Effects Of MiRNA-1 On Senescence And The Expression Of Muscle-specific MicroRNAs Of C2C12 Myotubes

Objective:In this study,we aim to investigate the effects of miRNA-1 on the senescence of myotubes and the relationship between miRNA-1 expression and other muscle-specific miRNA expression.We established the C2C12 myotubes model and transfected the artificially designed miRNA-1 mimics and inhibitors into the myotubes to affect the expression of miRNA-1.Methods:We cultured C2C12 cells in vitro and induced myogenic differentiation.Myotubes were transfected with either miRNA-1 mimics,inhibitors or negative control to affect the expression of miRNA-1.We expect to know the effects of miRNA-1 overexpression or inhibition on senescence and the expression of the muscle-specific microRNAs of myotubes.Experimental grouping:blank control group(group C),transfected with miRNA-1 mimics group(group M),transfected with miRNA-1 inhibitor group(group ?)and transfected with miRNA-1 negative control group(group N).In this study,in order to explore the effect of intervention on cell aging,the ?-Galactosidase Staining Kit was used to investigate the rate of senescent myotubes.At the same time,qPCR was used to validate the differential expression of miRNA-1,miRNA-133a,miRNA-133b,miRNA-181a,miRNA-206,miRNA-486 and miRNA-499 in myotubes.Results:1)Compared with group C,there was no significant difference in the rate of senescent myotubes in group N.The rate of senescent myotubes in group M increased significantly(P<0.01).The rate of senescent myotubes in group I was significantly decreased(P<0.01).2)Compared with group C,the expression of miRNA-133a and miRNA-133b in group M and I had no difference.In group M,the expression of miRNA-181a was significantly down-regulated in myotubes(P<0.05)and the expression of miRNA-206 and miRNA-486 was extremely significantly down-regulated(P<0.01),At the same time,the expression of miRNA-499 was significantly increased(P<0.01).Meanwhile,in group I,the expression of miRNA-181 a,miRNA-206 and miRNA-486 was significantly up-regulated in myotubes(P<0.01).While the expression of miR-499 was significantly decreased(P<0.05).Conclusion:1)The artificially designed stem ring miRNA-1 mimics and inhibitors in this study can effectively up-regulate or down-regulate the expression of miRNA-1 in myotubes.2)In myotubes,the overexpression of miRNA-1 induces the senescence of myotubes.Meanwhile,the inhibition of miRNA-1 can inhibit the senescence of myotubes.3)The overexpression of miRNA-1 significantly reduced the expression of miRNA-181 a,miRNA-206 and miRNA-486 in myotubes,and significantly increased the expression of miRNA-499,but had no significant effect on the expression of miRNA-133a and miRNA-133b.