人牙周膜干细胞的分离鉴定及骨形态发生蛋白-2对其趋化效应的研究

目的研究人牙周膜干细胞（PDLSCs）对骨形态发生蛋白-2（BMP-2）的趋化反应。方法通过有限稀释法分离、培养人PDLSCs,利用免疫荧光染色检测人PDLSCs波形丝蛋白及干细胞表面标志物STRO-1的表达,检测人PDLSCs多向分化能力,通过克隆形成实验和5-溴-2-脱氧尿嘧啶核苷（BrdU）共培养的方法检测其干细胞特性。利用24孔的Transwell细胞培养室来检测人PDLSCs对BMP-2的趋化反应,光镜下计迁移至滤膜下侧面的不同视野的细胞数。结果人PDLSCs抗波形丝蛋白染色阳性,表达干细胞表面标志物STRO-1,体外诱导培养的人PDLSCs能够向成骨细胞和成脂细胞分化,具有较高的自我更新能力,并在体外呈克隆状生长。在100、200 ng·mL-1 BMP-2实验组,Transwell细胞培养室中迁移的细胞数目显著多于空白对照组（P<0.01）。结论BMP-2对人PDLSCs有趋化效应。

Culturing and characterization of human periodontal ligament stem cells and investigating their chemotactic responses to bone morphogenetic protein-2

Objective To investigate the chemotactic response of human periodontal ligament stem cells(PDLSCs) to bone morphogenetic protein-2(BMP-2).Methods Human PDLSCs were obtained from clinically healthy premolars extracted for orthodontic reasons and used to isolate PDLSCs by limited dilution method.The expression of Vimentin and stem cell marker STRO-1 on PDLSCs were demonstrated with immunocytochemical staining.Differentiation assay was used to detect the differentiation potential of PDLSCs.Cloning formation experiment and 5-bromo-2-deoxyuridine(BrdU) incorporation assay were used to determine the stem cell characteristics of PDLSCs.The chemotactic effect of BMP-2 on PDLSCs was detected by using a 24-multiwell Transwell cell culture chamber.The number of net migrated cells was counted in different microscope fields.Results Human PDLSCs displayed positive staining for Vimentin and expressed the stem cell marker STRO-1.These cells differentiated into osteoblasts and adipocytes under defined culture conditions,possessed high self-renewal potential and formed single-cell colonies in vitro.The number of cells migrating at concentrations of 100,200 ng·mL-1 of BMP-2 in Transwell cell culture chamber was significantly higher than that of negative control(P<0.01).Conclusion BMP-2 may participate in regulating chemotaxis of human PDLSCs.