Repair Of Hematopoietic Injury For Human Umbilical Cord Blood-derived Stromal Cells Compare To Bone Marrow Stromal Cells

Introduction:Hematopoietic inductive microenvironment (HIM) is the important survival environment oforigin, proliferation, differentiation and development of hematopoietic stem cell (HSC).Thehematopoietic injury caused by chemotherapy and radiotherapy in cancer patients has a strongimpact in therapeutic effect, because the injury of HIM is much longer and more serious than HSC,which has become one of the main reasons impacting follow-up for neoplastic disorders. The studyfound that ectogenic infusion of bone marrow stromal cells can promote hematopoieticreconstitution and decrease the incidence of GVHD, promote success rate of transplantation. Butthe bone marrow stromal cells are associated with problems of limited supply, the pain and dangerin bone marrow collection of donor, and the quantity and the capacity about proliferation anddifferentiation of human bone marrow stromal cells (hBMSCs) can be impacted by donor age.Many patients’ own stromal cells are defective, which can significantly reduce the effect ofAHSCT(autologous hematopoietic stem cell transplantation). However, allogenic haemopoieticstem cell transplantation also maybe faced with the problem of histocompatibility, which all limitthe use of hBMSCs in clinic.The human umbilical cord blood derived stromal cells (hUCBDSCs) are new type of stromalcells cultured by our department, which have been confirmed that they can support theproliferation of hematopoietic stem cell, especially in the part of megalokaryocyte colonyformation. This study compared the role of these two types of cell in repair of hematopoietic injuryof mouse, to prove the prospect of hUCBDSCs in clinic.Methods：The hUCBDSCs and hBMSCs were cultured as previous report. Immunocytochemistry andcytochemistry were used to evaluate the cell components of hUCBDSCs and hBMSCs and try toimprove the condition and method of subculture of hUCBDSCs. All BALB/c mouse were received6.0Gy60Co rays total body irradiation in order to constructthe animal model of hematopietic injury.The hUCBDSCs and hBMSCs was infused into the animal model. The relevant metric wasobserved in order to compare the capacity in the repair of hematopoietic function between thesetwo cells.Result：1. The culture and evaluation of hUCBDSCs and hBMSCs:1) The morphology characteristicof hUCBDSCs: There are three different cell components of hUCBDSCs including fibroblast-likedcell, macrophage-liked cell and small-sphere liked cell. Cytochemistry stain: the positive ratereached100%in PAS stain, ALP stain manifest30%positive. Immunocytochemistry stain: thepositive rate of hBMSCs for CD106, CD50，CD44and Fn was respective. CD45show negative.2)The morphology characteristic of hBMSCs: The fusiform cells are just the only component.2. Subculture method of hUCBDSCs and hBMSCs: After the density of cells were above70%-80%confluence, hUCBDSCs were subcultured with1:1ratio under the same culture mediumand condition, however, hBMSCs were subcultured with1:3. With the increase of the number ofsubculture, the morph of hUCBDSCs trend to uniformity. Fibroblast liked cell is the maincomponent cell, macrophage liked cell and small-sphere liked cell decrease remarkablely.hUCBDSCs can be subcultured for4generations under preasent condition. However hBMSCs aremainly fusiform cells in the primary cultured cells, and with increase of the number of subculture,the change in shape is small.3. The effect in the hematopoetic recovery between hUCBDSCs and hBMSCs: white bloodcell, platelet and red blood cell declined on3days after transplantation in both groups, picked upon the seventh day. The hUCBDSCs group was higher than that of in hBMSCs group (P<0.05) andwas fastest in the three groups(P<0.05).The myelogram of hUCBDSCs goup and hBMSCs goupwere restrained on﹢7days, and the nucleated cells were more than control group on﹢7days,butthe erythroid cells were hypoplastic. The CFU-E, BFU-E, CFU-GM, CFU-GEMM counts inhUCBDSCs group on+21days were also higher than that in hBMSCs group and isotonic NaC1group(P<0.05),and all the mice were survival. Results among the three groups were statisticallysignificant difference.(P<0.05)1. hUCBDSCs possess the fundamental character of hematopoietic stromal cells.2. Both hUCBDSCs and hBMSCs can repair the hematopoietic injury. 3. hUCBDSCs are better than hBMSCs in hemopoietic repair,esperially in the recover ofplatelet and leukocyte.4. Ectogenic infusion of human umbilical cord blood derived stromal cells can repair thehematopoietic injury quickly, which may give clinical prospective significance.