Diabetic Vasculopathy and Mitochondrial eNOS

糖尿病血管病变和线粒体 eNOS

基本信息

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
项目类别：
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

项目摘要

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) 由内皮一氧化氮合酶 (eNOS) 产生，在维持血管健康和肾功能。长期接触高葡萄糖会引发四氢生物蝶呤的氧化。 (BH4)，一种重要的 eNOS 辅助因子，导致二氢生物蝶呤 (BH2) 在血管中积聚在优异奖支持的最初阶段，我们发现 BH2 与高浓度的 eNOS 结合。研究表明，BH2 可以取代 BH4，并将 eNOS 产物从 NO 转换为超氧化物。与 eNOS 结合可以启动关键的 feed-fonivar 分子级联，驱动氧化应激和 NO 糖尿病血管供血不足，导致严重的糖尿病血管并发症，从而导致研究还证明了一种新颖的功效。破坏糖尿病患者 NO 不足和氧化应激级联反应的药理学方法血管，利用通过与超氧化物（和/或衍生的值得注意的是，超氧化物依赖性 NO 释放是 eNOS 催化中间体的特性， N'¿ -羟基精氨酸 (NOMA)，一种内源性分子，在下午 5-10 点同时在血液中进行检修。清除氧化剂并释放 NO，施用 NOMA 可以选择性地将 NO 递送至血管事实上，氧化应激位点，增加 BH4:BH2 并恢复 eNOS 偶联和 NO 产生。遗传性糖尿病 db/db 的慢性 NOMA 治疗可预防内皮功能障碍的发展，高血压和 NO 不足，而这些在媒介物处理的 NOMA（或相关的对照）中发生。羟基胍）可以通过为糖尿病提供靶向治疗来满足主要的未满足的临床需求作为一流的超氧化物依赖性 NO 释放剂来治疗血管疾病研究的总体目标。在此期间提出优异奖延长期限是为了增强我们对生化作用的理解糖尿病中 NO 的作用，并扩展我们对 NOHA 对糖尿病血管病变潜在治疗的评估。将包括 NOHA 药代动力学、代谢、反应机制、对代谢的影响的评估糖尿病损伤伤口愈合、血管生成和四肢血液的啮齿动物模型的治疗效果研究将依赖于最初建立的新的研究方法和分析方法。优异奖期 - 包括用于全球非目标代谢物分析的强大 LC/MS/MS 平台（以调查数千个分子（50 - 1000 m/z）的表达变化以及蛋白质组学方法发现由未偶联的 eNOS 产生并可能导致血管病变的硝化蛋白和位点。