Role of the MAPK pathway in human lung epithelial-like A549 cells apoptosis induced by paraquat.

This study aims to investigate the value of mitogen-activated protein kinases (MAPKs) for paraquat (PQ)-induced apoptosis in human lung epithelial-like A549 cells and the specific mechanism. A549 cell apoptosis were induced by PQ. These cells were divided into six groups: control group (cells were cultured in RPMI-1640 medium); SP600125 group (cells were preconditioned with SP600125); SB203580 group (cells were preconditioned with SB203580); PQ group (cells were treated with PQ); SP600125+PQ group (cells were preconditioned with SP600125 following PQ); SB203580+PQ group (cells were preconditioned with SB203580 following PQ). The cell survival rate, apoptosis rate, and activities of caspase-3 and -9 were detected. When compared with the control group, both SP600125 and SB203580 groups had no significant difference in the detected indicators. When compared with PQ group, the cells in both SP600125+PQ group and SB203580+PQ group had significantly increased viability and level of anti-apoptotic protein Bcl-2; and had decreased apoptotic rates, decreased levels of caspase-3 and -9, and decreased level of pro-apoptotic protein Bax. The ratio of p-JNK/JNK protein expression in the SP600125+PQ group significantly decreased, while the ratio of the p-P38/P38 protein expression in the SB203580+PQ group decreased. PQ induced A549 cell apoptosis through the MAPKs pathway.