Apolipoprotein H: a novel regulator of fat accumulation in duck myoblasts

Apolipoprotein H (APOH) primarily engages in fat metabolism and inflammatory disease response. This study aimed to investigate the effects of APOH on fat synthesis in duck myoblasts (CS2s) by APOH overexpression and knockdown. CS2s overexpressing APOH showed enhanced triglyceride (TG) and cholesterol (CHOL) contents and elevated the mRNA and protein expression of AKT serine/threonine kinase 1 (AKT1), ELOVL fatty acid elongase 6 (ELOVL6), and acetyl-CoA carboxylase 1 (ACC1) while reducing the expression of protein kinase AMP-activated catalytic subunit alpha 1 (AMPK), peroxisome proliferator activated receptor gamma (PPARG), acyl-CoA synthetase long chain family member 1 (ACSL1), and lipoprotein lipase (LPL). The results showed that knockdown of APOH in CS2s reduced the content of TG and CHOL, reduced the expression of ACC1, ELOVL6, and AKT1, and increased the gene and protein expression of PPARG, LPL, ACSL1, and AMPK. Our results showed that APOH affected lipid deposition in myoblasts by inhibiting fatty acid beta-oxidation and promoting fatty acid biosynthesis by regulating the expression of the AKT/AMPK pathway. This study provides the necessary basic information for the role of APOH in fat accumulation in duck myoblasts for the first time and enables researchers to study the genes related to fat deposition in meat ducks in a new direction.