解離的小鼠牙胚上皮細胞在重聚發(fā)育過程仍維持牙齒發(fā)育基因的表達

胡雪峰，林陳勝，王冰梅，韓萍萍，張彥定

福建師范大學生命科學學院 福建省發(fā)育與神經(jīng)生物學重點實驗室，福州 350108

組織工程與細胞培養(yǎng)

解離的小鼠牙胚上皮細胞在重聚發(fā)育過程仍維持牙齒發(fā)育基因的表達

胡雪峰，林陳勝，王冰梅，韓萍萍，張彥定

福建師范大學生命科學學院 福建省發(fā)育與神經(jīng)生物學重點實驗室，福州 350108

為了解牙胚細胞解離重聚過程的細胞形態(tài)和分子機制，將小鼠帽狀期牙胚解離細胞重聚，移植到小鼠腎囊膜下培養(yǎng)，組織切片，HE染色，觀察再生牙齒的形態(tài)發(fā)生過程，并用原位雜交的方法進一步檢測了與牙上皮發(fā)育密切相關的基因在再生牙上皮中的表達情況。結果發(fā)現(xiàn)，解離重聚的牙胚細胞在牙齒器官的再生過程重現(xiàn)了正常牙齒的形態(tài)發(fā)生過程；解離的牙上皮細胞在重聚和再生過程中保持Fgf8、Noggin和Shh等牙上皮發(fā)育基因表達。以上結果表明，即便是被解離形成分散狀態(tài)的牙上皮細胞，在與牙胚間充質(zhì)細胞重新聚合后，仍保持牙向分化的潛能。該結果為理解牙齒再生的機理提供新的實驗數(shù)據(jù)，對利用干細胞進行牙齒再生的研究有重要的提示意義。

牙齒再生，細胞重聚，牙上皮，基因表達

Abstract:Generation of bio-engineered teeth by using stem cells will be a major approach for bioengineered implantation.Previous studies have demonstrated that dissociated tooth germ cells are capable of generating a tooth after reaggregationin vitro.However, the cellular and molecular mechanisms underlying this tooth regeneration are not clear. In this study, we dispersed E13.5 molar germ into single cells, immediately reaggregated them into cell pellet, then grafted the reaggregates under mouse kidney capsule for various times of culture. We investigated the morphogenesis and the expression of several developmental genes in dental epithelial cells in reaggregates of tooth germ cells. We found that dissociated tooth germ cells, after reaggregation, recapitulated normal tooth developmental process. In additon, dissociated dental epithelial cells retained the expression ofFgf8,Noggin, andShhduring reaggregation and tooth regeneration processes. Our results demonstrated that, despite of under dissociated status, dental epithelial cells maintained their odontogenic fate after re-aggregation with dental mesenchymal cells. These results provided important information for futurein vitrogeneration of bio-engineered teeth from stem cells.

Keywords:tooth regeneration, reaggregation, dental epithelium, gene expression

在組織工程研究領域中，牙齒再生技術的建立已經(jīng)成為該領域引人注目的發(fā)展方向[1-6]。有關牙齒再生的研究已有多年的嘗試。將兔子切牙牙胚的上皮和間充質(zhì)打散后，植入到雞胚的尿蘘絨毛膜上培養(yǎng)，這些分散的細胞可以重新聚集起來，形成發(fā)育良好的牙齒結構[7]。……