iPSC-derived cardiomyocytes at the single-cell level

Currently, cardiomyocytes differentiated from human induced pluripotent stem cells (iPSCs) are routinely generated for disease research and drug development as an alternative to animal models. To assess which cell types are present at day 30 of differentiation, we conducted single-cell RNA sequencing using a female and a male line. Our analysis showed that the majority (84-87%) of cells express marker genes typical of cardiomyocytes. Most iPSC-CMs display either ventricular-like (40%) or atrial-like (35-39%) gene expression profiles, whereas a small subset (8-9%) correspond to immature, proliferative cells. The remaining cells expressed extracellular matrix genes and typical epicardial markers. Most likely, these cells underwent suboptimal WNT inhibition following mesoderm induction and differentiated along an epicardial-derived lineage, as reported previously.