诱导颅神经嵴细胞向第一鳃弓外胚间充质细胞分化的实验研究

目的 研究体外成纤维细胞生长因子8(FGF-8)对颅神经嵴细胞向第一鳃弓表型分化的影响，并确立其时相效应，为进一步探讨颅神经嵴细胞的牙颌向分化诱导提供实验依据。方法 组织块法无血清条件培养颅神经嵴细胞，通过同源盒基因Hoxa2原位杂交及波形蛋白免疫细胞化学染色，观察不同剂量FGF-8对颅神经嵴细胞迁出前、后及其向第一鳃弓外胚间充质细胞表型分化的影响。结果 迁出前颅神经嵴细胞在100μg／LFGF-8作用下，呈现Hoxa2阴性表达、波形蛋白阳性表达，迁出后颅神经嵴细胞诱导组及对照组Hoxa2、波形蛋白表达均为阳性。结论 FGF-8可诱导颅神经嵴细胞向第一鳃弓外胚间充质细胞表型分化，具有早期诱导时相性特征。

In vitro study on cranial neural crest differentiating into ectomesenchymal cell of the first branchial arch by FGF-8

Objective To investigate the effects of FGF-8 on cranial neural crest cell(CNCC) differentiating into ectomesenchymal cell of the first branchial arch , and determine the appropriate dose and stage of CNCC exposure to FGF-8.Methods Cranial neural crest explants were cultured in free-serum medium containing modified DMEM/F12 and different doses of FGF-8.The differentiation type of CNCC were determined by in situ hybridization for Hoxa2 and immunocytochemistry for vimentin. Results Pre-emigrating CNCC demonstrated the negative Hoxa2 stain and positive vimentin stain after treated by 100 ug/ FGF-8 . Both post-emigrating CNCC group and contral group were positive for Hoxa2 and vimentin stain.Conclusions On the early stage of CNCC emigration, the first branchial arch phenotype of CNCC could be induced by FGF-8.This experiment could provide in vitro model for study on the mechanism of tooth-jaw regeneration.