Blood pressure regulation by smooth muscle cell ion channels

平滑肌细胞离子通道调节血压

基本信息

批准号：
9912820
负责人：
Jonathan H Jaggar
金额：
$ 38万
依托单位：
UNIVERSITY OF TENNESSEE HEALTH SCI CTR
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-04-01 至 2023-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9912820
关键词：
Ablation Agonist Arteries Attenuated Biotinylation Blood Pressure Calcium Cardiovascular Diseases Cations Cell membrane Cells Co-Immunoprecipitations Complex Data Electrophysiology (science)Fluorescence Resonance Energy Transfer Goals Human Hypertension Image Immunofluorescence Immunologic Ion Channel Knock-out Knockout Mice Knowledge Measures Membrane Membrane Potentials Methods Modeling Mus Muscle Cells Myography Pathologic Phenylephrine Physiological Population Probability Property Proteins Regulation Resistance Reverse Transcriptase Polymerase Chain Reaction Signal Transduction Smooth Muscle Myocytes Stimulus Surface Systemic blood pressure Systemic hypertension TRP channel Telemetry Testing Vasoconstrictor Agents Western Blotting arteriole blood pressure regulation constriction experimental study in vivo normotensive novel patch clamp polycystic kidney disease 1 protein pressure receptor stem trafficking vasoconstriction

项目摘要

Systemic blood pressure is regulated by smooth muscle cells (myocytes) of small (resistance-size) arteries and arterioles. A key regulator of arterial myocyte contractility is membrane potential, which is controlled by plasma membrane ion channels. Arteries from hypertensive subjects are depolarized, leading to vasoconstriction, but mechanisms involved in this pathological alteration are unclear. Arterial myocytes express several different transient receptor potential (TRP) channels, but physiological systemic blood pressure regulation and involvement of these proteins during hypertension is unclear. This lack of knowledge exists largely because TRP subfamily expression, regulation and function in myocytes of arteries that control blood pressure is unclear, there are no specific TRP channel modulators and global TRP channel knockout mice produced confusing effects on blood pressure. Arterial myocytes express TRP polycystin 1 (TRPP1) channels, but blood pressure regulation by these proteins, signaling mechanisms involved and the concept that targeting of these proteins alleviates hypertension have not been studied. For this proposal, we created the first conditional, myocyte-specific TRPP1 knockout (TRPP1sm-/-) mice to test these hypotheses. Cellular current (I) generated by a membrane ion channel population is determined by number (N), open probability (Po) and single channel current (i), such that I=N.Po.i. Previous studies have primarily examined cell currents (I) generated by TRP channels in myocytes. In contrast, contributions of N and Po to currents are poorly understood. This application stems from novel preliminary data suggesting that regulation of myocyte TRPP1 channel surface N and Po controls arterial contractility and blood pressure, TRPP1 channels are upregulated during hypertension, and myocyte-specific TRPP1 knockout alleviates hypertension. Three specific aims will be investigated. Aim 1 will examine the hypothesis that myocyte TRPP1 channels control arterial contractility and systemic blood pressure using novel, inducible, myocyte-specific TRPP1 knockout mice. Aim 2 will investigate the hypothesis that physiological stimuli regulate both TRPP1 channel surface abundance and open probability in myocytes to control arterial contractility. Aim 3 will explore the hypothesis that systemic hypertension is associated with an increase in arterial myocyte TRPP1 channel surface expression that contributes to vasoconstriction and that myocyte-specific TRPP1 ablation attenuates hypertension. Methods used to test these hypotheses will include arterial biotinylation, FRET, co-IP, immunofluorescence, patch-clamp electrophysiology, membrane potential recording, intracellular Ca2+ imaging, arterial myography and blood pressure telemetry. This proposal will provide significant novel information concerning blood pressure regulation by arterial myocyte TRPP1 channels.

全身性血压受小（电阻大小）动脉的平滑肌细胞（肌细胞）调节小动脉。动脉肌细胞收缩力的关键调节剂是膜电位，由等离子体控制膜离子通道。高血压受试者的动脉被去极化，导致血管收缩，但这种病理改变涉及的机制尚不清楚。动脉肌细胞表达几种不同瞬态受体电位（TRP）通道，但生理系统性血压调节和这些蛋白质在高血压期间的参与尚不清楚。缺乏知识的存在很大程度上是因为控制血压的动脉肌细胞中TRP亚家族表达，调节和功能尚不清楚，没有特定的TRP通道调节器和产生的全局TRP通道敲除小鼠对血压的影响令人困惑。动脉肌细胞表达TRP polycystin 1（TRPP1）通道，但血液这些蛋白质的压力调节，涉及的信号传导机制以及针对这些的概念尚未研究蛋白质减轻高血压。对于此建议，我们创建了第一个条件，心肌细胞特异性TRPP1敲除（TRPP1SM - / - ）小鼠以检验这些假设。生成的蜂窝电流（i）由膜离子通道总体由数（n），开放概率（PO）和单个通道确定当前（i），使得i = n.po.i。先前的研究主要检查了TRP产生的细胞电流（i）肌细胞中的频道。相反，N和PO对电流的贡献知之甚少。这应用源于新的初步数据，表明对心肌细胞TRPP1通道表面N的调节n PO控制动脉收缩和血压，高血压期间TRPP1通道被上调，而特定于心肌细胞的TRPP1敲除可以减轻高血压。将研究三个具体目标。目标1 将研究肌细胞TRPP1通道控制动脉收缩和全身血液的假设使用新颖的，可诱导的肌细胞特异性TRPP1敲除小鼠的压力。 AIM 2将研究假设这种生理刺激调节了TRPP1通道表面丰度和心肌细胞的开放概率控制动脉收缩。 AIM 3将探讨系统性高血压与增加动脉肌细胞TRPP1通道表面表达，导致血管收缩，并且肌细胞特异性TRPP1消融可减轻高血压。用于检验这些假设的方法将包括动脉生物素化，FRET，co-IP，免疫荧光，斑块钳电生理学，膜电位记录，细胞内Ca2+成像，动脉典范和血压遥测。该提议将提供有关动脉肌细胞TRPP1血压调节的重要新信息频道。