IV (DPP-4) inhibitors have been released as therapeutic drugs for type 2 diabetes in many countries. In spite of their diverse chemical structures, no comparative studies of their binding modes in the active site of DPP-4 have been disclosed. We determined the co-crystal structure of vildagliptin with DPP-4 by X-ray crystallography and compared the binding modes of six launched inhibitors in DPP-4. The inhibitors were categorized into three classes on the basis of their binding subsites: (i) vildagliptin and saxagliptin (Class 1) form interactions with the core S1 and S2 subsites and a covalent bond with Ser630 in the catalytic triad; (ii) alogliptin and linagliptin (Class 2) form interactions with the S1' and/or S2' subsites in addition to the S1 and S2 subsites; and (iii) sitagliptin and teneligliptin (Class 3) form interactions with the S1, S2 and S2 extensive subsites. The present study revealed that the additional interactions with the S1', S2' or S2 extensive subsite may increase DPP-4 inhibition beyond the level afforded by the fundamental interactions with the S1 and S2 subsites and are more effective than forming a covalent bond with Ser630. The pharmacologic management of type 2 diabetes has changed dramatically in the past two decades. We have moved from a situation of only having two choices, insulin and sulfonylureas, to a position of myriad choices from 11 categories of medications (insulin, sulfonylureas, biguanides, α-glucosidase inhibitors, gliptins (dipeptidyl peptidase 4 [DPP IV] inhibitors), bromocriptine, glucagon-like peptide analogues, thiazolidinediones, glinides, amylin analogues and bile acid sequestrants. One of the most recent additions to this list are the DPP IV inhibitors commonly known as gliptins. Currently, there are four DPP IV inhibitors available in various countries-alogliptin, sitagliptin, vildagliptin and saxagliptin (1). Of these, two have been approved for clinical use in the United States: sitagliptin and saxagliptin. Additionally, linagliptin, vildagliptin and alogliptin are currently in phase III development in the United States while studies with another DPP IV inhibitor, dutogliptin, have been terminated (2). Alogliptin was approved for use in Japan under the trade name Nesina® in April 2010 (3). This manuscript will review alogliptin, its chemistry, pharmacokinetics/pharmacodynamics, drug interactions, clinical trials and its current state of FDA review. Preclinical animal data have been reviewed elsewhere and will not be outlined in this manuscript. The interested reader is referred to those recent reviews (4, 5). AIM: We assessed the efficacy of dipeptidyl peptidase-4 (DPP-4) inhibitors vildagliptin, sitagliptin, saxagliptin and alogliptin to reach the haemoglobin HbA1c target of <7% in people with type 2 diabetes. METHODS: We conducted an electronic search for randomized controlled trials (RCTs) involving DPP-4 inhibitors through September 2010. RCTs were included if they lasted at least 12 weeks, included 30 patients or more and reported the proportion of patients reaching the HbA1c target of <7%. RESULTS: A total of 43 RCTs reporting 52 comparisons met the selection criteria, which included 19 101 study participants evaluated for the primary endpoint, 10 467 treated with a DPP-4 inhibitor and 8634 treated with placebo or a comparator drug. DPP-4 inhibitors showed a statistically significant reduction in HbA1c compared to placebo and approximately 40% of participants achieved the HbA1c goal of <7%: this was associated with weight neutrality and no greater hypoglycaemia. The reduction of the HbA1c level and the rate of HbA1c goal attainment was not different from comparator drugs, with similar hypoglycaemia, and different effect on weight owing to the nature of comparator (metformin, sulfonylurea or glitazones). Baseline HbA1c was the best predictor for achievement of A1C target (overall weighted r(2) value = 0.410, p < 0.001). CONCLUSIONS: A greater proportion of type 2 diabetic patients can achieve the HbA1c goal <7% with DPP-4 inhibitors compared to placebo, with no weight gain, and no hypoglycaemic risk when used alone; DPP-4 inhibitors were not different from comparator drugs. BACKGROUND: Meta-analyses of randomized clinical trials have reported that dipeptidyl peptidase IV (DPP-4) inhibitors are well tolerated and that the incidence of hypoglycemia with the use of DPP-4 inhibitors is similar to that observed with placebos. However, in general, provider-oriented methods using medical record reviews offer lower rates of non-serious, symptomatic adverse drug reactions (ADRs) than patient-oriented methods. Moreover, severe hypoglycemia occurred in three clinical trials using sitagliptin, but in two of these trials this phenomenon has been previously described only in the drug application data in the US. OBJECTIVE: The aim of this study was to assess the profile of patient-reported symptomatic ADRs under DPP-4 inhibitor therapy and to detect risk factors for hypoglycemic and non-hypoglycemic adverse symptoms in daily clinical practice. METHODS: We analyzed a subpopulation of participants in the Drug Event Monitoring (DEM) project of the Japan Pharmaceutical Association. An anonymous survey was conducted in February 2012 to assess the self-perception of adverse symptoms during a median 28 (4-88) days after the last prescription of DPP-4 inhibitors by means of interviews of pharmacists using structured questionnaires. RESULTS: A total of 864 males and 686 females were included. The prescribed DPP-4 inhibitors included sitagliptin (75.4 %), alogliptin (15.5 %), vildagliptin (8.8 %) and linagliptin (0.3 %). Mild hypoglycemic symptoms were reported by 34 individuals (2.2 %) receiving monotherapy of sitagliptin (10/402) or alogliptin (3/65), or combination therapy of sitagliptin (15/767) or alogliptin (6/176) with other hypoglycemic agents. In the multiple regression model, hypoglycemic symptoms were found to be significantly associated with liver disease, female sex and alcohol consumption more than three times per week. Non-hypoglycemic symptoms were reported by 57 individuals (3.7 %), the most common symptoms of which were gastrointestinal symptoms (2.1 %). Combination therapy was only found to be associated with nonhypoglycemic symptoms. CONCLUSIONS: The present study suggested that hypoglycemic symptoms under therapy with sitagliptin or alogliptin may be associated with liver disease, female sex and alcohol consumption, all of which are potentially capable of leading to poor gluconeogenesis because they decrease the counter-regulatory hormonal responses to hypoglycemia. Dipeptidyl peptidase-4 (DPP-4) inhibitors collectively comprise a presently unique form of disease management for persons with type 2 diabetes mellitus. The aim of this review is to compare the clinical pharmacokinetics of available DPP-4 inhibitors (alogliptin, linagliptin, saxagliptin, sitagliptin and vildagliptin) for the purpose of identifying potential selection preferences according to individual patient variables and co-morbidities. DPP-4 inhibitors are readily absorbed orally. Following oral ingestion, absorption occurs mainly in the small intestine, with median times to maximum (peak) plasma concentration ranging from 1 to 3 hours. The fraction of each dose absorbed ranges from approximately 30% with linagliptin to 75-87% for all others. Numerical differences in maximum (peak) plasma drug concentrations and areas under the plasma concentration-time curve among the DPP-4 inhibitors vary by an order of magnitude. However, functional capacity measured in terms of glucose-lowering ability remains comparable among all available DPP-4 inhibitors. Distribution of DPP-4 inhibitors is strongly influenced by both lipophilicity and protein binding. Apparent volumes of distribution (V(d)) for most agents range from 70 to 300 L. Linagliptin exhibits a V(d) of more than 1000 L, indicating widespread distribution into tissues. Binding to target proteins in plasma and peripheral tissues exerts a major influence upon broadening linagliptin distribution. DPP-4 inhibitor metabolism is widely variable, with reported terminal half-lives ranging from approximately 3 to more than 200 hours. Complex relationships between rates of receptor binding and dissociation appear to strongly influence the durations of action of those DPP-4 inhibitors with comparatively shorter half-lives. Durations of activity often are not reflective of clearance and, with the exception of vildagliptin which may be administered either once daily in the evening or twice daily, these medications are effective when used with a once-daily dosing schedule. Saxagliptin and, to a lesser extent, sitagliptin are largely metabolized by hepatic cytochrome P450 (CYP) 3A4 and 3A5 isoforms. With the exception of the primary hydroxylated metabolite of saxagliptin, which is 2-fold less potent than its parent molecule, metabolic products of hepatic biotransformation are minimally active and none appreciably contribute to either the therapeutic or the toxic effects of DPP-4 inhibitors. No DPP-4 inhibitor has been shown to inhibit or to induce hepatic CYP-mediated drug metabolism. Accordingly, the number of clinically significant drug-drug interactions associated with these agents is minimal, with only saxagliptin necessitating dose adjustment if administered concurrently with medications that strongly inhibit CYP3A4. Linagliptin undergoes enterohepatic cycling with a large majority (85%) of the absorbed dose eliminated in faeces via biliary excretion. Other DPP-4 inhibitors predominantly undergo renal excretion, with 60-85% of each dose eliminated as unchanged parent compound in the urine. Systematic reviews of clinical trials suggest that the overall efficacy of DPP-4 inhibitors in patients with type 2 diabetes generally is similar. Apart from these generalizations, pharmacokinetic distinctions that potentially influence product selection are tentative. When considered in total, data reviewed in this report suggest that the best overall balance between potency and the clinical pharmacokinetic characteristics of distribution, metabolism and elimination may be observed with linagliptin followed closely by vildagliptin, saxagliptin, sitagliptin and alogliptin. Dipeptidyl peptidase -4 inhibitors represent a novel way to augment the incretin system and one of the newest class of medications in the treatment of type 2 diabetes mellitus. Their mechanism of action is to decrease the inactivation of glucagon-like peptide 1 and glucose-dependent insulinotropic polypeptide, both of which are involved in maintaining euglycemia subsequent to carbohydrate intake. Currently investigated agents include sitagliptin, vildagliptin, saxagliptin, linagliptin, and alogliptin. Each agent has been shown to provide significant improvements in glycemic control compared to placebo. They are effective when added to other oral diabetes agents and in the cases of sitagliptin, vildagliptin, and alogliptin in addition to insulin. These agents may not provide as significant improvement in glucose concentrations as some other medications including metformin, thiazolidinediones, or glucagon-like peptide 1 agonists. The lack of head to head clinical data comparing the various dipeptidyl peptidase 4 inhibitors does not allow for specific recommendations if one agent is more effective or safer than another within the class. Their side effect profile suggests they are very well tolerated and have few drug interactions. For patients with mildly elevated glucose concentrations, they are therapeutic options in both drug-naive patients as well as those not optimally controlled on other diabetes medications. INTRODUCTION: Lipid profile is an important determinant of cardiovascular risk in type 2 diabetic patients. Available glucose-lowering agents can affect lipid levels. Dipeptidyl peptidase-4 (DPP-4) inhibitors have been reported to reduce total cholesterol, but results are inconsistent across trials. The present metaanalysis was designed to assess the effect of DPP-4 inhibitors on blood lipids, verifying possible differences across compounds of this class. METHODS: An extensive search of Medline and the Cochrane Library (any date up to December 31, 2010, restricted to randomized clinical trials, published in English) was performed for all trials containing, in any field, the words "sitagliptin," "vildagliptin," "saxagliptin," "alogliptin," "linagliptin," and/or "dutogliptin." Completed but unpublished trials were identified through a search of the ClinicalTrials.gov website, using the same keywords as above. Differences in the endpoint levels and absolute or percent variations of lipids were assessed. A metaregression was performed on the trials specified above to assess the effect of putative moderators on the effect of DPP-4 inhibitors on plasma lipids, considering all drugs together and each one separately. RESULTS: Although the number of trials of appropriate size and duration was high (n=53), only a small fraction of those (n=17) reported data on endpoint total, high-density lipoprotein, and low-density lipoprotein cholesterol, and triglyceride. The difference-in-means for endpoint versus baseline total cholesterol in patients on DPP-4 inhibitors treatment was significantly higher in comparison with controls, meaning that treatment with DPP-4 inhibitors is associated with a significant reduction in total cholesterol (-0.18 [-0.29; -0.06] mmol/L (-7.0 [-11.2; -2.50] mg/dL); P=0.002). CONCLUSIONS: This meta-analysis suggests a possible beneficial effect of DPP-4 inhibitors on cholesterol, which, although small, could contribute to the reduction of cardiovascular risk. There are many advantages of combining incretin therapy [glucagon-like peptide-1 (GLP-1) receptor agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors] with insulin therapy as a glucose-lowering strategy in type 2 diabetes. One important advantage is the complementary mode of the mechanistic action of incretin and insulin therapy. Another advantage is the reduction in risk of hypoglycemia and weight gain when adding incretin therapy to insulin. Several clinical trials have studied the addition of GLP-1 receptor agonists [exenatide BID (twice daily), lixisenatide, albiglutide] or DPP-4 inhibitors (vildagliptin, sitagliptin, saxagliptin, alogliptin, linagliptin) to ongoing insulin therapy or adding insulin to ongoing therapy with a GLP-1 receptor agonist (liraglutide). These studies show improved glycemia in the presence of limited risk for hypoglycemia and weight gain with the combination of incretin therapy with insulin. This article reviews the background and clinical studies on this combination. BI 1356 [proposed trade name ONDERO; (R)-8-(3-amino-piperidin-1-yl)-7-but-2-ynyl-3-methyl-1-(4-methyl-quinazolin-2-ylmethyl)-3,7-dihydro-purine-2,6-dione] is a novel dipeptidyl peptidase (DPP)-4 inhibitor under clinical development for the treatment of type 2 diabetes. In this study, we investigated the potency, selectivity, mechanism, and duration of action of BI 1356 in vitro and in vivo and compared it with other DPP-4 inhibitors. BI 1356 inhibited DPP-4 activity in vitro with an IC(50) of approximately 1 nM, compared with sitagliptin (19 nM), alogliptin (24 nM), saxagliptin (50 nM), and vildagliptin (62 nM). BI 1356 was a competitive inhibitor, with a K(i) of 1 nM. The calculated k(off) rate for BI 1356 was 3.0 x 10(-5)/s (versus 2.1 x 10(-4)/s for vildagliptin). BI 1356 was >/=10,000-fold more selective for DPP-4 than DPP-8, DPP-9, amino-peptidases N and P, prolyloligopeptidase, trypsin, plasmin, and thrombin and was 90-fold more selective than for fibroblast activation protein in vitro. In HanWistar rats, the DPP-4 inhibition 24 h after administration of BI 1356 was more profound than with any of the other DPP-4 inhibitors. In C57BL/6J mice and Zucker fatty (fa/fa) rats, the duration of action on glucose tolerance decreased in the order BI 1356 > (sitagliptin/saxagliptin) > vildagliptin. These effects were mediated through control of glucagon-like peptide-1 and insulin. In conclusion, BI 1356 inhibited DPP-4 more effectively than vildagliptin, sitagliptin, saxagliptin, and alogliptin and has the potential to become the first truly once-a-day DPP-4 inhibitor for the treatment of type 2 diabetes. Three-dimensional pharmacophore hypothesis was established based on a set of known DPP-IV inhibitor using PharmaGist software program understanding the essential structural features for DPP-IV inhibitor. The various marketed or under developmental status, potential gliptins have been opted to build a pharmacophore model, e.g. Sitagliptin (MK- 0431), Saxagliptin, Melogliptin, Linagliptin (BI-1356), Dutogliptin, Carmegliptin, Alogliptin and Vildagliptin (LAF237). PharmaGist web based program is employed for pharmacophore development. Four points pharmacophore with the hydrogen bond acceptor (A), hydrophobic group (H), Spatial Features and aromatic rings (R) have been considered to develop pharmacophoric features by PharmaGist program. The best pharmacophore model bearing the Score 16.971, has been opted to screen on ZincPharmer database to derive the novel potential anti-diabetic ligands. The best pharmacophore bear various Pharmacophore features, including General Features 3, Spatial Features 1, Aromatic 1 and Acceptors 2. The PharmaGist employed algorithm to identify the best pharmacophores by computing multiple flexible alignments between the input ligands. The multiple alignments are generated by combining alignments pair-wise between one of the gliptin input ligands, which acts as pivot and the other gliptin as ligand. The resulting multiple alignments reveal spatial arrangements of consensus features shared by different subsets of input ligands. The best pharmacophore model has been derived using both pair-wise and multiple alignment methods, which have been weighted in Pharmacophore Generation process. The highest-scoring pharmacophore model has been selected as potential pharmacophore model. In conclusion, 3D structure search has been performed on the "ZincPharmer Database" to identify potential compounds that have been matched with the proposed pharmacophoric features. The 3D ZincPharmer Database has been matched with various thousands of Ligands hits. Those matches were screened through the RMSD and max hits per molecule. The physicochemical properties of various "ZincPharmer Database" screened ligands have been calculated by PaDELDescriptor software. The all "ZincPharmer Database" screened ligands have been filtered based on the Lipinski's rule-of-five criteria (i.e. Molecular Weight < 500, H-bond acceptor ≤ 10, H-bond donor ≤ 5, Log P ≤ 5) and were subjected to molecular docking studies to get the potential antidiabetic ligands. We have found various substituted as potential antidiabetic ligands, which can be used for further development of antidiabetic agents. In the present research work, we have covered rational of DPP-IV inhibitor based on Ligand-Based Pharmacophore detection, which is validated via the Docking interaction studies as well as Maximal Common Substructure (MCS). Inhibitors of dipeptidylpeptidase IV (DPP-IV) represent a novel class of frequently used anti-diabetic drugs. In addition to its function in metabolic regulation, DPP-IV also plays a role in the immune system. Whether the DPP-IV inhibitors sitagliptin, vildagliptin or saxagliptin impair immune responses is, however, currently unknown. Here, we investigated the effect of these agents on both innate and adaptive immunity. We found that the DPP-IV inhibitors did not affect the innate immune response induced by Toll-like receptor (TLR) ligands, as cytokine secretion and induction of co-stimulatory molecules by human blood mononuclear cells was not impaired. Furthermore, proliferation of T cells and suppressive function of regulatory T cells was preserved. Mice treated with vildagliptin showed normal cytokine production, immune cell activation and lymphocyte trafficking upon TLR activation. Thus, crucial immunological parameters remain unaffected upon treatment with DPP-IV inhibitors, a fact that is reassuring with respect to safety of these drugs. BACKGROUND: An up-to-date assessment of dipeptidyl peptidase-4 (DPP-4) inhibitors is needed to include newly available data. OBJECTIVE: To assess the efficacy and safety of DPP-4 inhibitors, including sitagliptin, saxagliptin, vildagliptin, and linagliptin, in type 2 diabetes. METHODS: We conducted a search of MEDLINE for randomized controlled trials (RCTs) of DPP-4 inhibitors in type 2 diabetes through November 2011, using the key terms sitagliptin, saxagliptin, vildagliptin, and linagliptin. We also searched for completed, but unpublished, trials at relevant web sites. RCTs were selected for meta-analysis if they (1) compared DPP-4 inhibitors with placebo or an antihyperglycemic agent; (2) had study duration of 12 or more weeks; (3) had 1 or more baseline and posttreatment efficacy and/or safety outcome; and (4) were published in English. RESULTS: In 62 evaluated articles, DPP-4 inhibitors lowered hemoglobin A(1c) (A1C) significantly more than placebo (weighted mean difference [WMD] -0.76%; 95% CI -0.83 to -0.68); however, heterogeneity was substantial (I(2) = 82%). Exclusion of Japanese trials (n = 7) resulted in a reduction of heterogeneity (I(2) = 59%). In the non-Japanese RCTs (n = 55), DPP-4 inhibitors were associated with a reduction in A1C (WMD -0.65%; 95% CI -0.71 to -0.60) but higher risk of hypoglycemia (odds ratio [OR] 1.30; 95% CI 1.00 to 1.68) compared to placebo. The 7 Japanese-specific RCTs showed a greater reduction in A1C (WMD -1.67%; 95% CI -1.89 to -1.44) and a nonsignificant increase in risk of hypoglycemia (OR 1.41; 95% CI 0.51 to 3.88) with DPP-4 inhibitors versus placebo. When comparing DPP-4 inhibitors to active comparators, the I(2) was still high after deleting Japanese studies. In these 17 active comparator trials, there was no significant difference in A1C reduction (WMD 0.04%; 95% CI -0.09 to 0.16) or risk of hypoglycemia (OR 0.60; 95% CI 0.22 to 1.61) for DPP-4 inhibitors compared to other antihyperglycemics. There were similar odds of any or serious adverse events with DPP-4 inhibitors compared to placebo, but a decreased risk compared to other antihyperglycemics. CONCLUSIONS: DPP-4 inhibitors were associated with a reduction in A1C with comparable safety profiles compared to placebo, but no significant difference in A1C compared to other hyperglycemics. Differences in efficacy and safety were observed between Japanese and non-Japanese patients. OBJECTIVE: Dipeptidyl peptidase-4 inhibitors (DPP4i) have been recently associated with increased risk of pancreatitis and cancer. The aim of the present meta-analysis of randomized clinical trials is the assessment of the effect of DPP4i on the incidence of major cardiovascular events (MACE), cancer, and pancreatitis. RESEARCH DESIGN AND METHODS: An extensive Medline and Embase search for 'vildagliptin', 'sitagliptin', 'saxagliptin', 'alogliptin', 'linagliptin', and 'dutogliptin' was performed, collecting all randomized clinical trials on humans up to March 1, 2011. The present meta-analysis was therefore performed including all randomized clinical trials with a duration of at least 24 weeks, enrolling patients with type 2 diabetes, comparing DPP4i with either placebo or active drugs. Completed but still unpublished trials were identified through a search of www.clinicaltrials.gov, Food and Drug Administration, and European Medicines Agency website. RESULTS: Fifty-three trials enrolling 20,312 and 13,569 patients for DPP4i and comparators, respectively, were included, reporting 176 malignancies, 257 MACE, and 22 pancreatitis. DPP4i, compared with placebo or other treatment, were associated with a similar risk of cancer (MH-OR 1.020 [0.742-1.402]; p = 0.90) and pancreatitis (0.786 [0.357-1.734], p = 0.55), and with a reduced risk of MACE (MH-OR 0.689 [0.528-0.899], p = 0.006). CONCLUSIONS: The present meta-analysis seems to exclude any relevant short term effect of DPP4i on the incidence of cancer and suggest a possible protection from cardiovascular events. This result should be interpreted with caution, as those events were not the principal endpoint, the trial duration was short, and the characteristics of patients included could be different from routine clinical practice. Dipeptidyl peptidase-4 (DPP-4) inhibition is a well- characterized treatment for type 2 diabetes mellitus (T2DM). The objective of this model-based meta-analysis was to describe the time course of HbA1c response after dosing with alogliptin (ALOG), saxagliptin (SAXA), sitagliptin (SITA), or vildagliptin (VILD). Publicly available data involving late-stage or marketed DPP-4 inhibitors were leveraged for the analysis. Nonlinear mixed-effects modeling was performed to describe the relationship between DPP-4 inhibition and mean response over time. Plots of the relationship between metrics of DPP-4 inhibition (ie, weighted average inhibition [WAI], time above 80% inhibition, and trough inhibition) and response after 12 weeks of daily dosing were evaluated. The WAI was most closely related to outcome, although other metrics performed well. A model was constructed that included fixed effects for placebo and drug and random effects for intertrial variability and residual error. The relationship between WAI and outcome was nonlinear, with an increasing response up to 98% WAI. Response to DPP-4 inhibitors could be described with a single drug effect. The WAI appears to be a useful index of DPP-4 inhibition related to HbA1c. Biomarker to response relationships informed by model-based meta-analysis can be leveraged to support study designs including optimization of dose, duration of therapy, and patient population. BACKGROUND & AIMS: Recently, the SAVOR TIMI-53 (Saxagliptin Assessment of Vascular Outcomes Recorded in patients with diabetes mellitus--Thrombolysis in Myocardial Infarction-53) reported a significant increase in the risk of hospitalizations for heart failure in patients treated with saxagliptin in comparison with placebo. Aim of the present meta-analysis is the systematic collection and synthesis of information on treatment-emergent cases of acute heart failure described in randomized clinical trials with DPP4. DATA SOURCES: An extensive Medline, Embase, and Cochrane Database search for "vildagliptin", "sitagliptin", "saxagliptin", "alogliptin", "linagliptin", and "dutogliptin" was performed, collecting all randomized clinical trials on humans up to October 1st, 2013. Studies were included if they satisfied the following criteria: i) randomized trials, ii) duration ≥24 weeks; iii) on type 2 diabetes; iv) comparison of DPP4i with placebo or active drugs. The principal outcome was the effect of DPP4i on the incidence of acute heart failure. A total of 84 eligible trials was identified. The overall risk of acute heart failure was higher in patients treated with DPP4i in comparison with those treated with placebo/active comparators (MH-OR: 1.19[1.03; 1.37]; p = 0.015). When trials with non-cardiovascular outcomes were analysed separately no signal of risk was detectable. CONCLUSION: Available data from RCTs suggest that DPP4i could be associated with an increased risk of heart failure, without any clear evidence of differences among drugs of the class. Although it is plausible that the risk is greater in some sub-populations of patients, current evidence is not yet sufficient to identify susceptible patients. Vildagliptin is a dipeptidyl peptidase-4 (DPP-4) inhibitor that is being evaluated in the treatment of patients with type 2 diabetes mellitus. It improves glycaemic control by inhibiting DPP-4 from inactivating the incretin hormones glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide, prolonging incretin activity in response to ingestion of nutrients. This allows for increased insulin sensitivity, decreased glucagon secretion and improved beta-cell function in a glucose-dependent manner. Glycaemic control with vildagliptin 50 or 100 mg/day, measured by a change from baseline in mean glycosylated haemoglobin (HbA(1c)) at study endpoint, was improved relative to placebo in several well designed clinical trials of vildagliptin monotherapy in patients with type 2 diabetes. In randomised active comparator studies, noninferiority of vildagliptin in reducing HbA(1c) levels from baseline was established to rosiglitazone, but not to metformin. Vildagliptin also showed efficacy in reducing HbA(1c) levels in patients with type 2 diabetes when used in combination with metformin, pioglitazone or insulin. Vildagliptin was generally well tolerated when administered alone or in combination with additional antidiabetic treatment. Gastrointestinal adverse events were mild to moderate in intensity, and occurred less frequently than with metformin. Hypoglycaemic events were rare and occurred at a similar incidence to that with placebo. OBJECTIVE: To investigate the long-term safety and efficacy of empagliflozin, a sodium glucose cotransporter 2 inhibitor; sitagliptin; and metformin in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: In this randomized, open-label, 78-week extension study of two 12-week, blinded, dose-finding studies of empagliflozin (monotherapy and add-on to metformin) with open-label comparators, 272 patients received 10 mg empagliflozin (166 as add-on to metformin), 275 received 25 mg empagliflozin (166 as add-on to metformin), 56 patients received metformin, and 56 patients received sitagliptin as add-on to metformin. RESULTS: Changes from baseline in HbA1c at week 90 were -0.34 to -0.63% (-3.7 to -6.9 mmol/mol) with empagliflozin, -0.56% (-6.1 mmol/mol) with metformin, and -0.40% (-4.4 mmol/mol) with sitagliptin. Changes from baseline in weight at week 90 were -2.2 to -4.0 kg with empagliflozin, -1.3 kg with metformin, and -0.4 kg with sitagliptin. Adverse events (AEs) were reported in 63.2-74.1% of patients on empagliflozin and 69.6% on metformin or sitagliptin; most AEs were mild or moderate in intensity. Hypoglycemic events were rare in all treatment groups, and none required assistance. AEs consistent with genital infections were reported in 3.0-5.5% of patients on empagliflozin, 1.8% on metformin, and none on sitagliptin. AEs consistent with urinary tract infections were reported in 3.8-12.7% of patients on empagliflozin, 3.6% on metformin, and 12.5% on sitagliptin. CONCLUSIONS: Long-term empagliflozin treatment provided sustained glycemic and weight control and was well tolerated with a low risk of hypoglycemia in patients with type 2 diabetes.

Which is the most important prognosis sub-classification in Chronic Lymphocytic Leukemia?

The mutational status of the immunoglobulin heavy variable (IGHV) genes, defines two subsets: mutated and unmutated CLL. Unmutated CLL patients show a shorter progression-free and overall survival than mutated CLL patients.

[19500131, 17786276, 16014569, 23468975, 16083281, 20353875, 22560084, 16825496, 19127482, 20090781]

In B-cell chronic lymphocytic leukemia (CLL), Rai stage, immunoglobulin gene mutational status, chromosomal abnormalities, CD38 and ZAP-70 expression were used as prognostic markers. In this study, to understand the molecular basis of chromosomal abnormalities leading to tumor progression, 90 CLL patients were grouped into poor prognosis (with 11q deletion and trisomy 12) and good prognosis (with normal karyotype and 13q deletion) and their clinical outcome was assessed. Gene expression profiles of 35 CLL samples with poor outcome (11q deletion, n=9; trisomy 12, n=5) and good outcome (13q deletion, n=13; normal karyotype, n=8) were analyzed using oligonucleotide microarray. Significance analysis of microarray (SAM) identified 27 differentially expressed genes between these two subgroups with significant overexpression of ATF5 and underexpression of CDC16, PCDH8, SLAM, MNDA and ATF2 in CLL patients with poor outcome. ATF5 gene expression in CLL was further studied because of its role in the regulation of cell cycle progression/differentiation and apoptosis. The overexpression of ATF5 was confirmed by real-time PCR using 39 CLL samples from the poor and good outcome groups. ATF5 was significantly (p<0.001) overexpressed in the poor outcome group. Furthermore, ATF5 expression was significantly higher in the 11q deletion as well as trisomy 12 group alone compared to the 13q deletion and normal karyotype groups. ATF5 overexpression was also associated with significantly (p=0.04) shorter time to treatment. Similarly, expression of five underexpressed genes also correlated with longer time to treatment. Thus, this report demonstrates that ATF5 may be one of the key genes involved in increased proliferation and survival in 11q deletion or trisomy 12, whereas CD16, CD86, SLAM, MNDA and ATF2 may be involved in the decreased proliferation of CLL cells with 13q deletion or normal karyotype. The ataxia telangiectasia mutated (ATM) protein is the principal activator of the p53 protein in the response to DNA double-strand breaks. Mutations in the ATM gene have been previously found in B-cell chronic lymphocytic leukemias (B-CLLs) but their clinical significance is unknown. We analyzed 155 CLL tumors and found 12% with ATM mutations and 4% with TP53 mutations; 2 tumors contained mutations in both genes. Retrospective analysis on selected samples indicated that the ATM mutations were usually present at diagnosis. Compared with patients with wild-type ATM/TP53 genes, patients with ATM mutations had statistically significantly reduced overall and treatment-free survival. Although present in both IGVH mutation subgroups, ATM mutations were associated with unmutated IGVH genes and they provided independent prognostic information on multivariate analysis. Mutations in the ATM gene resulted in impaired in vitro DNA damage responses. Tumors with ATM mutations only partially correlated with tumors with loss of an ATM allele through an 11q deletion and, interestingly, those 11q-deleted tumors with a second wild-type ATM allele had a preserved DNA damage response. The majority of patients with ATM mutations were refractory to DNA damaging chemotherapeutic drugs and as such might benefit from therapies that bypass the ATM/p53 pathway. BACKGROUND: Chronic lymphocytic leukemia (CLL) is typically regarded as an indolent B-cell malignancy. However, there is wide variability with regards to need for therapy, time to progressive disease, and treatment response. This clinical variability is due, in part, to biological heterogeneity between individual patients' leukemias. While much has been learned about this biological variation using genomic approaches, it is unclear whether such efforts have sufficiently evaluated biological and clinical heterogeneity in CLL. METHODS: To study the extent of genomic variability in CLL and the biological and clinical attributes of genomic classification in CLL, we evaluated 893 unique CLL samples from fifteen publicly available gene expression profiling datasets. We used unsupervised approaches to divide the data into subgroups, evaluated the biological pathways and genetic aberrations that were associated with the subgroups, and compared prognostic and clinical outcome data between the subgroups. RESULTS: Using an unsupervised approach, we determined that approximately 600 CLL samples are needed to define the spectrum of diversity in CLL genomic expression. We identified seven genomically-defined CLL subgroups that have distinct biological properties, are associated with specific chromosomal deletions and amplifications, and have marked differences in molecular prognostic markers and clinical outcomes. CONCLUSIONS: Our results indicate that investigations focusing on small numbers of patient samples likely provide a biased outlook on CLL biology. These findings may have important implications in identifying patients who should be treated with specific targeted therapies, which could have efficacy against CLL cells that rely on specific biological pathways. Recently developed molecular prognostic tests in patients with early Binet stage chronic lymphocytic leukemia (B-CLL) are costly and often require a high level of technologic expertise. Recent data give evidence for the prognostic relevance of the percentage of smudge cells in B-CLL. In our study we analysed the prognostic potential of this novel marker in a cohort of 100 CLL patients. The percentage of smudge cells ranged from 0% to 70% (median 21%). Patients with <or=20% smudge cells (according to ROC analysis) had a significantly shorter time to first treatment and overall survival than patients with >20% smudge cells. Multivariate Cox regression analysis identified percentages of smudge cells, stage according to Binet and CD38 expression as independent prognostic markers. The percentage of smudge cells was significantly lower in CD38+, ZAP-70+ and unmutated IgVH patients. Combined analysis of smudge cell percentages with CD38 expression provided complementary prognostic information identifying three patient subgroups with good, intermediate and poor prognosis. Comparing gene expression profiles in a subset of 12 patients we identified eight differentially expressed genes in groups with high vs. low percentage of smudge cells suggesting a role of these differentially expressed genes, especially for Tribbles homolog 2 (Trib2), in the disease progression of high risk CLL patients. In conclusion, our data confirm previous studies showing that the simple and inexpensive microscopic detection of smudge cells on blood smears prepared for routine diagnostic purposes is a novel independent factor predicting overall survival in CLL. The mutational status and configuration of immunoglobulin heavy variable (IGHV) gene rearrangements was analyzed in 85 Serbian patients with chronic lymphocytic leukemia (CLL). We found that 55.3% of cases belonged to mutated and 44.7% to unmutated CLL, progressive disease predominating in the unmutated subset. IGHV gene use resembled that obtained for Mediterranean countries, except for underrepresentation of the IGHV4 subgroup in our cohort. BACKGROUND: Chronic lymphocytic leukemia (CLL) results from the clonal expansion of mature B lymphocytes and is characterized by extreme clinical heterogeneity. One of the most reliable prognostic markers in chronic lymphocytic leukemia (CLL) is the mutational status of immunoglobulin heavy variable (IGHV) genes, which defines 2 subsets, mutated CLL (M-CLL) and unmutated CLL (U-CLL), with different clinical courses. Biased IGHV gene use between M-CLL and U-CLL clones, as well as population differences in the IGHV gene repertoire have been reported. PATIENTS AND METHODS: In this study, mutational status and configuration of IGHV-IGHD-IGHJ rearrangements in 85 Serbian patients were analyzed using reverse transcriptase-polymerase chain reaction (RT-PCR) and sequencing methodology. RESULTS: We found that 55.3% of cases belonged to M-CLL and 44.7% belonged to U-CLL, with progressive disease predominating in the unmutated subset. Most frequently expressed was the IGHV3 subgroup (55.7%), followed by IGHV1 (27.3%), IGHV4 (12.5%), IGHV5 (2.3%), IGHV2 (1.1%), and IGHV6 (1.1%). The distribution of IGHD subgroups was as follows: IGHD3, 39.1%; IGHD2, 21.8%; IGHD6, 12.6%; IGHD1, 10.3%; IGHD4, 8%; IGHD5, 6.9%; and IGHD7, 1.1%. The most frequent IGHJ gene was IGHJ4 (48.9%), followed by IGHJ6 (28.4%), IGHJ3 (11.4%), and IGHJ5 (11.4%). In 15.3% of cases, heavy complementarity-determining region 3 (VH CDR3) amino acid sequences could be assigned to previously defined stereotyped clusters. CONCLUSIONS: Our study showed a strong correlation between IGHV gene mutational status and clinical course of CLL. IGHV gene use was comparable to that obtained for Mediterranean countries, with the exception of the IGHV4 subgroup, which was underrepresented in our cohort. CD38 expression of tumor cells has been identified as an important prognostic factor in B-cell chronic lymphocytic leukemia (B-CLL). Although CD38 is involved in effector functions of T cells, the prognostic value of CD38+ T cells has not yet been addressed in B-CLL. In the present study, CD38-expression levels in B-CLL cells and T cells from 204 patients were analyzed by flow cytometry and correlated with clinical and molecular risk parameters. CD38 expression significantly differed in the neoplastic clone from patients with low versus advanced stage, irrespective of the sex of patients. In contrast, CD38 expression was generally higher in T cells from female compared with male patients but only increased in male patients in a stage-dependent manner. In male patients, combined analysis of CD38 in T cells and B-CLL cells identified 4 subgroups with significantly different treatment-free survival. Multivariate analysis including Rai stage and molecular risk parameters of the neoplastic clone identified CD38-expression levels in T cells as an independent prognostic factor in male patients. Combined analysis of CD38 in B-CLL and T cells is superior in predicting outcome of male B-CLL patients than either parameter alone. Further studies are needed to elucidate the underlying mechanisms of the sex-specific role of CD38+ T cells in B-CLL. Chronic lymphocytic leukaemia (CLL) is a heterogeneous disease exhibiting variable clinical course and survival rates. Mutational status of the immunoglobulin heavy chain variable regions (IGHVs) of CLL cells offers useful prognostic information for high-risk patients, but time and economical costs originally prevented it from being routinely used in a clinical setting. Instead, alternative markers of IGHV status, such as zeta-associated protein (ZAP70) or messenger RNA levels are often used. We report a (1)H-NMR-based metabolomics approach to examine serum metabolic profiles of early stage, untreated CLL patients (Binet stage A) classified on the basis of IGHV mutational status or ZAP70. Metabolic profiles of CLL patients (n=29) exhibited higher concentrations of pyruvate and glutamate and decreased concentrations of isoleucine compared with controls (n=9). Differences in metabolic profiles between unmutated (UM-IGHV; n=10) and mutated IGHV (M-IGHV; n=19) patients were determined using partial least square discriminatory analysis (PLS-DA; R(2)=0.74, Q(2)=0.36). The UM-IGHV patients had elevated levels of cholesterol, lactate, uridine and fumarate, and decreased levels of pyridoxine, glycerol, 3-hydroxybutyrate and methionine concentrations. The PLS-DA models derived from ZAP70 classifications showed comparatively poor goodness-of-fit values, suggesting that IGHV mutational status correlates better with disease-related metabolic profiles. Our results highlight the usefulness of (1)H-NMR-based metabolomics as a potential non-invasive prognostic tool for identifying CLL disease-state biomarkers.

Is MammaPrint cleared by the United States Food and Drug Administration?

Yes. MammaPrint is cleared by the FDA for breast cancer recurrence.

[21479927, 18786252, 19506735]

BACKGROUND: Numerous studies have used microarrays to identify gene signatures for predicting cancer patient clinical outcome and responses to chemotherapy. However, the potential impact of gene expression profiling in cancer diagnosis, prognosis and development of personalized treatment may not be fully exploited due to the lack of consensus gene signatures and poor understanding of the underlying molecular mechanisms. METHODS: We developed a novel approach to derive gene signatures for breast cancer prognosis in the context of known biological pathways. Using unsupervised methods, cancer patients were separated into distinct groups based on gene expression patterns in one of the following pathways: apoptosis, cell cycle, angiogenesis, metastasis, p53, DNA repair, and several receptor-mediated signaling pathways including chemokines, EGF, FGF, HIF, MAP kinase, JAK and NF-kappaB. The survival probabilities were then compared between the patient groups to determine if differential gene expression in a specific pathway is correlated with differential survival. RESULTS: Our results revealed expression of cell cycle genes is strongly predictive of breast cancer outcomes. We further confirmed this observation by building a cell cycle gene signature model using supervised methods. Validated in multiple independent datasets, the cell cycle gene signature is a more accurate predictor for breast cancer clinical outcome than the previously identified Amsterdam 70-gene signature that has been developed into a FDA approved clinical test MammaPrint. CONCLUSION: Taken together, the gene expression signature model we developed from well defined pathways is not only a consistently powerful prognosticator but also mechanistically linked to cancer biology. Our approach provides an alternative to the current methodology of identifying gene expression markers for cancer prognosis and drug responses using the whole genome gene expression data.

Is amantadine effective for treatment of disorders conciousness?

Amantadine, a dopaminergic agent, has been shown to be effective for induction of recovery from disorders of consciousness. Amantadine is a commonly prescribed medication for patients with prolonged disorders of consciousness after traumatic brain injury. Amantadine accelerates the pace of functional recovery during active treatment in patients with post-traumatic disorders of consciousness. Higher dosing of amantadine may be considered in the setting of brain injury.

[24025056, 24025057, 19404190, 22375973, 15825541, 20129511, 20658796, 18540467, 20460949, 19894299, 15759228, 24025054]

Oxygen based neurotransmitters in the synapses of the brain are proposed to play an important role in the generation of consciousness. They include the amino acids glutamate and GABA which use Krebs cycle precursors for their synthesis, and the monoamines dopamine, noradrenalin, adrenalin and serotonin, which are derived from tyrosine and tryptophan. During ischemia after an acute brain injury, a GABA surge often initiates brain suppression. It has been proposed that with chronic ischemia, a secondary, possibly epigenetic response occurs when neurotransmitters deplete, a glucose and oxygen saving mechanism termed neurodormancy that may invoke alternative long term low energy metabolic pathways in the brain, encountered in Disorders of Consciousness. Some medications can reverse Disorders of Consciousness in some patients. Virtually all of them act on neurotransmitter systems that use oxygen as a building block or as an energy source within the brain. Pharmaceuticals that act in the oxygen based amino acid systems of the brain include the GABAergic medications zolpidem and baclofen, while those that act in the monoamine axes include the dopaminergic medications L Dopa, amantadine, bromocriptine, apomorphine and methylphenidate, and the noradrenergic and serotonergic medications desipramine, amitriptyline, protriptyline and fluoxetine. Another group are the cholinesterase inhibitors, responsible for increasing acetylcholine, which is synthesized from the Krebs cycle initiator, acetyl CoA. It appears that pharmaceuticals that are active in the oxygen based neurotransmitter pathways of the brain are successful to arouse to consciousness patients that suffer from its disorders. Research needs to be supported as foundation to understand the biochemical mechanisms that are involved in consciousness disorders and to explore further the pharmacological treatment possibilities for these devastating neurological conditions. Survivors of severe brain injuries may end up in a state of 'wakeful unresponsiveness' or in a minimally conscious state. Pharmacological treatments of patients with disorders of consciousness aim to improve arousal levels and recovery of consciousness. We here provide a systematic overview of the therapeutic effects of amantadine, apomorphine and zolpidem in patients recovering from coma. Evidence from clinical trials using these commonly prescribed pharmacological agents suggests positive changes of the patients' neurological status, leading sometimes to dramatic improvements. These findings are discussed in the context of current hypotheses of these agents' therapeutic mechanisms on cerebral function. In order to improve our understanding of the underlying pathophysiological mechanisms of these drugs, we suggest combining sensitive and specific behavioral tools with neuroimaging and electrophysiological measures in large randomized, double-blind, placebo-controlled experimental designs. We conclude that the pharmacokinetics and pharmacodynamics of amantadine, apomorphine and zolpidem need further exploration to determine which treatment would provide a better neurological outcome regarding the patient's etiology, diagnosis, time since injury and overall condition. OBJECTIVE: To conduct a pilot study of amantadine in children with impaired consciousness caused by acquired brain injury, to establish design feasibility, and to assess the effect on level of arousal and consciousness. DESIGN: Randomized, double-blind, placebo-controlled crossover trial. Seven subjects (mean age, 12.7 yrs) with an acquired brain injury (mean duration, 6 wks) were randomized to receive either 3 wks of placebo or amantadine, followed by a 1-wk washout period and then 3 wks of the other agent. Main outcome measures were the Coma/Near-Coma Scale and Coma Recovery Scale-Revised, each done three times per week. Subjective evaluations of change in arousal and consciousness by the parent and physician were done weekly. RESULTS: Five subjects completed the study. There was no significant difference in the slopes of recovery during either arm for the Coma/Near-Coma Scale (P = 0.24) or the Coma Recovery Scale-Revised (P = 0.28), although improvements in consciousness were noted by the physician during weeks when amantadine was given (P = 0.02). CONCLUSIONS: This study suggests that amantadine facilitates recovery of consciousness in pediatric acquired brain injury and provides important information necessary to design future more definitive studies. OBJECTIVE: To evaluate the pharmacokinetics of amantadine in children with impaired consciousness from acquired brain injury. DESIGN: Randomized, double-blind, placebo-controlled, crossover study with sparse sampling for pharmacokinetics. SETTING: Tertiary care pediatric hospital. PARTICIPANTS: Children, ages 6-18 years, with impaired consciousness 5-10 weeks after acquired brain injury. METHODS: Subjects received amantadine for 3 weeks. Subjects were randomized to placebo or amantadine 4 mg/kg/day for 7 days followed by 6 mg/kg/day for 14 days. Crossover was after a 7-day washout period. MAIN OUTCOME MEASURES: The Coma/Near-Coma Scale and Coma Recovery Scale-Revised were done 3 times per week to evaluate arousal and consciousness. Plasma concentrations of amantadine were determined for pharmacokinetic parameter estimation and evaluation of the exposure-response relationship. Adverse events were monitored. RESULTS: Nine subjects met the final inclusion and exclusion criteria, 7 of whom agreed to participate. Five subjects completed both arms of the study. Amantadine total body clearance was 0.17 L/h/kg with a half-life of 13.9 hours. Higher exposure of amantadine (average concentration of amantadine during 6 mg/kg/day > 1.5 mg/L) may be associated with better recovery of consciousness. CONCLUSIONS: Amantadine was well-tolerated in children with acquired brain injury and demonstrates pharmacokinetics similar to those reported for healthy young adults. Based on the preliminary data, higher dosing may be considered in the setting of brain injury. Disorders of consciousness (DOC) include coma, vegetative state (VS) and minimally conscious state (MCS). Coma is a condition of unarousability with a complete absence of wakefulness and awareness, whereas VS is characterized by a lack of awareness despite a preserved wakefulness. Patients in coma are unconscious because they lack both wakefulness and awareness. Patients in a VS are unconscious because, although they are wakeful, they lack awareness. Patients in a MCS show minimal but definite behavioural evidence of self and environmental awareness. Coma results from diffuse bilateral hemispheric lesions or selective damage to the ascending reticular system (which is functionally connected to the cerebral cortex by intralaminar thalamic nuclei). VS is a syndrome that is considered to be the result of a disconnection of different cortical networks rather than a dysfunction of a single area or a global reduction in cortical metabolism. As revealed by functional imaging studies, clinical recovery is often associated with a functional restoration of cortico-thalamo-cortical connections. Depending on the amount of network restored, patients may regain full consciousness or remain in a MCS. Molecular and neural mediators may indirectly contribute to the above restoration processes owing to their role in the phenomenon of neural synaptic plasticity. Therefore, there is growing interest in the possible effects of drugs that act at the level of the CNS in promoting emergence from DOC. Sporadic cases of dramatic recovery from DOC after the administration of various pharmacological agents, such as baclofen, zolpidem and amantadine, have been recently supported by intriguing scientific observations. Analysis of the reported cases of recovery, with particular attention paid to the condition of the patients and to the association of their improvement with the start of drug administration, suggests that these treatments might have promoted the clinical improvement of some patients. These drugs are from various and diverging classes, but can be grouped into two main categories, CNS stimulants and CNS depressants. Some of these treatments seem to directly encourage a consciousness restoration, while others play a more determinant role in improving cognitive domains, especially in patients with residual cognitive impairment, than in the field of consciousness. Given the great interest recently generated in the scientific community by the increasing number of papers addressing this issue, further investigation of the above treatments, with particular attention paid to their mechanisms of action, the neurotransmitters involved and their effects on cortico-thalamo-cortical circuitry, is needed. The paper gives the results of the first multicenter study of the efficiency of using amantadine sulfate (PK-Merz) in patients with acute cerebral disease during coma emergence. The study has shown a positive effect of this drug at coma emergence, which manifested itself as clinical improvement and a better outcome of the disease. Full objectivism of the findings requires further studies. BACKGROUND/AIMS: The purpose of the present article is a systematic review of the proposed medical or surgical treatments in patients in chronic vegetative state (VS) or minimally conscious state (MCS), as well as of their mechanisms of action and limitations. METHODS: For this review, we have agreed to include patients in VS or MCS having persisted for over 6 months in posttraumatic cases, and over 3 months in nontraumatic cases, before the time of intervention. Searches were independently conducted by 2 investigators between May 2009 and September 2009 in the following databases: Medline, Web of Science and the Cochrane Library. The electronic search was complemented by cross-checking the references of all relevant articles. Overall, 16 papers were eligible for this systematic review. RESULTS: According to the 16 eligible studies, medical management by dopaminergic agents (levodopa, amantadine), zolpidem and median nerve stimulation, or surgical management by deep brain stimulation, extradural cortical stimulation, spinal cord stimulation and intrathecal baclofen have shown to improve the level of consciousness in certain cases. CONCLUSION: The treatments proposed for disorders of consciousness have not yet gained the level of 'evidence-based treatments'; moreover, the studies to date have led to inconclusiveness. The published therapeutic responses must be substantiated by further clinical studies of sound methodology. OBJECTIVES: To develop predictive models of recovery from the vegetative state (VS) and minimally conscious state (MCS) after traumatic brain injury (TBI) and to gather preliminary evidence on the impact of various psychotropic medications on the recovery process to support future randomized controlled trials. Design Longitudinal observational cohort design, in which demographic information, injury and acute care history, neuroimaging data, and an initial Disability Rating Scale (DRS) score were collected at the time of study enrollment. Weekly follow-up data, consisting of DRS score, current psychoactive medications, and medical complications, were gathered until discharge from inpatient rehabilitation. SETTING: Seven acute inpatient rehabilitation facilities in the United States and Europe with specialized programs for treating patients in the VS and MCS. PARTICIPANTS: People with TBI (N=124) who were in the VS or MCS 4 to 16 weeks after injury. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: DRS score at 16 weeks after injury and time until commands were first followed (among those participants demonstrating no command following at study enrollment). Results DRS score at enrollment, time between injury and enrollment, and rate of DRS change during the first 2 weeks of poststudy observation were all highly predictive of both outcomes. No variables related to injury characteristics or lesions on neuroimaging were significant predictors. Of the psychoactive medications, amantadine hydrochloride was associated with greater recovery and dantrolene sodium was associated with less recovery, in terms of the DRS score at 16 weeks but not the time until commands were followed. More detailed analysis of the timing of functional improvement, with respect to the initiation of amantadine provided suggestive, but not definitive, evidence of the drug's causal role. CONCLUSIONS: These findings show the feasibility of improving outcome prediction from the VS and MCS using readily available clinical variables and provide suggestive evidence for the effects of amantadine and dantrolene, but these results require confirmation through randomized controlled trials. The neurobiological approach to consciousness moves from the assumption that all phenomenal experiences are based on neuronal activity in the brain. Consciousness has two main components: wakefulness and awareness. While it may be relatively easy to determine the neuronal correlates of wakefulness, it is not the same for awareness, of which the neural correlates are poorly understood. Knowledge of the circuitry and the neurochemistry of the sleep/wake condition is necessary but not sufficient to understand the circuitry and neurochemistry of consciousness. Disorders of consciousness (DOCs) include coma, vegetative state and minimally conscious state. The study of DOCs and of the electrophysiological changes underlying general anaesthesia-induced loss of consciousness may help in understanding the neuronal correlates of consciousness. In turn, the understanding of the neural bases of consciousness may help in designing interventions aimed at restoring consciousness in DOC patients. Sporadic cases of recovery from a DOC have been reported after the administration of various pharmacological agents (baclofen, zolpidem, amantadine etc.). This review provides an overview of such drugs, which are from various and diverging classes but can be grouped into two main categories: CNS stimulants and CNS depressants. The available data seem to suggest an awakening effect obtained with CNS depressants rather than stimulants, the latter being more effective at improving functional cognitive and behavioral recovery in patients who have spontaneously regained an appreciable level of consciousness. There is a need for more rigorous systematic trials and further investigation of the above treatments, with particular attention paid to their mechanisms of action and the neurotransmitters involved.

What is needed for MMP proteins to be functional?

Extracellular matrix metalloproteinases (MMPs) are a family of zinc-dependent neutral endopeptidases.

[24570026, 26087627, 23001203, 26150355, 26013370, 25360794, 22257051]

RATIONALE: The structural and functional integrity of the endothelium is crucial in maintaining vascular homeostasis and preventing atherosclerosis. Patients with systemic lupus erythematosus (SLE) have an increased risk of developing endothelial dysfunction and premature cardiovascular disease. Neutrophil extracellular trap (NET) formation is increased in SLE and has been proposed to contribute to endothelial damage, but the mechanism remains unclear. OBJECTIVE: To determine the mechanism by which enhanced NET formation by low-density granulocytes (LDGs) in SLE contributes to endothelial damage and disrupts the endothelium. RESULTS: The putative role of NET-externalised matrix metalloproteinases (MMPs) in altering the functional integrity of the endothelium was examined. MMP-9 externalised by lupus LDGs during NET formation specifically impaired murine aortic endothelium-dependent vasorelaxation and induced endothelial cell apoptosis. Endothelial dysfunction correlated with the activation of endothelial MMP-2 by MMP-9 present in NETs, while inhibition of MMP-2 activation restored endothelium-dependent function and decreased NET-induced vascular cytotoxicity. Moreover, immunogenic complexes composed of MMP-9 and anti-MMP-9 were identified in SLE sera. These complexes, as well as anti-MMP-9 autoantibodies, induced NETosis and enhanced MMP-9 activity. CONCLUSIONS: These observations implicate activation of endothelial MMP-2 by MMP-9 contained in NETs as an important player in endothelial dysfunction, and MMP-9 as a novel self-antigen in SLE. These results further support that aberrant NET formation plays pathogenic roles in SLE. AIM: To study the impact of a polymorphic variant of the matrix metalloproteinase-3 (MMP-3) gene on the development and course of chronic heart failure (CHF) in patients with coronary heart disease. SUBJECTS AND METHODS: A total of 277 patients with New York Heart Association (NYHA) Functional Class (FC) II-IV CHF were examined. MMP-3 -1171 5A/6A genetic polymorphism was studied by polymerase chain reaction. A control group included 136 patients (mean age 53.6 ± 4.8 years) with no signs of cardiovascular diseases, as evidenced by the examination. RESULTS: The frequency of the 5A allele and the 5A/5A genotype of the 1171 5A/6A polymorphic locus in the MMP-3 gene proved to be higher in the patients with CHF than that in the control group. Thus, the variability of the 5A allele (odds ratio (OR), 1.39; 95% confidence interval (CI): 1.033 to 1.869; p = 0.03) and the 5A/5A genotype (OR, 2.15; 95% CI: 1.131 to 4.070; p = 0.02) was associated with increased risk for CHF. There were significant differences in the frequency of MMP-3 alleles and genotypes in relation to FC of CHF. The frequency of the 5A/5A genotype was substantially higher in the patients with NYHA FC IV CHF than that in those with NYHA FC II CHF (32.8% versus 15.2%; p = 0.039). The frequency of the 5A allele was significantly higher in the patients with NYHA FC IV CHF than that in those with NYHA FC II CHF (55.5% and 39.3%; respectively; p = 0.019). Thus, the carriage of the 5A allele and the 5A/5A genotype of the 1171 5A/6A polymorphic locus in the MMP-3 gene is a risk factor of severe CHF. CONCLUSION: The determination of MMP-3 -1171 5A/6A polymorphism may be recommended for the early prediction of a risk for the development and severe course of CHF. Extracellular matrix metalloproteinases (MMPs) are a family of endopeptydases which recquire a zinc ion at their active site, for proteolityc activity. There are six members of the MMP family: matrilysins, collagenases, stromelysins, gelatinases, membrane MMPs and other MMPs. Activity of MMPs is regulated at the level of gene transcription, mRNA stability, zymogene proteolitic activation, inhibition of an active enzyme and MMP degradation. Tissue inhibitors of metalloproteinases (TIMPs) are main intracellular inhibitors of MMPs. Host cells can be stimulated by tumor cells to produce MMPs by secreted interleukins, interferons, growth factors and an extracellular matrix metalloproteinase inducer (EMMPRIN). MMPs are produced by tumor cells, fibroblasts, macrophages, mast cells, polimorphonuclear neutrophiles (PMNs) and endothelial cells (ECs). MMPs affect many stages of tumor development, facilitating its growth through promoting tumor cells proliferation, invasion and migration, new blood vessels formation and blocking tumor cells apoptosis. MMPs can promote tumor development in several ways. ECM degradation results in release of peptide growth factors. Growth factors linked with cell surface or binding proteins can also be liberated by MMPs. MMPs can indirectly regulate integrin signalling or cleave E-cadherins, facilitating cell migration. MMPs support metastasis inducing an epithelial to mesenchymal transition (EMT). MMP also support transendothelial migration. MMPs support angiogenesis by releasing pro-angiogenic factors and degrading ECM to support ECs migration. Cell surface growth factor receptors are also cleaved by MMPs, which results in inhibition of tumor development, so is release of anti-angiogenic factors from ECM. Matrix metalloproteinase-9 (MMP-9) is a secreted glycoprotein with a major role in shaping the extracellular matrix and a detailed understanding of the secretory mechanism could help identify methods to correct diseases resulting from dysregulation of secretion. MMP-9 appears to follow a canonical secretory pathway through a quality control cycle in the endoplasmic reticulum (ER) before transport of the properly folded protein to the Golgi apparatus and beyond for secretion. Through a complementation assay, we determined that LMAN1, a well-studied lectin-carrier protein, interacts with a secretion-competent N-glycosylated MMP-9 in the ER while N-glycosylation-deficient secretion-compromised MMP-9 does not. In contrast, co-immunoprecipitation demonstrated protein interaction between LMAN1 and secretion-compromised N-glycosylation-deficient MMP-9. MMP-9 secretion was reduced in the LMAN1 knockout cell line compared to control cells confirming the functional role of LMAN1. These observations support the role of LMAN1 as a lectin-carrier protein mediating efficient MMP-9 secretion. Author information: (1)Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India; Institute of Tropical Medicine and International Health, Charité Universitätsmedizin Berlin, Berlin, Germany; Department of Medicine, Komfo Anoyke Teaching Hospital, School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. (2)Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India; Institute of Tropical Medicine and International Health, Charité Universitätsmedizin Berlin, Berlin, Germany; Department of Medicine, Komfo Anoyke Teaching Hospital, School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana [email protected]. Gelatinase B/matrix metalloproteinase-9 (MMP-9) (EC 3.4.24.35) cleaves many substrates and is produced by most cell types as a zymogen, proMMP-9, in complex with the tissue inhibitor of metalloproteinases-1 (TIMP-1). Natural proMMP-9 occurs as monomers, homomultimers and heterocomplexes, but our knowledge about the overall structure of proMMP-9 monomers and multimers is limited. We investigated biochemical, biophysical and functional characteristics of zymogen and activated forms of MMP-9 monomers and multimers. In contrast with a conventional notion of a dimeric nature of MMP-9 homomultimers, we demonstrate that these are reduction-sensitive trimers. Based on the information from electrophoresis, AFM and TEM, we generated a 3D structure model of the proMMP-9 trimer. Remarkably, the proMMP-9 trimers possessed a 50-fold higher affinity for TIMP-1 than the monomers. In vivo, this finding was reflected in a higher extent of TIMP-1 inhibition of angiogenesis induced by trimers compared with monomers. Our results show that proMMP-9 trimers constitute a novel structural and functional entity that is differentially regulated by TIMP-1.

What is hyperosmia

Hyperosmia is increased olfactory acuity

[24302690, 23520356, 21250223]

Hyperosmia is suspected in pregnancy; however, no empirical study using validated measures of olfactory function has clearly confirmed the anecdotal reports of this phenomenon. The goal of the current study is to compare the olfactory sensitivity of pregnant women to that of nonpregnant women and men. All participants rated their sense of smell and pregnant women listed the odors to which they were most sensitive. Detection thresholds were measured using a well-validated protocol. A group of pregnant and nonpregnant women was studied longitudinally using a signal detection procedure designed to detect small differences in sensitivity. Pregnant women, particularly in the 1st trimester, rated their sense of smell to be higher than nonpregnant women and men and indicated many (primarily unpleasant) odors to which they were more sensitive. Women rated their sense of smell higher than men. However, there was no sex difference in thresholds and neither thresholds nor signal detection measures of sensitivity were significantly affected by either sex or pregnancy status. The implications of the lack of relationship between self-report and measures of olfactory sensitivity, particularly in pregnancy, are discussed. We investigated everyday odor experiences in 55 people (14-75 years old) who rated their sense of smell as far better than average. Compared to 55 gender- and age-matched controls, the self-reported hyperosmics scored higher on the Affective Impact of Odor Scale, rated negative consequences and unpleasant memories due to odors as more likely, rated environmental odors as more annoying, reported increased sensitivity to specific odors more frequently, paid more attention to odors, and agreed more strongly that their sense of smell has caused inconvenience to them. Based on these data, subjective hyperosmia is associated with primarily negative odor-related experiences. Hyperosmia is increased olfactory acuity, and hypoosmia is diminished olfactory acuity. Anosmia, the inability to recognize odors, may be unilateral or bilateral. Dysosmia is an abnormal sense of smell.

What is the number of long non coding RNAs in the human genome

Different estimates put currently the number of human long non coding RNAs between 10,000 and 20,000

[23126680, 23846593, 23369519]

Long noncoding RNAs (lncRNAs) have been detected in nearly every cell type and found to be fundamentally involved in many biological processes. The characterization of lncRNAs has immense potential to advance our comprehensive understanding of cellular processes and gene regulation, along with implications for the treatment of human disease. The recent ENCODE (Encyclopedia of DNA Elements) study reported 9,640 lncRNA loci in the human genome, which corresponds to around half the number of protein-coding genes. Because of this sheer number and their functional diversity, it is crucial to identify a pool of potentially relevant lncRNAs early on in a given study. In this review, we evaluate the methods for isolating lncRNAs by immunoprecipitation and review the advantages, disadvantages, and applications of three widely used approaches - microarray, tiling array, and RNA-seq - for identifying lncRNAs involved in gene regulation. We also look at ways in which data from publicly available databases such as ENCODE can support the study of lncRNAs. BACKGROUND: Over 10,000 long intergenic non-coding RNAs (lincRNAs) have been identified in the human genome. Some have been well characterized and known to participate in various stages of gene regulation. In the post-transcriptional process, another class of well-known small non-coding RNA, or microRNA (miRNA), is very active in inhibiting mRNA. Though similar features between mRNA and lincRNA have been revealed in several recent studies, and a few isolated miRNA-lincRNA relationships have been observed. Despite these advances, the comprehensive miRNA regulation pattern of lincRNA has not been clarified. METHODS: In this study, we investigated the possible interaction between the two classes of non-coding RNAs. Instead of using the existing long non-coding database, we employed an ab initio method to annotate lincRNAs expressed in a group of normal breast tissues and breast tumors. RESULTS: Approximately 90 lincRNAs show strong reverse expression correlation with miRNAs, which have at least one predicted target site presented. These target sites are statistically more conserved than their neighboring genetic regions and other predicted target sites. Several miRNAs that target to these lincRNAs are known to play an essential role in breast cancer. CONCLUSION: Similar to inhibiting mRNAs, miRNAs show potential in promoting the degeneration of lincRNAs. Breast-cancer-related miRNAs may influence their target lincRNAs resulting in differential expression in normal and malignant breast tissues. This implies the miRNA regulation of lincRNAs may be involved in the regulatory process in tumor cells.

Which is the most known bacterium responsible for botulism (sausage-poisoning)?

Botulism is a severe neuroparalytic disease caused by botulinum neurotoxin (BoNT), and affects humans, all warm-blooded animals, birds, and some fishes. Botulinum toxin is produced under anaerobic conditions by the bacterium Clostridium botulinum, which is the most known etiological agent of the disease, and some other clostridia, and is one of the most dangerous toxin in the world.

[24961027, 21171846, 21975066, 24252701, 20961439, 18388640, 15839401, 23239346, 23523511, 24253240, 23421373, 17458494, 24252222, 19573697, 24206405, 21747146, 11153358, 24246230, 23971804, 23971806, 23971808, 15027048, 20569065, 21130733, 24997242, 16080379, 23025151]

Botulism is a rare but potentially life-threatening neuroparalytic syndrome resulting from the action of a neurotoxin elaborated by the microorganism Clostridium botulinum. This disease has a lengthy history; the first investigation of botulism occurred in the 1820s with a case report on hundreds of patients with "sausage poisoning" in a southern German town. Several decades later in Belgium, the association was demonstrated between a neuromuscular paralysis and ham infected by a spore forming bacillus that was isolated from the ham. The organism was named Bacillus botulinus after the Latin word for sausage, botulus. There are seven known serotypes of botulism, designated A through G; almost all human cases of botulism are caused by types A, B, and E. Botulism type E is the predominant serotype causing disease associated with native Arctic foods. In the circumpolar regions of the world, the coastal soils are rich in botulism type E, and consumption of fish and marine animals in these areas are the sources of clusters of botulism. Unlike spores of type A and B, botulism type E can withstand freezing down to 3.5°C. Alaskan native fermentation of fish heads, fish eggs, and beaver tail allow proper anaerobic conditions for botulinum toxin to be elaborated from Clostridium botulinum. The consumption of whale meat, "muktuk" has also been associated with outbreaks of botulism in Alaska and the Canadian Arctic. Elsewhere in the Arctic regions, type E botulism has been associated with Norwegian "rakfisk" prepared by a process similar to fermented Alaskan foods. Outbreaks in Egypt with the salted gray mullet "faseikh", in Israel and New York linked to salted uneviscerated whitefish "kapchunka", in Iran from eating "ashbal" an uncooked salmon, and in Japan with "izushi" a traditional fermented fish preserved in rice have occurred. Importation of vacuum-packed whitefish from Alaska and Canada has also been associated with sporadic cases of botulism type E in Europe. In March 2010, the Center for Disease Control and Prevention released the heptavalent antitoxin (H-BAT) for use in the USA, under an Investigational New Drug program, as the preferred treatment for food-borne botulism, including type E, which had not been covered by the bivalent antitoxin, the prior approved antitoxin product in the USA. Botulism is a disease characterized by neuromuscular paralysis and is produced from botulinum neurotoxins (BoNTs) found within the Gram positive bacterium Clostridium botulinum. This bacteria produces the most deadliest toxin known, with lethal doses as low as 1 ng/kg. Due to the relative ease of production and transport, the use of these agents as potential bioterrorist weapons has become of utmost concern. No small molecule therapies against BoNT intoxication have been approved to date. However, 3,4-diaminopyridine (3,4-DAP), a potent reversible inhibitor of voltage-gated potassium channels, is an effective cholinergic agonist used in the treatment of neuromuscular degenerative disorders that require cholinergic enhancement. 3,4-DAP has also been shown to facilitate recovery of neuromuscular action potential post botulinum intoxication by blocking K(+) channels. Unfortunately, 3,4-DAP displays toxicity largely due to blood-brain-barrier (BBB) penetration. As a dual-action prodrug approach to cholinergic enhancement we have designed carbamate and amide conjugates of 3,4-DAP. The carbamate prodrug is intended to be a slowly reversible inhibitor of acetylcholinesterase (AChE) along the lines of the stigmines thereby allowing increased persistence of released acetylcholine within the synaptic cleft. As a secondary activity, cleavage of the carbamate prodrug by AChE will afford the localized release of 3,4-DAP, which in turn, will enhance the pre-synaptic release of additional acetylcholine. Being a competitive inhibitor with respect to acetylcholine, the activity of the prodrug will be greatest at the synaptic junctions most depleted of acetylcholine. Here we report upon the synthesis and biochemical characterization of three new classes of prodrugs intended to limit previously reported stability and toxicity issues. Of the prodrugs examined, compound 32, demonstrated the most clinically relevant half-life of 2.76 h, while selectively inhibiting AChE over butyrylcholinesterase--a plasma-based high activity esterase. Future in vivo studies could provide validation of prodrug 32 as a potential treatment against BoNT intoxication as well as other neuromuscular disorders. Cattle botulism is a fatal intoxication caused by botulinum neurotoxins (BoNTs) produced by Clostridium botulinum serotypes C and D resulting in economic losses. Vaccination is the most effective way to control botulism. However, the commercially available vaccines are difficult and hazardous to produce. Neutralizing antibodies against the C-terminal fragment of the BoNT heavy chain (HC) are known to protect against lethal doses of BoNTs. We report the vaccination of cattle with a previously tested recombinant chimera consisting of Escherichia coli heat-labile enterotoxin B subunit and the HC of BoNTs C and D. Vaccinated animals produced neutralizing antibodies against serotypes C and D averaging 5±0 and 6.14±1.06IU/mL, respectively. For BoNT D, the titers were greater than those measured for the commercial vaccine, which induced titers of 5±0 and 2.85±1.35 against the respective serotypes, suggesting that this chimera is effective against cattle botulism. Botulism is a neuroparalytic disease caused by neurotoxins produced by the bacteria Clostridium botulinum. Botulinum neurotoxins (BoNTs) are among the most potent naturally occurring toxins and are a category A biological threat agent. The 7 toxin serotypes of BoNTs (serotypes A-G) have different toxicities, act through 3 different intracellular protein targets, and exhibit different durations of effect. Botulism may follow ingestion of food contaminated with BoNT, from toxin production of C botulinum present in the intestine or wounds, or from inhalation of aerosolized toxin. Intoxication classically presents as an acute, symmetrical, descending flaccid paralysis. Early diagnosis is important because antitoxin therapy is most effective when administered early. Confirmatory testing of botulism with BoNT assays or C botulinum cultures is time-consuming, and may be insensitive in the diagnosis of inhalational botulism and in as many as 32% of food-borne botulism cases. Therefore, the decision to initiate botulinum antitoxin therapy is primarily based on symptoms and physical examination findings that are consistent with botulism, with support of epidemiological history and electrophysiological testing. Modern clinical practice and antitoxin treatment has reduced botulism mortality rates from approximately 60% to < or =10%. The pentavalent botulinum toxoid is an investigational product and has been used for more than 45 years in at-risk laboratory workers to protect against toxin serotypes A to E. Due to declining immunogenicity and potency of the pentavalent botulinum toxoid, novel vaccine candidates are being developed. Clostridium botulinum is a species of spore-forming anaerobic bacteria defined by the expression of any one or two of seven serologically distinct botulinum neurotoxins (BoNTs) designated BoNT/A-G. This Gram-positive bacterium was first identified in 1897 and since then the paralyzing and lethal effects of its toxin have resulted in the recognition of different forms of the intoxication known as food-borne, infant, or wound botulism. Early microbiological and biochemical characterization of C. botulinum isolates revealed that the bacteria within the species had different characteristics and expressed different toxin types. To organize the variable bacterial traits within the species, Group I-IV designations were created. Interestingly, it was observed that isolates within different Groups could express the same toxin type and conversely a single Group could express different toxin types. This discordant phylogeny between the toxin and the host bacteria indicated that horizontal gene transfer of the toxin was responsible for the variation observed within the species. The recent availability of multiple C. botulinum genomic sequences has offered the ability to bioinformatically analyze the locations of the bont genes, the composition of their toxin gene clusters, and the genes flanking these regions to understand their variation. Comparison of the genomic sequences representing multiple serotypes indicates that the bont genes are not in random locations. Instead the analyses revealed specific regions where the toxin genes occur within the genomes representing serotype A, B, C, E, and F C. botulinum strains and C. butyricum type E strains. The genomic analyses have provided evidence of horizontal gene transfer, site-specific insertion, and recombination events. These events have contributed to the variation observed among the neurotoxins, the toxin gene clusters and the bacteria that contain them, and has supported the historical microbiological, and biochemical characterization of the Group classification within the species. Botulinum neurotoxin (BoNT), the causative agent of the deadly neuroparalytic disease botulism, is the most poisonous protein known for humans. Produced by different strains of the anaerobic bacterium Clostridium botulinum, BoNT effects cellular intoxication via a multistep mechanism executed by the three modules of the activated protein. Endocytosis, the first step of cellular intoxication, is triggered by the ~50 kDa, heavy-chain receptor-binding domain (HCR) that is specific for a ganglioside and a protein receptor on neuronal cell surfaces. This dual receptor recognition mechanism between BoNT and the host cell's membrane is well documented and occurs via specific intermolecular interactions with the C-terminal sub-domain, Hcc, of BoNT-HCR. The N-terminal sub-domain of BoNT-HCR, Hcn, comprises ~50% of BoNT-HCR and adopts a β-sheet jelly roll fold. While suspected in assisting cell surface recognition, no unambiguous function for the Hcn sub-domain in BoNT has been identified. To obtain insights into the potential function of the Hcn sub-domain in BoNT, the first crystal structure of a BoNT with an organic ligand bound to the Hcn sub-domain has been obtained. Here, we describe the crystal structure of BoNT/CD-HCR determined at 1.70 Å resolution with a tetraethylene glycol (PG4) moiety bound in a hydrophobic cleft between β-strands in the β-sheet jelly roll fold of the Hcn sub-domain. The PG4 moiety is completely engulfed in the cleft, making numerous hydrophilic (Y932, S959, W966, and D1042) and hydrophobic (S935, W977, L979, N1013, and I1066) contacts with the protein's side chain and backbone that may mimic in vivo interactions with the phospholipid membranes on neuronal cell surfaces. A sulfate ion was also observed bound to residues T1176, D1177, K1196, and R1243 in the Hcc sub-domain of BoNT/CD-HCR. In the crystal structure of a similar protein, BoNT/D-HCR, a sialic acid molecule was observed bound to the equivalent residues suggesting that residues T1176, D1177, K1196, and R1243 in BoNT/CD may play a role in ganglioside binding. Botulism is a serious foodborne neuroparalytic disease, caused by botulinum neurotoxin (BoNT), produced by the anaerobic bacterium Clostridium botulinum. Seven toxin serotypes (A-H) have been described. The majority of human cases of botulism are caused by serotypes A and B followed by E and F. We report here a group of serotype B specific monoclonal antibodies (mAbs) capable of binding toxin under physiological conditions. Thus, they serve as capture antibodies for a sandwich (capture) ELISA. The antibodies were generated using recombinant peptide fragments corresponding to the receptor-binding domain of the toxin heavy chain as immunogen. Their binding properties suggest that they bind a complex epitope with dissociation constants (KD's) for individual antibodies ranging from 10 to 48 × 10-11 M. Assay performance for all possible combinations of capture-detector antibody pairs was evaluated and the antibody pair resulting in the lowest level of detection (L.O.D.), ~20 pg/mL was determined. Toxin was detected in spiked dairy samples with good recoveries at concentrations as low as 0.5 pg/mL and in ground beef samples at levels as low as 2 ng/g. Thus, the sandwich ELISA described here uses mAb for both the capture and detector antibodies (binding different epitopes on the toxin molecule) and readily detects toxin in those food samples tested. Avian botulism, a paralytic disease of birds, often occurs on a yearly cycle and is increasingly becoming more common in the Great Lakes. Outbreaks are caused by bird ingestion of neurotoxins produced by Clostridium botulinum, a spore-forming, gram-positive, anaerobe. The nuisance, macrophytic, green alga Cladophora (Chlorophyta; mostly Cladophora glomerata L.) is a potential habitat for the growth of C. botulinum. A high incidence of botulism in shoreline birds at Sleeping Bear Dunes National Lakeshore (SLBE) in Lake Michigan coincides with increasingly massive accumulations of Cladophora in nearshore waters. In this study, free-floating algal mats were collected from SLBE and other shorelines of the Great Lakes between June and October 2011. The abundance of C. botulinum in algal mats was quantified and the type of botulism neurotoxin (bont) genes associated with this organism were determined by using most-probable-number PCR (MPN-PCR) and five distinct bont gene-specific primers (A, B, C, E, and F). The MPN-PCR results showed that 16 of 22 (73%) algal mats from the SLBE and 23 of 31(74%) algal mats from other shorelines of the Great Lakes contained the bont type E (bont/E) gene. C. botulinum was present up to 15000 MPN per gram dried algae based on gene copies of bont/E. In addition, genes for bont/A and bont/B, which are commonly associated with human diseases, were detected in a few algal samples. Moreover, C. botulinum was present as vegetative cells rather than as dormant spores in Cladophora mats. Mouse toxin assays done using supernatants from enrichment of Cladophora containing high densities of C. botulinum (>1000 MPN/g dried algae) showed that Cladophora-borne C. botulinum were toxin-producing species (BoNT/E). Our results indicate that Cladophora provides a habitat for C. botulinum, warranting additional studies to better understand the relationship between this bacterium and the alga, and how this interaction potentially contributes to botulism outbreaks in birds. Botulinum toxin poisoning has afflicted mankind through the mists of time. However, the first incident of food-borne botulism was documented as late as the 18th century, when the consumption of meat and blood sausages gave rise to many deaths throughout the kingdom of Württemberg in South Western Germany. The district medical officer Justinus Kerner (1786--1862), who was also a well-known German poet, published the first accurate and complete descriptions of the symptoms of food-borne botulism between 1817 and 1822 and attributed the intoxication to a biological poison. Kerner also postulated that the toxin might be used for treatment purposes. In 1895, an outbreak of botulism in the small Belgian village of Ellezelles led to the discovery of the pathogen "Clostridium botulinum" by Emile Pierre van Ermengem. Modern botulinum toxin treatment was pioneered by Alan B. Scott and Edward J. Schantz in the early 1970s, when the type-A serotype was used in medicine to correct strabismus. Other preparations of the type-A toxin were developed and manufactured in the United Kingdom, Germany, and China, whereas a therapeutic type-B toxin was prepared in the United States. To date, the toxin has been used to treat a wide variety of conditions associated with muscular hyperactivity, glandular hypersecretions and pain. Botulism in horses in the USA is attributed to Clostridium botulinum types A, B or C. In this study, a duplex quantitative real-time PCR (qPCR) for detection of the neurotoxin genes of C. botulinum types A and B, and a singleplex qPCR for detection of the neurotoxin gene of C. botulinum type C, were optimized and validated for equine gastrointestinal, faecal and feed samples. The performance of these assays was evaluated and compared to the standard mouse bioassay (MBA) using 148 well-characterized samples, most of which were acquired from a repository of veterinary diagnostic samples from cases of botulism: 106 samples positive for C. botulinum (25 type A, 27 type B, 28 type C, 1 type D and 25 type E) and 42 negative samples. The sensitivities of the qPCR assays were 89%, 86% and 96% for C. botulinum types A, B and C, respectively. The overall sensitivity of the mouse bioassay for types A, B and C was 81%. The specificities of the qPCR assays were 99-100% and the specificity of the mouse bioassay was 95%. The ability to form botulinum neurotoxin is restricted to six phylogenetically and physiologically distinct bacteria (Clostridium botulinum Groups I-IV and some strains of C. baratii and C. butyricum). The botulinum neurotoxin is the most potent toxin known, with as little as 30-100 ng potentially fatal, and is responsible for botulism, a severe neuroparalytic disease that affects humans, animals, and birds. In order to minimize the hazards presented by the botulinum neurotoxin-forming clostridia, it is necessary to extend understanding of the biology of these bacteria. Analyses of recently available genome sequences in conjunction with studies of bacterial physiology are beginning to reveal new and exciting information on the biology of these dangerous bacteria. At the whole organism level, substantial differences between the six botulinum neurotoxin-forming clostridia have been reported. For example, the genomes of proteolytic C. botulinum (C. botulinum Group I) and non-proteolytic C. botulinum (C. botulinum Group II) are highly diverged and show neither synteny nor homology. It has also emerged that the botulinum neurotoxin-forming clostridia are not overtly pathogenic (unlike C. difficile), but saprophytic bacteria that use the neurotoxin to kill a host and create a source of nutrients. One important feature that has contributed to the success of botulinum neurotoxin-forming clostridia is their ability to form highly resistant endospores. The spores, however, also present an opportunity to control these bacteria if escape from lag phase (and hence growth) can be prevented. This is dependent on extending understanding of the biology of these processes. Differences in the genetics and physiology of spore germination in proteolytic C. botulinum and non-proteolytic C. botulinum have been identified. The biological variability in lag phase and its stages has been described for individual spores, and it has been shown that various adverse treatments extend different stages of lag phase. For example, heat treatment primarily extended germination, while incubation at a chilled temperature primarily extended outgrowth. The neurotoxin gene is present within a cluster of associated genes, and can be located on the chromosome, a plasmid or a bacteriophage. Two basic types of neurotoxin cluster have been identified. Evolution of the neurotoxin gene and cluster has occurred independently of the organism, and involved a series of recombination events but is still poorly understood. Factors affecting the regulation of neurotoxin formation also remain poorly understood, and will be the focus of much future research. BACKGROUND: Botulism is a serious neuroparalytic disease caused by toxins of Clostridium botulinum. Botulinum toxin is produced under anaerobic conditions and is one of the most dangerous toxin in the world. Rapid diagnosis of botulism is very essential for successful therapy. In this study, we reviewed data of cases of botulism in Iran from April 2004 through March 2010. MATHERIALS AND METHODS: From a total of 1140 samples of suspected botulism samples, 477 serum, 294 stool, 111 gastric secretions, and 258 food samples were collected from 21 provinces. These samples belonged to 432 distinct patients. All samples were tested for botulism by mouse bioassay, a gold standard method for detection of botulism. RESULTS: From 1140 received samples, 64 (5.6 %) positive samples of botulism were identified. Of these, 14 (21.8 %) cases had toxin type A, seven (11 %) cases had toxin type B, 22 (34.3 %) cases had toxin type E, and seven (11 %) cases had toxin type AB. The toxin type could not been identified in 14 (21.8 %) cases. The highest positive results were in Gilan, Tehran, Golestan, and Hamedan provinces. Seafoods and locally- made cheese were the most implicated foods in type E and type A botulism, respectively. CONCLUSION: Accurate and rapid diagnosis of botulism is very important because every case of botulism can be a public health emergency. During the study period, the median number of positive cases per year was 2.7 (range: one to18). Therefore, it is suggested that all clinicians are required to submit the collected samples from patients with botulism symptoms to the botulism reference laboratory for specific diagnosis and confirmation of botulism. Botulinumtoxin (BTX) is a neurotoxin produced from Clostridium botulinum under anaerobic conditions and is responsible for botulism, a notifiable, bacterial form of food poisoning. The first case of botulism is believed to have occurred in 1735. An epidemic in Southern Germany in 1793 claimed the death of over the half of those patients who had become ill through eating uncooked blood sausages. The term "pharmakon" is Greek and implicates that a drug originates from poison (potion, remedy). Theophrastus Bombast von Hohenheim known as Paracelsus (1493/94-1541) first described this duality with his dictum "alle ding sind gift und nichts on gift; alein die dosis macht das ein ding kein gift ist" (only the dose makes a remedy poisonous). In Baden-Württemberg in 1817, the poet and physician Dr. Justinus Christian Kerner described the symptoms of botulism, so that at this time botulism was also called Kerner disease. Until the turn of the century the reason for poisoning was not known. Van Ermengem succeeded in isolating the anaerobic bacterium causing botulism, but the specific mechanism of BTX was only established after the second World War. In the late seventies the ophthalmologist Dr. Alan Scott used BTX the first time in the treatment of strabismus. The drug was then used in the treatment of several muscle spasticities such as, for example, torticollis or hemifacial spasm. Only recently BTX has been successfully used for focal hyperhidrosis. We review the history of botulinum toxin from its discovery in the nineteenth century and the research into its effect in the middle of the 20th century up to its clinical use at the present time. Food-borne botulism probably has accompanied mankind since its beginning. However, we have only few historical sources and documents on food poisoning before the 19th century. Some ancient dietary laws and taboos may reflect some knowledge about the life-threatening consumption of poisoned food. One example of such a dietary taboo is the 10th century edict of Emperor Leo VI of Byzantium in which manufacturing of blood sausages was forbidden. Some ancient case reports on intoxications with Atropa belladonna probably described patients with food-borne botulism, because the combination of dilated pupils and fatal muscle paralysis cannot be attributed to an atropine intoxication. At the end of the 18th century, some well-documented outbreaks of "sausage poisoning" in Southern Germany, especially in Württemberg, prompted early systematic botulinum toxin research. The German poet and district medical officer Justinus Kerner (1786-1862) published the first accurate and complete descriptions of the symptoms of food-borne botulism between 1817 and 1822. Kerner did not succeed in defining the suspected "biological poison" which he called "sausage poison" or "fatty poison." However, he developed the idea of a possible therapeutic use of the toxin. Eighty years after Kerner's work, in 1895, a botulism outbreak after a funeral dinner with smoked ham in the small Belgian village of Ellezelles led to the discovery of the pathogen Clostridium botulinum by Emile Pierre van Ermengem, Professor of bacteriology at the University of Ghent. The bacterium was so called because of its pathological association with the sausages (Latin word for sausage = "botulus") and not-as it was suggested-because of its shape. Modern botulinum toxin treatment was pioneered by Alan B. Scott and Edward J. Schantz. The botulinum neurotoxins (BoNTs) produced by different strains of the bacterium Clostridium botulinum are responsible for the disease botulism and include a group of immunologically distinct serotypes (A, B, E, and F) that are considered to be the most lethal natural proteins known for humans. Two BoNT serotypes, C and D, while rarely associated with human infection, are responsible for deadly botulism outbreaks afflicting animals. Also associated with animal infections is the BoNT C-D mosaic protein (BoNT/CD), a BoNT subtype that is essentially a hybrid of the BoNT/C (∼two-third) and BoNT/D (∼one-third) serotypes. While the amino acid sequence of the heavy chain receptor binding (HCR) domain of BoNT/CD (BoNT/CD-HCR) is very similar to the corresponding amino acid sequence of BoNT/D, BoNT/CD-HCR binds synaptosome membranes better than BoNT/D-HCR. To obtain structural insights for the different membrane binding properties, the crystal structure of BoNT/CD-HCR (S867-E1280) was determined at 1.56 Å resolution and compared to previously reported structures for BoNT/D-HCR. Overall, the BoNT/CD-HCR structure is similar to the two sub-domain organization observed for other BoNT HCRs: an N-terminal jellyroll barrel motif and a C-terminal β-trefoil fold. Comparison of the structure of BoNT/CD-HCR with BoNT/D-HCR indicates that K1118 has a similar structural role as the equivalent residue, E1114, in BoNT/D-HCR, while K1136 has a structurally different role than the equivalent residue, G1132, in BoNT/D-HCR. Lysine-1118 forms a salt bridge with E1247 and may enhance membrane interactions by stabilizing the putative membrane binding loop (K1240-N1248). Lysine-1136 is observed on the surface of the protein. A sulfate ion bound to K1136 may mimic a natural interaction with the negatively changed phospholipid membrane surface. Liposome-binding experiments demonstrate that BoNT/CD-HCR binds phosphatidylethanolamine liposomes more tightly than BoNT/D-HCR. Botulism is a potentially lethal disease caused by one of seven homologous neurotoxic proteins usually produced by the bacterium, Clostridium botulinum. This neuromuscular disorder occurs through an exquisite series of molecular events, ultimately ending with the arrest of acetylcholine release and hence, flaccid paralysis. There are three types of botulism: food, wound, and infant botulism. Most strains of the bacterium produce a potent, respiratory muscle-paralyzing neurotoxin, botulinum toxin (BTX). It can lead to death unless appropriate therapy is promptly initiated. Due to the severity and potency of BTX, its importance as a biological weapon is of major concern to public health officials. Nevertheless, BTX is also medicament. Botulism is caused by botulinum neurotoxin produced by the bacterium Clostridium botulinum. It is a flaccid paralysis in which consciousness and nociception are preserved. Natural botulism typically results from ingestion of inadequately heated or unheated vacuum-packed foods. In addition, botulinum toxin is one of the most feared biological weapons. In the diagnosis and treatment of botulism early suspicion is essential. Several coinciding or local clusters without a typical connecting source, or an uncommon type of toxin may indicate an intentionally caused epidemic.

What is the association of spermidine with α-synuclein neurotoxicity?

Spermidine protects against α-synuclein neurotoxicity. In the fruit fly, simple feeding with spermidine inhibited loss of climbing activity and early organismal death upon heterologous expression of human α-synuclein, which is thought to be the principal toxic trigger of Parkinson's Disease (PD). In this line, administration of spermidine rescued α-synuclein-induced loss of dopaminergic neurons, a hallmark of PD, in nematodes. Alleviation of PD-related neurodegeneration by spermidine was accompanied by induction of autophagy, suggesting that this cytoprotective process may be responsible for the beneficial effects of spermidine administration.

[22662273, 25483063]

As our society ages, neurodegenerative disorders like Parkinson`s disease (PD) are increasing in pandemic proportions. While mechanistic understanding of PD is advancing, a treatment with well tolerable drugs is still elusive. Here, we show that administration of the naturally occurring polyamine spermidine, which declines continuously during aging in various species, alleviates a series of PD-related degenerative processes in the fruit fly Drosophila melanogaster and the nematode Caenorhabditis elegans, two established model systems for PD pathology. In the fruit fly, simple feeding with spermidine inhibited loss of climbing activity and early organismal death upon heterologous expression of human α-synuclein, which is thought to be the principal toxic trigger of PD. In this line, administration of spermidine rescued α-synuclein-induced loss of dopaminergic neurons, a hallmark of PD, in nematodes. Alleviation of PD-related neurodegeneration by spermidine was accompanied by induction of autophagy, suggesting that this cytoprotective process may be responsible for the beneficial effects of spermidine administration.

List symptoms of 4H leukodystrophy.

Hypomyelination, hypodontia, and hypogonadotropic hypogonadism are major symptoms of 4H leukodystrophy.

[21855841, 18671210, 25339210, 23242285, 23307887, 24190003, 22451160, 22855961]

AIM: To report one patient with slowly progressive encephalopathy, ataxia, central hypomyelination, hypodontia and hypogonadotropic hypogonadism, the 4H syndrome. This clinical picture has been described recently and there are only four patients reported previously. CASE REPORT: A girl with a previously normal early psychomotor development, presented a slowly progressive deterioration since 15 months of age. Now, she is 14 years old, and has a severe cerebellar ataxia, with tremor and dysmetria. She can't neither walk nor remain standing alone. She has lost the sphincter control and has an immature expressive language. She has no puberal development and definitive hypodontia of upper central incisors. The brain magnetic resonance imaging shows a diffuse hypomyelination, that is confirmed with diffusion and spectroscopy studies. CONCLUSION: The hypomyelinating leukoencephalopathies are disorders with abnormally low amount of myelin. The diagnosis is difficult in most of the patients. The hypomyelinating leukoencephalopathies include classic disorders and new leukoencephalopathies, described in the past few years. Author information: (1)From the Departments of Child Neurology (N.I.F., M.B., M.S.v.d.K.), Clinical Genetics (R.M.L.v.S., E.S.), and Pathology (M.B.), Neuroscience Campus (N.I.F., M.B., M.S.v.d.K.), and the Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (M.S.v.d.K.), VU University Medical Center, Amsterdam, the Netherlands; the Center for Genetic Medicine Research, Department of Neurology (A.V., A.P.), Children's National Medical Center, Washington, DC; the Institute of Metabolic Disease (R.S.), Baylor Research Institute, Dallas, TX; the Departments of Neurology and Neurosurgery and Human Genetics (B.B.), Montreal Neurological Institute, Canada; the Department of Paediatric Neurology (C.C.-B.), Erasmus University Hospital-Sophia Children's Hospital; the Department of Pathology (J.M.K.), Erasmus Medical Center, Rotterdam, the Netherlands; the Neuroradiology Department (P.S.P.), Centro Hospitalar do Porto, Portugal; the Division of Neurology (D.P.), Children's Hospital of Eastern Ontario, University of Ottawa, Canada; the Department of Paediatric Neurology (S.T.), Royal Belfast Hospital for Sick Children, UK; the Department of Clinical Neurosciences for Children (P.S.), Oslo University Hospital, Ullevål; University of Oslo (P.S.), Norway; the Department of Neurology (T.d.G.), Cincinnati School of Medicine and Cincinnati Children's Hospital Medical Center, OH; INSERM-IECB (S.F.), Pessac, France; the Department of Pediatric Neurology (M.D.), University of British Columbia and British Columbia Children's Hospital, Vancouver, Canada; Kennedy Krieger Institute/Johns Hopkins Medical Institutions (S.N.), Baltimore, MD; and the Departments of Pediatrics, Neurology, and Neurosurgery, Division of Pediatric Neurology (K.G., G.B.), Montreal Children's Hospital, McGill University Health Center, Montreal, Canada. [email protected]. (2)From the Departments of Child Neurology (N.I.F., M.B., M.S.v.d.K.), Clinical Genetics (R.M.L.v.S., E.S.), and Pathology (M.B.), Neuroscience Campus (N.I.F., M.B., M.S.v.d.K.), and the Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (M.S.v.d.K.), VU University Medical Center, Amsterdam, the Netherlands; the Center for Genetic Medicine Research, Department of Neurology (A.V., A.P.), Children's National Medical Center, Washington, DC; the Institute of Metabolic Disease (R.S.), Baylor Research Institute, Dallas, TX; the Departments of Neurology and Neurosurgery and Human Genetics (B.B.), Montreal Neurological Institute, Canada; the Department of Paediatric Neurology (C.C.-B.), Erasmus University Hospital-Sophia Children's Hospital; the Department of Pathology (J.M.K.), Erasmus Medical Center, Rotterdam, the Netherlands; the Neuroradiology Department (P.S.P.), Centro Hospitalar do Porto, Portugal; the Division of Neurology (D.P.), Children's Hospital of Eastern Ontario, University of Ottawa, Canada; the Department of Paediatric Neurology (S.T.), Royal Belfast Hospital for Sick Children, UK; the Department of Clinical Neurosciences for Children (P.S.), Oslo University Hospital, Ullevål; University of Oslo (P.S.), Norway; the Department of Neurology (T.d.G.), Cincinnati School of Medicine and Cincinnati Children's Hospital Medical Center, OH; INSERM-IECB (S.F.), Pessac, France; the Department of Pediatric Neurology (M.D.), University of British Columbia and British Columbia Children's Hospital, Vancouver, Canada; Kennedy Krieger Institute/Johns Hopkins Medical Institutions (S.N.), Baltimore, MD; and the Departments of Pediatrics, Neurology, and Neurosurgery, Division of Pediatric Neurology (K.G., G.B.), Montreal Children's Hospital, McGill University Health Center, Montreal, Canada. The 4H syndrome (hypomyelination, hypodontia, hypogonadotropic hypogonadism) is a newly recognized leukodystrophy. The classical form is characterized by the association of hypomyelination, abnormal dentition, and hypogonadotropic hypogonadism, but the recent identification of 2 genes responsible for the syndrome demonstrates that these 3 main characteristics can be variably combined among "Pol-III (polymerase III)-related leukodystrophies." The pathophysiology of this group of diseases is still to be elucidated, and there are no neuropathologic descriptions of brain tissue. We report the clinical, neuroradiologic, and neuropathologic findings of a patient affected by 4H syndrome with confirmed POLR3A mutations. We found a marked loss of oligodendrocytes, varying in severity in different brain regions, and accompanied by severe loss of myelin, moderately severe loss of axons, and patchy perivascular regions of better preserved white matter. There was relatively mild white matter astrogliosis and microgliosis. A macrophage reaction involving viable normal-appearing oligodendroglia suggests the possibility of an immunologic process in this disorder. Cortical laminar astrogliosis and mineralization of Layers I and II in particular were present. Thus, despite the uniformly hypomyelinating pattern seen on magnetic resonance imaging, neuropathologic examination reveals a complex heterogeneous leukodystrophy with prominent neuroaxonal and glial involvement in this disorder. An 18-year-old German woman presented with progressive cerebellar ataxia since early childhood, delayed cognitive development, and hypogonadotropic hypogonadism. MRI demonstrated diffuse cerebral hypomyelination, cerebellar atrophy, and thin corpus callosum; X-ray revealed persistent milk teeth and hypoplastic crowns and roots (figure), indicative of 4H syndrome (hypomyelination, hypodontia, hypogonadotropic hypogonadism). POLR3B sequencing(1) revealed 2 compound heterozygous mutations (C527R [C.1579T>C] and the common ancestral V523E [C.1568T>A](2)). OBJECTIVE: To report a novel clinical and genetic presentation of a patient with 4H syndrome, which is a recently described leukodystrophy syndrome characterized by ataxia, hypomyelination, hypodontia, and hypogonadotropic hypogonadism. DESIGN: Case report. SETTING: University teaching hospital. PATIENT: A 20-year-old male patient with 4H syndrome. RESULTS: The patient was found to have delayed tooth eruption and a late-onset growth hormone deficiency without overt growth failure. He was a compound heterozygote for the novel missense mutations R1005H and A1331T of POLR3A, which codes for the largest subunit of RNA polymerase III. CONCLUSION: This is the first report of this type of leukodystrophy from southeastern Europe, which suggests that POLR3A mutations should be suspected in patients with hypomyelination and various central nervous system–based endocrine abnormalities. CLINICAL CHARACTERISTICS: POLR3-related leukodystrophy, a hypomyelinating leukodystrophy with specific features on brain MRI, is characterized by varying combinations of four major clinical findings: Neurologic dysfunction, typically predominated by motor dysfunction (progressive cerebellar dysfunction, and to a lesser extent extrapyramidal [i.e., dystonia], pyramidal [i.e., spasticity] and cognitive dysfunctions). Abnormal dentition (delayed dentition, hypodontia, oligodontia, and abnormally placed or shaped teeth). Endocrine abnormalities such as short stature (in ~50% of individuals) with or without growth hormone deficiency, and more commonly, hypogonadotropic hypogonadism manifesting as delayed, arrested, or absent puberty. Ocular abnormality in the form of myopia, typically progressing over several years and becoming severe. POLR3-related leukodystrophy and 4H leukodystrophy are the two recognized terms for five previously described overlapping clinical phenotypes (initially described as distinct entities before their molecular basis was known). These include: Hypomyelination, hypodontia, hypogonadotropic hypogonadism (4H syndrome); Ataxia, delayed dentition, and hypomyelination (ADDH); Tremor-ataxia with central hypomyelination (TACH); Leukodystrophy with oligodontia (LO); Hypomyelination with cerebellar atrophy and hypoplasia of the corpus callosum (HCAHC). Age of onset is typically in early childhood but later-onset cases have also been reported. An infant with Wiedemann-Rautenstrauch syndrome (neonatal progeroid syndrome) was recently reported to have pathogenic variants in POLR3A on exome sequencing. Confirmation of this as a very severe form of POLR3-related leukodystrophy awaits replication in other individuals with a clinical diagnosis of Wiedemann-Rautenstrauch syndrome. DIAGNOSIS/TESTING: POLR3-related leukodystrophy is diagnosed by the combination of classic clinical findings, typical brain MRI features, and the presence of biallelic pathogenic variants in POLR3A, POLR3B, or POLR1C. MANAGEMENT: Treatment of manifestations: Individualized care by a multidisciplinary team including a pediatric neurologist, clinical geneticist, physiotherapist, occupational therapist, speech and language pathologist, neuropsychologist, rehabilitation physician, dentist, endocrinologist, ophthalmologist, ear-nose-and-throat specialist, and primary care physician is recommended. Special caution needs to be taken when managing dysphagia in this disorder as it is known to vary widely, even in a single day. Swallowing difficulties will progress over time and dystonia should be monitored and treated to prevent complications and improve the quality of life. GENETIC COUNSELING: POLR3-related leukodystrophy is inherited in an autosomal recessive manner. At conception, each sib of an affected individual has a 25% chance of being affected, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected and not a carrier. Carrier testing for at-risk relatives and prenatal diagnosis for pregnancies at increased risk are possible if both pathogenic variants in the family are known.

What is the extracellular core "matrisome"?

The "matrisome" is defined as the ensemble of extracellular matrix proteins (ECM) proteins and associated factors. The core matrisome have been defined in mammals through the analysis of whole genome sequences and comprises of ~ 300 proteins.

[23539364, 22159717, 21937732]

The extracellular matrix (ECM) not only provides physical support for tissues, but it is also critical for tissue development, homeostasis and disease. Over 300 ECM molecules have been defined as comprising the "core matrisome" in mammals through the analysis of whole genome sequences. During tooth development, the structure and functions of the ECM dynamically change. In the early stages, basement membranes (BMs) separate two cell layers of the dental epithelium and the mesenchyme. Later in the differentiation stages, the BM layer is replaced with the enamel matrix and the dentin matrix, which are secreted by ameloblasts and odontoblasts, respectively. The enamel matrix genes and the dentin matrix genes are each clustered in two closed regions located on human chromosome 4 (mouse chromosome 5), except for the gene coded for amelogenin, the major enamel matrix protein, which is located on the sex chromosomes. These genes for enamel and dentin matrix proteins are derived from a common ancestral gene, but as a result of evolution, they diverged in terms of their specific functions. These matrix proteins play important roles in cell adhesion, polarity, and differentiation and mineralization of enamel and dentin matrices. Mutations of these genes cause diseases such as odontogenesis imperfect (OI) and amelogenesis imperfect (AI). In this review, we discuss the recently defined terms matrisome and matrixome for ECMs, as well as focus on genes and functions of enamel and dentin matrix proteins. The extracellular matrix (ECM) is a complex meshwork of cross-linked proteins providing both biophysical and biochemical cues that are important regulators of cell proliferation, survival, differentiation, and migration. We present here a proteomic strategy developed to characterize the in vivo ECM composition of normal tissues and tumors using enrichment of protein extracts for ECM components and subsequent analysis by mass spectrometry. In parallel, we have developed a bioinformatic approach to predict the in silico "matrisome" defined as the ensemble of ECM proteins and associated factors. We report the characterization of the extracellular matrices of murine lung and colon, each comprising more than 100 ECM proteins and each presenting a characteristic signature. Moreover, using human tumor xenografts in mice, we show that both tumor cells and stromal cells contribute to the production of the tumor matrix and that tumors of differing metastatic potential differ in both the tumor- and the stroma-derived ECM components. The strategy we describe and illustrate here can be broadly applied and, to facilitate application of these methods by others, we provide resources including laboratory protocols, inventories of ECM domains and proteins, and instructions for bioinformatically deriving the human and mouse matrisome. Completion of genome sequences for many organisms allows a reasonably complete definition of the complement of extracellular matrix (ECM) proteins. In mammals this "core matrisome" comprises ∼300 proteins. In addition there are large numbers of ECM-modifying enzymes, ECM-binding growth factors, and other ECM-associated proteins. These different categories of ECM and ECM-associated proteins cooperate to assemble and remodel extracellular matrices and bind to cells through ECM receptors. Together with receptors for ECM-bound growth factors, they provide multiple inputs into cells to control survival, proliferation, differentiation, shape, polarity, and motility of cells. The evolution of ECM proteins was key in the transition to multicellularity, the arrangement of cells into tissue layers, and the elaboration of novel structures during vertebrate evolution. This key role of ECM is reflected in the diversity of ECM proteins and the modular domain structures of ECM proteins both allow their multiple interactions and, during evolution, development of novel protein architectures.

Is GAGA associated with nucleosome-free regions (NFR)?

The GAGA factor is a protein known to be involved in the formation and/or maintenance of nucleosome-free regions of chromatin. The interactions of GAGA factor and heat shock factor with their binding sites in chromatin occurred in two modes. Their interaction with binding sites in the nucleosome-free regions did not require ATP. In the presence of ATP both factors interacted also with nucleosomal binding sites, causing nucleosome rearrangements and a refinement of nucleosome positions. While chromatin remodeling upon transcription factor interaction has previously been interpreted to involve nucleosome disruption, the data suggest energy-dependent nucleosome sliding as main principle of chromatin reorganization.

[8474442, 15579691, 11158316, 7737124]

Previous analysis of the hsp26 gene of Drosophila melanogaster has shown that in addition to the TATA box and the proximal and distal heat shock elements (HSEs) (centered at -59 and -340, relative to the start site of transcription), a segment of (CT)n repeats at -135 to -85 is required for full heat shock inducibility (R.L. Glaser, G.H. Thomas, E.S. Siegfried, S.C.R. Elgin, and J.T. Lis, J. Mol. Biol. 211:751-761, 1990). This (CT)n element appears to contribute to formation of the wild-type chromatin structure of hsp26, an organized nucleosome array that leaves the HSEs in nucleosome-free, DNase I-hypersensitive (DH) sites (Q. Lu, L.L. Wallrath, B.D. Allan, R.L. Glaser, J.T. Lis, and S.C.R. Elgin, J. Mol. Biol. 225:985-998, 1992). Inspection of the sequences upstream of hsp26 has revealed an additional (CT)n element at -347 to -341, adjacent to the distal HSE. We have analyzed the contribution of this distal (CT)n element (-347 to -341), the proximal (CT)n element (-135 to -85), and the two HSEs both to the formation of the chromatin structure and to heat shock inducibility. hsp26 constructs containing site-directed mutations, deletions, substitutions, or rearrangements of these sequence elements have been fused in frame to the Escherichia coli lacZ gene and reintroduced into the D. melanogaster genome by P-element-mediated germ line transformation. Chromatin structure of the transgenes was analyzed (prior to gene activation) by DNase I or restriction enzyme treatment of isolated nuclei, and heat-inducible expression was monitored by measuring beta-galactosidase activity. The results indicate that mutations, deletions, or substitutions of either the distal or the proximal (CT)n element affect the chromatin structure and heat-inducible expression of the transgenes. These (CT)n repeats are associated with a nonhistone protein(s) in vivo and are bound by a purified Drosophila protein, the GAGA factor, in vitro. In contrast, the HSEs are required for heat-inducible expression but play only a minor role in establishing the chromatin structure of the transgenes. Previous analysis indicates that prior to heat shock, these HSEs appear to be free of protein. Our results suggest that GAGA factor, an abundant protein factor required for normal expression of many Drosophila genes, and heat shock factor, a specific transcription factor activated upon heat shock, play distinct roles in gene regulation: the GAGA factor establishes and/or maintains the DH sites prior to heat shock induction, while the activated heat shock factor recognizes and binds HSEs located within the DH sites to trigger transcription. In the work reported here we have undertaken a functional dissection of a Polycomb response element (PRE) from the iab-7 cis-regulatory domain of the Drosophila melanogaster bithorax complex (BX-C). Previous studies mapped the iab-7 PRE to an 860-bp fragment located just distal to the Fab-7 boundary. Located within this fragment is an approximately 230-bp chromatin-specific nuclease-hypersensitive region called HS3. We have shown that HS3 is capable of functioning as a Polycomb-dependent silencer in vivo, inducing pairing-dependent silencing of a mini-white reporter. The HS3 sequence contains consensus binding sites for the GAGA factor, a protein implicated in the formation of nucleosome-free regions of chromatin, and Pleiohomeotic (Pho), a Polycomb group protein that is related to the mammalian transcription factor YY1. We show that GAGA and Pho interact with these sequences in vitro and that the consensus binding sites for the two proteins are critical for the silencing activity of the iab-7 PRE in vivo. The chromatin structure at the Drosophila hsp26 promoter in vivo is characterized by two DNase I-hypersensitive (DH) sites harboring regulatory elements. Proximal and distal DH sites are separated by a positioned nucleosome. To study the contribution of transcription factors to the establishment of this specific chromatin configuration we assembled nucleosomes on the hsp26 promoter using a cell-free reconstitution system derived from fly embryos. Both DH sites were readily reconstituted from extract components. They were separated by a nucleosome which was less strictly positioned than its in vivo counterpart. The interactions of GAGA factor and heat shock factor with their binding sites in chromatin occurred in two modes. Their interaction with binding sites in the nucleosome-free regions did not require ATP. In the presence of ATP both factors interacted also with nucleosomal binding sites, causing nucleosome rearrangements and a refinement of nucleosome positions. While chromatin remodeling upon transcription factor interaction has previously been interpreted to involve nucleosome disruption, the data suggest energy-dependent nucleosome sliding as main principle of chromatin reorganization.

Which are the plant DNA (cytosine-5) methyltransferase families?

The plant DNA (cytosine-5)methyltransferases are classified into the families: MET, CMT, and the de novo DRM.

[8389441, 21542302, 18640997, 19132393, 21060858, 10845458, 10781108, 17689048, 9680985, 11353082, 20331964, 8152926]

A plant cytosine methyltransferase cDNA was isolated using degenerate oligonucleotides, based on homology between prokaryote and mouse methyltransferases, and PCR to amplify a short fragment of a methyltransferase gene. A fragment of the predicted size was amplified from genomic DNA from Arabidopsis thaliana. Overlapping cDNA clones, some with homology to the PCR amplified fragment, were identified and sequenced. The assembled nucleic acid sequence is 4720 bp and encodes a protein of 1534 amino acids which has significant homology to prokaryote and mammalian cytosine methyltransferases. Like mammalian methylases, this enzyme has a C terminal methyltransferase domain linked to a second larger domain. The Arabidopsis methylase has eight of the ten conserved sequence motifs found in prokaryote cytosine-5 methyltransferases and shows 50% homology to the murine enzyme in the methyltransferase domain. The amino terminal domain is only 24% homologous to the murine enzyme and lacks the zinc binding region that has been found in methyltransferases from both mouse and man. In contrast to mouse where a single methyltransferase gene has been identified, a small multigene family with homology to the region amplified in PCR has been identified in Arabidopsis thaliana. The methylation patterns of the MET1 gene in organs of Arabidopsis thaliana were studied by Southern blot hybridization of DNA samples hydrolyzed with differentially methylation-sensitive restriction endonucleases. A highly methylated on internal cytosine residue CCGG site was found 1.5 kb upstream of the gene, whereas CCGG sites located in more proximal parts of the 5'-flanking region and the gene itself are essentially unmethylated. This methylation pattern was observed in different organs of plants belonging to two different ecotypes as well as in different transgenic plant lines. The methylation level ofa CCGG site in exon 3 (2.1 kb from the gene's 5'-end) occurred to be variable between different transgenic plant lines and two ecotypes studied. Transcription levels of the MET1 gene vary slightly in organs of wild-type plants without any obvious correlation with its methylation. The transgenic antisense MET1 constructs expressed in plant genome do affect both MET1 methylation and its transcription but again without any obvious correlation. The comparative investigation of transcription levels of different genes of cytosine DNA methyltransferase family MET (MET1, MET2a, MET2b, MET3) and their methylation patterns shows that there may exist some mechanisms defending the most actively transcribed gene MET1 of this family from methylation mediated silencing. In contrast to DRM2 gene we could not find any adenine methylated GATC sites in the MET1 gene. In oil palm (Elaeis guineensis Jacq.), approximately 5% of somatic embryo-derived regenerants show homeotic changes during floral development, involving an apparent feminization of male parts in flowers of both sexes, called the 'mantled' phenotype. This variant phenotype is associated with a reduction in the level of global DNA methylation. To explore possible relationships between DNA methylation level and accumulation of DNA-(cytosine-5) methyltransferase (DNMT) transcripts, the full-length coding sequences corresponding to three different DNMT families in oil palm, namely the MET, CMT, and DRM classes, have been isolated and characterized. The corresponding genes were designated as EgMET1, EgCMT1, and EgDRM1, and encode predicted polypeptides of 1543, 925, and 591 amino acid residues, respectively. Expression of oil palm DNMTs was compared between normal and variant calli and inflorescence tissues using quantitative reverse-transcription PCR. A consistent increase in transcript levels of EgMET1 and EgCMT1 was found in variant fast-growing calli relative to nodular-compact calli. Nodular-compact calli give rise to about 5% of abnormal regenerants whereas fast-growing calli generate 95% of 'mantled' palms in their clonal offspring and were previously demonstrated as having markedly hypomethylated DNA. In immature abnormal inflorescences only EgMET1 transcript levels were increased, while no changes in relative abundance of the EgCMT1 or EgDRM1 transcripts were observed. Therefore, the genome-wide hypomethylation previously described in 'mantled' material cannot be explained by a decrease in expression levels of the de novo or maintenance DNMTs, a paradox which has been previously reported in tumour cells, where there is evidence for global hypomethylation of DNA. Eukaryotic DNA cytosine methylation can be used to transcriptionally silence repetitive sequences, including transposons and retroviruses. This silencing is stable between cell generations as cytosine methylation is maintained epigenetically through DNA replication. The Arabidopsis thaliana Dnmt3 cytosine methyltransferase ortholog DOMAINS rearranged methyltransferase2 (DRM2) is required for establishment of small interfering RNA (siRNA) directed DNA methylation. In mammals PIWI proteins and piRNA act in a convergently evolved RNA-directed DNA methylation system that is required to repress transposon expression in the germ line. De novo methylation may also be independent of RNA interference and small RNAs, as in Neurospora crassa. Here we identify a clade of catalytically mutated DRM2 paralogs in flowering plant genomes, which in A.thaliana we term domains rearranged methyltransferase3 (DRM3). Despite being catalytically mutated, DRM3 is required for normal maintenance of non-CG DNA methylation, establishment of RNA-directed DNA methylation triggered by repeat sequences and accumulation of repeat-associated small RNAs. Although the mammalian catalytically inactive Dnmt3L paralogs act in an analogous manner, phylogenetic analysis indicates that the DRM and Dnmt3 protein families diverged independently in plants and animals. We also show by site-directed mutagenesis that both the DRM2 N-terminal UBA domains and C-terminal methyltransferase domain are required for normal RNA-directed DNA methylation, supporting an essential targeting function for the UBA domains. These results suggest that plant and mammalian RNA-directed DNA methylation systems consist of a combination of ancestral and convergent features. DNA methylation plays a critical role in controlling states of gene activity in most eukaryotic organisms, and it is essential for proper growth and development. Patterns of methylation are established by de novo methyltransferases and maintained by maintenance methyltransferase activities. The Dnmt3 family of de novo DNA methyltransferases has recently been characterized in animals. Here we describe DNA methyltransferase genes from both Arabidopsis and maize that show a high level of sequence similarity to Dnmt3, suggesting that they encode plant de novo methyltransferases. Relative to all known eukaryotic methyltransferases, these plant proteins contain a novel arrangement of the motifs required for DNA methyltransferase catalytic activity. The N termini of these methyltransferases contain a series of ubiquitin-associated (UBA) domains. UBA domains are found in several ubiquitin pathway proteins and in DNA repair enzymes such as Rad23, and they may be involved in ubiquitin binding. The presence of UBA domains provides a possible link between DNA methylation and ubiquitin/proteasome pathways. In Arabidopsis a SWI2/SNF2 chromatin remodeling factor-related protein DDM1 and a cytosine methyltransferase MET1 are required for maintenance of genomic cytosine methylation. Mutations in either gene cause global demethylation. In this work we have assessed the effects of these mutations on the PAI tryptophan biosynthetic gene family, which consists of four densely methylated genes arranged as a tail-to-tail inverted repeat plus two unlinked singlet genes. The methylation mutations caused only partial demethylation of the PAI loci: ddm1 had a strong effect on the singlet genes but a weaker effect on the inverted repeat, whereas met1 had a stronger effect on the inverted repeat than on the singlet genes. The double ddm1 met1 mutant also displayed partial demethylation of the PAI genes, with a pattern similar to the ddm1 single mutant. To determine the relationship between partial methylation and expression for the singlet PAI2 gene we constructed a novel reporter strain of Arabidopsis in which PAI2 silencing could be monitored by a blue fluorescent plant phenotype diagnostic of tryptophan pathway defects. This reporter strain revealed that intermediate levels of methylation correlate with intermediate suppression of the fluorescent phenotype. DNA methyltransferase2 (DNMT2) is always deemed to be enigmatic, because it contains highly conserved DNA methyltransferase motifs but lacks the DNA methylation catalytic capability. Here we show that Arabidopsis DNA methyltransferase2 (AtDNMT2) is localized in nucleus and associates with histone deacetylation. Bimolecular fluorescence complementation and pull-down assays show AtDNMT2 interacts with type-2 histone deacetylases (AtHD2s), a unique type of histone deacetylase family in plants. Through analyzing the expression of AtDNMT2: ss-glucuronidase (GUS) fusion protein, we demonstrate that AtDNMT2 has the ability to repress gene expression at transcription level. Meanwhile, the expression of AtDNMT2 gene is altered in athd2c mutant plants. We propose that AtDNMT2 possibly involves in the activity of histone deacetylation and plant epigenetic regulatory network. Using the 1kb 3' terminal DNA fragment of the mouse methyltransferase cDNA as a probe and low stringent hybridisation conditions, a new potential methyltransferase (MTase) gene family was isolated from an Arabidopsis thaliana genomic DNA library. One clone (MTase-11), which gave the strongest signal at the Northern blot, was entirely sequenced (11483 bp) and further characterised. Under consideration of the likely open reading frames and our preliminary cDNA experiments we propose that the clone 11 gene encodes for an approximately 90 kD protein. As deduced form the DNA sequence this protein contains all conserved sequence motifs specific for the 5m cytosine MTases. MTase-11 gene expression was demonstrable in callus and during germination but not in one month old plants or in leaves.

Where is the histone variant CENPA preferentially localized?

Centromere protein A (Cenpa for mouse, CENP-A for other species) is an essential histone H3-like protein that localizes to the centromeric region of eukaryotic chromosomes, where it replaces conventional histone H3 and together with centromere-specific-DNA-binding factors directs the assembly of active kinetochores.

[12011073, 18314594, 12953060, 21888900, 20940262, 12217960, 20119530, 10655499, 18411404, 24213134, 23562479, 16314512, 23439889, 12906131, 19778997, 9465302, 9605877, 21508988]

Poly(ADP-ribose) polymerase-1 (PARP-1) is activated by DNA strand breaks during cellular genotoxic stress response and catalyzes poly(ADP-ribosyl)ation of acceptor proteins. These acceptor proteins include those involved in modulation of chromatin structure, DNA synthesis, DNA repair, transcription, and cell cycle control. Thus, PARP-1 is believed to play a pivotal role in maintaining genome integrity through modulation of protein-protein and protein-DNA interactions. We previously described the association of PARP-1 with normal mammalian centromeres and human neocentromeres by affinity purification and immunofluorescence. Here we investigated the interaction of this protein with, and poly(ADP-ribosyl)ation of, three constitutive centromere proteins, Cenpa, Cenpb, and Cenpc, and a spindle checkpoint protein, Bub3. Immunoprecipitation and Western blot analyses demonstrate that Cenpa, Cenpb, and Bub3, but not Cenpc, interacted with PARP-1, and are poly(ADP-ribosyl)ated following induction of DNA damage. The results suggest a role of PARP-1 in centromere assembly/disassembly and checkpoint control. Demonstration of PARP-1-binding and poly(ADP-ribosyl)ation in three of the four proteins tested further suggests that many more centromere proteins may behave similarly and implicates PARP-1 as an important regulator of diverse centromere function. Poly(ADP-ribose) polymerase 2 (PARP-2) is a newly discovered member of the PARP family. We report the association of PARP-2 with mammalian centromeres in a cell-cycle-dependent manner, accumulating at centromeres during prometaphase and metaphase, disassociating during anaphase, and disappearing from the centromeres by telophase. Analysis of a pseudodicentric chromosome and a human neocentromere indicates that PARP-2 binding occurs only at active centromeres in a sequence-independent manner. Centromere binding peaks at the outer centromere region, and is significantly enhanced upon treatment with microtubule-inhibiting drugs. Co-immunoprecipitation assay demonstrates interaction between PARP-2 and its functional homolog PARP-1, constitutive centromere proteins Cenpa and Cenpb, and spindle checkpoint protein Bub3, but not with a third constitutive centromere protein Cenpc. These results, together with our previous demonstration that PARP-1 displays an identical binding pattern with Cenpa, Cenpb and Bub3, but not Cenpc, and that all three proteins undergo significant poly(ADP-ribosyl)ation upon gamma-irradiation of cells, point to possible diverse roles of PARP-2 and PARP-1 in modulating the structure and checkpoint functions of the mammalian centromere, in particular during radiation-induced DNA damage. Inheritance of genetic material requires that chromosomes segregate faithfully during cell division. Failure in this process can drive to aneuploidy phenomenon. Kinetochores are unique centromere macromolecular protein structures that attach chromosomes to the spindle for a proper movement and segregation. A unique type of nucleosomes of centromeric chromatin provides the base for kinetochore formation. A specific histone H3 variant, CENPA, replaces conventional histone H3 and together with centromere-specific-DNA-binding factors directs the assembly of active kinetochores. Recent studies on CENPA nucleosomal structure, epigenetic inheritance of centromeric chromatin and transcription of pericentric heterochromatin provide new clues to our understanding of centromere structure and function. This review highlights the role and dynamics of CENPA assembly into centromeres and the potential contribution of this kinetochore protein to autoimmune and cancer diseases in humans. Centromere protein A (Cenpa for mouse, CENP-A for other species) is a histone H3-like protein that is thought to be involved in the nucleosomal packaging of centromeric DNA. Using gene targeting, we have disrupted the mouse Cenpa gene and demonstrated that the gene is essential. Heterozygous mice are healthy and fertile whereas null mutants fail to survive beyond 6.5 days postconception. Affected embryos show severe mitotic problems, including micronuclei and macronuclei formation, nuclear bridging and blebbing, and chromatin fragmentation and hypercondensation. Immunofluorescence analysis of interphase cells at day 5.5 reveals complete Cenpa depletion, diffuse Cenpb foci, absence of discrete Cenpc signal on centromeres, and dispersion of Cenpb and Cenpc throughout the nucleus. These results suggest that Cenpa is essential for kinetochore targeting of Cenpc and plays an early role in organizing centromeric chromatin at interphase. The evidence is consistent with the proposal of a critical epigenetic function for CENP-A in marking a chromosomal region for centromere formation. A key element for defining the centromere identity is the incorporation of a specific histone H3, CENPA, known as Cnp1p in Schizosaccharomyces pombe. Previous studies have suggested that functional S. pombe centromeres lack regularly positioned nucleosomes and may involve chromatin remodeling as a key step of kinetochore assembly. We used tiling microarrays to show that nucleosomes are, in fact, positioned in regular intervals in the core of centromere 2, providing the first high-resolution map of regional centromere chromatin. Nucleosome locations are not disrupted by mutations in kinetochore protein genes cnp1, mis18, mis12, nuf2, mal2; overexpression of cnp1; or the deletion of ams2, which encodes a GATA-like factor participating in CENPA incorporation. Bioinformatics analysis of the centromere sequence indicates certain enriched motifs in linker regions between nucleosomes and reveals a sequence bias in nucleosome positioning. In addition, sequence analysis of nucleosome-free regions identifies novel binding sites of Ams2p. We conclude that centromeric nucleosome positions are stable and may be derived from the underlying DNA sequence. The Forkhead box m1 (Foxm1) gene is critical for G(1)/S transition and essential for mitotic progression. However, the transcriptional mechanisms downstream of FoxM1 that control these cell cycle events remain to be determined. Here, we show that both early-passage Foxm1(-)(/)(-) mouse embryonic fibroblasts (MEFs) and human osteosarcoma U2OS cells depleted of FoxM1 protein by small interfering RNA fail to grow in culture due to a mitotic block and accumulate nuclear levels of cyclin-dependent kinase inhibitor (CDKI) proteins p21(Cip1) and p27(Kip1). Using quantitative chromatin immunoprecipitation and expression assays, we show that FoxM1 is essential for transcription of the mitotic regulatory genes Cdc25B, Aurora B kinase, survivin, centromere protein A (CENPA), and CENPB. We also identify the mechanism by which FoxM1 deficiency causes elevated nuclear levels of the CDKI proteins p21(Cip1) and p27(Kip1). We provide evidence that FoxM1 is essential for transcription of Skp2 and Cks1, which are specificity subunits of the Skp1-Cullin 1-F-box (SCF) ubiquitin ligase complex that targets these CDKI proteins for degradation during the G(1)/S transition. Moreover, early-passage Foxm1(-)(/)(-) MEFs display premature senescence as evidenced by high expression of the senescence-associated beta-galactosidase, p19(ARF), and p16(INK4A) proteins. Taken together, these results demonstrate that FoxM1 regulates transcription of cell cycle genes critical for progression into S-phase and mitosis. CENP-A is an essential histone H3-like protein that localizes to the centromeric region of eukaryotic chromosomes. Heterozygous and homozygous Cenpa-GFP fusion-protein mouse mutants, generated through targeted insertion of the green fluorescent protein (GFP) gene into the mouse Cenpa gene locus, show specific localized fluorescence at all the centromeres. Heterozygous mice are healthy and fertile. Cenpa-GFP homozygotes (Cenpag/g) undergo many cell divisions, giving rise to up to one million cells that show relatively accurate differentiation into distinct mouse embryonic tissues until day 10.5 when significant levels of chromosome missegregation, aneuploidy and apoptosis result in death. Cenpag/g embryos assemble functional kinetochores that bind to a host of centromere-specific structural and mitotic spindle checkpoint proteins (Cenpc, BubR1, Mad2 and Zw10). Examination of the nucleosomal phasing of centromeric minor and pericentromeric major satellite sequences indicates that the formation of Cenpag/g homotypic nucleosomes is not accompanied by any overt alteration to the overall size of the monomeric nucleosomal structure or the spacing of these structures. This study provides the first example of an essential centromeric protein gene variant in which subtle perturbation at the centromeric nucleosomal/chromatin level manifests in a significantly delayed lethality when compared with Cenpa null mice. We have determined the genomic structure and organization of the mouse Cenpa and Cenpc genes. CENPA is a member of the histone H3-like proteins and is thought to replace histone H3 in centromeric nucleosomes. CENPC is a DNA-binding protein that is located at the inner kinetochore plate of active mammalian centromeres. The Cenpa cDNA encodes a 134-amino-acid product that is 70% identical and 84% similar to its human homolog. The mouse Cenpa gene is approximately 8 kb in length and contains five exons. Sequence analysis of the 5' DNA sequence of the gene revealed two consensus CAAT boxes, a putative TFIID-binding site, an Sp1-binding domain, and two cell cycle regulatory motifs, but no consensus TATA element. The mouse Cenpc gene spans 60 kb and contains 19 exons that range in size from 44 to 602 bp. Sequence analysis of the C+G-rich promoter region showed the presence of known promoter elements, including a CpG island, a CAAT box, and several GC boxes, but the absence of a consensus TATA element. Using a previously isolated mouse centromere protein A (Cenpa) probe, we have localized the gene to the proximal region of mouse Chromosome 5, between the known Il6 and Yes1 loci near [Adra2C-D5H4S43-Hdh]. Comparison of this localization with that of human CENPA, which maps to chromosome 2, is consistent with the presence of a new region of conserved synteny between the two species. Fidelity during chromosome segregation is essential to prevent aneuploidy. The proteins and chromatin at the centromere form a unique site for kinetochore attachment and allow the cell to sense and correct errors during chromosome segregation. Centromeric chromatin is characterized by distinct chromatin organization, epigenetics, centromere-associated proteins and histone variants. These include the histone H3 variant centromeric protein A (CENPA), the composition and deposition of which have been widely investigated. Studies have examined the structural and biophysical properties of the centromere and have suggested that the centromere is not simply a 'landing pad' for kinetochore formation, but has an essential role in mitosis by assembling and directing the organization of the kinetochore.

In which proteins is the chromodomain present?

The chromodomain (chromatin organizer modifier domain) is a highly conserved motif, 40-50 amino acids in length, present in a wide range of animal and plant proteins involved in chromatin organization. Chromodomain-containing proteins can be classified into boader families based, particularly, on the presence of other types of domains. Chromodomain is present in: the heterochromatin proteins HP1 alpha and HP1 beta, chromointgrases (e.g. Tf1 integrase) the chromodomain helicase DNA-binding proteins (CHD) and CHD 1-like (CHD1L), CReMM (chromatin-related mesenchymal modulator), dna methyltransferase 3 (cmt3), the chromointegrase of the LTR-retrotransposons, the Polycomb group (PcG) proteins, the mouse Polycomb homologs (Cbx2, Cbx4, Cbx6, Cbx7, Cbx8), the chromodomain Y chromosome (CDY) family of proteins and the CDY-like protein (CDYL), the histone acetyltransferases TgMYST-A and –B, MRG-1 and -15 (MORF4-Related Gene on chromosome 15), ADP/ATP translocase 1, MPP8, MSL3, NlMof, Chp1, Chriz, dMi-2, Corto, cpSRP43, KISMET, PICKLE (PKL), ScoHET1 and ScoHET2.

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Homologous chromosome pairing is a prerequisite to establish physical linkage between homologs, which is critical for faithful chromosome segregation during meiosis I. The establishment of pairing is genetically separable from subsequent synapsis, defined as stabilization of pairing by the synaptonemal complex (SC). The underlying mechanism of presynaptic pairing is poorly understood. In the nematode Caenorhabditis elegans, a unique cis-acting element, the pairing center (PC), is essential for presynaptic pairing; however, it is not known whether and how the remainder of the chromosome contributes to presynaptic pairing. Here we report direct evidence for presynaptic pairing activity intrinsic to non-PC regions, which is facilitated by a conserved chromodomain protein, MRG-1. In mrg-1 loss-of-function mutants, pairing is compromised specifically in non-PC regions, leading to nonhomologous SC assembly. Our data support a model in which presynaptic alignment in non-PC regions collaborates with initial PC pairing to ensure correct homologous synapsis. CHD7 is a member of the chromodomain helicase DNA binding domain (CHD) family of ATP-dependent chromatin remodelling enzymes. It is mutated in CHARGE syndrome, a multiple congenital anomaly condition. CHD7 is one of a subset of CHD proteins, unique to metazoans that contain the BRK domain, a protein module also found in the Brahma/BRG1 family of helicases. We describe here the NMR solution structure of the two BRK domains of CHD7. Each domain has a compact betabetaalphabeta fold. The second domain has a C-terminal extension consisting of two additional helices. The structure differs from those of other domains present in chromatin-associated proteins. Chromatin remodelers are ATP-dependent machines that dynamically alter the chromatin packaging of eukaryotic genomes by assembling, sliding, and displacing nucleosomes. The Chd1 chromatin remodeler possesses a C-terminal DNA-binding domain that is required for efficient nucleosome sliding and believed to be essential for sensing the length of DNA flanking the nucleosome core. The structure of the Chd1 DNA-binding domain was recently shown to consist of a SANT and SLIDE domain, analogous to the DNA-binding domain of the ISWI family, yet the details of how Chd1 recognized DNA were not known. Here we present the crystal structure of the Saccharomyces cerevisiae Chd1 DNA-binding domain in complex with a DNA duplex. The bound DNA duplex is straight, consistent with the preference exhibited by the Chd1 DNA-binding domain for extranucleosomal DNA. Comparison of this structure with the recently solved ISW1a DNA-binding domain bound to DNA reveals that DNA lays across each protein at a distinct angle, yet contacts similar surfaces on the SANT and SLIDE domains. In contrast to the minor groove binding seen for Isw1 and predicted for Chd1, the SLIDE domain of the Chd1 DNA-binding domain contacts the DNA major groove. The majority of direct contacts with the phosphate backbone occur only on one DNA strand, suggesting that Chd1 may not strongly discriminate between major and minor grooves. Polycomb group (PcG) proteins are essential to maintain gene expression patterns during development. Transcriptional repression by PcG proteins involves trimethylation of H3K27 (H3K27me3) by Polycomb Repressive Complex 2 (PRC2) in animals and plants. PRC1 binds to H3K27me3 and is required for transcriptional repression in animals, but in plants PRC1-like activities have remained elusive. One candidate protein that could be involved in PRC1-like functions in plants is LIKE HETEROCHROMATIN PROTEIN 1 (LHP1), because LHP1 associates with genes marked by H3K27me3 in vivo and has a chromodomain that binds H3K27me3 in vitro. Here, we show that disruption of the chromodomain of Arabidopsis thaliana LHP1 abolishes H3K27me3 recognition, releases gene silencing and causes similar phenotypic alterations as transcriptional lhp1 null mutants. Therefore, binding to H3K27me3 is essential for LHP1 protein function. The chromodomain, helicase, DNA-binding protein 5 (CHD5) is a chromatin remodeling enzyme which is implicated in tumor suppression. In this study, we demonstrate the ability of the CHD5 PHD fingers to specifically recognize the unmodified N-terminus of histone H3. We use two distinct modified peptide-library platforms (beads and glass slides) to determine the detailed histone binding preferences of PHD(1) and PHD(2) alone and the tandem PHD(1-2) construct. Both domains displayed similar binding preferences for histone H3, where modification (e.g., methylation, acetylation, and phosphorylation) at H3R2, H3K4, H3T3, H3T6, and H3S10 disrupts high-affinity binding, and the three most N-terminal amino acids (ART) are crucial for binding. The tandem CHD5-PHD(1-2) displayed similar preferences to those displayed by each PHD finger alone. Using NMR, surface plasmon resonance, and two novel biochemical assays, we demonstrate that CHD5-PHD(1-2) simultaneously engages two H3 N-termini and results in a 4-11-fold increase in affinity compared with either PHD finger alone. These studies provide biochemical evidence for the utility of tandem PHD fingers to recruit protein complexes at targeted genomic loci and provide the framework for understanding how multiple chromatin-binding modules function to interpret the combinatorial PTM capacity written in chromatin. Emerging evidence implicates the chromodomain helicase/ATPase DNA binding protein 1-like gene (CHD1L) as a specific oncogene in human hepatocellular carcinoma (HCC). To better understand the molecular mechanisms underlying HCC cases carrying CHD1L amplification (>50% HCCs), we identified a CHD1L target, translationally controlled tumor protein (TCTP), and investigated its role in HCC progression. Here, we report that CHD1L protein directly binds to the promoter region (nt -733 to -1,027) of TCTP and activates TCTP transcription. Overexpression of TCTP was detected in 40.7% of human HCC samples analyzed and positively correlated with CHD1L overexpression. Clinically, overexpression of TCTP was significantly associated with the advanced tumor stage (P = 0.037) and overall survival time of HCC patients (P = 0.034). In multivariate analyses, TCTP was determined to be an independent marker associated with poor prognostic outcomes. In vitro and in vivo functional studies in mice showed that TCTP has tumorigenic abilities, and overexpression of TCTP induced by CHD1L contributed to the mitotic defects of tumor cells. Further mechanistic studies demonstrated that TCTP promoted the ubiquitin-proteasome degradation of Cdc25C during mitotic progression, which caused the failure in the dephosphorylation of Cdk1 on Tyr15 and decreased Cdk1 activity. As a consequence, the sudden drop of Cdk1 activity in mitosis induced a faster mitotic exit and chromosome missegregation, which led to chromosomal instability. The depletion experiment proved that the tumorigenicity of TCTP was linked to its role in mitotic defects. CONCLUSION: Collectively, we reveal a novel molecular pathway (CHD1L/TCTP/Cdc25C/Cdk1), which causes the malignant transformation of hepatocytes with the phenotypes of accelerated mitotic progression and the production of aneuploidy. Chromatin remodelers are ATP-dependent machines responsible for directionally shifting nucleosomes along DNA. We are interested in defining which elements of the chromodomain helicase DNA-binding protein 1 (Chd1) remodeler are necessary and sufficient for sliding nucleosomes. This work focuses on the polypeptide segment that joins the ATPase motor to the C-terminal DNA-binding domain. We identify amino acid positions outside the ATPase motor that, when altered, dramatically reduce nucleosome sliding ability and yet have only ∼3-fold reduction in ATPase stimulation by nucleosomes. These residues therefore appear to play a role in functionally coupling ATP hydrolysis to nucleosome sliding, and suggest that the ATPase motor requires cooperation with external elements to slide DNA past the histone core. AIM: Chromodomain helicase DNA-binding protein 5 (CHD5) plays a role in normal neural development and in tumorigenesis of various human cancers. However, its role in primary gallbladder carcinoma (PGC) is still unclear. The aim of this study was to investigate CHD5 expression in PGC and its clinical significance. METHODS: CHD5 mRNA and protein expression in 120 PGC and 20 normal gallbladder specimens was determined by quantitative reverse transcription-polymerase chain reaction (QRT-PCR) and Western blotting analysis, respectively. RESULTS: The expression levels of CHD5 mRNA and protein in PGC tissues were both significantly lower than those in the normal epithelium of the gallbladder (mRNA: P = 0.006; protein: P = 0.01). CHD5 mRNA expression was closely correlated with its protein expression (r = 0.8; P < 0.001). Additionally, the low expression of CHD5 protein was significantly associated with high pathologic T stage (P = 0.01) and clinical stage (P = 0.008), and advanced histologic grade (P = 0.009). The expression levels of CHD5 protein in PGC tissues with positive nodal metastasis were also significantly lower than those without (P = 0.01). Survival analysis showed that low CHD5 expression was associated with shorter disease-free (P = 0.01) and overall survival (P = 0.008) compared to those with high CHD5 expression in PGC patients. Furthermore, multivariate analyses showed that the decreased expression of CHD5 was an independent prognostic marker for both unfavorable disease-free (P = 0.01) and overall survival (P = 0.006). CONCLUSION: CHD5 may be involved in carcinogenesis of PGC and its down-regulation may be significantly correlated with unfavorable clinicopathologic features including poor overall and disease-free survival in patients. MRG15 is a novel chromodomain protein that is a member of a family of genes related to MORF4. MORF4 (mortality factor on chromosome 4) induces senescence in a subset of human tumor cell lines. Our previous results indicated that MRG15 (MORF-related gene on chromosome 15) could derepress the B-myb promoter by association with Rb. In this study, sucrose gradient analysis demonstrated that MRG15 was present in two distinct nuclear protein complexes, MAF1 (MRG15-associated factor 1) and MAF2. Rb was associated with MRG15 and PAM14 (a novel coil-coil protein) in MAF1, and a histone acetyl transferase, hMOF, was an MRG15 partner in MAF2. Analysis of deletion mutants of MRG15 indicated that the leucine zipper at the C-terminal region of MRG15 was important for the protein associations in MAF1 and that the N-terminal chromodomain was required for the assembly of the MAF2 protein complex. Consistent with these data was the fact that a histone acetyltransferase activity associated with MRG15 was lost when the chromodomain was deleted and that both mutant MRG15 proteins failed to activate the B-myb promoter. The various mechanisms by which MRG15 could activate gene transcription are discussed. Mutations in the CHD7 (chromodomain helicase DNA binding protein 7) gene cause CHARGE syndrome. At present, however, genetic testing of the CHD7 gene is not commonly applied in clinical settings because the currently available assays are technically and financially demanding, mainly because of the size of the gene. In the present study, we optimized the highly sensitive and specific mutation scanning method automated denaturing high-performance liquid chromatography (DHPLC) to analyze the entire coding region of CHD7. The coding region was amplified by 39 primer pairs, all of which have the same cycling conditions, aliquoted on a 96-well format polymerase chain reaction (PCR) plate. In this manner, all of the exons were amplified simultaneously using a single block in a thermal cycler. We then wrote a computer script to analyze each segment of the CHD7 gene by DHPLC in a serial manner using conditions that were optimized for each amplicon. The implementation of this screening method for CHD7 will help medical geneticists confirm their clinical impressions and provide accurate genetic counseling to the patients with CHARGE syndrome and their families. Centromeres serve as platforms for the assembly of kinetochores and are essential for nuclear division. Here we identified Neurospora crassa centromeric DNA by chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) of DNA associated with tagged versions of the centromere foundation proteins CenH3 (CENP-A) and CEN-C (CENP-C) and the kinetochore protein CEN-T (CENP-T). On each chromosome we found an ∼150- to 300-kbp region of enrichment for all three proteins. These regions correspond to intervals predicted to be centromeric DNA by genetic mapping and DNA sequence analyses. By ChIP-seq we found extensive colocalization of CenH3, CEN-C, CEN-T, and histone H3K9 trimethylation (H3K9me3). In contrast, H3K4me2, which has been found at the cores of plant, fission yeast, Drosophila, and mammalian centromeres, was not enriched in Neurospora centromeric DNA. DNA methylation was most pronounced at the periphery of centromeric DNA. Mutation of dim-5, which encodes an H3K9 methyltransferase responsible for nearly all H3K9me3, resulted in altered distribution of CenH3-green fluorescent protein (GFP). Similarly, CenH3-GFP distribution was altered in the absence of HP1, the chromodomain protein that binds to H3K9me3. We conclude that eukaryotes with regional centromeres make use of different strategies for maintenance of CenH3 at centromeres, and we suggest a model in which centromere proteins nucleate at the core but require DIM-5 and HP1 for spreading. A major challenge in chromatin biology is to understand the mechanisms by which chromatin is remodeled into active or inactive states as required during development and cell differentiation. One complex implicated in these processes is the nucleosome remodeling and histone deacetylase (NuRD) complex, which contains both histone deacetylase and nucleosome remodeling activities and has been implicated in the silencing of subsets of genes involved in various stages of cellular development. Chromodomain-helicase-DNA-binding protein 4 (CHD4) is a core component of the NuRD complex and contains a nucleosome remodeling ATPase domain along with two chromodomains and two plant homeodomain (PHD) fingers. We have previously demonstrated that the second PHD finger of CHD4 binds peptides corresponding to the N terminus of histone H3 methylated at Lys(9). Here, we determine the solution structure of PHD2 in complex with H3K9me3, revealing the molecular basis of histone recognition, including a cation-π recognition mechanism for methylated Lys(9). Additionally, we demonstrate that the first PHD finger also exhibits binding to the N terminus of H3, and we establish the histone-binding surface of this domain. This is the first instance where histone binding ability has been demonstrated for two separate PHD modules within the one protein. These findings suggest that CHD4 could bind to two H3 N-terminal tails on the same nucleosome or on two separate nucleosomes simultaneously, presenting exciting implications for the mechanism by which CHD4 and the NuRD complex could direct chromatin remodeling. BACKGROUND: We have previously demonstrated that the Y-specific ampliconic fertility genes DAZ (deleted in azoospermia) and CDY (chromodomain protein Y) varied with respect to copy number and position among chimpanzees (Pan troglodytes). In comparison, seven Y-chromosomal lineages of the bonobo (Pan paniscus), the chimpanzee's closest living relative, showed no variation. We extend our earlier comparative investigation to include an analysis of the intraspecific variation of these genes in gorillas (Gorilla gorilla) and orangutans (Pongo pygmaeus), and examine the resulting patterns in the light of the species' markedly different social and mating behaviors. METHODOLOGY/PRINCIPAL FINDINGS: Fluorescence in situ hybridization analysis (FISH) of DAZ and CDY in 12 Y-chromosomal lineages of western lowland gorilla (G. gorilla gorilla) and a single lineage of the eastern lowland gorilla (G. beringei graueri) showed no variation among lineages. Similar findings were noted for the 10 Y-chromosomal lineages examined in the Bornean orangutan (Pongo pygmaeus), and 11 Y-chromosomal lineages of the Sumatran orangutan (P. abelii). We validated the contrasting DAZ and CDY patterns using quantitative real-time polymerase chain reaction (qPCR) in chimpanzee and bonobo. CONCLUSION/SIGNIFICANCE: High intraspecific variation in copy number and position of the DAZ and CDY genes is seen only in the chimpanzee. We hypothesize that this is best explained by sperm competition that results in the variant DAZ and CDY haplotypes detected in this species. In contrast, bonobos, gorillas and orangutans-species that are not subject to sperm competition-showed no intraspecific variation in DAZ and CDY suggesting that monoandry in gorillas, and preferential female mate choice in bonobos and orangutans, probably permitted the fixation of a single Y variant in each taxon. These data support the notion that the evolutionary history of a primate Y chromosome is not simply encrypted in its DNA sequences, but is also shaped by the social and behavioral circumstances under which the specific species has evolved. Eukaryotic cells have evolved a variety of parallel and redundant DNA damage response pathways that function in a coordinated fashion to prevent the fixation of DNA damage as mutations. Despite the wealth of knowledge on DNA damage signaling on downstream cellular events, the mechanisms of DNA damage recognition, DNA repair as well as DNA damage signaling in the context of chromatin is poorly understood. Chromodomain helicase DNA-binding proteins (CHD) belong to a group of highly conserved chromatin remodeling proteins that are implicated in regulation of transcription. In an effort to understand the physiological role of one of the CHD members in a mammalian model system, we developed a mutant mouse model for the Chd2 gene. The Chd2 mutant mice are highly susceptible to spontaneous lymphoid tumor formation. In this study, we present evidence that the Chd2 mutant cells are defective in their ability to repair DNA damage induced by ionizing and ultraviolet radiation. Consistent with the role of Chd2 in regulating DNA damage responses, the Chd2 mutant cells are also sensitive to DNA damaging agents in clonogenic assays. In summary, our data suggest that the Chd2 protein is involved in regulating the DNA damage responses at the chromatin level. CHARGE (coloboma of the eye, heart defects, choanal atresia, retarded growth and development, genital hypoplasia and ear anomalies and/or hearing loss) syndrome is a rare genetic, multiple-malformation syndrome. About 80% of patients with a clinical diagnose, have a mutation or a deletion in the gene encoding chromodomain helicase DNA-binding protein 7 (CHD7). Genotype-phenotype correlation is only partly known. In this nationwide study, phenotypic characteristics of 18 Danish CHD7 mutation positive CHARGE individuals (N = 18) are presented. We studied patient records, clinical photographs, computed tomography, and magnetic resonance imaging (MRI). Information was not available for all traits in all subjects. Therefore, the results are presented as fractions. The following prevalence of cardinal symptoms were found: coloboma, 16/17; heart defects, 14/18; choanal atresia, 7/17; retarded growth and development, 11/13; genital abnormalities, 5/18; ear anomalies, 15/17 and sensorineural hearing loss, 14/15. Vestibular dysfunction (10/13) and swallowing problems (12/15) were other frequent cranial nerve dysfunctions. Three-dimensional reconstructions of MRI scans showed temporal bone abnormalities in >85%. CHARGE syndrome present a broad phenotypic spectrum, although some clinical features are more frequently occurring than others. Here, we suggest that genetic testing for CHD7 mutation should be considered in neonates with a specific combination of several clinical symptoms. Several key transcription factors and coregulators important to peripheral nerve myelination have been identified, but the contributions of specific chromatin remodeling complexes to peripheral nerve myelination have not been analyzed. Chromodomain helicase DNA-binding protein 4 (Chd4) is the core catalytic subunit of the nucleosome remodeling and deacetylase (NuRD) chromatin remodeling complex. Previous studies have shown Chd4 interacts with Nab (NGFI-A/Egr-binding) corepressors, which are required for early growth response 2 (Egr2/Krox20), to direct peripheral nerve myelination by Schwann cells. In this study, we examined the developmental importance of the NuRD complex in peripheral nerve myelination through the generation of conditional Chd4 knock-out mice in Schwann cells (Chd4(loxP/loxP); P0-cre). Chd4 conditional null mice were found to have delayed myelination, radial sorting defects, hypomyelination, and the persistence of promyelinating Schwann cells. Loss of Chd4 leads to elevated expression of immature Schwann cell genes (Id2, c-Jun, and p75), and sustained expression of the promyelinating Schwann cell gene, Oct6/Scip, without affecting the levels of Egr2/Krox20. Furthermore, Schwann cell proliferation is upregulated in Chd4-null sciatic nerve. In vivo chromatin immunoprecipitation studies reveal recruitment of Chd4 and another NuRD component, Mta2, to genes that are positively and negatively regulated by Egr2 during myelination. Together, these results underscore the necessity of Chd4 function to guide proper terminal differentiation of Schwann cells and implicate the NuRD chromatin remodeling complex as a requisite factor in timely and stable peripheral nerve myelination. We report here the molecular and cytological characterization of two proteins, ScoHET1 and ScoHET2 (for Sciara coprophila heterochromatin), which associate to constitutive heterochromatin in the dipteran S. coprophila. Both proteins, ScoHET1 of 37 kDa and ScoHET2 of 44 kDa, display two chromodomain motifs that contain the conserved residues essential for the recognition of methylated histone H3 at lysine 9. We raised antibodies to analyze the chromosomal location of ScoHET1 and ScoHET2 in somatic and germline cells. In S. coprophila polytene chromosomes, both proteins associate to the pericentromeric regions and to the heterochromatic subterminal bands of the chromosomes. In germinal nuclei, ScoHET1 and ScoHET2 proteins distribute to the heterochromatic regions of the regular chromosome complement and are abundantly present along the heterochromatic germline-limited "L" chromosomes. We investigated histone methylation modifications and found that all heterochromatic regions enriched in ScoHET1/ScoHET2 proteins exhibit high levels of di- and tri-methylated histone H3 at lysine 9. Taken together, our results support that the association of ScoHET1/ScoHET2 to heterochromatin is mediated by histone H3K9 methylation. Using 5-methylcytosine antibodies, we proved the cytological detection of DNA methylation in S. coprophila. From our observations in L germline chromosomes, heterochromatin in S. coprophila is highly enriched in DNA 5-methylcytosine residues. The chromodomain (CD) is a highly conserved motif present in a variety of animal and plant proteins, and its probable role is to assemble a variety of macromolecular complexes in chromatin. The importance of the CD to the survival of mammalian cells has been tested. Accordingly, we have ablated CD function using two single-chain intracellular Fv (scFv) fragments directed against non-overlapping epitopes within the HP1 CD motif. The scFv fragments can recognize both CD motifs of HP1 and Polycomb (Pc) in vitro and, when expressed intracellularly, interact with and dislodge the HP1 protein(s) from their heterochromatin localization in vivo. Mouse and human fibroblasts expressing anti-chromodomain scFv fragments show a cell-lethal phenotype and an apoptotic morphology becomes apparent soon after transfection. The mechanism of cell death appears to be p53 independent, and the cells are only partly rescued by incubation with the wide spectrum caspase inhibitor Z-VAD fmk. We conclude that expression of anti-chromodomain intracellular antibodies is sufficient to trigger a p53-independent apoptotic pathway that is only partly dependent on the known Z-VAD-inhibitable caspases, suggesting that CD function is essential for cell survival. BACKGROUND: An underlying tenet of the epigenetic code hypothesis is the existence of protein domains that can recognize various chromatin structures. To date, two major candidates have emerged: (i) the bromodomain, which can recognize certain acetylation marks and (ii) the chromodomain, which can recognize certain methylation marks. RESULTS: The Epc-N (Enhancer of Polycomb-N-terminus) domain is formally defined herein. This domain is conserved across eukaryotes and is predicted to form a right-handed orthogonal four-helix bundle with extended strands at both termini. The types of amino acid residues that define the Epc-N domain suggest a role in mediating protein-protein interactions, possibly specifically in the context of chromatin binding, and the types of proteins in which it is found (known components of histone acetyltransferase complexes) strongly suggest a role in epigenetic structure formation and/or recognition. There appear to be two major Epc-N protein families that can be divided into four unique protein subfamilies. Two of these subfamilies (I and II) may be related to one another in that subfamily I can be viewed as a plant-specific expansion of subfamily II. The other two subfamilies (III and IV) appear to be related to one another by duplication events in a primordial fungal-metazoan-mycetozoan ancestor. Subfamilies III and IV are further defined by the presence of an evolutionarily conserved five-center-zinc-binding motif in the loop connecting the second and third helices of the four-helix bundle. This motif appears to consist of a PHD followed by a mononuclear Zn knuckle, followed by a PHD-like derivative, and will thus be referred to as the PZPM. All non-Epc-N proteins studied thus far that contain the PZPM have been implicated in histone methylation and/or gene silencing. In addition, an unusual phyletic distribution of Epc-N-containing proteins is observed. CONCLUSION: The data suggest that the Epc-N domain is a protein-protein interaction module found in chromatin associated proteins. It is possible that the Epc-N domain serves as a direct link between histone acetylation and methylation statuses. The unusual phyletic distribution of Epc-N-containing proteins may provide a conduit for future insight into how different organisms form, perceive and respond to epigenetic information. Green-striped burrowing frogs, Cyclorana alboguttata, survive droughts by entering a metabolic depression called aestivation, characterised by a reduction in resting oxygen consumption by 80%. Aestivation in C. alboguttata is manifest by transcriptional silencing of skeletal muscle bioenergetic genes, such as NADH ubiquinone oxidoreductase 1, ATP synthase and superoxide dismutase 2. In this study, we hypothesised that aestivation is associated with epigenetic change in frog muscle. We assessed mRNA transcript abundance of seven genes that code for proteins with established roles in epigenetically-mediated gene silencing [transcriptional co-repressor SIN3A, DNA (cytosine-5-) methyltransferase 1, methyl CpG binding protein 2, chromodomain helicase DNA binding protein 4, histone binding protein rbbp4, histone deacetylase 1 and nuclear receptor co-repressor 2] using qRT-PCR. These seven genes showed a modest (1.1-3.5-fold) but coordinated upregulation in 6-month aestivating muscle. This reached significance for SIN3A and DNA cytosine-5-methyltransferase 1 in standard pair-wise comparisons (p < 0.05), and the candidates as a whole when analysed by Fisher's combined probability test (p < 0.01). These data are consistent with the hypothesis that the transcriptional silencing and metabolic depression that occurs during seasonal dormancy are associated with chromatin remodelling, and present a novel example of an environmentally induced epigenetic modification in an adult vertebrate. Chromatin insulators are boundary elements between distinctly regulated, neighboring chromosomal domains, and they function by blocking the effects of nearby enhancers in a position-dependent manner. Here, we show that the SNF2-like chromodomain helicase protein CHD8 interacts with the insulator binding protein CTCF. Chromatin immunoprecipitation analysis revealed that CHD8 was present at known CTCF target sites, such as the differentially methylated region (DMR) of H19, the locus control region of beta-globin, and the promoter region of BRCA1 and c-myc genes. RNA interference-mediated knockdown of CHD8 significantly abolished the H19 DMR insulator activity that depends highly on CTCF, leading to reactivation of imprinted IGF2 from chromosome of maternal origin. Further, the lack of CHD8 affected CpG methylation and histone acetylation around the CTCF binding sites, adjacent to heterochromatin, of BRCA1 and c-myc genes. These findings provide insight into the role of CTCF-CHD8 complex in insulation and epigenetic regulation at active insulator sites. M-phase phosphoprotein 8 (MPP8) harbors an N-terminal chromodomain and a C-terminal ankyrin repeat domain. MPP8, via its chromodomain, binds histone H3 peptide tri- or di-methylated at lysine 9 (H3K9me3/H3K9me2) in submicromolar affinity. We determined the crystal structure of MPP8 chromodomain in complex with H3K9me3 peptide. MPP8 interacts with at least six histone H3 residues from glutamine 5 to serine 10, enabling its ability to distinguish lysine-9-containing peptide (QTARKS) from that of lysine 27 (KAARKS), both sharing the ARKS sequence. A partial hydrophobic cage with three aromatic residues (Phe59, Trp80 and Tyr83) and one aspartate (Asp87) encloses the methylated lysine 9. MPP8 has been reported to be phosphorylated in vivo, including the cage residue Tyr83 and the succeeding Thr84 and Ser85. Modeling a phosphate group onto the side-chain hydroxyl oxygen of Tyr83 suggests that the negatively charged phosphate group could enhance the binding of positively charged methyl-lysine or create a regulatory signal by allowing or inhibiting binding of other protein(s). HP1 proteins are major components of heterochromatin, which is generally perceived to be an inert and transcriptionally inactive chromatin structure. Yet, HP1 binding to chromatin is highly dynamic and robust silencing of heterochromatic genes can involve RNA processing. Here, we demonstrate by a combination of in vivo and in vitro experiments that the fission yeast HP1(Swi6) protein guarantees tight repression of heterochromatic genes through RNA sequestration and degradation. Stimulated by positively charged residues in the hinge region, RNA competes with methylated histone H3K9 for binding to the chromodomain of HP1(Swi6). Hence, HP1(Swi6) binding to RNA is incompatible with stable heterochromatin association. We propose a model in which an ensemble of HP1(Swi6) proteins functions as a heterochromatin-specific checkpoint, capturing and priming heterochromatic RNAs for the RNA degradation machinery. Sustaining a functional checkpoint requires continuous exchange of HP1(Swi6) within heterochromatin, which explains the dynamic localization of HP1 proteins on heterochromatin. Chromodomain helicase DNA binding protein 5 (CHD5) is a potent tumor suppressor that serves as a master regulator of a tumor-suppressive network. Examination of the role played by CHD5 in a wide range of human cancers is warranted. In this study, we focused on the epigenetic modification and tumor-suppressive role of CHD5 in lung cancer. We measured CHD5 mRNA and protein expression in lung cancer cells, lung cancer tissues, and their corresponding noncancerous lung tissues using real-time PCR and Western blot analysis. We then determined the methylation status of the CHD5 promoter in these samples using methylation-specific sequencing and analyzed CHD5 re-expression in lung cancer cells treated with or without 5-aza-2-deoxycytidine, an inhibitor of DNA methylation. Next, the lung cancer cell clones stably expressing EGFP-CHD5 protein or EGFP protein, respectively, were obtained and the effects of restored CHD5 expression on cell proliferation, colony formation, and tumorigenicity were assessed. CHD5 expression ranged from low to absent in the lung cancer cell lines and tissues examined; the CHD5 promoter was hyperethylated in these samples. Treatment with 5-aza-dC resulted in a localized decrease in methylation density and an increase in CHD5 expression. Clonogenicity and tumor growth were abrogated in A549 and H1299 cells upon restoration of CHD5 expression. A significant reduction in clonogenicity was observed; an average of 47.83 ± 4.6% reduction for A549-EGFP-CHD5 was observed compared to A549-EGFP, and an average of 56.39 ± 5.3% reduction for H1299-EGFP-CHD5 was observed compared to H1299-EGFP. A549-EGFP exhibited an average tumor size of 452.3 ± 36.5 mm(3), whereas A549-EGFP-CHD5 exhibited an average tumor size of only 57.7 ± 18.5 mm(3). Thus, our findings indicate that CHD5 is a potential tumor suppressor gene that is inactivated via an epigenetic mechanism in lung cancer. Histone acetylation is a vital mechanism for the post-translational modifications of chromatin components. Histone acetyltransferases (HATs) are critical elements that determine histone acetylation and regulate chromatin dynamics and gene expression. While histone acetyltransferases have been well studied in mammals and Drosophila melanogaster, information from agriculturally important insect pests is still limited. In our effort to understand the epigenetic mechanisms regulating development in the brown planthopper, Nilaparvata lugens (Stål) (Hemiptera: Geometroidea), a major rice pest in many parts of Asia, two full-length cDNA sequences encoding HAT members of the GNAT and MYST family, namely NlElp3 and NlMof, respectively, were isolated and structurally and phylogenetically characterized. The NlElp3 contains an open reading frame (ORF) of 1656bp encoding a protein of 551 amino acids. The NlMof contains a 1353bp ORF encoding a protein of 450 amino acids. Sequence analysis showed that NlElp3 contains GNAT-type HAT domain and Radical SAM domain, and NlMof contains chromodomain and MOZ-SAS acetyltransferase domain. Multiple sequence alignments showed that NlElp3 and NlMof have high amino acid sequence identity with other insect homologues. Expression analysis of the NlElp3 and NlMof revealed significant differences in mRNA expression levels among N. lugens developmental stages, suggesting that HAT activities of NlElp3 and NlMof may be controlled, at least in part, by their developmental regulation. Remarkably, the mRNA expression levels of NlElp3 and NlMof in female adults were significantly higher than that in male adults, supporting an important role for both genes in female reproductive function in N. lugens. Analysis of the Neurospora crassa chromodomain protein CDP-2, a component of a newly characterized HP1-containing complex, reveals a second gene-silencing mechanism and provides insights into the dynamic nature of chromatin domains that possess shared components. Cell differentiation is mediated by lineage-determining transcription factors. We show that chromodomain helicase DNA-binding domain 2 (Chd2), a SNF2 chromatin remodelling enzyme family member, interacts with MyoD and myogenic gene regulatory sequences to specifically mark these loci via deposition of the histone variant H3.3 prior to cell differentiation. Directed and genome-wide analysis of endogenous H3.3 incorporation demonstrates that knockdown of Chd2 prevents H3.3 deposition at differentiation-dependent, but not housekeeping, genes and inhibits myogenic gene activation. The data indicate that MyoD determines cell fate and facilitates differentiation-dependent gene expression through Chd2-dependent deposition of H3.3 at myogenic loci prior to differentiation. Heterochromatin patterns were analyzed in the genus Ctenomys from Uruguay which exhibits high karyotype variability. Different amounts and localizations of heterochromatin were observed in species and populations analyzed. While species as C. rionegrensis presented heterochromatic arms in all the chromosomes of the karyotype, other species like C. torquatus showed only few chromosomes with pericentric heterochromatin. At the pachytene stage, bivalents merge in densely stained chromocenters. We detected in these chromocenters the typical highly repeated DNA of this genus after in situ hybridization, the M31 chromodomain through immunofluorescence as well as dense Giemsa staining after C-banding. In species that present low amounts of heterochromatin, only 1 or 2 chromocenters were observed in which bivalents merge as observed in C. rionegrensis. After BRCA1 immunodetection we observed in early pachytene cells positive spots located over heterochromatic chromocenters that strongly suggest heterochromatic DNA repair. Mechanical stress mainly due to increasing chromatin compactness before metaphase I might be a mechanism to spread heterochromatin between different chromosomes within a karyotype. Polycomb repression controls the expression of hundreds of genes involved in development and is mediated by essentially two classes of chromatin-associated protein complexes. The Polycomb repressive complex 2 (PRC2) trimethylates histone H3 at lysine 27, an epigenetic mark that serves as a docking site for the PRC1 protein complex. Drosophila core PRC1 is composed of four subunits: Polycomb (Pc), Posterior sex combs (Psc), Polyhomeotic (Ph) and Sex combs extra (Sce). Each of these proteins has multiple orthologs in vertebrates, thus generating an enormous scope for potential combinatorial diversity. In particular, mammalian genomes encode five Pc family members: CBX2, CBX4, CBX6, CBX7 and CBX8. To complicate matters further, distinct isoforms might arise from single genes. Here, we address the functional role of the two human CBX2 isoforms. Owing to different polyadenylation sites and alternative splicing events, the human CBX2 locus produces two transcripts: a 5-exon transcript that encodes the 532-amino acid CBX2-1 isoform that contains the conserved chromodomain and Pc box and a 4-exon transcript encoding a shorter isoform, CBX2-2, lacking the Pc box but still possessing a chromodomain. Using biochemical approaches and a novel in vivo imaging assay, we show that the short CBX2-2 isoform lacking the Pc box, does not participate in PRC1 protein complexes, but self-associates in vivo and forms complexes of high molecular weight. Furthermore, the CBX2 short isoform is still able to repress transcription, suggesting that Polycomb repression might occur in the absence of PRC1 formation. DNA CpG methylation and histone H3 lysine 9 (H3K9) methylation are two major repressive epigenetic modifications, and these methylations are positively correlated with one another in chromatin. Here we show that G9a or G9a-like protein (GLP) dimethylate the amino-terminal lysine 44 (K44) of mouse Dnmt3a (equivalent to K47 of human DNMT3A) in vitro and in cells overexpressing G9a or GLP. The chromodomain of MPP8 recognizes the dimethylated Dnmt3aK44me2. MPP8 also interacts with self-methylated GLP in a methylation-dependent manner. The MPP8 chromodomain forms a dimer in solution and in crystals, suggesting that a dimeric MPP8 molecule could bridge the methylated Dnmt3a and GLP, resulting in a silencing complex of Dnmt3a-MPP8-GLP/G9a on chromatin templates. Together, these findings provide a molecular explanation, at least in part, for the co-occurrence of DNA methylation and H3K9 methylation in chromatin. The methyl-cytosine binding domain 2 (MBD2)-nucleosome remodeling and deacetylase (NuRD) complex recognizes methylated DNA and silences expression of associated genes through histone deacetylase and nucleosome remodeling functions. Our previous structural work demonstrated that a coiled-coil interaction between MBD2 and GATA zinc finger domain containing 2A (GATAD2A/p66α) proteins recruits the chromodomain helicase DNA-binding protein (CHD4/Mi2β) to the NuRD complex and is necessary for MBD2-mediated DNA methylation-dependent gene silencing in vivo (Gnanapragasam, M. N., Scarsdale, J. N., Amaya, M. L., Webb, H. D., Desai, M. A., Walavalkar, N. M., Wang, S. Z., Zu Zhu, S., Ginder, G. D., and Williams, D. C., Jr. (2011) p66α-MBD2 coiled-coil interaction and recruitment of Mi-2 are critical for globin gene silencing by the MBD2-NuRD complex. Proc. Natl. Acad. Sci. U.S.A. 108, 7487-7492). The p66α-MBD2 interaction differs from most coiled-coils studied to date by forming an anti-parallel heterodimeric complex between two peptides that are largely monomeric in isolation. To further characterize unique features of this complex that drive heterodimeric specificity and high affinity binding, we carried out biophysical analyses of MBD2 and the related homologues MBD3, MBD3-like protein 1 (MBD3L1), and MBD3-like protein 2 (MBD3L2) as well as specific mutations that modify charge-charge interactions and helical propensity of the coiled-coil domains. Analytical ultracentrifugation analyses show that the individual peptides remain monomeric in isolation even at 300 μM in concentration for MBD2. Circular dichroism analyses demonstrate a direct correlation between helical content of the coiled-coil domains in isolation and binding affinity for p66α. Furthermore, complementary electrostatic surface potentials and inherent helical content of each peptide are necessary to maintain high-affinity association. These factors lead to a binding affinity hierarchy of p66α for the different MBD2 homologues (MBD2 ≈ MBD3 > MBD3L1 ≈ MBD3L2) and suggest a hierarchical regulatory model in tissue and life cycle stage-specific silencing by NuRD complexes. Repressed PHO5 gene chromatin, isolated from yeast in the native state, was remodeled by yeast extract in a gene activator-dependent, ATP-dependent manner. The product of the reaction bore the hallmark of the process in vivo, the selective removal of promoter nucleosomes, without effect on open reading frame nucleosomes. Fractionation of the extract identified a single protein, chromodomain helicase DNA binding protein 1 (Chd1), capable of the remodeling activity. Deletion of the CHD1 gene in an isw1Δ pho80Δ strain abolished PHO5 gene expression, demonstrating the relevance of the remodeling reaction in vitro to the process in vivo. BACKGROUND: Chromodomain-helicase-DNA-binding protein 5 (CHD5) is a newly identified tumor suppressor that is frequently downregulated in a variety of human cancers. Our previous work revealed that the low expression of CHD5 in colorectal cancer is correlated with CHD5 promoter CpG island hypermethylation. In this study, we investigated the effect of microRNA-211 (miR-211)-regulated CHD5 expression on colorectal tumorigenesis. METHODOLOGY/PRINCIPAL FINDINGS: miR-211 was predicted to target CHD5 by TargetScan software analysis. A stably expressing exogenous miR-211 colorectal cancer cell line (HCT-116(miR-211)) was generated using lentiviral transduction and used as a model for in vitro and in vivo studies. The expression level of miR-211 in HCT-116(miR-211) cells was upregulated by 16-fold compared to vector control cells (HCT-116(vector)). Exogenous miR-211 directly binds to the 3'-untranslated region (3'-UTR) of CHD5 mRNA, resulting in a 50% decrease in CHD5 protein level in HCT-116(miR-211) cells. The levels of cell proliferation, tumor growth, and cell migration of HCT-116(miR-211) cells were significantly higher than HCT-116(vector) cells under both in vitro and in vivo conditions, as determined using the methods of MTT, colony formation, flow cytometry, scratch assay, and tumor xenografts, respectively. In addition, we found that enforced expression of miR-211 in HCT-116 cells was able to alter p53 pathway-associated regulatory proteins, such as MDM2, Bcl-2, Bcl-xL, and Bax. CONCLUSION/SIGNIFICANCE: Our results demonstrate that CHD5 is a direct target of miR-211 regulation. Enforced expression of miR-211 promotes tumor cell growth at least in part by downregulating the expression level of the CHD5 tumor suppressor. Our results provide a better understanding of the association of between miR-211-regulated CHD5 expression and CHD5 function in colorectal tumorigenesis. The chromodomain of the HP1 family of proteins recognizes histone tails with specifically methylated lysines. Here, we present structural, energetic, and mutational analyses of the complex between the Drosophila HP1 chromodomain and the histone H3 tail with a methyllysine at residue 9, a modification associated with epigenetic silencing. The histone tail inserts as a beta strand, completing the beta-sandwich architecture of the chromodomain. The methylammonium group is caged by three aromatic side chains, whereas adjacent residues form discerning contacts with one face of the chromodomain. Comparison of dimethyl- and trimethyllysine-containing complexes suggests a role for cation-pi and van der Waals interactions, with trimethylation slightly improving the binding affinity. BACKGROUND: Apicomplexan parasites are responsible for some of the most deadly parasitic diseases afflicting humans, including malaria and toxoplasmosis. These obligate intracellular parasites exhibit a complex life cycle and a coordinated cell cycle-dependant expression program. Their cell division is a coordinated multistep process. How this complex mechanism is organised remains poorly understood. METHODS AND FINDINGS: In this study, we provide evidence for a link between heterochromatin, cell division and the compartmentalisation of the nucleus in Toxoplasma gondii. We characterised a T. gondii chromodomain containing protein (named TgChromo1) that specifically binds to heterochromatin. Using ChIP-on-chip on a genome-wide scale, we report TgChromo1 enrichment at the peri-centromeric chromatin. In addition, we demonstrate that TgChromo1 is cell-cycle regulated and co-localised with markers of the centrocone. Through the loci-specific FISH technique for T. gondii, we confirmed that TgChromo1 occupies the same nuclear localisation as the peri-centromeric sequences. CONCLUSION: We propose that TgChromo1 may play a role in the sequestration of chromosomes at the nuclear periphery and in the process of T. gondii cell division. Coloboma, heart defect, atresia choanae, retarded growth and development, genital hypoplasia, ear anomalies (CHARGE) syndrome is a genetic syndrome in which hypogonadism is a frequent feature. A causative mutation within the chromodomain helicase DNA-binding protein-7 gene, which plays an important role in the embryonic development, is present in 2/3 of affected patients. We describe the clinical, hormonal and molecular characteristics of a young man from Ecuador who was diagnosed as having CHARGE syndrome at an adult age. The patient showed several phenotypic features of the syndrome, associated with a prepubertal state and cryptorchidism; hypogonadotrophic hypogonadism with undetectable testosterone levels not responsive to hCG testing and severe osteoporosis were ascertained. Molecular evaluation of the CHD7 gene showed the novel frameshift truncating heterozygous mutation p.Tyr1046Glyfs*23 in exon 12. Magnetic resonance imaging revealed mild hypoplasia of the pituitary gland and hypoplasia of the posterior cranial fossa. Parenteral testosterone therapy led to sexual development over time and, in combination with diphophonate therapy and calcium-vitamin D supplementation, significantly improved bone mineralisation. Early proper hormonal treatment of hypogonadism in patients with complex genetic syndromes is important to achieve normal sexual maturation, improve quality of life and avoid significant comorbidities, such as osteoporosis. The DNA damage response encompasses a complex series of signaling pathways that function to regulate and facilitate the repair of damaged DNA. Recent studies have shown that the repair of transcriptionally inactive chromatin, named heterochromatin, is dependent upon the phosphorylation of the co-repressor, Krüppel-associated box (KRAB) domain-associated protein (KAP-1), by the ataxia telangiectasia-mutated (ATM) kinase. Co-repressors, such as KAP-1, function to regulate the rigid structure of heterochromatin by recruiting histone-modifying enzymes, such HDAC1/2, SETDB1, and nucleosome-remodeling complexes such as CHD3. Here, we have characterized a phosphorylation site in the HP1-binding domain of KAP-1, Ser-473, which is phosphorylated by the cell cycle checkpoint kinase Chk2. Expression of a nonphosphorylatable S473A mutant conferred cellular sensitivity to DNA-damaging agents and led to defective repair of DNA double-strand breaks in heterochromatin. In addition, cells expressing S473A also displayed defective mobilization of the HP1-β chromodomain protein. The DNA repair defect observed in cells expressing S473A was alleviated by depletion of HP1-β, suggesting that phosphorylation of KAP-1 on Ser-473 promotes the mobilization of HP1-β from heterochromatin and subsequent DNA repair. These results suggest a novel mechanism of KAP-1-mediated chromatin restructuring via Chk2-regulated HP1-β exchange from heterochromatin, promoting DNA repair. Chromodomain helicase DNA-binding protein 5 (CHD5) has been found to be a candidate tumor suppressor gene (TSG) in malignant neural tumors. In mice heterozygous for chd5 deficiency, the first tumor observed was pathological squamous cell carcinoma. More than 95% of primary laryngeal cancer is squamous cell carcinoma. Thus, we explored the expression of CHD5 in 65 patients with laryngeal squamous cell carcinoma (LSCC) using real-time PCR, immunohistochemistry and Western blotting. DNA methylation was detected using bisulfate-specific sequencing. The potential function of CHD5 was determined using MTT, apoptosis and transwell migration assays in CHD5-transfected Hep-2 cells. Our results revealed that the mRNA and protein expression levels of CHD5 in LSCC tissues were significantly lower than those in clear surgical margin tissues (p<0.05), and there is a significant correlation between the mRNA and protein expression levels of CHD5 (p<0.01). In addition, there were significant differences in CHD5 mRNA and protein levels with respect to the patient's clinical stage (p<0.05). Aberrant methylation of the CHD5 promoter was frequently found in the Hep-2 cell line and LSCC tumor tissues, especially tumor tissues from advanced TNM (p<0.05) or older patients (p<0.05). Finally, ectopic expression of CHD5 in laryngeal cancer cells led to significant inhibition of growth and invasiveness. Our data suggest that CHD5 is a tumor suppressor gene that is epigenetically downregulated in LSCC. Chromodomains are found in many regulators of chromatin structure, and most of them recognize methylated lysines on histones. Here, we investigate the role of the Drosophila melanogaster protein Corto's chromodomain. The Enhancer of Trithorax and Polycomb Corto is involved in both silencing and activation of gene expression. Over-expression of the Corto chromodomain (CortoCD) in transgenic flies shows that it is a chromatin-targeting module, critical for Corto function. Unexpectedly, mass spectrometry analysis reveals that polypeptides pulled down by CortoCD from nuclear extracts correspond to ribosomal proteins. Furthermore, real-time interaction analyses demonstrate that CortoCD binds with high affinity RPL12 tri-methylated on lysine 3. Corto and RPL12 co-localize with active epigenetic marks on polytene chromosomes, suggesting that both are involved in fine-tuning transcription of genes in open chromatin. RNA-seq based transcriptomes of wing imaginal discs over-expressing either CortoCD or RPL12 reveal that both factors deregulate large sets of common genes, which are enriched in heat-response and ribosomal protein genes, suggesting that they could be implicated in dynamic coordination of ribosome biogenesis. Chromatin immunoprecipitation experiments show that Corto and RPL12 bind hsp70 and are similarly recruited on gene body after heat shock. Hence, Corto and RPL12 could be involved together in regulation of gene transcription. We discuss whether pseudo-ribosomal complexes composed of various ribosomal proteins might participate in regulation of gene expression in connection with chromatin regulators. BACKGROUND: H3K9 trimethylation (H3K9me3) and binding of PcG repressor complex-1 (PRC1) may play crucial roles in the epigenetic silencing of the p16 gene. However, the mechanism of the initiation of this trimethylation is unknown. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we found that upregulating the expression of PRC1 component Cbx7 in gastric cancer cell lines MGC803 and BGC823 led to significantly suppress the expression of genes within the p16-Arf-p15 locus. H3K9me3 formation was observed at the p16 promoter and Regulatory Domain (RD). CBX7 and SUV39H2 binding to these regions were also detectable in the CBX7-stably upregulated cells. CBX7-SUV39H2 complexes were observed within nucleus in bimolecular fluorescence complementation assay (BiFC). Mutations of the chromodomain or deletion of Pc-box abolished the CBX7-binding and H3K9me3 formation, and thus partially repressed the function of CBX7. SiRNA-knockdown of Suv39h2 blocked the repressive effect of CBX7 on p16 transcription. Moreover, we found that expression of CBX7 in gastric carcinoma tissues with p16 methylation was significantly lower than that in their corresponding normal tissues, which showed a negative correlation with transcription of p16 in gastric mucosa. CONCLUSION/SIGNIFICANCE: These results demonstrated for the first time, to our knowledge, that CBX7 could initiate H3K9me3 formation at the p16 promoter. BACKGROUND: M-phase phosphoprotein 8 (MPP8) was initially identified to be a component of the RanBPM-containing large protein complex, and has recently been shown to bind to methylated H3K9 both in vivo and in vitro. MPP8 binding to methylated H3K9 is suggested to recruit the H3K9 methyltransferases GLP and ESET, and DNA methyltransferase 3A to the promoter of the E-cadherin gene, mediating the E-cadherin gene silencing and promote tumor cell motility and invasion. MPP8 contains a chromodomain in its N-terminus, which is used to bind the methylated H3K9. METHODOLOGY/PRINCIPAL FINDINGS: Here, we reported the crystal structures of human MPP8 chromodomain alone and in complex with the trimethylated histone H3K9 peptide (residue 1-15). The complex structure unveils that the human MPP8 chromodomain binds methylated H3K9 through a conserved recognition mechanism, which was also observed in Drosophila HP1, a chromodomain containing protein that binds to methylated H3K9 as well. The structure also reveals that the human MPP8 chromodomain forms homodimer, which is mediated via an unexpected domain swapping interaction through two β strands from the two protomer subunits. CONCLUSIONS/SIGNIFICANCE: Our findings reveal the molecular mechanism of selective binding of human MPP8 chromodomain to methylated histone H3K9. The observation of human MPP8 chromodomain in both solution and crystal lattice may provide clues to study MPP8-mediated gene regulation furthermore. Murine Chd1 (chromodomain helicase DNA-binding protein 1), a chromodomain-containing chromatin remodeling protein, is necessary for embryonic stem (ES) cell pluripotency. Chd1 binds to nucleosomes trimethylated at histone 3 Lys 4 (H3K4me3) near the beginning of active genes but not to bivalent domains also containing H3K27me3. To address the mechanism of this specificity, we reproduced H3K4me3- and CHD1-stimulated gene activation in HeLa extracts. Multidimensional protein identification technology (MuDPIT) and immunoblot analyses of purified preinitiation complexes (PICs) revealed the recruitment of CHD1 to naive chromatin but enhancement on H3K4me3 chromatin. Studies in depleted extracts showed that the Mediator coactivator complex, which controls PIC assembly, is also necessary for CHD1 recruitment. MuDPIT analyses of CHD1-associated proteins support the recruitment data and reveal numerous components of the PIC, including Mediator. In vivo, CHD1 and Mediator are recruited to an inducible gene, and genome-wide binding of the two proteins correlates well with active gene transcription in mouse ES cells. Finally, coimmunoprecipitation of CHD1 and Mediator from cell extracts can be ablated by shRNA knockdown of a specific Mediator subunit. Our data support a model in which the Mediator coordinates PIC assembly along with the recruitment of CHD1. The combined action of the PIC and H3K4me3 provides specificity in targeting CHD1 to active genes. BACKGROUND: Histone post-translational modifications (PTMs) constitute a branch of epigenetic mechanisms that can control the expression of eukaryotic genes in a heritable manner. Recent studies have identified several PTM-binding proteins containing diverse specialized domains whose recognition of specific PTM sites leads to gene activation or repression. Here, we present a high-throughput proteogenomic platform designed to characterize the nucleosomal make-up of chromatin enriched with a set of histone PTM binding proteins known as histone PTM readers. We support our findings with gene expression data correlating to PTM distribution. RESULTS: We isolated human mononucleosomes bound by the bromodomain-containing proteins Brd2, Brd3 and Brd4, and by the chromodomain-containing heterochromatin proteins HP1β and HP1α. Histone PTMs were quantified by mass spectrometry (ChIP-qMS), and their associated DNAs were mapped using deep sequencing. Our results reveal that Brd- and HP1-bound nucleosomes are enriched in histone PTMs consistent with actively transcribed euchromatin and silent heterochromatin, respectively. Data collected using RNA-Seq show that Brd-bound sites correlate with highly expressed genes. In particular, Brd3 and Brd4 are most enriched on nucleosomes located within HOX gene clusters, whose expression is reduced upon Brd4 depletion by short hairpin RNA. CONCLUSIONS: Proteogenomic mapping of histone PTM readers, alongside the characterization of their local chromatin environments and transcriptional information, should prove useful for determining how histone PTMs are bound by these readers and how they contribute to distinct transcriptional states. Binding of heterochromatin protein 1 (HP1) to the histone H3 lysine 9 trimethylation (H3K9me3) mark is a hallmark of establishment and maintenance of heterochromatin. Although genetic and cell biological aspects have been elucidated, the molecular details of HP1 binding to H3K9me3 nucleosomes are unknown. Using a combination of NMR spectroscopy and biophysical measurements on fully defined recombinant experimental systems, we demonstrate that H3K9me3 works as an on/off switch regulating distinct binding modes of hHP1β to the nucleosome. The methyl-mark determines a highly flexible and very dynamic interaction of the chromodomain of hHP1β with the H3-tail. There are no other constraints of interaction or additional multimerization interfaces. In contrast, in the absence of methylation, the hinge region and the N-terminal tail form weak nucleosome contacts mainly with DNA. In agreement with the high flexibility within the hHP1β-H3K9me3 nucleosome complex, the chromoshadow domain does not provide a direct binding interface. Our results report the first detailed structural analysis of a dynamic protein-nucleosome complex directed by a histone modification and provide a conceptual framework for understanding similar interactions in the context of chromatin. Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired disorder characterized by chronic intravascular hemolysis as the primary clinical manifestation and morbidities that include anemia, thrombosis, renal impairment, pulmonary hypertension, and bone marrow failure. The prevalence of the PNH clone (from <1-100% PNH granulocytes) is approximately 16 per million, and careful monitoring is required. The average age of onset of the clinical disease is the early 30s, although it can present at all ages. PNH is caused by the acquisition of a somatic mutation of the gene phosphatidylinositol glycan anchor (PIG-A) in a multipotent hematopoietic stem cell (HSC), with clonal expansion of the mutated HSC. The mutation causes a deficiency in the synthesis of glycosylphosphatidylinositol (GPI). In cells derived from normal HSCs, the complement regulatory proteins CD55 and CD59 are anchored to the hematopoietic cell membrane surface via GPI, protecting the cells from complement-mediated lysis. However, in patients with PNH, these 2 proteins, along with numerous other GPI-linked proteins, are absent from the cell surface of red cells, granulocytes, monocytes, and platelets, resulting in complement-mediated intravascular hemolysis and other complications. Lysis of red blood cells is the most obvious manifestation, but as other cell lineages are also affected, this complement-mediated attack contributes to additional complications, such as thrombosis. Eculizumab, a humanized monoclonal antibody against the C5 complement protein, is the only effective drug therapy for PNH patients. The antibody prevents cleavage of the C5 protein by C5 convertase, in turn preventing generation of C5b-9 and release of C5a, thereby protecting from hemolysis of cells lacking the CD59 surface protein and other complications associated with complement activation. Drs. Ilene C. Weitz, Anita Hill, and Jeff Szer discuss 3 recent cases of patients with PNH. Aside from polyploidy, transposable elements are the major drivers of genome size increases in plants. Thus, understanding the diversity and evolutionary dynamics of transposable elements in sunflower (Helianthus annuus L.), especially given its large genome size (∼3.5 Gb) and the well-documented cases of amplification of certain transposons within the genus, is of considerable importance for understanding the evolutionary history of this emerging model species. By analyzing approximately 25% of the sunflower genome from random sequence reads and assembled bacterial artificial chromosome (BAC) clones, we show that it is composed of over 81% transposable elements, 77% of which are long terminal repeat (LTR) retrotransposons. Moreover, the LTR retrotransposon fraction in BAC clones harboring genes is disproportionately composed of chromodomain-containing Gypsy LTR retrotransposons ('chromoviruses'), and the majority of the intact chromoviruses contain tandem chromodomain duplications. We show that there is a bias in the efficacy of homologous recombination in removing LTR retrotransposon DNA, thereby providing insight into the mechanisms associated with transposable element (TE) composition in the sunflower genome. We also show that the vast majority of observed LTR retrotransposon insertions have likely occurred since the origin of this species, providing further evidence that biased LTR retrotransposon activity has played a major role in shaping the chromatin and DNA landscape of the sunflower genome. Although our findings on LTR retrotransposon age and structure could be influenced by the selection of the BAC clones analyzed, a global analysis of random sequence reads indicates that the evolutionary patterns described herein apply to the sunflower genome as a whole. The restructuring of chromatin precedes tightly regulated events such as DNA transcription, replication, and repair. One type of chromatin remodeling involves the covalent modification of nucleosomes by histone acetyltransferase (HAT) complexes. The observation that apicidin exerts antiprotozoal activity by targeting a histone deacetyltransferase has prompted our search for more components of the histone modifying machinery in parasitic protozoa. We have previously identified GNAT family HATs in the opportunistic pathogen Toxoplasma gondii and now describe the first MYST (named for members MOZ, Ybf2/Sas3, Sas2, and Tip60) family HATs in apicomplexa (TgMYST-A and -B). The TgMYST-A genomic locus is singular and generates a approximately 3.5-kb transcript that can encode two proteins of 411 or 471 amino acids. TgMYST-B mRNA is approximately 7.0 kb and encodes a second MYST homologue. In addition to the canonical MYST HAT catalytic domain, both TgMYST-A and -B possess an atypical C2HC zinc finger and a chromodomain. Recombinant TgMYST-A exhibits a predilection to acetylate histone H4 in vitro at lysines 5, 8, 12, and 16. Antibody generated to TgMYST-A reveals that both the long and short (predominant) versions are present in the nucleus and are also plentiful in the cytoplasm. Moreover, both TgMYST-A forms are far more abundant in rapidly replicating parasites (tachyzoites) than encysted parasites (bradyzoites). A bioinformatics survey of the Toxoplasma genome reveals numerous homologues known to operate in native MYST complexes. The characterization of TgMYST HATs represents another important step toward understanding the regulation of gene expression in pathogenic protozoa and provides evolutionary insight into how these processes operate in eukaryotic cells in general. The pp32 (ANP32A) gene acts as a tumor suppressor while its closely related homologue pp32r1 (ANP32C) is oncogenic and is overexpressed in breast, prostate and pancreatic tumors. The transduction of p53wt cell lines (ACHN and HeLa) with pp32r1 or pp32r1Y140H lentivirus increased the proliferation of p53wt cell lines compared to the untransduced control cells while transduction of the p53(R248W) MiaPaCa2 cell line had no effect. Cell cycle analysis of transduced ACHN cells by PI staining and BrdU incorporation illustrated a pronounced shift toward the S-phase of the cell cycle in cells overexpressing the pp32r1 and pp32r1Y140H proteins. Confocal microscopy and western blotting demonstrated that pp32r1 and the pp32r1Y140H mutant protein reside predominantly in the cytoplasm in constrast to pp32 which is a nuclear/cytoplasmic shuttling protein. To determine the effects of pp32r1 or pp32r1Y140H overexpression at the proteomic level we performed a comprehensive proteome analysis on ACHN, ACHN-pp32r1 and ACHN-pp32r1Y140H cell lysates using the isotope-coded protein label (ICPL) method. Among those proteins with >40% regulation were Macrophage Capping protein (CAPG) and Chromodomain Helicase DNA binding protein 4 (CHD4) proteins which were significantly upregulated by pp32r1 and pp32r1Y140H overexpression. This increase in CHD4 also appears to influence a number of cell cycle regulator genes including; p53, p21 and cyclinD1 as judged by western blotting. Silencing of CHD4 in ACHN-pp32r1Y140H cells using specific shRNA reverted the cell cycle dysregulation caused by pp32r1Y140H expression to that of the untransduced ACHN cell line, suggesting that CHD4 is the prominent effector of the pp32r1/pp32r1Y140H phenotype. CHARGE syndrome is an autosomal dominant multisystem disorder caused by mutation in the CHD7 gene, encoding chromodomain helicase DNA-binding protein 7. Molecular diagnostic testing for CHD7 mutation has been available in a clinical setting since 2005. We report here the results from the first 642 unrelated proband samples submitted for testing. Thirty-two percent (n = 203) of patient samples had a heterozygous pathogenic variant identified. The lower mutation rate than that published for well-characterized clinical samples is likely due to referral bias, as samples submitted for clinical testing may be for "rule-out" diagnoses, rather than solely to confirm clinical suspicion. We identified 159 unique pathogenic mutations, and of these, 134 mutations were each seen in a single individual and 25 mutations were found in two to five individuals (n =69). Of the 203 mutations, only 9 were missense, with 107 nonsense, 69 frameshift, and 15 splice-site mutations likely leading to haploinsufficiency at the cellular level. An additional 72 variations identified in the 642 tested samples (11%) were considered to have unknown clinical significance. Copy number changes (deletion/duplication of the entire gene or one/several exons) were found to account for a very small number of cases (n = 3). This cohort represents the largest CHARGE syndrome sample size to date and is intended to serve as a resource for clinicians, genetic counselors, researchers, and other diagnostic laboratories. In Schizosaccharomyces pombe the RNAi machinery and proteins mediating heterochromatin formation regulate the transcription of non-coding centromeric repeats. These repeats share a high sequence similarity with telomere-linked helicase (tlh) genes, implying an ancestral relationship between the two types of elements and suggesting that transcription of the tlh genes might be regulated by the same factors as centromeric repeats. Indeed, we found that mutants lacking the histone methyltransferase Clr4, the Pcu4 cullin, Clr7 or Clr8, accumulate high levels of tlh forward and reverse transcripts. Mutations and conditions perturbing histone acetylation had similar effects further demonstrating that the tlh genes are normally repressed by heterochromatin. In contrast, mutations in the RNAi factors Dcr1, Ago1 or Rdp1 led only to a modest derepression of the tlh genes indicating an alternate pathway recruits heterochromatin components to telomeres. The telomere-binding protein Taz1 might be part of such a redundant pathway, tlh transcripts being present at low levels in Deltataz1 mutants and at higher levels in Deltataz1 Deltadcr1 double mutants. Surprisingly, the chromodomain protein Chp1, a component of the Ago1-containing RITS complex, contributes more to tlh repression than Ago1, indicating the repressive effects of Chp1 are partially independent of RITS. The tlh genes are found in the subtelomeric regions of several other fungi raising the intriguing possibility of conserved regulation and function. Chromodomain on Y-like (CDYL) is a chromodomain protein that has sequence homology to members of the enoyl CoA hydratase family. Although the chromodomain of CDYL has been implicated in chromatin remodeling during mammalian spermatogenesis, the function of the Cdyl gene remains unclear. Recently, induced pluripotent stem cells (iPS cells) have been derived from somatic cells by the forced expression of several transcription factors. iPS cells resemble embryonic stem cells in many respects. Therefore, iPS cells represent a powerful tool for the study of gene function. In this study, we have investigated whether iPS cells derived from Cdyl-/- and Cdyl+/+ fibroblasts have different characteristics. Our results showed that both Cdyl-/- and Cdyl+/+ fibroblasts could be induced to become iPS cells, but the spontaneous neuronal differentiation capacity of Cdyl-/- iPS cells was much greater than that of the Cdyl+/+ iPS cells. These results provide some insight into the molecular function of the Cdyl gene, showing that it inhibited the neuronal differentiation of iPS cells. The chromodomain (CD) of the Drosophila Polycomb protein exhibits preferential binding affinity for histone H3 when trimethylated at lysine 27. Here we have investigated the five mouse Polycomb homologs known as Cbx2, Cbx4, Cbx6, Cbx7, and Cbx8. Despite a high degree of conservation, the Cbx chromodomains display significant differences in binding preferences. Not all CDs bind preferentially to K27me3; rather, some display affinity towards both histone H3 trimethylated at K9 and H3K27me3, and one CD prefers K9me3. Cbx7, in particular, displays strong affinity for both H3K9me3 and H3K27me3 and is developmentally regulated in its association with chromatin. Cbx7 associates with facultative heterochromatin and, more specifically, is enriched on the inactive X chromosome. Finally, we find that, in vitro, the chromodomain of Cbx7 can bind RNA and that, in vivo, the interaction of Cbx7 with chromatin, and the inactive X chromosome in particular, depends partly on its association with RNA. We propose that the capacity of this mouse Polycomb homolog to associate with the inactive X chromosome, or any other region of chromatin, depends not only on its chromodomain but also on the combination of histone modifications and RNA molecules present at its target sites. Mutations in CHD7, a chromodomain gene, are present in a majority of individuals with CHARGE syndrome, a multiple anomaly disorder characterized by ocular Coloboma, Heart defects, Atresia of the choanae, Retarded growth and development, Genital hypoplasia and Ear anomalies. The clinical features of CHARGE syndrome are highly variable and incompletely penetrant. Olfactory dysfunction is a common feature in CHARGE syndrome and has been potentially linked to primary olfactory bulb defects, but no data confirming this mechanistic link have been reported. On the basis of these observations, we hypothesized that loss of Chd7 disrupts mammalian olfactory tissue development and function. We found severe defects in olfaction in individuals with CHD7 mutations and CHARGE, and loss of odor evoked electro-olfactogram responses in Chd7 deficient mice, suggesting reduced olfaction is due to a dysfunctional olfactory epithelium. Chd7 expression was high in basal olfactory epithelial neural stem cells and down-regulated in mature olfactory sensory neurons. We observed smaller olfactory bulbs, reduced olfactory sensory neurons, and disorganized epithelial ultrastructure in Chd7 mutant mice, despite apparently normal functional cilia and sustentacular cells. Significant reductions in the proliferation of neural stem cells and regeneration of olfactory sensory neurons in the mature Chd7(Gt/+) olfactory epithelium indicate critical roles for Chd7 in regulating neurogenesis. These studies provide evidence that mammalian olfactory dysfunction due to Chd7 haploinsufficiency is linked to primary defects in olfactory neural stem cell proliferation and may influence olfactory bulb development. The chromodomain protein, Chromator, can be divided into two main domains, a NH(2)-terminal domain (NTD) containing the chromodomain (ChD) and a COOH-terminal domain (CTD) containing a nuclear localization signal. During interphase Chromator is localized to chromosomes; however, during cell division Chromator redistributes to form a macro molecular spindle matrix complex together with other nuclear proteins that contribute to microtubule spindle dynamics and proper chromosome segregation during mitosis. It has previously been demonstrated that the CTD is sufficient for targeting Chromator to the spindle matrix. In this study, we show that the NTD domain of Chromator is required for proper localization to chromatin during interphase and that chromosome morphology defects observed in Chromator hypomorphic mutant backgrounds can be largely rescued by expression of this domain. Furthermore, we show that the ChD domain can interact with histone H1 and that this interaction is necessary for correct chromatin targeting. Nonetheless, that localization to chromatin still occurs in the absence of the ChD indicates that Chromator possesses a second mechanism for chromatin association and we provide evidence that this association is mediated by other sequences residing in the NTD. Taken together these findings suggest that Chromator's chromatin functions are largely governed by the NH(2)-terminal domain whereas functions related to mitosis are mediated mainly by COOH-terminal sequences. At the nuclear envelope in higher eukaryotic cells, the nuclear lamina and the heterochromatin are adjacent to the inner nuclear membrane, and their attachment is presumably mediated by integral membrane proteins. In a yeast two-hybrid screen, the nucleoplasmic domain of lamin B receptor (LBR), an integral protein of the inner nuclear membrane, associated with two human polypeptides homologous to Drosophila HP1, a heterochromatin protein involved in position-effect variegation. LBR fusion proteins bound to HP1 proteins synthesized by in vitro translation and present in cell lysates. Antibodies against LBR also co-immunoprecipitated HP1 proteins from cell extracts. LBR can interact with chromodomain proteins that are highly conserved in eukaryotic species and may function in the attachment of heterochromatin to the inner nuclear membrane in cells. Proper morphogenesis of inner ear semicircular canals requires precise regulation of cellular proliferation, epithelial-to-mesenchymal transition, and fusion of epithelial plates. Epigenetic regulation of these processes is not well understood, but is likely to involve chromatin remodeling enzymes. CHD7 is a chromodomain-containing, ATP dependent helicase protein that is highly expressed in the developing ear and is required for semicircular canal development in both humans and mice. Here we report that mice with heterozygous loss of Chd7 function exhibit delayed semicircular canal genesis, delayed Netrin1 expression and disrupted expression of genes that are critical for semicircular canal formation (Bmp2, Bmp4, Msx1 and Fgf10). Complete loss of Chd7 results in aplasia of the semicircular canals and sensory vestibular organs, with reduced or absent expression of Otx1, Hmx3, Jagged1, Lmo4, Msx1 and Sox2. Our results suggest that Chd7 may have critical selector gene functions during inner ear morphogenesis. Detailed analysis of the epigenetic modifications underlying these gene expression changes should provide insights into semicircular canal development and help in the design of therapies for individuals with inner ear malformations. BACKGROUND: Lymphocytic hypophysitis is an organ-specific autoimmune disease of the pituitary gland. A specific and sensitive serological test currently does not exist to aid in the diagnosis. OBJECTIVE: To identify target autoantigens in lymphocytic hypophysitis and develop a diagnostic assay for these proteins. DESIGN/METHODS: A pituitary cDNA expression library was immunoscreened using sera from four patients with lymphocytic hypophysitis. Relevant cDNA clones from screening, along with previously identified autoantigens pituitary gland-specific factor 1a and 2 (PGSF1a and PGSF2) and neuron-specific enolase (NSE) were tested in an in vitro transcription and translation immunoprecipitation assay. The corticotroph-specific transcription factor, TPIT, was investigated separately as a candidate autoantigen. RESULTS: Significantly positive autoantibody reactivity against TPIT was found in 9/86 hypophysitis patients vs 1/90 controls (P = 0.018). The reactivity against TPIT was not specific for lymphocytic hypophysitis with autoantibodies detectable in the sera from patients with other autoimmune endocrine diseases. Autoantibodies were also detected against chromodomain-helicase-DNA binding protein 8, presynaptic cytomatrix protein (piccolo), Ca(2+)-dependent secretion activator, PGSF2 and NSE in serum samples from patients with lymphocytic hypophysitis, but at a frequency that did not differ from healthy controls. Importantly, 8/86 patients with lymphocytic hypophysitis had autoantibodies against any two autoantigens in comparison with 0/90 controls (P = 0.0093). CONCLUSIONS: TPIT, a corticotroph-specific transcription factor, was identified as a target autoantigen in 10.5% of patients with lymphocytic hypophysitis. Further autoantigens related to vesicle processing were also identified as potential autoantigens with different immunoreactivity patterns in patients and controls. The molecular motor protein CHD1 has been implicated in the regulation of transcription and in the transcription-independent genome-wide incorporation of H3.3 into paternal chromatin in Drosophila melanogaster. A key feature of CHD1 is the presence of two chromodomains, which can bind to histone H3 methylated at lysine 4 and thus might serve to recruit and/or maintain CHD1 at the chromatin. Here, we describe genetic and biochemical approaches to the study of the Drosophila CHD1 chromodomains. We found that overall localization of CHD1 on polytene chromosomes does not appreciably change in chromodomain-mutant flies. In contrast, the chromodomains are important for transcription-independent activities of CHD1 during early embryonic development as well as for transcriptional regulation of several heat shock genes. However, neither CHD1 nor its chromodomains are needed for RNA polymerase II localization and H3K4 methylation but loss of CHD1 decreases transcription-induced histone eviction at the Hsp70 gene in vivo. Chromodomain mutations negatively affect the chromatin assembly activities of CHD1 in vitro, and they appear to be involved in linking the ATP-dependent motor to the chromatin assembly function of CHD1. The Tf1 retrotransposon represents a group of long terminal repeat retroelements that use an RNA self-primer for initiating reverse transcription while synthesizing the minus-sense DNA strand. Tf1 reverse transcriptase (RT) was found earlier to generate the self-primer in vitro. Here, we show that this RT can remove from the synthesized cDNA the entire self-primer as well as the complete polypurine tract (PPT) sequence (serving as a second primer for cDNA synthesis). However, these primer removals, mediated by the RNase H activity of Tf1 RT, are quite inefficient. Interestingly, the integrase of Tf1 stimulated the specific Tf1 RT-directed cleavage of both the self-primer and PPT, although there was no general enhancement of the RT's RNase H activity (and the integrase by itself is devoid of any primer cleavage). The RTs of two prototype retroviruses, murine leukemia virus and human immunodeficiency virus, showed only a partial and nonspecific cleavage of both Tf1-associated primers with no stimulation by Tf1 integrase. Mutagenesis of Tf1 integrase revealed that the complete Tf1 integrase protein (excluding its chromodomain) is required for stimulating the Tf1 RT primer removal activity. Nonetheless, a double mutant integrase that has lost its integration functions can still stimulate the RT's activity, though heat-inactivated integrase cannot enhance primer removals. These findings suggest that the enzymatic activity of Tf1 integrase is not essential for stimulating the RT-mediated primer removal, while the proper folding of this protein is obligatory for this function. These results highlight possible new functions of Tf1 integrase in the retrotransposon's reverse transcription process. A-kinase anchoring proteins (AKAPs) bind the regulatory subunits of protein kinase A (PKA) and localize the holoenzyme to discrete signaling microdomains in multiple subcellular compartments. Despite emerging evidence for a nuclear pool of PKA that rapidly responds to activation of the PKA signaling cascade, only a few AKAPs have been identified that localize to the nucleus. Here we show a PKA-binding domain in the amino terminus of Chd8, and demonstrate subcellular colocalization of Chd8 with RII. RII overlay and immunoprecipitation assays demonstrate binding between Chd8-S and RIIα. Binding is abrogated upon dephosphorylation of RIIα. By immunofluorescence, we identified nuclear and perinuclear pools of Chd8 in HeLa cells and rat neonatal cardiomyocytes. We also show high levels of Chd8 mRNA in RNA extracted from post-natal rat hearts. These data add Chd8 to the short list of known nuclear AKAPs, and implicate a function for Chd8 in post-natal rat cardiac development. Transposable elements with long terminal direct repeats (LTR TEs) are one of the best studied groups of mobile elements. They are ubiquitous elements present in almost all eukaryotic genomes. Their number and state of conservation can be a highlight of genome dynamics. We searched all published fungal genomes for LTR-containing retrotransposons, including both complete, functional elements and remnant copies. We identified a total of over 66,000 elements, all of which belong to the Ty1/Copia or Ty3/Gypsy superfamilies. Most of the detected Gypsy elements represent Chromoviridae, i.e. they carry a chromodomain in the pol ORF. We analyzed our data from a genome-ecology perspective, looking at the abundance of various types of LTR TEs in individual genomes and at the highest-copy element from each genome. The TE content is very variable among the analyzed genomes. Some genomes are very scarce in LTR TEs (<50 elements), others demonstrate huge expansions (>8000 elements). The data shows that transposon expansions in fungi usually involve an increase both in the copy number of individual elements and in the number of element types. The majority of the highest-copy TEs from all genomes are Ty3/Gypsy transposons. Phylogenetic analysis of these elements suggests that TE expansions have appeared independently of each other, in distant genomes and at different taxonomical levels. We also analyzed the evolutionary relationships between protein domains encoded by the transposon pol ORF and we found that the protease is the fastest evolving domain whereas reverse transcriptase and RNase H evolve much slower and in correlation with each other. INTRODUCTION: The chromodomain helicase DNA binding protein 5 (CHD5) has recently been identified as a tumor suppressor in a mouse model. The CHD5 locus at 1p36 is deleted, and its mutation has been detected in breast cancer. We, therefore, evaluated whether CHD5 plays a role in human breast cancer. METHODS: We screened mutations in 55 tumors, determined promoter methylation in 39 tumors, measured RNA expression in 90 tumors, analyzed protein expression in 289 tumors, and correlated expression changes with clinicopathological characteristics of breast cancer. Functional effects of CHD5 on cell proliferation, invasion and tumorigenesis were also tested. RESULTS: Although only one mutation was detected, CHD5 mRNA expression was significantly reduced, accompanied by frequent genomic deletion and promoter methylation, in breast cancer. The extent of methylation was significantly associated with reduced mRNA expression, and demethylating treatment restored CHD5 expression. Lower CHD5 mRNA levels correlated with lymph node metastasis (P = 0.026). CHD5 protein expression was also reduced in breast cancer, and lack of CHD5 expression significantly correlated with higher tumor stage, ER/PR-negativity, HER2 positivity, distant metastasis and worse patient survival (P ≤ 0.01). Functionally, ectopic expression of CHD5 in breast cancer cells inhibited cell proliferation and invasion in vitro and tumorigenesis in nude mice. Consistent with the inhibition of invasion, CHD5 down-regulated mesenchymal markers vimentin, N-cadherin and ZEB1 in breast cancer cells. CONCLUSION: Down-regulation of CHD5, mediated at least in part by promoter methylation, contributes to the development and progression of human breast cancer. The conserved band-interband pattern is thought to reflect the looped-domain organization of insect polytene chromosomes. Previously, we have shown that the chromodomain protein Chriz and the zinc-finger protein Z4 are essentially required for the maintenance of polytene chromosome structure. Here we show that both proteins form a complex that recruits the JIL-1 kinase to polytene chromosomes, enabling local H3S10 phosphorylation of interband nucleosomal histones. Interband targeting domains were identified at the N-terminal regions of Chriz and Z4, and our data suggest partial cooperation of the complex with the BEAF boundary element protein in polytene and diploid cells. Reducing the core component Chriz by RNAi results in destabilization of the complex and a strong reduction of interband-specific histone H3S10 phosphorylation. Chloroplasts contain a unique signal recognition particle (cpSRP). Unlike the cytoplasmic forms, the cpSRP lacks RNA but contains a conserved 54-kDa GTPase and a novel 43-kDa subunit (cpSRP43). Recently, three functionally distinct chromodomains (CDs) have been identified in cpSRP43. In the present study, we report the three-dimensional solution structures of the three CDs (CD1, CD2, and CD3) using a variety of triple resonance NMR experiments. The structure of CD1 consists of a triple-stranded beta-sheet segment. The C-terminal helical segment typically found in the nuclear chromodomains is absent in CD1. The secondary structural elements in CD2 and CD3 include a triple-stranded antiparallel beta-sheet and a C-terminal helix. Interestingly, the orientation of the C-terminal helix is significantly different in the structures of CD2 and CD3. Critical comparison of the structures of the chromodomains of cpSRP43 with those found in nuclear chromodomain proteins revealed that the diverse protein-protein interactions mediated by the CDs appear to stem from the differences that exist in the surface charge potentials of each CD. Results of isothermal titration calorimetry experiments confirmed that only CD2 is involved in binding to cpSRP54. The negatively charged C-terminal helix in CD2 possibly plays a crucial role in the cpSRP54-cpSRP43 interaction. Heterochromatin Protein 1 (HP1) was first discovered in Drosophila as a dominant suppressor of position-effect variegation and a major component of heterochromatin. The HP1 family is evolutionarily conserved, with members in fungi, plants and animals but not prokaryotes, and there are multiple members within the same species. The amino-terminal chromodomain binds methylated lysine 9 of histone H3, causing transcriptional repression. The highly conserved carboxy-terminal chromoshadow domain enables dimerization and also serves as a docking site for proteins involved in a wide variety of nuclear functions, from transcription to nuclear architecture. In addition to heterochromatin packaging, it is becoming increasingly clear that HP1 proteins have diverse roles in the nucleus, including the regulation of euchromatic genes. HP1 proteins are amenable to posttranslational modifications that probably regulate these distinct functions, thereby creating a subcode within the context of the 'histone code' of histone posttranslational modifications. Chromodomains typically recruit protein complexes to chromatin and read the epigenetic histone code by recognizing lysine methylation in histone tails. We report the crystal structure of the chloroplast signal recognition particle (cpSRP) core from Arabidopsis thaliana, with the cpSRP54 tail comprising an arginine-rich motif bound to the second chromodomain of cpSRP43. A twinned aromatic cage reads out two neighboring nonmethylated arginines and adapts chromodomains to a non-nuclear function in post-translational targeting. Mi-2/nucleosome remodeling and deacetylase (NuRD) chromatin remodeling complexes are important regulators of chromatin structure and DNA accessibility. We examined requirements for individual domains of chromodomain helicase DNA-binding protein 4 (CHD4), a core catalytic component of NuRD complexes, as well as the NuRD subunit methyl-binding domain protein 2 (MBD2) and methylated DNA, for NuRD function in the context of tissue-specific transcription. By itself, loss of NuRD activity is not sufficient for transcriptional activation. However, NuRD complexes greatly reduce activation of the B cell-specific mb-1 (Cd79a) gene by the transcription factors EBF1 and Pax5. Using our B cell model system, we determined that the two chromodomains and ATPase/helicase and C-terminal domains (CTD) of CHD4 are all necessary for repression of mb-1 promoters by NuRD. All of these domains except the CTD are required for efficient association of CHD4 with mb-1 promoter chromatin. Loss of MBD2 expression or of DNA methylation impaired association of CHD4 with mb-1 promoter chromatin and enhanced its transcription. We conclude that repressive functions of MBD2-containing NuRD complexes are dependent on cooperative interactions between the major domains of CHD4 with histones and DNA and on binding of methylated DNA by MBD2. Linker histone (H1) and heterochromatin protein 1 (HP1) are essential components of heterochromatin which contribute to the transcriptional repression of genes. It has been shown that the methylation mark of vertebrate histone H1 is specifically recognized by the chromodomain of HP1. However, the exact biological role of linker histone binding to HP1 has not been determined. Here, we investigate the function of the Caenorhabditis elegans H1 variant HIS-24 and the HP1-like proteins HPL-1 and HPL-2 in the cooperative transcriptional regulation of immune-relevant genes. We provide the first evidence that HPL-1 interacts with HIS-24 monomethylated at lysine 14 (HIS-24K14me1) and associates in vivo with promoters of genes involved in antimicrobial response. We also report an increase in overall cellular levels and alterations in the distribution of HIS-24K14me1 after infection with pathogenic bacteria. HIS-24K14me1 localization changes from being mostly nuclear to both nuclear and cytoplasmic in the intestinal cells of infected animals. Our results highlight an antimicrobial role of HIS-24K14me1 and suggest a functional link between epigenetic regulation by an HP1/H1 complex and the innate immune system in C. elegans. The chromatin organizer modifier domain (chromodomain) is present in proteins that contribute to chromatin organization and mediates their binding to methylated histone H3. Despite a high level of sequence conservation, individual chromodomains manifest substantial differences in binding preference for methylated forms of histone H3, suggesting that posttranslational modification of the chromodomain might be an important determinant of binding specificity. We now show that mouse Cbx2 (also known as M33), a homolog of Drosophila Polycomb protein, is highly phosphorylated in some cell lines. A low-mobility band of Cbx2 observed on SDS-polyacrylamide gel electrophoresis was thus converted to a higher-mobility band by treatment with alkaline phosphatase. Mass spectrometric analysis revealed serine-42, a conserved amino acid in the chromodomain, as a phosphorylation site of Cbx2. Phosphorylation of the chromodomain of Cbx2 on this residue in vitro resulted in a reduced level of binding to an H3 peptide containing trimethylated lysine-9 as well as an increase in the extent of binding to an H3 peptide containing trimethylated lysine-27, suggesting that such phosphorylation changes the binding specificity of Cbx2 for modified histone H3. Phosphorylation of the chromodomain of Cbx2 may therefore serve as a molecular switch that affects the reading of the histone modification code and thereby controls epigenetic cellular memory. Members of the chromodomain helicase DNA-binding (CHD) family of proteins are thought to regulate gene expression. Among mammalian CHD proteins, CHD8 was originally isolated as a negative regulator of the Wnt-β-catenin signaling pathway that binds directly to β-catenin and suppresses its transactivation activity. The mechanism by which CHD8 inhibits β-catenin-dependent transcription has been unclear, however. Here we show that CHD8 promotes the association of β-catenin and histone H1, with formation of the trimeric complex on chromatin being required for inhibition of β-catenin-dependent transactivation. A CHD8 mutant that lacks the histone H1 binding domain did not show such inhibitory activity, indicating that histone H1 recruitment is essential for the inhibitory effect of CHD8. Furthermore, either depletion of histone H1 or expression of a dominant negative mutant of this protein resulted in enhancement of the response to Wnt signaling. These observations reveal a new mode of regulation of the Wnt signaling pathway by CHD8, which counteracts β-catenin function through recruitment of histone H1 to Wnt target genes. Given that CHD8 is expressed predominantly during embryogenesis, it may thus contribute to setting a threshold for responsiveness to Wnt signaling that operates in a development-dependent manner. GATA binding protein 3 (Gata3) is a GATA family transcription factor that controls differentiation of naïve CD4 T cells into T helper 2 (Th2) cells. However, it is unknown how Gata3 simultaneously activates Th2-specific genes while repressing those of other Th lineages. Here we show that chromodomain helicase DNA-binding protein 4 (Chd4) forms a complex with Gata3 in Th2 cells that both activates Th2 cytokine transcription and represses the Th1 cytokine IFN-γ. We define a Gata3/Chd4/p300 transcriptional activation complex at the Th2 cytokine loci and a Gata3/Chd4-nucleosome remodeling histone deacetylase repression complex at the Tbx21 locus in Th2 cells. We also demonstrate a physiological role for Chd4 in Th2-dependent inflammation in an in vivo model of asthmatic inflammation. Thus, Gata3/Chd4 forms functionally distinct complexes, which mediate both positive and negative gene regulation to facilitate Th2 cell differentiation. Two overlapping cDNAs that encode a 197-kDa sequence-selective DNA-binding protein were isolated from libraries derived from mouse lymphoid cell mRNA. In addition to a DNA-binding domain, the protein contains both a chromodomain, which occurs in proteins that are implicated in chromatin compaction, and an SNF2/SWI2-like helicase domain, which occurs in proteins that are believed to activate transcription by counteracting the repressive effects of chromatin structure. A Southern blot analysis indicated that this protein, which we have named CHD-1, for chromodomain-helicase-DNA-binding protein, is present in most, if not all, mammalian species. A Northern blot analysis revealed multiple CHD mRNA components that differed both qualitatively and quantitatively among various cell types. The various mRNAs, which are probably produced by alternative RNA processing, could conceivably encode tissue-specific and developmental stage-specific isoforms of the protein. Based on its interesting combination of features, we suspect that CHD-1 plays an important role in gene regulation. During meiotic cell division, proper chromosome synapsis and accurate repair of DNA double strand breaks (DSBs) are required to maintain genomic integrity, loss of which leads to apoptosis or meiotic defects. The mechanisms underlying meiotic chromosome synapsis, DSB repair and apoptosis are not fully understood. Here, we report that the chromodomain-containing protein MRG-1 is an important factor for genomic integrity in meiosis in Caenorhabditis elegans. Loss of mrg-1 function resulted in a significant increase in germ cell apoptosis that was partially inhibited by mutations affecting DNA damage checkpoint genes. Consistently, mrg-1 mutant germ lines exhibited SPO-11-generated DSBs and elevated exogenous DNA damage-induced chromosome fragmentation at diakinesis. In addition, the excessive apoptosis in mrg-1 mutants was partially suppressed by loss of the synapsis checkpoint gene pch-2, and a significant number of meiotic nuclei accumulated at the leptotene/zygotene stages with an elevated level of H3K9me2 on the chromatin, which was similarly observed in mutants deficient in the synaptonemal complex, suggesting that the proper progression of chromosome synapsis is likely impaired in the absence of mrg-1. Altogether, these findings suggest that MRG-1 is critical for genomic integrity by promoting meiotic DSB repair and synapsis progression in meiosis. BACKGROUND AND AIMS: Glomerular diseases are the third leading cause of kidney failure worldwide, behind only diabetes and hypertension. The molecular mechanisms underlying the cause of glomerular diseases are still largely unknown. The identification and characterization of new molecules associated with glomerular function should provide new insights into understanding the diverse group of glomerular diseases. The Chd2 protein belongs to a family of enzymes involved in ATP-dependent chromatin remodeling, suggesting that it likely functions as an epigenetic regulator of gene expression via the modification of chromatin structure. METHODS: In this study, we present a detailed histomorphologic characterization of mice containing a mutation in the chromodomain helicase DNA-binding protein 2 (Chd2). RESULTS: We show that Chd2-mutant mice present with glomerulopathy, proteinuria, and significantly impaired kidney function. Additionally, serum analysis revealed decreased hemoglobin and hematocrit levels in Chd2-mutant mice, suggesting that the glomerulopathy observed in these mice is associated with anemia. CONCLUSION: Collectively, the data suggest a role for the Chd2 protein in the maintenance of kidney function. DNA and histone modifications direct the functional state of chromatin and thereby the readout of the genome. Candidate approaches and histone peptide affinity purification experiments have identified several proteins that bind to chromatin marks. However, the complement of factors that is recruited by individual and combinations of DNA and histone modifications has not yet been defined. Here, we present a strategy based on recombinant, uniformly modified chromatin templates used in affinity purification experiments in conjunction with SILAC-based quantitative mass spectrometry for this purpose. On the prototypic H3K4me3 and H3K9me3 histone modification marks we compare our method with a histone N-terminal peptide affinity purification approach. Our analysis shows that only some factors associate with both, chromatin and peptide matrices but that a surprisingly large number of proteins differ in their association with these templates. Global analysis of the proteins identified implies specific domains mediating recruitment to the chromatin marks. Our proof-of-principle studies show that chromatin templates with defined modification patterns can be used to decipher how the histone code is read and translated. BACKGROUND: Mutations in the chromodomain helicase DNA binding protein 7 gene (CHD7) lead to CHARGE syndrome, an autosomal dominant multiple malformation disorder. Proteins involved in chromatin remodeling typically act in multiprotein complexes. We previously demonstrated that a part of human CHD7 interacts with a part of human CHD8, another chromodomain helicase DNA binding protein presumably being involved in the pathogenesis of neurodevelopmental (NDD) and autism spectrum disorders (ASD). Because identification of novel CHD7 and CHD8 interacting partners will provide further insights into the pathogenesis of CHARGE syndrome and ASD/NDD, we searched for additional associated polypeptides using the method of stable isotope labeling by amino acids in cell culture (SILAC) in combination with mass spectrometry. PRINCIPLE FINDINGS: The hitherto uncharacterized FAM124B (Family with sequence similarity 124B) was identified as a potential interaction partner of both CHD7 and CHD8. We confirmed the result by co-immunoprecipitation studies and showed a direct binding to the CHD8 part by direct yeast two hybrid experiments. Furthermore, we characterized FAM124B as a mainly nuclear localized protein with a widespread expression in embryonic and adult mouse tissues. CONCLUSION: Our results demonstrate that FAM124B is a potential interacting partner of a CHD7 and CHD8 containing complex. From the overlapping expression pattern between Chd7 and Fam124B at murine embryonic day E12.5 and the high expression of Fam124B in the developing mouse brain, we conclude that Fam124B is a novel protein possibly involved in the pathogenesis of CHARGE syndrome and neurodevelopmental disorders. Cucurbit[7]uril selectively binds the epigenetic mark N(ε),N(ε),N(ε)-trimethyllysine (LysMe(3), K(CB[7]) = (1.8 ± 0.6)× 10(6) dm(3) mol(-1)) by 3500-fold over lysine ((5.3 ± 0.7) × 10(2) dm(3) mol(-1)) in aqueous solution, using ion-dipole interactions and the hydrophobic effect, rather than cation-π interactions, as in the "aromatic cages" of p-SO(3)-calix[4]arene hosts or chromodomain proteins which recognize LysMe(3). The trend in K(CB[7]) of LysMe(3) > LysMe(2) > LysMe > Lys follows the recognition pattern of the chromodomain HP1 and other LysMe(n) protein readers. With CB[6], protonation of the guest carboxylate group is required for the formation of inclusion complexes with the LysMe(n) series. The CB[7] host also displays modest selectivity between the asymmetric ((2.0 ± 0.3) × 10(3) dm(3) mol(-1)) and symmetric ((6.1 ± 0.6) × 10(3) dm(3) mol(-1)) dimethylarginines, both of which bind more strongly than the parent arginine or monomethylarginine. The male-specific lethal (MSL) complex upregulates the single male X chromosome to achieve dosage compensation in Drosophila melanogaster. We have proposed that MSL recognition of specific entry sites on the X is followed by local targeting of active genes marked by histone H3 trimethylation (H3K36me3). Here we analyze the role of the MSL3 chromodomain in the second targeting step. Using ChIP-chip analysis, we find that MSL3 chromodomain mutants retain binding to chromatin entry sites but show a clear disruption in the full pattern of MSL targeting in vivo, consistent with a loss of spreading. Furthermore, when compared to wild type, chromodomain mutants lack preferential affinity for nucleosomes containing H3K36me3 in vitro. Our results support a model in which activating complexes, similarly to their silencing counterparts, use the nucleosomal binding specificity of their respective chromodomains to spread from initiation sites to flanking chromatin. Ocular coloboma, heart malformation, choanal atresia, retardation of growth and/or development, genital hypoplasia, and ear anomalies associated with deafness (CHARGE) syndrome is a rare, usually sporadic, autosomal dominant disorder, caused by mutations within the CHD7 (chromodomain helicase DNA-binding protein 7) gene, in nearly 70% of cases. Because human CHD7 is relatively large (38 exons encoding a 300-kDa protein), genetic analysis requires cost-effective and time-consuming techniques. Herein, we propose an alternative screening method to quickly detect CHD7 mutations using mainly denaturing high-performance liquid chromatography. The entire coding region with exon-intron boundaries was amplified under the same experimental conditions. Each amplicon of the same CHD7 region was subjected to denaturing high-performance liquid chromatography analysis, and resulting chromatograms were compared within small series of patients. Because a CHD7 mutation differs generally from one patient to another, corresponding chromatograms exhibited a unique pattern that is significantly different from common polymorphisms. Only amplicons exhibiting a unique profile were subjected to DNA sequencing analysis. Intragenic rearrangements were investigated with only nine multiplex PCRs. In conclusion, using our protocol, we can quickly detect the right containing mutation amplicon and we provide a robust, rapid, and cheaper method to screen CHD7 microrearrangements or an entire deletion. The development of the Drosophila melanogaster wing depends on its subdivision into anterior and posterior compartments, which constitute two independent cell lineages since their origin in the embryonic ectoderm. The anterior-posterior compartment boundary is the place where signaling by the Hedgehog pathway takes place, and this requires pathway activation in anterior cells by ligand expressed exclusively in posterior cells. Several mechanisms ensure the confinement of hedgehog expression to posterior cells, including repression by Cubitus interruptus, the co-repressor Groucho and Master of thick veins. In this work we identified Kismet, a chromodomain-containing protein of the SNF2-like family of ATPases, as a novel component of the hedgehog transcriptional repression mechanism in anterior compartment cells. In kismet mutants, hedgehog is ectopically expressed in a domain of anterior cells close to the anterior-posterior compartment boundary, causing inappropriate activation of the pathway and changes in the development of the central region of the wing. The contribution of Kismet to the silencing of hedgehog expression is limited to anterior cells with low levels of the repressor form of Cubitus interruptus. We also show that knockdown of CHD8, the kismet homolog in Xenopus tropicalis, is also associated with ectopic sonic hedgehog expression and up-regulation of one of its target genes in the eye, Pax2, indicating the evolutionary conservation of Kismet/CHD8 function in negatively controlling hedgehog expression. Facultative heterochromatin is reversibly established and disrupted during differentiation, but its regulation remains mechanistically unclear. Here, we show that two meiotic gene loci in fission yeast, mei4 and ssm4, comprise facultative heterochromatin that is regulated in a developmental stage-dependent manner. This heterochromatin coordinates expression levels by associating with a chromodomain protein Chp1 and an antisilencing factor Epe1. It has been recently shown that an RNA surveillance machinery for eliminating meiotic gene transcripts, which involves a cis-element called the determinant of selective removal (DSR) and transacting factors, Mmi1 and Red1, also participates in heterochromatin formation at the meiotic genes, but the molecular mechanism underlying the process is largely unknown. By dissecting the mei4 gene, we identified a region that promotes DSR-dependent methylation of histone H3 lysine 9 (H3K9). Integration of this mei4 region together with DSR into an unrelated gene results in ectopic H3K9 methylation. Moreover, our results suggest that transcription of these elements induces chromatin association of Mmi1, which, in turn, recruits Red1 interacting with Clr4/Suv39h H3K9 methyltransferase. Mmi1 remains associated in cells lacking Red1, suggesting that the recruitment of Red1 follows the chromatin association of Mmi1. Overall, we provide detailed insights into the facultative heterochromatin regulation in fission yeast. Polycomb-repressive complex 1 (PRC1) has a central role in the regulation of heritable gene silencing during differentiation and development. PRC1 recruitment is generally attributed to interaction of the chromodomain of the core protein Polycomb with trimethyl histone H3K27 (H3K27me3), catalyzed by a second complex, PRC2. Unexpectedly we find that RING1B, the catalytic subunit of PRC1, and associated monoubiquitylation of histone H2A are targeted to closely overlapping sites in wild-type and PRC2-deficient mouse embryonic stem cells (mESCs), demonstrating an H3K27me3-independent pathway for recruitment of PRC1 activity. We show that this pathway is mediated by RYBP-PRC1, a complex comprising catalytic subunits of PRC1 and the protein RYBP. RYBP-PRC1 is recruited to target loci in mESCs and is also involved in Xist RNA-mediated silencing, the latter suggesting a wider role in Polycomb silencing. We discuss the implications of these findings for understanding recruitment and function of Polycomb repressors. BACKGROUND & AIMS: Chromodomain helicase/adenosine triphosphatase DNA binding protein 1-like (CHD1L) is an SNF2-like transcription factor involved in the development of human hepatocellular carcinoma (HCC). Sparc/osteonectin, cwcv, and kazal-like domains proteoglycan 1 (SPOCK1) is up-regulated by CHD1L; we investigated its role in hepatocellular carcinogenesis. METHODS: We investigated interactions between SPOCK1 and CHD1L using electrophoretic mobility shift and luciferase reporter assays. Levels of SPOCK1 messenger RNA (mRNA) and protein were measured in samples of HCC and adjacent nontumor liver tissues (135 pairs) and compared using Pearson correlation coefficients. Effects of SPOCK1 overexpression and silencing were determined in HCC cell lines (QGY-7703, PLC-8024, BEL-7402, and QGY-7701). RESULTS: The CHD1L protein bound directly to the promoter region (nt-1662 to +34) of SPOCK1 and activated transcription. Levels of SPOCK1 mRNA and protein were increased in 60% of human HCC samples, compared with nontumor live tissues, and was associated significantly with clinical stage. Levels of SPOCK1 mRNA were increased among tumors that became metastatic, compared with those that did not, and among patients with shorter overall and disease-free survival times. Ectopic expression of SPOCK1 in HCC cells increased proliferation, foci formation, and colony formation in soft agar; these cells also formed larger xenograft tumors, more rapidly, in nude mice than control HCC cells. Silencing SPOCK1 expression with short hairpin RNA had the opposite effects. We found that SPOCK1 prevents apoptosis of HCC cells by activating Akt, to block release of cytochrome c and activation of caspase-9 and caspase-3; these effects were reversed with an Akt inhibitor. HCC cells that overexpressed SPOCK1 expressed higher levels of matrix metallopeptidase 9, were more invasive in Matrigel assays, and formed more metastatic nodules in immunodeficient mice than control HCC cells. CONCLUSIONS: CHD1L activates expression of SPOCK1, which activates Akt signaling to block apoptosis and invasion by HCC cells, in culture and in mice. Levels of SPOCK1 increase with progression of human HCC. SPOCK1 might be used as a prognostic factor or therapeutic target. Proteins containing defined recognition modules mediate readout and translation of histone modifications. These factors are thought to initiate downstream signaling events regulating chromatin structure and function. We identified CDYL1 as an interaction partner of histone H3 trimethylated on lysine 9 (H3K9me3). CDYL1 belongs to a family of chromodomain factors found in vertebrates. We show that three different splicing variants of CDYL1, a, b, and c, are differentially expressed in various tissues with CDYL1b being the most abundant variant. Although all three splicing variants share a common C-terminal enoyl-CoA hydratase-like domain, only CDYL1b contains a functional chromodomain implicated in H3K9me3 binding. A splicing event introducing an N-terminal extension right at the beginning of the chromodomain of CDYL1a inactivates its chromodomain. CDYL1c does not contain a chromodomain at all. Although CDYL1b displays binding affinity to methyl-lysine residues in different sequence context similar to chromodomains in other chromatin factors, we demonstrate that the CDYL1b chromodomain/H3K9me3 interaction is necessary but not sufficient for association of the factor with heterochromatin. Indeed, multimerization of the protein via the enoyl-CoA hydratase-like domain is essential for H3K9me3 chromatin binding in vitro and heterochromatin localization in vivo. In agreement, overexpression of CDYL1c that can multimerize, but does not interact with H3K9me3 can displace CDYL1b from heterochromatin. Our results imply that multimeric binding to H3K9me3 by CDYL1b homomeric complexes is essential for efficient chromatin targeting. We suggest that similar multivalent binding stably anchors other histone modification binding factors on their target chromatin regions. Genetic deletion or mutations of presenilin genes (PS1/PS2) cause familial Alzheimer's disease and calcium (Ca²⁺) signaling abnormalities. PS1/PS2 act as endoplasmic reticulum (ER) Ca²⁺ leak channels that facilitate passive Ca²⁺ leak across ER membrane. Studies with PS1/PS2 double knockout (PS1/PS2-DKO) mouse embryonic fibroblasts showed that PS1/PS2 were responsible for 80% of passive Ca²⁺ leak from the lumen of endoplasmic reticulum to cytosol. Transient transfection of the wild type PS1 expression construct increased cytoplasmic Ca²⁺ as a result of Ca²⁺ leak across ER membrane whereas the FADPS1 (PS1-M146V) mutation construct alone or in combination with the wild type PS1 expression construct abrogated Ca²⁺ leak in SK-N-SH cells. Inhibition of basal c-jun-NH2-terminal kinase (JNK) activity by JNK inhibitor SP600125 repressed PS1 transcription and PS1 protein expression by augmenting p53 protein level in SK-N-SH cells (Lee and Das 2008). In this report we also showed that repression of PS1 transcription by JNK inhibitor SP600125 inhibited passive Ca²⁺ leak across ER membrane which could be rescued by expressing PS1 wild type and not by expressing FADPS1 (PS1-M146V) under a SP600125 non-responsive promoter. Treatment of SK-N-SH cells with SP600125 also triggered InsP3R-mediated Ca²⁺ release from the ER by addition of 500 nM bradykinin, an agonist of InsP3 receptor (InsP3R1) without changing the expression of InsP3R1. This data confirms that SP600125 increases the Ca²⁺ store in the ER by inhibiting PS1-mediated Ca²⁺ leak across ER membrane. p53, ZNF237 and Chromodomain helicase DNA-binding protein 3 which are repressors of PS1 transcription, also reduced Ca²⁺ leak across ER membrane in SK-N-SH cells but γ-secretase inhibitor or dominant negative γ-secretase-specific PS1 mutant (PS1-D257A) had no significant effect. Therefore, p53, ZNF237, and Chromodomain helicase DNA-binding protein 3 inhibit the function ER Ca²⁺ leak channels to regulate both ER and cytoplasmic Ca²⁺ levels and may potentially control Ca²⁺-signaling function of PS1. Fluorescent chromatin tagging by the lacO operator/lac repressor system in Arabidopsis thaliana is useful to trace distinct chromatin domains in living cells. Nevertheless, the tandem repeats of the tagging system may alter the spatial organisation of chromatin within nuclei by increasing homologous pairing as well as association with heterochromatin. Efficient homologous pairing occurs if lacO repeat arrays of ∼10 kb are present at two loci, either on the same chromosome or on different chromosomes. DNA hypomethylation of lacO repeats results in reduced homologous pairing. Because, in plants, DNA methylation can serve as a signal for H3-lysine9-dimethylation (H3K9me2), and subsequently for non-CG-context DNA methylation, SET-domain histone methyltransferase and chromodomain dna methyltransferase 3 (cmt3) mutations were introgressed. In suvh4 suvh5 suvh6 and cmt3 mutants, H3K9me2 associated with lacO repeats is diminished, but homologous pairing persists. Thus, neither H3K9me2 nor CMT3-mediated non-CG methylation are required at wild-type level for homologous pairing of lacO repeat loci. Heterochromatin Protein 1 (HP1a) is a well-known conserved protein involved in heterochromatin formation and gene silencing in different species including humans. A general model has been proposed for heterochromatin formation and epigenetic gene silencing in different species that implies an essential role for HP1a. According to the model, histone methyltransferase enzymes (HMTases) methylate the histone H3 at lysine 9 (H3K9me), creating selective binding sites for itself and the chromodomain of HP1a. This complex is thought to form a higher order chromatin state that represses gene activity. It has also been found that HP1a plays a role in telomere capping. Surprisingly, recent studies have shown that HP1a is present at many euchromatic sites along polytene chromosomes of Drosophila melanogaster, including the developmental and heat-shock-induced puffs, and that this protein can be removed from these sites by in vivo RNase treatment, thus suggesting an association of HP1a with the transcripts of many active genes. To test this suggestion, we performed an extensive screening by RIP-chip assay (RNA-immunoprecipitation on microarrays), and we found that HP1a is associated with transcripts of more than one hundred euchromatic genes. An expression analysis in HP1a mutants shows that HP1a is required for positive regulation of these genes. Cytogenetic and molecular assays show that HP1a also interacts with the well known proteins DDP1, HRB87F, and PEP, which belong to different classes of heterogeneous nuclear ribonucleoproteins (hnRNPs) involved in RNA processing. Surprisingly, we found that all these hnRNP proteins also bind heterochromatin and are dominant suppressors of position effect variegation. Together, our data show novel and unexpected functions for HP1a and hnRNPs proteins. All these proteins are in fact involved both in RNA transcript processing and in heterochromatin formation. This suggests that, in general, similar epigenetic mechanisms have a significant role on both RNA and heterochromatin metabolisms. To ensure genome stability, cells have evolved a robust defense mechanism to detect, signal, and repair damaged DNA that is generated by exogenous stressors such as ionizing radiation, endogenous stressors such as free radicals, or normal physiological processes such as DNA replication. Homologous recombination (HR) repair is a critical pathway of repairing DNA double strand breaks, and it plays an essential role in maintaining genomic integrity. Previous studies have shown that BRIT1, also known as MCPH1, is a key regulator of HR repair. Here, we report that chromodomain helicase DNA-binding protein 4 (CHD4) is a novel BRIT1 binding partner that regulates the HR repair process. The BRCA1 C-terminal domains of BRIT1 are required for its interaction with CHD4. Depletion of CHD4 and overexpression of the ATPase-dead form of CHD4 impairs the recruitment of BRIT1 to the DNA damage lesions. As a functional consequence, CHD4 deficiency sensitizes cells to double strand break-inducing agents, reduces the recruitment of HR repair factor BRCA1, and impairs HR repair efficiency. We further demonstrate that CHD4-depleted cells are more sensitive to poly(ADP-ribose) polymerase inhibitor treatment. In response to DNA damage induced by poly(ADP-ribose) polymerase inhibitors, CHD4 deficiency impairs the recruitment of DNA repair proteins BRIT1, BRCA1, and replication protein A at early steps of HR repair. Taken together, our findings identify an important role of CHD4 in controlling HR repair to maintain genome stability and establish the potential therapeutic implications of targeting CHD4 deficiency in tumors. MSL3 resides in the MSL (male-specific lethal) complex, which upregulates transcription by spreading the histone H4 Lys16 (H4K16) acetyl mark. We discovered a DNA-dependent interaction of MSL3 chromodomain with the H4K20 monomethyl mark. The structure of a ternary complex shows that the DNA minor groove accommodates the histone H4 tail, and monomethyllysine inserts in a four-residue aromatic cage in MSL3. H4K16 acetylation antagonizes MSL3 binding, suggesting that MSL function is regulated by a combination of post-translational modifications. Tandem repeats are found in both coding and non-coding sequences of higher organisms. These sequences can be used in cancer genetics and diagnosis to unravel the genetic basis of tumor formation and progression. In this study, a possible relationship between SSR distributions and lung cancer was studied by comparative analysis of EST-SSRs in normal and lung cancerous tissues. While the EST-SSR distribution was similar between tumorous tissues, this distribution was different between normal and tumorous tissues. Trinucleotides tandem repeats were highly different; the number of trinucleotides in ESTs of lung cancer was 3 times higher than normal tissue. Significant negative correlation between normal and cancerous tissue showed that cancerous tissue generates different types of trinucleotides. GGC and CGC were the more frequent expressed trinucleotides in cancerous tissue, but these SSRs were not expressed in normal tissue. Similar to the EST level, the expression pattern of EST-SSRs-derived amino acids was significantly different between normal and cancerous tissues. Arg, Pro, Ser, Gly, and Lys were the most abundant amino acids in cancerous tissues, and Leu, Cys, Phe, and His were significantly more abundant in normal tissues than in cancerous tissues. Next, the putative functions of triplet SSR-containing genes were analyzed. In cancerous tissue, EST-SSRs produce different types of proteins. Chromodomain helicase DNA binding proteins were one of the major protein products of EST-SSRs in the cancerous library, while these proteins were not produced from EST-SSRs in normal tissue. For the first time, the findings of this study confirmed that EST-SSRs in normal lung tissues are different than in unhealthy tissues, and tagged ESTs with SSRs cause remarkable differences in amino acid and protein expression patterns in cancerous tissue. We suggest that EST-SSRs and EST-SSRs differentially expressed in cancerous tissue may be suitable candidate markers for lung cancer diagnosis and prediction. BACKGROUND AND OBJECTIVE: The tooth root is one of the critical parts to maintain tooth function; however, the molecular mechanisms of root development remain unknown. We aimed to identify specific factors for root morphogenesis using a newly developed experimental system. MATERIAL AND METHODS: Tentative cementoblasts and periodontal ligament cells from mouse mandibular molars were isolated using laser capture microdissection. More than 500 cementoblasts and periodontal ligament cells were separately captured. After RNA extraction and amplification, mRNA expression in isolated cementoblasts was compared with that of periodontal ligament cells by cDNA microarray analysis. Then, putative cementoblast-specific genes were subjected to in situ hybridization analysis to confirm the results in mouse mandible. RESULTS: Approximately 2000 genes were differentially expressed between these tissues. Among those genes, zinc finger helicase (ZFH), also termed chromodomain-helicase-DNA-binding protein 3 (Chd3), was one of the highly expressed transcripts in tentative cementoblasts. In situ hybridization revealed that ZFH/Chd3 was strongly expressed in Hertwig's epithelial root sheath rather than in cementum. Moreover, its expression disappeared when root formation was advanced in the first molar. In contrast, Chd3 was continuously expressed in dental epithelial cells of the cervical loop, in which root extension is never terminated. CONCLUSION: These results suggest that ZFH/Chd3 might play an important role in tooth root development and subsequent cementogenesis. Histone lysine methylation is a critical marker for controlling gene expression. The position and extent of methylation (mono-, di-, or tri-) controls the binding of effector proteins that determine whether the associated DNA is expressed or not. Dysregulation of histone protein methylation has been associated with a number of types of cancer, and development of inhibitors for the effector proteins is becoming an active area of research. For this reason, understanding the mechanism by which effector proteins obtain selectivity for the different methylation states of lysine is of great interest. To this end, we have performed mutation studies on the Drosophila HP1α chromodomain, which binds H3K9Me(2) and H3K9Me(3) with approximately equal affinities. The selectivity of HP1α chromodomain for H3K9Me(3) over H3K9Me(2) was investigated by mutating E52 to remove or weaken the hydrogen bond to K9Me(2) while maintaining affinity for K9Me(3,) including E52F, E52I, E52V, E52D, an E52Q. The E52Q mutant exhibited the greatest degree of selectivity for KMe3, with 3.5-fold weaker binding to the dimethylated peptide (K(D) =52 μM) compared to the trimethylated peptide (K(D) =15 μM). These studies provide insight into the role of electrostatic interactions and hydrogen bonding in the differentiation of methylation states and have implications regarding the evolutionary pressure for selectivity in this protein-protein interaction. Moreover, the information from this study may help guide inhibitor development for this class of proteins. The phosphorylation of heterochromatin protein 1 (HP1) has been previously described in studies of mammals, but the biological implications of this modification remain largely elusive. Here, we show that the N-terminal phosphorylation of HP1α plays a central role in its targeting to chromatin. Recombinant HP1α prepared from mammalian cultured cells exhibited a stronger binding affinity for K9-methylated histone H3 (H3K9me) than that produced in Escherichia coli. Biochemical analyses revealed that HP1α was multiply phosphorylated at N-terminal serine residues (S11-14) in human and mouse cells and that this phosphorylation enhanced HP1α's affinity for H3K9me. Importantly, the N-terminal phosphorylation appeared to facilitate the initial binding of HP1α to H3K9me by mediating the interaction between HP1α and a part of the H3 tail that was distinct from the methylated K9. Unphosphorylatable mutant HP1α exhibited severe heterochromatin localization defects in vivo, and its prolonged expression led to increased chromosomal instability. Our results suggest that HP1α's N-terminal phosphorylation is essential for its proper targeting to heterochromatin and that its binding to the methylated histone tail is achieved by the cooperative action of the chromodomain and neighboring posttranslational modifications. Chromatin-remodeling proteins have a pivotal role in normal cell function and development, catalyzing conformational changes in DNA that ultimately result in changes in gene expression patterns. Chromodomain helicase DNA-binding protein 4 (CHD4), the defining subunit of the nucleosome remodeling and deacetylase (NuRD) complex, is a nucleosome-remodeling protein of the SNF2/ISWI2 family, members of which contain two chromo domains and an ATP-dependent helicase module. CHD3, CHD4 and CHD5 also contain two contiguous PHD domains and have an extended N-terminal region that has not previously been characterized. We have identified a stable domain in the N-terminal region of CHD4 and report here the backbone and side chain resonance assignments for this domain at pH 7.5 and 25 °C (BMRB No. 18906). The transcriptional output at a genomic locus in eukaryotes is determined, in part, by the pattern of histone modifications that are read and interpreted by key effector proteins. The histone deacetylase activity of the evolutionarily conserved Rpd3S/Sin3S complex is crucial for suppressing aberrant transcription from cryptic start sites within intragenic regions of actively transcribed genes. Precise targeting of the complex relies on the chromatin binding activities of the MRG15 (MRG stands for mortality factor on chromosome 4 related gene) and Pf1 subunits. Whereas the molecular target of the MRG15 chromodomain (CD) has been suggested to be H3K36me(2/3), the precise molecular target of the Pf1 plant homeodomain 1 (PHD1) has remained elusive. Here, we show that Pf1 PHD1 binds preferentially to the unmodified extreme N-terminus of histone H3 (H3K4me(0)) but not to H3K4me(2/3), which are enriched in the promoter and 5' regions of genes. Unlike previously characterized CD and PHD domains that bind to their targets with micromolar affinity, both MRG15 CD and Pf1 PHD1 bind to their targets with >100 μM affinity, offering an explanation for why both MRG15 CD and Pf1 PHD1 domains are required to target the Rpd3S/Sin3S complex to chromatin. Our results also suggest that bivalency, rather than cooperativity, is the operative mechanism by which Pf1 and MRG15 combine to engage H3 in a biologically significant manner. Finally, the studies reveal an unanticipated role of Pf1 PHD1 in engaging the MRG15 MRG domain, albeit in a Pf1 MRG-binding-domain-dependent manner, implying a key role for the MRG15 MRG-Pf1 MBD interaction in chromatin targeting of the Rpd3S/Sin3S complex. Knowledge of protein domains that function as the biological effectors for diverse post-translational modifications of histones is critical for understanding how nuclear and epigenetic programs are established. Indeed, mutations of chromatin effector domains found within several proteins are associated with multiple human pathologies, including cancer and immunodeficiency syndromes. To date, relatively few effector domains have been identified in comparison to the number of modifications present on histone and non-histone proteins. Here we describe the generation and application of human modified peptide microarrays as a platform for high-throughput discovery of chromatin effectors and for epitope-specificity analysis of antibodies commonly utilized in chromatin research. Screening with a library containing a majority of the Royal Family domains present in the human proteome led to the discovery of TDRD7, JMJ2C, and MPP8 as three new modified histone-binding proteins. Thus, we propose that peptide microarray methodologies are a powerful new tool for elucidating molecular interactions at chromatin. Although regulation of histone methylation is believed to contribute to embryonic stem cell (ESC) self-renewal, the mechanisms remain obscure. We show here that the histone H3 trimethyl lysine 4 (H3K4me3) demethylase, KDM5B, is a downstream Nanog target and critical for ESC self-renewal. Although KDM5B is believed to function as a promoter-bound repressor, we find that it paradoxically functions as an activator of a gene network associated with self-renewal. ChIP-Seq reveals that KDM5B is predominantly targeted to intragenic regions and that it is recruited to H3K36me3 via an interaction with the chromodomain protein MRG15. Depletion of KDM5B or MRG15 increases intragenic H3K4me3, increases cryptic intragenic transcription, and inhibits transcriptional elongation of KDM5B target genes. We propose that KDM5B activates self-renewal-associated gene expression by repressing cryptic initiation and maintaining an H3K4me3 gradient important for productive transcriptional elongation. AIMS: Chromodomain helicase DNA-binding protein (CHD) is a regulator of the chromatin remodelling process. The aim was to determine the CHD1, CHD2, CHD3, CHD4, CHD7, CHD8 and CHD9 mutational status of mononucleotide repeats in gastric and colorectal cancers with microsatellite instability (MSI). METHODS AND RESULTS: The repeats were determined in 28 gastric cancers (GCs) with high MSI (MSI-H), 45 GCs with low MSI (MSI-L)/stable MSI (MSS), 35 colorectal cancers (CRCs) with MSI-H and 45 CRCs with MSI-L/MSS by single-strand conformation polymorphism analysis. CHD4 and CHD8 expression was also examined in GCs and CRCs by immunohistochemistry. CHD1, CHD2, CHD3, CHD4, CHD7, CHD8 and CHD9 mutations were found in five, 19, three, five, seven, 10 and seven cancers, respectively. They were detected in MSI-H cancers, but not in MSI-L/MSS cancers. Loss of CHD4 expression was observed in 56.4% of the GCs and 55.7% of the CRCs, and loss of CHD8 was observed in 35.7% of the GCs and 28.6% of the CRCs. The cancers with CHD4 and CHD8 mutations showed loss of CHD4 and CHD8 expression, respectively. CONCLUSIONS: Frameshift mutation and loss of expression of CHD genes are common in GCs and CRCs with MSI-H.These alterations might contribute to cancer pathogenesis by deregulating CHD-mediated chromatin remodelling. Somitogenesis is a complex process during early vertebrate development involving interactions between many factors to form a bilateral somite series. A role for chromatin remodelers in somitogenesis has not yet been demonstrated. Here, we investigate the function of chromodomain helicase DNA binding protein 7 (chd7) during zebrafish somitogenesis. We show that Chd7 deficiency leads to asymmetric segmentation of the presomitic mesoderm (PSM), as revealed by expression of the somitogenesis genes, cdx1a, dlc, her7, mespa, and ripply1. Moreover, we show that abrogation of Chd7 results in the loss of asymmetric expression of spaw in the lateral plate mesoderm, which is consistent with more general laterality defects. Based on the observation that insufficient Chd7 leads to left-right asymmetry defects during PSM segmentation, and because CHD7 has been linked to human spinal deformities, we suggest that zebrafish chd7 morphants may be a good in vivo model to examine the pathophysiology of these diseases. A large portion of the eukaryotic genome is packaged into transcriptionally silent heterochromatin. Several factors that play important roles during the establishment and maintenance of this condensed form have been identified. Methylation of lysine 9 within histone H3 and the subsequent binding of the chromodomain protein heterochromatin protein 1 (HP1) are thought to initiate heterochromatin formation in vivo and to propagate a heterochromatic state lasting through several cell divisions. For the present study we analyzed the binding of HP1 to methylated chromatin in a fully reconstituted system. In contrast to its strong binding to methylated peptides, HP1 binds only weakly to methylated chromatin. However, the addition of recombinant SU(VAR) protein, such as ACF1 or SU(VAR)3-9, facilitates HP1 binding to chromatin methylated at lysine 9 within the H3 N terminus (H3K9). We propose that HP1 has multiple target sites that contribute to its recognition of chromatin, only one of them being methylated at H3K9. These findings have implications for the mechanisms of recognition of specific chromatin modifications in vivo. Mammalian Mi-2, an auto-antigen for dermatomyositis, is known to be an adenosine triphosphate (ATP)-dependent nucleosome remodelling factor. The Drosophila homologue of Mi-2 (dMi-2) gene is located at 76D5-6 on the left arm of the third chromosome and is transcribed into two alternate transcripts (dMi-2a and dMi-2b). Both transcripts are present at high levels in the ovary and during the first 8 h of embryogenesis when detected by Northern blot analysis. The localization of protein was nuclear, which is consistent with its proposed function as a component of the chromatin remodelling complex. Several lines of recessive mutants including mutations in dMi-2 were isolated and classified into four different complementation groups. Four alleles of dMi-2 mutants were further characterized in molecular nature; dMi-2(BL1) was found to have a mutation in the ATP-binding motif of the ATPase domain, dMi-2(BL7) in the core histidine of the first plant homeodomain zinc finger and dMi-2(BL12) in a conserved serine in the chromodomain. On the other hand, dMi-2(BL3) did not have any change in the coding region. The expression pattern of dMi-2 and the embryonic lethal phenotypes of mutants indicate that dMi-2 is essential for embryonic development in Drosophila melanagaster. Integration of DNA copies in a host genome is a necessary stage in the life cycle of retroviruses and LTR-retrotransposons. There is still no clear understanding of integration specificity of retroelements into a target site. The selection of the target DNA is believed to potentially affect a number of factors such as transcriptional status, association with histones and other DNA-binding proteins, and DNA bending. The authors performed a comprehensive computer analysis of the integration specificity of Drosophila melanogaster LTR-retrotransposons and retroviruses including an analysis of the nucleotide composition of targets, terminal sequences of LTRs, and integrase sequences. A classification of LTR-retrotransposons based on the integration specificity was developed. All the LTR-retrotransposons of the gypsy group with three open frames (errantiviruses) and their derivatives with two open frames demonstrate strict specificity to a target DNA selection. Such specificity correlates with the structural features of the target DNA: bendability, A-philicity, or protein-induced deformability. The remaining LTR-retrotransposons (copia and BEL groups, blastopia and 412 subgroups of the gypsy group) do not show specificity of integration. Chromodomain is present in the integrase structures of blastopia and 412 subgroup LTR-retrotransposons and may facilitate the process of non-specific integration. Dosage compensation in Drosophila is mediated by genes known as "male-specific lethals" (msls). Several msls, including male-specific lethal-3 (msl-3), encode proteins of unknown function. We cloned the Drosophila virilis msl-3 gene. Using the information provided by the sequences of the Drosophila melanogaster and D. virilis genes, we found that sequences of other species can be aligned along their entire lengths with msl-3. Among them, there are genes in yeasts (the Schizosaccharomyces pombe Alp13 gene, as well as a putative Alp13 homolog, found in Saccharomyces cerevisae) and in mammals (MRG15 and MSL3L1 and their relatives) plus uncharacterized sequences of the nematode Caenorhabditis elegans and the plants Arabidopsis thaliana, Lycopersicon esculentum, and Zea mays. A second Drosophila gene of this family has also been found. It is thus likely that msl-3-like genes are present in all eukaryotes. Phylogenetic analyses suggest that msl-3 is orthologous to the mammalian MSL3L1 genes, while the second Drosophila melanogaster gene (which we have called Dm MRG15) is orthologous to mammalian MRG15. These analyses also suggest that the msl-3/MRG15 duplication occurred after the fungus/animal split, while an independent duplication occurred in plants. The proteins encoded by these genes have similar structures, including a putative chromodomain close to their N-terminal end and a putative leucine zipper at their C-terminus. The possible functional roles of these proteins are discussed. Controlling cell fate-determining gene expression is key to stem cell differentiation, tissue regeneration, and cancer therapy. To date, custom-built transcription factors recognize the information encoded in specific DNA sequences. Chromatin proteins undergo covalent modifications and form complexes that encode a second layer of information that determines proximal gene activity. Here, we employ a novel gene-targeting approach that exploits a specific chromatin modification to reactivate silenced loci in human cells. We used the human Polycomb chromatin protein and homologues from other species to construct modular synthetic transcription factors, called Pc-TFs, that recognize the repressive trimethyl-histone H3 lysine 27 (H3K27me3) signal and switch silenced genes to an active state. Pc-TF expression in U2OS osteosarcoma cells leads to increased transcription of the senescence locus CDKN2A (p16) and other loci in a chromodomain- and activation module-dependent manner, a switch to a senescence phenotype, and reduced cell proliferation. These results indicate that silenced developmental regulators can be reactivated by a synthetic transcription factor that interacts with chromatin rather than DNA, resulting in an altered cell state. As such, our work extends the flexibility of transcription factor engineering and is the first example of chromatin-mediated synthetic transcription factor targeting. BACKGROUND: Our recent studies suggested that the chromodomain helicase DNA binding protein 1-like (CHD1L) gene plays an oncogenic role in human hepatocellular carcinoma. However, the status of CHD1L protein expression in ovarian cancer and its clinical/prognostic significance are obscure. METHODS: In this study, immunohistochemistry (IHC) for CHD1L was performed on a tissue microarray (TMA) containing 102 primary ovarian carcinomas and 44 metastatic lesions (omental metastasis). Receiver-operator curve (ROC) analysis was used to evaluate patients' survival status. RESULTS: There is an augmented tendency of CHD1L expression in ovarian carcinoma metastasis than in primary lesions (P<0.05). A significant association was found between positive expression of CHD1L and tumors histological type (P <0.05). By univariate survival analysis of the ovarian carcinoma cohorts, positive expression of CHD1L was significantly correlated with shortened patient survival (mean 66.7 months versus 97.4 months, P<0.05). Moreover, CHD1L expression was evaluated to be a significant and independent prognostic factor in multivariate analysis (P<0.05). CONCLUSIONS: These findings provide evidence that positive expression of CHD1L protein is significantly correlated with the metastasis proceeding of ovarian carcinoma, and CHD1L protein expression, as examined by IHC, may act as a novel prognostic biomarker for patients with ovarian carcinoma. Though prostate cancer is often indolent, it is nonetheless a leading cause of cancer death. Defining the underlying molecular genetic alterations may lead to new strategies for prevention or treatment. Towards this goal, we performed array-based comparative genomic hybridization (CGH) on 86 primary prostate tumors. Among the most frequent alterations not associated with a known cancer gene, we identified focal deletions within 5q21 in 15 out of 86 (17%) cases. By high-resolution tiling array CGH, the smallest common deletion targeted just one gene, the chromatin remodeler chromodomain helicase DNA-binding protein 1 (CHD1). Expression of CHD1 was significantly reduced in tumors with deletion (P=0.03), and compared with normal prostate (P=0.04). Exon sequencing analysis also uncovered nonsynonymous mutations in 1 out of 7 (14%) cell lines (LAPC4) and in 1 out of 24 (4%) prostate tumors surveyed. RNA interference-mediated knockdown of CHD1 in two nontumorigenic prostate epithelial cell lines, OPCN2 and RWPE-1, did not alter cell growth, but promoted cell invasiveness, and in OPCN2-enhanced cell clonogenicity. Taken together, our findings suggest that CHD1 deletion may underlie cell invasiveness in a subset of prostate cancers, and indicate a possible novel role of altered chromatin remodeling in prostate tumorigenesis. Fission yeast heterochromatin is formed at centromeres, telomeres, and in the mating-type region where it mediates the transcriptional silencing of the mat2-P and mat3-M donor loci and the directionality of mating-type switching. We conducted a genetic screen for directionality mutants. This screen revealed the essential role of two previously uncharacterized factors, Clr7 and Clr8, in heterochromatin formation. Clr7 and Clr8 are required for localization of the Swi6 chromodomain protein and for histone H3 lysine 9 methylation, thereby influencing not only mating-type switching but also transcriptional silencing in all previously characterized heterochromatic regions, chromosome segregation, and meiotic recombination in the mating-type region. We present evidence for physical interactions between Clr7 and the mating-type region and between Clr7 and the S. pombe cullin Pcu4, indicating that a complex containing these proteins mediates an early step in heterochromatin formation and implying a role for ubiquitination at this early stage prior to the action of the Clr4 histone methyl-transferase. Like Clr7 and Clr8, Pcu4 is required for histone H3 lysine 9 methylation, and bidirectional centromeric transcripts that are normally processed into siRNA by the RNAi machinery in wild-type cells are easily detected in cells lacking Clr7, Clr8, or Pcu4. Another physical interaction, between the nucleoporin Nup189 and Clr8, suggests that Clr8 might be involved in tethering heterochromatic regions to the nuclear envelope by association with the nuclear-pore complex. Centromeric heterochromatin assembly in fission yeast requires the RNAi pathway. Chp1, a chromodomain (CD) protein, forms the Ago1-containing RNA-induced transcriptional silencing (RITS) complex and recruits siRNA-bound RITS to methylated histone H3 lysine 9 (H3K9me) via its CD. Here, we show that the CD of Chp1 (Chp1-CD) possesses unique nucleic acid-binding activities that are essential for heterochromatic gene silencing. Detailed electrophoretic-mobility shift analyses demonstrated that Chp1 binds to RNA via the CD in addition to its central RNA-recognition motif. Interestingly, robust RNA- and DNA-binding activity of Chp1-CD was strongly enhanced when it was bound to H3K9me, which was revealed to involve a positively charged domain within the Chp1-CD by structural analyses. These results demonstrate a role for the CD that provides a link between RNA, DNA, and methylated histone tails to ensure heterochromatic gene silencing. RNA interference (RNAi) is critical for the assembly of heterochromatin at Schizosaccharomyces pombe centromeres. Central to this process is the RNA-induced initiation of transcriptional gene silencing (RITS) complex, which physically anchors small noncoding RNAs to chromatin. RITS includes Ago1, the chromodomain protein Chp1, and Tas3, which forms a bridge between Chp1 and Ago1. Chp1 is a large protein with no recognizable domains, apart from its chromodomain. Here we describe how the structured C-terminal half of Chp1 binds the Tas3 N-terminal domain, revealing the tight association of Chp1 and Tas3. The structure also shows a PIN domain at the C-terminal tip of Chp1 that controls subtelomeric transcripts through a post-transcriptional mechanism. We suggest that the Chp1-Tas3 complex provides a solid and versatile platform to recruit both RNAi-dependent and RNAi-independent gene-silencing pathways for locus-specific regulation of heterochromatin. SUV39H1, the first identified histone lysine methyltransferase in human, is involved in chromatin modification and gene regulation. SUV39H1 contains a chromodomain in its N-terminus, which potentially plays a role in methyl-lysine recognition and SUV39H1 targeting. In this study, the structure of the chromodomain of human SUV39H1 was determined by X-ray crystallography. The SUV39H1 chromodomain displays a generally conserved structure fold compared with other solved chromodomains. However, different from other chromodomains, the SUV39H1 chromodomain possesses a much longer helix at its C-terminus. Furthermore, the SUV39H1 chromodomain was shown to recognize histone H3K9me2/3 specifically. Many co-regulator proteins are recruited by DNA-bound transcription factors to remodel chromatin and activate transcription. However, mechanisms for coordinating actions of multiple co-regulator proteins are poorly understood. We demonstrate that multiple protein-protein interactions by the protein acetyltransferase TIP60 are required for estrogen-induced transcription of a subset of estrogen receptor alpha (ERα) target genes in human cells. Estrogen-induced recruitment of TIP60 requires direct binding of TIP60 to ERα and the action of chromatin-remodeling ATPase BRG1, leading to increased recruitment of histone methyltransferase MLL1 and increased monomethylation of histone H3 at Lys4. TIP60 recruitment also requires preferential binding of the TIP60 chromodomain to histone H3 containing monomethylated Lys4, which marks active and poised enhancer elements. After recruitment, TIP60 increases acetylation of histone H2A at Lys5. Thus, complex cooperation of TIP60 with ERα and other chromatin-remodeling enzymes is required for estrogen-induced transcription. Talipes equinovarus is one of the most common congenital musculoskeletal anomalies and has a worldwide incidence of 1 in 1000 births. A genetic predisposition to talipes equinovarus is evidenced by the high concordance rate in twin studies and the increased risk to first-degree relatives. Despite the frequency of isolated talipes equinovarus and the strong evidence of a genetic basis for the disorder, few causative genes have been identified. To identify rare and/or recurrent copy number variants, we performed a genome-wide screen for deletions and duplications in 413 isolated talipes equinovarus patients using the Affymetrix 6.0 array. Segregation analysis within families and gene expression in mouse E12.5 limb buds were used to determine the significance of copy number variants. We identified 74 rare, gene-containing copy number variants that were present in talipes equinovarus probands and not present in 759 controls or in the Database of Genomic Variants. The overall frequency of copy number variants was similar between talipes equinovarus patients compared with controls. Twelve rare copy number variants segregate with talipes equinovarus in multiplex pedigrees, and contain the developmentally expressed transcription factors and transcriptional regulators PITX1, TBX4, HOXC13, UTX, CHD (chromodomain protein)1, and RIPPLY2. Although our results do not support a major role for recurrent copy number variations in the etiology of isolated talipes equinovarus, they do suggest a role for genes involved in early embryonic patterning in some families that can now be tested with large-scale sequencing methods. OBJECTIVE: Smooth muscle cell (SMC) differentiation is a critical process during cardiovascular formation and development, but the underlying molecular mechanism remains unclear. METHODS AND RESULTS: Here we demonstrated that chromobox protein homolog 3 (Cbx3) is crucial for SMC differentiation from stem cells and that the chromodomain and chromoshadow domain of Cbx3 are responsible for Cbx3-induced SMC differentiation. Moreover, we identified that 4 amino acids (165 to 168) within the chromoshadow domain of Cbx3 are key elements for Cbx3 interaction with Dia-1- and Cbx3-induced SMC differentiation. Mechanistically, we found that Cbx3 mediates SMC differentiation through modulating serum response factor (SRF) recruitment to the promoters of SMC genes, in which the interaction between Cbx3 and Dia-1/SRF plays a crucial role in this process. Moreover, our in vivo study demonstrated that the misexpression of Cbx3 within neural crest cells of chick embryos resulted in the death of chick embryos at early stages because of the maldevelopment of branchial arch arteries. CONCLUSIONS: Our findings suggest that the interaction between Cbx3 and Dia-1/SRF is essential for SMC differentiation from stem cells and for the development of functional cardiovascular system. The eight mammalian Cbx proteins are chromodomain-containing proteins involved in regulation of heterochromatin, gene expression, and developmental programs. They are evolutionarily related to the Drosophila HP1 (dHP1) and Pc (dPc) proteins that are key components of chromatin-associated complexes capable of recognizing repressive marks such as trimethylated Lys-9 and Lys-27, respectively, on histone H3. However, the binding specificity and function of the human homologs, Cbx1-8, remain unclear. To this end we employed structural, biophysical, and mutagenic approaches to characterize the molecular determinants of sequence contextual methyllysine binding to human Cbx1-8 proteins. Although all three human HP1 homologs (Cbx1, -3, -5) replicate the structural and binding features of their dHP counterparts, the five Pc homologs (Cbx2, -4, -6, -7, -8) bind with lower affinity to H3K9me3 or H3K27me3 peptides and are unable to distinguish between these two marks. Additionally, peptide permutation arrays revealed a greater sequence tolerance within the Pc family and suggest alternative nonhistone sequences as potential binding targets for this class of chromodomains. Our structures explain the divergence of peptide binding selectivity in the Pc subfamily and highlight previously unrecognized features of the chromodomain that influence binding and specificity.

What is Genomicus?

Genomicus had been developed as a database and a browser to study gene synteny in modern and ancestral genomes. It allows easy comparative genomic visualization in >150 eukaryote genomes and in four different phyla (Vertebrate, Fungi, Metazoan and Plants). It provides a way to explore spatial information related to gene organization within and between genomes and temporal relationships related to gene and genome evolution. For the specific vertebrate phylum, it also provides access to ancestral gene order reconstructions and conserved non-coding elements information. The graphical modules of Genomicus show how it is capable of revealing differential gene loss and gain, segmental or genome duplications and facilitate the study of the evolution of a locus through homology relationships. The Genomicus server provides access to ancestral gene orders, as well as computationally predicted regulatory interactions, thanks to the representation of conserved non-coding elements with their putative gene targets.

[20185404, 23193262, 25378326]

Comparative genomics remains a pivotal strategy to study the evolution of gene organization, and this primacy is reinforced by the growing number of full genome sequences available in public repositories. Despite this growth, bioinformatic tools available to visualize and compare genomes and to infer evolutionary events remain restricted to two or three genomes at a time, thus limiting the breadth and the nature of the question that can be investigated. Here we present Genomicus, a new synteny browser that can represent and compare unlimited numbers of genomes in a broad phylogenetic view. In addition, Genomicus includes reconstructed ancestral gene organization, thus greatly facilitating the interpretation of the data. AVAILABILITY: Genomicus is freely available for online use at http://www.dyogen.ens.fr/genomicus while data can be downloaded at ftp://ftp.biologie.ens.fr/pub/dyogen/genomicus. The Genomicus web server (http://www.genomicus.biologie.ens.fr/genomicus) is a visualization tool allowing comparative genomics in four different phyla (Vertebrate, Fungi, Metazoan and Plants). It provides access to genomic information from extant species, as well as ancestral gene content and gene order for vertebrates and flowering plants. Here we present the new features available for vertebrate genome with a focus on new graphical tools. The interface to enter the database has been improved, two pairwise genome comparison tools are now available (KaryoView and MatrixView) and the multiple genome comparison tools (PhyloView and AlignView) propose three new kinds of representation and a more intuitive menu. These new developments have been implemented for Genomicus portal dedicated to vertebrates. This allows the analysis of 68 extant animal genomes, as well as 58 ancestral reconstructed genomes. The Genomicus server also provides access to ancestral gene orders, to facilitate evolutionary and comparative genomics studies, as well as computationally predicted regulatory interactions, thanks to the representation of conserved non-coding elements with their putative gene targets.

Is amiodarone a class I anti-arrhythmic drug?

Although considered to be a class III anti-arrhythmic, amiodarone also has class I, II and IV actions, which gives it a unique pharmacological and anti-arrhythmic profile

[12491809, 17352036, 11825323, 15989900, 20041841, 21728182, 21626366]

Class III antiarrhythmic agents have been considered to lengthen the myocardial effective refractory period (ERP) without any significant effects on the conduction velocity. However, recent investigations have clarified the positive or negative dromotropic effects of these agents. Amiodarone, a representative class III agent, exerts negative dromotropism by suppressing the fast sodium current responsible for conduction in acute administration (class I effects). Chronic amiodarone causes prolongation of ERP (class III effects), which is sometimes associated with negative dromotropism based on the alteration of passive or active membrane properties. Sotalol shows neither significant positive nor negative dromotropism under the normoxic condition, whereas this agent is reported to exert positive dromotropism mediated by the cAMP-dependent facilitation of gap junctional electrical coupling under the hypoxic condition. Some pure class III agents such as nifekalant are suspected to elicit 'apparent' positive dromotropism in the premature impulse propagation. This is explained by the right and upward shift of the strength-interval curve, which theoretically transforms the graded premature response to the all-or-none response. Although the clinical relevancy of these phenomena remains to be investigated, such variable dromotropism of the individual class III agent may contribute to the better understanding and development of antiarrhythmic agents. Amiodarone, a class III antiarrhythmic drug, is one of the most effective drugs used in the treatment of ventricular and paroxysmal supraventricular tachyarrhythmia. Adverse effects of amiodarone including pulmonary toxicity, hepatotoxicity, aggravation of arrhythmia, and thyroid diseases are well understood. A 66-year old woman with acute pancreatitis was admitted to our hospital with the complaint of epigastralgia radiating to both flanks for two months. Her symptoms and elevation of pancreatic enzymes did not respond to conventional medical treatment of pancreatitis for 18 d. No known causal factors for pancreatitis such as biliary tract stone, hypertriglyceridemia and alcohol consumption could be identified. Under the suspicion of amiodarone-induced acute pancreatitis, amiodarone was substituted by propafenone. Her symptoms soon alleviated and serum lipase level declined. Three months after hospital discharge, the abdominal pain did not recur. Amiodarone was approved to treat recurrent ventricular fibrillation or sustained ventricular tachyarrhythmia that has been resistant to other medications since 1986. Pancreatitis is a very rare adverse effect associated with the use of amiodarone, and only four cases of amiodarone-induced pancreatitis have been reported in literature. We report a patient who developed acute pancreatitis during amiodarone therapy. Amiodarone has been used as an anti-arrhythmic drug since the 1970s and has an established role in the treatment of ventricular tachyarrhythmias. Although considered to be a class III anti-arrhythmic, amiodarone also has class I, II and IV actions, which gives it a unique pharmacological and anti-arrhythmic profile. Amiodarone is a structural analogue of thyroid hormone and some of its anti-arrhythmic properties and toxicity may be attributable to interactions with nuclear thyroid hormone receptors. The lipid solubility of amiodarone gives it an exceptionally long half-life. Oral amiodarone takes days to work in ventricular tachyarrhythmias, but iv. amiodarone has immediate effect and can be used in life threatening ventricular arrhythmias. Intravenous amiodarone administered after out-of-hospital cardiac arrest due to ventricular fibrillation improves survival to hospital admission. Many survivors of myocardial infarction (MI) die during the subsequent year, probably due to ventricular arrhythmia. Amiodarone reduces sudden death after MI and this benefit is predominantly observed in patients with preserved cardiac function. Sudden cardiac death, predominantly due to ventricular arrhythmias, is also commonly seen in patients with heart failure. The Grupo de Estudio de la Sobrevida en lsuficiencia Cardiaca en Argentina (GESICA) and Estudio Piloto Argentino de Muerte Subita y Amiodarona (EPAMSA) trials showed survival benefit of amiodarone in heart failure, whereas Congestive Heart Failure-Survival Trial of Anti-arrhythmic Therapy (CHF-STAT) did not. Subsequent meta-analysis established a survival benefit of amiodarone in heart failure. Implanted Cardioverter Def ibrillators (ICDs) also give survival benefit to patients at risk of sudden death. In patients with a history of ventricular fibrillation or haemodynamically-compromising ventricular tachycardia, ICDs have been shown to be superior to anti-arrhythmic drugs, principally amiodarone. Further analysis has been undertaken to ascertain which patients are most likely to benefit from ICDs, as these are more expensive than treatment with amiodarone. Patients with severely depressed ejection fractions should be the first to be considered for ICDs. A new indication for amiodarone is atrial fibrillation or flutter. Amiodarone is effective in chronic and recent onset atrial fibrillation and orally or iv. for atrial fibrillation after heart surgery. In atrial fibrillation amiodarone is more than or equi-effective with flecainide, quinidine, racemic sotalol, propafenone and diltiazem and therefore should be considered for first line therapy. Amiodarone is also safe and effective in controlling refractory tachyarrhythmias in infants and is safe after cardiac surgery.

Which is the prognostic meaning of delayed enhancement documented in patients hypertrophic cardiomyopathy?

Delayed enhancement by CMR has prognostic value in predicting adverse cardiovascular events among HCM patients, and is associated with cardiovascular mortality, heart failure death, and all-cause mortality in HCM.

[20667520, 19474054, 15861263, 22498326, 19477402, 20688032, 19808288, 22935464, 20102955, 23376948, 18208827, 21498307, 19784900, 18562248, 22128204, 12224720, 22348519, 20339815, 22135401, 22687593, 18204915, 21234292, 20079992, 19740409]

OBJECTIVES: We sought to establish the prognostic value of a comprehensive cardiovascular magnetic resonance (CMR) examination in risk stratification of hypertrophic cardiomyopathy (HCM) patients. BACKGROUND: With annual mortality rates ranging between 1% and 5%, depending on patient selection, a small but significant number of HCM patients are at risk for an adverse event. Therefore, the identification of and prophylactic therapy (i.e., defibrillator placement) in patients with HCM who are at risk of dying are imperative. METHODS: Two-hundred forty-three consecutive patients with HCM were prospectively enrolled. All patients underwent initial CMR, and 220 were available for clinical follow-up. The mean follow-up time was 1,090 days after CMR. End points were all-cause and cardiac mortality. RESULTS: During follow-up 20 of the 220 patients died, and 2 patients survived sudden cardiac death due to adequate implantable cardioverter-defibrillator discharge. Most events (n = 16) occurred for cardiac reasons; the remaining 6 events were related to cancer and accidents. Our data indicate that the presence of scar visualized by CMR yields an odds ratio of 5.47 for all-cause mortality and of 8.01 for cardiac mortality. This might be superior to classic clinical risk factors, because in our dataset the presence of 2 risk factors yields an odds ratio of 3.86 for all-cause and of 2.20 for cardiac mortality, respectively. Multivariable analysis also revealed the presence of late gadolinium enhancement as a good independent predictor of death in HCM patients. CONCLUSIONS: Among our population of largely low or asymptomatic HCM patients, the presence of scar indicated by CMR is a good independent predictor of all-cause and cardiac mortality. AIMS: To assess the relationship between cardiovascular magnetic resonance (CMR) parameters and both spontaneous ventricular tachycardia (VT) and risk of sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM) patients. METHODS AND RESULTS: One hundred and eight consecutive HCM patients (mean age 42 +/- 15 years, 76% males) underwent CMR evaluation and risk assessment. Delayed contrast enhancement (DCE) was quantified with a specifically designed score. Endpoints were either the presence of clinical VT/ventricular fibrillation (VF) or of acknowledged risk factors for SCD. Compared to patients without arrhythmia, those with VT/VF (n = 33) had a higher DCE score [median 8 (2-13) vs. 11 (6-20); P = 0.01]; DCE score was also the only independent predictor of VT/VF in the multivariable model. DCE score [median 6 (1-10.5) vs. 12 (6-18); P = 0.001], mean and maximal left ventricular (LV) wall thickness (MaxLVWT), as well as LV mass index were significantly greater among patients at risk for SCD (n = 51) compared with the remaining 57 patients at low risk. DCE score and MaxLVWT were independent predictors of SCD risk. CONCLUSION: In HCM patients several CMR parameters are associated with risk for SCD. A semi-quantitative index of DCE is a significant multivariable predictor of both clinical VT/VF and of risk for SCD and may contribute to risk assessment in borderline or controversial cases. Hypertrophic cardiomyopathy is a genetic disease that affects the cardiac sarcomere, resulting in myocardial hypertrophy and disarray. Affected patients have a predisposition for malignant ventricular tachyarrhythmias and, consequently, sudden cardiac death. With the availability of therapeutic measures that prevent sudden death, the identification of high-risk patients is now of greater importance. Clinical risk factors for sudden death (ie, age, syncope, family history of sudden cardiac death, cardiac arrest survivor, nonsustained ventricular tachycardia and abnormal blood pressure response to exercise) have been identified. The clinical electrophysiological study is of limited use for stratifying these patients. More recently, increased attention has been given to the degree of echocardiographically documented left ventricular hypertrophy and prognostically significant genetic mutations. Once a high-risk patient is identified, prophylactic treatment is warranted. For this purpose, amiodarone has been supplanted by the implantable cardioverter-defibrillator. Implantable cardioverter-defibrillator treatment appears to reduce the risk of sudden cardiac death in both primary and secondary prevention settings. Thus, tools are now available to identify and treat high-risk patients with hypertrophic cardiomyopathy. OBJECTIVES: The objective of this study was to perform a systematic review and meta-analysis of the predictive value of late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) for future cardiovascular events and death in hypertrophic cardiomyopathy (HCM). BACKGROUND: The utility of LGE for detecting myocardial fibrosis is well established. The prognostic value of LGE in HCM has been described in several studies, but controversy exists given the limited power of these studies to predict future events. METHODS: We searched multiple databases including PubMed for studies of LGE in HCM that reported selected clinical outcomes (cardiovascular mortality, sudden cardiac death [SCD], aborted SCD, and heart failure death). We performed a systematic review of the literature and meta-analysis to determine pooled odds ratios for these clinical events. RESULTS: Four studies evaluated 1,063 patients over an average follow-up of 3.1 years. The pooled prevalence of LGE was 60%. The pooled odds ratios (OR) demonstrate that LGE by CMR correlated with cardiac death (pooled OR: 2.92, 95% confidence interval [CI]: 1.01 to 8.42; p = 0.047), heart failure death (pooled OR: 5.68, 95% CI: 1.04 to 31.07; p = 0.045), and all-cause mortality (pooled OR: 4.46, 95% CI: 1.53 to 13.01; p = 0.006), and showed a trend toward significance for predicting sudden death/aborted sudden death (pooled OR: 2.39, 95% CI: 0.87 to 6.58; p = 0.091). CONCLUSIONS: Late gadolinium enhancement by CMR has prognostic value in predicting adverse cardiovascular events among HCM patients. There are significant relationships between LGE and cardiovascular mortality, heart failure death, and all-cause mortality in HCM. Additionally, LGE and SCD/aborted SCD displayed a trend toward significance. The assessment of LGE by CMR has the potential to provide important information to improve risk stratification in HCM in clinical practice. BACKGROUND: The clinical, morphological, and electrocardiographical relevance of delayed enhancement (DE) in cardiac magnetic resonance (CMR) was studied in patients with hypertrophic cardiomyopathy (HCM). METHODS AND RESULTS: A total of 56 patients underwent both gadolinium-enhanced CMR and 12-lead electrocardiogram. The CMR demonstrated DE at the left ventricular (LV) wall in 39 patients. The patients with DE included more cases with dilated phase of HCM, higher New York Heart Association (NYHA) classes and incidence of ventricular tachyarrhythmias (VT), lower LV ejection fraction (LVEF) and mean LV wall thickness (WT), and a larger ratio of maximum to minimum LVWT. The QRS duration was prolonged and the QRS axis deviated toward left with increases in the DE volume (r = 0.58 and r = 0.41, P < .01). Abnormal Q waves were present in 5 patients and the location coincided with the DE segments in 4 patients, but the concordance was not significant. The amplitude of T waves correlated with the ratio of the apex to basal LVWT (r = 0.38, P < .01) and was more negative in cases with DE at the apex. CONCLUSIONS: In HCM, the DE was associated with higher NYHA classes and prevalence of VT, impaired global LV function and asymmetrical hypertrophy, and conduction disturbance, abnormal Q waves, and giant negative T waves. BACKGROUND: Contrast-enhanced cardiovascular magnetic resonance with delayed enhancement (DE) can provide in vivo assessment of myocardial fibrosis. However, the clinical significance of DE in hypertrophic cardiomyopathy (HCM) remains unresolved. METHODS AND RESULTS: Cine and cardiovascular magnetic resonance with DE were performed in 202 HCM patients (mean age, 42+/-17 years; 71% male), DE was compared with clinical and demographic variables, and patients were followed up for 681+/-249 days for adverse disease events. DE was identified in 111 (55%) HCM patients, occupying 9%+/-11% of left ventricular myocardial volume, including >25% DE in 10% of patients. The presence of DE was related to occurrence of heart failure symptoms (P=0.05) and left ventricular systolic dysfunction (P=0.001). DE was present in all patients with ejection fraction < or =50% but also in 53% (102/192) of patients with preserved ejection fraction (P<0.001); %DE was both inversely related to (r=-0.3; P<0.001) and an independent predictor of ejection fraction (r=-0.4; P<0.001). DE (7%+/-7% of left ventricle) was present in 54 patients who were asymptomatic (and with normal ejection fraction). Over the follow-up period, the annualized adverse cardiovascular event rate in patients with DE exceeded that in patients without DE but did not achieve statistical significance (5.5% versus 3.3%; P=0.5). CONCLUSIONS: In a large HCM cohort, DE was an independent predictor of systolic dysfunction but with only a modest relationship to heart failure symptoms. These data suggest an important role for myocardial fibrosis in the clinical course of HCM patients but are not sufficient at this time to consider DE as an independent risk factor for adverse prognosis. The aim of the present study was to evaluate, in patients with hypertrophic cardiomyopathy (HC), the association between late gadolinium enhancement and clinical end points, such as nonsustained ventricular tachycardia, arrhythmic risk factors, New York Heart Association class, symptoms, and left ventricular functional parameters. A total of 20 normal subjects (mean age 38 years, 16 men) and 100 patients with HC (mean age 46 years, 70 men) were enrolled in the present study. In the late gadolinium enhancement images, the extent of unenhanced, mildly enhanced, and higher enhanced myocardium was measured. Higher enhancement was present in 80% of the HC population and was significantly greater in patients with a New York Heart Association class >1. Mild enhancement was present in all the patients with HC. Receiver operating characteristic analysis revealed that a cutoff of >4.9% of mild enhancement had 100% sensitivity and 86% specificity to predict the occurrence of nonsustained ventricular tachycardia, and a cutoff of >2.4% of hyperenhancement had 77% sensitivity and 96% specificity. In conclusion, late gadolinium enhancement was associated with nonsustained ventricular tachycardia, arrhythmic risk factors, and worse New York Heart Association class. Risk assessment in hypertrophic cardiomyopathy: contemporary guidelines hampered by insufficient evidence. BACKGROUND: Hypertrophic cardiomyopathy (HCM) is reported to show patchy midwall myocardial hyperenhancement on delayed-enhancement magnetic resonance imaging (DE-MRI). The intramural distribution of myocardial hyperenhancement and its correlation with clinical symptoms, ventricular arrhythmias, and cardiac function have not been described forsymptomatic apical HCM. PURPOSE: To evaluate the features and significance of myocardial hyperenhancement on DE-MRI insymptomatic apical HCM. MATERIAL AND METHODS: Thirteen patients with symptomatic apical HCM and their 65 apical segments were investigated. Myocardial hyperenhancement and regional and global functional parameters were determined with MRI. We investigated the intramural distribution and frequencies of this myocardial hyperenhancement and compared them with the patients' clinical symptoms, the presence of ventricular arrhythmias, and cine MRI. RESULTS: Eight (61.5%) patients with symptomatic apical HCM displayed apical myocardial hyperenhancement, and 22 (33.8%) of the 65 apical segments examined showed myocardial hyperenhancement. Of the myocardial hyperenhancement observed, 81.8% showed a subendocardial pattern.The hyperenhanced apical myocardium had a lower percentage of systolic myocardial thickening, and was associated with serious symptoms (e.g. syncope) and ventricular arrhythmias. CONCLUSION: Patients with symptomatic apical HCMshowed myocardial hyperenhancement involving the subendocardial layer, which might be related to regional systolic dysfunction, serious clinical symptoms, and ventricular arrhythmias. INTRODUCTION: Hypertrophic cardiomyopathy (HCM) is associated with myocardial scarring and ventricular tachycardia (VT). Contrast-enhanced cardiac magnetic resonance imaging (CE-CMR) can quantify myocardial scar, and scar imaging has been documented in patients with HCM. We investigated the assessment of myocardial scar in HCM patients using CE-CMR, and its correlation with proven VT. METHODS: Twenty-five patients (mean age 54 +/- 8) with HCM who underwent CE-CMR were identified, and clinical data obtained from chart review. Parameters of LV function were calculated from cine imaging, and myocardial scar was assessed using delayed enhancement imaging following gadolinium administration. RESULTS: Myocardial scar was detected in 16 (64%) patients with a mean mass 9 +/- 15 g. Scar was patchy, mid-myocardial and located in the basal anteroseptum, and RV insertion sites. Scar was seen in septal, apical and concentric variants of HCM. Scar mass correlated with both LV Mass (r2 = 0.74) and maximal LV wall thickness (r2 = 0.42). VT occurred in 32% of patients, and was associated with both increased scar mass and wall thickness compared to non-VT patients (21 +/- 22 g vs. 4 +/- 6 g, and 2.4 +/- 0.5 cm vs. 1.8 +/- 0.5 cm, p < 0.05). LV size and function were similar in patients with and without VT. A scar mass of >7 g predicted the presence of VT with a sensitivity of 75% and specificity 82%. CONCLUSIONS: Myocardial scar imaged by CE-CMR is common in patients with HCM, and is predictive of VT. Scar is seen in all HCM variants, and is associated with maximal wall thickness. There may be a role for CE-CMR in improved risk stratification for individual patients with HCM. Myocardial fibrosis can occur in patients who have hypertrophic cardiomyopathy in the absence of epicardial coronary disease. In such patients, myocardial fibrosis has been linked to a poorer prognosis than in those without fibrosis. Gadolinium-DTPA delayed-enhancement magnetic resonance imaging (de-MRI) accurately identifies regions of myocardial fibrosis. We used de-MRI to screen for myocardial fibrosis in 8 patients with nonobstructive hypertrophic cardiomyopathy that had been diagnosed by 2-dimensional echocardiography. After localization of the heart and acquisition of electrocardiographically gated cine images, gadolinium-DTPA (0.2 mmol/kg) was administered to the patient. Fifteen minutes later, de-MRI images were obtained using a T1-weighted, inversion-recovery fast, low-angle shot sequence. Images were gated to end-diastole and obtained during a single breath-hold. The inversion time was modified iteratively to obtain maximal nulling of the signal from the ventricular myocardium. Regions of myocardium with abnormally high signals (>300% of remote normal myocardium) were designated as fibrotic. Eight patients with hypertrophic cardiomyopathy underwent de-MRI. The mean age was 52 years, the mean left ventricular mass was 201 grams, and the mean ejection fraction was 0.68. In the 6 patients with recent clinical deterioration, de-MRI showed clearly delineated areas of myocardial fibrosis; no such areas were seen in the 2 asymptomatic patients. We conclude that patients with symptomatic hypertrophic cardiomyopathy display regions of abnormal signal intensity on de-MRI that likely represent fibrosis. This technique may provide useful information in the evaluation of such patients and warrants further study. Hypertrophic cardiomyopathy (HCM) is the most common genetic disease of the heart. HCM is characterized by a wide range of clinical expression, ranging from asymptomatic mutation carriers to sudden cardiac death as the first manifestation of the disease. Over 1000 mutations have been identified, classically in genes encoding sarcomeric proteins. Noninvasive imaging is central to the diagnosis of HCM and cardiovascular magnetic resonance (CMR) is increasingly used to characterize morphologic, functional and tissue abnormalities associated with HCM. The purpose of this review is to provide an overview of the clinical, pathological and imaging features relevant to understanding the diagnosis of HCM. The early and overt phenotypic expression of disease that may be identified by CMR is reviewed. Diastolic dysfunction may be an early marker of the disease, present in mutation carriers prior to the development of left ventricular hypertrophy (LVH). Late gadolinium enhancement by CMR is present in approximately 60% of HCM patients with LVH and may provide novel information regarding risk stratification in HCM. It is likely that integrating genetic advances with enhanced phenotypic characterization of HCM with novel CMR techniques will importantly improve our understanding of this complex disease. BACKGROUND: The stratification of risk for sudden death in hypertrophic cardiomyopathy (HCM) continues to be a true challenge due to the great heterogeneity of this disease's presentation, as most individuals remain asymptomatic during their entire lives and others present sudden death as first symptom. Recent studies have suggested that myocardial fibrosis may represent an important substrate for the malignant ventricular arrhythmias, that are responsible for the cases of sudden death related to this disease. OBJECTIVE: To assess the prevalence and quantification of myocardial fibrosis (MF) in hypertrophic cardiomyopathy (HCM) patients with implantablecardioverter - defibrillator (ICD) indicated due to their high risk or recovered from cardiac sudden death. METHODS: Twenty-eight HCM patients with ICD were submitted to multidetector computed tomography to assess myocardial fibrosis by delayed enhancement technique. RESULTS: Myocardial fibrosis was present in 96% of these HCM patients with (20.38 +/- 15.55 g) comprising 15.96 +/- 10.20% of the total myocardial mass. MF was observed in a significantly higher prevalence as compared to other classical risk factors for sudden death. CONCLUSION: It is possible to conclude that there is a high prevalence of myocardial fibrosis in hypertrophic cardiomyopathy patients with high-risk or recovered from cardiac sudden death, like those with clinical indication to implantable cardioverter -defibrillator. The higher prevalence of myocardial fibrosis in comparison to classical risk factors of worse prognosis raise the hypothesis that the myocardial fibrosis may be an important substrate in the genesis of lifethreatening arrhythmias in these high risk HCM population. The use of cardiovascular magnetic resonance in patients with hypertrophic cardiomyopathy over the last decade has helped elucidate the diagnosis, prognosis, pathophysiology, and management of this disease. Studies have shown that the use of magnetic resonance imaging in a patient with a permanent pacemaker and implantable cardioverter defibrillator is safe. INTRODUCTION: Dilated cardiomyopathy (DCM) is associated with significant morbidity and mortality. Contrast-enhanced cardiac MRI (CE-CMR) can detect potentially prognostic myocardial fibrosis in DCM. We investigated the role of CE-CMR in New Zealand patients with DCM, both Maori and non-Maori, including the characteristics and prognostic importance of fibrosis. METHODS: One hundred and three patients (mean age 58 ± 13, 78 male) referred for CMR assessment of DCM were followed for 660 ± 346 days. Major adverse cardiac events (MACE) were defined as death, infarction, ventricular arrhythmias or rehospitalisation. CE-CMR used cines for functional analysis, and delayed enhancement to assess fibrosis. RESULTS: Myocardial fibrosis was present in 30% of patients, the majority of which was mid-myocardial (63%). Volumetric parameters were similar in patients with or without fibrosis. At 2 years patients with fibrosis had an increased rate of MACE (HR = 0.77, 95% CI 0.3-2.0). Patients with full thickness or subendocardial fibrosis had the highest MACE, even in the absence of CAD). More Maori had fibrosis on CE-CMR (40% vs. 28% for non-Maori), and the majority (75%) was mid-myocardial. Maori and non-Maori had similar outcomes (25% vs. 24% with events during follow-up). CONCLUSIONS: DCM patients frequently have myocardial fibrosis detected on CE-CMR, the majority of which is mid-myocardial. Fibrosis is associated with worse outcome in the medium term. The information obtained using CE-CMR in DCM may be of incremental clinical benefit. Cardiac magnetic resonance imaging (CMR) in hypertrophic cardiomyopathy (HCM) often shows delayed contrast enhancement (DE) representing regions of focal myocardial fibrosis. Atrial fibrillation (AF) is a commonly reported complication of HCM. We determined the relationship between the presence of left ventricular myocardial fibrosis (LVMF) detected by DE-CMR and the occurrence AF in a series of patients with HCM. 67 patients with HCM (47 males; mean age 50.1+/-18.5 years) were studied by CMR measuring mass of LVMF, left ventricular mass, volume and function, and left atrial (LA) area. AF was present in 17 (25%) patients. LVMF was observed in 57% of patients. AF was significantly more frequent in patients who also showed LVMF, compared with the group without LVMF (42.1% vs. 3.4%, respectively; p<0.0001). LA size was larger in patients showing DE (LA area: 37.4+/-11.1 vs. 25.9+/-6.8 cm(2); respectively, p=0.0001). AF in HCM is related with myocardial fibrosis detected by DE-CMR and dilatation of the LA. This fact adds to the proven adverse prognostic value of myocardial fibrosis in HCM, thus, reinforcing the usefulness of this technique in the assessment of these patients. OBJECTIVES: We sought to evaluate the relation between atrial fibrillation (AF) and the extent of myocardial scarring together with left ventricular (LV) and atrial parameters assessed by late gadolinium-enhancement (LGE) cardiovascular magnetic resonance (CMR) in patients with hypertrophic cardiomyopathy (HCM). BACKGROUND: AF is the most common arrhythmia in HCM. Myocardial scarring is also identified frequently in HCM. However, the impact of myocardial scarring assessed by LGE CMR on the presence of AF has not been evaluated yet. METHODS: 87 HCM patients underwent LGE CMR, echocardiography and regular ECG recordings. LV function, volumes, myocardial thickness, left atrial (LA) volume and the extent of LGE, were assessed using CMR and correlated to AF. Additionally, the presence of diastolic dysfunction and mitral regurgitation were obtained by echocardiography and also correlated to AF. RESULTS: Episodes of AF were documented in 37 patients (42%). Indexed LV volumes and mass were comparable between HCM patients with and without AF. However, indexed LA volume was significantly higher in HCM patients with AF than in HCM patients without AF (68 +/- 24 ml.m-2 versus 46 +/- 18 ml.m-2, p = 0.0002, respectively). The mean extent of LGE was higher in HCM patients with AF than those without AF (12.4 +/- 14.5% versus 6.0 +/- 8.6%, p = 0.02). When adjusting for age, gender and LV mass, LGE and indexed LA volume significantly correlated to AF (r = 0.34, p = 0.02 and r = 0.42, p < 0.001 respectively). By echocardiographic examination, LV diastolic dysfunction was evident in 35 (40%) patients. Mitral regurgitation greater than II was observed in 12 patients (14%). Multivariate analysis demonstrated that LA volume and presence of diastolic dysfunction were the only independent determinant of AF in HCM patients (p = 0.006, p = 0.01 respectively). Receiver operating characteristic curve analysis indicated good predictive performance of LA volume and LGE (AUC = 0.74 and 0.64 respectively) with respect to AF. CONCLUSION: HCM patients with AF display significantly more LGE than HCM patients without AF. However, the extent of LGE is inferior to the LA size for predicting AF prevalence. LA dilation is the strongest determinant of AF in HCM patients, and is related to the extent of LGE in the LV, irrespective of LV mass.

What is the COUGER tool?

COUGER takes as input two sets of genomic regions bound by paralogous TFs, and it identifies a small set of putative co-factors that best distinguish the two sets of sequences.

[24861628]

Most transcription factors (TFs) belong to protein families that share a common DNA binding domain and have very similar DNA binding preferences. However, many paralogous TFs (i.e. members of the same TF family) perform different regulatory functions and interact with different genomic regions in the cell. A potential mechanism for achieving this differential in vivo specificity is through interactions with protein co-factors. Computational tools for studying the genomic binding profiles of paralogous TFs and identifying their putative co-factors are currently lacking. Here, we present an interactive web implementation of COUGER, a classification-based framework for identifying protein co-factors that might provide specificity to paralogous TFs. COUGER takes as input two sets of genomic regions bound by paralogous TFs, and it identifies a small set of putative co-factors that best distinguish the two sets of sequences. To achieve this task, COUGER uses a classification approach, with features that reflect the DNA-binding specificities of the putative co-factors. The identified co-factors are presented in a user-friendly output page, together with information that allows the user to understand and to explore the contributions of individual co-factor features. COUGER can be run as a stand-alone tool or through a web interface: http://couger.oit.duke.edu.

Are there drugs for Tick-borne Encephalitis?

No drug therapy available today

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Tick-borne encephalitis (TBE) is a growing public health concern in central and northern European countries. Even though TBE is a notifiable disease in Croatia, there is a significant lack of information in regard to vector tick identification, distribution as well as TBE virus prevalence in ticks or animals. The aim of our study was to identify and to investigate the viral prevalence of TBE virus in ticks removed from red fox (Vulpes vulpes) carcasses hunted in endemic areas in northern Croatia and to gain a better insight in the role of wild ungulates, especially red deer (Cervus elaphus) in the maintenance of the TBE virus in the natural cycle. We identified 5 tick species (Ixodes ricinus, Ixodes hexagonus, Haemaphysalis punctata, Dermacentor reticulatus, Rhipicephalus sanguineus) removed from 40 red foxes. However, TBE virus was isolated only from adult I. ricinus and I. hexagonus ticks showing a viral prevalence (1.6%) similar to or higher than reported in endemic areas of other European countries. Furthermore, 2 positive spleen samples from 182 red deer (1.1%) were found. Croatian TBE virus isolates were genetically analyzed, and they were shown to be closely related, all belonging to the European TBE virus subgroup. However, on the basis of nucleotide and amino acid sequence analysis, 2 clusters were identified. Our results show that further investigation is needed to understand the clustering of isolates and to identify the most common TBE virus reservoir hosts in Croatia. Sentinel surveys based on wild animal species would give a better insight in defining TBE virus-endemic and possible risk areas in Croatia. The replication of tick-borne encephalitis virus (TBEV), like that of all flaviviruses, is absolutely dependent on proteolytic processing. Production of the mature proteins C and prM from their common precursor requires the activity of the viral NS2B/3 protease (NS2B/3(pro)) at the C-terminus of protein C and the host signal peptidase I (SPaseI) at the N-terminus of protein prM. Recently, we have shown in cell culture that the cleavage of protein C and the subsequent production of TBEV particles can be made dependent on the activity of the foot-and-mouth disease virus 3C protease, but not on the activity of the HIV-1 protease (HIV1(pro)) (Schrauf et al., 2012). To investigate this failure, we developed an in vitro cleavage assay to assess the two cleavage reactions performed on the C-prM precursor. Accordingly, a recombinant modular NS2B/3(pro), consisting of the protease domain of NS3 linked to the core-domain of cofactor NS2B, was expressed in E. coli and purified to homogeneity. This enzyme could cleave a C-prM protein synthesised in rabbit reticulocyte lysates. However, cleavage was only specific when protein synthesis was performed in the presence of canine pancreatic microsomal membranes and required the prevention of signal peptidase I (SPaseI) activity by lengthening the h-region of the signal peptide. The presence of membranes allowed the concentration of NS2B/3(pro) used to be reduced by 10-20 fold. Substitution of the NS2B/3(pro) cleavage motif in C-prM by a HIV-1(pro) motif inhibited NS2B/3(pro) processing in the presence of microsomal membranes but allowed cleavage by HIV-1(pro) at the C-prM junction. This system shows that processing at the C-terminus of protein C by the TBEV NS2B/3(pro) is highly membrane dependent and will allow the examination of how the membrane topology of protein C affects both SPaseI and NS2B/3(pro) processing. Tick-borne Encephalitis (TBE), which is caused by a Flavivirus, is the most common tick-transmitted disease in Central and Eastern Europe and Russia. Today, TBE is endemic in 27 European countries, and has become an international public health problem. The epidemiology of TBE is changing owing to various factors, such as improvements in diagnosis and case reporting, increased recreational activities in areas populated by ticks, and changes in climatic conditions affecting tick habitats. Vaccination remains the most effective protective measure against TBE for people living in risk zones, occupationally exposed subjects and travelers to endemic areas. The vaccines currently in use are FSME-Immun(®), Encepur(®), EnceVir(®) and TBE vaccine Moscow(®). The numerous studies performed on the efficacy and safety of these vaccines have shown a high level of immunogenicity and an excellent safety profile. Several studies have also shown a high level of cross-protection among strains belonging to different subtypes. In the present paper we attempted to describe the continuously changing epidemiology of TBE in European States and to overview clinical development of available vaccines paying particular attention on cross-protection elicited by the vaccines. OBJECTIVES: In this study, we demonstrated that TBEV-infected ticks have been distributed in the ROK, combined with our previous results. These results suggest that TBEV may exist in the ROK, and H. longicornis, H. flava, and I. nipponensis may be potential vectors of TBEV. In addition, these results emphasize the need for further epidemiological research of TBEV. METHODS: We examined for the presence of RNA of TBEV by reverse transcriptase-nested polymerase chain reaction (RT-nested PCR) using ixodid ticks captured in 25 localities of 10 provinces. Ticks were collected by the flagging and dragging method or using sentinel BG traps at forests, grass thickets, and grassland. A total of 13,053 ticks belonging to two genera and four species were collected and pooled (1292 pools), according to collection site, species of tick, and developmental stage. RESULTS: Among 1292 pools, the envelope (E) protein gene of TBEV was detected using RT-nested PCR in 10 pools (3 pools of the 1,331 adult ticks and 7 pools of the 11,169 nymph ticks) collected from Gangwon-do province, Jeonrabuk-do province, and Jeju Island. The minimum infection rates for TBEV of Haemaphysalis longicornis, Haemaphysalis flava, and Ixodes nipponensis were 0.06%, 0.17%, and 2.38%, respectively. Phylogenetic analysis based on the partial E protein gene was performed to identify relationships between the TBEV strains. This showed that 10 Korean strains clustered with the Western subtype. CONCLUSION: In this study, we investigated the prevalence of tick-borne encephalitis virus (TBEV) in ixodid ticks from various regions of the Republic of Korea (ROK) during 2011-2012 to identify whether TBEV is circulating and to determine the endemic regions of TBEV. To assess B-cell function in patients under immunoglobulin (IgG)-replacement therapy, the non-licensed artificial bacteriophage (ΦX174)-neo-antigen may be used despite limited availability and experience. Active immunization against tick-borne encephalitis (TBE) is performed in few European countries. To test the feasibility of using licensed TBE vaccination as (neo-)antigen to determine residual or restored B-cell function in patients under regular IgG substitution, TBE-IgG levels were analyzed in 18 patients with ≥ 1-2 years of regular intravenous or subcutaneous IgG substitution and in pharmaceutical IgG-preparations (n=21 batches, 10 products). Six individuals were boosted against TBE. Although TBE-specific IgG was detectable in concentrates (281-57,100 VieU/0.5 μL), levels were only borderline in patient sera (n=31, 18 individuals; median 132 VieU; positive >155). Thus, TBE vaccination may be used to test B-cell function under IgG replacement therapy because IgG substitution appears insufficient to yield protective TBE-specific antibody levels in children. BACKGROUND: In recent decades, sporadic cases and outbreaks in humans of West Nile virus (WNV) infection have increased. Serological diagnosis of WNV infection can be performed by enzyme-linked immunosorbent assay (ELISA), immunofluorescence assay (IFA) neutralization test (NT) and by hemagglutination-inhibition assay. The aim of this study is to collect updated information regarding the performance accuracy of WNV serological diagnostics. METHODOLOGY/PRINCIPAL FINDINGS: In 2011, the European Network for the Diagnostics of Imported Viral Diseases-Collaborative Laboratory Response Network (ENIVD-CLRN) organized the second external quality assurance (EQA) study for the serological diagnosis of WNV infection. A serum panel of 13 samples (included sera reactive against WNV, plus specificity and negative controls) was sent to 48 laboratories involved in WNV diagnostics. Forty-seven of 48 laboratories from 30 countries participated in the study. Eight laboratories achieved 100% of concurrent and correct results. The main obstacle in other laboratories to achieving similar performances was the cross-reactivity of antibodies amongst heterologous flaviviruses. No differences were observed in performances of in-house and commercial test used by the laboratories. IFA was significantly more specific compared to ELISA in detecting IgG antibodies. The overall analytical sensitivity and specificity of diagnostic tests for IgM detection were 50% and 95%, respectively. In comparison, the overall sensitivity and specificity of diagnostic tests for IgG detection were 86% and 69%, respectively. CONCLUSIONS/SIGNIFICANCE: This EQA study demonstrates that there is still need to improve serological tests for WNV diagnosis. The low sensitivity of IgM detection suggests that there is a risk of overlooking WNV acute infections, whereas the low specificity for IgG detection demonstrates a high level of cross-reactivity with heterologous flaviviruses. The sequences of the protease domain of the tick-borne encephalitis (TBE) virus NS3 protein have two amino acid substitutions, 16 R→K and 45 S→F, in the highly pathogenic and poorly pathogenic strains of the virus, respectively. Two models of the NS2B-NS3 protease complex for the highly pathogenic and poorly pathogenic strains of the virus were constructed by homology modeling using the crystal structure of West Nile virus NS2B-NS3 protease as a template; 20 ns molecular dynamic simulations were performed for both models, the trajectories of the dynamic simulations were compared, and the averaged distance between the two models was calculated for each residue. Conformational differences between two models were revealed in the identified pocket. The different conformations of the pocket resulted in different orientations of the NS2B segment located near the catalytic triad. In the model of the highly pathogenic TBE virus the identified pocket had a more open conformation compared to the poorly pathogenic model. We propose that conformational changes in the active protease center, caused by two amino acid substitutions, can influence enzyme functioning and the virulence of the virus. To combat neglected diseases, the Novartis Institute of Tropical Diseases (NITD) was founded in 2002 through private-public funding from Novartis and the Singapore Economic Development Board. One of NITD's missions is to develop antivirals for dengue virus (DENV), the most prevalent mosquito-borne viral pathogen. Neither vaccine nor antiviral is currently available for DENV. Here we review the progress in dengue drug discovery made at NITD as well as the major discoveries made by academia and other companies. Four strategies have been pursued to identify inhibitors of DENV through targeting both viral and host proteins: (i) HTS (high-throughput screening) using virus replication assays; (ii) HTS using viral enzyme assays; (iii) structure-based in silico docking and rational design; (iv) repurposing hepatitis C virus inhibitors for DENV. Along the developmental process from hit finding to clinical candidate, many inhibitors did not advance beyond the stage of hit-to-lead optimization, due to their poor selectivity, physiochemical or pharmacokinetic properties. Only a few compounds showed efficacy in the AG129 DENV mouse model. Two nucleoside analogs, NITD-008 and Balapiravir, entered preclinical animal safety study and clinic trial, but both were terminated due to toxicity and lack of potency, respectively. Celgosivir, a host alpha-glucosidase inhibitor, is currently under clinical trial; its clinical efficacy remains to be determined. The knowledge accumulated during the past decade has provided a better rationale for ongoing dengue drug discovery. Though challenging, we are optimistic that this continuous, concerted effort will lead to an effective dengue therapy. Viruses belonging to the Flaviviridae family primarily spread through arthropod vectors, and are the major causes of illness and death around the globe. The Flaviviridae family consists of 3 genera which include the Flavivirus genus (type species, yellow fever virus) as the largest genus, the Hepacivirus (type species, hepatitis C virus) and the Pestivirus (type species, bovine virus diarrhea). The flaviviruses (Flavivirus genus) are small RNA viruses transmitted by mosquitoes and ticks that take over host cell machinery in order to propagate. However, hepaciviruses and pestiviruses are not antropod-borne. Despite the extensive research and public health concern associated with flavivirus diseases, to date, there is no specific treatment available for any flavivirus infections, though commercially available vaccines for yellow fever, Japanese encephalitis and tick-born encephalitis exist. Due to the global threat of viral pandemics, there is an urgent need for new drugs. In many countries, patients with severe cases of flavivirus infections are treated only by supportive care, which includes intravenous fluids, hospitalization, respiratory support, and prevention of secondary infections. This review discusses the strategies used towards the discovery of antiviral drugs, focusing on rational drug design against Dengue virus (DENV), West Nile virus (WNV), Japanese encephalitis virus (JEV), Yellow Fever virus (YFV) and Hepatitis C virus (HCV). Only modified peptidic, nonpeptidic, natural compounds and fragment-based inhibitors (typically of mass less than 300 Da) against structural and non-structural proteins are discussed. Tick-borne encephalitis (TBE) is a substantial public health problem in many parts of Europe and Asia. To assess the effect of increasing TBE vaccination coverage in Austria, we compared incidence rates over 40 years for highly TBE-endemic countries of central Europe (Czech Republic, Slovenia, and Austria). For all 3 countries we found extensive annual and longer range fluctuations and shifts in distribution of patient ages, suggesting major variations in the complex interplay of factors influencing risk for exposure to TBE virus. The most distinctive effect was found for Austria, where mass vaccination decreased incidence to ≈16% of that of the prevaccination era. Incidence rates remained high for the nonvaccinated population. The vaccine was effective for persons in all age groups. During 2000-2011 in Austria, ≈4,000 cases of TBE were prevented by vaccination. Tick-borne encephalitis virus is the causative agent of tick-borne encephalitis, a potentially fatal neurological infection. Tick-borne encephalitis virus belongs to the family of flaviviruses and is transmitted by infected ticks. Despite the availability of vaccines, approximately 2000-3000 cases of tick-borne encephalitis occur annually in Europe for which no curative therapy is available. The antiviral effects of RNA mediated interference by small interfering RNA (siRNA) was evaluated in cell culture and organotypic hippocampal cultures. Langat virus, a flavivirus highly related to Tick-borne encephalitis virus exhibits low pathogenicity for humans but retains neurovirulence for rodents. Langat virus was used for the establishment of an in vitro model of tick-borne encephalitis. We analyzed the efficacy of 19 siRNA sequences targeting different regions of the Langat genome to inhibit virus replication in the two in vitro systems. The most efficient suppression of virus replication was achieved by siRNA sequences targeting structural genes and the 3' untranslated region. When siRNA was administered to HeLa cells before the infection with Langat virus, a 96.5% reduction of viral RNA and more than 98% reduction of infectious virus particles was observed on day 6 post infection, while treatment after infection decreased the viral replication by more than 98%. In organotypic hippocampal cultures the replication of Langat virus was reduced by 99.7% by siRNA sequence D3. Organotypic hippocampal cultures represent a suitable in vitro model to investigate neuronal infection mechanisms and treatment strategies in a preserved three-dimensional tissue architecture. Our results demonstrate that siRNA is an efficient approach to limit Langat virus replication in vitro. Therapeutical action of mexidol as compared to piracetam was evaluated in groups of patients with tick borne encephalitis in the acute period of disease. Mexidol was administered as add-on to antiviral treatment in 72 patients while 89 patients received piracetam. The drugs were introduced intravenously during the first 10 days and then were given as tablets during 2 months. Based on these results, we can recommend the inclusion of mexidol in the pathogenetic treatment (fever symptoms) of tick born encephalitis. The use of mexidol as compared to piracetam led to more pronounced positive changes, higher percentage of favorable outcomes and lower frequency of residual signs. A serological survey for West Nile virus (WNV) infection involved 395 horses from 43 administrative districts of the Czech Republic (163 animals) and 29 districts of Slovakia (232 animals), sampled between 2008 and 2011. Using a plaque-reduction neutralization microtest, antibodies to WNV were not detected in any horse from the Czech Republic, whereas 19 nonvaccinated horses from Slovakia had specific antibodies to WNV (no cross-reactions were observed with tick-borne encephalitis and Usutu flaviviruses in those animals). The seropositivity rate of nonvaccinated horses in Slovakia was 8.3% (95% confidence interval [CI] 4.7-11.9%), and autochthonous local infection with WNV occurred at least in 11, i.e., 4.8% (95% CI 2.0-7.6%) of the animals. All seropositive horses lived in six lowland districts of southern Slovakia; overall, 15.1% (95% CI 8.8-21.4%) of 126 nonvaccinated horses were seropositive in those districts, situated relatively closely to the border with Hungary, i.e., the country where WNV disease cases have been reported in birds, horses and humans since 2003. For the last 60 years, only a few cases of tick-borne encephalitis (TBE) have been detected in Bulgaria. Considering the remarkable increase in TBE morbidity in Europe over the past two decades, we conducted a study of TBE among patients with acute viral meningitis who were hospitalised in Bulgaria during 2009 to 2012. A total of 86 patients with viral meningitis of unknown aetiology during this period were tested. Acute TBE was confirmed in three of these patients. The last TBE case was detected in October 2012; the other two were diagnosed in 2009. To the best of our knowledge, these three patients are the first confirmed TBE cases reported in Bulgaria. The risk of TBE is underestimated in Bulgaria due to the low awareness of medical doctors. In order to obtain a better understanding of tick-borne encephalitis virus (TBEV) strain movements in central Europe the E gene sequences of 102 TBEV strains collected from 1953 to 2011 at 38 sites in the Czech Republic, Slovakia, Austria and Germany were determined. Bayesian analysis suggests a 350-year history of evolution and spread in central Europe of two main lineages, A and B. In contrast to the east to west spread at the Eurasian continent level, local central European spreading patterns suggest historic west to east spread followed by more recent east to west spread. The phylogenetic and network analyses indicate TBEV ingressions from the Czech Republic and Slovakia into Germany via landscape features (Danube river system), biogenic factors (birds, red deer) and anthropogenic factors. The identification of endemic foci showing local genetic diversity is of paramount importance to the field as these will be a prerequisite for in-depth analysis of focal TBEV maintenance and long-distance TBEV spread.

Is SLC22A3 expressed in the brain?

Yes, SLC22A3 (organic cation transporter (OCT3)) is widely expressed in various organs in humans, and involved in the disposition of many exogenous and endogenous compounds. Several lines of evidence have suggested that OCT3 expressed in the brain plays an important role in the regulation of neurotransmission.

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The polyspecific organic cation transporters OCT1 (SLC22A1), OCT2 (SLC22A2) and OCT3 (SLC22A3) mediate facilitated and bidirectional diffusion of small (< or = 500Da) organic cations with broad specificities for endogenous substrates such as choline, acetylcholine and monoamine neurotransmitters, as well as a variety of xenobiotics. Importantly, besides a wide range of clinically used drugs, these also include several toxins like the neurotoxin 1-methyl-4-phenylpyridinium (MPP(+)) and herbicide paraquat. OCT2-OCT-3 display differential tissue distribution: OCT1 is predominantly found in liver of humans, and liver and kidney in rodents; OCT2 is most strongly expressed in both human and rodent kidney, whereas is OCT3 primarily expressed in placenta, but also more widely detected in various tissues, including brain and lung. The physiological roles of OCTs as transporters for biogenic amines or acetylcholine in these tissues are still debated, in contrast to their involvement in providing access pathways for harmful/toxic cationic substrates into the body and particular tissues. This review highlights a novel role of human and rodent OCTs as carriers of the toxic fluorescent dye ethidium, as opposed to the less harmful related phenanthridine compound propidium, which is not transported. Additional uptake and efflux pathways for ethidium in pro- and eukaryotes are discussed. OCT-mediated pathways may determine major entry routes for ethidium into the body where toxicity via specific mechanisms may develop in tissues expressing OCTs. Considering the high affinity of OCTs for ethidium (K(m) = 1-2 microM) and their strong expression in various organs, strict safety guidelines for the handling of ethidium should be reinforced. Organic cation transporters (OCTs) are carrier-type permeases known to participate in general detoxification functions in peripheral tissues. Previous in vitro studies have suggested that OCTs ensure Uptake2, a low-affinity, corticosteroid-sensitive catecholamine removal system, which was characterized initially in sympathetically innervated tissues. Although the presence of both Uptake(2)-like transport and most OCT subtypes has also been demonstrated in the brain, the physiological role of this family of transporters in CNS remained totally unknown. In the present work, we show that the OCT3 transporter is found throughout the brain and highly expressed in regions regulating fluid exchange, including circumventricular organs such as area postrema and subfornical organ (SFO), and in other structures implicated in the sensing of changes in blood osmolarity and regulation of salt and water ingestion. OCT3/Slc22a3-deficient mice show an increase in the level of ingestion of hypertonic saline under thirst and salt appetite conditions, as well as alterations of the neural response in the SFO after sodium deprivation, as monitored by Fos immunoreactivity. This work demonstrates that the presence of OCT3 is critical for the balanced neural and behavioral responses to environmentally induced variations in osmolarity and provides for the first time physiological evidence of the importance of OCTs for CNS function. Mood disorders cause much suffering and are the single greatest cause of lost productivity worldwide. Although multiple medications, along with behavioral therapies, have proven effective for some individuals, millions of people lack an effective therapeutic option. A common serotonin (5-HT) transporter (5-HTT/SERT, SLC6A4) polymorphism is believed to confer lower 5-HTT expression in vivo and elevates risk for multiple mood disorders including anxiety, alcoholism, and major depression. Importantly, this variant is also associated with reduced responsiveness to selective 5-HT reuptake inhibitor antidepressants. We hypothesized that a reduced antidepressant response in individuals with a constitutive reduction in 5-HTT expression could arise because of the compensatory expression of other genes that inactivate 5-HT in the brain. A functionally upregulated alternate transporter for 5-HT may prevent extracellular 5-HT from rising to levels sufficiently high enough to trigger the adaptive neurochemical events necessary for therapeutic benefit. Here we demonstrate that expression of the organic cation transporter type 3 (OCT3, SLC22A3), which also transports 5-HT, is upregulated in the brains of mice with constitutively reduced 5-HTT expression. Moreover, the OCT blocker decynium-22 diminishes 5-HT clearance and exerts antidepressant-like effects in these mice but not in WT animals. OCT3 may be an important transporter mediating serotonergic signaling when 5-HTT expression or function is compromised. The organic cation transporter 3 (OCT3; synonymous: extraneuronal monoamine transporter, EMT, Slc22a3) encodes an isoform of the organic cation transporters and is expressed widely across the whole brain. OCTs are a family of high-capacity, bidirectional, multispecific transporters of organic cations. These also include serotonin, dopamine and norepinephrine making OCTs attractive candidates for a variety of neuropsychiatric disorders including anxiety disorders. OCT3 has been implicated in termination of monoaminergic signalling in the central nervous system. Interestingly, OCT3 mRNA is however also significantly up-regulated in the hippocampus of serotonin transporter knockout mice where it might serve as an alternative reuptake mechanism for serotonin. The examination of the behavioural phenotype of OCT3 knockout mice thus is paramount to assess the role of OCT3. We have therefore subjected mice lacking the OCT3 gene to a comprehensive behavioural test battery. While cognitive functioning in the Morris water maze test and aggression levels measured with the resident-intruder paradigm were in the same range as the respective control animals, OCT3 knockout animals showed a tendency of increased activity and were significantly less anxious in the elevated plus-maze test and the open field test as compared to their respective wild-type controls arguing for a role of OCT3 in the regulation of fear and anxiety, probably by modulating the serotonergic tone in limbic circuitries. The organic cation transporter (OCT) 3 is widely expressed in various organs in humans, and involved in the disposition of many exogenous and endogenous compounds. Several lines of evidence have suggested that OCT3 expressed in the brain plays an important role in the regulation of neurotransmission. Relative to wild-type (WT) animals, Oct3 knockout (KO) mice have displayed altered behavioral and neurochemical responses to psychostimulants such as amphetamine (AMPH) and methamphetamine. In the present study, both in vitro and in vivo approaches were utilized to explore potential mechanisms underlying the disparate neuropharmacological effects observed following AMPH exposure in Oct3 KO mice. In vitro uptake studies conducted in OCT3 transfected cells indicated that dextroamphetamine (d-AMPH) is not a substrate of OCT3. However, OCT3 was determined to be a high-capacity and low-affinity transporter for the neurotransmitters dopamine (DA), norepinephrine (NE), and serotonin (5-HT). Inhibition studies demonstrated that d-AMPH exerts relatively weak inhibitory effects on the OCT3-mediated uptake of DA, NE, 5-HT, and the model OCT3 substrate 4-(4-(dimethylamino)styryl)-N-methylpyridinium iodide. The IC(50) values were determined to be 41.5 +/- 7.5 and 24.1 +/- 7.0 microM for inhibiting DA and 5-HT uptake, respectively, while 50% inhibition of NE and 4-(4-(dimethylamino)styryl)-N-methylpyridinium iodide uptake was not achieved by even the highest concentration of d-AMPH applied (100 microM). Furthermore, the disposition of d-AMPH in various tissues including the brain, liver, heart, kidney, muscle, intestine, spleen, testis, uterus, and plasma were determined in both male and female Oct3 KO and WT mice. No significant difference was observed between either genotypes or sex in all tested organs and tissues. Our findings suggest that OCT3 is not a prominent factor influencing the disposition of d-AMPH. Additionally, based upon the inhibitory potency observed in vitro, d-AMPH is unlikely to inhibit the uptake of monoamines mediated by OCT3 in the brain. Differentiated neuropharmacological effects of AMPHs noted between Oct3 KO and WT mice appear to be due to the absence of Oct3 mediated uptake of neurotransmitters in the KO mice. Organic cation transporters (OCTs) are carrier-type polyspecific permeases known to participate in low-affinity extraneuronal catecholamine uptake in peripheral tissues. OCT3 is the OCT subtype most represented in the brain, yet its implication in central aminergic neurotransmission in vivo had not been directly demonstrated. In a detailed immunohistochemistry study, we show that OCT3 is expressed in aminergic pathways in the mouse brain, particularly in dopaminergic neurons of the substantia nigra compacta, non-aminergic neurons of the ventral tegmental area, substantia nigra reticulata (SNr), locus coeruleus, hippocampus and cortex. Although OCT3 was found mainly in neurons, it was also occasionally detected in astrocytes in the SNr, hippocampus and several hypothalamic nuclei. In agreement with this distribution, OCT3/Slc22a3-deficient mice show evidence of altered monoamine neurotransmission in the brain, with decreased intracellular content and increased turnover of aminergic transmitters. The behavioral characterization of these mutants reveal subtle behavioral alterations such as increased sensitivity to psychostimulants and increased levels of anxiety and stress. Altogether our data support a role of OCT3 in the homeostatic regulation of aminergic neurotransmission in the brain.

Has the protein TIEG1 been associated with apoptosis?

Yes, TIEG1 (also known as KLF10) seems to play a role in regulating apoptosis.

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Nitric oxide serves various roles in mammalian cells, including intracellular signaling and cell killing. To recognize the dynamic molecular changes in response to NO, microarray analysis was applied to human fibroblasts (IMR-90) exposed to sublethal levels of NO. Among the > 300 transcripts induced by NO, we focused on the mRNA encoded by the transforming growth factor-beta- (TGF-beta-) inducible early response 1 gene (TIEG1), which plays a pivotal role in TGF-beta-regulated cell growth control and apoptosis. Northern blotting analysis demonstrated that NO upregulates TIEG1 mRNA in a dose-dependent manner. Anti-TGF-beta antibodies prevented TIEG1 mRNA induction by TGF-beta, but not the induction by NO. Conversely, NO had no effect on the amounts of total TGF-beta or its active form in culture supernatants. However, the half-life of the TIEG1 transcript was strongly increased (6-fold) upon exposure of the cells to NO. Thus, NO upregulates TIEG1 mRNA by stabilization independently of TGF-beta. The TIEG1 mRNA now joins heme oxygenase-1 mRNA in displaying regulation by NO-mediated stabilization. It remains to be determined whether the same control mechanism operates on these and perhaps other messages. Transforming growth factor-beta (TGF-beta) plays an important role during the period of developmental cell death in the nervous system. Using the oligodendroglial precursor cell line OLI-neu, we have previously established an in vitro system to analyze TGF-beta-mediated cell death on the molecular level. We could show that the Krüppel-like Zn-finger transcription factor TIEG1 was up-regulated after TGF-beta stimulation of OLI-neu cells and mimicked TGF-beta effects in these cells; i.e., overexpression of TIEG1 in OLI-neu cells induced apoptosis as shown by apoptosis ELISA, DNA fragmentation, and caspases-3 activation. The apoptotic pathway seemed to be initiated by repressing the expression of the antiapoptotic protein Bcl-XL. In contrast, the reporter activity of a SMAD consensus promoter was induced, whereas the promoter activity of the inhibitory SMAD7 was reduced, suggesting that SMAD-dependent TGF-beta responses, such as TGF-beta-induced apoptosis, are enhanced in the presence of TIEG1. Dairy cows mobilise body tissues to support milk production and, because glucose supplies are limited, lipids are used preferentially for energy production. Lipogenic activity is switched off and lipolytic mechanisms in adipose tissue increase through changes in the expression of several key enzymes. This results in a loss of body condition, together with high circulating concentrations of non-esterified fatty acids. Changes in the synthesis, secretion and signalling pathways of somatotrophic hormones (insulin, growth hormone, insulin-like growth factor 1) and adipokines (e.g. leptin) are central to the regulation of these processes. A high reliance on fatty acids as an energy source in the peripartum period causes oxidative damage to mitochondria in metabolically active tissues, including the liver and reproductive tract. The expression of genes involved in insulin resistance (PDK4, AHSG) is increased, together with expression of TIEG1, a transcription factor that can induce apoptosis via the mitochondrial pathway. Polymorphisms in TFAM and UCP2, two autosomal mitochondrial genes, have been associated with longevity in dairy cows. Polymorphisms in many other genes that affect lipid metabolism also show some associations with fertility traits. These include DGAT1, SCD1, DECR1, CRH, CBFA2T1, GH, LEP and NPY. Excess lipid accumulation in oocytes and the regenerating endometrium reduces fertility via reductions in embryo survival and increased inflammatory changes, respectively. A novel TGFbeta Inducible Early Gene-1 (TIEG1) was discovered in human osteoblast (OB) cells by our laboratory. Over the past decade, a handful of laboratories have revealed a multitude of organismic, cellular, and molecular functions of this gene. TIEG1 is now classified as a member of the 3 zinc finger family of Krüppel-like transcription factors (KLF10). Other closely related factors [TIEG2 (KLF11) and TIEG3/TIEG2b] have been reported and are briefly compared. As described in this review, TIEG1 is shown to play a role in regulating estrogen and TGFbeta actions, the latter through the Smad signaling pathway. In both cases, TIEG1 acts as an inducer or repressor of gene transcription to enhance the TGFbeta/Smad pathway, as well at other signaling pathways, to regulate cell proliferation, differentiation, and apoptosis. This review outlines TIEG1's molecular functions and roles in skeletal disease (osteopenia/osteoporosis), heart disease (hypertrophic cardiomyopathy), and cancer (breast and prostate). Transforming growth factor-beta (TGF-beta) inducible early gene 1 (TIEG1) is known to induce apoptosis in TGF-beta sensitive pancreatic cancer cells, yet its effect on TGF-beta resistant cancer cells remains unclear. In this study, TIEG1 was found to induce apoptosis in TGF-beta resistant cancer cells and concurrently enhanced gemcitabine chemosensitivity. Down-regulation of stathmin was noted to associate with TIEG1 expression, whilst ectopic overexpression of stathmin prevented TIEG1 mediated growth inhibition of tumor cells. Small interfering RNAs targeting stathmin inhibited pancreatic cancer cell growth. These suggest that stathmin is a downstream target of TIEG1. TIEG1 (TGF-β inducible early gene 1) plays a significant role in regulating cell proliferation and apoptosis in various cell types. Previous studies have shown a close relationship between the expression level of TIEG1 and various cancers, including breast, prostate, colorectal and pancreatic cancer. In this study, we up-regulated the gene expression of TIEG1 in SW1990 pancreatic cancer cell line by a lentivirus transfection system and investigated its potential as a therapeutic target for pancreatic cancer. The results showed that lentivirus-mediated overexpression of TIEG1 gene inhibited human pancreatic cancer SW1990 cell proliferation and caused the cell cycle arrest at the G1-phase in vitro. SW1990 cells transduced with lenti-TIEG1 showed significant inhibition of colony formation and cancer cell growth in 3-D culture model. Moreover, overexpression of TIEG1 gene significantly slowed the growth of SW1990 xenografts in nude mice. Taken together, these data provided evidence that overexpression of TIEG1 gene by a lentivirus transfection system led to suppressed human pancreatic cancer cell growth and might therefore be a feasible approach in the clinical management of pancreatic cancer. TGF-beta-induced apoptosis is essential for embryonic development and mainteanance of adult tissues. Impairment of the apoptotic pathway, regulated by TGF-beta, plays a center role in tumorigenesis and manifestations of different diseases. TIEG2/KLF11 is a recently identified human TGF-beta-inducible zinc finger protein belonging to the family of Sp1/KLF-like transcription factors. In human and murine tissues it has been shown that TIEG1 and TIEG2 induce apoptosis and inhibit cell growth. Since TGF-beta and Tieg1 are able to induce apoptosis in the oligodendroglial cell line OLI-neu, we analysed the ability of TIEG2 to mimic the effects observed after treatment with TGF-beta and overexpression of Tieg1. Herein we report that TIEG2 induces Caspase3-dependent apoptosis in murine OLI-neu cells. Furthermore, we could demonstrate that TIEG2 decreases the levels of the anti-apoptotic protein Bcl-X(L) and inhibits transcription driven by the Bcl-X(L) promoter. These data suggest that TIEG2 serves as a downstream mediator of TGF-beta, bridging TGF-beta-dependent signaling to the intracellular pathway of apoptosis. The bone marrow microenvironment regulates early B lymphopoiesis and protects leukemia cells against chemotherapy treatment, thus the microenvironment may serve as a sanctuary site for these cells. Yet, few factors that contribute to this process are known. We have explored the role of transforming growth factor beta (TGFbeta) and bone morphogenetic protein-6 (BMP-6) and one target gene, TGFbeta inducible early gene 1 (TIEG1), in the communication between stroma cells and acute lymphoblastic leukemia (ALL) cell lines and their escape from chemotherapy. Here, we have demonstrated TIEG1 expression in both normal B progenitor cells and ALL cells, which increased rapidly upon TGFbeta and BMP-6 treatment. Stimulation with TGFbeta or BMP-6, as well as overexpression of TIEG1 inhibited proliferation. Furthermore, interaction with stroma cells induced TIEG1 expression in ALL cells, inhibited their proliferation and protected the cells against chemotherapeutic treatment. Similarly, treatment with TGFbeta or BMP-6, as well as overexpression of TIEG1, protected ALL cells against chemotherapy-induced cell death. These data suggest that TGFbeta and BMP-6 in the bone marrow microenvironment allow leukemia cells to escape therapy. Further, the data indicate that TIEG1 might be involved in mediating this effect from the microenvironment onto the leukemia cells. Pancreatic cancers frequently have defects in components of the transforming growth factor-beta (TGF-beta) signaling pathway. TIEG1 (TGF-beta inducible early gene) is a recently characterized transcription factor regulated by TGF-beta that induces apoptosis when overexpressed in pancreatic adenocarcinoma cell lines. Alterations on chromosome 8q, where TIEG1 is located, are also relatively frequent in pancreatic cancers. To determine if TIEG1 may be involved in the tumorigenesis of pancreatic cancer, we performed mutational screening of this gene in 22 pancreatic cancer cell lines. No sequence alterations were observed. Reverse transcription-polymerase chain reaction analysis was also performed to rule out the possibility that the expression of the gene is altered by genetic events other than mutation. Likewise, no alterations in expression were found. Thus, an essential role of TIEG1 in pancreatic cancer can be excluded. Krüppel-like factor 10 (KLF10) has been suggested to be a putative tumor suppressor. In the present study, we generated KLF10 deficient mice to explore this hypothesis in vivo. KLF10 deficient mice exhibited increased predisposition to skin tumorigenesis and markedly accelerated papilloma development after DMBA/TPA treatment. On the other hand, KLF10 deficient keratinocytes showed increased proliferation and apoptosis. In colony formation assays after oncogenic H-Ras transfection, KLF10 deficient mouse embryonic fibroblasts (MEFs) yielded more colonies than wild-type MEFs. Furthermore, KLF10 dose-dependently activated p21(WAF1/CIP1) transcription, which was independent of p53 and Sp1 binding sites in p21(WAF1/CIP1) promoter. This study demonstrates that KLF10 is a tumor suppressor and that it targets p21(WAF1/CIP1) transcription. TIEG1 can induce apoptosis of cancer cells, but its role in inhibiting invasion and metastasis has not been reported and is unclear. In this study, we find that decreased TIEG1 expression is associated with increased human epidermal growth factor receptor (EGFR) expression in breast cancer tissues and cell lines. TIEG1 plays an important role in suppressing transcription of EGFR by directly binding to the EGFR promoter. While overexpression of TIEG1 attenuates EGFR expression, knockdown of TIEG1 stimulates EGFR expression. Furthermore, TIEG1 and HDAC1 form a complex, which binds to Sp1 sites on the EGFR promoter and inhibits its transcription by suppressing histone acetylation. TIEG1 significantly inhibits breast cancer cell invasion, suppresses mammary tumorigenesis in xenografts in mice, and decreases lung metastasis by inhibition of EGFR gene transcription and the EGFR signaling pathway. Therefore, TIEG1 is an antimetastasis gene product; regulation of EGFR expression by TIEG1 may be part of an integral signaling pathway that determines and explains breast cancer invasion and metastasis. Transforming growth factor beta(1) (TGF-beta(1))-inducible transcription factors have recently elicited interest because of their critical role in the regulation of cell proliferation, differentiation, and apoptosis. We have previously reported that the TGF-beta(1)-inducible transcription factor, TIEG1, induces apoptosis in a pancreas-derived cell line. However, the mechanisms underlying the apoptotic effects of this transcription factor remain to be defined. In this study, using the TGF-beta(1)-sensitive Hep 3B cell line, we have defined the mechanistic sequence of events that characterize TIEG1-mediated apoptosis and compared these events with the changes observed during TGF-beta(1)-induced apoptosis. Both TGF-beta(1)- and TIEG1-induced cell death were accompanied by an increase in the generation of reactive oxygen species and a loss of the mitochondrial membrane potential preceding the morphological changes of apoptosis. In contrast, increases in caspase 3-like activity and glutathione (GSH) depletion occurred later in the apoptotic process, concurrent with the morphological features of apoptosis. The antioxidant, trolox, decreased the formation of reactive oxygen species and apoptosis. These results demonstrate that similar to TGF-beta(1), TIEG1 induces apoptosis by a mechanism involving the formation of reactive oxygen species. Previous studies documented the ability of quinazoline-based alpha1-adrenoceptor antagonists to induce apoptosis in prostate cancer cells via an alpha 1-adrenoceptor-independent mechanism. In this study we investigated the molecular events initiating this apoptotic effect. Since transforming growth factor-beta 1 (TGF-beta 1) mediates prostate epithelial cell apoptosis, we hypothesised that the activation of the TGF-beta 1 pathway underlies the quinazoline-based apoptotic effect in prostate cancer cells. Treatment of the androgen-independent human prostate cancer cells PC-3 with doxazosin resulted in a strong caspase-3 activation within 24 h, whereas tamsulosin, a sulphonamide-based alpha 1-adrenoceptor antagonist, had no significant apoptotic effect against prostate cancer cells. To identify the molecular components involved in this quinazoline-mediated apoptosis, cDNA microarray analysis of PC-3 prostate cancer cells treated with doxazosin (3 h) was performed. Induced expression of several genes was observed including p21(WAF-1) and I kappa B alpha (inhibitor of NF-kappa B alpha). Relative quantitative reverse transcription-polymerase chain reaction analysis revealed induction of several TGF-beta1 signalling effectors: Induction of mRNA for Smad4 and the TGF-beta1-regulated apoptosis-inducing transcription factor TGF-beta1-inducible early gene (TIEG1) was detected within the first 6 h of doxazosin treatment. Upregulation of I kappa B alpha at both the mRNA and protein level was also detected after 6 h of treatment. Furthermore, doxazosin resulted in a considerable elevation in Smad4 and TIEG protein expression (6 h). A 'latent' increase in TGF-beta mRNA expression was detected after 48 h of treatment. These findings suggest that the quinazoline-based doxazosin mediates prostate cancer apoptosis by initially inducing the expression of TGF-beta1 signalling effectors and subsequently I kappa B alpha. The present study provides an initial insight into the molecular targets of the apoptotic action of quinazolines against prostate cancer cells. TGF-beta-inducible early-response gene (TIEG) is a family of primary response genes induced by TGF-beta, which are well recognized in regulating cellular proliferation and apoptosis. However, their expression profile has never been investigated during embryogenesis in different organs. In this study, we aimed to investigate the transcriptional level of both TIEG1 and TIEG2 during development in various mice organs, including the brain cortex, cerebellum and stem, brain striatum, muscle, heart, liver, kidney, and lung. Quantitative real-time PCR was used to profile the change of transcriptional level of the two TIEG members in the mice tissues at six developmental stages. Taken together, the expression of TIEG1 and TIEG2 was specific in different organs yet varied with different developmental time points. Their dynamic changes were moderately consistent in most organs including the brain cortex, striatum, liver, kidney, and lung. However, their mRNA expression in both the heart and muscle was significantly different at all developmental stages, which might propose a compensation of functions in the TIEG family. Nevertheless, our data indicate that both the TIEG genes are essential in regulating the normal organ development and functioning in murine model, as their expressions were ubiquitous and tissue specific at various developmental stages. TGF-β Inducible Early Gene-1 (TIEG1) is a Krüppel-like transcription factor (KLF10) that was originally cloned from human osteoblasts as an early response gene to TGF-β treatment. As reported previously, TIEG1(-/-) mice have decreased cortical bone thickness and vertebral bone volume and have increased spacing between the trabeculae in the femoral head relative to wildtype controls. Here, we have investigated the role of TIEG1 in osteoclasts to further determine their potential role in mediating this phenotype. We have found that TIEG1(-/-) osteoclast precursors differentiated more slowly compared to wildtype precursors in vitro and high RANKL doses are able to overcome this defect. We also discovered that TIEG1(-/-) precursors exhibit defective RANKL-induced phosphorylation and accumulation of NFATc1 and the NFATc1 target gene DC-STAMP. Higher RANKL concentrations reversed defective NFATc1 signaling and restored differentiation. After differentiation, wildtype osteoclasts underwent apoptosis more quickly than TIEG1(-/-) osteoclasts. We observed increased AKT and MEK/ERK signaling pathway activation in TIEG1(-/-) osteoclasts, consistent with the roles of these kinases in promoting osteoclast survival. Adenoviral delivery of TIEG1 (AdTIEG1) to TIEG1(-/-) cells reversed the RANKL-induced NFATc1 signaling defect in TIEG1(-/-) precursors and eliminated the differentiation and apoptosis defects. Suppression of TIEG1 with siRNA in wildtype cells reduced differentiation and NFATc1 activation. Together, these data provide evidence that TIEG1 controls osteoclast differentiation by reducing NFATc1 pathway activation and reduces osteoclast survival by suppressing AKT and MEK/ERK signaling. AIM: To investigate the role of transforming growth factor (TGF)-β-inducible early gene 1 (TIEG1) in TGF-β-induced growth inhibition in hepatocellular carcinoma (HCC) cells. METHODS: Human hepatocyte and HCC cell lines with varied susceptibilities to TGF-β1 were tested by methylthiazoletetrazolium (MTT) assay. The expression changes of Smad2, Smad3, Smad4, Smad7, TIEG1 and TIEG2 gene following treatment with TGF-β1 in a TGF-β-sensitive hepatocyte cell line (MIHA), a TGF-β-sensitive hepatoma cell line (Hep3B) and two TGF-β-insensitive hepatoma cell lines (HepG2 and Bel7404) were examined. SiRNA targeting TIEG1 was transfected into Hep3B cells and the sensitivity of cells to TGF-β1 was examined. Overexpression of TIEG1 was induced by lentiviral-mediated transduction in TGF-β1-resistant hepatoma cell lines (Bel7404 and HepG2). MTT assay and 4',6-Diamidino-2-phenylindole staining were used to identify cell viability and apoptosis, respectively. The expression level of stathmin was measured by reverse transcriptase polymerase chain reaction and Western-blotting analysis, and stathmin promoter activity by TIEG1 was monitored by a luciferase reporter gene system. RESULTS: TIEG1 was significantly upregulated by TGF-β1 in the TGF-β1-sensitive HCC cell line, Hep3B, but not in the resistant cell lines. The suppression of TIEG1 by siRNAs decreased the sensitivity of Hep3B cells to TGF-β1, whereas the overexpression of TIEG1 mediated growth inhibition and apoptosis in TGF-β1-resistant HCC cell lines, which resembled those of TGF-β1-sensitive HCC cells treated with TGF-β1. Our data further suggested that stathmin was a direct target of TIEG1, as stathmin was significantly downregulated by TIEG1 overexpression, and stathmin promoter activity was inhibited by TIEG1 in a dose-dependent manner. CONCLUSION: Our data suggest that transactivation of TIEG1 conferred growth inhibition of TGF-β-susceptible human HCC cells.

Which is the cellular localization of the protein Opa1?

The Opa1 protein localizes to the mitochondria.

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The mitochondria-shaping protein optic atrophy 1 (OPA1) has genetically distinguishable roles in mitochondrial morphology and apoptosis. The latter depends on the presenilin associated rhomboid like (PARL) protease, essential for the accumulation of a soluble intermembrane space form of OPA1 (IMS-OPA1). Here we show that OPA1 and PARL participate in the heat shock response, a stereotypical cellular process of adaptation to thermal stress. Upon heat shock, long forms of OPA1 are lost and mitochondria fragment. However, mitochondrial fusion is dispensable to maintain viability, whereas IMS-OPA1 is required. Upon conditioning-a process of mild heat shock and recovery-IMS-OPA1 accumulates, OPA1 oligomers increase and mitochondria release less cytochrome c, ultimately resulting in cellular resistance to subsequent apoptotic inducers. In Parl(-/-) cells accumulation of IMS-OPA1 is blunted and conditioning fails to protect from cytochrome c release and apoptosis. Thus, the OPA1/PARL dependent pathway of cristae remodeling is implicated in heat shock. This article is part of a Special Issue entitled: 17th European Bioenergetics Conference (EBEC 2012). Mitochondrial dysfunction, especially a defect in mitochondrial biogenesis, is an early and prominent feature of Alzheimer's disease (AD). Previous studies demonstrated that the number of mitochondria is significantly reduced in susceptible hippocampal neurons from AD patients. Neural stem cell (NSC) transplantation in AD-like mice can compensate for the neuronal loss resulting from amyloid-beta protein deposition. The effects of NSC transplantation on mitochondrial biogenesis and cognitive function in AD-like mice, however, are poorly understood. In this study, we injected NSCs or vehicle into 12-month-old amyloid precursor protein (APP)/PS1 transgenic mice, a mouse model of AD-like pathology. The effects of NSC transplantation on cognitive function, the amount of mitochondrial DNA, the expression of mitochondrial biogenesis factors and mitochondria-related proteins, and mitochondrial morphology were investigated. Our results show that in NSC-injected APP/PS1 (Tg-NSC) mice, the cognitive function, number of mitochondria, and expression of mitochondria-related proteins, specifically the mitochondrial fission factors (dynamin-related protein 1 [Drp1] and fission 1 [Fis1]) and the mitochondrial fusion factor optic atrophy 1 (OPA1), were significantly increased compared with those in age-matched vehicle-injected APP/PS1 (Tg-Veh) mice, whereas the expression of mitochondrial fusion factors mitofusion 1 (Mfn1) and Mfn2 was significantly decreased. These data indicate that NSC transplantation may enhance mitochondria biogenesis and further rescue cognitive deficits in AD-like mice. Mutations in LRRK2 cause autosomal dominant Parkinson's disease (PD). LRRK2 encodes a multi-domain protein containing GTPase and kinase domains, and putative protein-protein interaction domains. Familial PD mutations alter the GTPase and kinase activity of LRRK2 in vitro. LRRK2 is suggested to regulate a number of cellular pathways although the underlying mechanisms are poorly understood. To explore such mechanisms, it has proved informative to identify LRRK2-interacting proteins, some of which serve as LRRK2 kinase substrates. Here, we identify common interactions of LRRK2 with members of the dynamin GTPase superfamily. LRRK2 interacts with dynamin 1-3 that mediate membrane scission in clathrin-mediated endocytosis and with dynamin-related proteins that mediate mitochondrial fission (Drp1) and fusion (mitofusins and OPA1). LRRK2 partially co-localizes with endosomal dynamin-1 or with mitofusins and OPA1 at mitochondrial membranes. The subcellular distribution and oligomeric complexes of dynamin GTPases are not altered by modulating LRRK2 in mouse brain, whereas mature OPA1 levels are reduced in G2019S PD brains. LRRK2 enhances mitofusin-1 GTP binding, whereas dynamin-1 and OPA1 serve as modest substrates of LRRK2-mediated phosphorylation in vitro. While dynamin GTPase orthologs are not required for LRRK2-induced toxicity in yeast, LRRK2 functionally interacts with dynamin-1 and mitofusin-1 in cultured neurons. LRRK2 attenuates neurite shortening induced by dynamin-1 by reducing its levels, whereas LRRK2 rescues impaired neurite outgrowth induced by mitofusin-1 potentially by reversing excessive mitochondrial fusion. Our study elucidates novel functional interactions of LRRK2 with dynamin-superfamily GTPases that implicate LRRK2 in the regulation of membrane dynamics important for endocytosis and mitochondrial morphology. A new member of the dynamin GTPase family (OPA1) was recently identified in humans and shown to be mutated in patients with dominant optic atrophy. To understand better the function of mammalian OPA1, we isolated a mouse ortholog (mOPA1) from brain and raised a specific antibody against its C terminus. The subcellular distribution of mOPA1 overexpressed in COS-7 cells largely overlapped that of endogenous cytochrome c, a well known mitochondrial marker, and dramatically affected mitochondrial morphology, altering it from tubular to vesicular. Mitochondrial targeting was mediated by the N-terminal region of mOPA1 as follows: deletion of the 124 N-terminal amino acids eliminated mitochondrial targeting, although fusion of the N-terminal 60 or 90 amino acids of mOPA1 with green fluorescent protein resulted in its mitochondrial targeting. mOPA1 was expressed widely in the mouse brain, especially in neurons of olfactory bulb, cerebral cortex, piriform cortex, hypothalamus, hippocampus, red nucleus, cochlear nucleus, motor trigeminal nucleus, facial nucleus, cerebellar nucleus, and Purkinje cells. Within dissociated cerebellar cells, mOPA1 protein was clearly observed in the dendrites and somas of neuronal cells, as well as in astrocytes and meningeal cells. In each case, it was distributed in the vesicular pattern seen in other cell types. Mitochondria are highly dynamic organelles, and mitochondrial fission is a crucial step of apoptosis. Although Oma1 is believed to be responsible for long form Opa1 (L-Opa1) processing during mitochondrial fragmentation, whether and how Oma1 is involved in L-Opa1 processing and participates in the regulation of chemoresistance is unknown. Chemosensitive and chemoresistant ovarian (OVCA) and cervical (CECA) cancer cells were treated with cisplatin (CDDP). Mitochondrial dynamics and protein contents were assessed by immunofluorescence and Western blot, respectively. The requirements of Oma1 and p53 for CDDP-induced L-Opa1 processing, mitochondrial fragmentation, and apoptosis were examined by siRNA or cDNA. CDDP induces L-Opa1 processing and mitochondrial fragmentation in chemosensitive but not in chemoresistant cells. CDDP induced Oma1 40-kDa form increases in OV2008 cells, not in C13* cells. Oma1 knockdown inhibited L-Opa1 processing, mitochondrial fragmentation, and apoptosis. Silencing p53 expression attenuated the effects of CDDP in Oma1 (40 kDa) increase, L-Opa1 processing, mitochondrial fragmentation, and apoptosis in chemosensitive OVCA cells, whereas reconstitution of p53 in p53 mutant or null chemoresistant OVCA cells induced Oma1 (40 kDa) increase, L-Opa1 processing, mitochondrial fragmentation, and apoptosis irrespective of the presence of CDDP. Prohibitin 1 (Phb1) dissociates from Opa1-Phb1 complex and binds phosphorylated p53 (serine 15) in response to CDDP in chemosensitive but not chemoresistant CECA cells. These findings demonstrate that (a) p53 and Oma1 mediate L-Opa1 processing, (b) mitochondrial fragmentation is involved in CDDP-induced apoptosis in OVCA and CECA cells, and (c) dysregulated mitochondrial dynamics may in part be involved in the pathophysiology of CDDP resistance. OPA1 is a cause gene for autosomal dominant optic atrophy and possesses eight alternative splicing variants. Here, we identified two isoforms of OPA1 proteins in HeLa cells and examined their submitochondrial localization and complex formations. RT-PCR shows that HeLa cells mainly express isoforms 7 and 1 of OPA1. Since the third cleavage site is mainly utilized in HeLa cells, the predicted molecular masses of their processed proteins are consistent with the 93- and 88-kDa proteins. Biochemical examinations indicate that both of the OPA1 isoforms are present in the intermembrane space. Submitochondrial fractionation by sucrose density-gradient centrifugation shows that the 88-kDa protein predominantly associates with the mitochondrial outer membrane, on the contrary, the 93-kDa protein associates with the inner membrane. Gel filtration analysis indicates that they compose the different molecular mass complexes in mitochondria. These differences between two isoforms of OPA1 would suggest their crucial role involved in the mitochondrial membrane formation. Mutations in the OPA1 gene are associated with autosomal dominant optic atrophy. OPA1 encodes a dynamin-related protein orthologous to Msp1 of Schizosaccharomyces pombe and Mgm1p of Saccharomyces cerevisiae, both involved in mitochondrial morphology and genome maintenance. We present immuno-fluorescence and biochemical evidences showing that OPA1 resides in the mitochondria where it is imported through its highly basic amino-terminal extension. Proteolysis experiments indicate that OPA1 is present in the inter-membrane space and electron microscopy further localizes it close to the cristae. The strong association of OPA1 with membranes suggests its anchoring to the inner membrane. The mitochondria are dynamic organelles that constantly fuse and divide. An equilibrium between fusion and fission controls the morphology of the mitochondria, which appear as dots or elongated tubules depending the prevailing force. Characterization of the components of the fission and fusion machineries has progressed considerably, and the emerging question now is what role mitochondrial dynamics play in mitochondrial and cellular functions. Its importance has been highlighted by the discovery that two human diseases are caused by mutations in the two mitochondrial pro-fusion genes, MFN2 and OPA1. This review will focus on data concerning the function of OPA1, mutations in which cause optic atrophy, with respect to the underlying pathophysiological processes. PURPOSE: Mutations in the optic atrophy 1 gene (OPA1) have been reported in patients with autosomal dominant optic atrophy (ADOA). OPA1 plays important roles in mitochondrial dynamics and cell apoptosis. The link between OPA1 mutations and changes in bioenergetics is still not fully resolved. The aim of this study was to investigate the effects of OPA1 mutations on the mitochondrial tubular network and bioenergetics. METHODS: We established lymphoblastoid cell lines from four ADOA families harboring different OPA1 mutations, unaffected relatives (internal control cell lines), and unrelated normal controls (normal control cell lines). OPA1 splice variants and mRNA were analyzed by reverse transcription-PCR and quantitative real-time PCR. Protein isoforms were examined by Western blotting. The mitochondrial network was visualized by confocal microscopy. Mitochondrial bioenergetics were assessed using a Seahorse XF24 flux analyzer. Mitochondrial membrane potential and oxidative damage were analyzed by flow cytometry. RESULTS: OPA1 mutant cell lines showed significant decreases in OPA1 mRNA and protein expression, mitochondrial membrane potential, and ATP synthesis. A marked deficiency of the long isoform of OPA1 was observed in cells with OPA1 mutations in the middle domain and GTPase effector domain. Confocal microscopy revealed increased mitochondrial fragmentation in OPA1 mutant cells. OPA1 mutant cells also displayed reduced oxygen consumption and underwent glycolysis to produce ATP. Moreover, OPA1 mutations caused the accumulation of oxidative damage. CONCLUSIONS: Our experiments demonstrated that OPA1 mutations induced mitochondrial fragmentation, uncoupled mitochondrial respiration, and elicited dysfunctional bioenergetics. However, there were no significant differences among the various OPA1 mutations. Cellular mechanisms involved in multiple neurodegenerative diseases converge on mitochondria to induce overproduction of reactive oxygen species, damage to mitochondria, and subsequent cytochrome c release. Little is currently known regarding the contribution mitochondrial dynamics play in cytochrome c release following oxidative stress in neurodegenerative disease. Here we induced oxidative stress in the HT22 cell line with glutamate and investigated key mediators of mitochondrial dynamics to determine the role this process may play in oxidative stress induced neuronal death. We report that glutamate treatment in HT22 cells induces increase in reactive oxygen species (ROS), release of the mitochondrial fusion protein Opa1 into the cytosol, with concomitant release of cytochrome c. Furthermore, following the glutamate treatment alterations in cell signaling coincide with mitochondrial fragmentation which culminates in significant cell death in HT22 cells. Finally, we report that treatment with the antioxidant tocopherol attenuates glutamate induced-ROS increase, release of mitochondrial Opa1 and cytochrome c, and prevents cell death. BACKGROUND: Mitochondria have been suggested to be involved in the pathology of bipolar disorder (BD) and schizophrenia. However, the mechanism underlying mitochondrial dysfunction is unclear. Mitochondrial network dynamics, which reflects cellular metabolic state, is important for embryonic development, synapse formation, and neurodegeneration. This study aimed to investigate mitochondrial network dynamics and its plausible association with abnormal cellular oxygen consumption in schizophrenia. METHODS: Viable Epstein-Barr virus (EBV)-transformed lymphocytes (lymphoblastoids) from DSM-IV diagnosed patients with schizophrenia (n = 17), BD (n = 15), and healthy control subjects (n = 15) were assessed for mitochondrial respiration, mitochondrial dynamics, and relevant protein levels by oxygraph, confocal microscopy, and immunoblotting, respectively. RESULTS: Respiration of schizophrenia-derived lymphoblastoids was significantly lower compared with control subjects, and was twice as sensitive to dopamine (DA)-induced inhibition. Unlike DA, haloperidol inhibited complex I-driven respiration to a similar extent in both schizophrenia and the control cells. Both drugs interact with complex I but at different sites. At the site of DA interaction, we found alterations in protein levels of three subunits of complex I in schizophrenia. In addition, we observed structural and connectivity perturbations in the mitochondrial network, associated with alterations in the profusion protein OPA1, which was similarly reduced in schizophrenia prefrontal cortex specimens. None of these alterations were observed in the BD cells, which were similar to control cells. CONCLUSIONS: We show impaired mitochondrial network dynamics associated with reduced cellular respiration and complex I abnormalities in schizophrenia but not in BD. If these findings represent disease-specific alterations, they may become an endophenotype biomarker for schizophrenia. Cristae, the organized invaginations of the mitochondrial inner membrane, respond structurally to the energetic demands of the cell. The mechanism by which these dynamic changes are regulated and the consequences thereof are largely unknown. Optic atrophy 1 (OPA1) is the mitochondrial GTPase responsible for inner membrane fusion and maintenance of cristae structure. Here, we report that OPA1 responds dynamically to changes in energetic conditions to regulate cristae structure. This cristae regulation is independent of OPA1's role in mitochondrial fusion, since an OPA1 mutant that can still oligomerize but has no fusion activity was able to maintain cristae structure. Importantly, OPA1 was required for resistance to starvation-induced cell death, for mitochondrial respiration, for growth in galactose media and for maintenance of ATP synthase assembly, independently of its fusion activity. We identified mitochondrial solute carriers (SLC25A) as OPA1 interactors and show that their pharmacological and genetic blockade inhibited OPA1 oligomerization and function. Thus, we propose a novel way in which OPA1 senses energy substrate availability, which modulates its function in the regulation of mitochondrial architecture in a SLC25A protein-dependent manner. Mitochondria are dynamic cellular organelles that balance fission and fusion to regulate organelle morphology, distribution, and activity, and Opa1 is one of three GTPases known to regulate mitochondrial fusion. In humans, loss of a single Opa1 allele causes dominant optic atrophy, a degenerative condition that leads to loss of vision. Here we demonstrate that the lilR3 mutant mouse phenotype is due to a point mutation in the Opa1 gene resulting in mislocalized Opa1 protein from the mitochondria to the cytosol. Importantly, the mutation is in the middle domain of the Opa1 protein, for which no function had been described. Lack of mitochondrial retention of Opa1 is sufficient to cause the cellular Opa1 loss-of-function phenotype as the mitochondria are fragmented, indicating an inability to fuse. Despite the normally ubiquitous expression of Opa1 and the essential nature of mitochondria, embryos with aberrant Opa1 survived through midgestation and died at E11.5. These mutants displayed growth retardation, exencephaly, and abnormal patterning along the anterior-posterior axis, although the A-P axis itself was intact. The complex relationship between mitochondrial dynamics and cell death is emphasized by apoptosis in specific cell populations of lilR3 embryos. Our results define, for the first time, a function of the middle domain of the Opa1 protein and demonstrate that mitochondrial retention of Opa1 protein is essential for normal embryogenesis. We have previously described that silencing of the mitochondrial protein OPA1 enhances mitochondrial Ca(2+) signaling and aldosterone production in H295R adrenocortical cells. Since extramitochondrial OPA1 (emOPA1) was reported to facilitate cAMP-induced lipolysis, we hypothesized that emOPA1, via the enhanced hydrolysis of cholesterol esters, augments aldosterone production in H295R cells. A few OPA1 immunopositive spots were detected in ∼40% of the cells. In cell fractionation studies OPA1/COX IV (mitochondrial marker) ratio in the post-mitochondrial fractions was an order of magnitude higher than that in the mitochondrial fraction. The ratio of long to short OPA1 isoforms was lower in post-mitochondrial than in mitochondrial fractions. Knockdown of OPA1 failed to reduce db-cAMP-induced phosphorylation of hormone-sensitive lipase (HSL), Ca(2+) signaling and aldosterone secretion. In conclusion, OPA1 could be detected in the post-mitochondrial fractions, nevertheless, OPA1 did not interfere with the cAMP - PKA - HSL mediated activation of aldosterone secretion. During cancer cell invasion, faster moving cancer cells play a dominant role by invading further and metastasizing earlier. Despite the importance of these outlier cells, the source of heterogeneity in their migratory behavior remains poorly understood. Here, we show that anterior localization of mitochondria, in between the nucleus and the leading edge of migrating epithelial cancer cells, correlates with faster migration velocities and increased directional persistence. The asymmetry of mitochondrial localization along the axis of migration is absent during spontaneous cell migration on two-dimensional surfaces and only occurs in the presence of chemical attractant cues or in conditions of mechanical confinement. Moreover, perturbing the asymmetric distribution of mitochondria within migrating cells by interfering with mitochondrial fusion (opa-1) or fission (drp-1) proteins, significantly reduces the number of cells with anterior localization of mitochondria and significantly decreases the velocity and directional persistence of the fastest moving cells. We also observed similar changes after perturbing the linkage between mitochondria and microtubules by the knockdown of mitochondrial rhoGTPase-1 (miro-1). Taken together, the changes in migration velocity and directional persistence in cells with anterior-localized mitochondria could account for an order of magnitude differences in invasive abilities between cells from otherwise homogenous cell populations. The dynamin-related GTPase protein OPA1, localized in the intermembrane space and tethered to the inner membrane of mitochondria, participates in the fusion of these organelles. Its mutation is the most prevalent cause of Autosomal Dominant Optic Atrophy. OPA1 controls the diameter of the junctions between the boundary part of the inner membrane and the membrane of cristae and reduces the diffusibility of cytochrome c through these junctions. We postulated that if significant Ca²⁺ uptake into the matrix occurs from the lumen of the cristae, reduced expression of OPA1 would increase the access of Ca²⁺ to the transporters in the crista membrane and thus would enhance Ca²⁺ uptake. In intact H295R adrenocortical and HeLa cells cytosolic Ca²⁺ signals evoked with K⁺ and histamine, respectively, were transferred into the mitochondria. The rate and amplitude of mitochondrial [Ca²⁺] rise (followed with confocal laser scanning microscopy and FRET measurements with fluorescent wide-field microscopy) were increased after knockdown of OPA1, as compared with cells transfected with control RNA or mitofusin1 siRNA. Ca²⁺ uptake was enhanced despite reduced mitochondrial membrane potential. In permeabilized cells the rate of Ca²⁺ uptake by depolarized mitochondria was also increased in OPA1-silenced cells. The participation of Na⁺/Ca²⁺ and Ca²⁺/H⁺ antiporters in this transport process is indicated by pharmacological data. Altogether, our observations reveal the significance of OPA1 in the control of mitochondrial Ca²⁺ metabolism. Mgm1 is a member of the dynamin family of GTP-binding proteins. Mgm1 was first identified in yeast, where it affects mitochondrial morphology. The human homologue of Mgm1 is called OPA1. Mutations in the OPA1 gene are the prevailing cause of dominant optic atrophy, a hereditary disease in which progressive degeneration of the optic nerve can lead to blindness. Here we investigate the properties of the Mgm1/OPA1 protein in mammalian cells. We find that Mgm1/OPA1 is localized to the mitochondrial intermembrane space, where it is tightly bound to the outer surface of the inner membrane. Overexpression of wild type or mutant forms of the Mgm1/OPA1 protein cause mitochondria to fragment and, in some cases, cluster near the nucleus, whereas the loss of protein caused by small interfering RNA (siRNA) leads to dispersal of mitochondrial fragments throughout the cytosol. The cristae of these fragmented mitochondria are disorganized. At early time points after transfection with Mgm1/OPA1 siRNA, the mitochondria are not yet fragmented. Instead, the mitochondria swell and stretch, after which they form localized constrictions similar to the mitochondrial abnormalities observed during the early stages of apoptosis. These abnormalities might be the earliest effects of losing Mgm1/OPA1 protein. Peripheral nerves have peculiar energetic requirements because of considerable length of axons and therefore correct mitochondria functioning and distribution along nerves is fundamental. Mitochondrial dynamics refers to the continuous change in size, shape, and position of mitochondria within cells. Abnormalities of mitochondrial dynamics produced by mutations in proteins involved in mitochondrial fusion (mitofusin-2, MFN2), fission (ganglioside-induced differentiation-associated protein-1, GDAP1), and mitochondrial axonal transport usually present with a Charcot-Marie-Tooth disease (CMT) phenotype. MFN2 mutations cause CMT type 2A by altering mitochondrial fusion and trafficking along the axonal microtubule system. CMT2A is an axonal autosomal dominant CMT type which in most cases is characterized by early onset and rather severe course. GDAP1 mutations also alter fission, fusion and transport of mitochondria and are associated either with recessive demyelinating (CMT4A) and axonal CMT (AR-CMT2K) and, less commonly, with dominant, milder, axonal CMT (CMT2K). OPA1 (Optic Atrophy-1) is involved in fusion of mitochondrial inner membrane, and its heterozygous mutations lead to early-onset and progressive dominant optic atrophy which may be complicated by other neurological symptoms including peripheral neuropathy. Mutations in several proteins fundamental for the axonal transport or forming the axonal cytoskeleton result in peripheral neuropathy, i.e., CMT, distal hereditary motor neuropathy (dHMN) or hereditary sensory and autonomic neuropathy (HSAN), as well as in hereditary spastic paraplegia. Indeed, mitochondrial transport involves directly or indirectly components of the kinesin superfamily (KIF5A, KIF1A, KIF1B), responsible of anterograde transport, and of the dynein complex and related proteins (DYNC1H1, dynactin, dynamin-2), implicated in retrograde flow. Microtubules, neurofilaments, and chaperones such as heat shock proteins (HSPs) also have a fundamental role in mitochondrial transport and mutations in some of related encoding genes cause peripheral neuropathy (TUBB3, NEFL, HSPB1, HSPB8, HSPB3, DNAJB2). In this review, we address the abnormalities in mitochondrial dynamics and their role in determining CMT disease and related neuropathies. Prohibitins comprise an evolutionarily conserved and ubiquitously expressed family of membrane proteins with poorly described functions. Large assemblies of PHB1 and PHB2 subunits are localized in the inner membrane of mitochondria, but various roles in other cellular compartments have also been proposed for both proteins. Here, we used conditional gene targeting of murine Phb2 to define cellular activities of prohibitins. Our experiments restrict the function of prohibitins to mitochondria and identify the processing of the dynamin-like GTPase OPA1, an essential component of the mitochondrial fusion machinery, as the central cellular process controlled by prohibitins. Deletion of Phb2 leads to the selective loss of long isoforms of OPA1. This results in an aberrant cristae morphogenesis and an impaired cellular proliferation and resistance toward apoptosis. Expression of a long OPA1 isoform in PHB2-deficient cells suppresses these defects, identifying impaired OPA1 processing as the primary cellular defect in the absence of prohibitins. Our results therefore assign an essential function for the formation of mitochondrial cristae to prohibitins and suggest a coupling of cell proliferation to mitochondrial morphogenesis. The dynamin-related protein Opa1 is localized to the mitochondrial intermembrane space, where it facilitates fusion between mitochondria. Apoptosis causes Opa1 release into the cytosol and causes mitochondria to fragment. Loss of mitochondrial membrane potential also causes mitochondrial fragmentation but not Opa1 release into the cytosol. Both conditions induce the proteolytic cleavage of Opa1, suggesting that mitochondrial fragmentation is triggered by Opa1 inactivation. The opposite effect was observed with knockdown of the mitochondrial intermembrane space protease Yme1. Knockdown of Yme1 prevents the constitutive cleavage of a subset of Opa1 splice variants but does not affect carbonyl cyanide m-chlorophenyl hydrazone or apoptosis-induced cleavage. Knockdown of Yme1 also increases mitochondrial connectivity, but this effect is independent of Opa1 because it also occurs in Opa1 knockdown cells. We conclude that Yme1 constitutively regulates a subset of Opa1 isoforms and an unknown mitochondrial morphology protein, whereas the loss of membrane potential induces the further proteolysis of Opa1. Optic atrophy type 1 (OPA1, MIM 165500) is a dominantly inherited optic neuropathy occurring in 1 in 50,000 individuals that features progressive loss in visual acuity leading, in many cases, to legal blindness. Phenotypic variations and loss of retinal ganglion cells, as found in Leber hereditary optic neuropathy (LHON), have suggested possible mitochondrial impairment. The OPA1 gene has been localized to 3q28-q29 (refs 13-19). We describe here a nuclear gene, OPA1, that maps within the candidate region and encodes a dynamin-related protein localized to mitochondria. We found four different OPA1 mutations, including frameshift and missense mutations, to segregate with the disease, demonstrating a role for mitochondria in retinal ganglion cell pathophysiology. Opa1, also known as Mgm1 in yeast, is a mitochondrial member of the dynamin family. Unlike other dynamin family members, Opa1 has an N-terminal mitochondrial targeting sequence, suggesting that this protein is imported into mitochondria. Here, we describe biochemical techniques, such as mitochondrial isolation, digitonin extraction, a protease protection assay, and carbonate extraction, that were used to determine that mammalian Opa1 resides in the intermembrane space where it is tightly bound to the inner membrane. In addition, we describe bacterial expression of the Opa1 GTPase domain, methods for purification, and an in vitro assay for GTP hydrolysis. Mitochondria in mammalian cells are visualized as a network or as filaments that undergo continuous changes in shape and in localization within the cells. These changes are a consequence of the activity of different processes such as mitochondrial fusion and fission, and mitochondrial remodelling. In all, these processes are referred to as mitochondrial dynamics, and relevant questions, still unexplained, are why cells require such an active dynamics, or why mitochondria move to specific cellular regions. In this review we will summarize some of the biological functions assigned to the proteins identified as participating in mitochondrial fusion, namely mitofusin 1, mitofusin 2 and OPA1. In addition to the capacity of these proteins to promote fusion, mitofusin 2 or OPA1 regulate mitochondrial metabolism and loss-of-function reduces oxygen consumption and the capacity to oxidize substrates. We propose that mitochondrial fusion proteins operate as integrators of signals so they regulate both mitochondrial fusion and metabolism. Carboxyl-terminal modulator protein (CTMP) is a tumor suppressor-like binding partner of Protein kinase B (PKB/Akt) that negative regulates this kinase. In the course of our recent work, we identified that CTMP is consistently associated with leucine zipper/EF-hand-containing transmembrane-1 (LETM1). Here, we report that adenovirus-LETM1 increased the sensitivity of HeLa cells to apoptosis, induced by either staurosporine or actinomycin D. As shown previously, LETM1 localized to the inner mitochondrial membrane. Electron-microscopy analysis of adenovirus-LETM1 transduced cells revealed that mitochondrial cristae were swollen in these cells, a phenotype similar to that observed in optic atrophy type-1 (OPA1)-ablated cells. OPA1 cleavage was increased in LETM1-overexpressing cells, and this phenotype was reversed by overexpression of OPA1 variant-7, a cleavage resistant form of OPA1. Taken together, these data suggest that LETM1 is a novel binding partner for CTMP that may play an important role in mitochondrial fragmentation via OPA1-cleavage.

Which are the drugs utilized for the burning mouth syndrome?

Dopaminergic drugs should be given in patients with BMS. Catuama reduces the symptoms of BMS and may be a novel therapeutic strategy for the treatment of this disease. Capsaicin, alpha-lipoic acid (ALA), and clonazepam were those that showed more reduction in symptoms of BMS. Treatment with placebos produced a response that was 72% as large as the response to active drugs

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OBJECTIVE: To study the cost-effectiveness of four alternative treatments for burning mouth syndrome (BMS). METHODS: A cost-effectiveness analysis was conducted from a healthcare payer perspective of four therapy strategies (amisulpride, paroxetine, sertraline and topical clonazepam), using a decision-tree model that incorporated direct healthcare costs and probabilities associated with the possible events and outcomes. Average cost-effectiveness and incremental cost-effectiveness ratios were calculated. Sensitivity analyses included the costs of brand name and generic drugs in five European countries (France, Italy, the Netherlands, Spain and UK), as well as two scenarios with different treatment length. RESULTS: Of the drugs analysed, topical clonazepam proved to be the most cost-effective therapy. Although generic proved more efficient than brand name drugs, they displayed no advantage over brand name topical clonazepam. The Netherlands was the country with the highest overall drug efficiency. Sensitivity analyses highlighted the robustness of the model, because topical clonazepam proved to be the most efficient therapy under all the different scenarios. CONCLUSIONS: Topical clonazepam, which previous analyses of clinical evidence have shown to be the drug of choice for BMS, also proved to be the most cost-effective of the drugs analysed for this condition. Complaint of a burning mouth is an increasingly common problem in the aging population. This has remained an enigma for the treating clinician, because visible pathologic lesions or processes are usually not evident. Local, systemic and environmental causes must be assessed to elicit the predisposing factors. Some suggestions for managing burning mouth syndrome are offered. BMS is a common condition characterized by chronic oral mucosal pain condition and primarily affects elderly women. Although clonazepam therapy has been widely used due to its efficacy, it is not always effective because of the complexity of BMS pathogenesis. In this study, we have investigated outcome predictors of clonazepam therapy in patients with BMS. One hundred patients with BMS (7 men and 93 women, mean age 58.5 ± 10.8 years) were instructed to take 0.5mg of clonazepam once or twice daily for 4 weeks. The patients were sub-grouped according to psychological status, salivary flow rate, presence of psychiatric medications, symptom area and duration, symptom severity, presence of oral parafunctions, and accompanying oral complaints. The changes in symptoms were analyzed and compared between the sub-groups. Subjects with T-scores ≤50 for each psychological symptom dimension, a greater degree of initial symptoms (visual analog scale (VAS)≥5), and accompanying oral complaints, such as xerostomia and taste disturbance, displayed greater decreases in symptoms compared with their counterparts. In conclusion, psychological status, initial symptom severity, and the presence of xerostomia and/or taste disturbance can serve as outcome predictors of clonazepam therapy for patients with BMS. The aim of the study was to determine, in a group of patients with therapy-resistant burning mouth syndrome (BMS), the possible deficiency of vitamins B1, B2, and B6 and the effect of proper vitamin replacement therapy. Sixteen individuals, aged 47 to 81 years, participated in the study. All underwent a base-line examination comprising anamnestic information, subjective assessment of symptoms, dietary registration, salivary analysis, and serum analysis of thiamine (B1), riboflavine (B2), and pyridoxine (B6). Fifteen individuals had low thiamine and/or riboflavine levels in accordance with suggested levels in the literature and were given replacement therapy. No effect on BMS of vitamin replacement therapy or placebo therapy could be demonstrated. INTRODUCTION: Glossodynia or burning mouth syndrome (BMS) is a common and poorly understood disorder. Its treatment is uncertain. Otherwise, there is some evidence of the importance of psychological factors in the genesis of this disease. OBJECTIVES: Verify the usefulness of group psychotherapy as an adjuvant therapeutic method in the treatment of BMS. CASUISTICS AND METHODS: The study group consisted of 64 consecutive patients with a clinical diagnosis of BMS seen at the Stomatology Outpatient Clinic, ENT Department, Sao Paulo University Medical School, between May 2002 and May 2007. All the patients were submitted to physical examination, laboratorial screening tests, psychological assessment (Crown-Crisp Experimental Inventory), and answered a short form of the McGill Pain Questionnaire. Only 44 patients who did not show any abnormality in the protocol exams entered the study. Twenty-four of them underwent group psychotherapy. Twenty patients received placebo. Chi-square test was applied to compare the results of treatment with or without psychotherapy. RESULTS: There were 15 men and 29 women in the study group. Tongue burning was the main complaint of the patients. Improvement of symptoms was reported by 17 (70.8%) of the patients undergoing psychotherapy, while among those who did not eight (40%) had improvement of symptoms (P=.04). CONCLUSION: Psychological assessment demonstrated a close correlation between symptoms and psychological factors, suggesting that group psychotherapy is an important alternative to conventional treatment methods. INTRODUCTION: Although a significant amount of evidence indicates the efficacy of some antidepressants in treating psychogenic pain and somatoform disorder, very few studies have investigated their possible therapeutic action in burning mouth syndrome (BMS). The purpose of this 8-week, single-blind study was to provide preliminary data on the efficacy and tolerability of amisulpride and the selective serotonin reuptake inhibitors (SSRIs) paroxetine and sertraline for patients with BMS. METHOD: Seventy-six patients with BMS (diagnosed according to the criteria in the literature and integrating the Diagnostic Interview Schedule-Revised for a complete psychiatric assessment), with no possible local or systemic causes and without concurrent major depression, were randomly assigned to receive amisulpride (50 mg/day), paroxetine (20 mg/day), or sertraline (50 mg/day). Efficacy assessments included a visual analogue scale (VAS) for pain intensity, the Hamilton Rating Scale for Depression (HAM-D), the Hamilton Rating Scale for Anxiety (HAM-A), and the Clinical Global Impressions scale (CGI). RESULTS: All 3 treatment regimens resulted in a significant improvement from baseline in burning mouth symptoms at week 8 as demonstrated by the quantitative (mean reduction in VAS, HAM-D, and HAM-A scores) and qualitative (percentage of responders) analyses. Amisulpride showed a shorter response latency than the SSRIs. No serious adverse events were reported, and the incidence of side effects did not differ among the 3 groups. None of the patients who received amisulpride withdrew from the trial, whereas withdrawal from the trial occurred within the first week of treatment in 11.5% of patients (N = 3) treated with paroxetine and in 21.7% of patients (N = 5) treated with sertraline. CONCLUSION: The data suggest that amisulpride and SSRIs may be effective treatments for BMS; they are equally effective and equally well tolerated in the short-term treatment of BMS. Amisulpride is associated with better compliance within the first week of treatment and with a shorter response latency in comparison with SSRIs. This finding may indicate that amisulpride is especially useful at the beginning of drug therapy of BMS. Double-blind, placebo-controlled trials are needed to further document the efficacy of amisulpride and SSRIs in the treatment of BMS. The burning mouth syndrome is a pathology characterized by burning oral mucoses. The etiological factors can be numerous. The Authors suggest a nosologic classification of this disease. OBJECTIVES/HYPOTHESIS: In the treatment of burning mouth syndrome (BMS), various approaches have been tried with equivocal results. The aim of the present randomized clinical trial was to determine the efficacy of clonazepam, a GABA agonist designed as an antiepileptic drug that exerts the typical effects of benzodiazepines. STUDY DESIGN: Randomized clinical trial. METHODS: Twenty patients with idiopathic BMS were carefully selected. Clonazepam (0.5 mg/day, n = 10) or placebo (lactose, n = 10) were randomly assigned to the patients. RESULTS: Patients on clonazepam significantly improved in pain ratings (P < .001). These changes were less pronounced in the placebo group (P < .11). No significant changes were observed in a mood scale (P = .56) or for depression scores (P = .56). Taste test and salivary flow increased over sessions, but were not different between groups (P = .83 and P = .06, respectively). CONCLUSIONS: Clonazepam appears to have a positive effect on pain in BMS patients. Burning mouth syndrome (BMS) is defined as a chronic pain condition, characterized symptomatically by a generalized or localized burning sensation in the oral cavity. Various drugs have been used in attempting to treat BMS, but there is insufficient evidence to show the effect of any effective treatment. The aim of this review was to assess the effectiveness of therapies for BMS. Randomized controlled trials (RCTs) enrolling patients with a diagnosis of BMS were identified by searching Pubmed and Scoppus databases. The methodological quality of included studies was assessed on the basis of the method of allocation concealment, blindness of the study, loss of participants, size sample, and outcome concealment. A total of 12 relevant articles were analyzed. Therapies that used capsaicin, alpha-lipoic acid (ALA), and clonazepam were those that showed more reduction in symptoms of BMS. However, many studies of therapeutic interventions in BMS lack consistency in their results, because they use in their methodology, sample and a relatively short time of therapy and often do not provide a follow-up of patients treated. Thus, future studies are required to establish the treatment for patients suffering from this chronic and painful syndrome. Placebo controls play a critical role in the evaluation of any pharmacotherapy. This review surveys the placebo arm in 12 randomized controlled trials (RCTs) investigating burning mouth syndrome (BMS) and documents a positive placebo response in 6 of them. On average, treatment with placebos produced a response that was 72% as large as the response to active drugs. The lack of homogeneity in the use of placebos adds to the difficulty in comparing results and aggregating data. Future RCTs investigating BMS would benefit from larger sample sizes, adequate follow-up periods, and use of a standard placebo. Burning mouth syndrome (BMS) is characterized by the presence of burning sensation of the oral mucosa in the absence of clinically apparent mucosal alterations. It occurs more commonly in middle-aged and elderly women and often affects the tongue tip and lateral borders, lips, and hard and soft palate. In addition to a burning sensation, the patients with BMS may also complain unremitting oral mucosal pain, dysgeusia, and xerostomia. BMS can be classified into two clinical forms: primary and secondary BMS. The primary BMS is essential or idiopathic, in which the organic local/systemic causes cannot be identified and a neuropathological cause is likely. The diagnosis of primary BMS depends mainly on exclusion of etiological factors. The secondary BMS is caused by local, systemic, and/or psychological factors; thus, its diagnosis depends on identification of the exact causative factor. When local, systemic or psychological factors are present, treatment or elimination of these factors usually results in a significant clinical improvement of BMS symptoms. Vitamin, zinc, or hormone replacement therapy has been found to be effective for reducing the oral burning or pain symptom in some BMS patients with deficiency of the corresponding factor. If patients still have the symptoms after the removal of potential causes, drug therapy should be instituted. Previous randomized controlled clinical trials found that drug therapy with capsaicin, alpha-lipoic acid, clonazepam, and antidepressants may provide relief of oral burning or pain symptom. In addition, psychotherapy and behavioral feedback may also help eliminate the BMS symptoms. Burning mouth syndrome is characterized by a burning sensation in one or several oral structures. Multiple causal factors have been proposed, and reports on their relative importance are conflicting. Lack of diagnostic criteria, differences in sampling procedures, incomplete workups, and lack of controlled studies make the reliable interpretation of the importance of proposed causal factors and the efficacy of specific treatment modalities difficult. This article summarizes the available data, critically analyzes their scientific merit, and proposes a protocol for clinical management. OBJECTIVES: The aim of this study was to evaluate the efficacy of aloe vera (AV) applied in combination with a tongue protector, comparing this with a placebo. METHODS: A total of 75 patients with burning mouth syndrome (BMS) were divided into three groups randomly: Group I (tongue protector three times a day), Group II (tongue protector and 0.5 ml AV at 70% three times a day) and Group III (tongue protector and 0.5 ml placebo three times a day). Symptoms were evaluated by visual analogue scale (VAS), while patient psychological profiles were assessed using the Hospital Anxiety-Depression scale and their quality of life using the Oral Health Impact Profile 49 (OHIP-49). Treatment continued for 3 months. RESULTS: Visual analogue scale pain values improved for all three study groups but without statistically significant differences between the groups (P = 0.210). Regarding quality of life, no significant differences were found between groups with the exception of the OHIP-49 score for handicap. The overall clinical improvement was greater for Group II, with a difference almost reaching significance. CONCLUSIONS: The concomitant prescription of tongue protector and AV is effective for treating patients with BMS. Burning mouth syndrome (BMS) has been associated with a wide variety of etiological factors. A selective review of these factors as well as an approach to the management of this condition are presented. Though it has been the subject of much research, burning mouth syndrome--a chronic oral-facial pain condition that affects many U.S. adults--remains poorly understood. It has been associated with numerous oral and systemic conditions. Treatment options frequently include various medications. While patients with symptoms of BMS are more likely to seek care from physicians, dentists should be involved in the evaluation and management of these patients. Symptoms of a burning sensation of the oral mucosa mainly occur in the elderly, more often in women than in men. Often accompanying symptoms are complaints of a dry mouth and taste disturbances, all together referred to as the burning mouth syndrome. In the majority of cases there is no detectable cause. Although a psychogenic aetiology has often been put forward, no scientific evidence has ever been provided on this matter. In the majority of patients the burning mouth syndrome will disappear spontaneously, although this may take many years. Burning mouth syndrome is a complicated, poorly understood, predominantly oral condition that affects more than 1 million people in the United States. Women are particularly affected by the condition; they are diagnosed with symptoms seven times more frequently than males. Burning mouth syndrome is characterized by a burning, painful sensation of the oral mucosa that most commonly involves the anterior tongue. Many precipitating factors to burning mouth syndrome have been proposed, and treatment addressing these factors has had limited success. Patients with burning mouth syndrome are more likely to be evaluated by physicians, and therefore it is advantageous for the physician to be familiar with this oral condition. This paper reviews burning mouth syndrome, associated causative factors, and treatment strategies for the physician. OBJECTIVE: The purpose of this study was to evaluate the efficacy of the topical use of benzydamine hydrochloride 0.15% oral mouthwashes in the control of burning mouth syndrome symptoms. STUDY DESIGN: In this double-blind, randomized, longitudinal investigation, each of 30 patients with burning mouth syndrome was assigned to one of 3 management modalities. Those in group A received an oral rinse solution of benzydamine hydrochloride 0.15% 3 times a day for 4 weeks, those in group B received a placebo 3 times a day for 4 weeks, and those in group C did not receive any kind of treatment. A visual analog scale was used for evaluation of the symptoms; a Kruskal-Wallis analysis of variance exact test was performed on the resulting data. RESULTS: The findings of this investigation failed to reveal significant differences among the groups. CONCLUSIONS: The clinical application of benzydamine hydrochloride oral rinses in the treatment of patients with burning mouth syndrome did not demonstrate significative efficacy in comparison with use of a placebo solution. Burning Mouth Syndrome (BMS) is a difficult disease for patients and clinicians. Moreover, there is not a general consensus on how to treat the disease. The main objective of this paper is to evaluate BMS patients' response to topical clonazepam treatment. A double blind study was performed. Among a total of 66 patients, 33 were treated with tablets of clonazepam and another 33 were treated with a placebo. Symptoms were evaluated after 1 month and 6 months of treatment and scored on an analogical scale from 0 to 10. Among the 33 patients treated with clonazepam, 23 showed at least a 50% reduction in symptoms after 1 month of treatment. On the contrary, only 4 in the placebo group exhibited significant improvement. After 6 months, significant differences were observed again, as 23 of the 33 patients treated with the drug reported at least a 50% reduction in symptoms, whereas only 2 among those treated with the placebo significantly improved. However, when measured in terms of a complete cure (lack of symptoms), the differences were not significant: 5 drug-treated patients and one belonging to the placebo group were asymptomatic after one month of treatment. In summary, it seems that clonazepam applied topically was effective in treating BMS in a large proportion of patients. AIMS: To evaluate retrospectively the efficacy of administering an anticonvulsant medication, clonazepam, by dissolving tablets slowly orally before swallowing, for the management of burning mouth syndrome (BMS). METHODS: A retrospective clinical records audit was performed of patients diagnosed with BMS between January 2006 and June 2009. Patients were prescribed 0.5 mg clonazepam three times daily, and changes were made to this regimen based on their individual response. Patients were asked to dissolve the tablet orally before swallowing and were reviewed over a 6-month period. Pain was assessed by patients on an 11-point numerical scale (0 to 10). A nonparametric (Spearman) two-tailed correlation matrix and a two-tailed Mann-Whitney test were performed. RESULTS: A total of 36 patients (27 women, 9 men) met the criteria for inclusion. The mean (± SEM) pain score reduction between pretreatment and final appointment was 4.7 ± 0.4 points. A large percentage (80%) of patients obtained more than a 50% reduction in pain over the treatment period. One patient reported no reduction in pain symptoms, and one third of the patients had complete pain resolution. Approximately one third of patients experienced side effects that were transient and mild. CONCLUSION: This pilot study provides preliminary evidence that the novel protocol of combined topical and systemic clonazepam administration provides an effective BMS management tool. Burning mouth syndrome is characterized by a burning sensation in the tongue or other oral sites, usually in the absence of clinical and laboratory findings. Affected patients often present with multiple oral complaints, including burning, dryness and taste alterations. Burning mouth complaints are reported more often in women, especially after menopause. Typically, patients awaken without pain but note increasing symptoms through the day and into the evening. Conditions that have been reported in association with burning mouth syndrome include chronic anxiety or depression, various nutritional deficiencies, type 2 diabetes (formerly known as non-insulin-dependent diabetes) and changes in salivary function. However, these conditions have not been consistently linked with the syndrome, and their treatment has had little impact on burning mouth symptoms. Recent studies have pointed to dysfunction of several cranial nerves associated with taste sensation as a possible cause of burning mouth syndrome. Given in low dosages, benzodiazepines, tricyclic antidepressants or anticonvulsants may be effective in patients with burning mouth syndrome. Topical capsaicin has been used in some patients. Burning mouth syndrome (BMS) is a chronic condition characterized by burning of the oral mucosa, with or without dysgeusia and xerostomia, in the setting of no underlying systemic disease or identifiable abnormalities on physical examination or laboratory testing. BMS disproportionately affects postmenopausal women. The pathophysiology of the disease is unknown; no single treatment has proven universally successful. In light of these shortcomings, having a practical approach to the evaluation and management of patients with BMS can improve both patient quality of life and physician satisfaction. OBJECTIVE: the aim of this study is to investigate the clinical evolution, the spontaneous remission of the symptomatology and the response to different treatments in a group of burning mouth syndrome patients. STUDY DESIGN: the sample was formed by a group of patients that were visited in the Unit of Oral Medicine of the Dentistry Clinic of the University of Barcelona, from the year 2000 to 2011. After revising the clinical records of all the patients that had been under control for a period of time of 18 months or longer, they were contacted by telephone. In the telephone interview, they were questioned about the symptomatology evolution and the response to the treatments received, noting down the data in a questionnaire previously performed. RESULTS: the average duration of the symptoms was 6.5 years (+/-2.5 years). The most frequent treatments were: chlorhexidine mouthrinses, oral benzodiazepines, topical clonazepam, antiinflamatory drugs, antidepressants, antifungicals, vitamins, psycotherapy, salivary substitutes and topical corticoids. The specialists that were consulted with a higher frequency were: dermatologists (30%), othorrynolaringologists (10%) and psychiatrists (3%). In 41 patients the oral symptoms did not improve, 35 reported partial improvements, 12 patients worsened, and only in 3 patients the symptoms remitted. CONCLUSIONS: In three of the 91 patients studied the symptoms remitted spontaneously within the five years of treatment. Only 42% of the study population had improved the symptomatology significantly, and this improvement would reach 60% if clonazepam were associated to psychotherapy. Burning mouth syndrome is a debilitating disorder involving oral pain that may have at least 4 underlying causes. Although several treatments have been proposed, none seems to be universally effective. We report the case of a 67-year-old woman with unremitting oral burning that is increased with the application of anesthetic agents. Initial treatments with nortriptyline hydrochloride and sertraline hydrochloride were contraindicated because of adverse effects, but the administration of gabapentin significantly reduced oral burning. The present case illustrates the effectiveness of gabapentin as a treatment of burning mouth syndrome. Clinical characteristics and treatment responses were studied in 130 patients with burning mouth syndrome (BMS). Most patients were postmenopausal women, and the tongue was the most frequently afflicted site. Although 39% of the patients complained of dry mouth, no causative factors were evident. Therefore BMS is assumed to be a functional disorder. This was at least partially confirmed because the most effective management was in response to mood-altering drugs. From our data BMS appears to be a chronic condition with variations in symptoms among patients and without a predictable endpoint. OBJECTIVE: To observe the clinical efficacy of livial on postmenopause women with burning mouth syndrome. METHODS: Fifty six postmenopause women with burning mouth syndrome were randomly divided into two groups, 26 patients were treated with livial as the treatment group, 30 patients were treated with oryzanol and vitamin E as the control. To evaluate the effect, all the patients were observed in 3-6 months after therapy. RESULTS: The result showed that the total effective rate of the treatment group was 84.62% after 3 months, 88.46% after 6 months, and significantly higher than that in the control(P < 0.005). CONCLUSION: It is indicated that livial is safer and more effective than nylestriol in treatment with burning mouth syndrome. Burning mouth syndrome (BMS) is a chronic disease characterized by burning of the oral mucosa associated with a sensation of dry mouth and/or taste alterations. BMS occurs more frequently among postmenopausal women. The pathophysiology of the disease is still unknown, and evidence is conflicting; although some studies suggest a central origin, others point to a peripheral neuropathic origin. The efficacy of some medications in the treatment of BMS suggests that the dopaminergic system may be involved. OBJECTIVE: To report the first published case of clonazepam-induced burning mouth syndrome (BMS). CASE SUMMARY: A 52-year-old white woman presented to the clinic with burning mouth symptoms. The patient was previously maintained on alprazolam therapy for anxiety, but was switched to clonazepam because of increased anxiety and panic. Clonazepam significantly relieved her symptoms, but after four weeks of therapy, she reported a constant, mild, oral burning sensation. An oral examination was negative for mucosal abnormalities, and laboratory tests were unremarkable. The clonazepam dose was reduced, and the symptoms decreased, but remained intolerable. Clonazepam was discontinued, and the burning mouth symptoms completely resolved. Since no other medications relieved the anxiety and panic symptoms, the patient requested clonazepam to be reinitiated, but she again developed intolerable burning mouth symptoms. As clonazepam was discontinued, the symptoms resolved. DISCUSSION: The clinical presentation of BMS includes burning and painful sensations of the mouth in the absence of mucosal abnormalities. Candidiasis, anemia, menopause, diabetes mellitus, medications, anxiety, and depression are some causes of this syndrome. Paradoxically, clonazepam has been studied for the treatment of BMS and has demonstrated mild to moderate improvement. In this patient, underlying causes of BMS were eliminated when possible. The association between clonazepam and BMS was highly probable according to the Naranjo probability scale. CONCLUSIONS: This is the first published report describing BMS with a benzodiazepine. Although uncommon, clinicians should be aware of this potential adverse effect due to the widespread use of benzodiazepines. INTRODUCTION: Burning mouth syndrome mainly affects women, particularly after the menopause, when its prevalence may be 18-33%. METHODS AND OUTCOMES: We conducted a systematic review and aimed to answer the following clinical question: What are the effects of treatments for burning mouth syndrome? We searched: Medline, Embase, The Cochrane Library, and other important databases up to February 2007 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). RESULTS: We found 12 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. CONCLUSIONS: In this systematic review we present information relating to the effectiveness and safety of the following interventions: anaesthetics (local), antidepressants, benzodiazepines (topical clonazepam), benzydamine hydrochloride, cognitive behavioural therapy (CBT), dietary supplements, and hormone replacement therapy (HRT) in postmenopausal women. Burning mouth syndrome is a common condition particularly affecting elderly women. Numerous precipitating factors are recognized that lead to a burning sensation in clinically normal mucosa. By taking each precipitating factor into account, a favorable treatment outcome usually can be achieved. This article highlights the significance of precipitating factors in burning mouth syndrome and suggests a treatment protocol based on current scientific evidence. The burning mouth syndrome is characterized by burning and painful sensations of the mouth in the absence of significant mucosal abnormalities. For patients in whom no causative factor can be identified, empiric antifungal, nutritional, and estrogen replacement therapy can be initiated. If these fail, long-term therapy with antidepressants, benzodiazepines, and clonazepam can be considered. Topical capsaicin and laser therapy have been reported beneficial in a few patients. Burning mouth syndrome (BMS) has been considered an enigmatic condition because the intensity of pain rarely corresponds to the clinical signs of the disease. Various local, systemic and psychological factors are associated with BMS, but its etiology is not fully understood. Also there is no consensus on the diagnosis and classification of BMS. A substantial volume of research has been focused on BMS during the last two decades. Progress has been made but the condition remains a fascinating, yet poorly understood area, in the field of oral medicine. Recently, there has been a resurgence of interest in this disorder with the discovery that the pain of BMS may be neuropathic in origin and originate both centrally and peripherally. The aim of this paper is to explore the condition of BMS with the specific outcome of increasing awareness of the condition. Key words:Burning mouth syndrome, stomatodynia, oral dysesthesia, pain management. Pain in the tongue or oral tissues described as "burning" has been referred to by many terms including burning mouth syndrome. When a burning sensation in the mouth is caused by local or systemic factors, it is called secondary burning mouth syndrome and when these factors are treated the pain will resolve. When burning mouth syndrome occurs in the absence of identified risk indicators, the term primary burning mouth syndrome is utilized. This article focuses on descriptions, etiologic theories, and management of primary burning mouth syndrome, a condition for which underlying causative agents have been ruled out. OBJECTIVE: To provide a review on the aetiology and therapeutic options for the management of patients with burning mouth syndrome (BMS). BACKGROUND: BMS is a chronic disorder that frequently affects women and is characterised by burning symptoms of the oral mucosa without clinical signs. This syndrome has a complex and multifactorial characteristics, but its aetiology remains unknown and this makes it difficult with regard to the treatment and management of such patients. Despite not being accompanied by evident organic changes and not presenting risks to health, BMS can significantly reduce the quality of life for patients. METHODS AND MATERIALS: The article reviews the literature regarding aetiologic factors, clinical implications and treatment of BMS. CONCLUSION: involvement of neurological, emotional and hormonal alterations is proposed in BMS aetiology. However the mechanisms of its development are complex and not completely understood. Tricyclic antidepressants, benzodiazepines and antipsychotic drugs are the most accepted options in treatment and show variable results. The correct diagnosis of BMS and the exclusion of possible local or systemic factors that can be associated with the symptoms are fundamental. It is also important to evaluate the quality of life for these patients to recognise the potential impact of this condition on their lives. BACKGROUND: Burning mouth syndrome (BMS) has features of a neuropathy and could be related to the production of the toxic free radicals that are released in stress situations. Alpha-lipoic acid is an antioxidant able to increase the levels of intracellular glutathione and eliminate free radicals. This study aimed to examine the effectiveness of alpha-lipoic acid in the therapy of BMS. METHOD: This was a double blind, controlled study conducted for two months on 60 patients with constant BMS. Comparing alpha-lipoic acid (test) with cellulose starch (placebo), there was no laboratory evidence of deficiencies in iron, vitamins or thyroid function and no hyperglycaemia. RESULTS AND CONCLUSION: Following treatment with alpha-lipoic acid, there was a significant symptomatic improvement, compared with placebo, with the majority showing at least some improvement after 2 months, thus supporting the hypothesis that burning mouth syndrome is a neuropathy. This improvement was maintained in over 70% of patients at the 1 year follow-up. Burning Mouth Syndrome (BMS) is a frequent disease characterized by a burning or painful sensation in the tongue and/or other oral sites without clinical mucosal abnormalities or lesions. The etiopathology is unknown although local, systemic and psychological factors have been connected with BMS. As this syndrome is a multifactorial disease, the diagnostic and therapeutic approach should be multidisciplinary. In this paper a review of the literature is presented and the most recent advancement on clinical, etiologic, diagnostic and therapeutic aspects of BMS are discussed. PURPOSE: To provide an overview of burning mouth syndrome (BMS), describe the role of the clinician when a patient presents with the burning mouth complaint, offer guidance in differentiating the cause of the complaint, and identify potential treatment options for the patient suffering from BMS. DATA SOURCES: A search of MD Consult, Medline, and EBSCO Host Research Databases with the terms "burning mouth" and "BMS." CONCLUSIONS: BMS is a common, chronic disorder of unknown etiology with no underlying or systemic causes or oral signs identified. It affects more than 1 million people in the United States, predominantly postmenopausal women. Despite the common nature of the disorder, it is often misunderstood. Palliative treatment, education, and support should be offered to the patient with idiopathic BMS. A variety of treatment options exist, including benzodiazepines, tricyclic antidepressants, anticonvulsants, alpha-lipoic acid, topical capsaicin, and cognitive therapy can be added to the medication regimen for greater benefit. IMPLICATIONS FOR PRACTICE: The role of the clinician is to obtain a meticulous history and physical examination of the patient, order relevant diagnostic tests, and rule out treatable conditions that may be causing the burning mouth symptom. If secondary causes of BMS are ruled out, the clinician should present treatment options to the patient and consider referral to specialists as necessary. A combination of medications may be more effective than a single medication. Burning mouth syndrome is characterized by a painful burning or stinging sensation affecting the tongue or other areas of the mouth without obvious signs of an organic cause on physical examination. A burning mouth sensation can occur in several cutaneous or systemic diseases that must be ruled out prior to making a diagnosis of burning mouth syndrome, since this term is used exclusively to refer to idiopathic forms and is included within the cutaneous sensory disorders. In most cases, patients with burning mouth syndrome have accompanying psychologic or psychiatric conditions. Consequently, the syndrome has traditionally been included among the psychogenic dermatoses. However, it is currently unclear whether psychologic factors are a cause or a consequence of the syndrome, or whether each exacerbates the other. Recent studies propose the etiology to be neurologic, either neuropathic or related to taste. OBJECTIVE AND STUDY DESIGN: This open study of 192 otherwise healthy persons with burning mouth syndrome, examined the efficacy on control of symptoms of psychotherapy alone with two hour sessions weekly for two months; alpha lipoic acid (ALA, tioctic acid; Tiobec) 600 mg/day alone for two months; or combination therapy of psychoanalysis and 600 mg/day ALA for two months. Controls received placebo alone. RESULTS: Most benefit was obtained with combination therapy. Combination therapy of psychoanalysis and alpha lipoic acid (ALA, tioctic acid; Tiobec. 600 mg/day) for two months gave most benefit and significantly more than psychoanalysis alone for two 1 hour sessions weekly for two months (p<0.0005), or ALA 600 mg/day alone for two months (p<0.0005). CONCLUSION: The present results suggest that alpha lipoic acid may complement psychotherapy and can be an acceptable alternative to psychoactive agents, but trials to compare the two approaches are now warranted. AIMS: To compare burning mouth syndrome (BMS) patients with age- and gender-matched controls for psychologic conditions, to analyze the effect of menstrual state on the intensity of burning, and to assess the efficacy of an antidepressant medication on the burning pain and psychologic status. METHODS: Ninety-four patients with BMS and 94 matched control subjects participated in the study. Anxiety and depression were analyzed by means of the Spielberger State-Trait Anxiety Inventory and Zung Self-Rating Depression Scale, and the severity of the burning sensation was measured by means of a visual analog scale (VAS). In female BMS patients and controls, the menstrual state was noted (menstruating, menopausal, or postmenopausal). BMS patients were treated with the antidepressant moclobemide (150 mg 2 times daily) for 3 months. Thereafter, anxiety, depression, and burning pain intensity were reassessed. Patient-perceived satisfactory improvement for burning sensation was assessed using a 5-point categorical rating of change scale. RESULTS: BMS patients had significantly higher anxiety and depression scores than controls (P < .05). After treatment, anxiety and depression scores as well as the VAS values for burning pain decreased significantly (P < .001). Thirty-seven patients reported good to very good improvement, and 44 reported satisfactory improvement. No adverse reactions were reported. CONCLUSIONS: The study confirmed earlier reports that BMS patients have higher anxiety and depression levels than controls. An antidepressant medication may be effective in alleviating the burning pain, at least in the short-term. Burning in the mouth in and of itself is not all that uncommon. It may result from a variety of local or generalized oral mucosal disorders, or may be secondary to referred phenomena from other locations. Primary burning mouth syndrome, on the other hand, is relatively uncommon. Burning mouth syndrome is an idiopathic pain disorder, which appears to be neuropathic in origin. Thoughts on management of secondary and particularly primary burning mouth syndrome are discussed. Burning mouth syndrome (BMS) is an oral dysesthesia presenting as a burning sensation of the tongue and other oral and perioral mucosae. A painful symptomatology in different bodily regions (extraoral) may also be a common feature in patient with BMS. The management of BMS is challenging and there is no clear guideline for the management of idiopathic BMS. Herein, we describe a group of patients (5 patients) in whom symptoms of BMS responded to levodopa. In parallel, four patients fulfilled the criteria for restless legs syndrome (RLS). Family history of RLS was positive in two patients. We reviewed the literature and noted a marked overlap between BMS and RLS. Overlaps were noted in epidemiological profiles, pattern of clinical features and even in neurophysiological observations (alterations in the striatal dopaminergic system). We suggest that a subset of patients with BMS may be a phenotypic variant of RLS and a trial of dopaminergic drugs should be given in patients with BMS who has a history suggestive of RLS or in a patient who do not show a response to usual therapies for BMS. Stomatodynia is a difficult disease for both patients and clinicians. When facing true stomatodynia, i.e., idiopathic burning mouth, patients are offered poorly effective treatment. This open study reports the results of local application of clonazepam (0.5 or 1 mg) two or three times daily in 25 subjects who suffered from idiopathic stomatodynia. At the first evaluation, 4 weeks after the beginning of treatment, a visual analogue scale (VAS) that represented the intensity of pain decreased significantly from 6.2 +/- 0.3 to 3.0 +/- 0.5. At the second evaluation, 3 to 29 months after the first consultation, the VAS scores dropped significantly further to 2.6 +/- 0.5. Analysis of the individual results showed that 10 patients were totally cured and needed no further treatment, 6 patients had no benefit at all, and the remaining 9 patients had some improvement but were not considered to be cured since they did not wish to stop the treatment. Blood level tests that were performed 1 and 3 hours after the topical application revealed the presence of small amounts of the drug (3.3 ng/mL +/- 0.66 and 3.3 ng/mL +/- 0.52, respectively). The hypothesis that clonazepam acts locally to disrupt the neuropathologic mechanism that underlies stomatodynia is proposed. The risk factors that are recognized for this condition could decrease the density and/or ligand affinity of peripheral benzodiazepine receptors. This, in turn, could cause spontaneous pain from the tissues concerned. OBJECTIVE: Current treatment for burning mouth syndrome is usually directed at correction of detected organic causes or is empiric, and it often involves the use of tricyclic antidepressants. Recently, there has been renewed interest in the use of benzodiazepines for burning mouth syndrome. The present study was designed to assess the effect of clonazepam in burning mouth syndrome. STUDY DESIGN: Thirty patients, each with a chief complaint of mouth burning without oral mucosal lesions, were entered into the study. All patients underwent routine blood screens. Identified abnormalities were corrected, when possible, before clonazepam was prescribed. The starting dose was 0.25 mg daily, with an increase in dose of 0.25 mg on a weekly basis if symptoms continued. RESULTS: The subject population consisted of 29 women and 1 man. All subjects had been symptomatic (average premorbid burning intensity, 7.0 +/- 1.9 on 10-point scale) for 1 month to 12 years (mean, 3.9 +/- 3.4 years; median, 2.75 years), and 16% had had burning for more than 2 years. Three groups of patients were identified: those who experienced partial to complete relief with clonazepam and who were using the medication at the last follow-up (group 1; 43%); those who found the clonazepam helpful but withdrew from the medication because of side effects--usually drowsiness (group 2; 27%); and those who did not benefit from clonazepam (group 3; 30%). Among the 3 groups, age was found to be significantly lower for group 1 than for group 2 but not significantly lower for group 1 than for group 3. Although the difference did not reach significance, the mean dose of clonazepam appeared lower for group 1 patients than for the other 2 patient groups. The number of patients with burning for less than 2 years was larger in group 1 than in the other groups. CONCLUSIONS: The results suggest that clonazepam may be helpful in burning mouth syndrome, inasmuch as 70% of patients (groups 1 and 2) experienced pain reduction with effects at low doses. These findings suggest that the mechanism of action of clonazepam may be specific and separate from the anxiolytic effect of the benzodiazepines and that clonazepam may represent a useful therapy in a subset of patients with burning mouth syndrome. Double-blind, placebo-controlled trials are warranted. Thirty-three patients complaining of a burning mouth were investigated for deficiencies which might cause the symptoms. No deficiencies could be demonstrated. They were also questioned on their state of mind in the preceding period and their daily intake of medicine. More than half described their state of mind as normal. Benzodiazepines was the drug group used most. A treatment protocol for these patients is described.

Is PTEN involved in follicular thyroid carcinoma?

The PTEN mutation frequency in unselected cases of follicular thyroid carcinoma was 4.8%.

[16487009, 9790504, 12203792, 11297621, 18055323, 21417916, 9832031]

The PTEN (MMAC1/TEP1) tumor suppressor gene was recently isolated and mapped to human chromosome band 10q23. Homozygous deletions and mutations of PTEN were observed in cell lines and sporadic cancers of the breast, kidney, and central nervous system. Germline mutations in PTEN were recently found in Cowden disease, an autosomal dominant inherited syndrome, previously mapped to chromosome bands 10q22-23. This disease is associated with a wide variety of malignancies and hamartomas of ectodermal, mesodermal, and endodermal origin. The most common neoplasms in Cowden disease patients arise in the breast, skin, and thyroid (follicular subtype). To determine the involvement of PTEN in sporadic follicular thyroid tumors, we first analyzed sporadic follicular adenomas and carcinomas for deletions of the PTEN gene. Loss of heterozygosity was found in 7/26 (27%) follicular carcinomas and 2/27 (7%) follicular adenomas, one of which was a small hemizygous deletion (approximately 3 cm). Sequence analysis of the entire PTEN coding region revealed two mutations in carcinomas with 10q loss. Our findings suggest that the PTEN tumor suppressor gene is occasionally inactivated in sporadic follicular thyroid tumors. Germline mutations in the tumor-suppressor gene PTEN (MMAC1, TEP1) are found in Cowden syndrome, which predisposes to hamartomas, breast cancer, trichilemmomas, and thyroid tumors of follicular epithelium. PTEN has also been found to be somatically deleted, mutated, and/or silenced in various sporadically occurring cancers such as glioblastoma, breast cancer, kidney cancer, malignant melanoma, and endometrial cancer. Loss or reduction of PTEN protein expression as well as inappropriate subcellular compartmentalization is seen in non-medullary thyroid cancers. However, although allelic loss of the PTEN locus in 10q23.3 is frequently seen, this is not coupled with mutations in the PTEN gene. To approach further the frequency and mechanism behind PTEN silencing, we screened a panel of 87 sporadic thyroid tumors for PTEN mRNA expression, including 14 anaplastic carcinomas, 37 follicular carcinomas, 21 atypical adenomas, and 15 ordinary adenomas. Complete loss of PTEN mRNA expression was evident in six of the tumors, including four anaplastic carcinomas, one widely invasive carcinoma, and one ordinary adenoma. The transcriptional silencing of PTEN was significantly associated with the anaplastic subtype, suggesting that PTEN is involved in the carcinogenesis of highly malignant or late-stage thyroid cancers, whereas this particular mechanism appears to be of minor importance in differentiated follicular thyroid tumors. No association was observed between the expression, loss of heterozygosity, and mutation status in the 33 cases in which these parameters were compared. This indicates that PTEN silencing is a result of a wide variety of epigenetic and/or structural silencing mechanisms rather than a consequence of structural biallelic inactivation of the classical type. Furthermore, the high rate of alterations in the 10q23 region might indicate the presence of an as-yet unknown tumor-suppressor gene with an important role in the development of thyroid tumors. Various genes have been identified to play a role in the pathogenesis of follicular thyroid tumors. Cowden syndrome is the only known familial syndrome with an increased risk of both follicular thyroid adenoma (FA) and carcinoma (FTC). Germline mutations in the tumor suppressor gene PTEN, which encodes a dual-specificity phosphatase, have been found in up to 80% of patients with Cowden syndrome suggesting a role of PTEN in the pathogenesis of follicular thyroid tumors. Although somatic intragenic mutations in PTEN, which maps to 10q23.3, are rarely found in follicular tumors, loss of heterozygosity (LOH) of markers within 10q22-24 occurs in about 25%. Recently, another phosphatase gene, MINPP1, has been localized to 10q23.3. MINPP1 has the ability to remove 3-phosphate from inositol phosphate substrates, a function that overlaps that of PTEN. Because of this overlapping function with PTEN and the physical location of MINPP1 to a region with frequent LOH in follicular thyroid tumors, we considered it to be an excellent candidate gene that could contribute to the pathogenesis of follicular thyroid tumors. We analyzed DNA from tumor and corresponding normal tissue from 23 patients with FA and 15 patients with FTC for LOH and mutations at the MINPP1 locus. LOH was identified in four malignant and three benign tumors. One of these FTCs with LOH was found to harbor a somatic c.122C > T or S41L mutation. We also found two germline sequence variants, c.809A > G (Q270R) and IVS3 + 34T > A. The c.809A > G variant was found in only one patient with FA but not in patients with FTC or normal controls. More interestingly, IVS3 + 34T > A was found in about 15% of FA cases and normal controls but not in patients with FTC. These results suggest a role for MINPP1 in the pathogenesis of at least a subset of malignant follicular thyroid tumors, and MINPP1 might act as a low penetrance predisposition allele for FTC. BACKGROUND: Differentiated thyroid cancer (DTC) is seen in 3%-10% of individuals carrying a germline PTEN mutation. Patients with PTEN mutations are at risk for additional neoplasms as are their affected offspring. However, the frequency of PTEN mutations among DTC cases has not been systematically analyzed. The objective of this study was to determine the frequency of PTEN mutations in an unselected group of patients with DTC and to identify whether additional clinical features might indicate the need for referral for genetic counseling and possible testing. METHODS: We collected personal medical and family history information, head circumference data, and blood from 259 consecutively identified clinic-based patients with DTC, unselected for personal or family history. Individuals were categorized for diagnostic criteria for Cowden syndrome (CS) using the 2009 National Comprehensive Cancer Network (NCCN) guidelines and underwent germline PTEN mutation analysis. RESULTS: Two of the 259 patients (0.8%), with both follicular thyroid carcinoma and macrocephaly, were found to carry a germline mutation in the PTEN gene. The PTEN mutation frequency in unselected cases of follicular thyroid carcinoma was 4.8%. CONCLUSION: The frequency of germline pathogenic PTEN mutations in an unselected series of patients with DTC is relatively low, but it is enriched by considering follicular histology and macrocephaly. These results suggest that by adding head circumference to the clinical assessment, thyroid cancer specialists can more effectively identify patients needing referral for cancer genetic services. Cowden syndrome (CS) or multiple hamartoma syndrome (MIM 158350) is an autosomal dominant disorder with an increased risk for breast and thyroid carcinoma. The diagnosis of CS, as operationally defined by the International Cowden Consortium, is made when a patient, or family, has a combination of pathognomonic major and/or minor criteria. The CS gene has recently been identified as PTEN, which maps at 10q23.3 and encodes a dual specificity phosphatase. PTEN appears to function as a tumour suppressor in CS, with between 13-80% of CS families harbouring germline nonsense, missense, and frameshift mutations predicted to disrupt normal PTEN function. To date, only a small number of tumour suppressor genes, including BRCA1, BRCA2, and p53, have been associated with familial breast or breast/ovarian cancer families. Given the involvement of PTEN in CS, we postulated that PTEN was a likely candidate to play a role in families with a "CS-like" phenotype, but not classical CS. To answer these questions, we gathered a series of patients from families who had features reminiscent of CS but did not meet the Consortium Criteria. Using a combination of denaturing gradient gel electrophoresis (DGGE), temporal temperature gel electrophoresis (TTGE), and sequence analysis, we screened 64 unrelated CS-like subjects for germline mutations in PTEN. A single male with follicular thyroid carcinoma from one of these 64 (2%) CS-like families harboured a germline point mutation, c.209T-->C. This mutation occurred at the last nucleotide of exon 3 and within a region homologous to the cytoskeletal proteins tensin and auxilin. We conclude that germline PTEN mutations play a relatively minor role in CS-like families. In addition, our data would suggest that, for the most part, the strict International Cowden Consortium operational diagnostic criteria for CS are quite robust and should remain in place.

Which genome browser database for DNA shape annotations is available?

The Genome Browser for DNA shape annotations (GBshape; freely available at http://rohslab.cmb.usc.edu/GBshape/) provides minor groove width, propeller twist, roll, helix twist and hydroxyl radical cleavage predictions for the entire genomes of 94 organisms. Additional genomes can easily be added using the GBshape framework. GBshape can be used to visualize DNA shape annotations qualitatively in a genome browser track format, and to download quantitative values of DNA shape features as a function of genomic position at nucleotide resolution.

[25326329]

Many regulatory mechanisms require a high degree of specificity in protein-DNA binding. Nucleotide sequence does not provide an answer to the question of why a protein binds only to a small subset of the many putative binding sites in the genome that share the same core motif. Whereas higher-order effects, such as chromatin accessibility, cooperativity and cofactors, have been described, DNA shape recently gained attention as another feature that fine-tunes the DNA binding specificities of some transcription factor families. Our Genome Browser for DNA shape annotations (GBshape; freely available at http://rohslab.cmb.usc.edu/GBshape/) provides minor groove width, propeller twist, roll, helix twist and hydroxyl radical cleavage predictions for the entire genomes of 94 organisms. Additional genomes can easily be added using the GBshape framework. GBshape can be used to visualize DNA shape annotations qualitatively in a genome browser track format, and to download quantitative values of DNA shape features as a function of genomic position at nucleotide resolution. As biological applications, we illustrate the periodicity of DNA shape features that are present in nucleosome-occupied sequences from human, fly and worm, and we demonstrate structural similarities between transcription start sites in the genomes of four Drosophila species.

What is known about clinical efficacy of ceftriaxone for treatment of amyotrophic lateral sclerosis?

There have been a few case reports to suggest that ceftriaxone can be effective for treatment of amyotrophic lateral sclerosis. However, other case reports did not report clinical benefit of ceftriaxone therapy for ALS. Ceftriaxone has been reported to reduce neuronal damage in amyotrophic lateral sclerosis a through increased expression and activity of the glutamate transporter, GLT1. Clinical trials investigating potential clinical benefits of ceftriaxone in ALS are ongoing.

[18326497, 22680643, 16723044, 19697382, 16832072, 17212618, 15907788, 20638444, 23613806, 19008722, 24771634, 15635412, 25297012, 19694903, 8161465, 21970974]

Emerging evidence indicates that many aspects of alcohol and drug dependence involve changes in glutamate transmission. A number of studies have reported that drugs of abuse, including alcohol and cocaine, alter glutamate transport. Extracellular glutamate is regulated by a number of glutamate transporters in various brain regions. Of these transporters, glutamate transporter (GLT1) is a key player in the removal of most of the extracellular glutamate. Similar to neurodegenerative disease models, in which there is dysfunction of the glutamatergic excitatory system, the role of GLT1 has been tested in drug dependence models that show dysfunction of glutamate transmission. We and others have recently found that ceftriaxone, an FDA-approved drug known to elevate GLT1 expression, attenuates cue-induced cocaine relapse. Moreover, we recently found that alcohol-preferring rats treated with ceftriaxone showed a significant dosedependent reduction in alcohol consumption. We also demonstrated that ceftriaxone-induced upregulation of GLT1 expression was associated with increases in glutamate uptake in Huntington's disease mouse model. Importantly, ceftriaxone is currently in clinical trials for the treatment of amyotrophic lateral sclerosis. This review provides information about the potential therapeutic role of GLT1 for the treatment of alcohol abuse and dependence. Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterised by loss of motor neurons. The cause of disease is unknown other than in the rare cases of familial disease arising from mutations in the superoxide dismutase 1 gene. Many theories for pathogenesis have been proposed - including oxidative stress, excitotoxicity, mitochondrial dysfunction and abnormal protein aggregation - based on studies of human post mortem tissue, research on animal models, and in vitro work. Here we review the evidence for the main pathogenic mechanisms and outline how they might interact to cause motor neuron death. Clinical trials have as yet failed to identify any truly effective therapies in ALS, with only riluzole providing a modest improvement in survival. Ongoing trials are exploring the value of antiglutamatergic agents, including the cephalosporin antibiotic ceftriaxone, as well as antioxidants, mitochondrial enhancers and anti-apoptotic drugs. It is likely that effective therapy will involve combinations of agents acting on different mechanisms. Gene therapy with neurotrophic factors will soon be in clinical trials, while work on stem cell therapy remains preclinical. In addition to finding effective therapies, research also needs to identify early disease markers because therapy is likely to be of most benefit when given early in the course of disease. Lyme disease is sometimes part of the differential diagnosis for amyotrophic lateral sclerosis (ALS). Herein we report on 414 individuals with ALS at the Massachusetts General Hospital who underwent laboratory testing for Lyme disease. Twenty-four (5.8%) were seropositive, but only 4 (0.97%) had confirmed past immunoreactive infection. Two of these patients received ceftriaxone for 1 month without clinical improvement. Lyme disease was rare in 414 patients with ALS and is not likely to be causative. BACKGROUND: Riluzole is currently the only Food and Drug Administration-approved treatment for ALS, but its effect on survival is modest. OBJECTIVE: To identify potential neuroprotective agents for testing in phase III clinical trials and to outline which data need to be collected for each drug. METHODS: The authors identified 113 compounds by inviting input from academic clinicians and researchers and via literature review to identify agents that have been tested in ALS animal models and in patients with ALS. The list was initially narrowed to 24 agents based on an evaluation of scientific rationale, toxicity, and efficacy in previous animal and human studies. These 24 drugs underwent more detailed pharmacologic evaluation. RESULTS: Twenty drugs were selected as suitable for further development as treatments for patients with ALS. Talampanel and tamoxifen have completed early phase II trials and have demonstrated preliminary efficacy. Other agents (ceftriaxone, minocycline, ONO-2506, and IGF-1 polypeptide) are already in phase III trials involving large numbers of patients with ALS. Remaining agents (AEOL 10150, arimoclomol, celastrol, coenzyme Q10, copaxone, IGF-1-viral delivery, memantine, NAALADase inhibitors, nimesulide, scriptaid, sodium phenylbutyrate, thalidomide, trehalose) require additional preclinical animal data, human toxicity and pharmacokinetic data including CNS penetration prior to proceeding to large scale phase III human testing. Further development of riluzole analogues should be considered. CONCLUSIONS: Several potential neuroprotective compounds, representing a wide range of mechanisms, are available and merit further investigation in ALS. This report summarizes what we believe to be the first verifiable case of a significant and progressive motor neuron disease (MND) consistent with amyotrophic lateral sclerosis that resolved during treatment with i.v. ceftriaxone plus oral atovaquone and mefloquine. The rationale for use of these antibiotics was (i) positive testing for Borrelia burgdorferi and (ii) red blood cell ring forms consistent with Babesia species infection. The patient has continued to be free of MND signs and symptoms for 15 months, although some symptoms consistent with disseminated Borreliosis remain. Recently, Rothstein et al. reported that beta-lactam antibiotics, including penicillin and ceftriaxone, are potential therapeutic drugs to treat some neurological disorders, e.g., amyotrophic lateral sclerosis (ALS), by modulating the expression of glutamate transporter GLT1 via gene activation. However, considering the facts that: (i) many neurological diseases (including ALS) are associated with transition metal ions and redox stress, and ALS can be efficiently prevented by metal chelators, e.g., diethyl-dithiocarbamate (DDC); (ii) beta-lactam antibiotics have long been known as metal chelators, we argue that the beneficial effect of beta-lactam antibiotics on ALS likely involves Cu(II)-attenuating ability. This is partially supported by our theoretical calculations. Mutations in the Cu/Zn superoxide dismutase (SOD1) gene are detected in 20% of familial and 3% of sporadic amyotrophic lateral sclerosis (ALS) cases. Although mutant SOD1 is known to induce motor neuron death via multiple adverse acquired functions, its exact pathogenic mechanism is not well defined. SOD1 toxicity is dose dependent; levels of mutant SOD1 protein in transgenic mice determine disease susceptibility, onset and rate of progression. We therefore sought to identify small molecules that reduce SOD1 levels by inhibiting the SOD1 promoter. We tested pyrimethamine (previously reported to suppress SOD1 expression), several compounds currently in trials in human and murine ALS, and a set of 1040 FDA-approved compounds. In a PC12 cell-based assay, no compounds reduced SOD1 promoter activity without concomitant cytotoxicity. Additionally, pyrimethamine failed to repress levels of SOD1 protein in HeLa cells or homogenates of liver, spinal cord and brain of wild-type mice. Thirty-four compounds (including riluzole, ceftriaxone, minocyclin, PBA, lithium, acetylcysteine) in human and mouse ALS trials and an additional set of 1040 FDA-approved compounds also showed no effect on SOD1 promoter activity. This present study thus failed to identify small molecule inhibitors of SOD1 gene expression. Conflict of interest statement: Competing Interests: JDB has served as a consultant to Biogen Idec and as a paid speaker for Oakstone Publishing. He receives research report from the Muscular Dystrophy Association and ALS Therapy Alliance. JMS has served as a consultant to Biogen Idec, Cytokinetics, Trophos, ISIS, Glaxo Smith Kline, and receives research support from the Muscular Dystrophy Association, ALS Association, ALS Therapy Alliance, Cytokinetics, Biogen Idec, Sanofi Aventis, Neuraltus. RC is employed at the National Institute of Neurological Disorders and Stroke. DS, over the last 24 months, has served as a biostatistical consultant to Averion, Inc, Gerson Lehrman Group, Guidepoint Global, Neuronova, Cytokinetics, Glaxo Smith Kline, Merck, Aggennix, Pfizer, Biogen Idec, and Elan. He has received research support from AstraZeneca, Roche, CytRx, and ISIS. MK has no relevant disclosures to report. DF has received research funds from Euroimmune, Allere, Focus, Biokit, BioRad and Diasorin, Chronic Fatigue Initiative. LK has no relevant disclosures to report. WSD has no relevant disclosures to report. FV has no relevant disclosures to report. AP receives revenue related to antibody patent licenses from Athena; owns stock in Johnson & Johnson; directs the Washington University Neuromuscular Clinical Laboratory which performs antibody testing; and receives research support from the National Institutes of Health, Muscular Dystrophy Association, Neuromuscular Research Fund, Insmed, Knopp, Cytokinetics, Biogen Idec, ISIS, Genzyme, GSK, Ultragenyx & Sanofi. JBC has no relevant disclosures to report. JK has no relevant disclosures to report. ES has no relevant disclosures to report. JR has served on scientific advisory boards and/or as a consultant for Hill-ROM Inc, Cytokinetics and Avanir Pharmaceuticals. RP has no relevant disclosures to report. JG receives research support from the Muscular Dystrophy Association and from the National Institute of Neurological Disorders and Stroke. KR has no relevant disclosures to report. JR has research funding from National Institutes of Health, Department of Defense, P2ALS, Muscular Dystrophy Association, Robert Packard Center for ALS Research at Johns Hopkins. He has acted as a consultant to Biogen Idec, Cytokinetics and Psyadon Pharmaceuticals, Inc. DJG has no relevant disclosures to report. MEC served on DSMB for Synapse and Trophos and was a consultant for TEVA, Millenium, GlaxoSmithKline and Biogen. This does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials. OBJECTIVE: Ceftriaxone has been reported to reduce neuronal damage in amyotrophic lateral sclerosis and in an in-vitro model of neuronal ischaemia through increased expression and activity of the glutamate transporter, GLT1. We tested the effects of ceftriaxone on mortality, neurological outcome, and infarct size in experimental stroke in rats and looked for underlying mechanisms. METHODS: Male normotensive Wistar rats received ceftriaxone (200 mg/kg intraperitoneal) as a single injection 90 min after middle cerebral artery occlusion (90 min with reperfusion). Forty-eight hours after middle cerebral artery occlusion, infarct size (MRI) and neurological deficits were estimated. GLT1 expression was determined by real time RT-PCR, immunoblotting and promoter reporter assay, astrocyte GLT1 activity by measuring glutamate uptake. Bacterial load in various organs was measured by real time RT-PCR, neurotrophins and IL-6 by immunoblotting. RESULTS: Ceftriaxone dramatically reduced early (24-h) mortality from 34.5% (vehicle treatment, n = 29) to 0% (P < 0.01, n = 19). In a subgroup, followed up for 4 weeks, mortality persisted at 0%. Ceftriaxone strongly tended to reduce infarct size, it significantly improved neuronal survival within the penumbra, reduced neurological deficits (P < 0.001) and led to an upregulation of neurotrophins (P < 0.01) in the peri-infarct zone. Ceftriaxone did not increase GLT1 expression, but increased GLT1 activity (P < 0.05). CONCLUSION: Ceftriaxone causes a significant reduction in acute stroke mortality in a poststroke treatment regimen in animal studies. Improved neurological performance and survival may be due to neuroprotection by activation of GLT1 and a stimulation of neurotrophins resulting in an increased number of surviving neurons in the penumbra. Glutamate is the principal excitatory neurotransmitter in the nervous system. Inactivation of synaptic glutamate is handled by the glutamate transporter GLT1 (also known as EAAT2; refs 1, 2), the physiologically dominant astroglial protein. In spite of its critical importance in normal and abnormal synaptic activity, no practical pharmaceutical can positively modulate this protein. Animal studies show that the protein is important for normal excitatory synaptic transmission, while its dysfunction is implicated in acute and chronic neurological disorders, including amyotrophic lateral sclerosis (ALS), stroke, brain tumours and epilepsy. Using a blinded screen of 1,040 FDA-approved drugs and nutritionals, we discovered that many beta-lactam antibiotics are potent stimulators of GLT1 expression. Furthermore, this action appears to be mediated through increased transcription of the GLT1 gene. beta-Lactams and various semi-synthetic derivatives are potent antibiotics that act to inhibit bacterial synthetic pathways. When delivered to animals, the beta-lactam ceftriaxone increased both brain expression of GLT1 and its biochemical and functional activity. Glutamate transporters are important in preventing glutamate neurotoxicity. Ceftriaxone was neuroprotective in vitro when used in models of ischaemic injury and motor neuron degeneration, both based in part on glutamate toxicity. When used in an animal model of the fatal disease ALS, the drug delayed loss of neurons and muscle strength, and increased mouse survival. Thus these studies provide a class of potential neurotherapeutics that act to modulate the expression of glutamate neurotransmitter transporters via gene activation. BACKGROUND: Glutamate excitotoxicity might contribute to the pathophysiology of amyotrophic lateral sclerosis. In animal models, decreased excitatory aminoacid transporter 2 (EAAT2) overexpression delays disease onset and prolongs survival, and ceftriaxone increases EAAT2 activity. We aimed to assess the safety and efficacy of ceftriaxone for amyotrophic lateral sclerosis in a combined phase 1, 2, and 3 clinical trial. METHODS: This three-stage randomised, double-blind, placebo-controlled study was done at 59 clinical sites in the USA and Canada between Sept 4, 2006, and July 30, 2012. Eligible adult patients had amyotrophic lateral sclerosis, a vital capacity of more than 60% of that predicted for age and height, and symptom duration of less than 3 years. In stages 1 (pharmacokinetics) and 2 (safety), participants were randomly allocated (2:1) to ceftriaxone (2 g or 4 g per day) or placebo. In stage 3 (efficacy), participants assigned to ceftriaxone in stage 2 received 4 g ceftriaxone, participants assigned to placebo in stage 2 received placebo, and new participants were randomly assigned (2:1) to 4 g ceftriaxone or placebo. Participants, family members, and site staff were masked to treatment assignment. Randomisation was done by a computerised randomisation sequence with permuted blocks of 3. Participants received 2 g ceftriaxone or placebo twice daily through a central venous catheter administered at home by a trained caregiver. To minimise biliary side-effects, participants assigned to ceftriaxone also received 300 mg ursodeoxycholic acid twice daily and those assigned to placebo received matched placebo capsules. The coprimary efficacy outcomes were survival and functional decline, measured as the slope of Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) scores. Analyses were by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00349622. FINDINGS: Stage 3 included 66 participants from stages 1 and 2 and 448 new participants. In total, 340 participants were randomly allocated to ceftriaxone and 173 to placebo. During stages 1 and 2, mean ALSFRS-R declined more slowly in participants who received 4 g ceftriaxone than in those on placebo (difference 0·51 units per month, 95% CI 0·02 to 1·00; p=0·0416), but in stage 3 functional decline between the treatment groups did not differ (0·09, -0·06 to 0·24; p=0·2370). No significant differences in survival between the groups were recorded in stage 3 (HR 0·90, 95% CI 0·71 to 1·15; p=0·4146). Gastrointestinal adverse events and hepatobiliary adverse events were more common in the ceftriaxone group than in the placebo group (gastrointestinal, 245 of 340 [72%] ceftriaxone vs 97 of 173 [56%] placebo, p=0·0004; hepatobiliary, 211 [62%] vs 19 [11%], p<0·0001). Significantly more participants who received ceftriaxone had serious hepatobiliary serious adverse events (41 participants [12%]) than did those who received placebo (0 participants). INTERPRETATION: Despite promising stage 2 data, stage 3 of this trial of ceftriaxone in amyotrophic lateral sclerosis did not show clinical efficacy. The adaptive design allowed for seamless transition from one phase to another, and central venous catheter use in the home setting was shown to be feasible. FUNDING: National Institute of Neurological Disorders and Stroke. In amyotrophic lateral sclerosis, down-regulation of the astrocyte-specific glutamate excitatory amino acid transporter 2 is hypothesized to increase extracellular glutamate, thereby leading to excitotoxic motor neuron death. The antibiotic ceftriaxone was recently reported to induce excitatory amino acid transporter 2 and to prolong the survival of mutant superoxide dismutase 1 transgenic mice. Here we show that ceftriaxone also protects fibroblasts and the hippocampal cell line HT22, which are not sensitive to excitotoxicity, against oxidative glutamate toxicity, where extracellular glutamate blocks cystine import via the glutamate/cystine-antiporter system x(c)(-). Lack of intracellular cystine leads to glutathione depletion and cell death because of oxidative stress. Ceftriaxone increased system x(c)(-) and glutathione levels independently of its effect on excitatory amino acid transporters by induction of the transcription factor Nrf2 (nuclear factor erythroid 2-related factor 2), a known inducer of system x(c)(-), and the specific x(c)(-) subunit xCT. No significant effect was apparent in fibroblasts deficient in Nrf2 or xCT. Similar ceftriaxone-stimulated changes in Nrf2, system x(c)(-), and glutathione were observed in rat cortical and spinal astrocytes. In addition, ceftriaxone induced xCT mRNA expression in stem cell-derived human motor neurons. We conclude that ceftriaxone-mediated neuroprotection might relate more strongly to activation of the antioxidant defense system including Nrf2 and system x(c)(-) than to excitatory amino acid transporter induction. We describe two patients with lateral amyotrophic sclerosis who, after informed consent, received empirical treatment with intravenous cephtriaxone at a dose of 2 g/24 hours for three weeks, with no positive results. The pharmacokinetics of this cephalosporin is analyzed, along with the relationship between motor neuron disease, neuroborreliosis and immunoreactivity to Borrelia burgdorferi. Some antibiotics are suggested to exert neuroprotective effects via regulation of glial responses. Attenuation of microglial activation by minocycline prevents neuronal death in a variety of experimental models for neurological diseases, such as cerebral ischemia, Parkinson's and Huntington's disease. Ceftriaxone delays loss of neurons in genetic animal models of amyotrophic lateral sclerosis through upregulation of astrocytic glutamate transporter expression (GLT-1). However, it remains largely unknown whether these antibiotics are able to protect neurons in axotomy models for progressive motor neuron diseases. Recent studies have shown that the axotomized motoneurons of the adult rat can survive, whereas those of the adult mouse undergo neuronal degeneration. We thus examined the possible effects of ceftriaxone and minocycline on neuronal loss and glial reactions in the mouse hypoglossal nucleus after axotomy. The survival rate of lesioned motoneurons at 28 days after axotomy (D28) was significantly improved by ceftriaxone and minocycline treatment. There were no significant differences in the cellular densities of astrocytes between ceftriaxone-treated and saline-treated animals. Ceftriaxone administration increased the expression of GLT-1 in the hypoglossal nucleus, while it suppressed the reactive increase of glial fibrillary acidic protein (GFAP) expression to control level. The cellular densities of microglia at D28 were significantly lower in minocycline-treated mice than in saline-treated mice. The time course analysis showed that immediate increase in microglia at D3 and D7 was not suppressed by minocycline. The present observations show that minocycline and ceftriaxone promote survival of lesioned motoneurons in the mouse hypoglossal nucleus, and also suggest that alterations in glial responses might be involved in neuroprotective actions of antibiotics.

What is the relationship between TailorX and Oncotype?

The TAILORx trial uses the Oncotype DX recurrence score to assign estrogen receptor-positive (ER+), node-negative patients to chemotherapy plus hormonal therapy versus hormonal therapy alone.

[25240289, 18922117, 20665886, 23411384, 23643806]

INTRODUCTION: The use of chemotherapy in node-negative, (O)Estrogen Receptor (ER)-positive breast cancer has changed significantly since the introduction of Oncotype DX to determine systemic recurrence risk based on tumour genomic signature. AIMS: This study aims to METHODS: A cohort study was undertaken, including consecutive patients with early node-negative, ER-positive breast cancer diagnosed between 2006 and May 2013, including a period of prospective clinical trial (Trial Assigning Individualised Options for Treatment (TAILORx)) recruitment. Data were collected regarding patient demographics, tumour clinico-pathological features, Oncotype DX use and recurrence score and chemotherapy use. All therapeutic decisions were made following multidisciplinary discussion, with adherence to guidelines and consideration of trial protocol and Oncotype DX recurrence scores. RESULTS: 479 consecutive patients were included in the study, of whom 241 (50%) underwent Oncotype DX testing, 97 as part of the TAILORx clinical trial. Oncotype DX testing began on a trial basis in 2007 and until October 2011, only patients enrolled on TAILORx availed of genomic profiling. From October 2011, Oncotype DX was used in all eligible patients as per National Cancer Control Programme (NCCP) guidelines. A total of 216 (45%) patients received chemotherapy. The use of chemotherapy changed in inverse proportion to the availability of the genomic assay. Of those patients in whom Oncotype DX was utilised, 138 (57%) were spared chemotherapy. CONCLUSION: This study validates the use of molecular testing in the rationalisation of systemic therapy. Novel genetic profiling tests of breast cancer tissue have been shown to be prognostic for overall survival and predictive of local and distant rates of recurrence in breast cancer patients. One of these tests, Oncotype DXtrade mark, is a diagnostic test comprised of a 21-gene assay applied to paraffin-embedded breast cancer tissue, which allows physicians to predict subgroups of hormone-receptor-positive, node-negative patients who may benefit from hormonal therapy alone or require adjuvant chemotherapy to attain the best survival outcome. The results of the assay are converted to a recurrence score (0-100) that has been found to be predictive of 10- and 15-year local and distant recurrence in node-negative, estrogen-receptor-positive breast cancer patients. Previous studies have shown that patients with high recurrence scores benefit from adjuvant chemotherapy, whereas patients with low recurrence scores do not. To evaluate the ability to guide treatment decisions in the group with a mid-range recurrence score, the North American Cooperative Groups developed the Trial Assessing IndiviuaLized Options for Treatment for breast cancer, a randomized trial of chemotherapy followed by hormonal therapy versus hormonal therapy alone on invasive disease-free survival-ductal carcinoma in situ (IDFS-DCIS) survival in women with node-negative, estrogen-receptor-positive breast cancer with a recurrence score of 11-25. The study was initiated in May 2006 and approximately 4500 patients will be randomized. This article describes the rationale, methodology, statistical ana-lysis and implications of the results on clinical practice. BACKGROUND: Oncotype DX breast cancer assay (Genomic Health, Redwood City, Calif) stratifies patients with early breast cancer according to risk of distant recurrence. The authors hypothesized that the test is ordered when clinicopathological variables yield equivocal risk estimates. The current study also showed how often the test clarifies clinically ambiguous risk status. METHODS: The authors examined clinical/pathological characteristics and calculated risk of recurrence with Adjuvant! for 309 consecutive patients who underwent Oncotype DX testing at M. D. Anderson Cancer Center. RESULTS: Of the patients comprising this study, most had stage I/II (n = 306, 99%) and grade I/II tumors (n = 236, 76%). The median risk of recurrence by Adjuvant! was 16% (IQR 11.2 to 20.4). Oncotype DX stratified 52% (n = 160), 40% (n = 122) and 9% (n = 27) of this clinically intermediate risk population into low, intermediate, and high risk groups, respectively. Correlation between projected risk of recurrence by Adjuvant! (Adjuvant!, online software and website) and Oncotype DX was minimal (r = 0.13). Recurrence score (P < .0001), but not age or tumor size, was higher in patients who received adjuvant chemotherapy. In all 3 grade subsets, recurrence score was higher in those who received chemotherapy compared with those who did not (P = .02, P < .0001, and P = .0009, respectively). All lobular carcinomas (n = 40) were classified as low/intermediate risk. CONCLUSIONS: Oncotype DX yielded potentially informative risk assignments in patients considered indeterminate risk by routine clinical variables. However, 40% of the time test results reflected intermediate risk, with widely used recurrence score thresholds. This proportion increased to 66% using revised thresholds implemented by National Cancer Institute's Trial Assigning IndividuaLized Options for Treatment (Rx), or TAILORx. Oncotype DX, PAM50, and MammaPrint are multigene tests that are being used clinically for early-stage breast cancer to predict recurrence risk and guide adjuvant chemotherapy decisions. These tests have been validated in multiple retrospective studies, and prospective clinical trials are in progress. The TAILORx trial uses the Oncotype DX recurrence score to assign estrogen receptor-positive (ER+), node-negative patients to chemotherapy plus hormonal therapy versus hormonal therapy alone. The RxPONDER (SWOG S1007) trial uses Oncotype DX in a similar approach but on node-positive patients, and it includes the PAM50 test as a secondary analysis. The MINDACT trial uses Mamma-Print and Adjuvant! Online for treatment arm assignments. MINDACT has very broad eligibility criteria and 2 secondary randomizations for selecting chemotherapy and hormonal therapy regimens. This article discusses how the latest results on cancer genome sequencing apply to early-stage breast cancer. Several hundred breast cancers have already undergone genome sequencing, and the somatic DNA changes found in the tumor, compared with the patient's normal DNA, have been identified. Higher rates of point mutations and chromosomal translocations are found in aromatase inhibitor-resistant ER+ cancers and in the basal-like and HER2-enriched breast cancer subtypes. Correlations of somatic mutations with neoadjuvant aromatase inhibitor response are discussed. Genome sequencing can potentially identify the molecular abnormalities that underlie the poor risk identified by multigene tests and provide potential new targets for therapy, but more clinical trials correlating clinical outcome and somatic DNA changes are needed. Oncotype DX is an RT-PCR assay used to predict which patients with ER-positive node-negative (NN) disease will benefit from chemotherapy. Each patient is stratified into a risk category based on a recurrence score (RS) and the TAILORx trial is determining the benefit of chemotherapy for patients with mid-range RSs. We tested if Oncotype DX and TAILORx risk categories could be predicted by standard pathological features and protein markers corresponding to 10 genes in the assay (ER, PR, Ki67, HER2, BCL2, CD68, Aurora A kinase, survivin, cyclin B1 and BAG1) on 52 patients who enrolled on TAILORx. Immunohistochemistry for the protein markers was performed on whole tissue sections. Classification and regression tree (CART) analysis correctly classified 69% of cases into Oncotype DX risk categories based on the expression of PR, survivin and nuclear pleomorphism. All tumours with PR staining (Allred score ≥ 2) and marked nuclear pleomorphism were in the high-risk category. No case with PR <2, low survivin (≤ 15.5%) and nuclear pleomorphism <3 was high-risk. Similarly, 77% of cases were correctly classified into TAILORx categories based on nuclear pleomorphism, survivin, BAG1 and cyclin B1. Ki67 was the only variable that predicted the absolute RS with a cut-off for positivity of 15% (p = 0.003). In conclusion, CART revealed key predictors including proliferation markers, PR and nuclear pleomorphism that correctly classified over two thirds of ER-positive NN cancers into Oncotype DX and TAILORx risk categories. These variables could be used as an alternative to the RT-PCR assay to reduce the number of patients requiring Oncotype DX testing.

Does strenuous physical activity affect thyroid hormone metabolism?

YES

[18057380, 16175495, 2807143, 8743723, 8325717, 7198038, 596247, 14637241, 3101339]

Thyroid hormones are important regulators of energy metabolism and may influence energy processes during physical exercise. There are controversial results concerning thyroid hormone metabolism during strenuous exercise in adult athletes and only scant data concerning the impact of strenuous exercise on thyroid hormone metabolism in children and adolescents. Although some studies demonstrate a transient change in thyroid hormones during intense physical performance, most studies agree that these changes are of minor impact, practically reflecting the relative negative energy balance during strenuous exercise. This state of hypometabolism during intense physical performance has also been confirmed in highly trained female young athletes, who may be also characterized by reproductive axis dysfunction, manifested either as luteal-phase deficiency or amenorrhea, alongside the typical constellation of low T3, insulin and leptin levels. More importantly, strenuous exercise during childhood or adolescence is mostly accompanied by a delay of skeletal maturation, and height and may have a long-lasting negative effect on growth and acquisition of maximum bone mass. In conclusion, although thyroid hormones are only transiently or insignificantly changed during strenuous exercise, adequate caloric intake should be guaranteed in highly performing young athletes in order to counteract the relative negative energy balance and prevent alterations in endocrine-metabolic profile. Moreover, when growth and pubertal progression in very young athletes are significantly impaired, a reduction in the intensity of the physical exercise should be advocated in order to guarantee better final height and adequate acquisition of bone mass. Significant increases in the concentration of plasma glucagon-like immunoreactivity (GLI) and plasma levels of free fatty acids (FFA) and triglycerides (TG) concomitant with decreases in circulating levels of thyroxine (T4) and triiodothyronine (T3) and T3/T4 ratio were observed in homing pigeons, untrained for 3 months, after a flight of 48 km lasting 90-160 min. The increased level of FFA is attributed to glucagon stimulated lipolysis. The elevation of TG levels may be due to altered partitioning and utilization of lipoprotein in adipose tissue and muscle. Reductions in plasma T4, T3 and T3/T4 ratio are probably due to inhibition of T4 secretion and 5'-monodeiodination with possible conversion of T4 to reverse T3 (rT3). These processes may represent a mechanism for regulation of thyroid hormone metabolism during strenuous and extended flight. The purpose of the present study was to compare endocrine parameters reflecting reproductive function and metabolism in ten amenorrheic (AR) and eumenorrheic (ER) adolescent female runners and seven untrained controls (SE). Additionally, responses to diagnostic criteria for eating disorders (DSM-III) were compared among groups. AR ran more miles/day and consumed fewer kcal/d to support energy expenditure compared to ER (p < 0.05). Mean levels of fasting plasma estradiol, luteinizing hormone, follicle-stimulating hormone, free thyroxine and triiodothyronine were significantly lower in AR compared to ER and SE. AR indicated they were very concerned about their weight and were fearful of gaining fat mass. Female adolescents who participate in strenuous training exhibit alterations in hormone levels reflecting reproductive function and metabolism. Serum lipids and thyroxine were determined in 26 men participating in a 90-km cross-country ski race, before, immediately after, and on the following days. Serum cholesterol was unchanged immediately after the race, but then fell significantly and remained low during the observation period. During the race the fatty acid composition of serum free fatty acids changed towards the composition of ordinary adipose tissue. The compostiion of serum triglycerides showed similar but less pronouced changes. On the following days an increase in the arachidonic, and a decrease in the linoleic acid fraction of the total serum lipids were observed. Total thyroxine and free thyroxine in serum were significantly increased at the end of the race, but had returned to the pre-raced levels during the rest of the observation period. The observations correspond to the findings during acute, severe illness, and are compatible with the hypothesis that some of the changes in serum lipids following severe somatic stress are due to increased thyroid hormone activity. Interscapular brown adipose tissue (IBAT) activity is controlled by the sympathetic nervous system, and factors that influence thermogenesis appear to act centrally to modify the sympathetic outflow to IBAT. Cold exposure produces a rise in IBAT temperature as a result of the increase in sympathetic outflow to IBAT. This is associated with an increased thyroid activity. 3,5,3'-triiodothyronine (T3) and T4 levels increase during strenuous exercise, and, at the end of the exercise bout, a decrease of T3 and T4 levels, with an increase in TSH during the following 4-5 days, is seen. We evaluated the effect of strenuous exercise on 5'-deiodinase (5'-D) activity in IBAT in normal environmental conditions and after short (30 min) cold exposure. 5'-D activity is lower in rats at basal condition. Short cold exposure (SCE) increases 5'-D in IBAT both in exercising rats and in sedentary rats. However, this increase is lower in exercising animals. Strenuous exercise can reduce 5'-D activity in normal environmental conditions and after SCE. Probably, other compensatory mechanisms of heat production are active in exercising rodents. The effects of endurance training and season on the function of the anterior pituitary-thyroid axis were studied in 18 female runners and their 12 controls, and in 13 joggers and their 11 controls in Northern Finland, with a large seasonal difference in environmental factors. The serum concentrations of thyrotropin (TSH), thyroxine (T4), free thyroxine (fT4), triiodothyronine (T3), thyroxine binding globulin (TBG) and oestradiol (E2) were measured during one menstrual cycle in the light training season (autumn) and in the hard training season (spring). The responses of TSH to intravenous TRH stimulation were also measured in the luteal phase of the cycle during the hard training season. Endurance running did not affect the basal or TRH-stimulated serum TSH concentrations, while those of T4 and fT4 in runners were lowered in both seasons and that of T3 in the light training season in relation to control subjects. The serum concentrations of TBG were also significantly lower in runners than their controls in the luteal phase in both seasons. The effect of jogging on thyroid hormones was less pronounced. Serum concentrations of TSH, T4, fT4, T3 and TBG were generally slightly higher in spring than in autumn. Strenuous endurance training seems to have minor changes on the function of the thyroid gland. Depressed T4 levels in runners may rather be due to lowered TBG levels than due to direct effect of training. In spring the function of anterior pituitary-thyroid axis is more active than in autumn.

Which is the main function of "RNA sponges"?

Natural RNA circles function as efficient microRNA sponges. Recently, miRNA activity has been shown to be affected by the presence of miRNA sponge transcripts, the so-called competing endogenous RNA in humans and target mimicry in plants.

[23446346, 25957803, 23615404, 25483404, 25630703, 25404635, 26052092, 25580223]

Author information: (1)Institute for Molecular Infection Biology, University of Würzburg, Josef-Schneider-Straße 2, 97080 Würzburg, Germany. (2)Institute for Molecular Infection Biology, University of Würzburg, Josef-Schneider-Straße 2, 97080 Würzburg, Germany. Electronic address: [email protected]. The POU transcription factor OCT4 is a pleiotropic regulator of gene expression in embryonic stem cells. Recent studies demonstrated that OCT4 is aberrantly expressed in multiple types of human cancer; however, the underlying molecular mechanism remains largely unknown. In this study, we report that OCT4-pg4, a pseudogene of OCT4, is abnormally activated in hepatocellular carcinoma (HCC). The expression level of OCT4-pg4 is positively correlated with that of OCT4, and both gene transcripts can be directly targeted by a tumor-suppressive micro RNA miR-145. We find that the non-coding RNA OCT4-pg4 is biologically active, as it can upregulate OCT4 protein level in HCC. Mechanistic analysis revealed that OCT4-pg4 functions as a natural micro RNA sponge to protect OCT4 transcript from being inhibited by miR-145. In addition, our study also showed that OCT4-pg4 can promote growth and tumorigenicity of HCC cells, thus exerting an oncogenic role in hepatocarcinogenesis. Furthermore, survival analysis suggests that high OCT4-pg4 level is significantly correlated with poor prognosis of HCC patients. Taken together, our finding adds a new layer of post-transcriptional regulation of OCT4 and sheds new light on the treatment of human HCC. A significant portion of the mammalian genome encodes numerous transcripts that are not translated into proteins, termed long non-coding RNAs. Initial studies identifying long non-coding RNAs inferred these RNA sequences were a consequence of transcriptional noise or promiscuous RNA polymerase II activity. However, the last decade has seen a revolution in the understanding of regulation and function of long non-coding RNAs. Now it has become apparent that long non-coding RNAs play critical roles in a wide variety of biological processes. In this review, we describe the current understanding of long non-coding RNA-mediated regulation of cellular processes: differentiation, development, and disease. There is an expanding list of examples by which one mRNA can posttranscriptionally influence the expression of others. This can involve RNA sponges that sequester regulatory RNAs of mRNAs in the same regulon, but the underlying molecular mechanism of such mRNA cross talk remains little understood. Here, we report sponge-mediated mRNA cross talk in the posttranscriptional network of GcvB, a conserved Hfq-dependent small RNA with one of the largest regulons known in bacteria. We show that mRNA decay from the gltIJKL locus encoding an amino acid ABC transporter generates a stable fragment (SroC) that base-pairs with GcvB. This interaction triggers the degradation of GcvB by RNase E, alleviating the GcvB-mediated mRNA repression of other amino acid-related transport and metabolic genes. Intriguingly, since the gltIJKL mRNA itself is a target of GcvB, the SroC sponge seems to enable both an internal feed-forward loop to activate its parental mRNA in cis and activation of many trans-encoded mRNAs in the same pathway. Disabling this mRNA cross talk affects bacterial growth when peptides are the sole carbon and nitrogen sources. Recently, the sex determining region Y ( Sry) and the cerebellar degeneration-related protein 1 ( CDR1as) RNA transcripts have been described to function as a new class of post-transcriptional regulatory RNAs that behave as circular endogenous RNA sponges for the micro RNAs (miRNAs) miR-138 and miR-7, respectively. A special feature of the Sry gene is its ability to generate linear and circular transcripts, both transcribed in the sense orientation. Here we remark that both sense (e.g. Sry RNA) and antisense (e.g. CDR1as) transcripts could circularize and behave as miRNAs sponges, and importantly, that also protein-coding segments of mRNAs could also assume this role. Thus, it is reasonable to think that the linear Sry sense transcript could additionally act as a miRNA sponge, or as an endogenous competing RNA for miR-138.

Is the gene MAOA epigenetically modified by methylation?

In recent years, the role of epigenetic phenomenon, such as methylation, in mediating vulnerability to behavioral illness has become increasingly appreciated. One prominent locus at which epigenetic phenomena are thought to be in play is the monoamine oxidase A (MAOA) locus. We conclude that methylation of MAOA may play a significant role in common psychiatric illness and that further examination of epigenetic processes at this locus is in order.

[22198720, 20505345, 18454435, 22948232, 22906985, 20421737, 22436428, 16893905, 23116433, 22139575, 19777560]

This study was undertaken to analyze DNA methylation profiling at the monoamine oxidase A (MAOA) locus, in order to determine whether abnormal DNA methylation is involved in the development of schizophrenia. We recruited a total of 371 patients with paranoid schizophrenia (199 males and 172 females) and 288 unrelated control subjects (123 males and 165 females) for analysis of DNA methylation. Diagnosis was made based on the Structured Clinical Interview for DSM-VI. Genomic DNA extracted from peripheral blood was chemically modified using bisulfite, and DNA methylation profiles of the MAOA promoter were determined by BSP-sequencing. DNA methylation ratios of individual CpG residues and overall methylation ratios were measured on each subject. The results showed that there was no significant difference in overall DNA methylation ratios between patients and controls either in the female group (P = 0.42) or in the male group (P = 0.24). Of 15 CpG residues that showed significant differences in DNA methylation status between the patient group and the control group in females, eight of which had an increased level and seven, a decreased level, with a combined P value of 1 (df = 160). In male subjects, however, six individual CpG residues showed an increased methylation level with a combined P value of 5.80E-35 (df = 158). In conclusion, abnormalities of DNA methylation at the MAOA promoter may be associated with schizophrenia in males. DNA methylation is a key epigenetic mechanism involved in the developmental regulation of gene expression. Alterations in DNA methylation are established contributors to inter-individual phenotypic variation and have been associated with disease susceptibility. The degree to which changes in loci-specific DNA methylation are under the influence of heritable and environmental factors is largely unknown. In this study, we quantitatively measured DNA methylation across the promoter regions of the dopamine receptor 4 gene (DRD4), the serotonin transporter gene (SLC6A4/SERT) and the X-linked monoamine oxidase A gene (MAOA) using DNA sampled at both ages 5 and 10 years in 46 MZ twin-pairs and 45 DZ twin-pairs (total n=182). Our data suggest that DNA methylation differences are apparent already in early childhood, even between genetically identical individuals, and that individual differences in methylation are not stable over time. Our longitudinal-developmental study suggests that environmental influences are important factors accounting for interindividual DNA methylation differences, and that these influences differ across the genome. The observation of dynamic changes in DNA methylation over time highlights the importance of longitudinal research designs for epigenetic research. Human brain function is mediated by biochemical processes, many of which can be visualized and quantified by positron emission tomography (PET). PET brain imaging of monoamine oxidase A (MAO A)-an enzyme metabolizing neurotransmitters-revealed that MAO A levels vary widely between healthy men and this variability was not explained by the common MAOA genotype (VNTR genotype), suggesting that environmental factors, through epigenetic modifications, may mediate it. Here, we analyzed MAOA methylation in white blood cells (by bisulphite conversion of genomic DNA and subsequent sequencing of cloned DNA products) and measured brain MAO A levels (using PET and [(11)C]clorgyline, a radiotracer with specificity for MAO A) in 34 healthy non-smoking male volunteers. We found significant interindividual differences in methylation status and methylation patterns of the core MAOA promoter. The VNTR genotype did not influence the methylation status of the gene or brain MAO A activity. In contrast, we found a robust association of the regional and CpG site-specific methylation of the core MAOA promoter with brain MAO A levels. These results suggest that the methylation status of the MAOA promoter (detected in white blood cells) can reliably predict the brain endophenotype. Therefore, the status of MAOA methylation observed in healthy males merits consideration as a variable contributing to interindividual differences in behavior. The monoamine oxidase A (MAOA) gene has been suggested as a prime candidate in the pathogenesis of panic disorder. In the present study, DNA methylation patterns in the MAOA regulatory and exon 1/intron 1 region were investigated for association with panic disorder with particular attention to possible effects of gender and environmental factors. Sixty-five patients with panic disorder (44 females, 21 males) and 65 healthy controls were analysed for DNA methylation status at 42 MAOA CpG sites via direct sequencing of sodium bisulfate treated DNA extracted from blood cells. The occurrence of recent positive and negative life events was ascertained. Male subjects showed no or only very minor methylation with some evidence for relative hypomethylation at one CpG site in intron 1 in patients compared to controls. Female patients exhibited significantly lower methylation than healthy controls at 10 MAOA CpG sites in the promoter as well as in exon/intron 1, with significance surviving correction for multiple testing at four CpG sites (p≤0.001). Furthermore, in female subjects the occurrence of negative life events was associated with relatively decreased methylation, while positive life events were associated with increased methylation. The present pilot data suggest a potential role of MAOA gene hypomethylation in the pathogenesis of panic disorder particularly in female patients, possibly mediating a detrimental influence of negative life events. Future studies are warranted to replicate the present finding in independent samples, preferably in a longitudinal design. BACKGROUND: Atherosclerosis is a complex process involving both genetic and epigenetic factors. The monoamine oxidase A (MAOA) gene regulates the metabolism of key neurotransmitters and has been associated with cardiovascular risk factors. This study investigates whether MAOA promoter methylation is associated with atherosclerosis, and whether this association is confounded by familial factors in a monozygotic (MZ) twin sample. METHODS: We studied 84 monozygotic (MZ) twin pairs drawn from the Vietnam Era Twin Registry. Carotid intima-media thickness (IMT) was measured by ultrasound. DNA methylation in the MAOA promoter region was quantified by bisulfite pyrosequencing using genomic DNA isolated from peripheral blood leukocytes. The association between DNA methylation and IMT was first examined by generalized estimating equation, followed by matched pair analyses to determine whether the association was confounded by familial factors. RESULTS: When twins were analyzed as individuals, increased methylation level was associated with decreased IMT at four of the seven studied CpG sites. However, this association substantially reduced in the matched pair analyses. Further adjustment for MAOA genotype also considerably attenuated this association. CONCLUSIONS: The association between MAOA promoter methylation and carotid IMT is largely explained by familial factors shared by the twins. Because twins reared together share early life experience, which may leave a long-lasting epigenetic mark, aberrant MAOA methylation may represent an early biomarker for unhealthy familial environment. Clarification of familial factors associated with DNA methylation and early atherosclerosis will provide important information to uncover clinical correlates of disease.

Which mutations of phopspholamban have been found in patients with cardiomyopathy?

PLN mutation R14del [or c.40_42delAGA(p.Arg14del)] was identified in 12 (12 %) ARVC patients and in 39 (15 %) DCM patients. Another PLN mutation is a T116G point mutation, substituting a termination codon for Leu-39 (L39stop), and it was identified in two families with hereditary heart failure. Hereditary mutants of phospholamban, such as Arg(9) to Cys, Arg(9) to Leu, Arg(9) to His, cause lethal, hereditary dilated cardiomyopathy.in specific, two patients presented a G-T missense mutation at the G26 nucleotide, which encodes an Arg-Leu substitution at codon 9 (R9L).One patient presented a G-A missense mutation at the same nucleotide, which encodes an Arg-His substitution at codon 9 (R9H). A missense mutation in PLN cytoplasmic domain (R9C) triggers dilated cardiomyopathy in humans, leading to premature death.

[22155237, 12610310, 16829191, 22820313, 22707725, 17010801, 21332051, 23568436, 21282613, 12639993, 23871674, 22137083, 16432188]

Depressed Ca-handling in cardiomyocytes is frequently attributed to impaired sarcoplasmic reticulum (SR) function in human and experimental heart failure. Phospholamban (PLN) is a key regulator of SR and cardiac function, and PLN mutations in humans have been associated with dilated cardiomyopathy (DCM). We previously reported the deletion of the highly conserved amino acid residue arginine 14 (nucleic acids 39, 40 and 41) in DCM patients. This basic amino acid is important in maintaining the upstream consensus sequence for PKA phosphorylation of Ser 16 in PLN. To assess the function of this mutant PLN, we introduced the PLN-R14Del in cardiac myocytes of the PLN null mouse. Transgenic lines expressing mutant PLN-R14Del at similar protein levels to wild types exhibited no inhibition of the initial rates of oxalate-facilitated SR Ca uptake compared to PLN-knockouts (PLN-KO). The contractile parameters and Ca-kinetics also remained highly stimulated in PLN-R14Del cardiomyocytes, similar to PLN-KO, and isoproterenol did not further stimulate these hyper-contractile basal parameters. Consistent with the lack of inhibition on SR Ca-transport and contractility, confocal microscopy indicated that the PLN-R14Del failed to co-localize with SERCA2a. Moreover, PLN-R14Del did not co-immunoprecipitate with SERCA2a (as did WT-PLN), but rather co-immunoprecipitated with the sarcolemmal Na/K-ATPase (NKA) and stimulated NKA activity. In addition, studies in HEK cells indicated significant fluorescence resonance energy transfer between PLN-R14Del-YFP and NKAα1-CFP, but not with the NKA regulator phospholemman. Despite the enhanced cardiac function in PLN-R14Del hearts (as in PLN-knockouts), there was cardiac hypertrophy (unlike PLN-KO) coupled with activation of Akt and the MAPK pathways. Thus, human PLN-R14Del is misrouted to the sarcolemma, in the absence of endogenous PLN, and alters NKA activity, leading to cardiac remodeling. Molecular etiologies of heart failure, an emerging cardiovascular epidemic affecting 4.7 million Americans and costing 17.8 billion health-care dollars annually, remain poorly understood. Here we report that an inherited human dilated cardiomyopathy with refractory congestive heart failure is caused by a dominant Arg --> Cys missense mutation at residue 9 (R9C) in phospholamban (PLN), a transmembrane phosphoprotein that inhibits the cardiac sarcoplasmic reticular Ca2+-adenosine triphosphatase (SERCA2a) pump. Transgenic PLN(R9C) mice recapitulated human heart failure with premature death. Cellular and biochemical studies revealed that, unlike wild-type PLN, PLN(R9C) did not directly inhibit SERCA2a. Rather, PLN(R9C) trapped protein kinase A (PKA), which blocked PKA-mediated phosphorylation of wild-type PLN and in turn delayed decay of calcium transients in myocytes. These results indicate that myocellular calcium dysregulation can initiate human heart failure-a finding that may lead to therapeutic opportunities. BACKGROUND: Phospholamban is an endogenous sarcoplasmic reticulum calcium ATPase inhibitor with a regulatory effect on cardiac contraction/relaxation coupling. Mutations in the phospholamban gene (PLN) have been associated with primary cardiomyopathies. AIMS: To screen for PLN mutations in our population of patients with primary cardiomyopathies and to perform functional analysis of the mutations identified. METHODS: We performed SSCP mutational screening and DNA sequencing of the PLN gene in 186 patients with either hypertrophic or dilated cardiomyopathy. To study promoter strength we constructed reporter plasmids containing the luciferase gene and performed transient transfection analysis in C6 and C2C12 cell lines. RESULTS: The PLN -42 C>G mutation was found in one patient with late onset familial apical hypertrophic cardiomyopathy. This mutation decreased phospholamban promoter activity by 43% and 47%, in C6 and C2C12 cell lines respectively. One son had mild apical hypertrophic cardiomyopathy and carried the mutation, another son with normal ECG and echocardiogram also had the mutation. CONCLUSION: The PLN -42 C>G mutation is associated with a benign form of apical hypertrophic cardiomyopathy in this family, though the presence of a healthy adult carrier suggests that other genetic and environmental factors could be involved. Otherwise, mutations in the PLN gene are not a frequent cause of cardiomyopathies in our population. AIMS: To investigate whether phospholamban gene (PLN) mutations underlie patients diagnosed with either arrhythmogenic right ventricular cardiomyopathy (ARVC) or idiopathic dilated cardiomyopathy (DCM). METHODS AND RESULTS: We screened a cohort of 97 ARVC and 257 DCM unrelated index patients for PLN mutations and evaluated their clinical characteristics. PLN mutation R14del was identified in 12 (12 %) ARVC patients and in 39 (15 %) DCM patients. Haplotype analysis revealed a common founder, estimated to be between 575 and 825 years old. A low voltage electrocardiogram was present in 46 % of R14del carriers. Compared with R14del- DCM patients, R14del+ DCM patients more often demonstrated appropriate implantable cardioverter defibrillator discharge (47 % vs. 10 % , P < 0.001), cardiac transplantation (18 % vs. 2 % , P < 0.001), and a family history for sudden cardiac death (SCD) at < 50 years (36 % vs. 16 % , P = 0.007). We observed a similar pattern in the ARVC patients although this was not statistically significant. The average age of 26 family members who died of SCD was 37.7 years. Immunohistochemistry in available myocardial samples revealed absent/depressed plakoglobin levels at intercalated disks in five of seven (71 %) R14del+ ARVC samples, but in only one of nine (11 %) R14del+ DCM samples (P = 0.03). CONCLUSIONS: The PLN R14del founder mutation is present in a substantial number of patients clinically diagnosed with DCM or ARVC. R14del+ patients diagnosed with DCM showed an arrhythmogenic phenotype, and SCD at young age can be the presenting symptom. These findings support the concept of 'arrhythmogenic cardiomyopathy'. The sarcoplasmic reticulum calcium pump (SERCA) and its regulator, phospholamban, are essential components of cardiac contractility. Phospholamban modulates contractility by inhibiting SERCA, and this process is dynamically regulated by β-adrenergic stimulation and phosphorylation of phospholamban. Herein we reveal mechanistic insight into how four hereditary mutants of phospholamban, Arg(9) to Cys, Arg(9) to Leu, Arg(9) to His, and Arg(14) deletion, alter regulation of SERCA. Deletion of Arg(14) disrupts the protein kinase A recognition motif, which abrogates phospholamban phosphorylation and results in constitutive SERCA inhibition. Mutation of Arg(9) causes more complex changes in function, where hydrophobic substitutions such as cysteine and leucine eliminate both SERCA inhibition and phospholamban phosphorylation, whereas an aromatic substitution such as histidine selectively disrupts phosphorylation. We demonstrate that the role of Arg(9) in phospholamban function is multifaceted: it is important for inhibition of SERCA, it increases the efficiency of phosphorylation, and it is critical for protein kinase A recognition in the context of the phospholamban pentamer. Given the synergistic consequences on contractility, it is not surprising that the mutants cause lethal, hereditary dilated cardiomyopathy. The regulatory interaction of phospholamban (PLN) with Ca(2+)-ATPase controls the uptake of calcium into the sarcoplasmic reticulum, modulating heart muscle contractility. A missense mutation in PLN cytoplasmic domain (R9C) triggers dilated cardiomyopathy in humans, leading to premature death. Using a combination of biochemical and biophysical techniques both in vitro and in live cells, we show that the R9C mutation increases the stability of the PLN pentameric assembly via disulfide bridge formation, preventing its binding to Ca(2+)-ATPase as well as phosphorylation by protein kinase A. These effects are enhanced under oxidizing conditions, suggesting that oxidative stress may exacerbate the cardiotoxic effects of the PLN(R9C) mutant. These results reveal a regulatory role of the PLN pentamer in calcium homeostasis, going beyond the previously hypothesized role of passive storage for active monomers. In human disease and experimental animal models, depressed Ca(2+) handling in failing cardiomyocytes is widely attributed to impaired sarcoplasmic reticulum (SR) function. In mice, disruption of the PLN gene encoding phospholamban (PLN) or expression of dominant-negative PLN mutants enhances SR and cardiac function, but effects of PLN mutations in humans are unknown. Here, a T116G point mutation, substituting a termination codon for Leu-39 (L39stop), was identified in two families with hereditary heart failure. The heterozygous individuals exhibited hypertrophy without diminished contractile performance. Strikingly, both individuals homozygous for L39stop developed dilated cardiomyopathy and heart failure, requiring cardiac transplantation at ages 16 and 27. An over 50% reduction in PLN mRNA and no detectable PLN protein were noted in one explanted heart. The expression of recombinant PLN-L39stop in human embryonic kidney (HEK) 293 cells and adult rat cardiomyocytes showed no PLN inhibition of SR Ca(2+)-ATPase and the virtual absence of stable PLN expression; where PLN was expressed, it was misrouted to the cytosol or plasma membrane. These findings describe a naturally-occurring loss-of-function human PLN mutation (PLN null). In contrast to reported benefits of PLN ablation in mouse heart failure, humans lacking PLN develop lethal dilated cardiomyopathy. Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is frequently associated with desmosomal mutations. However, nondesmosomal mutations may be involved. The aim of this study was to assess the contribution of a phospholamban (PLN) gene mutation to ARVD/C diagnosis according to the revised 2010 task force criteria (TFC). In 142 Dutch patients (106 men, mean age 51 ± 13 years) with proven ARVD/C (fulfillment of 2010 TFC for diagnosis), 5 known desmosomal genes (PKP2, DSP, DSC2, DSG2, and JUP) and the nondesmosomal PLN gene were screened. After genetic analysis, phenotypic characteristics of desmosomal versus PLN mutation carriers were compared. In 59 of 142 patients with ARVD/C (42%), no desmosomal mutation was found. In 19 of 142 patients (13%), the PLN founder mutation c.40_42delAGA (p.Arg14del) was identified. PLN mutation carriers more often had low-voltage electrocardiograms (p = 0.004), inverted T waves in leads V4 to V6 (p <0.001), and additional structural (p = 0.007) or functional (p = 0.017) left ventricular impairment, whereas desmosomal mutation carriers had more solitary right ventricular abnormalities. The revised TFC included 21 of 142 patients with proven ARVD/C who did not meet the 1994 TFC, including 7 PLN mutation carriers. In conclusion, there is a substantial contribution of PLN mutation to ARVD/C diagnosis by the 2010 TFC. In 32% of patients (19 of 59) with genetically unexplained proven ARVD/C, this nondesmosomal mutation was found. PLN mutation carriers have ARVD/C characteristics, including important right ventricular involvement, and additionally more often low-voltage electrocardiograms, inverted T waves in the left precordial leads, and left ventricular involvement. The sarcoplasmic reticulum Ca(2+)-cycling proteins are key regulators of cardiac contractility, and alterations in sarcoplasmic reticulum Ca(2+)-cycling properties have been shown to be causal of familial cardiomyopathies. Through genetic screening of dilated cardiomyopathy patients, we identified a previously uncharacterized deletion of arginine 14 (PLN-R14Del) in the coding region of the phospholamban (PLN) gene in a large family with hereditary heart failure. No homozygous individuals were identified. By middle age, heterozygous individuals developed left ventricular dilation, contractile dysfunction, and episodic ventricular arrhythmias, with overt heart failure in some cases. Transgenic mice overexpressing the mutant PLN-R14Del recapitulated human cardiomyopathy exhibiting similar histopathologic abnormalities and premature death. Coexpression of the normal and mutant-PLN in HEK-293 cells resulted in sarcoplasmic reticulum Ca(2+)-ATPase superinhibition. The dominant effect of the PLN-R14Del mutation could not be fully removed, even upon phosphorylation by protein kinase A. Thus, by chronic suppression of sarcoplasmic reticulum Ca(2+)-ATPase activity, the nonreversible superinhibitory function of mutant PLN-R14Del may lead to inherited dilated cardiomyopathy and premature death in both humans and mice.

Which are the supplemental antioxidant in athletes?

There are several antioxidant supplements belonging to different families, i.e. Vitamins, Polyphenols, alpha-lipoic acid, ubiquinones, n-3- polyunsaturated acids (PUFAs), minerals and others. Nonetheless the widespread use of these supplements, it is still debated their true usefulness, and it is not unanimously advised their use in athletes.

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This investigation examined the effect of supplementation with Biostimine, extract from Aloe arborescens Mill. leaves, on the levels of pro-oxidant-antioxidant equilibrium markers and anti- and proinflammatory cytokines in rowers subjected to exhaustive exercise. This double-blind study included 18 members of the Polish Rowing Team. Subjects were randomly assigned to the supplemented group (n = 9), which received one ampoule of Biostimine once daily for 4 weeks, or to the placebo group (n = 9). Subjects performed a 2,000-meter-maximum test on a rowing ergometer at the beginning and end of the preparatory camp. Blood samples were obtained from the antecubital vein before each exercise test, 1 min after completing the test and after a 24-hr recovery period. Superoxide dismutase and glutathione peroxidase activity as well as the concentration of thiobarbituric acid reactive substances (TBARS) were assessed in erythrocytes. In addition, total antioxidant capacity (TAC) and creatine kinase activity were measured in plasma samples, and cytokine (IL-6, IL-10) concentrations were determined in the serum. Before and after Biostimine supplementation, exercise significantly increased the values of SOD, IL-6, IL-10, and TBARS in both groups. However, postexercise and recovery levels of TBARS were significantly lower in athletes receiving Biostimine than in controls. After supplementation, TAC was the only variable with the level being significantly higher in the supplemented group than in the placebo group. Consequently, we can conclude that Biostimine supplementation reduces the postexercise level of TBARS by increasing the antioxidant activity of plasma but has no effect on inflammatory markers. BACKGROUND: A number of clinical trials have successfully been performed using whey and/or soy proteins in the treatment of many diseases. They both have antioxidant properties, which appears to be a factor in aerobic physical performance as well. In addition, these are the most often used supplements that sportsmen take to increase their performance. AIM OF THE STUDY: To investigate the effect of whey and soy protein supplementation on redox parameters in the muscle, on body weight, and body composition in swimming-trained and non-trained animals. METHODS: The effect of whey and soy protein-isolate supplementation on muscle redox parameters, body weight, and body composition in trained and non-trained mice was investigated after a single exhaustive bout of exercise. Steady state free radical concentration measured using electron spin resonance (ESR) spectroscopy, reduced and oxidized glutathione ratio, thiobarbituric acid-reactive substances (TBARS), and protein carbonyl levels of the red leg muscle were measured. RESULTS: Free radical concentrations and glutathione composition of the tissue indicated that whey protein supplementation of the regular diet was able to prevent oxidative stress regardless of training. Soy protein supplementation decreased TBARS only in the muscle of untrained animals, while training per se lowered protein damage in all investigated groups. A mixture of soy and whey protein supplementation resulted in leaner animals after training, but had no synergistic effect on either of the measured redox parameters. CONCLUSIONS: Athletes consuming these supplements could train with higher exercise intensity. The antioxidant effect of the two proteins is based on different mechanisms of action. Acute sport exercise leads to a strong stimulation of muscle tissue and a change in the organism energy demands. This study was designed to investigate the effect of oral melatonin supplementation on human physiological functions associated with acute exercise. Immune, endocrine and metabolic parameters were measured in 16 young male football players, who were divided into two groups, an experimental group (supplementation with 6 mg of melatonin administered 30 min prior to exercise) and a control group (placebo without melatonin). They performed a continuous exercise of high intensity (135 beats/min). Samples were collected 30 min before the exercise and 3, 15 and 60 min during the exercise. The results indicated that the acute sport training presented: a) increased lipid peroxidation products (MDA) in both groups, control and experimental, with levels significantly decreased in the group treated with melatonin after 15 and 60 min of high-intensity exercise, b) the total antioxidant activity (TAS) was lower in the control group than in the experimental, the latter showing significant differences at 60 min of high-intensity exercise c) the lipid profile of subjects in the experimental group showed lower triglyceride levels than the control group after 15 and 60 min of high-intensity exercise, d) immunological studies only showed, in the experimental group, an increase in IgA levels at 60 min after the exercise, and finally there were no significant differences between the groups for any of the other variables. In conclusion these results indicated that treatment with melatonin in acute sports exercise reversed oxidative stress, improved defenses and lipid metabolism, which would result in an improvement in fitness. The aim of this study was to evaluate the effect of Lactobacillus rhamnosus IMC 501 and Lactobacillus paracasei IMC 502 on oxidative stress in athletes during a four-week period of intense physical activity. Two groups of twelve subjects each were selected for this analysis. The first group consumed a daily dose of a mixture of the two probiotic strains (1:1 L. rhamnosus IMC 501 and L. paracasei IMC 502; ~10(9) cells/day) for 4 weeks. The second group (control) did not consume any supplements during the 4 weeks. Blood samples collected immediately before and after the supplementation were analyzed, and plasma levels of reactive oxygen metabolites and biological antioxidant potential were determined. Faeces were also collected and analyzed before and at the end of the probiotic supplementation. Antioxidative activity and oxidative stress resistance of the two strains were determined in vitro. Results demonstrated that intense physical activity induced oxidative stress and that probiotic supplementation increased plasma antioxidant levels, thus neutralizing reactive oxygen species. The two strains, L. rhamnosus IMC 501(®) and L. paracasei IMC 502(®), exert strong antioxidant activity. Athletes and all those exposed to oxidative stress may benefit from the ability of these probiotics to increase antioxidant levels and neutralize the effects of reactive oxygen species. Conditions in the body during aerobic exercise increase the level of lipid peroxidation (LP). LP is associated with elevated concentration of modified low-density lipoproteins that are implicated in development of cardiovascular disease. Supplementation with antioxidant vitamin E to athletes at 267 mg (400 IUs) or greater has been reported to reduce levels of LP associated with exercise. Little is currently known about the effects of modest supplementation of vitamin E on previously sedentary adults who initiate an aerobic fitness program. In the present study, sedentary subjects (n = 14) kept 24-hour diet records to establish antioxidant intake of vitamins E and C and collected 24-hour urine samples that were used to determine baseline urinary malondialdehyde (MDA) concentrations, one measure of in vivo LP. No significant differences were noted in the parameters between groups. Seven subjects were randomly selected and supplemented daily with 133 mg (200 IUs) of vitamin E. All subjects participated in moderate-intensity aerobic training for 8 weeks. Post-training, non-supplemented subjects excreted significantly more MDA (p<0.05) and consumed significantly fewer antioxidants than the supplemented group. Vitamin E supplementation appears to suppress elevated LP associated with beginning an aerobic exercise regimen in previously sedentary subjects. This study aims to examine the effect of zinc supplementation on free-radical formation and antioxidant system in individuals who are actively engaged in wrestling as a sport. The study registered a total of 40 male subjects, of whom 20 were wrestlers and 20 were sedentary individuals. The subjects were equally allocated to four groups: group 1, zinc-supplemented sportsmen group; group 2, sportsmen group without supplementation; group 3, zinc-supplemented sedentary group; group 4, sedentary group without supplementation. Blood samples were collected from all subjects twice, once at the beginning of the study and once again at the end of 8-week procedures. The blood samples collected were analyzed to determine the levels of malondialdehyde (MDA), serum glutathione (GSH), serum glutathione peroxidase (GPx) activity, serum superoxide dismutase (SOD) activity (ELISA colorimetric method) and zinc (colorimetric method). No difference was found between MDA levels of the study groups in the beginning of the study. The highest MDA value at the end of the study was obtained in group 4 (p < 0.01). MDA levels in group 2 were established to be significantly higher than those in groups 1 and 3 (p < 0.01). GSH level, GPx, and SOD activities and zinc level measured in the beginning of the study were not different between groups. Measurements performed at the end of the study showed that groups 1 and 3 (zinc-supplemented groups) had the highest GSH level, GPx, and SOD activities and zinc level (p < 0.01). These parameters were not different in the groups without supplementation (groups 2 and 4). Results obtained at the end of the study indicate that zinc supplementation prevents production of free radicals by activating the antioxidant system. In conclusion, physiologic doses of zinc supplementation to athletes may beneficially contribute to their health and performance. Consumption of plant flavonoids, antioxidants, and n-3 fatty acids is proposed to have many potential health benefits derived primarily through antioxidant and anti-inflammatory activities. This study examined the effects of 1,000 mg quercetin + 1,000 mg vitamin C (QC); 1,000 mg quercetin, 1,000 mg vitamin C, 400 mg isoquercetin, 30 mg epigallocatechin gallate, and 400 mg n-3 fatty acids (QFO); or placebo (P), taken each day for 2 wk before and during 3 d of cycling at 57% W(max) for 3 hr, on plasma antioxidant capacity (ferricreducing ability of plasma [FRAP], oxygen-radical absorbance capacity [ORAC]), plasma oxidative stress (F(2)-isoprostanes), and plasma quercetin and vitamin C levels. Thirty-nine athletes were recruited and randomized to QC, QFO, or P. Blood was collected at baseline, after 2 wk supplementation, immediately postexercise, and 14 hr postexercise. Statistical design used a 3 (groups) × 4 (times) repeated-measures ANOVA with post hoc analyses. Plasma quercetin was significantly elevated in QC and QFO compared with P. Plasma F(2)-isoprostanes, FRAP, and vitamin C were significantly elevated and ORAC significantly decreased immediately postexercise, but no difference was noted in the overall pattern of change. Post hoc analyses revealed that the QC and QFO groups did not exhibit a significant increase in F(2)-isoprostanes from baseline to immediately postexercise compared with P. This study indicates that combining flavonoids and antioxidants with n-3 fatty acids is effective in reducing the immediate postexercise increase in F(2)-isoprostanes. Moreover, this effect occurs independently of changes in plasma antioxidant capacity. AIM: The purpose of the current study was to examine the effect of Astaxanthin (Asx) supplementation on muscle enzymes as indirect markers of muscle damage, oxidative stress markers and antioxidant response in elite young soccer players. METHODS: Thirty-two male elite soccer players were randomly assigned in a double-blind fashion to Asx and placebo (P) group. After the 90 days of supplementation, the athletes performed a 2 hour acute exercise bout. Blood samples were obtained before and after 90 days of supplementation and after the exercise at the end of observational period for analysis of thiobarbituric acid-reacting substances (TBARS), advanced oxidation protein products (AOPP), superoxide anion (O2•¯), total antioxidative status (TAS), sulphydril groups (SH), superoxide-dismutase (SOD), serum creatine kinase (CK) and aspartate aminotransferase (AST). RESULTS: TBARS and AOPP levels did not change throughout the study. Regular training significantly increased O2•¯ levels (main training effect, P<0.01). O2•¯ concentrations increased after the soccer exercise (main exercise effect, P<0.01), but these changes reached statistical significance only in the P group (exercise x supplementation effect, P<0.05). TAS levels decreased significantly post- exercise only in P group (P<0.01). Both Asx and P groups experienced increase in total SH groups content (by 21% and 9%, respectively) and supplementation effect was marginally significant (P=0.08). Basal SOD activity significantly decreased both in P and in Asx group by the end of the study (main training effect, P<0.01). All participants showed a significant decrease in basal CK and AST activities after 90 days (main training effect, P<0.01 and P<0.001, respectively). CK and AST activities in serum significantly increased as result of soccer exercise (main exercise effect, P<0.001 and P<0.01, respectively). Postexercise CK and AST levels were significantly lower in Asx group compared to P group (P<0.05) CONCLUSION: The results of the present study suggest that soccer training and soccer exercise are associated with excessive production of free radicals and oxidative stress, which might diminish antioxidant system efficiency. Supplementation with Asx could prevent exercise induced free radical production and depletion of non-enzymatic antioxidant defense in young soccer players. Master athletes are more than 35 years of age and continue to train as hard as their young counterparts despite the aging process. All life long, they are capable of accomplishing exceptional sporting performances. For these participants in endurance events, matching energy intake and expenditure is critical to maintain health and performance. The proportions of carbohydrate, fat, and protein must be optimized to provide enough calories to sustain the energy requirements of competition or training, and for recovery. In addition, endurance athletes must include adequate vitamins and minerals in their diets to maintain healthy immune function. Vitamins and minerals may be sufficient in the diets of endurance athletes, who have a high energy intake. This would make it unnecessary to use vitamin and mineral supplements. Furthermore, one major limitation for these athletes is the management of oxidative stress, which, when in excess, can be deleterious for the organism. For individuals exposed to oxidative stress, micronutritional supplementations rich in vitamins and minerals can be also an alternative strategy. Although these supplementations are increasingly used by master athletes, very few data are available on their effects on oxidative stress, muscle recovery, and physical performance. The potential benefits of supplement use in athletes are thus questionable. Some studies indicate no benefits, while others highlight potential negative side effects of vitamin supplementation. Additional studies are warranted in order to design adapted prescriptions in antioxidant vitamins and minerals. Rahimi, R. Creatine supplementation decreases oxidative DNA damage and lipid peroxidation induced by a single bout of resistance exercise. J Strength Cond Res 25(12): 3448-3455, 2011-Creatine (Cr), or methyl guanidine-acetic acid, can be either ingested from exogenous sources, such as fish or meat, or produced endogenously by the body, primarily in the liver. It is used as an ergogenic aid to improve muscle mass, strength, and endurance. Heretofore, Cr's positive therapeutic benefits in various oxidative stress-associated diseases have been reported in the literature and, recently, Cr has also been shown to exert direct antioxidant effects. Therefore, the purpose of this study was to investigate the effects of an acute bout of resistance exercise (RE) on oxidative stress response and oxidative DNA damage in male athletes and whether supplementation with Cr could negate any observed differences. Twenty-seven resistance-trained men were randomly divided into a Cr supplementation group (the Cr group [21.6 ± 3.6 years], taking 4 × 5 g Cr monohydrate per day) or a placebo (PL) supplementation group (the PL group [21.2 ± 3.2 years], taking 4 × 5 g maltodextrin per day). A double-blind research design was employed for a 7-day supplementation period. Before and after the seventh day of supplementation, the subjects performed an RE protocol (7 sets of 4 exercises using 60-90 1 repetition maximum) in the flat pyramid loading pattern. Blood and urine samples taken before, immediately, and 24-hour postexercise were analyzed for plasma malondialdehyde (MDA) and urinary 8-hydroxy-2-deoxyguanosine (8-OHdG) excretion. Before the supplementation period, a significant increase in the urinary 8-OHdG excretion and plasma MDA levels was observed after RE. The Cr supplementation induces a significant increase in athletics performance, and it attenuated the changes observed in the urinary 8-OHdG excretion and plasma MDA. These results indicate that Cr supplementation reduced oxidative DNA damage and lipid peroxidation induced by a single bout of RE. The authors evaluated the role of a high-protein, low-calorie, polyunsaturated fatty-acid (PUFA) -supplemented diet on anthropometric parameters, erythrocyte-membrane fatty-acid composition, and plasma antioxidant defenses of nonprofessional volleyball athletes. The athletes were divided in two groups: One (n = 5) followed the Mediterranean diet, and the other (n = 6) followed a high-protein, low-calorie diet with a 3-g/day fish-oil supplementation. All the athletes had anthropometric measurements taken, both at the beginning and at the end of the study, which lasted for 2 months. Body-mass index and total body fat were significantly diminished in the second group, while they remained unchanged in the first. Plasma total antioxidant activity (TAA) was significantly increased in the plasma of both groups, with no differences between the groups, suggesting that physical activity, not the different diets, is the main contributor to the increase of plasma TAA. The second group showed a significant increase in erythrocyte-membrane PUFA content and in the unsaturation index value (UI) because of the fish-oil supplementation.A high-protein, low-carbohydrate, fish-oil-supplemented diet seems to be useful only when the aim of the diet is to obtain weight loss in a short-term period. The significant increase in the UI of erythrocyte membranes indicates the potential for harm, because a high intake of PUFA might increase susceptibility to lipid peroxidation not counterbalanced by a higher increase in TAA. Adherence to the Mediterranean diet seems to be the better choice. The main aim of this investigation was to evaluate the changes in total antioxidant capacity (TAC) and aerobic and anaerobic performance induced by supplementation of coffeeberry (CB) formulation for 4 weeks in college athletes. Twenty college athletes (14 males and 6 females) were allocated to two randomly assigned trials. Subjects in the CB group orally ingested capsules that contained CB formulation at a dose of 800 mg per day in two equal doses for 28 days, while subjects in the placebo (P) group ingested an equal number of identical-looking caps that contained cellulose. There were no changes in glucose, cholesterol, and lipoproteins within or between trials (p > 0.05). Total antioxidant capacity (TAC) was significantly higher in the CB versus P trial at the post- supplementation trial (1.66 +/- 0.16 vs. 1.51 +/- 0.05 mmol/L; p < 0.05). There were no statistically significant changes in average anaerobic power, index of anaerobic fatigue, maximal heart rate, blood lactate, and maximal oxygen uptake within or between trials (p > 0.05). Heart rate recovery (HRR) index increased significantly in CB group as compared with baseline level (38 +/- 4 vs. 32 +/- 5 beats/min; p < 0.05). Blood lactate after 10 min of recovery (Lact(rec)) significantly decreased in the CB group after supplementation protocol as compared with initial results (7.6 +/- 4.2 vs. 5.5 +/- 2.6 mmol/L; p < 0.05). No subject reported any side effects from CB or P. The results of the present study indicate that supplementation with a CB formulation slightly increased antioxidant capacity, but there were minimal effects on recovery parameters after exercise in college athletes. The idea that dietary supplements can improve athletic performance is popular among athletes. The use of antioxidant supplements is widespread among endurance athletes because of evidence that free radicals contribute to muscle fatigue during prolonged exercise. Furthermore, interest in vitamin D supplementation is increasing in response to studies indicating that vitamin D deficiency exists in athletic populations. This review explores the rationale for supplementation with both antioxidants and vitamin D and discusses the evidence to support and deny the benefits of these dietary supplements. The issue of whether athletes should use antioxidant supplements remains highly controversial. Nonetheless, at present there is limited scientific evidence to recommend antioxidant supplements to athletes or other physically active individuals. Therefore, athletes should consult with their health care professional and/or nutritionist when considering antioxidant supplementation. The issue of whether athletes should supplement with vitamin D is also controversial. While arguments for and against vitamin D supplementation exist, additional research is required to determine whether vitamin D supplementation is beneficial to athletes. Nevertheless, based upon the growing evidence that many athletic populations are vitamin D deficient or insufficient, it is recommended that athletes monitor their serum vitamin D concentration and consult with their health care professional and/or nutritionist to determine if they would derive health benefits from vitamin D supplementation. OBJECTIVE: The goal of this study was to evaluate the effects of creatine (Cr) supplementation on oxidative stress and inflammation markers after acute repeated-sprint exercise in humans. METHODS: Twenty-five players under age 20 y were randomly assigned to two groups: Cr supplemented and placebo. Double-blind controlled supplementation was performed using Cr (0.3 g/kg) or placebo tablets for 7 d. Before and after 7 d of supplementation, the athletes performed two consecutive Running-based Anaerobic Sprint Tests (RAST). RAST consisted of six 35-m sprint runs at maximum speed with 10 sec rest between them. Blood samples were collected just prior to start of test (pre), just after the completion (0 h), and 1 h after completion. RESULTS: Average, maximum, and minimum power values were greater in the Cr-supplemented group compared with placebo (P < 0.05). There were significant increases (P < 0.05) in plasma tumor necrosis factor alpha (TNF-α) and C-reactive protein (CRP) up to 1 h after acute sprint exercise in the placebo-supplemented group. Malondialdehyde, lactate dehydrogenase (LDH), catalase, and superoxide dismutase enzymes also were increased after exercise in both groups. Red blood cell glutathione was lower after exercise in both groups. Cr supplementation reversed the increase in TNF-α and CRP as well as LDH induced by acute exercise. Controversially, Cr supplementation did not inhibit the rise in oxidative stress markers. Also, antioxidant enzyme activity was not different between placebo and Cr-supplemented groups. CONCLUSION: Cr supplementation inhibited the increase of inflammation markers TNF-α and CRP, but not oxidative stress markers, due to acute exercise. The aim of this investigation was to assess the effects of 6 wk of eicosapentanoic acid (EPA) and docosahexanoic acid (DHA) supplementation on resting and exercise-induced lipid peroxidation and antioxidant status in judoists. Subjects were randomly assigned to receive a placebo or a capsule of polyunsaturated fatty acids (PUFAs; 600 mg EPA and 400 mg DHA). Blood samples were collected in preexercise and postexercise conditions (judo-training session), both before and after the supplementation period. The following parameters were analyzed: α-tocopherol, retinol, lag phase , maximum rate of oxidation (Rmax) during the propagating chain reaction, maximum amount of conjugated dienes (CDmax) accumulated after the propagation phase, nitric oxide (NO) and malondyaldehide (MDA) concentrations, salivary glutathione peroxidase activity, and the lipid profile. Dietary data were collected using a 7-day dietary record. A significant interaction effect between supplementation and time (p < .01) on triglycerides was noted, with values significantly lower in the n-3 long-chain-PUFA (LCPUFA) group after supplementation than in the placebo group. Significant interaction effects between supplementation and time on resting MDA concentrations and Rmax were found (p = .03 and p = .04, respectively), with elevated values in the n-3 LCPUFA group after supplementation and no change in the placebo group's levels. The authors observed a significantly greater NO and oxidative-stress increase with exercise (MDA, Rmax, CDmax, and NO) in the n-3 LCPUFA group than with placebo. No main or interaction effects were found for retinol and α-tocopherol. These results indicate that supplementation with n-3 LCPUFAs significantly increased oxidative stress at rest and after a judo-training session. Exercise-induced oxidative stress is implicated in muscle damage and fatigue which has led athletes to embark on antioxidant supplementation regimes to negate these effects. This study investigated the intake of vitamin C (VC) (1 g), blackcurrant (BC) juice (15 mg VC, 300 mg anthocyanins) and placebo in isocaloric drink form on training progression, incremental running test and 5-km time-trial performance. Twenty-three trained female runners (age, 31 ± 8 y; mean ± SD) completed three blocks of high-intensity training for 3 wks and 3 days, separated by a washout (~3.7 wks). Changes in training and performance with each treatment were analysed with a mixed linear model, adjusting for performance at the beginning of each training block. Markers of oxidative status included protein carbonyl, malondialdehyde (in plasma and in vitro erythrocytes), ascorbic acid, uric acid and erythrocyte enzyme activity of superoxide dismutase, catalase and glutathione peroxidase were analysed. There was a likely harmful effect on mean running speed during training when taking VC (1.3%; 90% confidence limits ±1.3%). Effects of the two treatments relative to placebo on mean performance in the incremental test and time trial were unclear, but runners faster by 1 SD of peak speed demonstrated a possible improvement on peak running speed with BC juice (1.9%; ±2.5%). Following VC, certain oxidative markers were elevated: catalase at rest (23%; ±21%), protein carbonyls at rest (27%; ±38%) and superoxide dismutase post-exercise (8.3%; ±9.3%). In conclusion, athletes should be cautioned about taking VC chronically, however, BC may improve performance in the elite.

Is glycyl-tRNA synthetase gene involved in the development of Charcot-Marie-Tooth disease?

Dominant mutations in GARS, encoding the essential enzyme glycyl-tRNA synthetase (GlyRS), result in a form of Charcot-Marie-Tooth disease, type 2D (CMT2D), predominantly characterized by lower motor nerve degeneration.

[24368416, 23990368, 25168514, 17035524, 24669931, 24898252, 23279345, 16982418, 22144914, 12690580, 19470612, 25420567, 17545306]

Charcot-Marie-Tooth disease type 2D is a hereditary axonal and glycyl-tRNA synthetase (GARS)-associated neuropathy that is caused by a mutation in GARS. Here, we report a novel GARS-associated mouse neuropathy model using an adenoviral vector system that contains a neuronal-specific promoter. In this model, we found that wild-type GARS is distributed to peripheral axons, dorsal root ganglion (DRG) cell bodies, central axon terminals, and motor neuron cell bodies. In contrast, GARS containing a G240R mutation was localized in DRG and motor neuron cell bodies, but not axonal regions, in vivo. Thus, our data suggest that the disease-causing G240R mutation may result in a distribution defect of GARS in peripheral nerves in vivo. Furthermore, a distributional defect may be associated with axonal degradation in GARS-associated neuropathies. Charcot-Marie-Tooth disease type 2D (CMT2D) is an autosomal-dominant axonal peripheral neuropathy characterized by impaired motor and sensory function in the distal extremities. Mutations in the glycyl-tRNA synthetase (GARS) gene cause CMT2D. GARS is a member of the ubiquitously expressed aminoacyl-tRNA synthetase (ARS) family and is responsible for charging tRNA with glycine. To date, 13 GARS mutations have been identified in patients with CMT disease. While functional studies have revealed loss-of-function characteristics, only four GARS mutations have been rigorously studied. Here, we report the functional evaluation of nine CMT-associated GARS mutations in tRNA charging, yeast complementation, and subcellular localization assays. Our results demonstrate that impaired function is a common characteristic of CMT-associated GARS mutations. Additionally, one mutation previously associated with CMT disease (p.Ser581Leu) does not demonstrate impaired function, was identified in the general population, and failed to segregate with disease in two newly identified families with CMT disease. Thus, we propose that this variant is not a disease-causing mutation. Together, our data indicate that impaired function is a key component of GARS-mediated CMT disease and emphasize the need for careful genetic and functional evaluation before implicating a variant in disease onset. BACKGROUND: Glycyl-tRNA synthetase (GARS) is an aminoacyl-tRNA synthetase (ARS) that links the amino acid glycine to its corresponding tRNA prior to protein translation and is one of three bifunctional ARS that are active within both the cytoplasm and mitochondria. Dominant mutations in GARS cause rare forms of Charcot-Marie-Tooth disease and distal spinal muscular atrophy. CASE PRESENTATION: We report a 12-year old girl who presented with clinical and biochemical features of a systemic mitochondrial disease including exercise-induced myalgia, non-compaction cardiomyopathy, persistent elevation of blood lactate and alanine and MRI evidence of mild periventricular leukomalacia. Using exome sequencing she was found to harbor compound heterozygous mutations within the glycyl-tRNA synthetase (GARS) gene; c.1904C > T; p.Ser635Leu and c.1787G > A; p.Arg596Gln. Each mutation occurred at a highly conserved site within the anticodon binding domain. CONCLUSION: Our findings suggest that recessive mutations in GARS may cause systemic mitochondrial disease. This phenotype is distinct from patients with previously reported dominant mutations in this gene, thereby expanding the spectrum of disease associated with GARS dysregulation. Glycyl-tRNA synthetase (GARS), which encodes the enzyme responsible for charging tRNA(Gly) with glycine in both the cytoplasm and mitochondria, is implicated to Charcot-Marie-Tooth disease 2D (CMT2D) and distal hereditary motor neuropathy type V (dHMN-V). We performed whole exome sequencing (WES) to identify the genetic defects in the two dHMN families. WES revealed several decades of non-synonymous variants in the CMT and aminoacyl-tRNA synthetase genes. The subsequent capillary sequencing for family members and controls revealed two novel causative mutations, c.598G>A (D200N) and c.794C>T (S265F), in the GARS gene in each dHMN family. Both mutations were cosegregated with affected individuals in each family, and were not found in the 200 controls. The mutation sites were well conserved between the different species and in silico analysis predicted that both mutations may affect protein function. Therefore, we believe that these two novel GARS mutations are the underlying causes of the dHMN phenotype. Of the many inherited Charcot-Marie-Tooth peripheral neuropathies, type 2D (CMT2D) is caused by dominant point mutations in the gene GARS, encoding glycyl tRNA synthetase (GlyRS). Here we report a dominant mutation in Gars that causes neuropathy in the mouse. Importantly, both sensory and motor axons are affected, and the dominant phenotype is not caused by a loss of the GlyRS aminoacylation function. Mutant mice have abnormal neuromuscular junction morphology and impaired transmission, reduced nerve conduction velocities, and a loss of large-diameter peripheral axons, without defects in myelination. The mutant GlyRS enzyme retains aminoacylation activity, and a loss-of-function allele, generated by a gene-trap insertion, shows no dominant phenotype in mice. These results indicate that the CMT2D phenotype is caused not by reduction of the canonical GlyRS activity and insufficiencies in protein synthesis, but instead by novel pathogenic roles for the mutant GlyRS that specifically affect peripheral neurons. Mutations in the enzyme glycyl-tRNA synthetase (GARS) cause motor and sensory axon loss in the peripheral nervous system in humans, described clinically as Charcot-Marie-Tooth type 2D or distal spinal muscular atrophy type V. Here, we characterise a new mouse mutant, Gars(C201R), with a point mutation that leads to a non-conservative substitution within GARS. Heterozygous mice with a C3H genetic background have loss of grip strength, decreased motor flexibility and disruption of fine motor control; this relatively mild phenotype is more severe on a C57BL/6 background. Homozygous mutants have a highly deleterious set of features, including movement difficulties and death before weaning. Heterozygous animals have a reduction in axon diameter in peripheral nerves, slowing of nerve conduction and an alteration in the recovery cycle of myelinated axons, as well as innervation defects. An assessment of GARS levels showed increased protein in 15-day-old mice compared with controls; however, this increase was not observed in 3-month-old animals, indicating that GARS function may be more crucial in younger animals. We found that enzyme activity was not reduced detectably in heterozygotes at any age, but was diminished greatly in homozygous mice compared with controls; thus, homozygous animals may suffer from a partial loss of function. The Gars(C201R) mutation described here is a contribution to our understanding of the mechanism by which mutations in tRNA synthetases, which are fundamentally important, ubiquitously expressed enzymes, cause axonopathy in specific sets of neurons.

Is there any software for automated analysis of FISH images?

FISH is a popular molecular cytogenetic method. The output of a single FISH analysis is a set of several tens or hundreds microscopic images — a single evaluated sample is of roughly 20mm diameter. The goal of an automated evaluation is to replace the subjective evaluation of images by the laboratory technician to achieve higher uniformity of results. Following explanation of the principle of the method and the typical contents of images, the processing flow of image segmentation is outlined and the results are presented on several example images. Based on results there are software for automated analysis of FISH images.

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HER2-positive breast cancer is characterized by aggressive growth and poor prognosis. Women with metastatic breast cancer with over-expression of HER2 protein or excessive presence of HER2 gene copies are potential candidates for Herceptin (Trastuzumab) targeted treatment that binds to HER2 receptors on tumor cells and inhibits tumor cell growth. Fluorescence in situ hybridization (FISH) is one of the most widely used methods to determine HER2 status. Typically, evaluation of FISH images involves manual counting of FISH signals in multiple images, a time consuming and error prone procedure. Recently, we developed novel software for the automated evaluation of FISH images and, in this study, we present the first testing of this software on images from two separate research clinics. To our knowledge, this is the first concurrent evaluation of any FISH image analysis software in two different clinics. The evaluation shows that the developed FISH image analysis software can accelerate evaluation of HER2 status in most breast cancer cases. Phosphorylation of the H2AX protein is an early step in the double strand break (DSB) repair pathway; therefore, phosphorylated histone (γH2AX) foci scoring is widely used as a measure for DSBs. Foci scoring is performed either manually or semi-automatically using hand-operated capturing and image analysis software. In general, both techniques are laborious and prone to artifacts associated with manual scoring. While a few fully automated methods have been described in the literature, none of them have been used to quantify γH2AX foci in combination with a cell cycle phase analysis. Adding this feature to a rapid automated γH2AX foci quantification method would reduce the scoring uncertainty that arises from the variations in the background level of the γH2AX signal throughout the cell cycle. The method was set up to measure DNA damage induced in human mammary epithelial cells by irradiation under a mammogram device. We adapted a FISH (fluorescent in situ hybridization) Spot-counting system, which has a slide loader with automatic scanning and cell capture system throughout the thickness of each cell (z-stack), to meet our assay requirements. While scanning the sample, the system classifies the selected nuclei according to the signal patterns previously described by the user. For our purposes, a double staining immunofluorescence was carried out with antibodies to detect γH2AX and pericentrin, an integral component of the centrosome. We could thus distinguish both the number of γH2AX foci per cell and the cell cycle phase. Furthermore, restrictive settings of the program classifier reduced the "touching nuclei" problem described in other image analysis software. The automated scoring was faster than and as sensitive as its manually performed counterpart. This system is a reliable tool for γH2AX radio-induced foci counting and provides essential information about the cell cycle stage. It thus offers a more complete and rapid assessment of DNA damage. 1. Fluorescence in situ hybridization (FISH) is a molecular diagnostic technique in which a fluorescent labeled probe hybridizes to a target nucleotide sequence of deoxyribose nucleic acid. Upon excitation, each chromosome containing the target sequence produces a fluorescent signal (spot). Because fluorescent spot counting is tedious and often subjective, automated digital algorithms to count spots are desirable. New technology provides a stack of images on multiple focal planes throughout a tissue sample. Multiple-focal-plane imaging helps overcome the biases and imprecision inherent in single-focal-plane methods. This paper proposes an algorithm for global spot counting in stacked three-dimensional slice FISH images without the necessity of nuclei segmentation. It is designed to work in complex backgrounds, when there are agglomerated nuclei, and in the presence of illumination gradients. It is based on the morphological top-hat transform, which locates intensity spikes on irregular backgrounds. After finding signals in the slice images, the algorithm groups these together to form three-dimensional spots. Filters are employed to separate legitimate spots from fluorescent noise. The algorithm is set in a comprehensive toolbox that provides visualization and analytic facilities. It includes simulation software that allows examination of algorithm performance for various image and algorithm parameter settings, including signal size, signal density, and the number of slices. BACKGROUND: The simultaneous detection of protein expression and gene copy number changes in patient samples, like paraffin-embedded tissue sections, is challenging since the procedures of immunohistochemistry (IHC) and Fluorescence in situ Hybridization (FISH) negatively influence each other which often results in suboptimal staining. Therefore, we developed a novel automated algorithm based on relocation which allows subsequent detection of protein content and gene copy number changes within the same cell. METHODS: Paraffin-embedded tissue sections of colorectal cancers were stained for CD133 expression. IHC images were acquired and image coordinates recorded. Slides were subsequently hybridized with fluorescently labeled DNA probes. FISH images were taken at the previously recorded positions allowing for direct comparison of protein expression and gene copy number signals within the same cells/tissue areas. Relocation, acquisition of the IHC and FISH images, and enumeration of FISH signals in the immunophenotyped tumour areas were done in an automated fashion. RESULTS: Automated FISH analysis was performed on 13 different colon cancer samples that had been stained for CD133; each sample was scored for MYC, ZNF217 and Chromosome 6 in CD133 positive and negative glands. From the 13 cases four (31%) showed amplification for the MYC oncogene and seven of 13 (54%) cases were amplified for ZNF217. There was no significant difference between CD133 positive tumour and CD133 negative tumour cells. CONCLUSION: The technique and algorithm presented here enables an easy and reproducible combination of IHC and FISH based on a novel automated algorithm using relocation and automated spot counting. Multiplex fluorescence in situ hybridization (M-FISH) is a recently developed technology that enables multi-color chromosome karyotyping for molecular cytogenetic analysis. Each M-FISH image set consists of a number of aligned images of the same chromosome specimen captured at different optical wavelength. This paper presents embedded M-FISH image coding (EMIC), where the foreground objects/chromosomes and the background objects/images are coded separately. We first apply critically sampled integer wavelet transforms to both the foreground and the background. We then use object-based bit-plane coding to compress each object and generate separate embedded bitstreams that allow continuous lossy-to-lossless compression of the foreground and the background. For efficient arithmetic coding of bit planes, we propose a method of designing an optimal context model that specifically exploits the statistical characteristics of M-FISH images in the wavelet domain. Our experiments show that EMIC achieves nearly twice as much compression as Lempel-Ziv-Welch coding. EMIC also performs much better than JPEG-LS and JPEG-2000 for lossless coding. The lossy performance of EMIC is significantly better than that of coding each M-FISH image with JPEG-2000. Fluorescence in situ Hybridization (FISH) is a major cytogenetic technique for clinical genetic diagnosis of both inherited and acquired chromosomal abnormalities. Although FISH techniques have evolved and are often used together with other cytogenetic methods like CGH, PRINS and PNA-FISH, the process continues to be a manual, labour intensive, expensive and time consuming technique, often taking over 3 5 days, even in dedicated labs. We have developed a novel microFISH device to perform metaphase FISH on a chip which overcomes many shortcomings of the current laboratory protocols. This work also introduces a novel splashing device for preparing metaphase spreads on a microscope glass slide, followed by a rapid adhesive tape-based bonding protocol leading to rapid fabrication of the microFISH device. The microFISH device allows for an optimized metaphase FISH protocol on a chip with over a 20-fold reduction in the reagent volume. This is the first demonstration of metaphase FISH on a microfluidic device and offers a possibility of automation and significant cost reduction of many routine diagnostic tests of genetic anomalies. MOTIVATION: Fluorescence in situ hybridization (FISH) is used to study the organization and the positioning of specific DNA sequences within the cell nucleus. Analyzing the data from FISH images is a tedious process that invokes an element of subjectivity. Automated FISH image analysis offers savings in time as well as gaining the benefit of objective data analysis. While several FISH image analysis software tools have been developed, they often use a threshold-based segmentation algorithm for nucleus segmentation. As fluorescence signal intensities can vary significantly from experiment to experiment, from cell to cell, and within a cell, threshold-based segmentation is inflexible and often insufficient for automatic image analysis, leading to additional manual segmentation and potential subjective bias. To overcome these problems, we developed a graphical software tool called FISH Finder to automatically analyze FISH images that vary significantly. By posing the nucleus segmentation as a classification problem, compound Bayesian classifier is employed so that contextual information is utilized, resulting in reliable classification and boundary extraction. This makes it possible to analyze FISH images efficiently and objectively without adjustment of input parameters. Additionally, FISH Finder was designed to analyze the distances between differentially stained FISH probes. AVAILABILITY: FISH Finder is a standalone MATLAB application and platform independent software. The program is freely available from: http://code.google.com/p/fishfinder/downloads/list. Fluorescence in situ hybridization (FISH) of neural activity-regulated, immediate-early gene (IEG) expression provides a method of functional brain imaging with cellular resolution. This enables the identification, in one brain, of which specific principal neurons were active during each of two distinct behavioral epochs. The unprecedented potential of this differential method for large-scale analysis of functional neural circuits is limited, however, by the time-intensive nature of manual image analysis. A comprehensive software tool for processing three-dimensional, multi-spectral confocal image stacks is described which supports the automation of this analysis. Nuclei counterstained with conventional DNA dyes and FISH signals indicating the sub-cellular distribution of specific, IEG RNA species are imaged using different spectral channels. The DNA channel data are segmented into individual nuclei by a three-dimensional multi-step algorithm that corrects for depth-dependent attenuation, non-isotropic voxels, and imaging noise. Intra-nuclear and cytoplasmic FISH signals are associated spatially with the nuclear segmentation results to generate a detailed tabular/database and graphic representation. Here we present a comprehensive validation of data generated by the automated software against manual quantification by human experts on hippocampal and parietal cortical regions (96.5% concordance with multi-expert consensus). The high degree of reliability and accuracy suggests that the software will generalize well to multiple brain areas and eventually to large-scale brain analysis.

How do histone methyltransferases cause histone modification?

Histone methyltransferases (HMTs) are responsible for the site-specific addition of covalent modifications on the histone tails, which serve as markers for the recruitment of chromatin organization complexes. There are two major types of HMTs: histone-lysine N-Methyltransferases and histone-arginine N-methyltransferases. The former methylate specific lysine (K) residues such as 4, 9, 27, 36, and 79 on histone H3 and residue 20 on histone H4. The latter methylate arginine (R) residues such as 2, 8, 17, and 26 on histone H3 and residue 3 on histone H4. Depending on what residue is modified and the degree of methylation (mono-, di- and tri-methylation), lysine methylation of histones is linked to either transcriptionally active or silent chromatin.

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Epigenetic regulation of gene expression by covalent modification of histones is important for germ line cell development. In mammals, histone H3 lysine 9 (H3K9)-specific histone methyltransferases (HMTases), such as G9a, SETDB1, and SUV39H, play critical roles, but the contribution of H3K9-specific HMTases in Drosophila remains to be clarified, especially in male sperm. Here, we performed immunocytochemical analyses with a specific antibody to dG9a, Drosophila G9a ortholog, and demonstrated localization in the cytoplasm from the growth to elongation stages of spermatogenesis. In the subsequent early canoe stage, strong dG9a signals were detected exclusively in nuclei, suggesting a regulatory role. However, mono-, di-, and trimethylated H3K9 signals were not extensively decreased in a homozygous dG9a null mutant throughout these stages. In contrast, mono- and trimethylated H3K9 signals were extensively decreased in a heterozygous DmSetdb1 mutant during spermatogenesis, and similar reduction in monomethylated H3K9 signals was observed in a homozygous Su(var)3-9 mutant. Therefore, DmSETDB1 is likely to be mainly responsible for mono- and trimethylation of H3K9 and SU(VAR)3-9 for monomethylation of H3K9 during spermatogenesis. However, the reduced methylation of H3K9 in premeiotic spermatocytes did not influence X-Y chromosome disjunction in male meiosis, suggesting that it may not be critical for spermatogenesis in Drosophila. The SAS3-dependent NuA3 histone acetyltransferase complex was originally identified on the basis of its ability to acetylate histone H3 in vitro. Whether NuA3 is capable of acetylating histones in vivo, or how the complex is targeted to the nucleosomes that it modifies, was unknown. To address this question, we asked whether NuA3 is associated with chromatin in vivo and how this association is regulated. With a chromatin pulldown assay, we found that NuA3 interacts with the histone H3 amino-terminal tail, and loss of the H3 tail recapitulates phenotypes associated with loss of SAS3. Moreover, mutation of histone H3 lysine 14, the preferred site of acetylation by NuA3 in vitro, phenocopies a unique sas3Delta phenotype, suggesting that modification of this residue is important for NuA3 function. The interaction of NuA3 with chromatin is dependent on the Set1p and Set2p histone methyltransferases, as well as their substrates, histone H3 lysines 4 and 36, respectively. These results confirm that NuA3 is functioning as a histone acetyltransferase in vivo and that histone H3 methylation provides a mark for the recruitment of NuA3 to nucleosomes. The Epstein-Barr virus (EBV) predominantly establishes latent infection in B cells, and the reactivation of the virus from latency is dependent on the expression of the viral BZLF1 protein. The BZLF1 promoter (Zp) normally exhibits only low basal activity but is activated in response to chemical or biological inducers, such as 12-O-tetradecanoylphorbol-13-acetate (TPA), calcium ionophores, or histone deacetylase (HDAC) inhibitors. In some cell lines latently infected with EBV, an HDAC inhibitor alone can induce BZLF1 transcription, while the treatment does not enhance expression in other cell lines, such as B95-8 or Raji cells, suggesting unknown suppressive mechanisms besides histone deacetylation in those cells. Here, we found the epigenetic modification of the BZLF1 promoter in latent Raji cells by histone H3 lysine 27 trimethylation (H3K27me3), H3K9me2/me3, and H4K20me3. Levels of active markers such as histone acetylation and H3K4me3 were low in latent cells but increased upon reactivation. Treatment with 3-deazaneplanocin A (DZNep), an inhibitor of H3K27me3 and H4K20me3, significantly enhanced the BZLF1 transcription in Raji cells when in combination with an HDAC inhibitor, trichostatin A (TSA). The knockdown of Ezh2 or Suv420h1, histone methyltransferases for H3K27me3 or H4K20me3, respectively, further proved the suppression of Zp by the methylations. Taken together, the results indicate that H3K27 methylation and H4K20 methylation are involved, at least partly, in the maintenance of latency, and histone acetylation and H3K4 methylation correlate with the reactivation of the virus in Raji cells. Mammalian telomeres have heterochromatic features, including trimethylated histone H3 at lysine 9 (H3K9me3) and trimethylated histone H4 at lysine 20 (H4K20me3). In addition, subtelomeric DNA is hypermethylated. The enzymatic activities responsible for these modifications at telomeres are beginning to be characterized. In particular, H4K20me3 at telomeres could be catalyzed by the novel Suv4-20h1 and Suv4-20h2 histone methyltransferases (HMTases). In this study, we demonstrate that the Suv4-20h enzymes are responsible for this histone modification at telomeres. Cells deficient for Suv4-20h2 or for both Suv4-20h1 and Suv4-20h2 show decreased levels of H4K20me3 at telomeres and subtelomeres in the absence of changes in H3K9me3. These epigenetic alterations are accompanied by telomere elongation, indicating a role for Suv4-20h HMTases in telomere length control. Finally, cells lacking either the Suv4-20h or Suv39h HMTases show increased frequencies of telomere recombination in the absence of changes in subtelomeric DNA methylation. These results demonstrate the importance of chromatin architecture in the maintenance of telomere length homeostasis and reveal a novel role for histone lysine methylation in controlling telomere recombination. SET domain-containing proteins represent an evolutionarily conserved family of epigenetic regulators, which are responsible for most histone lysine methylation. Since some of these genes have been revealed to be essential for embryonic development, we propose that the zebrafish, a vertebrate model organism possessing many advantages for developmental studies, can be utilized to study the biological functions of these genes and the related epigenetic mechanisms during early development. To this end, we have performed a genome-wide survey of zebrafish SET domain genes. 58 genes total have been identified. Although gene duplication events give rise to several lineage-specific paralogs, clear reciprocal orthologous relationship reveals high conservation between zebrafish and human SET domain genes. These data were further subject to an evolutionary analysis ranging from yeast to human, leading to the identification of putative clusters of orthologous groups (COGs) of this gene family. By means of whole-mount mRNA in situ hybridization strategy, we have also carried out a developmental expression mapping of these genes. A group of maternal SET domain genes, which are implicated in the programming of histone modification states in early development, have been identified and predicted to be responsible for all known sites of SET domain-mediated histone methylation. Furthermore, some genes show specific expression patterns in certain tissues at certain stages, suggesting the involvement of epigenetic mechanisms in the development of these systems. These results provide a global view of zebrafish SET domain histone methyltransferases in evolutionary and developmental dimensions and pave the way for using zebrafish to systematically study the roles of these genes during development. A novel histone methyltransferase, termed Set9, was isolated from human cells. Set9 contains a SET domain, but lacks the pre- and post-SET domains. Set9 methylates specifically lysine 4 (K4) of histone H3 (H3-K4) and potentiates transcription activation. The histone H3 tail interacts specifically with the histone deacetylase NuRD complex. Methylation of histone H3-K4 by Set9 precludes the association of NuRD with the H3 tail. Moreover, methylation of H3-K4 impairs Suv39h1-mediated methylation at K9 of H3 (H3-K9). The interplay between the Set9 and Suv39h1 histone methyltransferases is specific, as the methylation of H3-K9 by the histone methyltransferase G9a was not affected by Set9 methylation of H3-K4. Our studies suggest that Set9-mediated methylation of H3-K4 functions in transcription activation by competing with histone deacetylases and by precluding H3-K9 methylation by Suv39h1. Our results suggest that the methylation of histone tails can have distinct effects on transcription, depending on its chromosomal location, the combination of posttranslational modifications, and the enzyme (or protein complex) involved in the particular modification. BACKGROUND: Tax is the oncoprotein of HTLV-1 which deregulates signal transduction pathways, transcription of genes and cell cycle regulation of host cells. Transacting function of Tax is mainly mediated by its protein-protein interactions with host cellular factors. As to Tax-mediated regulation of gene expression of HTLV-1 and cellular genes, Tax was shown to regulate histone acetylation through its physical interaction with histone acetylases and deacetylases. However, functional interaction of Tax with histone methyltransferases (HMTase) has not been studied. Here we examined the ability of Tax to interact with a histone methyltransferase SUV39H1 that methylates histone H3 lysine 9 (H3K9) and represses transcription of genes, and studied the functional effects of the interaction on HTLV-1 gene expression. RESULTS: Tax was shown to interact with SUV39H1 in vitro, and the interaction is largely dependent on the C-terminal half of SUV39H1 containing the SET domain. Tax does not affect the methyltransferase activity of SUV39H1 but tethers SUV39H1 to a Tax containing complex in the nuclei. In reporter gene assays, co-expression of SUV39H1 represses Tax transactivation of HTLV-1 LTR promoter activity, which was dependent on the methyltransferase activity of SUV39H1. Furthermore, SUV39H1 expression is induced along with Tax in JPX9 cells. Chromatin immunoprecipitation (ChIP) analysis shows localization of SUV39H1 on the LTR after Tax induction, but not in the absence of Tax induction, in JPX9 transformants retaining HTLV-1-Luc plasmid. Immunoblotting shows higher levels of SUV39H1 expression in HTLV-1 transformed and latently infected cell lines. CONCLUSION: Our study revealed for the first time the interaction between Tax and SUV39H1 and apparent tethering of SUV39H1 by Tax to the HTLV-1 LTR. It is speculated that Tax-mediated tethering of SUV39H1 to the LTR and induction of the repressive histone modification on the chromatin through H3 K9 methylation may be the basis for the dose-dependent repression of Tax transactivation of LTR by SUV39H1. Tax-induced SUV39H1 expression, Tax-SUV39H1 interaction and tethering to the LTR may provide a support for an idea that the above sequence of events may form a negative feedback loop that self-limits HTLV-1 viral gene expression in infected cells. Methylation of position-specific lysine residues in histone N termini is a central modification for regulating epigenetic transitions in chromatin. Each methylatable lysine residue can exist in a mono-, di-, or trimethylated state, thereby extending the indexing potential of this particular modification. Here, we examine all possible methylation states for histone H3 lysine 9 (H3-K9) and lysine 27 (H3-K27) in mammalian chromatin. Using highly specific antibodies together with quantitative mass spectrometry, we demonstrate that pericentric heterochromatin is selectively enriched for H3-K27 monomethylation and H3-K9 trimethylation. This heterochromatic methylation profile is dependent on the Suv39h histone methyltransferases (HMTases) but independent of the euchromatic G9a HMTase. In Suv39h double null cells, pericentric heterochromatin is converted to alternative methylation imprints and accumulates H3-K27 trimethylation and H3-K9 monomethylation. Our data underscore the selective presence of distinct histone lysine methylation states in partitioning chromosomal subdomains but also reveal a surprising plasticity in propagating methylation patterns in eukaryotic chromatin. AIM: The aim of the present study was to examine DNA methylation and histone modification changes in hepatocellular carcinomas (HCC). METHODS: DNA methylation in the P16, RASSF1a, progesterone receptor (PGR) and estrogen receptor alpha (ERalpha) promoters was determined by quantitative bisulfite-pyrosequencing technique in HCC patients. Histone H3-lysine (K) 4, H3-K9 and H3-K27 modifications in all these four genes were examined by chromatin immunoprecipitation (ChIP) assay in HCC cell lines. Expression of two DNA methyltransferases (DNMT1 and DNMT3b) and three histone methyltransferases (SUV39H1, G9a and EZH2) in HCC patients was measured by real-time polymerase chain reaction. RESULTS: Aberrant DNA methylation was detected in all the HCC. Patients with DNA methylation in the RASSF1a, PGR andERalpha promoters in cancers also had substantial DNA methylation in their non-cancerous liver tissues, whereas DNA methylation in the P16 promoter was cancer specific. Epigenetic states in HCC cell lines showed that silencing of P16 and RASSF1a depended on DNA methylation and histone H3-K9 methylation. However, silencing of the PGR and ERalpha genes was more closely related to H3-K27 methylation rather than DNA methylation. Consistent with the alteration of histone status, higher expression of G9a and EZH2 was found in HCC than in non-cancerous liver tissues (P < 0.01). CONCLUSION: These data suggest that multiple epigenetic silencing mechanisms are inappropriately active in HCC cells. Gene transcription is critically influenced by chromatin structure and the modification status of histone tails. Methylation of lysine residues in histone tails is dynamically regulated by the opposing activities of histone methyltransferases and histone demethylases. Here we show that JARID1C/SMCX, a JmjC-domain-containing protein implicated in X-linked mental retardation and epilepsy, possesses H3K4 tri-demethylase activity and functions as a transcriptional repressor. An SMCX complex isolated from HeLa cells contains additional chromatin modifiers (the histone deacetylases HDAC1 and HDAC2, and the histone H3K9 methyltransferase G9a) and the transcriptional repressor REST, suggesting a direct role for SMCX in chromatin dynamics and REST-mediated repression. Chromatin immunoprecipitation reveals that SMCX and REST co-occupy the neuron-restrictive silencing elements in the promoters of a subset of REST target genes. RNA-interference-mediated depletion of SMCX derepresses several of these targets and simultaneously increases H3K4 trimethylation at the sodium channel type 2A (SCN2A) and synapsin I (SYN1) promoters. We propose that loss of SMCX activity impairs REST-mediated neuronal gene regulation, thereby contributing to SMCX-associated X-linked mental retardation. The covalent modification of histone tails has regulatory roles in various nuclear processes, such as control of transcription and mitotic chromosome condensation. Among the different groups of enzymes known to catalyze the covalent modification, the most recent additions are the histone methyltransferases (HMTases), whose functions are now being characterized. Here we show that a SET domain-containing protein, G9a, is a novel mammalian lysine-preferring HMTase. Like Suv39 h1, the first identified lysine-preferring mammalian HMTase, G9a transfers methyl groups to the lysine residues of histone H3, but with a 10-20-fold higher activity. It was reported that lysines 4, 9, and 27 in H3 are methylated in mammalian cells. G9a was able to add methyl groups to lysine 27 as well as 9 in H3, compared with Suv39 h1, which was only able to methylate lysine 9. Our data clearly demonstrated that G9a has an enzymatic nature distinct from Suv39 h1 and its homologue h2. Finally, fluorescent protein-labeled G9a was shown to be localized in the nucleus but not in the repressive chromatin domains of centromeric loci, in which Suv39 h1 family proteins were localized. This finding indicates that G9a may contribute to the organization of the higher order chromatin structure of non-centromeric loci. BACKGROUND: The rate of transcription of the HIV-1 viral genome is mediated by the interaction of the viral protein Tat with the LTR and other transcriptional machinery. These specific interactions can be affected by the state of post-translational modifications on Tat. Previously, we have shown that Tat can be phosphorylated and acetylated in vivo resulting in an increase in the rate of transcription. In the present study, we investigated whether Tat could be methylated on lysine residues, specifically on lysine 50 and 51, and whether this modification resulted in a decrease of viral transcription from the LTR. RESULTS: We analyzed the association of Tat with histone methyltransferases of the SUV39-family of SET domain containing proteins in vitro. Tat was found to associate with both SETDB1 and SETDB2, two enzymes which exhibit methyltransferase activity. siRNA against SETDB1 transfected into cell systems with both transient and integrated LTR reporter genes resulted in an increase in transcription of the HIV-LTR in the presence of suboptimal levels of Tat. In vitro methylation assays with Tat peptides containing point mutations at lysines 50 and 51 showed an increased incorporation of methyl groups on lysine 51, however, both residues indicated susceptibility for methylation. CONCLUSION: The association of Tat with histone methyltransferases and the ability for Tat to be methylated suggests an interesting mechanism of transcriptional regulation through the recruitment of chromatin remodeling proteins to the HIV-1 promoter. Histone methyltransferases catalyze site-specific deposition of methyl groups, enabling recruitment of transcriptional regulators. In mammals, trimethylation of lysine 4 in histone H3, a modification localized at the transcription start sites of active genes, is catalyzed by six enzymes (SET1a and SET1b, MLL1-MLL4) whose specific functions are largely unknown. By using a genomic approach, we found that in macrophages, MLL4 (also known as Wbp7) was required for the expression of Pigp, an essential component of the GPI-GlcNAc transferase, the enzyme catalyzing the first step of glycosylphosphatidylinositol (GPI) anchor synthesis. Impaired Pigp expression in Wbp7(-/-) macrophages abolished GPI anchor-dependent loading of proteins on the cell membrane. Consistently, loss of GPI-anchored CD14, the coreceptor for lipopolysaccharide (LPS) and other bacterial molecules, markedly attenuated LPS-triggered intracellular signals and gene expression changes. These data link a histone-modifying enzyme to a biosynthetic pathway and indicate a specialized biological role for Wbp7 in macrophage function and antimicrobial response. Residue and degree-specific methylation of histone lysines along with other epigenetic modifications organizes chromatin into distinct domains and regulates almost every aspect of DNA metabolism. Identification of histone methyltransferases and demethylases, as well as proteins that recognize methylated lysines, has clarified the role of each methylation event in regulating different biological pathways. Methylation of histone H4 lysine 20 (H4K20me) plays critical roles in diverse cellular processes such as gene expression, cell cycle progression and DNA damage repair, with each of the three degrees of methylation (mono-, di- and tri-methylation) making a unique contribution. Here we discuss recent studies of H4K20me that have greatly improved our understanding of the regulation and function of this fascinating histone modification. Nuclear DNA in eukaryotic cells is assembled into the hierarchical chromatin structure via a process that is dynamically affected by the combinatorial set of post-translational modifications (PTMs) of histones in a dynamic manner responsive to physiological and environmental changes. The precise quantification of these complex modifications is challenging. Here we present a robust MS-based quantitative proteomics method for studying histone PTMs using (15)N metabolically labeled histones as the internal reference. Using this approach, we identified Tetrahymena trithorax related 1 (Txr1p) as a histone methyltransferase in Tetrahymena thermophila and characterized the relationships of the Txr1p and Ezl2p methyltransferases to histone H3 modification. We identified 32 PTMs in more than 60 tryptic peptides from histone H3 of the ciliate model organism Tetrahymena thermophila, and we quantified them (average coefficient of variation: 13%). We examined perturbations to histone modification patterns in two knockout strains of SET-domain-containing histone methyltransferases (HMT). Knockout of TXR1 led to progressively decreased mono-, di-, and tri-methylation of H3K27 and apparent reduced monomethylation of H3K36 in vivo. In contrast, EZL2 knockout resulted in dramatic reductions in both di- and tri-methylation of H3K27 in vivo, whereas the levels of monomethylation of H3K27 increased significantly. This buildup of monomethyl H3K27 is consistent with its role as a substrate for Ezl2p. These results were validated via immunoblotting using modification site-specific antibodies. Taken together, our studies define Txr1p as an H3K27 monomethylation-specific HMT that facilitates the buildup of H3K27 di- and trimethylation by the canonical H3K27-specific HMT, Ezl2p. Our studies also delineate some of the interdependences between various H3 modifications, as compensatory increases in monomethylation at H3K4, H3K23, and H3K56 were also observed for both TXR1 and ELZ2 mutants. SU(VAR)3-9 like histone methyltransferases control heterochromatic domains in eukaryotes. In Arabidopsis, 10 SUVH genes encode SU(VAR)3-9 homologues where SUVH1, SUVH2 and SUVH4 (KRYPTONITE) represent distinct subgroups of SUVH genes. Loss of SUVH1 and SUVH4 causes weak reduction of heterochromatic histone H3K9 dimethylation, whereas in SUVH2 null plants mono- and dimethyl H3K9, mono- and dimethyl H3K27, and monomethyl H4K20, the histone methylation marks of Arabidopsis heterochromatin are significantly reduced. Like animal SU(VAR)3-9 proteins SUVH2 displays strong dosage-dependent effects. Loss of function suppresses, whereas overexpression enhances, gene silencing, causes ectopic heterochromatization and significant growth defects. Furthermore, modification of transgene silencing by SUVH2 is partially transmitted to the offspring plants. This epigenetic stability correlates with heritable changes in DNA methylation. Mutational dissection of SUVH2 indicates an implication of its N-terminus and YDG domain in directing DNA methylation to target sequences, a prerequisite for consecutive histone methylation. Gene silencing by SUVH2 depends on MET1 and DDM1, but not CMT3. In Arabidopsis, SUVH2 with its histone H3K9 and H4K20 methylation activity has a central role in heterochromatic gene silencing. Recently developed biochemical techniques have enabled researchers to study histone modifications more easily and accurately. One of these modifications, histone lysine methylation, has been shown to be highly stable and to represent an epigenetic alteration. Extensive biochemical analyses have led to discoveries about the nature and functions of this modification, thus accelerating our understanding of this crucial epigenetic event. Here we describe basic methods for purification and biochemical analysis of lysine-directed, histone methyltransferases from HeLa cell-derived extracts. In the section on substrate preparation, we describe a simple method for the preparation of recombinant substrates, although we recommend using native substrates for initial detection of the activities. The purification protocols for several histone methyltransferases have been streamlined so that those researchers with a basic understanding of biochemistry can perform them. We also describe many tips and provide suggestions to avoid common pitfalls in the biochemical analysis of histone methyltransferases.

Is there an increased risk for cancer in Dyskeratosis Congenita?

People with DC are at increased risk for progressive bone marrow failure (BMF), myelodysplastic syndrome (MDS) or acute myelogenous leukemia (AML), solid tumors (usually squamous cell carcinoma of the head/neck or anogenital cancer), and pulmonary fibrosis

[23541441, 19558498, 20507306, 18054794, 22058220, 24034063, 20925138, 23352883, 20301779, 22932338, 22362038, 23619122, 18938267, 19327580, 17825470]

Dyskeratosis congenita (DC) encompasses a large spectrum of diseases and clinical manifestations generally related to premature aging, including bone marrow failure and cancer predisposition. The major risk factor for DC is to carry germline telomere-related mutations - in telomerase or telomere shelterin genes - which results in premature telomere dysfunction, thus increasing the risk of premature aging impairments. Despite the advances that have been accomplished in DC research, the molecular aspects underlying the phenotypic variability of the disease remain poorly understood. Here different aspects of telomere biology, concerning adult stem cells senescence, tumor suppression and cancer are considered in the context of DC, resulting in two translational models: late onset of DC symptoms in telomere-related mutations carriers is a potential indicator of increased cancer risk and differences in tumor suppression capacities among the genetic subgroups are (at least partial) causes of different clinical manifestations of the disease. The limitations of both models are presented, and further experiments for their validation, as well as clinical implications, are discussed. Dyskeratosis congenita (DC) is characterized by the triad of reticulate skin pigmentation, nail dystrophy and leukoplakia. Epidermal atrophy, hair growth defects, bone marrow failure and increased risk of cancer are also common in DC patients. DC is caused by mutations in genes encoding for telomerase complex factors. Although there is an association of epidermal abnormalities with DC, epidermal cells from DC donors have not been previously characterized. We have isolated skin keratinocytes from affected members of a family with an autosomal dominant form of DC that is caused by a mutation in the RNA component of telomerase, TERC. Here, we demonstrate that, similar to DC fibroblasts from these donors, DC keratinocytes have short telomeres and a short lifespan. DC keratinocytes also exhibited impaired colony forming efficiency (CFE) and migration capacity. Exogenous expression of the reverse transcriptase (RT) component of telomerase, TERT, activated telomerase levels to half that of TERT expressing normal cells and maintained telomeres at a short length with concomitant extension of lifespan. Unlike fibroblasts, transduction of human papillomavirus type 16 E6/E7 genes into DC keratinocytes activated telomerase to half that of E6/E7 expressing normal cells, and robust proliferation was observed. While expression of TERC has no measurable effect on telomerase in fibroblasts, expression of TERC in keratinocytes upregulated telomerase activity and, rarely, allowed rescue of proliferative defects. Our results point to important differences between DC fibroblasts and keratinocytes and show, for the first time, that expression of TERC can increase the lifespan of primary human epithelial cells. Fanconi anaemia (FA), dyskeratosis congenita (DC), Diamond-Blackfan anaemia (DBA), and Shwachman-Diamond syndrome (SDS) comprise major inherited bone marrow failure syndromes (IBMFS). Adverse events include severe bone marrow failure (BMF), myelodysplastic syndrome (MDS), acute myeloid leukaemia (AML), and solid tumours (ST). The natural history of FA is well characterised; hazard rates in the other syndromes have not yet been quantified. An open cohort was established at the National Cancer Institute (NCI) in 2002. Patients enrolled prior to December, 2007 were followed up to December, 2008. Diagnoses were confirmed with standard tests. Age-associated risks of adverse events were calculated. Most patients in each syndrome survived to young adulthood. Patients with FA had earlier onset of cancers, need for stem cell transplant, and death; followed by DC; DBA and SDS were mildest. While FA and DC patients had markedly increased risks of cancer, AML and MDS, there were no cases of leukaemia in DBA or SDS patients. The NCI cohort provides the first direct quantitative comparison of timing and magnitude of cancer risk in the IBMFS. The findings demonstrate that both FA and DC are major cancer susceptibility syndromes. The IBMFS, historically considered paediatric disorders, have important management implications for physicians treating adult patients. BACKGROUND: Dyskeratosis congenita is a cancer-prone bone marrow failure syndrome caused by aberrations in telomere biology. DESIGN AND METHODS: We studied 65 patients with dyskeratosis congenita and 127 unaffected relatives. Telomere length was measured by automated multicolor flow fluorescence in situ hybridization in peripheral blood leukocyte subsets. We age-adjusted telomere length using Z-scores (standard deviations from the mean for age). RESULTS: We confirmed that telomere lengths below the first percentile for age are very sensitive and specific for the diagnosis of dyskeratosis congenita. We provide evidence that lymphocytes alone and not granulocytes may suffice for clinical screening, while lymphocyte subsets may be required for challenging cases, including identification of silent carriers. We show for the first time using flow fluorescence in situ hybridization that the shortest telomeres are associated with severe variants (Hoyeraal-Hreidarsson and Revesz syndromes), mutations in DKC1, TINF2, or unknown genes, and moderate or severe aplastic anemia. In the first longitudinal follow up of dyskeratosis congenita patients, we demonstrate that telomere lengths decline with age, in contrast to the apparent stable telomere length observed in cross-sectional data. CONCLUSIONS: Telomere length by flow fluorescence in situ hybridization is an important diagnostic test for dyskeratosis congenita; age-adjusted values provide a quantitative measure of disease severity (clinical subset, mutated gene, and degree of bone marrow failure). Patients with dyskeratosis congenita have accelerated telomere shortening. This study is registered at www.clinicaltrials.gov (identifier: NCT00027274). BACKGROUND: Dyskeratosis congenita (DC) is characterized by the clinical triad of reticular skin pigmentation, oral leukoplakia, and nail dystrophy associated with bone marrow failure (BMF) and an high risk to develop cancer and pulmonary complications. The only curative treatment for patients with DC and BMF is stem cell transplantation. Due to the rarity of the disease, the best transplant procedure is not yet known. The use of myeloablative procedures has been associated with high mortality. In the last 2 decades, encouraging results have been obtained with nonmyeloablative procedures. Heavily transfused patients have an additional risk of graft failure. CASE REPORT: Herein we have reported a 4-year-old boy with DC and severe BMF at the time of transplantation, who had been transfused with nonleucodepleted blood products for 18 months. He experienced a favorable outcome after nonmyeloablative transplant conditioning using low-dose cyclophosphamide (40 mg/kg), fludarabine (180 mg/kg), and rabbit antithymocyte globulin (10 mg/kg). The patient received a peripheral stem cell graft containing 7.52 × 10(6) CD34/kg from an HLA identical sister. Graft versus host disease (GVHD) prophylaxis consisted of a short-term combination of cyclosporine and methotrexate. RESULTS: We observed rapid neutrophil engraftment on day +21 and for platelets on day +40. No early or late complications were recorded during 15 months follow-up. The patient developed only grade I skin GVHD. On day +30, chimerism assay showed 100% donor cells. CONCLUSION: Long-term follow-up is essential to establish the efficacy and safety of this procedure. Point mutations in the DKC1 gene that encodes dyskerin cause the rare inherited syndrome called X-linked dyskeratosis congenita, characterized by a failure of proliferating tissues and increased susceptibility to cancer. Dyskerin is a nucleolar protein with different functions, all fundamental to basic cellular events such as protein expression, growth, and proliferation. The two best-characterized dyskerin activities are the stabilization of the telomerase RNA component, allowing the proper function telomerase enzymatic complex, and the modification of specific uridine residues of ribosomal RNA by converting them to pseudouridine, thus allowing proper ribosome processing and function. In light of the recent findings, this review focuses on the molecular pathogenesis of dyskeratosis congenita, discussing how a defect in ribosomal function might impact on the translation of a subset of mRNAs encoding for tumour suppressors, thus providing an explanation for the apparent paradox of dyskeratosis congenita in which reduced cell proliferation is associated with cancer susceptibility. In addition, the current evidence pointing to a role played by dyskerin in tumours in the general population is also discussed. Dyskeratosis congenita is a rare inherited bone marrow failure characterized by excessively short telomeres in highly proliferative tissues. These abnormalities are due to disturbance of the telomere maintenance machinery. The clinical presentation is characterized by skin pigmentation, nail dystrophy, and mucosal leukoplakia. All these mucocutaneous features are rare in childhood: they usually appear between 5 and 10 years of age. In young children, the initial presentation can associate bone marrow failure and neurological or ocular problems: Hoyeraal-Hreidarsson and Revesz syndromes, respectively. Clinical progression of the disease can lead to aplastic anemia (86% of all patients) and to pulmonary or hepatic complications. These patients also have an increased risk of cancer. Diagnosis is often suspected on bone marrow failure with no clinical or biological abnormalities compatible with Fanconi anemia diagnosis. The telomere length study can be helpful for diagnosis in case of aplastic anemia in children before studying gene mutations. Until now, 6 genes (DKC1, TERT, TERC, NOLA2, NOLA3, TINF2) have been identified in dyskeratosis congenita. Transmission of the disease can be autosomal recessive, autosomal dominant, or X-linked. In half of the cases, the genetic abnormality is unknown. Treatment of DC has to be adapted to each patient, from symptomatic or androgenic treatment to hematopoietic stem cell transplantation. Diamond Blackfan anemia (DBA) is an inherited bone marrow failure syndrome characterized by red cell aplasia and congenital anomalies. A predisposition to cancer has been suggested but not quantified by case reports. The DBA Registry of North America (DBAR) is the largest established DBA patient cohort, with prospective follow-up since 1991. This report presents the first quantitative assessment of cancer incidence in DBA. Among 608 patients with 9458 person-years of follow-up, 15 solid tumors, 2 acute myeloid leukemias, and 2 cases of myelodysplastic syndrome were diagnosed at a median age of 41 years in patients who had not received a bone marrow transplant. Cancer incidence in DBA was significantly elevated. The observed-to- expected ratio for all cancers combined was 5.4 (P < .05); significant observed-to-expected ratios were 287 for myelodysplastic syndrome, 28 for acute myeloid leukemia, 36 for colon carcinoma, 33 for osteogenic sarcoma, and 12 for female genital cancers. The median survival was 56 years, and the cumulative incidence of solid tumor/leukemia was approximately 20% by age 46 years. As in Fanconi anemia and dyskeratosis congenita, DBA is both an inherited bone marrow failure syndrome and a cancer predisposition syndrome; cancer risks appear lower in DBA than in Fanconi anemia or dyskeratosis congenita. This trial was registered at www.clinicaltrials.gov as #NCT00106015. BACKGROUND: Patients with dyskeratosis congenita (DC) have an increased risk of cancer, but also exhibit heightened radiation sensitivity. Proton therapy improves sparing of normal tissue, and thus may reduce radiation toxicity in patients with DC. OBSERVATIONS: We present a pediatric patient with DC who was treated with adjuvant proton therapy for oropharyngeal cancer. He experienced more severe skin toxicity and mucositis than expected. With reduced fractions per week and extensive supportive care, he completed the full radiation course. CONCLUSIONS: Proton therapy can improve normal tissue sparing, allowing successful delivery of radiation therapy in DC patients. Dyskeratosis congenita (DC) is an inherited bone marrow failure syndrome that is characterized by lacey reticular hyperpigmentation of the skin, dystrophic nails, mucous membrane leukoplakia and pancytopenia. Diagnosis may be delayed until clinical signs are apparent. Severe pancytopenia frequently causes early mortality of DC patients, who have an increased risk of developing oropharyngeal squamous cell carcinoma. Several case reports have described oral changes in DC, which include oral leukoplakia, increased dental caries, hypodontia, thin enamel structure, aggressive periodontitis, intraoral brown pigmentation, tooth loss, taurodontism and blunted roots. We determined the prevalence of these previously reported findings in a cohort of 17 patients with DC and 23 family members. The most common oral changes in DC patients were oral leukoplakia (65% of the entire DC population), decreased root/crown ratio (75% with sufficient tooth development) and mild taurodontism (57% with sufficient tooth development). From the clinical perspective, a diagnosis of DC or other inherited bone marrow failure syndrome should be considered in young persons with oral leukoplakia, particularly those with no history of smoking. Multiple permanent teeth with decreased root/crown ratios further suggest DC. Dyskeratosis congenita (DC) is an inherited bone marrow failure syndrome characterized clinically by the triad of abnormal nails, reticular skin pigmentation, and oral leukoplakia, and is associated with high risk of developing aplastic anemia, myelodysplastic syndrome, leukemia, and solid tumors. Patients have very short germline telomeres, and approximately half have mutations in one of six genes encoding proteins that maintain telomere function. Accurate diagnosis of DC is critical to ensure proper clinical management, because patients who have DC and bone marrow failure do not respond to immunosuppressive therapy and may have increased morbidity and mortality associated with hematopoietic stem cell transplantation.

Does MicroRNA-21 (miR-21) contribute to cardiovascular disease?

MicroRNA-21 (miR-21) is a highly expressed microRNA (miRNA) in cardiovascular system. Recent studies have revealed that its expression is deregulated in heart and vasculature under cardiovascular disease conditions such as proliferative vascular disease, cardiac hypertrophy and heart failure, and ischemic heart disease. miR-21 is found to play important roles in vascular smooth muscle cell proliferation and apoptosis, cardiac cell growth and death, and cardiac fibroblast functions. Accordingly, miR-21 is proven to be involved in the pathogenesis of the above-mentioned cardiovascular diseases as demonstrated by both loss-of-function and gain-of-function approaches

[19706597, 20649511, 20959496, 21464712, 19043405, 20560046, 21712654, 22882958, 22960625, 20219857, 19336275, 22038740, 23691029, 20980922, 22859901, 20015039]

Several recent reports have suggested that microRNAs (miRNAs) might play critical roles in acute myocardial infarction (AMI). However, the miRNA expression signature in the early phase of AMI has not been identified. In this study, the miRNA expression signature was investigated in rat hearts 6 h after AMI. Compared with the expression signature in the noninfarcted areas, 38 miRNAs were differentially expressed in infarcted areas and 33 miRNAs were aberrantly expressed in the border areas. Remarkably, miR-21 expression was significantly down-regulated in infarcted areas, but was up-regulated in border areas. The down-regulation of miR-21 in the infarcted areas was inhibited by ischemic preconditioning, a known cardiac protective method. Overexpression of miR-21 via adenovirus expressing miR-21 (Ad-miR-21) decreased myocardial infarct size by 29% at 24 h and decreased the dimension of left ventricles at 2 weeks after AMI. Using both gain-of-function and loss-of-function approaches in cultured cardiac myocytes, we identified that miR-21 had a protective effect on ischemia-induced cell apoptosis that was associated with its target gene programmed cell death 4 and activator protein 1 pathway. The protective effect of miR-21 against ischemia-induced cardiac myocyte damage was further confirmed in vivo by decreased cell apoptosis in the border and infarcted areas of the infarcted rat hearts after treatment with Ad-miR-21. The results suggest that miRNAs such as miR-21 may play critical roles in the early phase of AMI. MicroRNAs (miRNAs) are a broad class of small non-coding RNAs that control expression of complementary target messenger RNAs. Dysregulation of miRNAs has been described in various disease states including cancer and cardiac disease. A particular miRNA that was consistently reported to be upregulated in both cancer and various forms of cardiovascular diseases is miR-21. MiR-21 exerts oncogenic activity and therefore is considered as an oncomir. In the cardiovascular system miR-21 is enriched in fibroblasts and contributes to the development of fibrosis and heart failure. MiR-21 therefore emerges as an interesting candidate for the development of therapeutic strategies against many forms of cancer as well as heart diseases. Indeed, treatment with anti-miR-21 oligonucleotides reduced breast cancer growth. Inhibition of miR-21 by synthetic miRNA antagonists (antagomirs) improved heart function in a cardiac disease model. The same beneficial effects were observed in miR-21 knockout mice subjected to pressure-overload of the left ventricle underlining the key role of miR-21 as a therapeutic target. We here overview the current patent situation about the therapeutic use of miR-21 modulation in cancer and cardiovascular disease. MicroRNAs comprise a broad class of small non-coding RNAs that control expression of complementary target messenger RNAs. Dysregulation of microRNAs by several mechanisms has been described in various disease states including cardiac disease. Whereas previous studies of cardiac disease have focused on microRNAs that are primarily expressed in cardiomyocytes, the role of microRNAs expressed in other cell types of the heart is unclear. Here we show that microRNA-21 (miR-21, also known as Mirn21) regulates the ERK-MAP kinase signalling pathway in cardiac fibroblasts, which has impacts on global cardiac structure and function. miR-21 levels are increased selectively in fibroblasts of the failing heart, augmenting ERK-MAP kinase activity through inhibition of sprouty homologue 1 (Spry1). This mechanism regulates fibroblast survival and growth factor secretion, apparently controlling the extent of interstitial fibrosis and cardiac hypertrophy. In vivo silencing of miR-21 by a specific antagomir in a mouse pressure-overload-induced disease model reduces cardiac ERK-MAP kinase activity, inhibits interstitial fibrosis and attenuates cardiac dysfunction. These findings reveal that microRNAs can contribute to myocardial disease by an effect in cardiac fibroblasts. Our results validate miR-21 as a disease target in heart failure and establish the therapeutic efficacy of microRNA therapeutic intervention in a cardiovascular disease setting. The small regulatory RNA microRNA-21 (miR-21) plays a crucial role in a plethora of biological functions and diseases including development, cancer, cardiovascular diseases and inflammation. The gene coding for pri-miR-21 (primary transcript containing miR-21) is located within the intronic region of the TMEM49 gene. Despite pri-miR-21 and TMEM49 are overlapping genes in the same direction of transcription, pri-miR-21 is independently transcribed by its own promoter regions and terminated with its own poly(A) tail. After transcription, primiR- 21 is finally processed into mature miR-21. Expression of miR-21 has been found to be deregulated in almost all types of cancers and therefore was classified as an oncomiR. During recent years, additional roles of miR-21 in cardiovascular and pulmonary diseases, including cardiac and pulmonary fibrosis as well as myocardial infarction have been described. MiR-21 additionally regulates various immunological and developmental processes. Due to the critical functions of its target proteins in various signaling pathways, miR-21 has become an attractive target for genetic and pharmacological modulation in various disease conditions. BACKGROUND: Various human cardiovascular pathophysiological conditions associate aberrant expression of microRNAs (miRNAs) and circulating miRNAs are emerging as promising biomarkers. In mice, myocardial miR-21 overexpression is related to cardiac fibrosis elicited by pressure overload. This study was designed to determine the role of myocardial and plasmatic miR-21 in the maladaptive remodeling of the extracellular matrix induced by pressure overload in aortic stenosis (AS) patients and the clinical value of miR-21 as a biomarker for pathological myocardial fibrosis. METHODS: In left ventricular biopsies from 75 AS patients and 32 surgical controls, we quantified the myocardial transcript levels of miR-21, miR-21-targets and ECM- and TGF-β-signaling-related elements. miR-21 plasma levels were determined in 25 healthy volunteers and in AS patients. In situ hybridization of miR-21 was performed in myocardial sections. RESULTS: The myocardial and plasma levels of miR-21 were significantly higher in the AS patients compared with the controls and correlated directly with the echocardiographic mean transvalvular gradients. miR-21 overexpression was confined to interstitial cells and absent in cardiomyocytes. Using bootstrap validated multiple linear regression, the variance in myocardial collagen expression was predicted by myocardial miR-21 (70% of collagen variance) or plasma miR-21 (52% of collagen variance), together with the miR-21 targets RECK and PDCD4, and effectors of TGF-ß signaling. CONCLUSIONS: Our results support the role of miR-21 as a regulator of the fibrotic process that occurs in response to pressure overload in AS patients and underscore the value of circulating miR-21 as a biomarker for myocardial fibrosis. Cardiac fibrosis is characterized by aberrant proliferation of cardiac fibroblasts and exaggerated deposition of extracellular matrix (ECM) in the myocardial interstitial, and ultimately impairs cardiac function. It is still controversial whether microRNA-21 (miR-21) participates in the process of cardiac fibrosis. Our previous study confirmed that transforming growth factor beta receptor III (TGFβRIII) is a negative regulator of TGF-β pathway. Here, we aimed to decipher the relationship between miR-21 and TGFβRIII in the pathogenic process of myocardial fibrosis. We found that TGF-β1 and miR-21 were up-regulated, whereas TGFβRIII was down-regulated in the border zone of mouse hearts in response to myocardial infarction. After transfection of miR-21 into cardiac fibroblasts, TGFβRIII expression was markedly reduced and collagen content was increased. And, luciferase results confirmed that TGFβRIII was a target of miR-21. It suggests that up-regulation of miR-21 could increase the collagen content and at least in part through inhibiting TGFβRIII. Conversely, we also confirmed that overexpression of TGFβRIII could inhibit the expression of miR-21 and reduce collagen production in fibroblasts. Further studies showed that overexpression of TGFβRIII could also deactivate TGF-β1 pathway by decreasing the expression of TGF-β1 and phosphorylated-Smad3 (p-Smad3). TGF-β1 has been proven as a positive regulator of miR-21. Taken together, we found a novel reciprocal loop between miR-21 and TGFβRIII in cardiac fibrosis caused by myocardial infarction in mice, and targeting this pathway could be a new strategy for the prevention and treatment of myocardial remodeling. AIMS: The aims of the present study are to determine the miRNA expression signature in rat hearts after ischaemic preconditioning (IP) and to identify an IP-regulated miRNA, miR-21, in IP-mediated cardiac protection, and the potential cellular and molecular mechanisms involved. METHODS AND RESULTS: The miRNA expression signature was investigated in rat hearts. Among the 341 arrayed miRNAs, 40 miRNAs were differentially expressed (21 up and 19 down) in rat hearts with IP, compared with their controls. Some of these differentially expressed miRNAs were further verified by quantitative reverse transcriptase-polymerase chain reaction. Remarkably, miR-21 was one of most upregulated miRNAs in hearts after IP. In vivo, IP-mediated cardiac protection against ischaemia/reperfusion injury was inhibited by knockdown of cardiac miR-21. In cultured cardiac myocytes, we identified that miR-21 also had a protective effect on hypoxia/reoxygenation-induced cell apoptosis that was associated with its target gene, programmed cell death 4. The protective effect of miR-21 on cardiac cell apoptosis was further confirmed in rat hearts after ischaemia/reperfusion injury in vivo. CONCLUSION: The results suggest that miRNAs are involved in IP-mediated cardiac protection. Identifying the roles of IP-regulated miRNAs in cardiac protection may provide novel therapeutic and preventive targets for ischaemic heart disease. Reactive oxygen species (ROS)-induced cardiac cell injury via expression changes of multiple genes plays a critical role in the pathogenesis of numerous heart diseases. MicroRNAs (miRNAs) comprise a novel class of endogenous, small, noncoding RNAs that negatively regulate about 30% of the genes in a cell via degradation or translational inhibition of their target mRNAs. Currently, the effects of ROS on miRNA expression and the roles of miRNAs in ROS-mediated injury on cardiac myocytes are uncertain. Using quantitative real-time RT-PCR (qRT-PCR), we demonstrated that microRNA-21 (miR-21) was upregulated in cardiac myocytes after treatment with hydrogen peroxide (H(2)O(2)). To determine the potential roles of miRNAs in H(2)O(2)-mediated gene regulation and cellular injury, miR-21 expression was downregulated by miR-21 inhibitor and upregulated by pre-miR-21. H(2)O(2)-induced cardiac cell death and apoptosis were increased by miR-21 inhibitor and was decreased by pre-miR-21. Programmed cell death 4 (PDCD4) that was regulated by miR-21 and was a direct target of miR-21 in cardiac myocytes. Pre-miR-21-mediated protective effect on cardiac myocyte injury was inhibited in H(2)O(2)-treated cardiac cells via adenovirus-mediated overexpression of PDCD4 without miR-21 binding site. Moreover, Activator protein 1 (AP-1) was a downstream signaling molecule of PDCD4 that was involved in miR-21-mediated effect on cardiac myocytes. The results suggest that miR-21 is sensitive to H(2)O(2) stimulation. miR-21 participates in H(2)O(2)-mediated gene regulation and functional modulation in cardiac myocytes. miR-21 might play an essential role in heart diseases related to ROS such as cardiac hypertrophy, heart failure, myocardial infarction, and myocardial ischemia/reperfusion injury. Myocardial ischaemia/reperfusion (I/R)-induced remodelling generally includes cell death (necrosis and apoptosis), myocyte hypertrophy, angiogenesis, cardiac fibrosis, and myocardial dysfunction. It is becoming increasingly clear that microRNAs (miRNAs or miRs), a group of highly conserved small (∼18-24 nucleotide) non-coding RNAs, fulfil specific functions in the reperfused myocardium towards post-infarct remodelling. While miR-21, -133, -150, -195, and -214 regulate cardiomyocyte hypertrophy, miR-1/-133 and miR-208 have been elucidated to influence myocardial contractile function. In addition, miR-21, -24, -133, -210, -494, and -499 appear to protect myocytes against I/R-induced apoptosis, whereas miR-1, -29, -199a, and -320 promote apoptosis. Myocardial fibrosis can be regulated by the miR-29 family and miR-21. Moreover, miR-126 and miR-210 augment I/R-induced angiogenesis, but miR-24, -92a, and -320 suppress post-infarct neoangiogenesis. In this review, we summarize the latest advances in the identification of myocardial ischaemia-associated miRNAs and their functional significance in the modulation of I/R-triggered remodelling. Controversial effects of some miRNAs in post-infarct remodelling will be also discussed. Preconditioning (PC) of the heart by sublethal ischemia, mild heat shock, or hypoxia has evolved as a powerful experimental tool to discover novel signaling mechanisms in cardioprotection. The ultimate goal is to determine novel therapeutic targets for potential application in humans to protect the heart against ischemia-related injuries. In recent years, there has been a tremendous interest in understanding the role of small noncoding RNAs, microRNAs (miRs), in cardiovascular diseases. miRs have been recognized as regulators of gene expression by destabilization and translational inhibition of target messenger RNAs. Studies have shown that several miRs, including miR-1, miR-133, miR-21, miR-126, miR-320, miR-92a, and miR-199a, are regulated after preconditioning and play an active role in protecting the heart against ischemia/reperfusion injury. These miRs also drive the synthesis of important cardioprotective proteins including heat shock protein (HSP)-70, endothelial nitric oxide synthase, inducible nitric oxide synthase, HSP-20, Sirt1, and hypoxia-inducible factor 1a. We believe that identification and targeted delivery of miR(s) in the heart could have an immense therapeutic potential in reducing myocardial infarction in patients suffering from heart disease. OBJECTIVE: To determine the role of microRNA 21(miR-21) on left ventricular remodeling of rat heart with ischemia-reperfusion (I/R) injury and to investigate the underlying mechanism of miR-21 mediated myocardium protection. METHODS: Rats were randomly divided into three groups: an I/R model group with Ad-GFP (Ad-GFP group), an I/R model group with Ad-miR-21 (Ad-miR-21 group) and a sham-surgery group. Changes in hemodynamic parameters were recorded at 1 week after I/R. Histological diagnosis was achieved by hematoxylin and eosin (H&E). Left ventricular (LV) dimensions, myocardial infarct size, LV/BW, collagen type Ⅰ, type Ⅲ and PCNA positive cells were measured. Primary cultures of neonatal rat cardiac ventricular myocytes were performed and cell ischemic injury was induced by hypoxia in a serum- and glucose-free medium, and reoxygenation (H/R). MiR-21 inhibitor and pre-miR-21 were respectively added to the culture medium for the miR-21 knockdown and for the miR-21 up-regulation. qRT-PCR was used to determine the miR-21 levels in cultured cells. Flow cytometry was performed to examine the cell apoptosis. RESULTS: In the Ad-miR-21 group, LV dimensions, myocardial infarct size, LV/BW, collagen type Ⅰ, type Ⅲ and PCNA positive cells all significantly decreased compared with the Ad-GFP group. At 1 week after I/R, the Ad-miR-21 significantly improved LVSP, LV +dp/dt(max), LV - dp/dt(min), and decreased heart rate (HR) and LVEDP compared with the Ad-GFP group. Compared with the Ad-GFP, the cell apoptotic rate significantly decreased in the Ad-miR-21 group. The miR-21 inhibitor exacerbated cardiac myocyte apoptosis and the pre-miR-21 decreased hypoxia/reoxygenation- induced cardiac myocyte apoptosis. CONCLUSIONS: Ad-miR-21 improves LV remodeling and decreases the apoptosis of myocardial cells, suggesting the possible mechanism by which Ad-miR-21 functions in protecting against I/R injury.

What is the enzymatic activity of the breast cancer associated gene BRCA1?

E3-ubiquitin ligase activity is the only known enzymatic activity of BRCA1, which is mediated by the N-terminal RING finger domain.BRCA1 nuclear transport and ubiquitin E3 ligase enzymatic activity are tightly regulated by the BRCA1 dimeric binding partner BARD1 and further modulated by cancer mutations and diverse signaling pathways.

[20681793, 22034435, 19088202, 16479151, 24278741, 17420471, 16710298, 15254397]

Germline mutations of the breast cancer 1 (BRCA1) gene are a major cause of familial breast and ovarian cancer. The BRCA1 protein displays E3 ubiquitin ligase activity, and this enzymatic function is thought to be required for tumor suppression. To test this hypothesis, we generated mice that express an enzymatically defective Brca1. We found that this mutant Brca1 prevents tumor formation to the same degree as does wild-type Brca1 in three different genetically engineered mouse (GEM) models of cancer. In contrast, a mutation that ablates phosphoprotein recognition by the BRCA C terminus (BRCT) domains of BRCA1 elicits tumors in each of the three GEM models. Thus, BRCT phosphoprotein recognition, but not the E3 ligase activity, is required for BRCA1 tumor suppression. Hereditary cases of breast and ovarian cancer are often attributed to germ-line mutations of the BRCA1 tumor suppressor gene. Although BRCA1 is involved in diverse cellular processes, its role in the maintenance of genomic integrity may be a key component of its tumor suppression activity. The protein encoded by BRCA1 interacts in vivo with the related BARD1 protein to form a heterodimeric complex that acts as a ubiquitin E3 ligase. Because the enzymatic activity of the BRCA1/BARD1 heterodimer is conserved over a broad phylogenetic range, it is thought to be critical for the central functions of BRCA1. To test this hypothesis, we have generated isogenic clones of embryonic stem cells that do or do not express an enzymatically proficient Brca1 polypeptide. Surprisingly, cells lacking the ubiquitin ligase activity of BRCA1 are viable and do not accumulate spontaneous cytogenetic rearrangements. Gene targeting efficiencies are modestly reduced in these cells, and chromosomal rearrangements arise at elevated rates in response to genotoxic stress. Nonetheless, cells lacking Brca1 enzymatic activity are not hypersensitive to the DNA cross-linking agent mitomycin C. They also form Rad51 focus in response to ionizing radiation and repair chromosome breaks by homologous recombination at wild-type levels. These results indicate that key aspects of BRCA1 function in genome maintenance, including its role in homology-directed repair of double-strand DNA breaks, do not depend on the E3 ligase activity of BRCA1. Inherited mutations in the BRCA1 gene predispose to a higher risk of breast/ovarian cancer. The BRCA1 tumor suppressor is a 1863 amino acid protein with multiple protein interaction domains that facilitate its roles in regulating DNA repair and maintenance, cell cycle progression, transcription, and cell survival/apoptosis. BRCA1 was first identified as a nuclear phosphoprotein, but has since been shown to contain different transport sequences including nuclear export and nuclear localization signals that enable it to shuttle between specific sites within the nucleus and cytoplasm, including DNA repair foci, centrosomes, and mitochondria. BRCA1 nuclear transport and ubiquitin E3 ligase enzymatic activity are tightly regulated by the BRCA1 dimeric binding partner BARD1 and further modulated by cancer mutations and diverse signaling pathways. This paper will focus on the transport, dynamics, and multiple intracellular destinations of BRCA1 with emphasis on how regulation of these events has impact on, and determines, a broad range of important cellular functions. Polycomb group proteins Ring1b and Bmi1 (B-cell-specific Moloney murine leukaemia virus integration site 1) are critical components of the chromatin modulating PRC1 complex. Histone H2A ubiquitination by the PRC1 complex strongly depends on the Ring1b protein. Here we show that the E3-ligase activity of Ring1b on histone H2A is enhanced by Bmi1 in vitro. The N-terminal Ring-domains are sufficient for this activity and Ring1a can replace Ring1b. E2 enzymes UbcH5a, b, c or UbcH6 support this activity with varying processivity and selectivity. All four E2s promote autoubiquitination of Ring1b without affecting E3-ligase activity. We solved the crystal structure of the Ring-Ring heterodimeric complex of Ring1b and Bmi1. In the structure the arrangement of the Ring-domains is similar to another H2A E3 ligase, the BRCA1/BARD1 complex, but complex formation depends on an N-terminal arm of Ring1b that embraces the Bmi1 Ring-domain. Mutation of a critical residue in the E2/E3 interface shows that catalytic activity resides in Ring1b and not in Bmi1. These data provide a foundation for understanding the critical enzymatic activity at the core of the PRC1 polycomb complex, which is implicated in stem cell maintenance and cancer. The BRCA1 tumor suppressor gene is expressed in all mammalian cells. Within these cells, the BRCA1 protein product interacts with several seemingly distinct nuclear complexes. Proteins within these complexes are potential targets for the E3-ubiquitin ligase activity associated with BRCA1:BARD1 complexes. Recent breakthroughs have centered on elucidating critical DNA repair and chromatin-remodeling functions associated with BRCA1 activity. During both DNA replication and DNA repair, BRCA1 appears to serve both adaptor and enzymatic functions. Roles include transient physical recruitment of NBS1, gammaH2AX, FANCD2 and other proteins in specific repair associated complexes, and enzymatic activity as an E3-ubiquitin ligase against a subset of these proteins. BRCA1 has also been implicated as a regulator of transcription. It is in this second capacity that progress has been much more difficult to assess. In particular, unambiguous adaptor and enzymatic functions have yet to be demonstrated in transcriptional machinery. Addressing the critical gap in our understanding of enzymatic targets of BRCA1 will be required for significant future progress in this field. The following review puts forward a model for BRCA1 interactions with the transcriptional complex in undamaged cells, and a potential mechanism for substrate switching between transcription and DNA-repair complexes following exposure of cells to proliferative or genotoxic stress. This model incorporates recent evidence that BRCA1 interacts predominantly with hyper-phosphorylated, enzymatically active, RNA polymerase II (RNAPII) in undamaged cells. The model proposes that BRCA1 binds processive RNA polymerase as part of a genome surveillance function, upstream of critical roles in DNA repair.

List markers for autophagy.

Expression of LC3-II and BECN1 as well as SQSTM1 are used as markers of autophagy activity.

[23182945, 23626658, 23598404, 22807527, 24255881, 23117929, 23437259, 24231340, 23940944, 24291536, 23727153, 23737395, 22652752, 23822101, 24141623, 23608825, 23193914, 24126619]

Preischemic hyperglycemia exacerbates brain damage caused by cerebral ischemia. In the present experiment, we studied the effects of preischemic hyperglycemia on protein markers that are related to mitochondrial fission and fusion, mitochondrial biogenesis, and autophagy in mice subjected to 30-min transient focal ischemia. The fission proteins dynamin-related protein 1 (Drp1) and fission 1 (Fis1), fusion proteins optic atrophy 1 (Opa1) and mitofusin 2 (Mfn2), mitochondrial biogenesis regulators nuclear respiratory factor 1 (NRF1) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), and autophagy marker beclin 1 and microtubule-associated protein light chain 3 (LC3) were analyzed in control, 30 min middle cerebral artery occlusion (MCAO) plus 6-, 24-, and 72 h of reperfusion in normo- and hyperglycemic conditions. Cerebral ischemia increased the levels of Drp1 and decreased Fis1 after reperfusion. Preischemic hyperglycemia further augmented the increase of Drp1 and induced elevation in Fis1. Ischemia inhibited the levels of Opa1 and Mfn2 and hyperglycemia further decreased the level of Opa1. Further, NRF1 increased after reperfusion in both normo- and hyperglycemic animals. However, such increase was caused by reperfusion rather than glucose level. Finally, ischemia increased beclin 1 level at 6 and 24 h of reperfusion and hyperglycemia further increased the beclin 1 level and caused LC3-II increase as well. Hyperglycemia enhances the ischemia-induced mitochondrial dynamic imbalance towards fission that may favor mitochondrial fragmentation and subsequent damage. Hyperglycemia elevated autophagy markers may represent an adapting reaction to the severe damage incurred in hyperglycemic animals or a third pathway of cell death. Ovarian cancer is a leading cause of cancer death in women in the United States. While the majority of ovarian cancers are serous, some rarer subtypes (i.e. clear cell) are often associated with endometriosis, a benign gynecological disease. Iron is rich in the cyst fluid of endometriosis-associated ovarian cancers and induces persistent oxidative stress. The role of iron, an essential nutrient involved in multiple cellular functions, in normal ovarian cell survival and ovarian cancer remains unclear. Iron, presented as ferric ammonium citrate (FAC), dramatically inhibits cell survival in ovarian cancer cell types associated with Ras mutations, while it is without effect in immortalized normal ovarian surface epithelial (T80) and endometriotic epithelial cells (lacking Ras mutations). Interestingly, FAC induced changes in cytoplasmic vacuolation concurrently with increases in LC3-II levels (an autophagy marker); these changes occurred in an ATG5/ATG7-dependent, beclin-1/hVps34-independent, and Ras-independent manner. Knockdown of autophagy mediators in HEY ovarian cancer cells reversed FAC-induced LC3-II levels, but there was little effect on reversing the cell death response. Intriguingly, transmission electron microscopy of FAC-treated T80 cells demonstrated abundant lysosomes (confirmed using Lysotracker) rich in iron particles, which occurred in a Ras-independent manner. Although the mitogen-activated protein kinase (MAPK) inhibitor, U0126, reversed FAC-induced LC3-II/autophagic punctae and lysosomes in a Ras-independent manner, it was remarkable that U0126 reversed cell death in malignant ovarian cells associated with Ras mutations. Moreover, FAC increased heme oxygenase-1 expression in H-Ras-overexpressing T80 cells, which was associated with increased cell death when overexpressed in T80 cells. Disruption of intracellular iron levels, via chelation of intracellular iron (deferoxamine), was also detrimental to malignant ovarian cell survival; thus, homeostatic intracellular iron levels are essential for cell survival. Collectively, our results implicate iron in modulating cell death in a Ras- and MAPK-dependent manner in ovarian cancer cells. Chlamydia trachomatis is an obligate intracellular bacterium responsible for one of the most common sexually transmitted diseases. In epithelial cells, C. trachomatis resides in a modified membrane-bound vacuole known as an inclusion, which is isolated from the endocytic pathway. However, the maturation process of C. trachomatis within immune cells, such as macrophages, has not been studied extensively. Here, we demonstrated that RAW macrophages effectively suppressed C. trachomatis growth and prevented Golgi stack disruption, a hallmark defect in epithelial cells after C. trachomatis infection. Next, we systematically examined association between C. trachomatis and various endocytic pathway markers. Spinning disk confocal time-lapse studies revealed significant and rapid association between C. trachomatis with Rab7 and LAMP1, markers of late endosomes and lysosomes. Moreover, pretreatment with an inhibitor of lysosome acidification led to significant increases in C. trachomatis growth in macrophages. At later stages of infection, C. trachomatis associated with the autophagy marker LC3. TEM analysis confirmed that a significant portion of C. trachomatis resided within double-membrane-bound compartments, characteristic of autophagosomes. Together, these results suggest that macrophages can suppress C. trachomatis growth by targeting it rapidly to lysosomes; moreover, autophagy is activated at later stages of infection and targets significant numbers of the invading bacteria, which may enhance subsequent chlamydial antigen presentation. AIM: To investigate the effects of mammalian target of rapamycin (mTOR) inhibition on liver regeneration and autophagy in a surgical resection model. METHODS: C57BL/6 mice were subjected to a 70% partial hepatectomy (PH) and treated intraperitoneally every 24 h with a combination of the mTOR inhibitor rapamycin (2.5 mg/kg per day) and the steroid dexamethasone (2.0 mg/kg per day) in phosphate buffered saline (PBS) or with PBS alone as vehicle control. In the immunosuppressant group, part of the group was treated subcutaneously 4 h prior to and 24 h after PH with a combination of human recombinant interleukin 6 (IL-6; 500 μg/kg per day) and hepatocyte growth factor (HGF; 100 μg/kg per day) in PBS. Animals were sacrificed 2, 3 or 5 d after PH and liver tissue and blood were collected for further analysis. Immunohistochemical staining for 5-Bromo-2'-deoxyuridine (BrdU) was used to quantify hepatocyte proliferation. Western blotting was used to detect hepatic microtubule-associated protein 1 light chain 3 (LC3)-II protein expression as a marker for autophagy. Hepatic gene expression levels of proliferation-, inflammation- and angiogenesis-related genes were examined by real-time reverse transcription-polymerase chain reaction and serum bilirubin and transaminase levels were analyzed at the clinical chemical core facility of the Erasmus MC-University Medical Center. RESULTS: mTOR inhibition significantly suppressed regeneration, shown by decreased hepatocyte proliferation (2% vs 12% BrdU positive hepatocyte nuclei at day 2, P < 0.01; 0.8% vs 1.4% at day 5, P = 0.02) and liver weight reconstitution (63% vs 76% of initial total liver weight at day 3, P = 0.04), and furthermore increased serum transaminase levels (aspartate aminotransferase 641 U/L vs 185 U/L at day 2, P = 0.02). Expression of the autophagy marker LC3-II, which was reduced during normal liver regeneration, increased after mTOR inhibition (46% increase at day 2, P = 0.04). Hepatic gene expression showed an increased inflammation-related response [tumor necrosis factor (TNF)-α 3.2-fold upregulation at day 2, P = 0.03; IL-1Ra 6.0-fold upregulation at day 2 and 42.3-fold upregulation at day 5, P < 0.01] and a reduced expression of cell cycle progression and angiogenesis-related factors (HGF 40% reduction at day 2; vascular endothelial growth factor receptor 2 50% reduction at days 2 and 5; angiopoietin 1 60% reduction at day 2, all P ≤ 0.01). Treatment with the regeneration stimulating cytokine IL-6 and growth factor HGF could overcome the inhibitory effect on liver weight (75% of initial total liver weight at day 3, P = 0.02 vs immunosuppression alone and P = 0.90 vs controls) and partially reversed gene expression changes caused by rapamycin (TNF-α and IL-1Ra levels at day 2 were restored to control levels). However, no significant changes in hepatocyte proliferation, serum injury markers or autophagy were found. CONCLUSION: mTOR inhibition severely impairs liver regeneration and increases autophagy after PH. These effects are partly reversed by stimulation of the IL-6 and HGF pathways. Autophagy, an evolutionary conserved process aimed at recycling damaged organelles and protein aggregates in the cell, also modulates proinflammatory cytokine production in peripheral blood mononuclear cells. Because adipose tissue inflammation accompanied by elevated levels of proinflammatory cytokines is characteristic for the development of obesity, we hypothesized that modulation of autophagy alters adipose tissue inflammatory gene expression and secretion. We tested our hypothesis using ex vivo and in vivo studies of human and mouse adipose tissue. Levels of the autophagy marker LC3 were elevated in sc adipose tissue of obese vs. lean human subjects and positively correlated to both systemic insulin resistance and morphological characteristics of adipose tissue inflammation. Similarly, autophagic activity levels were increased in adipose tissue of obese and insulin resistant animals as compared with lean mice. Inhibition of autophagy by 3-methylalanine in human and mouse adipose tissue explants led to a significant increase in IL-1β, IL-6, and IL-8 mRNA expression and protein secretion. Noticeably, the enhancement in IL-1β, IL-6, and keratinocyte-derived chemoattractant (KC) by inhibition of autophagy was more robust in the presence of obesity. Similar results were obtained by blocking autophagy using small interfering RNA targeted to ATG7 in human Simpson-Golabi-Behmel syndrome adipocytes. Our results demonstrate that autophagy activity is up-regulated in the adipose tissue of obese individuals and inhibition of autophagy enhances proinflammatory gene expression both in adipocytes and adipose tissue explants. Autophagy may function to dampen inflammatory gene expression and thereby limit excessive inflammation in adipose tissue during obesity. OBJECTIVE: To investigate the regulation of different hypoxia on cell survival and autophagy. METHODS: PC12 cells were treated with different hypoxia. The cell survival was measured by MTT assay, expressions of LC3 and p62 were marked for autophagy detected by Western Blot, and the level of reactive oxygen species (ROS) was analyzed by flow cytometry. RESULTS: The cell viability was different under different hypoxia: moderate hypoxia promoted cell viability, and severe hypoxia caused a decrease in cell viability; autophagy marker molecules, p62 and LC3-II expressions were different: moderate hypoxia increased p62 and LC3-II expressions, in contrast, severe hypoxia led to the decrease of p62 and LC3-II expressions; compared to normoxia, moderate hypoxia did not change the levels of ROS, while severe hypoxia increased the levels; 3-MA, the inhibitor of autophagy, elevated the levels of ROS in the three oxygen concentrations, additionally, the increased amplitudes in the moderate and severe hypoxia groups were higher than that in the normoxia group. CONCLUSION: Moderate hypoxia promotes cell survival, severe hypoxia causes the cell death, and the autophagy activity may mediate the effects of different hypoxia. To explore the effect of short-term calorie restriction (CR) on renal aging, 8-week CR with 60% of the food intake of the ad libitum group was administered in 25-month-old male Sprague-Dawley rats. Aged rats subjected to short-term CR had lower body weight, level of triglycerides and ratio of urine protein to urine creatinine, respectively. Short-term CR blunted the increased glomerular volume, the degree of fibrosis, p16 and the positive rate of senescence-associated β-galactosidase staining of the kidneys in old ad libitum group. Light chain 3/Atg8 as an autophagy marker exhibited a marked decline in aged kidneys, which was increased by short-term CR. The levels of p62/SQSTM1 and polyubiquitin aggregates, which were increased in older kidneys, were blunted by short-term CR. Short-term CR retarded the level of 8-hydroxydeoxyguanosine, a marker of mitochondrial DNA oxidative damage. Moreover, we found an increased level of SIRT1 and AMPK, and a decreased level of mTOR in aged kidneys after short-term CR. These results suggested that short-term CR could be considered as a potential intervention for retardation of renal senescence by increasing autophagy and subsequently reducing oxidative damage. Three master regulators of energy metabolism, SIRT1, AMPK and mTOR are associated with these effects. Macrophages are engaged in many essential host functions, and their activation is a dynamic process that results in diverse functional outcomes such as the potentiation of bactericidal activity and production of chemokines, cytokines, and mediators that coordinate the inflammatory response. This pro-inflammatory response is bimodal, comprising a "prime" event, classically through interferon-γ (IFN-γ), and a "trigger," such as lipopolysaccharide (LPS). Recently, autophagy, which is one of the major degradative pathways in eukaryotic cells, has been shown to play an important role in both IFN-γ-primed and LPS-activated macrophages. In this study, we sought to characterize the mechanisms of autophagy activation in primed and activated macrophages. To this end, we established a macrophage RAW 264.7 cell line that expressed high levels of a tandem fluorescently tagged LC3 (tfLC3) autophagy marker. By using this macrophage cell line, autophagosome formation was observed in both IFN-γ- and LPS-stimulated cells. Moreover, our data demonstrated that IFN-γ, but not LPS, facilitated autophagosome maturation to autophagolysosomes, suggesting that 2 distinct mechanisms regulating autophagy exist in IFN-γ-primed and LPS-activated macrophages. Ursolic acid (UA) has been reported to possess anticancer activities. Although some of the anticancer activities of UA have been explained by its apoptosis-inducing properties, the mechanisms underlying its anticancer actions are largely unknown. We have found that UA-activated autophagy induced cytotoxicity and reduced tumor growth of cervical cancer cells TC-1 in a concentration-dependent manner. UA did not induce apoptosis of TC-1 cells in vitro as determined by annexin V/propidium iodide staining, DNA fragmentation, and Western blot analysis of the apoptosis-related proteins. We found that UA increased punctate staining of light chain 3 (LC3), which is an autophagy marker. LC3II, the processed form of LC3I which is formed during the formation of double membranes, was induced by UA treatment. These results were further confirmed by transmission electron microscopy. Wortmannin, an inhibitor of autophagy, and a small interfering RNA (siRNA) for autophagy-related genes (Atg5) reduced LC3II and simultaneously increased the survival of TC-1 cells treated with UA. We also found that LC3II was significantly reduced and that survival was increased in Atg5-/- mouse embryonic fibroblast (MEF) cells compared to Atg5+/+ MEF cells under UA treatment. However, silencing BECN1 by siRNA affected neither the expression of LC3II nor the survival of TC-1 cells under UA treatment. These results suggest that autophagy is a major mechanism by which UA kills TC-1 cells. It is Atg5 rather than BECN1 that plays a crucial role in UA-induced autophagic cell death in TC-1 cells. The activation of autophagy by UA may become a potential cancer therapeutic strategy complementing the apoptosis-based therapies. Furthermore, regulation of Atg5 may improve the efficacy of UA in cancer treatment. PURPOSE: This study sought to investigate the prognostic value of the autophagy marker microtubule-associated protein chain 3B (LC3B) in patients with residual tumors after neoadjuvant chemotherapy (NCT) for locally advanced breast cancer (LABC). PATIENTS AND METHODS: The expression of LC3B in residual breast cancer cells was assessed by immunohistochemistry in surgical specimens from 229 patients diagnosed with histologically proven invasive breast cancer. All patients underwent NCT followed by mastectomy and were considered nonpathologic complete responders (non-pCR) after a pathologic evaluation. The prognostic value of various clinicopathologic factors was evaluated. RESULTS: The LC3B density was similar between the peripheral and central area of the tumors (P = 0.328) but was significantly lower in the extratumoral area (P < 0.001 and P < 0.001, respectively). Furthermore, LC3B density, which correlated with Beclin-1 expression, Ki-67 index, and breast cancer subtype, served as an independent prognostic factor for both relapse-free survival (RFS; P = 0.012) and overall survival (OS; P = 0.008); the prognostic value of LC3B was most significant in triple-negative patients. Using a combination of LC3B expression and the status of residual involved lymph nodes, the patients were classified into four groups with different risks of relapse and death (P < 0.001 for RFS and P = 0.003 for OS). CONCLUSION: LC3B can be used as a prognostic marker in patients with non-pCR after NCT for breast cancer, which highlights the importance of autophagy in the biologic behavior of chemoresistant cancer cells. Furthermore, evaluating and targeting autophagy in the neoadjuvant setting may help prevent disease relapse in patients with non-pCR. Sporadic inclusion body myositis (sIBM) and polymyositis (PM) are characterized by muscle inflammation, with sIBM showing additional degenerative alterations. In this study we investigated human beta defensins and associated TLRs to elucidate the role of the innate immune system in idiopathic inflammatory myopathies (IIM), and its association with inflammatory and degenerative alterations. Expression levels of human beta-defensin (HBD)-1, HBD-2, HBD-3 and TLR2, 3, 4, 7 and 9 were analysed by quantitative real-time PCR in skeletal muscle tissue. Localization of HBD-3, collagen 6, dystrophin, CD8-positive T-cells, CD-68-positive macrophages, β-amyloid, the autophagy marker LC3, and TLR3 were detected by immunofluorescence and co-localization was quantified. HBD-3 and all TLRs except for TLR9 were overexpressed in both IIM with significant overexpression of TLR3 in sIBM. HBD-3 showed characteristic intracellular accumulations near deposits of β-amyloid, LC3 and TLR3 in sIBM, and was detected in inflammatory infiltrations and macrophages invading necrotic muscle fibres in both IIM. The characteristic intracellular localization of HBD-3 near markers of degeneration and autophagy, and overexpression of endosomal TLR3 in sIBM hint at different pathogenetic mechanisms in sIBM compared with PM. This descriptive study serves as a first approach to the role of the innate immune system in sIBM and PM. Neuroendocrine (NE) phenotypes characterize a spectrum of lung tumors, including low-grade typical and intermediate-grade atypical carcinoid, high-grade large-cell NE carcinoma and small cell lung carcinoma. Currently, no effective treatments are available to cure NE lung tumors, demanding identification of biological features specific to these tumors. Here, we report that autophagy has an important role for NE lung tumor cell proliferation and survival. We found that the expression levels of the autophagy marker LC3 are relatively high in a panel of lung tumor cell lines expressing high levels of neuron-specific enolase (NSE), a key NE marker in lung tumors. In response to bafilomycin A1 and chloroquine, NE lung tumor cells exhibited cytotoxicity whereas non-NE lung tumor cells exhibited cytostasis, indicating a distinct role of autophagy for NE lung tumor cell survival. Intriguingly, in certain NE lung tumor cell lines, the levels of processed LC3 (LC3-II) were inversely correlated with AKT activity. When AKT activity was inhibited using AKTi or MK2206, the levels of LC3-II and SQSTM1/p62 were increased. In contrast, torin 1, rapamycin or mTOR knockdown increased p62 levels, suggesting that these two pathways have opposing effects on autophagy in certain NE lung tumors. Moreover, inhibition of one pathway resulted in reduced activity of the other, suggesting that these two pathways crosstalk in the tumors. These results suggest that NE lung tumor cells share a common feature of autophagy and are more sensitive to autophagy inhibition than non-NE lung tumor cells.

Are there any statistical methods for normalizing and identifying differential regions in histone modification ChIP-seq data?

Yes. ChIPnorm is a two-stage statistical method to normalize ChIP-seq data, and to find differential regions in the genome, given two libraries of histone modifications of different cell types.

[22870189]

The advent of high-throughput technologies such as ChIP-seq has made possible the study of histone modifications. A problem of particular interest is the identification of regions of the genome where different cell types from the same organism exhibit different patterns of histone enrichment. This problem turns out to be surprisingly difficult, even in simple pairwise comparisons, because of the significant level of noise in ChIP-seq data. In this paper we propose a two-stage statistical method, called ChIPnorm, to normalize ChIP-seq data, and to find differential regions in the genome, given two libraries of histone modifications of different cell types. We show that the ChIPnorm method removes most of the noise and bias in the data and outperforms other normalization methods. We correlate the histone marks with gene expression data and confirm that histone modifications H3K27me3 and H3K4me3 act as respectively a repressor and an activator of genes. Compared to what was previously reported in the literature, we find that a substantially higher fraction of bivalent marks in ES cells for H3K27me3 and H3K4me3 move into a K27-only state. We find that most of the promoter regions in protein-coding genes have differential histone-modification sites. The software for this work can be downloaded from http://lcbb.epfl.ch/software.html.

Is CD84 genetically associated with arthritis?

Three members of this gene family, Ly108, Ly9, and CD84, exhibit polymorphisms that strongly influence susceptibility to systemic autoimmunity, notably in mice, but also in some human populations. Our study demonstrates that an allele associated with response to etanercept therapy is also associated with CD84 gene expression, and further that CD84 expression correlates with Rheumatoid Arthritis disease activity.

[21094032, 23555300, 21255096]

We performed partial evaluation of pemphigus vulgaris (PV) autoantibody profile using the protein array technology. The sera from seven patients with acute PV and five healthy donors were probed for the presence of autoantibodies characteristic of the organ-non-specific autoimmune disorders rheumatoid arthritis, lupus erythematosus, scleroderma, diabetes and some other autoimmune disorders, but not to desmosomal proteins. The array targeted 785 human genes amplified using Mammalian Gene Clone Collection with gene-specific primers containing 20-bp nucleotide extension complementary to ends of linear pXT7 vector. The array identified PV antibodies significantly (P<0.05) differentially reactive with 16 antigens, most of which were cell-surface proteins, such as CD2, CD31, CD33, CD36, CD37, CD40, CD54, CD66c and CD84 molecules, nicotinamide/nicotinic acid mononucleotide adenylyltransferase, immunoglobulin heavy chain constant region gamma 2 and others. Reactivity with Fc-IgG helps explain an ability of the chimeric desmoglein constructs to absorb out all disease-causing PV antibodies. Anti-M(1) muscarinic receptor antibody was also identified, consistent with the facts that while blockade of this receptor causes keratinocyte detachment, its activation is therapeutic in PV. Further proteomics analysis of PV antibodies should help elucidate the immunopathogenic mechanisms underlying keratinocyte detachment and blistering.

What is the function of Neu5Gc (N-Glycolylneuraminic acid)?

N-glycolylneuraminic acid (Neu5Gc) is an immunogenic sugar of dietary origin that metabolically incorporates into diverse native glycoconjugates in humans. Humans lack a functional cytidine monophosphate-N-acetylneuraminic acid hydroxylase (CMAH) protein and cannot synthesize the sugar Neu5Gc, an innate mammalian signal of self. N-Glycolylneuraminic acid (Neu5Gc) can be incorporated in human cells and can trigger immune response, a response that is diverse and polyclonal. As dietary Neu5Gc is primarily found in red meat and milk products, it is suggested that this ongoing antigen-antibody reaction may generate chronic inflammation, possibly contributing to the high frequency of diet-related carcinomas and other diseases in humans.

[11786991, 25003133, 23945141, 18669916, 25124893, 23520510]

Acellular materials of xenogenic origin are used worldwide as xenografts, and phase I trials of viable pig pancreatic islets are currently being performed. However, limited information is available on transmission of porcine endogenous retrovirus (PERV) after xenotransplantation and on the long-term immune response of recipients to xenoantigens. We analyzed the blood of burn patients who had received living pig-skin dressings for up to 8 wk for the presence of PERV as well as for the level and nature of their long term (maximum, 34 y) immune response against pig Ags. Although no evidence of PERV genomic material or anti-PERV Ab response was found, we observed a moderate increase in anti-αGal Abs and a high and sustained anti-non-αGal IgG response in those patients. Abs against the nonhuman sialic acid Neu5Gc constituted the anti-non-αGal response with the recognition pattern on a sialoglycan array differing from that of burn patients treated without pig skin. These data suggest that anti-Neu5Gc Abs represent a barrier for long-term acceptance of porcine xenografts. Because anti-Neu5Gc Abs can promote chronic inflammation, the long-term safety of living and acellular pig tissue implants in recipients warrants further evaluation. Human heterophile antibodies that agglutinate animal erythrocytes are known to detect the nonhuman sialic acid N-glycolylneuraminic acid (Neu5Gc). This monosaccharide cannot by itself fill the binding site (paratope) of an antibody and can also be modified and presented in various linkages, on diverse underlying glycans. Thus, we hypothesized that the human anti-Neu5Gc antibody response is diverse and polyclonal. Here, we use a novel set of natural and chemoenzymatically synthesized glycans to show that normal humans have an abundant and diverse spectrum of such anti-Neu5Gc antibodies, directed against a variety of Neu5Gc-containing epitopes. High sensitivity and specificity assays were achieved by using N-acetylneuraminic acid (Neu5Ac)-containing probes (differing from Neu5Gc by one less oxygen atom) as optimal background controls. The commonest anti-Neu5Gc antibodies are of the IgG class. Moreover, the range of reactivity and Ig classes of antibodies vary greatly amongst normal humans, with some individuals having remarkably large amounts, even surpassing levels of some well-known natural blood group and xenoreactive antibodies. We purified these anti-Neu5Gc antibodies from individual human sera using a newly developed affinity method and showed that they bind to wild-type but not Neu5Gc-deficient mouse tissues. Moreover, they bind back to human carcinomas that have accumulated Neu5Gc in vivo. As dietary Neu5Gc is primarily found in red meat and milk products, we suggest that this ongoing antigen-antibody reaction may generate chronic inflammation, possibly contributing to the high frequency of diet-related carcinomas and other diseases in humans. Human sialic acid biology is unusual and thought to be unique among mammals. Humans lack a functional cytidine monophosphate-N-acetylneuraminic acid hydroxylase (CMAH) protein and cannot synthesize the sugar Neu5Gc, an innate mammalian signal of self. Losing this sugar changed how humans interact with some of our deadliest pathogens: malaria, influenza, and streptococcus among others. We show that the New World monkeys, comprising the third of all primate species, have human-like sialic acid biology. They have lost Neu5Gc because of an independent CMAH inactivation ~30 million years ago (mya) (compared to ~3 mya in hominids). This parallel loss of Neu5Gc opens sialic acid biology to comparative phylogenetic analysis and reveals an unexpected conservation priority. New World monkeys risk infection by human pathogens that can recognize cells in the absence of Neu5Gc. This striking molecular convergence provides a mechanism that could explain the long-standing observation that New World monkeys are susceptible to some human diseases that cannot be transmitted to other primates. N-glycolylneuraminic acid (Neu5Gc) is an immunogenic sugar of dietary origin that metabolically incorporates into diverse native glycoconjugates in humans. Anti-Neu5Gc antibodies are detected in all human sera, though with variable levels and epitope-recognition profiles. These antibodies likely play a role in several inflammation-mediated pathologies including cardiovascular diseases and cancer. In cancer, they have dualistic and opposing roles, either stimulating or repressing disease, as a function of their dose, and some of these antibodies serve as carcinoma biomarkers. Thus, anti-Neu5Gc antibodies may signify risk of inflammation-mediated diseases, and changes in their levels could potentially be used to monitor disease progression and/or response to therapy. Currently, it is difficult to determine levels of anti-Neu5Gc antibodies in individual human samples because these antibodies recognize multiple Neu5Gc-epitopes. Here we describe a simple and specific method for detection and overall estimation of human anti-Neu5Gc antibodies. We exploit the difference between two mouse models that differ only by Neu5Gc-presence (wild-type) or Neu5Gc-absence (Cmah(-/-) knockout). We characterize mouse serum from both strains by HPLC, lectin and mass-spectrometry analysis and show the target Neu5Gc-epitopes. We then use Cmah(-/-) knockout sera to inhibit all non-Neu5Gc-reactivity followed by binding to wild-type sera to detect overall anti-Neu5Gc response in a single assay. We applied this methodology to characterize and quantify anti-Neu5Gc IgG and IgA in sera of patients with Kawasaki disease (KD) at various stages compared to controls. KD is an acute childhood febrile disease characterized by inflammation of coronary arteries that untreated may lead to coronary artery aneurysms with risk of thrombosis and myocardial infarction. This estimated response is comparable to the average of detailed anti-Neu5Gc IgG profile analyzed by a sialoglycan microarray. Both assays revealed an elevated response in acute KD patients with normal coronaries compared to patients with aneurysm or dilated coronaries. Implications of these findings are discussed.

Are there any specific antidotes for rivaroxaban?

Currently, there is no specific antidote for rivaroxaban

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Warfarin and heparin are the traditional mainstay anticoagulant therapies for treating thromboembolic disease. These drugs, with a documented history of utility, also have inherent difficulties in usage; in particular, the complicated monitoring and numerous drug-drug interactions of warfarin, and the need for parenteral administration of heparins. New agents have recently emerged that target specific elements of the clotting pathway. Rivaroxaban, which inhibits activated factor X (Xa), is currently in clinical trials and is the most advanced factor Xa inhibitor. The drug offers once-daily oral dosing, with no need for injections, dose titration, or frequent blood tests to monitor the international normalised ratio. It has a rapid onset of action and, although there is no specific antidote, it has a short plasma elimination half-life (about 5-9 hours). Evidence from recently published large-scale phase III clinical trials shows rivaroxaban to be superior to enoxaparin for prophylaxis of venous thromboembolism after major orthopaedic surgery. Studies have shown rivaroxaban to have a sound safety profile, with an incidence of bleeding similar to enoxaparin in phase III clinical trials. Few side effects and drug-drug interactions between rivaroxaban and common medications have been found thus far, although some interactions with potent cytochrome P450 3A4 inhibitors have been observed. It is hoped that rivaroxaban may be used as a first-line anticoagulant for prophylaxis of venous thromboembolic disease in postsurgical patients. For more than 60 years, vitamin K antagonists have been the only available oral anticoagulants for the prevention of stroke and systemic embolism in atrial fibrillation (AF). Several new molecules, with a favorable pharmacokinetic profile and avoiding routine monitoring, have been recently developed, opening a new era in anticoagulation. The oral direct thrombin inhibitor, dabigatran, and the oral activated factor X inhibitors, rivaroxaban and apixaban, are the novel oral anticoagulants with data from large randomized clinical trials showing that these drugs are noninferior to warfarin in the prevention of stroke and thromboembolic complications of AF, with the advantage of less hemorrhagic stroke and intracranial bleeding. While these trial data are extremely encouraging, several practical issues (e.g., lack of specific antidote, safety of long-term treatment or cost-effectiveness in "real-life" clinical practice) still need to be elucidated. Dabigatran, rivaroxaban, and apixaban are the new oral anticoagulants (NOAC) which have been investigated in patients with atrial fibrillation (AF) for primary and secondary prevention of stroke and thromboembolism. In these trials NOAC had a similar efficacy and safety profile compared to traditional vitamin-K-antagonists such as warfarin. We advise caution in the use of NOAC in patients with stroke or cerebral hemorrhage because of the following reasons: 1) Patients with cerebral bleeding were excluded from the trials. 2) Stroke within 14 days and severe stroke within 6 months before screening were exclusion criteria in the trials investigating dabigatran and rivaroxaban. 3) There is no antidote for reversal and no reliable laboratory monitoring of the anticoagulant effect for emergency situations. 4) NOAC are either substrates of the P-glycoprotein (P-gp) or are metabolized by the cytochrome P450 (CYP) system, or both. Drug-drug interactions between NOAC and P-gp and CYP-affecting drugs are largely unknown. 5) Long-term effects of thrombin generation inhibition on the occurrence of infections, malignancies, dementia, and other diseases are unknown. Based on these considerations it is our opinion that studies of NOAC in patients with stroke compared with other prevention strategies, as well as more post marketing surveillance data, are required. The range of anticoagulants has been very active recently with the development of new compounds including injectable anti-Xa such as fondaparinux, and new oral drugs which can be divided into anti-IIa with dabigatran, and anti-Xa, such as rivaroxaban and apixaban still in the development stage. Others are coming forward. They are more convenient to use and do not require routine coagulation monitoring. However, several points need to be clarified and the place for each drug remains to be determined. In case of massive bleeding, management is unclear and none of these newer agents has a specific antidote that completely reverses its anticoagulant effect. An increasing number of patients receive anticoagulant therapy to prevent and treat arterial or venous thromboembolism. The major complication of anticoagulant therapy is the increase of the individual bleeding risk. All anticoagulant drugs can cause haemorrhages, that can sometimes be life-threatening. Although heparins and the vitamin K antagonists have been the most widely used anticoagulants for decades, the correct management of bleeding complications associated with these agents has been poorly studied. More recently, new anticoagulant drugs, both parenteral and oral, have been approved for clinical use. Currently, none of these new agents has a specific antidote, and little advise can be given on how to manage a major bleeding event. The aim of this article is to describe the haemorrhagic risk and the management of bleeding complications associated with the principal anticoagulant drugs. Direct new oral anticoagulants (NOACs) - inhibitors of thrombin or factor Xa - are intended to be used largely in the treatment of venous thromboembolic disease or the prevention of systematic embolism in atrial fibrillation, instead of vitamin K antagonists. Like any anticoagulant treatment, they are associated with spontaneous or provoked haemorrhagic risk. Furthermore, a significant proportion of treated patients are likely to be exposed to emergency surgery or invasive procedures. Given the absence of a specific antidote, the action to be taken in these situations must be defined. The lack of data means that it is only possible to issue proposals rather than recommendations, which will evolve according to accumulated experience. The proposals presented here apply to dabigatran (Pradaxa(®)) and rivaroxaban (Xarelto(®)); data for apixaban and edoxaban are still scarce. For urgent surgery with haemorrhagic risk, the drug plasma concentration should be less or equal to 30ng/mL for dabigatran and rivaroxaban should enable surgery associated with a high bleeding risk. Beyond that, if possible, the intervention should be postponed by monitoring the drug concentration. The course to follow is then defined according to the NOAC and its concentration. If the anticoagulant dosage is not immediately available, worse propositions, based on the usual tests (prothrombin time and activated partial thromboplastin time), are presented. However, these tests do not really assess drug concentration or the risk of bleeding that depends on it. In case of serious bleeding in a critical organ, the effect of anticoagulant therapy should be reduced using a non-specific procoagulant drug as a first-line approach: activated prothrombin complex concentrate (aPCC) (FEIBA(®) 30-50U/kg) or non-activated PCC (50U/kg). In addition, for any other type of severe haemorrhage, the administration of a procoagulant drug, which is potentially thrombogenic in these patients, is discussed according to the NOAC concentration and the possibilities of mechanical haemostasis. The direct oral factor Xa-inhibitors are at present in clinical use as antithrombotics, after their efficiency and safety have been proved in clinical studies. Three products are actually in the market, rivaroxaban (Xarelto®) apixaban (Eliquis®) and edoxaban (Lixiana®). Efficacy and safety have been tested for rivaroxaban and apixaban in large study programmes with more than 60'000 patients each. For edoxaban large phase III studies are under way. Based on these data rivaroxaban was registered in the EU and CH for primary prophylaxis against thrombosis after major orthopaedic surgery, such as hip- and knee-joint protheses, for treatment and prophylaxis of deep vein thrombosis and pulmonary embolism and for prophylaxis against thromboembolic stroke in patients with atrial fibrillation. Apixaban is presently registered in the EU and CH for prophylaxis against thrombosis after major orthopaedic surgery, Edoxaban is registered only in Japan for the same indication. These products have been shown to be non-inferior or superior compared with vitamin K antagonists or low-molecular weight heparins, they are administered once or twice a day, they do not need laboratory monitoring. But they have disadvantages also, they depend on renal clearance, they can interact with other medicaments and they lack a specific antidote. In total, though, they are considered as a progress for the appropriate patients in terms of quality of treatment. Amongst numerous promising anticoagulant molecules, rivaroxaban (Xarelto(®)), dabigatran (Pradaxa(®)) and apixaban (Eliquis(®)) have been registered outside the USA in the prevention of thromboembolic events in patients undergoing total hip or knee prosthetic replacement. Rivaroxaban however has been granted authorisation by the FDA for the thromboprophylaxis after surgery for total hip or knee surgery. Dabigatran has been granted authorisation by the FDA in non-valvular atrial fibrillation (RE-LY trial) while rivaroxaban is expecting approval in this same indication (ROCKET trial). Phase III results in the treatment and in the secondary prevention of established venous thrombosis and pulmonary embolism are encouraging. These small molecules are obtained by chemical synthesis, their molecular weight is lower than 500 daltons. Many coagulation tests may be affected by these molecules. Those modifications should be known in order to avoid misinterpretation of the tests but could also be used to measure plasma concentrations of these products. The choice of a non specific global and readily available test has been documented (Quick time for rivaroxaban and aPTT for dabigatran). Anti-Xa (for rivaroxaban) and anti-IIa (for dabigatran) activities should however be preferred, expressed in ng/ml with calibrated plasmas (containing predetermined concentration of the tested drug). The half-life is around 8 to 12 hours, with a peak activity 2 to 4 hours after ingestion. Dabigatran is mainly eliminated via the kidney, hence requiring dose-adjustment in case of moderate renal insufficiency, and contra-indicated in case of severe renal insufficiency. Rivaroxaban being excreted via kidney and liver, some precautions should apply in case of liver insufficiency. No data are available in pregnancy or pediatrics, clinical trials are ongoing. There are few interactions with concomitant drugs, which should not be ignored. The short half-life of these new agents compensates for the lack of any specific antidote in many instances. Their oral administration, without the need for dose adjustment, and without requirement for a laboratory monitoring will increase their use in a large number of patients, in those indications for which an approval has been granted by health authorities. New oral anticoagulants which specifically inhibit factor Xa (FXa) or thrombin (FIIa) do not require routine laboratory monitoring. However, they induce a state of hypocoagulation and increase the risk of bleeding. In some clinical situations, such as emergency surgery, hemorrhagic episodes, or recurrent stroke, coagulation monitoring may be useful. A significant number of publications have reported uncontrollable hemorrhagic complications and deaths in patients treated with these new anticoagulants. The selection of the most appropriate clotting assay is based on the drug used and the availability of the test. The new anticoagulants influence all global clot-based tests. Prothrombin time and partial thromboplastin time measured before and after treatment are considered as qualitative tests since they are not specific. Specific anti-Xa and anti-IIa assays are available and results can be expressed in nanogram per milliliter of plasma using calibrated plasmas containing well-established amounts of drug. The fact that there is no specific antidote to reverse the anticoagulant action of the new anticoagulants can impair management of hemorrhagic complications; clinical experience is still limited. Pro-hemostatic treatment with non-activated or activated prothrombin complexes (FEIBA(®)), or as a last recourse with FVIIa concentrates (NovoSeven(®)), has been used with variable results. Some suggestions for the management of patients with bleeding have been published but there is still little clinical evidence for these interventions. New anticoagulant and antiplatelet medications have been approved and are prescribed with increased frequency. Intracranial hemorrhage is associated with the use of these medications. Therefore, neurosurgeons need to be aware of these new medications, how they are different from their predecessors, and the strategies for the urgent reversal of their effects. Utilization of intraluminal stents by endovascular neurosurgeons has resulted in the need to have a thorough understanding of antiplatelet agents. Increased use of dabigatran, rivaroxaban, and apixaban as oral anticoagulants for the treatment of atrial fibrillation and acute deep venous thrombosis has increased despite the lack of known antidotes to these medications. When a bleeding complication occurs during therapy with heparin or vitamin K antagonists, there is an option to give a specific antidote. Several new anticoagulants have been developed that are likely to have some risk of bleeding complications, for which no specific antidotes are available. Interestingly, it is unknown how often the use of an antidote is necessary in clinical practice. We investigated 1877 patients treated for venous thromboembolism included in three large clinical trials, of which 181 (9.6%) had a total of 225 adjudicated bleeding episodes; 46 hemorrhages being designated as major. Some form of antidote was given to 26 (14.4%) patients with a hemorrhage. Of the patients with at least one major hemorrhage, 19 (41.3%) received an antidote. Vitamin K was given to 23 (1.2%) patients, one (0.05%) patient received protamin sulfate and seven (0.4%) patients received fresh frozen plasma. The use of antidotes was comparable for initial and long-term treatment. Antidotes were statistically significantly more frequently given in Canada as compared to other participating countries. Vitamin K was more frequently given in case of a higher international normalized ratio value. Although antidotes against anticoagulant treatment are widely available, our analysis shows that in only a very small number of patients a direct, or slow-acting antidote to reverse the anticoagulant effect was used. Dabigatran, rivaroxaban and apixaban are oral anticoagulants used to prevent or treat thrombosis in a variety of situations. Like all anticoagulants, these drugs can provoke bleeding. How should patients be managed if bleeding occurs during dabigatran, rivaroxaban or apixaban therapy? How can the risk of bleeding be reduced in patients who require surgery or other invasive procedures? To answer these questions, we reviewed the available literature, using the standard Prescrire methodology. In clinical trials, warfarin, enoxaparin, dabigatran, rivaroxaban and apixaban were associated with a similar frequency of severe bleeding. Numerous reports of severe bleeding associated with dabigatran have been recorded since this drug was first marketed. Some situations are associated with a particularly high bleeding risk, including: even mild renal failure, advanced age, extremes in body weight and drug-drug interactions, particularly with antiplatelet agents (including aspirin), nonsteroidal antiinflammatory drugs, and many drugs used in cardiovascular indications. In patients treated with dabigatran, rivaroxaban or apixaban, changes in the INR (international normalised ratio) and activated partial thromboplastin time (aPTT) do not correlate with the dose. In early 2013, there is still no routine coagulation test suitable for monitoring these patients; specific tests are only available in specialised laboratories. In early 2013 there is no antidote for dabigatran, rivaroxaban or apixaban, nor any specific treatment with proven efficacy for severe bleeding linked to these drugs. Recommendations on the management of bleeding in this setting are based mainly on pharmacological parameters and on scarce experimen-Haemodialysis reduces the plasma concentration of dabigatran, while rivaroxaban and apixaban cannot be eliminated by dialysis. Prothrombin complex concentrates and recombinant activated factor VII seem to have little or no efficacy, and they carry a poorly documented risk of thrombosis. For patients undergoing surgery or other invasive procedures, clinical practice guidelines are primarily based on pharmacokinetic parameters and on extrapolation of data on vitamin K antagonists. The decision on whether or not to discontinue anticoagulation before the procedure mainly depends on the likely risk of bleeding. In patients at high risk of thrombosis, heparin can be proposed when the anticoagulant is withdrawn. In early 2013, difficulties in the management of bleeding and of situations in which there is a risk of bleeding weigh heavily in the balance of potential harm versus potential benefit of dabigatran, rivaroxaban and apixaban. When an oral anticoagulant is required, it is best to choose warfarin, a vitamin K antagonist, and the drug with which we have the most experience, except in those rare situations in which the INR cannot be maintained within the therapeutic range. The target-specific oral anticoagulants represent the first new oral anti-thrombotic therapy in over 50 years and have the potential to make therapy easier and hence more accessible to many patients. Like any new therapy, the potential benefits must be weighed against the potential challenges and one of the most concerning aspects of the new target-specific oral anticoagulants is the lack of a proven method to reverse their effect. Unlike the vitamin K antagonist, i.e. warfarin, there is no specific antidote for these medications. This paper will review the limited data on the use of non-specific therapies to reverse anticoagulation for the new agents. We hope to prepare clinicians who are faced with a patient who has serious bleeding or needs emergent surgery while taking dabigatran, rivaroxaban or apixaban. The prevalence of atrial fibrillation (AF) and the embolic risk increase with age. Elderly AF patients are undertreated with vitamin K antagonists (VKA). The new oral anticoagulants (NOAC) dabigatran, rivaroxaban and apixaban have been shown to be non-inferior to VKA for stroke prevention in AF. We summarize the knowledge about primary and secondary stroke prevention by NOAC in AF patients >75 years of age. A literature search was carried out using the terms 'dabigatran', 'rivaroxaban', 'apixaban', 'elderly', 'octogenarians', 'atrial fibrillation' and 'anticoagulation' from 1998 to 2013. Randomized clinical trials, longitudinal studies, case series and case reports were included. Whereas studies investigating the use of VKA for stroke prevention in the 1990s were carried out by industry-independent institutions, all NOAC-investigating trials were sponsored by the manufacturers of the respective drugs. Frail elderly people were not represented in NOAC-investigating trials because of various exclusion criteria, and only one-third of patients were aged >75 years. A subgroup analysis from the dabigatran-investigating trial indicated that elderly patients might have a higher risk for extracranial bleeding complications with NOAC than with VKA. Further concerns about the use of NOAC in the elderly are the high prevalence of renal insufficiency in AF patients >75 years of age, the largely unknown risk of drug-drug and drug-food interactions, the lack of easily available laboratory monitoring tests of anticoagulant activity and the lack of an antidote. There is a need for independent studies comparing the efficacy and risk of side effects of NOAC with that of VKA in elderly AF patients.

Which metabolite activates AtxA?

Upon infection of a mammalian host, Bacillus anthracis responds to host cues, and particularly to elevated temperature (37°C) and bicarbonate/CO2 concentrations, with increased expression of virulence factors that include the anthrax toxins and extracellular capsular layer. Cultures grown with elevated CO(2) /bicarbonate exhibited increased AtxA dimer/monomer ratios and increased AtxA activity, relative to cultures grown without added CO(2) /bicarbonate, suggesting that this host-associated signal enhances AtxA function by shifting the dimer/monomer equilibrium towards the dimeric state. CO2-enhanced toxin gene transcription is not observed in atx4-null mutants. Overall data indicate a clear association of atxA with CO2-enhanced gene expression in B. anthracis and provide evidence that atxA regulates genes other than the structural genes for the anthrax toxin proteins.

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Bacillus anthracis plasmid pXO1 carries the structural genes for the three anthrax toxin proteins, cya (edema factor), lef (lethal factor), and pag (protective antigen). Expression of the toxin genes by B. anthracis is enhanced during growth under elevated levels of CO2. This CO2 effect is observed only in the presence of another pXO1 gene, atxA, which encodes a transactivator of anthrax toxin synthesis. Here we show that transcription of atxA does not appear to differ in cells grown in 5% CO2 compared with cells grown in air. Using a new efficient method for gene replacement in B. anthracis, we constructed an atxA-null mutant in which the atxA-coding sequence on pXO1 is replaced with an omega km-2 cassette. Transcription of all three toxin genes is decreased in the absence of atxA. The pag gene possesses two apparent transcription start sites, P1 and P2; only transcripts with 5' ends mapping to P1 are decreased in the atxA-null mutant. Deletion analysis of the pag promoter region indicates that the 111 bp region upstream of the P1 site is sufficient for atxA-mediated activation of this transcript. The cya and lef genes each have one apparent start site for transcription. Transcripts with 5' ends mapping to these sites are not detected in the atxA-null mutant. The atxA-null mutant is avirulent in mice. Moreover, the antibody response to all three toxin proteins is decreased significantly in atxA-null mutant-infected mice. These data suggest that the atxA gene product also regulates toxin gene expression during infection. The two major virulence factors of Bacillus anthracis are the tripartite toxin and the polyglutamate capsule, which are encoded by genes on the large plasmids, pXO1 and pXO2, respectively. The genes atxA, located on pXO1, and acpA, located on pXO2, encode positive trans-acting proteins that are involved in bicarbonate-mediated regulation of toxin and capsule production, respectively. A derivative strain cured of pXO1 produced less capsular substance than the parent strain harbouring both pXO1 and pXO2, and electroporation of the strain cured of pXO1 with a plasmid containing the cloned atxA gene resulted in an increased level of capsule production. An acpA-null mutant was complemented by not only acpA but also the atxA gene. The cap region, which is essential for encapsulation, contains three genes capB, capC, and capA, arranged in that order. The atxA gene stimulated capsule synthesis from the cloned cap region. Transcriptional analysis of cap by RNA slot-blot hybridization and primer-extension analysis revealed that atxA activated expression of cap in trans at the transcriptional level. These results indicate that cross-talk occurs, in which the pXO1-located gene, atxA, activates transcription of the cap region genes located on pXO2. We identified two major apparent transcriptional start sites, designated P1 and P2, located at positions 731 bp and 625 bp, respectively, upstream of the translation-initiation codon of capB. Transcription initiated from P1 and P2 was activated by both atxA and acpA, and activation appeared to be stimulated by bicarbonate. Deletion analysis of the upstream region of the cap promoter revealed that activation by both atxA and acpA required a DNA segment of 70 bp extending upstream of the P1 site. These results suggest that cross-talk by atxA to the genes encoding capsule synthesis is caused by the interaction of the atxA gene product with a regulatory sequence upstream of cap. The Bacillus anthracis toxin genes, cya, lef, and pag, can be viewed as a regulon, in which transcription of all three genes is activated in trans by the same regulatory gene, atxA, in response to the same signal, CO2. In atxA+ strains, toxin gene expression is increased 5- to 20-fold in cells grown in 5% CO2 relative to cells grown in air. CO2-enhanced toxin gene transcription is not observed in atx4-null mutants. Here, we used two independent techniques to obtain evidence for additional CO2-induced atxA-regulated genes. First, total protein preparations from atxA4+ and atxA isolates grown in 5% CO2 and in air were examined by two-dimensional electrophoresis. Comparison of the resulting protein patterns indicated that synthesis of non-toxin proteins is influenced by growth in elevated CO2 and the toxin gene regulator, atxA. Second, we generated random transcriptional lacZ fusions in B. anthracis with transposon Tn917-LTV3. Transposon-insertion libraries were screened for mutants expressing CO2-enhanced atxA-dependent beta-galactosidase activity. DNA sequence analysis of transposon insertion sites in 17 mutants carrying CO2- and atxA-regulated fusions revealed 10 mutants carrying independent insertions on the 185-kb toxin plasmid pXO1 which did not map to the toxin genes. The tcr-lacZ fusion mutants (tcr for toxin coregulated) were Tox+, indicating that these genes may not be involved in anthrax toxin gene activation. Our data indicate a clear association of atxA with CO2-enhanced gene expression in B. anthracis and provide evidence that atxA regulates genes other than the structural genes for the anthrax toxin proteins. Expression of genes for Bacillus anthracis toxin and capsule virulence factors are dependent upon the AtxA transcription factor. The mechanism by which AtxA regulates the transcription of its target genes is unknown. Here we report that bioinformatic analyses suggested the presence in AtxA of two PTS (phosphenolpyruvate : sugar phosphotransferase system) regulation domains (PRD) generally regulated by phosphorylation/dephosphorylation at conserved histidine residues. By means of amino acid substitutions that mimic the phosphorylated (H to D) or the unphosphorylated (H to A) state of the protein, we showed that phosphorylation of H199 of PRD1 is likely to be necessary for AtxA activation while phosphorylation of H379 in PRD2 is inhibitory to toxin gene transcription. In vivo labelling experiments with radioactive phosphate allowed us to propose that H199 and H379 are AtxA residues subject to regulated phosphorylation. In support to these notions, we also show that deletion of ptsHI, encoding the HPr intermediate and the EI enzymes of PTS, or growth in the presence of glucose affect positively and negatively, respectively, the activity of AtxA. Our results link virulence factor production in B. anthracis to carbohydrate metabolism and, for the first time, provide a mechanistic explanation for AtxA transcriptional activity. Transcription of the major Bacillus anthracis virulence genes is triggered by CO2, a signal mimicking the host environment. A 182-kb plasmid, pXO1, carries the anthrax toxin genes and the genes responsible for their regulation of transcription, namely atxA and, pagR, the second gene of the pag operon. AtxA has major effects on the physiology of B. anthracis. It coordinates the transcription activation of the toxin genes with that of the capsule biosynthetic enzyme operon, located on the second virulence plasmid, pXO2. In rich medium, B. anthracis synthesises alternatively two S-layer proteins (Sap and EA1). An exponential phase "Sap-layer" is subsequently replaced by a stationary phase "EA1-layer". S-layer gene transcription is controlled by alternative sigma factors and by Sap acting as a transcriptional repressor of eag. Furthermore, in vitro in presence of CO2 and in vivo, AtxA is part of the sap and eag regulatory network. Only eag is significantly expressed in these conditions and this is due to AtxA activating eag and repressing sap transcription. PagR, and not AtxA itself, is the direct effector of this regulation by binding to sap and eag promoter regions. Therefore, PagR mediates the effect of AtxA on eag and sap and is the most downstream element of a signalling cascade initiated by AtxA. Taken together, these results indicate that the B. anthracis transcriptional regulator AtxA is controlling the synthesis of the three toxin components and of the surface elements (capsule and S-layer). Thus, AtxA is a master regulator that coordinates the response to host signals by orchestrating positive and negative controls over genes located on all genetic elements. AtxA, a unique regulatory protein of unknown molecular function, positively controls expression of the major virulence genes of Bacillus anthracis. The 475 amino acid sequence of AtxA reveals DNA binding motifs and regions similar to proteins associated with the phosphoenolpyruvate: carbohydrate phosphotransferase system (PTS). We used strains producing native and functional epitope-tagged AtxA proteins to examine protein-protein interactions in cell lysates and in solutions of purified protein. Co-affinity purification, non-denaturing polyacrylamide gel electrophoresis and bis(maleimido)hexane (BMH) cross-linking experiments revealed AtxA homo-multimers. Dimers were the most abundant species. BMH cross-links available cysteines within 13 Å. To localize interaction sites, six AtxA mutants containing distinct Cys→Ser substitutions were tested for multimerization and cross-linking. All mutants multimerized, but one mutation, C402S, prevented cross-linking. Thus, BMH uses C402 to make the inter-molecular bond between AtxA proteins, but C402 is not required for protein-protein interaction. C402 is in a region bearing amino acid similarity to Enzyme IIB proteins of the PTS. The AtxA EIIB motif may function in protein oligomerization. Finally, cultures grown with elevated CO(2) /bicarbonate exhibited increased AtxA dimer/monomer ratios and increased AtxA activity, relative to cultures grown without added CO(2) /bicarbonate, suggesting that this host-associated signal enhances AtxA function by shifting the dimer/monomer equilibrium towards the dimeric state. BACKGROUND: Upon infection of a mammalian host, Bacillus anthracis responds to host cues, and particularly to elevated temperature (37°C) and bicarbonate/CO2 concentrations, with increased expression of virulence factors that include the anthrax toxins and extracellular capsular layer. This response requires the presence of the pXO1 virulence plasmid-encoded pleiotropic regulator AtxA. To better understand the genetic basis of this response, we utilized a controlled in vitro system and Next Generation sequencing to determine and compare RNA expression profiles of the parental strain and an isogenic AtxA-deficient strain in a 2 × 2 factorial design with growth environments containing or lacking carbon dioxide. RESULTS: We found 15 pXO1-encoded genes and 3 chromosomal genes that were strongly regulated by the separate or synergistic actions of AtxA and carbon dioxide. The majority of the regulated genes responded to both AtxA and carbon dioxide rather than to just one of these factors. Interestingly, we identified two previously unrecognized small RNAs that are highly expressed under physiological carbon dioxide concentrations in an AtxA-dependent manner. Expression levels of the two small RNAs were found to be higher than that of any other gene differentially expressed in response to these conditions. Secondary structure and small RNA-mRNA binding predictions for the two small RNAs suggest that they may perform important functions in regulating B. anthracis virulence. CONCLUSIONS: A majority of genes on the virulence plasmid pXO1 that are regulated by the presence of either CO2 or AtxA separately are also regulated synergistically in the presence of both. These results also elucidate novel pXO1-encoded small RNAs that are associated with virulence conditions. Anthrax toxin gene expression in Bacillus anthracis is dependent on the presence of atxA, a trans-acting regulatory gene located on the resident 185-kb plasmid pXO1. In atxA+ strains, expression of the toxin genes (pag, lef, and cya) is enhanced by two physiologically significant signals: elevated CO2/bicarbonate and temperature. To determine whether increased toxin gene expression in response to these signals is associated with increased atxA expression, we monitored steady-state levels of atxA mRNA and AtxA protein in cells cultured in different conditions. We purified histidine-tagged AtxA [AtxA(His)] from Escherichia coli and used anti-AtxA(His) serum to detect AtxA in protein preparations from B. anthracis cells. AtxA was identified as a protein with an apparent size of 56 kDa in cytoplasmic fractions of B. anthracis cells. Our data indicate that atxA expression is not influenced by CO2/bicarbonate levels. However, the steady-state level of atxA mRNA in cells grown in elevated CO2/bicarbonate at 37 degrees C is five- to sixfold higher than that observed in cells grown in the same conditions at 28 degrees C. A corresponding difference in AtxA protein was also seen at the different growth temperatures. When atxA was cloned on a multicopy plasmid in B. anthracis, AtxA levels corresponding to the atxA gene copy number were observed. However, this strain produced significantly less pag mRNA and protective antigen protein than the parental strain harboring atxA in single copy on pXO1. These results indicate that increased AtxA expression does not lead to a corresponding increase in pag expression. Our data strongly suggest that an additional factor(s) is involved in regulation of pag and that the relative amounts of such a factor(s) and AtxA are important for optimal toxin gene expression.

What is the function of 6SRNA in bacteria?

6S RNA, first described as a ncRNA in E. coli, mimics an open promoter structure, which has a large bulge with two hairpin/stalk structures that regulate transcription through interactions with RNA polymerase. Escherichia coli 6S RNA represents a non-coding RNA (ncRNA), which, based on the conserved secondary structure and previous functional studies, had been suggested to interfere with transcription. The carboxy terminus containing the Arg-Gly-Gly (RGG) repeat domains in these proteins are necessary for cis-repression of transcription activation and HAT activity by the N-terminal glutamine-rich domain.

[23667906, 22214309, 17332013, 58611, 2579060, 15262935]

6S RNA is a bacterial transcriptional regulator,which accumulates during stationary phase and inhibits transcription from many promoters due to stable association with σ 70 -containing RNA polymerase. This inhibitory RNA polymerase ∼ 6S RNA complex dissociates during nutritional upshift, when cells undergo outgrowth from stationary phase, releasing active RNA polymerase ready for transcription. The release reaction depends on a characteristic property of 6S RNAs, namely to act as template for the de novo synthesis of small RNAs, termed pRNAs.Here, we used limited hydrolysis with structure-specific RNases and in-line probing of isolated 6S RNA and 6SRNA ∼ pRNA complexes to investigate the molecular details leading to the release reaction. Our results indicate that pRNA transcription induces the refolding of the 6S RNA secondary structure by disrupting part of the closing stem(conserved sequence regions CRI and CRIV) and formation of a new hairpin (conserved sequence regions CRIII and CRIV). Comparison of the dimethylsulfate modification pattern of 6S RNA in living cells at stationary growth and during outgrowth confirmed the conformational change observed in vitro. Based on our results, a model describing the individual steps of the release reaction is presented. The majority of the noncoding regions of mammalian genomes have been found to be transcribed to generate noncoding RNAs (ncRNAs), resulting in intense interest in their biological roles. During the past decade, numerous ncRNAs and aptamers have been identified as regulators of transcription. 6S RNA, first described as a ncRNA in E. coli, mimics an open promoter structure, which has a large bulge with two hairpin/stalk structures that regulate transcription through interactions with RNA polymerase. B2 RNA, which has stem-loops and unstructured single-stranded regions, represses transcription of mRNA in response to various stresses, including heat shock in mouse cells. The interaction of TLS (translocated in liposarcoma) with CBP/p300 was induced by ncRNAs that bind to TLS, and this in turn results in inhibition of CBP/p300 histone acetyltransferase (HAT) activity in human cells. Transcription regulator EWS (Ewing's sarcoma), which is highly related to TLS, and TLS specifically bind to G-quadruplex structures in vitro. The carboxy terminus containing the Arg-Gly-Gly (RGG) repeat domains in these proteins are necessary for cis-repression of transcription activation and HAT activity by the N-terminal glutamine-rich domain. Especially, the RGG domain in the carboxy terminus of EWS is important for the G-quadruplex specific binding. Together, these data suggest that functions of EWS and TLS are modulated by specific structures of ncRNAs. Escherichia coli 6S RNA represents a non-coding RNA (ncRNA), which, based on the conserved secondary structure and previous functional studies, had been suggested to interfere with transcription. Selective inhibition of sigma-70 holoenzymes, preferentially at extended -10 promoters, but not stationary-phase-specific transcription was described, suggesting a direct role of 6S RNA in the transition from exponential to stationary phase. To elucidate the underlying mechanism, we have analysed 6S RNA interactions with different forms of RNA polymerase by gel retardation and crosslinking. Preferred binding of 6S RNA to Esigma(70) was confirmed, however weaker binding to Esigma(38) was also observed. The crosslinking analysis revealed direct contact between a central 6S RNA sequence element and the beta/beta' and sigma subunits. Promoter complex formation and in vitro transcription analysis with exponential- and stationary-phase-specific promoters and the corresponding holoenzymes demonstrated that 6S RNA interferes with transcription initiation but does not generally distinguish between exponential- and stationary-phase-specific promoters. Moreover, we show for the first time that 6S RNA acts as a template for the transcription of defined RNA molecules in the absence of DNA. In conclusion, this study reveals new aspects of 6S RNA function. (1) The RNA replicase induced by bacteriophage Qbeta consists of four non-identical subunits designated as alpha (mol. wt. 74000), beta (mol. wt. 64000), gamma (mol. wt. 47000) and delta (mol. wt. 33000), only one (subunit beta) of which is specified by the phage genome. (2) Subunit alpha (30 S ribosomal protein "S1" as well as translational interference factor "i") is required only for (+) strand-directed RNA synthesis in the presence of the host factor. (3) Qbeta replicase lacking subunit alpha (R-alpha) is capable of replicating templates other than (+) strand, such as (--), "6S" RNA, poly(C) etc., in the absence of the host factor. (4) Subunit beta is suggested to be the nucleotide-polymerizing enzyme, but is unable to initiate RNA synthesis by itself. (5) Subunits gamma and delta are identical to the protein synthesis elongation factors, EF-Tu and EF-Ts, respectively, and are required only for initiation of RNA synthesis, but not for elongation. (6) A model of Qbeta replicase is presented in order to discuss observed template-enzyme interactions. The gene coding for the metabolically stable 6S RNA of Escherichia coli has been cloned, sequenced, and partially characterized in expression analyses. The DNA sequence results confirm the accuracy of the previously established RNA sequence and, with genomic hybridization data, reveal that there is only one copy of the 6S DNA in the chromosome. Consistent with its relaxed mode of expression, the promoter region of the 6S RNA gene was found to lack the hypothetical GC-rich discriminator domain common to other stable RNA genes under stringent control. The sequence results also revealed the occurrence of a 540-base-pair open reading frame immediately downstream from the 6S RNA coding region. Results from the expression analyses show that the protein and RNA coding regions are cotranscribed in vitro and that the open reading frame is translated in vivo. 6S RNA was identified in Escherichia coli >30 years ago, but the physiological role of this RNA has remained elusive. Here, we demonstrate that 6S RNA-deficient cells are at a disadvantage for survival in stationary phase, a time when 6S RNA regulates transcription. Growth defects were most apparent as a decrease in the competitive fitness of cells lacking 6S RNA. To decipher the molecular mechanisms underlying the growth defects, we have expanded studies of 6S RNA effects on transcription. 6S RNA inhibition of sigma(70)-dependent transcription was not ubiquitous, in spite of the fact that the vast majority of sigma(70)-RNA polymerase is bound by 6S RNA during stationary phase. The sigma(70)-dependent promoters inhibited by 6S RNA contain an extended -10 promoter element, suggesting that this feature may define a class of 6S RNA-regulated genes. We also discovered a secondary effect of 6S RNA in the activation of sigma(S)-dependent transcription at several promoters. We conclude that 6S RNA regulation of both sigma(70) and sigma(S) activities contributes to increased cell persistence during nutrient deprivation.

Is cytisine superior to nicotine replacement therapy for smoking cessation?

Yes, one clinical trial that directly compared smoking cessation rates with cytisine versus nicotine replacement therapy reported that cytisine was superior to nicotine-replacement therapy in helping smokers quit smoking, but it was associated with a higher frequency of self-reported adverse events.

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OBJECTIVES: Cytisine (Tabex) has been licensed in Eastern Europe as an aid to smoking cessation for 40 years. Cytisine is a partial agonist with high affinity binding to the alpha4beta2 nicotinic acetylcholine receptor believed to be central to the rewarding effect of nicotine. There is insufficient information on effectiveness to warrant licensing by modern standards. To assess whether full-scale controlled trials are warranted, this study sought to obtain an estimate of the 12-month continuous abstinence rates of smokers using cytisine with minimal behavioural support. DESIGN: An uncontrolled, open-label trial. SETTING: A smokers' clinic in an oncology centre in Warsaw, Poland. SUBJECTS: 436 consecutive attendees of the smokers' clinic of whom 191 were male. The mean dependence score (Fagerstrom Test for Nicotine Dependence) was 6.1. INTERVENTION: The standard regimen of Tabex (cytisine) was used, involving 25 days of treatment with minimal behavioural support. MAIN OUTCOME MEASURE: Self-reported continuous abstinence for 12 months; with abstinence verified by carbon monoxide at the final follow up (after 12 months). RESULTS: 60 participants (13.8% of the total sample) were abstinent for 12 months. Of the 315 subjects, who had taken the drug, 49 (15.5%) stopped cytisine because of adverse effects (mostly gastric disturbances and nausea), although they were not serious. The frequency of the minor adverse effects, primarily gastric disturbance, was similar to that observed in previous studies with the drug. CONCLUSIONS: The long-term abstinence rates were similar to those observed in smokers receiving nicotine replacement therapy. Full-scale randomised trials of cytisine (Tabex), conducted to the standards required by regulatory authorities, are warranted. BACKGROUND: Placebo-controlled trials indicate that cytisine, a partial agonist that binds the nicotinic acetylcholine receptor and is used for smoking cessation, almost doubles the chances of quitting at 6 months. We investigated whether cytisine was at least as effective as nicotine-replacement therapy in helping smokers to quit. METHODS: We conducted a pragmatic, open-label, noninferiority trial in New Zealand in which 1310 adult daily smokers who were motivated to quit and called the national quitline were randomly assigned in a 1:1 ratio to receive cytisine for 25 days or nicotine-replacement therapy for 8 weeks. Cytisine was provided by mail, free of charge, and nicotine-replacement therapy was provided through vouchers for low-cost patches along with gum or lozenges. Low-intensity, telephone-delivered behavioral support was provided to both groups through the quitline. The primary outcome was self-reported continuous abstinence at 1 month. RESULTS: At 1 month, continuous abstinence from smoking was reported for 40% of participants receiving cytisine (264 of 655) and 31% of participants receiving nicotine-replacement therapy (203 of 655), for a difference of 9.3 percentage points (95% confidence interval, 4.2 to 14.5). The effectiveness of cytisine for continuous abstinence was superior to that of nicotine-replacement therapy at 1 week, 2 months, and 6 months. In a prespecified subgroup analysis of the primary outcome, cytisine was superior to nicotine-replacement therapy among women and noninferior among men. Self-reported adverse events over 6 months occurred more frequently in the cytisine group (288 events among 204 participants) than in the group receiving nicotine-replacement therapy (174 events among 134 participants); adverse events were primarily nausea and vomiting and sleep disorders. CONCLUSIONS: When combined with brief behavioral support, cytisine was found to be superior to nicotine-replacement therapy in helping smokers quit smoking, but it was associated with a higher frequency of self-reported adverse events. (Funded by the Health Research Council of New Zealand; Australian New Zealand Clinical Trials Registry number, ACTRN12610000590066.). BACKGROUND: A recent rigorous study has shown that cytisine, a low-cost drug, is effective for smoking cessation. A number of earlier studies exist, mostly from former communist countries where cytisine has been used since the 1960s. The key question now is whether there is sufficient evidence to warrant licensing cytisine or whether more work is needed. A systematic review was undertaken to assess the efficacy of cytisine in smoking cessation. METHODS: The Cochrane Library, CINAHL, Embase, Medline and PsycINFO databases were searched for relevant data. Data from controlled trials were entered into two separate meta-analyses. The first considered the strictest definition of outcome and longest follow-up from all available studies and the second pooled outcomes from studies with biochemically validated abstinence and follow-up of 6 months or longer. RESULTS: Eight controlled trials were identified. Seven trials provided extractable data and, when pooled (first meta-analysis), produced a risk ratio (RR) of 1.57 (95% CI 1.42 to 1.74). Data from two high-quality studies (second meta-analysis) produced a pooled RR of 3.29 (95% CI 1.84 to 5.90). Patients on cytisine reported more gastrointestinal symptoms than patients on placebo (RR=1.76, 95% CI 1.28 to 2.42). There was no difference in overall reports of adverse events and no specific safety concerns emerged. CONCLUSIONS: Cytisine is an effective treatment for smoking cessation with efficacy comparable to that of other currently licensed treatments. Given its low cost and potential for public health benefit, expedited licensing of cytisine for smoking cessation is warranted. INTRODUCTION: Māori experience a disproportionate amount of smoking-related harm (46% of adult Māori smoke). Effective cessation treatments that are both accessible and attractive to Māori are urgently needed. Cytisine (a plant extract found in Golden Rain [Cytisus laburnum L.] and the New Zealand Kowhai [Sophora tetraptera L.] has a similar molecular makeup to nicotine, has been used successfully as a cessation product in central and eastern Europe and central Asia for many years, and is low priced. Recent reviews have found that cytisine is twice as effective as a placebo for smoking cessation. This study aimed to explore cytisine's potential as a 'rongoā Māori' (traditional Māori remedy) and its attractiveness to Māori smokers compared with other cessation products. METHODS: Māori that smoked were interviewed in two focus groups and eight individual semi-structured interviews. Two key informants were interviewed also. RESULTS: Barriers to using cessation products were financial and effort cost, pervasive smoking among family and peers, environments permissive of smoking, and perceived cultural inappropriateness of treatments. Participants were very interested in cytisine, supported the idea that it would be acceptable to package it as a rongoā Māori, and all wanted to use it. Named appropriately, packaged and promoted as a Māori cessation product, participants thought cytisine would contribute to the restoration of Māori identity and traditional beliefs and practices in addition to reducing smoking. CONCLUSIONS: Presented as a rongoā Māori, cytisine would likely be more attractive to Māori than currently available cessation products. Confirmation of efficacy and safety will be needed before promotion of the product could occur. BACKGROUND: Smoking is the leading preventable cause of illness and premature death worldwide. Some medications have been proven to help people to quit, with three licensed for this purpose in Europe and the USA: nicotine replacement therapy (NRT), bupropion, and varenicline. Cytisine (a treatment pharmacologically similar to varenicline) is also licensed for use in Russia and some of the former socialist economy countries. Other therapies, including nortriptyline, have also been tested for effectiveness. OBJECTIVES: How do NRT, bupropion and varenicline compare with placebo and with each other in achieving long-term abstinence (six months or longer)? How do the remaining treatments compare with placebo in achieving long-term abstinence? How do the risks of adverse and serious adverse events (SAEs) compare between the treatments, and are there instances where the harms may outweigh the benefits? METHODS: The overview is restricted to Cochrane reviews, all of which include randomised trials. Participants are usually adult smokers, but we exclude reviews of smoking cessation for pregnant women and in particular disease groups or specific settings. We cover nicotine replacement therapy (NRT), antidepressants (bupropion and nortriptyline), nicotine receptor partial agonists (varenicline and cytisine), anxiolytics, selective type 1 cannabinoid receptor antagonists (rimonabant), clonidine, lobeline, dianicline, mecamylamine, Nicobrevin, opioid antagonists, nicotine vaccines, and silver acetate. Our outcome for benefit is continuous or prolonged abstinence at least six months from the start of treatment. Our outcome for harms is the incidence of serious adverse events associated with each of the treatments. We searched the Cochrane Database of Systematic Reviews (CDSR) in The Cochrane Library, for any reviews with 'smoking' in the title, abstract or keyword fields. The last search was conducted in November 2012. We assessed methodological quality using a revised version of the AMSTAR scale. For NRT, bupropion and varenicline we conducted network meta-analyses, comparing each with the others and with placebo for benefit, and varenicline and bupropion for risks of serious adverse events. MAIN RESULTS: We identified 12 treatment-specific reviews. The analyses covered 267 studies, involving 101,804 participants. Both NRT and bupropion were superior to placebo (odds ratios (OR) 1.84; 95% credible interval (CredI) 1.71 to 1.99, and 1.82; 95% CredI 1.60 to 2.06 respectively). Varenicline increased the odds of quitting compared with placebo (OR 2.88; 95% CredI 2.40 to 3.47). Head-to-head comparisons between bupropion and NRT showed equal efficacy (OR 0.99; 95% CredI 0.86 to 1.13). Varenicline was superior to single forms of NRT (OR 1.57; 95% CredI 1.29 to 1.91), and to bupropion (OR 1.59; 95% CredI 1.29 to 1.96). Varenicline was more effective than nicotine patch (OR 1.51; 95% CredI 1.22 to 1.87), than nicotine gum (OR 1.72; 95% CredI 1.38 to 2.13), and than 'other' NRT (inhaler, spray, tablets, lozenges; OR 1.42; 95% CredI 1.12 to 1.79), but was not more effective than combination NRT (OR 1.06; 95% CredI 0.75 to 1.48). Combination NRT also outperformed single formulations. The four categories of NRT performed similarly against each other, apart from 'other' NRT, which was marginally more effective than NRT gum (OR 1.21; 95% CredI 1.01 to 1.46). Cytisine (a nicotine receptor partial agonist) returned positive findings (risk ratio (RR) 3.98; 95% CI 2.01 to 7.87), without significant adverse events or SAEs. Across the 82 included and excluded bupropion trials, our estimate of six seizures in the bupropion arms versus none in the placebo arms was lower than the expected rate (1:1000), at about 1:1500. SAE meta-analysis of the bupropion studies demonstrated no excess of neuropsychiatric (RR 0.88; 95% CI 0.31 to 2.50) or cardiovascular events (RR 0.77; 95% CI 0.37 to 1.59). SAE meta-analysis of 14 varenicline trials found no difference between the varenicline and placebo arms (RR 1.06; 95% CI 0.72 to 1.55), and subgroup analyses detected no significant excess of neuropsychiatric events (RR 0.53; 95% CI 0.17 to 1.67), or of cardiac events (RR 1.26; 95% CI 0.62 to 2.56). Nortriptyline increased the chances of quitting (RR 2.03; 95% CI 1.48 to 2.78). Neither nortriptyline nor bupropion were shown to enhance the effect of NRT compared with NRT alone. Clonidine increased the chances of quitting (RR 1.63; 95% CI 1.22 to 2.18), but this was offset by a dose-dependent rise in adverse events. Mecamylamine in combination with NRT may increase the chances of quitting, but the current evidence is inconclusive. Other treatments failed to demonstrate a benefit compared with placebo. Nicotine vaccines are not yet licensed for use as an aid to smoking cessation or relapse prevention. Nicobrevin's UK license is now revoked, and the manufacturers of rimonabant, taranabant and dianicline are no longer supporting the development or testing of these treatments. AUTHORS' CONCLUSIONS: NRT, bupropion, varenicline and cytisine have been shown to improve the chances of quitting. Combination NRT and varenicline are equally effective as quitting aids. Nortriptyline also improves the chances of quitting. On current evidence, none of the treatments appear to have an incidence of adverse events that would mitigate their use. Further research is warranted into the safety of varenicline and into cytisine's potential as an effective and affordable treatment, but not into the efficacy and safety of NRT. Cytisine, a natural plant alkaloid, has been marketed in Central and Eastern Europe for over 40 years for the clinical management of smoking cessation. Despite the fact that cytisine has been used by millions of smokers, its characteristics have not been reviewed in scientific literature in English, and presently existing clinical studies on its effectiveness and safety are insufficient to warrant licensing by modern standards. Understanding of the mechanism of cytisine action as a smoking cessation aid provides a necessary basis for conducting clinical trials to confirm its efficacy as an optimal antismoking therapy. Hereafter, we present a review of current knowledge about the pharmacokinetics, pharmacodynamics, toxicity, therapeutic efficacy and safety of cytisine, and about its derivatives that are under development. Recent pharmacological research has elucidated that the drug is a low efficacy partial agonist of alpha4beta2 nicotinic acetylcholine receptors, which are believed to be central to the effect of nicotine (NIC) on the reward pathway. The drug reduces the effects of NIC on dopamine release in the mesolimbic system when given alone, while simultaneously attenuating NIC withdrawal symptoms that accompany cessation attempts. Clinical studies on cytisine as a smoking cessation aid have demonstrated that the drug is effective and safe. Our recent uncontrolled trial has shown that a 12-month carbon monoxide-verified continuous abstinence rate following a standard course of treatment with cytisine with minimal behavioral support is similar (13.8%; N = 436) to that observed following treatment with NIC replacement therapy. Since cytisine exhibits a desirable pharmacological profile which makes it an attractive smoking cessation drug, it should be advanced to randomized clinical trials. However, more detailed preclinical studies on its pharmacokinetics and safety profile are required. BACKGROUND: Nicotine receptor partial agonists may help people to stop smoking by a combination of maintaining moderate levels of dopamine to counteract withdrawal symptoms (acting as an agonist) and reducing smoking satisfaction (acting as an antagonist). Varenicline was developed as a nicotine receptor partial agonist from cytisine, a drug widely used in central and eastern Europe for smoking cessation. The first trial reports of varenicline were released in 2006, and further trials have now been published or are currently underway. OBJECTIVES: The primary objective of this review is to assess the efficacy and tolerability of nicotine receptor partial agonists, including varenicline and cytisine, for smoking cessation. SEARCH STRATEGY: We searched the Cochrane Tobacco Addiction Group's specialised register for trials, using the terms ('varenicline' or 'cytisine' or 'Tabex' or 'nicotine receptor partial agonist') and 'smoking' in the title or abstract, or as keywords. We also searched MEDLINE, EMBASE, PsycINFO and CINAHL using MeSH terms and free text, and we contacted authors of trial reports for additional information where necessary. The latest search was in September 2010. SELECTION CRITERIA: We included randomized controlled trials which compared the treatment drug with placebo. We also included comparisons with bupropion and nicotine patches where available. We excluded trials which did not report a minimum follow-up period of six months from start of treatment. DATA COLLECTION AND ANALYSIS: We extracted data on the type of participants, the dose and duration of treatment, the outcome measures, the randomization procedure, concealment of allocation, and completeness of follow up.The main outcome measured was abstinence from smoking after at least six months from the beginning of treatment. We used the most rigorous definition of abstinence, and preferred biochemically validated rates where they were reported. Where appropriate we performed meta-analysis to produce a risk ratio, using the Mantel-Haenszel fixed-effect model. MAIN RESULTS: We found 11 trials of varenicline compared with placebo for smoking cessation; three of these included a bupropion experimental arm. We also found one relapse prevention trial, comparing varenicline with placebo, and two open-label trials comparing varenicline with nicotine replacement therapy (NRT). We also include one trial in which all the participants were given varenicline, but received behavioural support either online or by phone calls, or by both methods. This trial is not included in the analyses, but contributes to the data on safety and tolerability. The included studies covered >10,300 participants, 6892 of whom used varenicline. We identified one trial of cytisine (Tabex) for inclusion.The pooled risk ratio (RR) (10 trials, 4443 people, excluding one trial evaluating long term safety) for continuous abstinence at six months or longer for varenicline at standard dosage versus placebo was 2.31 (95% confidence interval [CI] 2.01 to 2.66). Varenicline at lower or variable doses was also shown to be effective, with an RR of 2.09 (95% CI 1.56 to 2.78; 4 trials, 1272 people). The pooled RR for varenicline versus bupropion at one year was 1.52 (95% CI 1.22 to 1.88; 3 trials, 1622 people). The RR for varenicline versus NRT for point prevalence abstinence at 24 weeks was 1.13 (95% CI 0.94 to 1.35; 2 trials, 778 people). The two trials which tested the use of varenicline beyond the 12-week standard regimen found the drug to be well-tolerated during long-term use. The main adverse effect of varenicline was nausea, which was mostly at mild to moderate levels and usually subsided over time. Post-marketing safety data raised questions about a possible association between varenicline and depressed mood, agitation, and suicidal behaviour or ideation. The labelling of varenicline was amended in 2008, and the manufacturers produced a Medication Guide. Thus far, surveillance reports and secondary analyses of trial data lend little support to a causal relationship.The one cytisine trial included in this review found that more participants taking cytisine stopped smoking compared with placebo at two-year follow up, with an RR of 1.61 (95% CI 1.24 to 2.08). AUTHORS' CONCLUSIONS: Varenicline at standard dose increased the chances of successful long-term smoking cessation between two- and threefold compared with pharmacologically unassisted quit attempts. Lower dose regimens also conferred benefits for cessation, while reducing the incidence of adverse events. More participants quit successfully with varenicline than with bupropion. Two open-label trials of varenicline versus NRT suggested a modest benefit of varenicline but confidence intervals did not rule out equivalence. Limited evidence suggests that varenicline may have a role to play in relapse prevention. The main adverse effect of varenicline is nausea, but mostly at mild to moderate levels and tending to subside over time. Possible links with serious adverse events, including depressed mood, agitation and suicidal thoughts, have been reported but are so far not substantiated.There is a need for further independent community-based trials of varenicline, to test its efficacy and safety in smokers with varying co-morbidities and risk patterns. There is a need for further trials of the efficacy of treatment extended beyond 12 weeks. Cytisine may also increase the chances of quitting, but the evidence at present is inconclusive. BACKGROUND: Nicotine receptor partial agonists may help smokers to quit by a combination of maintaining moderate levels of dopamine to counteract withdrawal symptoms (acting as an agonist) and reducing smoking satisfaction (acting as an antagonist). Varenicline was developed as a nicotine receptor partial agonist from cytisine, a drug widely used in central and eastern Europe for smoking cessation. The first trial reports of varenicline were released in 2006, and further trials are underway. OBJECTIVES: The primary objective of this review is to assess the efficacy and tolerability of nicotine receptor partial agonists, including varenicline and cytisine, for smoking cessation. SEARCH STRATEGY: We searched the Cochrane Tobacco Addiction Group's specialised register for trials, using the terms ('varenicline' or 'cytisine' or 'Tabex' or 'nicotine receptor partial agonist') and 'smoking' in the title or abstract, or as keywords. We also searched MEDLINE, EMBASE, PsycINFO and CINAHL using MeSH terms and free text, and we contacted authors of trial reports for additional information where necessary. The last search was in October 2006. SELECTION CRITERIA: We included randomized controlled trials which compared the treatment drug with placebo. We also included comparisons with bupropion where available. We excluded trials which did not report a minimum follow-up period of six months from start of treatment. DATA COLLECTION AND ANALYSIS: We extracted data in duplicate on the type of participants, the dose and duration of treatment, the outcome measures, the randomization procedure, concealment of allocation, and completeness of follow up. The main outcome measured was abstinence from smoking after at least six months from the beginning of treatment. We used the most rigorous definition of abstinence, and preferred biochemically validated rates where they were reported. Where appropriate we performed meta-analysis using the Mantel-Haenszel fixed-effect model. MAIN RESULTS: We found five trials of varenicline compared with placebo for smoking cessation; three of these also included a bupropion experimental arm. We also found one relapse prevention trial, comparing varenicline with placebo. The six trials covered 4924 participants, 2451 of whom used varenicline. We identified one trial of cytisine (Tabex) for inclusion. The pooled odds ratio (OR) for continuous abstinence at 12 months for varenicline versus placebo was 3.22 (95% confidence interval [CI] 2.43 to 4.27). The pooled OR for varenicline versus bupropion was 1.66 (95% CI 1.28 to 2.16). The main adverse effect of varenicline was nausea, which was mostly at mild to moderate levels and usually subsided over time. The two trials which tested the use of varenicline beyond the 12-week standard regimen found the drug to be well-tolerated and effective during long-term use. The one cytisine trial included in this review found that more participants taking cytisine stopped smoking compared with placebo at two-year follow up, with an OR of 1.77 (95% CI 1.30 to 2.40). AUTHORS' CONCLUSIONS: Varenicline increased the odds of successful long-term smoking cessation approximately threefold compared with pharmacologically unassisted quit attempts. In trials reported so far, more participants quit successfully with varenicline than with bupropion. The effectiveness of varenicline as an aid to relapse prevention has not been clearly established. The main adverse effect of varenciline is nausea, but this is mostly at mild to moderate levels and tends to reduce with habituation. There is a need for independent trials of varenicline versus placebo, to test the early findings. There is also a need for direct comparisons with nicotine replacement therapy, and for further trials with bupropion, to establish the relative efficacy of the treatments.Cytisine may also increase the chances of quitting, but the evidence at present is inconclusive. BACKGROUND: Tobacco smoking is one of the leading causes of deaths worldwide. Nearly one-fifth of adults in the UK regularly smoke cigarettes. The ill-health associated with smoking costs the NHS over £3B every year. A number of pharmacological interventions are available that can help people to quit smoking. These include nicotinic receptor partial agonists such as varenicline or cytisine. Varenicline is a synthetic product licensed for use in the UK, while cytisine is derived naturally from the seeds of the plant Cytisus laborinum L. (golden rain acacia). OBJECTIVES: To review the evidence on the clinical effectiveness and safety of cytisine from smoking cessation compared with varenicline; to develop an economic model to estimate the cost-effectiveness of cytisine and varenicline; and to provide recommendations based on value of information analyses as to whether or not a head-to-head trial of cytisine and varenicline would represent effective use of resources. DATA SOURCES: Efficacy and adverse events data were sourced from a recent Cochrane review. These data were supplemented with an updated search of twelve electronic databases, including MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature and The Cochrane Library, for the period from December 2011 to January 2013. The review included randomised controlled trials (RCTs) of adult smokers attempting to quit using varenicline or cytisine. Further interventions were considered (placebo, nicotine replacement therapy, bupropion) to allow an indirect comparison between varenicline and cytisine. The primary outcome was abstinence at a minimum of 6 months' follow-up. Secondary outcomes were common adverse events such as abnormal dreams, headache, nausea, insomnia and serious adverse events. REVIEW METHODS: A systematic review and network meta-analysis of the clinical evidence was undertaken. A random-effects model was used to allow for heterogeneity between studies. The economic model structure was based on a published model. Probabilistic sensitivity analyses were undertaken to estimate the treatment expected to be most cost-effective given current information. Formal expected value of perfect information, perfect partial information and of sample information were performed. RESULTS: Twenty-three (RCTs) were included in the systematic review, comprising a total of 10,610 participants. Twenty-one trials of varenicline of differing dosing schedules and two trials of cytisine at standard dose met the inclusion criteria. No head-to-head trials comparing varenicline with cytisine were identified. The methodological quality of the studies was judged to be moderate to good. Cytisine was more efficacious than placebo [hazard ratio (HR) 4.27, 95% credible interval (CrI) 2.05 to 10.05], as was standard-dose varenicline (HR 2.58, 95% Crl 2.16 to 3.15). Standard-dose varenicline treatment was associated with significantly higher rates of headache, insomnia and nausea than placebo; there was no significant difference in the rates of abnormal dreams. There were no significant differences in the rates of headache or nausea between cytisine and placebo; data were identified for neither abnormal dreams nor insomnia. Using expected values, cytisine is anticipated to dominate varenicline, in that it produces more quality-adjusted life-years at a lower associated cost. This occurred in approximately 90% of the scenarios performed. However, owing to the large number of people who wish to quit smoking (estimated to be 3 million over a 10-year period), the implications of making an incorrect decision is large. The expected value of sample information indicated that conducting a head-to-head trial of cytisine and varenicline was worthwhile, and that 1000 smokers per arm was an appropriate number to recruit. CONCLUSIONS: On the basis of the evidence included in this review, varenicline and cytisine are both effective interventions to aid smoking cessation when compared with placebo. Cytisine is estimated to be both more clinically effective and cost-effective than varenicline. However, there is uncertainty in the decision, and a head-to-head trial of cytisine and varenicline would appear to be an effective use of resources. STUDY REGISTRATION: The study was registered as PROSPERO CRD42012003455. FUNDING DETAILS: The National Institute for Health Research Health Technology Assessment programme. One in three adults in India uses tobacco, a highly addictive substance in one or other form. In addition to prevention of tobacco use, offering evidence-based cessation services to dependent tobacco users constitutes an important approach in addressing this serious public health problem. A combination of behavioral methods and pharmacotherapy has shown the most optimal results in tobacco dependence treatment. Among currently available pharmacological agents, drugs that preferentially act on the α4 β2-nicotinic acetyl choline receptor like varenicline and cytisine appear to have relatively better cessation outcomes. These drugs are in general well tolerated and have minimal drug interactions. The odds of quitting tobacco use are at the very least doubled with the use of partial agonists compared with placebo and the outcomes are also superior when compared to nicotine replacement therapy and bupropion. The poor availability of partial agonists and specifically the cost of varenicline, as well as the lack of safety data for cytisine has limited their use world over, particularly in developing countries. Evidence for the benefit of partial agonists is more robust for smoking rather than smokeless forms of tobacco. Although more studies are needed to demonstrate their effectiveness in different populations of tobacco users, present literature supports the use of partial agonists in addition to behavioral methods for optimal outcome in tobacco dependence. BACKGROUND: Smokers need effective support to maximise the chances of successful quit attempts. Current smoking cessation medications, such as nicotine replacement therapy (NRT), bupropion, nortriptyline or varenicline, have been shown to be effective in clinical trials but are underused by smokers attempting to quit due to adverse effects, contraindications, low acceptability and/or high cost. Cytisine is a low-cost, plant-based alkaloid that has been sold as a smoking cessation aid in Eastern Europe for 50 years. A systematic review of trial evidence suggests that cytisine has a positive impact on both short- and long-term abstinence rates compared to placebo. However, the quality of the evidence is poor and insufficient for licensing purposes in many Western countries. A large, well-conducted placebo-controlled trial (n = 740) of cytisine for smoking cessation has recently been published and confirms the findings of earlier studies, with 12-month continuous abstinence rates of 8.4% in the cytisine group compared to 2.4% in the placebo group (Relative risk = 3.4, 95% confidence intervals 1.7-7.1). No research has yet been undertaken to determine the effectiveness of cytisine relative to that of NRT. METHODS/DESIGN: A single-blind, randomised controlled, non-inferiority trial has been designed to determine whether cytisine is at least as effective as NRT in assisting smokers to remain abstinent for at least one month. Participants (n = 1,310) will be recruited through the national telephone-based Quitline service in New Zealand and randomised to receive a standard 25-day course of cytisine tablets (Tabex®) or usual care (eight weeks of NRT patch and/or gum or lozenge). Participants in both study arms will also receive a behavioural support programme comprising an average of three follow-up telephone calls delivered over an eight-week period by Quitline. The primary outcome is continuous abstinence from smoking at one month, defined as not smoking more than five cigarettes since quit date. Outcome data will also be collected at one week, two months and six months post-quit date. DISCUSSION: Cytisine appears to be effective compared with placebo, and given its (current) relative low cost may be an acceptable smoking cessation treatment for smokers, particularly those in low- and middle-income countries. Cytisine's 'natural' product status may also increase its acceptability and use among certain groups of smokers, such as indigenous people, smokers in countries where the use of natural medicines is widespread (e.g. China, India), and in those people who do not want to use NRT or anti-depressants to help them quit smoking. However it is important to ascertain the effectiveness of cytisine compared with that of existing cessation treatments. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ACTRN12610000590066). BACKGROUND: Nicotine receptor partial agonists may help people to stop smoking by a combination of maintaining moderate levels of dopamine to counteract withdrawal symptoms (acting as an agonist) and reducing smoking satisfaction (acting as an antagonist). Varenicline was developed as a nicotine receptor partial agonist from cytisine, a drug widely used in central and eastern Europe for smoking cessation. The first trial reports of varenicline were released in 2006, and further trials have now been published or are currently are underway. OBJECTIVES: The primary objective of this review is to assess the efficacy and tolerability of nicotine receptor partial agonists, including varenicline and cytisine, for smoking cessation. SEARCH STRATEGY: We searched the Cochrane Tobacco Addiction Group's specialised register for trials, using the terms ('varenicline' or 'cytisine' or 'Tabex' or 'nicotine receptor partial agonist') and 'smoking' in the title or abstract, or as keywords. We also searched MEDLINE, EMBASE, PsycINFO and CINAHL using MeSH terms and free text, and we contacted authors of trial reports for additional information where necessary. The latest search was in March 2008. SELECTION CRITERIA: We included randomized controlled trials which compared the treatment drug with placebo. We also included comparisons with bupropion and nicotine patches where available. We excluded trials which did not report a minimum follow-up period of six months from start of treatment. DATA COLLECTION AND ANALYSIS: We extracted data in duplicate on the type of participants, the dose and duration of treatment, the outcome measures, the randomization procedure, concealment of allocation, and completeness of follow up. The main outcome measured was abstinence from smoking after at least six months from the beginning of treatment. We used the most rigorous definition of abstinence, and preferred biochemically validated rates where they were reported. Where appropriate we performed meta-analysis to produce a risk ratio, using the Mantel-Haenszel fixed-effect model. MAIN RESULTS: We found seven trials of varenicline compared with placebo for smoking cessation; three of these also included a bupropion experimental arm. We found one relapse prevention trial, comparing varenicline with placebo. We also found one open-label trial comparing varenicline with nicotine replacement therapy. The nine trials covered 7267 participants, 4744 of whom used varenicline. We identified one trial of cytisine (Tabex) for inclusion. The pooled risk ratio (RR) for continuous abstinence at six months or longer for varenicline versus placebo was 2.33 (95% confidence interval [CI] 1.95 to 2.80). The pooled RR for varenicline versus bupropion at one year was 1.52 (95% CI 1.22 to 1.88). The RR for varenicline versus NRT at one year was 1.31 (95% CI 1.01 to 1.71). The two trials which tested the use of varenicline beyond the 12-week standard regimen found the drug to be well-tolerated during long-term use. The main adverse effect of varenicline was nausea, which was mostly at mild to moderate levels and usually subsided over time. Post-marketing safety data suggest that varenicline may be associated with depressed mood, agitation, and suicidal behaviour or ideation. The labelling of varenicline has been amended, and the FDA is conducting a safety review. The one cytisine trial included in this review found that more participants taking cytisine stopped smoking compared with placebo at two-year follow up, with an RR of 1.61 (95% CI 1.24 to 2.08). AUTHORS' CONCLUSIONS: Varenicline increased the chances of successful long-term smoking cessation between two- and threefold compared with pharmacologically unassisted quit attempts. More participants quit successfully with varenicline than with bupropion. One open-label trial of varenicline versus nicotine replacement therapy demonstrated a modest benefit of varenicline. The effectiveness of varenicline as an aid to relapse prevention has not been clearly established. The main adverse effect of varenicline is nausea, but mostly at mild to moderate levels and tending to subside over time. Possible links with serious adverse events, including depressed mood, agitation and suicidal thoughts, are currently under review. There is a need for independent community-based trials of varenicline, to test its efficacy and safety in smokers with varying co-morbidities and risk patterns. There is a need for further trials of the efficacy of treatment extended beyond 12 weeks. Cytisine may also increase the chances of quitting, but the evidence at present is inconclusive.

Which amino acid residue appears mutated in most of the cases reported with cadasil syndrome?

CADASIL is caused mostly by missense mutations in the NOTCH3 gene, invariably involving a cysteine residue.

[19006080, 18710532, 11706120, 22367627, 15304596, 21038489, 16717210, 24086431, 21772710, 20224942, 23587639, 19043263, 17726918, 22082899, 18313300, 22623959, 23799017, 21616505, 23597439]

CADASIL is a cerebrovascular disease caused by mutations in the NOTCH3 gene. Most mutations result in a gain or loss of cysteine residue in one of the 34 epidermal growth factor-like repeats in the extracellular domain of the Notch3 protein, thus sparing the number of cysteine residues. To date, more than 130 different mutations in the NOTCH3 gene have been reported in CADASIL patients, of which 95% are missense point mutations. Many polymorphisms have also been identified in the NOTCH3 coding sequence, some of them leading to amino acid substitutions. The aim of the present study was to analyze the NOTCH3 gene in a large group of patients affected by leukoencephalopathy and to investigate the presence of genetic variants. The molecular analysis revealed several nucleotide alterations. In particular, we identified 20 different mutations, 22 polymorphisms, and 8 genetic variants of unknown pathological significance never reported previously. We hope that this NOTCH3 gene mutational analysis, performed in such a significant number of unrelated and related patients affected by leukoencephalopathy, will help in molecular screening for the NOTCH3 gene, thus contributing to enlargement of the NOTCH3 gene variation database. Mutations in NOTCH3 are the cause of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), a hereditary angiopathy causing stroke and vascular dementia. All CADASIL mutations identified so far result in the loss or gain of one cysteine residue within epidermal growth factor (EGF)-like repeat domains. Here an in-frame deletion causing a loss of three cysteine residues within EGF repeat 6 is reported. These data are consistent with the hypothesis that the change toward an odd number of cysteine residues within a given EGF repeat and therefore an unpaired, reactive cysteine residue is the common and critical molecular event in CADASIL. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited microangiopathy caused by NOTCH3 mutations. It is characterized by migraine, with or without aura, ischemic events, psychiatric and cognitive disturbances. There is no approved treatment for migraine prophylaxis in CADASIL, but acetazolamide has been anecdotally reported to be effective. We retrospectively reviewed our database of patients with a genetic diagnosis of CADASIL to identify how many of them were treated with acetazolamide for the prophylaxis of migraine. The efficacy and the tolerability of this treatment were checked looking at the clinic reports. Acetazolamide was prescribed in seven patients; the mean duration of treatment was 6 months, and the daily dose ranged from 125 to 500 mg. Three patients had a total and sustained remission, while in two patients a reduction in attacks and an improvement of the headache intensity were recorded. In one of these, acetazolamide was deliberately taken only during the migraine attack and the beneficial effect started 1 h after administration. In two patients, the drug did not produce any beneficial effect. Mild side effects were recorded in two patients. Our preliminary experience expands previous reports and confirms the possible efficacy of acetazolamide in CADASIL migraine. Based on these data, a randomized controlled trial seems worthy to be carried out to test the efficacy and safety of this drug. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is caused by mutations in the NOTCH3 gene and is clinically characterized by recurrent stroke, cognitive decline, psychiatric disturbances and migraine. The prevalence of migraine in CADASIL is slightly higher than in the general population, and the proportion of migraine with aura is much higher. The pathophysiological mechanism that leads to increased aura prevalence in CADASIL is unknown. Possible mechanisms of the excess of migraine with aura are an increased susceptibility to cortical spreading depression (CSD) or a different expression of CSD. It is also possible that the brainstem migraine area is involved in CADASIL. Last, it is possible that the NOTCH3 mutation acts as a migraine aura susceptibility gene by itself. In this narrative review we summarize the literature about migraine in CADASIL, with a special focus on what CADASIL might teach us about the pathophysiology of migraine. OBJECTIVE: To elucidate the phenotype, genotype, and MRI findings of Korean patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and mutation carriers. METHODS: The authors studied 40 members of nine unrelated Korean CADASIL families. After genetic analysis of Notch3, clinical and MRI findings were correlated in 27 mutation carriers. RESULT: Notch3 mutation sites were C174R (one family, n = 3), R133C (one family, n = 3), R587C (one family, n = 1), R544C (two families, n = 5), and R75P (four families, n = 15). The clinical features were typical of CADASIL, but the frequency of migraine in the Korean population appears low. MRI abnormalities were found in 54% of the mutant carriers, the most common being white matter hyperintensities. The prevalence of lacunes and microbleeds increased with patient age. Anterior temporal areas were less often involved in subjects with R75P mutations than in those where mutations occurred in other sites (p = 0.02). Gradient echo imaging identified microbleedings in 33% of mutation carriers (64% of those with abnormal MRI), whereas diffusion-weighted MRI showed abnormal findings in only one patient. Neurologic disability was related to the number of lacunar infarcts and the lesion volume of white matter hyperintensities (p < 0.001) whereas MMSE score was related to the number of lacunar infarcts (p < 0.005). CONCLUSIONS: Although Korean cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) mutation carriers show similar clinical and MRI findings, these abnormalities appear less frequently than in other populations. Relatively frequent microbleedings on gradient echo imaging suggest that treatment should be individualized according to MRI findings. The novel mutation of R75P, not involving a cysteine residue, is related to less frequent involvement of the anterior temporal area, thus broadening the spectrum of CADASIL. Cerebral autosomal dominant arteriopathy with subcortical infarct and leukoencephalopathy: A rare syndrome raising anesthetic concerns! We reviewed the characteristics of headache in patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), to verify the appropriateness of the International Classification of Headache Disorders, second edition (ICHD-II) criteria. Available data were found through Medline/PubMed using the keyword "cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)". The search was restricted to studies published in English in the years between 1993 and 2008. We excluded studies that did not report original data on CADASIL and information regarding the presence of headache. We found 34 studies reporting data on 749 patients overall; 387 (51.7%) patients had headache. According to the authors' definition, 356 (92%) patients were reported as having migraine and 31 (8%) as having headache. Of the 356 patients who were defined as migraineurs, 125 (35.1%) had migraine with aura, 7 (2%) migraine without aura, 156 (43.8%) unspecified migraine and 68 (19.1%) had more than one type of migraine. Among the 31 patients reported as suffering from headache, the headache was not further detailed in 18 (58.1%) patients; it was defined as chronic in 6 (19.3%), as resembling migraine with aura in 4 (12.9%), as resembling migraine without aura in 2 (6.5%) and as tension type in 1 (3.2%) patient. In patients with CADASIL, the headache was usually referred to as migraine and mostly as migraine with aura. However, this referral is formally incorrect since the diagnostic criteria for any type of migraine in the ICHD-II require that the disturbance is not attributed to another disorder. For this reason, we suggest updating the ICHD-II in relation to CADASIL. Our suggestion is to insert a new category referred to as Headache attributed to genetic disorder including Headache attributed to CADASIL. Most previously reported mutations in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) result in an odd number of cysteine residues within the epidermal growth factor (EGF)-like repeats in Notch3. We report here R75P mutation in two Japanese CADASIL families not directly involving cysteine residues located within the first EGF-like repeats. Probands in both families had repeated episodes of stroke, depression, dementia as well as T2 high-intensity lesions in the basal ganglia and periventricular white matter, but fewer white matter lesions in the temporal pole on MRI. These families provide new insights into the diagnosis and pathomechanisms of CADASIL. Le CADASIL, ou Cerebral autosomal dominant arteriopathy with subcortical infarcts and Ieukoencephalopathy est une affection héréditaire des petites artères cérébrabes survenant chez l'adulte d'âge moyen, due à des mutations du gène Notch3. La maladie est responsable de lésions diffuses de la substance blanche associées à des infarctus lacunaires au niveau des régions sous-corticales cérébrales. Elle est à l'origine de crises de migraine avec aura, d'accidents ischémiques cérébraux et est associée à différents degrés d'altération cognitive et à des troubles de l'humeur. CADASIL est considéré comme un modébe unique d'étude des «démences sous-corticales d'origine ischémique». Des données récentes suggèrent que le nombre d'infarctus lacunaires et la sévérité de l'atrophie cérébrale sont les principaux marqueurs de la maladie associés au handicap cognitif et moteur de la maladie. Les troubles de l'humeur sont rapportés par 10 à 20% des patients, le plus souvent en association avec des altérations cognitives. Leur origine exacte demeure indéterminée, la présence de lésions ischémiques au niveau des noyaux gris ou au sein de la substance blanche frontale pourrait favoriser l'apparition de ces symptômes. Des études complémentaires sont nécessaires pour mieux comprendre les relations entre les lésions cérébrales et les symptômes cognitifs et psychiatriques observés au cours de cette maladie des petits vaisseaux du cerveau. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy is a cerebrovasuclar disease caused by NOTCH3 mutations, usually localized to exons 3 and 4. This report describes the clinical and neuroradiological findings of 2 subjects of two unrelated Japanese families who shared a common p.Arg332Cys mutation. The subject from family A presented syncope attacks as the sole clinical presentation at the beginning of his disease course. The subject from family B showed recurrent ischemic attacks, followed by a large intracranial hemorrhage. This is the first report to describe the detailed phenotypes of patients with a rare p.Arg332Cys mutation in Japan. BACKGROUND: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited disease leading to recurrent ischemic stroke and vascular dementia. Numerous mutations in the 23 exons of the NOTCH3 gene have been reported to cause CADASIL in Caucasian populations, but the full spectrum of genetic changes leading to this disease is yet to be known and, especially, very few reports are available on CADASIL in Asian populations. METHODS AND RESULTS: We genotyped members of a 5-generational Han Chinese family with CADASIL patients and identified an R133C mutation in the NOTCH3 gene. Clinical analysis demonstrated that the penetrance of the mutation was not complete. Five of the mutation carriers, not exposed to the known vascular risk factors, did not show any clinical feature of CADASIL, suggesting the importance of environmental factors to the development of this disease. CONCLUSIONS: Members of a 5-generational Han Chinese family with CADASIL patients had an R133C mutation in the NOTCH3 gene but only individuals exposed to known vascular risk factors developed CADASIL. BACKGROUND AND PURPOSE: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is caused by NOTCH3 gene mutations that result in vascular smooth muscle cell (VSMC) degeneration. Its distinctive feature by electron microscopy (EM) is granular osmiophilic material (GOM) detected in VSMC indentations and/or the extracellular space close to VSMCs. Reports of the sensitivity of EM in detecting GOM in biopsies from CADASIL patients are contradictory. We present data from 32 patients clinically suspected to have CADASIL and discuss the role of EM in its diagnosis in this retrospective study. METHODS: Skin, skeletal muscle, kidney and pericardial biopsies were examined by EM; the NOTCH3 gene was screened for mutations. Skin and muscle biopsies from 12 patients without neurological symptoms served as controls. RESULTS AND DISCUSSION: All GOM-positive patients exhibited NOTCH3 mutations and vice versa. This study i) confirms that EM is highly specific and sensitive for CADASIL diagnosis; ii) extends our knowledge of GOM distribution in tissues where it has never been described, e.g. pericardium; iii) documents a novel NOTCH3 mutation in exon 3; and iv) shows that EM analysis is critical to highlight the need for comprehensive NOTCH3 analysis. Our findings also confirm the genetic heterogeneity of CADASIL in a small Italian subpopulation and emphasize the difficulties in designing algorithms for molecular diagnosis. Some missense mutations and small deletions in the NOTCH3 gene, not involving cysteine residues, have been described in patients considered to be affected by paucisymptomatic CADASIL. However, the significance of such molecular variants is still unclear. We describe a 49-year-old woman with a CADASIL-like phenotype, carrying a novel cysteine-sparing mutation in exon 29 of the NOTCH3 gene, and discuss the possible pathogenetic role of this molecular variant. Even though atypical clinical and MRI findings make a diagnosis of CADASIL unlikely in this patient, our report nevertheless underlines the intriguing genotype-phenotype relationship in NOTCH3 mutations and the importance of functional investigation to ascertain the role of new NOTCH3 mutations in CADASIL pathogenesis.

Which syndromes are associated with mutations in the EZH2 gene?

EZH2 mutations that cause Weaver syndrome are primarily missense variants and the rare truncating mutations reported to date are in the last exon, suggesting that simple haploinsufficiency is unlikely to be generating the overgrowth phenotype although the exact mechanism has not yet been determined. Recent studies have shown that EZH2 mutations are often associated with RUNX1 mutations in MDS patients, although its pathological function remains to be addressed. These data show that mutations in EZH2 cause Weaver syndrome. The EZH2 gene is a homolog of the Drosophila Polycomb group (PcG) gene enhancer of zest, a crucial regulator of homeotic gene expression.

[22177091, 24507812, 24852293, 23099237, 22190405, 24214728, 10780782, 21856302, 25177364, 23592277, 22475286, 24760151, 24218139, 24953053]

We used trio-based whole-exome sequencing to analyze two families affected by Weaver syndrome, including one of the original families reported in 1974. Filtering of rare variants in the affected probands against the parental variants identified two different de novo mutations in the enhancer of zeste homolog 2 (EZH2). Sanger sequencing of EZH2 in a third classically-affected proband identified a third de novo mutation in this gene. These data show that mutations in EZH2 cause Weaver syndrome. BACKGROUND: Overgrowth conditions are a heterogeneous group of disorders characterised by increased growth and variable features, including macrocephaly, distinctive facial appearance and various degrees of learning difficulties and intellectual disability. Among them, Sotos and Weaver syndromes are clinically well defined and due to heterozygous mutations in NSD1 and EZH2, respectively. NSD1 and EZH2 are both histone-modifying enzymes. These two epigenetic writers catalyse two specific post-translational modifications of histones: methylation of histone 3 lysine 36 (H3K36) and lysine 27 (H3K27). We postulated that mutations in writers of these two chromatin marks could cause overgrowth conditions, resembling Sotos or Weaver syndromes, in patients with no NSD1 or EZH2 abnormalities. METHODS: We analysed the coding sequences of 14 H3K27 methylation-related genes and eight H3K36 methylation-related genes using a targeted next-generation sequencing approach in three Sotos, 11 'Sotos-like' and two Weaver syndrome patients. RESULTS: We identified two heterozygous mutations in the SETD2 gene in two patients with 'Sotos-like' syndrome: one missense p.Leu1815Trp de novo mutation in a boy and one nonsense p.Gln274* mutation in an adopted girl. SETD2 is non-redundantly responsible for H3K36 trimethylation. The two probands shared similar clinical features, including postnatal overgrowth, macrocephaly, obesity, speech delay and advanced carpal ossification. CONCLUSIONS: Our results illustrate the power of targeted next-generation sequencing to identify rare disease-causing variants. We provide a compelling argument for Sotos and Sotos-like syndromes as epigenetic diseases caused by loss-of-function mutations of epigenetic writers of the H3K36 histone mark. Somatic mutations of epigenetic gene regulators are common in patients with myelodysplastic syndromes (MDS) and correlate with some clinical and laboratory features. We studied mutations in TET2, ASXL1 and EZH2 in 153 Chinese patients with MDS. TET2 mutations were detected in 35 patients (23%), ASXL1 in 33 patients (22%) and EZH2 in 8 (5%). ASXL1 mutations were associated with increased colony formation of BFU-E, CFU-E and CFU-GM (P-values, 0.049, 0.011 and 0.006). EZH2 mutations were common in patients with poor IPSS cytogenetics (P=0.001) and in patients in the IPSS intermediate-2/high-risk cohorts (P=0.06). In uni- but not multi-variate analyses, mutated TET2 was associated with longer survival (P=0.044) whereas EZH2 mutations were associated with an increased risk of transformation to acute myeloid leukemia (AML; P=0.039). These data suggest ASXL1 mutations might results in dominance of the mutant clone in Chinese with MDS whereas EZH2 mutations might predict an increased risk of transformation to AML. Collaborators: Amor D, Andries S, Archer H, Armstrong R, Ashton-Prolla P, Baralle D, Barnicoat A, Barrow M, Beales P, Becker K, Beckh-Arnold E, Berg J, Bernhard B, Bhat M, Birch J, Bitner M, Blair E, Bliek J, Blyth M, Brady A, Brice G, Brueton L, Burn J, Canham N, Castle B, Cecconi M, Chandler K, Chandrasena R, Cilliers D, Clarke A, Clayton-Smith J, Clericuzio C, Cole T, Colley A, Collins A, Connell F, Cook J, Crow Y, Dabir T, Dalton A, Danda S, Davies S, Day R, Dennis N, Deshpande C, Desouza B, Devlin L, Differ AM, Dinwiddie R, Dobbie A, Donnai D, Ellis I, Elmslie F, Firth H, Fisher R, Fitzpatrick D, Flinter F, Foley P, Foulds N, Fryer A, Gallagher A, Garcia S, Gardiner C, Gibbons R, Gillerot Y, Goudie D, Gowrishanker K, Graham C, Gregersen N, Harper J, Hughes H, Henderson A, Hennekam R, Hobson E, Holder S, Homfray T, Huma Z, Hurst J, Irving M, Izatt L, Jagadeeth S, Jessen C, Johnson D, Josifova D, Joss S, Kerr B, Liebelt J, Kini U, Krause A, Kumar A, Kumar D, Lam W, Lapunzina P, Lees M, Leonard N, Livesey A, Longman C, Lucassen A, Lunt P, Lynch S, MacDonnell J, Magee A, Maher E, Male A, Mansour S, McConnell V, McEntagart M, McKee S, McKeown C, Mehta S, Metcalfe K, Mohammed S, Monaghan G, Montgomery T, Morgan A, Morrison P, Morton J, Mudgal R, Murday V, Nampoothiri S, Nemeth A, Newbury-Ecob R, Oley C, Owen C, Park SM, Parker M, Patel C, Patton M, Pilz D, Pinkney M, Pocha M, Pottinger C, Prescott K, Price S, Proctor A, Quarrell O, Rankin J, Raymond L, Rea G, Reardon W, Reid E, Robards M, Roposch A, Rosser E, Rourke D, Ruddy D, Saggar A, Sampson J, Sandford R, Sarkar A, Scott R, Semple R, Sharif S, Shaw A, Shaw-Smith C, Shears D, Shelagh J, Smith G, Smithson S, Splitt M, Stevens M, Stewart F, Stewart H, Stopps K, Suri M, Sweeney E, Tanateles G, Taylor C, Temple K, Tischowitz M, Tolmie J, Tomkins S, Turnpenny P, Van-Haelst M, Van Maldergem L, Vandersteen A, Vasudevan P, Wakeling E, Walker L, Williams D, Wilson L, Woods G, Wright M, Zankl A. The EZH2 gene is a homolog of the Drosophila Polycomb group (PcG) gene enhancer of zest, a crucial regulator of homeotic gene expression. Several lines of evidence suggest a critical role for the EZH2 protein during normal and perturbed development of the haematopoietic and central nervous systems. Indeed, the EZH2 protein has been shown to associate with the Vav proto-oncoprotein and with the XNP protein, the product of a mental retardation gene. The EZH2 gene was previously reported to be located on chromosome 21q22 and was proposed as a candidate gene for some characteristics of the Down syndrome phenotype. We report here the genomic structure and fine mapping of the EZH2 gene. We demonstrate that the functional gene actually maps to chromosome 7q35 and that the sequence previously isolated from a chromosome 21 cosmid corresponds to a pseudogene. Finally, the nature of the EZH2 protein and its mapping to the critical region for malignant myeloid disorders lead us to propose the EZH2 gene is involved in the pathogenesis of 7q35-q36 aberrations in myeloid leukaemia. Advances in genome-wide molecular cytogenetics allow identification of novel submicroscopic DNA copy number alterations (aCNAs) and copy-neutral loss of heterozygosity (cnLOH) resulting in homozygosity for known gene mutations in myeloid neoplasms. We describe the use of an oligo-SNP array for genomic profiling of aCNA and cnLOH, together with sequence analysis of recurrently mutated genes, in a patient with myelodysplastic syndrome (MDS) presenting with normal karyotype and FISH results. Oligo-SNP array analysis revealed a hemizygous deletion of 896 kb at chromosome 5q31.2, representing the smallest 5q deletion reported to date. The deletion involved multiple genes, including two tumor suppressor candidate genes (CTNNA1 and HSPA9) that are associated with MDS/AML. The SNP-array study also detected 3 segments of somatic cnLOH: one involved the entire long arm of chromosome 4; the second involved the distal half of the long arm of chromosome 7, and the third encompassed the entire chromosome 22 (UPD 22). Sequence analysis revealed mutations in TET2 (4q), EZH2 (7q), ASXL1 (20q11.21), and RUNX1 (21q22.3). Coincidently, TET2 and EZH2 were located at segments of cnLOH resulting in their homozygosity. Loss of heterozygosity affecting these two chromosomes and mutations in TET2 and EZH2 are indicative of a myelodysplastic syndrome with a poor prognosis. Deletion of the tumor suppressor genes CTNNA1 and HSPA9 is also likely to contribute to a poor prognosis. Furthermore, the original cnLOHs in multiple chromosomes and additional cnLOH 14q in the follow-up study suggest genetic evolution of the disease and poor prognosis. This study attests to the fact that some patients with a myelodysplastic syndrome who exhibit a normal karyotype may have underlying genetic abnormalities detectable by chromosomal microarray and/or targeted mutation analyses. Previous epigenetics research in myelodysplastic syndromes (MDS) mainly focused on the DNA methylation of tumor suppressor genes. Recent studies reported that around 6% of MDS patients have several EZH2 mutations including missense, frameshift and truncated mutations. Histone methyltransferase EZH2 plays a critical role in epigenetic regulation as a bridge between histone methylation/deacetylation and DNA methylation. EZH2 is frequently overexpressed and considered to be an oncogene in cancers; nevertheless, EZH2 is considered as a candidate tumor suppressor gene in MDS due to EZH2 mutations associated with poor survival. Many questions still need further discussion. Moreover, 3-deazaneplanocin can reduce EZH2 levels and H3K27 trimethylation, and synergistic effects are seen in combination with DNA demethylation agents or histone deacetylation inhibitors. All of the above give us more chances to improve epigenetic therapy in MDS. Therefore, the molecular mechanisms of EZH2 in tumorigenesis and the role of EZH2 in MDS are studied. Author information: (1)1] Department of Cellular and Molecular Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan [2] JST, CREST, 7 Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan. (2)1] Department of Hematology and Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan [2]. (3)Division of Molecular Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan. (4)1] Division of Radiation Information Registry, Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan [2]. (5)1] Department of Cellular and Molecular Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan [2] Department of Hematology, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. (6)1] Division of Pathology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229-3026, USA [2] Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229-3026, USA. (7)Department of Allergy and Clinical Immunology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. (8)1] JST, CREST, 7 Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan [2] Laboratory for Lymphocyte Development, RIKEN Center for Integrative Medical Sciences, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan. (9)Division of Cellular Therapy and Division of Stem Cell Signaling, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato, Tokyo 108-8639, Japan.

Which databases exist for experimentally determined topologies of α-helical transmembrane proteins ?

ExTopoDB and TMPDB.

[12520035, 20601677]

TMPDB is a database of experimentally-characterized transmembrane (TM) topologies. TMPDB release 6.2 contains a total of 302 TM protein sequences, in which 276 are alpha-helical sequences, 17 beta-stranded, and 9 alpha-helical sequences with short pore-forming helices buried in the membrane. The TM topologies in TMPDB were determined experimentally by means of X-ray crystallography, NMR, gene fusion technique, substituted cysteine accessibility method, N-linked glycosylation experiment and other biochemical methods. TMPDB would be useful as a test and/or training dataset in improving the proposed TM topology prediction methods or developing novel methods with higher performance, and as a guide for both the bioinformaticians and biologists to better understand TM proteins. TMPDB and its subsets are freely available at the following web site: http://bioinfo.si.hirosaki-u.ac.jp/~TMPDB/. ExTopoDB is a publicly accessible database of experimentally derived topological models of transmembrane proteins. It contains information collected from studies in the literature that report the use of biochemical methods for the determination of the topology of α-helical transmembrane proteins. Transmembrane protein topology is highly important in order to understand their function and ExTopoDB provides an up to date, complete and comprehensive dataset of experimentally determined topologies of α-helical transmembrane proteins. Topological information is combined with transmembrane topology prediction resulting in more reliable topological models. AVAILABILITY: http://bioinformatics.biol.uoa.gr/ExTopoDB.

Which disease is characterized by congenital absence of intrinsic ganglion cells of the gastrointestinal tract?

Hirschsprung disease (HSCR, aganglionic megacolon) is a common congenital malformation leading to bowel obstruction, with an incidence of 1/5,000 live births. It is characterized by the absence of intrinsic ganglion cells in the myenteric and submucosal plexuses along variable lengths of the gastrointestinal tract.

[8894691, 10980580, 21656899, 22184102, 20860806, 23272425, 8401580, 22974608, 9556633, 22131258, 16080919, 16618617, 23836442, 23043324, 8896569]

BACKGROUND: Hirschsprung disease (HSCR) is a congenital disorder characterized by an absence of intrinsic ganglion cells in the nerve plexuses of the lower colon. The Semaphorin 3A (SEMA3A) gene is involved in the migration of enteric neural precursors (ENPs). To analyze the function of SEMA3A in HSCR, the SEMA3A expression in different colon segments in HSCR was examined. METHODS: The expression levels of SEMA3A in both ganglionic and aganglionic colon tissues of 32 patients with HSCR and in colon tissue of 5 newborn unaffected individuals were examined by real-time RT-PCR, Western-blot, and immunohistology. RESULTS: Comparison of SEMA3A expression levels between ganglionic and aganglionic tissues in HSCR revealed upregulation of SEMA3A expression in 43.75% (14/32) of the aganglionic colons. SEMA3A was expressed in the ganglion cells of the myenteric plexus, submucosa, as well as in the longitudinal and circular muscle layer of the normal colon of both unaffected newborns and patients with HSCR. In the aganglionic segment of patients with HSCR, SEMA3A was highly expressed in the circular muscle layer and was also detected in the submucosa and in the longitudinal muscles layer. The fluorescence intensity of SEMA3A in the circular muscle layer in the aganglionic segment was much higher than that in ganglionic segment (p < .001). CONCLUSION: SEMA3A expression was upregulated in the aganglionic smooth muscle layer of the colon in some patients with HSCR and our data suggest that increased SEMA3A expression may be a risk factor for HSCR pathology in a subset of patients. BACKGROUND: Hirschsprung disease (HSCR) is a congenital disorder characterized by an absence of intrinsic ganglion cells in the nerve plexuses of the lower colon. Our previous results showed increased semaphorin 3A (SEMA3A) expression may be the risk factor for HSCR pathology in a subset of patients. Therefore, the association between polymorphisms in SEMA3A and the risk of HSCR was examined. METHODS: The genotypes of two SNPs (rs7804122 and rs797821) in the SEMA3A gene in 119 patients with HSCR and 93 controls were examined using PCR-sequencing to determine the contribution of SEMA3A to the HSCR phenotype. PCR reaction with cDNA template was also used to find out whether a novel mutation (Chr7:83634610A→T) influences the SEMA3A pre-mRNA splicing. RESULTS: Genotypes comprising allele G of rs7804122 (GG or AG) were over-represented in patients (48.74 vs. 24.8%; p = 0.0013) which indicated that the risk of HSCR was significantly higher among subjects with the GG or AG genotype than among the subjects with the AA genotype. No statistically significant associations were found for SNP rs797821 at the allele or genotype levels. The differences in genotypes and allele distributions of rs7804122 and rs797821 between various clinical classifications were not statistically significant. The novel heterozygous mutation (Chr7:83634610A→T) 30bp away from an intron/exon boundary, had no detectable effect on splicing efficiency. CONCLUSION: Our results for rs7804122 provided preliminary evidence that the SEMA3A gene is involved in the susceptibility to HSCR in the Northeastern Chinese population. BACKGROUND: Hirschsprung disease (HSCR) is a neurocristopathy characterized by the absence of parasympathetic intrinsic ganglion cells in the submucosal and myenteric plexuses along a variable portion of the intestinal tract. In approximately 18% of the cases HSCR also presents with multiple congenital anomalies including recognized syndromes. METHODS: A combination of MLPA and microarray data analysis have been undertaken to refine a duplication at the Xq28 region. RESULTS: In this study we present a new clinical association of severe neonatal encephalopathy (Lubs syndrome) and HSCR, in a male patient carrying a duplication at the Xq28 region which encompasses the MECP2 and L1CAM genes. CONCLUSIONS: While the encephalopathy has been traditionally attributed to the MECP2 gene duplication in patients with Lubs syndrome, here we propose that the enteric phenotype in our patient might be due to the dosage variation of the L1CAM protein, together with additional molecular events not identified yet. This would be in agreement with the hypothesis previously forwarded that mutations in L1CAM may be involved in HSCR development in association with a predisposing genetic background. BACKGROUND: Hirschsprung's Disease (HD) is a developmental disorder of enteric nervous system characterised by the absence of ganglion cells in submucosal (Meissner's) and myenteric (Aurbach's) plexuses of distal bowel. The purpose of the present study was to observe and report the morphological patterns of ganglion related enteric neuronal abnormalities in children presented with clinical features of (HD) in a Pakistani population. METHODS: A total of 92 patients with clinical presentation of HD were enrolled between March 2009 and October 2009. Among them, 8 were excluded according to the exclusion criteria. After detailed history and physical examination, paraffin embedded H and E stained sections were prepared from the serial open biopsies from colorectum. The data was analysed using SPSS-17. Frequencies and percentages are given for qualitative variables. Non-parametric Binomial Chi-Square test was applied to observe within group associations and p<0.05 was considered statistically significant. RESULTS: Among 84 patients, 13 (15.5%) proved to be normally ganglionic whereas 71 (84.5%) showed ganglion related enteric neuronal abnormalities namely isolated hypoganglionosis 9 (12.7%), immaturity of ganglion cells 9 (12.7%), isolated hyperganglionosis (IND Type B) 2 (2.8%) and Hirschsprung's disease 51 (71.8%). Among HD group, 34 (66.7%) belonged to isolated form and 17 (33.3%) showed combined ganglion related abnormalities. CONCLUSIONS: Hirschsprung's disease is common in Pakistani population, followed by hypoganglionosis, immaturity of ganglion cells and IND type B. The presence of hypertrophic nerve fibres was significant in HD, hyperganglionosis and hypoganglionosis, whereas, no hypertrophic nerve fibres were appreciated in immaturity of ganglion cell group. Hirschsprung disease (HSCR) is a frequent congenital disorder (1 in 5,000 newborns) of unknown origin characterized by the absence of parasympathetic intrinsic ganglion cells of the hindgut. Taking advantage of a proximal deletion of chromosome 10q (del 10q11.2-q21.2) in a patient with total colonic aganglionosis, and of a high-density genetic map of microsatellite DNA markers, we performed genetic linkage analysis in 15 non-syndromic long-segment and short-segment HSCR families. Multipoint linkage analysis indicated that the most likely location for a HSCR locus is between loci D10S208 and D10S196, suggesting that a dominant gene for HSCR maps to 10q11.2, a region to which other neural crest defects have been mapped. BACKGROUND/PURPOSE: Hirschsprung disease (HSCR) is a congenital disorder characterized by the absence of intramural ganglion cells along with variable lengths of the gastrointestinal tract. Recent studies have indicated the potential function of neuregulin-1 (NRG1) in HSCR, which encodes the heregulins and other mitogenic ligands for the ErbB family. The purpose of this study was to further clarify the role of NRG1 in the pathogenesis of HSCR. METHODS: We examined the NRG1 messenger RNA (messenger RNA) and protein expression levels in gut tissues of 63 patients with sporadic HSCR (both stenotic and dilated gut tissues) and 35 controls. Moreover, using the methylation-specific polymerase chain reaction, we examined the methylation pattern of exon 1 of the NRG1 gene. RESULTS: The mRNA expression levels of NRG1 were significantly higher in tissues of HSCR than those in controls, and the increased NRG1 protein levels in HSCR were consistent with the mRNA levels. However, no methylation pattern change was observed in exon 1 of the gene among different groups. CONCLUSIONS: Our study demonstrates that the aberrant expression of NRG1 may play an important role in the pathology of HSCR. DNA methylation of the gene seems not to be involved in the mechanism of such aberrant expression, and other factors should be explored. Hirschsprung's disease is an inherited disorder characterized by the absence of ganglion cells in the distal bowel. Neurocutaneous melanosis is a rare congenital syndrome characterized by proliferation of melanin-producing cells in the skin and leptomeninges. The authors described a newborn patient with neurocutaneous melanosis associated with Hirschsprung's disease. This male baby had congenital hydrocephalus, large and multiple pigmented skin nevi, and severe abdominal distension. He showed marked hydrocephalus at birth and underwent a ventriculo-peritoneal shunt at the age of 5 days. Investigations for gut motility disorders revealed typical findings consistent with Hirschsprung's disease involving the rectosigmoid colon. He was surgically treated for Hirschsprung's disease after transanal endorectal pull-through at the age of 7 months. After settlement of the ventriculo-peritoneal shunt, the transanal approach was of significant value for keeping the intraperitoneal catheter clean. The association of developmental disorders of melanocytes and enteric ganglia, both of which originated from the neural crest, suggested the presence of mutual pathogenetic factors in the patient.

What is the disease in which patients are sensitive to DNA crosslinking agents, presenting with a high frequency of chromosomal aberrations?

Fanconi anemia (FA) is an autosomal disorder that causes genome instability and manifests by defects in DNA repair, hypersensitivity to DNA crosslinking agents, and a high degree of chromosomal aberrations.

[16115458, 21568838, 7116934, 7011307, 8876687, 20132664, 8058745]

Fanconi anemia (FA) is an autosomal disorder that causes genome instability. FA patients suffer developmental abnormalities, early-onset bone marrow failure, and a predisposition to cancer. The disease is manifested by defects in DNA repair, hypersensitivity to DNA crosslinking agents, and a high degree of chromosomal aberrations. The FA pathway comprises 13 disease-causing genes involved in maintaining genomic stability. The fast pace of study of the novel DNA damage network has led to the constant discovery of new FA-like genes involved in the pathway that when mutated lead to similar disorders. A majority of the FA proteins act as signal transducers and scaffolding proteins to employ other pathways to repair DNA. This review discusses what is known about the FA proteins and other recently linked FA-like proteins. The goal is to clarify how the proteins work together to carry out interstrand crosslink repair and homologous recombination-mediated repair of damaged DNA. Cells from patients wtih Fanconi's anemia are unusually sensitive to agents which are capable of crosslinking DNA. This increased sensitivity can be detected both by cytogenetic and flow cytometric methods. An elevated frequency of chromosome aberrations, which is further exaggerated by exposure of cells to DNA crosslinking agents, is a general feature of Fanconi's anemia. Information about the formation of sister chromatid exchanges in this disease is less consistent. Cytogenetic analysis of cells from patients with Fanconi's anemia can be compromised by a low mitotic index. This is reflected in an accumulation of cells In the G2 phase of the cycle, after exposure to the bifunctional alkylating agent, mitomycin C. New methods for differentiating individuals with Fanconi's anemia from unaffected individuals should be of empirical use and might also facilitate mechanistic studies of this disease. Though the roles of some specific DNA lesions in the production of chromosomal aberrations is clearly established, those of others remain unclear. While the study of aberration production in human genetic DNA repair deficiency diseases has been extremely rewarding already, eukaryotic repair systems are obviously complex, and one is tempted to feel that such studies may have raised as many questions as they have provided answers. For example, the "standard" sort of xeroderma pigmentosum is chromosomally sensitive to ultraviolet light and to those chemical agents inducing ultraviolet-type DNA repair. But both it and the variant form have been reported to also be sensitive to the crosslinking agent mitomycin C in one study [18], implying a common step or steps in the repair of pyrimidine cyclobutane dimers and DNA crosslinks. However, just to complicate matters, another study of chromosomal aberration production in xeroderma pigmentosum cells had found them no more sensitive to mitomycin C than normal cells [50]. Similarly, Fanconi's anemia cells, which are chromosomally sensitive to crosslinking agents, and appear to be defective in the "unhooking" of linked polynucleotide strands [15, 16, 49, 51], are reported to be chromosomally sensitive to ethyl methanesulfonate as well [29], and to be sensitive to ionizing radiation [7, 19, ]0], again implying overlapping repair systems. It seems certain that further study of chromosomal aberration production in repair deficient cells by agents inducing various DNA lesions will reveal even greater complexity in eukaryotic DNA repair systems and their role in chromosomal aberration production. Nevertheless, there seems hope, at least, that such studies may also ultimately lead to a complete understanding of the molecular mechanisms involved. Fanconi anemia (FA) is a rare autosomal recessive genetic disease, associated with congenital anomalies and a predisposition to cancers. FA patients exhibit spontaneous chromosome breakage and FA cells are sensitive to DNA interstrand crosslink agents and expresses high frequency of chromosome breakage. Recently 13 genes have been shown to be involved with the FA phenotype. We have carried out a detailed study in clinically diagnosed FA patients in an Indian population. Thirty three patients were clinically diagnosed with FA and had aplastic anemia and bleeding abnormalities. The genetic analysis revealed a significantly (P<0.0001) high frequency (36.4%) of parental consanguinity in FA patients compared to controls (3.33%). Chromosomal analysis revealed spontaneous chromosome breakage in 63.64% FA patients. The mitomycin C and diepoxybutane induced cultures showed a significantly (P<0.001) high frequency of chromosome breakage and radial formation compared to controls. Among 33 patients, nine (27.27%) patients developed malignancies and chromosomal abnormalities were detected in five (55.5%) patients bone marrow cells including monosomy 5 and 7, trisomy 10, der(1q) and inv(7). Cytogenetic investigation is important in aplastic anemia to rule out FA. The clinical presentation and the associated high frequency of consanguinity in FA, and the molecular analysis are complementary in the study of an Indian population. Features of chromosomal aberrations, hypersensitivity to DNA crosslinking agents, and predisposition to malignancy have suggested a fundamental anomaly of DNA repair in Fanconi anemia. The function of the recently isolated FACC (Fanconi anemia group C complementing) gene for a subset of this disorder is not yet known. The notion that FACC plays a direct role in DNA repair would predict that the polypeptide should reside in the nucleus. In this study, a polyclonal antiserum raised against FACC was used to determine the subcellular location of the polypeptide. Immunofluorescence and subcellular fractionation studies of human cell lines as well as COS-7 cells transiently expressing human FACC showed that the protein was localized primarily to the cytoplasm under steady-state conditions, transit through the cell cycle, and exposure to crosslinking or cytotoxic agents. However, placement of a nuclear localization signal from the simian virus 40 large tumor antigen at the amino terminus of FACC directed the hybrid protein to the nuclei of transfected COS-7 cells. These observations suggest an indirect role for FACC in regulating DNA repair in this group of Fanconi anemia.

How is oprozomib administered?

Oprozomib is administered orally.

[24239172, 22929803, 24712303, 24471924, 24103732, 22763387, 24915039]

Inhibition of proteasome, a proteolytic complex responsible for the degradation of ubiquitinated proteins, has emerged as a powerful strategy for treatment of multiple myeloma (MM), a plasma cell malignancy. First-in-class agent, bortezomib, has demonstrated great positive therapeutic efficacy in MM, both in pre-clinical and in clinical studies. However, despite its high efficiency, a large proportion of patients do not achieve sufficient clinical response. Therefore, the development of a second-generation of proteasome inhibitors (PIs) with improved pharmacological properties was needed. Recently, several of these new agents have been introduced into clinics including carfilzomib, marizomib and ixazomib. Further, new orally administered second-generation PI oprozomib is being investigated. This review provides an overview of main mechanisms of action of PIs in MM, focusing on the ongoing development and progress of novel anti-proteasome therapeutics. Proteasome inhibitors (PIs), namely bortezomib, have become a cornerstone therapy for multiple myeloma (MM), potently reducing tumor burden and inhibiting pathologic bone destruction. In clinical trials, carfilzomib, a next generation epoxyketone-based irreversible PI, has exhibited potent anti-myeloma efficacy and decreased side effects compared with bortezomib. Carfilzomib and its orally bioavailable analog oprozomib, effectively decreased MM cell viability following continual or transient treatment mimicking in vivo pharmacokinetics. Interactions between myeloma cells and the bone marrow (BM) microenvironment augment the number and activity of bone-resorbing osteoclasts (OCs) while inhibiting bone-forming osteoblasts (OBs), resulting in increased tumor growth and osteolytic lesions. At clinically relevant concentrations, carfilzomib and oprozomib directly inhibited OC formation and bone resorption in vitro, while enhancing osteogenic differentiation and matrix mineralization. Accordingly, carfilzomib and oprozomib increased trabecular bone volume, decreased bone resorption and enhanced bone formation in non-tumor bearing mice. Finally, in mouse models of disseminated MM, the epoxyketone-based PIs decreased murine 5TGM1 and human RPMI-8226 tumor burden and prevented bone loss. These data demonstrate that, in addition to anti-myeloma properties, carfilzomib and oprozomib effectively shift the bone microenvironment from a catabolic to an anabolic state and, similar to bortezomib, may decrease skeletal complications of MM. Acquired resistance to proteasome inhibitors represents a considerable impediment to their effective clinical application. Carfilzomib and its orally bioavailable structural analog oprozomib are second-generation, highly-selective, proteasome inhibitors. However, the mechanisms of acquired resistance to carfilzomib and oprozomib are incompletely understood, and effective strategies for overcoming this resistance are needed. Here, we developed models of acquired resistance to carfilzomib in two head and neck squamous cell carcinoma cell lines, UMSCC-1 and Cal33, through gradual exposure to increasing drug concentrations. The resistant lines R-UMSCC-1 and R-Cal33 demonstrated 205- and 64-fold resistance, respectively, relative to the parental lines. Similarly, a high level of cross-resistance to oprozomib, as well as paclitaxel, was observed, whereas only moderate resistance to bortezomib (8- to 29-fold), and low level resistance to cisplatin (1.5- to 5-fold) was seen. Synergistic induction of apoptosis signaling and cell death, and inhibition of colony formation followed co-treatment of acquired resistance models with carfilzomib and the histone deacetylase inhibitor (HDACi) vorinostat. Synergism was also seen with other combinations, including oprozomib plus vorinostat, or carfilzomib plus the HDACi entinostat. Synergism was accompanied by upregulation of proapoptotic Bik, and suppression of Bik attenuated the synergy. The acquired resistance models also exhibited elevated levels of MDR-1/P-gp. Inhibition of MDR-1/P-gp with reversin 121 partially overcame carfilzomib resistance in R-UMSCC-1 and R-Cal33 cells. Collectively, these studies indicate that combining carfilzomib or oprozomib with HDAC or MDR-1/P-gp inhibitors may be a useful strategy for overcoming acquired resistance to these proteasome inhibitors.

What is a Caveolae?

Caveolae, plasma membrane invaginations of 60-80nm in diameter, are a subset of lipid rafts enriched in cholesterol and sphingolipids.

[24023653, 24013596, 24013648, 24308657, 23610576, 23521716, 7407830, 23899671, 23787000, 23727353, 23593340, 23340574]

Mutations that lead to muscular dystrophy often create deficiencies in cytoskeletal support of the muscle sarcolemma causing hyperactive mechanosensitive cation channel (MSC) activity and elevated intracellular Ca(2+). Caveolae are cholesterol-rich microdomains that form mechanically deformable invaginations of the sarcolemma. Mutations to caveolin-3, the main scaffolding protein of caveolae in muscle, cause Limbe-Girdle muscular dystrophy. Using genetic and acute chemical perturbations of developing myotubes we investigated whether caveolae are functionally linked to MSCs. MSC sensitivity was assayed using suction application to patches and probe-induced indentation during whole-cell recordings. Membrane mechanical stress in patches was monitored using patch capacitance/impedance. Cholesterol depletion disrupted caveolae and caused a large increase in MSC current. It also decreased the membrane mechanical relaxation time, likely reflecting cytoskeleton dissociation from the bilayer. Reduction of Cav3 expression with miRNA also increased MSC current and decreased patch relaxation time. In contrast Cav3 overexpression produced a small decrease in MSC currents. To acutely and specifically inhibit Cav3 interactions, we made a chimeric peptide containing the antennapedia membrane translocation domain and the Cav3 scaffolding domain (A-CSD3). A-CSD3 action was time dependent initially producing a mild Ca(2+) leak and increased MSC current, while longer exposures decreased MSC currents coinciding with increased patch stiffening. Images of GFP labeled Cav3 in patches showed that Cav3 doesn't enter the pipette, showing patch composition differed from the cell surface. However, disruption via cholesterol depletion caused Cav3 to become uniformly distributed over the sarcolemma and Cav3 appearance in the patch dome. The whole-cell indentation currents elicited under the different caveolae modifying conditions mirror the patch response supporting the role of caveolae in MSC function. These studies show that normal expression levels of Cav3 are mechanoprotective to the sarcolemma through multiple mechanisms, and Cav3 upregulation observed in some dystrophies may compensate for other mechanical deficiencies. Since its inception, electron microscopy (EM) has revealed that cellular membranes are organized into structurally distinct subdomains, created by localized protein and lipid assemblies to perform specific complex cellular functions. Caveolae are membrane subdomains that function as signaling platforms, endocytic carriers, sensors of membrane tension, and mechanical stress, as well as in lipid homeostasis. They were first discovered almost 60 years ago by pioneering electron microscopists. While new and exciting developments in SUPER-resolution fluorescent light microscopy facilitate studies of the spatial organization of fluorescently labeled protein components, these techniques cannot reveal the underlying cellular structures. Thus, equally exciting are developments in EM: genetically encoded probes for protein localization at sub-10 nm resolution, more powerful instruments that allow imaging of larger cell volumes, and computational methods for reconstructing three-dimensional images. Used in combination, as done by Ludwig et al. in the current issue of PLOS Biology, these tools reveal high-resolution insights into the composition and organization of the caveolae coat and the formation of these specialized structures. Together, these advances are contributing to a resurgence in EM. Caveolae are an abundant feature of the plasma membrane of many mammalian cell types, and have key roles in mechano-transduction, metabolic regulation, and vascular permeability. Caveolin and cavin proteins, as well as EHD2 and pacsin 2, are all present in caveolae. How these proteins assemble to form a protein interaction network for caveolar morphogenesis is not known. Using in vivo crosslinking, velocity gradient centrifugation, immuno-isolation, and tandem mass spectrometry, we determine that cavins and caveolins assemble into a homogenous 80S complex, which we term the caveolar coat complex. There are no further abundant components within this complex, and the complex excludes EHD2 and pacsin 2. Cavin 1 forms trimers and interacts with caveolin 1 with a molar ratio of about 1∶4. Cavins 2 and 3 compete for binding sites within the overall coat complex, and form distinct subcomplexes with cavin 1. The core interactions between caveolin 1 and cavin 1 are independent of cavin 2, cavin 3, and EHD2 expression, and the cavins themselves can still interact in the absence of caveolin 1. Using immuno-electron microscopy as well as a recently developed protein tag for electron microscopy (MiniSOG), we demonstrate that caveolar coat complexes form a distinct coat all around the caveolar bulb. In contrast, and consistent with our biochemical data, EHD2 defines a different domain at the caveolar neck. 3D electron tomograms of the caveolar coat, labeled using cavin-MiniSOG, show that the caveolar coat is composed of repeating units of a unitary caveolar coat complex. Caveolae are flask-shaped plasma membrane invaginations formed by constitutive caveolin proteins and regulatory cavin proteins. Caveolae harbor a range of signaling components such as receptors, ion channels and regulatory molecules. There is now increasing evidence that caveolins and cavins play an important role in a variety of diseases. However, the mechanisms by which these caveolar proteins affect lung health and disease are still under investigation, with emerging data suggesting complex roles in disease pathophysiology. This review summarizes the current state of understanding of how caveolar proteins contribute to lung structure and function and how their altered expression and/or function can influence lung diseases. It is estimated that the elderly (> 65 years of age) will increase from 13%-14% to 25% by 2035. If this trend continues, > 50% of the United States population and more than two billion people worldwide will be "aged" in the next 50 years. Aged individuals face formidable challenges to their health, as aging is associated with a myriad of diseases. Cardiovascular disease is the leading cause of morbidity and mortality in the United States with > 50% of mortality attributed to coronary artery disease and > 80% of these deaths occurring in those age 65 and older. Therefore, age is an important predictor of cardiovascular disease. The efficiency of youth is built upon cellular signaling scaffolds that provide tight and coordinated signaling. Lipid rafts are one such scaffold of which caveolae are a subset. In this review, we consider the importance of caveolae in common cardiovascular diseases of the aged and as potential therapeutic targets. We specifically address the role of caveolin in heart failure, myocardial ischemia, and pulmonary hypertension. Caveolae are non-clathrin invaginations of the plasma membrane in most cell types; they are involved in signalling functions and molecule trafficking, thus modulating several biological functions, including cell growth, apoptosis and angiogenesis. The major structural protein in caveolae is caveolin-1, which is known to act as a key regulator in cancer onset and progression through its role as a tumour suppressor. Caveolin-1 can also promote cell proliferation, survival and metastasis as well as chemo- and radioresistance. Here, we discuss recent findings and novel concepts that support a role for caveolin-1 in cancer development and its distant spreading. We also address the potential application of caveolin-1 in tumour therapy and diagnosis. Caveolae or membrane vesicles are commonly observed in smooth and skeletal muscle as well as in working heart muscle. Using sections of fixed tissue and replicas of freeze-cleaved material, we show in this study that caveolae are also very numerous in sinus node cells of the rabbit, and to a lesser degree, in the atrial cells. Caveolae increase the plasma membrane surface area by 115% in the leading sinus node, and by 56% in the atrial cells. In these two cell types, the membrane of the caveolae contains four times fewer intramembranous particles than the rest of the plasma membrane, and this difference applies to both PF and EF faces. The role of the caveolae is still unclear, but it does not seem that they have a pinocytotic function. Stem cells are an important resource for tissue repair and regeneration. While a great deal of attention has focused on derivation and molecular regulation of stem cells, relatively little research has focused on how the subcellular structure and composition of the cell membrane influences stem cell activities such as proliferation, differentiation and homing. Caveolae are specialized membrane lipid rafts coated with caveolin scaffolding proteins, which can regulate cholesterol transport and the activity of cell signaling receptors and their downstream effectors. Caveolin-1 is involved in the regulation of many cellular processes, including growth, control of mitochondrial antioxidant levels, migration and senescence. These activities are of relevance to stem cell biology, and in this review evidence for caveolin-1 involvement in stem cell biology is summarized. Altered stem and progenitor cell populations in caveolin-1 null mice suggest that caveolin-1 can regulate stem cell proliferation, and in vitro studies with isolated stem cells suggest that caveolin-1 regulates stem cell differentiation. The available evidence leads us to hypothesize that caveolin-1 expression may stabilize the differentiated and undifferentiated stem cell phenotype, and transient downregulation of caveolin-1 expression may be required for transition between the two. Such regulation would probably be critical in regenerative applications of adult stem cells and during tissue regeneration. We also review here the temporal changes in caveolin-1 expression reported during tissue repair. Delayed muscle regeneration in transgenic mice overexpressing caveolin-1 as well as compromised cardiac, brain and liver tissue repair and delayed wound healing in caveolin-1 null mice suggest that caveolin-1 plays an important role in tissue repair, but that this role may be negative or positive depending on the tissue type and the nature of the repair process. Finally, we also discuss how caveolin-1 quiescence-inducing activities and effects on mitochondrial antioxidant levels may influence stem cell aging. AIMS: Caveolae are membrane microdomains where important signalling pathways are assembled and molecular effects transduced. In this study, we hypothesized that shear stress-mediated vasodilation (SSD) of mouse small coronary arteries (MCA) is caveolae-dependent. METHODS AND RESULTS: MCA (80-150 μm) isolated from wild-type (WT) and caveolin-1 null (Cav-1(-/-)) mice were subjected to physiological levels of shear stress (1-25 dynes/cm(2)) with and without pre-incubation of inhibitors of nitric oxide synthase (L-NAME), cyclooxygenase (indomethacin, INDO), or cytochrome P450 epoxygenase (SKF 525A). SSD was endothelium-dependent in WT and Cav-1(-/-) coronaries but that in Cav-1(-/-) was significantly diminished compared with WT. Pre-incubation with L-NAME, INDO, or SKF 525A significantly reduced SSD in WT but not in Cav-1(-/-) mice. Vessels from the soluble epoxide hydrolase null (Ephx2(-/-)) mice showed enhanced SSD, which was further augmented by the presence of arachidonic acid. In donor-detector-coupled vessel experiments, Cav-1(-/-) donor vessels produced diminished dilation in WT endothelium-denuded detector vessels compared with WT donor vessels. Shear stress elicited a robust intracellular Ca(2+) increase in vascular endothelial cells isolated from WT but not those from Cav-1(-/-) mice. CONCLUSION: Integrity of caveolae is critical for endothelium-dependent SSD in MCA. Cav-1(-/-) endothelium is deficient in shear stress-mediated generation of vasodilators including NO, prostaglandins, and epoxyeicosatrienoic acids. Caveolae plays a critical role in endothelial signal transduction from shear stress to vasodilator production and release. Caveolae, plasma membrane invaginations of 60-80nm in diameter, are a subset of lipid rafts enriched in cholesterol and sphingolipids. Caveolae are expressed in various tissues and cell types, such as endothelial cells, macrophages, neutrophils and adipocytes. The functions of caveolae are diverse and include endocytosis, transcytosis, potocytosis, calcium signaling, and regulation of various signaling events. Although growing evidence has increased our understanding of caveolae function, the role of caveolae in sepsis is still a controversial issue. In this review, we present a number of studies addressing caveolae and sepsis and describe the signaling pathways involved, including the LPS-eNOS-TLR4-NFκB, MKK3/p38 MAPK, cPLA2/p38 MAPK, STAT3/NFκB and IL-1β-IL-1R1 pathways. Different studies using endotoxemia and bacteremia animal models have provided distinct conclusions about the function of caveolae, and we discuss these inconsistencies. Taken together, the current data suggest that the function of caveolae in sepsis, which involves a number of signaling pathways, is complex and warrants further studies. PURPOSE: Caveolae are cholesterol and sphingolipids rich subcellular domains on plasma membrane. Caveolae contain a variety of signaling proteins which provide platforms for signaling transduction. In addition to enriched with cholesterol and sphingolipids, caveolae also contain a variety of fatty acids. It has been well-established that acylation of protein plays a pivotal role in subcellular location including targeting to caveolae. However, the fatty acid compositions of caveolae and the type of acylation of caveolar proteins remain largely unknown. In this study, we investigated the fatty acids in caveolae and caveolin-1 bound fatty acids. METHODS: Caveolae were isolated from Chinese hamster ovary (CHO) cells. The caveolar fatty acids were extracted with Folch reagent, methyl esterificated with BF3, and analyzed by gas chromatograph-mass spectrometer (GC/MS). The caveolin-1 bound fatty acids were immunoprecipitated by anti-caveolin-1 IgG and analyzed with GC/MS. RESULTS: In contrast to the whole CHO cell lysate which contained a variety of fatty acids, caveolae mainly contained three types of fatty acids, 0.48 µg palmitic acid, 0.61 µg stearic acid and 0.83 µg oleic acid/caveolae preparation/5 × 10(7) cells. Unexpectedly, GC/MS analysis indicated that caveolin-1 was not acylated by myristic acid; instead, it was acylated by palmitic acid and stearic acid. CONCLUSION: Caveolae contained a special set of fatty acids, highly enriched with saturated fatty acids, and caveolin-1 was acylated by palmitic acid and stearic acid. The unique fatty acid compositions of caveolae and acylation of caveolin-1 may be important for caveolae formation and for maintaining the function of caveolae. Caveolae are submicroscopic, plasma membrane pits that are abundant in many mammalian cell types. The past few years have seen a quantum leap in our understanding of the formation, dynamics and functions of these enigmatic structures. Caveolae have now emerged as vital plasma membrane sensors that can respond to plasma membrane stresses and remodel the extracellular environment. Caveolae at the plasma membrane can be removed by endocytosis to regulate their surface density or can be disassembled and their structural components degraded. Coat proteins, called cavins, work together with caveolins to regulate the formation of caveolae but also have the potential to dynamically transmit signals that originate in caveolae to various cellular destinations. The importance of caveolae as protective elements in the plasma membrane, and as membrane organizers and sensors, is highlighted by links between caveolae dysfunction and human diseases, including muscular dystrophies and cancer.

Which are the roles of chromatin compartments in the eukaryotic nucleus?

The complexity in composition and function of the eukaryotic nucleus is achieved through its organization in specialized nuclear compartments. Chromosome conformation capture approaches have shown that interphase chromatin is partitioned into spatially segregated Mb-sized compartments and sub-Mb-sized topological domains. This compartmentalization is thought to facilitate the matching of genes and regulatory elements. Cohesin-based chromatin interactions enable regulated gene expression within preexisting architectural compartments. Therefore, concentrating proteins needed to perform different steps of RNA synthesis within specialized nuclear compartments is important in orchestrating events required for efficient gene expression.

[24002784, 18974210, 18434402, 21637796, 25409831, 9587055, 9636146, 15791412, 9291094, 15140983, 11909528, 22198682, 11186332]

Chromosome conformation capture approaches have shown that interphase chromatin is partitioned into spatially segregated Mb-sized compartments and sub-Mb-sized topological domains. This compartmentalization is thought to facilitate the matching of genes and regulatory elements, but its precise function and mechanistic basis remain unknown. Cohesin controls chromosome topology to enable DNA repair and chromosome segregation in cycling cells. In addition, cohesin associates with active enhancers and promoters and with CTCF to form long-range interactions important for gene regulation. Although these findings suggest an important role for cohesin in genome organization, this role has not been assessed on a global scale. Unexpectedly, we find that architectural compartments are maintained in noncycling mouse thymocytes after genetic depletion of cohesin in vivo. Cohesin was, however, required for specific long-range interactions within compartments where cohesin-regulated genes reside. Cohesin depletion diminished interactions between cohesin-bound sites, whereas alternative interactions between chromatin features associated with transcriptional activation and repression became more prominent, with corresponding changes in gene expression. Our findings indicate that cohesin-mediated long-range interactions facilitate discrete gene expression states within preexisting chromosomal compartments. Chromatin structure is strictly regulated during the cell cycle. DNA viruses occasionally disturb the spatial organization of the host cell chromatin due to formation of the viral DNA replication compartment. To examine chromatin behavior in baculovirus-infected cells, we constructed recombinant plasmids expressing fluorescent protein-tagged histone H4 molecules and visualized the intracellular localization of chromatin by their transient expression in live infected cells. Similar to other DNA viruses, the baculovirus Bombyx mori nucleopolyhedrovirus induced marginal relocation of chromatin within the nuclei of BmN cells, simultaneously with expansion of the viral DNA replication compartment, the virogenic stroma (VS). In the late stage of infection, however, the peristromal region (PR), another virus-induced subnuclear compartment, was also excluded from the chromatin-localizing area. Provided that late-gene products such as PR proteins (e.g., envelope proteins of the occlusion-derived virus) were expressed, blockage of viral DNA synthesis failed to inhibit chromatin relocation, despite abrogation of VS expansion. Instead, chromatin became marginalized concomitantly with PR expansion, suggesting that the PR contributes directly to chromatin replacement. In addition, chromatin was excluded from relatively large subnuclear structures that were induced in uninfected cells by cotransfection with four baculovirus genes, ie1, lef3, p143, and hr. Omission of any of the four genes, however, failed to result in formation of the large structures or chromatin exclusion. This correlation between compartmentalization and chromatin exclusion suggests the possibility that a chromatin-exclusive property of viral molecules, at least in part, supports nuclear compartmentalization of virus-infected cells. The complexity in composition and function of the eukaryotic nucleus is achieved through its organization in specialized nuclear compartments. The Drosophila chromatin remodeling ATPase ISWI plays evolutionarily conserved roles in chromatin organization. Interestingly, ISWI genetically interacts with the hsrω gene, encoding multiple non-coding RNAs (ncRNA) essential, among other functions, for the assembly and organization of the omega speckles. The nucleoplasmic omega speckles play important functions in RNA metabolism, in normal and stressed cells, by regulating availability of hnRNPs and some other RNA processing proteins. Chromatin remodelers, as well as nuclear speckles and their associated ncRNAs, are emerging as important components of gene regulatory networks, although their functional connections have remained poorly defined. Here we provide multiple lines of evidence showing that the hsrω ncRNA interacts in vivo and in vitro with ISWI, regulating its ATPase activity. Remarkably, we found that the organization of nucleoplasmic omega speckles depends on ISWI function. Our findings highlight a novel role for chromatin remodelers in organization of nucleoplasmic compartments, providing the first example of interaction between an ATP-dependent chromatin remodeler and a large ncRNA. Nuclear elimination accompanies differentiation in such specialized cell types such as erthyrocytes and lens fibre cells. It also accompanies apoptosis which has suggested that similar processes could operate in both. Denucleation occurs in the lens in order to reduce light scatter and this process is often disrupted in cataract. Using the adult bovine lens as a model system, nuclear changes accompanying denucleation are described with particular emphasis on the lamina, nucleolar and coiled body compartments in lens nuclei. Nuclear shape, chromatin reorganization and chromatin breakdown were also monitored to correlate the timing of events. Rearrangement of both A- and B-type nuclear lamins occurred in parallel with chromatin condensation and preceded changes in nuclear shape. The earliest changes detected in this study occurred in the coiled body and nucleolar compartments using coilin and fibrillarin antibodies respectively, suggesting that a shutdown in transcription is an early event in denucleation. Fibrillarin redistributed from an open floret pattern to several condensed spots which gradually decreased in intensity and eventually disappeared. Coilin, however, was localized in several microfoci prior to being reorganized into fewer larger foci. Prior to chromatin condensation, coilin redistributed to the nucleolar compartment and was absent from nuclei where chromatin had begun to condense. Such nuclei were positive by TUNEL staining. In contrast to the nucleus, mitochondrial degradation in lens fibre cells was a rapid process and involved a relatively sharp transition between positive and negative fibre cells for two mitochondrial specific markers, BAP 37 and prohibitin. A link between the changes in the nuclear lamina and chromatin with the initiation of mitochondrial fragmentation was also observed. Therefore, it is possible that the signal for the initiation of denucleation could originate from the mitochondria as proposed for apoptosis. Differences between apoptosis and lens fibre cell denucleation were noted and included the timescale of nuclear changes as well as the persistence of a nuclear remnant. These studies suggest that transcriptional shutdown precedes lamina reorganization and chromatin breakdown during lens fibre cell denucleation. The PML/SP100 nuclear bodies (NBs) were first described as discrete subnuclear structures containing the SP100 protein. Subsequently, they were shown to contain the PML protein which is part of the oncogenic PML-RARalpha hybrid produced by the t(15;17) chromosomal translocation characteristic of acute promyelocytic leukemia. Yet, the physiological role of these nuclear bodies remains unknown. Here, we show that SP100 binds to members of the heterochromatin protein 1 (HP1) families of non-histone chromosomal proteins. Further, we demonstrate that a naturally occurring splice variant of SP100, here called SP100-HMG, is a member of the high mobility group-1 (HMG-1) protein family and may thus possess DNA-binding potential. Both HP1 and SP100-HMG concentrate in the PML/SP100 NBs, and overexpression of SP100 leads to enhanced accumulation of endogenous HP1 in these structures. When bound to a promoter, SP100, SP100-HMG and HP1 behave as transcriptional repressors in transfected mammalian cells. These observations present molecular evidence for an association between the PML/SP100 NBs and the chromatin nuclear compartment. They support a model in which the NBs may play a role in certain aspects of chromatin dynamics. Histone posttranslational modifications mediate establishment of structurally and functionally distinct chromatin compartments of eukaryotic nuclei. The association of different histone modifications with euchromatic and heterochromatic compartments is relatively conserved in highly divergent model organisms such as Drosophila and mammals. However, some differences between these model systems have been uncovered while limited data are available from organisms nearer the invertebrate-vertebrate transition. We identified a chromatin compartment in both diploid and endocycling cells of the urochordate, Oikopleura dioica, enriched in heterochromatic histone modifications and DNA methylation. Surprisingly, this compartment also contained high levels of histone H3 trimethylated at lysine 4 (H3 Me(3)K4), a modification thus far associated with actively transcribed sequences. Although in Drosophila and mouse cells, H3 Me(3)K4 was prevalently associated with euchromatin, we also detected it in their pericentromeric heterochromatin. We further showed that H3 Me(3)K4 abundance was not necessarily proportional to local levels of transcriptional activity in either euchromatin or heterochromatin. Our data indicate greater plasticity across evolution in the association of histone lysine methylation with functionally distinct chromatin domains than previously thought and suggest that H3 Me(3)K4 participates in additional processes beyond marking transcriptionally active chromatin. In this study, we have used immunoprecipitation and mass spectrometry to identify over 50 cellular and viral proteins that are associated with the herpes simplex virus 1 (HSV-1) ICP8 single-stranded DNA-binding protein. Many of the coprecipitating cellular proteins are known members of large cellular complexes involved in (i) DNA replication or damage repair, including RPA and MSH6; (ii) nonhomologous and homologous recombination, including the catalytic subunit of the DNA-dependent protein kinase, Ku86, and Rad50; and (iii) chromatin remodeling, including BRG1, BRM, hSNF2H, BAF155, mSin3a, and histone deacetylase 2. It appears that DNA mediates the association of certain proteins with ICP8, while more direct protein-protein interactions mediate the association with other proteins. A number of these proteins accumulate in viral replication compartments in the infected cell nucleus, indicating that these proteins may have a role in viral replication. WRN, which functions in cellular recombination pathways via its helicase and exonuclease activities, is not absolutely required for viral replication, as viral yields are only very slightly, if at all, decreased in WRN-deficient human primary fibroblasts compared to control cells. In Ku70-deficient murine embryonic fibroblasts, viral yields are increased by almost 50-fold, suggesting that the cellular nonhomologous end-joining pathway inhibits HSV replication. We hypothesize that some of the proteins coprecipitating with ICP8 are involved in HSV replication and may give new insight into viral replication mechanisms. The spatial folding of chromatin has been proposed to be involved in the regulation and coordination of gene expression. The mammalian Hox gene clusters form a particularly interesting case of coordinated gene regulation. Within each Hox cluster, the linear order of the genes closely reflects their temporal and anatomical expression pattern. This striking phenomenon suggests that the overall structure of the Hox clusters is important for their regulation. Recent studies employing chromatin conformation capture techniques indicate that Hox clusters adopt a remarkable spatial configuration, in which active and inactive genes are segregated into two distinct chromatin compartments. Here we discuss the possible underlying mechanisms and regulatory roles of this spatial compartmentalization. Advances in the specific fluorescent labeling of chromatin in fixed and living human cells in combination with three-dimensional (3D) and 4D (space plus time) fluorescence microscopy and image analysis have opened the way for detailed studies of the dynamic, higher-order architecture of chromatin in the human cell nucleus and its potential role in gene regulation. Several features of this architecture are now well established: 1. Chromosomes occupy distinct territories in the cell nucleus with preferred nuclear locations, although there is no evidence of a rigid suprachromosomal order. 2. Chromosome territories (CTs) in turn contain distinct chromosome arm domains and smaller chromatin foci or domains with diameters of some 300 to 800 nm and a DNA content in the order of 1 Mbp. 3. Gene-dense, early-replicating and gene-poor, middle-to-late-replicating chromatin domains exhibit different higher-order nuclear patterns that persist through all stages of interphase. In mitotic chromosomes early replicating chromatin domains give rise to Giemsa light bands, whereas middle-to-late-replicating domains form Giemsa dark bands and C-bands. In an attempt to integrate these experimental data into a unified view of the functional nuclear architecture, we present a model of a modular and dynamic chromosome territory (CT) organization. We propose that basically three nuclear compartments exist, an "open" higher-order chromatin compartment with chromatin domains containing active genes, a "closed" chromatin compartment comprising inactive genes, and an interchromatin domain (ICD) compartment (Cremer et al., 1993; Zirbel et al., 1993) that contains macromolecular complexes for transcription, splicing, DNA replication, and repair. Genes in "open," but not in "closed" higher-order chromatin compartments have access to transcription and splicing complexes located in the ICD compartment. Chromatin domains that build the "open" chromatin compartment are organized in a way that allows the direct contact of genes and nascent RNA to transcription and splicing complexes, respectively, preformed in the ICD compartment. In contrast, chromatin domains that belong to the "closed" compartment are topologically arranged and compacted in a way that precludes the accessibility of genes to transcription complexes. We argue that the content of the ICD compartment is highly enriched in DNA depleted biochemical matrix preparations. The ICD compartment may be considered as the structural and functional equivalent of the in vivo nuclear matrix. A matrix in this functional sense is compatible with but does not necessitate the concept of a 3D nuclear skeleton existing of long, extensively arborized filaments. In the absence of unequivocal evidence for such a structural matrix in the nucleus of living cells we keep an agnostic attitude about its existence and possible properties in maintaining the higher-order nuclear architecture. Quantitative modeling of the 3D and 4D human genome architecture in situ shows that such an assumption is not necessary to explain presently known aspects of the higher-order nuclear architecture. We expect that the interplay of quantitative modeling and experimental tests will result in a better understanding of the compartmentalized nuclear architecture and its functional consequences.

Is the abnormal dosage of ultraconserved elements disfavored in cancer cells?

No. Abnormal dosage of ultraconserved elements is highly disfavored in healthy cells but not cancer cells.

[25340765]

Ultraconserved elements (UCEs) are strongly depleted from segmental duplications and copy number variations (CNVs) in the human genome, suggesting that deletion or duplication of a UCE can be deleterious to the mammalian cell. Here we address the process by which CNVs become depleted of UCEs. We begin by showing that depletion for UCEs characterizes the most recent large-scale human CNV datasets and then find that even newly formed de novo CNVs, which have passed through meiosis at most once, are significantly depleted for UCEs. In striking contrast, CNVs arising specifically in cancer cells are, as a rule, not depleted for UCEs and can even become significantly enriched. This observation raises the possibility that CNVs that arise somatically and are relatively newly formed are less likely to have established a CNV profile that is depleted for UCEs. Alternatively, lack of depletion for UCEs from cancer CNVs may reflect the diseased state. In support of this latter explanation, somatic CNVs that are not associated with disease are depleted for UCEs. Finally, we show that it is possible to observe the CNVs of induced pluripotent stem (iPS) cells become depleted of UCEs over time, suggesting that depletion may be established through selection against UCE-disrupting CNVs without the requirement for meiotic divisions.

Does thyroid hormone regulate calcium transient in the myocardium?

YES

[9875761, 19298522, 9773867, 2428004]

BACKGROUND: Conflicting results have been reported regarding the acute effects of triiodothyronine (T3) on myocardial contractile performance. The present study analyzes the role of T3 in reversing the depressant effect of excessive catecholamine stimulation in isolated porcine left ventricular myocardium. METHODS: Thirty-six left ventricular trabeculae (0.4 x 6.0 mm) obtained from 6 pigs were used for measurements of isometric force development, isotonic shortening, and intracellular calcium in three experimental series (measurement conditions: 37 degrees C; optimal length; supramaximal electrical stimulation, 1 Hz; calcium measurement, fura-2 ratio method; frequency, 225 Hz). In series 1, isometric force development was measured before and after a 60-minute incubation with 10(-7) mol/L epinephrine in preparations with (n = 6) and without (n = 6) preceding fura-2 loading for calcium measurements. In series 2, the acute effects of a 30-minute administration of T3 (10(-9) mol/L) on isometric force and intracellular calcium were analyzed (n = 6). In series 3, after simultaneous fura-2 loading and a 6-hour 10(-7) mol/L epinephrine exposure the effects of T3 (10(-9) mol/L, 30 minutes) on force development, shortening, and intracellular calcium transient were analyzed. RESULTS: Long-term and high-dose epinephrine exposure induced a severe contractile depression with a significant reduction of isometric force development (p < 0.05) and increased diastolic (p < 0.001) and systolic calcium (p < 0.001). In normal porcine myocardium T3 had no effect on the extent of isometric force generation but accelerated the time course of force development (p < 0.05) and increased the calcium transient (p < 0.001). After induction of myocardial depression by epinephrine exposure T3 accelerated the intracellular calcium transients and reduced diastolic calcium. Triiodothyronine increased the shortening amplitude and the force amplitude (p < 0.01). CONCLUSIONS: Triiodothyronine reverses depressed contractile performance after preceding high-dose epinephrine exposure in isolated porcine myocardium. Increased force amplitudes and unaltered or even reduced intracellular calcium transients argue in favor of a resensitization of the contractile apparatus for calcium by T3. The study supports a potential role for T3 treatment in depressed myocardium after previous excessive catecholamine exposure (eg, brain death, catecholamine treatment, ischemia). 3-iodothyronamine (T(1)AM) is a novel endogenous relative of thyroid hormone, able to interact with trace amine-associated receptors, a class of plasma membrane G protein-coupled receptors, and to produce a negative inotropic and chronotropic effect. In the isolated rat heart 20-25 microM T(1)AM decreased cardiac contractility, but oxygen consumption and glucose uptake were either unchanged or disproportionately high when compared to mechanical work. In adult rat cardiomyocytes acute exposure to 20 microM T(1)AM decreased the amplitude and duration of the calcium transient. In patch clamped cardiomyocytes sarcolemmal calcium current density was unchanged while current facilitation by membrane depolarization was abolished consistent with reduced sarcoplasmic reticulum (SR) calcium release. In addition, T(1)AM decreased transient outward current (I(to)) and I(K1) background current. SR studies involving 20 microM T(1)AM revealed a significant decrease in ryanodine binding due to reduced B(max), no significant change in the rate constant of calcium-induced calcium release, a significant increase in calcium leak measured under conditions promoting channel closure, and no effect on oxalate-supported calcium uptake. Based on these observations we conclude T(1)AM affects calcium and potassium homeostasis and suggest its negative inotropic action is due to a diminished pool of SR calcium as a result of increased diastolic leak through the ryanodine receptor, while increased action potential duration is accounted for by inhibition of I(to) and I(K1) currents. BACKGROUND: This study analyzes in the experimental model of isolated human atrial myocardium whether the myocardial contractile depression occurring after high-dose/long-term catecholamine exposure (as typically occurring in brain-dead organ donors) can be reversed by thyroid hormone administration. METHODS: Isolated trabeculae were prepared from atrial myocardium from patients undergoing coronary artery bypass (n = 15). Initial measurements of isometric force were carried out (measurement conditions of 37 degrees C, Krebs Henseleit solution, supramaximal electrical stimulation, 1 Hz, at optimal length). Then the trabeculae were incubated for 6 hours at 26 degrees C in a Krebs Henseleit solution containing epinephrine 10(-7) mol/L and the fluorescent dye FURA-2/AM for calcium measurements. At the end of the incubation period, isometric force, isotonic shortening, and intracellular calcium transient (FURA-2 "ratio method") were measured. After 30 minutes administration of triiodothyronine (5 x 10(-9) mol/L), the measurements were repeated. Control groups included 6 hours incubation in 4 degrees C Krebs Henseleit solution (n = 5); 6 hours incubation in 26 degrees C FURA-2/AM (n = 5); and 6 hours incubation in epinephrine 10(-7) mol/L (n = 5). RESULTS: After 6 hours catecholamine exposure isometric force declined significantly to 56.8% (p < .0001) and isotonic shortening to 54% of its initial value (p < .01). Administration of triiodothyronine was associated with a significant recovery of the isotonic shortening amplitude (p < .005), of isometric force development (p < .01), an increased velocity of force development (p < .0001), and of diastolic force decay (p < .005). At the same time the shape of the intracellular calcium transient became smaller as a result of an accelerated diastolic decay. The amplitude of the calcium transient remained unaltered, whereas the calcium time integral was reduced (p < .05). CONCLUSION: In the model of isolated human myocardium, experimental depression of the contractile performance resulting from long-term catecholamine exposure could be reversed by a 30-minute triiodothyronine incubation. The experimental data showing increased force amplitudes at unaltered amplitudes of the intracellular calcium transient and an even-reduced calcium time integral provide strong evidence for a sensitization of the contractile apparatus for calcium by triiodothyronine. The data provide additional knowledge to explain the successful administration of triiodothyronine in donor heart management. The purpose of this study was to determine the influence of thyroid hormone on tension development and the intracellular calcium transient in mammalian ventricular muscle. A hyperthyroid (H) state was induced in ferrets by subcutaneous injection of L-thyroxine, 0.3 mg/kg daily, for 2-3 weeks. One-half of the age matched control group (C) were injected with vehicle. Aequorin was loaded into the cells of ferret papillary muscles by a chemical procedure. The muscles were stimulated at 0.33 Hz and isometric tension and the calcium transient were simultaneously recorded at 30 degrees C. Peak isometric tension in mN/mm2 (+/- SD) was 15.4 +/- 7.2 and 16.2 +/- 7.9 for C (n = 8) and H (n = 9) respectively. The time to peak tension and time to 80% relaxation from peak of tension were reduced by 22% and 28% respectively in H compared to C. After stimulation, the calcium transient reached a maximum in 56 +/- 6 ms in C and in 47 +/- 5 ms in H. The time to 80% decay of the peak calcium transient was 95 +/- 8 ms and 68 +/- 5 ms for C and H respectively. The ratio of the aequorin luminescence at the peak of the calcium transient over the calculated maximum luminescence, Lmax, were compared and they were not different. At 22 degrees C Log (L/Lmax) was -3.3 +/- 0.1 in C (n = 4) and -3.4 +/- 0.3 in H (n = 3). These results indicate that the thyroid state influences the time course of the calcium transient and are consistent with the abbreviation in the duration of contraction that is observed in the hyperthyroid state.

What are the biological roles proposed for proteins containing the SPRY domain?

defence against retroviral infection innate and adaptative immunity vesicular trafficking neural differentiation embryonic development

[16648259, 12479811, 16226405, 22872646, 23139046, 16313355, 15857996, 21035437, 23775985, 23886867, 15689398, 19184407, 23091002, 22337885, 17431422]

Primate tripartite motif 5alpha (TRIM5alpha) proteins mediate innate intracellular resistance to retroviruses. In humans, TRIM5 is located in a paralogous cluster that includes TRIM6, TRIM34, and TRIM22. Although TRIM6 and TRIM34 orthologs are found in other mammals, TRIM5 has to date been identified only in primates. Cow cells exhibit early blocks to infection by several retroviruses. We identify a cytoplasmic TRIM protein encoded by LOC505265 that is responsible for the restriction of infection by several lentiviruses and N-tropic murine leukemia virus in cow cells. Susceptibility of N-tropic murine leukemia virus to 505265-mediated restriction is determined primarily by residue 110 of the viral capsid protein. Phylogenetically, cow LOC505265 segregates with the TRIM5/TRIM6/TRIM34 group, but is not an ortholog of known TRIM genes. The B30.2/SPRY domain of 505265 exhibits long variable regions, a characteristic of the proteins encoded by this paralogous group, and shows evidence of positive selection. Apparently, cows have independently evolved a retroviral restriction factor from the same TRIM family that spawned TRIM5 in primates. Particular features of this subset of cytoplasmic TRIM proteins may be conducive to the convergent evolution of virus-restricting factors. VASA (VAS), a key protein in establishing the specialized translational activity of the Drosophila pole plasm, accumulates at the posterior pole of the developing oocyte. We identified a gene, gustavus (gus), that encodes a protein that interacts with VAS. A gus mutation blocks posterior localization of VAS, as does deletion of a segment of VAS containing the GUS binding site. Like VAS, GUS is present in cytoplasmic ribonucleoprotein particles. Heterozygotes for gus or a deletion including gus produce embryos with fewer pole cells and posterior patterning defects. Therefore, GUS is essential for the posterior localization of VAS. However, gus is not required for the posterior localization of oskar (osk). Apparent gus orthologs are present in mammalian genomes. Of the TRIM/RBCC family proteins taking part in a variety of cellular processes, TRIM50 is a stomach-specific member with no defined biological function. Our biochemical data demonstrated that TRIM50 is specifically expressed in gastric parietal cells and is predominantly localized in the tubulovesicular and canalicular membranes. In cultured cells ectopically expressing GFP-TRIM50, confocal microscopic imaging revealed dynamic movement of TRIM50-associated vesicles in a phosphoinositide 3-kinase-dependent manner. A protein overlay assay detected preferential binding of the PRY-SPRY domain from the TRIM50 C-terminal region to phosphatidylinositol species, suggesting that TRIM50 is involved in vesicular dynamics by sensing the phosphorylated state of phosphoinositol lipids. Trim50 knock-out mice retained normal histology in the gastric mucosa but exhibited impaired secretion of gastric acid. In response to histamine, Trim50 knock-out parietal cells generated deranged canaliculi, swollen microvilli lacking actin filaments, and excess multilamellar membrane complexes. Therefore, TRIM50 seems to play an essential role in tubulovesicular dynamics, promoting the formation of sophisticated canaliculi and microvilli during acid secretion in parietal cells. The SPRY domain is a protein interaction module found in 77 murine and ~100 human proteins, and is implicated in important biological pathways, including those that regulate innate and adaptive immunity. The current definition of the SPRY domain is based on a sequence repeat discovered in the splA kinase and ryanodine receptors. The greater SPRY family is divided into the B30.2 (which contains a PRY extension at the N-terminus) and "SPRY-only" sub-families. In this brief review, we examine the current structural and biochemical literature on SPRY/B30.2 domain involvement in key immune processes and highlight a PRY-like 60 amino acid region in the N-terminus of "SPRY-only" proteins. Phylogenetic, structural, and functional analyses suggest that this N-terminal region is related to the PRY region of B30.2 and should be characterized as part of an extended SPRY domain. Greater understanding of the functional importance of the N-terminal region in "SPRY only" proteins will enhance our ability to interrogate SPRY interactions with their respective binding partners. SPRY and B30.2 are homologous domains which can be identified in 11 protein families encoded in the human genome. These include cell surface receptors of the immunoglobulin super-family (BTNs), negative regulators of the JAK/STAT pathway (SOCS-box SSB1-4) and proteins encoded by the numerous TRIM genes. Collectively, proteins containing SPRY and B30.2 domains cover a wide range of functions, including regulation of cytokine signalling (SOCS), RNA metabolism (DDX1, hnRNPs), intracellular calcium release (RyR receptors), immunity to retroviruses (TRIM5alpha) as well as regulatory and developmental processes (HERC1, Ash2L). In order to clarify the evolutionary relationship between the two domains, we compiled a curated database of SPRY and B30.2-domain sequences. We show that while SPRY domains are evolutionarily ancient, B30.2 domains, found in BTN and TRIM proteins, are a more recent evolutionary adaptation, comprising the combination of SPRY with an additional domain, PRY. The combination of SPRY and PRY to produce B30.2 domains may have been selected and maintained as a component of immune defence. Vasa is a broadly conserved DEAD-box RNA helicase associated with germ line development and is expressed in multipotent cells in many animals. During embryonic development of the sea urchin Strongylocentrotus purpuratus, Vasa protein is enriched in the small micromeres despite a uniform distribution of vasa transcript. Here we show that the Vasa coding region is sufficient for its selective enrichment and find that gustavus, the B30.2/SPRY and SOCS box domain gene, contributes to this phenomenon. In vitro binding analyses show that Gustavus binds the N-terminal and DEAD-box portions of Vasa protein independently. A knockdown of Gustavus protein reduces both Vasa protein abundance and its propensity for accumulation in the small micromeres, whereas overexpression of the Vasa-interacting domain of Gustavus (GusΔSOCS) results in Vasa protein accumulation throughout the embryo. We propose that Gustavus has a conserved, positive regulatory role in Vasa protein accumulation during embryonic development. TRIM5α is a retroviral restriction factor, in which the B30.2 (SPRY) and coiled-coil domains cooperate to determine the specificity of TRIM5α-mediated capture of retroviral capsids. Here, all exons of TRIM5α were analyzed in 39 Vietnamese cynomolgus macaques (VCE) and 29 Chinese rhesus macaques (CR). Our results revealed the presence of 22 alleles using the PHASE 2.0 software package (PHylogenetics And Sequence Evolution), including two novel species-specific alleles with a low frequency in VCE in exons 4 and 8, which encoded the coiled-coil and B30.2 (SPRY) domains, respectively. Nine alleles were detected in both VCE and CR, while four alleles were likely shared between the species. Of these alleles, the highest frequencies of 38% and 26% occurred in VCE and CR, respectively. Importantly, we found that some alleles encoded the same coiled-coil domain, but not the SPRY domain. In contrast, other alleles encoded the same SPRY domain, but not the coiled-coil domain. Our findings will contribute to the understanding of the interaction between the two domains and the determination of the specificity of TRIM5α-mediated capture of retroviral capsids. Our results from the phylogenetic trees constructed for VCE and CR suggested that the macaques' ability to inhibit SIV replication became gradually stronger if they carried corresponding alleles in four clades (clades4-7). More interesting, in clade3, both novel allele pairs (4E100a, 10E147a) and allele pairs (7R17b and 13R11b), which had the strong ability to inhibit SIV replication, originated from the same ancestral allele, suggesting that the novel alleles might play a key role to determine an animal's ability to inhibit SIV/HIV replication. However, further studies are needed to increase our understanding of the genetic background of TRIM5α in these two macaque species. The restriction factor TRIM5α binds to the capsid protein of the retroviral core and blocks retroviral replication. The affinity of TRIM5α for the capsid is a major host tropism determinant of HIV and other primate immunodeficiency viruses, but the molecular interface involved in this host-pathogen interaction remains poorly characterized. Here we use NMR spectroscopy to investigate binding of the rhesus TRIM5α SPRY domain to a selection of HIV capsid constructs. The data are consistent with a model in which one SPRY domain interacts with more than one capsid monomer within the assembled retroviral core. The highly mobile SPRY v1 loop appears to span the gap between neighboring capsid hexamers making interhexamer contacts critical for restriction. The interaction interface is extensive, involves mobile loops and multiple epitopes, and lacks interaction hot spots. These properties, which may enhance resistance of TRIM5α to capsid mutations, result in relatively low affinity of the individual SPRY domains for the capsid, and the TRIM5α-mediated restriction depends on the avidity effect arising from the oligomerization of TRIM5α. The protein of the gustavus (gus) gene has a typical SOCS box domain and repeats in the splA and RyR (SPRY) domains. GUS can interact with Vasa and is necessary for the specification of germ cells. We cloned two zebrafish genes, SSB-1 and SSB-4 (SPRY domain SOCS box proteins). Phylogenetic analysis shows that zebrafish SSB-1 and SSB-4 are clustered into clades of SSB-1-like and SSB-4-like genes from other species. RT-PCR analysis of tissues revealed that zebrafish SSB-1 and -4 are expressed in the ovary and testis. We investigated the spatial expression patterns of zebrafish SSB-1 and -4 in embryos from the two-cell stage to 72 h postfertilization (hpf) using whole-mount in situ hybridization. SSB-1 and -4 transcripts were present in all blastomeres during the early embryonic stages, but the genes differ in their expression pattern. SSB-4 mRNA was located in the region of the primordial germ cells in 24 and 72 hpf embryos, but SSB-1 mRNA was not detected at these stages. We hypothesize that SSB-4 plays a role in the early development of germ cells. Tripartite motif protein isoform 5 alpha (TRIM5α) is a potent antiviral protein that restricts infection by HIV-1 and other retroviruses. TRIM5α recognizes the lattice of the retrovirus capsid through its B30.2 (PRY/SPRY) domain in a species-specific manner. Upon binding, TRIM5α induces premature disassembly of the viral capsid and activates the downstream innate immune response. We have determined the crystal structure of the rhesus TRIM5α PRY/SPRY domain that reveals essential features for capsid binding. Combined cryo-electron microscopy and biochemical data show that the monomeric rhesus TRIM5α PRY/SPRY, but not the human TRIM5α PRY/SPRY, can bind to HIV-1 capsid protein assemblies without causing disruption of the capsid. This suggests that the PRY/SPRY domain alone constitutes an important pattern-sensing component of TRIM5α that is capable of interacting with viral capsids of different curvatures. Our results provide molecular insights into the mechanisms of TRIM5α-mediated retroviral restriction. Tripartite motif (TRIM)-containing proteins, which are defined by the presence of a common domain structure composed of a RING finger, one or two B-box motifs and a coiled-coil motif, are involved in many biological processes including innate immunity, viral infection, carcinogenesis, and development. Here we show that TRIM67, which has a TRIM motif, an FN3 domain and a SPRY domain, is highly expressed in the cerebellum and that TRIM67 interacts with PRG-1 and 80K-H, which is involved in the Ras-mediated signaling pathway. Ectopic expression of TRIM67 results in degradation of endogenous 80K-H and attenuation of cell proliferation and enhances neuritogenesis in the neuroblastoma cell line N1E-115. Furthermore, morphological and biological changes caused by knockdown of 80K-H are similar to those observed by overexpression of TRIM67. These findings suggest that TRIM67 regulates Ras signaling via degradation of 80K-H, leading to neural differentiation including neuritogenesis.

How could we infer functional associations from gene fusion events?

The detection of gene fusion events across genomes can be used for the prediction of functional associations of proteins, based on the observation that related proteins in one organism (including physically interacting proteins/members of complexes, proteins involved in the same pathway) tend to be found in other species as a fused composite gene encoding a single multifunctional protein. For this purpose, gene fusion events may be used as the sole evidence or as independent information combined with other 'genome-aware' or similarity-based methods, and functional association may be predicted at different levels. An advantage of this approach is that it is not necessary to know the function of the composite/components to infer association.

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BACKGROUND: In order to understand how biological systems function it is necessary to determine the interactions and associations between proteins. Gene fusion prediction is one approach to detection of such functional relationships. Its use is however known to be problematic in higher eukaryotic genomes due to the presence of large homologous domain families. Here we introduce CODA (Co-Occurrence of Domains Analysis), a method to predict functional associations based on the gene fusion idiom. METHODOLOGY/PRINCIPAL FINDINGS: We apply a novel scoring scheme which takes account of the genome-specific size of homologous domain families involved in fusion to improve accuracy in predicting functional associations. We show that CODA is able to accurately predict functional similarities in human with comparison to state-of-the-art methods and show that different methods can be complementary. CODA is used to produce evidence that a currently uncharacterised human protein may be involved in pathways related to depression and that another is involved in DNA replication. CONCLUSIONS/SIGNIFICANCE: The relative performance of different gene fusion methodologies has not previously been explored. We find that they are largely complementary, with different methods being more or less appropriate in different genomes. Our method is the only one currently available for download and can be run on an arbitrary dataset by the user. The CODA software and datasets are freely available from ftp://ftp.biochem.ucl.ac.uk/pub/gene3d_data/v6.1.0/CODA/. Predictions are also available via web services from http://funcnet.eu/. The advent of whole-genome sequencing has led to methods that infer protein function and linkages. We have combined four such algorithms (phylogenetic profile, Rosetta Stone, gene neighbor and gene cluster) in a single database--Prolinks--that spans 83 organisms and includes 10 million high-confidence links. The Proteome Navigator tool allows users to browse predicted linkage networks interactively, providing accompanying annotation from public databases. The Prolinks database and the Proteome Navigator tool are available for use online at http://dip.doe-mbi.ucla.edu/pronav. Now that complete genome sequences are available for a variety of organisms, the elucidation of potential gene products function is a central goal in the post-genome era. Domain fusion analysis has been proposed recently to infer the functional association of the component proteins. Here, we took a new approach to the analysis of the structural features of the proteins involved in fusion events. An exhaustive survey of fusion events within 30 completely sequenced genomes and subsequent structure annotations to the component proteins at a SCOP superfamily level with hidden Markov models was carried out. A domain fusion map was then constructed. The results revealed that proteins with the class alpha/beta fold are frequently involved in fusion events, around 86% of the total 676 assigned single-domain fusion pairs including at least one component protein belonging to the alpha/beta fold class. Moreover, the domain fusion map in our work may offer an attractive framework for designing chimeric enzymes following Nature's lead, and may give useful hints for exploring the evolutionary history of proteins. (c) 2002 Elsevier Science Ltd. Recent work in computational genomics has shown that a functional association between two genes can be derived from the existence of a fusion of the two as one continuous sequence in another genome. For each of 30 completely sequenced microbial genomes, we established all such fusion links among its genes and determined the distribution of links within and among 15 broad functional categories. We found that 72% of all fusion links related genes of the same functional category. A comparison of the distribution of links to simulations on the basis of a random model further confirmed the significance of intracategory fusion links. Where a gene of annotated function is linked to an unclassified gene, the fusion link suggests that the two genes belong to the same functional category. The predictions based on fusion links are shown here for Methanobacterium thermoautotrophicum, and another 661 predictions are available at http://fusion.bu.edu. In order to understand how biological systems function it is necessary to determine the interactions and associations between proteins. Some proteins, involved in a common biological process and encoded by separate genes in one organism, can be found fused within a single protein chain in other organisms. By detecting these triplets, a functional relationship can be established between the unfused proteins. Here we use a domain fusion prediction method to predict these protein interactions for the human interactome. We observed that gene fusion events are more related to physical interaction between proteins than to other weaker functional relationships such as participation in a common biological pathway. These results suggest that domain fusion is an appropriate method for predicting protein complexes. The most reliable fused domain predictions were used to build protein-protein interaction (PPI) networks. These predicted PPI network models showed the same topological features as real biological networks and different features from random behaviour. We built the PPI domain fusion sub-network model of the human kinetochore and observed that the majority of the predicted interactions have not yet been experimentally characterised in the publicly available PPI repositories. The study of the human kinetochore domain fusion sub-network reveals undiscovered kinetochore proteins with presumably relevant functions, such as hubs with many connections in the kinetochore sub-network. These results suggest that experimentally hidden regions in the predicted PPI networks contain key functional elements, associated with important functional areas, still undiscovered in the human interactome. Until novel experiments shed light on these hidden regions; domain fusion predictions provide a valuable approach for exploring them. BACKGROUND: Genome comparisons have revealed major lateral gene transfer between the three primary kingdoms of life - Bacteria, Archaea, and Eukarya. Another important evolutionary phenomenon involves the evolutionary mobility of protein domains that form versatile multidomain architectures. We were interested in investigating the possibility of a combination of these phenomena, with an invading gene merging with a pre-existing gene in the recipient genome. RESULTS: Complete genomes of fifteen bacteria, four archaea and one eukaryote were searched for interkingdom gene fusions (IKFs); that is, genes coding for proteins that apparently consist of domains originating from different primary kingdoms. Phylogenetic analysis supported 37 cases of IKF, each of which includes a 'native' domain and a horizontally acquired 'alien' domain. IKFs could have evolved via lateral transfer of a gene coding for the alien domain (or a larger protein containing this domain) followed by recombination with a native gene. For several IKFs, this scenario is supported by the presence of a gene coding for a second, stand-alone version of the alien domain in the recipient genome. Among the genomes investigated, the greatest number of IKFs has been detected in Mycobacterium tuberculosis, where they are almost always accompanied by a stand-alone alien domain. For most of the IKF cases detected in other genomes, the stand-alone counterpart is missing. CONCLUSIONS: The results of comparative genome analysis show that IKF formation is a real, but relatively rare, evolutionary phenomenon. We hypothesize that IKFs are formed primarily via the proposed two-stage mechanism, but other than in the Actinomycetes, in which IKF generation seems to be an active, ongoing process, most of the stand-alone intermediates have been eliminated, perhaps because of functional redundancy. MOTIVATION: Gene fusion is an important evolutionary process. It can yield valuable information to infer the interactions and functions of proteins. Fused genes have been identified as non-transitive patterns of similarity in triplets of genes. To be computationally tractable, this approach usually imposes an a priori distinction between a dataset in which fused genes are searched for, and a dataset that may have provided genetic material for fusion. This reduces the 'genetic space' in which fusion can be discovered, as only a subset of triplets of genes is investigated. Moreover, this approach may have a high-false-positive rate, and it does not identify gene families descending from a common fusion event. RESULTS: We represent similarities between sequences as a network. This leads to an efficient formulation of previous methods of fused gene identification, which we implemented in the Python program FusedTriplets. Furthermore, we propose a new characterization of families of fused genes, as clique minimal separators of the sequence similarity network. This well-studied graph topology provides a robust and fast method of detection, well suited for automatic analyses of big datasets. We implemented this method in the C++ program MosaicFinder, which additionally uses local alignments to discard false-positive candidates and indicates potential fusion points. The grouping into families will help distinguish sequencing or prediction errors from real biological fusions, and it will yield additional insight into the function and history of fused genes. AVAILABILITY: FusedTriplets and MosaicFinder are published under the GPL license and are freely available with their source code at this address: http://sourceforge.net/projects/mosaicfinder. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online. We have previously shown that the detection of gene fusion events can contribute towards the elucidation of functional associations of proteins within entire genomes. Here we have analysed the entire genome of Drosophila melanogaster using fusion analysis and two additional constraints that improve the reliability of the predictions, viz. low sequence similarity and low degree of paralogy of the component proteins involved in a fusion event. Imposing these constraints, the total number of unique component pairs is reduced from 18 654 to a mere 220 cases, which are expected to represent some of the most reliably detected functionally associated proteins. Using additional information from sequence databases, we have been able to detect pairs of functionally associated proteins with important functions in cellular and developmental pathways, such as spermatogenesis and programmed cell death. One of the primary mechanisms of signal transduction in cells is protein phosphorylation. Upon ligand stimulation a series of phosphorylation events take place which eventually lead to transcription. Different sets of phosphorylation events take place due to different stimulating ligands in different types of cells. Knowledge of these phosphorylation events is essential to understand the underlying signaling mechanisms. We have developed a Bayesian framework to infer phosphorylation networks from time series measurements of phosphosite concentrations upon ligand stimulation. To increase the prediction accuracy we integrated different types of data, e.g., amino acid sequence data, genomic context data (gene fusion, gene neighborhood, and phylogentic profiles), primary experimental evidence (physical protein interactions and gene coexpression), manually curated pathway databases, and automatic literature mining with time series data in our inference framework. We compared our results with data available from public databases and report a high level of prediction accuracy. Phydbac (phylogenomic display of bacterial genes) implemented a method of phylogenomic profiling using a distance measure based on normalized BLAST scores. This method was able to increase the predictive power of phylogenomic profiling by about 25% when compared to the classical approach based on Hamming distances. Here we present a major extension of Phydbac (named here Phydbac2), that extends both the concept and the functionality of the original web-service. While phylogenomic profiles remain the central focus of Phydbac2, it now integrates chromosomal proximity and gene fusion analyses as two additional non-similarity-based indicators for inferring pairwise gene functional relationships. Moreover, all presently available (January 2004) fully sequenced bacterial genomes and those of three lower eukaryotes are now included in the profiling process, thus increasing the initial number of reference genomes (71 in Phydbac) to 150 in Phydbac2. Using the KEGG metabolic pathway database as a benchmark, we show that the predictive power of Phydbac2 is improved by 27% over the previous version. This gain is accounted for on one hand, by the increased number of reference genomes (11%) and on the other hand, as a result of including chromosomal proximity into the distance measure (16%). The expanded functionality of Phydbac2 now allows the user to query more than 50 different genomes, including at least one member of each major bacterial group, most major pathogens and potential bio-terrorism agents. The search for co-evolving genes based on consensus profiles from multiple organisms, the display of Phydbac2 profiles side by side with COG information, the inclusion of KEGG metabolic pathway maps the production of chromosomal proximity maps, and the possibility of collecting and processing results from different Phydbac queries in a common shopping cart are the main new features of Phydbac2. The Phydbac2 web server is available at http://igs-server.cnrs-mrs.fr/phydbac/. A response to Functional associations of proteins in entire genomes by means of exhaustive detection of gene fusions by AJ Enright, CA Ouzounis. Genome Biology 2000, 2:research0034.1-0034.7 BACKGROUND: Histidine biosynthesis is one of the best characterized anabolic pathways. There is a large body of genetic and biochemical information available, including operon structure, gene expression, and increasingly larger sequence databases. For over forty years this pathway has been the subject of extensive studies, mainly in Escherichia coli and Salmonella enterica, in both of which details of histidine biosynthesis appear to be identical. In these two enterobacteria the pathway is unbranched, includes a number of unusual reactions, and consists of nine intermediates; his genes are arranged in a compact operon (hisGDC [NB]HAF [IE]), with three of them (hisNB, hisD and hisIE) coding for bifunctional enzymes. We performed a detailed analysis of his gene fusions in available genomes to understand the role of gene fusions in shaping this pathway. RESULTS: The analysis of HisA structures revealed that several gene elongation events are at the root of this protein family: internal duplication have been identified by structural superposition of the modules composing the TIM-barrel protein. Several his gene fusions happened in distinct taxonomic lineages; hisNB originated within gamma-proteobacteria and after its appearance it was transferred to Campylobacter species (epsilon-proteobacteria) and to some Bacteria belonging to the CFB group. The transfer involved the entire his operon. The hisIE gene fusion was found in several taxonomic lineages and our results suggest that it probably happened several times in distinct lineages. Gene fusions involving hisIE and hisD genes (HIS4) and hisH and hisF genes (HIS7) took place in the Eukarya domain; the latter has been transferred to some delta-proteobacteria. CONCLUSION: Gene duplication is the most widely known mechanism responsible for the origin and evolution of metabolic pathways; however, several other mechanisms might concur in the process of pathway assembly and gene fusion appeared to be one of the most important and common. Functional links between proteins can often be inferred from genomic associations between the genes that encode them: groups of genes that are required for the same function tend to show similar species coverage, are often located in close proximity on the genome (in prokaryotes), and tend to be involved in gene-fusion events. The database STRING is a precomputed global resource for the exploration and analysis of these associations. Since the three types of evidence differ conceptually, and the number of predicted interactions is very large, it is essential to be able to assess and compare the significance of individual predictions. Thus, STRING contains a unique scoring-framework based on benchmarks of the different types of associations against a common reference set, integrated in a single confidence score per prediction. The graphical representation of the network of inferred, weighted protein interactions provides a high-level view of functional linkage, facilitating the analysis of modularity in biological processes. STRING is updated continuously, and currently contains 261 033 orthologs in 89 fully sequenced genomes. The database predicts functional interactions at an expected level of accuracy of at least 80% for more than half of the genes; it is online at http://www.bork.embl-heidelberg.de/STRING/. The detection of gene fusion events across genomes can be used for the prediction of functional associations of proteins, including physical interactions or complex formation. These predictions are obtained by the detection of similarity for pairs of 'component' proteins to 'composite' proteins. Since the amount of composite proteins is limited in nature, we augment this set by creating artificial fusion proteins from experimentally determined protein interacting pairs. The goal is to study the extent of protein interaction partners with increasing phylogenetic distance, using an automated method. We have thus detected component pairs within seven entire genome sequences of similar size, using artificially generated composite proteins that have been shown to interact experimentally. Our results indicate that protein interactions are not conserved over large phylogenetic distances. In addition, we provide a set of predictions for functionally associated proteins across seven species using experimental information and demonstrate the applicability of fusion analysis for the comparative genomics of protein interactions. The method described in this chapter can be used to infer putative functional links between two proteins. The basic idea is based on the principle of "guilt by association." It is assumed that two proteins, which are found to be transcribed by a single transcript in one (or several) genomes are likely to be functionally linked, for example by acting in a same metabolic pathway or by forming a multiprotein complex. This method is of particular interest for studying genes that exhibit no, or only remote, homologies with already well-characterized proteins. Combined with other non-homology based methods, gene fusion events may yield valuable information for hypothesis building on protein function, and may guide experimental characterization of the target protein, for example by suggesting potential ligands or binding partners. This chapter uses the FusionDB database (http://www.igs.cnrs-mrs.fr/FusionDB/) as source of information. FusionDB provides a characterization of a large number of gene fusion events at hand of multiple sequence alignments. Orthologous genes are included to yield a comprehensive view of the structure of a gene fusion event. Phylogenetic tree reconstruction is provided to evaluate the history of a gene fusion event, and three-dimensional protein structure information is used, where available, to further characterize the nature of the gene fusion. For genes that are not comprised in FusionDB, some instructions are given as how to generate a similar type of information, based solely on publicly available web tools that are listed here. Complex enzymes with multiple catalytic activities are hypothesized to have evolved from more primitive precursors. Global analysis of the Phytophthora sojae genome using conservative criteria for evaluation of complex proteins identified 273 novel multifunctional proteins that were also conserved in P. ramorum. Each of these proteins contains combinations of protein motifs that are not present in bacterial, plant, animal, or fungal genomes. A subset of these proteins were also identified in the two diatom genomes, but the majority of these proteins have formed after the split between diatoms and oomycetes. Documentation of multiple cases of domain fusions that are common to both oomycetes and diatom genomes lends additional support for the hypothesis that oomycetes and diatoms are monophyletic. Bifunctional proteins that catalyze two steps in a metabolic pathway can be used to infer the interaction of orthologous proteins that exist as separate entities in other genomes. We postulated that the novel multifunctional proteins of oomycetes could function as potential Rosetta Stones to identify interacting proteins of conserved metabolic and regulatory networks in other eukaryotic genomes. However ortholog analysis of each domain within our set of 273 multifunctional proteins against 39 sequenced bacterial and eukaryotic genomes, identified only 18 candidate Rosetta Stone proteins. Thus the majority of multifunctional proteins are not Rosetta Stones, but they may nonetheless be useful in identifying novel metabolic and regulatory networks in oomycetes. Phylogenetic analysis of all the enzymes in three pathways with one or more novel multifunctional proteins was conducted to determine the probable origins of individual enzymes. These analyses revealed multiple examples of horizontal transfer from both bacterial genomes and the photosynthetic endosymbiont in the ancestral genome of Stramenopiles. The complexity of the phylogenetic origins of these metabolic pathways and the paucity of Rosetta Stones relative to the total number of multifunctional proteins suggests that the proteome of oomycetes has few features in common with other Kingdoms. The complete human genome sequences in the public database provide ways to understand the blue print of life. As of June 29, 2006, 27 archaeal, 326 bacterial and 21 eukaryotes is complete genomes are available and the sequencing for 316 bacterial, 24 archaeal, 126 eukaryotic genomes are in progress. The traditional biochemical/molecular experiments can assign accurate functions for genes in these genomes. However, the process is time-consuming and costly. Despite several efforts, only 50-60 % of genes have been annotated in most completely sequenced genomes. Automated genome sequence analysis and annotation may provide ways to understand genomes. Thus, determination of protein function is one of the challenging problems of the post-genome era. This demands bioinformatics to predict functions of un-annotated protein sequences by developing efficient tools. Here, we discuss some of the recent and popular approaches developed in Bioinformatics to predict functions for hypothetical proteins. BACKGROUND: It has recently been shown that the detection of gene fusion events across genomes can be used for predicting functional associations of proteins, including physical interaction or complex formation. To obtain such predictions we have made an exhaustive search for gene fusion events within 24 available completely sequenced genomes. RESULTS: Each genome was used as a query against the remaining 23 complete genomes to detect gene fusion events. Using an improved, fully automatic protocol, a total of 7,224 single-domain proteins that are components of gene fusions in other genomes were detected, many of which were identified for the first time. The total number of predicted pairwise functional associations is 39,730 for all genomes. Component pairs were identified by virtue of their similarity to 2,365 multidomain composite proteins. We also show for the first time that gene fusion is a complex evolutionary process with a number of contributory factors, including paralogy, genome size and phylogenetic distance. On average, 9% of genes in a given genome appear to code for single-domain, component proteins predicted to be functionally associated. These proteins are detected by an additional 4% of genes that code for fused, composite proteins. CONCLUSIONS: These results provide an exhaustive set of functionally associated genes and also delineate the power of fusion analysis for the prediction of protein interactions. A large-scale effort to measure, detect and analyse protein-protein interactions using experimental methods is under way. These include biochemistry such as co-immunoprecipitation or crosslinking, molecular biology such as the two-hybrid system or phage display, and genetics such as unlinked noncomplementing mutant detection. Using the two-hybrid system, an international effort to analyse the complete yeast genome is in progress. Evidently, all these approaches are tedious, labour intensive and inaccurate. From a computational perspective, the question is how can we predict that two proteins interact from structure or sequence alone. Here we present a method that identifies gene-fusion events in complete genomes, solely based on sequence comparison. Because there must be selective pressure for certain genes to be fused over the course of evolution, we are able to predict functional associations of proteins. We show that 215 genes or proteins in the complete genomes of Escherichia coli, Haemophilus influenzae and Methanococcus jannaschii are involved in 64 unique fusion events. The approach is general, and can be applied even to genes of unknown function. BACKGROUND: Existing large-scale metabolic models of sequenced organisms commonly include enzymatic functions which can not be attributed to any gene in that organism. Existing computational strategies for identifying such missing genes rely primarily on sequence homology to known enzyme-encoding genes. RESULTS: We present a novel method for identifying genes encoding for a specific metabolic function based on a local structure of metabolic network and multiple types of functional association evidence, including clustering of genes on the chromosome, similarity of phylogenetic profiles, gene expression, protein fusion events and others. Using E. coli and S. cerevisiae metabolic networks, we illustrate predictive ability of each individual type of association evidence and show that significantly better predictions can be obtained based on the combination of all data. In this way our method is able to predict 60% of enzyme-encoding genes of E. coli metabolism within the top 10 (out of 3551) candidates for their enzymatic function, and as a top candidate within 43% of the cases. CONCLUSION: We illustrate that a combination of genome context and other functional association evidence is effective in predicting genes encoding metabolic enzymes. Our approach does not rely on direct sequence homology to known enzyme-encoding genes, and can be used in conjunction with traditional homology-based metabolic reconstruction methods. The method can also be used to target orphan metabolic activities. More than a decade ago, a number of methods were proposed for the inference of protein interactions, using whole-genome information from gene clusters, gene fusions and phylogenetic profiles. This structural and evolutionary view of entire genomes has provided a valuable approach for the functional characterization of proteins, especially those without sequence similarity to proteins of known function. Furthermore, this view has raised the real possibility to detect functional associations of genes and their corresponding proteins for any entire genome sequence. Yet, despite these exciting developments, there have been relatively few cases of real use of these methods outside the computational biology field, as reflected from citation analysis. These methods have the potential to be used in high-throughput experimental settings in functional genomics and proteomics to validate results with very high accuracy and good coverage. In this critical survey, we provide a comprehensive overview of 30 most prominent examples of single pairwise protein interaction cases in small-scale studies, where protein interactions have either been detected by gene fusion or yielded additional, corroborating evidence from biochemical observations. Our conclusion is that with the derivation of a validated gold-standard corpus and better data integration with big experiments, gene fusion detection can truly become a valuable tool for large-scale experimental biology.

The protein NONO forms heterodimers. With which proteins?

The protein NONO forms heterodimers with PSPC1, SFPQ.

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The methodology of protein crystallography provides a number of potential bottlenecks. Here, an approach to successful structure solution of a difficult heterodimeric complex of two human proteins, paraspeckle component 1 (PSPC1) and non-POU domain-containing octamer-binding protein (NONO), that are involved in gene regulation and the structural integrity of nuclear bodies termed paraspeckles is described. With the aid of bioinformatic predictions and systematic screening of a panel of constructs, bottlenecks of protein solubility, crystallization, crystal quality and crystallographic pseudosymmetry were overcome in order to produce crystals that ultimately revealed the structure. The progesterone receptor (PR) plays important roles in the establishment and maintenance of pregnancy. By dynamic interactions with coregulators, PR represses the expression of genes that increase the contractile activity of myometrium and contribute to the initiation of labor. We have previously shown that PTB-associated RNA splicing factor (PSF) can function as a PR corepressor. In this report, we demonstrated that the PSF heterodimer partner, p54nrb (non-POU-domain-containing, octamer binding protein), can also function as a transcription corepressor, independent of PSF. p54nrb Interacts directly with PR independent of progesterone. In contrast to PSF, p54nrb neither enhances PR protein degradation nor blocks PR binding to DNA. Rather, p54nrb recruits mSin3A through its N terminus to the PR-DNA complex, resulting in an inhibition of PR-mediated transactivation of the progesterone-response element-luciferase reporter gene. PR also repressed transcription of the connexin 43 gene (Gja1), an effect dependent on the presence of an activator protein 1 site within the proximal Gja1 promoter. Mutation of this site abolished PR-mediated repression and decreased the recruitment of PR and p54nrb onto the Gja1 promoter. Furthermore, knockdown p54nrb expression by small interfering RNA alleviated PR-mediated repression on Gja1 transcription, whereas overexpression of p54nrb enhanced it. In the physiological context of pregnancy, p54nrb protein levels decrease with the approach of labor in the rat myometrium. We conclude that p54nrb is a transcriptional corepressor of PR. Decreased expression of p54nrb at the time of labor may act to derepress PR-mediated inhibition on connexin 43 expression and contribute to the initiation of labor. P54nrb is a protein implicated in multiple nuclear processes whose specific functions may correlate with its presence at different nuclear locations. Here we characterize paraspeckles, a subnuclear domain containing p54nrb and other RNA-binding proteins including PSP1, a protein with sequence similarity to p54nrb that acts as a marker for paraspeckles. We show that PSP1 interacts in vivo with a subset of the total cellular pool of p54nrb. We map the domain within PSP1 that is mediating this interaction and show it is required for the correct localization of PSP1 to paraspeckles. This interaction is necessary but not sufficient for paraspeckle targeting by PSP1, which also requires an RRM capable of RNA binding. Blocking the reinitiation of RNA Pol II transcription at the end of mitosis with DRB prevents paraspeckle formation, which recommences after removal of DRB, indicating that paraspeckle formation is dependent on RNA Polymerase II transcription. Thus paraspeckles are the sites where a subset of the total cellular pool of p54nrb is targeted in a RNA Polymerase II-dependent manner. The paraspeckle component 1 (PSPC1) and non-POU-domain-containing octamer-binding protein (NONO) heterodimer is an essential structural component of paraspeckles, ribonucleoprotein bodies found in the interchromatin space of mammalian cell nuclei. PSPC1 and NONO both belong to the Drosophila behaviour and human splicing (DBHS) protein family, which has been implicated in many aspects of RNA processing. A heterodimer of the core DBHS conserved region of PSPC1 and NONO comprising two tandemly arranged RNA-recognition motifs (RRMs), a NONA/paraspeckle (NOPS) domain and part of a predicted coiled-coil domain has been crystallized in space group C2, with unit-cell parameters a = 90.90, b = 67.18, c = 94.08 Å, β = 99.96°. The crystal contained one heterodimer in the asymmetric unit and diffracted to 1.9 Å resolution using synchrotron radiation. RNF43 is an oncogenic RING finger protein overexpressed in colorectal cancer. To dissect its biological functions, we explored RNF43-interacting proteins by pull-down assay and MS. We identified a heterodimer, p54nrb and PSF, as RNF43's binding partners and confirmed their physical interaction in vivo by the co-immunoprecipitation experiment. Immunofluorescence analysis revealed that co-expression of PSF relocates RNF43 from the nuclear periphery to the nucleoplasm. Thus, proteomic identification of RNF43-associated proteins sheds light on its dynamic interaction network in nuclear events. Proteins of the Drosophila behavior/human splicing (DBHS) family include mammalian SFPQ (PSF), NONO (p54nrb), PSPC1, and invertebrate NONA and Hrp65. DBHS proteins are predominately nuclear, and are involved in transcriptional and posttranscriptional gene regulatory functions as well as DNA repair. DBHS proteins influence a wide gamut of biological processes, including the regulation of circadian rhythm, carcinogenesis, and progression of cancer. Additionally, mammalian DBHS proteins associate with the architectural long noncoding RNA NEAT1 (Menε/β) to form paraspeckles, subnuclear bodies that alter gene expression via the nuclear retention of RNA. Here we describe the crystal structure of the heterodimer of the multidomain conserved region of the DBHS proteins, PSPC1 and NONO. These proteins form an extensively intertwined dimer, consistent with the observation that the different DBHS proteins are typically copurified from mammalian cells, and suggesting that they act as obligate heterodimers. The PSPC1/NONO heterodimer has a right-handed antiparallel coiled-coil that positions two of four RNA recognition motif domains in an unprecedented arrangement on either side of a 20-Å channel. This configuration is supported by a protein:protein interaction involving the NONA/paraspeckle domain, which is characteristic of the DBHS family. By examining various mutants and truncations in cell culture, we find that DBHS proteins require an additional antiparallel coiled-coil emanating from either end of the dimer for paraspeckle subnuclear body formation. These results suggest that paraspeckles may potentially form through self-association of DBHS dimers into higher-order structures.

Are proteasome inhibitors good candidates for treatment of leukemia and solid tumors?

Yes, several compounds that inhibit different members of the proteasome pathway (for example Bortezomib) are on trial for treatment of leukemia and solid tumors. It seems that a combination with other drugs may be a useful therapy for solid tumors.

[20160034, 22057347, 19712963, 15169797, 23181572, 12171876, 22134540, 19821999, 23477519, 22353937, 16135477, 22012631, 17145882, 17431003, 22995770, 20219102]

Ubiquitin-tagged substrates are degraded by the 26S proteasome, which is a multisubunit complex comprising a proteolytic 20S core particle capped by 19S regulatory particles. The approval of bortezomib for the treatment of multiple myeloma validated the 20S core particle as an anticancer drug target. Here we describe the small molecule b-AP15 as a previously unidentified class of proteasome inhibitor that abrogates the deubiquitinating activity of the 19S regulatory particle. b-AP15 inhibited the activity of two 19S regulatory-particle-associated deubiquitinases, ubiquitin C-terminal hydrolase 5 (UCHL5) and ubiquitin-specific peptidase 14 (USP14), resulting in accumulation of polyubiquitin. b-AP15 induced tumor cell apoptosis that was insensitive to TP53 status and overexpression of the apoptosis inhibitor BCL2. We show that treatment with b-AP15 inhibited tumor progression in four different in vivo solid tumor models and inhibited organ infiltration in an acute myeloid leukemia model. Our results show that the deubiquitinating activity of the 19S regulatory particle is a new anticancer drug target. OBJECTIVE: To determine the activity and pharmacodynamics (PD) of bortezomib in platinum-sensitive epithelial ovarian or primary peritoneal cancer (EOC/PPC). PATIENTS AND METHODS: Eligible women with recurrent EOC/PPC progressing between 6 and 12 months after initial chemotherapy were treated with bortezomib on days 1, 4, 8, and 11 [1.5 (cohort I) and 1.3 (cohort II) mg/m(2)/dose]. Patients must have had initial chemotherapy only. Response Evaluation Criteria in Solid Tumors (RECIST) was assessed by computed tomography (CT) scan every 2 cycles. 20S proteasome activity was quantified in three pre-treatment and a 1-hour post-treatment (cycle one, day 1) whole blood lysates. RESULTS: Initially, 26 evaluable patients were treated at the 1.5 mg/m(2)/dose level. Objective response rate was 3.8% (1/26), a partial response. An additional 10 patients (38.5%) had stable disease. Given concerns that treatment discontinuations due to toxicity limited drug exposure/activity a second cohort of 29 evaluable patients was accrued at 1.3 mg/m(2)/dose. The 1.3 mg/m(2)/dose regimen is currently approved as an indication for multiple myeloma and mantle cell lymphoma. Treatment was more tolerable, although objective responses remained low at 6.9% (2/29, partial responses). Second stage accrual was not warranted at either dose. Bortezomib effectively inhibited 20S proteasome activity in whole blood lysates between 37 and 92% in 24/25 (96%) patients in cohort I, and 14-84% in 27/28 (96%) patients in cohort II who provided satisfactory pre- and post-treatment specimens for testing. CONCLUSION: Bortezomib has minimal activity as a single-agent in the treatment of recurrent platinum-sensitive EOC/PPC. Treatment with bortezomib at 1.5 mg/m(2)/dose was not feasible in this patient population due to excess toxicity. Bortezomib was well tolerated at 1.3 mg/m(2)/dose. INTRODUCTION: Proteasome inhibition provides an attractive approach to cancer therapy and may have application in the treatment of breast cancer. However, results of recent clinical trials to evaluate the effect of the proteasome inhibitor Bortezomib (Velcade, also called PS-341) in metastatic breast cancer patients have shown limited activity when used as a single agent. This underscores the need to find new and more efficacious proteasome inhibitors. In this study, we evaluate the efficacy of the novel proteasome inhibitor BU-32 (NSC D750499-S) using in vitro and in vivo breast cancer models. METHODS: We have recently synthesized a novel proteasome inhibitor (BU-32) and tested its growth inhibitory effects in different breast cancer cells including MCF-7, MDA-MB-231, and SKBR3 by in vitro cytotoxicity and proteasomal inhibition assays. The apoptotic potential of BU32 was tested using flow cytometry and analyzing cell cycle regulatory proteins. In vivo tumor xenograft studies for solid tumor as well as tumor metastasis were conducted using MDA-MB-231-GFP cells. RESULTS: We report for the first time that BU-32 exhibits strong cytotoxicity in a panel of cell lines: MDA-MB-231 (IC50 = 5.8 nM), SKBR3 (IC50 = 5.7 nM) and MCF-7 cells (IC50 = 5.8 nM). It downregulates a wide array of angiogenic marker genes and upregulates apoptotic markers, including Bid and Bax. Incubation of MDA-MB-231 cells with BU-32 results in the accumulation of cell cycle inhibitor proteins p21 and p27 and stabilization of the tumor suppressor protein p53. Studies in in vivo solid tumor and metastasis models show significant effect with a 0.06 mg/kg dose of BU-32 and marked reduction in tumor burden in the skeleton. CONCLUSIONS: We have shown that BU-32 is effective in cultured breast cancer cells and in breast cancer xenografts. The results suggest its potential benefit in breast cancer treatment. Proteasome inhibition has been recognized as a novel treatment modality in hematologic malignancies. Initially, the reversible proteasome inhibitor bortezomib demonstrated efficacy in multiple myeloma (MM), which supported its approval for relapsed and refractory MM in 2003. Later on, carfilzomib, a next-generation irreversible proteasome inhibitor was approved by the US FDA in July 2012 for relapsed/refractory MM. Currently, several other proteasome inhibitors are undergoing preclinical and clinical evaluation. The successes of proteasome inhibitors in MM are now being translated to other hematologic malignancies, including acute leukemia. The first clinical studies with bortezomib in leukemia revealed promising clinical activity, particularly when combined with conventional chemotherapeutics. In this review the position of proteasome inhibitors in acute leukemia treatment is summarized and discussed. Special focus is also attributed to immunoproteasome inhibitors. As a future perspective, it is anticipated that proteasome inhibitors may prove to be of added value in therapeutic interventions for acute leukemia. Bortezomib is well-known for inducing cell death in cancer cells, specifically through the mechanism of proteasome inhibition. Thiostrepton, a thiazole antibiotic, has also been described for its proteasome inhibitory action, although differing slightly to bortezomib in the proteasomal site to which it is active. Previously we had shown the synergic effect of bortezomib and thiostrepton in breast cancer cells in vitro, where sub-apoptotic concentrations of both proteasome inhibitors resulted in synergic increase in cell death when combined as a treatment. Here, we administered such a combination to MDA-MB-231 xenograft tumors in vivo, and found that the effect of complementary proteasome inhibitors reduced tumor growth rates more efficiently than compared with when administered alone. Increased induction of apoptotic activity in tumors was found be associated with the growth inhibitory activity of combination treatment. Further examination additionally revealed that combination-treated tumors exhibited reduced proteasome activity, compared with non-treated and single drug-treated tumors. These data suggest that this drug combination may be useful as a therapy for solid tumors. PURPOSE: We performed a phase I study of a day (D) 1 and D4 bortezomib administration once every 2 weeks to determine the recommended phase II dose and toxicity profile, and the extent of 20S proteasome inhibition obtained. PATIENTS AND METHODS: Patients with solid tumors or lymphomas were treated with bortezomib at 0.25 to 1.9 mg/m2 on D1 and D4, every 2 weeks. 20S proteasome levels in blood were assayed at baseline and at 1, 4, and 24 hours postdose in cycle 1. RESULTS: On this D1 and D4 every 2 weeks' schedule, dose-limiting toxicity (DLT) was evident at the 1.75 and 1.9 mg/m2 dose levels, most commonly in patients receiving individual total doses > or = 3.0 mg. The main DLT was peripheral neuropathy evident at the higher doses and in patients previously exposed to neurotoxic agents. Other DLTs included diarrhea and fatigue; grade 3 thrombocytopenia was also noted. Reversible inhibition of 20S proteasome activity was dose dependent and best fit a total dose (mg) per fraction rather than mg/m2; 70% of baseline activity was inhibited by a dose of 3.0 to 3.5 mg given on D1 and on D4 every other week. Antitumor effects short of confirmed partial responses were observed in patients with melanoma, non-small-cell lung cancer, and renal cell carcinoma. CONCLUSION: Bortezomib (PS-341) is a novel antineoplastic agent that is well tolerated at doses not exceeding 3.0 mg (equivalent to 1.75 mg/m2), repeated on D1 and D4 every other week. This dose correlates with 70% inhibition of 20S proteasome activity. DLTs include neuropathy, fatigue, and diarrhea. The proteasome inhibitor bortezomib has shown remarkable clinical success in the treatment of multiple myeloma. However, the efficacy and mechanism of action of bortezomib in solid tumor malignancies is less well understood. In addition, the use of this first-in-class proteasome inhibitor is limited by several factors, including off-target effects that lead to adverse toxicities. We recently reported the impact and mechanisms of carfilzomib and oprozomib, second-in-class proteasome inhibitors with higher specificities and reduced toxicities, against head and neck squamous cell carcinoma (HNSCC). Carfilzomib and oprozomib potently inhibit HNSCC cell survival and the growth of HNSCC tumors. Both compounds promote upregulation of proapoptotic BIK and antiapoptotic MCL1, which serves to mediate and attenuate, respectively, the killing activities of these proteasome inhibitors. Both compounds also induce complete autophagic flux that is partially dependent on activation of the unfolded protein response (UPR) and upregulation of ATF4. Carfilzomib- and oprozomib-induced autophagy acts to promote HNSCC cell survival. Our study indicates that the therapeutic benefit of these promising proteasome inhibitors may be improved by inhibiting MCL1 expression or autophagy. BACKGROUND: We have previously shown that nuclear factor (NF)-kappaB activation of mouse Lewis lung carcinoma (LLC) specifically promotes the induction of malignant pleural effusions (MPE) by these cells. In the present studies we hypothesized that treatment of immunocompetent mice with bortezomib tailored to inhibit cancer cell NF-kappaB activation and not proliferation specifically inhibits MPE formation by LLC cells. RESULTS: Treatment of LLC cells with low concentrations of bortezomib (100 ng/ml) inhibited NF-kappaB activation and NF-kappaB-dependent transcription, but not cellular proliferation. Bortezomib treatment of immunocompetent C57BL/6 mice bearing LLC-induced subcutaneous tumors and MPEs significantly blocked tumor-specific NF-kappaB activation. However, bortezomib treatment did not impair subcutaneous LLC tumor growth, but was effective in limiting LLC-induced MPE. This specific effect was evidenced by significant reductions in effusion accumulation and the associated mortality and was observed with both preventive (beginning before MPE formation) and therapeutic (beginning after MPE establishment) bortezomib treatment. The favorable impact of bortezomib on MPE was associated with suppression of cardinal MPE-associated phenomena, such as inflammation, vascular hyperpermeability, and angiogenesis. In this regard, therapeutic bortezomib treatment had identical favorable results on MPE compared with preventive treatment, indicating that the drug specifically counteracts effusion formation. CONCLUSIONS: These studies indicate that proteasome inhibition tailored to block NF-kappaB activation of lung adenocarcinoma specifically targets the effusion-inducing phenotype of this tumor. Although the drug has limited activity against advanced solid lung cancer, it may prove beneficial for patients with MPE.

Is there any link between CTF4 and CTF18 during sister chromatid cohesion?

Yes. CTF4 and CTF18 are required for high-fidelity chromosome segregation. Both exhibit genetic and physical ties to replication fork constituents. Absence of either CTF4 or CTF18 causes sister chromatid cohesion failure and leads to a preanaphase accumulation of cells that depends on the spindle assembly checkpoint. The physical and genetic interactions between CTF4, CTF18, and core components of replication fork complexes suggest that both gene products act in association with the replication fork to facilitate sister chromatid cohesion.

[19430531, 11287619, 23036200, 15226378, 23334284, 16962805, 17483413, 14742714]

Mutations in the ELG1 gene of yeast lead to genomic instability, manifested in high levels of genetic recombination, chromosome loss, and gross chromosomal rearrangements. Elg1 shows similarity to the large subunit of the Replication Factor C clamp loader, and forms a RFC-like (RLC) complex in conjunction with the 4 small RFC subunits. Two additional RLCs exist in yeast: in one of them the large subunit is Ctf18, and in the other, Rad24. Ctf18 has been characterized as the RLC that functions in sister chromatid cohesion. Here we present evidence that the Elg1 RLC (but not Rad24) also plays an important role in this process. A genetic screen identified the cohesin subunit Mcd1/Scc1 and its loader Scc2 as suppressors of the synthetic lethality between elg1 and ctf4. We describe genetic interactions between ELG1 and genes encoding cohesin subunits and their accessory proteins. We also show that defects in Elg1 lead to higher precocious sister chromatid separation, and that Ctf18 and Elg1 affect cohesion via a joint pathway. Finally, we localize both Ctf18 and Elg1 to chromatin and show that Elg1 plays a role in the recruitment of Ctf18. Our results suggest that Elg1, Ctf4, and Ctf18 may coordinate the relative movement of the replication fork with respect to the cohesin ring. CTF4 and CTF18 are required for high-fidelity chromosome segregation. Both exhibit genetic and physical ties to replication fork constituents. We find that absence of either CTF4 or CTF18 causes sister chromatid cohesion failure and leads to a preanaphase accumulation of cells that depends on the spindle assembly checkpoint. The physical and genetic interactions between CTF4, CTF18, and core components of replication fork complexes observed in this study and others suggest that both gene products act in association with the replication fork to facilitate sister chromatid cohesion. We find that Ctf18p, an RFC1-like protein, directly interacts with Rfc2p, Rfc3p, Rfc4p, and Rfc5p. However, Ctf18p is not a component of biochemically purified proliferating cell nuclear antigen loading RF-C, suggesting the presence of a discrete complex containing Ctf18p, Rfc2p, Rfc3p, Rfc4p, and Rfc5p. Recent identification and characterization of the budding yeast polymerase kappa, encoded by TRF4, strongly supports a hypothesis that the DNA replication machinery is required for proper sister chromatid cohesion. Analogous to the polymerase switching role of the bacterial and human RF-C complexes, we propose that budding yeast RF-C(CTF18) may be involved in a polymerase switch event that facilities sister chromatid cohesion. The requirement for CTF4 and CTF18 in robust cohesion identifies novel roles for replication accessory proteins in this process. Cohesion between sister chromatids mediated by a multisubunit complex called cohesin is established during DNA replication and is essential for the orderly segregation of chromatids during anaphase. In budding yeast, a specialized replication factor C called RF-C(Ctf18/Dcc1/Ctf8) and the DNA-polymerase-alpha-associated protein Ctf4 are required to maintain sister-chromatid cohesion in cells arrested for long periods in mitosis. We show here that CTF8, CTF4 and a helicase encoded by CHL1 are required for efficient sister chromatid cohesion in unperturbed mitotic cells, and provide evidence that Chl1 functions during S-phase. We also show that, in contrast to mitosis, RF-C(Ctf18/Dcc1/Cft8), Ctf4 and Chl1 are essential for chromosome segregation during meiosis and for the viability of meiotic products. Our finding that cells deleted for CTF8, CTF4 or CHL1 undergo massive meiosis II non-disjunction suggests that the second meiotic division is particularly sensitive to cohesion defects. Using a functional as well as a cytological assay, we demonstrate that CTF8, CHL1 and CTF4 are essential for cohesion between sister centromeres during meiosis but dispensable for cohesin's association with centromeric DNA. Our finding that mutants in fission yeast ctf18 and dcc1 have similar defects suggests that the involvement of the alternative RF-C(Ctf18/Dcc1/Ctf8) complex in sister chromatid cohesion might be highly conserved. Cohesion between sister chromatids, mediated by the chromosomal cohesin complex, is a prerequisite for their alignment on the spindle apparatus and segregation in mitosis. Budding yeast cohesin first associates with chromosomes in G1. Then, during DNA replication in S-phase, the replication fork-associated acetyltransferase Eco1 acetylates the cohesin subunit Smc3 to make cohesin's DNA binding resistant to destabilization by the Wapl protein. Whether stabilization of cohesin molecules that happen to link sister chromatids is sufficient to build sister chromatid cohesion, or whether additional reactions are required to establish these links, is not known. In addition to Eco1, several other factors contribute to cohesion establishment, including Ctf4, Ctf18, Tof1, Csm3, Chl1 and Mrc1, but little is known about their roles. Here, we show that each of these factors facilitates cohesin acetylation. Moreover, the absence of Ctf4 and Chl1, but not of the other factors, causes a synthetic growth defect in cells lacking Eco1. Distinct from acetylation defects, sister chromatid cohesion in ctf4Δ and chl1Δ cells is not improved by removing Wapl. Unlike previously thought, we do not find evidence for a role of Ctf4 and Chl1 in Okazaki fragment processing, or of Okazaki fragment processing in sister chromatid cohesion. Thus, Ctf4 and Chl1 delineate an additional acetylation-independent pathway that might hold important clues as to the mechanism of sister chromatid cohesion establishment. Two identical sister copies of eukaryotic chromosomes are synthesized during S phase. To facilitate their recognition as pairs for segregation in mitosis, sister chromatids are held together from their synthesis onward by the chromosomal cohesin complex. Replication fork progression is thought to be coupled to establishment of sister chromatid cohesion, facilitating identification of replication products, but evidence for this has remained circumstantial. Here we show that three proteins required for sister chromatid cohesion, Eco1, Ctf4, and Ctf18, are found at, and Ctf4 travels along chromosomes with, replication forks. The ring-shaped cohesin complex is loaded onto chromosomes before S phase in an ATP hydrolysis-dependent reaction. Cohesion establishment during DNA replication follows without further cohesin recruitment and without need for cohesin to re-engage an ATP hydrolysis motif that is critical for its initial DNA binding. This provides evidence for cohesion establishment in the context of replication forks and imposes constraints on the mechanism involved. Sister-chromatid cohesion, the process of pairing replicated chromosomes during mitosis and meiosis, is mediated through the essential cohesin complex and a number of nonessential cohesion genes, but the specific roles of these nonessential genes in sister-chromatid cohesion remain to be clarified. We analyzed sister-chromatid cohesion in double mutants of mrc1Delta, tof1Delta, and csm3Delta and identified additive cohesion defects that indicated the existence of at least two pathways that contribute to sister-chromatid cohesion. To understand the relationship of other nonessential cohesion genes with respect to these two pathways, pairwise combinations of deletion and temperature-sensitive alleles were tested for cohesion defects. These data defined two cohesion pathways, one containing CSM3, TOF1, CTF4, and CHL1, and the second containing MRC1, CTF18, CTF8, and DCC1. Furthermore, we found that the nonessential genes are not important for the maintenance of cohesion at G(2)/M. Thus, our data suggest that nonessential cohesion genes make critical redundant contributions to the establishment of sister-chromatid cohesion and define two cohesion pathways, thereby establishing a framework for understanding the role of nonessential genes in sister-chromatid cohesion. Ctf8p is a component of Ctf18-RFC, an alternative replication factor C-like complex required for efficient sister chromatid cohesion in Saccharomyces cerevisiae. We performed synthetic genetic array (SGA) analysis with a ctf8 deletion strain as a primary screen to identify other nonessential genes required for efficient sister chromatid cohesion. We then assessed proficiency of cohesion at three chromosomal loci in strains containing deletions of the genes identified in the ctf8 SGA screen. Deletion of seven genes (CHL1, CSM3, BIM1, KAR3, TOF1, CTF4, and VIK1) resulted in defective sister chromatid cohesion. Mass spectrometric analysis of immunoprecipitated complexes identified a physical association between Kar3p and Vik1p and an interaction between Csm3p and Tof1p that we confirmed by coimmunoprecipitation from cell extracts. These data indicate that synthetic genetic array analysis coupled with specific secondary screens can effectively identify protein complexes functionally related to a reference gene. Furthermore, we find that genes involved in mitotic spindle integrity and positioning have a previously unrecognized role in sister chromatid cohesion.

What is the target of the drug Olaparib?

The drug Olaparib target the protein poly(ADP-ribose) polymerase.

[25275045, 25218906, 25128455, 25526472, 25374341, 25417706, 25144364, 25221646, 25302833, 25120693, 25366685, 25531448, 25139258, 25127709, 25483710, 25481791]

BACKGROUND: Olaparib is a poly(ADP-ribose) polymerase inhibitor and cediranib is an anti-angiogenic agent with activity against VEGF receptor (VEGFR) 1, VEGFR2, and VEGFR3. Both oral agents have antitumour activity in women with recurrent ovarian cancer, and their combination was active and had manageable toxicities in a phase 1 trial. We investigated whether this combination could improve progression-free survival (PFS) compared with olaparib monotherapy in women with recurrent platinum-sensitive ovarian cancer. METHODS: In our randomised, open-label, phase 2 study, we recruited women (aged ≥18 years) who had measurable platinum-sensitive, relapsed, high-grade serous or endometrioid ovarian, fallopian tube, or primary peritoneal cancer, or those with deleterious germline BRCA1/2 mutations from nine participating US academic medical centres. We randomly allocated participants (1:1) according to permuted blocks, stratified by germline BRCA status and previous anti-angiogenic therapy, to receive olaparib capsules 400 mg twice daily or the combination at the recommended phase 2 dose of cediranib 30 mg daily and olaparib capsules 200 mg twice daily. The primary endpoint was progression-free survival analysed in the intention-to-treat population. The phase 2 trial is no longer accruing patients. An interim analysis was conducted in November, 2013, after 50% of expected events had occurred and efficacy results were unmasked. The primary analysis was performed on March 31, 2014, after 47 events (66% of those expected). The trial is registered with ClinicalTrials.gov, number NCT01116648. FINDINGS: Between Oct 26, 2011, and June 3, 2013, we randomly allocated 46 women to receive olaparib alone and 44 to receive the combination of olaparib and cediranib. Median PFS was 17·7 months (95% CI 14·7-not reached) for the women treated with cediranib plus olaparib compared with 9·0 months (95% CI 5·7-16·5) for those treated with olaparib monotherapy (hazard ratio 0·42, 95% CI 0·23-0·76; p=0·005). Grade 3 and 4 adverse events were more common with combination therapy than with monotherapy, including fatigue (12 patients in the cediranib plus olaparib group vs five patients in the olaparib monotherapy group), diarrhoea (ten vs none), and hypertension (18 vs none). INTERPRETATION: Cediranib plus olaparib seems to improve PFS in women with recurrent platinum-sensitive high-grade serous or endometrioid ovarian cancer, and warrants study in a phase 3 trial. The side-effect profile suggests such investigations should include assessments of quality of life and patient-reported outcomes to understand the effects of a continuing oral regimen with that of intermittent chemotherapy. FUNDING: American Recovery and Reinvestment Act grant from the National Institutes of Health (NIH) (3 U01 CA062490-16S2); Intramural Program of the Center for Cancer Research; and the Division of Cancer Treatment and Diagnosis, National Cancer Institute, NIH. BACKGROUND: Preclinical studies have documented antitumor activity of PARP inhibition both in vitro and in vivo, against Ewing sarcoma cells. This study aimed to translate that observation into a clinical trial to assess the efficacy and tolerability of olaparib, a PARP inhibitor, in patients with advanced Ewing sarcoma (EWS) progressing after prior chemotherapy. METHODS: In this nonrandomized phase II trial, adult participants with radiographically measureable metastatic EWS received olaparib tablets, 400 mg orally twice daily, until disease progression or drug intolerance. Tumor measurements were determined by CT or MRI at 6 and 12 weeks after starting olaparib administration, and then every 8 weeks thereafter. Tumor response determinations were made according to RECIST 1.1, and adverse event determinations were made according to CTCAE, version 4.0. A total of 22 participants were planned to be enrolled using a conventional 2-step phase II study design. If no objective responses were observed after 12 participants had been followed for at least 3 months, further accrual would be stopped. RESULTS: 12 participants were enrolled, and all were evaluable. There were no objective responses (PR/CR), 4 SD (duration 10.9, 11.4, 11.9, and 17.9 wks), and 8 PD as best response. Of the SD, 2 had minor responses (-9% and -11.7% by RECIST 1.1). The median time to disease progression was 5.7 weeks. Further enrollment was therefore discontinued. No significant or unexpected toxicities were observed with olaparib, with only a single case each of grade 3 anemia and grade 3 thrombocytopenia observed. CONCLUSIONS: This study is the first report of a prospective phase II trial to evaluate the safety and efficacy of a PARP inhibitor in patients with advanced Ewing sarcoma after failure of standard chemotherapy. Olaparib administration was safe and well tolerated when administered to this small heavily pre-treated cohort at the 400 mg BID dose, although the median duration of dosing was for only 5.7 weeks. No significant responses or durable disease control was seen, and the short average interval to disease progression underscores the aggressiveness of this disease. Other studies to combine cytotoxic chemotherapy with PARP inhibition in EWS are actively ongoing. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01583543. Piperlongumine is a naturally-occurring small molecule with various biological activities. Recent studies demonstrate that piperlongumine selectively kills various types of transformed cells with minimal toxicity to non-transformed cells by inducing a high level of reactive oxygen species (ROS). ROS generates various types of DNA lesions, including base modifications and single strand breaks. In order to examine the contribution of ROS-induced DNA damage to the cytotoxicity by piperlongumine, various DNA repair-deficient chicken DT40 cell-lines with a single DNA repair gene deletion were tested for cellular sensitivity to piperlongumine. The results showed that cell lines defective in homologous recombination (HR) display hyper-sensitivity to piperlongumine, while other cell lines with a deficiency in non-homologous end joining (NHEJ), base excision repair (BER), nucleotide excision repair (NER), Fanconi anemia (FA) pathway, or translesion DNA synthesis (TLS) polymerases, show no sensitivity to piperlongumine. The results strongly implicate that double strand breaks (DSBs) generated by piperlongumine are major cytotoxic DNA lesions. Furthermore, a deletion of 53BP1 or Ku70 in the BRCA1-deficient cell line restored cellular resistance to piperlongumine. This strongly supports the idea that piperlongumine induces DSB- mediated cell death. Interestingly, piperlongumine makes the wild type DT40 cell line hypersensitive to a PARP-inhibitor, Olaparib. The results implicate that piperlongumine inhibits HR. Further analysis with cell-based HR assay and the kinetic study of Rad51 foci formation confirmed that piperlongumine suppresses HR activity. Altogether, we revealed novel mechanisms of piperlongumine-induced cytotoxicity. Non-small cell lung cancer (NSCLC) is the main cause of cancer-related death worldwide and new therapeutic strategies are urgently needed. In this study, we have characterized a panel of NSC lung cancer cell lines for the expression of coiled-coil-domain containing 6 (CCDC6), a tumor suppressor gene involved in apoptosis and DNA damage response. We show that low CCDC6 protein levels are associated with a weak response to DNA damage and a low number of Rad51 positive foci. Moreover, CCDC6 deficient lung cancer cells show defects in DNA repair via homologous recombination. In accordance with its role in the DNA damage response, CCDC6 attenuation confers resistance to cisplatinum, the current treatment of choice for NSCLC, but sensitizes the cells to olaparib, a small molecule inhibitor of the repair enzymes PARP1/2. Remarkably, the combination of the two drugs is more effective than each agent individually, as demonstrated by a combination index <1. Finally, CCDC6 is expressed at low levels in about 30% of the NSCL tumors we analyzed by TMA immunostaining. The weak CCDC6 protein staining is significatively correlated with the presence of lymph node metastasis (p ≤ 0.02) and negatively correlated to the disease free survival (p ≤ 0.01) and the overall survival (p ≤ 0.05). Collectively, the data indicate that CCDC6 levels provide valuable insight for OS. CCDC6 could represent a predictive biomarker of resistance to conventional single mode therapy and yield insight on tumor sensitivity to PARP inhibitors in NSCLC. Single nucleotide polymorphisms (SNPs) are associated with the development of certain types of cancer. The present study aimed to investigate the association between X-ray repair complementing defective repair in Chinese hamster cells 2 (XRCC2) SNPs and colorectal cancer (CRC) cell sensitivity to the poly(ADP-ribose) polymerase (PARP) 1 inhibitor olaparib (AZD2281). SNaPshot® analysis of XRCC2 SNPs was performed in five CRC cell lines. The AZD2281-sensitivities of the CRC cells were also analyzed using MTT assays. The effect of AZD2281 on XRCC2 and PARP1 expression was investigated in the five cell lines using quantitative polymerase chain reaction and western blot analyses. Parallel investigations were performed using a cisplatin (DDP) model of DNA damage. The XRCC2 rs3218536 SNP was found to be associated with the LoVo microsatellite instability CRC cell line. The relative rate of growth inhibition was found to be lower in the LoVo cells following treatment with AZD2281 compared with the other four cell lines (P=0.002). Furthermore, the XRCC2 mRNA level in the LoVo cells was observed to be significantly higher than that in the other four cell lines (P<0.05). Similar results were found using the DDP model of DNA damage (P<0.05). The present study indicated that the XRCC2 rs3218536 polymorphism decreases the sensitivity of CRC cells to AZD2281. Author information: (1)Bella Kaufman and Ronnie Shapira-Frommer, Sheba Medical Center, Tel Hashomer; Georgeta Fried, Institute of Oncology, Rambam Health Care Campus; Mariana Steiner, Linn Medical Centre, Haifa; Salomon M. Stemmer, Rabin Medical Center, Petah Tikva; Ayala Hubert, Hadassah-Hebrew University Hospital, Sharett Institute of Oncology; Ora Rosengarten, Shaare Zedek Medical Centre, Jerusalem, Israel; Rita K. Schmutzler, Center for Familial Breast and Ovarian Cancer and Center of Integrated Oncology, Cologne, Germany; M. William Audeh, Samuel Oschin Cancer Institute, Los Angeles, CA; Michael Friedlander, Prince of Wales Clinical School, University of New South Wales, Sydney, New South Wales; Gillian Mitchell, Peter MacCallum Cancer Centre, University of Melbourne, Melbourne, Victoria, Australia; Judith Balmaña, Vall d'Hebron Institute of Oncology, Barcelona, Spain; Niklas Loman, Skånes Universitetssjuk Lund, Lund, Sweden; Karin Bowen and Anitra Fielding, AstraZeneca, Macclesfield, United Kingdom; and Susan M. Domchek, Basser Research Center and Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA. (2)Bella Kaufman and Ronnie Shapira-Frommer, Sheba Medical Center, Tel Hashomer; Georgeta Fried, Institute of Oncology, Rambam Health Care Campus; Mariana Steiner, Linn Medical Centre, Haifa; Salomon M. Stemmer, Rabin Medical Center, Petah Tikva; Ayala Hubert, Hadassah-Hebrew University Hospital, Sharett Institute of Oncology; Ora Rosengarten, Shaare Zedek Medical Centre, Jerusalem, Israel; Rita K. Schmutzler, Center for Familial Breast and Ovarian Cancer and Center of Integrated Oncology, Cologne, Germany; M. William Audeh, Samuel Oschin Cancer Institute, Los Angeles, CA; Michael Friedlander, Prince of Wales Clinical School, University of New South Wales, Sydney, New South Wales; Gillian Mitchell, Peter MacCallum Cancer Centre, University of Melbourne, Melbourne, Victoria, Australia; Judith Balmaña, Vall d'Hebron Institute of Oncology, Barcelona, Spain; Niklas Loman, Skånes Universitetssjuk Lund, Lund, Sweden; Karin Bowen and Anitra Fielding, AstraZeneca, Macclesfield, United Kingdom; and Susan M. Domchek, Basser Research Center and Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA. [email protected]. Author information: (1)Department of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy; Unit of Neuro-Oncohematology, Santa Lucia Foundation-I.R.C.C.S., Rome, Italy. Electronic address: [email protected]. (2)Unit of Neuro-Oncohematology, Santa Lucia Foundation-I.R.C.C.S., Rome, Italy. Electronic address: [email protected]. (3)Unit of Neuro-Oncohematology, Santa Lucia Foundation-I.R.C.C.S., Rome, Italy; Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy. Electronic address: [email protected]. (4)Unit of Neuroimmunology, Santa Lucia Foundation-I.R.C.C.S., Rome, Italy. Electronic address: [email protected]. (5)Unit of Neuroimmunology, Santa Lucia Foundation-I.R.C.C.S., Rome, Italy. Electronic address: [email protected]. (6)Unit of Neuroimmunology, Santa Lucia Foundation-I.R.C.C.S., Rome, Italy. Electronic address: [email protected]. (7)Unit of Neuro-Oncohematology, Santa Lucia Foundation-I.R.C.C.S., Rome, Italy; Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy. Electronic address: [email protected]. (8)Unit of Neuro-Oncohematology, Santa Lucia Foundation-I.R.C.C.S., Rome, Italy; Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy. Electronic address: [email protected]. (9)Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy. Electronic address: [email protected]. (10)Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy. Electronic address: [email protected]. (11)Department of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy. Electronic address: [email protected]. (12)Unit of Neuro-Oncohematology, Santa Lucia Foundation-I.R.C.C.S., Rome, Italy; Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy. Electronic address: [email protected]. BACKGROUND: The poly(ADP-ribose) polymerase inhibitor olaparib has shown antitumour activity in patients with platinum-sensitive, recurrent, high-grade serous ovarian cancer with or without BRCA1 or BRCA2 mutations. The aim of this study was to assess the efficacy and tolerability of olaparib in combination with chemotherapy, followed by olaparib maintenance monotherapy, versus chemotherapy alone in patients with platinum-sensitive, recurrent, high-grade serous ovarian cancer. METHODS: In this randomised, open-label, phase 2 study, adult patients with platinum-sensitive, recurrent, high-grade serous ovarian cancer who had received up to three previous courses of platinum-based chemotherapy and who were progression free for at least 6 months before randomisation received either olaparib (200 mg capsules twice daily, administered orally on days 1-10 of each 21-day cycle) plus paclitaxel (175 mg/m(2), administered intravenously on day 1) and carboplatin (area under the curve [AUC] 4 mg/mL per min, according to the Calvert formula, administered intravenously on day 1), then olaparib monotherapy (400 mg capsules twice daily, given continuously) until progression (the olaparib plus chemotherapy group), or paclitaxel (175 mg/m(2) on day 1) and carboplatin (AUC 6 mg/mL per min on day 1) then no further treatment (the chemotherapy alone group). Randomisation was done by an interactive voice response system, stratified by number of previous platinum-containing regimens received and time to disease progression after the previous platinum regimen. The primary endpoint was progression-free survival according to Response Evaluation Criteria in Solid Tumors version 1.1, analysed by intention to treat. Prespecified exploratory analyses included efficacy by BRCA mutation status, assessed retrospectively. This study is registered with ClinicalTrials.gov, number NCT01081951, and has been completed. FINDINGS: Between Feb 12 and July 30, 2010, 173 patients at 43 investigational sites in 12 countries were enrolled into the study, of whom 162 were eligible and were randomly assigned to the two treatment groups (81 to the olaparib plus chemotherapy group and 81 to the chemotherapy alone group). Of these randomised patients, 156 were treated in the combination phase (81 in the olaparib plus chemotherapy group and 75 in the chemotherapy alone group) and 121 continued to the maintenance or no further treatment phase (66 in the olaparib plus chemotherapy group and 55 in the chemotherapy alone group). BRCA mutation status was known for 107 patients (either at baseline or determined retrospectively): 41 (38%) of 107 had a BRCA mutation (20 in the olaparib plus chemotherapy group and 21 in the chemotherapy alone group). Progression-free survival was significantly longer in the olaparib plus chemotherapy group (median 12.2 months [95% CI 9.7-15.0]) than in the chemotherapy alone group (median 9.6 months [95% CI 9.1-9.7) (HR 0.51 [95% CI 0.34-0.77]; p=0.0012), especially in patients with BRCA mutations (HR 0.21 [0.08-0.55]; p=0.0015). In the combination phase, adverse events that were reported at least 10% more frequently with olaparib plus chemotherapy than with chemotherapy alone were alopecia (60 [74%] of 81 vs 44 [59%] of 75), nausea (56 [69%] vs 43 [57%]), neutropenia (40 [49%] vs 29 [39%]), diarrhoea (34 [42%] vs 20 [27%]), headache (27 [33%] vs seven [9%]), peripheral neuropathy (25 [31%] vs 14 [19%]), and dyspepsia (21 [26%] vs 9 [12%]); most were of mild-to-moderate intensity. The most common grade 3 or higher adverse events during the combination phase were neutropenia (in 35 [43%] of 81 patients in the olaparib plus chemotherapy group vs 26 [35%] of 75 in the chemotherapy alone group) and anaemia (seven [9%] vs five [7%]). Serious adverse events were reported in 12 (15%) of 81 patients in the olaparib plus chemotherapy group and 16 of 75 (21%) patients in the chemotherapy alone group. INTERPRETATION: Olaparib plus paclitaxel and carboplatin followed by maintenance monotherapy significantly improved progression-free survival versus paclitaxel plus carboplatin alone, with the greatest clinical benefit in BRCA-mutated patients, and had an acceptable and manageable tolerability profile. FUNDING: AstraZeneca.

Are thyroid hormone receptor alpha1 mutations implicated in thyroid hormone resistance syndrome?

The lack of TR alpha1 exacerbates the manifestation of RTH in TR betaPV mice. Therefore, TR alpha1 could play a compensatory role in mediating the functions of T3 in heterozygous patients with RTH

[7913092, 8115332, 8068885, 8384535, 7711514, 8954015, 8475937, 15988389, 9350446, 8594618, 23633213, 15860414, 9092799, 17906375, 9685218, 17040361, 15913586, 12356724, 12750454]

Three novel point mutations at nucleotides 1249, 1282, and 1614 (exons 9 and 10) of the human thyroid hormone receptor-beta gene were observed in six individuals affected by the syndrome of resistance to thyroid hormone. All three mutations occurred in a heterozygous pattern and caused the following changes in the mature form of the receptor protein: Asp322 to Asn, Glu333 to Gln, and Lys443 to Asn, respectively. The first and third point mutations arose in two unrelated families from eastern Sicily, whereas the second concerned an individual from southern Calabria, apparently presenting a sporadic form of the resistance syndrome. The clinical and biochemical features of resistance to thyroid hormone, both before and after the administration of thyroid hormones, highlight the striking intrafamilial heterogeneity in the phenotypical presentation of the syndrome. Clinical syndromes of hormone resistance or independence have baffled clinicians for decades. These syndromes sometimes result from mutations or deficiencies in enzymes that activate prohormones or from alterations in signal transduction proteins. The majority of these conditions, however, arise from abnormalities of hormone receptors. We describe examples of syndromes that result from genetic mutations or misexpression of steroid/thyroid hormone receptors, with a specific emphasis on thyroid and androgen resistance syndromes, and estrogen independence in breast cancer. Resistance to thyroid hormone (RTH) is an inherited syndrome of reduced tissue responsiveness to thyroid hormone. To date, all individuals expressing the RTH phenotype have been found to harbor mutations in the thyroid hormone receptor beta (TR beta) gene that impair T3-mediated function. We describe a unique family in which the dominantly inherited RTH is not associated with abnormalities in the TR beta or TR alpha genes, as determined by gene sequencing and linkage analysis. However, affected family members manifest a severe form of RTH, with reduced responses of thyrotrophs and peripheral tissues requiring 8- to 10-fold the normal replacement doses of L-T4 and L-T3. No other endocrine abnormalities were detected. The defect developed de novo in the proposita and was transmitted to her two children of unrelated fathers. As cultured fibroblasts from the proposita responded poorly to T3 despite a normal concentration of TR, other abnormalities in the mediation of T3 action were sought. Nucleotide sequences of the TSH beta promoter, containing thyroid hormone response elements, and TR-interacting protein 1 were normal. Nuclear extracts (NE) of cultured skin fibroblasts from affected individuals of this family were tested for their interaction with normal TR beta and thyroid hormone response elements by the electrophoretic mobility shift assay. NE from the proposita showed a strong additional band compared to NEs from normal individuals and patients with RTH caused by TR beta mutations or deletion. Far Western analysis of NE from the affected daughter hybridized with labeled TR beta demonstrated an additional band that was not seen in NEs from a normal control or patients with TR beta gene defects. It is concluded that the etiology of RTH is not confined to abnormalities in the TR beta gene. An abnormal cofactor with a specific function in the regulation of thyroid hormone action is probably involved in the expression of the RTH phenotype in this family. The thyroid hormone resistance syndromes are disorders in which the body's tissues are resistant to the effects of thyroid hormone. Generalized resistance to thyroid hormone (GRTH) is characterized by resistance in the pituitary gland and in most or all of the peripheral tissues. Affected individuals have elevated serum thyroid hormone levels and inappropriately normal or elevated thyroid-stimulating hormone (TSH) but are usually clinically euthyroid and require no treatment. Selective pituitary resistance to thyroid hormone (PRTH) is characterized by resistance in the pituitary gland but not in peripheral tissues. Patients have elevated serum thyroid hormone levels and normal or elevated TSH levels and are clinically thyrotoxic. Therapy is usually necessary, but current choices are not completely satisfactory. Selective peripheral resistance to thyroid hormone (PerRTH) is characterized by resistance in peripheral tissues but not in the pituitary. The only patient thus far described had normal serum thyroid hormone and TSH levels but was clinically hypothyroid and improved with thyroid hormone administration. All of these disorders are probably more common than is generally recognized and are often misdiagnosed and inappropriately treated. GRTH, in most cases studied, results from a mutation in the thyroid hormone receptor beta gene causing an amino acid substitution in or a partial or complete deletion of the thyroid hormone-binding domain of the receptor. The causes of PRTH and PerRTH remain to be determined. Resistance to thyroid hormone (RTH) is usually dominantly inherited and is characterized by elevated free thyroid hormones in the serum and failure to suppress pituitary thyroid stimulating hormone (TSH) secretion with variable refractoriness to hormone action in peripheral tissues. Two major forms of the disorder are recognized: asymptomatic individuals with generalized resistance (GRTH) and patients with thyrotoxic features, suggesting predominant pituitary resistance (PRTH). Molecular genetic analyses indicate that both GRTH and PRTH are associated with diverse mutations in the thyroid hormone receptor beta gene, which localize to three regions in the hormone binding domain of the receptor. In addition to being functionally impaired, the mutant receptors are also able to inhibit their wild-type counterparts in a dominant negative manner. Recognized features of RTH include failure to thrive, growth retardation and attention-deficit hyperactivity disorder in childhood, and goitre and thyrotoxic cardiac symptoms in adults. The pathogenesis of variable tissue resistance is not fully understood but may be related to the differing tissue distributions of a and b thyroid hormone receptors and variable dominant negative activity of mutant receptors on different target genes. Thyroid hormones (T3, T4) exert multiple cellular effects through nuclear thyroid hormone receptors (TR alpha, TR beta). Thyroid hormone receptors are transcription factors that act by altering patterns of gene expression. Resistance to thyroid hormone (RTH) is a rare disorder caused by mutations in the TR beta gene. Biochemically, the syndrome is defined by elevated circulating levels of free thyroid hormones due to reduced target tissue responsiveness and normal, or elevated, levels of thyroid-stimulating hormone (TSH). This "inappropriate" TSH elevation contrasts with the situation in hyperthyroidism, where the pituitary secretion of TSH is suppressed. Patients with RTH usually present with goiter and an euthyroid or mildly hypothyroid metabolic state. Thus, pituitary resistance results in hypersecretion of TSH, which compensates, at least in part, for hormone resistance in peripheral tissues. Despite this compensation, clinical effects of RTH can include short stature, delayed bone maturation, hyperactivity, learning disabilities, and hearing defects, as well as variable features of hyper- and hypothyroidism. With the exception of a single sibship, which harbored a deletion of the entire coding sequence of the TR beta gene and a recessive pattern of inheritance, all other cases of RTH have been inherited in an autosomal dominant manner or have been de novo heterozygous mutations of the TR beta gene. The dominant pattern of inheritance is explained by the functional properties of the mutant receptors which act in a dominant negative manner to block the activity of normal TR alpha and TR beta receptors. Now that a large number of different RTH mutations have been identified, it is striking that the mutations are clustered within restricted domains in the carboxyterminal region of the receptor. Mutations in these regions have been shown to preserve critical receptor functions such as dimerization and DNA binding, while inactivating other activites such as T3 binding and transcriptional activation. The examination of patients with RTH and their mutated receptors has provided important insights into the mechanisms of thyroid hormone action, the structure-function relationship of the receptors, and the molecular mechanisms of dominant negative activity. CONTEXT: Recently the first patients with inactivating mutations in T₃ receptor (TR)-α1 have been identified. These patients have low free T₄, low T₄, high T₃, low rT₃, and normal TSH serum levels, in combination with growth retardation, delayed bone development, and constipation. OBJECTIVE: The aim of the current study was to report the effects of levothyroxine (LT4) treatment on the clinical phenotype of 2 patients (father and daughter) with a heterozygous inactivating mutation in TRα1. SETTING AND PARTICIPANTS: Both patients were treated with LT4 for the last 5 years. To evaluate the effect of LT4 treatment, LT4 was withdrawn for 35 days and subsequently reinitiated. Data were collected from medical records, by reanalysis of serum collected over the last 6 years, and by a detailed clinical evaluation. RESULTS: Treatment with LT4 resulted in a suppression of serum TSH and normalization of serum free T₄ and rT₃, whereas T₃ levels remained elevated in both patients. In addition, there was a normalization of the dyslipidemia as well as a response in serum IGF-I, SHBG, and creatine kinase in the index patient. All these parameters returned to pretreatment values when LT4 was briefly stopped. LT4 also resulted in an improvement of certain clinical features, such as constipation and nerve conductance. However, cognitive and fine motor skill defects remained. CONCLUSION: This study reports the consequences of LT4 treatment over a prolonged period of time in 2 of the first patients with a heterozygous mutation in TRα1. LT4 therapy leads to an improvement of certain but not all features of the clinical phenotype. Thyroid hormone receptors (TRs) are ligand-dependent transcription factors that mediate the biological activities of thyroid hormone (T3). Two THR genes (A and B), located on different chromosomes, yield four T3-binding isoforms with highly conserved sequences in the DNA- and ligand-binding domains. Mutations of THRB cause a human genetic disease, thyroid hormone resistance syndrome (RTH). Comprehensive genomic profiling unveiled the contribution of novel change-of-function mutations of TRbeta to the pathogenesis of RTH. In addition, abnormalities associated with mutations of the THRA gene have been uncovered recently. The phenotypic manifestations of mutated THRB and THRA genes are distinct, indicating isoform-dependent actions of TR mutants in vivo. Therefore, mutant TRs provide a new paradigm to understand the molecular basis of receptor disease. Nuclear hormone receptors are hormone-regulated transcription factors that play critical roles in chordate development and homeostasis. Aberrant nuclear hormone receptors have been implicated as causal agents in a number of endocrine and neoplastic diseases. The syndrome of Resistance to Thyroid Hormone (RTH) is a human genetic disease characterized by an impaired physiological response to thyroid hormone. RTH is associated with diverse mutations in the thyroid hormone receptor beta-gene. The resulting mutant receptors function as dominant negatives, interfering with the actions of normal thyroid hormone receptors coexpressed in the same cells. We report here that RTH receptors interact aberrantly with a newly recognized family of transcriptional corepressors variously denoted as nuclear receptor corepressor (N-CoR), retinoid X receptor interacting protein-13 (RIP-13), silencing mediator for retinoid and thyroid hormone receptors (SMRT), and thyroid hormone receptor-associating cofactor (TRAC). All RTH receptors tested exhibit an impaired ability to dissociate from corepressors in the presence of thyroid hormone. Two of the RTH mutations uncouple corepressor dissociation from hormone binding; two additional RTH mutants exhibit an unusually strong interaction with corepressor under all hormone conditions tested. Finally, artificial mutants that abolish corepressor binding abrogate the dominant negative activity of RTH mutants. We suggest that an altered corepressor interaction is likely to play a critical role in the dominant negative potency of RTH mutants and may contribute to the variable phenotype in this disorder. We here described a 39-year-old woman with a severe chronic mood disorder, refractory to antidepressive therapy who showed a significant improvement after a self-prescription of high doses of liothyronine (T(3)). A modified Refetoff protocol was carried out to study the role of thyroid hormones on her clinical and biochemical responses. Depression severity was assessed by the HAM-D and MADRS Depression Rating Scales. Sequencing of Thyroid Receptors (TR) alpha1 and beta1 genes was done. At the final stage of the study, plasma T3 and free T3 were >800 ng/dl (80-180) and 1409 pg/dl (230-420), respectively. No changes in the cardiovascular parameters, alkaline phosphatase isoenzymes, creatinine kinase, or ferritin were observed. However, an improvement in mood was detected by specific scores (HAM-D 24 to 8; MADRS 40 to 11). No mutations in DNA- and hormone-binding-domains of TRbeta1 and TRalpha1 genes were found in proband, suggesting that the defect could be due to an unknown mutation in either the TR gene or a post receptor abnormality. These results support the existence of a peripheral RTH manifestation as a refractory chronic depression reverted by high doses of T(3). Screening for RTH in refractory chronic depression may provide an alternative treatment for this psychiatric condition. The finding of increased thyroxine (T4) and tri-iodothyronine (T3) levels in a patient with normal or increased thyroid-stimulating hormone is unexpected and presents a differential diagnosis between a thyroid-stimulating hormone-secreting pituitary adenoma, generalized resistance to thyroid hormone (RTH) and laboratory artefact. Without careful clinical and biochemical evaluation, errors may occur in patient diagnosis and treatment. In the case of RTH, mutation of the thyroid hormone receptor beta gene results in generalized tissue resistance to thyroid hormone. As the pituitary gland shares in this tissue resistance, euthyroidism with a normal thyroid-stimulating hormone is usually maintained by increased thyroid hormones. To date, we have identified eight pedigrees in New Zealand with mutations in the thyroid hormone receptor beta gene, including two novel mutations. Mutational analysis of the thyroid hormone receptor beta gene allows definitive diagnosis of RTH, potentially avoiding the need for protracted and expensive pituitary function testing and imaging. Mutational analysis also enables family screening and may help to avoid potential misdiagnosis and inappropriate treatment. BACKGROUND: Thyroid hormones govern a wide range of metabolic processes in the body via thyroid hormone receptors (TR). We report a patient with mild resistance to thyroid hormone who was initially misdiagnosed and treated as having thyrotoxicosis. METHODS: We used direct DNA sequencing of the THRB gene. RESULTS: We identified a novel missense mutation, I276L, located in exon 8 of the gene. The mutation is located in cluster 3 of the ligand-binding domain, a protein domain associated with resistance to thyroid hormone. CONCLUSION: DNA-based diagnosis of thyroid hormone resistance syndrome is simple, reliable, and economical compared to traditional biochemical tests. Once the mutation is identified, targeted screening for the whole family can be performed and the unnecessary use of anti-thyroid drugs or thyroidectomy can be avoided. Most patients with the syndrome resistance to thyroid hormone (RTH) express a mutant thyroid hormone receptor beta (TRbeta) with transdominant negative transcriptional effects. Since no patient with a mutant TRalpha has been identified, we introduced a point mutation into the mouse thyroid hormone receptor (TRalpha1) locus originally found in the TRbeta gene, that reduces ligand binding 10-fold. Heterozygous 2- to 3-week- old mice exhibit a severe retardation of post-natal development and growth, but only a minor reduction in serum thyroxine levels. Homozygous mice died before 3 weeks of age. Adult heterozygotes overcome most of these defects except for cardiac function abnormalities, suggesting that other factors compensate for the receptor defect. However, the additional deletion of the TRbeta gene in this mouse strain caused a 10-fold increase in serum thyroxine, restored hormonal regulation of target genes for TRs, and rescued the growth retardation. The data demonstrate a novel array of effects mediated by a dominant negative TRalpha1, and may provide important clues for identification of a potentially unrecognized human disorder and its treatment. Resistance to thyroid hormone (RTH) is caused by mutations of the thyroid hormone receptor beta (TR beta) gene. Almost all RTH patients are heterozygous with an autosomal dominant pattern of inheritance. That most are clinically euthyroid suggests a compensatory role of the TR alpha1 isoform in maintaining the normal functions of thyroid hormone (T3) in these patients. To understand the role of TR alpha1 in the manifestation of RTH, we compared the phenotypes of mice with a targeted dominantly negative mutant TR beta (TR betaPV) with or without TR alpha1. TR betaPV mice faithfully recapitulate RTH in humans in that these mice demonstrate abnormalities in the pituitary-thyroid axis and impairment in growth. Here we show that the dysregulation of the pituitary-thyroid axis was worsened by the lack of TR alpha1 in TR betaPV mice, and severe impairment of postnatal growth was manifested in TR betaPV mice deficient in TR alpha1. Furthermore, abnormal expression patterns of T3-target genes in TR betaPV mice were altered by the lack of TR alpha1. These results demonstrate that the lack of TR alpha1 exacerbates the manifestation of RTH in TR betaPV mice. Therefore, TR alpha1 could play a compensatory role in mediating the functions of T3 in heterozygous patients with RTH. This compensatory role may be especially crucial for postnatal growth.

What is the role of RhoA in bladder cancer?

In urinary bladder cancer, RhoA was more commonly found to be activated in the later stages of the disease. This activation was related to poor tumor differentiation, muscle invasion, lymph node metastasis, and shortened disease-free and overall survival.

[22006759, 21054792, 18190825, 12855641, 19896475]

INTRODUCTION: Rho-kinase (ROCK) is a serine/threonine kinase and is one of the major downstream effectors of the small guanosine triphosphatase Rho. In the past few years, evidence has been accumulating to suggest that the RhoA/ROCK system may play an important role in the pathogenesis of a number of cardiovascular and urogenital disorders. AIM: The aim of this study is to review the literature pertaining to the role of the RhoA/ROCK system in male urogenital function. METHODS: Comprehensive literature review was performed using PubMed. MAIN OUTCOME MEASURES: Inhibitors of ROCK may have potential therapeutic applications, as derived from preclinical and a few clinical studies. RESULTS: Published reports suggest that elevated RhoA/Rho-kinase signaling plays a role in the development of benign prostatic hyperplasia, erectile dysfunction, kidney failure, ejaculation disorders, prostate and bladder cancer initiation, and eventual metastasis. CONCLUSIONS: This review focuses on our current understanding of the role of the RhoA/Rho-kinase pathway in the regulation of the male urogenital system. Rho-kinase inhibitors may evolve into an important pharmacologic option in the future treatment of urogenital system disorders. PURPOSE: The small GTP-binding protein Rho and its best-characterized downstream effector Rho-associated serine-threonine protein kinase, ROCK, participate in actin cytoskeleton organization, and are linked to pathogenesis and progression of several human tumors. We investigated the roles of Rho and ROCK in bladder cancer. EXPERIMENTAL DESIGN: Using Western blotting, we quantitated Rho and ROCK protein expression in paired tumor and nontumor surgical samples from 107 consecutive Japanese patients with bladder cancer. RESULTS: RhoA, RhoC, and ROCK were more abundant in tumors and metastatic lymph nodes than in nontumor bladder and uninvolved lymph nodes (P < 0.0001). Amounts of RhoA and RhoC protein, and ROCK protein expression correlated positively with one another (P < 0.0001). High RhoA, RhoC, and ROCK expression were related to poor tumor differentiation (P < 0.05, P < 0.01, and P < 0.01, respectively), muscle invasion (P < 0.001), and lymph node metastasis (P < 0.05). Kaplan-Meier plots linked high RhoA, RhoC, and ROCK protein expression to shortened disease-free and overall survival (P < 0.0001). By univariate analysis, high RhoA, RhoC, and ROCK protein expression predicted shortened disease-free and overall survival (P < 0.0001). By multivariate analysis, only RhoC was independently influenced in disease-free survival (P < 0.05), and RhoA and RhoC in overall survival (P < 0.001). In contrast, RhoB expression was inversely related to the grade and stage (P < 0.05), and its higher expression is associated with better overall survival (P < 0.05). In superficial tumors (Ta or T1; 63 patients), RhoA, RhoC, and ROCK were unrelated with recurrence-free survival. Overall survival in tumors invading muscle (T2 to T4; 44 patients) was significantly influenced by RhoA, RhoC, and ROCK in a Kaplan-Meier analysis (P < 0.0001, P < 0.0001, and P < 0.01, respectively). Whereas RhoA, RhoC, and ROCK independently predicted shortened overall survival in patients with invasive tumor by univariate analysis (P < 0.0001, P < 0.0001, and P < 0.01, respectively), only RhoC did so by multivariate analysis (P < 0.05). CONCLUSION: Rho/ROCK pathway apparently involved in occurrence and progression of bladder cancer may be valuable prognostic markers.

List human proteins that are subject to a dimer-to-tetramer transition.

GAC SHMT2 AMPAR Orai1 Orai3

[25548170, 23739980, 25619277, 21080238, 21987805]

Most fast excitatory synaptic transmission in the nervous system is mediated by glutamate acting through ionotropic glutamate receptors (iGluRs). iGluRs (AMPA, kainate, and NMDA receptor subtypes) are tetrameric assemblies, formed as a dimer of dimers. Still, the mechanism underlying tetramerization--the necessary step for the formation of functional receptors that can be inserted into the plasma membrane--is unknown. All eukaryotic compared to prokaryotic iGluR subunits have an additional transmembrane segment, the M4 segment, which positions the physiologically critical C-terminal domain on the cytoplasmic side of the membrane. AMPA receptor (AMPAR) subunits lacking M4 do not express on the plasma membrane. Here, we show that these constructs are retained in the endoplasmic reticulum, the major cellular compartment mediating protein oligomerization. Using approaches to assay the native oligomeric state of AMPAR subunits, we find that subunits lacking M4 or containing single amino acid substitutions along an "interacting" face of the M4 helix that block surface expression no longer tetramerize in either homomeric or heteromeric assemblies. In contrast, subunit dimerization appears to be largely intact. These experiments define the M4 segment as a unique functional unit in AMPARs that is required for the critical dimer-to-tetramer transition. Adaptive metabolic reprogramming gives cancer cells a proliferative advantage. Tumour cells extensively use glycolysis to sustain anabolism and produce serine, which not only refuels the one-carbon units necessary for the synthesis of nucleotide precursors and for DNA methylation, but also affects the cellular redox homeostasis. Given its central role in serine metabolism, serine hydroxymethyltransferase (SHMT), a pyridoxal 5'-phosphate (PLP)-dependent enzyme, is an attractive target for tumour chemotherapy. In humans, the cytosolic isoform (SHMT1) and the mitochondrial isoform (SHMT2) have distinct cellular roles, but high sequence identity and comparable catalytic properties, which may complicate development of successful therapeutic strategies. Here, we investigated how binding of the cofactor PLP controls the oligomeric state of the human isoforms. The fact that eukaryotic SHMTs are tetrameric proteins while bacterial SHMTs function as dimers may suggest that the quaternary assembly in eukaryotes provides an advantage to fine-tune SHMT function and differentially regulate intertwined metabolic fluxes, and may provide a tool to address the specificity problem. We determined the crystal structure of SHMT2, and compared it to the apo-enzyme structure, showing that PLP binding triggers a disorder-to-order transition accompanied by a large rigid-body movement of the two cofactor-binding domains. Moreover, we demonstrated that SHMT1 exists in solution as a tetramer, both in the absence and presence of PLP, while SHMT2 undergoes a dimer-to-tetramer transition upon PLP binding. These findings indicate an unexpected structural difference between the two human SHMT isoforms, which opens new perspectives for understanding their differing behaviours, roles or regulation mechanisms in response to PLP availability in vivo.

Inhibition of which transporter is the mechanism of action of drug Canagliflozin?

Inhibition of sodium glucose co-transporter 2 (SGLT2) is the major mechanism of action of canagliflozin. Canagliflozin is the first SGLT2 inhibitor to be approved in the USA for the treatment of type 2 diabetes and is under regulatory review in the EU. Other SGLT2 inhibitors include dapagliflozin and empagliflozin.

[23087012, 24040872, 22547464, 23729000, 10481836, 23590413, 23042029, 23563279, 23412078, 23326927, 22621689, 21680987, 24257692, 24025022, 23895803]

BACKGROUND: Despite the number of medications for type 2 diabetes, many people with the condition do not achieve good glycaemic control. Some existing glucose-lowering agents have adverse effects such as weight gain or hypoglycaemia. Type 2 diabetes tends to be a progressive disease, and most patients require treatment with combinations of glucose-lowering agents. The sodium glucose co-transporter 2 (SGLT2) receptor inhibitors are a new class of glucose-lowering agents. OBJECTIVE: To assess the clinical effectiveness and safety of the SGLT2 receptor inhibitors in dual or triple therapy in type 2 diabetes. DATA SOURCES: MEDLINE, Embase, Cochrane Library (all sections); Science Citation Index; trial registries; conference abstracts; drug regulatory authorities; bibliographies of retrieved papers. INCLUSION CRITERIA: Randomised controlled trials of SGLT2 receptor inhibitors compared with placebo or active comparator in type 2 diabetes in dual or combination therapy. METHODS: Systematic review. Quality assessment used the Cochrane risk of bias score. RESULTS: Seven trials, published in full, assessed dapagliflozin and one assessed canagliflozin. Trial quality appeared good. Dapagliflozin 10 mg reduced HbA1c by -0.54% (weighted mean differences (WMD), 95% CI -0.67 to -0.40) compared to placebo, but there was no difference compared to glipizide. Canagliflozin reduced HbA1c slightly more than sitagliptin (up to -0.21% vs sitagliptin). Both dapagliflozin and canagliflozin led to weight loss (dapagliflozin WMD -1.81 kg (95% CI -2.04 to -1.57), canagliflozin up to -2.3 kg compared to placebo). LIMITATIONS: Long-term trial extensions suggested that effects were maintained over time. Data on canagliflozin are currently available from only one paper. Costs of the drugs are not known so cost-effectiveness cannot be assessed. More data on safety are needed, with the Food and Drug Administration having concerns about breast and bladder cancers. CONCLUSIONS: Dapagliflozin appears effective in reducing HbA1c and weight in type 2 diabetes, although more safety data are needed. Sodium-glucose co-transporters (SGLT2) are mainly expressed in the kidneys and are responsible for the renal handling of glucose load. SGLT2 inhibitors represent the latest oral agents for diabetes treatment. Their unique mechanism of action, which practically spares the insulin secretion or insulin utilization, differentiates the SGLT2 inhibitors from any existing antidiabetic agent. Thus, it is hypothesized that SGLT2 inhibitors can be effectively (and probably safely) combined with any existing antidiabetic agent (including insulin), either as monotherapy, or in dual or triple combinations. All these hypotheses are currently tested in many clinical trials. Currently dapagliflozin, one of the three most advanced SGLT2 inhibitors in the development (along with canagliflozin and empagliflozin), is already in the market in few European countries and canagliflozin has been approved from the Food and Drug Administration (FDA) in US. The evidence so far shows that SGLT2 inhibitors are equally effective to established antidiabetic agents such as metformin or sulfonylureas in their ability to lower HbA1c. On the other hand, SGLT2 inhibitors increase the possibility of genitourinary infections in type 2 diabetic individuals. Their potency in different populations and with different background therapy, but more importantly their short and long term safety remains to be seen. Sodium-glucose co-transporters (SGLTs) have a key role in the re-absorption of glucose in the kidneys. Therefore, inhibition of SGLTs may provide a novel therapeutic strategy for diabetes mellitus. SGLT2 inhibitors enhance renal glucose excretion by inhibiting renal glucose re-absorption and reduce plasma glucose level, as well as they decrease the body weight. Their action is insulin independent and they improve insulin resistance in diabetes mellitus. Numerous SGLT2 inhibitors have been developed and evaluated in clinical trials. Phase III trials are needed to assess the safety of SGLT2 inhibitors. Results suggest that the beneficial effects of SGLT2 inhibition might be achieved without the development of significant side effects. Canagliflozin (Invokana™), an oral selective sodium-glucose co-transporter 2 (SGLT2) inhibitor, is under global development with Mitsubishi Tanabe Pharma and Janssen Pharmaceuticals, a subsidiary of Johnson and Johnson, for the treatment of type 2 diabetes mellitus. SGLT2 are mainly located in the proximal tubule of the kidney and are involved in the reabsorption of filtered glucose from the glomeruli into the body. Inhibition of SGLT2 lowers blood glucose in an insulin independent manner as a consequence of blocking reabsorption of filtered glucose in the glomeruli, thereby increasing urinary excretion of glucose and, in turn, potentially reducing bodyweight. Canagliflozin is the first SGLT2 inhibitor to be approved in the USA and is under regulatory review in the EU. This article summarizes the milestones in the development of canagliflozin, leading to its first approval for use in adults with type 2 diabetes. OBJECTIVE: Canagliflozin, a sodium glucose cotransporter (SGLT) 2 inhibitor, is also a low-potency SGLT1 inhibitor. This study tested the hypothesis that intestinal canagliflozin levels postdose are sufficiently high to transiently inhibit intestinal SGLT1, thereby delaying intestinal glucose absorption. RESEARCH DESIGN AND METHODS: This two-period, crossover study evaluated effects of canagliflozin on intestinal glucose absorption in 20 healthy subjects using a dual-tracer method. Placebo or canagliflozin 300 mg was given 20 min before a 600-kcal mixed-meal tolerance test. Plasma glucose, (3)H-glucose, (14)C-glucose, and insulin were measured frequently for 6 h to calculate rates of appearance of oral glucose (RaO) in plasma, endogenous glucose production, and glucose disposal. RESULTS: Compared with placebo, canagliflozin treatment reduced postprandial plasma glucose and insulin excursions (incremental 0- to 2-h area under the curve [AUC0-2h] reductions of 35% and 43%, respectively; P < 0.001 for both), increased 0- to 6-h urinary glucose excretion (UGE0-6h, 18.2 ± 5.6 vs. <0.2 g; P < 0.001), and delayed RaO. Canagliflozin reduced AUC RaO by 31% over 0 to 1 h (geometric means, 264 vs. 381 mg/kg; P < 0.001) and by 20% over 0 to 2 h (576 vs. 723 mg/kg; P = 0.002). Over 2 to 6 h, canagliflozin increased RaO such that total AUC RaO over 0 to 6 h was <6% lower versus placebo (960 vs. 1,018 mg/kg; P = 0.003). A modest (∼10%) reduction in acetaminophen absorption was observed over the first 2 h, but this difference was not sufficient to explain the reduction in RaO. Total glucose disposal over 0 to 6 h was similar across groups. CONCLUSIONS: Canagliflozin reduces postprandial plasma glucose and insulin by increasing UGE (via renal SGLT2 inhibition) and delaying RaO, likely due to intestinal SGLT1 inhibition. Human immunodeficiency virus type 1 protease (HIV-1 PR) and renin are primary targets toward AIDS and hypertension therapies, respectively. Molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) free-energy calculations and inhibition assays for canagliflozin, an antidiabetic agent verified its effective binding to both proteins (ΔG(pred) = -9.1 kcal mol(-1) for canagliflozin-renin; K(i,exp)= 628 nM for canagliflozin-HIV-1 PR). Moreover, drugs aliskiren (a renin inhibitor) and darunavir (an HIV-1 PR inhibitor) showed high affinity for HIV-1 PR (K(i,exp)= 76.5 nM) and renin (K(i,pred)= 261 nM), respectively. Importantly, a high correlation was observed between experimental and predicted binding energies (r(2) = 0.92). This study suggests that canagliflozin, aliskiren, and darunavir may induce profound effects toward dual HIV-1 PR and renin inhibition. Since patients on highly active antiretroviral therapy (HAART) have a high risk of developing hypertension and diabetes, aliskiren-based or canagliflozin-based drug design against HIV-1 PR may eliminate these side-effects and also facilitate AIDS therapy. Hyperglycemia is a defining characteristic of type 2 diabetes mellitus and is a major risk factor associated with the development of many microvascular complications. There are numerous therapies currently available to treat hyperglycemia, but glycemic control rates remain poor. One potential reason is the decline in ß-cell function over time, which decreases the effectiveness of therapies that rely on insulin action. The kidney occupies a central position in the control of glucose homeostasis by its role in gluconeogenesis and by regulating glucose excretion. Under normal conditions, glucose filtered by the kidney is virtually totally reabsorbed in the proximal tubule by the sodium-glucose co-transporter 2 (SGLT2). Inhibition of SGLT2 is an attractive, insulin-independent target for increasing glucose excretion in the setting of hyperglycemia. A number of SGLT2 inhibitors have been synthesized, and results from preclinical studies have shown that they increase glucose excretion and normalize plasma glucose in diabetic models. Initial clinical data are promising and suggest that SGLT2 inhibitors may be a new therapeutic option for treating type 2 diabetes mellitus. The proximal tubule's sodium-glucose linked transporter-2 (SGLT2) accounts for the vast majority of glucose reabsorption by the kidney. Its selective inhibition, accordingly, leads to substantial glycosuria, lowering blood glucose, and facilitating weight loss in individuals with diabetes. During the past year, two SGLT2 inhibitors, canagliflozin and dapagliflozin, have been approved for the treatment of type 2 diabetes. Beyond their anti-hyperglycemic properties, however, this new class of drugs has several other attributes that provide a theoretical basis for kidney protection. Like agents that block the renin-angiotensin system, SGLT2 inhibitors also reduce single-nephron glomerular filtration rate (SNGFR) in the chronically diseased kidney, though by quite different mechanisms. Additional potentially beneficial effects of SGLT2 inhibition include modest reductions in blood pressure and plasma uric acid. Finally, cell culture studies indicate that glucose uptake from the tubular lumen, as well as from the basolateral compartment, can contribute to proximal tubular production of extracellular matrix proteins. Whether such attributes will translate into reducing the progression of chronic kidney disease will require the undertaking of long-term, dedicated studies. The sodium glucose cotransporter 2 (SGLT2) is expressed primarily in the kidneys and is involved in the reabsorption of filtered glucose in the renal tubule. Clinical trials of SGLT2 inhibitors in patients with type 2 diabetes mellitus demonstrate a significant clinical effect in decreasing serum glucose, hemoglobin A1C, body weight, systolic blood pressure, improving β-cell function, and minimizing the risk of hypoglycemia. This report reviews the potentially beneficial effects of SGLT2 inhibitors in type 2 diabetes mellitus, specifically focusing on canagliflozin, the only SGLT2 inhibitor approved for use in the United States. Sodium glucose co-transporter 2 inhibition is a novel mode of treatment for type 2 diabetes mellitus (T2DM). The sodium glucose co-transporter 2 inhibitor canagliflozin lowered blood glucose, blood pressure, and body weight, with increased risk of urogenital infections in Phase 2 studies. Effects on macrovascular complications of diabetes remain to be determined. CANVAS is a double-blind, placebo-controlled trial designed to evaluate the effects of canagliflozin on the risk of cardiovascular disease and to assess safety and tolerability in patients with inadequately controlled T2DM and increased cardiovascular risk. The first of 2 planned phases randomized 4,330 individuals to placebo, canagliflozin 100 or 300 mg (1:1:1) with planned follow-up of about 2 years to substantiate potential cardiovascular protection by assessing key biomarkers and to achieve initial safety objectives. By the end of mid-September 2012, a total of 7174 patient-years of follow-up were accrued. Mean baseline age was 62 years, duration of diabetes 13 years; hemoglobin A1c 8.2%, fasting plasma glucose 9.3 mmol/L, and body mass index 32 kg/m(2). Of the participants, 34% are female and 57% had a history of atherosclerotic vascular disease. Participants will be followed up to achieve primary safety and tolerability objectives and to investigate secondary outcomes. The planned second phase will not be undertaken. CANVAS will define the effects of canagliflozin on biomarkers and provide data on cardiovascular safety against established regulatory parameters.

What is the prognostic role of thyroid hormone in patients with heart failure?

Altered thyroid profile, particularly sick euthyroid syndrome, is an independent predictor of mortality in patients with chronic heart failure, adding prognostic information to conventional clinical and functional cardiac parameters.

[19006851, 20978564, 12963854, 17893267, 9489964, 8960429, 15642542, 23369135, 15694896, 19110971, 20024637, 17315395, 18221125, 22870736, 2358611, 19917524, 23435988, 16499159, 8333797, 12165115, 19181292, 17966446, 15259379, 2189307, 23555069, 17923583]

BACKGROUND: It has been suggested that low thyroid hormones levels may be associated with increased mortality in patients with cardiovascular disease. AIM: To evaluate the prognostic role of thyroid function deficiency in patients with chronic heart failure (CHF). METHODS: We evaluated 338 consecutive outpatients with stable CHF receiving conventional therapy, all of whom underwent a physical examination, electrocardiography and echocardiography. Blood samples were drawn to assess renal function, and Na+, hemoglobin, NT-proBNPs, fT3, fT4 and TSH levels. Patients with hyperthyroidism were excluded. RESULTS: During the follow-up (15+/-8 months), heart failure progression was observed in 79 patients (including 18 who died of heart failure after hospitalisation and six who underwent transplantation). Univariate regression analysis showed that TSH (p<0.0001), fT3 (p<0.0001), fT4 (p=0.016) and fT3/fT4 (p<0.0001) were associated with heart failure progression but multivariate analysis showed that only TSH considered as a continuous variable (p = 0.001) as well as subclinical hypothyroidism (TSH &gt 5.5 mUI/l; p=0.014) remained significantly associated with the events. CONCLUSIONS: In CHF patients TSH levels even slightly above normal range are independently associated with a greater likelihood of heart failure progression. This supports the need for prospective studies aimed at clarifying the most appropriate therapeutic approach to sub-clinical hypothyroidism in such patients. Although low levels of free triiodothyronine and high levels of brain natriuretic peptide have been shown as independent predictors of death in chronic heart failure patients, few studies have compared their prognostic values. The aim of this prospective study was to measure free triiodothyronine and brain natriuretic peptide levels and to compare their prognostic values among such patients.A total of 334 patients (mean age, 62 ± 13 yr; 218 men) with ischemic and nonischemic dilated cardiomyopathy were included in the study. The primary endpoint was a major cardiac event.During the follow-up period, 92 patients (28%) experienced a major cardiac event. Mean free triiodothyronine levels were lower and median brain natriuretic peptide levels were higher in patients with major cardiac events than in those without. A significant negative correlation was found between free triiodothyronine and brain natriuretic peptide levels. Receiver operating characteristic curve analysis showed that the predictive cutoff values were < 2.12 pg/mL for free triiodothyronine and > 686 pg/mL for brain natriuretic peptide. Cumulative survival was significantly lower among patients with free triiodothyronine < 2.12 pg/mL and among patients with brain natriuretic peptide > 686 pg/mL. In multivariate analysis, the significant independent predictors of major cardiac events were age, free triiodothyronine, and brain natriuretic peptide.In the present study, free triiodothyronine and brain natriuretic peptide had similar prognostic values for predicting long-term prognosis in chronic heart failure patients. These results also suggested that combining these biomarkers may provide an important risk indicator for patients with heart failure. OBJECTIVE: Previous experimental studies have provided evidence showing that changes in thyroid hormone signaling correspond to alterations in myocardial function in animal models of heart failure. The present study further explores whether thyroid hormone alterations are correlated with the functional status of the myocardium in patients with heart failure. METHODS: In this study, 37 patients with mean ejection fraction (EF%) of 26.2 (8.2) were included. Myocardial performance was assessed by echocardiography and cardiopulmonary exercise testing. Total tri-iodothyronine (T3), thyroxine, and TSH levels were measured in plasma. RESULTS: Total T3 was strongly correlated with VO2max (r = 0.78, P = 2 x 10(-8)). Furthermore, multivariate analysis revealed that total T3 was an independent predictor of VO2max (P = 0.000 005). A weaker but significant correlation was also found between total T3 and EF% (r = 0.56, P = 0.0004), systolic (r = 0.43, P = 0.009) and diastolic (r = 0.46, P = 0.004) blood pressure. CONCLUSIONS: changes in thyroid hormone were closely correlated to myocardial functional status in patients with heart failure. These data probably indicate a possible role of thyroid hormone in the pathophysiology of heart failure and confirm previous experimental reports. Thyroid hormone directly affects the heart and peripheral vascular system. The hormone can increase myocardial inotropy and heart rate and dilate peripheral arteries to increase cardiac output. An excessive deficiency of thyroid hormone can cause cardiovascular disease and aggravate many preexisting conditions. In severe systemic illness and after major surgical procedures changes in thyroid function can occur, leading to the "euthyroid sick syndrome." Patients will have normal or decreased levels of T4, decreased free and total T3, and usually normal levels of thyroid stimulating hormone. This syndrome may be an adaptive response to systemic illness that usually will revert to normal without hormone supplementation as the illness subsides. Recently, however, many investigators have explored the benefits of thyroid hormone supplementation in those diseases associated with euthyroid sick syndrome. Thyroid hormone's effects on the cardiovascular system make it an attractive therapy for those patients with impaired hemodynamics and low T3. Thyroid hormone has also been considered a treatment for patients with congestive heart failure, for patients undergoing cardiopulmonary bypass and heart transplantation, and for patients with hyperlipidemia. At present there is no evidence suggesting a favorable treatment outcome using thyroid hormone supplementation for any systemic condition except in those patients with documented hypothyroidism. BACKGROUND: Changes in peripheral thyroid hormone concentration and metabolism can occur in euthyroid patients suffering from severe non-thyroidal illnesses. Recently, sick euthyroid syndrome has been reported in patients suffering from advanced heart failure. AIM: This study was to evaluate prospectively the presence and pathophysiological implications of sick euthyroid syndrome in moderate-to-severe chronic heart failure patients. METHODS: The study population were 199 chronic heart failure patients admitted over a 2-year period to our heart failure unit for assessment of cardiac transplantation. They were closely followed up with clinical and instrumental examinations (including clinical, hormonal, nutritional and cardiac function evaluations). Sick euthyroid syndrome was defined as a serum total triiodothyronine value of less than the lowest normal limit (< 1.23 nmol.l-1) in the presence of a normal serum thyroid stimulating hormone concentration. RESULTS: Sick euthyroid syndrome was found in 36/199 patients (18%). According to the New York Heart Association (NYHA) classification of severity of heart failure, sick euthyroid syndrome patients appear in higher NYHA classes (31% of classes III and IV, vs 7% of class I and II). Such patients also weigh less and are more frequently malnourished. Alterations in cardiac index, ventricular filling pressures, functional impairment, and the liver function parameters, were more significant in sick euthyroid syndrome than in non-sick euthyroid syndrome patients. Serum norepinephrine and atrial natriuretic factor were significantly higher, and insulin significantly lower in the sick euthyroid syndrome group. During follow-up, deaths were significantly more frequent in sick euthyroid syndrome patients (13/27, 48%) than in non-sick euthyroid syndrome (30/141, 21%; P < 0.005). In six sick euthyroid syndrome patients who underwent heart transplantation, mean total triiodothyronine values increased from 0.9 +/- 0.1 before to 1.96 +/- 0.3 nmol.l(-1)post-transplantation (P < 0.05). CONCLUSIONS: In a large and representative population of patients with moderate-to-severe heart failure, sick euthyroid syndrome shows a prevalence of 18%. Its occurrence was related to the degree of functional cardiac impairment, but was not an independent negative prognostic factor. Preliminary results indicate that heart transplantation is associated with reversibility of sick euthyroid syndrome. BACKGROUND: Abnormalities in thyroid function are frequent in patients with heart failure and are associated with increased mortality. However, the relation between thyroid hormone levels and echocardiographic parameters has not been investigated sufficiently. AIM: The aims of this study were to investigate the correlations of thyroid hormone levels with echocardiographic parameters and to evaluate their associations with subsequent mortality in a group of patients with dilated cardiomyopathy (DCMP). METHODS: Serum levels of thyroid hormones were measured in 111 consecutive patients with DCMP (35 female, 76 male, mean age: 62+/-12 years). All patients underwent echocardiographic examination and were followed-up for a period of 12+/-8 months. RESULTS: Twenty-three patients (21%) had abnormalities in thyroid function tests. Free triiodothyronine (fT3)/free thyroxine (fT4) ratio was significantly correlated with most of echocardiographic parameters, such as chamber diameters and ejection fraction. Sixteen patients (14%) died during the follow-up period; their fT3/fT4 ratio was significantly lower than the patients who survived (1.31+/-0.37 vs. 2.01+/-0.72, p<0.001). A fT3/fT4 ratio of <or=1.7 was associated with an increased risk of mortality (p<0.001), independent of other prognostic markers. Sensitivity, specificity, positive and negative predictivity of fT3/fT4 ratio <or=1.7 for cardiac mortality were 100%, 71%, 36% and 100%, respectively. CONCLUSION: Determination of FT3/FT4 ratio may be a valuable and simple predictor for identification of patients with DCMP who are at high risk of subsequent mortality. Thyroid hormones have relevant activity at cardiac and vascular level, by influencing heart rate, myocardial excitability as well as inotropic and lusitropic status, systemic vascular resistance and blood pressure. Moreover, they interact with neuro-hormonal systems such as sympathetic nervous system and renin-angiotensin-aldosterone system thus also indirectly influencing cardiovascular function. Due to these effects, both hypothyroidism and hyperthyroidism, either in their overt or subclinical forms, can have an unfavourable impact in the setting of cardiovascular diseases. The aim of this review is to focus on the prognostic consequences of thyroid disorders in heart failure patients. Moreover, the therapeutical approach and the possible beneficial effects of restoring euthyroidism are reviewed. Thyroid (dys)function in heart failure: is it a potential target for medical treatment? Interest in the role of thyroid hormones (TH) in heart failure is steadily increasing due to evidence for a physiological, homeostatic role of TH and the effects of altered TH metabolism on the cardiovascular system, particularly in presence of heart failure. Experimental studies have shown that altered TH metabolism modifies cardiovascular homeostasis by inducing alterations of cardiac histology, cardiomyocyte morphology and gene expression and consequently, of diastolic and systolic myocardial function. Clinical studies have shown that mild forms of thyroid dysfunction, both primary (subclinical hypothyroidism and subclinical hyperthyroidism) and secondary (low T(3) syndrome) have negative prognostic impact in patients with heart failure. In these patients, the administration of synthetic triiodothyronine (T(3)) was well tolerated and induced significant improvement in cardiac function without increased heart rate and metabolic demand. Large multicenter, placebo-controlled prospective studies are necessary to evaluate the safety and prognostic effects of chronic treatment with TH replacement therapy in patients with heart failure. The article also discusses recent patents in this field. OBJECTIVE: The objective of this paper was to investigate the diagnostic and prognostic value of plasma B type natriuretic peptide (BNP) and serum triiodothyronine (T3) in chronic congestive heart failure (CHF). METHODS: 156 cases of CHF patients and 75 cases of cardiac function I patients hospitalized over the same period were utilized in this study. On admission, the patient's BNP and T3 plasma concentrations were measured. The correlation analysis of plasma BNP and T3 in CHF patients with cardiac function classification was conducted. RESULTS: According to the NYHA grading systems, the plasma BNP levels in patients with II, III, and IV grade CHF were significantly higher than those with cardiac function I (P < 0.05); BNP levels and NYHA grading of cardiac function correlated positively. The BNP concentrations increased with CHF progression (P < 0.01). The T3 level and NYHA grading of cardiac function correlated negatively.TheT3 level decreased as the degree of heart failure increased. Using CHF in combination with BNP to predict the occurrence of CHF had a sensitivity value of 90.8% with 95.5% specificity, 86.3% accuracy, and a negative predictive value of 87.7%. CONCLUSIONS: Plasma BNP was more sensitive than T3 in the diagnosis of CHF. The T3 was more meaningful than the BNP in the prognosis of CHF. The BNP and T3 combination detection was more valuable in determining the severity of CHF and prognosis. Patients with advanced congestive heart failure are often severely ill and may experience substantial abnormalities in thyroid hormone metabolism. Thus, we examined this patient population to determine the prevalence and prognostic significance of altered thyroid hormone concentrations, the course of thyroid abnormalities in congestive heart failure survivors, and the potential relationship of thyroid abnormalities to overall metabolic rate. Our results indicate that thyroid hormone metabolism (ie, the triiodothyronine to reverse triiodothyronine ratio) is altered in a majority of patients with advanced congestive heart failure and is an independent predictor of mortality. Currently a study is underway that will provide further evidence for the mechanisms involved in congestive heart failure and abnormal thyroid hormone metabolism. BACKGROUND: Both low free triiodothyronine (fT3) and high brain natriuretic peptide (BNP) have been separately described as prognostic predictors for mortality in heart failure (HF). We investigated whether their prognostic value is independent. METHODS AND RESULTS: From January of 2001 to December of 2006, we prospectively evaluated 442 consecutive patients with systolic HF and no thyroid disease or treatment with drugs affecting thyroid function (age 65+/-12 years, mean +/- standard deviation, 75% were male, left ventricular ejection fraction 33% +/- 10%, New York Heart Association (NYHA) class I and II: 63%, NYHA class III and IV: 37%). All patients underwent full clinical and echocardiographic evaluation and assessment of BNP and thyroid function. Both cardiac and all-cause mortality (cumulative) were considered as end points. During a median 36-month follow-up (range 1-86 months), 110 patients (24.8%) died, 64 (14.4%) of cardiac causes. Univariate Cox model predictors of all-cause mortality and cardiac death were age, body mass index, creatinine, hemoglobin, ejection fraction, NYHA class, BNP, fT3, and thyroxine level. Multivariate analysis selected age, NYHA class, hemoglobin, BNP, and fT3 as independent predictors for all-cause mortality and NYHA class, BNP, and fT3 as independent predictors for cardiac mortality. Patients with low fT3 and higher BNP showed the highest risk of all-cause and cardiac death (odds ratio 11.6, confidence interval, 5.8-22.9; odds ratio 13.8, confidence interval, 5.4-35.2, respectively, compared with patients with normal fT3 and low BNP). CONCLUSION: fT3 and BNP hold an independent and additive prognostic value in HF. Thyroid hormones have many effects on the heart and vascular system. Although cardiac output is reduced in hypothyroidism, heart failure is relatively rare because there is a lower demand for peripheral oxygen delivery. Hypothyroidism may also result in accelerated atherosclerosis and coronary artery disease. We report the case of a 55-year-old man with severe heart failure associated with severe longstanding untreated hypothyroidism. The patient was admitted for shortness of breath and chest pain. On presentation, signs and symptoms of severe hypothyroidism and heart failure were noticed. The electrocardiogram showed sinus bradycardia and ischemia. Thyroid stimulating hormone was extremely elevated and thyroid hormone levels were undetectable. A cardiac ultrasonography exam revealed abnormalities of the left ventricular dimensions and function consistent with dilated cardiomyopathy. Coronary angiography showed severe multivessel disease. Coronary by-pass was deemed necessary, but surgery was postponed because of severe heart failure. After an increasingly downhill clinical course, the patient died, eight month after his initial presentation, owing to severe heart failure. This patient represents an example of an overlooked diagnosis of severe hypothyroidism, rarely encountered nowadays, leading to dramatic consequences. The derangement of neuro-endocrine control of circulation influences both disease evolution and response to treatment in patients with heart failure, but little data are available about the complex relationships between the degree of neuro-hormonal activation and clinical severity. We studied the relationships between cardiac natriuretic hormones (CNHs) and several neuro-hormones and immunological markers in a prospective cohort of 105 consecutive patients with cardiomyopathy (77 men and 28 women, mean age 66.7+/-12.4 years, range 33-89 years). We assayed the circulating levels of CNHs (atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP)), plasma renin activity (PRA), aldosterone, cortisol, adrenaline, noradrenaline, thyroid hormones and thyroid stimulating hormone (TSH), tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6). The concentrations of all CNHs and neurohormones were higher in patients with heart failure compared to normal subjects, except for free triiodothyronine (FT3), which was below normal values. ANP was positively related to NYHA class, IL-6, adrenaline, noradrenaline and cortisol, while negatively with ejection fraction and FT3. BNP was positively related to age, NYHA class, IL-6, TNF-alpha, adrenaline, noradrenaline and cortisol, while negatively with ejection fraction and FT3. A stepwise multiple linear regression indicated that plasma ANP depended only on ejection fraction, adrenaline and noradrenaline values, while for plasma BNP variation NYHA class contributed too. Our data confirm a progressive activation of hormonal and immunological systems in patients with heart failure. Furthermore, CNH circulating levels in heart failure are affected not only by cardiac function and disease severity, but also by activation of neuro-hormonal and stress-related cytokine systems, as well as by the thyroid hormones, even on usual medical treatment.

which mutations of phospholamban gene have been found to cause hypertrophic cardiomyopathy?

The following mutations of the phospholamban gene have been found to be associated with hypertrophic cardiomyopathy: PLN L39X nonsense mutation; PLN Leu39Ter; PLN -42 C>G and PLN -77A-->G

[17655857, 12705874, 21167350, 16829191]

BACKGROUND: hypertrophic cardiomyopathy (HCM) is a major cause of sudden death in young athletes and one of the most common inherited cardiovascular diseases, affecting 1 in 500 individuals. Often viewed as a disease of the cardiac sarcomere, mutations in genes encoding myofilament proteins are associated with disease pathogenesis. Despite a clinically available genetic test, a significant portion of HCM patients remain genetically unexplained. We sought to determine the spectrum and prevalence of mutations in PLN-encoded phospholamban in a large cohort of HCM cases as a potential cause of mutation-negative HCM. METHODS: comprehensive genetic interrogation of the promoter and coding region of PLN was conducted using polymerase chain reaction, denaturing high-performance liquid chromatography, and direct DNA sequencing. RESULTS: one L39X nonsense mutation was identified in 1 of 1,064 HCM proband cases with a family history of HCM, previously found to be negative for the current HCM genetic test panel. This mutation cosegregated with incidence of HCM in a multigenerational family. Compared with similar studies, we identified an overall yield of PLN-HCM mutations of 0.65%, similar to 3 genes that are part of current HCM genetic test panels. We did not observe any PLN coding sequence genetic variation in 600 reference alleles. CONCLUSIONS: overall, mutations in PLN are rare in frequency, yet the small size of the genetic locus may make it amenable to inclusion on HCM gene test panels, especially because the frequency of background genetic variation among otherwise healthy subjects appears negligible. The exact role of mutations in PLN and other calcium-handling proteins in the development of HCM warrants further investigation. BACKGROUND: Phospholamban is an endogenous sarcoplasmic reticulum calcium ATPase inhibitor with a regulatory effect on cardiac contraction/relaxation coupling. Mutations in the phospholamban gene (PLN) have been associated with primary cardiomyopathies. AIMS: To screen for PLN mutations in our population of patients with primary cardiomyopathies and to perform functional analysis of the mutations identified. METHODS: We performed SSCP mutational screening and DNA sequencing of the PLN gene in 186 patients with either hypertrophic or dilated cardiomyopathy. To study promoter strength we constructed reporter plasmids containing the luciferase gene and performed transient transfection analysis in C6 and C2C12 cell lines. RESULTS: The PLN -42 C>G mutation was found in one patient with late onset familial apical hypertrophic cardiomyopathy. This mutation decreased phospholamban promoter activity by 43% and 47%, in C6 and C2C12 cell lines respectively. One son had mild apical hypertrophic cardiomyopathy and carried the mutation, another son with normal ECG and echocardiogram also had the mutation. CONCLUSION: The PLN -42 C>G mutation is associated with a benign form of apical hypertrophic cardiomyopathy in this family, though the presence of a healthy adult carrier suggests that other genetic and environmental factors could be involved. Otherwise, mutations in the PLN gene are not a frequent cause of cardiomyopathies in our population.

Which gene strand is targeted by transcription-coupled repair (TCR)?

Nucleotide Excision Repair (NER) removes a variety of helix-distorting lesions from DNA. It has two sub-pathways, the global genome (gg) NER and the transcription-coupled repair (TCR). TCR is triggered when a RNA polymerase, translocating along the transcribed strand, is arrested at a lesion or unusual structure in the DNA. TCR is dedicated to target and repair the transcribed strand of an active gene.

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It has been previously shown that disruption of RAD26 in yeast strain W303-1B results in a strain that is deficient in transcription-coupled repair (TCR), the preferential repair of the transcribed strand of an expressed gene over the non-transcribed strand and the rest of the genome. RAD26 encodes a protein that is homologous to Cockayne syndrome group B protein (CSB) and is a member of the SWI2/SNF2 family of DNA-dependent ATPases involved in chromatin remodeling. Like the rad26 mutant, cells from Cockayne syndrome patients are defective in TCR. We examined the role of Rad26 in TCR by disrupting RAD26 in two repair-proficient laboratory strains and, remarkably, observed no effect upon TCR. Our results indicate that disruption of RAD26 alone is insufficient to impair TCR. Thus, W303-1B must already possess a mutation that, together with disruption of RAD26, causes a deficiency in TCR. We suggest that other genes are mutated in Cockayne syndrome cells that contribute to the deficiency in TCR. Surprisingly, deletion of RAD26 results in expression of genes that are repressed by flanking transposon delta elements, an Spt(-) phenotype. The delta elements appear to perturb local chromatin structure. Expression of genes flanked by delta elements in rad26Delta mutants is consistent with a role for Rad26 in chromatin remodeling. A specialized nucleotide excision repair pathway known as transcription-coupled repair (TCR) counteracts the toxic effects of DNA damage in transcriptionally active genes. The clustering of active genes into gene-rich chromosomal domains predicts that the sites of TCR are unevenly distributed through the genome. To elucidate the genomic organization and chromosomal localization of TCR, we isolated DNA fragments encompassing TCR-mediated repair sites from UV-C irradiated xeroderma pigmentosum group C cells, which can only repair the transcribed strand of active genes. This DNA was used as a molecular probe to visualize TCR in normal metaphase spreads by reverse fluorescence in situ hybridization. Whereas DNA repair sites in normal human cells are evenly distributed through the genome, TCR is highly localized at specific chromosomal domains. Particularly, clusters of TCR sites were identified at early-replicating gene-rich bands and telomeric regions of several chromosomes. High gene-density chromosomes such as chromosome 19 and the GC-rich domains of several chromosomes (T bands) are preferential locations of TCR. Our results demonstrate that the intragenomic localization of TCR resembles the uneven distribution of the human transcriptome, CpG islands, and hyperacetylated histones, enforcing the basic link between DNA repair, transcription, and nuclear organization in a complex genome. 7,8-Dihydro-8-oxoguanine (8-oxoG) is the most frequent mutagenic lesion caused by oxidative stress. Eukaryotic cells use a specific DNA glycosylase, OGG1, to excise 8-oxoG from DNA. The mild phenotype of OGG1 null mice has been attributed to the existence of alternative pathways, including Cockayne syndrome B (CSB)-dependent transcription coupled repair (TCR), for removal of 8-oxoG. We have studied repair and transcription activities at 8-oxoG lesions with a reconstituted transcription system (RTS; RNA polymerase II, TBP, TFIIA, TFIIB, TFIIE, TFIIF and TFIIH), as well as in cellular extracts and in vivo. All measurable repair activity at 8-oxoG lesions takes place in the 3'-direction from the lesion, indicating base excision repair (BER) activity and negligible role of nucleotide excision repair (NER). Although 8-oxoG has been shown to be preferentially removed from the transcribed strand, in vitro experiments with purified transcription factors failed to identify a definite block for RNA polymerase II at the lesion. However, a weak block was observed at the lesion during transcription carried out with RTS as well as with cellular extracts. RNA polymerase II was identified at the site of the lesion on obstructed templates. Wild-type cells, as well as cells carrying targeted mutations of genes required for removal of 8-oxoG, were transfected with a luciferase expression vector containing an 8-oxoG lesion. No significant obstruction at 8-oxoG lesions was observed by this in vivo approach. In control experiments transcription elongation was completely blocked by cisplatin. Nucleotide Excision Repair (NER), which removes a variety of helix-distorting lesions from DNA, is initiated by two distinct DNA damage-sensing mechanisms. Transcription Coupled Repair (TCR) removes damage from the active strand of transcribed genes and depends on the SWI/SNF family protein CSB. Global Genome Repair (GGR) removes damage present elsewhere in the genome and depends on damage recognition by the XPC/RAD23/Centrin2 complex. Currently, it is not well understood to what extent both pathways contribute to genome maintenance and cell survival in a developing organism exposed to UV light. Here, we show that eukaryotic NER, initiated by two distinct subpathways, is well conserved in the nematode Caenorhabditis elegans. In C. elegans, involvement of TCR and GGR in the UV-induced DNA damage response changes during development. In germ cells and early embryos, we find that GGR is the major pathway contributing to normal development and survival after UV irradiation, whereas in later developmental stages TCR is predominantly engaged. Furthermore, we identify four ISWI/Cohesin and four SWI/SNF family chromatin remodeling factors that are implicated in the UV damage response in a developmental stage dependent manner. These in vivo studies strongly suggest that involvement of different repair pathways and chromatin remodeling proteins in UV-induced DNA repair depends on developmental stage of cells. We examined the role of yeast transcription initiation factor IIE (TFIIE) in eukaryotic transcription-coupled repair (TCR), the preferential removal of DNA damage from the transcribed strands of genes over non-transcribed sequences. TFIIE can recruit the transcription initiation/repair factor TFIIH to the RNA polymerase II (RNA pol II) initiation complex to facilitate promoter clearance. Following exposure to UV radiation, the RNA pol II elongation complex is blocked at sites of UV-induced DNA damage, and may be recognized by nucleotide excision repair proteins, thus enabling TCR. The TFA1 gene encodes the large subunit of TFIIE. We determined how DNA repair is affected by TFA1 conditional mutations. In particular, we find proficient TCR in a heat-sensitive tfa1 mutant at the non-permissive temperature during which growth is inhibited and overall RNA pol II transcription is reported to be inhibited. We demonstrate that transcription of the RPB2 gene was reduced, but readily detectable, in the heat-sensitive tfa1 mutant at the non-permissive temperature and thereby prove that TCR does occur in an expressed gene in the absence of TFIIE in vivo. We demonstrate that TCR occurs even at low levels of transcription. The eukaryotic cell encounters more than one million various kinds of DNA lesions per day. The nucleotide excision repair (NER) pathway is one of the most important repair mechanisms that removes a wide spectrum of different DNA lesions. NER operates through two sub pathways: global genome repair (GGR) and transcription-coupled repair (TCR). GGR repairs the DNA damage throughout the entire genome and is initiated by the HR23B/XPC complex, while the CSB protein-governed TCR process removes DNA lesions from the actively transcribed strand. The sequence of events and the role of particular NER proteins are currently being extensively discussed. NER proteins also participate in other cellular processes like replication, transcription, chromatin maintenance and protein turnover. Defects in NER underlay severe genetic disorders: xeroderma pigmentosum (XP), Cockayne syndrome (CS) and trichothiodystrophy (TTD). Stem cells, one of the progenitors of cancer, exist predominately in a quiescent state. Thus, understanding the mechanisms of DNA repair and mutagenesis in such arrested cells may help unravel the complex process of tumorigenesis. Two major nucleotide excision repair (NER) pathways are known to remove bulky physical or chemical lesions from DNA. Transcription-coupled repair (TCR) acts solely on the transcribed strand of expressed genes, while global genomic repair (GGR) is responsible for the ubiquitous repair of the genome. Indirectly, it has been shown that while TCR functions in quiescent cells GGR does not. To explicitly elucidate this phenomenon, we adapted a quantitative PCR (QPCR) assay to study UV-damage repair via TCR and GGR in quiescent and proliferating cells. We present evidence that repair of untranscribed silent regions of the genome and repair of the non-transcribed strand of active genes proceeds by two discrete mechanisms in quiescent cells; rather than by GGR, which was believed to encompass both. Thus, our findings suggest the existence of an alternate NER pathway in quiescent cells. The proposed subcategories of NER are as follows: (i) TCR, responsible for maintenance of transcribed strands; (ii) GGR, responsible for ubiquitous genome repair; and (iii) non-transcribed strand repair (NTSR), predominantly responsible for the repair of the NTS in arrested cells. In quiescent cells, it is evident that TCR and NTSR function and GGR are arrested. As a consequence, mutation accumulation at temporally silent genes and incomplete or imperfect repair of transcribed genes, in quiescent stem cells, may provide a source of cancer causing mutations. Nucleotide excision repair (NER) mechanism is the major pathway responsible for the removal of a large variety of bulky lesions from the genome. Two different NER subpathways have been identified, i.e. the transcription-coupled and the global genome repair pathways. For DNA-damage induced by ultraviolet light both transcription-coupled repair and global genome repair are essential to confer resistance to cytotoxic effects. To gain further insight into the contribution of NER subpathways in the repair of bulky lesions and in their prevention of biological effects we measured the rate of repair of dG-C8-AF in active and inactive genes in normal human cells, XP-C cells (only transcription-coupled repair) and XP-A cells (completely NER-deficient) exposed to NA-AAF. XP-C cells are only slightly more sensitive to NA-AAF than normal cells and, like normal cells, they are able to recover RNA synthesis repressed by the treatment. In contrast, XP-A cells are sensitive to NA-AAF and unable to recover from RNA synthesis inhibition. Repair of dG-C8-AF in the active ADA gene proceeds in a biphasic way and without strand specificity, with a subclass of lesions quickly repaired during the first 8 h after treatment. Repair in the inactive 754 gene occurs more slowly than in the ADA gene. In XP-C cells, repair of dG-C8-AF in the ADA gene is confined to the transcribed strand and occurs at about half the rate of repair seen in normal cells. Repair in the inactive 754 gene in XP-C cells is virtually absent. Consistent with these results we found that repair replication in XP-C is drastically reduced when compared with normal cells and abolished by alpha-amanitin indicating that the repair in XP-C cells is mediated by transcription-coupled repair only. Our data suggest that dG-C8-AF is a target for transcription-coupled repair and that this repair pathway is the main pathway or recovery of RNA synthesis inhibition conferring resistance to cytotoxic effects of NA-AAF. In spite of this, repair of dG-C8-AF in active genes in normal cells by transcription-coupled repair and global genome repair is not additive, but dominated by global genome repair. This indicates that the subset of lesions which are capable of stalling RNA polymerase II, and are, therefore, a substrate for TCR, are also the lesions which are very efficiently recognized by the global genome repair system. The blockage of transcription elongation by RNA polymerase II (pol II) at a DNA damage site on the transcribed strand triggers a transcription-coupled DNA repair (TCR), which rapidly removes DNA damage on the transcribed strand of the expressed gene and allows the resumption of transcription. To analyze the effect of UV-induced DNA damage on transcription elongation, an in vitro transcription elongation system using pol II and oligo(dC)-tailed templates containing a cyclobutane pyrimidine dimer (CPD) or 6-4 photoproduct (6-4PP) at a specific site was employed. The results showed that pol II incorporated nucleotides opposite the CPD and 6-4PP and then stalled. Pol II formed a stable ternary complex consisting of pol II, the DNA damage template, and the nascent transcript. Furthermore, atomic force microscopy imaging revealed that pol II stalled at the damaged region. These findings may provide the basis for analysis of the initiation step of TCR. DNA damage results in the up-regulation of several genes involved in different cellular physiological processes, such as the nucleotide excision repair (NER) mechanism that copes with a broad range of DNA alterations, including the carcinogenic ultraviolet (UV) light-induced pyrimidine dimers (PDs). There are two NER sub-pathways: transcription coupled repair (TCR) that is specific for the transcribed strands (TS) of active genes and global genomic repair (GGR) that repairs non-transcribed DNA sequences (NTD) and the non-transcribed strands (NTS) of expressed genes. To elucidate the role of UV-dependent de novo protein synthesis in nucleotide excision repair in the budding yeast, we investigated the effect of the protein synthesis inhibitor, cycloheximide, on the removal of PDs. Log phase as well as G(1)-synchronized cells were treated with the drug shortly before UV irradiation and immediately thereafter, and the repair of damaged DNA was assessed with the high resolution primer extension technique. The results show that in both cellular conditions, the inhibition of UV-dependent de novo protein synthesis by cycloheximide impairs the excision repair of the transcriptionally active GAL10 and URA3 genes, with a greater effect on the non-transcribed strands. This indicates that UV-mediated de novo protein synthesis is required for efficient nucleotide excision repair, but not for the preferential repair of the TSs. On the other hand, cycloheximide did not affect the repair of either strand of the repressed GAL10 gene or the non-transcribed promoter region of the URA3 gene, showing that UV-induced de novo protein synthesis is not required for PD removal from transcriptionally inactive DNA sequences. Together, these data show that despite the fact that NTD and NTSs are normally repaired by the GGR sub-pathway, their requirement for UV-dependent de novo protein synthesis is different, which may suggest a difference in the processing of UV lesions in these non-transcribed sequences of the genome. In humans, DNA lesions such as pyrimidine dimers in the template strand of genes transcribed by RNA polymerase II are repaired faster than those in the coding strand and nontranscribed regions of the genome. This phenomenon, referred to as transcription-coupled repair (i) requires active transcription, (ii) does not require the XPC gene product which is essential for general/basal repair reactions, and (iii) requires the CSA and CSB proteins. We have developed an in vitro model system that consists of purified human excision repair factors and a DNA substrate analogous to a transcription bubble terminating at a cyclobutane thymine dimer. In this system the thymine dimer was excised independent of XPC. Furthermore, the thymine dimer in the bubble-containing substrate was removed approximately 3-fold faster by the excision repair nuclease reconstituted with or without XPC, compared with the removal of thymine dimer from a base paired duplex by the entire set of excision nuclease factors. These results provide important insight into the mechanism of transcription-coupled repair in humans. Transcription-coupled repair (TCR) is generally observed as more rapid or more efficient removal of certain types of DNA damage from the transcribed strands of expressed genes compared with the nontranscribed strands. It has been clearly demonstrated to be a subpathway of nucleotide excision repair (NER) in E. coli, yeast and mammalian cells. Genetic and biochemical studies indicate that it is a highly complex process and requires the participation of the NER pathway, the RNA polymerase complex and additional factors. An early event in TCR is likely the blocking of RNA polymerase complex elongation by damage present in the transcribed strands of expressed genes. Whether TCR is involved in base excision repair pathways or the repair of common forms of oxidative damage is less clear. This review is focused on the description of possible mechanisms of TCR in E. coli and mammalian cells. This review concerns reversion of the argE3 (ochre) nonsense mutation to prototrophy in E. coli AB1157 strain as an informative system for mutation detection. Strain AB1157 bears the argE3 (ochre), hisG4 (ochre) and thr-1 (amber) mutations, and the supE44 amber suppressor on its chromosome. The Arg(+) phenotype can be restored by (i) any base substitution at the argE3 site that changes the nonsense UAA codon to any sense nucleotide triplet or to UAG recognized by the supE44 amber suppressor, or (ii) suppressor mutations enabling the reading of the UAA nonsense codon. The argE3 → Arg(+) reversion-based system enables (i) determination of the spontaneous or induced mutation level; (ii) determination of base substitutions (suppressor analysis); (iii) examination of transcription-coupled repair (TCR) since targets for DNA damage are situated on the transcribed or coding strand of DNA; (iv) detection of mutations resulting from single stranded DNA damage. This review focuses on studies carried out since the early 1990s till now with the application of the AB1157-based mutation detection system. Recently, the system has been used to obtain new data on the processes of methyl methanesulfonate-induced mutagenesis and DNA repair in E. coli alkB⁻ mutants. Transcription coupled repair (TCR), a special sub-pathway of nucleotide excision repair (NER), removes transcription blocking lesions rapidly from the transcribing strand of active genes. In this study, we have evaluated the importance of the TCR pathway in the induction of chromosomal aberrations and apoptosis in isogenic Chinese hamster cell lines, which differ in TCR efficiency. AA8 is the parental cell line, which is proficient in the genome overall repair of UV-C radiation induced 6-4 photoproducts (6-4 PP) and the repair of cyclobutane pyrimidine dimer (CPD) from the transcribing strand of active genes. UV61 cells (hamster homologue of human Cockayne's syndrome (CS) group B cells) originally isolated from AA8, exhibit proficient repair of 6-4 PP but are deficient in CPD removal by the TCR pathway. Upon UV-C irradiation of cells in G1-phase, UV61 showed a dramatic increase in apoptotic response as compared to AA8 cells. Abolition of TCR by treatment with alpha-amanitin (an inhibitor of RNA polymerase II) in AA8 cells also resulted in an elevated apoptotic response like that observed in UV61 cells treated with UV alone. This suggests that the lack of TCR is largely responsible for increased apoptotic response in UV61 cells. Furthermore, the chromosomal aberrations and sister chromatid exchange (SCE) induced by UV were also found to be higher in UV61 cells than in TCR proficient AA8 cells. This study shows that the increased chromosomal aberrations and apoptotic death in UV61 cells is due to their inability to remove CPD from the transcribing strand of active genes and suggests a protective role for TCR in the prevention of both chromosomal aberrations and apoptosis induced by DNA damage. Furthermore, flow cytometry analysis and time-course appearance of apoptotic cells suggest that the conversion of UV-DNA damage into chromosomal aberrations precedes and determines the apoptotic process. Transcription-coupled repair (TCR) is a subpathway of nucleotide excision repair (NER) that acts specifically on lesions in the transcribed strand of expressed genes. First reported in mammalian cells, TCR was then documented in Escherichia coli. In this organism, an RNA polymerase arrested at a lesion is displaced by the transcription repair coupling factor, Mfd. This protein recruits the NER lesion-recognition factor UvrA, and then dissociates from the DNA. UvrA binds UvrB, and the assembled UvrAB* complex initiates repair. In mutants lacking active Mfd, TCR is absent. A gene transcribed by the bacteriophage T7 RNA polymerase in E. coli also requires Mfd for TCR. The CSB protein (missing or defective in cells of patients with Cockayne syndrome, complementation group B) is essential for TCR in humans. CSB and its homologs in higher eukaryotes are likely functional equivalents of Mfd. Transcription-coupled repair (TCR) is a pathway dedicated to the removal of damage from the template strands of actively transcribed genes. Although the detailed mechanism of TCR is not yet understood, it is believed to be triggered when a translocating RNA polymerase is arrested at a lesion or unusual structure in the DNA. Conventional assays for TCR require high doses of DNA damage for the statistical analysis of repair in the individual strands of DNA sequences ranging in size from a few hundred bases to 30kb. The single cell gel electrophoresis (Comet) assay allows detection of single- or double-strand breaks at a 10-100-fold higher level of resolution. Fluorescence in situ hybridization (FISH) combined with the Comet assay (Comet-FISH) affords a heightened level of sensitivity for the assessment of repair in defined DNA sequences of cells treated with physiologically relevant doses of genotoxins. This approach also reveals localized susceptibility to chromosomal breakage in cells from individuals with hypersensitivity to radiation or chemotherapy. Several groups have reported preferential repair in transcriptionally active genes or chromosomal domains using Comet-FISH. The prevailing interpretation of the behavior of DNA in the Comet assay assumes that the DNA is arranged in loops and matrix-attachment sites; that supercoiled, undamaged loops are contained within the nuclear matrix and appear in Comet "heads", and that Comet "tails" consist of relaxed DNA loops containing one or more breaks. According to this model, localization of FISH probes in Comet heads signifies that loops containing the targeted sequences are free of damage. This implies that preferential repair as detected by Comet-FISH might encompass large chromosomal domains containing both transcribed and non-transcribed sequences. We review the existing evidence and discuss the implications in relation to current models for the molecular mechanism of TCR. Nucleotide excision repair (NER) is a multistep process capable to remove a variety of DNA distorting lesions from prokaryotic and eukaryotic genomes. In eukaryotic cells, the process requires more than 30 proteins to perform the different steps, i.e. recognition of DNA damage, single strand incisions and excision of the lesion-containing DNA fragment and DNA repair synthesis/ligation. NER can operate via two subpathways: global genome repair (GGR) and a specialized pathway coupled to active transcription (transcription-coupled repair, TCR) and directed to DNA lesions in the transcribed strand of active genes. Both in vivo as well as in cultured cells the fast removal of transcription blocking lesions by TCR is crucial to escape from lethal effects of inhibited transcription inhibition The most delicate step in NER is the recognition of the DNA lesions in their different chromatin context and the mechanism of damage recognition in GGR and TCR is principally different and requires specific proteins. In GGR, the XPC-HR23B is essential for the formation of the incision complex. In TCR the Cockayne syndrome (CS) gene products are key players in the recognition of a stalled RNA polymerase the presumed signaling structure for repair of transcribed strands. In this study, we show that the extent of recovery of UV-inhibited transcription and TCR strictly depends on the amount of CSB protein as well as the amount of DNA damage present in the cell. This indicates that the ratio between DNA damage frequency and CSB protein concentration in the cell is rather critical for acute cellular response, i.e. recovery of inhibited transcription upon DNA damage infliction, and hence cellular survival. Transcription-coupled repair (TCR) and global genomic repair (GGR) of UV-induced cyclobutane pyrimidine dimers were investigated in the yeast GAL1-10 genes. Both Rpb9- and Rad26-mediated TCR are confined to the transcribed strands, initiating at upstream sites approximately 100 nucleotides from the upstream activating sequence shared by the two genes. However, TCR initiation sites do not correlate with either transcription start sites or TATA boxes. Rad16-mediated GGR tightly correlates with nucleosome positioning when the genes are repressed and are slow in the nucleosome core and fast in linker DNA. Induction of transcription enhanced GGR in nucleosome core DNA, especially in the nucleosomes around and upstream of the transcription start sites. Furthermore, when the genes were induced, GGR was slower in the transcribed regions than in the upstream regions. Finally, simultaneous deletion of RAD16, RAD26, and RPB9 resulted in no detectable repair in all sites along the region analyzed. Our results suggest that (a). TCR may be initiated by a transcription activator, presumably through the loading of RNA polymerase II, rather than by transcription initiation or elongation per se; (b). TCR and nucleosome disruption-enhanced GGR are the major causes of rapid repair in regions around and upstream of transcription start sites; (c). transcription machinery may hinder access of NER factors to a DNA lesion in the absence of a transcription-repair coupling factor; and (d). other than GGR mediated by Rad16 and TCR mediated by Rad26 and Rpb9, no other nucleotide excision repair pathway exists in these RNA polymerase II-transcribed genes. Transcription coupled repair (TCR) is a nucleotide excision repair (NER) pathway that is dedicated to repair in the transcribed strand of an active gene. The genome overall NER is called global genomic repair (GGR). Elc1, the yeast homolog of the mammalian elongation factor elongin C, has been shown to be a component of a ubiquitin ligase complex that contains Rad7 and Rad16, two factors that are specifically required for GGR. Elc1 has also been suggested to be present in another ubiquitin ligase complex that lacks Rad7 and Rad16 and is involved in UV-induced ubiquitylation and subsequent degradation of RNA polymerase II. Here we show that elc1 deletion increases UV sensitivity of TCR-deficient cells but does not affect the UV sensitivity of otherwise wild type and GGR-deficient cells. Cells deleted for elc1 show normal NER in the transcribed strand of an active gene but have no detectable NER in the non-transcribed strand. Elc1 does not affect UV-induced mutagenesis when TCR is operative, but plays an important role in preventing the mutagenesis if TCR is defective. Furthermore, the levels of Rad7 and Rad16 proteins are not significantly decreased in elc1 cells, and overexpression of Rad7 and Rad16 individually or simultaneously in elc1 cells does not restore repair in the non-transcribed strand of an active gene. Our results suggest that Elc1 has no function in TCR but plays an important role in GGR. Furthermore, the role of Elc1 in GGR may not be subsidiary to that of Rad7 and Rad16. A dedicated excision repair pathway, termed transcription-coupled repair (TCR), targets the removal of DNA lesions from transcribed strands of expressed genes. Transcription arrest at the site of the lesion has been proposed as the first step for initiation of TCR. In support of this model, a strong correlation between arrest of transcription by a lesion in vitro and TCR of that lesion in vivo has been found in most cases analyzed. TCR has been reported for oxidative DNA damage; however, very little is known about how frequently occurring and spontaneous DNA damage, such as depurination and base deamination, affects progression of the transcription complex. We have previously determined that the oxidative lesion, thymine glycol, is a significant block to transcription by T7 RNA polymerase (T7 RNAP) but has no detectable effect on transcription by RNA polymerase II (RNAP II) in a reconstituted system with all of the required factors. Another oxidative lesion, 8-oxoguanine, only slightly blocked T7 RNAP and caused RNAP II to briefly pause at the lesion before bypassing it. Because an abasic site is an intermediate in the repair of oxidative damage, it was of interest to learn whether it arrested transcription. Using in vitro transcription assays and substrates containing a specifically positioned lesion, we found that an abasic site in the transcribed strand is a 60% block to transcription by T7 RNAP but nearly a complete block to transcription by mammalian RNAP II. An abasic site in the nontranscribed strand did not block either polymerase. Our results clearly indicate that an abasic site is a much stronger block to transcription than either a thymine glycol or an 8-oxoguanine. Because the predominant model for TCR postulates that only lesions that block RNAP will be subject to TCR, our findings suggest that the abasic site may be sufficient to initiate TCR in vivo. Many different cellular pathways have evolved to protect the genome from the deleterious effects of DNA damage that result from exposure to chemical and physical agents. Among these is a process called transcription-coupled repair (TCR) that catalyzes the removal of DNA lesions from the transcribed strand of expressed genes, often resulting in a preferential bias of damage clearance from this strand relative to its non-transcribed counterpart. Lesions subject to this type of repair include cyclobutane pyrimidine dimers that are normally repaired by nucleotide excision repair (NER) and thymine glycols (TGs) that are removed primarily by base excision repair (BER). While the mechanism underlying TCR is not completely clear, it is known that its facilitation requires proteins used by other repair pathways like NER. It is also believed that the signal for TCR is the stalled RNA polymerase that results when DNA damage prevents its translocation during transcription elongation. While there is a clear role for some NER proteins in TCR, the involvement of BER proteins is less clear. To explore this further, we studied the removal of 7-methylguanine (7MeG) and 3-methyladenine (3MeA) from the dihydrofolate reductase (dhfr) gene of murine cell lines that vary in their repair phenotypes. 7MeG and 3MeA constitute the two principal N-methylpurines formed in DNA following exposure to methylating agents. In mammalian cells, alkyladenine DNA alkyladenine glycosylase (Aag) is the major enzyme required for the repair of these lesions via BER, and their removal from the total genome is quite rapid. There is no observable TCR of these lesions in specific genes in DNA repair proficient cells; however, it is possible that the rapid repair of these adducts by BER masks any TCR. The repair of 3MeA and 7MeG was examined in cells lacking Aag, NER, or both Aag and NER to determine if rapid overall repair masks TCR. The results show that both 3MeA and 7MeG are removed without strand bias from the dhfr gene of BER deficient (Aag deficient) and NER deficient murine cell lines. Furthermore, repair of 3MeA in this region is highly dependent on Aag, but repair of 7MeG is equally efficient in the repair proficient, BER deficient, and NER deficient cell lines. Strikingly, in the absence of both BER and NER, neither 7MeG nor 3MeA is repaired. These results demonstrate that NER, but not TCR, contributes to the repair of 7MeG, and to a lesser extent 3MeA. DNA damage is preferentially repaired in the transcribed strand of many active genes. Although the concept of DNA repair coupled with transcription has been widely accepted, its mechanisms remain elusive. We recently reported that in Chinese hamster ovary cells while ultraviolet light-induced cyclobutane pyrimidine dimers (CPDs) are preferentially repaired in the transcribed strand of dihydrofolate reductase gene, CPDs are efficiently repaired in both strands of adenine phosphoribosyltransferase (APRT) locus, in either a transcribed or nontranscribed APRT gene (1). These results suggested that the transcription dependence of repair may depend on genomic context. To test this hypothesis, we constructed transfectant cell lines containing a single, actively transcribed APRT gene, integrated at different genomic sites. Mapping of CPD repair in the integrated APRT genes in three transfectant cell lines revealed two distinct repair patterns, either preferential repair of CPDs in the transcribed strand or very poor repair in both strands. Similar kinetics of micrococcal nuclease digestion were seen for all three transfectant APRT gene domains and endogenous APRT locus. Our results suggest that both the efficiency and strand-specificity of repair of an actively transcribed gene are profoundly affected by genomic context but do not reflect changes in first order nucleosomal structure. We have used a non-replicating recombinant adenovirus, Ad5MCMVlacZ, which expresses the beta-galactosidase reporter gene, to examine both constitutive and inducible repair of UV-damaged DNA in repair proficient CHO-AA8 Chinese hamster ovary cells and in mutant CHO-UV61 cells which are deficient in the transcription-coupled repair (TCR) pathway of nucleotide excision repair. Host cell reactivation (HCR) of beta-galactosidase activity for UV-irradiated Ad5MCMVlacZ was significantly reduced in non-irradiated CHO-UV61 cells compared to that in non-irradiated CHO-AA8 cells suggesting that repair in the transcribed strand of the UV-damaged reporter gene in untreated cells utilizes TCR. Prior UV-irradiation of cells with low UV fluences resulted in a transient enhancement of HCR for expression of the UV-damaged reporter gene in CHO-AA8 cells but not in TCR deficient CHO-UV61 cells. These results suggest the presence of an inducible DNA pathway in CHO cells that results from an enhancement of TCR or a mechanism that involves the TCR pathway. Transcription-coupled repair, the targeted repair of the transcribed strands of active genes, is defective in bacteria, yeast, and human cells carrying mutations in mfd, RAD26 and ERCC6, respectively. Other factors probably are also uniquely involved in transcription-repair coupling. Recently, a defect was described in transcription-coupled repair for Escherichia coli mismatch repair mutants and human tumor cell lines with mutations in mismatch repair genes. We examined removal of UV-induced DNA damage in yeast strains mutated in mismatch repair genes in an effort to confirm a defect in transcription-coupled repair in this system. In addition, we determined the contribution of the mismatch repair gene MSH2 to transcription-coupled repair in the absence of global genomic repair using rad7 delta mutants. We also determined whether the Rad26-independent transcription-coupled repair observed in rad26 delta and rad7 delta rad26 delta mutants depends on MSH2 by examining repair deficiencies of rad26 delta msh2 delta and rad7 delta rad26 delta msh2 delta mutants. We found no defects in transcription-coupled repair caused by mutations in the mismatch repair genes MSH2, MLH1, PMS1, and MSH3. Yeast appears to differ from bacteria and human cells in the capacity for transcription-coupled repair in a mismatch repair mutant background. Defects in DNA mismatch repair have been shown to lead to increased genomic instability and mutability. We recently found that human cells defective in the DNA mismatch repair gene, hMSH2, were deficient in the transcription-coupled repair (TCR) of both oxidative DNA damage, including thymine glycols, and UV-induced DNA damage. However, in a hMLH1 mutant, only a reduction in the TCR of UV damage was observed. In this study, we examined whether TCR of thymine glycols in Saccharomyces cerecisiae also requires the genes involved in DNA mismatch repair. We found that yeast cells containing mutations in MSH2 were deficient in the removal of thymine glycols from the transcribed strand of the RPB2 gene, while cells with mutations in either MLH1 or PMS1 alone showed near normal levels of TCR of thymine glycols. Interestingly, double mutants in the MLH1 and PMS1 genes were deficient in TCR of thymine glycols. Taken together, these results suggest that these two MutL homologues can act independently of each other, but that they have overlapping roles in TCR. Overall levels of thymine glycol removal were not reduced in the mismatch repair mutants. In contrast to the results with thymine glycols, no defects in TCR of pyrimidine dimers were found in cells with mutations in MSH2, MLH1, PMS1, and MLH1/PMS1.

Abnormalities in which chromosomes were linked to the Moyamoya disease?

chromosomes 3, 6, 8, 12, 15, 17, 21, X and Y were implicated in the Moyamoya disease.

[11037190, 21968521, 20635402, 8898827, 18463369, 15362573, 22436252, 22426657, 23966756, 9973290, 16723886, 9128751, 20644152, 23077562, 21596366, 21048783, 23713105, 10754001, 15340753, 18576213, 19335127, 17431895, 19918425, 24167642, 15675355, 15675354, 18174554, 16164190, 10757474, 16475235, 17138018, 8937199, 21631222]

Moyamoya disease is a specific chronic cerebrovascular occlusive disease first reported by Japanese surgeons in 1957. The disease is characterized by stenosis or occlusion of the terminal portions of the bilateral internal carotid arteries and abnormal vascular network in the vicinity of the arterial occlusion. It may cause ischemic attacks or cerebral infarction, which is more frequent in children than in adults. In adults, cerebral hemorrhage may occur. The disease is distributed in all age groups, but the highest peak is in childhood at less than 10 years of age. The characteristic histopathologic features of the steno-occlusive arteries are fibrocellular thickening of the intima containing proliferated smooth muscle cells and prominently tortuous and often duplicated internal elastic lamina. There is usually no atheromatous plaque in the arterial wall. Etiology of the disease is still unknown; however, multifactorial inheritance is considered possible because of a higher incidence of the disease in Japanese and Koreans and approximately 10% of familial occurrence among the Japanese. Recent genetic studies suggest some responsible genetic foci in chromosomes 3, 6 and 17. A 20-year-old woman presented with mental retardation and a history of stroke related to moyamoya disease at the age of 8 years. She had cognitive impairment which became more pronounced after the stroke. This patient's parents were first cousins and six close family relatives had strokes in their 60s or 70s. The patient's 16-year-old sister had learning disability, chronic muscle pain, and an ECG suggestive of previous hypoxemic heart injury. The two sisters had similar dysmorphic facial appearance including a prominent philtrum, bulbous nose, and severe acne. They both had increased subcutaneous tissue in their faces, whereas their bodies were slim. Both sisters were found to have elevated levels of rheumatoid factor, C-reactive protein, and erythrocyte sedimentation rate on repeat measurements. Partial autoimmunity screening in one of the patients was negative. Chromosome analysis and array comparative genomic hybridization analyses were also normal. Nerve conduction findings in the younger sister were consistent with distal, predominantly motor, demyelinating neuropathy localized to the lower extremities. We propose that these two sisters suffer from a new autosomal recessive syndrome. Carrier status for this condition may predispose to later onset stroke. Aortic dilation and dissection are well-recognized cardiac abnormalities in women with Turner syndrome (TS), although the underlying pathophysiology is not fully understood. We report on a 46-year-old Hispanic woman who was previously diagnosed with moyamoya disease on magnetic resonance imaging after a presentation with stroke-like symptoms. Her features were consistent with TS and chromosome analysis revealed mosaicism in which 17% of the cells showed a pseudoisodicentric Y chromosome: 45,X (25)/46,X psu idic (Y)(11.2) (5). A preceding screening transthoracic echocardiogram had shown a bicuspid aortic valve (BAV) with an aortic diameter of 3.2 cm; at the time of moyamoya diagnosis, the aorta was 3.5 cm with mild aortic stenosis and mild aortic regurgitation. Four years later, the patient had had an acute aortic dissection, Stanford type A, which was repaired successfully. This case report is the third individual with TS associated with moyamoya disease and the first associated with dissection. The small number of cases does not allow detailed analysis other than noting patient age (two older than 40 years), karyotype (two others associated with isochrome Xq), and associated cardiac risk factors (one with BAV). Although this may be a chance occurrence, we hypothesize that moyamoya disease could be a manifestation of the vasculopathy in TS. Moyamoya disease (MIM 252350) is characterized by stenosis or occlusion of the terminal portions of the bilateral internal carotid arteries and by abnormal vascular networks at the base of the brain. There is a high incidence of moyamoya disease in Asia, especially in Japan. Multifactorial inheritance is estimated with lambda(s)>40. Previous linkage studies have indicated that susceptibility loci for the disease are located on chromosomes 3p, 6q, and 17q. In the present study, we searched for loci linked to the disease in 12 Japanese families using 428 microsatellite markers and found significant evidence for linkage to 8q23 [maximum LOD score (MLS) of 3.6] and suggestive evidence for linkage to 12p12 (MLS=2.3). The present study revealed a novel locus for moyamoya disease. BACKGROUND: Single-gene disorders related to ischemic stroke seem to be an important cause of stroke in young patients without known risk factors. To identify new genes responsible of such diseases, we studied a consanguineous Moroccan family with three affected individuals displaying hereditary leucoencephalopathy with ischemic stroke, dysmorphic syndrome and retinitis pigmentosa that appears to segregate in autosomal recessive pattern. METHODS: All family members underwent neurological and radiological examinations. A genome wide search was conducted in this family using the ABI PRISM linkage mapping set version 2.5 from Applied Biosystems. Six candidate genes within the region linked to the disease were screened for mutations by direct sequencing. RESULTS: Evidence of linkage was obtained on chromosome 17q24.2-25.3. Analysis of recombination events and LOD score calculation suggests linkage of the responsible gene in a genetic interval of 11 Mb located between D17S789 and D17S1806 with a maximal multipoint LOD score of 2.90. Sequencing of seven candidate genes in this locus, ATP5H, FDXR, SLC25A19, MCT8, CYGB, KCNJ16 and GRIN2C, identified three missense mutations in the FDXR gene which were also found in a homozygous state in three healthy controls, suggesting that these variants are not disease-causing mutations in the family. CONCLUSION: A novel locus for leucoencephalopathy with ischemic stroke, dysmorphic syndrome and retinitis pigmentosa has been mapped to chromosome 17q24.2-25.3 in a consanguineous Moroccan family. Stroke in trisomy 21 may be due to cardioembolism, atherosclerosis, vasculitis, moyamoya disease, sinus venous thrombosis, internal carotid hypoplasia or infections like endocarditis with septic emboli, meningitis or brain abscess. In rare cases, however, stroke etiology remains unexplained. We present a 19 year old Caucasian girl with trisomy 21 with a 47XX+21 karyotype who suffered at age 11 years from a transient ischemic attack with left hemiparesis, and at age 17 years from an ischemic stroke in the territory of the right cerebral medial artery. She suffered from arterial hypertension, obesity and hypercholesterolemia. Since blood coagulation studies, immunologic parameters, blood cultures, 24-h Holter monitoring, transthoracic and transesophageal echocardiography, magnetic resonance angiography of the extra- and intracranial vessels, thoracic and abdominal aorta and renal arteries did not provide any explanation for the stroke, implantation of a loop recorder is considered in order to detect episodes of clinically silent atrial fibrillation. Moyamoya disease is characterized by bilateral stenosis and/or occlusion of the terminal portion of the internal carotid artery. Moyamoya disease is prevalent among patients <10 years of age. Although most cases appear to be sporadic, approximately 10% occur as familial cases. The incidence of familial cases has been increasing because noninvasive diagnostic equipment, such as magnetic-resonance imaging and magnetic-resonance angiography, can detect the disease in almost all affected patients, including asymptomatic patients, during screening studies. In this study, we performed a total genome search to identify the location of a familial moyamoya disease gene in 16 families, assuming an unknown mode of inheritance. A linkage was found between the disease and markers located at 3p24.2-26. A maximum NPL score of 3.46 was obtained with marker D3S3050. This is the first genetic locus found to be involved in the molecular pathogenesis of familial moyamoya disease. OBJECTIVE: The genes encoding tissue inhibitor of metalloproteinase (TIMP) 4 and TIMP2 span chromosomes 3p24.2-p26 and 17q25, respectively, which are the locations of familial moyamoya disease (FMMD) genes. We investigated single nucleotide polymorphisms of the TIMP2 and TIMP4 genes in FMMD patients to determine genetic predispositions. METHODS: Eleven blood samples from FMMD patients were recruited. Controls included 50 blood samples from patients with nonfamilial moyamoya disease (MMD) and another 50 blood samples from non-MMD persons. We evaluated the promoter regions, exon-intron junctions, and the exons of the TIMP2 and TIMP4 genes by direct sequencing, and compared single nucleotide polymorphisms frequencies among the study groups. RESULTS: A significantly higher frequency of a heterozygous genotype was found in the TIMP2 promoter region at position -418 in FMMD; that is, the G/C heterozygous genotype at position -418 was observed in nine of 11 patients with FMMD, in 16 out of 50 nonfamilial MMD control participants, and in 14 out of 50 non-MMD control participants (FMMD versus nonfamilial MMD: odds ratio, 9.56; 95% confidence interval, 1.85-49.48; P = 0.005; and FMMD versus non-MMD: odds ratio, 10.50; 95% confidence interval, 2.02-54.55; P = 0.001). This base at position -418 corresponds to the third base of the GAGGCTGGG sequence, an Sp1 binding site. Thus, changes in this position may influence Sp1 binding and subsequent transcription of the gene. CONCLUSION: Our findings suggest that the presence of a G/C heterozygous genotype at position -418 in TIMP2 promoter could be a genetic predisposing factor for FMMD. Moyamoya disease is a progressive cerebrovascular occlusive disease that occurs frequently in children. The etiology is unknown. We examined changes in biological characteristics and responsiveness to serum mitogens during the in vitro cellular aging of arterial smooth muscle cell strains derived from patients with moyamoya disease (HMSMC) and compared them with those of cells from age-matched control patients (HCSMC). HMSMC had a normal human diploid chromosome constitution. HMSMC and HCSMC had almost the same in vitro life span and the age-related patterns of biological parameters were essentially the same. However, the doubling time at the early passages was significantly longer in moyamoya SMC than control SMC, although there was no significant difference at the late passages. Furthermore, the poor responsiveness of moyamoya SMC to platelet-derived growth factor was retained throughout the life span in vitro. These results support the hypothesis that functional alterations in vascular cells are involved in the mechanism of development of intimal thickening in moyamoya disease. OBJECTIVE: We report a detailed description of a family affected by a hereditary multisystem disorder associated with moyamoya syndrome. METHODS: In this family case report, we evaluated 9 members of the same family originating from Algeria. Investigations included neuroimaging, cardiologic and ophthalmologic evaluation, hormonal testing, hemoglobin electrophoresis, chromosomal karyotyping, muscle biopsy for morphology, immunohistochemistry and enzyme assays, mtDNA mutation screening, and haplotype analysis of 2 loci previously linked to moyamoya, on chromosomes 10 (ACTA2) and 17. RESULTS: Five males related through a maternal lineage were affected, suggesting an X-linked inheritance. Four of them had symptomatic moyamoya syndrome with an onset of acute neurologic manifestations between 4 and 32 years. Hypergonadotropic hypogonadism, azoospermia, short stature of postnatal onset (-2 to -4 SD in adulthood), premature graying of hair, and dysmorphism were present in all patients. The other features of the disease included early cataract in 4, dilated cardiomyopathy in 3, and partial growth hormone deficiency in 2 members. Muscle biopsy data did not reveal signs of a mitochondrial disorder. All conditions known to be associated with moyamoya syndrome such as Down syndrome, neurofibromatosis, and sickle cell disease were excluded. We also excluded linkage to the 2 loci previously reported to be involved in autosomal dominant syndromic and nonsyndromic moyamoya. Carrier females had normal phenotype and clinical history. CONCLUSIONS: These data strongly suggest that this family is affected by a hereditary moyamoya multisystem disorder with X-linked recessive pattern of inheritance. We conducted a case-control study to investigate whether vascular endothelial growth factor (VEGF -2578, -1154, -634, and 936) and kinase insert domain containing receptor (KDR -604, 1192, and 1719) polymorphisms are associated with moyamoya disease. Korean patients with moyamoya disease (n = 107, mean age, 20.9±15.9 years; 66.4% female) and 243 healthy control subjects (mean age, 23.0±16.1 years; 56.8% female) were included. The subjects were divided into pediatric and adult groups. Among the 64 surgical patients, we evaluated collateral vessel formation after 2 years and divided patients into good (collateral grade A) or poor (collateral grade B and C) groups. The frequencies and distributions of four VEGF (-2578, -1154, -634, and 936) and KDR (-604, 1192, and 1719) polymorphisms were assessed from patients with moyamoya disease and compared to the control group. No differences were observed in VEGF -2578, -1154, -634, and 936 or KDR -604, 1192, and 1719 polymorphisms between the control group and moyamoya disease group. However, we found the -634CC genotype occurred less frequently in the pediatric moyamoya group (p = 0.040) whereas the KDR -604C/1192A/1719T haplotype increased the risk of pediatric moyamoya (p = 0.024). Patients with the CC genotype of VEGF -634 had better collateral vessel formation after surgery. Our results suggest that the VEGF -634G allele is associated with pediatric moyamoya disease and poor collateral vessel formation. Moyamoya disease (MMD) shows progressive cerebral angiopathy characterized by bilateral internal carotid artery stenosis and abnormal collateral vessels. Although ∼ 15% of MMD cases are familial, the MMD gene(s) remain unknown. A genome-wide association study of 785,720 single-nucleotide polymorphisms (SNPs) was performed, comparing 72 Japanese MMD patients with 45 Japanese controls and resulting in a strong association of chromosome 17q25-ter with MMD risk. This result was further confirmed by a locus-specific association study using 335 SNPs in the 17q25-ter region. A single haplotype consisting of seven SNPs at the RNF213 locus was tightly associated with MMD (P = 5.3 × 10(-10)). RNF213 encodes a really interesting new gene finger protein with an AAA ATPase domain and is abundantly expressed in spleen and leukocytes. An RNA in situ hybridization analysis of mouse tissues indicated that mature lymphocytes express higher levels of Rnf213 mRNA than their immature counterparts. Mutational analysis of RNF213 revealed a founder mutation, p.R4859K, in 95% of MMD families, 73% of non-familial MMD cases and 1.4% of controls; this mutation greatly increases the risk of MMD (P = 1.2 × 10(-43), odds ratio = 190.8, 95% confidence interval = 71.7-507.9). Three additional missense mutations were identified in the p.R4859K-negative patients. These results indicate that RNF213 is the first identified susceptibility gene for MMD. BACKGROUND AND PURPOSE: Moyamoya disease is a cerebrovascular disease of unknown cause that mainly affects Japanese children. The incidence of familial occurrence accounts for 9% of cases. The characteristic lesions of moyamoya disease are occasionally seen in neurofibromatosis type 1, of which the causative gene (NF1) has been assigned to chromosome 17q11.2. METHODS: To determine whether a gene related to moyamoya disease is located on chromosome 17, we conducted microsatellite linkage analyses on 24 families containing 56 patients with moyamoya disease. Leukocyte DNA extracted from the family members was subjected to polymerase chain reaction for a total of 22 microsatellite markers on chromosome 17. The amplified polymerase chain reaction fragments were analyzed with GeneScan on an automated sequencer. RESULTS: Two-point linkage analysis gave a maximum log(10) odds (LOD) score of 3.11 at the recombination fraction of 0.00 for the marker at locus D17S939. The affected pedigree member method also showed a significantly low P value (<1. 0x10(-5)) for the 5 adjacent markers at 17q25. Multipoint linkage analysis also indicated that the disease gene is contained within the 9-cM region of D17S785 to D17S836, with a maximum LOD score of 4. 58. CONCLUSIONS: A gene for familial moyamoya disease is located on chromosome 17q25. OBJECTS: The pathogenesis of moyamoya disease is still unknown. The present study aimed to find out the responsible genes that are located in the 17q25 locus. METHODS: Considering the function, we selected nine genes as candidates from a total of 65 genes identified in the 9-cM region of D17S785-D17S836 in chromosome 17q25, and performed sequence analysis on the DNA samples obtained from a pedigree of familial moyamoya disease, which showed a complete linkage to the region by a haplotype analysis. Also, we attempted to identify candidate genes that have not been known but might be functionally relevant to the disease among a total of 2,100 expressed sequence tag (EST) sequences using bioinformatics techniques. RESULTS AND CONCLUSION: The sequence analysis could detect no mutation in the nine genes. Nor could we identify a novel candidate gene by the EST analysis. Further studies using alternative approaches are warranted to clarify the pathogenesis of moyamoya disease. Moyamoya, meaning a "hazy puff of smoke" in Japanese, is a chronic, occlusive cerebrovascular disease involving bilateral stenosis or occlusion of the terminal portion of the internal carotid arteries (ICAs) and/or the proximal portions of the anterior cerebral arteries and middle cerebral arteries (MCAs). The Ministry of Health and Welfare of Japan has defined 4 types of moyamoya disease (MMD): ischemic, hemorrhagic, epileptic, and "other." The ischemic type has been shown to predominate in childhood, while the hemorrhagic type is more often observed in the adult population. The highest prevalence of MMD is found in Japan, with a higher female to male ratio. Studies have shown a possible genetic association of MMD linked to chromosome 17 in Japanese cases as well as in cases found in other demographics. During autopsy, intracerebral hematoma is found and most commonly serves as the major cause of death in patients with MMD. Moyamoya vessels at the base of the brain are composed of medium-sized or small muscular arteries emanating from the circle of Willis, mainly the intracranial portions of ICAs, anterior choroidal arteries, and posterior cerebral arteries, forming complex channels that connect with distal positions of the MCAs. Off of these channels are small tortuous and dilated vessels that penetrate into the base of the brain at the site of the thalamoperforate and lenticulostriate arteries. On angiography, there is the characteristic stenosis or occlusion bilaterally at the terminal portion of the ICAs as well as the moyamoya vessels at the base of the brain. Six angiographic stages have been described, from Stage 1, which reveals a narrowing of the carotid forks, to Stage 6, in which the moyamoya vessels disappear and collateral circulation is produced solely from the external carotid arteries. Cases with milder symptoms are usually treated conservatively; however, more severe symptomatic cases are treated using revascularization procedures. Surgical treatments are divided into 3 types: direct, indirect, and combined/other methods. Direct bypass includes superficial temporal artery-MCA bypass or use of other graft types. Indirect procedures bring in circulation to the intracranial regions by introducing newly developed vasculature from newly approximated tissues. These procedures may not be enough to prevent further ischemia; therefore, a combination of direct and indirect procedures is more suitable. This article will give a review of the epidemiology, natural history, pathology, pathophysiology, and diagnostic criteria, including imaging, and briefly describe the surgical treatment of MMD. PATIENT: Male, 42 FINAL DIAGNOSIS: Moyamoya disease (MMD) Symptoms: Aphasia • concentration difficulty • dysarthria • personality change MEDICATION: - Clinical Procedure: - Specialty: Radiology. OBJECTIVE: Rare disease. BACKGROUND: Moyamoya disease (MMD) was first described in 1957 as "hypoplasia of the bilateral internal carotid arteries." The characteristic appearance of the associated network of abnormally dilated collateral vessels on angiography was later likened to "something hazy, like a puff of cigarette smoke," which, in Japanese, is Moyamoya. This paper describes the fulminant course of the disease in a Hispanic male involving the corpus callosum. CASE REPORT: A 42-year-old Hispanic male with progressive aphasia, slow mentation, and sudden onset of sensorimotor symptoms with gait disturbance was found to have multiple intracranial supratentorial infarcts of variable stages of evolution involving, but not limited to, the anterior corpus callosum, followed by rapid development of further infarcts. Angiography demonstrated right ACA occlusion, left supraclinoid ICA occlusion with a Moyamoya pattern of collateralization, and diffuse arteriopathy. A fulminant course ensued and the patient did not survive the acute phase of ischemic disease. CONCLUSIONS: Moyamoya disease may rarely present in North American Hispanic males, with advanced atypical clinical and imaging features involving the anterior corpus callosum and having a fulminant course. Moyamoya disease is a well-known cerebrovascular disorder of unknown pathogenesis affecting terminal portion of internal carotid arteries and causing ischemic attacks. Its familial occurrence suggests genetic background. We hypothesized that paternally imprinted gene might be associated with this disorder. To identify the expressed sequence tags (ESTs) with monoallelic expressions on chromosome 3, we used mouse A9 hybrid cells having human chromosome 3. Two ESTs showed only maternal expression in mouse A9 hybrid cells, and four showed non-expression in the lymphocytes derived from moyamoya patients. Although these ESTs are clustered on the same 150 kb region, we finally failed to identify cDNA in this region. Moyamoya disease is a cerebrovascular disorder of unknown etiology. Its high incidence in East Asia and accumulation in family members suggest a genetic background. A high incidence of maternal inheritance implicates genomic imprinting in this disorder. Based on this hypothesis, we studied the association between moyamoya disease and IGF2R gene on chromosome 6, but found no evidence for such association between them. On the other hand, heterogeneous expressions of IGF2R were confirmed in the lymphocytes. Some individuals showed monoallelic expression and others showed biallelic expression. We present familial Moyamoya disease in two European children and emphasize the importance of familial factors in the pathogenesis of this disease and its appearance not only in Asians but in the Western population as well. The first patient, a Greek female infant, also has coagulation disorders. Her mother, also suffering from Moyamoya and other family members, have similar coagulation disorders (Factor V Leiden, Methylene-tetrahydrofolic reductase and Factor II 20210A mutations). The second patient, a Scottish boy, is unique in that familial Moyamoya affects five members of three consecutive generations of his maternal family. Genetic analysis in the Greek family demonstrated no abnormality on chromosome 3p26, as in other cases. However, the mitochondrial DNA and Y chromosomal genotype showed that affected members had the same sequence of the Mitochondrial 3 portion of D-loop with Japanese patients. These findings suggest that the pathogenesis of Moyamoya may vary across races and ethnic groups. We reported an autopsy case of Down's syndrome with moyamoya syndrome. A 30-year-old male with Down's syndrome suffered from a cerebral infarction and died of brain herniation. Cerebral angiography showed vascular abnormalities that were the same as moyamoya disease. Pathological findings revealed multiple stenosis of main trunk of the cerebral arteries. Pathologically, the stenosed vessels showed eccentric intimal thickness with cholesterin deposit, unlike moyamoya disease. There are only two previous reports of autopsied cases of Down's syndrome with moyamoya syndrome. We postulate that a protein encoded on chromosome 21 may be related to the pathogenesis of Down's syndrome with moyamoya syndrome. Genetic factors have been suggested to contribute to the etiology of moyamoya disease. The authors have previously reported an association between moyamoya disease and several alleles for human leukocyte antigens (HLA). To further specify the genetic component of moyamoya disease, a linkage study of moyamoya disease using markers on chromosome 6, where the HLA gene is located, was performed. The 15 microsatellite markers of chromosome 6 were studied in 20 affected sibling pairs. From an identical-by-descent analysis of these markers, an allele with possible linkage to moyamoya disease was identified. Sharing of the allele among affected members in 19 families was investigated, considering the haplotype. The marker, D6S441, might be linked to moyamoya disease. Considering the haplotype, the allele was shared among the affected members in 16 (82%) of the 19 families, but not in two others. In one family, sharing of the allele could not be determined because of low heterozygosity. Further studies are necessary to clarify multiple genetic factors that are definitely linked with moyamoya disease. OBJECTIVES: To identify whether any mutations of candidate genes including SHH, ZIC2, SIX3, and TGIF exist in a Taiwanese family segregated with holoprosencephaly (HPE) and moyamoya disease. METHODS: Genotypes of the candidate genes SHH, ZIC2, SIX3, and TGIF were determined in the family members who were available for analysis by sequencing. In addition, genomic regions of another 50 unrelated Taiwanese (100 chromosomes) were studied to verify whether the nucleotide changes we found were mutations or polymorphisms. RESULTS: A novel missense mutation 377T > C and two polymorphisms (420A > G and 487C > T) in the TGIF gene were identified. No mutations in SHH, ZIC2 and SIX3 were found. The mother of the three HPE fetuses was found to be afflicted with moyamoya disease. A brief review of the mutations as well as polymorphisms reported in the TGIF gene up to 2005 is given. CONCLUSION: Molecular diagnosis can help genetic counseling in HPE, which is a heterogeneous disorder with its phenotypic and genotypic spectrum highly widened and variable. The possible association between TGIF mutation and moyamoya disease noted in our study also appeared to be novel. We report a case of Prader-Willi syndrome (PWS) complicated with juvenile stroke. The patient is a 19-year-old man with right hemiplegia, who has had a history of non-insulin-dependent diabetes mellitus (NIDDM) for ten years. The diagnosis of PWS was confirmed genetically by the method of fluorescence in situ hybridization which showed the deletion of chromosome 15. His brain MRI revealed abnormal signal intensities in the left basal ganglia and around the right trigone of the lateral ventricle. Angiographic examination showed occlusions of bilateral proximal middle cerebral arteries with basal moyamoya vessels. The left vertebral artery was also occluded at its origin. Only a few cases of PWS complicated with stroke have been reported before and, to date, there has been no case with arterial occlusion similar to our case. Though the cause of these arterial occlusions is unknown, it may be related to arteriosclerosis following NIDDM. OBJECT: Moyamoya disease (MMD) is a rare cerebrovascular disorder involving stenosis of the major vessels of the circle of Willis and proximal portions of its principal branches. Despite concerted investigation, the pathophysiology of the disorder has not been fully elucidated. Currently, the major proteins believed to play an active role in the pathogenesis include vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), hepatocyte growth factor (HGF), transforming growth factor-β₁ (TGFβ₁), and granulocyte colony-stimulating factor (G-CSF). In terms of the genetics, recent literature suggests a low penetrance autosomal dominant or polygenic mode of transmission involving chromosomes 3, 6, 8, 12, and 17 for familial MMD. This review summarizes the current knowledge on the histopathology, pathophysiology and genetics of MMD. METHODS: A PubMed/Medline systematic study of the literature was performed, from which 45 articles regarding MMD pathophysiology were identified and analyzed. CONCLUSIONS: Moyamoya disease is characterized by the intimal thickening and media attenuation of the proximal vessels of the circle of Willis as well as the development of an aberrant distal vascular network. The primary proteins that are currently implicated in the pathophysiology of MMD include VEGF, bFGF, HGF, TGFβ₁, and G-CSF. Furthermore, the current literature on familial MMD has pointed to a low penetrance autosomal dominant or polygenic mode of transmittance at loci on chromosomes 3, 6, 8, 12, and 17.

Which is the branch site consensus sequence in U12-dependent introns?

The branch site consensus sequence in U12-dependent introns is UUCCUUAAC.

[18824513]

Highly conserved sequences at the 5' splice site and branch site of U12-dependent introns are important determinants for splicing by U12-dependent spliceosomes. This study investigates the in vivo splicing phenotypes of mutations in the branch site consensus sequence of the U12-dependent intron F from a human NOL1 (P120) minigene. Intron F contains a fully consensus branch site sequence (UUCCUUAAC). Mutations at each position were analyzed for their effects on U12-dependent splicing in vivo. Mutations at most positions resulted in a significant reduction of correct U12-dependent splicing. Defects observed included increased unspliced RNA levels, the activation of cryptic U2-dependent 5' and 3' splice sites, and the activation of cryptic U12-dependent branch/3' splice sites. A strong correlation was observed between the predicted thermodynamic stability of the branch site: U12 snRNA interaction and correct U12-dependent splicing. The lack of a polypyrimidine tract between the branch site and 3' splice site of U12-dependent introns and the observed reliance on base-pairing interactions for correct U12-dependent splicing emphasize the importance of RNA/RNA interactions during U12-dependent intron recognition and proper splice site selection.

For what is Protein A from Staphylococcus aureus used in biochemistry?

Protein A from the bacterium Staphylococcus aureus (SpA) is used as an affinity ligand for purification of immunoglobulin G (IgG).

[23776704, 24033345, 22621885, 24184233, 12472184, 24291195, 23770556, 22136061]

Staphylococcus aureus protein A (SpA) is the most popular affinity ligand for immunoglobulin G1 (IgG1). However, the molecular basis for the dissociation dynamics of SpA-IgG1 complex is unclear. Herein, coarse-grained (CG) molecular dynamics (MD) simulations with the Martini force field were used to study the dissociation dynamics of the complex. The CG-MD simulations were first verified by the agreement in the structural and interactional properties of SpA and human IgG1 (hIgG1) in the association process between the CG-MD and all-atom MD at different NaCl concentrations. Then, the CG-MD simulation studies focused on the molecular insight into the dissociation dynamics of SpA-hIgG1 complex at pH 3.0. It is found that there are four steps in the dissociation process of the complex. First, there is a slight conformational adjustment of helix II in SpA. This is followed by the phenomena that the electrostatic interactions provided by the three hot spots (Glu143, Arg146 and Lys154) of helix II of SpA break up, leading to the dissociation of helix II from the binding site of hIgG1. Subsequently, breakup of the hydrophobic interactions between helix I (Phe132, Tyr133 and His137) in SpA and hIgG1 occurs, resulting in the disengagement of helix I from its binding site of hIgG1. Finally, the non-specific interactions between SpA and hIgG1 decrease slowly till disappearance, leading to the complete dissociation of the SpA-hIgG1 complex. This work has revealed that CG-MD coupled with the Martini force field is an effective method for studying the dissociation dynamics of protein-protein complex. Staphylococcal protein A (SpA) plays an important role in Staphylococcus aureus pathogenesis. The recombinant SpA is also widely used in biotechnology to purify polyclonal and monoclonal immunoglobulin G antibodies. In this study, expression and secretion of a truncated form of SpA containing five immunoglobulin-binding domains using its own native signal sequence were optimized in Escherichia coli. Optimization was carried out using response surface method (RSM), making use of the interaction between five variables. The initial results revealed that the signal peptide from S. aureus was recognized in E. coli and the resulting SpA was expressed and secreted into the medium. Compounds, such as glycine, affected the secretion of SpA into the culture medium. The central composite design experiment showed that the optimum conditions for the maximum expression of recombinant truncated SpA in E. coli included 10% (w/v) lactose, 1.77% (w/v) glycine, induction time of 11 H, an optical density (600) of 1.1, and a temperature of 33 °C. Optimization using RSM resulted in a fivefold increase in the secretion of SpA. To date, this is the first study of its kind regarding the definite influence of glycine concentration and duration of the cultivation period on the secretion of SpA. Affinity chromatography with protein A from Staphylococcus aureus (SpA) is the most widespread and accepted methodology for antibody capture during the downstream process of antibody manufacturing. A triazine based ligand (ligand 22/8) was previously developed as an inexpensive and robust alternative to SpA chromatography (Li et al. and Teng et al.). Despite the experimental success, there is no structural information on the binding modes of ligand 22/8 to antibodies, namely to Immunoglobulin G (IgG) molecules and fragments. In this work, we addressed this issue by a molecular docking approach allied to molecular dynamics simulations. Theoretical results confirmed the preference of the synthetic ligand to bind IgG through the binding site found in the crystallographic structure of the natural complex between SpA and the Fc fragment of IgG. Our studies also suggested other unknown "hot-spots" for specific binding of the affinity ligand at the hinge between V(H) and C(H)1 domains of Fab fragment. The best docking poses were further analysed by molecular dynamics studies at three different protonation states (pH 3, 7 and 11). The main interactions between ligand 22/8 and the IgG fragments found at pH 7 were weaker at pH 3 and pH 11 and in these conditions the ligand start losing tight contact with the binding site, corroborating the experimental evidence for protein elution from the chromatographic adsorbents at these pH conditions. Protein A from Staphylococcus aureus plays one key role as an immobilized affinity ligand for the purification of antibodies. A simple method for its extracellular expression in Escherichia coli and subsequent purification is reported herein. The N-terminus of the gene coding for the five IgG binding domains was fused to a pelB signal peptide which is responsible for periplasmic localization and which is removed after translocation into the periplasmic space of E.coli. Different additives, which were added at the same time with the induction of the protein expression by IPTG, were tested in order to facilitate the release of the target protein. With help of this optimized release protocol, more than 380mgL(-1) of protein A were obtained when Tris-HCl pH 8.5 was added up to a final concentration of 180mM in shaking flask experiments. Based on these observations, a protocol was developed for the extracellular production of SpA in a stirred tank bioreactor yielding 5.5gL(-1) of the secreted target protein. After cell removal by centrifugation, the protein A-containing supernatant was concentrated and dialyzed by tangential flow filtration. The target protein was subsequently purified by anion exchange chromatography with a total process yield of 90% and a final purity of ⩾95% (RP HPLC) was achieved. Affinity chromatography using protein A from Staphylococcus aureus as the ligand has been widely used for the isolation of immunoglobulin G (IgG) from various species. Since ligand leakage from the affinity support can occur, time consuming analytical controls are required to detect the presence of contaminants associated with the isolated IgG prior to its use for therapeutic purpose in humans. Besides, protein A is an expensive bacterial product, whose isolation involves complex and labor intensive procedures. Combinatorial chemistry enables the synthesis of a wide variety of ligands within a short period of time. Therefore, chemically defined, stable and inexpensive ligands, which can mimic the action of protein A, have been developed to isolate immunoglobulins. Two different types of ligands, synthesized following the techniques of combinatorial chemistry, have been used to isolate immunoglobulins. One of them is a synthetic peptide (TG 19318) comprising four identical tripeptide chains linked to a central polylysine core. Immobilized TG 19318 has been used to isolate polyclonal and monoclonal antibodies of different classes (IgG, IgM, IgA, IgE) from different sources (serum, ascities and cell supernatants) and species. The ligand has a binding capacity that can reach upto 25mg IgG/mL of the support. It is stable when treated with sanitation agents such as ethanol and 0.1 M sodium hydroxide. Computer-aided molecular design and combinatorial chemistry have been used to develop an IgG binding affinity ligand (22/8), which consists of two organic aromatic amines (3-aminophenol and 4-amino-1-napthol) linked to a scaffold of cyanuric chloride (triazine). Ligand 22/8 displayed wider specificity than protein A, as it isolated IgG from a number of species, the order of adsorption being human> chicken > cow > rabbit > pig > horse > rat > goat > sheep > mouse. It showed an apparent binding capacity of 51.9 mg IgG/g moist gel and can isolate human IgG from plasma in 60% yield with a purity of 92%. The ligand is stable, as it withstood incubation in 1M NaOH for a week without loss of binding capacity for IgG. These findings suggest that synthetic affinity ligands, which are inexpensive, stable and specific can facilitate the purification of immunoglobulins in a cost-effective manner. Staphylococcal protein A (SpA) binds Fcγ and VH3 clan Fab domains of human and animal immunoglobulin (Ig) with each of its five Ig binding domains (IgBDs), thereby supporting Staphylococcus aureus escape from opsonophagocytic killing and suppressing adaptive B cell responses. The variant SpAKKAA cannot bind Ig yet retains antigenic properties that elicit SpA-neutralizing antibodies and disease protection in mice, whereas S. aureus infection or SpA-immunization cannot elicit neutralizing antibodies. As a test for this model, we analyzed here mAb 358A76, which was isolated from SpA-immunized mice. Unlike SpAKKAA-derived mAbs, mAb 358A76 binds only the first IgBD (E) but not any of the other four IgBDs (D-A-B-C) and its binding can neutralize only the E domain of SpA, which does not provide disease protection in mice. These results are in agreement with a model whereby wild-type SpA-immunization generates a limited antibody response without neutralizing and/or disease protective attributes. Staphylococcal Protein A (SPA), a cell wall protein of Staphylococcus aureus, is in high demand because of its ability to bind immunoglobulins. Much of the SPA that we use today is recombinant SPA (rSPA), which is produced in Escherichia coli. As rSPA is obtained by expressing SPA as an intracellular protein, its purification is tedious and time consuming. In order to obtain a large amount of highly purified rSPA with relative ease, we expressed SPA as a secretory form in the yeast Pichia pastoris. To increase the expression level of SPA and repress its proteolysis during fermentation, the cell density (OD600), temperature and pH at which SPA expression was induced as well as the induction time were optimized. The final yield of SPA obtained was about 8.8 g per liter of culture, which under the optimized fermentation condition, accounted for 80% of the total protein in the culture supernatant. The expressed SPA was purified from the culture supernatant by DEAE ion-exchange chromatography (IEC) after the supernatant was subjected to a desalting step. The purified SPA was resolved as a single band by SDS-PAGE and as a single peak by HPLC. Its identity was confirmed by MALDI-TOF MS and western-blot. Moreover, the protein also exhibited excellent affinity for IgG when tested with human IgG. The production and purification of SPA described in this study offers a new method for obtaining high level of SPA in relatively pure form that is suitable for practical application.

What is the suggested therapy for Mycobacterium avium infection?

The activity of TLC G-65 (a liposomal gentamicin preparation), alone and in combination with rifapentine, clarithromycin, clofazimine and ethambutol, was evaluated in the beige mouse (C57BL/6J--bgj/bgj) model of disseminated Mycobacterium avium infection. TLC G-65 in combination with rifapentine appears to be an attractive regimen for the treatment of infections caused by bacteria in the M. avium complex. Rifampin 10 mg/kg daily, ciprofloxacin 500 mg twice daily, clofazimine 100 mg every day, and ethambutol 15 mg/kg orally daily for 24 weeks, with or without amikacin 10 mg/kg intravenously or intramuscularly 5 days weekly for the first 4 weeks. In vivo phage treatment may also be used in some cases.

[8733409, 16584300, 10714126, 1832527, 19929882, 1387133, 9875582, 11073759]

The turning point in antimicrobial therapy of Mycobacterium avium infections came with the development of two new macrolides, clarithromycin and azithromycin. Controlled clinical trials, the first ever conducted with any agent among patients with M. avium infection, indicated the high efficiency of clarithromycin, in either acquired immune deficiency syndrome (AIDS) patients having a disseminated infection or non-AIDS patients with localized pulmonary disease. Monotherapy with clarithromycin resulted in elimination of bacteremia in almost all patients with disseminated infection, which is inevitably followed by a relapse of bacteremia in patients who survived long enough to reach this event. The strains susceptible to clarithromycin isolated before therapy contained 10(-8) or 10(-9) resistant mutants, and the relapses of bacteremia were caused by multiplication of these pre-existing mutants. Clarithromycin-resistance was associated with a mutation in the 23S rRNA gene. Cross-resistance between clarithromycin and azithromycin was confirmed with laboratory mutants and clinical isolates. At least two methods for determining the susceptibility of the M. avium isolates to clarithromycin are available: one is minimum inhibitory concentration (MIC) determination on Mueller-Hinton agar (pH 7.4) supplemented with 10% Oleic acid-albumin-dextrose catalase, the other is MIC determination in 7H12 broth, also at pH 7.4. The breakpoints for 'susceptible' for these methods are < or = 8.0 micrograms/ml and < or = 2.0 micrograms/ml, respectively. The breakpoints for 'resistant' are > 128 micrograms/ml for the agar method and > 32.0 micrograms/ml for the broth method. The predictability value of MIC determination was confirmed by comparing the test results with the patients' clinical and bacteriological response to therapy. The remaining major problem in the therapy of the M. avium infections is a selection of companion drugs to be used in combination with clarithromycin (or azithromycin) to prevent the emergence of the macrolide-resistance. A number of clinical trials are now in progress to find a solution to this problem. The emergence of mycobacteria resistant to currently available antimicrobial agents has become an important problem in modern medicine. Mycobacterium avium and M. tuberculosis are intracellular pathogens that replicate and survive within the mononuclear phagocytes. TM4 is a lytic mycobacteriophage that kills both extracellular M. avium and M. tuberculosis. When delivered by M. smegmatis transiently infected with TM4, it kills both M. avium and M. tuberculosis within RAW 264.7 macrophages. To evaluate the treatment of M. avium infection with phage in vivo, C57 BL/6 mice were infected with M. avium 109 and, 7 days later, treated either once or twice with TM4 phage (7.9 x 10(10) PFU/ml), M. smegmatis (4 x 10(8) cFU/ml), or M. smegmatis with TM4 phage delivered intravenously (i.v.). Treatment with TM4 phage alone or M. smegmatis without TM4 did not show a significant decrease in number of intracellular bacteria in the spleen compared with untreated control. In contrast, administration of M. smegmatis-TM4 resulted in a significant decrease in the number of M. avium in the spleen. However, 23% of bacteria recovered from treated mice were resistant to TM4. These in vivo studies confirmed the in vitro findings that an avirulent mycobacterium can be used as a carrier to deliver antimycobacterial phage intracellularly. The most common presentations of nontuberculous mycobacterial infections in kidney transplant recipients (KTR) are cutaneous and disseminated diseases. Pleuropulmonary infection not associated with disseminated disease is rare. Its diagnosis can be difficult, requiring a combination of clinical, radiological, and bacteriological criteria. We report on a Mycobacterium avium complex pulmonary infection in a KTR with underlying chronic obstructive pulmonary disease. Chest computed tomography showed an excavated lesion of the right upper lobe, similar to a typical lesion of pulmonary tuberculosis. Evolution was favorable with multiple-drug therapy including rifampicin, ethambutol, and clarithromycin, along with a slight reduction in immunosuppression. We review the literature and discuss the epidemiology, diagnosis, management, and follow-up of this uncommon post-transplant complication. The activity of TLC G-65 (a liposomal gentamicin preparation), alone and in combination with rifapentine, clarithromycin, clofazimine and ethambutol, was evaluated in the beige mouse (C57BL/6J--bgj/bgj) model of disseminated Mycobacterium avium infection. TLC G-65 was found to be more active than amikacin. The combination of rifapentine and TLC G-65 was more active than either agent alone. The activity of clarithromycin in combination with TLC G-65 was similar to that of either agent alone. Clofazimine improved the activity of TLC G-65 with respect to the spleen, while ethambutol improved the activity with respect to the liver. Clofazimine and ethambutol enhanced the activity of TLC G-65 against bacteria in the lungs. TLC G-65 in combination with rifapentine appears to be an attractive regimen for the treatment of infections caused by bacteria in the M. avium complex. OBJECTIVE: To determine the clinical and microbiologic benefit of adding amikacin to a four-drug oral regimen for treatment of disseminated Mycobacterium avium infection in HIV-infected patients. DESIGN: A randomized, open-labeled, comparative trial. SETTING: Outpatient clinics. PATIENTS: Seventy-four patients with HIV and symptomatic bacteremic M. avium infection. INTERVENTIONS: Rifampin 10 mg/kg daily, ciprofloxacin 500 mg twice daily, clofazimine 100 mg every day, and ethambutol 15 mg/kg orally daily for 24 weeks, with or without amikacin 10 mg/kg intravenously or intramuscularly 5 days weekly for the first 4 weeks. MAIN OUTCOME MEASURE: Clinical and microbiologic response at 4 weeks; quantitative level of bacteremia with M. avium. RESULTS: No difference in clinical response was noted with the addition of amikacin to the four-drug oral regimen, and only 25% in either group had a complete or partial response at 4 weeks. A comparable quantitative decrease in bacteremia was noted in both treatment groups, with 16% of patients being culture-negative at 4 weeks and 38% at 12 weeks. Toxicities were mainly gastrointestinal. Amikacin was well tolerated. Median survival was 30 weeks in both groups. CONCLUSIONS: The addition of amikacin to a four-drug oral regimen of rifampin, ciprofloxacin, clofazimine, and ethambutol did not provide clinical or microbiologic benefit. Two hundred and forty-six patients infected with human immunodeficiency virus (HIV) who also had disseminated Mycobacterium avium complex received either azithromycin 250 mg every day, azithromycin 600 mg every day, or clarithromycin 500 mg twice a day, each combined with ethambutol, for 24 weeks. Samples drawn from patients were cultured and clinically assessed every 3 weeks up to week 12, then monthly thereafter through week 24 of double-blind therapy and every 3 months while on open-label therapy through the conclusion of the trial. The azithromycin 250 mg arm of the study was dropped after an interim analysis showed a lower rate of clearance of bacteremia. At 24 weeks of therapy, the likelihood of patients' developing 2 consecutive negative cultures (46% vs. 56%, P=.24) or 1 negative culture (59% vs. 61%, P=.80) was similar for azithromycin 600 mg (n=68) and clarithromycin (n=57), respectively. The likelihood of relapse was 39% versus 27% (P=.21) on azithromycin compared with clarithromycin, respectively. Of the 6 patients who experienced relapse, none of those randomized to receive azithromycin developed isolates resistant to macrolides, compared with 2 of 3 patients randomized to receive clarithromycin [corrected]. Mortality was similar in patients comprising each arm of the study (69% vs. 63%; hazard, 95.1% confidence interval, 1.1 [0.7, 1.7]). Azithromycin 600 mg, when given in combination with ethambutol, is an effective agent for the treatment of disseminated M. avium disease in patients infected with HIV.

What is the treatment of acute pericarditis?

A multidisciplinary approach is frequently necessary to treat acute pericarditis; the most frequent treatments are: antiinflammatory steroid and non-steroid drugs, antibiotic therapy, pericardial drainage and, less frequently ,intrapericardial irrigation of fibrinolytics; antituberculous chemotherapy in presence of Tuberculous Agent

[7375968, 17415329, 308705, 20074469, 6727432, 10560235, 12405580, 12379412, 6966005, 6726718, 10920507, 18924029, 17180574]

Acute febrile juvenile rheumatoid arthritis (JRA) of adult onset is often diagnosed by ruling out other problems. The classification of JRA is primarily based on the distinct type of onset, of which there are usually three: (1) acute febrile or Still's type, (2) polyarticular, and (3) monoarticular pauciarticular arthritis. Fever of unknown cause is frequently the initial symptom. This type of arthritis may be characterized by any or all of the following: unexplained high fever, rash, weight loss, lymphadenopathy, splenomegaly, pericarditis, pleurisy, pneumonitis, abdominal pain, myalgias, arthralgias, arthritis, sore throat, leukocytosis, anemia, circulating immune complexes, liver test abnormalities, and carpal-metacarpal and tarsal-metatarsal fusion. Patients often respond dramatically to anti-inflammatory agents. Corticosteroids, gold salts, penicillamine, and cytotoxic drugs have been effective for certain patients. The prognosis of the disease has been generally favorable. Although symptoms may recur, remission can be prolonged. Acute purulent pericarditis was treated successfully in five children between the ages of 27 months and 11 1/2 years during the past 5 years. The responsible organism was Hemophilus influenzae, type b, in two cases and Meningococcus, Pneumococcus, and coagulase-positive Staphylococcus aureus in one case each. No primary source of infection could be identified in two patients. A high index of suspicion, combined with immediate echocardiograms and pericardiocentesis, led to the diagnosis. Immediate antibiotic therapy was instituted on the basis of the gram stain of the pericardial fluid. All five patients had a pericardial window established--four through subxyphoid approach and the fifth, because of a left pleural effusion, through a left thoracotomy. When the subxyphoid approach was used, sump drains were left for postoperative suction and irrigation. All five patients survived without sequalae during follow-up periods of from 18 months to 5 years. We advocate an aggressive approach to the diagnosis and treatment of this problem. This report documents the safety, ease, and effectiveness of the subxyphoid approach as a means of drainage. Recurrences develop in up to 20-50% of patients with acute pericarditis. Although different causes of recurrent pericarditis have been identified, the etiology remains obscure in most cases which are therefore labelled as idiopathic. Autoinflammatory syndromes include familial Mediterranean fever (FMF), due to mutations in the MEFV gene, and tumor necrosis factor receptor-associated periodic syndrome (TRAPS), due to mutations in the TNFRSF1A gene. Recurrent pericarditis is a common feature of both conditions, but it rarely occurs alone. Colchicine is the standard treatment for FMF, while patients with TRAPS do not respond to colchicine therapy, but are responsive to corticosteroids. Based on the proven efficacy of colchicine in preventing polyserositis in FMF, colchicine has been proposed for the treatment of recurrent pericarditis and is able to decrease the recurrence rate. Our aim was to investigate the possible involvement of TNFRSF1A mutations in a group of patients with idiopathic recurrent pericarditis who were refractory to colchicine treatment. Thirty consecutive patients (17 males, 13 females) diagnosed with idiopathic recurrent pericarditis, who were characterized by a poor response to colchicine treatment, were enrolled in the study. Mutations of the TNFRSF1A gene were searched for by amplifying, using polymerase chain reaction (PCR), genomic DNA, and direct sequencing. TNFRSF1A mutations were found in 4 of the 30 patients. None of these 4 patients had a family history of recurrent inflammatory syndromes or history of pericarditis. One of the 4 patients had a novel heterozygous deletion (DeltaY103-R104) and three patients carried a heterozygous low-penetrance R92Q mutation. Our data suggest that TRAPS should be kept in mind in the differential diagnosis of recurrent pericarditis, and mutation analysis of the TNFRSF1A gene should be considered, in addition to MEFV analysis, in patients of Mediterranean origin. A poor response to colchicine treatment and/or a steroid-dependence may be the clue to investigate TNFRSF1A mutations in patients with idiopathic recurrent pericarditis. Two cases of Haemophilus influenzae type B pericarditis are presented which demonstrate the major clinical features and sequelae of this serious illness. These cases are analyzed together with 77 others from the literature to characterize the clinical features, natural history, and optimal therapy. H. influenzae pericarditis is an increasingly frequent disease of young children. A mild prodromal illness is often followed by rapid progression of cardiac compromise until death ensues, unless pericarditis is diagnosed and treated appropriately. The development of cardiomegaly in a febrile patient with a Haemophilus infection is an indication for echocardiography, which is diagnostic of the pericardial effusion. Initial cultures of pericardial aspirates will be positive in 75% of cases even when antibiotic therapy has been initiated. Use of appropriate parenterally administered antibiotics, in combination with early surgical pericardial drainage or partial pericardiectomy, should minimize morbidity and mortality and prevent acute constrictive sequelae. Constrictive pericarditis is a complication of tuberculous pericarditis that necessitates surgical intervention. In this study, we sought to identify echocardiographic features that could predict the development of constrictive pericarditis from acute or subacute pericarditis. From January 1988 through May 1998, all patients with a discharge diagnosis of tuberculous pericarditis were enrolled in the study, and their clinical features, laboratory findings, sonographic images, treatments, and outcomes were analyzed. Tuberculous pericarditis was demonstrated on the basis of positive Mycobacterium tuberculosis cultures from pericardial fluid or tissue in 11 patients; pericardial biopsy specimens demonstrating caseating granulomas in seven; and bacteriologic or histologic evidence of active extra-pericardial tuberculosis in conjunction with major pericardial effusion in four. Seventeen patients had effusive tuberculous pericarditis and five had constrictive tuberculous pericarditis as the initial diagnosis. The echocardiographic findings of effusive pericarditis were classified as shaggy-type effusion (n = 8) and non-shaggy-type effusion (9). Shaggy effusion was defined as the presence of multiple fibrin strands or a mass-like exudate coating the pericardium and bridging the pericardial effusion. Non-shaggy effusion was characterized by an anechoic pericardial space with or without a thickened pericardium, but no shaggy exudative coating. The mean duration between the onset of symptoms and diagnosis was longer in patients with shaggy-type effusion (39.6 +/- 8.7 vs 21.0 +/- 13.9 days, p < 0.05). Prednisolone (20-30 mg/d) was used in addition to antituberculous chemotherapy in 11 of the 17 patients with effusive pericarditis. Two of 11 patients (18%) who received steroid therapy, and five of the six patients (83%) who did not, developed constrictive pericarditis in the following year. Therefore, we concluded that adjuvant therapy with steroids significantly decreased the risk of constrictive pericarditis in patients with non-shaggy, but not shaggy, effusion. Purulent pericarditis is rarely the primary site of bacterial infection. It is usually a complication of an infection originating elsewhere in the body, arising by contiguous spread or haematogenous dissemination.This paper, however, describes a previously healthy young man, who developed a purulent streptococcal pericarditis with no localizable primary focus. Although many possibilities were investigated, the entry site of the pericarditis remains unknown. The incidence of purulent pericarditis has decreased considerably since the antibiotic era. It is typically an acute and potentially lethal disease, necessitating rapid diagnosis and adequate therapy to improve prognosis. Standard treatment combines appropriate antibiotic therapy with surgical drainage. However, the exact timing and type of surgery is still under discussion. Our patient was treated with antibiotics, subxiphoidal tube drainage of the pericardial fluid and intrapericardial thrombolysis. After three weeks, he developed tamponade, requiring partial pericardiectomy. He recovered completely and resumed his normal activities after a two-month hospitalisation. A 39-year-old man was admitted for upper abdominal pain and shortness of breath. The chest roentgenogram demonstrated cardiomegaly and left lower lobe atelectasis. Echocardiography showed circumferential pericardial effusion with signs of cardiac tamponade. Pericardial biopsy and fluid analysis were consistent with fibrino-purulent pericarditis. Despite broad-spectrum antibiotics, percutaneous and subsequently surgical drainage, pericardial effusion and tamponade recurred. We report successful treatment of a non-resolving fibrino-purulent pericardial effusion by combined intrapericardial irrigation of fibrinolytics and systemic corticosteroids administration as an alternative to pericardectomy. Acute purulent pericarditis is a well-recognized, though infrequently seen, manifestation of systemic Haemophilus influenzae type b disease. We recently studied two pediatric patients who developed signs of this septic complication during appropriate antibiotic treatment for bacteremia. These case reports should alert physicians to the possibility that pericarditis may become clinically evident in patients with systemic H. influenzae infections many days after initiation of appropriate therapy. The pathophysiology, diagnostic modalities and therapy are briefly reviewed. A 9-year-old boy with systemic onset juvenile rheumatoid arthritis (JRA) presented with fever and chest pain and rapidly developed pericarditis and cardiac tamponade. Despite corticosteroid treatment and pericardiocentesis, rapid deterioration necessitated the emergency placement of a pericardial window. This is the first reported instance of this type of emergency surgical intervention for JRA. Of 220 children with JRA followed for 12 years (7% systemic onset), 8 had evidence of acute pericarditis but no other had definite evidence of tamponade. Glucose 6-phosphate dehydrogenase deficiency is an important cause of hemolysis. People with this disease are prone to hemolytic crisis induced by drugs, including acetylsalicylic acid. Sodium salicylate is the main therapeutic choice for acute idiopathic pericarditis. In vitro studies have demonstrated the role played by sodium salicylate in the inhibition of glucose 6-phosphate dehydrogenase, but, at therapeutic doses, this inhibition is not enough to explain acetylsalicylic acid-induced hemolysis observed in vivo. We thus treated a patient affected by acute idiopathic pericarditis and glucose 6-phosphate dehydrogenase deficiency with sodium salicylate, obtaining complete resolution of fever and symptoms, without any hemolytic complication. Therapy with sodium salicylate could thus be a safe and effective alternative for patients with glucose 6-phosphate dehydrogenase who require anti-inflammatory therapy. We describe a case of a 56 year old man with myopericarditis complicated with cardiogenic shock within first 3 days, mimicking on admission acute myocardial infarction with ST elevation in inferior ECG leads. Additionally, patient presented hyperthyroidism and totally decompensated diabetes mellitus. He required during the first 3 days intravenous infusion of inotropic agents. Cardiac enzymes levels were elevated. Akinesia in mid-inferior and mid-posterior regions in ECHO was observed. On the 10th day ST segment elevation in I, II, V3-V6 and ST depression in aVR was observed in ECG. After stabilisation patient underwent coronarography which showed normal coronary arteries. The final diagnosis was acute myopericarditis complicated with acute heart failure and cardiogenic shock. Recurrent pericarditis is a rare disease in childhood. Nevertheless, it may represent a challenge to the clinician due to its resistance to anti-inflammatory treatment. The initial etiology often remains unclear; specific laboratory parameters predicting the frequency or severity of the recurrences are lacking. We report on four patients with recurrent pericarditis in whom antimyolemmal antibodies (AMLAs) were detected. A prolonged persistence of IgM-type AMLAs was found in three patients: two of them presented with acute inflammation as the initial event and one with 48 recurrences during 5.5 years. The fourth patient showed a fast conversion from IgM to IgG-type AMLAs after a less acute initial presentation and showed 4 mild recurrences during the 48-month follow-up. CONCLUSION: We were able to detect AMLAs in four children with recurrent pericarditis. This finding may be attributed to an auto-immunological disease following a first, acute event. We propose the detection of AMLAs in all children with unexplained recurrent pericarditis. Pediatric patients with a persistence of IgM-type AMLAs may face frequent recurrences and should be monitored therefore more closely. In addition, medical treatment may be changed in these patients with a slower tapering of the dosage of steroidal and non-steroidal antiinflammatory drugs.

What is the genetic basis of tuberous sclerosis?

The genetic basis of tuberous sclerosis has been attributed to mutations in one of two unlinked genes, TSC1 and TSC2. The functions of the TSC1 and TSC2 gene products, hamartin and tuberin, respectively, have remained ill defined until recently. Genetic, biochemical, and biologic analyses have highlighted their role as negative regulators of the mTOR signaling pathway. Tuberin, serving as a substrate of AKT and AMPK, mediates mTOR activity by coordinating inputs from growth factors and energy availability in the control of cell growth, proliferation, and survival. Emerging evidence also suggests that the TSC 1/2 complex may play a role in modulating the activity of beta-catenin and TGFbeta. These findings provide novel functional links between the TSC genes and other tumor suppressors.

[20073603, 15563017, 7546221, 24105488, 10823953, 9743993, 15579029, 15565817, 11520734]

CONTEXT: Lymphangioleiomyomatosis (LAM) is a cystic lung disease that can be included in the wide group of proliferative lesions named PEComas (perivascular epithelioid cell tumors). These proliferative tumors are characterized by the coexpression of myogenic and melanogenesis-related markers. In all these lesions, genetic alterations related to the tuberous sclerosis complex (TSC) have been demonstrated. Striking improvements in the understanding of the genetic basis of this autosomal dominant genetic disease are coupled to the understanding of the mechanisms that link the loss of TSC1 (9q34) or TSC2 (16p13.3) genes with the regulation of the Rheb/m-TOR/p70S6K pathway. These data have opened a new era in the comprehension of the pathogenesis of LAM and have also suggested new therapeutic strategies for this potentially lethal disease. OBJECTIVE: To present and discuss the pathologic and molecular features of LAM within the spectrum of PEComas, providing a rational approach to their diagnosis. DATA SOURCES: The published literature and personal experience. CONCLUSIONS: The inclusion of LAM within the PEComa category is supported by a variety of biologic data and can significantly help in providing a comprehensive view of this interesting and clinically relevant group of lesions. The demonstration of molecular alterations of the mTOR pathway in LAM and other PEComas represents a rational basis for innovative therapeutic approaches with inhibitors of mTOR signaling. We have recently identified on rat chromosome 10q a germline mutation in the tuberous sclerosis gene (Tsc2), the gene predisposing to renal carcinoma (RC) in the Eker rat. The homozygous mutant condition is lethal at around the 13th day of fetal life. In heterozygotes, RCs invariably develop in the first year of life. Histologically, RCs develop through multiple stages from early preneoplastic lesions (i.e., phenotypically altered tubules) to adenomas. The wild-type allele mutation has been found even in the earliest preneoplastic lesions, fitting Knudson's two-hit hypothesis and supporting the hypothesis that Tsc2 is a tumor suppressor gene. In this study, homozygous deletion of the Ink4 homologue on rat chromosome 5q was observed in 14 of 24 (58%) RC-derived cell lines. This may represent involvement of a second tumor suppressor gene, contributing to tumor progression. Considering previous results of studies of homozygous deletion of the Ifn alpha gene in five of 24 cases (21%) and the Ifn beta gene in one of 24 cases (4%), the order of the genes may be Ink4-Ifn alpha-Ifn beta. Microsatellite instability was not observed in 26 Eker rat tumors. Lymphangioleiomyomatosis (LAM) is a progressive and often fatal interstitial lung disease characterized by a diffuse proliferation of abnormal smooth muscle cells in the lungs. LAM is of unusual interest biologically because it affects almost exclusively young women. LAM can occur as an isolated disorder (sporadic LAM) or in association with tuberous sclerosis complex. Renal angiomyolipomas, which are found in most tuberous sclerosis patients, also occur in 60% of sporadic LAM patients. We previously found TSC2 loss of heterozygosity in 7 of 13 (54%) of angiomyolipomas from sporadic LAM patients, suggesting that LAM and TSC could have a common genetic basis. In this study, we report the identification of somatic TSC2 mutations in five of seven angiomyolipomas from sporadic LAM patients. In all four patients from whom lung tissue was available, the same mutation found in the angiomyolipoma was present in the abnormal pulmonary smooth muscle cells. In no case was the mutation present in normal kidney, morphologically normal lung, or lymphoblastoid cells. Our data demonstrate that somatic mutations in the TSC2 gene occur in the angiomyolipomas and pulmonary LAM cells of women with sporadic LAM, strongly supporting a direct role of TSC2 in the pathogenesis of this disease. Tuberous sclerosis is a relatively common inherited disease that causes multiple benign tumours in different organs, frequently leading to skin rashes, seizures and mental handicap. The disease can be caused by mutations in either of two genes, TSC2, identified in 1993, and TSC1, only recently identified. Here we review the current state of knowledge of the molecular genetics of tuberous sclerosis and the spectrum of mutations seen in and the implications of recent findings for patients. Although both genes appear to function as tumour suppressors, the function of their protein products is not understood. A speculative model of how these proteins might function is briefly described.