人牙髓干细胞体外分选分化的初步实验研究

目的体外培养人牙髓细胞，分选牙髓干细胞并诱导其分化。方法选择因正畸目的而拔除的健康完整双尖牙，酶消化法进行牙髓细胞培养，并进行来源鉴定。单抗Stro-1标记牙髓干细胞、免疫磁珠分选系统进行分选。矿化液定向诱导分选后的牙髓干细胞，比较诱导前后stro-1染色及改良Gomori钙钴法染色检测碱性磷酸酶（ALP）的改变。结果体外培养人牙髓细胞呈成纤维细胞样，抗波形丝蛋白染色阳性，抗角蛋白染色阴性。牙髓干细胞Stro-1检测阳性，牙髓细胞中干细胞阳性率约为10％。矿化诱导后细胞stro-1阴性、ALP阳性表达。结论采用免疫磁珠分选系统分离出人牙髓干细胞，初步验证干细胞分化潜能，为其后续生物学特性研究提供实验基础。

Preliminary Study of Human Dental Pulp Cells Culturing in vitro

Objective To isolate dental pulp stem cells(DPSCs)from human dental pulp cells (HDPCs)in vitro and examine their potential tO differentiate into osteoblast-like cells.Methods HDPCs were separated and cultured from dental pulp of youngman healthy premolars extracted for orthodontic purpose.Vimentin and cytokeratin expression were examined by immunocytochemical staining.DPSCs were isolated from cultured HDPCs by magnetic-activated cell sorting,S(MACS)indirect magnetic celllabeling and positive selection strategy with antibody Stm-1,and then they were induced to differentiation by mineralizing culture medium.The expression of Stro-1 and Alkaline phosphatase(ALP)were evaluated before and after induction.Resuits The cultured cells appeared to be fibroblast-like cells,staining positive for vimentin and negative for cytokeratin.The rate of human dental pulp-derived Stro-1+cells was about 10%.DPSCs demonstrated no expression of Stro-1 but strong expression of ALP after induced differentiation with conditional medium.Conclusions MACS may be the effective way to isolate DPSCs,which with differentiation potential.