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.

项目摘要/摘要阿尔茨海默氏病（AD）是一种复杂且高度异构疾病，其特征是沉积细胞外和细胞内蛋白质沉积物。累积数据表明自噬 - 赖斯体途径（ALP）在人AD中受到严重损害，ALP的激活可能具有治疗潜力在AD中打击神经变性。最近发现转录因子EB（TFEB），一个基本的螺旋环螺旋转录因子是整个ALP的主调节器。有趣的是，我们发现在AD患者中，以Braak阶段依赖性方式降低了核TFEB蛋白水平的选择性丧失，并且原发性神经元暴露于Aβ低聚物中也显着降低了TFEB免疫反应性。到目前为止的倍数世界各地的实验室一再证实了TFEB在明显降低蛋白质中的作用使用病毒矢量进行TFEB表达的APP/PS1和Tauopathy模型中的聚集体。经过首次生成FLAG-TFEB转基因小鼠，我们表明TFEB表达显着降低在tauopathy的P301S模型中，高磷酸化的tau。由于TFEB在AD模型中表现出了承诺影响，因此我们的持续投资使令人惊讶的发现，TFEB可能会在多个细胞系和原发性神经元。更重要的是，在这里我们首次表明TFEB表达在体内增加成熟的ADAM10蛋白水平。 SAPPα和ADAM10都有许多有益的特性包括神经保护，神经抑制，预防树突变性，记忆增强，抑制tau磷酸化并增加营养支持。更重要的是，ADAM10和SAPPα都已经在神经元前体细胞（NPC）和成人神经发生中表现出无可争议的作用。这大多数AD临床试验的失败可能表明Aβ水平的降低可能不足以应对 AD以及可能需要提高额外利益的机制。因此，在此提案中使用我们新生成的旗帜-TFEB小鼠我们要评估TFEB是否可以减轻与年龄相关的通过量化BRDU+，NEUN+，DCX+及其双重的NPC和神经发生数量的减少通过测量空间记忆，运动活动， ADAM10活性和SAPPα水平。更重要的是，我们还设计了实验来识别 TFEB在神经发生中作用的机理基础。我们还将测试TFEB是否可以提供重要的在器官培养物中的兴奋性毒性和Aβ低聚物的保护。使用反对的抗体 ADAM10/SAPPα，我们还将解决ADAM10/SAPPα是否负责神经保护。如果是积极的获得了结果，这可能导致有关TFEB的新研究及其角色的途径的主动性 AD和最终TFEB模型中的神经发生可能是AD的极好的治疗靶标。