中文摘要：

目的：分析人牙周膜干细胞（PDLSCs）的表型特点,为分离、鉴定和应用PDLSCs提供有效途径。方法：采用免疫磁珠法分离PDLSCs,制备细胞爬片。分别采用免疫荧光、免疫细胞化学染色法检测PDLSCs表面蛋白STRO-1、CD44、Vimentin、CK、COL-I、BSP的表达。收集PDLSCs,采用RT-PCR法检测PDLSCs Scleraxis mRNA、ColⅠ及CAP mRNA的表达情况。结果：PDLSCs表达间充质干细胞表面标志STRO-1、CD44,强阳性表达间充质来源细胞表面蛋白Vimentin,弱表达Col-I,不表达上皮细胞标志蛋白CK、成骨细胞相对特异性蛋白BSP。RT-PCR也显示PDLSCs表达韧带组织特异性基因Scleraxis和Col-I,不表达成牙骨质细胞特异性蛋白CAP。结论：本实验所分离的PDLSCs具有间充质来源的、牙周组织特异性的、未分化细胞的表型特点,该特点可作为PDLSCs分离和鉴定的重要依据。

英文摘要：

Objective： To analyze the pbenotypic characteristics of human periodontal ligament stem cells（PDLSCs）, andto provide new way for understanding and further application of PDLSCs. Materials and Methods. PDLSCs were isolated using an immunomagnetic bead selection system. The slides of the cells were prepared and immunofiuorescence and immunocytochemical straining were performed to detect the expression of specific proteins including STRO-1, CD44, Vimentin, CK, COL-I, BSP, respectively. In addition, PDLSCs were collected to detect the the gene expression of Scleraxis mRNA, Col I mRN and CAP mRNA by RT-PCR techniques. Results： PDLSCs expressed the surface markers of mesenchymal stem cells such as STRO-1 and CD44, and positively expressed the specific proteins of cells originated from mesenchymal tissue including Vimentin, weakly expressed CoL-I, and negatively expressed the CK which is expressed specially in epithelial cells. PDLSCs were also negatively expressed the marker of osteocytes of BSP. Results from RT-PCR showed that these cells positively expressed the specific marker of tendon tissue-Scleraxis, specific marker of membrane-Collagen I, and negatively expressed the specific marker of cementocyte-CAP. Conclusion： PDLSCs isolated by immunomagnetic bead selection system in this study showed the phenotypes of mesenchymal origination, periodontal specificity and undifferentiated cells. These characteristics may provide important evidences for isolation, identification, and futher application for PDLSCs.