Flow-Mediated Dilation of Human Coronary Arterioles

人冠状动脉的血流介导扩张

• 批准号: 7038684
• 负责人: David D. Gutterman
• 金额: $ 37.88万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-01-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7038684
• 关键词: antifungal antibiotics; antioxidants; arterioles; biological signal transduction; cellular respiration; clinical research; coronary vessels; cytoskeletal proteins; free radical oxygen; hemodynamics; human tissue; hydrogen peroxide; mitochondria; nitric oxide; shear stress; small interfering RNA; tissue /cell culture; tumor necrosis factor alpha; vascular endothelium; vasodilation; vasodilators

DESCRIPTION (provided by applicant): Shear stress acting on endothelial cells produces vasodilation. This is arguably the most physiologically important endothelial mechanism of dilation and occurs in virtually every vascular bed. Recent data from our laboratory indicate that flow-mediated dilation (FMD) occurs in coronary arterioles from patients with coronary disease however it operates through a novel mechanism involving endothelial production of reactive oxygen species (ROS) including hydrogen peroxide (H2O2). Surprisingly the mitochondrial respiratory chain plays a necessary role in FMD in the human heart, however it is not known how mitochondria are involved in the transduction of mechanical shear stress on the surface of the endothelium to elicit dilation. Our overall hypothesis is that shear acting on endothelial cells through attached cytoskeletal elements stimulates release from the mitochondria of H2O2, an endothelial derived hyperpolarizing factor (EDHF). We shall test this hypothesis in three ways. First antimycin A and TNFalpha will be used to determine if pharmacological stimulation of mitochondrial ROS release can elicit dilation of human coronary arterioles. In separate studies, we shall use novel antioxidants targeted to the mitochondrial inner membrane to determine whether H2O2 generated from within the mitochondria is necessary for FMD. A bioassay system will confirm whether H2O2 is indeed an EDHF mediating FMD in the human coronary circulation. Second we will use immunohistochemistry and specific pharmacological and molecular approaches including siRNA to determine whether endothelial cytoskeletal elements play a necessary role in FMD and mitochondrial ROS generation. Third, we shall test the hypothesis that nitric oxide through its inhibitory effect on mitochondrial respiration reduces FMD in the human heart. This will be done using nitric oxide donors, measuring mitochondrial complex activity and ROS generation. These experiments may identify a pathway not previously described by which nitric oxide can inhibit EDHF-mediated dilation; namely, by blocking mitochondrial production of ROS. Collectively these aims address a novel mechanism of endothelium-dependent vasodilation involving mitochondrial generation of ROS, thus far reported only in human hearts. These studies should identify new links among cell processes including mechanotransduction, respiration, and redox signaling that regulate physiological events such as vasodilation.

描述（由申请人提供）：作用于内皮细胞的剪切应力会产生血管舒张。可以说，这是扩张最重要的内皮内皮机理，几乎发生在每个血管床中。我们实验室的最新数据表明，流动介导的扩张（FMD）发生在冠状动脉疾病患者的冠状动脉菌中发生，但是它通过涉及内皮产生活性氧（ROS）的新机制运行，包括过氧化氢（H2O2）。令人惊讶的是，线粒体呼吸链在人心中的FMD中起必要的作用，但是尚不清楚线粒体如何参与内皮表面上机械剪应力的转导以引起扩张。我们的总体假设是，通过附着的细胞骨架元素在内皮细胞上作用剪切刺激从H2O2的线粒体释放，这是一种内皮衍生的超极化因子（EDHF）。我们将以三种方式检验这一假设。第一抗霉素A和TNFALPHA将用于确定线粒体ROS释放的药理刺激是否会引起人类冠状动脉的扩张。在单独的研究中，我们将使用针对线粒体内膜的新型抗氧化剂来确定FMD是否需要从线粒体内产生的H2O2。生物测定系统将确认H2O2是否确实是人类冠状动脉循环中介导FMD的EDHF。其次，我们将使用包括siRNA在内的免疫组织化学以及特定的药理和分子方法来确定内皮细胞骨架元素是否在FMD和线粒体ROS产生中起必要作用。第三，我们将检验以下假设：一氧化氮通过其对线粒体呼吸的抑制作用减少了人心中的FMD。这将使用一氧化氮供体，测量线粒体复合活性和ROS产生。这些实验可以确定一氧化氮可以抑制EDHF介导的扩张的途径。也就是说，通过阻断ROS的线粒体产生。这些目的共同解决了涉及线粒体产生ROS的内皮依赖性血管舒张的新机制，迄今仅在人类心脏中报道。这些研究应确定细胞过程之间的新联系，包括调节血管舒张等生理事件的机械转导，呼吸和氧化还原信号传导。