College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, P. R. China.
Poult Sci. 2011 May;90(5):1037-44. doi: 10.3382/ps.2010-01161.
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.
脂肪细胞脂肪酸结合蛋白（A-FABP）在脂肪细胞和巨噬细胞中均有表达。作为过氧化物酶体增殖物激活受体 γ（PPAR-γ）的下游基因之一，A-FABP 在哺乳动物和禽类脂肪细胞的脂质代谢中发挥重要作用。然而，在 A-FABP 敲除的小鼠巨噬细胞中的研究表明，A-FABP 是 PPAR-γ的关键调节因子，能够影响 PPAR-γ的表达。本研究旨在探讨在鸡脂肪细胞中是否存在与巨噬细胞中相同的机制。用 A-FABP 的干扰和过表达质粒转染鸡脂肪细胞 24 h 后，向培养基中加入油酸盐。然后，检测脂质积累、培养基中非酯化脂肪酸（NEFA）和脂质代谢相关基因的表达。结果表明，在 A-FABP 敲低的脂肪细胞中，与对照组相比，6 h 时脂质积累减少，1 和 6 h 时培养基中的 NEFA 升高（P < 0.05）。此外，脂蛋白脂肪酶、围脂滴蛋白和 PPAR-γ的基因表达水平均高于对照组（P < 0.05）。在 A-FABP 过表达的脂肪细胞中，脂质积累和脂质代谢相关基因的表达与对照组相似。然而，在添加油酸盐 1 h 后，A-FABP 过表达组的培养基中 NEFA 显著低于对照组（P < 0.05）。本研究表明，A-FABP 敲低可能导致鸡脂肪细胞中脂质积累减少和 PPAR-γ表达上调。
