(A) Myofibers were isolated from Anxa6gfp mice and laser-damaged in the presence of rA6-tdTomato. rA6-tdTomato (shown in red) colocalized with genomically encoded annexin A6GFP (green) at the site of muscle membrane injury (white arrow). (B) rA6-tdTomato cap size increased with increasing concentrations of rA6-tdTomato, 1.3–130 μg/mL. Genomically encoded annexin A6GFP cap size did not change with increasing concentrations of rA6-tdTomato. (C) rA6-tdTomato formed membranous blebs at the site of membrane injury. (D) Dose-dependent reduction of FM 4-64 dye (red) uptake, a marker of membrane injury, with increasing concentrations of recombinant annexin A6. (E) Anxa6gfp mice were crossed with mdx mice to generate mdx mice expressing genomically encoded annexin A6GFP. (F) Dystrophic histopathology is present in Anxa6gfp
mdx muscle. Scale bar: 100 μm. (G) Serum creatine kinase (CK) was elevated in Anxa6gfp
mdx mice compared to Anxa6gfp controls (n = 7). (H) Increased FM 4-64 dye (red) in injured Anxa6gfp
mdx myofibers compared with Anxa6gfp controls. (I and J) In Anxa6gfp mdx myofibers, genomically encoded annexin A6GFP formed a repair cap at the site of membrane injury. rA6-tdTomato cap size increased with increasing concentrations of rA6-tdTomato, 1.3–130 μg/mL. Genomically encoded annexin A6GFP cap size did not change significantly with varying concentrations of rA6-tdTomato in Anxa6gfp mdx myofibers. (K) Increasing concentrations of recombinant annexin A6 resulted in a dose-dependent reduction of FM 4-64 dye (red) uptake in dystrophic myofibers. Scale bar: 5 μm. A total of 4–9 myofibers from n ≥ 4 isolations. *P < 0.05 by 1-way ANOVA.