Figure 5.
DPP6 expression in mouse, canine ventricular tissue, and hiPSC‐CMs. A1, Representative immunoblots of DPP6 protein expression in mouse left ventricle, canine left ventricle, and hiPSC‐CMs. A2, Test for antibody specificity by preincubation with the antigen peptide. B1, Efficiency of siRNA‐mediated DPP6 knockdown (SiDPP6) in hiPSC‐CMs quantified by RT‐PCR and compared to non‐targeting control siRNA (SiNC) (N = 3). B2, Representative immunoblots of DPP6 in hiPSC‐CMs treated with siRNA targeting DPP6 (N = 3). B3, Time constants (τ) of the current inactivation in hiPSC‐CMs treated with siRNA targeting DPP6 and a non‐targeting control. Data obtained by fitting a single exponential equation (n = 9, *P < .05, **P < .01 vs SiNC). C1, Representative I to current traces recorded from the hiPSC‐CMs treated with SiNC or SiDPP6. C2, Effect of siRNA knockdown of DPP6 on the I–V relationships of I to and on the efficacy of NS5806‐mediated current inhibition in hiPSC‐CMs (left). Summary of the inhibitory effect of 10 μM NS5806 on I to in SiNC‐ or SiDPP6‐treated hiPSC‐CMs is shown on the right (n = 10, **P < .01). C3, Effect of DPP6 knockdown on the kinetics of I to inactivation in the presence of 10 μM NS5806 in hiPSC‐CMs (*P < .05, **P < .01 vs SiNC)