牙胚组织中可分离得到大量间充质干细胞

A large mass of mesenchymal stem cells isolated from tooth germs

背景:已经有研究从牙髓、牙囊和牙周组织中分离得到间充质干细胞。牙胚是牙的前体,能否从中直接分离间充质干细胞,目前未知。目的:从人流产胎儿牙胚中分离间充质干细胞,检测其生物学特征。方法:无菌条件下挖出水囊流产胎儿牙床中的整个牙胚,剪碎后分别用胶原酶Ⅱ和胰酶消化,过滤除去颗粒物后,细胞悬液用培养液洗涤,培养、扩增得到贴壁细胞,进行细胞形态学观察、免疫表型测定和多向分化功能鉴定。结果与结论:经过3次传代后,从单个胎儿牙胚中即可获得超过107形态均匀的、梭形贴壁细胞,其表达CD105、CD73、CD90和CD44等表面标志,不表达CD34、CD45标志;在体外向成骨、成脂分化,在体内可以分化为软骨细胞。提示用贴壁法可从人胎儿牙胚中分离得到大量的间充质干细胞。

BACKGROUND：Mesenchymal stem cells have been isolated from dental tissues such as the dental pulp,the dental follicle and the periodontal ligament.It is unclear whether mesenchymal stem cells can be isolated directly from tooth germs,the tooth precursors.OBJECTIVE：To isolate mesenchymal stem cells from tooth germs of aborted fetuses and to detect their biological characteristics.METHODS：The tooth germs were dug out entirely from fetal alveolar ridge aseptically.They were cut into small pieces and digested with collagenase Ⅱ and trypsin successively.After filtering the pieces out,the cells were washed and cultured.The expanded adherent cells were studied.Cell morphology,immunophenotype and multi-potential differentiation were analyzed.RESULTS AND CONCLUSION：After 3 passages,more than 107 homogenous,spindle-shaped adherent cells were obtained from one fetal tooth germ.These cells expressed the markers of CD105,CD73,CD90 and CD44,but they did not express CD34 and CD45.They could differentiate into osteoblasts and adipocytes in vitro,and chondrocytes in vivo.Mesenchymal stem cells can be isolated from fetal tooth germs by plastic adherence.