MicroRNA-mediated regulation of extracellular matrix formation modulates somatic cell reprogramming

Model for roles of microRNAs during the reprogramming process. MicroRNAs induced by the four factors regulate intracellular and extracellular processes involved in cell fate decisions. Intracellularly, microRNAs target signaling pathways that are barriers for iPSC generation, such as TGFβ signaling, the p53–p21 pathway, and cell cycle control. Meanwhile, some microRNAs, such as miR-135b, regulate expression of ECM genes to establish a growth environment that promotes the fully reprogrammed state. Both groups of microRNAs work collaboratively following 4F transduction to reprogram MEFs to iPSCs.