Distinct progenitor populations in skeletal muscle are bone marrow derived and exhibit different cell fates during vascular regeneration
J. Clin. Invest. Susan M. Majka, et al. 111:71 doi:10.1172/JCI16157 [Go to this article.]

Figure 5
Skeletal muscle-derived SP cells engraft into vascular endothelium. Six- to eight-week-old C57Bl/6 mice were anesthetized with Avertin, and both TA muscles were injected with 25 μl of a 1 mg/ml cardiotoxin. After 8 or 24 hours, the right limb TA muscle was injected with 2,000 LacZ-positive muscle SP cells, and the left leg was injected with HBSS alone. After 4 weeks, the TA muscles of each of four experimental animals were harvested and processed for frozen sectioning and immunohistochemical analysis. All sections were immunostained for β-gal and costained for either ICAM-2 or desmin to detect injury-induced engraftment of LacZ-positive SP cells into regenerated vascular endothelium and smooth muscle, respectively. β-gal expression in vascular structures was colocalized only with ICAM-2: (a and b) bright field, boxes indicate costained vessels; (c and d) β-gal immunohistochemistry; (e and f) ICAM-2 immunohistochemistry; (g and h) β-gal and ICAM-2 fluorescent images were merged to reveal areas of costaining, as evidenced by the yellow staining pattern. Magnification, ×400 (a, c, e, g); ×1,000 (b, d, f, h, and inset boxes in c, e, and g).