The role of N-methyladenosine modification in benzene-induced testicular damage and the protective effect of melatonin.

Benzene is a universal ambient pollutant. Population-based studies have shown that benzene exposure affects male fertility. However, the mechanism of benzene-induced reproductive toxicity is unknown. Here, we established a dynamic inhalation model and exposed C57BL/6J mice to 0, 10, and 50 ppm benzene (6 h/day, 6 days/week, 7 weeks). Our study revealed that benzene exposure caused testicular injury, including structural damage to spermatogenic tubules, reduced semen quality, and decreased testosterone levels. In addition, the decrease in the global level of N-Methyladenosine (mA) and the change of mA important regulatory enzymes in mice testes suggested that mA was involved in the benzene-induced testicular injury. Further genome-wide mA methylation analysis showed that 1469 differential mA peaks were present in the testes of control and benzene groups, indicating that benzene exposure modulated mA methylation in testes. Furthermore, the comprehensive analysis of mA-sequencing and transcriptome revealed that hypermethylated Rara and its consequent reduced expression impaired the sperm production process. In particular, melatonin alleviated benzene-induced testicular injury by modulating mA-related genes. Overall, our research provides a new idea and fundamental knowledge into the possible mechanisms of mA modifications in benzene-induced testicular impairment, as well as a new experimental basis for benzene-induced male fertility therapy.