Toksöz D, Dexter T M, Lord B I, Wright E G, Lajtha L G
Blood. 1980 Jun;55(6):931-6.
The isolation of a DNA synthesis inhibitor (NBME fraction IV) and stimulator (RBME fraction III) specific for the hemopoietic stem cell (CFU-s) from freshly isolated normal adult and regenerating murine bone marrow, respectively, has been well documented. We have utilized long-term liquid bone marrow cultures in a further analysis of the role of these factors in the regulation of CFU-s proliferation. Our results show that shortly after feeding, at a time when the cultured CFU-s are actively proliferating, high levels of the hemopoietic stem cell proliferation stimulator fraction III can be isolated from the culture medium. In contrast, the presence of essentially noncycling CFU-s found in cultures fed 8-10 days previously correlates with high levels of the hemopoietic stem cell inhibitor fraction IV. These results suggest that a certain balance between these factors determines CFU-s proliferation in the long-term cultures. In support of this, DNA synthesis in actively cycling CFU-s in the long-term cultures is inhibited for at least 3 days by the addition of excess NBME fraction IV (inhibitor). Furthermore, DNA synthesis in noncycling cultured CFU-s is stimulated for at least 5 days by the addition of RBME fraction III (stimulator).
从新鲜分离的正常成年和再生小鼠骨髓中分别分离出对造血干细胞（CFU-s）具有特异性的DNA合成抑制剂（NBME组分IV）和刺激剂（RBME组分III），这一点已有充分记录。我们利用长期液体骨髓培养进一步分析了这些因子在CFU-s增殖调节中的作用。我们的结果表明，在喂食后不久，即在培养的CFU-s活跃增殖时，可以从培养基中分离出高水平的造血干细胞增殖刺激剂组分III。相反，在8 - 10天前喂食的培养物中发现的基本处于非循环状态的CFU-s与高水平的造血干细胞抑制剂组分IV相关。这些结果表明，这些因子之间的某种平衡决定了长期培养中CFU-s的增殖。支持这一点的是，在长期培养中，通过添加过量的NBME组分IV（抑制剂），活跃循环的CFU-s中的DNA合成至少被抑制3天。此外，通过添加RBME组分III（刺激剂），非循环培养的CFU-s中的DNA合成至少被刺激5天。
