Regulation of the micromechanical properties of pulmonary endothelium by S1P and thrombin: Role of cortactin
Regulation of the micromechanical properties of pulmonary endothelium by S1P and thrombin: Role of cortactin
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DOI：
10.1529/biophysj.107.127167
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发表时间：
2008-07-15
影响因子：
3.4
通讯作者：
Dudek, Steven M.
中科院分区：
文献类型：
--
作者：
Arce, Fernando Teran;Whitlock, Jenny L.;Dudek, Steven M.
肺内皮细胞（EC）屏障功能的破坏是脓毒症和急性呼吸系统疾病应激综合征等高度病态炎症条件下的关键病理生理事件。肌动蛋白细胞骨架是内皮细胞通透性的重要调节剂，是一种动态结构，其刺激诱导的重排与屏障调节有关。在这里，我们使用原子力显微镜来表征培养的人肺动脉 EC 的 F-肌动蛋白细胞骨架在屏障增强（由 1-磷酸鞘氨醇 (S1P) 诱导）和屏障破坏（由凝血酶诱导）条件下的结构和机械变化。原子力显微镜弹性测量显示出不同的影响：对于屏障保护分子S1P，外围的弹性模量显着升高；另一方面，对于破坏屏障的分子凝血酶，其在细胞中央区域显着升高。力和弹性图与免疫荧光分析确定的 F-肌动蛋白重排相关。值得注意的是，cortactin（一种对 EC 屏障调节至关重要的肌动蛋白结合蛋白）的表达减少（通过 siRNA）导致 S1P 介导的弹性模式发生转变，变得更类似于对照、未刺激的内皮细胞。
Disruption of pulmonary endothelial cell (EC) barrier function is a critical pathophysiologic event in highly morbid inflammatory conditions such as sepsis and acute respiratory disease stress syndrome. Actin cytoskeleton, an essential regulator of endothelial permeability, is a dynamic structure whose stimuli-induced rearrangement is linked to barrier modulation. Here, we used atomic force microscopy to characterize structural and mechanical changes in the F-actin cytoskeleton of cultured human pulmonary artery EC in response to both barrier-enhancing (induced by sphingosine 1-phosphate (S1P)) and barrier-disrupting (induced by thrombin) conditions. Atomic force microscopy elasticity measurements show differential effects: for the barrier protecting molecule S1P, the elastic modulus was elevated significantly on the periphery; for the barrier-disrupting molecule thrombin, on the other hand, it was elevated significantly in the central region of the cell. The force and elasticity maps correlate with F-actin rearrangements as identified by immunofluorescence analysis. Significantly, reduced expression (via siRNA) of cortactin, an actin-binding protein essential to EC barrier regulation, resulted in a shift in the S1P-mediated elasticity pattern to more closely resemble control, unstimulated endothelium.