Novel nuclear and intracellular pathology in early AD

AD 早期的新核和细胞内病理学

• 批准号: 8702666
• 负责人: Paul D Gershon
• 金额: $ 24.45万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-05-01 至 2016-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8702666
• 关键词: 3xTg-AD mouse; Alzheimer' s Disease; Amyloid; Amyloid Fibrils; Amyloid beta-Protein Precursor; Antibodies; Area; Asses; Biogenesis; Biological Assay; Brain; Cell Nucleus; Clinical Trials; Cognitive deficits; DNA; Detergents; Development; Digestion; Disease; Effectiveness; Endopeptidase K; Epitopes; Etiology; Event; Excision; Fluorescent Dyes; Generic Drugs; Genes; Goals; Human; Human Genetics; Immune Sera; Impaired cognition; Mass Spectrum Analysis; Mediator of activation protein; Modeling; Monoclonal Antibodies; Mus; Neurites; Neurons; Nuclear; Pathogenesis; Pathology; Pathway interactions; Patients; Peptide Hydrolases; Peptides; Post-Translational Protein Processing; Presenile Alzheimer Dementia; Production; Protein Fragment; Proteins; Proteolysis; Proteolytic Processing; Public Health; Reporting; Resistance; Resources; Risk Factors; Senile Plaques; Serum; Solubility; Source; Spatial Distribution; Staging; Staining method; Stains; Structure; Testing; Thinking; Time; Transgenic Mice; Trypsin; Western Blotting; aged; alpha synuclein; amyloid precursor protein processing; brain tissue; extracellular; gamma secretase; immunoreactivity; inhibitor/antagonist; islet amyloid polypeptide; mind control; neuron loss; novel; prevent; protein aggregate; protein misfolding; public health relevance; response; therapeutic development

DESCRIPTION (provided by applicant): This proposal seeks to transform our understanding of the causes and mechanisms of Alzheimer's disease. Alzheimer's disease is one of the most serious and economically important diseases for which there is no disease modifying therapy. The problem for therapeutic development in AD is that there is no commonly understood mechanism for AD pathogenesis. Human genetics implicates the APP and its proteolytic processing and the production of the amyloid A? peptide as a mediator of pathogenesis, but human clinical trials targeting the secretion of A? or the removal of plaques have demonstrated little or no effectiveness or have actually accelerated cognitive decline. Recent trials of gamma secretase inhibitors that prevent the secretion of A? reported that treated patients were cognitively worse than controls, suggesting that out understanding of the disease mechanisms is flawed or incomplete. The goal of this proposal is to identify and characterize the proteins and protein fragments that accumulate in and around the nuclei that are reactive to the fibril specific monoclonal antibody M78. We will test the hypothesis that APP and its amyloidogenic fragments misfold and aggregate into insoluble species prior to their proteolytic conversion to A? and accumulate intracellularly due to the intrinsic resistance of the aggregated A? domain to proteolysis. In preliminary studies we have discovered a novel amyloid fibril immunoreactivity in and around nuclei using a fibril specific monoclonal antibody, M78, which recognizes a discontinuous A? epitope in A? fibrils. Our studies suggest that M78 immunoreactivity colocalizes with both intracellular perinuclear APP and early extracellular plaque stages of AD prior to significant cognitive dysfunction and at intermediate times of pathogenesis in 3xTg-Ad mice. Some of the nuclear M78 immunoreactivity colocalizes with APP and A? as visualized with APP and A? specific antibodies suggesting that M78 immunoreactivity may represent misfolded, aggregated APP or APP fragments accumulating as "intracellular amyloid". In 3xTg-AD mice, M78 positive plaques accumulate at later times that are not stained with 6E10 or 4G8, suggesting that a unique type of plaque is also identified by this monoclonal antibody. We also observed that the same spatial distribution of M78 and APP immunoreactivity in neuritic plaques is colocalized with DNA visualized with the fluorescent dye DAPI located in the central core of the neuritic plaque surrounded by a halo of APP immunoreactivity in "dystrophic neurites". Together, our observations suggest a previously unidentified nuclear related intracellular pathway for amyloid pathogenesis and plaque biogenesis in AD. If this novel pathogenesis is a key event in AD, it will dramatically change our way of thinking about this disease, refocus the resources for therapeutic development and enable early clinical trials to alter the course of the disease.

描述（由申请人提供）：该提案旨在改变我们对阿尔茨海默氏病的原因和机制的理解。阿尔茨海默氏病是没有疾病修改治疗的最严重和经济上最重要的疾病之一。 AD治疗发展的问题是，没有普遍了解AD发病机理的机制。人类遗传学意味着该应用程序及其蛋白水解处理以及淀粉样蛋白A的产生？肽作为发病机理的介体，但是针对A分泌的人类临床试验？或清除斑块几乎没有或没有有效性或实际上加速了认知能力下降。最近对防止A分泌的伽马分泌酶抑制剂的试验？据报道，经过治疗的患者的认知性差比对照组还糟，这表明对疾病机制的理解是有缺陷或不完整的。该建议的目的是识别和表征蛋白质， 蛋白质片段在原子核内和周围积聚的蛋白质片段对原纤维特异性 单克隆抗体M78。我们将检验以下假设：在其蛋白水解转化为A之前，App及其淀粉样蛋白生成片段错误地折叠并汇总成不溶性物种？并且由于骨料A的固有阻力而在细胞内积聚？蛋白水解的领域。在初步研究中，我们使用原纤维特异性单克隆抗体M78发现了一种新型淀粉样蛋白纤维纤维免疫反应性，该抗体识别出不连续的A？表位？原纤维。我们的研究表明，M78免疫反应性与AD的细胞内核周围APP和早期的AD的早期细胞外斑块阶段都在显着的认知功能障碍之前和3xTG-AD小鼠的发病机理的中间时间共定位。一些核M78免疫反应性与APP和A共定位？如使用应用程序和a吗？表明M78免疫反应性的特定抗体可能代表堆积为“细胞内淀粉样蛋白”的错误折叠，汇总的应用程序或应用片段。在3XTG-AD小鼠中，M78阳性斑块在以后没有用6E10或4G8染色的时间积聚，这表明该单克隆抗体也鉴定出独特的斑块。我们还观察到，在神经斑块中M78和APP免疫反应性的相同空间分布与DNA共定位于与位于神经斑块中心的荧光染料DAPI可视化的神经斑块中，该神经斑块被APP免疫反应性的光环包围，在“营养不良神经突中”。总体而言，我们的观察结果表明，AD中的淀粉样发病机理和斑块生物发生的先前未鉴定的核相关细胞内途径。如果这种新颖的发病机理是AD中的关键事件，它将极大地改变我们对这种疾病的思考方式，重新关注治疗性发育的资源，并使早期的临床试验能够改变疾病的病程。