| 1. |
- Berge-Seidl, Victoria, et al.
(författare)
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The GBA variant E326K is associated with Parkinson's disease and explains a genome-wide association signal
- 2017
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Ingår i: Neuroscience Letters. - : Elsevier. - 0304-3940 .- 1872-7972. ; 658, s. 48-52
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Coding variants in the GBA gene have been identified as the numerically most important genetic risk factors for Parkinson's disease (PD). In addition, genome-wide association studies (GWAS) have identified associations with PD in the SYT11-GBA region on chromosome 1q22, but the relationship to GBA coding variants have remained unclear. The aim of this study was to sequence the complete GBA gene in a clinical cohort and to investigate whether coding variants within the GBA gene may be driving reported association signals. Methods: We analyzed high-throughput sequencing data of all coding exons of GBA in 366 patients with PD. The identified low-frequency coding variants were genotyped in three Scandinavian case-controls series (786 patients and 713 controls). Previously reported risk variants from two independent association signals within the SYT11-GBA locus on chromosome 1 were also genotyped in the same samples. We performed association analyses and evaluated linkage disequilibrium (LD) between the variants. Results: We identified six rare mutations (1.6%) and two low-frequency coding variants in GBA. E326K (rs2230288) was significantly more frequent in PD patients compared to controls (OR 1.65, p = 0.03). There was no clear association of T369M (rs75548401) with disease (OR 1.43, p = 0.24). Genotyping the two GWAS hits rs35749011 and rs114138760 in the same sample set, we replicated the association between rs35749011 and disease status (OR 1.67, p = 0.03), while rs114138760 was found to have similar allele frequencies in patients and controls. Analyses revealed that E326K and rs35749011 are in very high LD (r(2) 0.95). Conclusions: Our results confirm that the GBA variant E326K is a susceptibility allele for PD. The results suggest that E326K may fully account for the primary association signal observed at chromosome 1q22 in previous GWAS of PD.
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| 2. |
- Lunde, Kristin Aaser, et al.
(författare)
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Association of glucocerebrosidase polymorphisms and mutations with dementia in incident Parkinson's disease
- 2018
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Ingår i: Alzheimer's & Dementia. - : Elsevier. - 1552-5260 .- 1552-5279. ; 14:10, s. 1293-1301
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Tidskriftsartikel (refereegranskat)abstract
- IntroductionBoth polymorphisms and mutations in glucocerebrosidase (GBA) may influence the development of dementia in patients with Parkinson's disease.MethodsFour hundred forty-two patients and 419 controls were followed for 7 years. Dementia was diagnosed using established criteria. Participants were analyzed for GBA genetic variants, including E326K, T369M, and L444P. Associations between GBA carrier status and dementia were assessed with Cox survival analysis.ResultsA total of 12.0% of patients with Parkinson's disease carried a GBA variant, and nearly half (22/53) of them progressed to dementia during follow-up. Carriers of deleterious GBA mutations (adjusted hazard ratio 3.81, 95% confidence interval 1.35 to 10.72; P = .011) or polymorphisms (adjusted hazard ratio 1.79; 95% confidence interval 1.07 to 3.00; P = .028) progressed to dementia more rapidly than noncarriers.DiscussionGBA variants are of great clinical relevance for the development of dementia in Parkinson's disease, especially due to the relatively higher frequency of these alleles compared with other risk alleles.
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| 3. |
- Alves, Guido, et al.
(författare)
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Cerebrospinal fluid amyloid-β and phenotypic heterogeneity in de novo Parkinson's disease.
- 2013
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Ingår i: Journal of neurology, neurosurgery, and psychiatry. - : BMJ. - 1468-330X .- 0022-3050. ; 84:5, s. 537-43
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Tidskriftsartikel (refereegranskat)abstract
- In Parkinson's disease (PD), the motor presentation characterised by postural instability/gait difficulties (PIGD) heralds accelerated motor, functional and cognitive decline, as compared with the more benign tremor-dominant (TD) variant. This makes the PIGD complex an attractive target for the discovery of prognostic biomarkers in PD.
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| 4. |
- Alves, Guido, et al.
(författare)
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CSF amyloid-β and tau proteins, and cognitive performance, in early and untreated Parkinson's Disease: the Norwegian ParkWest study
- 2010
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Ingår i: Journal of neurology, neurosurgery, and psychiatry. - : BMJ. - 1468-330X .- 0022-3050. ; 81:10, s. 1080-1086
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Tidskriftsartikel (refereegranskat)abstract
- Background Alzheimer's disease (AD) pathology is found in a considerable portion of patients with Parkinson's disease (PD), particularly those with early dementia (PDD). Altered cerebrospinal fluid (CSF) levels of amyloid-beta (Abeta) and tau proteins have been found in PDD, with intermediate changes for Abeta42 in non-demented PD. The authors investigated whether AD-related CSF protein levels are altered and relate to neuropsychological performance in early, untreated PD. Methods CSF concentrations of Abeta42, Abeta40 and Abeta38 were measured by electrochemiluminiscene and levels of total tau (T-tau) and phosphorylated tau (P-tau) by ELISA in 109 newly diagnosed, unmedicated, non-demented, community-based PD patients who had undergone comprehensive neuropsychological testing, and were compared with those of 36 age-matched normal controls and 20 subjects with mild AD. Results PD patients displayed significant reductions in Abeta42 (19%; p=0.009), Abeta40 (15.5%; p=0.008) and Abeta38 (23%; p=0.004) but not T-tau (p=0.816) or P-tau (p=0.531) compared with controls. CSF Abeta42 reductions in PD were less marked than in AD (53%; p=0.002). Sequential regression analyses demonstrated significant associations between CSF levels of Abeta42 (beta=0.205; p=0.019), Abeta40 (beta=0.378; p<0.001) and Abeta38 (beta=0.288; p=0.001) and memory impairment, but not executive-attentional or visuospatial dysfunction. Tau protein levels did not correlate with cognitive measures. Conclusion CSF Abeta levels are altered in a subset of patients with early PD and relate to memory impairment. Our study suggests that alterations in Abeta protein metabolism may contribute to the heterogeneity in pattern and course of cognitive decline associated with PD. Longitudinal studies are needed to clarify the clinical significance of CSF Abeta peptides as prognostic biomarkers in PD.
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| 5. |
- Björkblom, Benny, et al.
(författare)
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Parkinson Disease Protein DJ-1 Binds Metals and Protects against Metal-induced Cytotoxicity
- 2013
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Ingår i: Journal of Biological Chemistry. - : American Society for Biochemistry and Molecular Biology. - 0021-9258 .- 1083-351X. ; 288:31, s. 22809-22820
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Tidskriftsartikel (refereegranskat)abstract
- The progressive loss of motor control due to reduction of dopamine-producing neurons in the substantia nigra pars compacta and decreased striatal dopamine levels are the classically described features of Parkinson disease (PD). Neuronal damage also progresses to other regions of the brain, and additional non-motor dysfunctions are common. Accumulation of environmental toxins, such as pesticides and metals, are suggested risk factors for the development of typical late onset PD, although genetic factors seem to be substantial in early onset cases. Mutations of DJ-1 are known to cause a form of recessive early onset Parkinson disease, highlighting an important functional role for DJ-1 in early disease prevention. This study identifies human DJ-1 as a metal-binding protein able to evidently bind copper as well as toxic mercury ions in vitro. The study further characterizes the cytoprotective function of DJ-1 and PD-mutated variants of DJ-1 with respect to induced metal cytotoxicity. The results show that expression of DJ-1 enhances the cells' protective mechanisms against induced metal toxicity and that this protection is lost for DJ-1 PD mutations A104T and D149A. The study also shows that oxidation site-mutated DJ-1 C106A retains its ability to protect cells. We also show that concomitant addition of dopamine exposure sensitizes cells to metal-induced cytotoxicity. We also confirm that redox-active dopamine adducts enhance metal-catalyzed oxidation of intracellular proteins in vivo by use of live cell imaging of redox-sensitive S3roGFP. The study indicates that even a small genetic alteration can sensitize cells to metal-induced cell death, a finding that may revive the interest in exogenous factors in the etiology of PD.
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| 6. |
- Björkblom, Benny, et al.
(författare)
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Reactive oxygen species-mediated DJ-1 monomerization modulates intracellular trafficking involving karyopherin beta 2
- 2014
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Ingår i: Molecular and Cellular Biology. - 0270-7306 .- 1098-5549. ; 34:16, s. 3024-3040
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Tidskriftsartikel (refereegranskat)abstract
- Mutations in DJ-1 are a cause of recessive, early-onset Parkinson's disease (PD). Although oxidative stress and mitochondrial integrity have been implicated in PD, it is largely unknown why neurons degenerate. DJ-1 is involved in oxidative stress-mediated responses and in mitochondrial maintenance; however, its specific function remains vague. Here we show that DJ-1 exhibits neuronal dynamic intracellular trafficking, with dimeric/monomeric cycling modulated by the oxidative environment. We demonstrate that oxidative stress enhances monomerization of wild-type cytosolic DJ-1, leading to nuclear recruitment. The pathogenic DJ-1/E163K variant is unable to homodimerize but is retained in the cytosol upon wild-type DJ-1 heterodimerization. We found that this wild-type/pathogenic heterodimer is disrupted by oxidative stress, leading to DJ-1/E163K mitochondrial translocation. We further demonstrated that endogenously expressed wild-type DJ-1 is imported into neuronal nuclei as a monomer and that nucleo-cytoplasmic transport is oxidative stress mediated. We identified a novel proline-tyrosine nuclear localization signal (PY-NLS) in DJ-1, and we found that nuclear monomeric DJ-1 import is mediated by an oxidative stress-dependent interaction with karyopherin beta 2. Our study provides evidence that oxidative stress-mediated intracellular trafficking of DJ-1, mediated by dynamic DJ-1 dimeric/monomeric cycling, is implicated in PD pathogenesis.
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| 7. |
- Førland, Marthe Gurine, et al.
(författare)
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Validation of a new assay for α-synuclein detection in cerebrospinal fluid.
- 2017
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Ingår i: Clinical chemistry and laboratory medicine. - : Walter de Gruyter GmbH. - 1437-4331 .- 1434-6621. ; 55:2, s. 254-260
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Tidskriftsartikel (refereegranskat)abstract
- Abnormal α-synuclein aggregation and deposition is the pathological hallmark of Parkinson's disease (PD) and dementia with Lewy bodies (DLB), but is also found in Alzheimer disease (AD). Therefore, there is a gaining interest in α-synuclein in cerebrospinal fluid (CSF) as potential biomarker for these neurodegenerative diseases. To broaden the available choices of α-synuclein measurement in CSF, we developed and validated a new assay for detecting total α-synuclein.
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| 8. |
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| 9. |
- Patil, Ketan S., et al.
(författare)
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Combinatory microRNA serum signatures as classifiers of Parkinson's disease
- 2019
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Ingår i: Parkinsonism & Related Disorders. - : Elsevier. - 1353-8020 .- 1873-5126. ; 64, s. 202-210
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: As current clinical diagnostic protocols for Parkinson's disease (PD) may be prone to inaccuracies there is a need to identify and validate molecular biomarkers, such as circulating microRNAs, which will complement current practices and increase diagnostic accuracy. This study identifies, verifies and validates combinatory serum microRNA signatures as diagnostic classifiers of PD across different patient cohorts. Methods: 370 PD (drug naive) and control serum samples from the Norwegian ParkWest study were used for identification and verification of differential microRNA levels in PD which were validated in a blind study using 64 NY Parkinsonism in UMea (NYPUM) study serum samples and tested for specificity in 48 Dementia Study of Western Norway (DemWest) study Alzheimer's disease (AD) serum samples using miRNA-microarrays, and quantitative (q) RT-PCR. Proteomic approaches identified potential molecular targets for these microRNAs. Results: Using Affymetrix GeneChip (R) miRNA 4.0 arrays and qRT-PCR we comprehensively analyzed serum microRNA levels and found that the microRNA (PARKmiR)-combinations, hsa-miR-335-5p/hsa-miR-3613-3p (95% CI, 0.87-0.94), hsa-miR-335-5p/hsa-miR-6865-3p (95% CI, 0.87-0.93), and miR-335-5p/miR-3613-3p/miR-6865-3p (95% CI, 0.87-0.94) show a high degree of discriminatory accuracy (AUC 0.9-1.0). The PARKmiR signatures were validated in an independent PD cohort (AUC <= 0.71) and analysis in AD serum samples showed PARKmiR signature specificity to PD. Proteomic analyses showed that the PAFtKmiRs regulate key PD-associated proteins, including alpha-synuclein and Leucine Rich Repeat Kinase 2. Conclusions: Our study has identified and validated unique miRNA serum signatures that represent PD classifiers, which may complement and increase the accuracy of current diagnostic protocols.
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| 10. |
- Piston, Dominik, et al.
(författare)
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DJ-1 is a redox sensitive adapter protein for high molecular weight complexes involved in regulation of catecholamine homeostasis
- 2017
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Ingår i: Human Molecular Genetics. - : Oxford University Press. - 0964-6906 .- 1460-2083. ; 26:20, s. 4028-4041
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Tidskriftsartikel (refereegranskat)abstract
- DJ-1 is an oxidation sensitive protein encoded by the PARK7 gene. Mutations in PARK7 are a rare cause of familial recessive Parkinson's disease (PD), but growing evidence suggests involvement of DJ-1 in idiopathic PD. The key clinical features of PD, rigidity and bradykinesia, result from neurotransmitter imbalance, particularly the catecholamines dopamine (DA) and noradrenaline. We report in human brain and human SH-SY5Y neuroblastoma cell lines that DJ-1 predominantly forms high molecular weight (HMW) complexes that included RNA metabolism proteins hnRNPA1 and PABP1 and the glycolysis enzyme GAPDH. In cell culture models the oxidation status of DJ-1 determined the specific complex composition. RNA sequencing indicated that oxidative changes to DJ-1 were concomitant with changes in mRNA transcripts mainly involved in catecholamine metabolism. Importantly, loss of DJ-1 function upon knock down (KD) or expression of the PD associated form L166P resulted in the absence of HMW DJ-1 complexes. In the KD model, the absence of DJ-1 complexes was accompanied by impairment in catecholamine homeostasis, with significant increases in intracellular DA and noraderenaline levels. These changes in catecholamines could be rescued by re-expression of DJ-1. This catecholamine imbalance may contribute to the particular vulnerability of dopaminergic and noradrenergic neurons to neurodegeneration in PARK7-related PD. Notably, oxidised DJ-1 was significantly decreased in idiopathic PD brain, suggesting altered complex function may also play a role in the more common sporadic form of the disease.
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