Mechanism of fatty acid transposase (CD36) promoting fat accumulation in mule ducks

ABSTRACT: Mule ducks accumulate a large amount of fat in their livers when fed high-energy feed, which is predominantly used for producing fatty livers. Nevertheless, there is limited research on the molecular mechanisms underlying the formation of fatty liver in mule ducks. Fatty acid translocase (CD36) is a sensor for fatty acids and lipid metabolism regulator, which may play a crucial role in the accumulation of fat in the liver of mule ducks. In this study, Overexpression and CD36 gene interference for 24 h was followed by induction of liver cells with 400 µmol/L palmitic acid (PA) for 24 h. The results demonstrated that CD36 overexpression increased hepatic triglyceride content, lipid droplet deposition, oxidative stress, and cell apoptosis. However, interference with CD36 had the opposite effect. CD36 overexpression suppressed the expression of AMPK and CPT-1A genes but enhanced the expression of ACC1 and LKB1 genes, with interference yielding contrasting results. Additionally, the expression of CD36 inhibited the AMPK pathway, reduced AMPK phosphorylation, downregulated AMPK protein expression, and upregulated SREBP1 protein expression. This promoted palmitic acid-induced hepatocyte fat accumulation. In summary, CD36 promotes palmitic acid-induced fat accumulation in primary mule duck liver cells through the AMPK signaling pathway.