Genotype‐Dependent Effects of Mechanical Stretch and GATA4‐Targeted Compound 3i‐1262 in Cardiomyopathy Patient–Derived hiPSC‐Cardiomyocytes

FIGURE 1. Effects of cardiomyopathy‐associated mutations on the expression of hypertrophy‐related genes. Baseline gene expression of HCM (A) and DCM (B) cardiomyocytes. The bars represent the mean, error bars represent SEM, and dots represent results from individual independent experiments. Results are normalised to the control line. n = 5–7, *p < 0.05; **p < 0.01; ***p < 0.001 (Mann–Whitney U test). log2FC, log2 fold change.

FIGURE 2. Differential gene expression in hiPSC‐cardiomyocytes after 24 h of mechanical stretching, 3i‐1262 treatment or their combination. Results are presented as mean + SEM and normalised to the respective unstretched sample. n = 3–9, *p < 0.05; **p < 0.01; ***p < 0.001 compared to the respective unstretched sample, or as indicated (Mann–Whitney U test). CTRL, control cardiomyocytes; HCM, HCM cardiomyocytes; DCM, DCM cardiomyocytes.

FIGURE 3. Differential gene expression in hiPSC‐cardiomyocytes induced by 72 h of mechanical stretching, 3i‐1262 treatment or their combination. Results are presented as mean + SEM and normalised to the respective unstretched sample. n = 3–9, *p < 0.05; **p < 0.01; ***p < 0.001 compared to the respective unstretched sample, or as indicated (Mann–Whitney U test). CTRL, control cardiomyocytes; HCM, HCM cardiomyocytes; DCM, DCM cardiomyocytes.

FIGURE 4. Quantification of proANP, α‐MHC, β‐MHC and cTnT protein expression in control (CTRL), HCM, and DCM hiPSC‐cardiomyocytes. (A) Basal protein levels are presented as mean + SEM and normalised to the control line (n = 3–6; *p < 0.05; ***p < 0.001; Welch's t‐test). (B) Effects of 24 h mechanical stretch on protein levels. Results are presented as mean + SEM and normalised to the respective, unstretched sample (n = 3–6; *p < 0.05; Welch's t‐test). See Supplementary Information Figures S2–S5 for the original Western blots and corresponding total protein images.

FIGURE 5. Effects of the cardiomyopathy‐causing mutations on the expression of mechanosensitive and metabolism‐related genes. Baseline gene expression of HCM (A) and DCM (B) cardiomyocytes. The bars represent the mean, error bars represent SEM and dots represent results from individual independent experiments. Results are normalised to the control line. n = 5–7, **p < 0.01; ***p < 0.001 (Mann–Whitney U test). log2FC, log2 fold change.

FIGURE 6. Mechanosensitive gene expression in hiPSC‐cardiomyocytes following 24 or 72 h of mechanical stretch, 3i‐1262 treatment or their combination. Results are presented as mean + SEM and normalised to the respective unstretched sample. n = 3–8, *p < 0.05; **p < 0.01; ***p < 0.001 compared to the respective unstretched sample (Mann–Whitney U test). CTRL, control cardiomyocytes; HCM, HCM cardiomyocytes; DCM, DCM cardiomyocytes.

FIGURE 7. Metabolism‐related gene expression in hiPSC‐cardiomyocytes following 24 h (A) or 72 h (B) of mechanical stretch, 3i‐1262 treatment or their combination. Results are presented as mean + SEM and normalised to the respective unstretched sample. n = 3–7, *p < 0.05; **p < 0.01; ***p < 0.001 compared to the respective unstretched sample, or as indicated (Mann–Whitney U test). CTRL, control cardiomyocytes; HCM, HCM cardiomyocytes; DCM, DCM cardiomyocytes.