Glucagon-Like Peptide-2 Ameliorates Lipid Metabolism in Metabolic Dysfunction-Associated Steatotic Liver Disease Through the Adiponectin-Adiponectin Receptor-Mediated AMPK/PPARalpha Pathway.

Abstract

The aim of this study was to investigate the mechanisms by which glucagon-like peptide-2 (GLP-2) improves metabolic dysfunction-associated steatotic liver disease (MASLD) induced by free fatty acids (FFAs) in HepG2 cells, with a focus on the regulation of the adiponectin (ADPN) signaling axis and the downstream AMP-activated protein kinase (AMPK)/peroxisome proliferator-activated receptor alpha (PPARalpha) pathway. An MASLD model was established in HepG2 cells by FFA exposure. Following GLP-2 treatment, improvements in lipid metabolism were evaluated using the Cell Counting Kit-8, Oil Red O staining, and biochemical assays. Differential gene expression was examined using RNA sequencing, and potential mechanisms were evaluated through Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analysis. Western blotting and reverse transcription polymerase chain reaction (RT-PCR) were performed to assess the expression of key molecular components within the signaling pathway. FFA treatment led to significant lipid accumulation in HepG2 cells, whereas GLP-2 reduced intracellular lipid droplet formation (p<0.01) and decreased triglyceride and total cholesterol levels in a dose-dependent manner (p<0.05). KEGG enrichment analysis indicated that GLP-2 acted on the adipokine, AMPK, and PPARalpha pathways. Western blotting and RT-PCR confirmed that GLP-2 restored protein expression (p<0.01) and mRNA expression (p<0.05) of adiponectin receptor 1, adiponectin receptor 2, and downstream signaling molecules AMPK and PPARalpha in FFA-treated HepG2 cells. GLP-2 alleviated FFA-induced hepatocyte steatosis by modulating the AMPK/PPARalpha pathway through the regulation of ADPN and its receptors. These findings provide a theoretical foundation for the potential use of gut hormones in the treatment of MASLD. Keywords Adiponectin " AMPK " Glucagon-like peptide-2 " Metabolic dysfunction-associated steatotic liver disease " PPARalpha.