Trelagliptin succinate: DPP-4 inhibitor to improve insulin resistance in adipocytes.

Trelagliptin inhibits the enzyme dipeptidyl-4 (DPP-4) to treat type 2 diabetes and it may possess the potential to improve insulin resistance. However, the molecular mechanism is not known. In this study, the effect of trelagliptin succinate in improving insulin resistance was investigated. The differentiation system of 3T3-L1 mouse preadipocytes was used to determine the content of adipokines and the content of GLUT4 in the outer membrane. The expression of AKT, P-AKT, IRS-1 and P-IRS-1 in differentiated 3T3-L1 adipocytes was determined by western blotting. Our results demonstrated that trelagliptin succinate increased the expression of AKT, P-AKT, IRS-1 and P-IRS-1 in the PI-3K/AKT insulin signaling pathway. These events promote the trans-membrane function of GLUT4 and concomitant glucose intake in adipocytes. In addition, the secretion of free fatty acids and resistin were decreased. In conclusion, our study suggested that trelagliptin succinate improved insulin resistance in adipocytes via regulation of PI-3K/AKT/GLUT4 insulin signaling pathway.