Impaired expression of GJA5 and SCN5A in IRX5-mutated hiPS-CMs. (A) TaqMan® analysis showing mRNA expression of SCN5A and GJA5 in control (n = 24), A150P (n = 15) and N166K (n = 19) IRX5-mutated hiPS-CMs. Cts were normalized to ACTB and each normalized expression value was expressed as compared to the average normalized expression for the control group, generating 2−ΔΔCt values. A logarithmic scale (log2) was used for the Y axis. * and **P < 0.05 and P < 0.01 vs. control, respectively (Mann–Whitney test). (B) Representative immunoblots for Nav1.5 and Cx40 and ratios of Nav1.5 and Cx40 expression levels normalized to Transferrin receptor (TFRC). Blots were quantified using Image Lab software. ** and ***P<0.01 and P<0.001 vs. control, respectively (t-test). Ctrl: n = 38; A150P: n = 22; N166K: n = 22. (C) Representative confocal images for immunostainings of Nav1.5 and Cx40 (green) in Troponin I positive (red) control and IRX5-mutated hiPS-CMs. Nuclei are stained in blue using DAPI.
