Inhibitory Effect of Hsa-miR-590-5p on Cardiosphere-derived Stem Cells Differentiation Through Downregulation of TGFB Signaling

The cardiac cells generation via stem cells differentiation is a promising approach to restore the myocardial infarction. Promoted by our primary bioinformatics analysis as well as some previously published data on potential role of hsa-miR-590-3p in cardiogenesis, we have tried to decipher the role of miR-590-5p during the course of differentiation of cardiosphere-derived cells (CDCs). The differentiation induction of CDCs by TGFB1 was confirmed by real-time PCR, ICC, and flow cytometry. The expression pattern of hsa-miR-590-5p and some related genes were examined during the differentiation process. In order to study the role of miR-590-5p in cardiac differentiation, the effect of miR-590 overexpression in CDCs was studied. Evaluating the expression patterns of miR-590 and its potential targets (TGFBRs) during the course of differentiation, demonstrated a significant downregulation of miR-590 and an upregulation of TGFBR2, following the treatment of CDCs with TGFB1. Therefore, we proposed a model in which TGFB1 exerts its differentiation induction via downregulation of miR-590, and hence the higher transcriptional expression level of TGFBR2. In accordance with our proposed model, transfection of CDCs by a pLenti-III-hsa-mir-590-GFP expression vector before or after the first TGFB1 treatment caused a significant alteration in the expression levels of TGFBRs. Moreover, our data revealed that overexpression of miR-590 before TGFB1 induction was able to attenuate the CDCs differentiation probably via the reduction of TGFBR2 expression level. Altogether, our data suggest an inhibitory role of miR-590 during the cardiac differentiation of CDCs which its suppression might elevate the rate of differentiation. J. Cell. Biochem. 116: 179-191, 2015. (c) 2014 Wiley Periodicals, Inc.