Transcriptomic analysis of the mechanism of male reproductive injuries caused by the mixture of three phthalates in rats

Phthalates (PEs) are widespread in environment, and human beings are unavoidably exposing to the mixture of PEs, which may induce male reproductive health risks. In order to investigate the mechanism of male reproductive injuries caused by the mixture of di-2-ethylhexyl phthalate, dibutyl phthalate and butyl benzyl phthalate (MPEs), male rats were orally exposed to 16 mg/kg/d MPEs (L-MPEs) and 450 mg/kg/d MPEs (H-MPEs) for 90 days, and the results showed that MPEs decreased the weights of testes, epididymis and periepididymis fat, decreased serum levels of male hormones, increased abnormal sperm rate, and caused testicular histopathological damages, such as atrophy and cavitation of seminiferous tubules, spermatids exfoliation, Leydig cells hyperplasia and accumulation of lipid droplets in the testicular interstitium. Testicular transcriptomic analysis identified 100 differently expressed genes (DEGs) in L-MPEs group and 10,880 DEGs in H-MPEs group, and these DEGs mainly involved in signaling pathways of focal adhesion, PI3K-Akt, AGE-RAGE, axon guidance, PPAR, MAPK and etc. Testicular Paxillin and vinculin were significantly upregulated in MPEs treated groups, initially verified that focal adhesion was a pathway of male reproductive injuries induced by MPEs. This study provides new ideas for the further researches on the mechanism of MPEs' male reproductive toxicity.