The role of HNF4a in maintaining intestinal epithelial cell homeostasis in the presence of microbes

HNF4a 在微生物存在下维持肠上皮细胞稳态的作用

• 批准号: 9911109
• 负责人: Cecelia Kelly
• 金额: $ 3.75万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2023-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9911109
• 关键词: Acetylation; Address; Anti-Inflammatory Agents; Autoimmune Diseases; Binding; Binding Sites; Biological Markers; Cecum; Cells; ChIP-seq; Chemicals; Chromatin; Chronic; Colitis; Colon; Complex; Crohn' s disease; Data; Defect; Development; Disease; Enhancers; Environmental Risk Factor; Epithelial; Epithelial Cells; Epithelium; Etiology; Family; Gastroenterology; Gastrointestinal tract structure; Gene Expression; Gene Expression Profile; Genes; Genetic; Genetic Polymorphism; Genetic Transcription; Genome; Genomics; Germ Cells; Germ-Free; Gnotobiotic; Goals; HNF4A gene; Health; Histologic; Histones; Homeostasis; Human; Immune; In Vitro; Inflammation; Inflammatory; Inflammatory Bowel Diseases; Inflammatory Response; Intestines; Kidney; Knock-out; Knowledge; Lamina Propria; Lead; Link; Liver; Lysine; Maintenance; Mediating; Mediator of activation protein; Metabolism; Microbe; Mission; Mouse Strains; Mus; Natural Immunity; Nuclear Receptors; Nucleic Acid Regulatory Sequences; Orthologous Gene; Outcome; Output; Pancreas; Pathogenesis; Patients; Pattern; Phenotype; Physiological; Public Health; Regulation; Research; Role; Scientist; Signal Transduction; Small Intestines; Stimulus; Testing; Tissues; Training; Transcription Coactivator; Transcriptional Regulation; Ulcerative Colitis; United States National Institutes of Health; Work; Zebrafish; bacterial lysate; burden of illness; career; cell type; gene repression; genetic variant; genome wide association study; genomic locus; germ free condition; gut microbiota; host microbiome; human model; immune activation; in vivo; inflammatory disease of the intestine; innovation; intestinal crypt; intestinal epithelium; intestinal homeostasis; microbial; microbial colonization; microbiome; microbiota; microorganism; monolayer; mouse model; mutant; nutrient absorption; programs; response; skills; transcription factor; transcriptome sequencing

Abstract Loss of homeostatic relationships with microbiota can result in inflammatory diseases such as the inflammatory bowel diseases (IBD). Maintaining homeostasis with microbiota is predicated on the ability of host cells to adjust their transcriptional programs in response to signals from microbiota. Intestinal epithelial cells (IECs) serve critical roles as a barrier against microbiota. IECs perform these roles by integrating external signals into various transcriptional programs which output appropriate physiologic responses. Hepatocyte nuclear factor 4 alpha (HNF4A) is a nuclear receptor transcription factor (TF) that is highly expressed in the vertebrate digestive tract. In IECs, HNF4A acts predominantly as a transcriptional activator regulating genes involved in IEC development, barrier function, metabolism, and nutrient absorption. Genetic variants at the HNF4A gene locus and HNF4A transcription factor binding motifs have been identified in GWAS for human IBD. Intestine specific knockout of Hnf4a in mice results in highly penetrant spontaneous intestinal inflammation. However, it is unknown whether this phenotype is due to intrinsic anti-inflammatory roles for HNF4A in IECs or barrier defects that result in activation of immune cells in the lamina propria. The overall objective of this project is to understand the role of HNF4A in maintaining homeostasis with microbiota in the intestine and in regulating microbiota-responsive enhancers in IECs. Our lab recently made the key discovery that HNF4A activity in the IEC genome is suppressed by microbiota in mice and zebrafish. Additionally we found that Hnf4a protects zebrafish from a microbiota-driven transcriptional shift which correlates with transcriptional shifts seen in human IBD. We also identified a subset of enhancers that are regulated by the microbiota in mouse IECs, which are also bound by HNF4A. However the role of HNF4A in maintaining intestinal homeostasis with microbiota by acting on these enhancers is unknown. I will test the central hypothesis that HNF4A promotes intestinal homeostasis in the presence of microbiota by mediating microbiota-induced alterations in enhancer activity across the IEC genome. In Specific Aim 1, I will derive a mouse strain lacking Hnf4a in IECs (Hnf4aΔIEC) into germ free (GF) conditions to test the role of microbiota in the intestinal inflammation phenotype of this mouse model of IBD. Additionally, I will generate enteroid cultures from primary IECs of these mice to study the role of HNF4A in mediating IEC intrinsic responses to microbiota in vitro. In Specific Aim 2, I will define the role of HNF4A at microbiota responsive enhancers using GF and ex-GF conventionalized (CV) Hnf4aΔIEC mice and wild-type controls. The outcomes of this work will provide innovative in vivo genetic evidence establishing the role of HNF4A as a mediator of IEC transcriptional programs protective against microbiota-driven intestinal inflammation. This research addresses a critical knowledge gap of the role of HNF4A in maintaining intestinal homeostasis with microbiota.

摘要 与微生物群的稳态关系的丧失可导致炎性疾病，如炎性微生物群。 肠道疾病（IBD）。维持微生物群的稳态是基于宿主细胞的调节能力， 它们的转录程序响应来自微生物群的信号。肠上皮细胞（IEC） 作为微生物的屏障。IEC通过将外部信号集成到各种 转录程序输出适当的生理反应。肝细胞核因子4 α HNF 4A是一种在脊椎动物消化道中高度表达的核受体转录因子。 在IEC中，HNF 4A主要作为转录激活因子调节参与IEC发育的基因， 屏障功能、代谢和营养吸收。HNF 4A基因座的遗传变异和HNF 4A 已经在人IBD的GWAS中鉴定了转录因子结合基序。肠特异性敲除 hnf 4a在小鼠中导致高度渗透性自发性肠道炎症。然而，不知道是否 这种表型是由于HNF 4A在IEC中的内在抗炎作用或导致 激活固有层中的免疫细胞。本项目的总体目标是了解 HNF 4A在维持肠道微生物群的稳态和调节微生物群反应性中的作用 IEC中的增强子。我们的实验室最近取得了关键发现，即IEC基因组中的HNF 4A活性是 在小鼠和斑马鱼中被微生物群抑制。此外，我们发现Hnf 4a可以保护斑马鱼免受 微生物群驱动的转录转变，其与在人IBD中观察到的转录转变相关。我们也 确定了一个由小鼠IEC中的微生物群调节的增强子子集，这些增强子也被 HNF4A。然而，HNF 4A通过作用于这些微生物群来维持肠道内稳态的作用是不确定的。 增强剂未知。我将检验HNF 4A促进肠道稳态的中心假设 通过介导微生物群诱导的IEC基因组中增强子活性的改变来调节微生物群的存在。 在具体目标1中，我将IEC中缺乏Hnf 4a的小鼠品系（Hnf 4a ΔIEC）衍生到无菌（GF）条件下， 测试微生物群在IBD小鼠模型的肠道炎症表型中的作用。另外，我将 从这些小鼠的原代IEC产生肠样培养物，以研究HNF 4A在介导IEC内在 对体外微生物群的反应。在具体目标2中，我将定义HNF 4A在微生物群反应中的作用。 使用GF和ex-GF常规化（CV）Hnf 4a ΔIEC小鼠和野生型对照，使用增强子进行增强。的成果 这项工作将提供创新的体内遗传学证据，确定HNF 4A作为IEC介导者的作用 转录程序保护免受微生物驱动的肠道炎症。这项研究涉及一个 HNF 4A在维持肠道菌群稳态中的作用的关键知识缺口。