TRPC3 Regulates Islet Beta‐Cell Insulin Secretion

• Published in: Advanced science Vol. 10; no. 6; pp. e2204846 - n/a
• Main Authors: Rached, Gaëlle, Saliba, Youakim, Maddah, Dina, Hajal, Joelle, Smayra, Viviane, Bakhos, Jules‐Joel, Groschner, Klaus, Birnbaumer, Lutz, Fares, Nassim
• Format: Journal Article
• Language: English
• Published: Germany John Wiley & Sons, Inc 01.02.2023; John Wiley and Sons Inc; Wiley
• Subjects: Animals; Antibodies; beta cells; calcium; Calcium - metabolism; diabetes; Diabetes Mellitus, Experimental - metabolism; Glucose; Glucose - metabolism; Humans; Insulin; Insulin - metabolism; Insulin Secretion; Insulin-Secreting Cells; Mice; Molecular weight; Physiology; Plasma; TRPC3; calcium; TRPC3; insulin; diabetes; beta cells
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202204846

Insulin release is tightly controlled by glucose‐stimulated calcium (GSCa) through hitherto equivocal pathways. This study investigates TRPC3, a non‐selective cation channel, as a critical regulator of insulin secretion and glucose control. TRPC3's involvement in glucose‐stimulated insulin secretion (GSIS) is studied in human and animal islets. TRPC3‐dependent in vivo insulin secretion is investigated using pharmacological tools and Trpc3−/− mice. TRPC3's involvement in islet glucose uptake and GSCa is explored using fluorescent glucose analogue 2‐[N‐(7‐nitrobenz‐2‐oxa‐1,3‐diazol‐4‐yl) amino]‐2‐deoxy‐D‐glucose and calcium imaging. TRPC3 modulation by a small‐molecule activator, GSK1702934A, is evaluated in type 2 diabetic mice. TRPC3 is functionally expressed in human and mouse islet beta cells. TRPC3‐controlled insulin secretion is KATP‐independent and primarily mediated by diacylglycerol channel regulation of the cytosolic calcium oscillations following glucose stimulation. Conversely, glucose uptake in islets is independent of TRPC3. TRPC3 pharmacologic inhibition and knockout in mice lead to defective insulin secretion and glucose intolerance. Subsequently, TRPC3 activation through targeted small‐molecule enhances insulin secretion and alleviates diabetes hallmarks in animals. This study imputes a function for TRPC3 at the onset of GSIS. These insights strengthen one's knowledge of insulin secretion physiology and set forth the TRPC3 channel as an appealing candidate for drug development in the treatment of diabetes. TRPC3, a non‐selective calcium channel, is identified as a regulator of glucose‐stimulated insulin release in human and mouse beta cells via a KATP‐independent mechanism. Small‐molecule TRPC3 modulation improves insulin secretion and diabetic hallmarks in animals. These findings advance the understanding of insulin secretion physiology and render the TRPC3 channel an appealing diabetes treatment target.