Chicken adipocyte fatty acid-binding protein knockdown affects expression of peroxisome proliferator-activated receptor γ gene during oleate-induced adipocyte differentiation

Abstract

Adipocyte fatty acid-binding protein (A-FABP) is expressed in both adipose cells and macrophages. As one of the downstream genes of peroxisome proliferator-activated receptor γ (PPAR-γ), A-FABP plays an important role in the lipid metabolism of adipocytes in mammal and poultry. However, studies in A-FABP null macrophages of mice showed that A-FABP was a critical regulator of PPAR-γ and could affect the expression of PPAR-γ. The current study was designed to investigate whether the same mechanism as that in macrophages exists in chicken adipocytes. After transfection with interference and overexpression plasmids of A-FABP in chicken adipocytes for 24 h, oleate was added to the medium. Then, lipid accumulation, nonesterified fatty acids (NEFA) in the medium, and expression of lipid metabolism-related genes were detected. The results showed that in the A-FABP knockdown adipocytes, lipid accumulation was decreased at 6 h and NEFA in the medium was higher at 1 and 6 h compared with that in the control group. Moreover, gene expression levels of lipoprotein lipase, perilipin, and PPAR-γ were higher than that of the control group (P < 0.05). In the A-FABP overexpression adipocytes, lipid accumulation and expression of lipid metabolism related genes were similar to that of the control group. However, NEFA in the medium was significantly lower in the A-FABP overexpression group 1 h after adding oleate (P < 0.05). The present study suggested that the A-FABP knockdown might lead to decreased lipid accumulation and upregulated expression of PPAR-γ in chicken adipocytes.