Lipid metabolism-mediated fertility decline in male mice exposed to Fluorene-9-bisphenol: An integrated DNA methylation and transcriptomics analysis

Fluorene-9-bisphenol (BHPF), a widely recognized alternative to bisphenol A (BPA), has been increasingly used in a wide range of industries. However, despite numerous studies, the direct mechanism underlying its male reproductive toxicity remains poorly understood. Here, a BHPF-exposed mouse model was established to evaluate the effect of BHPF on male fertility. The results showed that BHPF exposure induced reproductive dysfunction, including testis damage, spermatogenesis impairment, steroid hormone disruption and sperm quality degradation. Mechanistically, over 90,000 differentially methylated regions were identified and increased global testicular methylation levels indicated that DNA methylation may be associated with BHPF-induced testicular damage. Transcriptome analysis revealed 221 up-regulated genes and 227 down-regulated genes in BHPF-exposed mice, mainly enriched in the steroid biosynthetic pathway. Further combined methylome and transcriptome analysis revealed the critical methylated genes potentially involved in lipid metabolism. The differentially expressed genes (Cyp4a10 and Rdh1) were further confirmed to correlate with impaired male mouse fertility. Taken together, the results of this study provide a better understanding of the molecular mechanisms of toxicity effects induced by BHPF exposure from the perspective of methylome and transcriptome.