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Wei, J.

Publications and source records attributed to Wei, J..

At least 109 records · Page 6Linked to original sources

Inhibition of KLK8 promotes pulmonary endothelial repair by restoring VE-cadherin/Akt/FOXM1 pathway

The tissue kallikrein-related peptidases (KLKs) are secreted serine proteases deeply involved in angiogenesis. However, whether KLKs are involved in the regulation of endothelial regeneration during sepsis remains unknown. By comparing the mRNA levels of 15 KLKs, we found that KLK8 was the highest induced KLK member in lung tissues or primary isolated mouse lung vascular endothelial cells (MLVECs) exposed to lipopolysaccharide (LPS). Adenovirus-mediated overexpression of KLK8 caused endothelial hyperpermeability both in vitro and in vivo. Inhibition of KLK8, by either gene knockout or KLK8 neutralizing antibodies, alleviated sepsis-induced endothelial hyperpermeability, acute lung injury and mortality. Mechanistically, transcription profiling of KLK8-overexpressed endothelial cells revealed a central role of forkhead box M1 (FOXM1) downregulation in mediating the pro-injury and anti-proliferation effects of KLK8. KLK8 cleaved VE-cadherin and consequently suppressed FOXM1 expression by inactivation of the VE-cadherin/Akt pathway. KLK8 deficiency or blockade rescued VE-cadherin/Akt/FOXM1 pathway, thus promoting endothelium regeneration. This study reveals a critical role for KLK8-induced inactivation of VE-cadherin/Akt/FOXM1 pathway in mediating the impairment of endothelial regeneration and the consequent lung vascular leakiness in response to sepsis. HighlightsO_LIUpregulated KLK8 mediates lung endothelial barrier dysfunction during sepsis C_LIO_LIKLK8 inactivates VE-cadherin/Akt/FOXM1, thus impairing endothelium regeneration C_LIO_LIKLK8 deficiency or blockade rescues VE-cadherin/Akt/FOXM1 signaling pathway C_LIO_LIKLK8 deficiency or blockade promotes endothelium regeneration during sepsis C_LIO_LIKLK8 deficiency or blockade attenuates sepsis-induced acute lung injury and mortality C_LI

physiology↗

NS2B-D55E and NS2B-E65D Variations are Responsible for Differences in NS2B-NS3 Protease Activities Between Japanese Encephalitis Virus Genotype I and III in Fluorogenic Peptide Model

Japanese Encephalitis Virus (JEV) NS2B-NS3 is a protein complex composed of NS3 proteases and a NS2B cofactor. The N-terminal protease domain (180 residues) of NS3 (NS3(pro)) interacts directly with a central 40-amino acid hydrophilic domain of NS2B (NS2B(H)) to form an active serine protease. In this study, the recombinant NS2B(H)-NS3(pro) proteases were prepared in E. coli and used to compare the enzymatic activity between genotype I (GI) and III (GIII) NS2B-NS3 proteases. The GI NS2B(H)-NS3(pro) was able to cleave the sites at internal C, NS2A/NS2B, NS2B/NS3 and NS3/NS4A junctions that were identical to the sites proteolytically processed by GIII NS2B(H)-NS3(pro). Analysis of the enzymatic activity of recombinant NS2B(H)-NS3(pro) proteases using a model of fluorogenic peptide substrate revealed that the proteolytical processing activity of GIII NS2B(H)-NS3(pro) was significantly higher than that of GI NS2B(H)-NS3(pro). There were eight amino acid variations between GI and GIII NS2B(H)-NS3(pro), which may be responsible for the difference in enzymatic activities between GI and GIII proteases. Therefore, recombinant mutants were generated by exchanging NS2B(H) and NS3(pro) domains between GI and GIII NS2B(H)-NS3(pro) and subjected to protease activity analysis. Substitution of NS2B(H) significantly altered the protease activities, as compared to the parental NS2B(H)-NS3(pro), suggesting that NS2B(H) played an essential role in regulation of NS3(pro) protease activity. To further identify the amino acids responsible for the difference in protease activities, multiple substitution mutants including the individual and combined mutations at the variant residue 55 and 65 of NS2B(H) were generated and subjected to protease activity analysis. Replacement of NS2B-55 and NS2B-65 of GI to GIII significantly increased the enzymatic activity of GI NS2B(H)-NS3(pro) protease, whereas mutation of NS2B-55 and NS2B-65 of GIII to GI remarkably reduced the enzymatic activity of GIII NS2B(H)-NS3(pro) protease. Overall, these data demonstrated that NS2B-55 and NS2B-65 variations in hydrophilic domain of NS2B co-contributed to the difference in NS2B(H)-NS3(pro) protease activities between GI and GIII. These observations gain an insight into the role of NS2B in regulation of NS3 protease activities, which is useful for understanding the replication of JEV GI and GIII viruses.

microbiology↗

A dipteran parasite regulates 20E synthesis and antibacterial activity of the host for development through inducing host nitric oxide production

Parasites primarily rely on the host to survive, and have evolved diverse survival strategies. In the present study, we report a specific survival strategy of a dipteran parasite Exorista sorbillans (Diptera: Tachinidae), which is a potential biological control agent for agricultural pests and a pest in sericulture. We found that the expression levels of host nitric oxide synthase (NOS) and nitric oxide (NO) production were increased after E. sorbillans infection. Reducing NOS expression and NO production with a NOS inhibitor (L-NAME) in infected hosts significantly impeded the growth of E. sorbillans larvae. Moreover, the 20-hydroxyecdysone (20E) biosynthesis of infected hosts was elevated with increasing NO production, and inhibiting NOS expression also lowered 20E biosynthesis. More importantly, induced NO synthesis was required to eliminate intracellular bacterial pathogens that presumably competed for shared host resources. Inhibiting NOS expression down-regulated the transcription of antimicrobial peptide genes and increased the number of bacteria in infected hosts. Collectively, this study revealed a new perspective on the role of NO in host-parasite interactions and a novel mechanism for parasite regulation of host to support its development. Author summaryParasites are ubiquitous on earth and diverse, and have evolved various strategies to match their own specific requirements for survival within the host. In this study, we found that Exorista sorbillans, an endoparasite of many agricultural pests and the main insect pest in sericulture, used a novel strategy to manipulate its host NO synthesis for survival within its host Bombyx mori. Specifically, NOS expression and the production of NO in the host were up-regulated by E. sorbillans infection, which benefited larval E. sorbillans development. Meanwhile, increased NO production in host activated 20E synthesis of parasitized hosts and triggered the expression of AMPs against the invasion of pathogenic bacteria to avoid nutritional competence in the host. Our study provides innovative insights into the mechanisms by which a parasite manipulates host NO production for development and may help to expand our knowledge of other parasitic systems.

pathology↗

Robust and Adaptive Deep Model Ensemble Framework Fine-tuned by Structural Information for Drug-Target Interactions

In the fields of new drug development and drug repositioning, drug-target interactions (DTI) play a pivotal role. Although deep learning models have already made significant contributions in this domain, the state-of-the-art models still exhibit shortcomings in predictive performance and issues of false-negative errors. Based on these observations, we constructed a streamlined yet effective base learner model. With our designed adaptive feature weight network, the model can capture key features within drugs (targets). Furthermore, by cross-partitioning the training data, multiple base learners are integrated into a powerful ensemble model named EADTN. The performance of the model is further enhanced as the number of base learners increases. Additionally, we employed a single-linkage clustering algorithm to cluster drugs and proteins and leveraged this clustering information to fine-tune the base learners, which elevates the value of EADTN in real-world applications like drug repositioning and targeted drug development. Our designed substructure importance ranking method also demonstrates the models exceptional capability to recognize key substructures. Benefiting from the models low generalization error capability, we successfully identified false-negative samples within the dataset, revealing new interaction relationships. Experimental results indicate that EADTN consistently outperforms existing state-of-the-art models across multiple datasets. More importantly, the ensemble learning and clustering fine-tuning approaches adopted by our model offer a fresh perspective for related fields.

bioinformatics↗

Differences in syncytia formation by SARS-CoV-2 variants modify host chromatin accessibility and cellular senescence via TP53

COVID-19 remains a significant public health threat due to the ability of SARS-CoV-2 variants to evade the immune system and cause breakthrough infections. Although pathogenic coronaviruses such as SARS-CoV-2 and MERS-CoV lead to severe respiratory infections, how these viruses affect the chromatin proteomic composition upon infection remains largely uncharacterized. Here we used our recently developed integrative DNA And Protein Tagging (iDAPT) methodology to identify changes in host chromatin accessibility states and chromatin proteomic composition upon infection with pathogenic coronaviruses. SARS-CoV-2 infection induces TP53 stabilization on chromatin, which contributes to its host cytopathic effect. We mapped this TP53 stabilization to the SARS-CoV-2 spike and its propensity to form syncytia, a consequence of cell-cell fusion. Differences in SARS-CoV-2 spike variant-induced syncytia formation modify chromatin accessibility, cellular senescence, and inflammatory cytokine release via TP53. Our findings suggest that differences in syncytia formation alter senescence-associated inflammation, which varies among SARS-CoV-2 variants.

microbiology↗

CellGO: A novel deep learning-based framework and webserver for cell type-specific gene function interpretation

Interpreting the function of genes and gene sets identified from omics experiments remains a challenge, as current pathway analysis tools often fail to account for complex interactions across genes and pathways under specific tissues and cell types. We introduce CellGO, a tool for cell type-specific gene functional analysis. CellGO employs a deep learning model to simulate signaling propagation within a cell, enabling the development of a heuristic pathway activity measuring system to identify cell type-specific active pathways given a single gene or a gene set. It is featured with additional functions to uncover pathway communities and the most active genes within pathways to facilitate mechanistic interpretation. This study demonstrated that CellGO can effectively capture cell type-specific pathways even when working with mixed cell-type markers. CellGOs performance was benchmarked using gene knockout datasets, and its implementation effectively infers the cell type-specific pathogenesis of risk genes associated with neurodevelopmental and neurodegenerative disorders, suggesting its potential in understanding complex polygenic diseases. CellGO is accessible through a python package and a four-mode web interface for interactive usage with pretrained models on 71 single-cell datasets from human and mouse fetal and postnatal brains.

bioinformatics↗

Anti-PD-1-iRGD Peptide Conjugate Boosts Antitumor Efficacy via Engagement Augmentation and Penetration Enhancement of T cells

Despite the important breakthroughs of immune-checkpoint inhibitors (ICIs) in recent years, the overall objective response rate (ORR) remains limited in various cancers. Here, we synthesized programmed cell death protein-1 (PD-1) antibody iRGD conjugate (PD-1-(iRGD)2) through glycoengineering and bio-orthogonal reaction. PD-1-(iRGD)2 exhibited extra iRGD receptor dependent affinity to several cancer cell lines rather than normal cell lines. Via dual targeting, PD-1-(iRGD)2 engageed tumor cells and T cells thus mediating T cell activation and facilitating tumor elimination. Besides, the attachment of iRGD impressively improved the penetrability of both PD-1 antibody and PD-1+ T cells. In multiple syngeneic mouse models, PD-1-(iRGD)2 effectively reduced tumor growth with satisfactory biosafety. Moreover, results of flow cytometry and single-cell RNA-seq revealed that PD-1-(iRGD)2 remodeled the tumor microenvironment (TME) and expanded a unique population of "better effector" CD8+ tumor infiltrating T cells (TILs) expressing stem and memory associated genes including Tcf7, Il7r, Lef1 and Bach2. Conclusively, PD-1-(iRGD)2 could be a novel and promising therapeutic approach for cancer immunotherapy. Statement of significanceDesigned against the clinical dilemma of unsatisfied response rate after contemporary cancer immunotherapy, PD-1-(iRGD)2 engages T cells and tumor cells, promotes T cell infiltration and expands a unique population of "better effectors" with enhanced therapeutic potential for the treatment of cancer.

immunology↗

m6A mRNA Methylation Regulates Early Pancreatic β-Cell Differentiation

N6-methyladenosine (m6A) is the most abundant chemical modification in mRNA, and plays important roles in human and mouse embryonic stem cell pluripotency, maintenance, and differentiation. We have recently reported, for the first time, the role of m6A in the postnatal control of {beta}-cell function in physiological states and in Type 1 and 2 Diabetes. However, the precise mechanisms by which m6A acts to regulate the development of human and mouse {beta}-cells are unexplored. Here, we show that the m6A landscape is dynamic during human pancreas development, and that METTL14, one of the m6A writer complex proteins, is essential for the early differentiation of both human and mouse {beta}-cells.

developmental biology↗

Distinct ossification trade-offs illuminate the shoulder girdle reconfiguration at the water-to-land transition.

The mechanisms of the pectoral girdle transformation at the origin of terrestrial locomotion in vertebrates remains an outstanding problem in evolutionary biology1. The loss of dermal bones and the enlargement of endochondral bones resulted in the disarticulation of the pectoral girdle from the skull and the formation of the neck during the fish-to-tetrapod transition2-5. Despite the functional implications of this skeletal shift in the emergence of terrestrial vertebrates, the underlying genetic-developmental alterations have remained enigmatic. Here, we discovered that in zebrafish pectoral girdle mesodermal cells expressing gli3, a transcription factor in the Hedgehog signaling pathway, contribute to both dermal and endochondral bones. We show that Gli3 regulates expression of activin A receptor type 1-like, a BMP type 1 receptor lost in tetrapod lineages, and thereby determines endochondral and dermal ossification. Intriguingly, Gli and Hedgehog compound knockout fish exhibited an unexpected combination of actinopterygian fish and stem-tetrapod pectoral girdle characteristics. These ontogenetic and anatomical data suggest that a trade-off between the two distinct ossification pathways is a deeply embedded developmental program in bony fishes, with potential for tuning of this trade-off to generate novel pectoral girdle forms akin to stem-tetrapods at the dawn of vertebrate terrestrialization.

evolutionary biology↗

Rare GPR37L1 variants reveal potential roles in anxiety and migraine disorders

GPR37L1 is an orphan receptor that couples through heterotrimeric G-proteins to regulate physiological functions. Since its role in humans is not fully defined, we used an unbiased computational approach to assess the clinical significance of rare GPR37L1 genetic variants found among 51,289 whole exome sequences from the DiscovEHR cohort. Briefly, rare GPR37L1 coding variants were binned according to predicted pathogenicity, and analyzed by Sequence Kernel Association testing to reveal significant associations with disease diagnostic codes for epilepsy and migraine, among others. Since associations do not prove causality, rare GPR37L1 variants were then functionally analyzed in SK-N-MC cells to evaluate potential signaling differences and pathogenicity. Notably, receptor variants exhibited varying abilities to reduce cAMP levels, activate MAPK signaling, and/or upregulate receptor expression in response to the agonist prosaptide (TX14(A)), as compared to the wild-type receptor. In addition to signaling changes, knockout of GPR37L1 or expression of certain rare variants altered cellular cholesterol levels, which were also acutely regulated by administration of the agonist TX14(A) via activation of the MAPK pathway. Finally, to simulate the impact of rare nonsense variants found in the large patient cohort, a knockout (KO) mouse line lacking Gpr37L1 was generated, revealing loss of this receptor produced sex-specific changes implicated in migraine-related disorders. Collectively, these observations define the existence of rare GPR37L1 variants in the human population that are associated with neuropsychiatric conditions and identify the underlying signaling changes that are implicated in the in vivo actions of this receptor in pathological processes leading to anxiety and migraine. SIGNIFICANCE STATEMENTG-protein coupled receptors (GPCRs) represent a diverse group of membrane receptors that contribute to a wide range of diseases and serve as effective drug targets. However, a number of these receptors have no identified ligands or functions, i.e., orphan receptors. Over the past decade, advances have been made, but there is a need for identifying new strategies to reveal their roles in health and disease. Our results highlight the utility of rare variant analyses of orphan receptors for identifying human disease associations, coupled with functional analyses in relevant cellular and animal systems, to ultimately reveal their roles as novel drug targets for treatment of neurological disorders that lack wide-spread efficacy.

neuroscience↗

Spatially-resolved single-cell atlas of ascidian endostyle provides insights into the origin of vertebrate pharyngeal organs

The pharynx is an endoderm innovation in deuterostome ancestors, the vertebrate descendent structure of which is a pharyngeal developmental organizer involving multi-germ layer and organ derivatives. However, the evolutionary origination of complicated pharynx organs in vertebrates is still largely unknown. Endostyle, a transitional pharyngeal organ exclusively in basal chordates provides an opportunity to reveal the origin of pharyngeal organs. Here, utilizing cutting-edged Stereo-seq and single-cell RNA-seq, we constructed the first spatially-resolved single-cell atlas in the endostyle of urochordate ascidian Styela clava, where the spatial location of Stereo-seq and high capture efficiency of single-cell RNA-seq complement each other and identified 23 highly differentiated cell types. We identified a previously overlooked hemolymphoid region (HLR), which harbors immune and blood cell clusters with enriched stemness capacities, illuminating a mixed rudiment and stem-cell niches for the blood and lymphoid system. More excitingly, we discovered a mechanical-sensitive hair cell candidate in zone 3 homologous to vertebrate acoustico-lateralis system, which was supported by the expression of in situ hybridization-verified inner ear-specific markers, including PTPRQ, USH2A, WHRN, and ADGRV1, ultracellular structure evidence and cross-species comparison. These results thoroughly renewed the comprehension of the basal-chordate pharynx and provides expressional evidence for multiplexed pharyngeal organ evolution.

evolutionary biology↗

Transcriptome Analysis Reveals Organ-Specific Effects of 2-Deoxyglucose Treatment in Healthy Mice

ObjectiveGlycolytic inhibition via 2-deoxy-D-glucose (2DG) has potential therapeutic benefits for a range of diseases, including cancer, epilepsy, systemic lupus erythematosus (SLE), and rheumatoid arthritis (RA), and COVID-19, but the systemic effects of 2DG on gene function across different tissues are unclear. MethodsThis study analyzed the transcriptional profiles of nine tissues from C57BL/6J mice treated with 2DG to understand how it modulates pathways systemically. Principal component analysis (PCA), weighted gene co-network analysis (WGCNA), analysis of variance, and pathway analysis were all performed to identify modules altered by 2DG treatment. ResultsPCA revealed that samples clustered predominantly by tissue, suggesting that 2DG affects each tissue uniquely. Unsupervised clustering and WGCNA revealed six distinct tissue-specific modules significantly affected by 2DG, each with unique key pathways and genes. 2DG predominantly affected mitochondrial metabolism in the heart, while in the small intestine, it affected immunological pathways. ConclusionsThese findings suggest that 2DG has a systemic impact that varies across organs, potentially affecting multiple pathways and functions. The study provides insights into the potential therapeutic benefits of 2DG across different diseases and highlights the importance of understanding its systemic effects for future research and clinical applications.

systems biology↗

Migratory herbivorous waterfowl couple the seed wave and the green wave during spring migration

East Asian herbivorous waterfowl intensively use farmland in spring, next to their natural habitat. Accordingly, they might have expanded their migration strategy from merely tracking the green wave of newly emerging vegetation to also incorporating the availability of post-harvest agricultural seeds (here dubbed the seed wave). However, if and how waterfowl use multiple food resources to time their seasonal migration is still unknown. We test this migration strategy using 167 spring migration tracks of five East Asian herbivorous waterfowl species and mixed-effect resource selection function models. We find all study species arrive at their core stopover sites in the Northeast China Plain after agricultural seeds become available, extend their stay after spring vegetation emerges, and arrive at breeding sites around the emergence of vegetation. Moreover, the cue used in exploiting the availability of both food resources varies in different regions and among species. At the core stopover sites, larger-bodied species use the seed wave and smaller-bodied ones adopt the green wave. At the breeding sites, the former follow the green wave, and the latter track the snow-free time. Our findings suggest that waterfowl track multiple resource waves to finetune their migration, highlighting new opportunities for conservation.

ecology↗

Assisting and Accelerating NMR Assignment with Restrainted Structure Prediction

NMR experiments can detect in situ structures and dynamic interactions, but the NMR assignment process requires expertise and is time-consuming, thereby limiting its applicability. Deep learning algorithms have been employed to aid in experimental data analysis. In this work, we developed a RASP model which can enhance structure prediction with restraints. Based on the Evoformer and structure module architecture of AlphaFold, this model can predict structure based on sequence and a flexible number of input restraints. Moreover, it can evaluate the consistency between the predicted structure and the imposed restraints. Based on this model, we constructed an iterative NMR NOESY peak assignment pipeline named FAAST, to accelerate assignment process of NOESY restraints and obtaining high quality structure ensemble. The RASP model and FAAST pipeline not only allow for the leveraging of experimental restraints to improve model prediction, but can also facilitate and expedite experimental data analysis with their integrated capabilities.

bioinformatics↗

Metformin regulates bone marrow stromal cells to accelerate bone healing in diabetic mice

Diabetes mellitus is a group of chronic diseases characterized by high blood glucose levels. Diabetic patients have a higher risk of sustaining osteoporotic fractures than non-diabetic people. The fracture healing is usually impaired in diabetics and our understanding of the detrimental effects of hyperglycemia on fracture healing is still inadequate. Metformin is the first-line medicine for type-2 diabetes (T2D). However, its effects on bone in T2D patients remain to be studied. To assess the impacts of metformin on fracture healing, we compared the healing process of closed wound fixed fracture, non-fixed radial fracture, and femoral drill-hole injury models in T2D mice with and without metformin treatment. Our results demonstrated that metformin rescued the delayed bone healing and remolding in T2D mice in all the three injury models. The proliferation, osteogenesis, chondrogenesis of the bone marrow stromal cells (BMSCs) derived from WT and T2D mice treated with or without metformin were compared in vitro and in vivo by assessing the subcutaneous ossicle formation of the BMSC implants in recipient T2D mice. In vivo treatment with metformin to T2D mice could effectively rescue the impaired differentiation potential and detrimental lineage commitment of BMSCs, caused by the hyperglycemic conditions. Moreover, the Safranin O staining of cartilage formation in the endochondral ossification under hyperglycemic condition significantly increased at day 14 post-fracture in T2D mice receiving metformin treatment. The chondrocyte transcript factor SOX9 and PGC1, important to maintain chondrocyte homeostasis, were both significantly upregulated in callus tissue isolated at the fracture site of metformin-treated MKR mice on day 12 post-fracture. Metformin also rescued the chondrocyte disc formation of BMSCs isolated from T2D mice. Taken together, our study demonstrated that metformin facilitated bone healing, bone formation and chondrogenesis in T2D mouse models.

cell biology↗

Urine proteomic characterization of active and recovered COVID-19 patients

BackgroundThe molecular changes in COVID-19 patients have been reported in many studies. However, there were limited attention has been given to the disease sequelae in the recovered COVID-19 patients. MethodsHere, we profiled the urine proteome of a cohort of 29 COVID-19 patients in their disease onset and recovery period, including mild, severe, and fatal patients and survivors who recovered from mild or severe symptoms. ResultsThe molecular changes in the COVID-19 onset period suggest that viral infections, immune response changes, multiple organ damage, cell injury, coagulation system changes and metabolic changes are associated with COVID-19 progression. The patients who recovered from COVID-19 still exhibited an innate immune response, coagulation system changes and central nervous system changes. We also proposed four potential biomarkers to monitor the whole progression period of COVID-19. ConclusionsOur findings provide valuable knowledge about the potential molecular pathological changes and biomarkers that can be used to monitor the whole period of COVID-19.

biochemistry↗

Single Nucleus Transcriptomics Reveals Pervasive Glial Activation in Opioid Overdose Cases

Dynamic interactions of neurons and glia in the ventral midbrain (VM) mediate reward and addiction behavior. We studied gene expression in 212,713 VM single nuclei from 95 human opioid overdose cases and drug-free controls. Chronic exposure to opioids left numerical proportions of VM glial and neuronal subtypes unaltered, while broadly affecting glial transcriptomes, involving 9.5 - 6.2% of expressed genes within microglia, oligodendrocytes, and astrocytes, with prominent activation of the immune response including interferon, NFkB signaling, and cell motility pathways, sharply contrasting with down-regulated expression of synaptic signaling and plasticity genes in VM non-dopaminergic neurons. VM transcriptomic reprogramming in the context of opioid exposure and overdose included 325 genes with genetic variation linked to substance use traits in the broader population, thereby pointing to heritable risk architectures in the genomic organization of the brains reward circuitry.

neuroscience↗

Redox Regulation of m6A Methyltransferase METTL3 in Human β-cells Controls the Innate Immune Response in Type 1 Diabetes

Type 1 Diabetes (T1D) is characterized by autoimmune-mediated destruction of insulin-producing {beta}-cells. Several observations have renewed interest in the innate immune system as an initiator of the disease process against {beta}-cells. Here, we show that N6-Methyladenosine (m6A) is an adaptive {beta}-cell safeguard mechanism that accelerates mRNA decay of the 2-5-oligoadenylate synthetase (OAS) genes to control the antiviral innate immune response at T1D onset. m6A writer methyltransferase 3 (METTL3) levels increase drastically in human and mouse {beta}-cells at T1D onset but rapidly decline with disease progression. Treatment of human islets and EndoC-{beta}H1 cells with pro-inflammatory cytokines interleukin-1 {beta} and interferon mimicked the METTL3 upregulation seen at T1D onset. Furthermore, m6A-sequencing revealed the m6A hypermethylation of several key innate immune mediators including OAS1, OAS2, and OAS3 in human islets and EndoC-{beta}H1 cells challenged with cytokines. METTL3 silencing in human pseudoislets or EndoC-{beta}H1 cells enhanced OAS levels by increasing its mRNA stability upon cytokine challenge. Consistently, in vivo gene therapy, to prolong Mettl3 overexpression specifically in {beta}-cells, delayed diabetes progression in the non-obese diabetic (NOD) mouse model of T1D by limiting the upregulation of Oas pointing to potential therapeutic relevance. Mechanistically, the accumulation of reactive oxygen species blocked METTL3 upregulation in response to cytokines, while physiological levels of nitric oxide promoted its expression in human islets. Furthermore, for the first time to our knowledge, we show that the cysteines in position C276 and C326 in the zinc finger domain of the METTL3 protein are sensitive to S-nitrosylation (SNO) and are significant for the METTL3 mediated regulation of OAS mRNA stability in human {beta}-cells in response to cytokines. Collectively, we report that m6A regulates human and mouse {beta}-cells to control the innate immune response during the onset of T1D and propose targeting METTL3 to prevent {beta}-cell death in T1D.

molecular biology↗