Endothelial lipid droplet turnover and regulation of metabolic function

内皮脂滴周转和代谢功能的调节

• 批准号: 10667806
• 负责人: Nabil Boutagy
• 金额: $ 10.19万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10667806
• 关键词: Acute; Address; Adipose tissue; Aerobic Exercise; Animals; Biogenesis; Biological Availability; Biology; Blood; Blood Vessels; Blood flow; Buffers; Cardiometabolic Disease; Cardiovascular Diseases; Cells; Chronic; Complex; Cyclic GMP; Diet; Diglycerides; Doctor of Philosophy; Endoplasmic Reticulum; Endothelial Cells; Endothelium; Enzymes; Exercise; Fatty acid glycerol esters; Genetic; Glucose Transporter; Goals; High Fat Diet; Homeostasis; Hydrolysis; In Vitro; Insulin Resistance; Knock-out; Knockout Mice; Laboratories; Link; Lipase; Lipids; Maintenance; Mediating; Mentors; Metabolic; Metabolic Diseases; Metabolic stress; Metabolism; Mitochondria; Molecular; Mouse Strains; Mus; Muscle Fibers; Mutation; NOS3 gene; Nitric Oxide; Non-Insulin-Dependent Diabetes Mellitus; Nonesterified Fatty Acids; Obesity; Olive oil preparation; Organelles; Participant; Pathway interactions; Pharmacology; Physiology; Play; Principal Investigator; Protein Isoforms; Proteins; Regulation; Reporting; Research; Risk; Role; Scientist; Skeletal Muscle; Supervision; Tissues; Training; Training Programs; Transferase; Triglycerides; Vascular Endothelium; Work; career development; diacylglycerol O-acyltransferase; diet-induced obesity; endoplasmic reticulum stress; endothelial dysfunction; global health; glucose uptake; in vivo; insight; insulin sensitivity; metabolic abnormality assessment; mouse model; response; tool

Project Summary Accumulating evidence demonstrates that the vascular endothelium plays an important role in the regulation of metabolic homeostasis. In accordance, endothelial dysfunction contributes to metabolic derangements associated with obesity and insulin resistance. Our laboratory provided the first evidence that endothelial cells (ECs) have the capacity to form lipid droplets (LDs) in vivo and demonstrated that LD turnover (i.e., synthesis and degradation) is necessary for maintaining EC quiescence and function. Specifically, pharmacological inhibition of key enzymes in the LD synthesis pathway, diacylglycerol acetyl transferase (DGAT) 1 and 2, led to endoplasmic reticulum (ER) stress. Alternatively, endothelial specific deletion of adipose triglyceride lipase (ATGL), the rate-limiting enzyme in LD hydrolysis, led to a profound reduction in endothelial nitric oxide synthase (eNOS) protein levels and nitric oxide (NO) bioavailability in standard chow fed mice. Indeed, these vascular perturbations have been linked to derangements in whole-body metabolism, but the role of EC LD turnover as it relates to the control of vascular and metabolic function is unknown. Therefore, in this proposal, I will define the specific role of endothelial LD turnover in maintaining vascular and metabolic function during normal physiology, DIO and in response to acute and chronic exercise. To achieve these ends, I will generate inducible, endothelial specific ATGL knockout (iECKO), DGAT1-iECKO and DGAT2-iECKO mice as tools to dissect the molecular mechanisms by which LD turnover controls vascular and whole-body metabolic homeostasis. In aim 1, I will dissect the cellular mechanisms by which disruption in LD turnover leads to endothelial dysfunction under normal physiology and DIO via rigorous and meticulous molecular and metabolic characterization. In aim 2, I will decipher the importance of endothelial LD turnover in maintaining insulin sensitivity in normal physiology and DIO via comprehensive in vivo metabolic studies and ex vivo tissue analysis. Lastly, in aim 3, I will establish the role of endothelial LD turnover in the regulation of adaptations in response to an acute bout of exercise bout and chronic endurance training using a similar approach as aim 2. Collectively, these studies will address a heretofore unknown role of EC LD turnover in whole-body metabolism. Results from these studies will provide a better understanding of the interrelationship between vascular and metabolic function during normal physiology and in the setting of obesity and type II diabetes. In addition to these research aims, this proposal describes a five-year intensive mentored training program with the goal of developing the Principal Investigator (PI, Nabil Boutagy, Ph.D.) into an independent and high impact, scientist in the fields of vascular biology and metabolism under the supervision of his primary mentor, Dr. William Sessa, and co-mentor, Dr. Gerald Shulman. Furthermore, a team of world-class scientists has been assembled to provide oversight and guidance in achieving all aspects of the proposed research and the PI’s career development.

项目摘要 积累的证据表明，血管内皮在 代谢稳态的调节。根据，内皮功能障碍有助于代谢 与肥胖和胰岛素抵抗相关的进化。我们的实验室提供了第一个证据 内皮细胞（EC）具有体内形成脂质液滴（LDS）的能力，并证明了LD更新 （即合成和降解）对于维持EC静止和功能是必要的。具体来说， LD合成途径，二酰基甘油乙酰转移酶（DGAT）中关键酶的药理抑制作用 1和2，导致内质网（ER）应力。或者，脂肪的内皮特异性缺失 甘油三酸酯脂肪酶（ATGL），LD水解中的速率限制酶，导致内皮的大幅降低 一氧化氮合酶（ENOS）蛋白水平和一氧化氮（NO）生物利用度在标准食物喂养的小鼠中。 实际上，这些血管扰动与全身代谢的进化有关，但角色 与控制血管和代谢功能的控制有关的EC LD更新尚不清楚。因此，在此 提案，我将定义内皮LD周转率在维持血管和代谢中的特定作用 在正常生理，DIO以及响应急性和慢性运动的过程中的功能。实现这些 末端，我将生成可诱导的，内皮特定的ATGL淘汰（IECKO），DGAT1-IECKO和DGAT2-IECKO 小鼠作为解剖LD离职控制血管和全身的分子机制的工具 代谢稳态。在AIM 1中，我将剖析LD失误导致中断的细胞机制 通过严格而细致的分子和代谢，在正常生理学下的内皮功能障碍和DIO下 表征。在AIM 2中，我将破译内皮LD离职率在维持胰岛素方面的重要性 正常生理学和DIO的敏感性通过全面的体内代谢研究和离体组织分析。 最后，在AIM 3中，我将确定内皮LD离职的作用 使用与AIM 2相似的方法进行的急性锻炼和慢性耐力训练。 这些研究将介绍迄今为止EC LD转换在全身代谢中的未知作用。结果 这些研究将更好地了解血管和代谢功能之间的相互关系 在正常生理学和肥胖和II型糖尿病的情况下。除了这些研究目的， 该提案描述了一项五年的密集修补培训计划，目的是开发校长 研究人员（PI，Nabil Boutagy，Ph.D.）成为独立和高影响力的血管领域的科学家 在其主要心理的威廉·塞萨（William Sessa）博士的监督下，生物学和新陈代谢，院士博士 杰拉尔德·舒尔曼（Gerald Shulman）。此外，一支世界一流的科学家团队已经组成了监督和 实现拟议研究和PI职业发展的各个方面的指导。