MAPKs通路在转化生长因子β_1诱导气道上皮细胞转化中的作用

MAPKs signaling pathway is involved in transdifferentiation of airway epithelial cells into myofibroblasts induced by transforming growth factor-β_1 in vitro

目的探讨丝裂原活化蛋白激酶(MAPKs)信号通路在转化生长因子β1(TGF-β1)体外诱导气道上皮细胞表型向肌成纤维细胞转化中的作用。方法TGF-β1(10μg/L)刺激气道上皮细胞株16HBE-14o,采用Westernblot方法检测刺激5min,15min,30min,1h和24h后细胞内磷酸化p38、Erk1/2和JNK的表达。分别预先加入p38MAPK、ERK1/2和JNK的特异性抑制剂孵育1h,再加入TGF-β1刺激16HBE-14o48h,免疫荧光方法检测E-cadherin、α-SMA和F-actin的表达。结果TGF-β1刺激5min后磷酸化p38、Erk1/2表达量较未予TGF-β1刺激的正常对照组明显增加,刺激15min,30min和1h后表达量稍有下降但仍较正常对照组明显增加,刺激24h后表达量恢复至基础水平。正常对照组与TGF-β1刺激组均有极微弱的磷酸化JNK表达,表达量无显著差别。加入p38MAPK和ERK1/2特异性抑制剂组,绝大多数细胞F-actin和E-cadherin仍定位在细胞边缘,表达α-SMA的阳性细胞数显著减少;加入JNK特异性抑制剂组E-cadherin、α-SMA和F-actin的表达与单纯TGF-β1刺激组相似。结论TGF-β1活化了16HBE-14o细胞内MAPKs信号通路,MAPKs(p38MAPK和ERK1/2)信号通路参与了TGF-β1诱导的16HBE-14o向肌成纤维细胞的转化过程。

Objective To investigate the signaling mechanism of the transdifferentiation of airway epithelial cells into myofibroblasts induced by recombined human transforming growth factor β1 （rhTGF-β1）. Methods Cultured 16HBE-14o cells were exposed to rhTGF-β1 （10 μg/L ）. Phosphorylated p38, phosphorylated ERK1/2 and phosphorylatcd JNK in cell lyses were detected at different time points ＇after the treatment of rhTGF-β1 by western blotting method. Meanwhile 16HBE-14o cells were pre-incubated with the specific inhibitors for either p38MAPK,or ERK1/2 or JNK for 1 h,then the expression of α-SMA, E-cadherin and the formation of stress fiber were detected in those cells 48 h after being treated by rhTGF-β1 by using immunofluorescent staining. Results The phosphorylation of Erk1/2 and p38 were significantly increased at 5 min after TGF-β1 stimulation,and this effect lasted for at least 1 h. The phosphorylation of JNK could be detected in neither TGF-β1 treated group nor normal control group. ERK inhibitor and p38 inhibitor partly reversed TGF-β1 induced expression of E-cadherin, F-actin and α-SMA. Conclusion Activation of MAPKs（p38MAPK,ERK1/2） induced by TGF-β1 was involved in the initiation of the transdifferentiation of airway epithelial cells towards myofibroblasts.