伴侣分子AnxA6调节孕晚期胎脑白质发育形成作用机制的研究

项目名称： 伴侣分子AnxA6调节孕晚期胎脑白质发育形成作用机制的研究

项目编号： No.31471148

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 生理学与整合生物学

项目作者： 李红丽

作者单位： 中国人民解放军第三军医大学

项目金额： 84万元

中文摘要： 孕晚期胎脑白质发育不良与神经祖细胞(NPCs)增殖分化能力受抑制有关。已明确非经典Wnt/Ryk通路参与NPCs分化调节，但如何调控实现向少突胶质细胞(OLs)分化及所涉及的具体分子机制知之甚少。本课题前期预实验观察到OLs分化中伴侣分子Annexin A6(AnxA6)是Ryk相互作用蛋白；生物信息学预测AnxA6具有EFhand结构域特征；高表达Ryk的NPCs分化OLs比例增多且伴钙敏感受体的表达增加。我们推测：AnxA6可能作为Ryk调控子与Ca2+协同影响Ryk活性和其核浆分布，启动下游基因参与NPCs向OLs分化。本项目将采用生物信息预测模拟技术、RNAi技术和胚胎电转染等技术，从离体和在体两方面，明确AnxA6的EFhand结合域对Ryk调控NPCs向少突分化中的协同作用和影响机制。阐明AnxA6/Ca2+与Wnt/Ryk信号通路间的调控机制，为防治白质发育不良提供实验依据。

中文关键词： 神经祖细胞；胎脑白质；胚胎发育；EF-手样结构域；信号通路

英文摘要： Inhibited proliferation and differentiation of neural progenitor cells (NPCs) has been implicated in the maldevelopment of white matter during the third trimester of pregnancy. Evidences have shown that the noncanonical Wnt/Ryk (receptor related to tyrosine kinase) signaling pathway participates in differentiation of NPCs, However, the mechanisms of Ryk regulates the differentiation of NPCs into oligodendrocytes (OLs) are still unclear. Our preliminary experiment results show that the nuclear membrane chaperone molecule annexin A6(AnxA6) interact with the Ryk protein. AnxA6 has a typical structure features of EF-hand motif (Ca2+-binding domain) by using Bioinformatics approaches prediction. The number of differentiated OLs from Ryk overexpression NPCs was found increase, and the expression of calcium sensing receptor also showed higher level than the normal control. Therefore, we hypothesize that AnxA6 may play a key role of molecular chaperone in cooperating with Ca2+ to regulate the nucleoplasm distribution of Ryk, as well as accelerate the transcription of the downstream target genes during NPCs differentiation into OLs. In this project, we will utilize Bioinformatics spatial analysis, RNAi knockdown and embryo electric transfection technology to determine whether AnxA6 synergizes with Ryk to regulate NPCs differentiation and promote the development of OLs in vitro and in vivo. This research results gained from the proposed studies will identify the function of the annexin in the development of the embryological nervous system and illuminate the molecular (or pathogenic) mechanisms of the AnxA6/ Ca2+ interacte with Wnt/Ryk signaling pathway during fetal neurogenesis, and provide the theoretical and experimental basis for preventing and treating the abnormal development of white matter.

英文关键词： neural progenitor cells;fetal brain white matter;embryonic development;EF-hand motif;Signaling pathway