The Role of DENND5B in Dietary Lipid Absorption

DENND5B 在膳食脂质吸收中的作用

• 批准号: 10661074
• 负责人: Scott M Gordon
• 金额: $ 51.19万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-15 至 2027-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10661074
• 关键词: AGFG1 gene; Acute; Address; Affect; Apolipoproteins B; Atherosclerosis; Autophagocytosis; Biogenesis; Bioinformatics; Body Composition; Body mass index; Cardiometabolic Disease; Cardiovascular Diseases; Cell membrane; Cells; Chylomicrons; Circulation; Co-Immunoprecipitations; Complex; Conscious; Data; Data Set; Diet; Dietary Fats; Dyslipidemias; Enterocytes; Equilibrium; Esterification; Exhibits; Fasting; Fat-Soluble Vitamin; Fatty acid glycerol esters; Fistula; Foundations; Genes; Golgi Apparatus; Guanine Nucleotide Exchange Factors; Health; High Fat Diet; Homeostasis; Human; In Vitro; Ingestion; Insulin Resistance; Intestinal Absorption; Intestinal Secretions; Intestines; Knowledge; Link; Lipids; Lipolysis; Lipoproteins; Literature; Lymph; Maintenance; Mass Spectrum Analysis; Measurement; Measures; Membrane Fusion; Metabolic; Metabolism; Methods; Mission; Mitochondria; Modeling; Mucous Membrane; Mus; Non-Insulin-Dependent Diabetes Mellitus; Nonesterified Fatty Acids; Obesity; Organism; Particle Size; Pathway interactions; Peripheral; Plasma; Play; Process; Proteins; Publishing; Regulation; Resistance; Risk Factors; Role; Secretory Vesicles; Sucrose; Tissues; Tracer; Transmembrane Transport; Triglycerides; United States National Institutes of Health; Variant; Very low density lipoprotein; Wild Type Mouse; Work; absorption; cardiometabolism; cardiovascular disorder risk; cardiovascular risk factor; cell type; crosslink; dietary; exome sequencing; experimental study; gene network; gene regulatory network; improved; insight; intestinal epithelium; lipid metabolism; mouse model; novel; particle; response; single-cell RNA sequencing; trafficking; transcriptome; uptake

Project Summary Postprandial plasma triacylglyceride levels are independently associated with risk of cardiovascular disease. The intestine plays a key role in the regulation of dietary triacylglyceride absorption by packaging and secreting lipids in chylomicron particles. The intracellular steps of chylomicron biogenesis and transport have been fairly well described, however, there is a significant gap in our understanding of the mechanism for the final steps of chylomicron secretion by enterocytes, specifically post-Golgi transport and secretion. We recently identified a protein that plays a critical role in this pathway, DENND5B. Our newly generated Dennd5b-/- mouse demonstrates an essential role for this gene in Golgi to plasma membrane transport of chylomicron secretory vesicles. Dennd5b-deficient mice are resistant to diet-induced: obesity, changes in plasma lipids, and atherosclerosis. In humans, exome sequencing studies reveal that a common DENND5B variant is correlated with body mass index. These studies establish an important role for DENND5B in post-Golgi chylomicron secretion and a subsequent influence on body composition and peripheral lipoprotein metabolism. The overall objective of this proposal is to gain fundamental knowledge about the process of dietary lipid absorption by the intestine and to examine the impact of this process on systemic metabolic health. This objective aligns well with the NIH mission to seek fundamental knowledge about living systems and to apply this knowledge to enhance health. The Specific Aims of this proposal use our novel mouse model and in vitro experiments to examine the mechanistic role of DENND5B in the intestine and its systemic metabolic effects. Aim 1 will quantify the impact of Dennd5b on dietary lipid absorption and generate a comprehensive spatial single-cell RNAsequencing data set for examination of gene networks that participate in regulation of dietary lipid absorption. Aim 2 will examine the mechanism underlying Dennd5b action in CM transport. Furthermore, this aim will use mass spectrometry and interactomics analysis to expand our understanding of this process by identifying other interacting proteins which may form a complex to facilitate chylomicron secretion by the intestine. Aim 3 will determine the impact of Dennd5b on enterocyte metabolic function and peripheral lipid metabolism. Successful completion of this proposal will fill a significant knowledge gap in the process of dietary lipid absorption. This work will advance the field by providing mechanistic details for a key step in chylomicron secretion that can affect systemic lipid homeostasis and metabolic health.

项目概要 餐后血浆三酰甘油水平与心血管疾病风险独立相关 疾病。肠道在调节膳食三酰甘油吸收方面发挥着关键作用 在乳糜微粒中包装和分泌脂质。乳糜微粒的细胞内步骤 生物发生和运输已经得到相当好的描述，然而，我们的研究还存在很大差距 了解肠细胞乳糜微粒分泌的最后步骤的机制，特别是 高尔基体后运输和分泌。我们最近发现了一种在这一过程中发挥关键作用的蛋白质 途径，DENND5B。我们新生成的 Dennd5b-/- 小鼠在这方面发挥了重要作用 高尔基体中的基因将乳糜微粒分泌囊泡转运至质膜。 Dennd5b 缺陷小鼠 对饮食引起的：肥胖、血脂变化和动脉粥样硬化具有抵抗力。在人类中，外显子组 测序研究表明，常见的 DENND5B 变异与体重指数相关。这些 研究证实 DENND5B 在高尔基体后乳糜微粒分泌和随后的 对身体成分和外周脂蛋白代谢的影响。本次活动的总体目标 建议是获得有关肠道吸收膳食脂质过程的基础知识 并检查这一过程对全身代谢健康的影响。这一目标与 NIH 的使命是寻求有关生命系统的基础知识并将这些知识应用于 增强健康。该提案的具体目标是使用我们的新型小鼠模型和体外 检查 DENND5B 在肠道中的机制作用及其全身代谢的实验 影响。目标 1 将量化 Dennd5b 对膳食脂质吸收的影响并生成 用于检查基因网络的综合空间单细胞 RNA 测序数据集 参与膳食脂质吸收的调节。目标 2 将检查潜在的机制 Dennd5b 在 CM 运输中的作用。此外，该目标将使用质谱和相互作用组学 通过识别其他相互作用的蛋白质来扩展我们对这一过程的理解，这些蛋白质可能 形成复合物以促进肠道分泌乳糜微粒。目标 3 将确定影响 Dennd5b 对肠细胞代谢功能和外周脂质代谢的影响。顺利完成 该提案将填补膳食脂质吸收过程中的重大知识空白。这项工作将 通过提供乳糜微粒分泌的关键步骤的机制细节来推进该领域，该步骤可以影响 全身脂质稳态和代谢健康。