Fetal and neonatal exposure to the endocrine disruptor methoxychlor causes epigenetic alterations in adult ovarian genes

Aparna Mahakali Zama, Mehmet Uzumcu

Research output: Contribution to journalArticle

85 Citations (Scopus)

Abstract

Exposure to endocrine-disrupting chemicals during development could alter the epigenetic programming of the genome and result in adult-onset disease. Methoxychlor (MXC) and its metabolites possess estrogenic, antiestrogenic, and antiandrogenic activities. Previous studies showed that fetal/neonatal exposure to MXC caused adult ovarian dysfunction due to altered expression of key ovarian genes including estrogen receptor (ER)-β, which was down-regulated, whereas ERα was unaffected. The objective of the current study was to evaluate changes in global and gene-specific methylation patterns in adult ovaries associated with the observed defects. Rats were exposed to MXC (20 μg/kg·d or 100 mg/kg·d) between embryonic d 19 and postnatal d 7. We performed DNA methylation analysis of the known promoters of ERα and ERβ genes in postnatal d 50-60 ovaries using bisulfite sequencing and methylation-specific PCRs. Developmental exposure to MXC led to significant hypermethylation in the ERβ promoter regions (P < 0.05), whereas the ERα promoter was unaffected. We assessed global DNA methylation changes using methylation-sensitive arbitrarily primed PCR and identified 10 genes that were hypermethylated in ovaries from exposed rats. To determine whether the MXC-induced methylation changes were associated with increased DNA methyltransferase (DNMT) levels, we measured the expression levels of Dnmt3a, Dnmt3b, and Dnmt3l using semiquantitative RT-PCR. Whereas Dnmt3a and Dnmt3l were unchanged, Dnmt3b expression was stimulated in ovaries of the 100 mg/kg MXC group (P < 0.05), suggesting that increased DNMT3B may cause DNA hypermethylation in the ovary. Overall, these data suggest that transient exposure to MXC during fetal and neonatal development affects adult ovarian function via altered methylation patterns.

Original languageEnglish (US)
Pages (from-to)4681-4691
Number of pages11
JournalEndocrinology
Volume150
Issue number10
DOIs
StatePublished - Oct 1 2009

Fingerprint

Methoxychlor
Endocrine Disruptors
Epigenomics
Estrogen Receptors
Methylation
Ovary
Genes
DNA Methylation
Polymerase Chain Reaction
DNA
Methyltransferases
Fetal Development
Genetic Promoter Regions
Genome

All Science Journal Classification (ASJC) codes

  • Endocrinology

Cite this

@article{a08bbbad82e3418892328a346f604dd2,
title = "Fetal and neonatal exposure to the endocrine disruptor methoxychlor causes epigenetic alterations in adult ovarian genes",
abstract = "Exposure to endocrine-disrupting chemicals during development could alter the epigenetic programming of the genome and result in adult-onset disease. Methoxychlor (MXC) and its metabolites possess estrogenic, antiestrogenic, and antiandrogenic activities. Previous studies showed that fetal/neonatal exposure to MXC caused adult ovarian dysfunction due to altered expression of key ovarian genes including estrogen receptor (ER)-β, which was down-regulated, whereas ERα was unaffected. The objective of the current study was to evaluate changes in global and gene-specific methylation patterns in adult ovaries associated with the observed defects. Rats were exposed to MXC (20 μg/kg·d or 100 mg/kg·d) between embryonic d 19 and postnatal d 7. We performed DNA methylation analysis of the known promoters of ERα and ERβ genes in postnatal d 50-60 ovaries using bisulfite sequencing and methylation-specific PCRs. Developmental exposure to MXC led to significant hypermethylation in the ERβ promoter regions (P < 0.05), whereas the ERα promoter was unaffected. We assessed global DNA methylation changes using methylation-sensitive arbitrarily primed PCR and identified 10 genes that were hypermethylated in ovaries from exposed rats. To determine whether the MXC-induced methylation changes were associated with increased DNA methyltransferase (DNMT) levels, we measured the expression levels of Dnmt3a, Dnmt3b, and Dnmt3l using semiquantitative RT-PCR. Whereas Dnmt3a and Dnmt3l were unchanged, Dnmt3b expression was stimulated in ovaries of the 100 mg/kg MXC group (P < 0.05), suggesting that increased DNMT3B may cause DNA hypermethylation in the ovary. Overall, these data suggest that transient exposure to MXC during fetal and neonatal development affects adult ovarian function via altered methylation patterns.",
author = "Zama, {Aparna Mahakali} and Mehmet Uzumcu",
year = "2009",
month = "10",
day = "1",
doi = "10.1210/en.2009-0499",
language = "English (US)",
volume = "150",
pages = "4681--4691",
journal = "Endocrinology",
issn = "0013-7227",
publisher = "The Endocrine Society",
number = "10",

}

Fetal and neonatal exposure to the endocrine disruptor methoxychlor causes epigenetic alterations in adult ovarian genes. / Zama, Aparna Mahakali; Uzumcu, Mehmet.

In: Endocrinology, Vol. 150, No. 10, 01.10.2009, p. 4681-4691.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Fetal and neonatal exposure to the endocrine disruptor methoxychlor causes epigenetic alterations in adult ovarian genes

AU - Zama, Aparna Mahakali

AU - Uzumcu, Mehmet

PY - 2009/10/1

Y1 - 2009/10/1

N2 - Exposure to endocrine-disrupting chemicals during development could alter the epigenetic programming of the genome and result in adult-onset disease. Methoxychlor (MXC) and its metabolites possess estrogenic, antiestrogenic, and antiandrogenic activities. Previous studies showed that fetal/neonatal exposure to MXC caused adult ovarian dysfunction due to altered expression of key ovarian genes including estrogen receptor (ER)-β, which was down-regulated, whereas ERα was unaffected. The objective of the current study was to evaluate changes in global and gene-specific methylation patterns in adult ovaries associated with the observed defects. Rats were exposed to MXC (20 μg/kg·d or 100 mg/kg·d) between embryonic d 19 and postnatal d 7. We performed DNA methylation analysis of the known promoters of ERα and ERβ genes in postnatal d 50-60 ovaries using bisulfite sequencing and methylation-specific PCRs. Developmental exposure to MXC led to significant hypermethylation in the ERβ promoter regions (P < 0.05), whereas the ERα promoter was unaffected. We assessed global DNA methylation changes using methylation-sensitive arbitrarily primed PCR and identified 10 genes that were hypermethylated in ovaries from exposed rats. To determine whether the MXC-induced methylation changes were associated with increased DNA methyltransferase (DNMT) levels, we measured the expression levels of Dnmt3a, Dnmt3b, and Dnmt3l using semiquantitative RT-PCR. Whereas Dnmt3a and Dnmt3l were unchanged, Dnmt3b expression was stimulated in ovaries of the 100 mg/kg MXC group (P < 0.05), suggesting that increased DNMT3B may cause DNA hypermethylation in the ovary. Overall, these data suggest that transient exposure to MXC during fetal and neonatal development affects adult ovarian function via altered methylation patterns.

AB - Exposure to endocrine-disrupting chemicals during development could alter the epigenetic programming of the genome and result in adult-onset disease. Methoxychlor (MXC) and its metabolites possess estrogenic, antiestrogenic, and antiandrogenic activities. Previous studies showed that fetal/neonatal exposure to MXC caused adult ovarian dysfunction due to altered expression of key ovarian genes including estrogen receptor (ER)-β, which was down-regulated, whereas ERα was unaffected. The objective of the current study was to evaluate changes in global and gene-specific methylation patterns in adult ovaries associated with the observed defects. Rats were exposed to MXC (20 μg/kg·d or 100 mg/kg·d) between embryonic d 19 and postnatal d 7. We performed DNA methylation analysis of the known promoters of ERα and ERβ genes in postnatal d 50-60 ovaries using bisulfite sequencing and methylation-specific PCRs. Developmental exposure to MXC led to significant hypermethylation in the ERβ promoter regions (P < 0.05), whereas the ERα promoter was unaffected. We assessed global DNA methylation changes using methylation-sensitive arbitrarily primed PCR and identified 10 genes that were hypermethylated in ovaries from exposed rats. To determine whether the MXC-induced methylation changes were associated with increased DNA methyltransferase (DNMT) levels, we measured the expression levels of Dnmt3a, Dnmt3b, and Dnmt3l using semiquantitative RT-PCR. Whereas Dnmt3a and Dnmt3l were unchanged, Dnmt3b expression was stimulated in ovaries of the 100 mg/kg MXC group (P < 0.05), suggesting that increased DNMT3B may cause DNA hypermethylation in the ovary. Overall, these data suggest that transient exposure to MXC during fetal and neonatal development affects adult ovarian function via altered methylation patterns.

UR - http://www.scopus.com/inward/record.url?scp=70349313124&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=70349313124&partnerID=8YFLogxK

U2 - 10.1210/en.2009-0499

DO - 10.1210/en.2009-0499

M3 - Article

C2 - 19589859

AN - SCOPUS:70349313124

VL - 150

SP - 4681

EP - 4691

JO - Endocrinology

JF - Endocrinology

SN - 0013-7227

IS - 10

ER -