Comparative proteomic analysis of cellular response of human airway epithelial cells (A549) to benzo(a)pyrene

This work aimed to investigate the cellular response of human airway epithelial cells (A549) to oxidative stress induced by benzo(a)pyrene [B(a)P]. Levels of intracellular reactive oxygen species (ROS) and lipid peroxidation were investigated in A549 cells treated with varying concentrations of B(a)P. A comparative proteomic analysis of total proteins was performed in cells treated with 1 µM B(a)P [B(a)P-1] and untreated cells. The expression of Mn superoxide dismutase (Mn SOD), one of the identified down-regulated proteins in B(a)P-1 cells, was then analyzed by Western blotting. The total antioxidant activity, total superoxide dismutase activity, catalase (CAT) activity, and glutathione reductase (GR) activity were all analyzed after B(a)P treatment. Our results demonstrated that 1 µM B(a)P could induce ROS generation and lead to lipid peroxidation in A549 cells, and 23 differentially expressed proteins were identified. The expression levels of Mn SOD and the total SOD were induced at 0.1 µM and suppressed at 1 µM and 10 µM. Up-regulation of CAT and GR activity resulted in an increase in total antioxidant activity in A549 after exposure to B(a)P. These findings provide a basis for understanding the mechanisms of mitochondrial dysfunction and perturbation of antioxidant status induced by B(a)P on airway epithelial cells.