Research and Development, Finnish Red Cross Blood Service, R&D, Kivihaantie 7, FIN-00310 Helsinki, Finland.
J Mol Cell Biol. 2011 Apr;3(2):99-107. doi: 10.1093/jmcb/mjq041. Epub 2010 Dec 12.
Umbilical cord blood (UCB) is an efficient and valuable source of hematopoietic stem cells (HSCs) for transplantation. In addition to HSCs it harbours low amounts of mesenchymal stem cells (MSCs). No single marker to identify cord blood-derived stem cells, or to indicate their multipotent phenotype, has been characterized so far. SSEA-3 and -4 are cell surface globoseries glycosphingolipid epitopes that are commonly used as markers for human embryonic stem cells, where SSEA-3 rapidly disappears when the cells start to differentiate. Lately SSEA-3 and -4 have also been observed in MSCs. As there is an ongoing discussion and variation of stem-cell markers between laboratories, we have now comprehensively characterized the expression of these epitopes in both the multipotent stem-cell types derived from UCB. We have performed complementary analysis using gene expression analysis, mass spectrometry and immunochemical methods, including both flow cytometry and immunofluoresence microscopy. SSEA-4, but not SSEA-3, was expressed on MSCs but absent from HSCs. Our findings indicate that SSEA-3 and/or -4 may not be optimal markers for multipotency in the case of stem cells derived from cord blood, as their expression may be altered by cell-culture conditions.
脐带血 (UCB) 是一种高效且有价值的造血干细胞 (HSCs) 移植来源。除了 HSCs 之外，它还含有少量的间充质干细胞 (MSCs)。到目前为止，还没有一个单一的标记物可以识别脐带血来源的干细胞，或者表明它们的多能表型。SSEA-3 和 -4 是细胞表面的糖鞘脂类抗原，常用于作为人胚胎干细胞的标记物，当细胞开始分化时，SSEA-3 会迅速消失。最近，SSEA-3 和 -4 也在 MSCs 中被观察到。由于实验室之间对干细胞标记物的讨论和变化，我们现在已经全面描述了这些抗原在 UCB 衍生的多能干细胞类型中的表达情况。我们使用基因表达分析、质谱和免疫化学方法（包括流式细胞术和免疫荧光显微镜）进行了互补分析。SSEA-4 而不是 SSEA-3 表达在 MSCs 上，但不存在于 HSCs 上。我们的发现表明，SSEA-3 和/或 -4 可能不是源自脐带血的干细胞多能性的最佳标记物，因为它们的表达可能会受到细胞培养条件的影响而改变。
