Sphingosine-1-phosphate receptor 1 signaling stimulates human pluripotent stem cell-derived cardiomyocyte differentiation and maturation

The development of human-relevant in vitro cardiac models is essential for evaluating cardiotoxicity and drug efficacy. Although wingless-related integration site signaling-based protocols have enabled cardiomyocyte (CM) differentiation from pluripotent stem cells, issues such as low efficiency, immature phenotype, and variability across cell lines remain to be resolved. Here, we present an improved differentiation strategy that robustly enhances both the efficiency and functional maturity of CMs, comparable to the functional characteristics of human adult myocardial tissue. Although fetal bovine serum enhanced differentiation, we disclosed that the interaction between sphingosine-1-phosphate (S1P) and its receptor S1PR1 is a major contributor. Gene-based and protein-based analyses and electrophysiological analysis via multielectrode array confirmed that activation of S1PR1 using S1P or its agonist SEW2871 increased the generation of spontaneously beating CMs, whereas S1PR1-deficient pluripotent stem cells exhibited impaired differentiation and functional maturity of S1P-S1PR1-derived CMs. Furthermore, we observed improved cardiac function and reduced fibrosis in a myocardial infarction mouse model induced by left descending artery ligation following transplantation of CMs differentiated more robustly by treatment with S1P or SEW2871. Collectively, S1PR1 activator-treated CMs offer a cost-effective platform for drug discovery and regenerative medicine.