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：
10348645
负责人：
Cecelia Kelly
金额：
$ 3.87万
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/10348645
关键词：
Acetylation Address Anti-Inflammatory Agents Autoimmune Diseases Binding Binding Sites Biological Markers Cecum Cells ChIP-seq Chemicals Chromatin Chronic Colitis Colon Colonic inflammation Complex Crohn&apos s disease Data Defect Development Disease Enhancers Environmental Risk Factor Epithelial Epithelial Cells 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 Persons 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 inflammation gut microbiota host microbiome human model immune activation in vivo 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.

抽象的与微生物群的体内平衡关系的丧失会导致炎症性疾病，例如炎症肠病（IBD）。预测宿主细胞调整能力的能力可以预测与菌群保持体内平衡他们的转录程序是针对微生物群信号的响应。肠上皮细胞（IEC）服务作为对微生物群的障碍的关键作用。 IEC通过将外部信号集成到各种输出适当生理反应的转录程序。肝细胞核因子4α （HNF4A）是一种核受体转录因子（TF），在脊椎动物消化道中高度表达。在IEC中，HNF4A主要充当参与IEC开发的转录激活因子基因，障碍功能，代谢和营养滥用。 HNF4A基因基因座和HNF4A的遗传变异转录因子结合基序已在GWAS中的人IBD中鉴定出来。肠道特定的淘汰小鼠中的HNF4A导致高度渗透的赞助肠炎。但是，未知是否该表型是由于HNF4A在IEC或屏障缺陷中的固有抗炎作用引起的固有椎板中免疫细胞的激活。该项目的总体目的是了解 HNF4A在肠内维持微生物群维持稳态和调节微生物群反应 IEC中的增强剂。我们的实验室最近提出了一个关键发现，IEC基因组中的HNF4A活动是在小鼠和斑马鱼中被微生物群抑制。此外，我们发现HNF4A保护斑马鱼免受微生物群驱动的转录移位与人IBD中看到的转录移位相关。我们也是确定了由小鼠IEC中微生物群调节的增强子的子集 HNF4A。然而增强剂是未知的。我将测试HNF4A促进肠内稳态的中心假设通过介导微生物群诱导的IEC基因组增强子活性的改变来存在微生物群。在特定的目标1中，我将在IEC（HNF4AΔIEC）中缺乏HNF4A的小鼠菌株为无胚膜（GF）条件测试微生物群在该小鼠IBD模型的肠道注射表型中的作用。另外，我会的从这些小鼠的主要IEC产生肠培养物，以研究HNF4A在介导IEC固有中的作用体外对微生物群的反应。在特定目标2中，我将定义HNF4A在微生物群中的作用使用GF和EX-GF常规（CV）HNF4AΔIEC小鼠和野生型对照的增强子。结果这项工作将提供创新的体内遗传证据，以确立HNF4A作为IEC中介的作用转录程序可以防止微生物群驱动的肠道注射。这项研究解决了 HNF4A在维持肠内稳态中的作用的关键知识差距。