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最重要的生理调节因子之一。血流刺激血管内皮细胞释放血管舒张因子，随后放松底层平滑肌，这种反应通常称为血流介导的扩张（FMD）。在人类冠状动脉（HCA）中，FMD由两种完全独立的扩张因子的释放引起：无冠状动脉疾病（CAD）的受试者中的一氧化氮（NO），以及CAD患者中的活性氧（ROS），特别是来自线粒体电子传递链的过氧化氢（H2 O2）。然而，它仍然没有解决如何剪切诱导释放这两个不同的松弛因子。目前的建议将测试一个中心的假设，瞬时受体电位香草素4（TRPV 4）通道作为一个共同的机制，释放两个否则diabetes调节松弛因子（NO和H2 O2）负责FMD在人类冠状动脉微循环。我们进一步提出，信号级联发生在细胞膜和线粒体之间的新型相互作用的小窝。将使用整合分子生物学、电生理学和荧光/电子成像技术的综合方法对分离的HCA和培养的内皮细胞进行研究，并对血管反应性进行体外评估。基因工程小鼠也将被用来提供更明确的人类数据的确证。提出了三个具体目标。目的1将确定FMD是否需要患有或不患有CAD的患者的HCA中的内皮TRPV 4。我们将测试药物抑制和siRNA下调TRPV 4对CAD和非CAD受试者HCA中血流诱导的Ca 2+内流、ROS/NO释放和血管舒张的影响。在目标2中，我们将研究内皮TRPV 4通道是否与小窝相关，以及这种相关性是否对剪切诱导的TRPV 4激活至关重要。我们将测试三个小窝相关的信号事件有助于TRPV 4的激活：即，TRPV 4易位，小窝蛋白-1调节，和磷脂酶A2-环氧二十碳三烯酸激活。在目标3中，我们将确定剪切是否通过涉及小窝TRPV 4和邻近线粒体的局部Ca 2+信号传导增加线粒体ROS，以及该过程是否受NO负调控。拟议的研究将首次将内皮TRPV 4，小窝和线粒体作为人类FMD的重要信号传导成分联系起来。我们预计，这一提议的结果将大大增加我们对人类冠状动脉微循环中FMD所涉及的复杂信号传导机制的理解，并可能为治疗CAD和/或其他心血管疾病带来新的治疗靶点。