脂肪酸对成肌细胞增殖和分化的影响

Effects of fatty acids on proliferation and differentiation of myoblast

目的研究不同种类的脂肪酸对成肌细胞增殖和分化的影响。方法采用不同浓度(200、100、50、25和12.5μmol/L)的棕榈酸(PA)、油酸(OA)和亚麻酸(LA)处理C2C12、L6和3T3-L1细胞,分别于不同时间(2、4、6和8d)MTT法检测细胞增殖;为了考察脂肪酸对成肌细胞分化的影响,分别在C2C12和L6细胞诱导分化前2d,分化第0、2和4d采用25μmol/L的PA、OA或LA处理细胞,油红O染色观察细胞转分化,姬姆萨染色和肌酸激酶(CK)测定观察细胞分化。结果 3种脂肪酸对细胞增殖的抑制作用及其时间-效应和剂量-效应随脂肪酸种类和细胞株不同而具有明显的差异。PA和OA比LA具有更显著的细胞增殖抑制作用,且OA对3种细胞的抑制作用没有明显的剂量依赖关系,而LA在100μmol/L以下时对C2C12和L6成肌细胞的增殖没有明显的时间-效应;与3T3-L1比较,C2C12和L6细胞增殖对脂肪酸的抑制作用更加敏感。在成肌细胞C2C12和L6诱导分化后用脂肪酸处理未观察到显著的作用,但在诱导分化前2d加入脂肪酸能显著影响成肌细胞的分化,LA处理使多核肌管数量和CK含量增加,促进向骨骼肌细胞的分化,而PA和OA处理使细胞内脂滴积累,多核肌管数量和CK含量下降,抑制向骨骼肌的分化而促进向脂肪细胞的转分化。结论脂肪酸暴露影响体外培养的成肌细胞的增殖和分化,其作用与脂肪酸种类、细胞类型和暴露时期有关。

Objective To explore the effects of different fatty acids on the proliferation and differentiation of myoblast.Methods C2C12,L6,3T3-L1 cells were treated with different concentrations（200,100,50,25 and 12.5μmol/L） of palmitic acid（PA）,oleic acid（OA） or linolenic acid（LA） for different time（2,4,6,8 days）,the cells proliferation were tested by MTT assay.In order to observe the effects of fatty acids on differentiation of myoblasts,C2C12 and L6 cells were treated with PA,OA or LA of 25μmol/L at the 2 days before and 0,2,4 days after induced differentiation,then the oil red Ostaining,Giemsa staining and creatine kinase（CK） assay were used to determine the effects of fatty acids on cell differentiation or tans-differentiation.Results The inhibitory effect of the three kinds of fatty acids on cell proliferation and their time-dependent effects and dose-dependent effects were significantly different with changes of fatty acids and cell lines.PA and OA had more significant inhibition of cell proliferation than LA,and the inhibitory effects of OA showed no significant dose dependent for the three cell lines,while LA of below 100μmol/L showed no significant time dependent for C2C12 and L6 myoblasts.Compared with 3T3-L1,cell proliferation of C2C12 and L6 was more sensitive to inhibitory effects of fatty acids.Fatty acid exposure afer differentiation had no significant effects on differention of C2C12 and L6 myoblasts,while fatty acid exposure at 2 adys before differentiation remarkably affected differentiation of the myoblasts.LA exposure could increase multinucleated myotubes and creatine kinase,and promote skeletal differentiaon of myoblasts.Conversely,PA or OA exposure induced the intracellular accumulation of lipid droplets and decreased multinucleated myotubes and creatine kinase,inhibited differentiaon to skeletal cells and promoted the tans-differentiation to adipocytes of myoblast.Conclusion Fatty acids exposure affect the proliferation and differentiation of in vitro cultured myoblasts,and its function was related to fatty acid composition,cell type and exposure time.