Lin N-H, Menicanin D, Mrozik K, Gronthos S, Bartold P M
School of Dentistry, University of Adelaide, Adelaide, SA, Australia.
J Periodontal Res. 2008 Oct;43(5):514-23. doi: 10.1111/j.1600-0765.2007.01061.x. Epub 2008 Jul 4.
Human postnatal stem cells have been identified in periodontal ligament, with the potential to regenerate the periodontium in vivo. However, it is unclear if periodontal ligament stem cells are present in regenerating periodontal tissues. The aim of this study was to identify and localize putative stem cells in block biopsies and explant cultures of regenerating human periodontal tissues.
Guided tissue regeneration was carried out on the molars of three human volunteers. After 6 wk, the teeth with the surrounding regenerating tissues and bone were surgically removed and processed for immunohistochemistry. The mesenchymal stem cell-associated markers STRO-1, CD146 and CD44 were used to identify putative stem cells. Cell cultures established from regenerating tissue explants were analysed by flow cytometry to assess the expression of these markers. Mineralization, calcium concentration and adipogenic potential of regenerating tissue cells were assessed and compared with periodontal ligament stem cells, bone marrow stromal stem cells and gingival fibroblasts.
STRO-1(+), CD44(+) and CD146(+) cells were identified in the regenerating tissues. They were found mainly in the paravascular and extravascular regions. Flow cytometry revealed that cultured regenerating tissue cells expressed all three mesenchymal stem cell associated markers. The regenerating tissue cells were able to form mineral deposits and lipid-containing adipocytes. However, the level of mineralization in these cells was lower than that of periodontal ligament stem cells and bone marrow stromal stem cells.
Cells with characteristics of putative mesenchymal stem cells were found in regenerating periodontal tissues, implying their involvement in periodontal regeneration.
人出生后的干细胞已在牙周韧带中被鉴定出来，具有在体内使牙周组织再生的潜力。然而，目前尚不清楚再生的牙周组织中是否存在牙周韧带干细胞。本研究的目的是在再生的人牙周组织的块状活检标本和外植体培养物中鉴定并定位假定的干细胞。
对三名人类志愿者的磨牙进行引导组织再生。6周后，手术切除带有周围再生组织和骨的牙齿，并进行免疫组织化学处理。使用间充质干细胞相关标志物STRO-1、CD146和CD44来鉴定假定的干细胞。对从再生组织外植体建立的细胞培养物进行流式细胞术分析，以评估这些标志物的表达。评估再生组织细胞的矿化、钙浓度和成脂潜力，并与牙周韧带干细胞、骨髓基质干细胞和牙龈成纤维细胞进行比较。
在再生组织中鉴定出STRO-1(+)、CD44(+)和CD146(+)细胞。它们主要位于血管旁和血管外区域。流式细胞术显示，培养的再生组织细胞表达所有三种间充质干细胞相关标志物。再生组织细胞能够形成矿化沉积物和含脂质的脂肪细胞。然而，这些细胞中的矿化水平低于牙周韧带干细胞和骨髓基质干细胞。
在再生的牙周组织中发现了具有假定间充质干细胞特征的细胞，这意味着它们参与了牙周再生。
