Cyclic stretch induces alveolar epithelial barrier dysfunction via calpain-mediated degradation of p120-catenin
Cyclic stretch induces alveolar epithelial barrier dysfunction via calpain-mediated degradation of p120-catenin
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DOI：
10.1152/ajplung.00048.2011
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发表时间：
2011-08-01
影响因子：
4.9
通讯作者：
Hu, Guochang
中科院分区：
文献类型：
--
作者：
Wang, Yuelan;Minshall, Richard D.;Hu, Guochang
王勇，明什，德，施瓦茨，德，胡G。循环拉伸通过钙蛋白酶介导的p120-连环蛋白的降解，诱导肺泡上皮屏障功能障碍。AM J Physiol肺细胞分子Physiol 301：L197-L206,2011。2011年5月13日首次出版；DOI：10.1152/ajpeng.00048.2011。-肺过度膨胀被认为是呼吸机诱导的肺损伤发病机制中的一个重要因素。机械拉伸导致上皮屏障功能障碍和肺泡通透性增加，尽管确切的机制尚未完全阐明。P120-catenin是一种黏附连接相关蛋白，调节细胞间的黏附。在这项研究中，我们确定了p120-catenin在周期性牵张诱导的肺泡上皮屏障功能障碍中的作用。将培养的肺泡上皮细胞(MLE-12)置于0~8或20%表面积变化的均匀循环(0.5 Hz)双轴拉伸0、1、2或4h后，用Western印迹法检测细胞裂解后p120-catenin的表达。P120-连环蛋白和F-肌动蛋白免疫荧光染色以评估单层的完整性和上皮间缝隙的形成。与未拉伸的对照细胞相比，20%的拉伸导致p120-catenin的表达显著减少，这与上皮间缝隙的形成有关。用小干扰RNA(SiRNA)敲除p120-catenin可剂量依赖性地增加拉伸诱导的缝隙形成，而过表达p120-catenin则抑制拉伸诱导的缝隙形成。此外，用特定的siRNA抑制或耗尽Calain-1的药理作用可以防止p120-连环蛋白的丢失和随后拉伸诱导的缝隙形成。我们的研究结果表明，p120-catenin在周期性牵张诱导的肺泡屏障功能障碍中起着重要的保护作用，因此，维持p120-catenin的表达可能是防治呼吸机相关性肺损伤的一种新的治疗策略。
Wang Y, Minshall RD, Schwartz DE, Hu G. Cyclic stretch induces alveolar epithelial barrier dysfunction via calpain-mediated degradation of p120-catenin. Am J Physiol Lung Cell Mol Physiol 301: L197-L206, 2011. First published May 13, 2011; doi:10.1152/ajplung.00048.2011.-Lung hyperinflation is known to be an important contributing factor in the pathogenesis of ventilator-induced lung injury. Mechanical stretch causes epithelial barrier dysfunction and an increase in alveolar permeability, although the precise mechanisms have not been completely elucidated. p120-catenin is an adherens junction-associated protein that regulates cell-cell adhesion. In this study, we determined the role of p120-catenin in cyclic stretch-induced alveolar epithelial barrier dysfunction. Cultured alveolar epithelial cells (MLE-12) were subjected to uniform cyclic (0.5 Hz) biaxial stretch from 0 to 8 or 20% change in surface area for 0, 1, 2, or 4 h. At the end of the experiments, cells were lysed to determine p120-catenin expression by Western blot analysis. Immunofluorescence staining of p120-catenin and F-actin was performed to assess the integrity of monolayers and interepithelial gap formation. Compared with unstretched control cells, 20% stretch caused a significant loss in p120-catenin expression, which was coupled to interepithelial gap formation. p120-Catenin knockdown with small interfering RNA (siRNA) dose dependently increased stretch-induced gap formation, whereas overexpression of p120-catenin abolished stretch-induced gap formation. Furthermore, pharmacological calpain inhibition or depletion of calpain-1 with a specific siRNA prevented p120-catenin loss and subsequent stretch-induced gap formation. Our findings demonstrate that p120-catenin plays a critical protective role in cyclic stretch-induced alveolar barrier dysfunction, and, thus, maintenance of p120-catenin expression may be a novel therapeutic strategy for the prevention and treatment of ventilator-induced lung injury.