Department of Orthodontics, Okayama University Hospital, Kita-ku, Japan.
Differentiation. 2010 Feb;79(2):74-83. doi: 10.1016/j.diff.2009.10.005. Epub 2009 Nov 27.
The periodontal ligament (PDL) comprises adult stem cells, which are responsible for periodontal tissue regeneration. In the present study, we investigated the specific profile of the stem cells in the human PDL. Microscopic analysis demonstrated that PDL cells showed a fibroblastic appearance, forming flat and loose aggregates. PDL cells expressed embryonic stem cell-associated antigens (SSEA-1, SSEA-3, SSEA-4, TRA-1-60, TRA-1-81, OCT4, NANOG, SOX2, and REX1, and alkaline phosphatase activity), as well as conventional mesenchymal stem cell markers. When PDL cells were cultured in the presence of all-trans-retinoic acid, the numbers of SSEA-3+ and SSEA-4+ PDL cells were significantly decreased, while that of SSEA-1+ was increased. SSEA-4+ PDL cells showed a greater telomere length and growth rate. SSEA-4+ PDL cells exhibited the potential to generate specialized cells derived from three embryonic germ layers: mesodermal (adipocytes, osteoblasts, and chondrocytes), ectodermal (neurons), and endodermal (hepatocytes) lineages. Our findings demonstrated that SSEA-4, a major antigen to distinguish human embryonic stem cells, could also be used to identify multipotent stem cells in the PDL. Hence, SSEA-4+ human PDL cells appear to be a promising source of stem cells for regenerative medicine.
牙周韧带（PDL）包含成体干细胞，这些细胞负责牙周组织再生。在本研究中，我们研究了人牙周韧带中干细胞的特定特征。显微镜分析表明，PDL 细胞呈成纤维细胞样外观，形成扁平而疏松的聚集物。PDL 细胞表达胚胎干细胞相关抗原（SSEA-1、SSEA-3、SSEA-4、TRA-1-60、TRA-1-81、OCT4、NANOG、SOX2 和 REX1，以及碱性磷酸酶活性）以及常规间充质干细胞标志物。当 PDL 细胞在全反式视黄酸存在下培养时，SSEA-3+和 SSEA-4+PDL 细胞的数量明显减少，而 SSEA-1+的数量增加。SSEA-4+PDL 细胞具有更长的端粒长度和更高的增长率。SSEA-4+PDL 细胞具有分化为三个胚胎胚层来源的特化细胞的潜力：中胚层（脂肪细胞、成骨细胞和软骨细胞）、外胚层（神经元）和内胚层（肝细胞）谱系。我们的研究结果表明，SSEA-4 是区分人胚胎干细胞的主要抗原，也可用于鉴定牙周韧带中的多能干细胞。因此，SSEA-4+人牙周韧带细胞似乎是再生医学中干细胞的有前途来源。
