Research Paper Volume 4, Issue 8 pp 553—566

Figure 1. Old intramuscular CD11b+ cells produce elevated levels of OPN as compared to young. (A) TA muscle of young (2-4 months) and old (22-24 months) C57BL6/J mice (resting and injured by cardiotoxin, CTX) was isolated at indicated days of post injury (DPI), was sectioned (10 μm) and immuno-stained with Hematoxylin and Eosin (H&E). (B) OPN protein (~30 KDa) was detected by western blotting in young and old CD11b+ cells that were isolated from injured young and old muscle at 3 days and 5 days post injury (DPI); (C) OPN was found to be significantly higher in the old cells, as compared to young (OPN is normalized to actin; young =1). (D) OPN-specific qRT-PCR was performed on CD11b+ cells that were isolated from young and old injured muscle at 3 and 5 DPI. Sustained increased expression of OPN mRNA was observed at both time points in old CD11b+ cells (n=3-5, p**≤0.05).