Pharmacological Restoration of Diabetic Vascular Dysfunction

问题：糖尿病（DM）增加了心血管（CV）和全因死亡率，尽管有侵袭性风险 因子修正我们的长期目标是确定降低糖尿病心血管风险的新靶点。 血管线粒体是一个潜在的新靶点。线粒体调节内皮功能， 肌细胞（SMC）增殖和线粒体功能障碍是糖尿病的标志。练习eldegan 健康血管中线粒体质量的适应性改善;这种反应在糖尿病中不存在。的 该提案中提出的问题是，是否用胰高血糖素药理学靶向eNOS和SIRT- 类肽1（GLP-1）可以恢复线粒体生物合成的信号传导，并改善线粒体动力学 和血管功能。GLP-1是一种糖尿病药物，也可诱导eNOS、SIRT 1、线粒体 生物发生和自噬21.新的初步数据表明，沙格列汀（SAXA），一种二肽基肽酶-4 增加循环内源性GLP-1的抑制剂，恢复eNOS和线粒体蛋白的诱导 表达与运动在DM和提高跑步距离。 假设：线粒体功能异常和应激介导的线粒体损伤 GLP-1通过eNOS和SIRT 1信号传导改善糖尿病脉管系统中的动力学。 SA #1：GLP-1对DM患者血管线粒体适应性的影响是什么？ 原理：经过8天运动的对照大鼠显示线粒体生物合成的激活增加， 线粒体功能改善，融合增加，分裂减少。我们将研究GLP-1的影响 对糖尿病血管线粒体功能和周转的影响以及使用eNOS、内皮细胞 (EC)SIRT 1、SMC SIRT 1，在运动或不运动的情况下测试体内线粒体稳态适应。 假设1.1：GLP-1的干预将通过增强血管内皮细胞的功能来改善线粒体功能。 高脂诱导的糖尿病中线粒体对运动的适应（生物发生、融合和自噬）。 假设1.2：eNOS和/或SIRT 1是GLP-1拯救线粒体适应所必需的。方法： 1a.将接受普通饲料与高脂肪（HF）饮食10周的雄性C57 BL 6随机分配至GLP-1或溶媒组， 8天不锻炼。1b. c57 eNOS-/-和c57 b eNOS +/+将按照SA 1a进行处理。1c. c57小鼠 用EC或SMC删除SIRT 1，对照将如SA 1a中那样处理。这些实验将阐明 eNOS和SIRT 1对血管线粒体适应体内运动的重要性，并确定其影响 糖尿病和GLP-1在这些通路上的作用。 SA #2：糖尿病如何影响体外血管细胞的动态线粒体适应？ 基本原理：线粒体功能的调节需要线粒体生物基因- 通过分裂、融合和自噬进行增殖和重塑。假设2.1：内皮细胞和/或平滑 来自DM模型的肌细胞将具有受损的线粒体动力学。假设2.2：GLP-1将改善 通过eNOS和/或SIRT在DM细胞中的线粒体功能和动力学。方法：这些实验 将研究DM和GLP-1对体外线粒体质量和动力学的影响，并采用遗传学方法， 方法来定义eNOS和SIRT的相对贡献的线粒体质量在血管细胞。 对退伍军人群体的影响：线粒体动力学是降低过度CV的新靶点 糖尿病的风险。针对线粒体ROS的干预在人类中一直是无效的。 问题研究我们观察到用SAXA治疗8天恢复了线粒体血管诱导， 生物发生提供了概念证据，即受损的血管线粒体适应是可靶向的 用一种目前可用的药物糖尿病患者线粒体动力学的药理学恢复可以 与糖尿病的大血管和微血管并发症有关。

Problem: Diabetes (DM) increases cardiovascular (CV) and all-cause mortality despite aggressive risk factor modification. Our long term goal is to define novel targets for cardiovascular risk reduction in diabetes. Vascular mitochondria are a potential new target. Mitochondria regulate endothelial function and smooth muscle cell (SMC) proliferation and mitochondrial dysfunction is a hallmark of diabetes. Exercise elicits an adaptive improvement in mitochondrial quality in healthy vessels; this response is absent in diabetes. The question addressed in this proposal is whether pharmacological targeting of eNOS and SIRT with glucagon- like peptide 1 (GLP-1) can restore signaling to mitochondrial biogenesis and improve mitochondrial dynamics and vascular function. GLP-1 is a diabetes medication that also induces eNOS, SIRT1, mitochondrial biogenesis and autophagy 21. New preliminary data suggest that saxagliptin (SAXA), a dipeptidyl peptidase-4 inhibitor that increases circulating endogenous GLP-1, restores induction of eNOS and mitochondrial protein expression with exercise in DM and improves running distance. Hypotheses: Abnormal mitochondrial function and impaired stress mediated mitochondrial dynamics in the diabetic vasculature will be improved by GLP-1 via eNOS and SIRT1 signaling. SA #1: What is the impact of GLP-1 on vascular mitochondrial adaptation in DM? Rationale: Control rats subjected to 8 day exercise show increased activation of the mitochondrial biogenesis, improved mitochondrial function plus increased fusion and decreased fission. We will examine the impact of GLP-1 on vascular mitochondrial function and turnover in diabetes and use targeted deletion of eNOS, endothelial cell (EC) SIRT1, SMC SIRT1 with or without exercise to test mitochondrial homeostatic adaptation in vivo. Hypothesis 1.1: Intervention with GLP-1 will improve mitochondrial function through augmentation of vascular mitochondrial adaptation (biogenesis, fusion and autophagy) to exercise in high fat induced diabetes. Hypothesis 1.2: eNOS and/or SIRT1 are required for GLP-1 rescue of mitochondrial adaptation. Approach: 1a. Male C57BL6 on chow versus high fat (HF) diet for 10 weeks will be randomized to GLP-1 or vehicle with or without exercise for 8 days. 1b. c57eNOS -/- and c57b eNOS +/+ will be treated as in SA1a. 1c. c57 mice with EC or SMC deletion of SIRT1 and controls will be treated as in SA1a. These experiments will clarify the importance of eNOS and SIRT1 for vascular mitochondrial adaptation to exercise in vivo and define the impact of diabetes and GLP-1 on these pathways. SA #2: How does diabetes affect dynamic mitochondrial adaptation in vascular cells in vitro? Rationale: Regulation of mitochondrial function requires a complex interplay between mitochondrial biogene- sis and remodeling through fission, fusion and autophagy. Hypothesis 2.1: Endothelial cells and/or smooth muscle cells from DM models will have impaired mitochondrial dynamics. Hypothesis 2.2: GLP-1 will improve mitochondrial function and dynamics in DM cells through eNOS and/or SIRT. Approach: These experiments will examine the impact of DM and GLP-1 on mitochondrial quality and dynamics in vitro and employ genetic approaches to define the relative contribution of eNOS and SIRT for mitochondrial quality in vascular cells. Impact on the Veteran Population: Mitochondrial dynamics are a novel target to decrease excess CV risk in diabetes. Interventions targeting mitochondrial ROS have been consistently ineffective in human studies. Our observation that 8 days of treatment with SAXA restores vascular induction of mitochondrial biogenesis provides proof of concept that impaired vascular mitochondrial adaptation is targetable with a currently available drug. Pharmacological restoration of mitochondrial dynamics in diabetes could have implications for macrovascular and microvascular complications of diabetes.