Pancreatic β 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 β 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 β cells. Mice with β cell–specific Sucnr1 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.
Joan Sabadell-Basallote, Brenno Astiarraga, Carlos Castaño, Miriam Ejarque, Maria Repollés-de-Dalmau, Ivan Quesada, Jordi Blanco, Catalina Núñez-Roa, M-Mar Rodríguez-Peña, Laia Martínez, Dario F. De Jesus, Laura Marroquí, Ramon Bosch, Eduard Montanya, Francesc X. Sureda, Andrea Tura, Andrea Mari, Rohit N. Kulkarni, Joan Vendrell, Sonia Fernández-Veledo
SUCNR1 levels in islets are dysregulated in obesity and T2D.