Diethylstilbestrol (DES)-Stimulated Hormonal Toxicity is Mediated by ER α Alteration of Target Gene Methylation Patterns and Epigenetic Modifiers ( DNMT3A , MBD2 , and HDAC2 ) in the Mouse Seminal Vesicle

Abstract

Background: Diethylstilbestrol (DES) is a synthetic estrogen associated with adverse effects on reproductive organs. DES-induced toxicity of the mouse seminal vesicle (SV) is mediated by estrogen receptor α (ERα), which alters expression of seminal vesicle secretory protein IV (Svs4) and lactoferrin (Ltf) genes.Objectives: We examined a role for nuclear receptor activity in association with DNA methylation and altered gene expression.Methods: We used the neonatal DES exposure mouse model to examine DNA methylation patterns via bisulfite conversion sequencing in SVs of wild-type (WT) and ERα-knockout (αERKO) mice.Results: The DNA methylation status at four specific CpGs (–160, –237, –306, and –367) in the Svs4 gene promoter changed during mouse development from methylated to unmethylated, and DES prevented this change at 10 weeks of age in WT SV. At two specific CpGs (–449 and –459) of the Ltf gene promoter, DES altered the methylation status from methylated to unmethylated. Alterations in DNA methylation of Svs4 and Ltf were not observed in αERKO SVs, suggesting that changes of methylation status at these CpGs are ERα dependent. The methylation status was associated with the level of gene expression. In addition, gene expression of three epigenetic modifiers—DNMT3A, MBD2, and HDAC2—increased in the SV of DES-exposed WT mice.Conclusion: DES-induced hormonal toxicity resulted from altered gene expression of Svs4 and Ltf associated with changes in DNA methylation that were mediated by ERα. Alterations in gene expression of DNMT3A, MBD2, and HDAC2 in DES-exposed male mice may be involved in mediating the changes in methylation status in the SV.Citation: Li Y, Hamilton KJ, Lai AY, Burns KA, Li L, Wade PA, Korach KS. 2014. Diethylstilbestrol (DES)-stimulated hormonal toxicity is mediated by ERα alteration of target gene methylation patterns and epigenetic modifiers (DNMT3A, MBD2, and HDAC2) in the mouse seminal vesicle. Environ Health Perspect 122:262–268; http://dx.doi.org/10.1289/ehp.1307351

Environmental factors, epigenetics, and developmental origin of reproductive disorders

“…Neonatal BPA exposure elevates gene expression of specific DNA methylation enzymes ( Dnmt1 and Dnmt3b ) and methyl-CpG binding proteins ( Mbd2 , Mbd4 ) in PND10 prostate tissues [118]. Similarly, neonatal exposure to DES alters the expression of Dnmt3a , Dnmt3b , and Mbd2 in seminal vesicles [152]. Concordant aberrant methylation of gene promoters such as Hmgn5 , Pde4d and Hpcal1 in adult prostate [116, 118] alters the expression and/or activities of DNA methylation enzymes or methyl-CpG binding protein gene expression through developmental reprogramming.…”

Multigenerational and transgenerational effects of endocrine disrupting chemicals: A role for altered epigenetic regulation?

“…Interestingly, multigenerational reproductive effects have also been observed in both female and male grandchildren of DES-treated women [95]. At the molecular level, studies have reported various epigenetic modifications in both human and rodent tissues exposed to DES [95], and these effects appear to be mediated, at least in part, by ERα (Table 1) [96–98]. Studies to determine transgenerational transmission of DES-induced phenotypes in humans are ongoing, as the grandchildren of DES-exposed mothers are beginning to approach reproductive age.…”

Environmentally induced epigenetic transgenerational inheritance of disease susceptibility

“…The children and grandchildren of women treated with DES during pregnancy show abnormalities or increased risk of disease. In animal model systems these abnormalities are associated with epigenetic changes [20-22]. However, negligible abnormalities have been shown for the F3 (great-grandchildren) generation in humans [23].…”