Effect of ACSL3 Expression Levels on Preadipocyte Differentiation in Chinese Red Steppe Cattle.

ABSTRACT

Domestic cattle are an important type of livestock, with beef production playing a major role in the agricultural economy. Adipocyte levels and fat content are interrelated, with meat quality being highly dependent on its fat content and distribution. Acyl-CoA synthetases of long-chain (ACSL) fatty acids (FAs) play an integral role in virtually every metabolic pathway in mammalian biochemistry, including complex lipid biosynthesis, protein modification, and ß-oxidation processes. ACSL3 activity is also known to be associated with adipocyte differentiation; however, its biological mechanism of action is currently unclear. Gene expression in subcutaneous preadipocytes isolated from subcutaneous deposits of Chinese Red Steppe cattle has been studied using in vitro cell transfection, real-time polymerase chain reaction and western blot analysis. The lipid and triglyceride contents of lipid droplets have also been measured to verify the levels of gene expression. These combined studies show that ACSL3 is induced during adipocyte differentiation, with its overexpression promoting an increase in the triglyceride content of lipid droplets. Furthermore, mRNA and protein expression levels for adipocyte differentiation marker genes, such as peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer-binding protein alpha (C/EBPα), were markedly increased during mature adipocyte cell differentiation. Knockdown of ACSL3 expression using ACSL3 small interfering RNAs (siRNAs) resulted in a decrease in lipid content of cattle adipocytes, providing further evidence that ACSL3 plays a key role in the differentiation process.