Department of Obstetrics and Gynecology, University Medical Centre Ljubljana, Slajmerjeva 3, Ljubljana, 1000, Republic of Slovenia.
Institute for Anatomy and Cell Biology, Medical Faculty, University of Heidelberg, Im Neuenheimer Feld 307, Heidelberg, 69120, Germany.
J Ovarian Res. 2013 Apr 9;6:24. doi: 10.1186/1757-2215-6-24. eCollection 2013.
It has already been found that very small embyronic-like stem cells (VSELs) are present in adult human tissues and organs. The aim of this study was to find if there exists any similar population of cells in cell cultures of reproductive tissues and embryonic stem cells, and if these cells have any relation to pluripotency and germinal lineage.
Here we report that a population of small SSEA-4-positive cells with diameters of up to 4 μm was isolated by fluorescence-activated cell sorting (FACS) from the human ovarian cell cultures after enzymatic degradation of adult cortex tissues. These small cells - putative ovarian stem cells - were also observed during cell culturing of up to 6 months and more. In general, small putative ovarian stem cells, isolated by FACS, showed a relatively low gene expression profile when compared to human embryonic stem cells (hESCs) and human adult fibroblasts; this may reflect the quiescent state of these cells. In spite of that, small putative ovarian stem cells expressed several genes related to primordial germ cells (PGCs), pluripotency and germinal lineage, including VASA. The PGC-related gene PRDM1 was strongly expressed in small putative ovarian stem cells; in both hESCs and fibroblasts it was significantly down-regulated. In addition, putative ovarian stem cells expressed other PGC-related genes, such as PRDM14 and DPPA3. Most of the pluripotency and germinal lineage-related genes were up-regulated in hESCs (except VASA). When compared to fibroblasts, there were several pluripotency-related genes, which were up-regulated in small putative ovarian stem cells. Similar populations of small cells were also isolated by FACS from human testicular and hESC cultures.
Our results confirm the potential embryonic-like character of small putative stem cells isolated from human adult ovaries and their possible relation to germinal lineage.
已经发现，非常小的胚胎样干细胞（VSELs）存在于成人组织和器官中。本研究的目的是确定在生殖组织和胚胎干细胞的细胞培养物中是否存在类似的细胞群体，以及这些细胞是否与多能性和生殖谱系有关。
我们报告了一种直径可达 4μm 的小 SSEA-4 阳性细胞群体，通过酶解成人皮质组织后，通过荧光激活细胞分选（FACS）从人卵巢细胞培养物中分离出来。这些小细胞——推测是卵巢干细胞——在长达 6 个月的细胞培养过程中也被观察到。一般来说，通过 FACS 分离的小推测卵巢干细胞与人类胚胎干细胞（hESCs）和人类成纤维细胞相比，其基因表达谱相对较低；这可能反映了这些细胞的静止状态。尽管如此，小推测卵巢干细胞表达了几个与原始生殖细胞（PGCs）、多能性和生殖谱系相关的基因，包括 VASA。PGC 相关基因 PRDM1 在小推测卵巢干细胞中强烈表达；在 hESCs 和成纤维细胞中，它的表达显著下调。此外，推测卵巢干细胞还表达了其他与 PGC 相关的基因，如 PRDM14 和 DPPA3。大多数与多能性和生殖谱系相关的基因在 hESCs 中上调（除了 VASA）。与成纤维细胞相比，小推测卵巢干细胞中有几个与多能性相关的基因上调。通过 FACS 还从小鼠睾丸和 hESC 培养物中分离出类似的小细胞群体。
我们的结果证实了从小鼠卵巢中分离的小推测干细胞具有潜在的胚胎样特征，它们可能与生殖谱系有关。
