OBJECTIVETo explore the effects of basic fibroblast growth factor (bFGF) on human bone marrow mesenchymal stem cell (hBMMSC) damaged by irradiation and its underlying mechanisms.

METHODShBMMSC was irradiated with 0, 6, 12 Gy X ray, then flow cytometry, cell counting kit-8 (CCK-8), Western blot and alizarin red staining were used to detect the effects of X ray on apoptosis, proliferation and osteogenic differentiation of hBMMSC; 0, 1, 5, 10, 20 ng/ml bFGF was added to hBMMSC irradiated with X ray for selecting the suitable bFGF reaction concentration; then the Western blot was used to detect the expression of PDGFRα so as to evaluate whether the expression of PDGFRα participated in bFGF-mediated recovery of hBMMSC proliferation and osteogenic differentiation after irradiation.

RESULTSThe proliferation and osteogenic differentiation of hBMMSC decreased remarkably after irradiation. bFGF promoted the recovery of proliferation and osteogenic differentiation of irradiated hBMMSC compared with untreated irradiated hBMMSC (P < 0.05); 5 ng/ml bFGF was identified as the optimal concentration. A significant difference in the number of apoptotic cells could be detected only between the 0 Gy group and 12 Gy group at the 24 h time point, while no differences were detected at later time points. Irradiated hBMMSC showed remarkable decrease of PDGFRα expression, while the PDGFRα expression increased after bFGF was added.

CONCLUSIONIrradiation dose not show significant effect on apoptosis of hBMMSC, but the bFGF displays a effect on repairing the irradiation damage of hBMMSC and promotes the recovery of hBMMSC proliferation and osteogenic differentiation. The damage of hBMMSC proliferation and osteogenic differentiation associates with downregulation of PDGFRα expression induced by irrediation. PDGFRα involves in repairing effect of bFGF on irradiation damage of hBMMSC.