Fig. 7. Purified PVCs participate in muscle regeneration in vivo. Isolated Anxa5-lacZ⁺ PVCs of adult brain meninges were injected into regenerating areas of crushed tibialis anterior (TA) muscle of immunodeficient NOD/SCID mice. By day 13, consecutive muscle sections were analyzed for ß-galactosidase activity by X-gal staining and expression of desmin (B,E), PECAM (C) as well as CD34 (F) by immunohistochemistry. Injected Anxa5-lacZ⁺ cells were detected at day 13 in the zone of regeneration (arrows, A,D) in columnar structures associated with intact desmin-positive muscle fibers (B,E). No staining was seen in intact fibers. lacZ-expressing cells were found in areas positive for CD34⁺ (D,F) but not in areas positive for PECAM (A,C). Scale bars: 50 µm.