二氧化硅对人支气管上皮细胞发生上皮-间质转型的诱导作用

Silica induced epithelial mesenchymal transition in human bronchial epithelial cells

目的探讨二氧化硅(SiO2)是否诱导人支气管上皮细胞(human bronchial epithelial cells,HBE)上皮-间质转型(epithelial-mesenchymal transition,EMT)。方法以200μg/ml SiO2诱导的HBE细胞为模型,倒置显微镜观察HBE细胞超微结构改变,免疫细胞化学链霉素抗生物素蛋白-过氧化物酶连接法(SP法)检测上皮细胞标志物E-钙粘蛋白(E-cadherin,E-cad)和间质细胞标志物波形蛋白(Vimentin,Vim)、α-平滑肌肌动蛋白(α-smooth muscle actin,α-SMA)表达的改变。结果200μg/ml SiO2诱导HBE后,细胞呈梭形、纺锤形改变,间隙略微增宽。免疫细胞化学结果显示,200μg/ml SiO2作用于HBE细胞,上皮细胞标志物E-cad表达下调,其平均染色强度积分(intensityscore,Is)由2.58±0.06减少为0.28±0.03,而间质细胞标志物Vim和α-SMA表达上调,Vim的Is值由0.14±0.01增加为1.99±0.03,α-SMA的Is值由0.14±0.02增加为1.64±0.06,差异均有统计学意义(P<0.05)。结论 SiO2可诱导HBE发生EMT。

Objective To explore whether silica could induce epithelial mesenchymat transition（EMT）in human bronchial epithelial cells（HBE）. Methods The HBE cells induced by silica（200 μg/ml）were taken as the model, the morphological changes of HBE were observed by inverted microscope. Immunocytochemistry （SP） was used to detect the changes in protein expression of E-cadherin, Vimentin, and α-smooth muscle actin. Results After HBE cells were induced by silica（200 μg/ml）, inverted microscope observed that the cobblestone-shaped cells were changed into spindle-shaped. Immunocytochemistry demonstrated that silica（200 μg/ml）exposure led to a decreased of E-cad expression whose intensity score（Is）decreased [rom 2.58±0.06 to 0. 28±0. 03, however, Vim expression increased whose Is increased [rom 0.14±0.01 to 1.99±0.03, and also an increase of α-SMA expression with Is from 0. 14±0.02 to 1.64±0.06（P〈0.05）. Conclusions Silica could induce epithelial mesenchymal transition in human bronchial epithelial cells.