Exon 45–55 multiskipping and rescue of dystrophin expression in mdx52 mice by local mixture-ESE2 injections. (A) Detection of exon 45–55 skipped dystrophin mRNA by RT-PCR with primers flanking exons 44 (44F1) and 56 (56R1) at 2 wk after injection of mixture-ESE2, targeting exons 45–55 except exon 52 into tibialis anterior (TA) muscles. Representative data are shown. M, molecular marker; no-treat TA, untreated TA muscles from mdx52 mice; treated TA, treated TA muscles from mdx52 mice. (B) Immunohistochemical staining of dystrophin exon 50 in the TA muscle of WT and treated mdx52 mice (Left) and dystrophin exon 57 in the TA muscle of untreated and treated mdx52 mice (Right). Representative data are shown. BL6 TA, TA muscle from a wild-type C57/BL6. (Scale bar, 100 μm.) (C) Percentage of dystrophin-positive fibers after local injections with the 10 vPMO cocktail. Data (n = 6) are presented as mean ± SD ***P < 0.001. (D) Recovery of dystrophin-associated proteins with exon 45–55 skipping. Immunohistochemical staining of dystrophin exons 57, 46, and 50, neuronal nitric oxide synthase (nNOS), α1-syntrophin, and β-dystroglycan in the TA muscle of WT, untreated, and treated mdx52 mice. Representative data are shown. BL6TA, TA muscle from a wild-type C57/BL6; no-treat TA, untreated TA muscles from mdx52 mice. (Scale bar, 100 μm.) (E) Western blotting after the mixture 10 vPMOs local injections to detect the expression of full-length dystrophin, 380-kDa quasidystrophin, nNOS, α1-syntrophin, α-tubulin, β-dystroglycan, and α-sarcoglycan in TA muscles of WT, untreated, and treated mdx52 mice. Representative data are shown.