GLP-1RAs regulate lipid metabolism and induce autophagy through AMPK/SIRT1 pathway to improve NAFLD

Human hepatoma HepG2 cells and HL-7702 cells were obtained from the Procell Life Science &Technology Co. Ltd (Wuhan, China) and were grown in Dulbecco’s modified Eagle’s medium (DMEM) supplemented with 10% fetal bovine serum (FBS) in a 37°C incubator with 5% CO2. To induce hepatic steatosis, cells were treated with 1 mM palmitic acid and oleic acid mixture (FFA, Sigma-Aldrich, USA) for 24 hours, For the LRG experiments, cells were incubated for an additional 24 hours in varying LRG concentrations (25, 50, 100 nM) while equal amounts of fatty acid-free bovine serum albumin (BSA) were added to the control cells. To evaluate autophagy, cells were treated with LRG (100 nM) plus chloroquine (CQ, 20 µM, Sigma-Aldrich, USA) or rapamycin (RAPA, 1 µM, Sigma-Aldrich, USA) In addition, steatotic HepG2 cells were exposed to compound C (CC,10 µM, Selleck Chemicals, USA) in the presence of LRG (100 nM) for 24 hours.