Novel role of microtubules in thrombin-induced endothelial barrier dysfunction
Novel role of microtubules in thrombin-induced endothelial barrier dysfunction
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DOI：
10.1096/fj.04-2328com
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发表时间：
2004-12-01
期刊：
影响因子：
4.8
通讯作者：
Verin, AD
中科院分区：
文献类型：
--
作者：
Birukova, AA;Birukov, KG;Verin, AD
内皮细胞 (EC) 屏障调节的紊乱很大程度上取决于 EC 肌动蛋白细胞骨架的重排。然而，微管（MT）网络在调节 EC 通透性中的作用尚不清楚。我们检查了 MT 重塑在凝血酶诱导的 EC 通透性中的参与情况，并探索了异三聚体 G12/13 蛋白和小 GTPase Rho 对 MT 的调节。凝血酶诱导 MT 调节蛋白 tau Ser(409) 和 Ser(262) 磷酸化以及外周 MT 解体，这与 EC 通透性增加有关。紫杉醇对 MT 的稳定作用减弱了凝血酶诱导的通透性、肌动蛋白重塑和细胞旁间隙形成，并减少了凝血酶诱导的 Rho 和 Rho 激酶的激活。参与凝血酶介导信号传导的活化 Galpha12/13 亚基的表达或其参与 Rho 激活的效应器 p115RhoGEF 导致 MT 解体，而 p115RhoGEF 特异性负调节因子 RGS 使 MT 免受凝血酶诱导的解体。与这些结果一致，活化的 RhoA 和 Rho 激酶的表达诱导 MT 解体。相反，凝血酶诱导的外周 MT 网络解体可通过显性失活 RhoA 和 Rho 激酶突变体的表达或通过 Rho 激酶的药理学抑制而减弱。总的来说，我们的数据首次证明了 MT 分解在凝血酶诱导的 EC 屏障功能障碍中的关键参与，并表明了凝血酶诱导的 MT 改变的 G 蛋白依赖性机制。
Disturbances in endothelial cell (EC) barrier regulation are critically dependent upon rearrangements of EC actin cytoskeleton. However, the role of microtubule (MT) network in the regulation of EC permeability is not well understood. We examined involvement of MT remodeling in thrombin-induced EC permeability and explored MT regulation by heterotrimeric G12/13 proteins and by small GTPase Rho. Thrombin induced phosphorylation of MT regulatory protein tau at Ser(409) and Ser(262) and peripheral MT disassembly, which was linked to increased EC permeability. MT stabilization by taxol attenuated thrombin-induced permeability, actin remodeling, and paracellular gap formation and diminished thrombin-induced activation of Rho and Rho-kinase. Expression of activated Galpha12/13 subunits involved in thrombin-mediated signaling or their effector p115RhoGEF involved in Rho activation caused MT disassembly, whereas p115RhoGEF-specific negative regulator RGS preserved MT from thrombin-induced disassembly. Consistent with these results, expression of activated RhoA and Rho-kinase induced MT disassembly. Conversely, thrombin-induced disassembly of peripheral MT network was attenuated by expression of dominant negative RhoA and Rho-kinase mutants or by pharmacological inhibition of Rho-kinase. Collectively, our data demonstrate for the first time a critical involvement of MT disassembly in thrombin-induced EC barrier dysfunction and indicate G-protein-dependent mechanisms of thrombin-induced MT alteration.