Sodium-Glucose Cotransporter-2 Inhibitor Enhances Hepatic Gluconeogenesis and Reduces Lipid Accumulation via AMPK-SIRT1 Activation and Autophagy Induction

Abstract

Background: Sodium-glucose cotransporter type 2 (SGLT2) inhibitors, such as dapagliflozin, are primarily used to lower glucose in type 2 diabetes. Recent studies suggest broader metabolic effects, particularly in the liver. This study explores the molecular mechanisms by which dapagliflozin influences hepatic glucose and lipid metabolism, hypothesizing that it activates the 5'-adenosine monophosphate-activated protein kinase (AMPK)-sirtuin 1 (Sirt1) pathway to promote gluconeogenesis and reduce lipid accumulation via autophagy. Methods: HepG2 hepatocellular carcinoma cells were treated with dapagliflozin, and Western blotting, quantitative reverse transcription polymerase chain reaction, and fluorescence microscopy were used to assess gluconeogenic enzyme expression and autophagy. In vivo, mice with liver-specific autophagy related 7 (Atg7) deletion and those on a high-fat diet were used to evaluate glucose regulation, lipid metabolism, and autophagy. Results: Dapagliflozin significantly increased expression of gluconeogenic enzymes like phosphoenolpyruvate carboxykinase (PEPCK) in HepG2 cells and enhanced autophagic flux, evidenced by increased light chain 3B (LC3B)-II levels and autophagosome formation. AMPK-Sirt1 activation was confirmed as the underlying mechanism. Additionally, dapagliflozin reduced fatty acid synthesis by suppressing enzymes such as acetyl-CoA carboxylase and fatty acid synthase, while promoting fatty acid degradation via carnitine palmitoyltransferase 1 alpha (CPT1 alpha) upregulation. In high-fat diet mice, dapagliflozin increased hepatic gluconeogenesis and reduced lipid accumulation, though serum cholesterol and triglyceride levels were unaffected. Conclusion: Dapagliflozin enhances hepatic gluconeogenesis and reduces steatosis by activating the AMPK-Sirt1 pathway and promoting autophagy. These findings suggest that SGLT2 inhibitors could offer therapeutic benefits for managing hepatic lipid disorders, beyond glycemic control.