Increased body weight induced by perinatal exposure to bisphenol A was associated with down-regulation zinc-alpha2-glycoprotein expression in offspring female rats

Abstract

We reported that perinatal exposure to bisphenol A (BPA) resulted in obesity in offspring female rats, and down-regulated zinc-alpha2-glycoprotein (ZAG) mRNA expression in subcutaneous adipose tissue maybe was associated with increased body weight in previous study. Considering that the mechanism of ZAG actions has not been clear, and ZAG gene expression levels are different with adipose tissues, we investigate the levels of ZAG mRNA and protein expression in visceral (perigonadal and perirenal) adipose tissue, and the mechanism of ZAG increasing body weight in BPA exposed rats. Pregnant rats were exposed to BPA in water at levels of either 1 μg/mL(low dose of BPA, LBPA) or 10 μg/mL (high dose of BPA, HBPA) from gestation day 6 to the end of lactation. ZAG mRNA and protein expression from visceral adipose tissue of offspring female rats on postnatal day 50 (PND50) were measured. The levels of fatty acid synthase (FAS) and hormone-sensitive lipase (HSL) gene expression, and peroxisome proliferator-activated receptors-γ (PPARγ) mRNA and protein in visceral adipose tissue were also determined. There was large size of adipocytes in perigonadal adipose tissues in BPA treated offspring female rats. Perinatal exposure to BPA could decrease the levels of ZAG and PPARγ mRNA and protein expression in visceral adipose tissues, and increase FAS gene expression, but decrease HSL gene expression. These findings indicated that BPA exposure during early development results in large size of adipocytes, which was associated with down-regulated ZAG gene. Low expression of ZAG gene increased lipogenesis and decreased lipolysis, which was associated with down-regulated PPARγ gene induced by BPA.