期刊
CIRCULATION RESEARCH
卷 111, 期 8, 页码 1027-+出版社
LIPPINCOTT WILLIAMS & WILKINS
DOI: 10.1161/CIRCRESAHA.112.277145
关键词
arterial smooth muscle; Cl-Ca channel; TMEM16A; ANO1; myogenic tone; contractility; smooth muscle cells; membrane potential
资金
- National Heart, Lung, and Blood Institute/National Institutes of Health [HL67061, HL110347, HL094378]
Rationale: Pressure-induced arterial depolarization and constriction (the myogenic response) is a smooth muscle cell (myocyte)-specific mechanism that controls regional organ blood flow and systemic blood pressure. Several different nonselective cation channels contribute to pressure-induced depolarization, but signaling mechanisms involved are unclear. Similarly uncertain is the contribution of anion channels to the myogenic response and physiological functions and mechanisms of regulation of recently discovered transmembrane 16A (TMEM16A), also termed Anoctamin 1, chloride (Cl-) channels in arterial myocytes. Objective: To investigate the hypothesis that myocyte TMEM16A channels control membrane potential and contractility and contribute to the myogenic response in cerebral arteries. Methods and Results: Cell swelling induced by hyposmotic bath solution stimulated Cl-currents in arterial myocytes that were blocked by TMEM16A channel inhibitory antibodies, RNAi-mediated selective TMEM16A channel knockdown, removal of extracellular calcium (Ca2+), replacement of intracellular EGTA with BAPTA, a fast Ca2+ chelator, and Gd3+ and SKF-96365, nonselective cation channel blockers. In contrast, nimodipine, a voltage-dependent Ca2+ channel inhibitor, or thapsigargin, which depletes intracellular Ca2+ stores, did not alter swelling-activated TMEM16A currents. Pressure-induced (-40 mm Hg) membrane stretch activated ion channels in arterial myocyte cell-attached patches that were inhibited by TMEM16A antibodies and were of similar amplitude to recombinant TMEM16A channels. TMEM16A knockdown reduced intravascular pressure-induced depolarization and vasoconstriction but did not alter depolarization-induced (60 mmol/L K+) vasoconstriction. Conclusions: Membrane stretch activates arterial myocyte TMEM16A channels, leading to membrane depolarization and vasoconstriction. Data also provide a mechanism by which a local Ca2+ signal generated by nonselective cation channels stimulates TMEM16A channels to induce myogenic constriction. (Circ Res. 2012;111:1027-1036.)
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据