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

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

SUBMITTER: Crutzen R

PROVIDER: S-EPMC4792454 | biostudies-literature | 2016 Apr

REPOSITORIES: biostudies-literature

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

Crutzen Raphaël R Virreira Myrna M Markadieu Nicolas N Shlyonsky Vadim V Sener Abdullah A Malaisse Willy J WJ Beauwens Renaud R Boom Alain A Golstein Philippe E PE

Pflugers Archiv : European journal of physiology 20151118 4

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 Cl(-) efflux from β-cells is mediated by the Ca(2+)-activated Cl(-) channel anoctamin 1 (Ano1). Ano1 expression in rat β-cells is demonstrated by reverse transcriptase-polymerase chain reaction, western blotting, and immunohistochemistry. Typical Ano1 currents are observed in whole-cell and inside-out patches in the presence ...[more]

PMID: 26582426

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Dataset Information

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

Publications

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

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