Transcriptional Factor Snail Mediates Epithelial-Mesenchymal Transition in Human Bronchial Epithelial Cells Induced by Silica.

ABSTRACT

Epithelial-mesenchymal transition (EMT) plays an important role in fibrotic diseases. We have previously showed that silica induces EMT in human bronchial epithelial cells (BECs); however, the underlying mechanism of silica-induced EMT is poorly understood. In the present study, we investigated the role of Snail in silica-induced EMT in human BECs in vitro. Human BECs were treated with silica at various concentrations and incubation times. Then MTT assay, western blot, electrophoretic mobility shift assay (EMSA), and small interfering RNA (siRNA) transfection were performed. We found that silica increased the expression and DNA binding activity of Snail in human BECs. SNAI siRNA inhibited the silica-induced expression of Snail. Moreover, SNAI siRNA upregulated the expression of epithelial marker E-cadherin, but attenuated the expression of mesenchymal marker α-smooth muscle actin and vimentin in silica-stimulated cells. These results suggest that Snail mediates the silica-induced EMT in human BECs.