Jackson Carlo Stephan, Durandt Chrisna, Janse van Rensburg Ilse, Praloran Vincent, Brunet de la Grange Philippe, Pepper Michael Sean
Department of Immunology, Institute for Cellular and Molecular Medicine, Faculty of Health Sciences, SAMRC Extramural Unit for Stem Cell Research and Therapy, University of Pretoria, South Africa.
University of Pretoria Biomedical Research Center, South Africa.
Stem Cell Res. 2017 May;21:124-131. doi: 10.1016/j.scr.2017.04.007. Epub 2017 Apr 20.
Culture conditions used for the expansion of hematopoietic stem and progenitor cells (HSCs and HPCs, collectively HSPCs) should ideally favor the self renewal of long-term HSCs. At 20% O, the synthesis of HIF-1α is balanced by its hydroxylation and proteasomal degradation. This favors HSPC differentiation, but can be prevented by culturing CD34+ cord blood cells in the presence of dimethyloxaloylglycine (DMOG). This differentiation may also be reduced by culturing the cells in the presence of Stemregenin 1, an antagonist of the aryl hydrocarbon receptor (AhR). The objective of this study was to investigate how hypoxia, DMOG and Stemregenin 1 might affect the expansion of HSPCs with the aim of identifying optimal conditions for expansion in culture. It was found that DMOG decreased proliferation but was effective in preserving the number of cells in the primitive hematopoietic sub-populations in vitro. The effect of DMOG was similar to hypoxia, although differences were observed with regard to the side population and CD34+ sub-populations. Stemregenin 1 on the other hand increased the size of the primitive as well as the other HSC sub-populations. The use of Stemregenin 1 with DMOG increased the proportion of primitive HSCs to 3.54% compared to 2.61% for Stemregenin 1 alone. In vivo engraftment studies confirmed these findings and showed that fewer cells (3710) are required for long-term engraftment when HSCs are grown in Stemregenin 1 together with hypoxia than in Stemregenin 1 under conditions of normoxia (13430).
用于扩增造血干细胞和祖细胞（统称为造血干细胞和祖细胞，HSPCs）的培养条件理想情况下应有利于长期造血干细胞的自我更新。在20%氧气浓度下，HIF-1α的合成通过其羟基化和蛋白酶体降解达到平衡。这有利于HSPC分化，但可通过在二甲基草酰甘氨酸（DMOG）存在的情况下培养CD34+脐血细胞来防止。通过在芳烃受体（AhR）拮抗剂Stemregenin 1存在的情况下培养细胞，这种分化也可能会降低。本研究的目的是研究缺氧、DMOG和Stemregenin 1如何影响HSPCs的扩增，以确定培养扩增的最佳条件。研究发现，DMOG降低了增殖，但在体外有效保留了原始造血亚群中的细胞数量。DMOG的作用与缺氧相似，尽管在侧群和CD34+亚群方面观察到了差异。另一方面，Stemregenin 1增加了原始以及其他造血干细胞亚群的大小。与单独使用Stemregenin 1时的2.61%相比，将Stemregenin 1与DMOG联合使用可使原始造血干细胞的比例增加至3.54%。体内移植研究证实了这些发现，并表明当造血干细胞在Stemregenin 1与缺氧条件下共同培养时，与在常氧条件下的Stemregenin 1中培养相比，长期移植所需的细胞数量更少（3710个对13430个）。
