Figure 4.

Serial Injury of TA Muscle Treated with AAV9-CMV-CRISPR Demonstrates Sustained Expression of Dystrophin after Loss of AAV Vector Expression

(A) Schematic illustration of serial injury strategy. mdx mice were treated with AAV9-CMV-CRISPR constructs by intramuscular injection. 4 weeks later, mice were injured with 50 μL of 1.2% BaCl₂ to induce muscle degeneration and regeneration. BaCl₂ injections were administered a total of 2 or 3 times with a 2-week recovery period between each injection. (B) Western blot of the HA epitope tag on the C terminus of SaCas9 shows clearance of SaCas9 after three BaCl₂ injuries. (C) Representative immunofluorescence images of dystrophin restoration in mdx mice treated with AAV9-CMV-CRISPR and injured 0, 2, or 3 times with BaCl₂. Scale bar = 200 μM. (D) Quantification of dystrophin⁺ fibers after AAV9-CMV-CRISPR treatment with 0, 2, or 3 injuries with BaCl₂ (mean ± SEM, n = 4 mice).