Cell barcoding reveals lineage-dependent outcomes in hiPSC cardiac differentiation.

Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have potential applications in treating cardiovascular disease but are currently limited in their clinical translation. This can be attributed in large part to the complex molecular and cellular interactions that underly cardiac differentiation, with current differentiation approaches yielding heterogeneous outcomes due to inadequate understanding and control of these interactions. We hypothesize that clonal lineage-dependent responses to differentiation contribute to these heterogeneous outcomes, and as such cardiac differentiations can be improved by tracking and controlling for hiPSC clonal heterogeneity, a variable often overlooked in current differentiation approaches. "Fate priming," wherein clonal lineage identity determines differentiation fate, has been demonstrated in other stem cell differentiation pathways. We investigated fate priming in hiPSC cardiac differentiation using the ClonMapper cell barcoding platform to label, track, and isolate distinct hiPSC lineages from the same cell line. We show that certain hiPSC lineages preferentially differentiate into hiPSC-CMs or non-CMs. After isolating lineages with apparent fate priming, we found significant differences in cardiac differentiation outcomes between these single-clone populations and heterogeneous, multi-clone hiPSC populations. These findings indicate that lineage identity influences hiPSC cardiac differentiation outcomes.