Singhatanadgit Weerachai, Donos Nikolaos, Olsen Irwin
Periodontology Unit, Division of Clinical Research, UCL Eastman Dental Institute, University College London, London, United Kingdom.
Tissue Eng Part A. 2009 Sep;15(9):2625-36. doi: 10.1089/ten.TEA.2008.0442.
Cells derived from the periodontal ligament (PDL) have previously been reported to have stem cell-like characteristics and to play an important part in re-building damaged tissue, including alveolar bone. However, these populations have been heterogeneous, and thus far no highly purified periodontal stem cell (PSC) clone has yet been established from adult human PDL tissue. The present study was therefore carried out to isolate single cell-derived PDL clones and to delineate their phenotypic and functional characteristics. In this report we have obtained four homogeneous and distinct clones--namely, C5, C6, C7, and C8--and have found these to be highly proliferative and to express the stromal cell markers CD29 and CD44. In particular, C7 showed stem cell-like characteristics of small cell size with reduced cytoplasm, clonogenicity, and multilineage potential, including osteogenic activity in forming bone-like tissue in organoid micromass cultures. Clones C5 and C6 possessed osteoprogenitor features with mineralized matrix-forming activity, whereas C8 did not undergo osteogenic, adipogenic, or chondrogenic differentiation. The present study thus reports, for the first time, the isolation and cellular and molecular characterization of highly purified putative PSC and osteoprogenitors in adult human PDL, based on clonogenicity and multilineage differentiation potential, with PSC-C7 capable of bone formation in vitro, suggesting that such cells may have potential value for stem cell-based bone tissue engineering in vivo.
先前有报道称，源自牙周膜（PDL）的细胞具有干细胞样特征，并在包括牙槽骨在内的受损组织重建中发挥重要作用。然而，这些细胞群体具有异质性，迄今为止，尚未从成人PDL组织中建立高度纯化的牙周干细胞（PSC）克隆。因此，本研究旨在分离单细胞来源的PDL克隆，并描述其表型和功能特征。在本报告中，我们获得了四个同质且不同的克隆，即C5、C6、C7和C8，并发现它们具有高度增殖性，且表达基质细胞标志物CD29和CD44。特别是，C7表现出干细胞样特征，细胞体积小，细胞质减少，具有克隆形成能力和多向分化潜能，包括在类器官微团培养中形成骨样组织的成骨活性。克隆C5和C6具有成骨祖细胞特征，具有矿化基质形成活性，而C8未发生成骨、成脂或成软骨分化。因此，本研究首次报道了基于克隆形成能力和多向分化潜能，从成人PDL中分离出高度纯化的假定PSC和成骨祖细胞，并对其进行细胞和分子特征分析，其中PSC-C7能够在体外形成骨，这表明此类细胞可能在体内基于干细胞的骨组织工程中具有潜在价值。
