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

基本信息

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
项目类别：
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&apos 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

项目摘要

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.

抽象的与微生物群失去稳态关系可能导致炎症性疾病，例如炎症性疾病肠道疾病 (IBD) 维持微生物群的稳态取决于宿主细胞的调整能力。它们响应微生物群信号的转录程序发挥作用。 IEC 作为微生物群屏障的关键作用通过将外部信号整合到各种环境中来发挥这些作用。输出适当生理反应的转录程序。 (HNF4A) 是一种核受体转录因子 (TF)，在脊椎动物消化道中高表达。在 IEC 中，HNF4A 主要充当转录激活剂，调节参与 IEC 发育的基因， HNF4A 基因位点和 HNF4A 的屏障功能、代谢和营养吸收。 GWAS 已鉴定出转录因子结合基序可用于人类 IBD 的肠道特异性敲除。 Hnf4a 在小鼠体内会导致高度渗透性自发性肠道炎症，但尚不清楚是否如此。这种表型是由于 HNF4A 在 IEC 中的内在抗炎作用或屏障缺陷导致的该项目的总体目标是了解固有层中免疫细胞的作用。 HNF4A 在家庭中维持肠道微生物群平衡并调节微生物群反应我们的实验室最近做出了重要发现，即 IEC 基因组中的 HNF4A 活性是此外，我们发现 Hnf4a 可以保护斑马鱼免受微生物群的抑制。微生物群驱动的转录转变与人类 IBD 中观察到的转录转变相关。确定了由小鼠 IEC 中的微生物群调节的增强子子集，这些增强子也受然而，HNF4A 通过作用于这些微生物来维持肠道稳态。我将测试 HNF4A 促进肠道稳态的中心假设。通过介导微生物群诱导的整个 IEC 基因组增强子活性的改变来发现微生物群的存在。在具体目标 1 中，我将 IEC 中缺乏 Hnf4a 的小鼠品系 (Hnf4aΔIEC) 推导到无菌 (GF) 条件下，以测试微生物群在 IBD 小鼠模型肠道炎症表型中的作用。从这些小鼠的原代 IEC 中产生肠样培养物，以研究 HNF4A 在介导 IEC 内在作用中的作用在具体目标 2 中，我将定义 HNF4A 在微生物群反应中的作用。使用 GF 和 ex-GF 常规化 (CV) Hnf4aΔIEC 小鼠和野生型对照的增强剂的结果。这项工作将提供创新的体内遗传证据，证实 HNF4A 作为 IEC 调节剂的作用这项研究解决了针对微生物群驱动的肠道炎症的转录程序。 HNF4A 在维持肠道微生物群稳态中的作用的关键知识差距。