A New Model to Dissect the Molecular Mechanisms for ApoE-Associated Lipoprotein Complex Aggregation in the Brain

剖析大脑中 ApoE 相关脂蛋白复合物聚集分子机制的新模型

• 批准号: 10115987
• 负责人: AMANDA MARIA BROWN
• 金额: $ 40.94万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-30 至 2022-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10115987
• 关键词: Adult; Affect; Alleles; Alzheimer' s Disease; Amyloid; Anti-Inflammatory Agents; Apolipoprotein E; Biological Models; Brain; Buffers; Cell Death; Cells; Chronic; Complement; Complex; Dementia; Deposition; Development; Disease; Enzyme-Linked Immunosorbent Assay; Event; Formic Acids; Foundations; Frequencies; Functional disorder; Funding; Gene Expression Profiling; Genes; HIV; HIV Infections; HIV-1; Health; Hippocampus (Brain); Homeostasis; Human; Immune Sera; Immunochemistry; Immunohistochemistry; Impaired cognition; Impairment; In Vitro; Individual; Infection; Inflammation; Inflammatory; Injury; Investigation; Knowledge; Link; Lipoproteins; Microbe; Microglia; Modeling; Molecular; Monkeys; Multiple Sclerosis; Mus; National Institute of Neurological Disorders and Stroke; Nerve Degeneration; Neuraxis; Neurodegenerative Disorders; Neuroglia; Neuroimmune; Neuronal Injury; Neurons; Neuropathogenesis; Neurophysiology - biologic function; Parkinson Disease; Phenotype; Plasma; Population; Positron-Emission Tomography; Process; Proteins; Regulation; Reporting; Reproducibility; Role; Signal Transduction; Signal Transduction Pathway; Stains; Structure; Surface; Testing; Therapeutic; Time; Virus Diseases; brain tissue; cell injury; chronic infection; cost; genetic signature; humanized mouse; in vivo evaluation; interest; knock-down; member; monocyte; mouse model; neurodegenerative phenotype; neuroimaging; novel; osteopontin; pathogen; presenilin; progenitor; protein aggregation; rapid technique; response; single cell sequencing; synuclein; tau Proteins; tau-1; tool

Brain microglia become activated and upregulate pro-(and anti-) inflammatory signaling in response to neuronal cell damage, injury and invasion of the CNS by microbes. Osteopontin (OPN, secreted phosphoprotein-1, SPP1), is highly upregulated in Alzheimer’s disease (AD) and several other neurodegenerative disorders and piqued our interest in pursuing additional mechanistic studies into its function in the central nervous system. An understanding of the molecular mechanisms that underlie the development of the neuropathologic changes and inflammatory processes over time in these disorders remains incompletely understood, and are critical barriers to the development of urgently needed treatments for the growing population of those affected. Interestingly, a “neurodegenerative” microglia gene signature that includes OPN/SPP1 was described for AD. We have been using a mouse model of viral infection as the initial disruptor of brain homeostasis to investigate the role of OPN/SPP1 in neuronal injury and inflammation. We found using translocator protein (TSPO, [11C-DPA-713]) PET-neuroimaging of buffer controls versus HIV-infected humanized mice with knockdown of OPN/SPP1 expression or not, that OPN/SPP1 is a master regulator of microglial inflammatory signaling. A second well characterized marker of activated microglia, Iba-1 was also found by immunohistochemistry (IHC) to be significantly increased. With the prior link of OPN/SPP1 to the neurodegenerative microglia phenotype, we tested whether expression of other members of the reported signature were altered in our mice. To our surprise, we found that antisera against mouse ApoE revealed abundant staining of neurons and glial cells, as well as plaque-like structures and numerous ApoE- associated microparticles in the brains of HIV-infected mice expressing OPN/SPP1, but absent or low in those of HIV-infected OPN-, or OPN+ or OPN- buffer injected mice. We are very excited and believe that our model system, presents for the first time the opportunity to begin to dissect the molecular mechanisms of microglial activation and to test novel hypotheses centered on a regulatory role for OPN/SPP1 in ApoE- associated lipoprotein aggregation and neuropathogenesis. With the central role of microglia in AD, this line of investigation will fill critical gaps in knowledge needed for the advancement of therapeutic approaches aimed at microglia dysfunction.

脑小胶质细胞被激活，并上调促（和抗）炎症信号，以响应 神经元细胞损伤、损伤和微生物侵入CNS。骨桥蛋白（OPN，分泌型 磷蛋白-1，SPP 1）在阿尔茨海默病（AD）和其他几种疾病中高度上调。 神经退行性疾病，激发了我们对其功能进行更多机制研究的兴趣 在中枢神经系统中。了解发展的分子机制， 这些疾病中随时间的神经病理学变化和炎症过程仍然不完全 这是为日益增长的人口开发急需治疗的关键障碍 受影响的人。有趣的是，包括OPN/SPP 1在内的“神经退行性”小胶质细胞基因标记在 描述AD。我们一直在使用病毒感染的小鼠模型作为大脑的初始破坏者， 稳态，以研究OPN/SPP 1在神经元损伤和炎症中的作用。我们发现使用 转运蛋白（TSPO，[11 C-DPA-713]）缓冲液对照与HIV感染的PET神经成像 无论是否敲低OPN/SPP 1表达的人源化小鼠，OPN/SPP 1都是 小胶质细胞炎症信号传导。活化小胶质细胞的第二个充分表征的标志物Iba-1也被发现。 通过免疫组织化学（MHC）发现显着增加。由于OPN/SPP 1与 神经退行性小胶质细胞表型，我们测试了是否表达其他成员的报告， 在我们的老鼠身上改变了令我们惊讶的是，我们发现抗小鼠ApoE的抗血清显示， 神经元和神经胶质细胞的丰富染色，以及斑块样结构和大量ApoE- 在表达OPN/SPP 1的HIV感染小鼠的脑中， HIV感染的OPN-或OPN+或OPN-缓冲液注射小鼠的那些。我们非常兴奋，并相信我们的 模型系统，第一次提出了机会，开始剖析的分子机制， 小胶质细胞激活，并测试新的假设为中心的调节作用，OPN/SPP 1在ApoE- 相关的脂蛋白聚集和神经发病机制。由于小胶质细胞在AD中的核心作用， 研究将填补关键的知识空白，需要促进治疗方法， 小胶质细胞功能障碍