Regulation of Myoepithelial Differentiation in 3-Dimensional Culture The salivary gland can be permanently impaired by radiation treatment for head and neck cancers. Efforts at tissue regeneration have focused on saliva-producing acinar cells. However, myoepithelial cells are also critical to gland function, but mechanisms that regulate their differentiation are poorly defined. To study myoepithelial differentiation, we employed mSG-PAC1 murine salivary gland epithelial cells. We demonstrate that mSG-PAC1 spheroids exhibit phenotypic plasticity between pro-acinar and myoepithelial cell fates. Increased expression of pro-acinar/acinar or myoepithelial RNAs was identified from spheroids cultured under different media conditions by microarray followed by gene-set enrichment analysis. Spheroids cultured with different medium components expressed proteins typical of either acinar or myoepithelial cells, as detected by immunocytochemistry. We demonstrate that the pattern of TAZ expression in the epithelial compartment of the differentiating murine salivary gland correlates with the expression of the myoepithelial marker alpha-SMA, as is the case for TAZ expression in mSG-PAC1 spheroids. Our analysis also indicates that YAP/TAZ target genes are upregulated together with myoepithelial markers. Importantly, siRNA targeting of TAZ expression in mSG-PAC1 spheroids diminished the expression of myoepithelial markers. Our results in this in vitro cell model implicate TAZ signaling in myoepithelial differentiation.
Dynamic Phosphorylation of RGS Provides Spatial Regulation of MAP Kinase And Promotes Completion of Cytokinesis during the Yeast Pheromone Response Yeast use a G-protein coupled receptor (GPCR) signaling pathway to detect mating pheromone, arrest in G1, and direct polarized growth towards the potential mating partner. The primary negative regulator of this pathway is the regulator of G-protein signaling (RGS), Sst2, which induces G GTPase activity and subsequent inactivation of all downstream signaling including a MAPK cascade. The MAPK Fus3 phosphorylates the RGS in response to pheromone, but the role of this modification is unknown. We set out to examine the role of RGS phosphorylation during the pheromone response. We found that RGS phosphorylation peaks early in the pheromone response and diminishes RGS localization to the polarity site and focuses MAPK complexes there. At later time points, RGS is predominantly unphosphorylated, which promotes RGS localization to the polar cap and broadens the distribution of MAPK complexes relative to the Cdc42 polarity machinery. Surprisingly, we found that phosphorylation of the RGS is required for the completion of cytokinesis prior to pheromone induced growth. The completion of cytokinesis in the presence of pheromone is promoted by the formin Bnr1 and the kelch-repeat protein, Kel1, both proteins previously found to interact with the RGS.
Toxicity Profile of Artesunate in Rats and Dogs AO_SCPLOWBSTRACTC_SCPLOWO_ST_ABSOBJECTIVESC_ST_ABSThe objectives of these studies were to investigate the toxicity, safety and toxicokinetics of single and multiple doses of artesunate for injection in rats and dogs.

METHODSSprague-Dawley rats and Beagle dogs were treated intravenously or intramuscularly for 28 consecutive days with doses of up to 30 mg/kg artesunate, evaluating toxicity, kinetics, genotoxicity, and cardiovascular and central nervous safety parameters after single and 4-week repeated administrations. Furthermore, respiratory parameters were evaluated after a single intravenous administration in rats.

RESULTSArtesunate was well tolerated with no mortality and only minor effects on clinical pathology parameters. Following repeated intramuscular administration, local reactions at the injection site became evident.

CONCLUSIONSThe results obtained in these studies support the safe use of artesunate in humans.

Subchronic data for repeated intravenous and intramuscular artesunate in animals are available in the literature for a maximum duration of 14-days. Published results of genotoxicity studies in vitro in bacteria or cells of animal or human origin and in vivo in animals are equivocal, with a couple of negative results following oral administration and positive results in human cells.

With the studies performed in rats and dogs for a treatment period of 28-days including measures of safety pharmacology, toxicokinetic evaluation and in vivo genotoxicity data, a comparison of toxicity and exposure of intravenous versus intramuscular artesunate for a prolonged treatment period is possible, delivering important information, when a decision between both routes has to be made for use in patients. Results of the peripheral blood micronucleus assay in rats were positive, suggesting genotoxic potential for the intravenous route of administration of artesunate, what is, beside patients, likewise relevant for production and health care personnel. Synthetic Nanobody-Functionalized Nanoparticles for Accelerated Development of Rapid, Accessible Detection of Viral Antigens Successful control of emerging infectious diseases requires accelerated development of fast, affordable, and accessible assays to be widely implemented at a high frequency. Here we present a generalizable assay platform, nanobody-functionalized nanoparticles for rapid, electronic detection (Nano2RED), demonstrated in the detection of Ebola and COVID-19 antigens. To efficiently generate high-quality affinity reagents, synthetic nanobody co-binders and mono-binders with high affinity, specificity, and stability were selected by phage display screening of a vastly diverse, rationally randomized combinatorial library, bacterially expressed and site-specifically conjugated to gold nanoparticles (AuNPs) as multivalent in-solution sensors. Without requiring fluorescent labelling, washing, or enzymatic amplification, these AuNPs reliably transduce antigen binding signals upon mixing into physical AuNP aggregation and sedimentation processes, displaying antigen-dependent optical extinction readily detectable by spectrometry or simple electronic circuitry. With nanobodies against an Ebola virus secreted glycoprotein (sGP) and a SARS-CoV-2 spike protein receptor binding domain (RBD) as targets, Nano2RED showed a high sensitivity (limit of detection of [~]10 pg/mL for sGP and [~]40 pg/mL for RBD in diluted human serum), a high specificity, and a large dynamic range ([~]7 logs). Unlike conventional assays where slow mass transport for surface binding limits the assay time, Nano2RED features fast antigen diffusion at micrometer scale, and can be accelerated to deliver results within a few minutes. The rapid detection, low material cost (estimated < $0.01 per test), inexpensive and portable readout system (< $5 and < 100 cm3), and digital data output, make Nano2RED particularly suitable for screening of patient samples with simplified operation and accelerated data transmission. Our method is widely applicable for prototyping diagnostic assays for other antigens from new emerging viruses. Second Heart Field-derived Cells Contribute to Angiotensin II-mediated Ascending Aortopathies BackgroundThe ascending aorta is a common location for aneurysm and dissection. This aortic region is populated by a mosaic of medial and adventitial cells that are embryonically derived from either the second heart field (SHF) or the cardiac neural crest. SHF-derived cells populate areas that coincide with the spatial specificity of thoracic aortopathies. The purpose of this study was to determine whether and how SHF-derived cells contribute to ascending aortopathies.

MethodsAscending aortic pathologies were examined in patients with sporadic thoracic aortopathies and angiotensin II (AngII)-infused mice. Ascending aortas without overt pathology from AngII-infused mice were subjected to mass spectrometry assisted proteomics, and molecular features of SHF-derived cells were determined by single cell transcriptomic analyses. Genetic deletion of either low-density lipoprotein receptor-related protein 1 (Lrp1) or transforming growth factor-{beta} receptor 2 (Tgfbr2) in SHF- derived cells was conducted to examine the impact of SHF-derived cells on vascular integrity.

ResultsPathologies in human ascending aortic aneurysmal tissues were predominant in outer medial layers and adventitia. This gradient was mimicked in mouse aortas following AngII infusion that was coincident with the distribution of SHF-derived cells. Proteomics indicated that brief AngII infusion, prior to overt pathology, evoked downregulation of SMC proteins and differential expression of extracellular matrix proteins, including several LRP1 ligands. LRP1 deletion in SHF-derived cells augmented AngII-induced ascending aortic aneurysm and rupture. Single cell transcriptomic analysis revealed that brief AngII infusion decreased Lrp1 and Tgfbr2 mRNA abundance in SHF-derived cells and induced a unique fibroblast population with low abundance of Tgfbr2 mRNA. SHF-specific Tgfbr2 deletion led to embryonic lethality at E12.5 with dilatation of the outflow tract and retroperitoneal hemorrhage. Integration of proteomic and single cell transcriptomics results identified plasminogen activator inhibitor 1 (PAI1) as the most increased protein in SHF-derived SMCs and fibroblasts during AngII infusion. Immunostaining revealed a transmural gradient of PAI1 in both ascending aortas of AngII-infused mice and human ascending aneurysmal aortas that mimicked the gradient of medial and adventitial pathologies.

ConclusionSHF-derived cells exert a critical role in maintaining vascular integrity through LRP1 and TGF-{beta} signaling associated with increases of aortic PAI1.



O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=89 SRC="FIGDIR/small/930917v6_ufig1.gif" ALT="Figure 1">
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org.highwire.dtl.DTLVardef@185e3d9org.highwire.dtl.DTLVardef@131d702org.highwire.dtl.DTLVardef@11afa42org.highwire.dtl.DTLVardef@242786_HPS_FORMAT_FIGEXP  M_FIG C_FIG Clinical PerspectiveO_ST_ABSWhat is new?C_ST_ABS- SHF-derived SMCs and fibroblasts associate with AngII-induced aortic pathologies.
- AngII induces a distinct fibroblast sub-cluster that is less abundant for mRNAs related to major extracellular components and TGF{beta} ligands and receptors, but more abundant for proliferative genes.
- TGFBR2 deletion in SHF-derived cells are embryonic lethal with significant dilatation of the outflow tract in mice.
- SHF-specific deletion of LRP1 leads to aortic pathologies in mice, supporting the importance of SHF-derived cells in maintaining ascending aortic wall integrity.


What are the clinical implications?- Heterogeneity of the embryonic origins of SMCs and fibroblasts contributes to complex mechanisms of vasculopathy formation, which should be considered when investigating the pathogenesis of thoracic aortopathies. Avian haemosporidians (Plasmodium and Haemoproteus) status in selected bird groups (Old world Flycatchers, Warblers, Babblers, and Thrushes) of India and their phylogenetic relationships with other lineages of the world The avian haemosporidians (Plasmodium and Haemoproteus) are widely distributed and may affect the host populations from body damage at individual level to the extinction of a population. The knowledge about their status may help in future avifauna conservation plans. Hence, we examined the avian haemosporidians status, in selected bird groups (Old world Flycatchers, Warblers, Babblers, and Thrushes) of India, and their phylogenetic relationships with other known lineages of the world. We used the common genetic marker (Cytochrome b gene fragment of 479 bp) with information on the geographic distribution of parasite and host species available at MalAvi database. The prevalence of avian haemosporidians, from northern, eastern, and southern parts of India and phylogenetic genetic analysis of lineages was carried out to know the genetic relatedness among them at local and world level. The MCC tree revealed six Haemosporidian lineages in which one was common (H_MSP01) and five were unique (H_CYOPOL01, H_CHD01, H_CYORUB01, H_EUMTHA01, and P_GEOCIT01). The avian host richness Index was 2.0852. 9.9%, prevalence of Haemosporidian infection was found in 111 DNA samples belonging to 6 host species. The Haemoproteus prevalence was found to be 9.0 % across five host species (Phylloscopus trochiloides, Cyornis poliogenys, C. hainanus dialilaemus, C. rubeculoides, Eumiyas thalassinus) and Plasmodium prevalence was 0.9% in Geokichla citrina. Spatial phylogeny at global level showed H_MSP01 lineage, found in different host species in India, was genetically related to H. pallidus lineages (COLL2 and PFC1) in parts of Africa, Europe, North America, Malaysia, and Philippines. The Plasmodium lineage (P_GEOCIT01) was related to PADOM16 in Egypt with poor sequence similarity (93.89%). The statistical analysis suggested that the haemosporidians host species distribution range was directly and significantly associated with the altitude, minimum temperature, and relative humidity. H_MSP01 distribution was in accordance with H. pallidus having a wide geographic and host range. Diverse stem-chondrichthyan oral structures and evidence for an independently acquired acanthodid dentition The teeth of sharks famously form a series of transversely-organised files with conveyor-belt replacement that are borne directly on the jaw cartilages, in contrast to the dermal plate-borne dentition of bony fishes that undergoes site-specific replacement. A major obstacle in understanding how this system evolved is the poorly understood relationships of the earliest chondrichthyans and the profusion of morphologically and terminologically diverse bones, cartilages, splints and whorls that they possess. Here we use tomographic methods to investigate mandibular structures in several early branching  acanthodian-grade stem-chondrichthyans. We show that the dentigerous jaw bones of disparate genera of ischnacanthids are united by a common construction, being growing bones with non-shedding dentition. Mandibular splints, which support the ventro-lateral edge of the Meckels cartilage in some taxa, are formed from dermal bone and may be an acanthodid synapomorphy. We demonstrate that the teeth of Acanthodopsis are borne directly on the mandibular cartilage and that this taxon is deeply nested within an edentulous radiation, representing an unexpected independent origin of teeth. Many or even all of the range of unusual oral structures may be apomorphic, but they should nonetheless be considered when building hypotheses of tooth and jaw evolution, both in chondrichthyans and more broadly. Different contribution of the monkey prefrontal and premotor dorsal cortex in decision making during a transitive inference task Several studies have reported similar neural modulations between brain areas of the frontal cortex, such as the dorsolateral prefrontal (DLPFC) and the premotor dorsal (PMd) cortex, in tasks requiring encoding of the abstract rules for selecting the proper action. Here we compared the neuronal modulation of the DLPFC and PMd of monkeys trained to choose the higher rank from a pair of abstract images (target item), selected from an arbitrarily rank-ordered set (A>B>C>D>E>F) in the context of a transitive inference task. Once acquired by trial-and-error, the ordinal relationship between pairs of adjacent images (i.e., A>B; B>C; C>D; D>E; E>F), monkeys were tested in indicating the ordinal relation between items of the list not paired during learning. During these decisions, we observed that the choice accuracy increased and the reaction time decreased as the rank difference between the compared items enhanced. This result is in line with the hypothesis that after learning, the monkeys built an abstract mental representation of the ranked items, where rank comparisons correspond to the items position comparison on this representation. In both brain areas, we observed higher neuronal activity when the target item appeared in a specific location on the screen with respect to the opposite position and that this difference was particularly enhanced at lower degrees of difficulty. By comparing the time evolution of the activity of the two areas, we observed that the neural encoding of target item spatial position occurred earlier in the DLPFC than in the PMd. Quantifying the potential for red blood cell β-adrenergic sodium-proton exchangers to protect oxygen transport in hypoxic and hypercapnic white seabass White seabass (Atractoscion nobilis) are increasingly experiencing periods of low oxygen (O2; hypoxia) and high carbon dioxide (CO2, hypercapnia) due to climate change and eutrophication of the coastal waters of California. Hemoglobin (Hb) is the principal O2 carrier in the blood and in many teleost fishes Hb-O2 binding is compromised at low pH; however, the red blood cells (RBC) of some species regulate intracellular pH with adrenergically-stimulated sodium-proton-exchangers ({beta}-NHE). We hypothesized that RBC {beta}-NHEs in white seabass are an important mechanism that can protect the blood O2-carrying capacity during hypoxia and hypercapnia. We determined the O2-binding characteristics of white seabass blood, the response of RBCs to adrenergic stimulation, and quantified the protective effect of {beta}-NHE activity on Hb-O2 saturation. White seabass had typical teleost Hb characteristics, with a moderate O2 affinity (PO2 at half-saturation; P50 2.9 kPa) that was highly pH-sensitive (Bohr coefficient -0.92; Root effect 52%). The presence of RBC {beta}-NHEs was confirmed by functional, molecular and bioinformatic data and super-resolution imaging revealed, for the first time, the subcellular location of {beta}-NHE protein in vesicle-like structures and on the RBC membrane, and its translocation after adrenergic stimulation. The activation of RBC {beta}-NHEs increased Hb-O2 saturation by [~]8% in normoxia at 1 kPa PCO2, and by up to 20% in hypoxia. Our results confirm that RBC {beta}-NHE activity in white seabass has great potential to protect arterial O2 transport in environmentally relevant conditions of hypoxia and hypercapnia, but also reveal a potential vulnerability of fish to combinations of these stressors. Plant host shift: The viability and persistence of a polyphagous, non-native insect Assessing the effects of a plant-host shift is important for monitoring insect populations over long time periods and for interventions in a conservation or pest management framework. In a heterogeneous environment, individuals may disperse between sources and sinks in order to persist. Here we propose a single-species two-patch model that aims to capture the generational movement of an insect that exhibits density-dependent dispersal, to see how shifting between hosts could alter its viability and asymptotic dynamics. We then analyse the stability and persistence properties of the model and further validate it using parameter estimates derived from laboratory experiments. In order to evaluate the potential of this model, we applied it to Drosophila suzukii (Diptera: Drosophilidae), which has become a harmful pest in several countries around the world. Although many studies have investigated the preference and attractiveness of potential hosts on this invasive drosophilid, no studies thus far have investigated whether a shift of fruit host could affect such a species ecological viability or spatiotemporal persistence. The model results show that a shift in host choice can significantly affect the growth potential and fecundity of a species such as D. suzukii, which ultimately could aid such invasive populations in their ability to persist within a changing environment. Trade-offs in biosensor optimization for dynamic pathway engineering Recent progress in synthetic biology allows the construction of dynamic control circuits for metabolic engineering. This technology promises to overcome many challenges encountered in traditional pathway engineering, thanks to their ability to self-regulate gene expression in response to bioreactor perturbations. The central components in these control circuits are metabolite biosensors that read out pathway signals and actuate enzyme expression. However, the construction of metabolite biosensors is a major bottleneck for strain design, and a key challenge is to understand the relation between biosensor dose-response curves and pathway performance. Here we employ multiobjective optimization to quantify performance trade-offs that arise in the design and calibration of metabolite biosensors. Our approach reveals strategies for tuning dose-response curves along an optimal trade-off between production flux and the cost of an increased expression burden on the host. We explore properties of control architectures built in the literature, and identify their advantages and caveats in terms of performance and robustness to growth conditions and leaky promoters. We demonstrate the optimality of a control circuit for glucaric acid production in Escherichia coli, which has been shown to increase titer by 2.5-fold as compared to static designs. Our results lay the groundwork for the automated design of control circuits for pathway engineering, with applications in the food, energy and pharmaceutical sectors. Liver Endothelium Promotes HER3-mediated Cell Survival in KRAS Wild-type and Mutant Colorectal Cancer Cells We previously showed that liver endothelial cells (ECs) secreted soluble factors in a paracrine fashion and activated human epidermal growth factor receptor 3 (HER3, also known as ERBB3) for promoting colorectal cancer (CRC) growth and chemoresistance. However, RAS proteins play a critical role in receptor tyrosine kinase signaling pathways, and KRAS mutations mediate CRC resistance to therapies targeting EGFR, another HER protein. Therefore, the role of KRAS mutation status in EC-induced HER3 activation and CRC survival was investigated as it has therapeutic implications. We used CRC cell lines and patient-derived xenografts harboring KRAS wild-type or mutant genes and demonstrated that liver EC-secreted factors promoted HER3-mediated CRC cell growth independent of KRAS mutation status. Also, blocking HER3 in CRC cells by siRNAs or a HER3 antibody seribantumab blocked EC-induced CRC survival. Our findings highlight the potential of utilizing HER3 targeted therapies for treating patients with mCRC independent of RAS mutational status. Salmonella Typhimurium outer membrane protein A (OmpA) renders protection against nitrosative stress by promoting SCV stability in murine macrophages Porins are highly conserved bacterial outer membrane proteins involved in the selective transport of charged molecules across the membrane. Despite their significant contributions to the pathogenesis of Gram-negative bacteria, their precise role in salmonellosis remains elusive. In this study, we investigated the role of porins (OmpA, OmpC, OmpD, and OmpF) in Salmonella Typhimurium (STM) pathogenesis. OmpA played a multifaceted role in STM pathogenesis, and a strain deleted for ompA (STM{Delta} ompA) showed enhanced proneness to phagocytosis and compromised proliferation in macrophages. However, in the epithelial cells, despite being invasion deficient, it was hyper-proliferative. The poor colocalization of STM{Delta} ompA with LAMP-1 confirmed impaired stability of SCV membrane around the intracellular bacteria, resulting in its (STM{Delta} ompA) release into the cytosol of macrophages where it is assaulted with reactive nitrogen intermediates (RNI). The cytosolic localization of STM{Delta} ompA was responsible for the downregulation of SPI-2 encoded virulence factor SpiC, which is required to suppress the activity of iNOS. The reduced recruitment of nitrotyrosine on STM in the macrophage cytosol upon ectopically expressing Listeriolysin O (LLO) explicitly supported the pro-bacterial role of OmpA against the host nitrosative stress. Further, we show that the generation of time-dependent redox burst could be responsible for the enhanced sensitivity of STM{Delta} ompA towards nitrosative stress. The absence of OmpA in STM{Delta} ompA resulted in the loss of integrity and enhanced porosity of the bacterial outer membrane, which was attributed to the upregulated expression of ompC, ompD, and ompF. We showed the involvement of OmpF in the entry of excess nitrite in STM{Delta} ompA, thus increasing the susceptibility of the bacteria towards in vitro and in vivo nitrosative stress. In conclusion, we illustrated a mechanism of strategic utilization of OmpA compared to other porins by wildtype Salmonella for combating the nitrosative stress in macrophages. Rossmann-toolbox: a deep learning-based protocol for the prediction and design of cofactor specificity in Rossmann-fold proteins The Rossmann fold enzymes are involved in essential biochemical pathways such as nucleotide and amino acid metabolism. Their functioning relies on interaction with cofactors, small nucleoside-based compounds specifically recognized by a conserved {beta}{beta} motif shared by all Rossmann fold proteins. While Rossmann methyltransferases recognize only a single cofactor type, the S-Adenosylmethionine (SAM), the oxidoreductases, depending on the family, bind nicotinamide (NAD, NADP) or flavin-based (FAD) cofactors. In this study, we show that despite its short length, the {beta}{beta} motif unambiguously defines the specificity towards the cofactor. Following this observation, we trained two complementary deep learning models for the prediction of the cofactor specificity based on the sequence and structural features of the {beta}{beta} motif. A benchmark on two independent test sets, one containing {beta}{beta} motifs bearing no resemblance to those of the training set, and the other comprising 38 experimentally confirmed cases of rational design of the cofactor specificity, revealed the nearly perfect performance of the two methods. The Rossmann-toolbox protocols can be accessed via the webserver at https://lbs.cent.uw.edu.pl/rossmann-toolbox and are available as a Python package at https://github.com/labstructbioinf/rossmann-toolbox.

Key pointsO_LIThe Rossmann fold encompasses a multitude of diverse enzymes involved in most of the essential cellular pathways
C_LIO_LIProteins belonging to the Rossmann fold co-evolved with their nucleoside-based cofactors and require them for the functioning
C_LIO_LIManipulating the cofactor specificity is an important step in the process of enzyme engineering
C_LIO_LIWe developed an end-to-end pipeline for the prediction and design of the cofactor specificity of the Rossmann fold proteins
C_LIO_LIOwing to the utilization of deep learning approaches the pipeline achieved nearly perfect accuracy
C_LI Plant biomechanics and resilience to environmental changes are controlled by specific lignin chemistries in each vascular cell type and morphotype The biopolymer lignin, deposited in the cell walls of vascular cells, is essential for long-distance water conduction and structural support of plants. Independently of the species, each different vascular cell type contains a conserved lignin chemistry with specific aromatic and aliphatic substitutions. Yet, the biological role of this conserved and specific lignin chemistry for each cell type remained unclear. Herein, we investigate the role of specific lignin chemistries for cellular function by producing single cell analyses on vascular cell morphotypes, all enabling sap conduction but differing in morphology. We found that specific lignin chemistries accumulate in each morphotype. Moreover, lignin accumulates dynamically, increasing in quantity and changing composition, to alter the cell wall biomechanics of each morphotype during their maturation. For similar aromatic substitution, residues with alcohol aliphatic functions increased stiffness whereas aldehydes increased flexibility. Modifying this specific lignin chemistry impairs the cell wall biomechanics of each morphotype and consequently reduces their capacity to optimally conduct water in normal conditions, and to recover from drought. Altogether, lignin chemistry is differently controlled for each sap conducting cell types during their maturation to dynamically adjust their biomechanics and hydraulic properties to adapt to developmental and environmental constraints. Receptor-binding domain recombinant protein on alum-CpG induces broad protection against SARS-CoV-2 variants of concern We conducted preclinical studies in mice using a yeast-produced SARS-CoV-2 RBD subunit vaccine candidate formulated with aluminum hydroxide (alum) and CpG deoxynucleotides. This formulation is equivalent to the Corbevax vaccine that recently received emergency use authorization by the Drugs Controller General of India. We compared the immune response of mice vaccinated with RBD/alum to mice vaccinated with RBD/alum+CpG. We also evaluated mice immunized with RBD/alum+CpG and boosted with RBD/alum. Mice were immunized twice intramuscularly at a 21-day interval. Compared to two doses of the /alum formulation, the RBD/alum+CpG vaccine induced a stronger and more balanced Th1/Th2 cellular immune response, with high levels of neutralizing antibodies against the original Wuhan isolate of SARS-CoV-2 as well as the B.1.1.7 (Alpha), B. 1.351 (Beta), B. 1.617.2 and (Delta) variants. Neutralizing antibody titers against the B.1.1.529 (BA.1, Omicron) variant exceeded those in human convalescent plasma after Wuhan infection but were lower than against the other variants. Interestingly, the second dose did not benefit from the addition of CpG, possibly allowing dose-sparing of the adjuvant in the future. The data reported here reinforces that the RBD/alum+CpG vaccine formulation is suitable for inducing broadly neutralizing antibodies against SARS-CoV-2 including variants of concern. Antibody Resistance of SARS-CoV-2 Variants B.1.351 and B.1.1.7 The COVID-19 pandemic has ravaged the globe, and its causative agent, SARS-CoV-2, continues to rage. Prospects of ending this pandemic rest on the development of effective interventions. Single and combination monoclonal antibody (mAb) therapeutics have received emergency use authorization1-3, with more in the pipeline4-7. Furthermore, multiple vaccine constructs have shown promise8, including two with ~95% protective efficacy against COVID-199,10. However, these interventions were directed toward the initial SARS-CoV-2 that emerged in 2019. The recent emergence of new SARS-CoV-2 variants B.1.1.7 in the UK11 and B.1.351 in South Africa12 is of concern because of their purported ease of transmission and extensive mutations in the spike protein. We now report that B.1.1.7 is refractory to neutralization by most mAbs to the N-terminal domain (NTD) of spike and relatively resistant to a few mAbs to the receptor-binding domain (RBD). It is not more resistant to convalescent plasma or vaccinee sera. Findings on B.1.351 are more worrisome in that this variant is not only refractory to neutralization by most NTD mAbs but also by multiple individual mAbs to the receptor-binding motif on RBD, largely due to an E484K mutation. Moreover, B.1.351 is markedly more resistant to neutralization by convalescent plasma (9.4 fold) and vaccinee sera (10.3-12.4 fold). B.1.351 and emergent variants13,14 with similar spike mutations present new challenges for mAb therapy and threaten the protective efficacy of current vaccines. HYBRID REACTION-DIFFUSION AND CLOCK-AND-WAVEFRONT MODEL FOR THE ARREST OF OSCILLATIONS IN THE SOMITOGENESIS SEGMENTATION CLOCK AO_SCPLOWBSTRACTC_SCPLOWThe clock and wavefront paradigm is arguably the most widely accepted model for explaining the embryonic process of somitogenesis. According to this model, somitogenesis is based upon the interaction between a genetic oscillator, known as segmentation clock, and a differentiation wavefront, which provides the positional information indicating where each pair of somites is formed. Shortly after the clock and wavefront paradigm was introduced, Meinhardt presented a conceptually different mathematical model for morphogenesis in general, and somitogenesis in particular. Recently, Cotterell et al. rediscovered an equivalent model by systematically enumerating and studying small networks performing segmentation. Cotterell et al. called it a progressive oscillatory reaction-diffusion (PORD) model. In the Meinhardt-PORD model, somitogenesis is driven by short-range interactions and the posterior movement of the front is a local, emergent phenomenon, which is not controlled by global positional information. With this model, it is possible to explain some experimental observations that are incompatible with the clock and wavefront model. However the Meinhardt-PORD model has some important disadvantages of its own. Namely, it is quite sensitive to fluctuations and depends on very specific initial conditions (which are not biologically realistic). In this work, we propose an equivalent Meinhardt-PORD model, and then amend it to couple it with a wavefront consisting of a receding morphogen gradient. By doing so, we get a hybrid model between the Meinhardt-PORD and the clock-and-wavefront ones, which overcomes most of the deficiencies of the two originating models.

Somitogenesis, the process by which somites are formed, is an essential developmental stage in many vertebrates. This process occurs with a strikingly regular periodicity, that is preserved among embryos of a single species. The clock and wavefront paradigm is arguably the most widely accepted model for explaining somitogenesis. However, it is incapable of explaining some experimental facts, like the appearance of somites in the absence of an external wavefront (i.e. a receding morphogen gradient). Shortly after the clock and wavefront paradigm was introduced, Meinhardt presented a conceptually different mathematical model for morphogenesis in general, and somitogenesis in particular. Recently, Cotterell et al. rediscovered an equivalent model by systematically enumerating and studying small networks performing segmentation, and called it a progressive oscillatory reaction-diffusion (PORD) model. The Meinhardt-PORD model tackles some of the deficiencies of the clock and wave-front models, but it has some serious issues of its own. In the present work, we introduce an equivalent Meinhardt-PORD model, and then amend it to couple it with a receding morphogen gradient. By doing so, we get a hybrid model that incorporates characteristics of the Meinhardt-PORD and clock-and-wavefront models. We show that this hybrid model under-goes a bifurcation, from a stable to an unstable limit cycle, as the value of the parameter accounting for a background regulatory input (associated to the receding morphogen gradient) decreases. This bifurcation allows the model to explain why somites can form in the absence of an external wavefront, reassesses the role of the receding morphogen gradient as a conductor for somitogenesis, and makes the model behavior robust to random fluctuations, as well as independent from specific initial conditions (the latter, are two of the weak points of the Meinhardt-PORD model). We argue that this findings provide convincing evidence that reaction-diffusion and positional information (receding morphogen gradient) mechanisms could work together in somitogenesis. Preprints in motion: tracking changes between preprint posting and journal publication during a pandemic Amidst the COVID-19 pandemic, preprints in the biomedical sciences are being posted and accessed at unprecedented rates, drawing widespread attention from the general public, press and policymakers for the first time. This phenomenon has sharpened longstanding questions about the reliability of information shared prior to journal peer review. Does the information shared in preprints typically withstand the scrutiny of peer review, or are conclusions likely to change in the version of record? We assessed preprints from bioRxiv and medRxiv that had been posted and subsequently published in a journal through 30th April 2020, representing the initial phase of the pandemic response. We utilised a combination of automatic and manual annotations to quantify how an article changed between the preprinted and published version. We found that the total number of figure panels and tables changed little between preprint and published articles. Moreover, the conclusions of 7.2% of non-COVID-19-related and 17.2% of COVID-19-related abstracts undergo a discrete change by the time of publication, but the majority of these changes do not qualitatively change the conclusions of the paper. Single-molecule conformational dynamics of a transcription factor reveals a continuum of binding modes controlling association and dissociation Binding and unbinding of transcription factors to DNA are kinetically controlled to regulate the transcriptional outcome. Control of the release of the transcription factor NF-{kappa}B from DNA is achieved through accelerated dissociation by the inhibitor protein I{kappa}B. Using single-molecule FRET, we observe a continuum of conformations of NF-{kappa}B in free and DNA-bound states interconverting on the subseconds to minutes timescale, comparable to in vivo binding on the seconds timescale, suggesting that structural dynamics directly control binding kinetics. Much of the DNA-bound NF-{kappa}B is partially bound, allowing I{kappa}B invasion to facilitate DNA dissociation. I{kappa}B induces a locked conformation where the DNA-binding domains of NF-{kappa}B are too far apart to bind DNA, whereas the loss-of-function I{kappa}B mutant retains the NF-{kappa}B conformational ensemble. Overall, our results suggest a novel mechanism with a continuum of binding modes for controlling association and dissociation of transcription factors. The multi-level phenotypic impact of synonymous substitutions: heterologous gene expression in human cells. Redundancy in the genetic code allows for differences in transcription and/or translation efficiency between sequences carrying synonymous polymorphisms, potentially leading to phenotypic changes. It is commonly admitted that the evolution codon usage bias ("CUB", the over-representation of certain codons in a genome, a gene or in positions along a gene) are driven by a combination of neutral and selective processes, but their relative contribution is a matter of debate, especially in mammals. Particularly, integrative studies quantifying the phenotypic impact of CUB at different molecular and cellular levels are lacking. Here we report a multiscale analysis of the effects of synonymous codon recoding during heterologous gene expression in human cells.

Six synonymous versions of the shble antibiotic resistance gene were generated, fused to a fluorescent reporter, and independently expressed in HEK293 cells. Multiscale phenotype was assessed by means of: i) mRNA-to-DNA and protein-to-mRNA ratios for each shble version; ii) cellular fluorescence, using flow cytometry, as a proxy for single-cell level expression; and iii) real-time cell proliferation in absence or presence of antibiotic, as a proxy for the cell fitness.

We show that differences in CUB strongly impact the molecular and the cellular phenotype: i) they result in large differences in mRNA and in protein levels, as well in mRNA-to-protein ratio; ii) they introduce splicing events not predicted by current algorithms; iii) they lead to reproducible phenotypic heterogeneity; iv) they lead to a trade-off between the benefit of antibiotic resistance and the burden of heterologous expression.

We interpret that CUB modulate mRNA availability and suitability for translation in human cells, leading to differences in protein levels and eventually eliciting phenotypic differences.

AUTHOR SUMMARYThe genetic code is redundant, with several codons encoding for the same amino acid. These synonymous codons are not used with equal frequencies. Instead, codon usage bias (CUB) varies between species, genes, and even positions along a gene. At each of these levels, CUB are shaped by the overall balance between mutational biases and selection forces. To shed light on the molecular mechanisms underlying molecular and organism phenotypes, integrative studies quantifying the phenotypic impact of CUB at different levels of biological integration are necessary. Here, we monitored the multiscale changes induced by six synonymous versions of an antibiotic resistance gene independently expressed in a human cell line. We show that: 1. both mRNA levels, protein levels, and their ratios are affected by CUB; 2. potential effects on mRNA (splicing and availability for translation) seem to constitute the main level of action; 3. cell fitness is severely impacted by a trade-off between the burden of heterologous expression and the benefits of antibiotic resistance. This integrative study provides new insights on translation regulation and the associated phenotypic impact in human cells, associated to CU. Stress-dependent cell stiffening by tardigrade tolerance proteins through reversible formation of cytoskeleton-like filamentous network and gel-transition Tardigrades are able to tolerate almost complete dehydration by entering a reversible ametabolic state called anhydrobiosis and resume their animation upon rehydration. Dehydrated tardigrades are exceptionally stable and withstand various physical extremes. Although trehalose and late embryogenesis abundant (LEA) proteins have been extensively studied as potent protectants against dehydration in other anhydrobiotic organisms, tardigrades produce high amounts of tardigrade-unique protective proteins. Cytoplasmic-abundant heat-soluble (CAHS) proteins are uniquely invented in the lineage of eutardigrades, a major class of the phylum Tardigrada and are essential for their anhydrobiotic survival. However, the precise mechanisms of their action in this protective role are not fully understood. In the present study, we first postulated the presence of tolerance proteins that form protective condensates via phase separation in a stress-dependent manner and searched for tardigrade proteins that reversibly form condensates upon dehydration-like stress. Through comprehensive analysis, we identified 336 such proteins, collectively dubbed "Desolvataion-induced ReversiblY condensing Proteins (DRYPs)". Unexpectedly, we rediscovered CAHS proteins as highly enriched in DRYPs, 3 of which were major components of DRYPs. We revealed that these CAHS proteins reversibly polymerize into many cytoskeleton-like filaments depending on hyperosmotic stress in cultured cells and undergo reversible gel-transition in vitro. CAHS filamentation increases cell stiffness to resist deformation and improves resistance to dehydration-like stress. The conserved putative helical C-terminal region is necessary and sufficient for filament formation by CAHS proteins, and mutations disrupting the secondary structure of this region impaired both the filament formation and the gel transition. On the basis of these results, we propose that CAHS proteins are novel cytoskeletal proteins that form filamentous networks and undergo gel-transition in a stress-dependent manner to provide on-demand physical stabilization of cell integrity against deformative forces during dehydration and also contribute to the exceptional physical stability in a dehydrated state. Translation of upstream open reading frames does not trigger nonsense-mediated decay in Arabidopsis Upstream ORFs (uORFs) are widespread cis-regulatory elements in the 5 untranslated regions of eukaryotic genes. In addition to repressing main ORF translation, uORF translation in animals also reduces mRNA stability through nonsense-mediated decay (NMD). In contrast, the roles of uORFs in plants are less understood. One limitation of most prior studies is the inclusion of both translated and untranslated uORFs for analysis. Here, we identified actively translated uORFs (TuORFs) in Arabidopsis through ribosome profiling and examined their roles in gene expression by integrating multiple genome-wide datasets. Similar to animal systems, TuORFs are associated with 38%, 14%, and 43% reductions in translation efficiency, mRNA stability, and protein levels, respectively. Surprisingly, TuORF-containing mRNAs in plants have 51% higher transcript levels, which is opposite to the observations in animals. We present multiple lines of evidence showing that uORF translation generally does not trigger NMD in Arabidopsis. First, TuORF-containing mRNAs are not upregulated in various NMD mutants. Second, TuORF- containing mRNAs and known NMD targets have distinct expression patterns, and they are translationally repressed via different mechanisms. Finally, TuORF-containing mRNAs and NMD targets are degraded through separate pathways. Together, our results highlight fundamental differences in gene regulation mediated by TuORFs in plants and animals. Differential sphingosine-1-phosphate receptor-1 protein expression in the dorsolateral prefrontal cortex between schizophrenia Type 1 and Type 2 Understanding the etiology and treatment approaches in schizophrenia is challenged in part by the heterogeneity of this disorder. One encouraging progress is the growing evidence that there are subtypes of schizophrenia that may relate to disease duration and premorbid severity. Recent in vitro findings of messenger ribonucleic acid (mRNA) gene expression on postmortem dorsolateral prefrontal cortex (DLPFC) showed that schizophrenia has two subtypes, those with a relatively normal DLPFC transcriptome (Type 1) and those with differentially expressed genes (Type 2). Sphingosine-1-phosphate receptor-1 (S1PR1) is one of the genes that was highly upregulated in Type 2 compared to Type 1 and controls. The impact of that finding is limited because it only can be confirmed through analysis of autopsy tissue, and the clinical characteristics such as symptoms severity or illness duration was not available from that Medical Examiner based autopsy study. However, S1PR1 has great potential because it is a target gene that can be accessed via positron emission tomography (PET) in vivo using specific radioligands (starting with [11C]CS1P1) successfully developed at our center in human brain imaging. As a preliminary study to validate this PET target in schizophrenia, S1PR1 protein expression was assessed by receptor autoradiography (ARG) using [3H]CS1P1 and immunohistochemistry (IHC) in the DLPFC from patients with schizophrenia classified as Type 1 or Type 2 based on their DLPFC transcriptomes and from controls. Our analyses demonstrate that ARG S1PR1 protein expression is significantly higher in Type 2 compared to Type 1 (p < 0.05) and controls (p < 0.05), which was consistent with previous mRNA S1PR1. These findings support the possibility that PET S1PR1 can be used as a future imaging biomarker to distinguish these subgroups of schizophrenic patients during life with obvious implications for both patient management and the design of clinical trials to validate novel pharmacologic therapies. Microbial colonization of tannin-rich tropical plants: interplay between degradability, methane production and tannin disappearance in the rumen AO_SCPLOWBSTRACTC_SCPLOWCondensed tannins in plants are found free and attached to protein and fibre but it is not known whether these fractions influence rumen degradation and microbial colonization. This study explored the rumen degradation of tropical tannins-rich plants and the relationship between condensed tannins fractions disappearance and microbial communities colonising plant particles. Leaves from Calliandra calothyrsus, Gliricidia sepium, and Leucaena leucocephala, pods from Acacia nilotica and the leaves of two agricultural by-products: Manihot esculenta and Musa spp. were incubated in situ in the rumen of dairy cows. An in vitro approach was also used to assess the effects of these plants on rumen fermentation parameters. All plants contained more than 100 g/kg of condensed tannins with a large proportion (32 to 61%) bound to proteins. Calliandra calothyrsus had the highest concentration of condensed tannins at 361 g/kg, whereas Acacia nilotica was particularly rich in hydrolysable tannins (350 g/kg). Hydrolysable and free condensed tannins from all plants completely disappeared after 24 h incubation in the rumen. Disappearance of protein-bound condensed tannins was variable with values ranging from 93% for Gliricidia sepium to 21% for Acacia nilotica. In contrast, fibre-bound condensed tannins disappearance averaged ~82% and did not vary between plants. Disappearance of bound fractions of condensed tannins was not associated with degradability of plant fractions. The presence of tannins interfered with the microbial colonisation of plants. Each plant had distinct bacterial and archaeal communities after 3 and 12 h of incubation in the rumen and distinct protozoal communities at 3 h. Adherent communities in tannin-rich plants had a lower relative abundance of fibrolytic microbes, notably Fibrobacter spp. Whereas, archaea diversity was reduced in high tannin-containing Calliandra calothyrsus and Acacia nilotica at 12 h of incubation. Concurrently, in vitro methane production was lower for Calliandra calothyrsus, Acacia nilotica and Leucaena leucocephala although for the latter total volatile fatty acids production was not affected and was similar to control. Here we show that the total amount of hydrolysable and condensed tannins contained in a plant govern the interaction with rumen microbes affecting degradability and fermentation. The effect of protein- and fibre-bound condensed tannins on degradability is less important. The transmission of African Animal Trypanosomiasis (Nagana) in two districts in the forest zone of Ghana The African Animal Trypanosomiasis (nagana) is caused by several species of trypanosome species which results in significant clinical diseases. This consequently leads to huge economic losses. We carried out a cross-sectional survey to investigate the composition of vectors, parasite diversity and intensities in two districts in the Eastern region of Ghana. Cytochrome c oxidase subunit 1 (COI) and internal transcribed spacer (ITS1) dependent PCR assays identified tsetse fly species and trypanosome parasites circulating in the area. A total of 229 tsetse flies, 65 pigs and 20 were sampled. Female and male flies 155 (51.8%), 74 (32.3%) respectively were collected with biconical traps. The overall vector density of 4.3 flies/trap/day was observed. Typanosome prevalence of 58.9% (95% CI: 52.5-65.1), 46.2% (95% CI: 34.6-58.1) and 0.0% (95% CI: 0.0-16.1) in tsetse flies, pigs and cattle respectively were detected. Trypanosoma congolense was the predominant species with a prevalence of 80.7% (95% CI: 73.3-86.5) in flies and 60.0% (95% CI: 42.3-75.4). There was evidence of multiple trypanosome infection with T. congolense/T. simiae occurring highest with prevalence of 38.0% (95% CI: 30.7-46.9). The parasite prevalence in pigs across the communities was high with significant differences associated between locations (Chi2 = 28.06, 95% CI: 0.05-0.81, P=0.0009). Blood meal with flies revealed feeding on both domestic Sus scrofa domesticus (pig) and Phacochoerus africanus (warthog). Tsetse flies in this area remain highly infected with trypanosomes and continue to transmit the parasites to livestock and human populations in the communities.