Dibutyl phthalate induces DNA damage and activates ATM-Chk2-p53 signaling to disrupt the prepubertal blood-testis barrier.

Dibutyl phthalate (DBP) has been recognized as an endocrine disrupting chemical, which poses significant threats to male reproductive health, though its precise mechanism of testicular toxicity has not been fully clarified. We combined in vivo and in vitro experiments with transcriptome sequencing to investigate the toxicity of DBP and its active metabolite monobutyl phthalate (MBP) in prepubertal male mice and Sertoli cells, and explored the underlying molecular mechanisms. The results showed that DBP affected testicular development and disrupted the blood-testis barrier (BTB) in mice. Through bioinformatic analysis, we validated that MBP promoted G1 phase cell cycle arrest, apoptosis, and DNA damage in Sertoli cells. Furthermore, the increased expression of p-ATM, p-Chk2, p-p53 indicated that the ATM/Chk2/p53 signaling pathway was activated upon MBP treatment. Inhibition of p53 or ATM expression partially reversed the pro-apoptotic and cell cycle-arrested phenotypes, whereas p53 overexpression reverted these phenotypic abnormalities. These findings indicated that prepubertal DBP exposure impaird BTB integrity and induced DNA damage in association with pathological activation of the ATM/Chk2/p53 signaling pathway, thereby contributing to Sertoli cell apoptosis and proliferative arrest.