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.

该子项目是利用该技术的众多研究子项目之一 资源由 NIH/NCRR 资助的中心拨款提供。 研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金， 因此可以出现在其他 CRISP 条目中 列出的机构是。 对于中心来说，它不一定是研究者的机构。 问题和假设的简要背景： Tau 是一种微管相关蛋白，可稳定神经元细胞骨架并在囊泡运输和轴突极性中发挥作用，Tau 的病理改变被认为在多种神经退行性疾病中发挥着致病作用，包括阿尔茨海默病 (AD)、β-淀粉样蛋白。 (A¿) 沉积伴随着神经元细胞骨架逐渐被不溶性 NFT 取代，这些 NFT 是在 tau 修饰后形成的，包括过度磷酸化和然而，迄今为止，A¿ 之间的关系。 A¿ 之间的一种可能联系仍然未知。 NFT 是半胱天冬酶的异常激活，半胱天冬酶是负责程序性细胞死亡或细胞凋亡正确执行的蛋白水解酶。最近的研究已经确定，半胱天冬酶的激活可能将这两种标志性病理联系起来，因此，在人类 AD 大脑中，我们的实验室以及其他实验室。已证明 tau 蛋白的半胱天冬酶裂解产物 (CCP) 与 NFT 形成标记物相关。此外，半胱天冬酶裂解的 tau 蛋白也存在。与细胞内 A 共定位AD 大脑中的 1-42 是由 A¿ 诱导的1-42，在体外，这些结果总体表明缠结和淀粉样蛋白通过共同途径（即半胱天冬酶介导的蛋白水解）相互关联。 AD 小鼠模型（3xTg-AD 小鼠），其中小鼠过度表达抗凋亡蛋白 Bcl-2（Bcl-2 OE Tg 小鼠）。这种杂交将显示 caspase 激活的减弱以及与 3xTg-AD 小鼠相关的病理和行为问题的预防。 该提案的具体目标是： 目标 1：建立一种过表达抗凋亡蛋白 Bcl-2 的新型 AD 转基因小鼠模型。初步数据表明，在 3xTg-AD 小鼠中，tau 的 caspase 裂解以年龄依赖性方式发生，具有强大的抗凋亡作用。凋亡蛋白可以将多种类型的神经元从损伤或疾病引起的细胞凋亡中拯救出来，并可以提高神经元在发育过程中的存活率。为此，我们检验了后代产生的假设。杂交这两种 Tg 小鼠模型是可行的并且适当地过度表达 A¿ 、tau 和 Bcl-2 以年龄依赖的方式进行，因为所有后续特定目标只有在该特定目标成功后才能实现，因此我们将提供初步数据来证明此类后代的成功杂交和存活至少 24 个月。 。 目标 2：评估 Bcl-2 的过度表达是否会阻止 AD 小鼠中 caspase 激活、tau 和 APP 裂解并导致更少的缠结改变。最近的体外和体内数据表明，caspase 激活和随后的 tau 裂解可能是一个因素。连接A的关键事件为此，我们计划通过确定抗凋亡蛋白 Bcl-2 的过度表达是否会阻止 AD 动物模型中的 caspase 激活和 NFT 形成来直接检验这一假设。 目标 3：确定 3xTg-AD 小鼠中 Bcl-2 过度表达后，半胱天冬酶是否在淀粉样前体蛋白和 tau 的周转中发挥作用。有证据表明，淀粉样前体蛋白 (APP) 和 tau 都是半胱天冬酶的底物。 Bcl-2 的过度表达和 caspase 激活的减弱可能导致 APP、A¿ 水平的改变。我们急于在 3xTg-AD 小鼠中观察到 Bcl-2 过度表达后 APP 和 tau 的水平升高。 目标 4：确定 3xTg-AD 小鼠中 Bcl-2 的过度表达是否会改善认知能力。该提议的一个重要决定因素是不仅评估病理学，而且评估 Bcl-2 过度表达后的认知能力。除了使用涉及地点识别的新颖记忆范式之外，还可以采用这种方法。 总而言之，我们相信这个项目的设计和基本原理应该能让我们回答半胱天冬酶是否在 AD 相关的发病机制中发挥积极作用。我们相信这是一项重要且及时的研究，可以确定治疗 AD 的新靶点。该提案的结果可能会推动测试半胱天冬酶的药理学阻断作为治疗 AD 的治疗干预措施。