Role of Hydrogen Peroxide in the Mechanism of Flow-Induced Dilation of the Human

过氧化氢在人体血流诱发扩张机制中的作用

• 批准号: 7573073
• 负责人: David D. Gutterman
• 金额: $ 37.94万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7573073
• 关键词: Acids; Address; Affect; Aftercare; Animals; Arachidonic Acids; Arteries; Biological Assay; Blood Vessels; Calcium; Cell membrane; Cells; Cellular Mechanotransduction; Chronic; Communication; Coronary; Coronary heart disease; Cultured Cells; Cyclic GMP; Cyclic GMP-Dependent Protein Kinases; Cysteine; Cytochrome P450; Data; Dilator; Dimerization; Dinoprostone; Disulfides; Dithiothreitol; Dominant-Negative Mutation; Electron Transport; Endothelial Cells; Endothelium; Enzymes; Event; Exposure to; Figs - dietary; Focal Adhesion Kinase 1; Foundations; Generations; Goals; Guanosine; Guanylate kinase; Heart; Heart Diseases; Human; Hydrogen Peroxide; Laboratories; Link; Literature; Mechanics; Mediating; Membrane; Membrane Potentials; Mitochondria; Muscle; Muscle relaxation phase; NADP; NADPH Oxidase; Nitric Oxide; Nitric Oxide Synthase; Oxidants; Oxidases; Oxidation-Reduction; Pathway interactions; Patients; Peptide Signal Sequences; Perfusion; Physiological; Play; Potassium; Potassium Channel; Preparation; Process; Production; Prostaglandins; Protein Isoforms; Reactive Oxygen Species; Reporting; Resistance; Respiration; Respiratory Chain; Role; Signal Pathway; Signal Transduction; Small Interfering RNA; Smooth Muscle; Smooth Muscle Myocytes; Source; Stress; System; Techniques; Testing; Tissues; Vascular Smooth Muscle; Vasodilation; Vasomotor; Western Blotting; Work; arteriole; autocrine; base; catalase; clinically relevant; feeding; gp91ds-tat; human AKAP13 protein; inhibitor/antagonist; novel; oxidation; paracrine; patch clamp; prevent; public health relevance; research study; response; shear stress; vascular bed

DESCRIPTION (provided by applicant): Shear stress acting on endothelial cells produces vasodilation. This is arguably the most important physiological endothelial mechanism of dilation and occurs in virtually every vascular bed. Our recent data indicate that flow-mediated dilation (FMD) occurs in coronary arterioles from patients with coronary disease but 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. The overall goal of this application is to examine the FMD signaling sequence from endothelium to smooth muscle studying 3 aims. 1) We will examine the mechanism of endothelial production H2O2. Using fresh human coronary arterioles from subjects with coronary disease and cultured human endothelial cells from both microvascular tissue and conduit arteries for comparison. We shall pursue exciting preliminary data that indicate both mitochondria and NADPH oxidase are involved, possibly through a ROS- induced ROS release mechanism and activation of Rac1. 2) Using a novel bioassay technique to assess vasodilation and smooth muscle potassium channel opening, we shall identify the endothelial derived hyperpolarizing factor (EDHF) responsible for dilation. Both arachidonic acid metabolites and H2O2 are necessary for FMD, but preliminary studies point to H2O2 as the transferable dilator agent. 3) We shall determine the mechanism of H2O2 -induced dilation, examining the novel hypothesis that H2O2 directly acts on PKG11 by cysteine oxidation, yielding an activated disulfide dimeric form of the enzyme. These goals span a broad, clinically relevant redox signaling pathway from endothelial H2O2 formation, to H2O2 release as a transferable vasomotor substance, to its mechanism of action on underlying smooth muscle cells. Collectively these aims address a novel mechanism of endothelium-dependent dilation involving mitochondrial generation of ROS, thus far reported only in human hearts. Results should identify new links among cellular mechanotransduction, respiration, and redox signaling that regulates important physiological events such as arteriolar vasodilation, responsible for tissue perfusion. The direct relevance to humans with chronic coronary disease provides a strong foundation for this mechanistic approach to understanding microvascular reactivity. PUBLIC HEALTH RELEVANCE: Dilation resulting from shear stress acting on endothelial cells is arguably the most important physiological endothelial mechanism of dilation, and occurs in virtually every vascular bed. Although examined extensively in animals, we examine blood vessels directly from humans with heart disease to clarify the mechanisms involved. Our findings show a unique mechanism of dilation involving mitochondrial generation of ROS, thus far reported only in human hearts. Results of this proposal should identify new links among cellular mechanotransduction, respiration, and redox signaling that regulates important physiological events such as arteriolar vasodilation, responsible for tissue perfusion. The direct relevance to humans with chronic coronary disease provides a strong foundation for this mechanistic approach to understanding microvascular reactivity.

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，这是扩张的最重要的生理内皮机制，几乎发生在每个血管床中。我们最近的数据表明，流动介导的扩张（FMD）发生在冠状动脉疾病患者的冠状动脉动脉中，但通过涉及内皮产生活性氧（ROS）的新机制，包括过氧化氢（H2O2）。令人惊讶的是，线粒体呼吸链在人心脏的FMD中起必要的作用。该应用的总体目标是检查从内皮到平滑肌肉研究3个目标的FMD信号传导序列。 1）我们将检查内皮产生H2O2的机制。使用来自微血管组织和导管动脉的冠状动脉疾病和培养的人内皮细胞的新鲜人冠状动脉动脉进行比较。我们将追求令人兴奋的初步数据，以表明线粒体和NADPH氧化酶都参与其中，这可能是通过ROS诱导的ROS释放机制和Rac1的激活。 2）使用新型的生物测定技术评估血管舒张和平滑肌钾通道的开口，我们将确定负责扩张的内皮衍生的超极化因子（EDHF）。对于FMD，蛛网膜酸代谢产物和H2O2都是必需的，但初步研究指向H2O2是可转移的扩张剂。 3）我们应确定H2O2诱导的扩张的机制，研究H2O2直接通过半胱氨酸氧化直接作用于PKG11的新假设，从而产生了酶的活化二硫化物二聚体形式。这些目标跨越了从内皮H2O2形成到H2O2作为可转移的血管舒缩物质的广泛，临床相关的氧化还原信号通路，再到其对平滑肌细胞潜在的作用机理。这些目的共同解决了涉及线粒体产生ROS的内皮依赖性扩张的新机制，迄今仅在人类心脏中报道。结果应确定调节重要生理事件的细胞机械转导，呼吸和氧化还原信号之间的新联系，例如小动脉血管舒张，负责组织灌注。与慢性冠状动脉疾病的人类的直接相关性为理解微血管反应性的这种机械方法奠定了坚实的基础。公共卫生相关性：作用于内皮细胞的剪切应力引起的扩张是扩张的最重要的生理内皮机理，并且几乎发生在每个血管床中。尽管在动物中进行了广泛的检查，但我们直接检查了来自患有心脏病的人的血管，以阐明所涉及的机制。我们的发现显示了涉及线粒体产生ROS的独特机制，到目前为止，仅在人类心脏中报道。该提案的结果应确定细胞机械转导，呼吸和氧化还原信号之间的新联系，这些联系调节了重要的生理事件，例如小动脉血管舒张，负责组织灌注。与慢性冠状动脉疾病的人类的直接相关性为理解微血管反应性的这种机械方法奠定了坚实的基础。