Fetal and neonatal exposure to the endocrine disruptor methoxychlor causes epigenetic alterations in adult ovarian genes.
Fetal and neonatal exposure to the endocrine disruptor methoxychlor causes epigenetic alterations in adult ovarian genes.
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DOI：
10.1210/en.2009-0499
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发表时间：
2009-07
期刊：
影响因子：
4.8
通讯作者：
A. Zama;M. Uzumcu
中科院分区：
文献类型：
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作者：
A. Zama;M. Uzumcu
在发育过程中暴露于干扰内分泌的化学物质可能会改变基因组的表观遗传程序，导致成人发病。甲氧氯及其代谢物具有雌激素、抗雌激素和抗雄激素活性。先前的研究表明，胎儿/新生儿暴露于MXC会导致成人卵巢功能障碍，这是由于卵巢关键基因的表达改变，包括雌激素受体(ER)- β，其表达下调，而ER - α不受影响。当前研究的目的是评估与观察到的缺陷相关的成人卵巢中整体和基因特异性甲基化模式的变化。大鼠分别暴露于MXC （20 mg/ kgxd或100 mg/kg）。D)在胚胎期D 19和产后D 7之间。我们使用亚硫酸盐测序和甲基化特异性pcr对出生后50-60个卵巢中已知的erα和erβ基因启动子进行了DNA甲基化分析。发育暴露于MXC导致erβ启动子区域显著的高甲基化（P < 0.05），而erα启动子不受影响。我们使用甲基化敏感的任意引物PCR评估了全球DNA甲基化变化，并鉴定了暴露大鼠卵巢中高甲基化的10个基因。为了确定mxc诱导的甲基化变化是否与DNA甲基转移酶（DNMT）水平升高有关，我们使用半定量RT-PCR测量了Dnmt3a、Dnmt3b和Dnmt3l的表达水平。100 mg/kg MXC组卵巢中Dnmt3a和Dnmt3l表达不变，而Dnmt3b表达受到刺激（P < 0.05），提示Dnmt3b表达增加可能导致卵巢DNA高甲基化。总的来说，这些数据表明胎儿和新生儿发育期间短暂暴露于MXC会通过改变甲基化模式影响成年卵巢功能。
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)-beta, which was down-regulated, whereas ERalpha 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 microg/kgxd or 100 mg/kg.d) between embryonic d 19 and postnatal d 7. We performed DNA methylation analysis of the known promoters of ERalpha and ERbeta genes in postnatal d 50-60 ovaries using bisulfite sequencing and methylation-specific PCRs. Developmental exposure to MXC led to significant hypermethylation in the ERbeta promoter regions (P < 0.05), whereas the ERalpha 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.