title: Hepatic DNA methylation modifications in early development of rats resulting from perinatal BPA exposure contribute to insulin resistance in adulthood.
abstract: OBJECTIVE
  Perinatal exposure to bisphenol A (BPA), a widely distributed environmental endocrine disruptor, is associated with insulin resistance and diabetes in offspring. The underlying molecular mechanisms could involve epigenetics, as adverse effects induced by environmental exposure in early life are suggested through DNA methylation. In this study we sought to elucidate the relationship between perinatal BPA exposure and alteration of hepatic DNA methylation.
  
  
  METHODS
  Pregnant Wistar rats were administered BPA (50 μg/kg/day) or corn oil by oral gavage throughout gestation and lactation. Variables associated with insulin resistance and hepatic DNA methylation were examined at postnatal week 3 and week 21 in male offspring.
  
  
  RESULTS
  In BPA-treated offspring, serum insulin and HOMA-insulin resistance were increased, and the insulin sensitivity index and hepatic glycogen storage were decreased compared with controls at week 21. At week 3, none of these variables were significantly changed. However, hepatic global DNA methylation was decreased, accompanied by overexpression of DNA methyltransferase 3B mRNA at week 3. Meanwhile, perinatal exposure to BPA induced promoter hypermethylation and a reduction in gene expression of hepatic glucokinase. Moreover, increased promoter hypermethylation of Gck became more pronounced in BPA-treated offspring at week 21.
  
  
  CONCLUSIONS
  Abnormal DNA methylation in hepatic tissue precedes development of insulin resistance induced by perinatal BPA exposure. These findings support the potential role of epigenetics in fetal reprogramming by BPA-induced metabolic disorders.
authors.affiliation: Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China.
authors.forename: Y
authors.initials: Y
authors.lastname: Ma
authors.forename: W
authors.initials: W
authors.lastname: Xia
authors.forename: D Q
authors.initials: DQ
authors.lastname: Wang
authors.forename: Y J
authors.initials: YJ
authors.lastname: Wan
authors.forename: B
authors.initials: B
authors.lastname: Xu
authors.forename: X
authors.initials: X
authors.lastname: Chen
authors.forename: Y Y
authors.initials: YY
authors.lastname: Li
authors.forename: S Q
authors.initials: SQ
authors.lastname: Xu
mesh_terms: D000818:Animals; D001559:Benzhydryl Compounds / Q000633:toxicity*; D019175:DNA Methylation / Q000187:drug effects*; D005260:Female; D007333:Insulin Resistance / Q000502:physiology*; D008099:Liver / Q000378:metabolism*; D010636:Phenols / Q000633:toxicity*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D017208:Rats, Wistar; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D010636:Phenols; C006780:bisphenol A; D000098826:Bisphenol A Compounds