Pharmacological Restoration of Diabetic Vascular Dysfunction

问题：糖尿病(DM)会增加心血管疾病(CV)和各种原因的死亡率，尽管存在积极的风险 因子修改。我们的长期目标是确定降低糖尿病心血管风险的新目标。 血管线粒体是一个潜在的新靶点。线粒体调节血管内皮细胞功能 肌肉细胞(SMC)增殖和线粒体功能障碍是糖尿病的标志。锻炼会引发一种 健康血管中线粒体质量的适应性改善；糖尿病患者没有这种反应。这个 这项提案涉及的问题是，在药物靶向eNOS和SIRT与胰高血糖素- 类肽1(GLP-1)可以恢复线粒体生物发生的信号并改善线粒体动力学 和血管功能。GLP-1是一种糖尿病药物，它还可以诱导eNOS、SIRT1、线粒体 生物发生和自噬21。新的初步数据表明，萨格列平(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 运动在糖尿病中的表达，并提高跑步距离。 假设：线粒体功能异常和应激介导的线粒体受损 GLP-1通过eNOS和SIRT1信号通路改善糖尿病血管系统的动力学。 SA#1：GLP-1对糖尿病患者血管线粒体适应性的影响是什么？ 理论基础：8天运动的对照组大鼠表现出线粒体生物发生的激活增加， 改善线粒体功能，增加融合和减少分裂。我们将研究GLP-1的影响 糖尿病患者血管线粒体功能和代谢的研究及应用靶向缺失eNOS、内皮细胞的研究 (EC)SIRT1、SMC SIRT1加或不加运动以测试体内线粒体的动态平衡适应性。 假设1.1：GLP-1干预将通过增强血管改善线粒体功能 高脂糖尿病患者线粒体对运动的适应性(生物发生、融合和自噬)。 假设1.2：内皮型一氧化氮合酶和/或SIRT1是GLP-1挽救线粒体适应性所必需的。方法： 1A.雄性C57BL6在饮食和高脂(HF)饮食中持续10周将被随机分为GLP-1组或 或连续8天不运动。1B.C57eNOS-/-和c57b eNOS+/+将与SA1a一样处理。1C。C57小鼠 在EC或SMC删除SIRT1和对照的情况下，将按SA1a处理。这些实验将澄清 ENOS和SIRT1在体内血管线粒体运动适应中的重要性及其影响 糖尿病和GLP-1在这些途径上。 SA#2：糖尿病如何影响体外血管细胞的动态线粒体适应？ 理论基础：线粒体功能的调节需要线粒体生物基因- SIS和重塑通过分裂、融合和自噬。假设2.1：内皮细胞和/或光滑 糖尿病模型中的肌肉细胞线粒体动力学将受到损害。假设2.2：GLP-1将有所改善 内皮型一氧化氮合酶和/或SIRT在DM细胞中的线粒体功能和动力学方法：这些实验 将在体外检测DM和GLP-1对线粒体质量和动力学的影响，并采用基因 确定eNOS和SIRT对血管细胞线粒体质量的相对贡献的方法。 对退伍军人群体的影响：线粒体动力学是减少多余CV的新目标 患糖尿病的风险。针对线粒体ROS的干预在人类身上一直无效 学习。Saxa治疗8天可恢复线粒体血管诱导 生物发生学为受损的血管线粒体适应是有针对性的概念提供了证据 有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能 对糖尿病的大血管和微血管并发症有影响。

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.