INV OF ASTROCYTE CASPASE ACTV & CD40/CD40L SIGNALING INTERACTIONS IN ALZHEIMER?S

星形胶质细胞天冬氨酸蛋白酶活性的 INV

• 批准号: 7959938
• 负责人: TROY T ROHN
• 金额: $ 9.87万
• 依托单位: UNIVERSITY OF IDAHO
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7959938
• 关键词: Alzheimer' s Disease; Amyloid; Amyloid beta-Protein; Amyloid beta-Protein Precursor; Animal Model; Apoptosis; Apoptotic; Astrocytes; Axonal Transport; Brain; Caspase; Cleaved cell; Cognition; Computer Retrieval of Information on Scientific Projects Database; Crossbreeding; Cytoskeleton; Data; Deposition; Development; Disease; Event; Funding; Grant; Human; Idaho; In Vitro; Injury; Institution; Laboratories; Lead; Link; Mediating; Memory; Microtubule-Associated Proteins; Modification; Mus; Neurodegenerative Disorders; Neurofibrillary Tangles; Neurons; Pathogenesis; Pathology; Pathway interactions; Peptide Hydrolases; Play; Prevention; Problem behavior; Proteins; Proteolysis; Radial; Research; Research Personnel; Resources; Role; Signal Transduction; Source; Testing; Therapeutic Intervention; Transgenic Mice; United States National Institutes of Health; Upper arm; age related; attenuation; design; improved; in vivo; mouse model; neuron apoptosis; neuronal replacement; neuronal survival; novel; overexpression; prevent; programs; success; tau Proteins

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Brief Background of the problem and hypothesis: Tau is a microtubule-associated protein that stabilizes the neuronal cytoskeleton and functions in vesicular transport and axonal polarity. Pathological alterations in tau are thought to play a causative role in several neurodegenerative disorders, including Alzheimer's disease (AD). In AD, beta-amyloid (A¿) deposition is accompanied by the gradual replacement of the neuronal cytoskeleton with insoluble NFTs that develop following modifications of tau that include hyperphosphorylation and proteolytic cleavage. However, to date the relationship between A¿ deposition and NFTs remains unknown. One possible link between A¿ and NFTs is the aberrant activation of caspases, proteolytic enzymes responsible for the proper execution of programmed cell death or apoptosis. Recent studies have determined that caspase activation may interconnect these two hallmark pathologies. Thus, in the human AD brain our laboratory as well as others have demonstrated the presence of caspase-cleavage products (CCPs) of tau that are associated with markers of NFT formation. Furthermore, caspase-cleaved tau co-localizes with intracellular A¿1-42 in the AD brain and is induced by A¿1-42, in vitro. Collectively, these results indicate that tangles and amyloid are interconnected through a common pathway, namely caspase-mediated proteolysis. To test this hypothesis directly, we propose in the present application to examine the effects of crossing a novel Tg mouse model of AD (3xTg-AD mice) with mice overexpressing the antiapoptotic protein, Bcl-2 (Bcl-2 OE Tg mice). Our overall hypothesis is that progeny of such a cross will show attenuation in caspase activation and prevention in the pathology and behavioral problems associated with 3xTg-AD mice. The specific Aims of the proposal are: Aim 1: To establish a novel transgenic mouse model of AD that overexpresses the antiapoptotic protein, Bcl-2. Preliminary data suggest that caspase cleavage of tau occurs in an age-dependent manner in 3xTg-AD mice. Bcl-2 is powerful anti-apoptotic protein that rescues many types of neurons from apoptosis caused by injury or disease and can enhance neuronal survival during development. In this aim, we test the hypothesis that progeny resulting from crossing these two Tg mice models are viable and properly overexpress A¿, tau and Bcl-2 in an age-dependent manner. Because all subsequent specific aims can only be carried out following the success of this specific aim, we will provide preliminary data to demonstrate the successful crossbreeding and survival of such progeny for at least 24 months. Aim 2: Assess whether overexpression of Bcl-2 will prevent caspase activation, the cleavage of tau and APP and lead to fewer tangle alterations in AD mice. Recent in vitro and in vivo data suggest that caspase activation and subsequent cleavage of tau may be a key event linking A¿ with NFTs in AD. In this aim, we plan to test this hypothesis directly, by determining whether overexpression of an antiapoptotic protein, Bcl-2, prevents caspase activation and NFT formation in an animal model of AD. Aim 3: Determine whether caspases play a role in the turnover of the amyloid precursor protein and tau following the overexpression of Bcl-2 in 3xTg-AD mice. Evidence suggests that both the amyloid precursor protein (APP) and tau are substrates for caspase-mediated cleavage. The overexpression of Bcl-2 and attenuation of caspase activation may lead to alterations in the levels of APP, A¿ and tau in 3xTg-AD mice. We hypothesize that we will observe higher levels of both APP and tau following overexpression of Bcl-2. Aim 4: To determine whether overexpression of Bcl-2 in 3xTg-AD mice improves cognition. An important determinant for this proposal will be to assess not only the pathology but also cognition following overexpression of Bcl-2. Standard Morris or radial arm mazes will be employed in addition to using a novel memory paradigm involving place recognition. Taken together, we believe the design and rationale for this project should allow us to answer whether caspases play an active role in the pathogenesis associated with AD. We believe this to be both an important and timely study that could identify new targets for the treatment of this disease. Results from this proposal may provide impetus to test pharmacological blockade of caspases as a therapeutic intervention in treating AD.

该副本是使用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此可以在其他清晰的条目中代表。列出的机构是 对于中心，这是调查员的机构。 问题和假设的简短背景： TAU是一种微管相关的蛋白质，可稳定神经元细胞骨架和囊泡转运和轴突极性的功能。 tau的病理改变被认为在包括阿尔茨海默氏病（AD）在内的几种神经退行性疾病中起致病作用。在AD中，β-淀粉样蛋白（a？）的沉积是通过与不溶性NFT的级替换神经元细胞骨架来实现的，而NFT会随着TAU的修饰而形成，包括过度磷酸化和蛋白水解裂解。但是，迄今为止，A沉积与NFT之间的关系仍然未知。 a和NFT之间的一种可能的联系是胱天蛋白酶的异常激活，蛋白水解酶，负责适当执行程序性细胞死亡或凋亡。最近的研究确定胱天蛋白酶激活可能会相互联系这两种标志性病理。在人类广告中，我们的实验室以及其他人都证明了与NFT形成标记有关的Tau的caspase-cleavage产品（CCP）。此外，caspase插入的tau与AD大脑中的细胞内A¿1-42共定位，并在体外诱导了A€1-42。总的来说，这些结果表明缠结和淀粉样蛋白通过公共途径（即caspase介导的蛋白水解）相互联系。为了直接检验该假设，我们在本应用中提出，以检查与过表达抗凋亡蛋白Bcl-2（Bcl-2 OE TG小鼠）AD（3XTG-AD小鼠）新型TG小鼠模型（3XTG-AD小鼠）的影响。我们的总体假设是，这种十字架的进展将显示与3xTG-AD小鼠相关的病理和行为问题中的胱天蛋白酶激活和预防中的衰减。 该提案的具体目的是： 目标1：建立一种过表达抗凋亡蛋白Bcl-2的新型AD的转基因小鼠模型。初步数据表明，在3XTG-AD小鼠中，caspase的清洁以年龄的方式发生。 Bcl-2是强大的抗凋亡蛋白，它反应受损伤或疾病引起的多种神经元的反应，并且可以增强发育过程中神经元存活。在此目标中，我们检验了以下假设：跨越这两个TG小鼠模型所产生的进展是可行的，并且以年龄的依赖方式过度表达了Tau和Bcl-2。因为只有在此特定目标成功之后才能实现所有后续的特定目标，因此我们将提供初步数据，以证明这种后代至少24个月的成功杂交和生存。 目标2：评估Bcl-2的过表达是否会防止caspase激活，Tau和App的裂解，并导致AD小鼠的缠结改变更少。最近的体外和体内数据表明，caspase激活和随后的Tau裂解可能是与AD中NFT相关的关键事件。在此目标中，我们计划通过确定抗凋亡蛋白Bcl-2的过表达来直接检验该假设，从而阻止AD动物模型中的胱天蛋白酶激活和NFT形成。 AIM 3：确定胱天蛋白酶在3xTG-AD小鼠中Bcl-2过表达后是否在淀粉样蛋白前体蛋白和Tau的营业额中起作用。有证据表明，淀粉样蛋白前体蛋白（APP）和TAU都是caspase介导的裂解的底物。 Bcl-2的过表达和caspase激活的衰减可能会导致3xTG-AD小鼠的APP，A tau水平的改变。我们假设在Bcl-2过表达后，我们将观察到更高水平的APP和TAU。 目标4：确定3xTG-AD小鼠中Bcl-2的过表达是否可以改善认知。该提案的一个重要决定因素将不仅评估BCL-2过表达后的病理，而且还要评估认知。除了使用涉及位置识别的新型记忆范式外，还将雇用标准的莫里斯或径向手臂迷宫。 综上所述，我们认为该项目的设计和基本原理应该使我们能够回答胱天蛋白酶在与AD相关的发病机理中是否发挥积极作用。我们认为，这既是一项重要的及时研究，可以确定可以确定治疗该疾病的新目标。该提案的结果可能会为测试胱天蛋白酶的药物阻断作为治疗AD的治疗干预措施的动力。