牙胚细胞条件培养液诱导大鼠胚胎面突外胚间充质细胞向成牙本质样细胞分化

目的：探讨牙胚细胞条件培养液（TGC—CM）在诱导面突外胚间充质细胞向成牙本质样细胞分化中的作用。方法：取妊娠12．5d SD大鼠胎鼠第4代下颌突外胚间充质细胞，在牙胚细胞条件培养液（TGC—CM）的诱导下，通过形态学观察、免疫组化、RT—PCR等方法，探索牙胚细胞条件培养液诱导面突外胚间充质细胞向成牙本质样细胞分化的可能。结果：面突外胚间充质细胞在诱导培养基中生长良好。培养7d，在诱导组中细胞出现核极化，有很长的突起，细胞平行排列。抗牙本质涎蛋白（DSP）呈阳性反应。RT—PCR显示mRNA水平表达成牙本质细胞特异的牙本质涎磷蛋白（DSPP）和牙本质基质蛋白-1（DMP-1）。结论：面突外胚间充质细胞在含有多种细胞因子的TGC—CM的作用下能分化为成牙本质样细胞，能为研究牙齿的分化和发育提供良好的模型和实验依据。

Differentiation of Ectomesenchymal Cells Into Odontoblast-like Cells Induced by Tooth Germ Cell Conditioned Medium

Objective:To investigate the possibility and procedure of ectomesenchymal cells differentiating into odontoblast-like cells induced by tooth germ cells conditioned medium(TGC-CM).Methods:Rat ectomesenchymal cells of E12.5 Sprague-Dawley rat facial processes were isolated and co-cultured in tooth germ cells conditioned medium.The changes of cells were observed morphologically and immunohisto-chemically.RT-PCR was used to identify the expression of DSPP and DMP.Results:7 days after induction with TGC-CM,some cells were tall columnar and polarized with long processes which tended to align themselves in straight parallel line.The cells expressed dentin sialoprotein(DSP) in immunohistological assay.RT-PCR showed the cells expressed specific dentin sialophosphoprotein(DSPP) and dentin matrix protein 1(DMP 1).Conclusion:The results showed that TGC-CM contained multiple cytokine could create an odontogenic microenvironment and induce ectomesenchymal cells into odontoblast-like cells.