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: 7612754
• 负责人: MAHENDRA KAVDIA
• 金额: $ 31.87万
• 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 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7612754
• 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）：摘要内皮细胞（EC）功能障碍是许多糖尿病相关的微血管和大血管并发症的常见致病框架。 EC 释放的一氧化氮 (NO) 生物利用度降低是通常用于 EC 功能障碍的主要标志。然而，高血糖导致 NO 生物利用度降低的分子机制仍知之甚少。 [我们假设糖尿病内皮细胞功能障碍/NO 生物利用度降低是由活性氧 (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。相互作用的增加导致过氧亚硝酸盐 (ONOO-) 的形成增多，一氧化氮合酶 (eNOS) 活性从 NO 生成转变为 O2 生成，并导致 EC 损伤。通过减少 ROS 的形成和浓度可以防止有害影响。设计了具体目标来检验这些假设。目标1。确定高血糖条件下 EC 释放的 NO 和 O2- 以及细胞损伤。假设是：i) 高葡萄糖通过增加 ONOO- 和 O2- 的形成而长期导致内皮功能障碍，ii) O2- 形成的减少是减少内皮功能障碍的关键。我们将进行以下实验：i) 确定高葡萄糖在短期和长期内对 eNOS 和 NA(D)PH 表达、NO 和超氧化物释放、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 (HUVEC) 细胞凋亡的影响，以及 ii) 确定是增加 NO 还是减少 O2- 的形成将有效预防高葡萄糖的影响。目标2。开发反应动力学传输计算模型来模拟 Aim1 实验并预测 EC 水平上的 NO、O2- 和 ONOO- 水平。假设是：i) 由于 NO 和 O2- 之间的高度相互作用，NO 浓度降低且 ONOO- 增加，即使在高葡萄糖条件下内皮细胞释放的 NO 在短时间内增加；ii) 当高葡萄糖条件下 O2- 形成或浓度减少时，NO 浓度增加且 ONOO- 浓度降低。目标3。开发氧化应激过程中微循环中 NO、ROS (O2-) 和活性氮 (RNS; ONOO-) 运输的多尺度计算模型。假设是：i) 内皮细胞功能障碍是超氧化物形成增多的结果，ii) ROS 形成减少会增强 NO 生物利用度，iii) 超氧化物歧化酶水平增加不仅会降低 O2- 水平，还会增加 NO 水平，并通过反馈机制减少 NO 形成。在 EC 层面，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，我们将对含有小动脉血管的组织体积进行建模，并模拟 NO、ROS 和 RNS 的运输。]这种实验和计算相结合的方法对于我们理解 EC 功能障碍的分子机制和研究治疗 EC 功能障碍相关血管并发症的潜在疗法至关重要。公共卫生相关性：内皮细胞 (EC) 功能障碍是许多糖尿病相关微血管和大血管并发症的常见致病框架。高血糖引起的内皮细胞功能障碍的分子机制仍知之甚少。拟议的研究将使用综合计算和实验方法来评估分子、细胞和组织水平上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参数，不仅可以改善内皮细胞功能障碍/NO生物利用度，还可以指导我们开发糖尿病相关血管并发症的治疗方法。