[PM_2.5 dust induces autophagy and epithelial-mesenchymal transition in human bronchial epithelial 16HBE cells]

Objective To investigate the effect of particulate matter 2.5 (PM_2.5) dust on autophagy and epithelial-mesenchymal transition (EMT) in human bronchial epithelial 16HBE cells, and to further explore its underlying mechanism. Methods 16HBE cells were stimulated with PM_2.5 dust, and the cell viability was evaluated by CCK-8 assay. The cellular morphology of 16HBE was observed by microscopy and autophagy activation was observed by dansylcadaverine (MDC) staining. Reactive oxygen species (ROS) level was tested by flow cytometry, and protein levels of LC3-II, LC3-I, E-cadherin and α-SMA were examined by Western blot analysis before and after pretreatment with the autophagy inhibitor 3-MA. Resluts PM_2.5 dust reduced the survival rate of 16HBE cells. Some cells lost their epithelial characteristics and transformed into mesenchymal cells. Compared with control group, the expression of LC3-II/LC3-I, α-SMA and ROS in PM_2.5-treated group showed an increase and E-cadherin was found decreased. In addition, the autophagy inhibitor 3-MA down-regulated the expression of α-SMA, elevated the expression of E-cadherin, and significantly alleviated the ROS level. Conclusion PM_2.5 induced autophagy and EMT of 16HBE cells, and autophagy enhances EMT.