本研究分析了共轭亚油酸（CLA）对C2C12肌细胞生脂转分化和生肌分化的影响。分别培养并诱导C2C12鼠源肌细胞生脂转分化和正常的生肌分化，同时分别使用终浓度为50 μmol/L的c9，t11-CLA和t10，c12-CLA处理细胞，并设对照组，取生脂转分化第10天和生肌分化第8天的细胞用于实时定量PCR检测，观察c9，t11-CLA和t10，c12-CLA对C2C12肌细胞不同分化的影响。结果表明：1）与对照组相比，c9，t11-CLA促进了C2C12肌细胞的生脂转分化，显著增加了细胞内甘油三酯（TG）含量（P<0.05），显著上调了细胞内脂肪酸合成酶（FAS）、CCAAT增强子结合蛋白α（C/EBPα）、过氧化物酶体增殖剂激活受体γ（PPARγ）和脂肪酸结合蛋白4（FABP4）基因的表达水平（P<0.05）；与对照组相比，t10，c12-CLA则抑制了C2C12肌细胞的生脂转分化，显著减少了细胞内TG含量（P<0.05），显著下调了细胞内C/EBPα、PPARγ和FABP4基因的表达水平（P<0.05）。免疫印迹杂交结果显示FAS和FABP4的蛋白质表达水平也发生了与基因表达相一致的变化。2）与对照组相比，t10，c12-CLA抑制了C2C12肌细胞的生肌分化，显著减少了细胞内肌管数/细胞数（P<0.05），显著下调了细胞内肌细胞生成素（MYOG） 和成肌分化抗原（MYOD）基因的表达水平（P<0.05）；与对照组相比，c9，t11-CLA则显著上调了细胞内MYOG基因的表达水平（P<0.05），对C2C12肌细胞的生肌分化有一定程度的促进作用。免疫印迹杂交结果显示MYOG和MYOD的蛋白质表达水平也发生了与基因表达相一致的变化。以上结果表明，CLA对动物骨骼肌细胞的正常生肌分化和生脂转分化都具有重要的调节作用。
This study was conducted to evaluated the effects of conjugated linoleic acid (CLA) on adipogenic trans-differentiation and myogenic differentiation of C2C12 myoblasts. Either c9,t11-CLA or t10,c12-CLA (the final concentration was 50 μmol/L) was used to treat the C2C12 mouse origin myoblasts which were cultured and induced adipogenic trans-differentiation and normal myogenic differentiation, respectively. And set the control group. The C2C12 myoblasts adipogenic trans-differentiation on the tenth day and myogenic differentiation on the eighth day were used for real-time quantitative PCR detection, and to observed the effects of c9,t11-CLA and t10,c12-CLA on different differentiation of C2C12 myoblasts. The results showed as follows: 1) compared with the control group, c9,t11-CLA promoted adipogenic trans-differentiation of C2C12 myoblasts, significantly increased the intracellular triglycerides (TG) content and up-regulated intracellular genes expression levels of the fatty acid synthetase (FAS), CCAAT/enhancer binding protein α (C/EBPa), peroxisome proliferators-activated receptors γ (PPARγ) and fatty acid binding protein 4 (FABP4) (P<0.05). Compared with the control group, t10,c12-CLA inhibited the adipogenic trans-differentiation of C2C12 myoblasts, significantly decreased the intracellular TG content and down-regulated intracellular genes expression levels of C/EBPa, PPARγ and FABP4 (P<0.05). The results of Western blotting showed that protein expression levels of FAS and FABP4 also changed as same as the gene expression levels. 2) Compared with the control group, t10,c12-CLA inhibited the myogenic differentiation of C2C12 myoblasts, significantly decreased the intracellular myotube numbers/cell numbers and down-regulated intracellular genes expression levels of myogenin (MYOG) and myogenic differentiation antigen (MYOD) (P<0.05). Compared with the control group, c9,t11-CLA significantly down-regulated gene expression level of MYOG (P<0.05) and promoted the myogenic differentiation of C2C12 myoblasts to some degree. The results of Western blotting showed that protein expression levels of MYOG and MYOD also changed as same as the gene expression levels. All these results suggest that CLA has important regulation on normal myogenic differentiation and adipogenesis trans-differentiation of skeletal muscle cells in animals.
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