Figure 12.

ET‐1 strengthens pathological features in HCM iPSC‐derived cardiomyocytes in a concentration‐dependent manner. A, Cell surface areas of 789 to 822 randomly chosen cardiac troponin‐T (cTnT)‐positive cardiomyocytes in each group and condition were measured. The cardiomyocytes were dissociated from EBs at 60 days and cultured for 7 days with various concentrations of ET‐1 (1, 10, 100, or 1000 nmol/L) (1‐way ANOVA with Steel's multiple comparison post‐test). B, The percentages of cardiomyocytes with myofibrillar disarray were assessed by immunostaining for cTnT of the single cardiomyocytes after 7 days of culture with ET‐1. N=875 to 995 (per each group and condition). *P<0.05, **P<0.01, †P<0.0001 vs ET‐1–free (0 nmol/L) condition in the same group (χ² test). C and D, Nuclear translocation of NFATc4 was assessed by immunostaining for NFATc4 and cTnT. Isolated cardiomyocytes at 60 days were cultured for 7 days with or without ET‐1. The presented images were the iPSC‐derived cardiomyocytes cultured for 7 days with ET‐1. Scale bars, 20 μm. N=376 to 448 (per each group and condition). *P<0.01, **P<0.001 vs free condition in each group (χ² test). EBs indicates0 embryoid bodies; ET‐1, endothelin‐1; HCM, hypertrophic cardiomyopathy; iPSC, induced pluripotent stem cell; NFAT, nuclear factor of activated T cells.