PROCESSING OF OXIDATIVE STRESS IN ALZHEIMER

阿尔茨海默病氧化应激的处理

• 批准号: 6097875
• 负责人: VILHELM A. BOHR
• 金额: --
• 依托单位: NATIONAL INSTITUTE ON AGING
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6097875
• 关键词: Alzheimer's disease; DNA damage; DNA repair; family genetics; fibroblasts; fluorescence; gas chromatography mass spectrometry; oxidative stress; plasmids; radiation genetics; tissue /cell culture

Summary of work: Studies have demonstrated that several cellular markers of oxidative stress are higher in cells from Alzheimer disease (AD) patients as compared to normal age- matched controls. These markers include oxidative damage to lipids, proteins, and DNA in various tissues from AD patients. It has been proposed that AD cells may have a defect in the DNA repair processing of oxidative base lesion leading to accumulation of DNA damage in AD cells. We have investigated the repair of oxidative base lesions using whole cell extracts from cultured AD lymphoblasts. DNA substrates containing both pyrimidine and purine lesions were obtained by treatment of plasmid with either gamma irradiation or fluorescent light (FL). Plasmid DNA containing primarily thymine glycol or 8- hydroxyguanine was prepared by damaging DNA with either OsO4 or methylene blue plus light ,respectively. The DNA substrates were purified free of strand breaks and were used in DNA repair synthesis assays. FAD cells were proficient in repair of these substrates containing various oxidative base lesions. Extracts from FAD cells repaired the plasmids damaged by gamma or FL- irradiation with equal efficiency as extracts from unaffected individuals. Furthermore, DNA damaged with methylene blue plus light and OsO4 were repaired with greater efficiency using FAD extracts (approximately 0.5-fold increase) as compared to cells from unaffected individuals. Our data indicate that the DNA damages resulting from the oxidative stresses used here are repaired efficiently in FAD cells. It is possible that the repair of specific oxidative base damages, such as that seen for thymine glycol and 8-hydroxyguanine, may be upregulated in FAD due to chronic oxidative stress which has been previously implicated in this disease. Additionally, there have been reports of unusual accummulation of oxidative DNA damage in mitochondrial DNA from patients with AD, and we are have recently developed novel techniques to study DNA repair in these organelles. We thus plan to investigate the DNA repair efficiency in mitochondrai from individuals with AD.

工作概要：研究表明， 氧化应激的几种细胞标志物在来自 阿尔茨海默病（AD）患者与正常年龄相比- 匹配的控制。这些标志物包括氧化损伤， 脂质、蛋白质和DNA。它 已经提出AD细胞可能在DNA中存在缺陷， 氧化基底损伤的修复过程导致累积 AD细胞中的DNA损伤。我们调查了 使用来自培养的AD的全细胞提取物的氧化基底损伤 淋巴母细胞含有嘧啶和 嘌呤损伤通过用以下任一种处理质粒获得： γ辐射或荧光（FL）。质粒dna 主要含有胸腺嘧啶乙二醇或8-羟基鸟嘌呤， 通过用OsO4或亚甲蓝损伤DNA制备 加上光。纯化DNA底物，不含 链断裂并用于DNA修复合成测定。fad 细胞精通修复这些含有各种 氧化性基底损伤FAD细胞的提取物修复了 质粒被伽马或FL-辐射损伤， 有效性与未受影响个体的提取物相同。此外，委员会认为， 亚甲基蓝加光和OsO_4损伤的DNA， 使用FAD提取物（大约 0.5-倍数增加）。 我们的数据表明， 此处所用的氧化应激在FAD细胞中被有效修复。它 修复特定的氧化性碱损伤， 如胸腺嘧啶乙二醇和8-羟基鸟嘌呤所见， 由于慢性氧化应激， 以前与这种疾病有关。此外， 有报道称， 线粒体DNA，我们有 最近开发了新的技术来研究DNA修复在这些 细胞器因此，我们计划研究DNA修复效率， 线粒体膜电位的变化。