Fine particulate matters induce apoptosis via the ATM/P53/CDK2 and mitochondria apoptosis pathway triggered by oxidative stress in rat and GC-2spd cell.

Fine particulate matters (PM2.5) have been associated with male reproductive toxicity because it can penetrate into the lung's gas-exchange region, and spread to the whole body via circulatory system. Previous studies have shown that PM2.5 could induce DNA damage and apoptosis by reactive oxygen species (ROS). The aim of the present study is to determine the exact mechanism and role of apoptosis induced by PM2.5 in spermatocyte cells. Male Sprague-Dawley (SD) rats were treated with normal saline (control group) or PM2.5 with the doses of 1.8, 5.4 and 16.2 mg/kg bw. via intratracheal instillation every 3 days for 30 days. Mouse spermatocyte-derived cells (GC-2spd cells) were treated with various concentrations (0, 50, 100, 200 μg/mL) of PM2.5 for 24 h. The results showed that exposure to PM2.5 resulted in injury of testicular tissue and impaired mitochondria integrity in GC-2spd cells. Moreover, PM2.5 induced DNA damage and apoptosis in GC-2spad cells via ROS generation, and the ATM/P53/CDK2 and mitochondria apoptosis pathway autophagy signal pathway were activated. N-Acetyl-L-cysteine (NAC), a well-known antioxidant, ameliorated DNA damage, and inhibited apoptosis. These findings demonstrated PM2.5 might induce apoptosis via the mitochondrial apoptosis pathway through causing DNA damage resulting from oxidative stress, and finally caused spermatogenesis disorder.