Liraglutide modulates lipid metabolism via ZBTB20-LPL pathway.

OBJECTIVE: To investigate the mechanism of liraglutide affecting lipid metabolism by regulating lipolysis and lipogenesis in cells and ob/ob mice. METHODS: 3 T3-L1 cells were treated with liraglutide in vitro, and differentially expressed genes were screened by RNA sequencing. Gene Ontology (GO) and KEGG (Kvoto Encyclopedia of Genes and Genomes) enrichment analyses identified target genes for lipid regulation of liraglutide. 3 T3-L1 preadipocytes were induced to differentiate into adipocytes using a "cocktail method". Western blot and immunofluorescence were used to detect the expression of target genes and the lipid regulatory effect of liraglutide. 3 T3-L1 preadipocytes were transfected with lentivirus overexpressing Zbtb20 to study its role in adipogenesis, and gene expression was analyzed by RT-qPCR and Western blot. In vivo, ob/ob mice were subcutaneously injected with liraglutide or saline for 4 weeks. Blood lipids, adipose tissue volume and adipocyte size were detected. Immunohistochemical analysis and RT-qPCR were used to detect the expression of target genes in adipose tissue. RESULTS: Liraglutide reduced lipid droplets and TG levels and altered the expression of genes related to fatty acid metabolism, lipogenesis, fatty acid oxidation, and adipocyte browning. The results of PCR, Western blot and immunofluorescence confirmed that liraglutide could regulate the adipogenesis by downregulating the transcriptional suppressor ZBTB20, and overexpression of Zbtb20 inhibited the expression of LPL, the key enzyme for lipohydrolysis. CONCLUSIONS: Liraglutide regulates lipid metabolism through ZBTB20-LPL pathway to reveal its molecular mechanism.