GEF-H1 is involved in agonist-induced human pulmonary endothelial barrier dysfunction
GEF-H1 is involved in agonist-induced human pulmonary endothelial barrier dysfunction
复制标题
DOI：
10.1152/ajplung.00259.2005
复制
发表时间：
2006-03-01
影响因子：
4.9
通讯作者：
Verin, AD
中科院分区：
文献类型：
--
作者：
Birukova, AA;Adyshev, D;Verin, AD
内皮细胞（EC）渗透性由细胞骨架元件[肌动蛋白丝、微管（MT）、中间丝]和细胞接触蛋白复合物（粘着斑、粘着连接、紧密连接）精确控制。我们最近发现，促水肿激动剂凝血酶引起部分MT分解，这与小GTdR Rho的激活，Rho介导的肌动蛋白重塑，细胞收缩和肺EC屏障功能障碍有关。GEF-H1是MT相关的Rho特异性鸟苷核苷酸（GDP/GTP）交换因子，其在MT未结合状态下刺激Rho活性。在这项研究中，我们验证了GEF-H1可能是参与Rho激活、肌球蛋白轻链磷酸化、肌动蛋白重塑和与部分MT分解相关的EC屏障功能障碍的关键分子的假设。我们的研究结果表明，GEF-H1的缺失或显性负性GEF-H1突变体的表达显著减弱了由凝血酶或MT解聚剂诺考达唑诱导的渗透性增加、肌动蛋白应力纤维形成以及MLC和MYPT 1磷酸化增加。与此相反，野生型或激活GEF-H1突变体的表达显着增强凝血酶和诺考达唑对应力纤维形成和细胞收缩的影响。这些结果显示GEF-H1在MT分解引起的Rho活化中的关键作用，并表明GEF-H1是参与激动剂诱导的Rho依赖性EC屏障调节中MT和肌动蛋白细胞骨架之间的串扰的关键分子。
Endothelial cell (EC) permeability is precisely controlled by cytoskeletal elements [actin filaments, microtubules (MT), intermediate filaments] and cell contact protein complexes (focal adhesions, adherens junctions, tight junctions). We have recently shown that the edemagenic agonist thrombin caused partial MT disassembly, which was linked to activation of small GTPase Rho, Rho-mediated actin remodeling, cell contraction, and dysfunction of lung EC barrier. GEF- H1 is an MT-associated Rho-specific guanosine nucleotide (GDP/GTP) exchange factor, which in MT-unbound state stimulates Rho activity. In this study we tested hypothesis that GEF- H1 may be a key molecule involved in Rho activation, myosin light chain phosphorylation, actin remodeling, and EC barrier dysfunction associated with partial MT disassembly. Our results show that depletion of GEF- H1 or expression of dominant negative GEF- H1 mutant significantly attenuated permeability increase, actin stress fiber formation, and increased MLC and MYPT1 phosphorylation induced by thrombin or MT-depolymerizing agent nocodazole. In contrast, expression of wild-type or activated GEF-H1 mutants dramatically enhanced thrombin and nocodazole effects on stress fiber formation and cell retraction. These results show a critical role for the GEF- H1 in the Rho activation caused by MT disassembly and suggest GEF- H1 as a key molecule involved in cross talk between MT and actin cytoskeleton in agonist- induced Rho-dependent EC barrier regulation.