Fig. 6.
Metformin attenuates PM2.5-induced cell death and oxidative stress in BEAS-2B cells. Scramble shRNA (shScr)- and AMPKα2-specific shRNA (shAMPKα2)-stably transfected BEAS-2B cells were pretreated with PBS or 1 mM metformin for 2 h and then exposed to 50 μg/ml PM2.5 for 24 h. Cell viability (A) and intracellular ROS levels (B) were then determined. Lysates of the control and PM2.5-exposed shScr (C) or shAMPKα2 cells (D) with or without metformin pretreatment were examined by western blotting to determine the expression of phosphorylated AMPKα, SOD2, PRDX3, PRDX5 and TRXR2. β-Tubulin was used as a loading control. N = 3–4; data are presented as the mean ± SEM; * indicates p < 0.05, ** indicates p < 0.01, NS, not significant.