Koller M R, Bender J G, Miller W M, Papoutsakis E T
Department of Chemical Engineering, Northwestern University, Evanston, IL 60208-3120.
Exp Hematol. 1992 Feb;20(2):264-70.
Growth of hematopoietic stem and progenitor cells found in the mononuclear cell (MNC) fraction of human cord blood and bone marrow was evaluated under atmospheres containing reduced (5%) and normal (20%) oxygen tension. Cord blood MNC were grown in suspension and on preestablished irradiated bone marrow stromal layers, whereas bone marrow MNC were used to initiate one-step long-term bone marrow cultures (LTBMC). Reduced oxygen tension resulted in a substantial increase in both the number and frequency of colony-forming cells observed in all three types of long-term hematopoietic cultures (LTHC) studied. At various time points under low oxygen, progenitor cell numbers were as much as 12-fold, 3-fold, and 4-fold higher for granulocyte-macrophage colony-forming units (CFU-GM), erythroid burst-forming units (BFU-E), and granulocyte erythrocyte macrophage megakaryocyte colony-forming units (CFU-GEMM), respectively. In addition to these numerical increases, progenitor cells were maintained for 1-2 weeks longer under low oxygen conditions. Reduced oxygen tension also increased total cell numbers by as much as fivefold in cord blood suspension cultures, but this effect on total cell numbers was less pronounced in cultures containing a stromal layer. The rate of irradiated stromal layer degeneration, as judged by cell counts and microscopic examination, was reduced under low oxygen. Finally, the beneficial effect of reduced oxygen was comparable to the effect of an irradiated stromal layer for maintaining cord blood progenitor cells in LTHC. These results indicate that low oxygen, which better approximates the in vivo environment, enhances the growth and maintenance of both stromal and progenitor cells for a longer period of time in vitro.
在含低氧（5%）和正常氧（20%）张力的环境下，对人脐带血和骨髓单个核细胞（MNC）组分中造血干细胞和祖细胞的生长进行了评估。脐带血MNC在悬浮液中以及预先建立的经辐照的骨髓基质层上生长，而骨髓MNC用于启动一步长期骨髓培养（LTBMC）。低氧张力导致在所研究的所有三种类型的长期造血培养（LTHC）中观察到的集落形成细胞的数量和频率大幅增加。在低氧条件下的各个时间点，粒细胞-巨噬细胞集落形成单位（CFU-GM）、红系爆式集落形成单位（BFU-E）和粒细胞-红细胞-巨噬细胞-巨核细胞集落形成单位（CFU-GEMM）的祖细胞数量分别比正常氧条件下高出多达12倍、3倍和4倍。除了这些数量上的增加外，祖细胞在低氧条件下维持的时间延长了1 - 2周。低氧张力还使脐带血悬浮培养中的总细胞数增加了多达五倍，但这种对总细胞数的影响在含有基质层的培养物中不太明显。通过细胞计数和显微镜检查判断，低氧条件下经辐照的基质层退化速率降低。最后，低氧的有益作用与经辐照的基质层在LTHC中维持脐带血祖细胞的作用相当。这些结果表明，更接近体内环境的低氧在体外能更长时间地增强基质细胞和祖细胞的生长与维持。
