Essential Role of Cofilin-1 in Regulating Thrombin-induced RelA/p65 Nuclear Translocation and Intercellular Adhesion Molecule 1 (ICAM-1) Expression in Endothelial Cells
Essential Role of Cofilin-1 in Regulating Thrombin-induced RelA/p65 Nuclear Translocation and Intercellular Adhesion Molecule 1 (ICAM-1) Expression in Endothelial Cells
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DOI：
10.1074/jbc.m109.016444
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发表时间：
2009-07-31
影响因子：
4.8
通讯作者：
Rahman, Arshad
中科院分区：
文献类型：
--
作者：
Fazal, Fabeha;Bijli, Kaiser M.;Rahman, Arshad
RhoA/Rho相关激酶（ROCK）途径的激活以及凝血酶诱导的肌动蛋白细胞骨架的相关变化对于内皮细胞中NF-κ B的激活及其靶基因ICAM-1的表达至关重要。然而，作用于RhoA/ROCK下游以介导这些反应的事件仍不清楚。在这里，我们显示了cofilin-1，肌动蛋白结合蛋白，促进肌动蛋白解聚，在连接RhoA/ROCK途径的动态变化，在肌动蛋白细胞骨架的NF-κ B B的激活，从而在这些细胞中的ICAM-1的表达是必要的中心作用。凝血酶刺激人脐静脉内皮细胞导致cofilin的Ser（3）磷酸化/失活，并以ROCK依赖的方式形成肌动蛋白应力纤维。RNA干扰敲低cofilin-1稳定了肌动蛋白丝，抑制了凝血酶和RhoA诱导的NF-κ B活性。类似地，已知稳定肌动蛋白细胞骨架的cofilin-1的组成型失活突变体（Cofilin-1-S3 D）通过凝血酶抑制NF-κ B活性。已知使肌动蛋白细胞骨架不稳定的野生型cofilin-1或组成型活性的cofilin-1突变体（Cofilin-1-S3 A）的过表达也损害凝血酶诱导的NF-κ B活性。此外，cofilin-1的耗竭与凝血酶诱导的ICAM-1表达的显著降低相关。cofilin-1缺失对NF-κ B活性和ICAM-1表达的影响发生在I κ B α降解的下游，是RelA/p65核转位受损的结果，因此，RelA/p65与DNA结合。总之，这些数据表明，cofilin-1在RhoA-肌动蛋白途径中占据中心位置，介导RelA/p65的核转位和内皮细胞中ICAM-1的表达。
Activation of RhoA/Rho-associated kinase ( ROCK) pathway and the associated changes in actin cytoskeleton induced by thrombin are crucial for activation of NF-kappa B and expression of its target gene ICAM-1 in endothelial cells. However, the events acting downstream of RhoA/ROCK to mediate these responses remain unclear. Here, we show a central role of cofilin-1, an actin-binding protein that promotes actin depolymerization, in linking RhoA/ROCK pathway to dynamic alterations in actin cytoskeleton that are necessary for activation of NF-kappa B and thereby expression of ICAM-1 in these cells. Stimulation of human umbilical vein endothelial cells with thrombin resulted in Ser(3) phosphorylation/inactivation of cofilin and formation of actin stress fibers in a ROCK-dependent manner. RNA interference knockdown of cofilin-1 stabilized the actin filaments and inhibited thrombin- and RhoA-induced NF-kappa B activity. Similarly, constitutively inactive mutant of cofilin-1 (Cof1-S3D), known to stabilize the actin cytoskeleton, inhibited NF-kappa B activity by thrombin. Overexpression of wild type cofilin-1 or constitutively active cofilin-1 mutant (Cof1-S3A), known to destabilize the actin cytoskeleton, also impaired thrombin- induced NF-kappa B activity. Additionally, depletion of cofilin-1 was associated with a marked reduction in ICAM-1 expression induced by thrombin. The effect of cofilin-1 depletion on NF-kappa B activity and ICAM-1 expression occurred downstream of I kappa B alpha degradation and was a result of impaired RelA/p65 nuclear translocation and consequently, RelA/p65 binding to DNA. Together, these data show that cofilin-1 occupies a central position in RhoA-actin pathway mediating nuclear translocation of RelA/p65 and expression of ICAM-1 in endothelial cells.