SUCNR1 regulates insulin secretion and glucose elevates the succinate response in people with prediabetes

Pancreatic [beta] cell dysfunction is a key feature of type 2 diabetes, and novel regulators of insulin secretion are desirable. Here, we report that succinate receptor 1 (SUCNR1) is expressed in [beta] cells and is upregulated in hyperglycemic states in mice and humans. We found that succinate acted as a hormone-like metabolite and stimulated insulin secretion via a SUCNR1-Gq-PKC-dependent mechanism in human [beta] cells. Mice with [beta] cell-specific Sucnrl deficiency exhibited impaired glucose tolerance and insulin secretion on a high-fat diet, indicating that SUCNR1 is essential for preserving insulin secretion in diet-induced insulin resistance. Patients with impaired glucose tolerance showed an enhanced nutrition-related succinate response, which correlates with the potentiation of insulin secretion during intravenous glucose administration. These data demonstrate that the succinate/SUCNR1 axis is activated by high glucose and identify a GPCR- mediated amplifying pathway for insulin secretion relevant to the hyperinsulinemia of prediabetic states.
Introduction Insulin secretion by pancreatic [beta] cells is crucial for blood glucose homeostasis and is tightly controlled by a complex network of hormones, nutrients, and neurotransmitters. Impaired [beta] cell function [...]