{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T21:44:43Z","timestamp":1788299083558,"version":"build-2803163510"},"reference-count":42,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2021,5,17]],"date-time":"2021-05-17T00:00:00Z","timestamp":1621209600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Ministry of Science and Technology","award":["MOST 107-2314-B-038-043"],"award-info":[{"award-number":["MOST 107-2314-B-038-043"]}]},{"name":"Chi-Mei Medical Center","award":["110CM-TMU-13"],"award-info":[{"award-number":["110CM-TMU-13"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biomolecules"],"abstract":"<jats:p>Background: The most established pathognomonic protein of Parkinson\u2019s disease (PD), \u03b1-synuclein, is extensively investigated for disease diagnosis and prognosis; however, investigations into whether the free form of \u03b1-synuclein in the blood functions as a PD biomarker have not been fruitful. Extracellular vesicles (EVs) secreted from cells and present in blood transport molecules are novel platforms for biomarker identification. In blood EVs, \u03b1-synuclein originates predominantly from the brain without the interference of the blood\u2013brain barrier. The present study investigated the role of plasma EV-borne \u03b1-synuclein as a biomarker of PD. Methods: Patients with mild to moderate stages of PD (n = 116) and individuals without PD (n = 46) were recruited to serve as the PD study group and the control group, respectively. Plasma EVs were isolated, and immunomagnetic reduction\u2013based immunoassay was used to assess EV \u03b1-synuclein levels. Conventional statistical analysis was performed using SPSS 25.0, and p &lt; 0.05 was considered significant. Results: Compared with controls, we observed significantly lower plasma EV \u03b1-synuclein levels in the patients with PD (PD: 56.0 \u00b1 3.7 fg\/mL vs. control: 74.5 \u00b1 4.3 fg\/mL, p = 0.009), and the significance remained after adjustment for age and sex. Plasma EV \u03b1-synuclein levels in the patients with PD did not correlate with age, disease duration, Part I and II scores of the Unified Parkinson\u2019s Disease Rating Scale (UPDRS), or the Mini-Mental State Examination scores. However, such levels were significantly correlated with UPDRS Part III score, which assesses motor dysfunction. Furthermore, the severity of akinetic-rigidity symptoms, but not tremor, was inversely associated with plasma EV \u03b1-synuclein level. Conclusion: Plasma EV \u03b1-synuclein was significantly different between the control and PD group and was associated with akinetic-rigidity symptom severity in patients with PD. This study corroborates the possible diagnostic and subtyping roles of plasma EV \u03b1-synuclein in patients with PD, and it further provides a basis for this protein\u2019s clinical relevance and feasibility as a PD biomarker.<\/jats:p>","DOI":"10.3390\/biom11050744","type":"journal-article","created":{"date-parts":[[2021,5,17]],"date-time":"2021-05-17T12:19:57Z","timestamp":1621253997000},"page":"744","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":36,"title":["Plasma Extracellular Vesicle \u03b1-Synuclein Level in Patients with Parkinson\u2019s Disease"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6743-6667","authenticated-orcid":false,"given":"Chen-Chih","family":"Chung","sequence":"first","affiliation":[{"name":"Department of Neurology, Taipei Medical University\u2013Shuang Ho Hospital, New Taipei City 23561, Taiwan"},{"name":"Department of Neurology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan"},{"name":"Graduate Institute of Biomedical Informatics, Taipei Medical University, Taipei 11031, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5795-4460","authenticated-orcid":false,"given":"Lung","family":"Chan","sequence":"additional","affiliation":[{"name":"Department of Neurology, Taipei Medical University\u2013Shuang Ho Hospital, New Taipei City 23561, Taiwan"},{"name":"Department of Neurology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7982-0612","authenticated-orcid":false,"given":"Jia-Hung","family":"Chen","sequence":"additional","affiliation":[{"name":"Department of Neurology, Taipei Medical University\u2013Shuang Ho Hospital, New Taipei City 23561, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yi-Chieh","family":"Hung","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Department of Surgery, Chi-Mei Medical Center, Tainan 71004, Taiwan"},{"name":"Department of Recreation and Healthcare Management, Chia Nan University of Pharmacy and Science, Tainan 71710, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chien-Tai","family":"Hong","sequence":"additional","affiliation":[{"name":"Department of Neurology, Taipei Medical University\u2013Shuang Ho Hospital, New Taipei City 23561, Taiwan"},{"name":"Department of Neurology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,5,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"525","DOI":"10.1016\/S1474-4422(06)70471-9","article-title":"Epidemiology of Parkinson\u2019s disease","volume":"5","author":"Breteler","year":"2006","journal-title":"Lancet Neurol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"626","DOI":"10.1038\/nrn3549","article-title":"Parkinson\u2019s disease dementia: Convergence of \u03b1-synuclein, tau and amyloid-\u03b2 pathologies","volume":"14","author":"Irwin","year":"2013","journal-title":"Nat. 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