Endothelial cell barrier enhancement by ATP is mediated by the small GTPase Rac and cortactin
Endothelial cell barrier enhancement by ATP is mediated by the small GTPase Rac and cortactin
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DOI：
10.1152/ajplung.00343.2005
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发表时间：
2006-08-01
影响因子：
4.9
通讯作者：
Garcia, Joe G. N.
中科院分区：
文献类型：
--
作者：
Jacobson, Jeffrey R.;Dudek, Steven M.;Garcia, Joe G. N.
ATP是一种生理相关的激动剂，由各种来源（包括活化的血小板）释放，具有通过激活P-2嘌呤能受体介导的复杂效应。ATP诱导的内皮细胞（EC）产生前列环素和一氧化氮是公认的，和EC屏障增强诱发ATP已被描述。然而，ATP对EC屏障功能和血管通透性的影响仍然很差。虽然所涉及的机制尚不清楚，我们以前确定的小GTCRac的激活和corpine，肌动蛋白结合蛋白的易位，作为关键的EC屏障增强辛伐他汀和鞘氨醇1-磷酸诱导，因此检查这些分子在ATP诱导的EC屏障增强的作用。ATP诱导快速，剂量依赖性的屏障增强人肺动脉EC测量跨内皮电阻，峰值效应明显在25分钟（39%的增加，10 μ M）和持续2小时。这些影响与EC肌动蛋白细胞骨架的重排，早期肌球蛋白轻链磷酸化，和空间定义的（细胞周边）易位的Rac和coronin。ATP（10 μ M）处理的EC表现出Rac激活相对于对照组的显着增加，在10分钟的最大效果（类似于4倍增加）。最后，ATP诱导的屏障增强显着衰减的减少Rac或corpine（小干扰RNA）相对于对照组。我们的研究结果首次表明，ATP介导的屏障保护与细胞骨架激活，并依赖于Rac激活和coronin。
ATP is a physiologically relevant agonist released by various sources, including activated platelets, with complex effects mediated via activation of P-2 purinergic receptors. ATP-induced endothelial cell (EC) production of prostacyclin and nitric oxide is recognized, and EC barrier enhancement evoked by ATP has been described. ATP effects on EC barrier function and vascular permeability, however, remain poorly characterized. Although the mechanisms involved are unclear, we previously identified activation of the small GTPase Rac and translocation of cortactin, an actin-binding protein, as key to EC barrier augmentation induced by simvastatin and sphingosine 1-phosphate and therefore examined the role of these molecules in ATP-induced EC barrier enhancement. ATP induced rapid, dose-dependent barrier enhancement in human pulmonary artery EC as measured by transendothelial electrical resistance, with a peak effect appreciable at 25 min (39% increase, 10 mu M) and persisting at 2 h. These effects were associated with rearrangement of the EC actin cytoskeleton, early myosin light chain phosphorylation, and spatially defined (cell periphery) translocation of both Rac and cortactin. ATP (10 mu M)-treated EC demonstrated a significant increase in Rac activation relative to controls, with a maximal effect (similar to 4-fold increase) at 10 min. Finally, ATP-induced barrier enhancement was markedly attenuated by reductions of either Rac or cortactin (small interfering RNA) relative to controls. Our results suggest for the first time that ATP-mediated barrier protection is associated with cytoskeletal activation and is dependent on both Rac activation and cortactin.