Figure 4.
In Vivo Assessment of Migration and Engraftment of DLL4 and PDGF-BB-Treated SCs
(A) In vivo analysis of limb muscles from Sgca-null/scid/beige mice intra-arterially transplanted with 106 GFP+/β-GAL+ control or DLL4 and PDGF-BB-treated SCs after 3 weeks. Upper panel: exposure to X-gal revealed engraftment of β-GAL+ donor cells (blue; arrowhead) in the knee region and lower limb muscles of mice transplanted with DLL4 and PDGF-BB-treated SCs. Lower panel: assessment of X-gal in the gastrocnemius muscle of mice transplanted with treated SCs, revealing nuclear localization of β-GAL in a GFP+ myofiber (arrowheads). Graph quantifies the area of X-gal+ signal in muscles intra-arterially transplanted with treated or untreated SCs (lateral view of knee region) normalized to the volume of cell suspension delivered (N = 4).
(B) Quantification of transplanted cells that engrafted intramuscularly injected TA muscles (N = 5).
(C) Distribution across muscle length of X-gal+ nuclei per section of TA muscles transplanted with treated and untreated SCs (N = 5).
(D) Quantification of the localization (i.e., inside or outside myofibers) of X-gal+, treated/untreated, donor-derived nuclei in transplanted muscles (N = 5).
(E) Immunofluorescence panel showing a representative Scga-null/scid/beige muscle transplanted with 106 GFP+/nLacZ+ DLL4 and PDGF-BB-treated SCs intramuscularly 3 weeks before explant. SGCA (red) and X-gal (violet): donor-derived fibers and nuclei, respectively. LAMININ (green) and Hoechst (blue): extracellular matrix and nuclei, respectively.
(F) Quantification of the experiment in (E) showing the average number of donor-derived fibers from three mice.
Data: means ± SEM. Statistical significance based on unpaired Welch's t test. ∗p < 0.05; n.s., not significant. Scale bars, 2 mm (A, left panel), 250 μm (A, middle panel), 50 μm (A, right panel), and 50 μm (E).