外源性脂肪酸对罗非鱼脂肪细胞增殖与分化的影响

为了探究脂肪酸对罗非鱼(Oreochromis niloticus)脂肪细胞增殖和分化的影响, 在体外培养罗非鱼前脂肪细胞, 并在其增殖和分化过程中分别添加100 μmol/L的棕榈酸(Palmitic Acid, PA)、油酸(Oleic Acid, OA), 亚油酸(Linoleic Acid, LA)和α-亚麻酸(α-Linolenic Acid, LNA)进行处理。使用SRB (Sulforhodamine B)染色法和油红O染色法检测外源性脂肪酸对脂肪细胞增殖和分化的影响, Real-time qPCR检测增殖分化过程中基因表达情况。结果显示, 在培养8d时, 外源添加的不饱和脂肪酸可以促进罗非鱼前脂肪细胞增殖, 并且增殖过程中增殖相关基因(c-fos和c-myc)、脂解相关基因(ATGL)和脂合成相关基因(PPARγ和CD36)的表达与对照组相比均显著提高(P<0.05)。此外, 外源脂肪酸的加入可以抑制脂肪细胞的分化。棕榈酸的加入使得脂肪细胞中产生的脂滴面积较少, 数量较多; 分化过程中细胞的β氧化相关基因(CPT-1a)与对照组相比显著上调, 而脂解相关基因(ATGL)则显著下调。外源性不饱和脂肪酸可以促进罗非鱼前脂肪增殖, 而饱和脂肪酸主要抑制细胞分化。在增殖过程中, 过量的脂肪酸先通过脂合成储存在胞内, 再借助脂解等途径进行代谢, 从而帮助细胞适应环境中高浓度的脂肪酸。而在分化过程中, 添加外源脂肪酸, 可能通过抑制脂肪细胞内的脂合成和脂解的发生, 同时促进β氧化等方式来抑制脂肪细胞分化。

EFFECTS OF EXOGENOUS FATTY ACID ON THE PROLIFERATION AND DIFFERENTIATION OF NILE TILAPIA PREADIPOCYTES

To investigate the effects of fatty acids on the proliferation and differentiation of preadipocytes from Nile tilapia (Oreochromis niloticus), 100 μmol/L Palmitic acid (PA), Oleic acid (OA), Linoleic acid (LA) and α-Linolenic acid (LNA) were used. SRB (Sulforhodamine B) staining and oil red O staining were used to detect cell proliferation and preadipocyte differentiation. The expression level of genes related to proliferation and differentiation was detected by Real-time qPCR. The results showed that exogenous fatty acids promoted the preadipocyte proliferation in 8 days, and significantly increased the expression level of proliferation related genes (c-fos and c-myc), lipolysis related genes (ATGL) and adipogenesis related genes (PPAR, CD36 and FAS) (P<0.05). In addition, fatty acid inhibited preadipocyte differentiation into adipocyte by decreasing lipid droplets area and increasing the lipid droplets number. During differentiation, expression level of β-oxidation related gene (CPT-1a) significantly increased (P<0.05), while the expression level of lipolysis related genes (ATG) and adipogenesis related genes (PPARγ and FAS) declined. Our results showed that exogenous fatty acid promoted the proliferation and inhibited preadipocyte differentiation. In the process of proliferation, excess fatty acids stored in the preadipocyte that could be metabolized by lipolysis and β-oxidation during adipogenesis to help cells adapt to high concentrations of fatty acids in the environment. While during the differentiation, the exogenous fatty acids can inhibit adipogenesis and lipolysis of adipocyte and promote β-oxidation to reduce adipocyte differentiation.