ABSTRACT
Objective To identify the miR-122 which regulateing GATA4 expression during the induction of rat bone marrow mesenchymal stem cells (bMSCs) differentiating into cardiomyocyte-like cells. Methods BMSCs were isolat-ed from bone marrow and induced to differentiate into cardiomyocyte-like cells using 5-azacytidine. The miR-122 which may regulate expression of GATA4 were predicted using miRanda and TargetScan softwares and identified by dual luciferase report system. The expressions of miR-122 and GATA4 were determined using q-PCR during the differentiation of bMSCs into cardiomyocyte-like cells. Results The induced cells were completely in contacted with adjoining cells and uniform in shape and aligned parallelly. Cardiac troponin I (cTnI) expression was detected by immunofluorescence cytochemistry. Using dual luciferase reporter system in vitro, miR-122 were proved to be able to effectively inhibit GATA4 expression by binding the 3′UTR of GATA4 mRNA. q-PCR results showed that the expression of miR-122 is negatively correlated with that of GATA4 mRNA transcription. Conclusion These results indicated that miR-122 regulate the expression of GATA4 during the induction of cardiomyocyte-like cells.