Transgenerational effects of the endocrine disruptor vinclozolin on the methylation pattern of imprinted genes in the mouse sperm

Abstract

Endocrine-disrupting chemicals (EDCs), among which is the antiandrogen vinclozolin (VCZ), have been reported to affect the male reproductive system. In this study, VCZ was administered to pregnant mice at the time of embryo sex determination, and its possible effects on the differentially methylated domains (DMDs) of two paternally (H19 and Gtl2) and three maternally (Peg1, Snrpn, and Peg3) imprinted genes were tested in the male offspring. The CpGs methylation status within the five gene DMDs was analyzed in the sperm, tail, liver, and skeletal muscle DNAs by pyrosequencing. In the sperm of controls, the percentages of methylated CpGs were close to the theoretical values of 100 and 0% in paternally or maternally imprinted genes respectively. VCZ decreased the percentages of methylated CpGs of H19 and Gtl2 (respective values 83.1 and 91.5%) and increased those of Peg1, Snrpn, and Peg3 (respective values 11.3, 18.3, and 11.2%). The effects of VCZ were transgenerational, but they disappeared gradually from F1 to F3. The mean sperm concentration of the VCZ-administered female offspring was only 56% of that of the controls in the F1 offspring, and it was back to normal values in the F2 and F3 offspring. In the somatic cells of controls, the percentages of methylated CpGs were close to the theoretical value of 50% and, surprisingly, VCZ altered the methylation of Peg3. We propose that the deleterious effects of VCZ on the male reproductive system are mediated by imprinting defects in the sperm. The reported effects of EDCs on human male spermatogenesis might be mediated by analogous imprinting alterations.

Aberrant DNA methylation at imprinted genes in testicular sperm retrieved from men with obstructive azoospermia and undergoing vasectomy reversal

“…Gene mutations in other enzymes involved in methylation are possible, including DNMT1 (Li et al 1992) and MTHFR (Kelly et al 2005). Furthermore, exposure to endocrine disruptors has been associated with aberrant sperm DNA methylation at imprinted and non-imprinted genes (Anway et al 2005, Stouder & Paoloni-Giacobino 2010. It is also possible that factors limited to the testicular environment may be responsible for abnormal methylation in patients with obstruction.…”

Effects of Aroclor 1254 on the Dna Methylation of Imprinted Genes in the Adult Mouse Sperm

“…Poplinski et al determined that low sperm counts were clearly associated with Igf2 ⁄ H19 ICR1 hypomethylation and, even stronger, with Mest hypermethylation and idiopathic male infertility is strongly associated with imprinting defects at Igf2 ⁄ H19 ICR1 and Mest, with aberrant Mest methylation being a strong indicator for sperm quality (Poplinski et al, 2010). Stouder and Paoloni-Giacobino's studies using the xenoestrogen vinclozolin (Stouder and Paoloni-Giacobino, 2010) and methoxychlor (Stouder and Paoloni-Giacobino, 2011) have also shown changes in sperm imprinted genes that can be maintained up to the F2 generation. Indeed, methylation defects in the maternally http://www.…”

Origine développementale et environnementale de l’infertilité masculine

“…L'altération du profil de méthylation aurait pour origine la diminution d'expression des méthyltransférases (DNMT) dans le testicule [23]. Les effets, lors d'une exposition foetale à la vinclozoline, sur le profil de méthy-lation semblent être transgénérationnels de F1 à F4 [24], même si d'autres études n'ont pas réussi à confirmer ces données [18]. L'exposition néonatale au bisphénol A (BPA) induit, quant à elle, une hyperméthylation du promoteur des gènes codant les récepteurs des oestrogènes dans le testicule adulte qui est directement liée à une augmentation des taux d'ADN méthyltransférases 3a et 3b [25].…”