Vascular Insulin Resistance in Obesity: Role of Endoplasmic Reticulum Stress

描述(由申请人提供)：我的长期职业目标是开发一个独立的、有资金支持的研究项目，帮助了解肥胖和2型糖尿病导致血管胰岛素信号转导受损和心血管疾病的机制。在肥胖患者中，胰岛素刺激的流向骨骼肌的血流受到限制，从而削弱了葡萄糖的摄取，从而破坏了葡萄糖的稳态。然而，胰岛素诱导的血管扩张受损的机制在很大程度上还不清楚。这项拟议的研究将检验内质网(ER)应激介导胰岛素刺激的骨骼肌小动脉血管扩张受损的假设。肥胖引起的血管内质网应激和血管胰岛素抵抗与血管周围脂肪组织(PVAT)局部分泌炎性细胞因子有关。使用西方饮食诱导肥胖的成熟猪模型，Aim 1将测试肥胖相关的血管内质网应激是否导致一氧化氮和内皮素-1之间的失衡，从而导致胰岛素刺激的血管扩张受损。然后，目标2将确定肥胖的骨骼肌PVAT是否会导致血管内质网应激，从而导致胰岛素刺激的血管扩张受损。最后，Aim 3将检验体内ER功能的遗传和化学增强是否可以恢复与肥胖相关的受损的胰岛素刺激的血管扩张。这项拟议的工作在猪身上的贡献是显著的，因为靶向内质网应激可能是纠正血管胰岛素抵抗并最终预防/治疗肥胖引发的代谢和心血管疾病的一种新的治疗策略。密苏里大学(密苏里大学)校区在心血管科学、新陈代谢和运动生理学方面有着杰出的研究历史，是生命科学中心、道尔顿心血管研究中心、健康活动中心、糖尿病和心血管中心、国家猪资源和研究中心的所在地，作为该项目的资源。这些中心挤满了来自多个部门的教职员工，他们积极合作，为我的独立研究提供了一个无与伦比的研究环境。事实上，我将与大量高级调查人员互动，他们不仅将帮助我成功完成拟议的研究，还将在我迈向成功的独立调查人员的过程中促进我的职业发展。詹姆斯·R·索沃斯医学博士将是我的主要导师，弗兰克·W·布斯博士将担任我的联合导师。索沃斯博士是一名临床医生，也是一名在血管胰岛素作用和心脏代谢性疾病方面拥有专业知识的研究人员。布斯博士在脂肪组织生物学和体力活动方面拥有专业知识。我们共同组建了一个全面的研究培训计划和合作者团队，以促进收购 新的分子技术(即在体腺病毒转染、蛋白质组学)以及涉及分离的完整小动脉的体外制备技术，以增强我的能力 进行机械论研究。这些额外的技能，再加上我早期在人类血管研究方面的背景，将有助于我建立一个研究计划，使其能够使用肥胖/2型糖尿病动物模型以及人类患者进行体外和体内机制和翻译研究。简而言之，我的培训计划所提供的额外的技术、学术和职业发展将使我处于一个理想的位置，能够成功地启动一个富有成效的、独立的和翻译的研究项目。这份NIH K01申请代表着我作为一名年轻的早期调查员职业发展的下一个合乎逻辑的步骤，并将为我的第一个R01申请奠定基础。(摘要结束)

DESCRIPTION (provided by applicant): My long-term career goal is to develop an independent, funded research program that contributes to understanding the mechanisms by which obesity and type 2 diabetes lead to impaired vascular insulin signaling and cardiovascular disease. In obesity, insulin-stimulated blood flow to skeletal muscle is limited and this attenuate glucose uptake, thus contributing to impaired glucose homeostasis. However, the mechanism by which insulin-induced vasodilation becomes impaired is largely unknown. The proposed study will test the hypothesis that endoplasmic reticulum (ER) stress mediates the impairment in insulin-stimulated vasodilation in skeletal muscle arterioles. It is reasoned that vascular ER stress and vascular insulin resistance caused by obesity is attributable to the local secretion of inflammatory cytokines by perivascular adipose tissue (PVAT). Using a well-established pig model of Western diet-induced obesity, Aim 1 will test if obesity-associated vascular ER stress underlies the imbalance between nitric oxide and endothlein-1 leading to impaired insulin- stimulated vasodilation. Aim 2 will then determine if obese skeletal muscle PVAT can cause vascular ER stress, thus contributing to impaired insulin-stimulated vasodilation. Finally, Aim 3 will examine whether in vivo genetic and chemical enhancement of ER function can restore impaired insulin-stimulated vasodilation associated with obesity. The contribution of this proposed work in pigs is significant as targeting ER stress may be a novel therapeutic strategy to correct vascular insulin resistance and ultimately prevent/treat metabolic and cardiovascular disease fueled by obesity. The University of Missouri (MU) campus has a distinguished history of research in cardiovascular science, metabolism, and exercise physiology and is the home for the Life Sciences Center, the Dalton Cardiovascular Research Center, the Health Activity Center, the Diabetes and Cardiovascular Center, the National Swine Resource & Research Center as resources for this project. These centers are filled with faculty from multiple departments and divisions that actively collaborate, providing an unparalleled research environment to pursue my independent research. Indeed, I will be interacting with a large number of senior investigators who will not only help ensure successful completion of the proposed studies, but also facilitate my career development as I progress toward becoming a successful independent investigator. James R. Sowers, MD, will be my primary mentor and Frank W. Booth, PhD will act as my co-mentor. Dr. Sowers is a clinical physician as well as a researcher with expertise in vascular insulin actions and cardiometabolic disease. Dr. Booth has expertise in adipose tissue biology and physical activity. Together, we have assembled a comprehensive research training plan and team of collaborators that will facilitate the acquisition of new molecular techniques (i.e., in vivo adenoviral transfection, proteomics) as well as techniques involving in vitro preparations of isolated intact arterioles to enhance my abilities to conduct mechanistic research. These additional skills combined with my earlier background in human vascular research will contribute to my long-term goal of establishing a research program with capabilities to conduct in vitro and in vivo mechanistic and translational research using animal models of obesity/type 2 diabetes as well as human patients. In short, the additional technical, academic, and career development afforded by my training plan will place me in an ideal position to successfully launch a productive, independent and translational research program. This NIH K01 application represents the next logical step in my career development as a young early investigator and will set the stage for my first R01 application. (End of Abstract)