p38 MAPK Signal Pathway Mediated Epithelial-mesenchymal Transition Induced by SiO_2 in Human Bronchial Epithelial Cells

Objective To investigate the role of p38 MAPK in SiO2 induced epithelial-mesenchymal transition(EMT)in human bronchial epithelial cells(HBE)in vitro.Methods The human bronchial epithelial cells were exposed to SiO2 and assessed the activation of p38 MAPK;the human bronchial epithelial cells were pretreated by SB203580 with different concentrations after 1 hour,and assessed alterations in the protein expression of E-cadherin,Vimentin and α-SMA.Results Western Blot showed that the activities of p38 MAPK at different time points induced by 200 μg/ml SiO2 significantly increased the phosphorylated p38 MAPK started from 30 min,and then gradually declined.When cells were pre-incubated with SB203580(30 μmol/L)+SiO2(200 μg/ml),the expression of E-cadherin increased(1.77±0.26) times of the SiO2(200 μg/ml)group(P0.05).Meanwhile,α-SMA expression and Vimentin expression were suppressed,the inhibition rates were 34.67% and 55.44% respectively(P0.05).Conclusions SiO2 could activate p38,p38 MAPK signal pathway could mediate epithelial-mesenchymal transition induced by SiO2 in human bronchial epithelial cells.