Sodium selenite induced human lung cancer A549 cells apoptosis through Keap1/Nrf2/ARE signaling pathway / 中国药理学通报

ABSTRACT

Aim: To study the induction of apoptotic effect of sodium selenite on human lung cancer A549 cells and its mechanisms. Methods: A549 cells were exposed to different concentrations of sodium selenite for 24 h. MTT assay was applied to determine A549 cell proliferation. Inverted fluorescence microscope was used to investigate the morphological changes in A549 cells. Flow cytometry analysis was applied to assess the apoptotic rates of A549 cells. Laser confocal microscope was employed to measure the reactive oxygen species (ROS) fluorescence intensity. A multi-detection reader was used to determine the antioxidant parameter. Western blot was utilized to detect the expression of Keapl, Nrf2, HO-1 and Nrf2 in cytoplasm and nucleus. Results: MTT results showed that sodium selenite inhibited the proliferation of A549 cells in a concentration-dependent manner. After treatment with sodium selenite for 24 h, the apoptotic rate of A549 cells was markedly increased through Hoechst 33342 staining and flow cytometry measurement. Sodium selenite significantly up-regulated ROS and malondialdehyde (MDA) content and down-regulated the levels of superoxide dismutase (SOD) and glutathione (GSH). Meanwhile, sodium selenite treatment also reduced the expressions of Keapl, Nrf2 and HO-1 at protein levels and inhibited Nrf2 protein nuclear translocation in A549 cells. Conclusions: Treatment with sodium selenite induces A549 cells apoptosis, which may contribute to the anti-proliferation activity, induction of apoptosis and regulation of oxidative stress reaction and Keapl/Nrf2/ARE antioxidative signaling pathway expression.