中文摘要：

目的探讨周期性机械牵张对人支气管上皮细胞（HBE）水通道蛋白5（AQP5）表达的影响及可能的作用机制。方法利用周期性机械牵张加力装置对HBE细胞进行不同作用时间刺激，采用RT—PCR检测AQP5mRNA的表达，Western blot测定AQP5蛋白的表达及ERK的磷酸化水平变化。结果2000／zstrain机械牵张刺激时间依赖性的提高HBE细胞AQP5基因转录水平；加力3h时，AQP5蛋白表达量明显增加，至12h达到峰值。在2000μtstrain的周期性机械牵张刺激下，HBE细胞ERK的磷酸化活化具有时间依赖性，在1h时即与对照相比差异极显著（P〈0．01）。结论2000μstrain机械牵张刺激增加人支气管上皮细胞AQP5基因表达，ERK的磷酸化修饰有可能参与HBE细胞对周期性机械牵张刺激的应答。

英文摘要：

Objective To study the effect of cyclic mechanical stretch on the expression of Aquaporin 5. Methods Human bronchial epithelial cells （HBEC） were collected at different time after cyclic mechanical stretch loaded by fourpoint bending device. Total RNA and protein extracted from each sample were used to evaluate the effects of stretch on the expression of AQP5 and ERK1/2 by RT-PCR and western blot, respectively. Results 2000μ strain stretch increased the expression of AQP5 in HBE cells in a time-dependent manner. The AQP5 mRNA was significantly increased at 1 h compared with the control group （P〈0.05） and showed a sharp descending tendency after 6 h. The expression of AQP5 protein increased apparently at 3 h and reached its peak at 12 h when HBE cells were stimulated by 2000μ strain cyclic stretch. 2000μ strain cyclic stretch activated ERK1/2 in HBE cells in a time-dependent manner. Conclusion 2000μ strain cyclic mechanical stretch increases the expression of AQP5 in HBE cells and phosphorylation of ERK1/2 may be involved in it.