SAT-715 Bisphenol-A Alters Pancreatic B-Cell Proliferation and Mass in an Estrogen Receptor Beta-Dependent Manner

Abstract

Bisphenol-A (BPA) is one of the highest volume chemicals produced worldwide. It is used as the base compound in the manufacture of polycarbonate plastics, epoxies and resins. Humans are consistently exposed to BPA and consistently it has been detected in the majority of individuals examined. Experimental research in animals, as well as human epidemiological studies, converge to conclude that BPA is a risk factor for the development of type 2 diabetes. In previous studies we have demonstrated that the exposure to BPA during embryonic development promote an increment of pancreatic β-cell mass. This was correlated with increased β-cell division and altered global gene expression in pancreatic β-cells. The aim of this work was to determinate whether ERβ was involved in the in the β-cell mass and proliferation increment observed in male mice offspring. ERβ+/- pregnant mice were treated with vehicle or BPA (10 μg/kg/day) from day 9 to 16 of gestation. Offspring pancreatic β-cell mass was measured at postnatal day 0 (P0) and 30 (P30). For ex vivo experiments Wild-type (WT) and ERβ-/- neonates as well as adult male and female mice were used. For in vitro, single islets cells were cultured for 48 h in the presence of 10 μmol/L BrdU, and vehicle, BPA (1, 10, 100 nM) or the specific ERβ agonist WAY200070 (1, 10, 100 nM). β-cell proliferation rate was quantified as the percentage of BrdU-positive pancreatic β-cells. In vivo exposure to BPA during pregnancy promoted an increment of pancreatic β-cell mass and proliferation in WT mice at P30 which was absent in ERβ -/- mice. In order to explore if these changes were related to a direct action of BPA on pancreatic β-cell division we performed a series of ex vivo experiments. Augmented β-cell proliferation rate was observed in BPA-exposed β-cells isolated from both adult male and female WT animals in comparison to controls. The increment was significant at all BPA doses tested. The effect was imitated by the selective ERβ agonist, WAY200070, and was abolished in cells from ERβ-/- mice. We also explored the effects of BPA in pancreatic β-cells from neonates and found an increment in BPA-exposed cells compared to controls, although the difference was only significant at the dose of 1 nM. A similar effect was observed in neonate cells treated with WAY200070 (10 nM). The effects on β-cell replication were abolished in cells from ERβ-/- neonate mice treated either with BPA or WAY200070. Our findings suggest that BPA modulate pancreatic β-cell growth and mass in an ERβ-dependent manner. This could have important implications for metabolic programming of T2DM. Ministerio de Economía y Competitividad, Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (FEDER) grants BPU2017-86579-R (AN) and BFU2016-77125-R (IQ); Generalitat Valenciana PROMETEO II/2015/016 (AN). CIBERDEM is an initiative of the Instituto de Salud Carlos III.