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Biology subjects

Hou, G.

Publications and source records attributed to Hou, G..

At least 19 recordsLinked to original sources

EnSEMBLE: a framework for enhancer-anchored pathway analysis that locks in enhancer-corroborated pathways from transcriptome sequencing data for biological validation

Background Pathway discovery methods for transcriptome sequencing return tens to hundreds of redundant gene sets, and biologists often subjectively select the pathways fitting biological expectations. What is missing is not another statistical method, but a way to corroborate each candidate pathway against an independent, mechanistic line of evidence. Results We introduce EnSEMBLE (Enhancer-Set Enrichment & Mechanism-Based Linked Evidence), a tool that corroborates gene-level pathway enrichment with an orthogonal enhancer layer drawn from the same transcriptome sequencing data: active enhancers transcribe enhancer RNAs already present in standard RNA-seq, so a pathway's regulatory state can be scored from the very run that produced the gene-level signal, at no added cost. EnSEMBLE pairs pathway enrichments with Enhancer-Program Enrichment Analysis (EPEA), collapses redundant gene sets into process-level Themes, and retains only those that a concordant enhancer program corroborates. This dual-evidence requirement reduced reported signatures by >97% (hundreds of gene sets to 3-18 claims) across four datasets spanning cancer perturbations and iPSC-to-neuron differentiation. Surviving claims recovered expected biology--mesenchymal-program collapse upon SNAI1 knockout, regulatory convergence during neuronal differentiation--and named mechanisms pathway enrichments missed, including an mTOR-MYC-SPT5 elongation axis in rapamycin-treated PANC1 cells. A language AI agent performs narrative synthesis over deterministic statistics, with reproducibility enforced by temperature-zero inference and three-run consensus. We further provide enhancer over-representation analysis (eORA), mapping non-coding GWAS variants to the same programs to recover cell-type-selective trait associations. Conclusions EnSEMBLE shifts transcriptomic interpretation from enumerating possibilities to adjudicating evidence, yielding a compact, traceable set of enhancer-corroborated claims that identify the regulatory programs driving cellular change and prioritize them for experimental validation.

bioinformatics↗

Integration of proteogenomic analyses in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is still lack of clinically molecular subtyping and effective therapeutic strategies. Herein, a total of 46 paired tissue samples of esophageal squamous cell carcinoma (ESCC) were collected and subjected to a systematic proteogenomic evaluation. Consensus assessment of the ESCC-related transcriptomes and TCGA dataset revealed several consensual modes of gene expression related to ESCC specificity, with 8 plasma-detectable hub proteins that could discriminate ESCC from others. Three ESCC molecular subtypes were defined and validated based on proteome data, including pCC1 with activated immune response and best survival outcome, pCC2 as cell cycle subtype with relative worse outcome, and pCC3 with worst outcome that expressed more cell adhesion related proteins. Furthermore, we proposed potential therapeutic strategies for improving survival outcomes in patients with different ESCC molecular subtypes. This integrative proteogenomic analysis provided a novel view of ESCC-dependent molecular information.

cancer biology↗

DNA sequence quantitatively encodes CTCF-binding affinity at genome scale

CTCF is a central architectural protein that shapes 3D genome organization through sequence-specific DNA binding, but how DNA sequence quantitatively determines CTCF-binding strength remains poorly understood. Progress has been hampered by the lack of large, high-quality measurements of binding affinity. Here, we experimentally determine in vitro CTCF-binding affinity for 276,765 DNA sequences derived from the human genome, generating a comprehensive quantitative landscape of CTCF-DNA interactions. Leveraging these data, we develop DeepCTCF, a deep learning model that predicts CTCF-binding strength directly from DNA sequence and enables quantitative interpretation of CTCF motif grammar. Using this framework, we systematically dissect how specific sequence features modulate CTCF-binding affinity and generate quantitative predictions for disease-associated variants that alter CTCF binding. Together, this study defines general principles by which DNA sequence encodes CTCF-binding affinity and provides a quantitative framework for interpreting regulatory sequence variation. TeaserMapping how DNA encodes CTCF binding reveals quantitative rules across over 1{per thousand} of the human genome.

genomics↗

Single-Cell Genomics Elucidates Molecular Variations and Regulatory Mechanisms in Circulating Immune Cells

The human peripheral blood displays diverse molecular characteristics across populations, understanding the drivers and underlying mechanisms of which remains challenging. Here, we introduce the Chinese Immune Multi-Omics Atlas (CIMA), elucidating sex-, age-, and genetic-related molecular variations by analyzing multi-omics data from 428 adults with over 10 million immune cells. CIMA generated an enhancer-driven gene regulatory network, identifying 237 high-quality regulons and revealing cell type-specific regulatory mechanisms. Additionally, 11,521 lead cis-expression quantitative trait loci (eQTLs) and 46,339 chromatin accessibility QTLs (caQTLs) were identified at cell type level. CIMA also uncovered pleiotropic associations among immune-related disease risk loci, eQTLs, and caQTLs in a cell type-specific manner. Lastly, a novel cell language model, CIMA-CLM, was developed to predict chromatin accessibility and noncoding variant effects using chromatin sequences and gene expressions. This work represents a population-scale multi-omics resource of human immune cells, providing a valuable reference for future investigation of immune-related diseases.

immunology↗

Multi-omics Reveals Immune Response and Metabolic Profiles during High-Altitude Mountaineering

The physiological perturbations induced by high-altitude exposure in mountain climbers, manifesting as metabolic and immunologic deviations, have been previously reported but are not fully understood. In this study, we obtained longitudinal multi-omic profiles of blood samples for healthy mountain climbers during two mountaineering stages (acclimatization and extreme altitude mountaineering). Our integrative assay included metabolomics and lipidomics profiling of plasma coupled with single-cell transcriptomic analysis of 375,722 immune cells. Longitudinal analysis revealed dynamic immune response profiles, during the acclimatization period, characterized by the downregulation of inflammatory responses in monocytes and classical dendritic cells (cDCs) and an increase in the proportion of cytotoxic CD8+ T cells with enhanced immune effector processes. In contrast, during extreme altitude mountaineering, the activation of inflammatory responses and impairment of T cell effector function were observed, concomitant with an increased cellular response to hypoxia and oxidative stress pathways. Furthermore, we found upregulated glycolysis and antioxidant gene expression during extreme altitude mountaineering, which was primarily orchestrated by HIF1A and NFE2L2, while decreased expression of these genes was observed in dysregulated plasmacytoid dendritic cells (pDCs). Finally, high-resolution plasma metabolic analysis revealed significant alterations in the metabolism of climbers, involving enhanced glutamine and fatty acid metabolism.

bioinformatics↗

Inflammation induced Th17 cells synergize with the inflammation-trained microbiota to mediate host-resiliency against intestinal injury

Background and AimsInflammation can generate pathogenic Th17 cells and cause a inflammatory dysbiosis. In the context of Inflammatory Bowel Disease (IBD) these inflammatory Th17 cells and dysbiotic microbiota may perpetuate injury to intestinal epithelial cells (IECs). However, many models of IBD like T-cell transfer colitis and IL-10-/- mice rely on the absence of regulatory pathways, so it is difficult to tell if inflammationcan also induce protective Th17 cells. MethodsWe subjected C57BL6, RAG1-/- or JH-/- mice to systemic or gastrointestinal (GI) Citrobacter rodentium (Cr). Mice were then subject to 2.5% dextran sodium sulfate to cause epithelial injury. Fecal microbiota transfer was performed by bedding transfer and co-housing. Flow cytometry, qPCR, 16s sequencing and histology were used to assess parameters. ResultsTransient inflammation with GI but not systemic Cr was protective from subsequent intestinal injury. This was replicated with sequential DSS collectively indicating that transient inflammation provides tissue-specific protection. Inflammatory Th17 cells that have a tissue resident memory signature expanded in the intestine. Experiments with reconstituted RAG1-/-, JH-/- mice and cell trafficking inhibitors showed that inflammation induced Th17 cells were required for protection. Fecal microbiota transfer showed that the inflammation-trained microbiota was necessary for protection, likely by maintaining protective Th17 cells in situ. ConclusionInflammation can generate protective Th17 cells which synergize with the inflammation-trained microbiota to provide host resiliency against subsequent injury, indicating that inflammation induced Th17 tissue resident memory T cells are heterogenous and contain protective subsets.

immunology↗

IL-15 promotes inflammatory Th17 cells in the intestine

Ulcerative Colitis (UC) is a chronic gastrointestinal condition with high morbidity. While modern medical therapies have revolutionized the care of UC, 10-25% of patients fail medications and still progress to surgery. Thus, developing new treatments is a core problem in UC. T-cells, especially Th17 cells, are strongly linked with UC and are major targets of medications in UC. Tissue-resident memory T-cells (TRM) are a distinct class of T-cells that are highly enriched in the intestine, closely aligned with the microbiota, and are implicated in the pathogenesis of UC. Unlike circulating T-cells, TRM are difficult to target because they do not recirculate. Thus, we focused on cytokines like IL-15 which act as a tissue danger signal and regulate T-cells in situ. We found that the IL15 axis is upregulated in UC and predicts treatment response. IL-15 was redundant for Th17 differentiation but could activate terminally differentiated Th17 cells to promote intestinal inflammation. Finally, in CD4+ TRM from patients with UC, IL-15 upregulated RORC, the master transcription factor for Th17 cells, via a Janus Kinase (JAK)1 pathway. Thus, IL-15 promotes terminally differentiated inflammatory Th17 cells in the intestine raising the possibility that IL-15 may be a target for UC treatments.

immunology↗

Screening and identification of two pheromone receptors based on the coadaptation of pheromones and their receptors in rats

The coadaptation or genetic coupling of senders and receivers of sex signals in some animals has been described, but no empirical evidence shows whether sex pheromones and their receptors undergo coadaptation in mammals. In this study of the brown rat (Rattus norvegicus), we found markedly higher levels of two predominant male pheromones (2-heptanone and MUP13) in the North China subspecies [R. n. humiliatus (RNH)] than in the Northeast China subspecies [R. n. caraco (RNC)] by gas or liquid chromatography and mass spectrometry. Coincidently, two vomeronasal receptor genes (Vom1r68 and Vom2r53) were found to be expressed at higher levels in RNH females than in RNC females and were thus considered candidate receptors for 2-heptanone and MUP13, respectively. An immunofluorescence analysis showed that these two VR receptors colocalized with mTmG on the membrane of HEK293-T cells. We also verified the responsiveness of Vom1r68 to 2-heptanone and Vom2r53 to MUP13 in HEK293-T cells by calcium imaging. In conclusion, we screened and identified the receptors of two pheromones based on the coadaptation of pheromones and their receptors, which further verified their coevolution.

neuroscience↗

A recombinant murine rotavirus with Nano-Luciferase expression reveals tissue tropism, replication dynamics, and virus transmission

Rotaviruses (RVs) are one of the main causes of severe gastroenteritis, diarrhea, and death in children and young animals. Although suckling mice prove to be highly useful small animal models of RV infection and pathogenesis, direct visualization tools are lacking to track the temporal dynamics of RV replication and transmissibility in vivo. Here, we report the generation of the first recombinant murine RV that encodes a Nano-Luciferase reporter (NLuc) using a newly optimized RV reverse genetics system. The NLuc-expressing RV was replication-competent in cell culture and both infectious and virulent in neonatal mice in vivo. Strong luciferase signals were detected in the proximal and distal small intestines, colon, and mesenteric lymph nodes. We showed, via a noninvasive in vivo imaging system, that RV intestinal replication peaked at day 2 and day 5 post infection. Moreover, we successfully tracked RV transmission to uninoculated littermates as early as 3 days post infection, 1 day prior to clinically apparent diarrhea and 3 days prior to detectable fecal RV shedding in the uninoculated littermates. We also observed significantly increased viral replication in Stat1 knockout mice that lack the host interferon signaling. Our results suggest that the NLuc RV represents a non-lethal powerful tool for the studies of tissue tropism and host and viral factors that regulate RV replication and spread, as providing a new mechanism to facilitate the testing of prophylactic and therapeutic interventions in the future.

microbiology↗

Nrf2 prevents diabetic cardiomyopathy via antioxidation and normalization of glucose and lipid metabolism in the heart

ObjectiveMetabolic disorders and oxidative stress are the main causes of diabetic cardiomyopathy. Activation of nuclear factor erythroid 2-related factor 2 (Nrf2) exerts a powerful antioxidant effect and prevents the progression of diabetic cardiomyopathy. However, the mechanism of its cardiac protection and direct action on cardiomyocytes are not well understood. MethodsIn this study, cardiomyocyte-restricted Nrf2 transgenic mice (Nrf2-TG) were used to directly observe whether cardiomyocyte-specific overexpression of Nrf2 can prevent diabetic cardiomyopathy and correct glucose and lipid metabolism disorders in the heart. ResultsCompared to wild-type (WT) mice, Nrf2-TG mice showed resistance to diabetic cardiomyopathy in a streptozotocin (STZ)-induced type 1 diabetes mouse model. This was primarily manifested as improved echocardiography results as well as reduced myocardial fibrosis, cardiac inflammation, and oxidative stress. ConclusionThese results showed that Nrf2 can directly act on cardiomyocytes to play a cardioprotective role. Mechanistically, the cardioprotective effects of Nrf2 depend on its antioxidation activity, partially through improving glucose and lipid metabolism by targeting the metabolic pathways of Akt/GSK-3 {beta}/HK-II and AMPK/Sirt1/PGC-1.

molecular biology↗

m6A modifications regulate intestinal immunity and rotavirus infection

N6-methyladenosine (m6A) is an abundant mRNA modification and affects many biological processes. However, how m6A levels are regulated during physiological or pathological processes such as virus infections, and the in vivo function of m6A in the intestinal immune defense against virus infections are largely unknown. Here, we uncover a novel antiviral function of m6A modification during rotavirus (RV) infection in small bowel intestinal epithelial cells (IECs). We found that rotavirus infection induced global m6A modifications on mRNA transcripts by down-regulating the m6a eraser ALKBH5. Mice lacking the m6A writer enzymes METTL3 in IECs (Mettl3{Delta}IEC) were resistant to RV infection and showed increased expression of interferons (IFNs) and IFN-stimulated genes (ISGs). Using RNA-sequencing and m6A RNA immuno-precipitation (RIP)-sequencing, we identified IRF7, a master regulator of IFN responses, as one of the primary m6A targets during virus infection. In the absence of METTL3, IECs showed increased Irf7 mRNA stability and enhanced type I and III IFN expression. Deficiency in IRF7 attenuated the elevated expression of IFNs and ISGs and restored susceptibility to RV infection in Mettl3{Delta}IEC mice. Moreover, the global m6A modification on mRNA transcripts declined with age in mice, with a significant drop from 2 weeks to 3 weeks post birth, which likely has broad implications for the development of intestinal immune system against enteric viruses early in life. Collectively, we demonstrated a novel host m6A-IRF7-IFN antiviral signaling cascade that restricts rotavirus infection in vivo.

immunology↗

IntroSpect: motif-guided immunopeptidome database building tool to improve the sensitivity of HLA binding peptide identification

Although database search tools originally developed for shotgun proteome have been widely used in immunopeptidomic mass spectrometry identifications, they have been reported to achieve undesirably low sensitivities and/or high false positive rates as a result of the hugely inflated search space caused by the lack of specific enzymic digestions in immunopeptidome. To overcome such a problem, we have developed a motif-guided immunopeptidome database building tool named IntroSpect, which is designed to first learn the peptide motifs from high confidence hits in the initial search and then build a targeted database for refined search. Evaluated on three representative HLA class I datasets, IntroSpect can improve the sensitivity by an average of 80% comparing to conventional searches with unspecific digestions while maintaining a very high accuracy ([~]96%) as confirmed by synthetic validation experiments. A distinct advantage of IntroSpect is that it does not depend on any external HLA data so that it performs equally well on both well-studied and poorly-studied HLA types, unlike a previously developed method SpectMHC. We have also designed IntroSpect to keep a global FDR that can be conveniently controlled, similar to conventional database search engines. Finally, we demonstrate the practical value of IntroSpect by discovering neoantigens from MS data directly. IntroSpect is freely available at https://github.com/BGI2016/IntroSpect.

bioinformatics↗

The transcription factor Zeb2 drives differentiation of age-associated B cells

Age-associated B-cells (ABCs) accumulate during infection, aging and autoimmunity, contributing to lupus pathogenesis. Here, we screen for transcription factors driving ABC formation and find Zeb2 is required for human and mouse ABC differentiation in-vitro. ABCs are reduced in ZEB2 haploinsufficient individuals and in mice lacking Zeb2 in B-cells. In mice with TLR7-driven lupus, Zeb2 is essential for ABC formation and autoimmune pathology. Zeb2 binds to the +20kb intronic enhancer of Mef2b, repressing Mef2b-mediated germinal center B-cell differentiation and promoting ABC formation. Zeb2 also targets genes important for ABC specification and function including Itgax. Zeb2-driven ABC differentiation requires Jak-Stat signaling, and treatment with the Jak1/3 inhibitor tofacitinib reduces ABC accumulation in autoimmune mice and patients. Zeb2 thus emerges as a driver of B-cell autoimmunity. One-Sentence SummaryZeb2 is essential for Age-associated B cells differentiation and function.

immunology↗

Rotavirus NSP1 contributes to intestinal viral replication, pathogenesis, and transmission

Rotavirus (RV)-encoded non-structural protein 1 (NSP1), the product of gene segment 5, effectively antagonizes host interferon (IFN) signaling via multiple mechanisms. Recent studies with the newly established RV reverse genetics system indicate that NSP1 is not essential for the replication of simian RV SA11 strain in cell culture. However, the role of NSP1 in RV infection in vivo remains poorly characterized due to the limited replication of heterologous simian RVs in the suckling mouse model. Here, we used an optimized reverse genetics system and successfully recovered recombinant murine RVs with or without NSP1 expression. While the NSP1-null virus replicated comparably with the parental murine RV in IFN-deficient and IFN-competent cell lines in vitro, it was highly attenuated in 5-day-old wild-type suckling pups. In the absence of NSP1 expression, murine RV had significantly reduced replication in the ileum, systemic spread to mesenteric lymph nodes, fecal shedding, diarrhea occurrence, and transmission to uninoculated littermates. Of interest, the replication and pathogenesis defects of NSP1-null RV were only minimally rescued in Stat1 knockout pups, suggesting that NSP1 facilitates RV replication in an IFN-independent manner. Our findings highlight a pivotal function of NSP1 during homologous RV infections in vivo and identify NSP1 as an ideal viral protein for targeted attenuation for future vaccine development. IMPORTANCERotavirus remains one of the most important causes of severe diarrhea and dehydration in young children worldwide. Although NSP1 is dispensable for rotavirus replication in cell culture, its exact role in virus infection in vivo remains unclear. In this study, we demonstrate that in the context of a fully replication-competent, pathogenic, and transmissible murine rotavirus, loss of NSP1 expression substantially attenuated virus replication in the gastrointestinal tract, diarrheal disease, and virus transmission in suckling mice. Notably, the NSP1-deficient murine rotavirus also replicated poorly in mice lacking host interferon signaling. Our data provide the first piece of evidence that NSP1 is essential for murine rotavirus replication in vivo, making it an attractable target for developing improved next-generation rotavirus vaccines better suited for socioeconomically disadvantaged and immunocompromised individuals.

microbiology↗

CRISPRa screen on a genetic risk locus shared by multiple autoimmune diseases identifies a dysfunctional enhancer that affects IRF8 expression through cooperative lncRNA and DNA methylation machinery

Dysregulated transcription factors represent a major class of drug targets that mediate the abnormal expression of many critical genes involved in SLE and other autoimmune diseases. Although strong evidence suggests that natural human genetic variation affects basal and inducible gene expression, it is still a considerable challenge to establish a biological link between GWAS-identified non-coding genetic risk variants and their regulated gene targets. Here, we combine genetic data, epigenomic data, and CRISPR activation (CRISPRa) assays to screen for functional variants regulating IRF8 expression. Using CRISPR-mediated deletion and 3D chromatin structure analysis, we demonstrate that the locus containing rs2280381 is a cell-type-specific distal enhancer for IRF8 that spatially interacts with the IRF8 promoter. Further, rs2280381 mediates IRF8 expression through enhancer RNA AC092723.1, which recruits TET1 to the IRF8 promoter to modulate IRF8 expression by affecting methylation levels. The alleles of rs2280381 modulate PU.1 binding and chromatin state to differentially regulate AC092723.1 and IRF8 expression. Our work illustrates a strategy to define the functional genetic variants modulating transcription factor gene expression levels and identifies the biologic mechanism by which autoimmune diseases risk genetic variants contribute to the pathogenesis of disease.

genetics↗

Reverse-transcription recombinase-aided amplification assay for H5 subtype avian influenza virus

The H5 subtype Avian Influenza Virus has caused huge economic losses to the poultry industry and is a threat to human health. A rapid and simple test is needed to confirm infection in suspected cases during disease outbreaks. In this study, we developed a reverse-transcription recombinase-aided amplification assay for the detection of H5 subtype avian influenza virus. Assays were performed at a single temperature (39{degrees}C), and the results were obtained within 20 min. The assay showed no cross-detection with Newcastle disease virus or infectious bronchitis virus. The analytical sensitivity was 103 RNA copies per reaction at a 95% confidence interval according to probit regression analysis, with 100% specificity. Compared with published reverse-transcription quantitative real-time polymerase chain reaction assays, the {kappa} value of the reverse transcription recombinase-aided amplification assay in 365 avian clinical samples was 0.970 (p < 0.001). The sensitivity for avian clinical sample detection was 94.44% (95%CI, 70.63% - 99.71%), and the specificity was 100% (95%CI, 98.64% - 100%). These results indicated that our reverse-transcription recombinase-aided amplification assay may be a valuable tool for detecting H5 subtype avian influenza virus.

molecular biology↗

Nitazoxanide and JIB-04 have broad-spectrum antiviral activity and inhibit SARS-CoV-2 replication in cell culture and coronavirus pathogenesis in a pig model

Pathogenic coronaviruses represent a major threat to global public health. Here, using a recombinant reporter virus-based compound screening approach, we identified several small-molecule inhibitors that potently block the replication of the newly emerged severe acute respiratory syndrome virus 2 (SARS-CoV-2). Among them, JIB-04 inhibited SARS-CoV-2 replication in Vero E6 cells with an EC50 of 695 nM, with a specificity index of greater than 1,000. JIB-04 showed in vitro antiviral activity in multiple cell types against several DNA and RNA viruses, including porcine coronavirus transmissible gastroenteritis virus. In an in vivo porcine model of coronavirus infection, administration of JIB-04 reduced virus infection and associated tissue pathology, which resulted in improved weight gain and survival. These results highlight the potential utility of JIB-04 as an antiviral agent against SARS-CoV-2 and other viral pathogens.

microbiology↗

Cholesterol 25-hydroxylase suppresses SARS-CoV-2 replication by blocking membrane fusion

Cholesterol 25-hydroxylase (CH25H) is an interferon-stimulated gene (ISG) that shows broad antiviral activities against a wide range of enveloped viruses. Here, using an ISG screen against VSV-SARS-CoV and VSV-SARS-CoV-2 chimeric viruses, we identified CH25H and its enzymatic product 25-hydroxycholesterol (25HC) as potent inhibitors of virus replication. Mechanistically, internalized 25HC accumulates in the late endosomes and blocks cholesterol export, thereby restricting SARS-CoV-2 spike protein catalyzed membrane fusion. Our results highlight a unique antiviral mechanism of 25HC and provide the molecular basis for its possible therapeutic development.

microbiology↗