Abstract:

BACKGROUND: Bone marrow (BM) is the main source of mesenchymal stem cell (MSCs) at present, but because of the inconvenience of isolation, and the age-related decrease in the number of MSCs, amnion as a new source of MSCs has been widespreadly concerned recently.
OBJECTIVE: To explore the supportive effects of MSCs derived from human amnions on hematopoiesis in vitro and to elevate the success rate of co-transplantation of amniotic mesenchymal stem cells (AMSCs) and hematopoietic stem cells.
METHODS: MSCs were isolated and cultured from human amnions after childbirth by the tissue pieces culture method. Mononuclear cells (MNCs) were isolated from umbilical cord blood using density gradient centrifugation. CD34+ cells were isolated by magnetic cell sorting. The MNC and CD34+ cells were co-cultured with AMSCs for four weeks respectively. The concentration of the floating cells was recorded weekly. And as the control, they were co-cultured with the BM-MSCs and deeder layer-free group respectively as well. The MNC and CD34-positive cells were plated in semisolid culture medium separately, and the colony formation was assessed at 14 days after the plating.
RESULTS AND CONCLUSION: AMSCs promoted the expansion of human cord blood MNCs and CD34+ cells, and also promoted the formation of hematopoietic progenitor cell colony in methylcellulose semisolid culture medium. Its capacity of hematopoitic support was similar to that of BM-MSCs, without significant difference. These indicate that in vitro AMSCs had the capacity for hematopoietic support similar to BM-MSCs. Thus, they may be an ideal source of stem cells for the expansion of hematopoietic stem cells in vitro and the co-transplantation of MSCs and hematopoietic stem cells to improve the success rate of clinical transplantations.