Warren Alpert Medical School of Brown University, Rhode Island Hospital, 593 Eddy Street, Providence, RI, USA.
Adv Exp Med Biol. 2018;1056:3-9. doi: 10.1007/978-3-319-74470-4_1.
Hematopoietic stem cell biology has focused on stem cell purification and the definition of the regulation of purified stem cells in a hierarchical system. Work on the whole unpurified murine marrow cell population has indicated that a significant number of hematopoietic stem cells, rather than being dormant, are actively cycling, always changing phenotype and therefore resistant to purification efforts by current approaches. The bulk of cycling marrow stem cells are discarded with the standard lineage negative, stem cell marker positive separations. Therefore, the purified stem cells do not appear to be representative of the total hematopoietic stem cell population. In addition, baseline hematopoiesis does not appear to be determined by the transplantable stem cells but rather by many short-lived clones of varying differentiation potential. These systems appear to be impacted by tissue derived extracellular vesicles and a number of other variables. Thus hematopoietic stem cell biology is now at a fascinating new beginning with great promise.
造血干细胞生物学一直专注于干细胞的纯化以及在层次系统中对纯化干细胞的调控的定义。对整个未经纯化的鼠骨髓细胞群体的研究表明，相当数量的造血干细胞不是处于休眠状态，而是在活跃地循环，不断改变表型，因此对目前方法的纯化努力具有抗性。大量的循环骨髓干细胞与标准的谱系阴性、干细胞标志物阳性的分离方法一起被丢弃。因此，纯化的干细胞似乎不能代表整个造血干细胞群体。此外，基础造血似乎不是由可移植的干细胞决定的，而是由许多具有不同分化潜力的寿命短的克隆决定的。这些系统似乎受到组织衍生的细胞外囊泡和许多其他变量的影响。因此，造血干细胞生物学现在正处于一个迷人的新起点，充满了巨大的希望。
