Effect of miRNA-155 on hypertrophy of myocardial cells and expression of CaN-β and NFAT-4

Objective To study the effect of mRNA-155 on hypertrophy of myocardial cells and expression of CaN-βand NFAT-4.Methods Rat myocardial cells H9C2 were cultured.Hypertrophy of myocardial cells was induced with AngⅡ.mRNA-155 mimics and inhibitors were transfected into myocardial cells by lipofection.The myocardial cells were divided into control group,AngⅡ mimics group,AngⅡ inhibitors group,AngⅡ+mimics group and AngⅡ +inhibitors group.Expressions of miRNA-155,ANP,CaN-β,β--MHC,CaN-βmRNA,CaN-βand NFAT-4protein in myocardial cells were detected by RT-PCR and Western blot,respectively.Results The expression levels of ANP andβ-MHC were significantly higher and the surface area of myocardial cells was significantly smaller while the expression levels of CaN-βmRNA and protein and NFAT-4protein were significantly lower in AngⅡ+ mimics group than in AngⅡ group(P0.05).Conclusion CaN-βis the target of miRNA-155.miRNA-155 can reduce the expression of ANP andβ-MHC in myocardial cells and inhibit the hypertrophy of myocardial cells by down-regulating the expression of CaN-βand NFAT-4.