Symmetry of initial cell divisions among primitive hematopoietic progenitors is independent of ontogenic age and regulatory molecules
Symmetry of initial cell divisions among primitive hematopoietic progenitors is independent of ontogenic age and regulatory molecules
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DOI：
10.1182/blood.v94.8.2595.420k37_2595_2604
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发表时间：
1999-10-15
期刊：
影响因子：
20.3
通讯作者：
Ho, AD
中科院分区：
文献类型：
--
作者：
Huang, S;Law, P;Ho, AD
我们开发了一种延时照相系统，以在单细胞水平上跟踪造血干细胞（HSC）的复制历史和命运。结合单细胞培养，我们将早期复制行为与14天后的集落发育相关联。膜染料PKH 26用于监测细胞分裂。除了多次、同步和对称分裂外，来自胎肝（FLV）的单一分选的CD 34（+）/CD 38（-）细胞也产生了一个保持静止长达8天的子细胞，而另一个子细胞则呈指数增殖。在分离并作为单细胞重新接种到含有细胞因子混合物的培养基上后，60.6% +/-9.8%的初始静止细胞（PKH 26亮）再次产生集落，15.8% +/-7.8%产生可以重新接种的原始集落。然后，我们确定了各种调节分子对初始细胞分裂对称性的影响。单细胞分选后，将来自FLV的CD 34（+）/CD 38（-）细胞暴露于flt 3-配体、血小板生成素、干细胞因子（SCF）或含有细胞因子混合物（含SCF、白细胞介素-1、白细胞介素-6、粒细胞-巨噬细胞集落刺激因子和促红细胞生成素）的培养基。而有丝分裂率，集落效率，和不对称分裂可以改变使用各种调控分子，不对称分裂指数，定义为不对称分裂的数量与分裂细胞的数量，没有显着改变。这一观察结果表明，虽然谱系承诺和细胞增殖可以通过外部信号偏斜，早期分裂的对称性可能是内在因素的控制下。(C)1999年，美国血液学会。
We have developed a time-lapse camera system to follow the replication history and the fate of hematopoietic stem cells (HSC) at a single-cell level. Combined with single-cell culture, we correlated the early replication behavior with colony development after 14 days. The membrane dye PKH26 was used to monitor cell division. In addition to multiple, synchronous, and symmetric divisions, single-sorted CD34(+)/CD38(-) cells derived from fetal liver (FLV) also gave rise to a daughter cell that remained quiescent for up to 8 days, whereas the other daughter cell proliferated exponentially. Upon separation and replating as single cells onto medium containing a cytokine cocktail, 60.6% +/- 9.8% of the initially quiescent cells (PKH26 bright) gave rise again to colonies and 15.8% +/- 7.8% to blast colonies that could be replated. We have then determined the effects of various regulatory molecules on symmetry of initial cell divisions. After single-cell sorting, the CD34(+)/CD38(-) cells derived from FLV were exposed to flt3-ligand, thrombopoietin, stem cell factor (SCF), or medium containing a cytokine cocktail (with SCF, interleukin-1, interleukin-6, granulocyte-macrophage colony-stimulating factor, and erythropoietin). Whereas mitotic rate, colony efficiency, and asymmetric divisions could be altered using various regulatory molecules, the asymmetric division index, defined as the number of asymmetric divisions versus the number of dividing cells, was not altered significantly. This observation suggests that, although lineage commitment and cell proliferation can be skewed by extrinsic signaling, symmetry of early divisions is probably under the control of intrinsic factors. (C) 1999 by The American Society of Hematology.