title: In Vitro Effects of Bisphenol A β-D-Glucuronide (BPA-G) on Adipogenesis in Human and Murine Preadipocytes.
abstract: BACKGROUND
  Exposure to common environmental substances, such as bisphenol A (BPA), has been associated with a number of negative health outcomes. In vivo, BPA is rapidly converted to its predominant metabolite, BPA-glucuronide (BPA-G), which has long been believed to be biologically inactive because it lacks estrogenic activity. However, the effects of BPA-G on cellular metabolism have not been characterized. In the present study we examined the effect of BPA-G on adipogenesis.
  
  
  METHODS
  The effect of BPA-G on the differentiation of human and 3T3L1 murine preadipocytes was evaluated in vitro by quantifying lipid accumulation and the expression of adipogenic markers.
  
  
  RESULTS
  Treatment of 3T3L1 preadipocytes with 10 μM BPA-G induced a significant increase in lipid accumulation, mRNA expression of the adipogenic markers sterol regulatory element binding factor 1 (SREBF1) and lipoprotein lipase (LPL), and protein levels of LPL, aP2, and adipsin. Treatment of primary human preadipocytes with BPA-G also induced adipogenesis as determined by aP2 levels. Co-treatment of cells with the estrogen receptor (ER) antagonist fulvestrant (ICI) significantly inhibited the BPA-G-induced increase in LPL and aP2 levels, whereas treatment with ICI alone had no effect. Moreover, BPA-G did not display any significant estrogenic activity.
  
  
  CONCLUSIONS
  To our knowledge, this study is the first to report that BPA-G induces adipocyte differentiation and is not simply an inactive metabolite. The fact that BPA-G induced adipogenesis and was inhibited by an ER antagonist yet showed no estrogenic activity suggests that it has no classical ER transcriptional activation function and acts through a pathway that remains to be determined.
authors.affiliation: Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada.
authors.forename: Jonathan G
authors.initials: JG
authors.lastname: Boucher
authors.forename: Adèle
authors.initials: A
authors.lastname: Boudreau
authors.forename: Shaimaa
authors.initials: S
authors.lastname: Ahmed
authors.forename: Ella
authors.initials: E
authors.lastname: Atlas
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D050156:Adipogenesis / Q000187:drug effects; D000818:Animals; D001559:Benzhydryl Compounds / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D004958:Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology; D065171:Estrogen Receptor Antagonists / Q000494:pharmacology; D000077267:Fulvestrant; D005786:Gene Expression Regulation; D020719:Glucuronides / Q000494:pharmacology*; D006801:Humans; D050356:Lipid Metabolism; D051379:Mice; D010636:Phenols / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D004958:Estradiol; D065171:Estrogen Receptor Antagonists; D000077267:Fulvestrant; D020719:Glucuronides; D010636:Phenols; D012333:RNA, Messenger; C512161:bisphenol A glucuronide; D000098826:Bisphenol A Compounds