Objective      To determine the effect of granulocyte colony-stimulating factor (G-CSF) stimulation on cutaneous wound healing in green fluorescent protein (GFP) chimeric mice and investigate the underlying mechanism.       Methods      C57BL/6 mice were exposed to 8.5 Gy

60

Co γ irradiation and then received 5×10

6

bone marrow cells derived from C57BL/6-EGFP mice through tail vein in 4 h later to estab

lish GFP chimeric mice. The spleen of the chimeric mice was resected in 2 months after irradiation

and then divided into 2 groups

bone marrow mobilization group (G-CSF group) and control group. G-CSF of 50 μg·(kg·d)

-1

  was injected to the mice of the G-CSF group for 5 d before and for 3 d after wound cutting (1.3 cm×1.3 cm) on their back. Normal saline instead of G-CSF was injected in the mice of control group after wounding. Residual wound area and wound healing time were observed. On day 1 after wounding

the wound tissues were harvested and digested into single cell suspension to detect the ratio of GFP

+

cells by flow cytometry. On day 3

wound tissues were collected again for histological analysis of β-catenin expression.       Results      G-CSF treatment accelerated wound closure in mice than the control mice (12.5±0.9 vs 18.3±0.8 d). There were more GFP

+

cells on wound area in the mobilized group than the control mice (P0.05) on day 1. The expression of β-catenin was significantly enhanced in the wound of the mobilized group and mainly in located in the nuclei (P0.05).       Conclusion      G-CSF mobilization aggregates GFP

+

cells in the wound area

promotes the expression and nuclear translocation of β-catenin

and accelerates wound healing after skin injury.