Biphenol-S and Biphenol-F alter mouse pancreatic b-cell ion channel expression and activity and insulin release through an estrogen receptor ERb mediated pathway

Abstract

Bisphenol-S (BPS) and Bisphenol-F (BPF) are current Bisphenol-A (BPA) substitutes. Here we used pancreatic b-cells from wild type (WT) and estrogen receptor b (ERb) knockout (BERKO) mice to investigate the effects of BPS and BPF on insulin secretion, and the expression and activity of ion channels involved in b-cell function. BPS or BPF rapidly increased insulin release and diminished ATP-sensitive Kþ (KATP) channel activity. Similarly, 48 h treatment with BPS or BPF enhanced insulin release and decreased the expression of several ion channel subunits in b-cells from WT mice, yet no effects were observed in cells from BERKO mice. PaPE-1, a ligand designed to preferentially trigger extranuclear-initiated ER pathways, mimicked the effects of bisphenols, suggesting the involvement of extranuclear-initiated ERb pathways. Molecular dynamics simulations indicated differences in ERb ligand-binding domain dimer stabilization and solvation free energy among different bisphenols and PaPE-1. Our data suggest a mode of action involving ERb whose activation alters three key cellular events in b-cell, namely ion channel expression and activity, and insulin release. These results may help to improve the hazard identification of bisphenols.