Figure 6: R1R2 Overexpression Increases hESC-CM Contractility and Enhances Contractility of Coupled Cardiomyocytes

(A) Example of coupled green fluorescent protein (GFP)-expressing cell and WT cell. Contractile measurements were made individually on each cell in a doublet, as well as on uncoupled WT cells in culture. (B) Representative traces showing increased contractility of AV-R1 + AV-R2–treated cells and coupled WT cells compared with control cells. AV-R1 + AV-R2–treated hESC-CMs showed (C) significantly increased magnitude of contraction compared with AV-GFP–treated cells and (D) significantly increased maximum contraction velocity without affecting relaxation velocity. *p < 0.05; N.S. = not significant. (E) Schematic showing dATP generation in transplanted R1R2-overexpressing cells (dATP “Donor” cells) and the gap junction-mediated transfer of dATP through coupled host cardiomyocytes. hESC-CM = human embryonic stem cell-derived cardiomyocyte; WT = wild-type.