I型成纤维细胞生长因子受体（FGFR1）在腭发育中的作用机制研究

Cleft palate is the most common congenital craniofacial defect in human. Emerging evidence demonstrates that several related signal pathways are important in regulating palate development. In the palate, FGF and FGFR isoforms are expressed in a highly spatiotemporally specific manner and constitute a directional regulatory axis between the stromal and epithelial compartments, regulating palate development. FGFR1 mutation in human has been found to be associated with cleft palate. Neural crest cell derived mesenchymal cells constitute the major cell population in palate shelves, FGFR1 is highly expressed in mesenchymal cells.Yet, to date, the majority of studies have been focused on the FGF7/10-FGFR2 signaling axis that directionally mediated the mesenchyme to epithelium interaction. How FGF signaling, especially that mediated by FGFR1, in the CNC cells regulates palate formation is not understood. Our preliminary data showed that the tissue specific ablation of Fgfr1 with Wnt1Cre in neural crest cells caused completely cleft primary and secondary palates as well as cleft lip were readily seen in embryos in Fgfr1 knockout mice. Based on our previous study, we will further investigate how Fgfr1 deletion leads to cleft palate and to unreveal the molecular mechanism by which Fgfr1 regulate palatogenesis.

腭裂是最常见的先天性头面部畸形，最近研究表明多种基因信号通路在调节腭发育中发挥着重要作用。FGF和FGFR在腭中的表达存在着高度时空特异性，以此来调节腭发育，FGFR1突变是引起腭裂的原因之一。神经嵴来源间质细胞是形成腭的主要细胞，FGFR1主要在间质细胞表达。迄今为止，对腭发育的研究主要集中在介导间质上皮相互作用的FGF7/10-FGFR2信号轴上，对于FGF信号特别是FGFR1介导神经嵴来源间质细胞调节腭形成的分子机制仍然不是非常清楚。为了深入探讨FGFR1在腭发育中重要作用及其引起腭裂产生的具体机制，我们利用Cre/LoxP条件敲除系统在神经嵴细胞中特异性敲除Fgfr1，小鼠在胚胎期即表现出明显唇腭裂表型及其他多种头面部缺陷。本项目拟在前期工作基础上，进一步深入研究Fgfr1敲除对腭裂产生的具体机制，探讨Fgfr1影响颌面部尤其腭部发育的调控机理，为腭发育的基因研究提供新的科学依据。

腭裂是最常见的先天性头面部畸形，最近研究表明多种基因信号通路在调节腭发育中发挥着重要作用。FGF和FGFR在腭中的表达存在着高度时空特异性，以此来调节腭发育，FGFR1突变是引起腭裂的原因之一。神经嵴来源间质细胞是形成腭的主要细胞，FGFR1主要在间质细胞表达。迄今为止，对腭发育的研究主要集中在介导间质上皮相互作用的FGF7/10-FGFR2信号轴上，对于FGF信号特别是FGFR1介导神经嵴来源间质细胞调节腭形成的分子机制仍然不是非常清楚。我们研究发现，Wnt1Cre的转基因鼠与Fgfr1flox小鼠杂交特异性敲除神经嵴细胞Fgfr1，导致了小鼠唇腭裂及其他严重头面部缺陷。在本项目中，我们选择不同胚胎时期组织样品进行基因型检测，根据PCR结果将胚胎分为对照组和Fgfr1敲除组，比较神经嵴细胞Fgfr1敲除对小鼠腭突生长发育的影响。提取E10.5胚胎RNA进行相关基因的检测，分析可能的信号分子或调节因子的变化。H&E染色观察神经嵴细胞Fgfr1敲除不同时期腭突前部和后部形态的变化，免疫荧光染色检测Fgfr1敲除后腭突上皮细胞和间质细胞增殖、凋亡变化， 腭突体外培养观察组织体外融合情况，腭突上皮细胞标记蛋白分析神经嵴细胞Fgfr1对腭突上皮细胞完整性的影响。荧光定量PCR分析神经嵴细胞Fgfr1敲除对腭突发育过程中重要信号通路的影响。明确Fgfr1调控颌面部尤其腭部发育的调控机理，为腭发育的基因研究提供新的科学依据。