Reconstruction of Hematopoietic Function of Human Placental Hematopoietic Stem Cells in Non-Lethally Radiated Mice / 中国实验血液学杂志

ABSTRACT

OBJECTIVE@#To investigate the effect of human placental hematopoietic stem cells (PHSCs) on hematopoietic reconstruction in non-lethally irradiated mice.@*METHODS@#Human placental HSCs were extracted by mechanical method combined with zymolysis and were identified by flow cytometry and colony formationtest. Twenty-five NOG mice were divided randomly into 4 groups the blank control group (n=5), the irradiated group (n=4), the low dose PHSC group (n=8) and the high dose PHSC group (n=8). The mice in the irradiated, the low dose and the high dose PHSC groups were irradiated with X-rays at dose 1 Gy (100 cGy/min) under sterile condition. The mice in the low dose PHSC group and the high dose PHSC group were injected intravenously with 0.1 ml human placental HSC in dose of 2×10 and 1×10, respectively. The mice in the blank control and the irradiated group were injected with the same volume of saline. The mice were weighed weekly, and the changes of body weight were calculated. The peripheral blood was collected from each group at 4, 8 and 12 week for flow cytometrytic detection of human CD45 and myeloid and lymphoid cells.@*RESULTS@#The flow cytometry and cell-colong formation test showed that the human placental HSC accounted for more than 0.75% of total placental mononuclear cells, moreover possess the differentiation ability. Compared with the blank control group, the relative weight gain in the irradiated, the low dose PHSC, and the high dose PHSC groups decreased significantly, and the relative weight gain in the low dose PHSC and the high dose PHSC group increased significantly as compared with the irradiated group. Flow cytometry showed that at the tine-point of 12 weeks after transplantation, the human blood immune system in the high-dose PHSC mice began long-term reconstruction, while the ratio of human CD45 cells in the low-dose PHSC mice was very low.@*CONCLUSION@#After transplantation of human PHSC the non-lethally irradiated mice can obtain short-term and long-term reconstruetion of human blood cells, which demonstrated that human placental HSC can differentiate and reconstruct hematopoietic function in vivo of irradiated mice.