周期性机械牵拉诱导A549细胞p38MAPK的表达

Expression of p38 MAPK in A549 cells induced by cyclic mechanical stretch

目的探讨p38蛋白激酶（p38MAPK）是否参与周期性机械牵拉刺激在人肺泡Ⅱ型上皮A549细胞的信号转导过程。方法实验分对照组（刺激前）、机械牵拉（刺激后）5、15、30、60min共5组，每组3皿细胞。建立离体的A549细胞机械牵拉模型：以大小为1000μstrain的牵拉力刺激细胞，在刺激前和刺激后5、15、30、60min时间点进行观察。结果A549细胞经机械牵拉刺激后，磷酸化p38蛋白水平增加，以30min时间点最为明显。随着机械牵拉时间的延长，在60min时间点磷酸化p38蛋白水平下降至约基线水平。结论机械牵托刺激信号可激活A549细胞p38MAPK，从而引起继发细胞信号转导及功能改变。

Objective To explore whether p38 MAPK is involved in the meehanotransduction of A549 cells induced by cyclic mechanical stretch. Methods Cells were divided into five groups：stretch 5, 15,30,60 rain groups and control group. Three replicate wells were used in each group. Mechanical stretch model in vitro cultured A549 cells was established for the study. Cells were stimulated by stretch at the magnitude of 1000 μstrain for 5, 15,30, 60 min. Then the protein level of p38 was tested by Western blot. Results After mechanical stimulation, the protein level of phosphorylated p38 MAPK increased,which was most obviously at 30 min time point. However, the protein level of phosphorylated p38 MAPK returned to the original level at 60 min time point. Conclusions Mechanical stretch activates the expression of p38 in A549 cells,leading to secondary signal transduction and function change.