Biology subjects

Deng, M.

Publications and source records attributed to Deng, M..

At least 37 records · Page 2Linked to original sources

bioRxiv2023

Cancer initiation is influenced by sex-biased tissue environment or imbalanced hormones

There is extensive evidence of sex differences in the susceptibility and prognosis of non-reproductive cancers. In addition to external factors, biological sex bias (e.g., sex chromosomes, hormones, and immune function) is suspected to function as a selective pressure that influences the evolutionary process of carcinogenesis. However, there remains a lack of clarity concerning the extent of the effect of sex bias on carcinogenesis, as well as the underlying mechanism. In this study, we show that tissue sex bias, correlated to gonadotropin-releasing hormone, varies among tissues and is associated with two distinct age-specific patterns of cancer incidence: parallel and nonparallel. Additionally, we reveal that imbalances in estrogen receptor alpha and thyroid hormone receptors are associated with levels of hypoxia-inducible factors, which have three phases (hypoxia, hyperoxia, and "chaotic-oxia") that exist in most cancers and are linked to specific cancer subtypes, including cancers with microsatellites, the CpG island methylator phenotype, or hypermethylation. Our results suggest that sex-biased tissue environments and hormonal imbalances may influence the incidence pattern and direction of carcinogenesis, emphasizing the importance of maintaining hormonal homeostasis for cancer prevention and providing insights toward improving therapies for cancer types with hormonal imbalances. Plain English summarySex bias has been long observed in cancer susceptibility and prognosis. Hormone difference between the two sexes was believed to play a role. However, the mechanism is still largely unknown. Our study has shown that the activity of one hormone secreted from pituitary, namely gonadotropin-releasing hormone, are correlated to sex-biased tissue environment, which was speculated to influence incidence patterns of carcinogenesis. Furthermore, hormonal imbalance, particularly imbalance in receptors of estrogen and thyroid hormone, which is associated with specific cancer subtypes, was speculated to influence the direction of carcinogenesis. HighlightsO_LIThere are two distinct patterns of cancer age-specific incidence curve between the two sexes: parallel and nonparallel. C_LIO_LIThe parallel and nonparallel patterns are associated with sex bias in tissue environments which is correlated with sex-biased activity of gonadotropin-releasing hormone. C_LIO_LIThree sex-biased mutated genes: PTEN, PGM5 and LARP4B, have tissue-specific hotspot mutations which are associated with microsatellite instability (MSI), and the proportion of MSI exhibit sex bias in stomach cancer. C_LIO_LIThree hypoxia induce factors (HIFs) phases: hypoxia, hyperoxia, and "chaotic-oxia", exist in most cancers and are linked to specific cancer subtypes, including cancers with MSI, the CpG island methylator phenotype, and hypermethylation. C_LIO_LIThe phases of HIFs are associated with imbalances between estrogen receptor alpha and thyroid hormone receptors. C_LI

cancer biology↗

bioRxiv2023

Oncogenic Ras, Yki and Notch signals converge to confer clone competitiveness through Upd2

It has long been proposed that cell competition functions to remove precancerous clones. A classical model is the removal of polarity-deficient clones such as the scribble (scrib) mutant clones in Drosophila imaginal discs. The activation of Ras, Yki or Notch signaling robustly reverses the scrib mutant clonal fate from elimination to tumorous growth. Using single-cell transcriptomics techniques to profile wing imaginal discs harboring the scrib mutant clones in combination with different signals, we found that a critical converging point downstream of Ras, Yki and Notch signals is the upregulation of Upd2, which is necessary to promote tumorous growth. Unexpectedly, while Upd2 is not required for cell survival per se, Upd2-deficient clones are efficiently wiped out from epithelia, indicating that Upd2 is a previously unrecognized cell competition factor.

developmental biology↗

bioRxiv2023

A promising QTL QSns.sau-MC-3D.1 likely superior to WAPO1 for wheat spikelet number per spike shows no adverse effects on yield-related traits

Spikelet number per spike (SNS) is one of the crucial factors determining wheat yield. Thus, improving our understanding of the genes that regulate SNS could help develop higher-yielding wheat varieties. A genetic linkage map constructed using the GenoBaits Wheat 16K Panel and the 660K SNP array contained 5991 polymorphic SNP markers spanning 2813.26 cM. A total of twelve QTL for SNS were detected in the recombinant inbred line (RIL) population msf x Chuannong 16 (MC), and two of them, i.e., QSns.sau-MC-3D.1 and QSns.sau-MC-7A, were stably expressed. QSns.sau-MC-3D.1 had high LOD values ranging from 4.99 to 11.06 and explained 9.71-16.75% of the phenotypic variation. Comparison of QSns.sau-MC-3D.1 with previously reported SNS QTL suggested that it is likely a novel one. A kompetitive allele-specific PCR (KASP) marker, KASP-10, tightly linked to QSns.sau-MC-3D.1 was developed to successfully validate its effect in three segregated populations and a natural population. Genetic analysis indicated that WHEAT ORTHOLOG OFAPO1 (WAPO1) was a candidate gene for QSns.sau-MC-7A. The combined additive effect of QSns.sau-MC-3D.1 and WAP01 had a great additive effect increasing SNS by 7.10%. In addition, our results suggested that SNS is not affected by 1BL/1RS translocations in the MC RIL population. Correlation analysis between two major QTL and other agronomic traits showed that QSns.sau-MC-3D.1 was likely independent of these agronomic traits. However, the H2 haplotype of WAPO1 may affect effective tiller number and plant height. This indicated that the breeding potential of QSns.sau-MC-3D.1 is better than that of WAPO1. The geographical distribution of QSns.nsau-MC-3D.1 showed that QSns.sau-MC-3D.1 positive allele frequency was dominant in most wheat-producing regions of China and it has been positively selected among modern cultivars released in China since the 1940s. Two genes, TraesCS3D03G0222600 and TraesCS3D03G0216800, associated with SNS development were predicted in the physical interval of QSns.sau-MC-3D.1. qRT-PCR results of the two genes showed that only the expression level of TraesCS3D03G0216800 was significantly different between msf and CN16. These results enrich our understanding of the genetic basis of wheat SNS and will be useful for fine mapping and cloning of genes underlying QSns.sau-MC-3D.1, and provide a basis for marker-assisted selection breeding. Author summaryIn this study, we identified two major QTL (QSns.sau-MC-3D.1 and QSns.sau-MC-7A) in a RIL population. WAPO1 was demonstrated to be the candidate gene for QSns.sau-MC-7A. QSns.sau-MC-3D.1 was a novel and stably expressed QTL, and further confirmed in different genetic backgrounds. Our results further demonstrate that QSns.sau-MC-3D.1 has better breeding potential because of its no adverse effect on other agronomic traits than WAPO1, and it has been positively selected during Chinese breeding programs since the 1940s. Taken together, the identification of QSns.sau-MC-3D.1 offers a promising resource to further increase wheat yields.

genetics↗

bioRxiv2023

Preclinical Basis of the Efficacy and Pharmacodynamics of Finotonlimab, a Humanized Anti-PD-1 Monoclonal Antibody with Potent Implications for Clinical Benefit

BackgroundThe antibodies of programmed cell death protein 1 (PD-1) and its ligand (PD-L1) have dramatically changed the treatment landscapes for patients with cancer. Clinical uses of PD-1 antibodies have greatly improved the overall survival and durable responses in patients across selected tumor types. MethodsWe describe the preclinical characterization of Finotonlimab, a humanized anti-PD-1 antibody, by head to head comparison with Nivolumab or Pembrolizumab. Herein, we characterized the in vitro and in vivo efficacy, PK, PD and Fc mediated effector function of Finotonlimab. The single-agent anti-tumor activity of Finotonlimab was evaluated using humanized mouse models and a human PBMC reconstituted mouse model. Furthermore, in cynomolgus monkeys, comparative PK measurements confirmed better PK profiles of Finotonlimab than that of Pembrolizumab and Nivolumab. ResultsOur data showed Finotonlimab bind to human PD-1 with significantly high affinity and effectively inhibited its interaction with its ligands, PD-L1 and PD-L2, and thus could effectively stimulate the human T cell functions in vitro and exhibited significant antitumor efficacy in vivo. In addition, Finotonlimab showed minimal impact on Fc receptor dependent effector cell activation, which may contribute to the killing of PD-1+ T cells. In cynomolgus monkeys, Finotonlimab exhibited a non-linear pharmacokinetics (PK) profile in a dose-dependent manner, and approximately 90% of consistent receptor occupancy period was observed at 168 h after a single administration of 1 mg/kg. Following a 13-week successive administration of Finotonlimab, a pharmacodynamics study indicated a sustained mean receptor occupancy of [≥] 93% of PD-1 molecules on circulating T cells in cynomolgus monkeys up to 8 weeks even at 3 mg/kg. ConclusionsTaken together, these preclinical data are encouraging and provide a basis for the efficacy and pharmacodynamics of Finotonlimab in clinical trials.

immunology↗

bioRxiv2023

Establishment of primary renal lymphoma model and the clinical relevance

Extranodal dissemination was an important feature of aggressive B-cell lymphoma. Due to the lack of available animal model, the causes of extranodal dissemination of lymphoma were largely unknown. Here, we identified a novel cell line, named MA-K, which originated from the E-Myc;Cdkn2a-/- cell line, named MA-LN in this study. Compared to MA-LN, MA-K tended to disseminate in the kidney rather than lymph nodes in lymphoma transplantation model, resembling human primary renal lymphoma. The transcriptome analysis revealed that MA-K had undergone the transcriptional evolution during the culture. Specialized transcriptional pattern analysis, we proposed in this study, identified that FOXO1-BTG1-MYD88 pattern was formed in MA-K. Further analysis found that translation pathway was the most enriched pathway in specially expressed genes (SEGs) in MA-K. Among the SEGs, 3 up-regulated genes, RPLP2, RPS16 and MRPS16, and 5 down-regulated genes, SSPN, CD52, ANKRD37, CCDC82 and VPREB3, in MA-K were identified as promising biomarkers to predict the clinical outcomes of human DLBCL. Moreover, the joint expression of the 5-gene signature could effectively predict clinical outcomes of human DLBCL in triple groups. These findings suggested that the MA-K cell line had strong clinical relevance with human aggressive B-cell lymphoma. Moreover, the MA-K primary renal lymphoma model, as a novel syngenetic mouse model, would be greatly useful for both the basic research on lymphoma dissemination and preclinical efficacy evaluation of chemotherapy and immunotherapy.

cancer biology↗

bioRxiv2023

EFNB1 level affects drug response in DLBCL cell lines

Targeted therapy was a promising therapy for aggressive B-cell lymphoma. However, drug resistance was still an unavoidable problem. Here, we explored the effect of EFNB1 on drug response. Analysis of IC50 data showed that high level of EFNB1 was associated with resistance to most targeted drugs targeting BCR in human DLBCL cell lines. Drug response assay showed that Efnb1 could enhance SRC phosphorylation and increased the sensitivity of cells to SRC inhibitors. Meanwhile, Efnb1 could sensitize cells to most cytotoxic drugs, especially DOX and VCR. Efnb1 could confer cells sensitivity to VCR by enhancing the phosphorylation of Stmn1 at serine 28. Survival analysis revealed that the expression level of genes phosphorylated in Efnb1 cells were associated with poor prognosis of human DLBC. Together, this study revealed that EFNB1 level, as a non-genetic mechanism, greatly affected drug response of targeted drugs and cytotoxic drugs through the phosphorylation network. Our findings would provide important insights into EFNB1-SRC activated B-cell lymphoma and efficacy evaluation.

pharmacology and toxicology↗

bioRxiv2022

Bright and sensitive red voltage indicators for imaging action potentials in brain slices and pancreatic islets

As fast developing tools for observing cellular membrane potential, red-emitting genetically encoded voltage indicators (GEVIs) reduce auto-fluorescence background, allow multiplexed recordings, and enable all-optical electrophysiology, but have been limited by either insensitivity or dimness. Here, we report a pair of red GEVIs, Cepheid1b/s, with improved sensitivity, brightness, and photostability. Cepheid1 indicators faithfully report cellular excitability in pancreatic islets and neural activity in acute brain slices.

neuroscience↗

bioRxiv2022

Phylogenomics reveals the relationships of butterflies and moths (Lepidoptera): providing the potential landscape using universal single copy orthologues

BackgroundA robust and stable phylogenetic framework is a fundamental goal of evolutionary biology. As the third largest insect order following by Diptera and Coleoptera in the world, lepidoptera (butterflies and moths) play a central role in almost every terrestrial ecosystem as the indicators of environmental change and serve as important models for biologists exploring questions related to ecology and evolutionary biology. However, for such charismatic insect group, the higher-level phylogenetic relationships among its superfamilies are still poorly unresolved. Resultswe increased taxon sampling among Lepidoptera (40 superfamilies and 76 families contained 286 taxa) and filtered the unqualified samples, then acquired a series of large amino-acid datasets from 69,680 to 400,330 for phylogenomic reconstructions. Using these datasets, we explored the effect of different taxon sampling on tree topology by considering a series of systematic errors using ML and BI methods. Moreover, we also tested the effectiveness in topology robustness among the three ML-based models. The results showed that taxon sampling is an important determinant in tree robustness of accurate lepidopteran phylogenetic estimation. Long-branch attraction (LBA) caused by site-wise heterogeneity is a significant source of bias given rise to topologies divergence of ditrysia in phylogenomic reconstruction. Phylogenetic inference showed a most comprehensive framework by far to reveal the relationships among lepidopteran superfamilies, but limited by taxon sampling, it could only represent the current understanding of the lepidopteran tree of life. The relationships within the species-rich and relatively rapid radiation Ditrysia and especially Apoditrysia remain poorly unresolved, which need to increase taxon sampling and adopt lineage-specific genes for further phylogenomic reconstruction. ConclusionsThe present study further expands the taxon sampling of lepidopteran phylogeny and provides a potential phylogenomic foundation for further understanding its current higher-level relationships.

evolutionary biology↗

bioRxiv2022

Fat Extract Modulates Calcium Signaling and Protects Against Hyperactive Osteoclastogenesis in Bone Remodeling with Antioxidant Capacity

Osteoclasts are cells which are primarily involved in bone remodeling and osteolytic bone diseases. Hyperactive osteoclastogenesis leads to pathological bone loss and microarchitectural deterioration, particularly in postmenopausal osteoporosis. However, given the limitations of current first-line osteoclast inhibitors, there is an urgent need for a novel antiresorptive agent with higher efficiency and fewer side effects. Cell-free fat extract (CEFFE) is the liquid fraction obtained from human adipose tissues, which are enriched with a variety of cytokines and growth factors. This study aims to explore its pharmaceutical effect on hyperactive osteoclast formation in vivo and in vitro. CEFFE exhibits excellent potentials to attenuate osteoclast-associated bone loss in an ovariectomy (OVX) mouse model and to inhibit RANKL-induced osteoclastogenesis in primary bone marrow-derived monocytes. Furthermore, the cationic protein fraction of CEFFE (CEFFE-Cation) is identified as the main inhibitory component in osteoclast formation assay. Excessive reactive oxygen species (ROS) production is the main cause of osteoclast overactivation. According to LC-MS/MS analysis, the CEFFE-Cation fraction mainly consists of various antioxidant enzymes, extracellular matrix, and secreted cytokines, which endow it with a superior antioxidant capacity. Ca2+ signaling contributes to osteoclast maturation. In addition to scavenging ROS, CEFFE-Cation is also capable of mitigating Ca2+ oscillation, calcineurin activation, and subsequent NFATc1 nuclear translocation during osteoclastogenesis. Overall, this study elucidates the promising translational potential of CEFFE as a next-generation personalized antiresorptive agent for osteolytic bone disease treatment.

pathology↗

bioRxiv2022

Coevolution-based prediction of key allosteric residues for protein function regulation

Allostery is fundamental to many biological processes. Due to the distant regulation nature, how allosteric mutations, modifications and effector binding impact protein function is difficult to forecast. In protein engineering, remote mutations cannot be rationally designed without large scale experimental screen. Allosteric drugs have raised much attention due to their high specificity and possibility of overcoming existing drug-resistant mutations. However, optimization of allosteric compounds remains challenging. Here, we developed a novel computational method KeyAlloSite to predict allosteric site and to identify key allosteric residues (allo-residues) based on the evolutionary coupling model. We found that protein allosteric sites are strongly coupled to orthosteric site compared to non-functional sites. We further inferred key allo-residues by pairwise comparing the difference of evolutionary coupling scores of each residue in the allosteric pocket with the functional site. Our predicted key allo-residues are in accordance with previous experimental studies for typical allosteric proteins like BCR-ABL1, Tar and PDZ3, as well as key cancer mutations. We also showed that KeyAlloSite can be used to predict key allosteric residues distant from the catalytic site that are important for enzyme catalysis. Our study demonstrates that weak coevolutionary couplings contain important information of protein allosteric regulation function. KeyAlloSite can be applied in studying the evolution of protein allosteric regulation, designing and optimizing allosteric drugs, performing functional protein design and enzyme engineering.

biochemistry↗

bioRxiv2022

Testis-specific H2BFWT disrupts nucleosome integrity through reductions of DNA-histone interactions

During spermatogenesis, multiple testis-specific histone variants are involved in the dynamic chromatin transitions. H2BFWT is a primate testis-specific H2B variant with hitherto unclear functions, and SNPs of H2BFWT are closely associated with male non-obstructive infertility. Here, we found that H2BFWT is preferentially localized in the sub-telomeric regions and the promoters of genes highly expressed in testis from differentiated spermatogonia to early spermatocytes. Cryo-EM structural analysis shows that H2BFWT nucleosomes are defined by weakened interactions between H2A-H2BFWT dimer and H4, and between histone octamer and DNA. Furthermore, one of its SNPs, H2BFWTH100R further destabilizes nucleosomes and increases the nucleosome unwrapping rate by interfering with the interaction with H4K91. Our results suggest that H2BFWT may be necessary for the regulation of spermatogenesis-related gene expression by decreasing transcriptional barriers, and that H2BFWTH100R overdrives its nucleosome-destabilizing effects which causes infertility.

biochemistry↗

bioRxiv2021

Clustering single cell CITE-seq data with a canonical correlation based deep learning method

Single cell sequencing examines the sequence information from individual cells with optimized next generation sequencing (NGS) technologies. It provides researchers a higher resolution of cellular differences and a better understanding of the function of an individual cell in the context of its microenvironment. CITE-seq, or Cellular Indexing of Transcriptomes and Epitopes by sequencing, is one of the latest innovations in the domain of single cell sequencing. It enables researchers to simultaneously capture RNA and surface protein expression on the same cells so that we can correlate the two data types, identify biomarkers and better characterize cell phenotypes. Although multi-omics sequencing technologies developed rapidly, data analyzing methods tailored for multiomics sequencing data are lacking. Several serious problems have to be faced. An important one is how to integrate the information from different modalities, namely scRNA and protein data, efficiently. In this paper, we introduce a canonical correlation based deep learning method called scCTClust for clustering analysis over CITE-seq data. We impute and extract the characteristics of the high dimensional RNA part of data with a ZINB model-based autoencoder. A t-kernel distance is introduced to measure the similarity between query cell and cluster centroids. And the protein data rectifies the feature extraction of scRNA data in a canonical correlation analysis(CCA) way. Extensive data experiments shows that scCTClust can precisely recover the dropout values for RNA sequencing data and extract authentic information from both modalities, getting a much better clustering result than state-of-the-art methods, no matter single-omic or multi-omics clustering algorithms.

bioinformatics↗

bioRxiv2021

Portrait of a genus: the genetic diversity of Zea

Maize is a globally valuable commodity and one of the most extensively studied genetic model organisms. However, we know surprisingly little about the extent and potential utility of the genetic variation found in the wild relatives of maize. Here, we characterize a high-density genomic variation map from ~700 genomes encompassing maize and all wild taxa of the genus Zea, identifying over 65 million single nucleotide polymorphisms (SNPs), 8 million Insertion/Deletion (InDel) polymorphisms, and over one thousand novel inversions. The variation map reveals evidence of selection within taxa displaying novel adaptations such as perenniality and regrowth. We focus in detail on evidence of convergent adaptation in highland teosinte and temperate maize. This study not only indicates the key role of hormone related pathways in highland adaptation and flowering time related pathways in high latitude adaptation, but also identifies significant overlap in the genes underlying adaptations to both environments. To show how this data can identify useful genetic variants, we generated and characterized novel mutant alleles for two flowering time candidate genes. This work provides the most extensive sampling to date of the genetic diversity inherent in the genus Zea, resolving questions on evolution and identifying adaptive variants for direct use in modern breeding.

evolutionary biology↗

bioRxiv2020

The role of miR-31-5p in the development of intervertebral disk degeneration and its therapeutic potential

Intervertebral disc degeneration (IDD) refers to the abnormal response of cell-mediated progressive structural failure. In order to understand the molecular mechanism of the maintenance and destruction of the intervertebral disc, new IDD treatment methods are developed. Here, we first analyzed the key regulators of IDD through miRNA microarrays. The cell structure and morphology were discovered by Histological and radiographic. Then, the level of miR-31-5p was disclosed by qRT-PCR. The association between miR-31-5p and SDF-1/CXCR7 axis was discovered by 3'-Untranslated region (UTR) cloning and luciferase assay. The apoptosis of cells under different treatments was disclosed by Flow cytometer. The cell proliferation was discovered by EdU assay. Finally, the protein levels of SDF-1, CXCR7, ADAMTS-5, Col II, Aggrecan and MMP13 were discovered by Western blot. The results show that miR-31-5p is a key regulator of IDD and its level is down-regulated in IDD. Overexpression of miR-31-5p facilitates NP cell proliferation, inhibits apoptosis, facilitates ECM formation and inhibits the level of matrix degrading enzymes in NP cells. The SDF-1/CXCR7 axis is the direct target of miR-31-5p. miR-31-5p acts on IDD by regulating SDF-1/CXCR7. In vitro experiments further verified that the up-regulation of miR-31-5p prevented the development of IDD. In conclusion, overexpression of miR-31-5p can inhibit IDD by regulating SDF-1/CXCR7.

molecular biology↗

bioRxiv2020

PTEN Inhibition Ameliorates Muscle Degeneration and Improves Muscle Function in a Mouse Model of Duchenne Muscular Dystrophy

Duchenne Muscular Dystrophy (DMD) is caused by mutation of the muscle membrane protein dystrophin and characterized by severe degeneration of myofibers, progressive muscle wasting and loss of mobility, ultimately cardiorespiratory failure and premature death. Here we report that skeletal muscle-specific knockout (KO) of Phosphatase and tensin homolog (Pten) gene in an animal model of DMD (mdx mice) alleviates myofiber degeneration and restores muscle function without increasing tumor incidences. Specifically, Pten KO normalizes myofiber size and prevents muscular atrophy, and improves grip strength and exercise performance of mdx mice. Pten KO also reduces fibrosis and inflammation; and ameliorates muscle pathology in mdx mice. Moreover, we found that Pten KO upregulates extracellular matrix and basement membrane components positively correlated to wound healing, but suppresses negative regulators of wound healing and lipid biosynthesis; and restores the integrity of muscle basement membrane in mdx mice. Importantly, pharmacological inhibition of PTEN similarly ameliorates muscle pathology and improves muscle integrity and function in mdx mice. Our finding provides evidence that PTEN inhibition may represent a potential therapeutic strategy to restore muscle function in DMD.

developmental biology↗

bioRxiv2020

Spatial and single-cell transcriptional landscape of human cerebellar development

ABSTRACTCerebellar development and function require precise regulation of molecular and cellular programs to coordinate motor functions and integrate network signals required for cognition and emotional regulation. However, molecular understanding of human cerebellar development is limited. Here, we combined spatially resolved and single-cell transcriptomics to systematically map the molecular, cellular, and spatial composition of early and mid-gestational human cerebellum. This enabled us to transcriptionally profile major cell types and examine the dynamics of gene expression within cell types and lineages across development. The resulting ‘Developmental Cell Atlas of the Human Cerebellum’ demonstrates that the molecular organization of the cerebellar anlage reflects cytoarchitecturally distinct regions and developmentally transient cell types that are insufficiently captured in bulk transcriptional profiles. By mapping disease genes onto cell types, we implicate the dysregulation of specific cerebellar cell types, especially Purkinje cells, in pediatric and adult neurological disorders. These data provide a critical resource for understanding human cerebellar development with implications for the cellular basis of cerebellar diseases.Competing Interest StatementA.B.R, C.R., and G.Se. are shareholders of Split Bioscience.View Full Text

developmental biology↗

bioRxiv2020

CircGLCE alleviates intervertebral disc degeneration by regulating apoptosis and matrix degradation through the targeting of miR-587/STAP1

BackgroundIntervertebral disc degeneration (IDD) can induce profound global socioeconomic burdens. Recent studies have suggested that circular RNAs might have crucial functions in the progression of IDD. The purpose of this study was to identify a specific circular RNA and to investigate its regulatory mechanism in IDD. MethodsCircGLCE was selected after microarray analyses and was further analysed by RT-qPCR and FISH. After silencing CircGLCE, its function was assessed with RT-qPCR, immunofluorescence analysis and flow cytometry. Based on Sanger sequencing, miR-587 was identified as a direct target of CircGLCE, and it was further examined with RNA pulldown assays, RT-qPCR, dual luciferase assays and FISH. After silencing CircGLCE or miR-587, western blotting, immunofluorescence analysis, and flow cytometry were conducted. STAP1 was assessed by RT-qPCR and luciferase assay, and experiments with silenced and overexpressed miR-587 were performed. A rescue experiment was also included. In an IDD rat model, the in vivo effects of overexpressing CircGLCE on IDD were analysed with imaging techniques, TUNEL staining, FISH, western blotting, H&E staining and immunohistochemistry. ResultsCircGLCE was found to stably exist in the cytoplasm of nucleus pulposus (NP) cells. It was downregulated in IDD. Knockdown of CircGLCE promoted apoptosis and induced the expression of matrix-degrading enzymes in NP cells. CircGLCE served as a miR-587 sponge in NP cells. Inhibiting miR-587 counteracted the IDD-enhancing effect caused by silencing CircGLCE. STAP1 served as the miRNA target that mediated the functions of miR-587. Overexpressing CircGLCE alleviated IDD in vivo. ConclusionsCircGLCE attenuates IDD by regulating the apoptosis of NP cells and by regulating ECM degradation through the targeting of miR-587/STAP1. CircGLCE may be a potential therapeutic target for IDD treatments.

molecular biology↗

bioRxiv2020

PD-L1 upregulation by IFN-α/γ-mediated Stat1 suppresses anti-HBV T cell response

Programmed death ligand 1 (PD-L1) has been recently shown to be a major obstacle to antiviral immunity by binding to its receptor programmed death 1 (PD-1) on specific IFN-{gamma} producing T cells in chronic hepatitis B. Currently, IFN- is widely used to treat hepatitis B virus(HBV) infection, but its antiviral effect vary greatly and the mechanism is not totally clear. We found that IFN-/{gamma} induced a marked increase of PD-L1 expression in hepatocytes. Signal and activators of transcription (Stat1) was then identified as a major transcription factor involved in IFN-/{gamma}-mediated PD-L1 elevation both in vitro and in mice. Blockage of the PD-L1/PD-1 interaction by a specific mAb greatly enhanced HBV-specific T cell activity by the gp96 adjuvanted therapeutic vaccine, and promoted HBV clearance in HBV transgenic mice. Our results demonstrate the IFN-/{gamma}-Stat1-PD-L1 axis plays an important role in mediating T cell hyporesponsiveness and inactivating liver-infiltrating T cells in the hepatic microenvironment. These data raise further potential interest in enhancing the anti-HBV efficacy of IFN- and therapeutic vaccines.

molecular biology↗