ERK信号通路调控二氧化硅诱导的人支气管上皮细胞上皮-间质转化

ERK signaling pathway mediated epithelial-mesenchymal transition induced by SiO_2 in human bronchial epithelial cells

目的:探讨细胞外信号调节激酶(extracellular signal-regulated kinase,ERK)信号通路在二氧化硅(SiO2)诱导人支气管上皮细胞(human bronchial epithelial cells,HBEC)上皮-间质转型(epithelial-mesenchymaltransition,EMT)中的作用机制。方法:SiO2(0～300μg/mL)处理HBEC 72 h,或不同浓度的U0126(0～30μmol/L)干预1 h后再行200μg/mL SiO2刺激72 h,Western印迹检测E-cadherin和α-平滑肌肌动蛋白(α-SMA)表达的改变;使用丝裂原活化蛋白激酶(MAPK)活性检测试剂盒检测SiO2(200μg/mL)处理HBEC(0～8 h)后ERK激活情况。结果:SiO2刺激HBEC后,E-cadherin蛋白表达水平逐渐下调,以300μg/mL时最为明显(P<0.01),α-SMA蛋白表达水平逐渐上调,以200μg/mL时最为明显(P<0.01)。SiO2刺激HBEC后,ERK明显活化,ERK磷酸化水平于30 min开始升高,1 h后逐渐降低。ERK抑制剂U0126明显抑制SiO2诱导的E-cadherin和α-SMA蛋白表达的变化,浓度为30μmol/L时最为明显(P<0.01)。结论:ERK信号通路参与调控SiO2诱导的HBEC的EMT。

Objective To determine the role of extracellular signal regulated kinase（ERK） signaling pathway in SiO2 induced epithelial-mesenchymal transition（EMT） in human bronchial epithelial cells（HBEC） in vitro.Methods HBEC were treated with SiO2（0-300 μg/mL） for 72 h or pretreated with U0126（0-30 μmol/L） for 1 h and then treated with 200 μg/mL SiO2 for 72 h.Western blot was used to detect the protein expression of E-cadherin and α-smooth muscle actin（α-SMA）.The activity of ERK was examined by mitogen-activated protein kinase（MAPK） activity assay kit in HBEC exposing to SiO2（200 μg/mL） for 0-8 h.Results The expression of E-cadherin decreased gradually in SiO2-stimulated HBEC,and the effect was most significant at 300 μg/mL（P0.01）.The expression of α-SMA increased and the effect was most evident at 200 μg/mL（P0.01）.With SiO2 treatment,the activity of ERK was upregulated significantly.The phosphorylation of ERK increased at 30 min and decreased after 1 h.U0126 significantly inhibited SiO2-induced expression changes in E-cadherin and α-SMA.At 30 μmol/L,the effect was most evident（P0.01）.Conclusion ERK signaling pathway mediated EMT induced by SiO2 in HBEC.