Generation of PDGFRα⁺ Cardioblasts from Pluripotent Stem Cells

Isolating actively proliferating cardioblasts is the first crucial step for cardiac regeneration through cell implantation. However, the origin and identity of putative cardioblasts are still unclear. Here, we uncover a novel class of cardiac lineage cells, PDGFRα⁺Flk1^- cardioblasts (PCBs), from mouse and human pluripotent stem cells induced using CsAYTE, a combination of the small molecules Cyclosporin A, the rho-associated coiled-coil kinase inhibitor Y27632, the antioxidant Trolox, and the ALK5 inhibitor EW7197. This novel population of actively proliferating cells is cardiac lineage-committed but in a morphologically and functionally immature state compared to mature cardiomyocytes. Most important, most of CsAYTE-induced PCBs spontaneously differentiated into functional αMHC⁺ cardiomyocytes (M⁺CMs) and could be a potential cellular resource for cardiac regeneration.