TRP Channel-Dependent Regulation of Arterial Tone

TRP 通道依赖性动脉张力调节

• 批准号: 8403736
• 负责人: Scott Earley
• 金额: $ 42.28万
• 依托单位: COLORADO STATE UNIVERSITY
• 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 2014-06-26
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8403736
• 关键词: 1,2-diacylglycerol; Acute; Address; Agonist; Arteries; Blood Pressure; Blood Vessels; Blood flow; Calcium Signaling; Caliber; Cardiovascular system; Cell Line; Cell membrane; Cells; Cleaved cell; Coronary Arteriosclerosis; Coupled; Development; Diglycerides; Disease; Down-Regulation; Electrophysiology (science); Event; Generations; Goals; Health; Human; Hypertension; Image; Inositol; Investigation; Ion Channel Protein; Length; Life; Mediating; Mediator of activation protein; Membrane; Membrane Potentials; Microcirculation; Microelectrodes; Muscle; Muscle Cells; Muscle Proteins; Outcome; Pathology; Pharmacologic Substance; Phosphatidylinositol 4,5-Diphosphate; Phosphatidylinositols; Phospholipase C; Physiological; Property; Protein Isoforms; Protein Kinase C; Proteins; Regulation; Role; Sarcoplasmic Reticulum; Second Messenger Systems; Series; Signal Pathway; Signal Transduction; Site; Small Interfering RNA; Smooth Muscle; Smooth Muscle Myocytes; Stimulus; Stroke; Techniques; Technology; Testing; Travel; Vascular Smooth Muscle; Vascular resistance; Vasoconstrictor Agents; Video Microscopy; arteriole; cerebral artery; citrate carrier; constriction; drug discovery; improved; in vivo; novel; patch clamp; phosphatidylinositol phosphate, PtdIns(4,5)P2; pressure; prevent; receptor; research study; response; second messenger; trafficking; vasoconstriction; voltage

Project Summary: The luminal diameter of muscular arteries and arterioles of the microcirculation is the principal site of control of vascular resistance. These small blood vessels are significant regulators of blood pressure and local blood flow distribution, and impaired control of their luminal diameter is a major contributor to cardiovascular-related diseases. Vascular smooth muscle cell membrane potential depolarization is central to the actions of vasoconstrictors, including intravascular pressure. Despite considerable investigation, the mechanisms underlying membrane potential depolarization remain obscure. In this proposal, we will examine the novel concept that activation of the melastatin transient receptor potential (TRP) channel TRPM4 in arterial myocytes integrates signals activated by vasoconstrictor stimuli to cause membrane potential depolarization. Evidence is provided that activation of TRPM4 channels causes membrane depolarization, Ca2+ influx via voltage-dependent Ca2+ channels, and vasoconstriction. Thus, TRPM4 appears to be an important mediator of smooth muscle cell depolarization. As such, an increase in TRPM4 activity or channel number could contribute to vascular pathologies such as hypertension, which are characterized by smooth muscle membrane potential depolarization and vasoconstriction. TRPM4 therefore presents an attractive target for drug-discovery efforts, but currently, little is known about how activity of the channel is controlled under physiological conditions. Phospholipase C (PLC), protein kinase C (PKC), and intracellular Ca2+ dynamics contribute to the control of arterial tone in vivo, and are thought to be important regulators of TRPM4. This proposal will address the central hypothesis that these factors elicit vasoconstriction, in part, by modulating the activity of TRPM4. Experiments are proposed that will use patch-clamp electrophysiology and live-cell confocal imaging experiments to elucidate how TRPM4 activity is regulated by PLC and PKC activity in vascular smooth muscle cells (Specific Aim 1), and by dynamic Ca2+ events involving IP3-mediated Ca2+ release from intracellular stores (Specific Aim 2). Specific Aim 3 will extend these studies to the level of the intact vasculature and investigate the role of PLC, PKC, and Ca2+-dependent regulation of TRPM4 in pressure and agonist-induced vasoconstriction. These experiments will utilize intact cerebral arteries for intracellular microelectrode recordings of smooth muscle membrane potential confocal Ca2+ imaging, and simultaneous contractile and Ca2+ imaging studies. Additional experiments will employ siRNA technology to suppress TRPM4 expression in intact blood vessels. The outcome of these experiments will significantly enhance our understanding of the role of TRPM4 in blood pressure and blood flow regulation, findings that will contribute to the development of novel therapies for the treatment of cardiovascular-related diseases.

项目摘要：微循环的肌肉动脉和动脉的腔直径是 控制血管抗性的主要部位。这些小血管是血液的重要调节剂 压力和局部血流分布以及对腔直径的控制受损是主要贡献者 与心血管相关疾病。血管平滑肌细胞膜电势去极化是中心 血管收缩剂的作用，包括血管内压。尽管进行了大量调查，但 膜电势去极化的机制仍然晦涩。在此提案中，我们将检查 动脉中激活Melastatin瞬态受体电位（TRP）通道TRPM4的新颖概念 心肌细胞整合由血管收缩刺激激活的信号，从而导致膜潜在的去极化。 有证据表明，TRPM4通道的激活会导致膜去极化，Ca2+流入 电压依赖性Ca2+通道和血管收缩。因此，TRPM4似乎是 平滑肌细胞去极化。因此，TRPM4活动或通道号的增加可能会贡献 为血管病理（例如高血压），其特征是平滑肌膜电位 去极化和血管收缩。因此，TRPM4为药物发现努力提供了有吸引力的目标 但是目前，对于在生理条件下如何控制通道的活动知之甚少。 磷脂酶C（PLC），蛋白激酶C（PKC）和细胞内Ca2+动力学有助于控制 体内动脉张力，被认为是TRPM4的重要调节剂。该建议将解决 中心假设，即这些因素部分通过调节TRPM4的活性引起血管收缩。 提出了将使用贴片钳电生理学和活细胞共聚焦成像的实验 阐明如何通过PLC和PKC活性在血管平滑肌中调节TRPM4活性的实验 细胞（特定目标1），以及通过涉及IP3介导的Ca2+从细胞内存储释放的动态Ca2+事件 （特定目标2）。具体目标3将把这些研究扩展到完整的脉管系统水平并研究 PLC，PKC和Ca2+依赖性trpm4的作用在压力和激动剂诱导的 血管收缩。这些实验将利用完整的脑动脉进行细胞内微电极 光滑肌肉膜潜在共聚焦Ca2+成像的记录，同时收缩和 CA2+成像研究。其他实验将采用siRNA技术来抑制TRPM4的表达 完整的血管。这些实验的结果将显着增强我们对角色的理解 TRPM4在血压和血流调节中 治疗心血管相关疾病的疗法。