p75神经营养受体阳性外胚间充质干细胞的体外获取与生物学特性研究

The capacity and biological characteristic of the p75 neurotrophin receptor-positive ectomesenchymal stem cell in vitro

目的 研究鼠胚胎颌面组织中外胚间充质干细胞（ectomesenchymal stem cells,EMSC）的生物学特性,探讨p75＋EMSC的体外分化及影响因素,为揭示牙齿发生、发育机制提供实验依据.方法 通过提取12.5 d SD鼠胚胎颌面组织,用免疫荧光染色方法显示EMSC的迁移位置;用p75神经营养因子受体标记EMSC,通过流式细胞技术分选出p75＋EMSC,并检测细胞周期和干细胞相关细胞表面抗原.结果 免疫荧光染色结果说明颅神经嵴源性干细胞在鼠胚胎12.5 d迁移到颌突中.p75＋EMSC的阳性分选率为6.1％,细胞呈均匀成纤维细胞形态,生长曲线呈“S”型,在传代过程中S期的比例稳定.细胞特异性标志物CD29、CD146、Stro-1标记p75＋EMSC,其在p75＋EMSC中的表达均较高（＞90％）.结论 SD鼠受孕12.5 d时,胚胎的牙齿启动尚未发生;分选后的p75＋EMSC在传代过程中具有稳定的增殖能力和干细胞特征,尚未开始分化.

Objective To investigate the biological characteristic of ectomesenchymal stem cells （EMSC） and the differentiation of p75＋EMSC and influencing factors.Methods The immunohistochemical staining method was used to observe the migration of EMSC from 12.5 d SD rat embryonic facial process.Then EMSC was labeled by p75 neurotrophin receptor,and the cell cycle and stem cell surface antigens of the p75 ＋ EMSC was examined.Results Immunohistochemical staining showed that stem cells from the cranial neural crest migrated to embryonic rat facial process at 12.5 days.The sorting rate of the p75＋EMSC was 6.1%.The proportion of the p75 ＋EMSCs＇ S/G2/M phase was stable during subculture.The special substances CD29,CD146 and Stro-1 were marked for p75 ＋EMSC,and the expressions of the markers were all higher（〉90%） in p75＋EMSC.Conclusions The embryonic tooth did not start to grow on the conception 12.5 days of SD rats.The p75 ＋ EMSC after sorting had stable proliferation ability and had stem cell characteristics during subculture and didn＇t start differentiation.