Differentiation and characterization of conformational alpha-synuclein strains associated with Parkinson's disease and related synucleinopathies

联核病是一组不同的神经退行性疾病，以错误折叠为特征， 包括帕金森病在内的错折叠α-突触核蛋白(α-Syn)的聚集和积聚 疾病(PD)、多系统萎缩(MSA)和路易体痴呆(DLB)。尽管 具有相同的病理蛋白，不同的临床和病理表型典型 在不同的联体核病中观察到。开发有效治疗方法的主要障碍之一 对于并核病来说，缺乏在脑损伤发生之前的早期诊断和临床 这种疾病的症状。在临床上，区分一些不同的 联体核病(如PD和MSA)，特别是在疾病的早期阶段。这是一个 这是一个重要的问题，因为这些疾病的预后和治疗方式不同。 最近，我们发展了蛋白质错折叠循环扩增(PMCA)，也称为RT- Quic)技术用于高灵敏和特异地检测生物体液中的αSyn寡聚体 受联体核病影响的患者。αSYN-PMCA利用类Prion种子机制 循环放大蛋白质错误折叠的过程，使小分子能够有效地放大 大量的αSYN寡聚体，便于检测。我们有证据表明， 来自帕金森病患者和α患者脑脊液样本的SYN-PMCA可用于实验 杰出的。因此，我们假设αSyn聚合与不同的 并核病对应于不同构象的αSYN毒株/亚毒株，这些毒株可以 经αSyn-PMCA忠实扩增，产物可根据其生化特征进行区分， 结构和生物特性。在这项研究中，我们的主要目标是检测、区分和 从鼠脑组织和体液中扩增微量αSyn株/亚株 通过体外播种/扩增试验，对合并核病患者进行研究，并对这些患者的特征进行分析。 使用各种生化、结构和生物技术的α同步构象聚集体。 这些发现将为生物化学测试的发展奠定基础。 通过对不同α系统的敏感和特异检测来鉴别诊断突触核病 菌株/亚菌株，这将有助于患者分层，临床试验的目标登记和 个性化治疗。

Synucleinopathies are a diverse group of neurodegenerative diseases characterized by misfolding, aggregation and accumulation of misfolded alpha-synuclein (αSyn) which include Parkinson‘s disease (PD), multiple system atrophy (MSA) and dementia with Lewy bodies (DLB). Despite sharing the same pathological protein, different clinical and pathological phenotypes are typically observed in different synucleinopathies. One of the main obstacles to develop effective treatments for synucleinopathies is the lack of an early diagnosis before the onset of brain damage and clinical symptoms of the disease. Clinically, it is very challenging to discriminate between some of the synucleinopathies (e.g. PD and MSA), especially at early stages of the disease. This is an important problem because these diseases have different prognosis and modes of treatment. Recently, we developed the protein misfolding cyclic amplification (PMCA, also known as RT- QuIC) technology for highly sensitive and specific detection of αSyn oligomers in biological fluids of patients affected by synucleinopathies. αSyn-PMCA utilizes the prion-like seeding mechanism to cyclically amplify the process of protein misfolding, enabling the efficient amplification of small quantities of αSyn oligomers, facilitating their detection. We have evidence that the product of αSyn-PMCA coming from CSF samples of patients affected by PD and MSA can be experimentally distinguished. Thus, we hypothesize that αSyn aggregates associated with different synucleinopathies correspond to different conformational strains/ sub-strains of αSyn that can be faithfully amplified by αSyn-PMCA and the product can be differentiated by their biochemical, structural and biological properties. In this study, our main goal is to detect, differentiate and amplify minute amounts of αSyn strains/ sub-strains from biological fluids and brain tissue of patients with synucleinopathies by an in-vitro seeding/ amplification assay, and characterize these αSyn conformational aggregates using various biochemical, structural, and biological techniques. The findings obtained here will lay the foundation towards the development of a biochemical test for differential diagnosis of synucleinopathies by sensitive and specific detection of different αSyn strains/sub-strains, which will help in patients’ stratification, target enrollment for clinical trial and personalized treatment.