Small-molecule-based generation of functional cardiomyocytes from human umbilical cord-derived induced pluripotent stem cells.

The purpose of this study was to investigate the cardiac-differentiation potential of induced pluripotent stem cells (iPSCs) generated from human umbilical cord-derived mesenchymal cells. Spontaneous beating colonies were observed at day 7 after the sequential addition of CHIR99021 and IWP-4. The combined use of CHIR99021 and IWP-4 downregulated the expression of pluripotency markers while upregulating cardiac transcription factors and cardiomyocyte-specific markers. The derived cardiomyocytes demonstrated typical sarcomeric structures and action-potential features; most importantly, the derived cells exhibited responsiveness to β-adrenergic and muscarinic stimulations. The analyses of molecular, structural, and functional properties revealed that the derived cardiomyocytes were similar to cardiomyocytes derived from BJ foreskin fibroblast cells. In summary, our results demonstrate that functional cardiomyocytes can be generated from human umbilical cord-derived cells. The methodology described here has potential as a means for the production of functional cardiomyocytes from discarded human umbilical cord tissue.