Lucien Fabrice, Benarroch Eduardo E, Mullan Aidan, Ali Farwa, Boeve Bradley F, Mielke Michelle M, Petersen Ronald C, Kim Yohan, Stang Cole, Camerucci Emanuele, Ross Owen A, Wszolek Zbigniew K, Knopman David, Bower James, Singer Wolfgang, Savica Rodolfo
Department of Urology, Mayo Clinic, Rochester, Minnesota, United States of America.
Department of Neurology, Mayo Clinic, Rochester, Minnesota, United States of America.
PLoS One. 2022 Apr 8;17(4):e0264446. doi: 10.1371/journal.pone.0264446. eCollection 2022.
BACKGROUND/OBJECTIVE: Despite multiple attempts, no surrogate biomarker of Parkinson disease (PD) has been definitively identified. Alternatively, identifying a non-invasive biomarker is crucial to understanding the natural history, severity, and progression of PD and to guide future therapeutic trials. Recent work highlighted alpha synuclein-containing extracellular vesicles and Poly (ADP-ribose) polymerase (PARP-1) activity as drivers of PD pathogenesis and putative PD biomarkers. This exploratory study evaluated the role of alpha-synuclein-positive extracellular vesicles and PARP-1 activity in the plasma of PD patients as non-invasive markers of the disease's severity and progression.
We collected plasma of 57 PD patients (discovery cohort 20, replication cohort 37) and compared it with 20 unaffected individuals, 20 individuals with clinically diagnosed Alzheimer's disease, and 20 individuals with dementia with Lewy bodies. We analyzed alpha-synuclein-positive extracellular vesicles from platelet-free plasma by nanoscale flow cytometry and blood concentrations of poly ADP-ribose using sandwich ELISA kits.
Median concentration of α-synuclein extracellular vesicles was significantly higher in PD patients compared to the other groups (Kruskal-Wallis, p < .0001). In the discovery cohort, patients with higher α-synuclein extracellular vesicles had a higher Unified Parkinson Disease Rating Scale score (UPDRS III median = 22 vs. 5, p = 0.045). Seven out of 20 patients (35%) showed detectable PAR levels, with positive patients showing significantly higher levels of α-synuclein extracellular vesicles. In the replication cohort, we did not observe a significant difference in the PAR-positive cases in relationship with UPDRS III.
Non-invasive determination of α-synuclein-positive extracellular vesicles may provide a potential non-invasive marker of PD disease severity, and longitudinal studies are needed to evaluate the role of α-synuclein-positive extracellular vesicles as a marker of disease progression.
背景/目的：尽管进行了多次尝试，但尚未明确鉴定出帕金森病（PD）的替代生物标志物。另外，确定一种非侵入性生物标志物对于了解PD的自然病史、严重程度和进展以及指导未来的治疗试验至关重要。最近的研究强调了含α-突触核蛋白的细胞外囊泡和聚（ADP-核糖）聚合酶（PARP-1）活性是PD发病机制的驱动因素和假定的PD生物标志物。这项探索性研究评估了α-突触核蛋白阳性细胞外囊泡和PARP-1活性在PD患者血浆中作为疾病严重程度和进展的非侵入性标志物的作用。
我们收集了57例PD患者的血浆（发现队列20例，复制队列37例），并将其与20名未受影响的个体、20名临床诊断为阿尔茨海默病的个体和20名路易体痴呆个体进行比较。我们通过纳米级流式细胞术分析了无血小板血浆中α-突触核蛋白阳性细胞外囊泡，并使用夹心ELISA试剂盒分析了聚ADP-核糖的血药浓度。
与其他组相比，PD患者中α-突触核蛋白细胞外囊泡的中位浓度显著更高（Kruskal-Wallis检验，p <.0001）。在发现队列中，α-突触核蛋白细胞外囊泡水平较高的患者统一帕金森病评定量表（UPDRS）III评分更高（UPDRS III中位数 = 22对5，p = 0.045）。20例患者中有7例（35%）显示可检测到的PAR水平，阳性患者的α-突触核蛋白细胞外囊泡水平显著更高。在复制队列中，我们未观察到PAR阳性病例与UPDRS III之间存在显著差异。
α-突触核蛋白阳性细胞外囊泡的非侵入性测定可能提供一种潜在的PD疾病严重程度非侵入性标志物，需要进行纵向研究以评估α-突触核蛋白阳性细胞外囊泡作为疾病进展标志物的作用。
