VDAC1 is a target for pharmacologically induced insulin hypersecretion in β cells

Abstract

β cells are dysfunctional in type 2 diabetes (T2D) and congenital hyperinsulinism (HI), but the mechanisms linking hypersecretion to β cell failure are poorly understood. Here, we use proteomics and functional assays in human and mouse β cell lines to identify VDAC1 as a target for the small molecule hypersecretion inducer SW016789. By enhancing membrane depolarization, SW016789 acutely increases Ca²⁺ influx, eventually driving β cell dysfunction. Time-course transcriptomics analysis reveals a distinct hypersecretory response signature compared to classical endoplasmic reticulum (ER) stress, highlighting ER-associated degradation (ERAD) as a key adaptive pathway. While SW016789 reduces ERAD substrate OS-9 levels, broader ERAD component changes are limited in cell lines. However, immunostaining of the T2D human pancreas shows altered distributions of the ratios of the core ERAD components SEL1L, HRD1, and DERL3 in β cells. This work provides a detailed mechanistic characterization of a hypersecretion-specific stress response, revealing potential therapeutic targets, including VDAC1 and ERAD, for modulating β cell function and survival in disease.

Keywords: CP: Cell biology; CP: Metabolism; ER stress; ER-associated degradation; congenital hyperinsulinism; diabetes; hypersecretion; insulin secretion; pancreatic islets; target identification; transcriptomics; β cells.