AIM:To observe the effect of folic acid(FA)on C2C12 myoblast proliferation and differentia-tion,and to explore its mechanism.METHODS:During the proliferation stage,C2C12 myoblasts were treated with vari-ous concentrations of FA(0,2.5,5,10 and 20 μmol/L).The cell status was observed under a microscope,cell viability was detected using the MTT method,and cell proliferation was assessed using the EdU method.In the differentiation stage,C2C12 cells were divided into control(Ctrl)group(0 μmol/L FA)and FA group(10 μmol/L FA).On day 2 or 4 of differentiation,immunofluorescence staining and Western blot were employed to detect the expression of myoblast differen-tiation-related proteins,myoblast determination protein 1(MyoD),myogenin(MyoG)and myosin heavy chain(MyHC).The myotubule formation in each group was analyzed.On day 4 of differentiation,C2C12 cells were treated with FA for 0,1,3 and 6 h,and the protein levels of p-JNK,JNK,p-p38 MAPK and p38 MAPK at each time point were detected by Western blot.Additionally,C2C12 cells after 4-day differentiation were divided into Ctrl group,FA group,FA+ SP600125(specific inhibitor of JNK)group,and FA+SB203580(specific inhibitor of p38)group.The cells in FA+ SP600125 and FA+SB203580 groups were treated with 10 μmol/L SP600125 or SB203580 for 1 h,followed by treatment with 10 μmol/L FA for 24 h.The cells in FA group were treated with 10 μmol/L FA for 24 h,while the cells in Ctrl group were left untreated.The protein levels of p-JNK,JNK,p-p38 MAPK,p38 MAPK and MyHC were detected by Western blot.RESULTS:(1)Compared with 0 μmol/L FA group,the number of the cells in other concentration groups in-creased,cell viability was raised(P＜0.05 or P＜0.01),and the rate of EdU positive cells increased(P＜0.05).(2)Com-pared with Ctrl group,the expression levels of MyoD,MyoG and MyHC in FA group were increased(P＜0.05),and the myotube fusion index was raised(P＜0.05 or P＜0.01).(3)Compared with 0 h group,the ratios of p-JNK/JNK and p-p38 MAPK/p38 MAPK were elevated after FA treatment for 1,3 and 6 h(P＜0.05 or P＜0.01),and showed a trend of gradual increase with the extension of treatment time.(4)After FA treatment,the ratios of p-JNK/JNK and p-p38 MAPK/p38 MAPK,and the expression of MyHC were elevated(P＜0.01).Treatment with SP600125 decreased the ratio of p-JNK/JNK and the expression of MyHC(P＜0.05),while SB203580 intervention cut down the ratio of p-p38 MAPK/p38 MAPK and the expression of MyHC(P＜0.05 or P＜0.01).CONCLUSION:Folic acid can promote the differentiation of C2C12 myoblasts by activating the JNK/p38 MAPK signaling pathway.
国家科技期刊平台
NSTL
万方数据
维普
