Diabetic Vasculopathy and Mitochondrial eNOS

糖尿病血管病变和线粒体 eNOS

• 批准号: 8188798
• 负责人: Steven S Gross
• 金额: $ 42.25万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-02-01 至 2017-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8188798
• 关键词: 7,8-dihydrobiopterin; Admission activity; Amputation; Avidity; Award; Binding; Biochemical; Biological Assay; Blindness; Blood; Blood Vessels; Blood flow; Cardiovascular system; Cessation of life; Chronic; Clinical; Coupling; Development; Diabetes Mellitus; Diabetic Angiopathies; Drug Kinetics; Evaluation; Exposure to; Functional disorder; Glucose; Goals; Health; Hospitals; Hypertension; Impaired wound healing; Instruction; Kidney Failure; Lead; Limb structure; Metabolism; Mitochondria; Molecular; Nitrates; Nitric Oxide; Nitric Oxide Synthase; Noma; Oxidants; Oxidative Stress; Play; Production; Property; Proteins; Proteomics; Reaction; Renal function; Research; Rodent Model; Role; Site; Superoxides; Surveys; Therapeutic; Vascular Diseases; Vascular Endothelium; angiogenesis; base; cofactor; diabetic; diabetic patient; feeding; human NOS3 protein; liquid chromatography mass spectrometry; novel; oxidation; prevent; tetrahydrobiopterin

Nitric oxide (NO) is produced by endothelial NO synthase (eNOS) and plays a key role in maintaining vascular health and renal function. Chronic exposure to high glucose triggers oxidation of tetrahydrobiopterin (BH4), an essential eNOS cofactor, resulting in accumulation of dihydrobiopterin (BH2) in the vascular endothelium. During the initial period of Merit Award support, we discovered that BH2 binds eNOS with high avidity, replacing BH4 and switching the eNOS product from NO to superoxide. Studies suggest that BH2 binding to eNOS can initiate a pivotal feed-fonivard molecular cascade that drives oxidative stress and NO insufficiency in diabetic blood vessels, responsible for severe diabetic vascular complications that can lead to amputations, blindness, kidney failure and death. Research also demonstrates the efficacy of a novel pharmacological approach for disrupting the cascade of NO insufficiency and oxidative stress in diabetic blood vessels, utilizing agents that release NO via efficient reaction with superoxide (and/or derived oxidants). Remarkably, superoxide-dependent NO release is a property of the eNOS catalytic intermediate, N'¿-hydroxyarginine (NOMA), an endogenous molecule that circulates in blood at 5-10 pM. By concurrently scavenging oxidants and releasing NO, administered NOMA can selectively target NO delivery to vascular sites of oxidative stress, increasing BH4:BH2 and restoring eNOS coupling and NO production. Indeed, chronic NOMA treatment of genetically-diabetic db/db prevented development of endothelial dysfunction, hypertension and NO insufficiency that othenwise occurred in vehicle-treated controls. NOMA (or a related hydroxyguanidine) could fill a major unmet clinical need, by providing targeted therapy for diabetic vasculapathies as a first-in-class superoxide-dependent NO-releasing agent. The overall goal of studies proposed during this Merit Award extension period is to enhance our biochemical understanding of the role of NO in diabetes and extend our assessment of NOHA for potential therapy of diabetic vasculopathies. This will include evaluation of NOHA pharmacokinetics, metabolism, reaction mechanisms, effects on metabolism and therapeutic benefit in rodent models of diabetes-impaired wound healing, angiogenesis and limb blood flow insufficiency. Studies will rely on new research approaches and assays, established during the initial Merit Award period - including a powerful LC/MS/MS platform for global untargeted metabolite profiling (to survey expression changes in thousands of molecules, 50 - 1000 m/z) and a proteomic approach for discovering nitrated proteins and sites that result from uncoupled eNOS and may contribute to vasculopathy.

一氧化氮（NO）由内皮NO合酶（ENOS）产生，并在维持中起关键作用 血管健康和肾功能。长期暴露于高葡萄糖会触发四氢无菌蛋白的氧化 （BH4），一种必需的eNOS辅助因子，导致血管中的二氢生物蛋白（BH2）积累 内皮。在优点奖励支持的最初阶段，我们发现BH2绑定eNOS高 自然，取代BH4并将eNOS产品从NO转换为超氧化物。研究表明BH2 与eNOS的结合可以启动驱动氧化应激的关键饲料 - 触发分子级联 糖尿病血管不足，导致严重的糖尿病血管并发症，可能导致 截肢，失明，肾衰竭和死亡。研究还证明了小说的效率 糖尿病患者无需不足和氧化应激的级联反应的药理方法 血管，利用与超氧化物有效反应释放的药物（和/或衍生 值得注意的是，超氧化物依赖性无释放是eNOS催化中间体的特性， N'�-羟基氨酸氨酸（NOMA），一种内源性分子，在5-10 pm的血液中循环。同时 清除氧化物和释放NO，施用的Noma可以选择性地靶向无递送到血管 氧化应激部位，增加BH4：BH2并恢复eNOS耦合，没有产生。的确， 一般糖尿病DB/DB的慢性诺玛治疗可防止内皮功能障碍的发展， 高血压且没有否则会发生在车辆处理的控制中。诺玛（或相关的 羟基甘油可以通过提供糖尿病的靶向疗法来满足主要未满足的临床需求 血管质病作为第一类超氧化物依赖性无释放剂。研究的总体目标 在此优异奖奖励期间提出的提议是为了增强我们对角色的生化理解 糖尿病中的NO，并扩展了我们对NOHA对糖尿病血管病的潜在治疗的评估。这 将包括评估NOHA药代动力学，代谢，反应机制，对代谢的影响 以及糖尿病受损伤口愈合，血管生成和肢体血液的啮齿动物模型的热益处 流动不足。研究将依靠新的研究方法和测定 优异奖奖 - 包括一个强大的LC/MS/MS平台，用于全球非靶向代谢物分析（到 调查表达在数千个分子，50-1000 m/z）和蛋白质组学方法的变化变化 发现由未偶联的eNOS产生的硝化蛋白质和位点，并可能导致血管病。