Figure 3.

CAR-DCN localizes to sites of dystrophin deficient muscle damage. Staining of quadriceps muscles from mdxD2 mice injected IP, for three weeks with CAR-DCN or mCAR-DCN (in which the CAR homing peptide was mutated) reveals CAR targeted to sites of muscle damage by fluorescence microscopy. Slides were visualized with EBD for membrane permeability (red, first column) and anti-histidine antibodies for the recombinant proteins (green, middle column), and last column shows merged images. (A) The top row indicates co-localization of the CAR-DCN to the sarcolemma of damaged (red) cells and surrounding extracellular matrix (asterisks in top two rows). However, not all damaged cells have attracted the peptide (white arrows). The second row is a higher magnification illustrating CAR-DCN homing to regenerating skeletal muscle cells, which are negative for EBD and have likely resealed their membranes (arrow heads). (B) The quadriceps from mdxD2 mice were injected with mCAR-DCN. No co-localization of the peptide with damaged cells, in any pattern, was present. Original magnification for (A) panel top row and (B) panel was 10× and for (A) panel second row 40×.