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）是由内皮型一氧化氮合酶（eNOS）产生的，在维持血管紧张素Ⅱ（Ang Ⅱ）的活性中起关键作用。 血管健康和肾功能。慢性高糖暴露触发四氢生物蝶呤氧化 (BH4)，一种必需的eNOS辅因子，导致二氢生物蝶呤（BH 2）在血管中的积累， 内皮细胞在优异奖支持的最初阶段，我们发现BH 2与eNOS结合， 亲合力，取代BH 4，并将eNOS产物从NO转换为过氧化物。研究表明，BH 2 与eNOS结合可以启动一个关键的饲料-fonivard分子级联反应，驱动氧化应激和NO 糖尿病血管功能不全，导致严重的糖尿病血管并发症， 截肢失明肾衰竭和死亡研究还证明了一部小说的功效 阻断糖尿病患者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/或衍生物）的有效反应释放NO的试剂， 氧化剂）。值得注意的是，超氧化物依赖性NO释放是eNOS催化中间体的性质， N ′-羟基精氨酸（NOMA），一种内源性分子，在血液中以5-10 pM循环。通过同时 清除氧化剂和释放NO，给予NOMA可以选择性地靶向NO递送到血管 氧化应激位点，增加BH 4：BH 2和恢复eNOS偶联和NO产生。的确， 遗传性糖尿病db/db的长期NOMA治疗防止了内皮功能障碍的发展， 高血压和NO不足，这些在载体处理的对照中有时发生。NOMA（或相关 羟基胍）可以通过为糖尿病患者提供靶向治疗来填补主要未满足的临床需求， 血管病变作为一流的超氧化物依赖NO释放剂。研究的总体目标 在此期间提出的优异奖延长期是为了提高我们的生物化学的作用的理解 的NO在糖尿病和扩展我们的评估NOHA的潜在治疗糖尿病血管病变。这 将包括NOHA药代动力学、代谢、反应机制、对代谢的影响的评价 在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中的治疗益处 流量不足研究将依赖于新的研究方法和分析，建立在最初的 优异奖期间-包括用于全球非靶向代谢物分析的强大LC/MS/MS平台（至 在数千个分子中调查表达变化，50 - 1000 m/z）和蛋白质组学方法， 发现硝化蛋白质和由解偶联eNOS产生的位点，并可能导致血管病变。