Gene expression of DNMT3A, MBD2 and HDAC2 altered in DES-exposed

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

2013 Study 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 modifiersDNMT3A, MBD2, and HDAC2-increased in the SV of DES-exposed WT mice.

CONCLUSIONS
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.

  • Correlation between altered DNA methylation and the expression levels of specific genes in SVs of adult male mice neonatally treated with DES
  • Neonatal DES treatment alters the expression levels of epigenetic modifiers in the SVs of male mice

In the present study we found an association between DNA methylation and gene expression for the Svs4 and Ltf genes. A working model of this study is shown in Supplemental Material, Figure S6. Four specific CpGs (–160, –237, –306, and –367) in the Svs4 gene changed from methylated to unmethylated during development; however, methylation changes at these CpGs were not observed in mice neonatally treated with DES. Normal methylation changes in the Svs4 gene were not seen in αERKO mice, suggesting that ERα may play an active role in the methylation changes. In WT mice, DES altered the DNA methylation status from methylated to unmethylated at two specific CpGs (–449 and –459) in the Ltf gene promoter. In addition, DES treatment appeared to significantly regulate the expression levels of the epigenetic modifiers DNMT3A, MBD2, and HDAC2. Taken together, these results are consistent with the hypothesis that DES-induced toxicity is mediated by ERα alteration of target gene methylation patterns and through changes in gene expression of three epigenetic modifiers in the SV of adult male mice neonatally treated with DES.

Sources and more information
  • Full text (free access) : 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, Environmental Health Perspectives; DOI:10.1289/ehp.1307351, 2013 Dec 6.
  • Effect of neonatal DES exposure on Svs4 (A) or Ltf (B) gene expression in SVs of mice 10 weeks after treatment with vehicle or DES. Total RNA samples were extracted from SV tissues of three individual WT or αERKO mice per treatment group, and mRNA levels were quantified by real time-PCR. Data shown represent mean fold change (± SE) relative to SVs from WT vehicle-treated mice at week 5 featured image credit ehp.1307351.g002.
DES DIETHYLSTILBESTROL RESOURCES

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