Regulation of miR-1 and miR-133 a on L-type calcium channel Cavβ2 and α1C subunits in rat cardiomyocyte hypertrophy / 基础医学与临床

ABSTRACT

Objective To investigate the regulation of miR-1 and miR-133 a on L-type calcium channel β2 subunit ( Cavβ2 ) and α1C subunit during rat cardiomyocyte hypertrophy .Methods Cardiomyocyte hypertrophy was in-duced by isoproterenol (ISO, 10μmol/L).The targets of miR-1 and miR-133a were predicted by online database microCosm and Targetscan , respectively .The 3′untranslated region sequences of Cavβ2 andα1C were respectively cloned into reporter vector and then transiently transfected into HEK 293 cells.The luciferase activities of samples were measured for demonstrating the expression of luciferase reporter vector .The protein expression of Cavβ2 andα1C were evaluated by Western blot .The expression levels of Cavβ2 andα1C were inhibited by RNAi to determine theeffectsofCavβ2andα1Concardiomyocytehypertrophy.Results 1)Cavβ2wasoneofpotentialtargetsof miR-1,α1C was the one of potential targets of miR-133a.2) The luciferase activities of HEK293 cells with the plasmid containing widetype Cavβ2 3′UTR sequence or α1 C significantly decreased ( P <0.05 , P <0.01 ) . 3 ) Upregulation of the miR-1 and miR-133 a by miR-1 mimic and miR-133 a mimic transfection suppressed pro-tein expression of Cavβ2 and α1C, respectively(P<0.01, P<0.05).4)Downregulation of Cavβ2 andα1C by RNAi could markedly inhibit the increase of cell surface area ( P<0.01 ) , mRNA expression of ANP andβ-MHC (P<0.05).Conclusions Cavβ2 is the target gene of miR-1 and α1C is the target gene of miR-133a.miR-1 and miR-133a can negatively regulate the expression of L-type calcium channel Cavβ2 andα1C subunit, inhibi-ting cardiomyocyte hypertrophy.