Identifying genes required for digestive physiology and lipid metabolism

识别消化生理学和脂质代谢所需的基因

基本信息

批准号：
10223272
负责人：
STEVEN A FARBER
金额：
$ 63.64万
依托单位：
CARNEGIE INSTITUTION OF WASHINGTON, D.C.
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-09-01 至 2023-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10223272
关键词：
Acinetobacter Address Animals Apolipoproteins B Automobile Driving Bacteria Binding Biological Assay Blood Circulation CREB1 gene Calcium Cardiovascular system Cell physiology Cells Cellular Morphology Chylomicrons Consumption Diabetes Mellitus Dietary Fats Dietary Fatty Acid Digestion Digestive Physiology Distal Endoplasmic Reticulum Enterocytes Enteroendocrine Cell Enzymes Epithelial Cells Esters Etiology Fatty Acids Fatty acid glycerol esters Feedback Funding Gene Expression Gene Expression Regulation Genes Genetic Transcription Germ-Free Gnotobiotic Health High Fat Diet Hormones Human Image Impairment Incidence Ingestion Intestinal Absorption Intestines Knowledge Larva Lead Lipase Lipid Inclusion Lipids Lipolysis Lipoproteins Mediating Metabolic Diseases Methods Mission Molecular Mus Nonesterified Fatty Acids Nutrient Organ Outcome Pathway interactions Process Production Reaction Time Reporter Research Resistance Resolution Route Sensory Severities Signal Pathway System Testing Tissues Transgenic Organisms Triglycerides United States National Institutes of Health Up-Regulation Work Zebrafish absorption burden of illness cost efficient design dietary endoplasmic reticulum stress enzyme pathway gut microbiota host microbiota in vivo in vivo imaging inhibitor/antagonist intestinal epithelium lipid metabolism microbial microbiota mortality mutant novel particle programs response tool transcription factor uptake

项目摘要

Intestinal absorption of dietary nutrients is an important process contributing to the etiology of multiple metabolic diseases in humans. An animal’s response to a high-fat meal requires coordination between digestive tissues and intestinal microbiota. Enterocytes (EC) are the absorptive cells of the intestine that prepare lipids for circulation to distal tissues in Apolipoprotein B (ApoB)-containing lipoproteins. Sensory enteroendocrine cells (EEC) communicate nutrient information to other cells and tissues via calcium- dependent hormone release. However, the transcriptional and signaling pathways mediating EC and EEC postprandial responses to a high-fat meal are unclear, and how microbiota influence these interactions is unknown. To address these knowledge gaps, our research team has pioneered the zebrafish system for studies of lipid metabolism and host-microbiota interaction. This includes (1) novel methods to image digestive organ lipid uptake, transport and storage, (2) the first reporter line to quantify the size and numbers of ApoB- containing lipoproteins from vanishing small amounts of material, (3) a fluorescent indicator of EEC activity that permits analysis of in vivo real-time responses to dietary nutrients, and (4) methods for cost-efficient gnotobiotic manipulation. Leveraging these tools for high-resolution in vivo imaging only possible in the larval zebrafish, we have uncovered a dynamic integrative pathway underlying EC, EEC, and microbial postprandial responses to dietary lipids. This includes early postprandial interactions in EC between a host transcription factor and the lipoprotein synthesis enzyme pathway, and late postprandial adaptive responses by EEC that are mediated by microbiota. The objective of this proposal is to define the molecular mechanisms underlying these EC and EEC postprandial responses to dietary lipid, and the specific steps controlled by microbiota. We will test the central hypothesis that microbiota promote lipolysis of dietary fat into fatty acids that are absorbed by EC leading to activation of a transcriptional program and synthesis of ApoB-containing lipoprotein particles, which are collectively perceived by EEC to alter their activity. This competitive renewal leverages long-standing partnerships between three field-leading labs with a powerful set of mutant and novel transgenic reporter lines developed during the prior funding period. The expected outcomes of the proposed research are expected to have a significant impact because they are likely to lead to new strategies for rationally manipulating EC, EEC, and microbiota interactions and responses to dietary fat which could be used to reduce incidence and severity of metabolic diseases in humans.

肠道吸收膳食营养素是导致人类多种代谢疾病的一个重要过程，动物对高脂肪膳食的反应需要消化组织和肠道微生物群 (EC) 之间的协调。含有载脂蛋白 B (ApoB) 的脂蛋白，准备循环至远端组织的脂质。感觉肠内分泌细胞 (EEC) 通过钙传递营养信息至其他细胞和组织。然而，介导 EC 和 EEC 对高脂肪膳食的餐后反应的转录和信号通路尚不清楚，并且微生物群如何影响这些相互作用也是未知的。脂质代谢和宿主-微生物群相互作用的研究，包括 (1) 对消化器官脂质摄取、运输和储存进行成像的新方法，(2) 第一个定量来自 ApoB 的脂蛋白的大小和数量的报告线。消失少量的物质，(3) EEC 活性的荧光指示器允许分析体内对膳食营养素的实时反应，以及 (4) 具有成本效益的无菌操作方法，利用这些工具进行高分辨率的体内操作。通过仅在斑马鱼幼体中进行成像，我们发现了 EC、EEC 和微生物对膳食脂质的餐后反应的动态整合途径，这包括宿主之间 EC 的早期餐后相互作用。转录因子和脂蛋白合成酶途径，以及微生物群介导的 EEC 餐后晚期适应性反应。该提案的目的是确定这些 EC 和 EEC 餐后对饮食脂质反应的分子机制，以及由微生物群介导的餐后晚期适应性反应。我们将测试核心假设，即微生物群促进膳食脂肪脂解为脂肪酸，脂肪酸被 EC 吸收，从而激活转录程序并合成含有 ApoB 的脂蛋白颗粒，从而EEC 一致认为，这种竞争性更新利用了三个领域领先实验室之间的长期合作关系，以及在先前资助期间开发的一组强大的突变体和新型转基因报告基因系。预计将产生重大影响，因为它们可能会产生合理操纵 EC、EEC 和微生物群相互作用以及对膳食脂肪的反应的新策略，从而降低人类代谢疾病的发病率和严重程度。