| Objective: To investigate the protective effect of sulforaphane?SFN?on MLE-12 cell damage induced by PM2.5 and the underlying molecular mechanisms.Method:?1?MLE-12 cells were exposed to different concentrations of PM2.5 suspension?0,12.5,25,50,100,200 ?g/ml?for 24 h.After DCFA-DA incubation fluorescence microscope and multifunctional microplate reader were used to qualitative and quantitative analysis of cellular amount of ROS respectively.The cellular MDA level and viability of MLE-12 cell were detected.?2?MLE-12 cells after pretreatment with SFN?10?M?for 30 min were exposed to different concentrations of PM2.5 for 24 h.The viability of MLE-12 cell,apoptosis ratio were measured.Cellular ROS,MDA,and the GSH/total GSH ratio were analyzed.The antioxidantive gene expressions?Nrf-2,NQO-1,HO-1?,levels of apoptosis-related protein?Bad,Bax,Bcl-2?,as well as pro-survival proteins like Akt and ERK were determined.Results: It was shown that PM2.5 decreased MLE-12 cell viability,increased the ROS and MDA level.Comparison SFN-treated and untreated MLE-12 cells demonstrated that SFN increased MLE-12 cell viability,decreased the levels of ROS and MDA,reduced in the GSH/total GSH ratio.Furthermore,it was found that SFN enhanced the protein expression and phosphorylation of Akt and ERK,upregulated the expression of antioxidant genes including Nrf-2,NQO-1,HO-1.The pro-apoptotic protein Bax and Bad,as well as anti-apoptotic protein Bcl-2 were down-regulated and up-regulated respectively.Conclusion: PM2.5 induced the cell damge via oxidative stress.SFN inhibited the PM2.5-induced oxidative damage in MLE-12 type ? alveolar epithelial cell by activating Nrf-2 which can bind to ARE,then induced the expression of antioxidant proteins like NQO-1,HO-1,GSH by up-regulation of PI3K/AKT and ERK pathway,and down-regulated BCL-2 family involved in mitochondrial apoptosis pathway.This study provided evidence to explore effective way to prevent PM2.5-induced damage in lung. |
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