Experimental study of MSCs in treatment of acute hematopoietic radiation injury

Objective: To investigate the effect and mechanism of MSCs on hematopoietic reconstitution in irradiated mice with 5.5 Gy 60Co γ- rays. Methods: BALBPc mice irradiated with 5.5 Gy 60Co γ-rays were randomly divided into a control group and a MSCs-treated group. Peripheral leukocyte, platelet, erythrocyte counts, apoptosis and cell cycle of bone marrow cells (BMC), pathologic change of bone marrow and numbers of GM-CFU and F-CFU were observed. Results: Compared to the control group three series of BMC in MSC treated group decrease more slowly, but elevation of the nadir and recovery were more rapid. The apoptotic ratio and p53 expression in controls were superior to those in MSC-treated group. The ratio of G0/G1 was obviously dropped in the MSC-treated group (P<0.01); however ,the ratio of G2/M and the number of cells in S stage were higher in that group (P<0.01). The sternum marrow regenerated actively MSC treatment, while marked hypoplasia was seen in controls on day 4. More hematopoietic islands in the bone marrow were observed in MSC-treated group on day 20 and the CFU-GM and CFU-F counts were higher than those in controls. Conclusions: These results indicate that MSC injection may become a valuable strategy for acute hematopoietic injury. (authors)