THE AGING BRAIN-- OXIDANT STRESS

大脑老化——氧化应激

• 批准号: 6233464
• 负责人: CAROL A MILLER
• 金额: $ 32.03万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-05-01 至 2006-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6233464
• 关键词: Alzheimer's disease; JUN kinase; aging; apoptosis; biological signal transduction; brain; cerebral ischemia /hypoxia; growth factor receptors; guanine nucleotide exchange factors; human tissue; immunocytochemistry; laboratory mouse; mitogen activated protein kinase; neurons; neurophysiology; neurotransmitter transport; nucleoproteins; oxidative stress; phosphorylation; protein binding; protein protein interaction; protein structure function; synapses; tissue /cell culture; tumor necrosis factor alpha

DESCRIPTION: (Verbatim from the Applicant's Abstract) Signal-transduction pathways in the CNS provide key mechanisms for cellular responses to environmental stresses. Oxidant-stresses are operative in the aging brain with infarction and Alzheimer's disease. MAP kinases mediate these inputs to downstream targets, such as transcription factors. The result is either regeneration and protection, or cell death. DENN-MADD, a GDP/GTP exchange factor expressed in neurons has basal functions mediating release of neurotransmitters from presynaptic terminals. DENN-MADD, identified by two-hybrid screening of a human brain cDNA library using JNK3 as bait, is expressed in neurons as a 200KD protein. Functional domains include a nuclear localization signal,JNK binding domain, leucine-zipper and a death domain. Under oxidant stress conditions, DENN-MADD is translocated from the cytoplasm to the nucleolus, and the cell ultimately dies. To compare basal and stress-induced effects, we will first examine, interactions of JNK and other MAPKs with DENN-MADD, including binding and phosphorylation. Using cDNA deletion constructs transfected into neuronal cultures, mechanisms of nuclear translocation, including masking of the putative nuclear localization signal and interactions with other nucleolar-associated proteins will be examined. Second, the DENN-MADD death domain is known to bind to a death domain of the TNF receptor alpha-1, part of an apoptosis pathway. Interactions of DENN-MADD with TNFR and other death domain proteins will be compared under stress (hypoxia, A-beta). Third, effects of nuclear translocation of DENN-MADD on basal neuronal functions, specifically synaptic vesicle release will be tested to determine if stress results in reduced acetylcholine release. Fourth, possible synergistic stress effects of A-beta and hypoxia on DENN-MADD mediated cell death will be compared immunocytochemically in primary CNS tissue cultures and directly in brain tissues from AD, CNS infarction and normal, aged patients. Neurons vulnerable or resistant to oxidant stress will be compared for DENN-MADD nuclear translocation. This pivotal role of DENN-MADD provides a model for selective neuronal vulnerability in response to oxidant stress.

描述：（申请人摘要的逐字化）信号转导 中枢神经系统中的途径为细胞反应提供了关键机制 环境压力。氧化剂应力在衰老的大脑中具有操作 梗塞和阿尔茨海默氏病。映射激酶将这些输入介导 下游目标，例如转录因子。结果是 再生和保护或细胞死亡。 Denn-Madd，GDP/GTP交换 神经元中表达的因子具有介导的基础功能介导的释放 突触前末端的神经递质。 Denn-Madd，由 使用JNK3作为诱饵对人脑cDNA库进行两种杂交筛查，是 在神经元中表示为200kD蛋白。功能领域包括核 定位信号，JNK结合结构域，亮氨酸Zipper和死亡域。 在氧化应力条件下，丹恩 - 麦德（Denn-MADD）从细胞质中易位 到核仁，细胞最终死亡。比较基础和 压力诱导的效果，我们将首先检查JNK和其他的相互作用 带有DENN-MADD的MAPK，包括结合和磷酸化。使用cDNA 缺失构建转染为神经元培养物，核的机制 易位，包括推定核定位信号的掩盖 将检查与其他与核仁相关蛋白的相互作用。 其次，已知Denn-Madd死亡域与死亡领域结合 TNF受体α-1，凋亡途径的一部分。 Denn-Madd的相互作用 与TNFR和其他死亡结构域蛋白质将在压力下进行比较 （缺氧，A-beta）。第三，Denn-Madd的核易位对 将测试基础神经元功能，特别是突触囊泡的释放 确定应激是否导致乙酰胆碱释放减少。第四， A-Beta和缺氧对DENN-MADD介导的可能的协同应力影响 细胞死亡将在原发性中枢神经系统组织培养物中进行免疫细胞化学比较 直接在AD，CNS梗塞和正常的脑组织中 患者。将比较神经元脆弱或抗氧化应激 用于Denn-MADD核易位。 Denn-Madd的关键作用提供了 响应氧化应激的选择性神经元脆弱性的模型。