Hv1-deficiency protects ß cells from glucotoxicity through regulation of NOX4 level.

High glucose (HG)-induced oxidative stress contributes to the dysfunction of pancreatic ß cells in diabetes. The voltage-gated proton channel Hv1 has been proposed to support reactive oxygen species (ROS) production during respiratory bursts. However, the effect of Hv1 on glucotoxicity in pancreatic ß cells is not clear yet. In this study, we examined the protective effects of Hv1-deficiency in HG cultured ß cells. Following 48 h of treatment with 30 mM high glucose, Hv1 KO ß cells showed higher cell viability, lower cell apoptosis and a more stable insulin gene expression level compared to WT ß cells. In both control and HG cultured ß cells, deficiency of Hv1 decreased the glucose- and PMA-induced ROS production. Finally, HG incubation led to NOX4 upregulation in WT ß cells, which could be inhibited by HV1 deficiency. In conclusion, Hv1-deficiency prevents the HG treatment-induced NOX4 upregulation and protects ß cells from glucotoxicity.