TRP Channels In Regulation of Vascular Tone

TRP 通道调节血管张力

• 批准号: 8792399
• 负责人: David X. Zhang
• 金额: $ 37.47万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-02-04 至 2016-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8792399
• 关键词: Acids; Affect; Animals; Applications Grants; Arachidonic Acids; Blood Vessels; Blood flow; Calcium Channel; Cardiovascular Diseases; Cations; Caveolae; Cell membrane; Cell surface; Coronary; Coronary Arteriosclerosis; Coupling; Data; Dilator; Disease; Down-Regulation; Electron Transport; Electrons; Electrophysiology (science); Endoplasmic Reticulum; Endothelial Cells; Endothelium; Event; Fluorescence; Generations; Genetically Engineered Mouse; Goals; Health; Human; Hydrogen Peroxide; Imaging Techniques; In Vitro; Lead; Link; Mechanics; Mediating; Membrane; Microcirculation; Mitochondria; Molecular Biology; Mus; Muscle Cells; Nitric Oxide; Nitric Oxide Donors; Nitric Oxide Synthetase Inhibitor; Outcome; Patients; Phospholipase A2; Physiological; Process; Production; Reactive Oxygen Species; Regional Blood Flow; Regulation; Research; Role; Signal Transduction; Site; Small Interfering RNA; Smooth Muscle; Testing; Time; Tissues; Vanilloid; Vascular Endothelial Cell; Vasodilation; Vasodilator Agents; arteriole; caveolin 1; design; human data; innovation; knock-down; mouse model; new therapeutic target; novel; receptor; relaxing factor; response; shear stress; vascular bed

DESCRIPTION (provided by applicant): Shear stress generated by blood flow is one of the most important physiological regulators of vascular tone. Flow stimulates vascular endothelial cell to release vasodilator factors that subsequently relax underlying smooth muscle, a response often known as flow-mediated dilation (FMD). In human coronary arterioles (HCA), FMD results from the release of two entirely independent dilator factors: nitric oxide (NO) in subjects without coronary artery disease (CAD), and reactive oxygen species (ROS), specifically hydrogen peroxide (H2O2) derived from the mitochondrial electron transport chain, in CAD patients. However, it remains unsolved how shear induces the release of these two distinct relaxing factors. The present proposal will test a central hypothesis that the transient receptor potential vanilloid 4 (TRPV4) channel serves as a common mechanism for the release of two otherwise diversely regulated relaxing factors (NO and mitochondria-derived H2O2) responsible for FMD in the human coronary microcirculation. We further propose that the signaling cascade occurs within caveolae that host novel interactions between the plasma membrane and mitochondria. Studies will be conducted on isolated HCA and cultured endothelial cells using an integrated approach incorporating molecular biology, electrophysiology and fluorescence/electron imaging techniques with in vitro assessment of vessel reactivity. Genetically engineered mice will also be used to provide more definitive corroboration of the human data. Three specific aims are proposed. Aim 1 will determine whether FMD requires endothelial TRPV4 in HCA from patients with or without CAD. We will test the effects of pharmacological inhibition and siRNA downregulation of TRPV4 on flow-induced Ca2+ entry, ROS/NO release, and vasodilation in HCA from CAD and non-CAD subjects. In aim 2, we will examine whether endothelial TRPV4 channels are associated with caveolae and whether this association is essential for shear-induced TRPV4 activation. We will test three caveolae-associated signaling events contributing to TRPV4 activation: namely, TRPV4 translocation, caveolin-1 regulation, and phospholipase A2-epoxyeicosatrienoic acids activation. In aim 3, we will determine whether shear increases mitochondrial ROS through localized Ca2+ signaling involving caveolar TRPV4 and adjacent mitochondria and whether this process is negatively regulated by NO. The proposed research will, for the first time, link endothelial TRPV4, caveolae, and mitochondria as essential signaling components for FMD in humans. We expect the outcomes of this proposal will substantially increase our understanding of the intricate signaling mechanisms involved in FMD in the human coronary microcirculation, and may lead to new therapeutic targets for the treatment of CAD and/or other cardiovascular disorders.

描述（由申请人提供）：血流产生的剪切应力是血管张力的最重要的生理调节剂之一。流动刺激血管内皮细胞以释放血管舒张因子，后来放松基础平滑肌，这种反应通常称为流动介导的扩张（FMD）。在人类冠状动脉（HCA）中，FMD是由两个完全独立的扩张因子释放而产生的：没有冠状动脉疾病（CAD）的受试者中的一氧化物（NO）和反应性氧（ROS），特别是过氧化氢（H2O2），这些氧化物（H2O2）源自CAD患者，来自MITochrial电子传输链。然而，它仍然没有解决剪切如何诱导这两个不同的放松因子的释放。本提案将检验一个中心假设，即瞬态受体电位香草素4（TRPV4）通道是释放两个原本多样化的放松因子（NO和线粒体衍生的H2O2）的共同机制，负责人类冠状动脉微循环中FMD。我们进一步提出，信号级联反应发生在质膜和线粒体之间的新型相互作用中。研究将使用综合分子生物学，电生理学和荧光/电子成像技术对分离的HCA和培养的内皮细胞进行研究，并在体外评估血管反应性。基因工程的小鼠还将用于提供对人类数据的更确定性的佐证。提出了三个具体目标。 AIM 1将确定FMD是否需要患有或没有CAD患者的HCA中的内皮TRPV4。我们将测试TRPV4的药理抑制和siRNA下调对流动诱导的Ca2+进入，ROS/NO释放以及HCA中CAD和非CAD受试者的血管舒张的影响。在AIM 2中，我们将检查内皮TRPV4通道是否与小屋相关，以及该关联对于剪切诱导的TRPV4激活至关重要。我们将测试有助于TRPV4激活的三个小窝相关的信号事件：即TRPV4易位，小窝蛋白-1调节和磷脂酶A2-磷酸酶A2-钙氧基酸酯激活。在AIM 3中，我们将确定剪切是否通过涉及Caveolar TRPV4和相邻线粒体的局部CA2+信号传导增加线粒体ROS，以及该过程是否受NO的负调节。拟议的研究将首次将内皮TRPV4，Caveolae和线粒体作为人类FMD的基本信号传导组件联系起来。我们预计该提案的结果将大大提高我们对人类冠状动脉微循环中FMD的复杂信号传导机制的理解，并可能导致新的治疗靶标，用于治疗CAD和/或其他心血管疾病。