HO-1表达上调对成体海马神经再生的调控作用及机制研究

Adult hippocampus neurogenesis is crucial to maintain hippocampus function for Alzheimer’s disease and is the key to propose endogenous therapeutic strategy. We have proved that HO-1 long-term overexpressing is a pathogenic factor to AD. Surprisingly we found HO-1 inhibited the hippocampus neurogenesis and accelerated neural stem cell pool exhausting. It suggested that HO-1 is an important regulator in hippocampus neurogenesis. But up to now this idea hasn’t been reported. To verify the function of HO-1 in regulating adult hippocampus neurogenesis, we will use transgenic mouse model and retrovirus injection to mark and trace neural stem cell and illustrate the role of HO-1 using morphological and stereological methods. Furthermore, we present two pathways of HO-1 leading hippocampus neurogenesis decreasing and neural stem cell pool exhausting: HO-1/Wnt/β-catenin pathway and HO-1 /（Aβ/tau）oligomer pathway. To verify the methanism of HO-1 in regulating adult hippocampus neurogenesis, we will carry cell biological experiments, molecular biological experiments, CRISPR/Cas9 gene editing technology and culture primary adult hippocampus neural stem cell. At last, we will verify the conclusion under Alzheimer’s disease condition in HO-1/APP/PSEN1 trangenic mouse. Our study may reveal the new function of HO-1 in regulating adult hippocampus neurogenesis, explore new regulator and new mechanism of hippocampus neurogenesis in Alzheimer’s disease, and provide new ideas and target for endogenous therapeutic strategy of Alzheimer’s disease.

成体海马神经再生对于维持阿尔茨海默病（AD）海马正常功能至关重要，是提出内源性修复策略的关键。前期已证明HO-1表达上调是AD的致病因素，意外地在HO-1转基因鼠中发现HO-1抑制海马神经再生、促进海马神经干细胞池消耗，提示HO-1是AD海马神经再生的重要调控因素，目前未见报道。项目采用转基因动物和逆转录病毒脑定位注射技术内源性标记和追踪海马神经干细胞，通过形态学和体视学方法阐明HO-1的调控作用。此外，采用原代成体海马神经干细胞，运用分子生物学、CRISPR基因编辑技术验证：HO-1通过Wnt/β-catenin通路和Aβ/tau寡聚体通路发挥作用的分子机制。最后，用HO-1/APP/PSEN1模型鼠在AD状态下验证结论。本项研究将揭示HO-1在成体海马神经再生中的新功能，发掘AD海马神经再生新的调控因子和调控机制，为提出内源性防治策略提供新思路和新靶点。

成体海马神经再生对于维持阿尔茨海默病（AD）海马正常功能至关重要，成体海马神经再生障碍的发生机制是理解神经退行性疾病内源性神经修复机制、提出内源性治疗策略的关键。多项研究已报道HO-1在阿尔茨海默病中扮演重要角色，但是对于HO-1在成体海马神经再生中的作用和机制尚不清楚。本项目利用自主研发的HO-1转基因小鼠和阿尔茨海默病三转基因小鼠模型，应用海马神经干细胞体内标记及体视学分析，首次证明了HO-1表达上调能够导致成体海马神经再生能力下降。项目采用BrdU体内注射标记和原代培养成体海马神经干细胞开展体内/体外研究，证明了HO-1通过AKT途径增加GSK3β的活性——抑制β-catenin入核——从而抑制WNT/β-catenin信号通路的激活这一分子机制，并通过正反验证揭示了HO-1在调节神经干细胞的存活和增殖中起关键作用。项目在HO-1转基因小鼠中证明了HO-1对Tau寡聚体的调控作用，并应用原代神经元突触形态学分析验证了HO-1通过促进Tau寡聚体聚集影响神经元突触发育和认知功能。本项研究揭示了HO-1在成体海马神经再生中的新功能，较完整地阐释了HO-1调控成体海马神经再生的机制，本研究的成果对预防及治疗神经退行性疾病相关的神经再生障碍提供了新的理论依据及潜在的分子靶标。