Pregnancy Research Centre, Department of Perinatal Medicine, The Royal Women's Hospital, Parkville, Victoria, Australia.
Placenta. 2010 Mar;31(3):203-12. doi: 10.1016/j.placenta.2009.12.006. Epub 2010 Jan 13.
The chorionic villi of human term placentae are a rich source of mesenchymal stem cells (PMSCs). The stem cell "niche" within the chorionic villi regulates how PMSCs participate in placental tissue generation, maintenance and repair, but the anatomic location of the niche has not been defined. A number of cell surface markers for phenotypic characterisation of mesenchymal stem cells (MSCs) were employed to identify the stem cell niche within the chorionic villi of first trimester and term human placenta. This included antibodies to pericyte cell surface markers STRO-1 and 3G5, which have been used to identify mesenchymal stem cells in other tissues, but have not been studied in placental tissues. PMSCs were isolated from term human placentae and shown to have stem cell properties by their ability to grow on untreated plastic culture ware, capacity for forming clones (i.e. clonogenicity) and their capability to differentiate into adipocytes, chondrocytes and osteocytes. Western analysis confirmed that STRO-1 and 3G5 are present in placental protein extracts and in PMSCs. Immunocytochemistry revealed PMSCs were positive for MSC cell surface markers (STRO-1, 3G5, CD105, CD106, CD146, CD49a, alpha-SMA) and negative for haematopoietic stem cell markers (CD117, CD34) and endothelial markers (CD34, vWF). Immunohistochemistry with antibodies to MSC cell surface markers on first trimester and term tissues revealed a vascular niche for PMSCs. Dual-label immunofluorescence analysis was used to compare STRO-1 antibody staining with that of endothelial cell marker vWF and found no significant overlap in staining. This indicated that some PMSCs have a pericyte-like phenotype. We propose that the vascular niche harbours a pool of PMSCs that can give rise to committed progenitors for tissue maintenance and repair, and that PMSCs contribute to vessel maturation and stabilization.
人类足月胎盘的绒毛是间充质干细胞（PMSC）的丰富来源。绒毛内的干细胞“龛”调节 PMSC 如何参与胎盘组织的生成、维持和修复，但龛的解剖位置尚未确定。许多用于间充质干细胞（MSC）表型特征鉴定的细胞表面标志物被用于鉴定早孕和足月人胎盘绒毛内的干细胞龛。这包括针对周细胞表面标志物 STRO-1 和 3G5 的抗体，这些抗体已被用于鉴定其他组织中的间充质干细胞，但尚未在胎盘组织中研究过。从足月人胎盘分离出 PMSC，并通过其在未经处理的塑料培养器皿上生长的能力、形成克隆（即克隆形成能力）的能力以及分化为脂肪细胞、软骨细胞和成骨细胞的能力证明其具有干细胞特性。Western 分析证实 STRO-1 和 3G5 存在于胎盘蛋白提取物和 PMSC 中。免疫细胞化学显示 PMSC 对 MSC 细胞表面标志物（STRO-1、3G5、CD105、CD106、CD146、CD49a、α-SMA）呈阳性，对造血干细胞标志物（CD117、CD34）和内皮标志物（CD34、vWF）呈阴性。用针对早孕和足月组织 MSC 细胞表面标志物的抗体进行免疫组织化学染色显示 PMSC 的血管龛。用 STRO-1 抗体染色与内皮细胞标志物 vWF 的双重免疫荧光分析进行比较，发现染色没有明显重叠。这表明一些 PMSC 具有周细胞样表型。我们提出，血管龛内蕴藏着一群 PMSC，它们可以产生用于组织维持和修复的定向祖细胞，并且 PMSC 有助于血管成熟和稳定。
