Spermatogenesis dysfunction induced by PM 2.5 from automobile exhaust via the ROS-mediated MAPK signaling pathway.

Long-term exposure to particulate matter 2.5 (PM _2.5 ) from automobile exhaust impairs spermatogenesis through oxidative stress injury, but the underlying mechanism is unknown. To investigate the toxic mechanism of PM _2.5 -induced spermatogenesis impairment, we focused on the MAPK signaling pathway. We also examined the effects of treatment with vitamins C and E on spermatogenic function. Male SD rats were divided randomly into three groups: control (0.9% sterilized saline), PM _2.5 exposure (20 mg/kg.b.w.), and PM _2.5 exposure (20 mg/kg.b.w.) with vitamin intervention (vitamin C, 100 mg/kg.b.w.; vitamin E, 50 mg/kg.b.w.). Male rats showed a marked decline in fertility and decreased sperm quality after PM _2.5 exposure. The expression of SOD and Nrf2 was significantly decreased, and that of MDA was increased markedly. The expression of blood-testis barrier-associated proteins, such as ZO-1, occludin, connexin 43, and β-catenin, was significantly decreased, the Bcl-2/Bax ratio was downregulated, and the cleaved caspase-3 level was increased. Phosphorylation of MAPKs, including ERKs, JNKs, and p38, was upregulated. Treatment with vitamins C and E reversed the damage induced by PM _2.5 exposure. These results suggest that PM _2.5 from automobile exhaust disrupted spermatogenesis via ROS-mediated MAPK pathways, and that a combined vitamin C and E intervention effectively mitigated toxicity in the male reproductive system.
(Copyright © 2018. Published by Elsevier Inc.)