Transient exposure to miR‐203 enhances the differentiation capacity of established pluripotent stem cells

Full differentiation potential along with self‐renewal capacity is a major property of pluripotent stem cells (PSCs). However, the differentiation capacity frequently decreases during expansion of PSCs in vitro . We show here that transient exposure to a single microRNA, expressed at early stages during normal development, improves the differentiation capacity of already‐established murine and human PSCs. Short exposure to miR‐203 in PSCs ( mi PSCs) induces a transient expression of 2C markers that later results in expanded differentiation potency to multiple lineages, as well as improved efficiency in tetraploid complementation and human–mouse interspecies chimerism assays. Mechanistically, these effects are at least partially mediated by direct repression of de novo DNA methyltransferases Dnmt3a and Dnmt3b, leading to transient and reversible erasure of DNA methylation. These data support the use of transient exposure to miR‐203 as a versatile method to reset the epigenetic memory in PSCs, and improve their effectiveness in regenerative medicine. Synopsis Long‐term expansion of pluripotent stem cells (PSC) frequently results in decreased differentiation potential diminishing their utility. Here, a miRNA‐based strategy is shown to enhance PSC potency via resetting their epigenetic state, suggesting new opportunities for improved stem cell therapies. Developmental miR‐203 improves potential and plasticity of mouse and human PSCs in vivo . miR‐203 increases human‐mouse interspecies chimera competency. miR‐203 targets de novo DNA methyltransferases Dnmt3a/b inducing global and reversible DNA hypomethylation. Transient miR‐203 enhances PSC maturation into cardiomyocytes. Graphical Abstract Developmental potency of pluripotent stem cells is enhanced by short‐term exposure to a single microRNA.