Endothelial cell potassium channels

项目摘要 内皮细胞调节动脉平滑肌细胞收缩性，从而调节局部器官血流和全身血压。内皮细胞对收缩力的控制功能障碍是包括高血压在内的几种心血管疾病的标志，但对所涉及的病理机制了解甚少。膜电位控制内皮细胞功能，但涉及的离子通道和功能意义尚不清楚。瞬时受体电位（TRP）家族的几个成员在内皮细胞中表达，但生理功能尚不清楚。类似地，一些受体配体和刺激物是内皮依赖性血管扩张剂，但其信号传导机制知之甚少。我们的初步数据表明，在内皮细胞中，钾（K+）通道被附近的瞬时受体电位（TRP）通道激活，导致血管舒张。数据还表明，K+通道信号传导在高血压期间功能失调。 为此，我们将研究K+和TRP通道敲除小鼠。将研究三个具体目标。 目的1将验证内皮细胞K+电流调节动脉超极化和血管舒张的假设。目的2探讨TRP通道刺激内皮细胞K+通道产生血管舒张的假说。目的3将研究系统性高血压与内皮细胞中K+通道信号传导的病理性衰减相关的假设，所述病理性衰减通过这些蛋白抑制血管舒张。使用的方法将包括RT-PCR、蛋白质印迹、生物素化、FRET、RNAi、co-IP、免疫荧光、膜片钳电生理学、膜电位记录、细胞内Ca 2+成像、动脉肌电图和血压遥测。 这一建议将提供重要的新信息，血管调节内皮细胞K+通道。

Project Summary Endothelial cells regulate arterial smooth muscle cell contractility, thereby modulating regional organ blood flow and systemic blood pressure. Dysfunctional endothelial cell control of contractility is a hallmark of several cardiovascular diseases, including hypertension, but pathological mechanisms involved are poorly understood. Membrane potential controls endothelial cell functions, but ion channels involved and functional significance are unclear. Several members of the transient receptor potential (TRP) family, are expressed in endothelial cells, but physiological functions are unclear. Similarly, several receptor ligands and stimuli are endothelium-dependent vasodilators, but their signaling mechanisms are poorly understood. Our preliminary data demonstrate that in endothelial cells, potassium (K+) channels are activated by nearby transient receptor potential (TRP) channels, leading to vasodilation. Data also suggest that K+ channel signaling is dysfunctional during hypertension. For this proposal, we will study K+ and TRP channel knockout mice. Three specific aims will be investigated. Aim 1 will test the hypothesis that K+ currents in endothelial cells regulate arterial hyperpolarization and vasodilation. Aim 2 will investigate the hypothesis that TRP channels stimulate K+ channels in endothelial cells, producing vasodilation. Aim 3 will study the hypothesis that systemic hypertension is associated with a pathological attenuation in K+ channel signaling in endothelial cells that inhibits vasodilation by these proteins. Methods used will include RT-PCR, Western blotting, biotinylation, FRET, RNAi, 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 vasoregulation by endothelial cell K+ channels.