Abstract

Parkinson’s disease (PD) is the second most common neurodegenerative disorder. Alpha-synuclein misfolding and aggregation resulting in neurototoxicity is a hallmark of PD. The prion properties of alpha-synuclein are still under discussion. Exosomes (extrcellular vesicles 40–100 nm in size) can play a key role in the transport of pathogenic forms of alpha-synuclein. The most frequent inherited forms of the disease are PD associated with mutation in the leucine-rich repeat kinase 2 (LRRK2-PD) and glucocerebrosidase (GBA-PD) genes. The aim of our work is to evaluate the concentration and size of exosomes derived from blood plasma of patients with GBA-PD, asymptomatic GBA mutation carriers, and the effect of GBA and LRRK2 mutations on alpha-synuclein level in exosomes derived from peripheral blood plasma. Plasma extracellular vesicles were isolated via chemical precipitation and sequential ultracentrifugation and characterized by transmission electron microscopy, nanoparticle tracking analysis (NTA), and flow cytometry. Total alpha-synuclein level in plasma exosomes was estimated by enzyme-linked immunosorbent assay. Patients with sporadic PD, PD with dementia, patients with inherited PD (GBA-PD, LRRK2-PD), and GBA mutation carriers were included in the study. The concentration on plasma exosomes was higher in GBA-PD patients that in sporadic PD patients, asymptomatic carriers of mutations on GBA gene, and control (p = 0.004, 0.019 and 0.0001 respectively). The size of plasma exosomes was higher in GBA-PD patients compared to asymptomatic carriers of GBA mutations and control (p = 0.009 and 0.0001, respectively). No significant difference was found for exosomal alpha-synuclein levels in the studied groups. Our results allowed us to suggest that a decrease in GBA activity may affect the pool of plasma exosomes, and mutations in the LRRK2 and GBA genes do not influence the level of plasma exosomal alpha-synuclein.

中文翻译：

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帕金森氏病遗传形式的血浆外泌体

摘要

帕金森氏病（PD）是第二大最常见的神经退行性疾病。α-突触核蛋白的错误折叠和聚集导致神经毒性是PD的标志。α-突触核蛋白的病毒性质仍在讨论中。外泌体（大小在40-100 nm的细胞外囊泡）可以在致病性形式的α-突触核蛋白的运输中发挥关键作用。该病最常见的遗传形式是与富含亮氨酸的重复激酶2（LRRK2-PD）和葡萄糖脑苷脂酶（GBA-PD）基因突变相关的PD。我们的工作目的是评估GBA-PD，无症状GBA突变携带者的血浆中外泌体的浓度和大小，以及GBA和LRRK2的作用来自外周血浆的外泌体中α-突触核蛋白水平的突变。通过化学沉淀和连续超速离心分离血浆细胞外囊泡，并通过透射电子显微镜，纳米粒子跟踪分析（NTA）和流式细胞仪进行表征。通过酶联免疫吸附测定法估算血浆外泌体中的总α-突触核蛋白水平。散发性PD，痴呆的PD，遗传性PD（GBA-PD，LRRK2-PD）和GBA突变携带者的患者均纳入研究。GBA-PD患者血浆外泌体的浓度高于散发PD患者，GBA基因突变的无症状携带者和对照（p分别为0.004、0.019和0.0001）。与无症状的GBA突变和对照组相比，GBA-PD患者的血浆外泌体大小更高（分别为p = 0.009和0.0001）。在研究组中，外泌体α-突触核蛋白水平没有发现显着差异。我们的研究结果表明，GBA活性的降低可能会影响血浆外泌体的集合，而LRRK2和GBA基因的突变不会影响血浆外泌体α-突触核蛋白的水平。