FIG. 1.
Effect of HMOX1 overexpression on survival and proliferation of myoblasts transplanted intramuscularly to the gastrocnemius muscle of NOD/SCID mice. (A) Luciferase activity monitored in vivo using IVIS Lumina system. Images show the same individuals analyzed at 2nd, 11th, and 22nd day of experiment (blue: low intensity; red: high intensity). (B) Quantification of IVIS measurements. Total luminescence from each animal is expressed in relative luminescence units (RLU). (C, D) Luciferase activity measured in tissue lysates prepared from gastrocnemius muscles (C) or lungs (D) on 22nd day after injection. No signals were found in heart, liver, and kidney lysates. (E) Histology of gastrocnemius muscle of NOD/SCID mice, 22 days after cell transplantation (paraffin sections stained with H&E): E1: Mice injected with C2C12-Luc-GFP cells. E2–E6: Mice injected with C2C12-Luc-GFP-HO1 cells: hyperplastic tissue (E2), infiltrating the muscle (E3 and E4), with adipogenic (E5) or chondro-osteogenic (E6) accumulations. Paraffin sections stained with H&E. (F) Histochemical detection of GFP in gastrocnemius muscles 22 days after cell transplantation. Representative pictures (F1 and F2) C2C12-Luc-GFP-injected muscle: staining (F1) and negative control (F2). (F3 and F4) C2C12-Luc-GFP-HO1 injected muscle: staining (F3) and negative control (F4). (G) Semi-quantitative assessment of mitotic index. (H) Detection of proliferating cells by immunofluorescent staining of PCNA (red) 11 and 22 days after cell transplantation. Nuclei were visualized with DAPI (blue). Representative pictures. Each point or bar represents mean±SEM of 5–10 animals (B) or 5 animals (C, D, G); *p<0.05, **p<0.01, ***p<0.001 vs. C2C12-Luc-GFP cells.