Production and Distribution of well-characterized polymorphic variants of alpha-synuclein aggregates

摘要 阿尔茨海默氏病（AD）是最常见的痴呆形式，可能导致60- 70%的病例，其次是路易体痴呆（LBD），占17%的病例。AD和相关痴呆被认为是由错误折叠的蛋白质聚集体在大脑中的积累引起的。在AD中，蛋白质聚集体主要以淀粉样蛋白斑块和神经元缠结的形式出现，所述淀粉样蛋白斑块和神经元缠结分别由淀粉样蛋白-β（ABeta）和高度磷酸化的Tau组成。在LBD中，聚集体的主要组分是α-突触核蛋白（aSyn）蛋白。然而，病理学异常存在大量重叠，导致相对频繁地出现混合病理学，其特征在于在同一脑中存在多种蛋白质聚集体。事实上，高达30-40%的AD患者在他们的大脑中显示aSyn Lewy小体。尽管已经进行了大量的研究来了解aSyn和Tau聚集体在AD中的作用，但是很少有研究来评估aSyn在AD和相关痴呆中的贡献。最近，我们实施并开发了一种高度敏感和特异性的测定（称为aSyn-PMCA），以忠实地扩增存在于受各种突触核蛋白病（包括LBD）影响的患者的脑和生物体液中的aSyn种子。使用这种技术，我们能够从患者的样品中扩增有接种能力的aSyn聚集体，并鉴定与不同疾病相关的构象菌株。该项目的主要目标是利用aSyn-PMCA技术的可靠性来大规模扩增aSyn多态性变体，以便产生并向科学界分发从患者样品扩增的充分表征的aSyn聚集体。将使用各种体外、细胞和动物模型表征材料的尺寸、生物化学、生物物理、结构和生物学特性。具体目标包括：（1）通过aSyn-PMCA扩增从患有AD和LBD的患者的脑和CSF产生aSyn聚集体（以及其他共核蛋白病）和这些聚集体的大小、生物化学和生物物理特性的综合分析;（2）研究不同类型突触核蛋白病的结构基础，特别地，我们提出在原子分辨率下阐明与不同疾病有关的aSyn聚集体的结构折叠;（3）使用体外和体内模型研究源自AD、LBD和其他突触核蛋白病的aSyn聚集体的生物学特性。(4)生产并向科学界分发具有良好特征和生物相关性的aSyn聚集体。该项目产生的资源将充分提供给研究人员，以使试剂标准化，并确保研究结果的生物相关性。

ABSTRACT Alzheimer's disease (AD) is the most common form of dementia and may contribute to 60--70% of cases, followed in prevalence by Lewy body dementia (LBD), responsible for 17% of the cases. AD and related dementias are thought to be caused by the accumulation of misfolded protein aggregates in the brain. In AD, protein aggregates mostly appear in the form of amyloid plaques and neurofibrillary tangles composed of amyloid-beta (ABeta) and hyperphosporylated Tau, respectively. In LBD the main component of the aggregates is the alpha-synuclein (aSyn) protein. However, there is a substantial overlap of pathological abnormalities, leading to the relatively frequent appearance of mixed pathologies, characterized by the presence of multiple protein aggregates in the same brain. Indeed, up to 30-40% of AD patients display aSyn Lewy bodies in their brains. Although, much investigation has been devoted to understand the role of A~ and Tau aggregates in AD, little research has been done to evaluate the contribution of aSyn in AD and related dementias. Recently, we implemented and developed a highly sensitive and specific assay (termed aSyn-PMCA) to faithfully amplify aSyn seeds present in brain and biological fluids of patients affected by various synucleinopathies, including LBD. Using this technology we were able to amplify seeding competent aSyn aggregates from patients' samples and identify conformational strains associated to different diseases. The major goal of this project is to take advantage of the reliability of the aSyn-PMCA technology to massively amplify aSyn polymorphic variants in order to produce and distribute to the scientific community well-characterized aSyn aggregates amplified from patient's samples. Materials will be characterized for their size, biochemical, biophysical, structural and biological properties using various in vitro, cellular and animal models. Specific aims include: (1) Production of aSyn aggregates by aSyn-PMCA amplification from brain and CSF of patients affected by AD and LBD (as well as other synucleinopathies) and comprehensive analysis of the size, biochemical and biophysical properties of these aggregates; (2) Study the structural basis differentiating different synucleinopathies, in particular we propose to elucidate the structural fold at atomic resolution for aSyn aggregates implicated in different diseases; (3) Study the biological properties of aSyn aggregates derived from AD, LBD and other synucleinopathies using in vitro and in vivo models. (4) Produce and distribute to the scientific community well-characterized and biologically relevant aSyn aggregates. The resources generated in this project will be made fully available to researchers in order to standardize reagents and ensure the biological relevance of the findings.