Effect of Fenofibrate and Selective PPARα Modulator (SPPARMα), Pemafibrate on KATP Channel Activity and Insulin Secretion

Objective: Insulin secretion is regulated by ATP-sensitive potassium (K) channels in pancreatic beta-cells. Peroxisome proliferator-activated receptors (PPAR) α ligands are clinically used to treat dyslipidemia. A PPARα ligand, fenofibrate, and PPARγ ligands troglitazone and 15-deoxy-∆-prostaglandin J2 are known to close K channels and induce insulin secretion. The recently developed PPARα ligand, pemafibrate, became a new entry for treating dyslipidemia. Because pemafibrate is reported to improve glucose intolerance in mice treated with a high fat diet and a novel selective PPARα modulator, it may affect K channels or insulin secretion.

Results: The effect of fenofibrate (100 µM) and pemafibrate (100 µM) on insulin secretion from MIN6 cells was measured by using batch incubation for 10 and 60 min in low (2 mM) and high (10 mM) glucose conditions. The application of fenofibrate for 10 min significantly increased insulin secretion in low glucose conditions. Pemafibrate failed to increase insulin secretion in all of the conditions experimented in this study. The K channel activity was measured by using whole-cell patch clamp technique. Although fenofibrate (100 µM) reduced the K channel current, the same concentration of pemafibrate had no effect. Both fenofibrate and pemafibrate had no effect on insulin mRNA expression.