Division of Hematology/Oncology, Rhode Island Hospital/Brown University, 1 Hoppin St Coro West Building suite 5.01, Providence, RI, 02903, USA.
Stem Cell Rev Rep. 2022 Oct;18(7):2351-2364. doi: 10.1007/s12015-022-10374-4. Epub 2022 May 3.
Hematopoietic stem cells express differentiation markers B220 and Gr1 and are proliferative. We have shown that the expression of these entities changes with cell cycle passage. Overall, we conclude that primitive hematopoietic stem cells alter their differentiation potential with cell cycle progression. Murine derived long-term hematopoietic stem cells (LT-HSC) are cycling and thus always changing phenotype. Here we show that over one half of marrow LT-HSC are in the population expressing differentiation epitopes and that B220 and Gr-1 positive populations are replete with LT-HSC after a single FACS separation but if subjected to a second separation these cells no longer contain LT-HSC. However, with second separated cells there is a population appearing that is B220 negative and replete with cycling c-Kit, Sca-1 CD150 positive LT-HSC. There is a 3-4 h interval between the first and second B220 or GR-1 FACS separation during which the stem cells continue to cycle. Thus, the LT-HSC have lost B220 or GR-1 expression as the cells progress through cell cycle, although they have maintained the c-kit, Sca-1 and CD150 stem cells markers over this time interval. These data indicate that cycling stem cells express differentiation epitopes and alter their differentiation potential with cell cycle passage.
造血干细胞表达分化标志物 B220 和 Gr1，并且具有增殖能力。我们已经表明，这些实体的表达随着细胞周期的进行而变化。总的来说，我们得出结论，原始造血干细胞随着细胞周期的进展改变其分化潜能。来源于小鼠的长期造血干细胞（LT-HSC）是周期性的，因此其表型总是在变化。在这里，我们表明，超过一半的骨髓 LT-HSC 表达分化表位，并且 B220 和 Gr-1 阳性群体在经过一次 FACS 分离后充满 LT-HSC，但如果进行第二次分离，这些细胞不再含有 LT-HSC。然而，在经过第二次分离的细胞中，出现了一个 B220 阴性的群体，充满了周期性的 c-Kit、Sca-1 CD150 阳性的 LT-HSC。在第一次和第二次 B220 或 GR-1 FACS 分离之间有 3-4 小时的间隔，在此期间干细胞继续循环。因此，随着细胞周期的进行，LT-HSC 失去了 B220 或 GR-1 的表达，尽管在此期间它们一直保持着 c-kit、Sca-1 和 CD150 干细胞标志物。这些数据表明，循环干细胞表达分化表位，并随着细胞周期的进行改变其分化潜能。
