Novel role of TFEB in ADAM10 potentiation and proliferation of neural precursor cells relevant to Alzheimer's disease

TFEB 在 ADAM10 增强和与阿尔茨海默病相关的神经前体细胞增殖中的新作用

基本信息

批准号：
9981582
负责人：
Madepalli Krishnappa Lakshmana
金额：
$ 22.13万
依托单位：
FLORIDA INTERNATIONAL UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-08-01 至 2023-04-30
项目状态：
已结题

项目摘要

PROJECT SUMMARY/ABSTRACT Alzheimer’s disease (AD) is a complex and a highly heterogeneous disease characterized by the deposition of extracellular and intracellular protein deposits. Accumulating data suggest that autophagy-lysosome pathway (ALP) is severely compromised in human AD and activation of ALP is likely to have therapeutic potential for combating neurodegeneration in the AD. It was recently discovered that the transcription factor EB (TFEB), a basic helix-loop-helix transcription factor is a master regulator of the entire ALP. Interestingly, we found the selective loss of nuclear TFEB protein levels in Braak stage-dependent manner in AD patients and that exposure of primary neurons to Aβ oligomers also markedly reduced TFEB immunoreactivity. So far multiple laboratories around the world have repeatedly confirmed the role of TFEB in markedly reducing the protein aggregates in the APP/PS1 as well as tauopathy models using viral vectors for TFEB expression. By generating flag-TFEB transgenic mice for the first time, we showed that TFEB expression significantly reduces hyperphosphorylated tau in the P301S model of tauopathy. Since TFEB has demonstrated promising effects in models of AD, our continued investigations made a surprising discovery that TFEB potentiates the α-secretase ADAM10 expression and sAPPα generation in multiple cell lines and primary neurons. More importantly, here for the first time we show that TFEB expression increases mature ADAM10 protein levels in vivo. Both sAPPα and ADAM10 have many beneficial properties including neuroprotection, neurite extension, prevention of dendritic degeneration, memory enhancement, inhibition of tau phosphorylation and increased trophic support. More importantly, both ADAM10 and sAPPα have shown indisputable role in the proliferation of neural precursor cells (NPCs) and adult neurogenesis. The failure of most AD clinical trials may suggest that mere reductions in Aβ levels may be insufficient to combat AD and that a mechanism to increase additional benefits may be needed. Therefore in this proposal by using our newly generated flag-TFEB mice we want to assess whether TFEB can mitigate the age-associated decline in the number of NPCs and neurogenesis by quantifying BrdU+, NeuN+, DCX+ and their double positives.in the subventricular zone and subgranular zone by measuring spatial memory, motor activity, ADAM10 activity, and sAPPα levels. More crucially, we have also designed experiments to identify the mechanistic basis for TFEB’s role in neurogenesis. We will also test whether TFEB can provide significant protection against excitotoxicity and Aβ oligomers in the organotypic cultures. Using antibodies against ADAM10/sAPPα, we will also address whether ADAM10/sAPPα are responsible for neuroprotection. If positive results are obtained, it may lead to the initiation of a new line of research on TFEB and its pathway on the role of neurogenesis in models of AD and ultimately TFEB may turn out to be excellent therapeutic target for AD.

项目概要/摘要阿尔茨海默病（AD）是一种复杂且高度异质的疾病，其特征是沉积细胞外和细胞内蛋白质沉积表明自噬-溶酶体途径。 (ALP) 在人类 AD 中严重受损，ALP 的激活可能具有治疗潜力最近发现转录因子 EB (TFEB) 是一种抗 AD 神经退行性变的药物。碱性螺旋-环-螺旋转录因子是整个 ALP 的主要调节因子。 AD 患者核 TFEB 蛋白水平以 Braak 阶段依赖性方式选择性丧失迄今为止，将原代神经元暴露于 Aβ 寡聚体也显着降低了 TFEB 免疫反应性。世界各国实验室多次证实TFEB显着降低蛋白质的作用 APP/PS1 以及使用病毒载体进行 TFEB 表达的 tau 蛋白病模型中的聚集体。首次生成flag-TFEB转基因小鼠，我们发现TFEB表达显着降低 P301S tau 病模型中过度磷酸化的 tau 蛋白。由于 TFEB 在 AD 模型中表现出良好的效果，我们的持续研究取得了进展令人惊讶的发现，TFEB 增强了 α-分泌酶 ADAM10 的表达和 sAPPα 的生成更重要的是，我们首次展示了 TFEB 表达。增加体内成熟 ADAM10 蛋白水平。 sAPPα 和 ADAM10 均具有许多有益特性。包括神经保护、神经突延伸、预防树突变性、增强记忆、抑制 tau 磷酸化并增加营养支持，更重要的是 ADAM10 和 sAPPα。在神经前体细胞（NPC）增殖和成体神经发生中显示出无可争议的作用。大多数 AD 临床试验的失败可能表明，仅仅降低 Aβ 水平可能不足以对抗 AD AD 并且可能需要一种增加额外收益的机制，因此在本提案中使用。我们新生成的 flag-TFEB 小鼠我们想要评估 TFEB 是否可以减轻与年龄相关的通过量化 BrdU+、NeuN+、DCX+ 及其双倍来减少 NPC 和神经发生的数量通过测量空间记忆、运动活动，在室下区和颗粒下区中获得积极的结果， ADAM10 活性和 sAPPα 水平更重要的是，我们还设计了实验来鉴定我们还将测试 TFEB 是否可以提供重要的作用。使用针对器官型培养物的抗体来防止兴奋性毒性和 Aβ 寡聚体。 ADAM10/sAPPα，如果呈阳性，我们还将讨论 ADAM10/sAPPα 是否负责神经保护。结果的获得，可能会引发关于 TFEB 及其作用途径的新研究路线 AD 模型中神经发生的影响以及最终 TFEB 可能成为 AD 的极好治疗靶点。