American Journal of Physiology. Heart and Circulatory Physiology vol:303 issue:8 pages:H931-H939
MicroRNAs (miRNAs) are small sequences of non-coding RNAs that regulate gene expression by two basic processes: direct degradation of mRNA and translation inhibition. miRNAs are key molecules in gene regulation for embryonic stem cells (ESCs), since they are able to repress target pluripotent mRNA genes, including Oct4, Sox2 and Nanog. miRNAs are unlike other small non-coding RNAs in their biogenesis, since they derive from precursors that fold back to form a distinctive hairpin structure whereas other classes of small RNAs are formed from longer hairpins or bimolecular RNA duplexes (siRNAs) or precursors without double stranded character (piRNAs). An increasing amount of evidence suggests that miRNAs may have a critical role in the maintenance of the pluripotent cell state and in the regulation of early mammalian development. This review gives an overview of the current state of the art of miRNA expression and regulation in ESC differentiation. Current insights on controlling stem cell fate towards mesodermal, endodermal and ectodermal differentiation and cell reprogramming are also highlighted.