Macrophages are the prevailing VEGF source in the early phase of skin repair and demonstrate features of M1/M2 activation. (A) X-Gal staining of unwounded and wounded skin of VEGF-lacZ reporter mice. e indicates epidermis; d, dermis; sc, subcutaneous fat tissue; he, hyperproliferative epithelium; g, granulation tissue; st, scar tissue; pc, panniculus carnosus; sm, skeletal muscle; arrowheads, positive stained cells; dotted line, basement membrane; and arrow, tip of epithelial tongue; scale bars for unwounded skin and day 4, 100 μm; scale bars for day 7 and 14, 10 μm. (B) FDG⁺ wound cells from VEGF-lacZ reporter mice were isolated, analyzed by FACS, and gated for macrophages (F4/80⁺CD11b⁺), neutrophils (Gr-1⁺CD115⁻), and nonmyeloid cells (F4/80⁻Gr-1⁻). (C) Quantification of FACS-analyzed wound cells in VEGF-lacZ mice gated for F4/80⁺FDG⁻ and F4/80⁺FDG⁺ (n = 8-12 wounds on 2-3 mice per time point). (D) Relative expression of selected genes in F4/80⁺FDG⁻ and F4/80⁺FDG⁺ cells at different time points after injury (n = 3-6 mice per time point). Data are expressed as means ± SD. *P < .05; **P < .01; ***P < .001.