Vasoregulation by IP3 receptor coupling to TRPC channels

通过 IP3 受体与 TRPC 通道偶联进行血管调节

• 批准号: 7679753
• 负责人: Adebowale Adebiyi
• 金额: $ 11.19万
• 依托单位: UNIVERSITY OF TENNESSEE HEALTH SCI CTR
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-15 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7679753
• 关键词: 11p; ATP phosphohydrolase; Arteries; Attenuated; Biological Assay; Blood Pressure; Blood Vessels; Blood flow; Calcium; Caliber; Cations; Caveolae; Cell membrane; Cholesterol; Co-Immunoprecipitations; Computer software; Coupling; Data; Electrophysiology (science); Endothelium; Energy Transfer; Event; Figs - dietary; Fura-2; Genes; Glass; Hypertension; ITPR1 gene; Image; Immunofluorescence Immunologic; Inositol; Instruction; Knowledge; Lead; Measures; Mediating; Membrane; Membrane Potentials; Microelectrodes; Molecular; Molecular Biology; Mus; Muscle Cells; Myography; Organ; Pathway interactions; Phospholipase C; Physiology; Principal Investigator; Protein Isoforms; Proteins; Publishing; Regulation; Reporting; Reticulum; Role; Sarcoplasmic Reticulum; Second Messenger Systems; Signal Transduction; Smooth Muscle; Smooth Muscle Myocytes; Stroke; Structural Protein; TRP channel; TRPC3 ion channel; Techniques; Testing; Tissues; Vascular Diseases; Vasoconstrictor Agents; abstracting; caveolin 1; cerebral artery; computerized data processing; constriction; insight; methyl-beta-cyclodextrin; novel; patch clamp; ratiometric; receptor; receptor coupling; research study; second messenger; small hairpin RNA; vasoconstriction; voltage

DESCRIPTION (provided by applicant): Arterial diameter, a principal modulator of systemic blood pressure and organ blood flow is regulated by changes in the contractility of arterial myocytes. The contractile status of arterial myocytes is determined by several local and global intracellular calcium([Ca2+]i) signals. Ca2+ signal and diameter regulation byinositol 1,4,5-trisphophate (IPS), a phospholipase C-generated second messenger is poorly understood. The conventional view has been that IPS constricts arteries by stimulatingsarcoplasmic reticulum(SR) Ca2+ release in myocytes. Our recently published data indicateda novel mechanism of IPS-induced vasoconstriction that occurred independentlyof SRCa2+ release, and via IPS receptor (IP3R)-and canonicaltransient receptor potential (TRPC) 3-dependent cation current (ICat) activation.However, mechanisms by which IP3R activation stimulates TRPC channelsin arterial myocytes to regulate arterial diameter are unclear. Preliminary data suggest that physical couplingbetween myocyte IPSRs and TRPC3 channels regulates IPS-induced vasoconstriction. Data also indicate that arterial myocyte caveolae facilitate this IP3R-TRPCchannel vasoregulatory mechanism. The central hypothesis ofthis proposal is that in cerebral artery myocytes, caveolae facilitate TRPC3 channel couplingwith IPSRs to mediate vasoconstrictor and IPS-induced membrane depolarization, voltage-dependent Ca2+ channel activation, [Ca2+]i elevation, and contraction. This proposal will investigate 3 specific aims: Aim 1 will test the hypothesis that in cerebral artery myocytes, IP3R to TRPC3 channel physical couplingis required for IPS-inducedICat activation.Aim 2 will test the hypothesis that IP3R to TRPC3 couplingmediates IPS-induced membrane depolarization, [Ca2+]i elevation, and constriction in cerebral arteries. Aim 3 will examine the hypothesis that arterial myocyte caveolae mediate physical and functional coupling of TRPC3 channelsto IPSRs. Experiments to study these aims will integrate techniques performed at molecular, cellular,and intact tissue levels, including Ca2+ imaging,FRET, electrophysiology, pressurized artery myography, and gene suppression. RELEVANCE (See instructions): Mechanisms that regulate blood pressure and flow are incompletely understood. Alterations in arterial contractility are associated with vascular diseases, including stroke and hypertension. This proposal will enhance our knowledge of a novel signaling event that modulates arterial contractility, and will ultimately lead to better insights into alterations that occur in vascular disease. (End of Abstract)

描述（由申请人提供）：动脉直径是全身血压和器官血流的主要调节剂，通过动脉肌细胞收缩力的变化来调节。动脉肌细胞的收缩状态由多个局部和整体细胞内钙 ([Ca2+]i) 信号决定。肌醇 1,4,5-三磷酸酯 (IPS)（一种磷脂酶 C 生成的第二信使）对 Ca2+ 信号和直径的调节知之甚少。传统观点认为，IPS 通过刺激肌细胞中肌浆网 (SR) Ca2+ 的释放来收缩动脉。我们最近发表的数据表明，IPS 诱导的血管收缩的新机制独立于 SRCa2+ 释放而发生，并通过 IPS 受体 (IP3R) 和典型瞬时受体电位 (TRPC) 3 依赖性阳离子电流 (ICat) 激活。然而，IP3R 激活刺激动脉肌细胞中的 TRPC 通道以调节动脉直径的机制是 不清楚。初步数据表明，肌细胞 IPSR 和 TRPC3 通道之间的物理耦合可调节 IPS 诱导的血管收缩。数据还表明，动脉肌细胞小凹促进了这种 IP3R-TRPC 通道血管调节机制。该提议的中心假设是，在脑动脉肌细胞中，小窝促进 TRPC3 通道与 IPSR 偶联，介导血管收缩剂和 IPS 诱导的膜去极化、电压依赖性 Ca2+ 通道激活、[Ca2+]i 升高和收缩。该提案将研究 3 个具体目标：目标 1 将测试以下假设：在脑动脉肌细胞中，IP3R 与 TRPC3 通道物理耦合是 IPS 诱导的 ICat 激活所必需的。目标 2 将测试 IP3R 与 TRPC3 耦合介导 IPS 诱导的脑动脉膜去极化、[Ca2+]i 升高和收缩的假设。目标 3 将检验动脉肌细胞小凹介导 TRPC3 通道与 IPSR 的物理和功能耦合的假设。研究这些目标的实验将整合在分子、细胞和完整组织水平上进行的技术，包括 Ca2+ 成像、FRET、电生理学、加压动脉肌动描记术和基因抑制。相关性（参见说明）：调节血压和血流量的机制尚不完全清楚。动脉收缩力的改变与血管疾病有关，包括中风和高血压。该提议将增强我们对调节动脉收缩力的新型信号事件的了解，并最终更好地了解血管疾病中发生的变化。 （摘要完）