Figure 8.

Restoration of dystrophin in tibialis anterior muscles of mdx mice (aged 4–5 weeks) 2 weeks after intramuscular injection.

Notes: (A) Dystrophin was detected by immunohistochemistry with rabbit polyclonal antibody P7 against dystrophin. Blue nuclear staining with 4,6-diamidino-2-phenylindole. Muscles treated with PMOE23 (2 µg) only was used as controls. All other samples were from muscles treated with 2 µg polymer and 2 µg PMOE23 in 40 µL saline. Original magnification, 100×. (B) The percentage of dystrophin-positive fibers in muscles treated with 2 µg PMOE23 with and without polymers (2 µg). The maximum numbers of dystrophin-positive fibers were counted in a single cross-section (n=5, one-way analysis of variance test, ^#P≤0.05, there were significant difference between PE groups; Student’s t-test, *P≤0.05 compared with 2 µg PMO). (C) Detection of exon 23 skipping by reverse transcription-polymerase chain reaction. Total RNA of 100 ng from each sample was used for amplification of dystrophin mRNA from exon 20 to exon 26. The upper bands (indicated by E22 + E23 + E24) correspond to the normal mRNA, and the lower bands (indicated by E22 + E24) correspond to the mRNA with exon E23 skipped. (D) Western blots demonstrate the expression of dystrophin protein. Dystrophin detected with monoclonal antibody Dys 1. A loading control (α-actin) was used.

Abbreviations: Dys, dystrophin; PE, polyelectrolyte; PMO, phosphorodiamidate morpholino oligomer.