Hemangiopoietin Contributes to Hematopoietic Reconstitution in Radiation Damaged Mice / 中国生物工程杂志

ABSTRACT

Aim:To investigate the effect of Hemangiopoietin (HAPO) on the hematopoiesis reconstitution in sub-lethally irradiated Balb/c mice.Methods: Balb/c mice were underwent total body irradiation at 700 cGy 137Cs ? radiation and were treated with HAPO or recombinant human granulocyte colony stimulating factor (rhG-CSF) after irradiation. The hematopoiesis reconstitution of mice were detected. Cells from bone marrow of Balb/c mice were cultured with HAPO or rhG-CSF for 24 hours or 72 hours before or after the cells were irradiated. The viability of cells were assessed and the ability of in vitro hematopoiesis reconstitution were also detected. Result: rhG-CSF and HAPO treated mice both showed increased survival rate and increased colony forming units. The peripheral WBC number increased greatly. The HAPO group was most quickest compared with rhG-CSF group and PBS control group. The number of bone marrow cells at day 14 of rhG-CSF group was higher than that in HAPO group, but the number of bone marrow cells at day 32 of rhG-CSF was lower than that in HAPO group. The number of bone marrow cells at day 42 of rhG-CSF was below normal. The number of bone marrow cells at day 42 of HAPO group was nearly normal. The number of CFU-GEMM in HAPO group was most compared with that in rhG-CSF group and PBS control group at day 7, 14 and 21 after radiation. The survival rate of cells after radiation in HAPO group was markedly higher than that in PBS control group, but the survival rate of cells after radiation in rhG-CSF group was no notable difference compared with that in PBS control group. In MTT assay, both HAPO and rhG-CSF incubation stimulated proliferation of bone marrow cell at 72 hours after radiation. Bone marrow cells formed Hematopoietic islands in HAPO group after radiation and were positive for sca-1 and CD31. CD31 positive endothelial cells increased around the Hematopoietic islands. There was no Hematopoietic islands formation, few CD31 positive endothelial cells and no sca-1 positive cells in PBS control group. Conclusion: HAPO can promote hematopoiesis reconstitution in sub-lethally irradiated Balb/c mice. It can increase the survival rate of mice and stimulate the proliferation of hematopoietic stem cells.