Cilostazol Suppresses Angiotensin II-Induced Vasoconstriction via Protein Kinase A-Mediated Phosphorylation of the Transient Receptor Potential Canonical 6 Channel
Cilostazol Suppresses Angiotensin II-Induced Vasoconstriction via Protein Kinase A-Mediated Phosphorylation of the Transient Receptor Potential Canonical 6 Channel
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DOI：
10.1161/atvbaha.110.221010
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发表时间：
2011-10-01
影响因子：
8.7
通讯作者：
Kurose, Hitoshi
中科院分区：
文献类型：
--
作者：
Nishioka, Kinue;Nishida, Motohiro;Kurose, Hitoshi
本研究的目的是确定是否抑制瞬时受体电位典型（TRPC）通道的衰减血管紧张素II（Ang II）诱导的血管收缩的磷酸二酯酶（PDE）3 inhibit 1 n.Methods and Results-Pretreatment of rat thoracic aortic with cilostazol，一种选择性的PDE 3抑制剂，抑制血管收缩诱导的Ang II，但不诱导KCl。Ang II诱导的收缩在很大程度上依赖于通过受体操纵的阳离子通道的Ca 2+内流。西洛他唑通过蛋白激酶A（PKA）依赖性磷酸化HEK 293细胞中TRPC通道特异性抑制二酰基甘油激活的TRPC通道（TRPC 3/TRPC 6/TRPC 7）。与此相反，我们发现TRPC 6在Thr 69的磷酸化对于PDE 3抑制大鼠主动脉平滑肌细胞（RAoSMCs）中Ang II诱导的Ca 2+内流的抑制是必不可少的。西洛他唑特异性诱导内源性TRPC 6在Thr 69的磷酸化。在RAoSMC中，内源性TRPC 6而不是TRPC 3与PDE 3和PKA形成三元复合物，表明PDE 3抑制TRPC 6磷酸化的特异性。此外，PDE 3的抑制抑制了Ang II诱导的RAoSMC重构环的收缩，而TRPC 6的磷酸化缺陷突变体的表达则消除了这种抑制作用。结论PKA介导的TRPC 6的Thr 69磷酸化是PDE 3抑制对抗Ang II缩血管作用的血管舒张效应的关键。（Arterioscler Thromb Vasc Biol.2011;31：2278-2286.）
Objective-The goal of this study was to determine whether inhibition of transient receptor potential canonical (TRPC) channels underlies attenuation of angiotensin II (Ang II)-induced vasoconstriction by phosphodiesterase (PDE) 3 inhibition.Methods and Results-Pretreatment of rat thoracic aorta with cilostazol, a selective PDE3 inhibitor, suppressed vasoconstriction induced by Ang II but not that induced by KCl. The Ang II-induced contraction was largely dependent on Ca2+ influx via receptor-operated cation channels. Cilostazol specifically suppressed diacylglycerol-activated TRPC channels (TRPC3/TRPC6/TRPC7) through protein kinase A (PKA)-dependent phosphorylation of TRPC channels in HEK293 cells. In contrast, we found that phosphorylation of TRPC6 at Thr69 was essential for the suppression of Ang II-induced Ca2+ influx by PDE3 inhibition in rat aortic smooth muscle cells (RAoSMCs). Cilostazol specifically induced phosphorylation of endogenous TRPC6 at Thr69. The endogenous TRPC6, but not TRPC3, formed a ternary complex with PDE3 and PKA in RAoSMCs, suggesting the specificity of TRPC6 phosphorylation by PDE3 inhibition. Furthermore, inhibition of PDE3 suppressed the Ang II-induced contraction of reconstituted ring with RAoSMCs, which were abolished by the expression of a phosphorylation-deficient mutant of TRPC6.Conclusion-PKA-mediated phosphorylation of TRPC6 at Thr69 is essential for the vasorelaxant effects of PDE3 inhibition against the vasoconstrictive actions of Ang II. (Arterioscler Thromb Vasc Biol. 2011;31:2278-2286.)