Neurexin Research Articles

Involvement of retinoic acid receptor α in the autistic-like behavior of rats with vitamin A deficiency by regulating neurexin 1 in the visual cortex: a mechanism study.

To study the mechanism of retinoic acid receptor α (RARα) signal change to regulate neurexin 1 (NRXN1) in the visual cortex and participate in the autistic-like behavior in rats with vitamin A deficiency (VAD). The models of vitamin A normal (VAN) and VAD pregnant rats were established, and some VAD maternal and offspring rats were given vitamin A supplement (VAS) in the early postnatal period. Behavioral tests were performed on 20 offspring rats in each group at the age of 6 weeks. The three-chamber test and the open-field test were used to observe social behavior and repetitive stereotyped behavior. High-performance liquid chromatography was used to measure the serum level of retinol in the offspring rats in each group. Electrophysiological experiments were used to measure the long-term potentiation (LTP) level of the visual cortex in the offspring rats. Quantitative real-time PCR and Western blot were used to measure the expression levels of RARα, NRXN1, and N-methyl-D-aspartate receptor 1 (NMDAR1). Chromatin co-immunoprecipitation was used to measure the enrichment of RARα transcription factor in the promoter region of the NRXN1 gene. The offspring rats in the VAD group had autistic-like behaviors such as impaired social interactions and repetitive stereotypical behaviors, and VAS started immediately after birth improved most of the behavioral deficits in offspring rats. The offspring rats in the VAD group had a significantly lower serum level of retinol than those in the VAN and VAS groups (P<0.05). Compared with the offspring rats in the VAN and VAS groups, the offspring rats in the VAD group had significant reductions in the mRNA and protein expression levels of NMDAR1, RARα, and NRXN1 and the LTP level of the visual cortex (P<0.05). The offspring rats in the VAD group had a significant reduction in the enrichment of RARα transcription factor in the promoter region of the NRXN1 gene in the visual cortex compared with those in the VAN and VAS groups (P<0.05). RARα affects the synaptic plasticity of the visual cortex in VAD rats by regulating NRXN1, thereby participating in the formation of autistic-like behaviors in VAD rats.

Characterization of Different Subtypes of Immune Cell Infiltration in Glioblastoma to Aid Immunotherapy.

Glioblastoma multiforme (GBM) has been identified as a frequently occurring adult primary brain cancer that is highly aggressive. Currently, the prognostic outcome for GBM patients is dismal, even with intensive treatment, and the median overall survival (OS) is 14.6 months. Immunotherapy, which is specific at the cellular level and can generate persistent immunosurveillance, is now becoming a promising tool to treat diverse cancers. However, the complicated nature of the tumor microenvironment (TME) makes it challenging to develop anti-GBM immunotherapy because several cell types, cytokines, and signaling pathways are involved in generating the immunosuppressive environment. Novel immunotherapies can illustrate novel tumor-induced immunosuppressive mechanisms. Here, we used unsupervised clustering analysis to identify different subtypes of immune cell infiltration that actuated different prognoses, biological actions, and immunotherapy responses. Gene cluster A, with a hot immune cell infiltration phenotype, had high levels of immune-related genes (IRGs), which were associated with immune pathways including the interferon-gamma response and interferon-alpha response, and had low IDH1 and ATRX mutation frequencies. Gene cluster B, a cold immune cell infiltration subtype, exhibited a high expression of the KCNIP2, SCRT1, CPLX2, JPH3, UNC13A, GABRB3, ARPP21, DLGAP1, NRXN1, DLL3, CA10, MAP2, SEZ6L, GRIA2, and GRIA4 genes and a low expression of immune-related genes, i.e., low levels of immune reactivity. Our study highlighted the complex interplay between immune cell infiltration and genetic mutation in the establishment of the tumor immune phenotype. Gene cluster A was identified as an important subtype with a better prognosis and improved immunotherapy response.

Neurexins play a crucial role in cerebellar granule cell survival by organizing autocrine machinery for neurotrophins

Neurexins (NRXNs) are key presynaptic cell adhesion molecules that regulate synapse formation and function via trans-synaptic interaction with postsynaptic ligands. Here, we generate cerebellar granule cell (CGC)-specific Nrxn triple-knockout (TKO) mice for complete deletion of all NRXNs. Unexpectedly, most CGCs die in these mice, and this requirement for NRXNs for cell survival is reproduced in cultured CGCs. The axons of cultured Nrxn TKO CGCs that are not in contact with a postsynaptic structure show defects in the formation of presynaptic protein clusters and in action-potential-induced Ca2+ influxes. These cells also show impaired secretion of depolarization-induced, fluorescence-tagged brain-derived neurotrophic factor (BDNF) from their axons, and the cell-survival defect is rescued by the application of BDNF. These results suggest that CGC survival is maintained by autocrine neurotrophic factors and that NRXNs organize the presynaptic protein clusters and the autocrine neurotrophic-factor secretory machinery independent of contact with postsynaptic ligands.

Synthesis of genetic association studies on autism spectrum disorders using a genetic model-free approach.

Autism spectrum disorder (ASD) is a clinically and genetically heterogeneous group of neurodevelopmental disorders. Despite the extensive efforts of scientists, the etiology of ASD is far from completely elucidated. In an effort to enlighten the genetic architecture of ASDs, a meta-analysis of all available genetic association studies (GAS) was conducted. We searched in the Human Genome Epidemiology Navigator (HuGE Navigator) and PubMed for available case-control GAS of ASDs. The threshold for meta-analysis was two studies per genetic variant. The association between genotype distribution and ASDs was examined using the generalized linear odds ratio (ORG). For variants with available allele frequencies, the examined model was the allele contrast. Overall, 57 candidate genes and 128 polymorphisms were investigated in 159 articles. In total 28 genetic polymorphisms have been shown to be associated with ASDs, that are harbored in 19 genes. Statistically significant results were revealed for the variants of the following genes adenosine deaminase (ADA), bone marrow stromal cell antigen-1 (CD157/BST1), Dopamine receptor D1 (DRD1), engrailed homolog 2 (EN2), met proto-oncogene (MET), methylenetetrahydrofolate reductase (MTHFR), solute carrier family 6 member 4 (SLC6A4), Synaptosomal-associated protein, 25kDa (SNAP-25) and vitamin D receptor (VDR). In the allele contrast model of cases versus healthy controls, significant associations were observed for Adrenoceptor Alpha 1B (ADRA1B), acetyl serotonin O - methyltransferase (ASMT), complement component 4B (C4B), dopamine receptor D3 (DRD3), met proto-oncogene (MET), neuroligin 4, X-linked (NLGN4), neurexin 1 (NRXN1), oxytocin receptor (OXTR), Serine/Threonine-Protein Kinase PFTAIRE-1 (PFTK1), Reelin (RELN) and Ras-like without CAAX 2 (RIT2). These significant findings provide further evidence for genetic factors' implication in ASDs offering new perspectives in means of prevention and prognosis.

The Synaptic Gene Study: Design and Methodology to Identify Neurocognitive Markers in Phelan-McDermid Syndrome and NRXN1 Deletions.

Synaptic gene conditions, i.e., “synaptopathies,” involve disruption to genes expressed at the synapse and account for between 0.5 and 2% of autism cases. They provide a unique entry point to understanding the molecular and biological mechanisms underpinning autism-related phenotypes. Phelan-McDermid Syndrome (PMS, also known as 22q13 deletion syndrome) and NRXN1 deletions (NRXN1ds) are two synaptopathies associated with autism and related neurodevelopmental disorders (NDDs). PMS often incorporates disruption to the SHANK3 gene, implicated in excitatory postsynaptic scaffolding, whereas the NRXN1 gene encodes neurexin-1, a presynaptic cell adhesion protein; both are implicated in trans-synaptic signaling in the brain. Around 70% of individuals with PMS and 43–70% of those with NRXN1ds receive a diagnosis of autism, suggesting that alterations in synaptic development may play a crucial role in explaining the aetiology of autism. However, a substantial amount of heterogeneity exists between conditions. Most individuals with PMS have moderate to profound intellectual disability (ID), while those with NRXN1ds have no ID to severe ID. Speech abnormalities are common to both, although appear more severe in PMS. Very little is currently known about the neurocognitive underpinnings of phenotypic presentations in PMS and NRXN1ds. The Synaptic Gene (SynaG) study adopts a gene-first approach and comprehensively assesses these two syndromic forms of autism. The study compliments preclinical efforts within AIMS-2-TRIALS focused on SHANK3 and NRXN1. The aims of the study are to (1) establish the frequency of autism diagnosis and features in individuals with PMS and NRXN1ds, (2) to compare the clinical profile of PMS, NRXN1ds, and individuals with ‘idiopathic’ autism (iASD), (3) to identify mechanistic biomarkers that may account for autistic features and/or heterogeneity in clinical profiles, and (4) investigate the impact of second or multiple genetic hits on heterogeneity in clinical profiles. In the current paper we describe our methodology for phenotyping the sample and our planned comparisons, with information on the necessary adaptations made during the global COVID-19 pandemic. We also describe the demographics of the data collected thus far, including 25 PMS, 36 NRXN1ds, 33 iASD, and 52 NTD participants, and present an interim analysis of autistic features and adaptive functioning.

Analysis of CNTNAP1 gene variants in a Chinese pedigree affected with lethal congenital contracture syndrome type 7

To explore the genetic basis for a couple who had developed polyhydramnios during three pregnancies and given birth to two liveborns featuring limb contracture, dyspnea and neonatal death. Whole-exome sequencing (WES) was carried out on fetal tissue and peripheral blood samples from the couple. Suspected variants were verified by Sanger sequencing. The fetus was found to harbor homozygous nonsense c.3718C>T (p.Arg1240Ter) variants of the CNTNAP1 gene, which were respectively inherited from its mother and father. The variant was unreported previously. According to the guidelines of the American College of Medical Genetics and Genomics, the variant was predicted to be pathogenic (PVS1+PM2+PP4). The novel homozygous nonsense variants of the CNTNAP1 gene probably underlay the lethal congenital contracture syndrome type 7 (LCCS7) in this pedigree. Above finding has enabled genetic counseling and prenatal diagnosis for the family.

Quantification of the trans-synaptic partners neurexin-neuroligin in CSF of neurodegenerative diseases by parallel reaction monitoring mass spectrometry

SummaryBackgroundSynaptic proteins are increasingly studied as biomarkers for synaptic dysfunction and loss, which are early and central events in Alzheimer's disease (AD) and strongly correlate with the degree of cognitive decline. In this study, we specifically investigated the synaptic binding partners neurexin (NRXN) and neuroligin (Nlgn) proteins, to assess their biomarker's potential.Methodswe developed a parallel reaction monitoring mass spectrometric method for the simultaneous quantification of NRXNs and Nlgns in cerebrospinal fluid (CSF) of neurodegenerative diseases, focusing on AD. Specifically, NRXN-1α, NRXN-1β, NRXN-2α, NRXN-3α and Nlgn1, Nlgn2, Nlgn3 and Nlgn4 proteins were targeted.FindingsThe proteins were investigated in a clinical cohort including CSF from controls (n=22), mild cognitive impairment (MCI) due to AD (n=44), MCI due to other conditions (n=46), AD (n=77) and a group of non-AD dementia (n=28). No difference in levels of NRXNs and Nlgns was found between AD (both at dementia and MCI stages) or controls or the non-AD dementia group for any of the targeted proteins. NRXN and Nlgn proteins correlated strongly with each other, but only a weak correlation with the AD core biomarkers and the synaptic biomarkers neurogranin and growth-associated protein 43, was found, possibly reflecting different pathogenic processing at the synapse.Interpretationwe conclude that NRXN and Nlgn proteins do not represent suitable biomarkers for synaptic pathology in AD. The panel developed here could aid in future investigations of the potential involvement of NRXNs and Nlgns in synaptic dysfunction in other disorders of the central nervous system.Fundinga full list of funding can be found under the acknowledgments section.

Implications of Cell Adhesion Molecules in Autism Spectrum Disorder Pathogenesis.

Autism spectrum disorder (ASD) is a neurodevelopmental illness that leads to repetitive behavior and debilitates social communication. Genetic changes such as susceptible genes and environmental factors promote ASD pathogenesis. Mutations in neuroligins (NLGNs) and neurexin (NRXNs) complex which encode cell adhesion molecules have a significant part in synapses formation, transcription, and excitatory-inhibitory balance. The ASD pathogenesis could partly, at the least, be related to synaptic dysfunction. Here, the NRXNs and NLGNs genes and signaling pathways involved in the synaptic malfunction that causes ASD have been reviewed. Besides, a new insight of NLGNs and NRXNs genes in ASD will be conferred.

Genome-Wide Admixture Mapping of Estimated Glomerular Filtration Rate and Chronic Kidney Disease Identifies European and African Ancestry-of-Origin Loci in Hispanic and Latino Individuals in the United States.

Admixture mapping is a powerful approach for gene mapping of complex traits that leverages the diverse genetic ancestry in populations with recent admixture, such as Hispanic or Latino individuals in the United States. These individuals have an increased risk of CKD. We performed genome-wide admixture mapping for both CKD and eGFR in a sample of 12,601 participants from the Hispanic Community Health Study/Study of Latinos, with validation in a sample of 8191 Black participants from the Women's Health Initiative (WHI). We also compared the findings with those from a conventional genome-wide association study. Three novel ancestry-of-origin loci were identified on chromosomes 2, 14, and 15 for CKD and eGFR. The chromosome 2 locus comprises two European ancestry regions encompassing the FSHR and NRXN1 genes, with European ancestry at this locus associated with increased CKD risk. The chromosome 14 locus, found within the DLK1-DIO3 imprinted domain, was associated with lower eGFR and driven by European ancestry. The eGFR-associated locus on chromosome 15 included intronic variants of RYR3 and was within an African-specific genomic region associated with higher eGFR. The genome-wide association study failed to identify significant associations in these regions. We validated the chromosome 14 and 15 loci associated with eGFR in the WHI Black participants. This study provides evidence of shared ancestry-specific genomic regions influencing eGFR in Hispanic or Latino individuals and Black individuals and illustrates the potential for leveraging genetic ancestry in recently admixed populations for the discovery of novel candidate loci for kidney phenotypes.

LRRTM4 Terminal Exon Duplicated in Family with Tourette Syndrome, Autism and ADHD

Tourette syndrome (TS) is a neurodevelopmental disorder characterised by motor and vocal tics and strong association with autistic deficits, obsessive–compulsive disorder (OCD) and attention-deficit/hyperactivity disorder (ADHD). The genetic overlap between TS and autism spectrum disorder (ASD) includes those genes that encode the neurexin trans-synaptic connexus (NTSC) inclusive of the presynaptic neurexins (NRXNs) and postsynaptic neuroligins (NLGNs), cerebellin precursors (CBLNs in complex with the glutamate ionotropic receptor deltas (GRIDs)) and the leucine-rich repeat transmembrane proteins (LRRTMs). In this study, we report the first evidence of a TS and ASD association with yet another NTSC gene family member, namely LRRTM4. Duplication of the terminal exon of LRRTM4 was found in two females with TS from the same family (mother and daughter) in association with autistic traits and ASD.

The role of the KIBRA and APOE genes in developing spatial abilities in humans.

In the contemporary high-tech society, spatial abilities predict individual life and professional success, especially in the STEM (Science, Technology, Engineering, and Mathematics) disciplines. According to neurobiological hypotheses, individual differences in cognitive abilities may be attributed to the functioning of genes involved in the regulation of neurogenesis and synaptic plasticity. In addition, genome-wide association studies identified rs17070145 located in the KIBRA gene, which was associated with individual differences in episodic memory. Considering a significant role of genetic and environmental components in cognitive functioning, the present study aimed to estimate the main effect of NGF (rs6330), NRXN1 (rs1045881, rs4971648), KIBRA (rs17070145), NRG1 (rs6994992), BDNF (rs6265), GRIN2B (rs3764030), APOE (rs7412, rs429358), and SNAP25 (rs363050) gene polymorphisms and to assess the effect of gene-environment interactions on individual differences in spatial ability in individuals without cognitive decline aged 18–25 years (N = 1011, 80 % women). Spatial abilities were measured using a battery of cognitive tests including the assessment of “3D shape rotation” (mental rotation). Multiple regression analysis, which was carried out in the total sample controlling for sex, ethnicity and the presence of the “risk” APOE ε4 allele, demonstrated the association of the rs17070145 Т-allele in the KIBRA gene with enhanced spatial ability (β = 1.32; pFDR = 0.037) compared to carriers of the rs17070145 CC-genotype. The analysis of gene-environment interactions revealed that nicotine smoking (β = 3.74; p = 0.010) and urban/rural residency in childhood (β = –6.94; p = 0.0002) modulated the association of KIBRA rs17070145 and АРОЕ (rs7412, rs429358) gene variants with individual differences in mental rotation, respectively. The data obtained confirm the effect of the KIBRA rs17070145 Т-allele on improved cognitive functioning and for the first time evidence the association of the mentioned genetic variant with spatial abilities in humans. A “protective” effect of the APOE ε2 allele on enhanced cognitive functioning is observed only under certain conditions related to childhood rearing.

Hominini-specific regulation of CBLN2 increases prefrontal spinogenesis.

The similarities and differences between nervous systems of various species result from developmental constraints and specific adaptations1-4. Comparative analyses of the prefrontal cortex (PFC), a cerebral cortex region involved in higher-order cognition and complex social behaviours, have identified true and potential human-specific structural and molecular specializations4-8, such as an exaggerated PFC-enriched anterior-posterior dendritic spine density gradient5. These changes are probably mediated by divergence in spatiotemporal gene regulation9-17, which is particularly prominent in the midfetal human cortex15,18-20. Here we analysed human and macaque transcriptomic data15,20 and identified a transient PFC-enriched and laminar-specific upregulation of cerebellin 2 (CBLN2), a neurexin (NRXN) and glutamate receptor-δ GRID/GluD-associated synaptic organizer21-27, during midfetal development that coincided with the initiation of synaptogenesis. Moreover, we found that species differences in level of expression and laminar distribution of CBLN2 are, at least in part, due to Hominini-specific deletions containing SOX5-binding sites within a retinoic acid-responsive CBLN2 enhancer. In situ genetic humanization of the mouse Cbln2 enhancer drives increased and ectopic laminar Cbln2 expression and promotes PFC dendritic spine formation. These findings suggest a genetic and molecular basis for the anterior-posterior cortical gradient and disproportionate increase in the Hominini PFC of dendritic spines and a developmental mechanism thatmay link dysfunction of the NRXN-GRID-CBLN2 complex to the pathogenesis of neuropsychiatric disorders.

Key genes affecting the progression of nasopharyngeal carcinoma identified by RNA-sequencing and bioinformatic analysis.

Background: The present work was conducted to screen the potential biomarkers affecting nasopharyngeal carcinoma (NPC) progression through RNA-sequencing (RNA-seq), bioinformatic analysis and functional experiments.Materials and Methods: Six normal samples and five NPC clinical samples were collected for RNA-seq analysis. The expression levels in both groups were determined through student’s t-test. We identified genes of P < 0.01 as the differentially expressed genes (DEGs). In addition, gene set enrichment analysis (GSEA) was conducted. Afterwards, STRING V10 database was employed to extract protein interactions among the DEGs. Later, we established a protein-protein interaction (PPI) network, and used the Cytoscape software for network visualization. qRT-PCR was conducted to verify hub genes from clinical samples. Then, the function of CXCL10 in cell proliferation, apoptosis, invasion and migration was evaluated.Results: A total of 2024 DEGs were identified, among which, 1449 were down-regulated and 575 were up-regulated. The PPI was constructed, and the hub genes including Insulin Like Growth Factor 1 (IGF1), C-X-C Motif Chemokine Ligand 10 (CXCL10), Interleukin 13 (IL13), Intercellular Adhesion Molecule 1 (ICAM1), G Protein Subunit Gamma Transducin 1 (GNGT1), Matrix Metallopeptidase 1 (MMP1), Neurexin 1 (NRXN1) and Matrix Metallopeptidase 3 (MMP3) were obtained. The expression levels of CXCL10, IGF1, MMP3, MMP1, ICAM1, and IL-13 were significantly up-regulated in tumor tissues. High expression levels of CXCL10, MMP3 and ICAM1 predicted poor prognosis of NPC patients. CXCL10 silencing suppressed NPC cell proliferation and migration.Conclusions: CXCL10 may serve as a potential key gene affecting NPC genesis and progression.

In Silico Analysis of miRNA-mediated ceRNAs as Potential Molecular Biomarkers in Glioblastoma

Objectives: Glioblastoma multiforme (GBM) is defined as the most frequent and lethal form of the primary brain tumors in the central nervous system (CNS) in adults. Recent studies have focused on the identification of the new targets for the diagnosis and treatment of GBM and resulted in great interest for miRNAs due to their regulatory effects in cancer pathogenesis. Thus, we aimed to characterize novel molecular biomarkers for GBM by computational analysis. Methods: 118 miRNAs that are clinically related with glioblastoma and proven by experimentally were exported through miRTarBase database. 1016 genes projected by these 118 miRNAs were determined via ComiR database. Subsequently, the genes with transcribed ultraconserved regions (T-UCRs) in their exonic regions were designated and the genes which have potential competing endogenous RNA (ceRNA) activities were extracted. Genes with remarkable expression profile differences between glioblastoma and normal brain tissues among ceRNAs that are associated with glioblastoma involving T-UCR were identified. Results: The statistical analysis of the correlation between PBX3 and NRXN3 genes and glioblastoma was carried out by Spearman correlation test. PBX3 and NRXN3 expression was significantly higher and lower in glioblastoma than in normal brain tissues, respectively. On the other hand, the other genes did not have any remarkable differential expression pattern. Conclusion: Based on the findings of the current study, it is determined that NRXN3 acts as a tumor suppressor gene and NRXN3 gene is downregulated in GBM. PBX3 gene functions as an oncogene and is upregulated in GBM.

Is NRXN1 Gene Expression an Important Marker of Treatment of Depressive Disorders? A Pilot Study.

Aim: Due to the fact that NRXN1 is associated with neurodevelopmental disorders, the aim of this study was to investigate the role of the NRXN1 gene in the etiology and epigenetics of depression by comparison of NRXN1 mRNA expression and NRXN1 protein level expression in patients suffering from depression versus healthy controls, as well as to search for clinical variables related to expression of the analyzed gene. Material and Methods: A total of 180 people aged 19–64 qualified for the study. The experimental group consisted of 97 people who were psychiatrically hospitalized, diagnosed with recurrent depressive disorders (F33) or who met the diagnostic criteria of a depressive episode (F32) according to ICD-10. The control group included 83 healthy people who volunteered to participate in the study. A sample of peripheral blood was obtained from people who were positively qualified to participate in the study—twice in the experimental group and once in the control group for genetic testing. Sociodemographic variables and data on the course of the disorder were also gathered. Patients were examined on study entry and at the end of the hospitalization with the Hamilton Depression Scale. Obtained data were analyzed statistically. The study was approved by the University’s Bioethics Committee. Results: The gene expression of NRXN1 at both mRNA and protein level significantly differs and it is lower in the experimental group compared to expression in healthy people. The difference in gene expression of NRXN1 at both the mRNA and protein levels between the first and second measurement in the experimental group is also significant. The result demonstrates a higher expression level in the first measurement and lower expression level in the second measurement when reported depression symptoms are less severe. Conclusions: Results concerning expression of NRXN1 may play an important role in further researches about the etiopathogenesis of depressive disorders such as looking for depression biomarkers and identifying evidence which may be relevant to personalize treatment for depression.

Distinct Expression of SLM2 Underlies Splicing-Dependent Trans-Synaptic Signaling of Neurexin Across GABAergic Neuron Subtypes.

The mammalian brain contains multiple types of neuronal cells with complex assemblies and distinct structural and functional properties encoded by divergent gene programs. There is increasing evidence that alternative splicing (AS) plays fundamental roles in transcriptomic diversity and specifying synaptic properties of each neuronal cell type. However, the mechanisms underlying AS regulation and whether it controls synapse formation across GABAergic interneurons have not been fully elucidated. Here we show the differential expression levels of Sam68-like molecule 2 (SLM2), a major splicing regulator of neurexin (NRX), in GABAergic neuronal subtypes and its contribution to GABAergic synapse specification. Cortical SLM2 is strongly expressed not only in excitatory neurons but also in a subpopulation of GABAergic interneurons, especially in VIP-positive neurons that are originated from late-born caudal ganglionic eminence (GE)- derived cells. Using artificial synapse formation assay, we found that GE containing cortices form a strong synapse with LRRTM2, a trans-synaptic receptor of the alternatively spliced segment 4 (AS4)(-) of NRX. SLM2 knock-down reduced the NRX AS4(-) isoform expression and hence weaken LRRTM2-induced synapse formation. The addition of NRX AS4(-) was sufficient to rescue the synaptic formation by LRRTM2 in SLM2 knock-down neurons. Thus, our findings suggest a novel function of SLM2 in modifying network formation of a specific population of GABAergic interneurons and contribute to a better understanding of the roles AS plays in regulating synapse specificity and neuronal molecular diversity.

Neurexin 1 variants as risk factors for suicide death

Suicide is a significant public health concern with complex etiology. Although the genetic component of suicide is well established, the scope of gene networks and biological mechanisms underlying suicide has yet to be defined. Previously, we reported genome-wide evidence that neurexin 1 (NRXN1), a key synapse organizing molecule, is associated with familial suicide risk. Here we present new evidence for two non-synonymous variants (rs78540316; P469S and rs199784139; H885Y) associated with increased familial risk of suicide death. We tested the impact of these variants on binding interactions with known partners and assessed functionality in a hemi-synapse formation assay. Although the formation of hemi-synapses was not altered with the P469S variant relative to wild-type, both variants increased binding to the postsynaptic binding partner, leucine-rich repeat transmembrane neuronal 2 (LRRTM2) in vitro. Our findings indicate that variants in NRXN1 and related synaptic genes warrant further study as risk factors for suicide death.

Circ_0001367 inhibits glioma proliferation, migration and invasion by sponging miR-431 and thus regulating NRXN3

Many studies have reported that circular RNAs play a vital role in the malignant progression of human cancers. However, the role and underlying mechanism of circRNAs in the development of gliomas have not been fully clarified. In this study, we found that circ_0001367 was downregulated in glioma tissues and showed a close correlation with glioma patient survival. Functional assays demonstrated that upregulation of circ_0001367 could suppress the proliferation, migration and invasion of glioma cells in vitro and inhibit glioma growth in vivo. Furthermore, bioinformatics analysis, luciferase reporter assay and RNA immunoprecipitation assay indicated that circ_0001367 can serve as a sponge for miR-431 and that miR-431 acts as an oncogene by regulating neurexin 3 (NRXN3). In addition, rescue experiments verified that circ_0001367 could regulate both the expression and function of NRXN3 in a miR-431-dependent manner. In conclusion, circ_0001367 functions as an suppressor in glioma by targeting the miR-431/NRXN3 axis and may be a promising therapeutic target against gliomas.

Genetic and cytogenetic screening of autistic spectrum disorder: Genotype-phenotype profiles

Autism, a pervasive developmental disorder typically characterized by repetitive behaviour, social skills deficit (or a deficit in social communication), speech and language impairments. Our prime focus is to analyze the clinical features and phenotypical behavioural changes using the diagnostic and statistical manual of mental disorders, fourth edition, text revision (DSM IV-TR), and locating the biomarkers associated with specific autistic characters using karyotyping and fluorescence in situ hybridization (FISH) techniques. The prevalence rate of the neurexin 1 (NRXN1) gene polymorphism was also assessed in the current study. The study group involved 196 samples with 98 autistics, and equal age-matched (±2) controls based on their birth order and carrier. The participants include 35.2% males (n = 69) and 14.8% females (n = 29). The autistic and control participants were categorized based on their ages as group I (<12 yrs) with n = 62; males n = 41 (20.9%); females n = 21 (10.7%) and group II (≥12 yrs)-n = 36; males n = 28 (14.2%); females n = 08 (4.08%). Karyotyping was done for autism participants (n = 98) and the results showed that 90% of autistic participants were either the only child or the first child with a low perception and frequency in both the groups. Subsequently, we carried out the FISH assay on participants (n = 37) with higher DSM-IV TR score (≥30). Only 30 FISH tests were negative for subtelomeric deletions with NRXN1 polymorphism genotypic frequency as 62.50%, 25% and 25% for A/A, A/G and G/G genotype respectively. Our study suggests the link between a haplotype with clinical signs of autism for the single nucleotide sequence (SNP rs9636391) and links autistic characters and gene among autistic children according to their birth order, age and gender in India.

Transgene Mapping and Genotyping Protocol Design in a Transgenic Mouse Strain by Short‐Read Whole‐Genome Sequencing

[Aim] When creating transgenic mice, multiple lines with the same transgene are often created. For example, our laboratory has three lines of hAce2 transgenic mice (hAce2-Tg). For one of them (hAce2-Tg#16), we mapped the transgene using short-read whole-genome sequencing and designed genotyping PCR to identify the line. [Methods] We extracted genomic DNA from kidneys of hAce2-Tg#16. Using PCR-free libraries prepared with the genomic DNA, paired-end 150-bp reads were performed by DNBSEQG-400 sequencer (MGI Tech) (outsourced). In order to find the junction between the genome and the transgene, we created two search programs: one to search for matches between the transgene and each read and its complementary sequence from the front (5′ side, head-match), and the other to search for matches from the back (3′ side, tail-match). We selected reads with a match length of 5 to 145 bases. After the search, we selected reads containing the mouse genome sequence in the non-matching part by BLAST search of the Ensembl database. Based on this sequence information, we designed primers for genotyping PCR based on the flanking primer method. All animal experiments were conducted in accordance with the guidelines for animal experiments of the National Institutes of Biomedical Innovation, Health, and Nutrition, Osaka, Japan (authorization number: DS22-55). [Results and Discussion] In a total of 882,577,032 reads (total read length: about 132 GBase), the total numbers of head-matching and tail-matching reads were 1,498 and 3,060, respectively. Among them, eight reads in the head-matching reads had the same genomic sequence. Its genomic location was in the intron of the Nrxn3 gene on chromosome 12. The transgene was truncated by 82 bases from the 3′ end. On the other hand, none of the tail-matching reads contained the neighboring genomic sequence. Genotyping PCRs with flanking primers we designed based on the sequence near the junction between transgene and genome sequences confirmed that the presence or absence of the transgene only in the line (hAce2-Tg#16). The authors have already reported examples of transgene mapping by Genomic Walking (Exp Anim 53: 103-111, 2004) and whole genome sequencing of long reads (Exp Anim 69: 279-286, 2020). This study confirmed that short-read whole-genome sequencing was also useful for mapping transgenes and designing PCR for genotyping of transgenic mice.