Activation of endothelial transient receptor potential C3 channel is required for small conductance calcium-activated potassium channel activation and sustained endothelial hyperpolarization and vasodilation of cerebral artery.
Activation of endothelial transient receptor potential C3 channel is required for small conductance calcium-activated potassium channel activation and sustained endothelial hyperpolarization and vasodilation of cerebral artery.
复制标题
小型电导钙激活的钾通道激活和持续的内皮性超极化和脑动脉血管舒张需要，内皮瞬态受体电位C3通道的激活是必需的。
DOI：
10.1161/jaha.114.000913
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发表时间：
2014-08-20
影响因子：
5.4
通讯作者：
Marrelli SP
中科院分区：
文献类型：
--
作者：
Kochukov MY;Balasubramanian A;Abramowitz J;Birnbaumer L;Marrelli SP
瞬时受体电位C3（TRPC 3）已被证明通过内皮细胞（EC）超极化和内皮依赖性超极化介导的血管舒张参与血管张力的调节。然而，TRPC 3调节这些过程的机制仍然没有得到解决。我们测试了内皮受体刺激触发TRPC 3快速运输至质膜的假设，在质膜中，它为小电导钙激活K+（SKCa）通道激活和持续EC超极化提供了Ca2+内流的来源。用分离的小鼠大脑后动脉进行加压动脉研究。使用选择性TRPC 3阻断剂（Pyr3）治疗可显著减弱内皮依赖性超极化介导的血管舒张和内皮细胞对腔内ATP的Ca2+反应（EC特异性Ca2+生物传感器）。Pyr3处理还导致脑内皮细胞原代培养物中ATP刺激的整体Ca2+和Ca2+内流减少。用新鲜分离的脑EC进行的膜片钳研究证明了响应ATP的EC超极化和K+电流激活的2个组成部分。早期阶段依赖于中间电导钙激活K+通道激活，而后期持续阶段依赖于SKCa通道激活。SKCa通道依赖性阶段被TRPC 3通道抑制剂完全阻断，或在TRPC 3敲除小鼠的EC中完全阻断，并且与TRPC 3（而不是SKCa通道）向质膜的运输增加相关。我们提出TRPC 3通过受体依赖性运输到质膜来动态调节SKCa通道激活，在质膜上它为持续的SKCa通道激活、EC超极化和内皮依赖性超极化介导的血管舒张提供Ca2+内流的来源。
Transient receptor potential C3 (TRPC3) has been demonstrated to be involved in the regulation of vascular tone through endothelial cell (EC) hyperpolarization and endothelium‐dependent hyperpolarization–mediated vasodilation. However, the mechanism by which TRPC3 regulates these processes remains unresolved. We tested the hypothesis that endothelial receptor stimulation triggers rapid TRPC3 trafficking to the plasma membrane, where it provides the source of Ca2+ influx for small conductance calcium‐activated K+ (SKCa) channel activation and sustained EC hyperpolarization. Pressurized artery studies were performed with isolated mouse posterior cerebral artery. Treatment with a selective TRPC3 blocker (Pyr3) produced significant attenuation of endothelium‐dependent hyperpolarization–mediated vasodilation and endothelial Ca2+ response (EC‐specific Ca2+ biosensor) to intraluminal ATP. Pyr3 treatment also resulted in a reduced ATP‐stimulated global Ca2+ and Ca2+ influx in primary cultures of cerebral endothelial cells. Patch‐clamp studies with freshly isolated cerebral ECs demonstrated 2 components of EC hyperpolarization and K+ current activation in response to ATP. The early phase was dependent on intermediate conductance calcium‐activated K+ channel activation, whereas the later sustained phase relied on SKCa channel activation. The SKCa channel–dependent phase was completely blocked with TRPC3 channel inhibition or in ECs of TRPC3 knockout mice and correlated with increased trafficking of TRPC3 (but not SKCa channel) to the plasma membrane. We propose that TRPC3 dynamically regulates SKCa channel activation through receptor‐dependent trafficking to the plasma membrane, where it provides the source of Ca2+ influx for sustained SKCa channel activation, EC hyperpolarization, and endothelium‐dependent hyperpolarization–mediated vasodilation.