IntroductionAugmented reality (AR) is an advanced technology and emerging field that has been adopted into spine surgery to enhance care and outcomes. AR superimposes a three-dimensional computer-generated image over the normal anatomy of interest in order to facilitate visualization of deep structures without the ability to directly see them.ObjectiveTo summarize the latest literature and highlight AR from the annual “Spinal Navigation, Emerging Technologies and Systems Integration” meeting lectures presented by the Seattle Science Foundation (SSF) on the development and use of augmented reality in spinal surgery. Methods We performed a comprehensive literature review from 2016 to 2020 on PubMed to correlate with lectures given at the annual “Emerging Technologies” conferences. After the exclusion of papers that concerned non-spine surgery specialties, a total of 54 papers concerning AR in spinal applications were found. The articles were then categorized by content and focus.ResultsThe 54 papers were divided into six major focused topics: training, proof of concept, feasibility and usability, clinical evaluation, state of technology, and nonsurgical applications. The greatest number of papers were published during 2020. Each paper discussed varied topics such as patient rehabilitation, proof of concept, workflow, applications in neurological and orthopedic spine surgery, and outcomes data.ConclusionsThe recent literature and SSF lectures on AR provide a solid base and demonstrate the emergence of an advanced technology that offers a platform for an advantageous technique that is superior, in that it allows the operating surgeon to focus directly on the patient rather than a guidance screen. The concept of using the navigation in performing more accurate cranial and spinal procedures extends back to the novel concept of using fluoroscopy and television technology to perform a stereotactic cordotomy in the 1960s ,3. One oThe Seattle Science Foundation’s (SSF) annual “Spinal Navigation, Emerging Technologies and Systems Integration” meeting highlights emerging and advancing technologies in multiple disciplines of spinal surgery including intraoperative navigation and robotic surgery. The conference, now in its fifth year, has historically brought together surgeons inspired to incorporate novel technologies in the operating room and surgeons reporting the progress of the technology in their own clinical practices. The goal of the meeting is to talk about the benefits of new technologies for surgeons and patients, encourage further development of these technologies in the field, and discuss adoption across multiple institutions. This series of highlights will examine the use of augmented reality throughout the last five years of the conferences and offer insights into the future direction of the use of these technologies.A PubMed search was carried out with these search terms: augmented reality spine surgery, augmented reality neurosurgery, augmented reality orthopedic surgery, augmented reality surgery, mixed reality spine surgery, OR augmented reality spine surgery. Results were limited to 2016 through 2020, so as to correlate with lectures given at the SSF “Annual Emerging Technologies” conferences. The literature review resulted in 132 papers. Inclusion criteria were defined as papers pertaining directly to neurosurgical or orthopedic spine surgery and published within the 2016-2020 time frame. After the exclusion of papers related to non-spine surgery specialties, there were a total of 54 papers concerning AR in the field of spinal surgery. We then categorized by content and focus of each article.Following the review of the literature, the agendas of the annual “Spinal Navigation, Emerging Technologies, and Systems Integration” meeting were reviewed for lectures focused on the topic of AR. Six lectures were given across the 2016-2020 time period ranging from introductions to the technology to direct clinical applications and outcomes using FDA-approved AR systems. Lectures were reviewed and annotated into a series of highlights documenting the growth and evolution of AR over the past four years.Of the 54 papers identified in the literature review with queried terms that pertained to spine surgery, there was a steady increase of AR papers published per queried year, with 2 published in 2016, 4 published in 2017, 6 published in 2018, 10 published in 2019 and 31 published in 2020  Training, 2) Proof of Concept, (3) Feasibility & Usability, (4) Clinical Evaluation, 5) State of Technology, and 6) Nonsurgical Applications , a wireless battery-operated system, an independent navigational system and a series of tool mounts that allowed the xVision system to be agnostic with other manufactured spinal instrumentation systems Figure . PrelimiAt the 2019 conference, Dr. Timothy Witham updated the spine community on the developments within the field of AR. At the time of this 2019 talk, the FDA still had not approved the xVision system for commercial use. Dr. Witham began with the Carl et al. study, that had shown the use of AR to superimpose bony landmarks or the outline of tumors on microscopes while operating . It was xVision received FDA clearance in 2020 for clinical use, and Dr. James Lynch spoke of his experience with AR fitting into his practice. Dr. Lynch was the first private practice surgeon to use AR in a community hospital setting within the U.S., with the first documented case being on June 25th, 2020. The workflow was briefly discussed and was found to be similar in setup to spinal navigation with a small ergonomic footprint. At the time of his lecture at “Emerging Technologies,” Dr. Lynch presented his experience with over 50 AR-assisted cases. He demonstrated that AR had led to accurate pedicle screw placements across a variety of instrumentation systems. According to his experience, the learning curve was extremely straightforward with reported proficiency attained at approximately 5 cases. Due to the small ergonomic footprint and a relatively affordable cost of the system, he concluded that the xVision AR system would best find a place in a surgery center where traditional navigation may be too bulky or cost-prohibitive.The learning curveWith any technology, there is a limitation in the speed of adoption due to novelty and training required to become competent and integrate the system into everyday practice. Dr. Timur Urakov spoke about this process in relation to AR at the 2020 “Emerging Technologies” conference, in which he set out to discuss how AR could be used as an adjunct to already existing technologies instead of being considered an entirely new system workflow Figure . At the The adoption of AR is also more intuitive to those surgeons that use spinal navigation. The visual experience similarities between AR systems and spinal navigation systems are several. With spinal navigation the surgeon is directly viewing the patient’s bony anatomy and instrumentation through a direct-visualization computer screen workstation. The computer screen is typically placed at the head or foot of the bed, away from the patient’s body. AR displays are heads-up displays (HUDs) that show the same information as spinal navigation computer screens, directly onto the surgeon’s AR headset. Dr. Urakov has been able to demonstrate this when he successfully reported on an endoscopic lumbar discectomy with the direct endoscopic images being displayed to the surgeon’s lenses . With diApplication outside of the ORBoth Drs. Lynch and Urakov emphasized that although AR is promising in the OR, it need not only apply to the spine surgeon with instrumentation. There has been a growing push in health literacy to use tools such as AR to help a patient fully understand the details of their care . AlreadyDue to the reduced cost compared to navigation, AR may also play a role for surgeons looking to operate in rural parts of the U.S. or even be used on mission trips in resource-limited countries. With traditional navigation computers, cameras and sensors, traditional spinal navigation must be calibrated and present in the operating room for the systems to function properly. This becomes a feasibility issue when sending these systems to areas with limited infrastructure as they may not be able to support these advanced technologies. With further development of AR, a surgeon would simply need to take the AR headset, integrate any imaging modality and use the cross-compatibility seen in multiple AR systems to deploy precise spinal surgery anywhere in the world. Future directions In 2018, Dr. Molina suggested that AR would be used for minimally invasive applications, and by 2020, there was direct clinical application in Dr. Lynch’s practice in demonstrating that the system lent itself extremely well to accurate placement of pedicle screws in MIS cases.Dr. Molina also expected AR technology to continue to advance to a point where it would be utilized in complex cases such as atrophic/dysplastic bony anatomy, scoliosis with significant coronal and rotational deformities, tumor resection, transarticular screws and even cranial neurosurgery Figure . Dr. JuaAR is an emerging technology that has exponentially developed and is continuing to evolve into a superior technology. Its key advantage over robotics and navigated spine surgery is that the surgeon never has to take the focus from the patient. The superimposition of images directly onto the surgical field gives obvious and immediate safety and procedural advantages. As the technology continues to develop, integration of AR should be a tool considered by surgeons parallel to spinal navigation.


The design of digital technologies that support poststroke rehabilitation at home has been a topic of research for some time. If technology is to have a large-scale impact on rehabilitation practice, then we need to understand how to create technologies that are appropriate for the domestic environment and for the needs and motivations of those living there.This paper reflects on the research conducted in the Motivating Mobility project . We conducted sensitizing studies to develop a foundational understanding of the homes of stroke survivors, participatory design sessions situated in the home, and experimental deployments of prototype rehabilitation technologies.We identified four challenges specific to the homes of stroke survivors and relevant to the deployment of rehabilitation technologies: identifying a location for rehabilitation technology, negotiating social relationships present in the home, avoiding additional stress in households at risk of existential stress, and providing for patient safety.We conclude that skilled workers may be needed to enable successful technology deployment, systematizing the mapping of the home may be beneficial, and education is a viable focus for rehabilitation technologies. The design of interactive technologies to support rehabilitation from disability acquired through stroke has been a topic of research since 1991, when Dijkers et al  and to aMost rehabilitation takes place post discharge, frequently in the home, and this phase has historically been poorly supported by health services . As a reEvidence suggests that long-term, intense, task-specific, context-specific, goal-oriented, variable, and environmentally enriched poststroke rehabilitation improves function, independence, and quality of life ,13. SignEven at a technological level, the widespread provision of home-based technologies is a very different type of challenge to that of provision for the clinical environment. Home-based deployment of technology might naturally lend themselves to (and necessitate) technologies that are commodified, with a much lower unit price, to facilitate large-scale uptake. As a target for technology design and deployment, the home should not be thought of as a smaller-scale, lower-intensity version of a clinic. Foundational research within the fields of computer-supported cooperative work and human-computer interaction has sought to draw technology designers’ attention to the home as a playful place ,20; as aGiven that brain injuries can lead to profound and varied disabilities and hence inherently raise the difficulty of living in a space , the homMotivating Mobility: Interactive Systems to promote Physical Activity and Leisure for people with limited mobility, a 3-year research study funded by the UK Engineering and Physical Sciences Research Council. Motivating Mobility was a collaboration among researchers with expertise in psychology, physiotherapy, technology design, and technology deployment.As a contribution to this developing area of inquiry, this paper draws on the work conducted through In Motivating Mobility, we engaged in three phases of work selected to provide a rich understanding of the home and how rehabilitation technology targeted at upper-limb disabilities might find a place in it. This paper integrates results from published and unpublished Motivating Mobility studies to identify challenges in the deployment of rehabilitation technologies into the home environment and implications of these challenges for health care practices.Work in the Motivating Mobility study was situated within an emerging approach known as Research through Design, characterized effectively by Zimmerman et al , which pAs a piece of Research through Design, work in Motivating Mobility was structured into three phases. Phase 1 consisted of sensitizing studies that provided initial insights into the nature of the home environment to ground the work of the project. Phase 2 consisted of situated design case studies in which the research team visited the homes of 4 stroke survivors and worked collaboratively to identify technologies that might support rehabilitation and find an effective place in their homes. In phase 3, prototype implementations of technology were deployed into 4 homes, usage was captured through electronic logs, and interviews were conducted to understand how technologies were or were not appropriated. Detailed methods and findings are presented in studies by Egglestone et al , AxelrodIn this paper, we have reexamined the material collected by Motivating Mobility studies to present emergent findings that represent the totality of what we have learned through this work. Our focus was on what we have learned about the challenges of the domestic environment for rehabilitation technology design and deployment.Early in Motivating Mobility, a photographic study of the homes of stroke survivors was conducted . AlthougOne implication is that finding a physical space to place digital technologies may be more difficult in the homes of stroke survivors. This does not preclude the integration of technology; we found that participants were often willing to make changes to their homes to incorporate technologies that they believed to have benefits. This suggests that finding an appropriate location is a necessary part of the technology deployment process. It may also implicate work to persuade residents of the benefits of the technology versus the effort of integrating it into their space.The complexity of finding an appropriate location for a rehabilitation technology may be enhanced by long-term residency in a home, frequently measured in decades, and by the nature of the home as an ongoing project to create a pleasing and stimulating environment . In one emotional map .Technology deployment work may need to take into account these heightened reactions.A substantial body of literature describes integrating elements of the domestic environment directly into rehabilitation technologies. A study by Pridmore et al  has descGiven the challenges described earlier, finding an appropriate place in the home for technology quickly became a central question for our research. In our design case studies, we addressed this through an initial design session where we discussed issues of space and place with our participants. This often led to a specific first proposal for where a technology might be placed, which was then further discussed in subsequent design sessions with a participant.safe or stimulating space for a substantial proportion of their day, which had been specifically designed to support their well-being. The tactics that we observed in creating these spaces included the use of a comfortable armchair with accompanying photographs, entertainment systems, and necessary physical support (such as armrests), placed in a space in the home that was less likely to induce anxiety. The motivation for creating such spaces seemed to account for and ameliorate the negative effects of the difficulties in mobility acquired through stroke.One notable phenomenon was that our participants sometimes already inhabited a In two of our design case studies, we worked with participants to explore a tactic of appropriating these spaces for the purpose of introducing technology . This inThrough sensitizing studies, we learned of the active role that others sharing a home, such as partners, can take in the rehabilitation process. Participants told us of partners who had learned a great deal about stroke and rehabilitation theory to provide more expert support for ongoing rehabilitation efforts. They also told us of partners who had made substantial modifications to the home to support well-being. To learn about the potential role of coresidents in relation to technology, we invited partners to all participatory design sessions and scheduled these sessions to allow for the provision of input from partners wherever possible. For one design case study, with a stroke survivor in her 30s, parents were also invited, as they played a significant and active role in her care. All prototype deployments were in shared environments, and we explicitly included coresidents in the follow-up interview process.In addition to opportunities, we observed that the presence of others in the same household could create contention over the usage of space. In the design case study illustrated in Rehab Reader [One notable example of the way in which a partner might shape an interaction with a technology was provided in a design case study that we called the b Reader . The stuA prototype was deployed for a period of 7 months, and a total of 6621 grasp and release exercises were conducted during this period. Substantial grasp and release recovery was noted in the hand used to control the device. However, a contention emerged between Irene and her partner about the meaning of the device, and hence how it should be used. Irene saw the prototype as a leisure device, with exercise occurring as a side effect. Her partner saw it as an exercise device, similar in nature to how he saw a Nintendo Wii owned by a couple. Irene’s partner pressured her to use it at fixed and regular times during the day, so as to perform a reliable amount of exercise. She wanted to use it when she felt like it, and this contention in meaning caused arguments within the couple. It is possible that this contributed to the overuse of the device, as described in challenge 4. Although this is a very specific scenario, we present it to draw attention to the importance of understanding the social nature of interaction with rehabilitation technologies. Others in a social setting are key actors who need to be understood as part of a rehabilitation technology deployment and who can play a role in relation to it, which ranges from supportive to disruptive. As such, their engagement may need to be managed.One of our least successful prototype deployments involved a novel children’s toy specifically designed to allow a mother who had experienced a stroke in her 30s to perform rehabilitation motor exercise while playing with her young child, a key person on the social side of her existence . The tacWe learned through our sensitizing studies of the almost intolerable levels of existential stress that could be experienced in the homes of stroke survivors . Stress A household with continuing high levels of stress around their everyday existence may be a difficult environment to deploy new technologies, especially if those technologies require additional effort to learn about, engage with, or maintain in a working state. Potentially, rehabilitation technologies that do not take into account or which increase the already high levels of stress may be more likely to fail. In Motivating Mobility, we adopted a tactic of not building technologies that depended upon network connections, in the belief that having to maintain the functionality of a network connection would likely lead to excessive stress and hence lack of use of the technology. We note that our work was done in a period when domestic technology was frequently discussed as being unstable and requiring skilled work to maintain  . How to We have described four challenges that affect the design and deployment of effective home-based rehabilitation technologies for stroke. Our aim is to support effective deployment work in the future and therefore the successful uptake of rehabilitation technologies by health services, as a possible route toward recovery from disability acquired through brain injury. The following are three implications arising from these challenges. They were selected to provide insight into how rehabilitation technology deployments can be supported on a larger scale.Although our interest is in rehabilitation technology, much of the complexity we have observed relates to what might be described as human factors around the technology , for exaIf deployment work is to be done as part of health care systems, and as domestic rehabilitation technologies are a relatively new phenomenon, we might speculate that existing health care professions are, as a whole, unlikely to have the skills or knowledge required to immediately engage in effective deployment work and to negotiate all the challenging human factors identified earlier. In some cases, it seems likely that existing professions may be able to adapt; during deployment studies, we found that a team of physiotherapists were capable of monitoring usage and suggesting alterations to support successful and safe engagement, and we might expect a reasonable match with skills and knowledge present in professions such as occupational therapy.Regardless of whether rehabilitation technology deployments are supported by health care workers drawn from existing professions or by a new type of health care worker, it seems clear that new tools and potentially new forms of training might be needed to prepare such workers to perform the challenging work of selecting, deploying, and supporting rehabilitation technologies, and provision may be a requirement for the large-scale integration of rehabilitation technologies into real-world health care practice.One mechanism for supporting health care workers to perform technology deployment work may be evidence-based tools to systematize the mapping of the home and its routines, so as to enable a more rapid understanding of the complexities of this environment than that achieved by our study team. Identifying what features to map in the home of a stroke survivor and collecting mapping information took a significant amount of effort and discussion during our design case studies among a group of researchers with a substantial body of expertise in technology design and deployment. This level of effort would be impractical to repeat on a larger scale, but a strength of the Research through Design approach is that it allows for lessons learned through design-oriented research endeavors to be considered as a primary output of the research process, so as to support the work of others engaging in a similar space.Our work suggests the importance of considering prior usage of the home ; current and anticipated or hoped for future usage of the home; changes in emotional response due to stroke; any spaces purposefully created to support the well-being of a stroke survivor; social usage of a space that might have an impact on the technology integration process; and the availability of utilities necessary to support technologies, principally power sockets but potentially also access to a network. The latter can be affected by structural features such as thick boundary walls or the location of domestic routers. Tolmie et al  providedIf rehabilitation technologies are to be deployed on a wide scale across thousands of homes, then we would argue that mapping exercises, although vital, need to be completed quickly and efficiently. This seems to be an ideal candidate for the creation of standardized materials that systematize the mapping process and allow for the collection of information known to be useful in supporting technology deployment work. This would not exclude human judgment in the final decisions made around rehabilitation technology deployments; however, it would provide for a good foundation of knowledge to be collected to ensure that key decisions around place could be taken efficiently, hopefully increasing the scalability of the process of deploying rehabilitation technologies.How these standard measures might be made available to people doing technology deployment work, and how deployment specialists might be supported in quickly collecting and analyzing collected information, is a question for further investigation. However, we might imagine the creation of computer interfaces to support the collection of data in the field, as has been done in other areas involving specialist visits to particular locations, such as in the railway maintenance industry .Much of the technology rehabilitation literature is built around the design and deployment of technologies that encourage rehabilitation by showing people what to do in terms of exercises and by helping them do it, often in a repetitive manner. However, work on Motivating Mobility suggests that teaching people how to understand and conceptualize their rehabilitation is an important role for technology and might boost outcomes. This is very clear in the narrative presented in relation to challenge 3, where 2 partners had such a profound difference of view about how to use a technology. It was also embedded in a broad range of discussions with participants, who often described being motivated to do rehabilitation exercises but not knowing what was appropriate or safe to do and hence not engaging in them.Providing education about rehabilitation, in this case, from common mental health problems such as anxiety and depression, has been a core approach in the category of health technologies known as Computerized Cognitive Behavioral Therapy; examples of these technologies have been proven to work in large clinical trials . We mighThe design of interactive technologies to support rehabilitation from disability acquired through brain injury has been a topic of research since 1991, and hundreds of technology prototypes have been piloted and reported in the literature, with the domestic environment being a focus of research. We have conducted research work intended to support an understanding of how domestic rehabilitation technologies might be integrated into health care practice and considered a range of human factors at play in this process.We suggest that for large-scale deployments to become a practical reality, the preparation of health care professionals needs to be considered, and health care professionals need to be provided with appropriate tools .Deployments may also need to consider the provision of education for the recipients of technology , as a lack of knowledge of rehabilitation and how it can occur may be a barrier to engagement with the deployed technology.


The androgen receptor (AR) is a member of the nuclear receptor superfamily and has three functional domains, namely the N-terminal, DNA binding, and C-terminal domain. The N-terminal domain harbors potent transactivation functions, whereas the C-terminal domain binds to androgens and antiandrogens used to treat prostate cancer. AR has genomic activity being DNA binding-dependent or through interaction with other DNA-bound transcription factors, as well as a number of non-genomic, non-canonical functions, such as the activation of the ERK, AKT, and MAPK pathways. A bulk of evidence indicates that non-coding RNAs have functional interactions with AR. This type of interaction is implicated in the pathogenesis of human malignancies, particularly prostate cancer. In the current review, we summarize the available data on the role of microRNAs, long non-coding RNAs, and circular RNAs on the expression of AR and modulation of AR signaling, as well as the effects of AR on their expression. Recognition of the complicated interaction between non-coding RNAs and AR has practical importance in the design of novel treatment options, as well as modulation of response to conventional therapeutics. The androgen receptor (AR), alternatively named as NR3C4 , is a nuclear receptor  that is Notably, specific coregulators have been found to modulate the transcriptional activity of androgen/AR complex. The binding of coregulators with androgen/AR complex can either enhance (via coactivators) or suppress (via corepressors) its transactivation capability. This process is accomplished via the epigenetic changing of chromatin configuration and histone modifications .A bulk of evidence indicates that non-coding RNAs (ncRNAs) have functional interactions with AR. This type of interaction is implicated in the pathogenesis of human malignancies, particularly prostate cancer. In the current review, we summarize the available data on the role of microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) on expression of AR, as well as the effects of AR on their expression.Several miRNAs have been found to suppress the expression of AR. In fact, most of these miRNAs have been shown to bind with 3′UTR of AR transcript, thus inducing its degradation or translation suppression. The interactions between miRNAs and AR mRNA, mainly through binding with its 3′UTR, have been mostly assessed in the context of prostate cancer. MiR-299-3p is one of the AR-interacting miRNAs. Expression of miR-299-3p has been reported to be decreased in prostate cancer samples, compared to noncancerous prostate samples. The restoration of miR-299-3p in prostate cancer cells has led to the induction of cell cycle arrest, reduction of cell proliferation and migration, and enhancement of levels of apoptotic markers. Moreover, the up-regulation of miR-299-3p leads to reduced expressions of AR, PSA, and VEGFA, suppressed epithelial mesenchymal transition (EMT), reduced levels of Slug, TGF-β3, p-AKT, and p-PRAS40, and enhanced E-cadherin levels. Taken together, miR-299-3p exerts anti-tumor effects via affecting activity of AR and VEGFA pathways [Another study in prostate cancer cells has identified miR-185-binding sites in the 3′UTR of the AR transcript. Notably, the suppression of AR expression by miR-185 has compromised the interaction between AR and ARE and decreased the levels of the AR target gene PSA . MoreoveMiR-381 is another down-regulated miRNA in prostate cancer. Forced over-expression of miR-381 in LNCaP cells inhibited their proliferation, migratory aptitude, and invasion. Mechanistically, miR-381 suppresses AR mRNA expression by binding to its 3′UTR .MiR-let-7c is another miRNA that decreases expression and activity of AR in prostate cancer cells. It modulates AR transcription through c-Myc. MiR-let-7c-mediated inhibition of AR can reduce the proliferation of prostate cancer cells .On the other hand, a handful of miRNAs have been found to exert oncogenic roles in prostate cancer, through the regulation of transcription of AR expression or signaling. Following androgen deprivation therapy, hormone-sensitive prostate cancer can evolve to castration-resistant prostate cancer (CRPC). MiRNAs can contribute to this process. For instance, miR-221/-222 has been shown to be up-regulated in bone metastatic CRPC samples. In vitro studies have demonstrated that stable overexpression of miR-221 induces the androgen-independent growth of prostate cancer cells, by releasing these cells from androgen deprivation-related G1 arrest. The up-regulation of this miRNA in LNCaP has led to the reduction of expression of a subclass of androgen-responsive genes, without influencing the expression of AR or integrity of AR-androgen. MiR-221 has been found to regulate the expressions of HECTD2 and RAB1A, two genes being capable of the induction of CRPC phenotype in various prostate cancer cells. Further, the up-regulation of miR-221 has led to alterations in the expression levels of several cell cycle-related genes and the activation of EMT-related pathways. Taken together, it has been hypothesized that miR-221 has a major role in AR signaling reprogramming and the subsequent evolution of the CRPC phenotype .Experiments in mice models have indicated the effect of surgical castration in the induction of an early upsurge in the serum levels of miR-125b. Moreover, bicalutamide-mediated AR blocking has resulted in the prompt release of this miRNA into the media of cultured prostate cancer cells. NCOR2, as a corepressor of AR, has been shown to be targeted by miR-125b. Thus, miR-125b has been suggested as a key regulator of AR, which alters the efficacy of anti-androgen therapies .MiR-96 is another oncogenic miRNA that can target a RARγ network to control AR signaling. Down-regulation of RARγ, a member of the nuclear receptor superfamily, has been shown to significantly affect the viability of prostate cancer cells and gene signature of these cells. A gene network, comprising of numerous RARγ target genes, such as SOX15, has been found to be correlated with poor disease-free survival of prostate cancer patients [MiR-541 is another oncogenic miRNA that can affect prostate cancer course through modulation of AR signaling. In fact, infiltrating CD4(+) T cells, which are associated with poor clinical outcomes in this type of cancer, can increase FGF11 levels. Up-regulation of this growth factor leads to increase levels of miR-541. The subsequent down-regulation of AR signaling regulates MMP9 levels, in favor of tumor metastasis . Figure In addition to above-mentioned miRNAs, several miRNAs can directly or indirectly affect AR signaling by binding with 3′UTR, the coding region of AR, or influencing the levels of AR co-activators/co-repressors .In addition to prostate cancer, the effects of miRNAs on AR have been investigated in other cancer types . For insIn addition, miR-9-5p has been identified as a suppressor of AR expression in breast cancer. A feedback loop has been recognized between these genes in breast cancer cells, in which androgen agonists of AR can increase expression of miR-9-5p. In fact, miR-9-5p can inhibit the proliferation of breast cancer cells in a manner independent from the estrogen receptor (ER) status of these cells. Moreover, miR-9-5p can decrease the activity of AR-downstream signals, even in the conditions that breast cancer cells are induced by AR-agonists .In cervical cancer, the oncogenic miR-130a-3p has been found to target both ERα and AR. MiR-130a-3p silencing, ERα up-regulation, and AR up-regulation have suppressed proliferation and invasion of cervical cancer cells. Besides, antagomiR-130a could decrease tumor bulk in animal models. Taken together, miR-130a-3p has a possible role in the progression of cervical cancer, through the suppression of ERα and AR .In hepatocellular carcinoma, miR-135b-5p has been shown to suppress AR-mediated cell proliferation, through the regulation of HIF-2α/c-Myc/P27 axis . MoreoveIn glioma, the circ-ASPH/miR-599/AR/SOCS2-AS1 axis has been identified as a molecular mechanism for cancer progression. In fact, circ-ASPH could mediate this function by sponging miR-599 .SAT1 as AR-interacting partner. The expression of this lncRNA is down-regulated in PCa tumor tissue compared to non-tumor tissue indicating a tumor suppressive function. LncRNASAT1 is up-regulated by the treatment with supraphysiological androgen level (SAL) in PCa cells and human PCa tissue ex vivo and mediates the SAL-induced cellular senescence [SAT1 interacts with AR on chromatin level regulating AR transactivation and AR target gene expression [PCGEM1 is a lncRNA with important roles in splicing events. This lncRNA has been found to interact with the splicing factors heterogeneous nuclear ribonucleoprotein (hnRNP) A1 and U2AF65. Experiments have shown correlation between PCGEM1 and AR3, a principal and clinically important alternatively spliced form of AR in prostate cancer. Besides, androgen deprivation leads to enhanced expression of PCGEM1 and its accretion in nuclear speckles. Androgen deprivation-induced PCGEM1 has a role in regulation of the competition between two splicing factors for AR pre-mRNA . Recent nescence . Furtherpression . Anotherpression . In addipression . Figure Several other oncogenic lncRNAs have been found to regulate AR signaling. For instance, HOTAIR increases AR-mediated transcriptional program and induces CRPC phenotypes . MoreoveIn brief, lncRNAs can affect AR levels through interacting with AR on chromatin level, regulation of AR transactivation and modulation of AR target gene expression. Some lncRNAs can also regulate stability of AR transcripts and preventing its ubiquitination. The effects of lncRNAs on AR signaling have also been assessed in other types of cancers. In bladder cancer, XIST has been found to be up-regulated parallel with up-regulation of AR. Over-expression of XIST and AR has been correlated with advanced TNM stage in this cancer. XIST silencing has decreased proliferation, invasion, and migratory potential of bladder cancer through modulation of AR signaling. Mechanistically, XIST suppresses expression of miR-124 through direct interaction. Besides, miR-124 has been shown to target 3′UTR of AR . AnothercircZMIZ1 has been shown to be over-expressed in plasma samples of patients with prostate cancer compared with those having benign prostatic hyperplasia (BPH). In vitro studies have shown that circZMIZ1 silencing inhibits cell proliferation and arrests cells at G1. Functionally, circZMIZ1 enhances expression of AR and its splice variant 7 (AR-V7) .On the other hand, expression of cir-ITCH has been shown to be decreased in the tissues and cell lines of prostate cancer compared to corresponding controls. Up-regulation of cir-ITCH could suppress proliferation, migratory potential, and invasiveness of human prostate cancer cells. A reciprocal inhibitory effect has been found between this circRNA and miR-17. Several molecules within Wnt/β-catenin and PI3K/AKT/mTOR cascades have been found to be influenced by cir-ITCH. This circRNA could indirectly reduce expression of AR through regulating the coactivator of this nuclear factor . hsa_cirAR has been found to regulate the expression of several ncRNAs. For instance, activated AR has been shown to increase the expression of miR-203 and decrease the expression of SRC kinase in prostate cancer model systems. MiR-203 has a direct interaction with the 3′UTR of SRC and affects its stability following AR activation. A reduction in AR-induced miR-203 levels has been associated with an increased growth and migration potential of prostate cancer cells. The dysregulation of the AR signaling in prostate cancer cells results in the over-expression of SRC and enhancement of metastatic ability of these cells .Another experiment has shown that AR represses the expression of both miR-221/-222. The derepression of their expression after androgen deprivation has enhanced proliferation of prostate cancer cells via facilitating G1/S phase transition. Although this effect might be transient, it has a possible role in the evolution of CRPC. The restoration of AR activity via AR up-regulation could subsequently down-regulate miR-221/-222 . MiR-182AR has been shown to differentially affect the metastasis of prostate and breast cancers, through distinctively changing vasculogenic mimicry (VM) formation. In fact, AR can enhance miR-525-5p transcription in prostate cancer, while decreasing its transcription in breast cancer by binding to different AREs in the precursor promoter of this miRNA. NFIX and HDAC2 have been identified as co-factors of AR in prostate and breast cancer cells, respectively . Figure AR has also been shown to affect expression of several lncRNAs. For instance, LINC00304 is an androgen-responsive lncRNA that induces cell cycle transition and increases the proliferation of prostate cancer cells, through the regulation of CCNA1 . MoreoveOther studies, in the context of prostate cancer, have identified AR-regulated miRNAs and lncRNAs. Moreover, a number of circRNAs, such as circRNA-51217, circRNA-ARC1, and circZMIZ1, have been found to be influenced by AR signaling . A recenIn brief, the effect of AR on the expression of ncRNAs is mainly associated with its role as a transcription factor.Effects of AR on expression of ncRNAs are also implicated in the pathoetiology of bladder, breast, liver, renal, and gastric cancers . Yet, thAR has an essential role in the pathogenesis of human cancers, particularly prostate cancer. Since it is required for the development of prostate cancer, androgen deprivation therapy is regarded as a treatment for this type of cancer. Thus, the identification of the regulatory mechanisms of AR signaling is important in the design of treatment options. The importance of this process is further highlighted by the fact that castration resistance might occur during the course of treatment, as a result of expression of constitutively active AR splice variants , whose eIntegrative transcriptomic analyses of diverse cancer cell lines and tissues have resulted in the identification of several AR-interacting ncRNAs. In the current study, we have listed ncRNAs that affect expression of AR, as well as those being affected by AR. Notably, mutual interactions have been identified between AR and some of these non-coding transcripts. For instance, the expression of the lncRNA ARLNC1 has been shown to be enhanced by the AR protein. Conversely, ARLNC1 can increase the stability of the AR mRNA through RNA-RNA interaction .AR-targeting miRNAs have been suggested as potent tumor suppressors in prostate cancer. However, a number of other miRNAs have also been found to induce CRPC, by changing the activity of AR signaling. Moreover, AR signaling can affect the expression of miRNAs through different mechanisms, including feedback loops.LncRNAs and circRNAs that regulate AR signaling have been found to interact with miRNAs. MALAT1/miR-320, CCAT1/miR-28-5P, PlncRNA-1/miR-34c, PlncRNA-1/miR-297, XIST/miR-24, SARCC/miR-143-3p, circ-ITCH/miR-17, and circRNA17/miR-181c-5p are examples of the cooperation between lncRNAs/circRNAs and miRNAs in the regulation of AR signaling. Similarly, AR-regulated lncRNAs and circRNAs have been shown to influence the expression or bioavailability of miRNAs, adding novel layers of complexity in this interaction network.Taken together, the data presented above indicates the complexity of the transcriptional regulation of miRNAs by AR and the effects of AR on them. Moreover, the interactions between ncRNAs and AR signaling can be context-dependent.


Androgens are well known to be necessary for spermatogenesis. The purpose of this study was to determine Sertoli cell responsiveness to androgens according to age from birth to puberty.: group 1 (1–30 days), group 2 (1–3 months), group 3 (3–6 months), group 4 (0.5–3 years), group 5 (3–6 years), group 6 (6–12 years), and group 7 (12–16 years). We compared these data with those of 2 situations of pathology linked to androgens: 1/premature secretion of testosterone: 4 cases of Leydig cell tumor (LCT) in childhood; and 2 /defect of androgen receptors (AR): 4 cases of complete form of insensitivity to androgen syndrome (CAIS). In control boys, AR immunoreactivity (ir) in Sertoli cells appeared between 4.6 and 10.8 years of age, Anti-Mullerian Hormone (AMH) ir in Sertoli cells disappeared between 9.2 and 10.2 years of age. Connexin 43 (Cx43) ir in Sertoli cells and histological features of the onset of spermatogenesis appeared between 10.8 and 13,8 years of age. Cx43 ir was significantly higher in 12–16 year-olds than in younger boys. In case of CAIS, no spermatogenesis was observed, both AR and Cx43 ir were undetectable and AMH ir was elevated in Sertoli cells even at pubertal age. In the vicinity of LCTs, spermatogenesis occurred and both AR and Cx43 ir were strongly positive and AMH ir in Sertoli cells was low for age.Testicular tissue samples were studied in a population of 84 control boys classified into seven groups according to ageAndrogen action on Sertoli cells is required for onset of spermatogenesis and premature androgen secretion by LCT can induce spermatogenesis in the vicinity of the tumor. AR ir appeared earlier than onset of spermatogenesis, with large interindividual variability. The timing and mechanisms of Sertoli cell responsiveness to androgens are important issues for understanding the induction of spermatogenesis at puberty. Androgens are well known to be necessary for spermatogenesis. The period from birth to puberty is poorly studied to evaluate the establishment of spermatogenesis in humans. It would be interesting to study the role of androgens in the kinetics of the development of spermatogenesis.In adults, spermatogenesis duration is 74 days , close tIn adults, Sertoli cell stimulation by testosterone, locally produced by Leydig cells under the control of LH, is required for spermatogenesis. At minipuberty, Sertoli cells do not express androgen receptor (AR) and are unable to promote germ cell maturation despite the presence of FSH, LH and testosterone . Onset oThe aim of this study was to determine and characterize the evolution of Sertoli cells responsiveness to androgens according to age from birth to puberty by studying specific markers: AR, anti-Mullerian hormone (AMH) and connexin 43 (Cx43).Testicular tissue samples were collected in population of 84 control boys aged 0 to 16 years classified into 7 group according to age and compared between two situations of pathology linked to androgens: 1/ premature secretion of testosterone in childhood in case of Leydig cell tumor (LCT); and 2/ defect of androgen receptors (AR) in complete androgen insensitivity syndrome (CAIS). We reported tissue organization and cell content, onset of AR immunoreactivity (ir), decrease in AMH ir as a marker of the effect of testosterone on Sertoli cell [Patient records from June 1993 to December 2019 were identified by computerized search of our pathology register at the Lyon University Hospital. We excluded the following groups: neonates born at less than 37 weeks’ gestation or with intrauterine growth retardation, patients with testicular history , patients with pathology of penis development (micropenis or hypospadias) and patients with other endocrine diseases. We excluded poor sample quality with autolysis. Tissue samples were collected at necropsy (mainly carried out for sudden infant death syndrome) or from biopsy carried out for preservation of fertility before sterilizing cancer treatment or surgical exploration of testicular mass; these biopsies were taken at a distance from testis tumor, none of which were Leydig cell tumors. Samples were divided into seven age groups, in order to target the major stages of testicular development. We defined the groups according to previous studies and the Nistal classification : Group 1We also analyzed samples of testicular tissue located in the vicinity of a Leydig cell tumor (LCT) in 4 patients (three 6 year-olds and one 10 year-old) and samples of testicular tissue from 4 patients with complete androgen insensitivity syndrome (CAIS) aged 3 months, 14, 18 and 20 years. In three cases, point mutations  were observed, inducing amino acid change. Conversely in the fourth case, the mutation p.Q35X induced complete absence of the AR protein.Following institutional rules, all necropsies and testicular biopsies were authorized by the Local Ethics Committee of our University Hospital. Written consent from the closest relatives was obtained in all cases. Autopsies were carried out within 24 h (Collection declaration: DC-2008-72 / DC-2020-3919).n = 67) or acetic formalin alcohol (AFA) (n = 25). After paraffin embedding, tumor specimens were cut in 3 μm- thick sections and stained routinely with HPS . Immunohistochemistry staining was performed employing the streptavidin-biotin and peroxidase method on an automated immunohistochemical system  according to the manufacturer’s instructions and using the reagents supplied with the kit. Briefly, after deparaffinization and rehydration, sections were subjected to antigen retrieval . Tissue sections were covered with H2O2 to block endogenous peroxidase, followed by an additional washing procedure with the manufacturer’s buffer, and pretreated by ULTRA CC1 . Slides were then incubated with one of the following antibodies for Sertoli cell markers: AMH, a monoclonal mouse antibody ; AR, a monoclonal rabbit antibody, (Clone EPR1535(2) GeneTex, dil. 1/50, 32 min); or Connexin-43 (Cx43), a polyclonal rabbit antibody . After washing, tissues were incubated with biotinylated antibodies, followed by the streptavidin-biotin complex, the amplification reagent, and the streptavidin-peroxidase conjugate. Tissue staining was visualized with a DAB substrate chromogen solution . Counterstaining was performed using hematoxylin and Bluing Reagent . Positive controls were performed by using biopsies of adult men with obstructive azoospermia.Testicular tissues were studied in the Pathology Department at Lyon University Hospital. Tissue samples were fixed at least 24 h in 4% neutral buffered formalin  blind to the clinical data independently performed slide evaluation on a Leica DM2500 microscope. For analysis, five image fields at X10 magnification were taken from each section. All cords/tubules within these five image fields were evaluated and scored.The number of seminiferous cords/tubules per sample was counted. The diameter of the seminiferous cords/tubules was measured on round sections. The cords/tubules were considered as being round if the ratio of the longer to the smaller diameter of the tubule was ≤1.5. The presence of a lumen and the most advanced germ cell were noted. Germ cells were identified on the basis of their morphology  and location . The gerThe number of Leydig cells was estimated on three fields at 40x magnification, and classified as rare (< 15) or numerous (≥15).The following scoring approach in the assessment of immunostaining was used: 0 = no or non-specific cell staining; score 1 = weak (intensity) and incomplete  staining of > 10% of cells (quantity); 2 = moderate complete staining of > 10% of cells; 3 = strong complete staining of > 10% of cells .Median seminiferous cord/tubule diameter, S/T score, TFI and immunostaining scores were compared between groups by non-parametric Kruskal-Wallis test followed by Mann-Whitney test for pairwise comparison.Presence of advancing germ cells, presence of lumen in seminiferous tubules and Leydig cell amounts (rare versus numerous) were compared between groups by Fisher’s exact test.Since transition from prepubertal to pubertal state of markers could be modeled as a sigmoid curve , the poin = 43) or from biopsy carried out for preservation of fertility (n = 18) or surgical exploration (n = 23). We included samples in the different groups according to age: Group 1, newborns (n = 12), Group 2, mini-puberty (n = 12), Group 3 end of mini-puberty (n = 12), Group 4, early childhood (n = 12), Group 5, 2nd childhood period (n = 12), Group 6, onset of puberty (n = 11), and Group 7, adolescence (n = 13). Seventy-eight samples  contained more than 100 seminiferous cords/tubules, and 14 samples (groups 1–7) contained between 50 and 100. The context and number of seminiferous cords/tubules per group are given in Table From June 1993 to December 2019, 144 testicular samples were collected, from boys aged 1 day to 16 years. We excluded 60 samples , decreased during childhood (groups 4–6) and increased at puberty (group 7) in the control boys  during minipuberty (3–188 days). No AR ir was observed in Sertoli cells during childhood, until 4.6 years of age in our set. AR ir in Sertoli cells began to be positive in some boys 5/12) in group 5 (3–6 y.o.), increased significantly in group 6 (6–12 y.o.) and increased even more in group 7 (12–16 y.o.) . These gonads acquire the earliest ability to produce testosterone by Leydig cells  and AMH Initiation of spermatogenesis can be tracked by various parameters, including tubular morphological aspects and the presence of post-meiotic germ cells. In the present study, we analyzed numerous prepubertal and pubertal testicular samples with a large number of seminiferous cords/tubules for each sample. They were obtained in conditions allowing extrapolation to the physiology of testicular development from birth to puberty. Tubular diameter, S/T score, the post-meiotic germ cell and the presence of a lumen within the seminiferous tubule indicated that spermatogenesis began between 10.8 and 13.8 years. Younger subjects had only spermatogonia. Although some authors described the presence of occasional spermatocytes intended for apoptosis in some seminiferous cords during childhood [Androgens have been shown to be of major importance in the onset of spermatogenesis. This was demonstrated in an AR KO mouse model . Among t.In all the CAIS samples , Sertoli cell AR ir was absent, Sertoli cell AMH ir was high and Sertoli cell Cx43 ir and spermatogenesis were absent, as previously shown . But, asIn the present study, the kinetics of AR, AMH and Cx43 ir and histological markers of the onset of spermatogenesis according to age demonstrated that the increase in AR ir and decrease in AMH ir in Sertoli cells were observed earlier than Cx43 ir and the histological markers of the onset of spermatogenesis. A large variability in age at onset of AR ir in Sertoli cells was observed. The youngest boy with clearly positive AR ir in Sertoli cells was 4.6 y.o. and the oldest boy with still negative AR immunoreactivity in Sertoli cells was 10.8 y.o.; at the same time, AMH ir decreased. We cannot rule out that some of the negative immune localization results were due to suboptimal tissue fixation, but we consider this unlikely to affect our main findings because of the number of different samples that we employed across the age range. The increase in nocturnal gonadotropin secretion  and intrOur results were consistent with this timing: the significant increase in AR and decrease in AMH in Sertoli cells occurred at this time. However, Cx43 expression and onset of spermatogenesis did not occur until 11–13 years of age.Thus, it could be anticipated that the AR content in Sertoli cells in testicular tissue obtained ahead of oncological treatment will vary according to age and to individual variations in Sertoli cell maturation. The precise time remains to be determined. AR ir was evaluated before and during culture of five human prepubertal testicular tissues , and incSince AR ir and AMH ir have similar kinetics, Sertoli cell maturation could probably be monitored by measuring AMH in the culture medium, instead of histological evaluation of AR ir in the tissue.Kinetically, nocturnal gonadotropin secretion  and intrAlthough this study was retrospective, limited to histological and immunocytochemical methods, used post-mortem or peritumoral tissue samples, and the analysis of cord/tubule diameter was random in the field of the microscope, we demonstrated that there was a link between androgenic stimulation, upregulation of AR in Sertoli cells, decrease in AMH in Sertoli cells and initiation of spermatogenesis. Further studies are needed to determine the precise kinetics and molecular mechanisms and Leydig cell identification.These observations highlight the fact that androgen action is required for early pubertal maturation of Sertoli cells and the beginning of the spermatogenic process in humans in vivo, similarly to what is observed in animal models. In the perspective of initiation of spermatogenesis, stimulation by testosterone will be required. The interval between androgenic stimulation, upregulation of AR and decrease in AMH in Sertoli cells and the initiation of spermatogenesis remains to be determined.


Neuropilins are transmembrane glycoproteins that play important roles in cardiovascular and neuronal development, as well as in immunological system regulations. NRP1 functions as a co-receptor, binding numerous ligands, such as SEMA 3 or VEGF and, by doing so, reinforcing their signaling pathways and can also interface with the cytoplasmic protein synectin. NRP1 is expressed in many cancers, such as brain cancers, and is associated with poor prognosis. The challenge today for patients with pediatric brain tumors is to improve their survival rate while minimizing the toxicity of current treatments. The aim of this review is to highlight the involvement of NRP1 in pediatric brain cancers, focusing essentially on the roles of NRP1 in cancer stem cells and in the regulation of the immune system. For this purpose, recent literature and tumor databases were analyzed to show correlations between NRP1 and CD15 (a stem cancer cells marker), and between NRP1 and PDL1, for various pediatric brain tumors, such as high- and low-grade gliomas, medulloblastomas, and ependymomas. Finally, this review suggests a relevant role for NRP1 in pediatric brain tumors progression and identifies it as a potential diagnostic or therapeutic target to improve survival and life quality of these young patients. Neuropilins (NRPs) are transmembrane glycoproteins found in all vertebrates and are highly conserved across species. Two homologous NRPs isoforms have been identified, namely neuropilin-1 (NRP1) and neuropilin-2 (NRP2). NRPs are non-tyrosine kinase surface proteins that play important roles in neuronal development, cardiovascular development, and in the immune system . NRPs arIn children, primary tumors of the central nervous system (CNS) are the second most common cause of cancer after leukemia, accounting for approximately one fourth of all childhood cancers. There are approximately 5,000 new cases diagnosed each year in the United States among children younger than 18 years . ActuallAlthough the roles of NRP1 in tumor angiogenesis, tumor microenvironment, as well as its possible targeting in tumor progression, have recently been reviewed elsewhere –20, in tGliomas are the most frequently pediatric brain tumors and represent 25% of all brain tumors. They are heterogeneous and are divided into two main categories, low- and high-grade tumors, according to their aggressiveness and their prognosis. Low-grade gliomas (LGGs), such as pilocytic astrocytoma (PA), are usually curable while high-grade gliomas (HGGs), such as diffuse intrinsic pontine glioma (DIPG), are consistently fatal.LGGs, classified by the World Health Organization (WHO) as grade I or II, comprise several subgroups, including PA, pleomorphic xanthoastrocytomas (PXA), pilomyxoid astrocytomas (PMA), subependymal giant cell astrocytomas (SEGA), low-grade fibrillary astrocytomas, and diffuse astrocytomas. The most common LGG diagnosed in children aged 0 to 14 years is the PA, which accounts for 85% of all LGGs . Five-yeMedulloblastoma (MB) is the most common malignant brain tumor of the posterior fossa in pediatric, accounting for 15% to 20% of all childhood brain tumors. The survival rate of patients with embryonal tumors of the central nervous system, such as MB, is 54% at 5 years. The prognosis is significantly worse before the age of 1 year: 62% survival rate at 5 years, compared to 81% for children aged 10 to 14 years , 37. BecEpendymomas (EPNs) are the third cause of malignant brain tumors in children. These tumors affect mainly the children younger than 5 years. EPNs are usually located in the posterior fossa (70% of cases), but they can develop anywhere within the central nervous system. The histological grade score of the tumor is not reproducible and has no prognostic impact. Recent advances in molecular biology confirm that, depending on their localization , EPNs are different diseases. These tumors have a worse prognosis in children than in adults , 42. EPNThere is a wide diversity of pediatric brain tumors that are very rare, accounting for less than 30% of all tumors. Some of them, such as the choroid plexus papillomas, a benign (WHO grade I) neuroepithelial intraventricular tumor, have an excellent prognosis after complete surgical resection when they occur in children. Other tumors, such as craniopharyngiomas, arising from the sellar region, also have a very good overall survival after complete resection, but relapses may later occur that necessitate a complementary treatment by radiotherapy. The excellent overall survival of these tumors is unfortunately impaired by endocrine, and often visual, sequelae.Other embryonal tumors of the CNS, like atypical teratoid and rhabdoid tumors, and embryonal tumors with multilayered rosettes, are highly aggressive, poorly differentiated, and occur predominately in young children. Their treatment is therefore very challenging, and their prognosis is still grim.Unfortunately, despite the progress made in recent decades in the management of these cancer types, the effectiveness is still suboptimal and sequelae are frequent. Indeed, chemotherapy has been shown to provide significant toxicities and adverse side effects , 47. SimNRPs are transmembrane glycoproteins specific to vertebrates. There are two members in this family of proteins, NRP1 and NRP2, which are coded by two different genes located on two chromosomes (10p12 for NRP1 and 2q34 for NRP2). NRPs play an important role in biological processes, such as neuronal development, cardiovascular development, and immunological system Figure 1via the RhoA GTPase  , the hepAccording to the studies of West et al., NRP1 binds to FGF isoforms  and to their receptor FGFR-1, thus contributing to angiogenesis. The same team also showed that NRP1 binds to HGF, which is involved in various functions, such as cell proliferation, cell migration, and morphogenesis , 61. Thevia the regulation of TGF-β in endothelial cells , and lymphocytes, in particular regulatory T lymphocytes (LTreg) –121 and via the SEMA 3A/NRP1 signaling pathway  model of mice deficient in NRP1 on their T CD4+ lymphocytes (LT CD4+) and showed that mice presented aggravated EAE in contrast to mice over-expressing NRP1 on their LT CD4+, which did not develop EAE . This su pathway . We know pathway , 131. Al pathway . Further pathway . More re pathway . NRP2 is pathway , 132, an pathway . Further pathway .In addition to playing an immune-regulatory role, NRPs are also involved in the immune cell migration. For example, a study showed that SEMA 3A decreases the adhesion capacity of thymocytes expressing NRP1 and induces their migration by a repulsive effect . In the via MHC-I and MHC-II molecules, to present an antigen. APCs present antigen by forming an immunological synapse with LTs and thus stimulate their responses. NRP1 is expressed on both the surface of CDs and LTs and appears essential in their interaction to initiate the immune response , which have the ability, response . In partresponse . Moreoveresponse .Macrophages, another important player in immunity, also express NRPs , 126. ThThe immune system plays an essential role in our organism, especially during cancer when its immunological surveillance system is essential to control the tumor development and eliminate tumor cells. However, an important aspect of tumor progression is the ability of cancer cells to evade the monitoring and clearance by the immune system. Indeed, tumors cells avoid the immune system by different mechanisms, such as reducing the immune recognition, increasing the resistance to immune attacks, or creating an immunosuppressive microenvironment and recruiting specific immune cells that favor tumor growth and progression , 143. Bevia the SEMA-4A signaling pathway  cell responses , 135. Inr growth . Indeed,r growth .via its interaction with SEMA 3A, is involved in their migration. Indeed, the work of Casazza et al. shows that NRP1 controls the recruitment of TAMs within tumors. Its inhibition within macrophages causes a reduction of their pro-angiogenic and immunosuppressive effects and leads to an inhibition of tumor growth and metastasis (via the expression of IL10 or TGF-β for example (Another immune cell involved in anti-tumor immunity is the macrophage. Tumor-associated macrophages (TAMs) are strongly associated with tumorigenicity. NRP1, tastasis . A recentastasis . In this example .NRPs are, therefore, involved in anti-tumor immunity and it is questionable whether the same is true for brain tumors. The central nervous system was classically considered as an “immune-privileged site,” being immunologically inert and separated from the peripheral immune system by the blood-brain barrier (BBB). However, brain tumors represent a particular case in which the BBB is disrupted to various degrees, and therefore, acquired an innate immunity that may play a role in the development and growth of brain cancers. Most studies have focused on adult gliomas, and very few so far have focused on pediatric brain tumors. Several studies led by Miyauchi et al. have shown that NRP1 is expressed by macrophages and microglia associated with gliomas , 130. Inin vitro and in vivo have been developed  has been observed in pediatric tumors database. Moreover, NRP1 is involved in the activation of the immune cells, in particular in the interaction between T cells and DCs. NRP1 may also play a role in the regulation of immunogenicity of tumor cells, highlighted by the correlation between NRP1 and PDL-1. This role is not yet fully investigated, but we will focus our future research on this aspect. Numerous peptides or biological molecules that target NRP1 and whose efficacy has been tested eveloped  and moreeveloped . To concMD, PC, and CB contributed to redaction of this review. MD wrote the first draft of the manuscript. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Haemonchus contortus being introduced with sheep imported from the Netherlands. As elsewhere in the world, the livestock trade appears to be contributing to the spread of AR in the region and isolated cases of multidrug-resistant cases have also been reported. This is surprising given that the frequency of treatments here is much lower than in other countries where sheep production is economically more important. The prevailing nematodes are Haemonchus, Teledorsagia and Trichostrongylus, while on some farms Haemonchus is dominant and clinical haemonchosis has increasingly been observed in recent decades. The reasons for this are unclear, but are probably related to this parasite’s propensity to rapidly develop drug resistance and a general lack of awareness of the problem, possibly in combination with global warming and the increased livestock trade within the EU. In addition, domestic interactions through contacts with wildlife ruminants, alpacas may also be a contributing factor for transmission of AR.Gastrointestinal nematodes (GIN) in small ruminants result in production losses, and consequently economic losses, and are an animal welfare problem in most countries in the Nordic-Baltic region. Intensive use of anthelmintics to control helminth infections has led to anthelmintic resistance (AR), which has become a major issue in many European countries. Several studies have been performed in countries in the Nordic-Baltic region  showing increasing/emerging levels of AR. The aim of this paper is to provide an overview of the problem of AR on sheep and goat farms in the Nordic-Baltic region. This region has a limited number of registered anthelmintics. However, researchers in this area have discovered some surprising findings, such as ivermectin (IVM) resistance on a farm that had never used IVM. In Sweden there is evidence of macrocyclic lactone (ML)-resistant  Gastrointestinal nematode (GIN) infections remain the most prevalent and important parasitic disease in grazing ruminants worldwide, affecting the welfare and health of animals and resulting in significant economic losses, especially in the sheep and goat industry –3. InfecFrom the early 1960s broad-spectrum anthelmintics administered routinely have helped to control GIN, but intensive and incorrect use of anthelmintics, under-dosing and continuous treatments with the same anthelmintics have led to nematode populations resistant to anthelmintic drugs –9. AntheHaemonchus contortus being introduced with sheep imported from the Netherlands [The aim of this paper is to provide an overview of the problem of AR on sheep and goat farms in the Nordic-Baltic region. This region has a limited number of registered anthelmintics. However, researchers in this area have discovered some surprising findings, such as ivermectin (IVM) resistance on a farm that had never used IVM . In Swedherlands .http://www.ncbi.nlm.nih.gov/pubmed) using the terms “anthelmintic resistance or multidrug resistance, nematodes, goat, sheep, small ruminants”. The titles and abstracts were evaluated, and articles referring to AR were obtained and assessed in detail. The authors’ extensive experience with AR in small ruminants was used to critically evaluate the literature. Nematodes will be addressed at genus-level unless worm counts with proper identification of species have been performed.This overview is based on a search in PubMed (Intensive use of anthelmintics will inevitably lead to AR in GIN. There is widespread emergence of nematodes resistant to benzimidazoles (BZ), levamisole (LEV) and IVM and other ML around the world and it is expanding in many parts of Europe. After a brief overview of AR of GIN in the EU, a more detailed account of AR in the Nordic-Baltic region is given below.Haemonchus, but in Teladorsagia, Trichostrongylus, Cooperia and Nematodirus as well [AR in parasites is now widespread throughout Europe and has increased over a 41-year period, although there are still gaps in knowledge in some regions, especially eastern Europe . At the  as well , 21. In  as well , 22. Acc as well , a meta- as well , 24, as  as well . Multipl as well . Multidr as well , 13, 27  as well .The most widely used anthelmintics in small ruminants in Europe are BZ and IVM. AR to BZ has been found on up to 98% of sheep farms examined in the Czech Republic , 14% in Teladorsagia [Haemonchus contortus was the predominant species in around half of the farms pre-treatment. Resistance to one or more anthelmintics was detected in nine out of 10 herds (90%). In the FECRT, resistance to BZ (fenbendazole) was present in all three herds tested, and to IVM in eight herds (80%). Based on EHT, resistance to BZ  was found in 8 of the 10 herds [H. contortus and T. colubriformis was confirmed by the controlled efficacy test and pyrosequencing. IVM eliminated 100% of H. contortus and reduced T. colubriformis worm counts by 84–92% [AR is an increasing problem in all Nordic countries and several studies on this have been carried out in Denmark, Sweden, Norway and Lithuania. The first study on resistance in sheep nematodes carried out anywhere in the region was undertaken in Denmark and published in 1991, and described resistance to LEV in dorsagia . Later, dorsagia , 37. A 210 herds . Peña-Esy 84–92% .H. contortus, whereas IVM was highly effective [H. contortus by FECRT [H. contortus, in Swedish sheep flocks. This is possibly due in part to the introduction of resistant parasites with animal imports from Europe, with resistance to IVM reported in a more recent case study on a limited number of farms but focusing on a farm on Gotland in the Baltic Sea that had imported sheep from the Netherlands [In Sweden, AR in small ruminants used to be relatively low. In a survey on sheep farms carried out in the 1990s, BZ (febantel and fenbendazole) was implicated in resistance in ffective . Also, iby FECRT . Howeverby FECRT . Howeverherlands .A study in Norway based on FECRT showed that in randomly selected flocks of sheep, AR to BZ is presently at a low level (11%). However, when restricting the area to Rogaland County, eight out of ten (80%) sheep flocks, selected based on frequent deworming, application of the dose and move strategy or intensive use of grazing pasture, showed BZ resistance . RecentlDifferent surveys were conducted during 2013–2014 on Lithuanian sheep farms to detect AR , 46. BasNo published studies on AR were found for other countries in the region.Several questionnaire surveys to obtain information on small ruminant management and worm control practices in northern Europe have been undertaken.One of the first surveys of sheep farmers was conducted in Denmark in 1993. Based on a questionnaire survey, the majority of farmers (97%) used anthelmintics. The mean number of treatments per year for lambs and adult sheep was 1.9 and 2.3 respectively. BZ was the most-used anthelmintic and 81% of farmers had been using the same class of anthelmintic for three or more years . IVM hadA study in Norway from 2007 revealed that visual appraisal of individual weight was the most common means of estimating the anthelmintic dose used in flocks of sheep (79%) and herds of goats (85%). However, a recent study indicated that this method for estimating the actual dose in flocks of sheep has now reduced to 28% . BZ was An online survey was conducted on 20 conventional and 19 organic commercial sheep farms in Sweden with more than 70 ewes. Only minor differences were found between organic and conventional producers. The grazing management routines were similar, with the majority (59%) having a combination of natural pastures and arable land grazed by animal groups moved between paddocks at least three times per season (67%). The parasite control methods were also similar, with the majority (97%) relying on anthelmintics. Both ewes and lambs were usually treated one to two times per year, often at different times of the year. The most-used anthelmintic was IVM, followed by BZ . Treatment decisions were generally based on faecal egg counts, but some farmers relied on blanket treatments. Several farms (64%) reported alternating between different drug classes at least once a year or at every deworming event. Most farms (59%) had tested whether the anthelmintics used had the expected efficacy on at least one occasion .In 2015–2016, 71 sheep farmers and 37 goat farmers were surveyed in Lithuania. Based on the results from the questionnaires, chemotherapy and/or chemoprophylaxis have been used by 72% of sheep farmers and 54% of goat farmers. In Lithuania, the most-used classes of anthelmintics were ML (only IVM was used) (67% and 65%) and BZ (28% and 20%) for sheep and goat treatments respectively. LEV was used very sporadically (4% and 15%) on sheep and goat farms respectively. Sheep were usually treated twice (63%) in spring before turnout and in autumn before housing, and goats were usually treated once (41%) after the start of the housing period between November and December. Yearlings and adults were usually treated together , 51. No T. colubriformis to be resistant to both BZ and IVM [The evolution of multidrug resistance may lead to total anthelmintic failure . Multidr and IVM . Dual re and IVM . There iTeladorsagia and Trichostrongylus was found in one goat herd [Teladorsagia and Trichostrongylus were the dominant genera [Haemonchus in Sweden, but other genera such as Teledorsagia and Trichostrongylus can also be involved according to droplet digital polymerase chain reaction data [In Norwegian goat herds, the pre-treatment infection levels of GIN were low compared with those in sheep flocks, and AR to BZ in oat herd . In Litht genera , 51. In ion data .H. contortus on several farms, whereas LEV still had reasonable efficacy. However, despite always having a high efficacy of treatment with LEV, H. contortus in particular survived at a low level. Similarly, T. circumcincta survived treatment with either IVM or BZ, but to a lesser extent than H. contortus, and not at all after LEV treatment [H. contortus and T. colubriformis isolated from a farm with both sheep and goats [Based on a nematobiome study in Sweden, identified nematode species responded differently to IVM, BZ  and LEV. Of practical interest is that both IVM and ABZ were unable to control reatment . In Denmnd goats .In sheep and goats in the Nordic-Baltic region, AR is common observed to IVM, BZ and LEV, which are the most commonly used anthelmintics in these countries. However, MOX and LEV are highly effective in northern Europe compared with the rest of Europe. Little is known about closantel and the relatively new drug MOP because these drugs are not applied or not registered in some countries, for example in Lithuania. As elsewhere in the world, the livestock trade appears to be contributing to the spread of AR in the region and isolated cases of multidrug-resistant cases have also been reported. This is surprising given that the frequency of treatments here is much lower than in other countries where sheep production is economically more important.As in many other regions, many studies are case reports and surveys often suffer from lack of random sampling of farms. Studies on farms have been based on FECRT, MALDT, EHT and molecular methods. Although the gold standard for AR detection is CET, it is not a commonly used method in northern Europe because studies are usually conducted on commercial farms. In brief, standard methods for AR detection are needed not only in northern Europe but worldwide, and more thorough nationwide monitoring should be instituted .Haemonchus, Teledorsagia and Trichostrongylus. On some farms, Haemonchus is dominant and clinical haemonchosis has increasingly been observed in recent decades. The reasons for this are unclear, but are probably related to this parasite’s propensity to rapidly develop drug resistance and a general lack of awareness of the problem, possibly in combination with global warming and the increased livestock trade within the EU. The predicted patterns of climate change could alter the epidemiology of Haemonchus (and other strongyles) in northern Europe [In northern Europe the prevailing nematodes in sheep and goats are the same as in the rest of Europe: n Europe , and onerefugia , adopting novel non-chemical approaches, and improving pasture management and husbandry practices, and these should be included in any potential prophylactic control regimes suggested for GIN [refugia is required to avoid selection for resistance [The key factors in slowing down the development of AR are now considered to be maintaining part of a parasite population in  for GIN , 56. Howsistance .Haemonchus, Cooperia, Oesophagostomum and Trichostrongylus) that carry AR mutations as well as susceptible genotypes, and are a potential risk factor for transmission of AR [Haemonchus that are refractory to anthelmintic treatments [Improved diagnostics in wildlife ruminants, alpacas and imported small ruminants will help control the spread of AR in this region. Wild ruminants act as reservoirs for some GIN species  or drugs that are being re-introduced, such as levamisol and closantel.


We aimed to compare the quantitative angiographic aortic regurgitation (AR) into the left ventricular out flow tract (LVOT-AR) of five different types of transcatheter self-expanding valves and to investigate the impact of the learning curve on post-TAVR AR.Quantitative video densitometric aortography is an objective, accurate, and reproducible tool for assessment of AR following TAVR.This retrospective academic core-lab analysis, analyzed 1150 consecutive cine aortograms performed immediately post-TAVR. Quantitative angiographic AR of post-procedural aortography in 181 consecutive patients, who underwent TAVR with the Venus A-valve in a single Chinese center, were compared to the results of Evolut Pro, Evolut R, CoreValve,  and Acurate Neo  transcatheter heart valves (THVs), from a previously published pooled database. Among the 181 aortograms of patients treated with the Venus A-Valve, 113 (62.4%) were analyzable for quantitative assessment of AR. The mean LVOT-AR was 8.9% ± 10.0% with 14.2% of patients having moderate or severe AR in the Venus A-valve group. No significant difference in mean LVOT-AR was observed between Evolut Pro, Evolut R, Acurate Neo, and Venus A-valve. The incidence of LVOT-AR >17%, which correlates with echocardiographic derived ≥ moderate AR, with the Evolut Pro was lower than with the Venus A-valve , but was not different from the Evolut R , or the Acurate Neo (5.3% vs. 11.3% p = 0.16) systems. A landmark analysis after recruitment of the first half of patients treated with the Venus A valve (N = 56), showed a significantly lower mean LVOT-AR in the second half of the series . The incidence of LVOT-AR >17% in the latest 57 cases was also numerically lower  and compared favorably with the best in class of the self-expanding valves.The Venus A-valve has comparable mean LVOT-AR to other self-expanding valves but has a higher rate of moderate or severe AR than the Evolut Pro THV. However, after completion of a learning phase, results improved and compared favorably with the best in class of the commercially available self-expanding valves. These findings should be confirmed in prospective randomized comparisons of AR between different THVs. Quantitative video densitometric assessment of aortic regurgitation (AR) after transcatheter aortic valve replacement (TAVR) has been validated in silico, in vivo, in clinical trials and real-world populations . Moderat3AR following TAVR is mostly paravalvular leak (PVL) in nature. AR severity depends on the interaction between anatomical characteristics of the native aortic valve , on the type of THV platform and on the implantation technique 67. Modif68This is a retrospective, single-center analysis of consecutive aortograms in 181 consecutive TAVR patients treated with the Venus A-valve at the Xijing hospital. Video densitometry analysis of AR was performed by two physicians of the Xijing hospital (RW and CG) and remotely supervised by an independent core laboratory  using the CAAS A-valve 2.0.2 software . This quantitative assessment of the AR from the aorta into the left ventricle outflow tract is reported as the LVOT-AR parameter; the results are expressed in percentages and quantify the fraction of AR defined as the ratio between the area under the time-density curves assessed by video densitometry in the LVOT  and in the aortic root (reference area) during a conventional aortography. Technical details of video densitometry analysis and validation in silico, in vivo, in animal models as well as in clinical correlations with magnetic resonance imaging, transthoracic and transesophageal echocardiography have been extensively reported in literature 11121314.11121310The Venus A-valve is a self-expanding THV, consisting of a nitinol stent frame with supra-annular porcine pericardial leaflets, but without an anti-leak skirt, and was granted the China Food and Drug Administration approval in 2017. We aimed to assess the video densitometric AR with the Venus A-valve and to compare to the performance of four commercially available different types of SEVs. All procedures and evaluation were performed according to Good Clinical Practice and in accordance with the Declaration of Helsinki.Continuous variables were reported as mean ± standard deviations. Comparison of LVOT-AR was performed using one-way analysis of variance and two-by-two comparisons using the post-hoc Bonferroni test. A landmark analysis, comparing LVOT-AR between the first 56 cases and latest 57 cases with the Venus A-valve was performed using an unpaired student t–test. The continuous variable ‘LVOT-AR’ was stratified into categorical variables according to the following pre-determined threshold criteria: 1) none or trace (<6%); 2) mild (6% to ≤17%); and 3) moderate or severe (>17%)  were analyzable by quantitative assessment. The mean LVOT-AR was 8.9%±10.0% with 14.2% of the patients having a moderate or severe AR in the Venus A-valve group. For the other THVs, the lowest mean LVOT-AR was observed with the Evolut Pro , followed by Evolut R , Acurate Neo , and CoreValve  .First, only 62.4% of the Venus-A patients studied had aortograms that were suitable for video densitometric analysis. This is similar to previously reported rates from other retrospective series, while single-center studies abiding by a specific acquisition protocol, either with offline or online analysis, have analyzable data in 92.0% to 100.0% of cases 2223. Sec22When compared to historic and current other commercially available self-expanding THVs, the Venus A-valve has comparable mean LVOT-AR as assessed by quantitative video densitometric measurement, but has a higher proportion of patients with moderate or severe AR than the Evolut Pro THV. After a learning curve, the incidence of moderate or severe AR compared favorably with the best in class currently available SEV. Additional developments of the Venus A system such as the addition of a sealing skirt and the ability to recapture and reposition the valve are likely to improve LVOT-AR performance.