成纤维细胞生长因子信号调控早期鸡胚胎神经嵴细胞的迁移

Fibroblast growth factor signaling regulates the delamination and migration of neural crest cells in the early chick embryos

目的利用Sprouty2基因阻断成纤维细胞生长因子(FGF)信号,探讨FGF在早期鸡胚胎发育过程中对神经嵴细胞迁移的影响及其机制。方法通过体内培养的方法孵育鸡胚至HH9期,通过显微注射的方法将Sprouty2-绿色荧光蛋白(GFP)质粒注射入神经管腔内。实验侧使用电穿孔转染的方法转染胚胎半侧神经管,另一侧正常神经管设为对照侧。采用神经嵴细胞特异标记物HNK1免疫荧光的方法检测Sprouty2基因阻断FGF信号后是否影响胚胎头部和躯干部神经嵴细胞的迁移过程。随后,进一步通过检测神经细胞钙黏分子N-Cadherin的表达来观察细胞之间黏附作用的改变。结果 HNK1免疫荧光检测结果显示,Sprouty2转染侧即阻断FGF信号通路后,HNK1在早期鸡胚胎的头部和躯干部的表达量均比对照侧的表达量增多;而神经细胞钙黏分子N-Cadherin检测结果表明,Sprouty2转染侧和正常对照侧N-Cadherin在头部和躯干部神经管上表达量的差异均无显著性。结论 Sprouty2基因阻断FGF信号后,促进了早期鸡胚胎神经嵴细胞的迁移,但是FGF信号对此过程的影响可能不是由神经钙黏分子N-Cadherin介导的。

Objective To investigate the effect of FGF on the migration of the neural crest cell in early chick embryos after blocking FGF signaling with Sprouty2. Methods The chick embryos were incubated in vivo until HH9, Sprouty2 green fluorescent protein（GFP） plasmid was injected into the lumen of the neural tube using microinjection, and in vivo electroporation was performed to transfect Sprouty2-GFP at a half-side of the neural tube while another half-side was used as the control side. We employed the immunofluorescence staining method to detect the HNKl-positive neural crest cell, specially labeled dorsal-ventrally, in order to determine whether Sprouty2 over-expression affects the delamination and migration of cranial and trunk neural crest cells. We studied if the FGF-related neural crest cell migration induced by Spourty2 transfection was controlled by regulating Ca＋22-dependent N-Cadherin expression. Results The blocking FGF signaling via transfected Sprouty2-GFP resulted in more HNKl-positive neural crest ceils in Sprouty2-GFP transfected side than in the control side in both cranial and trunk regions of the early chick embryos. The N-Cadherin expression did not significantly affected by Sprouty2-GFP transfection. Conclusion The blocking FGF signaling using Sprouty2 promotes the neural crest cell delamination in the early chick embryos. However, N-Cadherin may not have the impact of FGF signaling on neural crest cell migration, on which further studies are required.