Protein kinase C modifications of VE-cadherin, p120, and β-catenin contribute to endothelial barrier dysregulation induced by thrombin
Protein kinase C modifications of VE-cadherin, p120, and β-catenin contribute to endothelial barrier dysregulation induced by thrombin
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DOI：
10.1152/ajplung.00075.2003
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发表时间：
2003-08-01
影响因子：
4.9
通讯作者：
Malik, AB
中科院分区：
文献类型：
--
作者：
Konstantoulaki, M;Kouklis, P;Malik, AB
粘附连接是由跨膜血管内皮钙粘蛋白（VEC）和细胞质连环蛋白（p120、β-连环蛋白、斑珠蛋白、α-连环蛋白）组成的多蛋白复合物，负责维持内皮屏障功能。钙粘蛋白/连环蛋白复合物的连接解体和修饰导致内皮屏障的细胞旁通透性增加。然而，连接解体的机制仍不清楚。在这项研究中，我们使用了促炎介质凝血酶妥协的屏障功能和测试的假设，磷酸化诱导的改变血管内皮细胞，β-连环蛋白，和p120调节连接拆卸和介导的内皮通透性增加的反应。该研究表明，凝血酶诱导VEC的去磷酸化，这与细胞-细胞接触的解体相耦合，但VEC仍以聚集体的形式留在质膜上。胞浆连环蛋白从内皮细胞胞浆区解离，形成上皮间隙中的薄膜突起。我们还发现，凝血酶诱导β-连环蛋白的去磷酸化和p120的磷酸化。凝血酶诱导的内皮间隙形成和内皮通透性增加被蛋白激酶C抑制作用阻断，使用白屈菜红碱和Go-6976，但不是LY-379196。白屈菜红碱也防止凝血酶诱导的钙粘蛋白/连环蛋白复合物的磷酸化变化。因此，本研究将VEC、β-连环蛋白和p120的翻译后修饰与凝血酶诱导的内皮通透性增加的机制联系起来。
The adherens junction is a multiprotein complex consisting of the transmembrane vascular endothelial cadherin (VEC) and cytoplasmic catenins (p120, beta-catenin, plakoglobin, alpha-catenin) responsible for the maintenance of endothelial barrier function. Junctional disassembly and modifications in cadherin/catenin complex lead to increased paracellular permeability of the endothelial barrier. However, the mechanisms of junctional disassembly remain unclear. In this study, we used the proinflammatory mediator thrombin to compromise the barrier function and test the hypothesis that phosphorylation-induced alterations of VEC, beta-catenin, and p120 regulate junction disassembly and mediate the increased endothelial permeability response. The study showed that thrombin induced dephosphorylation of VEC, which is coupled to disassembly of cell-cell contacts, but VEC remained in aggregates at the plasma membrane. The cytoplasmic catenins dissociated from the VEC cytoplasmic domain in thin membrane projections formed in interendothelial gaps. We also showed that thrombin induced dephosphorylation of beta-catenin and phosphorylation of p120. Thrombin-induced interendothelial gap formation and increased endothelial permeability were blocked by protein kinase C inhibition using chelerythrine and Go-6976 but not by LY-379196. Chelerythrine also prevented thrombin-induced phosphorylation changes of the cadherin/catenin complex. Thus the present study links posttranslational modifications of VEC, beta-catenin, and p120 to the mechanism of thrombin-induced increase in endothelial permeability.