Gemigliptin Alleviates Succinate-Induced Hepatic Stellate Cell Activation by Ameliorating Mitochondrial Dysfunction

BACKGROUND: Dipeptidyl peptidase-4 inhibitors (DPP-4Is) are used clinically as oral antidiabetic agents. Although DPP-4Is are known to ameliorate liver fibrosis, the protective mechanism of DPP-4Is in liver fibrosis remains obscure. In this study, gemigliptin was used to investigate the potential of DPP-4Is to alleviate the progression of liver fibrosis. METHODS: To clarify the effects and mechanisms of gemigliptin, we conducted various experiments in LX-2 cells (immortalized human hepatic stellate cells [HSCs], the principal effectors of hepatic fibrogenesis), which were activated by succinate and exhibited elevated expression of α-smooth muscle actin, collagen type 1, and pro-inflammatory cytokines and increased cell proliferation. In vivo, we examined the effects and mechanisms of gemigliptin on a high-fat, high-cholesterol–induced mouse model of nonalcoholic steatohepatitis (NASH). RESULTS: Gemigliptin decreased the expression of fibrogenesis markers and reduced the abnormal proliferation of HSCs. In addition, gemigliptin reduced the succinate-induced production of mitochondrial reactive oxygen species (ROS), intracellular ROS, and mitochondrial fission in HSCs. Furthermore, in the mouse model of NASH-induced liver fibrosis, gemigliptin alleviated both liver fibrosis and mitochondrial dysfunction. CONCLUSION: Gemigliptin protected against HSC activation and liver fibrosis by alleviating mitochondrial dysfunction and ROS production, indicating its potential as a strategy for preventing the development of liver disease.