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

摘要

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 (P <0. 01). The expression of α-SMA increased and the effect was most evident at 200 μg/mL (P < 0. 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 (P <0. 01). Conclusion ERK signaling pathway mediated EMT induced by SiO2 in HBEC.%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-mesenchymal transition,EMT)中的作用机制.方法:SiO2(0～ 300 μg/mL)处理HBEC 72 h,或不同浓度的U0126 (0 ～ 30μmol/L)干预1h后再行200 μg/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(200 μg/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300 μg/mL时最为明显(P＜0.01),α-SMA蛋白表达水平逐渐上调,以200 μg/mL时最为明显(P＜0.04).SiO2刺激HBEC后,ERK明显活化,ERK磷酸化水平于30 min开始升高,1h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30 μmol/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.