The Role of Caspase-8 in Alzheimer's Disease

Caspase-8 在阿尔茨海默病中的作用

• 批准号: 6348617
• 负责人: TROY T ROHN
• 金额: $ 12.25万
• 依托单位: BOISE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-01 至 2004-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6348617
• 关键词: Alzheimer's disease; CD95 molecule; active sites; antibody; antigen antibody reaction; apoptosis; biotechnology; brain; cell growth regulation; cell line; chemical cleavage; clone cells; cysteine endopeptidases; enzyme activity; enzyme structure; human tissue; immunocytochemistry; immunologic substance development /preparation; neuroblastoma; neurons; spectrin; tissue /cell culture; tumor necrosis factor alpha; western blottings; zymogens

DESCRIPTION (Adapted from applicant's abstract): A prominent feature of Alzheimer's disease (AD) is the loss of neurons by apoptotic cell death. Apoptosis is characterized by plasma membrane blebbing, nuclear condensation, and DNA fragmentation and is initiated by the activation of caspases, a family of aspartate proteases. The initiation of apoptosis involves the sequential activation of pro-caspases to their active form by proteolysis. Two key members of this family are caspase-8, the most apical member of the caspases, and caspase-3 that is commonly referred to as the executioner member of this family. Because caspases are specific, cleaving after aspartic residues, this generates caspase cleavage products (CCPs) that are antigenically distinct and therefore, represent desirable targets for cleavage site-directed antibodies. Using this approach, we designed an antibody to CCPs of fodrin, a neuronal cytoskeleton protein, and showed widespread accumulation of these products in Alzheimer's disease. Thus, while no staining was observed in control cases, labeling of neurons was observed in the hippocampus and entorhinal cortex of all AD cases, which increased as a function of disease progression. This study along with others has demonstrated a prominent role for the activation of apoptotic mechanisms in neurons of the AD brain. Presently, there are two major pathways of apoptosis: the death receptor pathway in which caspase-8 plays a critical initiator role and the mitochondrial pathway involving oxidative stress and activation of caspase-9. Induction of cell death via the Fas/TNFR super family of death receptors is mediated by adapter proteins (e.g., Fas-associated death domain, FADD) and initiation caspases (e.g., caspase-8). In the present application we test the role of the death receptor pathway and caspase-8 in Alzheimer's disease. To examine the role of caspase-8 in Alzheimer's disease we will propose to 1) develop cleavage site-directed antibodies against the active fragments of caspase-8; 2) characterize these antibodies using model systems of apoptosis; 3) use this antibody together with the fodrin CCP antibody to determine the role of caspase-8 in mediating the activation of caspase-3 in neurons of the AD brain. Elucidation of the exact apoptotic pathway involved in the eventual activation of caspase-3 will lead to the identification of newer, more specific targets for pharmacological intervention that may be useful for the treatment of Alzheimer's disease.

描述（改编自申请人摘要）： 阿尔茨海默病（AD）是由凋亡性细胞死亡引起的神经元损失。 细胞凋亡的特征是质膜起泡，核浓缩， 和DNA片段化，并通过激活半胱天冬酶，一个家族， 天冬氨酸蛋白酶。细胞凋亡的启动涉及细胞凋亡的顺序， 通过蛋白水解将前半胱天冬酶激活为它们的活性形式。两个关键成员 caspase-8是caspase-8的最顶端成员， 半胱天冬酶-3，通常被称为刽子手成员， 家人由于半胱天冬酶是特异性的，在天冬氨酸残基后切割， 产生抗原性不同的胱天蛋白酶裂解产物（CCP）， 因此代表切割位点导向抗体的理想靶。 使用这种方法，我们设计了一种针对胞衬蛋白CCP的抗体， 细胞骨架蛋白，并显示这些产品在细胞中广泛积累， 老年痴呆症因此，虽然在对照病例中没有观察到染色， 在海马和内嗅皮层观察到神经元的标记， 所有AD病例，随着疾病进展而增加。本研究 沿着与其他人已经证明了一个突出的作用，激活 AD脑神经元的凋亡机制。目前，有两个主要的 凋亡途径：死亡受体途径，其中半胱天冬酶-8起作用， 关键的引发剂作用和线粒体途径涉及氧化 应激和caspase-9活化。通过Fas/TNFR诱导细胞死亡 死亡受体超家族由衔接蛋白（例如， Fas相关死亡结构域，FADD）和起始半胱天冬酶（例如，caspase-8）。 在本申请中，我们测试了死亡受体途径的作用， caspase-8在阿尔茨海默病中的作用为了检测caspase-8在 阿尔茨海默氏病，我们将提出1）发展裂解定点 针对胱天蛋白酶-8的活性片段的抗体; 2）表征这些 使用细胞凋亡模型系统的抗体; 3）将该抗体与 胞衬蛋白CCP抗体，以确定半胱天冬酶-8介导的作用， AD脑神经元中caspase-3的活化。确切的解释 参与caspase-3最终激活的凋亡途径将导致 新的、更具体的药理学靶点的确定 可能对治疗阿尔茨海默病有用的干预。