Oleic Acid Increases Lipid Accumulation in Duck Hepatocytes by Promoting Apolipoprotein A1 Expression

Lipid overaccumulation in the liver predisposes ducks to metabolic disorders. The molecular mechanism of oleic acid (OA)-induced hepatic steatosis in ducks is not fully elucidated.

A cellular model of steatosis was established by treating primary duck hepatocytes with OA. Transcriptome sequencing was performed to identify key signaling pathways and candidate genes. The role of Apolipoprotein A1 (APOA1) was investigated through overexpression and knockdown experiments. Intracellular triglycerides (TGs) were quantified commercially; lipid droplets were visualized by Oil Red O staining.

Intracellular TG accumulation was induced by OA treatment in a dose-dependent manner. Through transcriptome analysis, 1045 differentially expressed genes (DEGs) were identified, with APOA1 being recognized as a key candidate within the peroxisome proliferator-activated receptor (PPAR) signaling pathway. The content of TGs and lipid droplets was increased by APOA1 overexpression, whereas these effects were suppressed by APOA1 knockdown. The expression of acetyl-CoA carboxylase alpha (ACACA) and fatty acid synthase (FASN) was upregulated by APOA1. Conversely, the expression of carnitine O-palmitoyltransferase 1 (CPT1), acyl-CoA oxidase 1 (ACOX1), and apolipoprotein B (APOB) was downregulated.

This study demonstrates that OA upregulates APOA1, suggesting the involvement of the PPAR pathway and providing a theoretical basis for modulating hepatic fat deposition.