Mobilization of bone marrow cells by CSF3 protects mice from bleomycin-induced lung injury.

BACKGROUND: Bone marrow-derived cells may play a role in tissue injury and repair. Growth factors facilitate the mobilization of bone marrow-derived cells to the site of injury. OBJECTIVES: The aim of this study was to determine the effect of the mobilization of autologous bone marrow-derived cells by granulocyte colony-stimulating factor (CSF3) on bleomycin-induced lung injury in mice. METHODS: The bone marrow from male green fluorescent protein transgenic (C57Bl/6J) mice was transplanted into irradiated female C57Bl/6J mice. Bleomycin lung injury was induced in these bone marrow-reconstituted mice and unreconstituted C57Bl/6J mice, and some mice were treated with recombinant CSF3. Lung histology, survival, cytokine expression and matrix metalloproteinase (MMP) expression were evaluated to determine the effect of CSF3 after bleomycin-induced lung injury. RESULTS: Histology and flow cytometry analysis showed successful mobilization of bone marrow-derived cells by CSF3 treatment in the recipient lungs. Importantly, CSF3 attenuated bleomycin-induced lung injury and improved survival. Furthermore, CSF3 administration regulated transforming growth factor-ß, interferon-γ, MMP9 and tissue inhibitors of MMP1 expression during bleomycin injury. CONCLUSIONS: These data demonstrated that the mobilization of bone marrow-derived cells by CSF3 has a protective effect against bleomycin-induced lung injury and fibrosis.

[The effect of autologous bone marrow-derived cells mobilized by granulocyte colony stimulating factor on bleomycin-induced lung injury in mice.].

OBJECTIVE: To investigate the contribution of mobilized autologous bone marrow-derived cells (BMDC) to lung repair after lung injury induced by bleomycin, and the mechanisms of any protective effects conferred by BMDC. METHODS: Sixty marrow-reconstructed mice were randomly divided into 2 groups: group A [bleomycin + granulocyte colony stimulating factor (G-CSF)] and group B (bleomycin + saline). Seventy-five normal mice were randomly divided into 3 groups: group C (bleomycin + G-CSF); group D (bleomycin + saline) and group N (saline only). Each group was further divided into 3 subgroups, which were sacrificed respectively on days 3, 7 and 14. Therapeutic evaluations were made by means of HE stain, Masson's trichrome stain, hydroxyproline concentration and pulmonary permeability index. The expressions of TGF-beta(1), IFN-gamma, MMP-9 and TIMP-1 in the lung tissue were detected by immunohistochemistry. Intrapulmonary BMDC was evaluated by flow cytometry and laser scanning confocal microscope. Another 20 mice were randomly divided into 2 groups including group E (bleomycin + G-CSF) and group F (bleomycin + saline). The survival time of each mouse was observed without end point. RESULTS: The alveolitis score (mean rank 15.3), the pulmonary fibrosis score (46 +/- 8), the hydroxyproline concentrations (0.44 +/- 0.09) microg/mg, the TGF-beta(1) level (111 +/- 23), the IFN-gamma level (250 +/- 72) and the MMP-9 level (59 +/- 19) were significantly decreased in reconstructed treatment group on day 7 as compared to reconstructed control group, which was respectively (mean rank 28.0), (73 +/- 10), (0.52 +/- 0.07) microg/mg, (161 +/- 35), (299 +/- 31) and (314 +/- 77). Likewise, the alveolitis (mean rank 22.7), the pulmonary fibrosis (27 +/- 15), the hydroxyproline concentrations (0.41 +/- 0.05) microg/mg, the pulmonary permeability index (43.8 +/- 9.9) x 10(-3), the TGF-beta(1) level (132 +/- 55), the IFN-gamma level (178 +/- 23), and the MMP-9 level (101 +/- 54) in non-reconstructed treatment group on day 7 were significantly lower than those in non-reconstructed control group, (mean rank 33.9), (56 +/- 13), (0.49 +/- 0.08) microg/mg, (54 +/- 9) x 10(-3), (320 +/- 98), (409 +/- 61), (288 +/- 75), the differences being statistically significant (P < 0.05). The intrapulmonary BMDC level of reconstructed treatment group (0.65 +/- 0.13) was significantly higher than that in reconstructed control group (0.46 +/- 0.11), P < 0.05. CONCLUSION: Mobilization of BMDC by G-CSF showed a protective effect on lung injury induced by bleomycin in mice, but did not have significant influence on survival time.