Role of Brain Ferroxidases in AD and sCJD Pathogenesis

脑铁氧化酶在 AD 和 sCJD 发病机制中的作用

基本信息

批准号：
8243115
负责人：
Neena Singh
金额：
$ 19.63万
依托单位：
CASE WESTERN RESERVE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-09-30 至 2014-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8243115
关键词：
3&apos Untranslated Regions Acetylcysteine Affect Alzheimer&apos s Disease Antioxidants Binding Proteins Biological Assay Brain Cell Line Cell model Cells Ceruloplasmin Creutzfeldt-Jakob Syndrome Data Disease Disease Progression Down-Regulation Electrophoretic Mobility Shift Assay Etiology Functional disorder Future Generations Hamsters Homeostasis Human Huntington Disease Hydroxyl Radical Immunohistochemistry India Infection Iron Joints Laboratories Mediating Metals Modeling Mus Nature Nerve Degeneration Neurodegenerative Disorders Neuroglia Oxidation-Reduction Oxidative Stress Parkinson Disease Pathogenesis Phenotype Play PrP PrPSc Proteins Prion Diseases Prions Process Protein Isoforms Protein Precursors Proteins RNA Reactive Oxygen Species Reading Regulation Reporting Role Sampling Scrapie Shipping Ships Testing Tg2576 Wild Type Mouse Work Zinc base brain tissue design familial Alzheimer disease insight iron metabolism mRNA Decay mouse model mutant neuroblastoma cell neurotoxicity oxidative damage protein complex response therapeutic development uptake

项目摘要

DESCRIPTION (provided by applicant): Several neurodegenerative conditions such as sporadic Creutzfeldt-Jakob disease (sCJD), Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD) are associated with imbalance of iron homeostasis in diseased brains, raising the possibility that redox-iron induced oxidative damage plays a significant role in the neurotoxicity associated with these disorders. Recent evidence from the Singh laboratory indicates a significant reduction of ferroxidase activity in sCJD affected human and scrapie infected mouse brains. Combined with the fact that sCJD brains show a phenotype of 'apparent' iron deficiency despite the presence of normal or increased brain iron levels, these observations suggest dysregulation of the normal iron homeostatic machinery in diseased brains. A recent report demonstrates decreased ferroxidase activity leading to iron accumulation in AD brains, suggesting that this phenomenon is shared by neurodegenerative disorders of disparate etiology. In an independent set of studies, the Mukhopadhayay laboratory reported that ceruloplasmin (Cp), a major ferroxidase in the brain, is down regulated by reactive oxygen species (ROS). Since iron is highly redox-active and a major contributor of ROS if mismanaged, it is likely that once initiated by a specific disease process, iron imbalance is perpetuated by ROS through down regulation of major brain ferroxidases. Based on these observations, we hypothesize that ROS mediated misregulation of brain specific ferroxidases contributes to iron imbalance in AD and sCJD. The proposed studies will test this hypothesis in two specific aims. In aim 1, the role of ROS in regulating specific ferroxidases will be investigated in cell models o AD and prion disease. Once the ferroxidases have been identified, their regulation will be compared with Cp which is known to be regulated by an mRNA decay mechanism in response to ROS. Subsequently, the minimal region of 3' UTR and binding proteins responsible for regulating ROS-mediated Cp activity will be identified. In aim 2, the ferroxidases identified in ai 1 will be evaluated for their expression and activity in mouse models of AD and scrapie infection during disease progression. The results will be compared with human brain tissue from AD and sCJD cases using ferroxidase assay and immunohistochemistry as the read-out. Successful completion of these studies will clarify the role of major brain ferroxidases in iron dyshomeostasis associated with AD and sCJD brains, and provide the ground-work for future studies on the mechanism of brain iron dyshomeostasis in PD, HD, and other neurodegenerative conditions associated with brain iron imbalance. PUBLIC HEALTH RELEVANCE: Accumulation of iron in diseased brains is a common feature of several neurodegenerative disorders including Alzheimer's disease (AD), Parkinson's disease, Huntington's disease, and sporadic Creutzfeldt-Jakob disease (sCJD). Since excess iron is redox-active, it is a significant cause of neurotoxicity in these disorders. Normally, brai iron metabolism is maintained by a group of proteins that regulate its uptake, release, and storage. Ceruplasmin (Cp) is a brain ferroxidase that regulates release of excess iron from cells. In this proposal we will investigate whether dysfunction of Cp or other brain ferroxidases causes accumulation of iron in diseased brains. These studies will clarify the cause of iron accumulation in AD and sCJD brains, and help in the development of therapeutic strategies aimed at restoring normal brain iron levels.

描述（申请人提供）：几种神经退行性疾病，例如零星的克鲁特兹菲尔特 - 贾科布疾病（SCJD），阿尔茨海默氏病（AD），帕金森氏病（PD）和亨廷顿氏病和亨廷顿氏病（HD）（HD），与play构成的塑料不平衡相关，可能会导致生物稳态的影响，这可能会导致氧化不平衡的生命力。与这些疾病相关的神经毒性。 SINGH实验室的最新证据表明，SCJD中铁氧化酶活性显着降低，影响了被杀伤的小鼠大脑。结合SCJD大脑表现出“明显”铁缺乏症的表型，尽管存在正常或脑铁的水平，这些观察结果表明患病大脑中正常铁稳态机械的失调失调。最近的一份报告表明，铁氧化酶活性的降低导致AD大脑中铁的积累，这表明这种现象是通过不同病因的神经退行性疾病共享的。在一系列独立的研究中，Mukhopadhayay实验室报告说，大脑中主要的铁氧化酶（CP）由活性氧（ROS）降低。由于铁具有很高的氧化还原活性，并且是ROS的主要贡献者，如果不雄厚，一旦通过特定的疾病过程引发，铁不平衡就会通过降低主要脑铁氧化酶的调节而被ROS永存。基于这些观察结果，我们假设ROS介导的大脑特异性铁氧化酶的不调节导致AD和SCJD中的铁不平衡。拟议的研究将以两个具体目标检验该假设。在AIM 1中，将研究ROS在调节特异性铁氧化酶中的作用在细胞模型和prion疾病中。一旦鉴定出铁氧化酶，它们的调节将与CP进行比较，CP被称为对ROS的mRNA衰减机制调节。随后，将鉴定出负责调节ROS介导的CP活性的3'UTR和结合蛋白的最小区域。在AIM 2中，将在AI 1中鉴定的铁氧化酶在疾病进展过程中的AD和CRAPIE感染的小鼠模型中的表达和活性进行评估。将使用铁氧化酶测定和免疫组织化学作为读出的AD和SCJD病例的人脑组织进行比较。这些研究的成功完成将阐明主要脑铁氧化酶在与AD和SCJD大脑相关的铁染色质抑制剂中的作用，并为将来的研究提供了关于PD，HD和其他神经退行性疾病的未来研究的基础研究。公共卫生相关性：患病大脑中铁的积累是几种神经退行性疾病的共同特征，包括阿尔茨海默氏病（AD），帕金森氏病，亨廷顿氏病以及零星的克鲁特兹菲尔德·贾科布病（SCJD）。由于过量铁具有氧化还原活性，因此这是这些疾病中神经毒性的重要原因。通常，Brai铁代谢由一组调节其摄取，释放和储存的蛋白质保持。 Ceruplasmin（CP）是一种脑铁氧化酶，可调节过量铁从细胞中释放。在此提案中，我们将研究CP或其他脑铁氧化酶的功能障碍是否导致患病大脑中铁的积累。这些研究将阐明AD和SCJD大脑中铁积累的原因，并有助于开发旨在恢复正常脑铁水平的治疗策略。