Plasma exosomal alpha-synuclein in inherited forms of Parkinson’s disease

Author(s):  
Д.Г. Кулабухова ◽  
А.К. Емельянов ◽  
К.А. Сенкевич ◽  
Е.В. Грачева ◽  
И.В. Милюхина ◽  
...  

Предполагается, что экзосомы (микровезикулы размером 40-100 нм) могут играть ключевую роль в транспорте патогенных форм альфа-синуклеина при болезни Паркинсона (БП). В настоящем исследовании проведена оценка влияния мутаций в генах GBA и LRRK2 на уровень альфа-синуклеина экзосом плазмы крови. Показано, что мутации в генах GBA и LRRK2 не влияют на уровень альфа-синуклеина экзосом плазмы крови. Parkinson’s disease (PD) is the second most frequent neurodegenerative disorder. Alpha-synuclein misfolding and aggregation resulting in neurototoxicity is a hallmark of PD. Exosomes (extrcellular vesicles 40-100 nm in size) can play a key role in the transport of pathogenic forms of alpha-synuclein. The aim of our work is to evaluate an effect of GBA and LRRK2 mutations on alpha-synuclein level in exosomes derived from peripheral blood plasma. No significant difference was found for exosomal alpha-synuclein levels patients with sporadic, GBA- and LRRK2- associated PD, PD with dementia compared to controls. Our results indicate that mutations in the LRRK2 and GBA genes do not influence on plasma exosomal alpha-synuclein level.

2021 ◽  
Vol 13 ◽  
Author(s):  
Yi Guo ◽  
Yan Sun ◽  
Zhi Song ◽  
Wen Zheng ◽  
Wei Xiong ◽  
...  

Parkinson's disease (PD) is the fastest-growing neurodegenerative disorder. Aging, environmental factors, and genetics are considered as risk factors. The alpha-synuclein gene (SNCA), the first pathogenic gene identified in a familial form of PD, was indisputably involved as a heritable component for familial and sporadic PD. In this study, whole-exome sequencing and Sanger sequencing were performed to evaluate the association between the SNCA gene variants and PD. The genetic data of 438 clinically diagnosed patients with PD and 543 matched control populations of the Han Chinese were analyzed. The literature review of SNCA variants for 231 cases reported in 89 articles was extracted from the PubMed and the Movement Disorder Society Genetic mutation database. No potentially causative variant(s) in the SNCA gene, excepting two single-nucleotide nonsynonymous variants c.158C>T (p.A53V, rs542171324) and c.349C>T (p.P117S, rs145138372), were detected. There was no statistically significant difference in the genotypic or allelic frequencies for either variant between the PD group and the control group (all P > 0.05). No copy number variants of the SNCA gene were detected. The results of this study suggest that the variants in the exons of the SNCA gene may have less or no role in the development of PD in the Han Chinese populations. The literature review suggests that psychiatric signs and cognitive decline/dementia were more common among patients with SNCA duplication or triplication (psychiatric signs: χ2 = 7.892, P = 0.005; cognitive decline/dementia: χ2 = 8.991, P = 0.003).


2016 ◽  
Vol 46 (4) ◽  
pp. 292-300 ◽  
Author(s):  
Lauren Hirsch ◽  
Nathalie Jette ◽  
Alexandra Frolkis ◽  
Thomas Steeves ◽  
Tamara Pringsheim

Background: Parkinson's disease (PD) is a common neurodegenerative disorder. Epidemiological studies on the incidence of PD are important to better understand the risk factors for PD and determine the condition's natural history. Objective: This systematic review and meta-analysis examine the incidence of PD and its variation by age and gender. Methods: We searched MEDLINE and EMBASE for epidemiologic studies of PD from 2001 to 2014, as a previously published systematic review included studies published until 2001. Data were analyzed separately for age group and gender, and meta-regression was used to determine whether a significant difference was present between groups. Results: Twenty-seven studies were included in the analysis. Meta-analysis of international studies showed rising incidence with age in both men and women. Significant heterogeneity was observed in the 80+ group, which may be explained by methodological differences between studies. While males had a higher incidence of PD in all age groups, this difference was only statistically significant for those in the age range 60-69 and 70-79 (p < 0.05). Conclusion: PD incidence generally increases with age, although it may stabilize in those who are 80+.


2021 ◽  
Vol 13 ◽  
Author(s):  
Ruichen Su ◽  
Tian Zhou

Parkinson’s disease (PD) is a neurodegenerative disorder closely related to immunity. An important aspect of the pathogenesis of PD is the interaction between α-synuclein and a series of immune cells. Studies have shown that accumulation of α-synuclein can induce an autoimmune response that accelerates the progression of PD. This study discusses the mechanisms underlying the interaction between α-synuclein and the immune system. During the development of PD, abnormally accumulated α-synuclein becomes an autoimmune antigen that binds to Toll-like receptors (TLRs) that activate microglia, which differentiate into the microglia type 1 (M1) subtype. The microglia activate intracellular inflammatory pathways, induce the release of proinflammatory cytokines, and promote the differentiation of cluster of differentiation 4 + (CD4 +) T cells into proinflammatory T helper type 1 (Th1) and T helper type 17 (Th17) subtypes. Given the important role of α-synuclein in the immune system of the patients with PD, identifying potential targets of immunotherapy related to α-synuclein is critical for slowing disease progression. An enhanced understanding of immune-associated mechanisms in PD can guide the development of associated therapeutic strategies in the future.


2015 ◽  
Vol 86 (11) ◽  
pp. e4.86-e4
Author(s):  
Hannah Goddard ◽  
Angus Macleod ◽  
Carl Counsell

BackgroundIdiopathic Parkinson's disease (PD) is a common, disabling, neurodegenerative disorder. The overall co-morbidity burden associated with PD is unclear, but may be important to adjust for when predicting prognosis or comparing cases and controls.Aims ▸ To determine how best to assess overall co-morbidity in PD▸ To compare PD co-morbidity burden to that of age- and sex-matched controlsMethodsData from an incident, community-based cohort of 205 patients with PD and 148 age-, sex- and GP-matched controls (the PINE study) were used. The intra- and inter-rater reliability and mortality predictive ability of three co-morbidity scales (the Charlson Co-Morbidity Index, the Cumulative Illness Rating Scale and a disease count) were evaluated. The co-morbidity burden of cases and controls was compared at baseline and over 5 years of follow-up.Results and conclusionsThe Charlson Co-Morbidity Index was more reliable for use in PD and was the only scale that was independently predictive of mortality (hazard ratio=1.20, [95% CI 1.07–1.34]). There was no significant difference between cases and controls at baseline (p=0.20). Charlson Co-Morbidity Index scores increased over time. This increase was greater in patients with PD than controls and greater in patients and controls who died earlier.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Anelya Kh. Alieva ◽  
Elena V. Filatova ◽  
Aleksey V. Karabanov ◽  
Sergey N. Illarioshkin ◽  
Petr A. Slominsky ◽  
...  

Parkinson’s disease (PD) is a widespread neurodegenerative disorder. Despite the intensive studies of this pathology, in general, the picture of the etiopathogenesis has still not been clarified fully. To understand better the mechanisms underlying the pathogenesis of PD, we analyzed the expression of 10 genes in the peripheral blood of treated and untreated patients with PD. 35 untreated patients with PD and 12 treated patients with Parkinson’s disease (Hoehn and Yahr scores 1-2) were studied. An analysis of the mRNA levels ofATP13A2,PARK2,PARK7,PINK1,LRRK2,SNCA,ALDH1A1,PDHB,PPARGC1A, andZNF746genes in the peripheral blood of patients was carried out using reverse transcription followed by real-time PCR. A statistically significant and specific increase by more than 1.5-fold in the expression of theATP13A2,PARK7, andZNF746genes was observed in patients with PD. Based on these results, it can be suggested that the upregulation of the mRNA levels ofATP13A2,PARK7, andZNF746in untreated patients in the earliest clinical stages can also be observed in the preclinical stages of PD, and that these genes can be considered as potential biomarkers of the preclinical stage of PD.


2020 ◽  
pp. 1-22
Author(s):  
Anne-Marie Castonguay ◽  
Claude Gravel ◽  
Martin Lévesque

Parkinson’s disease is a neurodegenerative disorder mainly characterized by the degeneration of dopaminergic neurons in the substantia nigra. Degenerating neurons contain abnormal aggregates called Lewy bodies, that are predominantly composed of the misfolded and/or mutated alpha-synuclein protein. Post-translational modifications, cellular stress, inflammation and gene mutations are thought to trigger its pathological misfolding and aggregation. With alpha-synuclein pathology being strongly associated with dopaminergic neuronal toxicity, strategies aimed to reduce its burden are expected to be beneficial in slowing disease progression. Moreover, multiple sources of evidence suggest a cell-to-cell transmission of pathological alpha-synuclein in a prion-like manner. Therefore, antibodies targeting extra- or intracellular alpha-synuclein could be efficient in limiting the aggregation and transmission. Several active and passive immunization strategies have been explored to target alpha-synuclein. Here, we summarize immunotherapeutic approaches that were tested in pre-clinical or clinical studies in the last two decades in an attempt to treat Parkinson’s disease.


2020 ◽  
Vol 17 (10) ◽  
pp. 1261-1269
Author(s):  
Yasir Hasan Siddique ◽  
Rahul ◽  
Mantasha Idrisi ◽  
Mohd. Shahid

Background: Parkinson’s disease is a common neurodegenerative disorder characterized by selective loss of dopaminergic neurons in the substantia nigra pars compacta. Introduction: The effects of alpha synuclein, parkin mutation and pharmacological agents have been studied in the Drosophila model. Methods: The effect of cabergoline was studied on the cognitive impairments exhibited by the transgenic Drosophila expressing human alpha-synuclein in the neurons. The PD flies were allowed to feed on the diet having 0.5, 1 and 1.5 μM of cabergoline. Results and Discussion: The exposure of cabergoline not only showed a dose-dependent significant delay in the cognitive impairments but also prevented the loss of dopaminergic neurons. Molecular docking studies showed the positive interaction between cabergoline and alpha-synuclein. Conclusion: The results suggest a protective effect of cabergoline against the cognitive impairments.


Author(s):  
Viola Volpato

Parkinson's disease (PD) is the second most prevalent late-onset neurodegenerative disorder worldwide after Alzheimer's disease for which available drugs only deliver temporary symptomatic relief. Loss of dopaminergic neurons (DaNs) in the substantia nigra and intracellular alpha-synuclein inclusions are the main hallmarks of the disease but the events that cause this degeneration remain uncertain. Despite cell types other than DaNs such as astrocytes, microglia and oligodendrocytes have been recently associated with the pathogenesis of PD, we still lack an in-depth characterisation of PD-affected brain regions at cell-type resolution that could help our understanding of the disease mechanisms. Nevertheless, publicly available large-scale brain-specific genomic, transcriptomic and epigenomic datasets can be further exploited to extract different layers of cell type-specific biological information for the reconstruction of cell type-specific transcriptional regulatory networks. By intersecting disease risk variants within the networks, it may be possible to study the functional role of these risk variants and their combined effects at cell type- and pathway levels, that, in turn, can facilitate the identification of key regulators involved in disease progression, which are often potential therapeutic targets.


2021 ◽  
Vol 13 ◽  
Author(s):  
Upasana Ganguly ◽  
Sukhpal Singh ◽  
Soumya Pal ◽  
Suvarna Prasad ◽  
Bimal K. Agrawal ◽  
...  

Parkinson’s disease (PD) is the second most common neurodegenerative disorder of the elderly, presenting primarily with symptoms of motor impairment. The disease is diagnosed most commonly by clinical examination with a great degree of accuracy in specialized centers. However, in some cases, non-classical presentations occur when it may be difficult to distinguish the disease from other types of degenerative or non-degenerative movement disorders with overlapping symptoms. The diagnostic difficulty may also arise in patients at the early stage of PD. Thus, a biomarker could help clinicians circumvent such problems and help them monitor the improvement in disease pathology during anti-parkinsonian drug trials. This review first provides a brief overview of PD, emphasizing, in the process, the important role of α-synuclein in the pathogenesis of the disease. Various attempts made by the researchers to develop imaging, genetic, and various biochemical biomarkers for PD are then briefly reviewed to point out the absence of a definitive biomarker for this disorder. In view of the overwhelming importance of α-synuclein in the pathogenesis, a detailed analysis is then made of various studies to establish the biomarker potential of this protein in PD; these studies measured total α-synuclein, oligomeric, and post-translationally modified forms of α-synuclein in cerebrospinal fluid, blood (plasma, serum, erythrocytes, and circulating neuron-specific extracellular vesicles) and saliva in combination with certain other proteins. Multiple studies also examined the accumulation of α-synuclein in various forms in PD in the neural elements in the gut, submandibular glands, skin, and the retina. The measurements of the levels of certain forms of α-synuclein in some of these body fluids or their components or peripheral tissues hold a significant promise in establishing α-synuclein as a definitive biomarker for PD. However, many methodological issues related to detection and quantification of α-synuclein have to be resolved, and larger cross-sectional and follow-up studies with controls and patients of PD, parkinsonian disorders, and non-parkinsonian movement disorders are to be undertaken.


2021 ◽  
Author(s):  
Eftychia Vasili ◽  
Antonio Dominguez-Meijide ◽  
Manuel Flores-León ◽  
Mohammed Al-Azzani ◽  
Angeliki Kanellidi ◽  
...  

Abstract Background Parkinson's disease is a progressive neurodegenerative disorder characterized by the accumulation of misfolded alpha-synuclein in intraneuronal inclusions known as Lewy bodies and Lewy neurites. Multiple studies strongly implicate the levels of alpha-synuclein as a major risk factor for the onset and progression of Parkinson’s disease. alpha-Synuclein pathology spreads progressively throughout interconnected brain regions but the precise molecular mechanisms underlying alpha-synuclein spreading and accumulation remain obscure. Methods Here, using stable cell lines expressing alpha-synuclein, we examined the correlation between endogenous alpha-synuclein levels and the seeding propensity by exogenous alpha-synuclein pre-formed fibrils. We applied biochemical approaches and imaging methods in stable cell lines expressing alpha-synuclein and in primary neurons to determine the impact of alpha-synuclein expression levels on seeding and aggregation. Results Our results indicate that alpha-synuclein levels define the pattern and severity of aggregation and the extent of p-alpha-synuclein deposition, likely explaining the selective vulnerability of different cell types in synucleinopathies. Conclusions The elucidation of the cellular processes involved in the pathological aggregation of alpha-synuclein will enable the identification of novel targets and the development of therapeutic strategies for Parkinson's disease and other synucleinopathies.


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