Promoting the proliferation of bone marrow mesenchymal stem cell by recombinant human granulocyte colony-stimulating factor

Objective To investigate the effects on proliferation of bone marrow mesenchymal stem cells (MSCs) by recombinant human granulocyte colony-stimulating factor in mice. Methods Kunming mice were randomly divided into G-CSF and control groups (n=15). The mice were subjected to subcutaneous injections of rhG-CSF at a dose of 80 μg/kg per day and control of saline for 5 days. The bone marrow was obtained on 6th, 12th and 168th h respectively after the final administration. The MSCs were separated and cultured, and the colony-forming unit-fibroblast (CFU-F) was evaluated. The cell cycle and the surface antigens were analyzed by flow cytometry. Results The number of CFU-F was increased after administration of the rhG-CSF (P 0.01). The number of CFU-F in G-CSF groups was negatively relevant to the sampling time from bone marrow (P 0.05), but there was no obvious difference between 12 h and 168 h (P 0.05). Flow cytometic detection of MSCs surface marks in fibroblast colony showed CD34~ -, CD133~ -, CD90~ + and CD105~ +, with the percentage of 2.5 %, 3.1 %, 67.0 % and 78.0 %, respectively. After mobilization with rhG-CSF, the percentage of G_0/G_1 phases in bone marrow MNCs was decreased (P 0.05), while that percentage of S+G_ 2/M phases increased (P 0.05), and the percentage of S+G_ 2/M phases in G-CSF groups at 6 h was significantly higher than that at 12 h and 168 h, respectively (P 0.05). Conclusion rhG-CSF treatment could promote bone marrow MNCs re-entering into cell cycle, and the peak value occurred at about 6 h after the final rhG-CSF administration.