Nitric Oxide-Superoxide Interactions in Endothelial Cell Dysfunction

一氧化氮-超氧化物相互作用在内皮细胞功能障碍中的作用

• 批准号: 7787434
• 负责人: MAHENDRA KAVDIA
• 金额: $ 9.49万
• 依托单位: UNIVERSITY OF ARKANSAS AT FAYETTEVILLE
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-14 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7787434
• 关键词: Antioxidants; Apoptosis; Biological Availability; Biological Process; Blood Vessels; Blood flow; Cells; Complex; Computer Simulation; Data; Development; Diabetes Mellitus; Endothelial Cells; Endothelium; Environmental Risk Factor; Enzymes; Feedback; Free Radical Formation; Functional disorder; Generations; Glucose; Goals; Human; Hyperglycemia; Impairment; In Vitro; Kinetics; Lipid Peroxidation; Literature; Measurement; Measures; Mediating; Microcirculation; Modeling; Molecular; Nitrates; Nitric Oxide; Nitric Oxide Synthase; Nitrites; Oxidative Stress; Pathway interactions; Peroxonitrite; Process; Production; Reaction; Reactive Nitrogen Species; Reactive Oxygen Species; Regulation; Research; Simulate; Superoxide Dismutase; Superoxides; System; Testing; Time; Tissues; Umbilical vein; Vasodilation; abstracting; cell injury; design; diabetes mellitus therapy; diabetic; human NOS3 protein; improved; multi-scale modeling; prevent; public health relevance; research study; response; shear stress; therapy development

DESCRIPTION (provided by applicant): Abstract Endothelial cell (EC) dysfunction is a common pathogenic framework of many of the diabetes-related micro- and macro- vascular complications. Reduced bioavailability of EC-released nitric oxide (NO) is a primary marker generally used for EC dysfunction. However, the molecular mechanisms of hyperglycemia induced reduced NO bioavailability remain poorly understood. [We hypothesize that the diabetic endothelial cell dysfunction/reduced NO bioavailability is mediated by reactive oxygen species (ROS) and is a results of increased interaction of NO and superoxide (O2-)at the endothelial cell level. The increased interactions results in higher peroxynitrite (ONOO-) formation, shifting nitric oxide synthase (eNOS) activity from NO production to O2 production, and EC damage. The deleterious effects can be prevented by reducing ROS formation and concentration. Specific aims are designed to test these hypotheses. Aim1. Determine the EC release of NO and O2- and cell damage in hyperglycemic conditions. Hypotheses are: i) the high glucose causes endothelial dysfunction over long periods by increasing ONOO- and O2- formation and ii) reduction in O2- formation is key to reducing endothelial dysfunction. We will perform the following experiments: i) determining the effect of high glucose on eNOS and NA(D)PH expressions, NO and superoxide releases, endothelial cell lipid peroxidation (an indicator of peroxynitrite formation) and apoptosis in human umbilical vein endothelial cells (HUVECs) over short and long time-periods, and ii) determining whether increasing NO or decreasing O2- formation will be effective in preventing effects of high glucose. Aim2. Develop a reaction kinetic-transport computational model to simulate experiments of Aim1 and predict levels of NO, O2- and ONOO- at EC level. Hypotheses are: i) the NO concentration is reduced and ONOO- is increased due to high interaction between NO and O2- even though the NO release from endothelial cell increases in high glucose over short periods and ii) the NO concentration increases and ONOO- concentration decreases when O2- formation or concentration is reduced in high glucose. Aim3. Develop a multi-scale computational model for NO, ROS (O2-), and reactive nitrogen species (RNS; ONOO-) transport in the microcirculation underlying the process of oxidative stress. Hypotheses are: i) endothelial cell dysfunction is a results of higher superoxide formation, ii) a reduction in ROS formation enhances NO bioavailability and iii) increased superoxide dismutase levels not only reduces the O2- levels but also increases the NO levels, and reduces NO formation through feedback mechanism. At EC level, we will model the regulation of eNOS and the release of NO and O2-. At tissue level, we will model a volume of tissue containing an arteriolar blood vessel and simulate transport of NO, ROS and RNS.] This combined experimental & computational approach is critical in our understanding of molecular mechanism of EC dysfunction and examine the potential therapies to treat EC dysfunction related vascular complications. PUBLIC HEALTH RELEVANCE: Endothelial cell (EC) dysfunction is a common pathogenic framework of many of the diabetes-related micro- and macro- vascular complications. The molecular mechanisms of hyperglycemia induced endothelial cell dysfunction remain poorly understood. The proposed research will use integrated computational and experimental approaches to assess endothelial cell dysfunction caused by oxidative stress due to high glucose at the molecular, cellular and tissue levels. The integrated experimental measurements and computational modeling of oxidative stress will provide an optimum set of parameters that will not only improve endothelial cell dysfunction/NO bioavailability but also will guide us in the development of therapies for diabetes related vascular complications.

描述（由申请人提供）：抽象的内皮细胞（EC）功能障碍是许多与糖尿病相关的微型和宏观血管并发症的常见致病框架。 EC释放的一氧化氮（NO）的生物利用度降低是用于EC功能障碍的主要标记。然而，高血糖诱导的分子机制降低没有生物利用度知识尚不清楚。 [我们假设糖尿病内皮细胞功能障碍/降低无生物利用度是由活性氧（ROS）介导的，并且是内皮细胞水平上NO和超氧化物（O2-）相互作用增加的结果。增加的相互作用会导致高氧化硝酸盐（ONOO-）形成，一氧化氮合酶（ENOS）活性从无生产转移到O2产生以及EC损伤。可以通过减少ROS的形成和浓度来预防有害影响。具体目标旨在检验这些假设。 AIM1。确定在高血糖条件下NO和O2和细胞损伤的EC释放。假设是：i）高葡萄糖在长期内增加了内皮功能障碍，通过增加ONOO-和O2形成，II）O2形成的减少是减少内皮功能障碍的关键。我们将执行以下实验：i）确定高葡萄糖对eNOS和Na（d）pH表达，NO和超氧化物的释放，内皮细胞脂质过氧化（过氧亚硝酸盐形成的指标）和人脐静脉内皮细胞（HUVECS）的影响，以及是否增加了II）。 O2形成将有效预防高葡萄糖的作用。 AIM2。开发一个反应动力学传输计算模型，以模拟AIM1的实验，并在EC级别预测NO，O2-和ONOO-的水平。假设是：i）i）由于NO和O2之间的高相互作用，NO浓度降低，并且在短葡萄糖中的NO释放中增加了NO释放，而II）NO浓度升高，而当O2形成或浓度降低时，高葡萄糖的浓度会降低。 AIM3。在微循环中开发NO，ROS（O2-）和反应性氮种（RNS; Onoo-）的多尺度计算模型，这是氧化应激过程的基础。假设是：i）内皮细胞功能障碍是较高的超氧化物形成的结果，ii）ROS形成的降低可增强无生物利用度，ii）增加了超氧化物歧化酶水平，不仅会降低O2水平，而且还会降低NO水平，并通过反馈机制降低NO级别。在EC级别，我们将对ENOS的调节以及NO和O2-的释放进行建模。在组织水平上，我们将建模含有动脉血管的组织量并模拟NO，ROS和RNS的运输。公共卫生相关性：内皮细胞（EC）功能障碍是许多与糖尿病相关的微型和宏观血管并发症的常见致病框架。高血糖诱导的内皮细胞功能障碍的分子机制仍然了解不足。拟议的研究将使用集成的计算和实验方法来评估由于分子，细胞和组织水平高葡萄糖引起的氧化应激引起的内皮细胞功能障碍。氧化应激的综合实验测量和计算模型将提供一组最佳的参数，不仅可以改善内皮细胞功能障碍/无生物利用度，而且还将指导我们开发与糖尿病相关血管并发症的疗法。