wnt/β-catenin通路与caveolin1串话在脑缺血后神经再生的作用及补阳还五汤的影响

Endogenous neurogenesis after cerebral ischemia is an important aspect of the nerve repair after cerebral ischemia, and regulated by many intracellular and extracellular cell factors. Caveolin1 (Cav1) is a key protein for signal transduction between intracellular and extracellular, In the previous fund we confirmed that Cav1 can reduce injury and promote the neural function recovery and neural regeneration after cerebral ischemic, Buyanghuanwu Decoction(BYHWD) can regulate nerve regeneration and Cav1 expression after cerebral ischemia, otherwise Cav1 can affect DKK1 (a wnt inhibitor) expression, but the molecular mechanism is not clear.Wnt pathway is a key signal of cell proliferation and differentiation and involved in brain ischemia injury and nerve regeneration, and can be regulated by Cav1 through its receptor or directly combined with it, there is crosstalk between Cav1 and WNT, So in this study we will explore the role of crosstalk Cav1 and WNT/β-catenin on neurogenesis and the mechanism of BYHWD using transgenic animals, stem cells, immune precipitation, then reveal the mechanism and new targets of neurogenesis after cerebral ischemia.

内源性神经再生是脑缺血后神经修复的重要方面，受细胞内外众多因子的调控, Caveolin1（Cav1）是细胞内外信号传递的关键，前一个基金研究证实Cav1能减轻脑缺血损伤、促进神经功能康复和神经再生，补阳还五汤能促脑缺血后的神经再生和Cav1表达，且Cav1能影响wnt 通路中DKK1的表达，但其分子机制尚不明确。Wnt/ β-catenin是一条调控细胞增殖、分化的关键、保守通路,与脑缺血损伤及神经再生密切相关，并可通过受体或直接结合而被Cav1调控，Cav1与wnt通路存在串话，那么Cav1与wnt/ β-catenin的串话是其调节脑缺血后神经再生的机制和补阳还五汤的作用机理吗？故本课题拟运用转基因动物、干细胞、特异性拮抗、免疫共沉淀等方法探讨Cav1与wnt/ β-catenin串话对神经再生影响的机制及补阳还五汤促神经再生的机理，揭示脑缺血后神经再生的调节机制和新的靶点。

内源性神经再生是脑缺血后神经修复的重要方面，受细胞内外众多因子的调控, Caveolin1（Cav1）是细胞内外信号传递的关键，既往研究证实Cav1 能减轻脑缺血损伤、促进神经功能康复和神经再生，补阳还五汤能促脑缺血后的神经再生和Cav1 表达，且Cav1 能影响wnt 通路中DKK1 的表达。本研究发现，脑缺血后，caveolin-1基因敲除小鼠梗死体积缩小速度明显慢于野生型小鼠。海马区NSCs增殖迁移分化少于野生型小鼠。Cav1敲除可降低缺血脑组织eNOS，VEGF及受体VEGFR-1、VEGFR-2的表达，上调iNOS表达， cav敲除能减弱脑缺血小鼠海马组织和低氧损伤神经干细胞Wnt通路相关分子Wnt1、Wnt3a、β-catenin、LEF-1、TCF-21蛋白及mRNA表达，上调Gsk3β表达，且以且第14d最显著；抑制神经分化因子neurogenin1、neurogenin2、NeuroD、Hes1，上调Hes5、Mash-1和细胞周期蛋白制Cyclin D1、Cdk2，补阳还五汤能不同程度调节上述因子的表达。同时运用wnt抑制剂DKK1后，缺血小鼠脑梗死体积增大，神经功能恢复速度减慢；野生型和敲除型比较，运用wnt抑制剂DKK1后，野生型缺血小鼠神经功能评分较敲除型缺血鼠低，其wnt信号下游信号Dsh、GSK-3、LRP、fzd3、β-catenin、neurogenin1、neurogenin2表达明显增强。研究还发现Cav1基因的缺失能使炎症因子IL-1β、IL-6 TNF-α、ICAM-1表达增加，补阳还五汤能减弱炎症反应。结果表明，Cav1与wnt/ β-catenin通路存在串话，补阳还五汤通过Cav1促脑缺血损伤后神经再生部分与调节wnt/ β-catenin有关，揭示了补阳还五汤抗脑缺血的新机制。项目培养博士2名，硕士6名，发表论文21篇，其中SCI2篇。