Anoctamin 1 (Ano1) is required for glucose-induced membrane potential oscillations and insulin secretion by murine β-cells

• DOI: 10.1007/s00424-015-1758-5
• Publication Date: 2015-11-18T06:23:11Z
• Authors: Raphaël Crutzen; Myrna Virreira; Nicolas Markadieu; Vadim Shlyonsky; Abdullah Sener; Willy J. Malaisse; Renaud Beauwens; Alain Boom; Philippe E. Golstein
• Keywords: DIDS; Bumetanide; Channel blocker

Anions such as Cl− and HCO3 − are well known to play an important role in glucose-stimulated insulin secretion (GSIS). In this study, we demonstrate that glucose-induced efflux from β-cells is mediated by the Ca2+-activated channel anoctamin 1 (Ano1). Ano1 expression rat demonstrated reverse transcriptase–polymerase chain reaction, western blotting, immunohistochemistry. Typical currents observed whole-cell inside-out patches presence of intracellular Ca++: at μM, current outwardly rectifying, 2 it becomes almost linear. The relative permeabilities monovalent anions NO3 (1.83 ± 0.10) > Br− (1.42 0.07) (1.0). A linear single-channel current–voltage relationship shows a conductance 8.37 pS. These nearly abolished blocking antibodies or inhibitors 2-(5-ethyl-4-hydroxy-6-methylpyrimidin-2-ylthio)-N-(4-(4-methoxyphenyl)thiazol-2-yl)acetamide (T-AO1) tannic acid (TA). induce strong decrease 16.7-mM action potential rate (at least 87 % on dispersed cells) partial membrane repolarization with T-AO1. They abolish strongly inhibit GSIS increment 8.3 mM 16.7 glucose. Blocking also increment. Combined treatment bumetanide acetazolamide low media provokes 65 reduction (AP) amplitude 15-mV AP peak repolarization. Although mechanism triggering opening remains be established, present data required sustain oscillations secretion.