Introduction: Accumulating evidence has shown that not only maternal health during pregnancy, but also the paternal metabolic status at the time of conception have an impact on the subsequent health of the offspring. Cholestatic liver diseases are metabolic conditions characterised by increased circulating serum bile acid and lipid levels. A previous study has shown that long-term cholestasis results in destruction of the bloodtestis barrier and germ cell apoptosis. We hypothesise that paternal cholestasis alters intratesticular homeostasis and impacts the sperm epigenome, resulting in altered disease susceptibility in the offspring.
Methods: A 79-week-old male mice were fed a RM3 normal chow (NC) diet or RM3 diet supplemented with 0.5% cholic acid (CA diet) for 10 weeks. At completion of feeding, the effects of cholestasis on sperm and testes were studied. Sperm DNA damage, global DNA methylation and hydroxymethylation, and sperm microRNA content were assessed. A separate cohort of male mice was fed a NC diet±supplementation with 0.5% CA for 10 weeks and mated to age-matched NC-fed females. Females were allowed to deliver and litters were standardised to five to six pups at day 1.
Results: CA feeding for 10 weeks resulted in a significant increase in sperm DNA damage (n=56, P value ≤0.05). Concomitantly, increased mRNA expression of the apoptotic marker FasL in the testes (n=56, P value ≤0.05) was observed. After 10 weeks of CA feeding, global sperm DNA methylation and hydroxymethylation showed a trend for decreased 5-mC% and 5-hmC% DNA content (n=56). Altered sperm miR-34c_1 content was also observed (n=56). Ongoing studies investigate the impact of paternal cholestasis on the phenotype of the offspring.
Conclusions: Male cholestasis was associated with DNA damage in the sperm, accompanied by increased apoptosis in the testes. Global sperm DNA methylation, hydroxymethylation, and microRNA content were affected by male cholestasis.