Functional significance of differential eNOS translocation
Functional significance of differential eNOS translocation
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DOI：
10.1152/ajpheart.00370.2006
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发表时间：
2006-09-01
影响因子：
4.8
通讯作者：
Duran, Walter N.
中科院分区：
文献类型：
--
作者：
Sanchez, Fabiola A.;Savalia, Nirav B.;Duran, Walter N.
一氧化氮（NO）调节流动和渗透性。ACh和血小板活化因子（PAF）导致内皮NO合酶（eNOS）磷酸化和NO释放。而ACh只引起血管舒张，PAF引起血管收缩和高通透性。区分血管舒张和高通透性的关键差异信号传导机制尚不清楚。我们测试的假设，差异易位可能作为一种调节机制，eNOS，以确定特定的血管反应。我们使用了永久转染eNOS-绿色荧光蛋白（ECVeNOS-GFP）的ECV-304细胞，并证明了激动剂激活eNOS并在这些细胞中重现其特征性内皮渗透性效应。我们评估eNOS定位脂筏分析和免疫荧光显微镜。在PAF和ACh之后，eNOS远离小窝。eNOS在对照细胞中既分布在质膜上，也分布在高尔基体上。ACh（10（-5）M，10（-4）M）优先将eNOS转运至trans-Golgi网络（TGN），PAF（10（-7）M）优先转运至胞浆。我们认为，PAF诱导的eNOS易位优先胞质溶胶反映了一个差异的信号转导机制，相关的通透性变化，而乙酰胆碱诱导的eNOS易位的TGN血管舒张。
Nitric oxide (NO) regulates flow and permeability. ACh and platelet-activating factor (PAF) lead to endothelial NO synthase (eNOS) phosphorylation and NO release. While ACh causes only vasodilation, PAF induces vasoconstriction and hyperpermeability. The key differential signaling mechanisms for discriminating between vasodilation and hyperpermeability are unknown. We tested the hypothesis that differential translocation may serve as a regulatory mechanism of eNOS to determine specific vascular responses. We used ECV-304 cells permanently transfected with eNOS-green fluorescent protein (ECVeNOS-GFP) and demonstrated that the agonists activate eNOS and reproduce their characteristic endothelial permeability effects in these cells. We evaluated eNOS localization by lipid raft analysis and immunofluorescence microscopy. After PAF and ACh, eNOS moves away from caveolae. eNOS distributes both in the plasma membrane and Golgi in control cells. ACh (10(-5) M, 10(-4) M) translocated eNOS preferentially to the trans-Golgi network (TGN) and PAF (10(-7) M) preferentially to the cytosol. We suggest that PAF-induced eNOS translocation preferentially to cytosol reflects a differential signaling mechanism related to changes in permeability, whereas ACh-induced eNOS translocation to the TGN is related to vasodilation.