周期性机械牵张对肺泡Ⅱ型上皮细胞Cyr61表达的影响

Effect of cyclic mechanical stretch on Cyr61 expression in typeⅡ alveolar epithelial cells

目的研究周期性牵张肺泡Ⅱ型上皮细胞株A549细胞对Cyr61表达的影响。方法对肺泡Ⅱ型上皮细胞株A549细胞施加周期性机械牵张应力。加载频率0.5 Hz,加载时间2 h,加载应力分别为5%,15%,30%。加载应力为15%,加载频率0.5 Hz,加载时间分别0,15 min,30 min,60 min,120 min。每个实验均设立空白对照即不给予机械应力。用PCR法测定Cyr61 mRNA的表达,用western法测定Cyr61蛋白含量。结果随着加载应力的增加和加载时间的延长,Cyr61蛋白含量和mRNA表达均增加(P<0.05);施加不同加载幅度后,Cyr61蛋白含量和mRNA表达均增加(P<0.05)。结论肺泡Ⅱ型上皮细胞IL-8的产生和释放与周期性的机械牵张应力呈强度和时间依赖性。

Objective To investigate the effect of cyclic mechanical stretch of type Ⅱ alveolar epithelial cells on the production and release of Cyr61.Methods The type Ⅱ alveolar epithelial cell line A549 cells were exposed to cyclic mechanical stretch.The experiment was performed in 2 parts.In part 1,A549 cells were exposed to different strains（5%,15%,30%） at the frequency of 0.5 HZ for 2 hours.In part 2,A549 cells were stretched for different lengths of time（15min,30min,60min,120min）.RT-PCR and Western blot were used to assess the levels of Cyr61 mRNA and proteins.Results A549 cells subjected to cyclic stretch produced and released cyr61 mRNA and protein in a time and intensity de pendent manner（P0.05）.Conclusion Cyclic mechanical stretch o f type Ⅱ epithelial cells can induce mRNA and proteins to produce cyr61 in a time and intensity dependent manner.