Differential effect of MLC kinase in TNF-α-induced endothelial cell apoptosis and barrier dysfunction
Differential effect of MLC kinase in TNF-α-induced endothelial cell apoptosis and barrier dysfunction
复制标题
DOI：
10.1152/ajplung.2001.280.6.l1168
复制
发表时间：
2001-06-01
影响因子：
4.9
通讯作者：
Garcia, JGN
中科院分区：
文献类型：
--
作者：
Petrache, I;Verin, AD;Garcia, JGN
肿瘤坏死因子（TNF）-α在急性炎性肺综合征中释放，与广泛的血管功能障碍有关，血管功能障碍与渗透性增加和内皮细胞凋亡有关。TNF-α诱导跨肺内皮细胞单层的跨细胞电阻显著降低，反映了血管屏障功能障碍（从4小时开始，持续48小时）。TNF-α也在4小时开始触发内皮细胞凋亡，这被半胱天冬酶抑制剂Z-Val-Ala-Asp-fluoromethylketone减弱。探索这些重要的内皮细胞反应中肌动球蛋白细胞骨架的参与，我们确定TNF-α显著增加肌球蛋白轻链（MLC）磷酸化，突出的应力纤维和细胞旁间隙形成，这阻止了跨细胞电阻降低的发生并增强了细胞凋亡。通过抑制MLC激酶（ML-7，霍乱毒素）或Rho激酶（Y-27632）降低MLC磷酸化显著减弱TNF-α诱导的应激纤维形成、凋亡指数和半胱天冬酶-8活性，但不减弱TNF-α诱导的屏障功能障碍。这些研究表明，内皮细胞细胞骨架在TNF-α介导的细胞凋亡中发挥核心作用，而TNF-α诱导的血管渗透性似乎独立于收缩张力的产生而发展。
Tumor necrosis factor (TNF)-alpha is released in acute inflammatory lung syndromes linked to the extensive vascular dysfunction associated with increased permeability and endothelial cell apoptosis. TNF-alpha induced significant decreases in transcellular electrical resistance across pulmonary endothelial cell monolayers, reflecting vascular barrier dysfunction (beginning at 4 h and persisting for 48 h). TNF-alpha also triggered endothelial cell apoptosis beginning at 4 h, which was attenuated by the caspase inhibitor Z-Val-Ala-Asp-fluoromethylketone. Exploring the involvement of the actomyosin cytoskeleton in these important endothelial cell responses, we determined that TNF-alpha significantly increased myosin light chain (MLC) phosphorylation, with prominent stress fiber and paracellular gap formation, which paralleled the onset of decreases in transcellular electrical resistance and enhanced apoptosis. Reductions in MLC phosphorylation by the inhibition of either MLC kinase (ML-7, cholera toxin) or Rho kinase (Y-27632) dramatically attenuated TNF-alpha -induced stress fiber formation, indexes of apoptosis, and caspase-8 activity but not TNF-alpha -induced barrier dysfunction. These studies indicate a central role for the endothelial cell cytoskeleton in TNF-alpha -mediated apoptosis, whereas TNF-alpha -induced vascular permeability appears to evolve independently of contractile tension generation.