Figure 6.

Exons 8–9 skipping restores dystrophin expression in Δ3–7 hiPSC-CMs

(A) RT-PCR analysis of dystrophin transcripts using primers on exons 2 and 12 from Δ3–7 hiPSC-CMs 14 d after treatment with Vivo-S.C. and Vivo-Morpholinos targeting exon 8 at 0.5–4 μM and untreated Δ3–9 hiPSC-CMs. Red octothorpe, Δ3–7; black octothorpe, Δ3–7 and Δ9; black double octothorpes, Δ3–8; blue octothorpe, Δ3–9. (B) Representative Western blot image showing dystrophin expression in untreated Δ3–9 and Δ3–7 hiPSC-CMs 14 d after administration of S.C. and Vivo-Morpholinos at 1.0–4.0 μM. GAPDH was used as a loading control. (C) Quantification of dystrophin internally truncated dystrophin, Dp116, and Dp71 proteins in (B). (D) Immunostaining of cTnT (green) and dystrophin (red) on untreated Δ3–9 hiPSC-CMs and Δ3–7 hiPSC-CMs treated with S.C. and 4 μM Vivo-Morpholino. DNA was counterstained with DAPI. Scale bar, 20 μm. (E) RT-PCR analysis of maturation marker gene ratios, including TNNI3/TNNI1, MYH7/MYH6, and MYL2/MYL7, from untreated Δ3–9 hiPSC-CMs and Δ3–7 hiPSC-CMs 14 d after administration of S.C. and Vivo-Morpholinos at 2.0–4.0 μM. Data are presented as mean ± SEM. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.005.