| 1. |
- Velickaite, Vilma, et al.
(författare)
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Cognitive function in very old men does not correlate to biomarkers of Alzheimer's disease
- 2017
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Ingår i: Bmc Geriatrics. - : Springer Science and Business Media LLC. - 1471-2318. ; 17
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Tidskriftsartikel (refereegranskat)abstract
- Background: The Alzheimer's disease (AD) brain displays atrophy with amyloid-beta (A beta) and tau deposition, whereas decreased A beta 42 and increased tau are measured in cerebrospinal fluid (CSF). The aim of this study was to relate cognitive performance to the degree of brain atrophy, CSF biomarker levels and neuropathology in a cohort of aged men. Methods: Fifty-eight 86-92-year-old men from the Uppsala Longitudinal Study of Adult Men (ULSAM) cohort underwent cognitive testing, brain computed tomography and lumbar puncture. Atrophy was graded with established scales. Concentrations of CSF A beta 42, t-tau and p-tau were measured by ELISA. Thirteen brains were examined post mortem. Results: Forty-six of the individuals were considered non-demented, whereas twelve were diagnosed with dementia, either at baseline (n = 4) or during follow-up (n = 8). When comparing subjects with and without dementia, there were no differences in the degree of atrophy, although the mini mental state examination (MMSE) scoring correlated weakly with the degree of medial temporal atrophy (MTA) (p = 0.04). Moreover, the CSF biomarker levels did not differ significantly between healthy (n = 27) and demented (n = 8) subjects (median values 715 vs 472 pg/ml for A beta 42, 414 vs 427 pg/ml for t-tau and 63 vs 60 pg/ml for p-tau). Similarly, there were no differences in the biomarker levels between individuals with mild (n = 24) and severe (n = 11) MTA (median values 643 vs 715 pg/ml for A beta 42, 441 vs 401 pg/ml for t-tau and 64 vs 53 pg/ml for p-tau). Finally, the neuropathological changes did not correlate with any of the other measures. Conclusion: In this cohort of aged men only a weak correlation could be seen between cognitive performance and MTA, whereas the various neuroradiological, biochemical and neuropathological measures did not correlate with each other. Thus, AD biomarkers seem to be less informative in subjects of an advanced age.
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| 2. |
- Englund, Hillevi, et al.
(författare)
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Increase in beta-amyloid levels in cerebrospinal fluid of children with down syndrome
- 2007
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Ingår i: Dementia and Geriatric Cognitive Disorders. - : S. Karger AG. - 1420-8008 .- 1421-9824. ; 24:5, s. 369-374
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Tidskriftsartikel (refereegranskat)abstract
- <i>Background:</i> Individuals with Down syndrome (DS) invariably develop Alzheimer’s disease (AD) during their life span. It is therefore of importance to study young DS patients when trying to elucidate early events in AD pathogenesis. <i>Aim:</i> To investigate how levels of different amyloid-β (Aβ) peptides, as well as tau and phosphorylated tau, in cerebrospinal fluid (CSF) from children with DS change over time. The first CSF sample was taken at 8 months and the following two samples at 20–40 and 54 months of age. <i>Results:</i> Individual levels of the Aβ peptides, as well as total Aβ levels in CSF increased over time when measured with Western blot. Tau in CSF decreased whereas there was no change in levels of phosphorylated tau over time. <i>Conclusion:</i> The increasing levels of Aβ in CSF during early childhood of DS patients observed in this study are probably due to the trisomy of the Aβ precursor APP, which leads to an overproduction of Aβ. Despite the increased CSF concentrations of Aβ, there were no signs of an AD-indicating tau pattern in CSF, since the levels of total tau decreased and phosphorylated tau remained unchanged. This observation further strengthens the theory of Aβ pathology preceding tau pathology in AD.
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| 3. |
- Fang, Xiaotian T., et al.
(författare)
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Brain mGluR5 in mice with amyloid beta pathology studied with in vivo [(11)C]ABP688 PET imaging and ex vivo immunoblotting
- 2017
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Ingår i: Neuropharmacology. - : Elsevier BV. - 0028-3908 .- 1873-7064. ; 113:Pt A, s. 293-300
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimer's disease (AD) is characterized by aggregation of amyloid beta (Aβ) into insoluble plaques. Intermediates, Aβ oligomers (Aβo), appear to be the mechanistic cause of disease. The de facto PET AD ligand, [(11)C]PIB, binds and visualizes Aβ plaque load, which does not correlate well with disease severity. Therefore, finding a dynamic target that changes with pathology progression in AD is of great interest. Aβo alter synaptic plasticity, inhibit long-term potentiation, and facilitate long-term depression; key mechanisms involved in memory and learning. In order to convey these neurotoxic effects, Aβo requires interaction with the metabotropic glutamate 5 receptor (mGluR5). The aim was to investigate in vivo mGluR5 changes in an Aβ pathology model using PET. Wild type C57/BL6 (wt) and AβPP transgenic mice (tg-ArcSwe), 4, 8, and 16 months old, were PET scanned with [(11)C]ABP688, which is highly specific to mGluR5, to investigate changes in mGluR5. Mouse brains were extracted postscan and mGluR5 and Aβ protofibril levels were assessed with immunoblotting and ELISA respectively. Receptor-dense brain regions (hippocampus, thalamus, and striatum) displayed higher [(11)C]ABP688 concentrations corresponding to mGluR5 expression pattern. Mice had similar uptake levels of [(11)C]ABP688 regardless of genotype or age. Immunoblotting revealed general decline in mGluR5 expression and elevated levels of mGluR5 in 16 months old tg-ArcSwe compared with wt mice. [(11)C]ABP688 could visualize mGluR5 in the mouse brain. In conclusion, mGluR5 levels were found to decrease with age and tended to be higher in tg-ArcSwe compared with wt mice, however these changes could not be quantified with PET.
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| 4. |
- Degerman Gunnarsson, Malin, et al.
(författare)
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Pittsburgh compound-B and Alzheimer's disease biomarkers in CSF, plasma and urine: An exploratory study.
- 2010
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Ingår i: Dementia and geriatric cognitive disorders. - Basel : S. Karger AG. - 1421-9824 .- 1420-8008. ; 29:3, s. 204-12
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The positron emission tomography (PET) radiotracer Pittsburgh Compound-B (PIB) is an in vivo ligand for measuring beta-amyloid (Abeta) load. Associations between PET PIB and cerebrospinal fluid (CSF) Abeta1-42 and apolipoprotein E epsilon4 (APOE epsilon4) have been observed in several studies, but the relations between PIB uptake and other biomarkers of Alzheimer's disease (AD) are less investigated. METHOD: PET PIB, PET 18Fluoro-2-deoxy-D-glucose and different AD biomarkers were measured twice in CSF, plasma and urine 12 months apart in 10 patients with a clinical diagnosis of mild to moderate AD. RESULTS: PIB retention was constant over 1 year, inversely related to low CSF Abeta1-42 (p = 0.01) and correlated positively to the numbers of the APOE epsilon4 allele (0, 1 or 2) (p = 0.02). There was a relation between mean PIB retention and CSF ApoE protein (r = -0.59, p = 0.07), and plasma cystatin C (r = -0.56, p = 0.09). CONCLUSION: PIB retention is strongly related to CSF Abeta1-42, and to the numbers of the APOE epsilon4 allele.
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| 5. |
- Degerman Gunnarsson, Malin, et al.
(författare)
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Re-Evaluation of Clinical Dementia Diagnoses with Pittsburgh Compound B Positron Emission Tomography
- 2013
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Ingår i: Dementia and Geriatric Cognitive Disorders Extra. - Basel : S. Karger. - 1664-5464. ; 3:1, s. 472-481
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: There is an overlap regarding Pittsburgh compound B (PIB) retention in patients clinically diagnosed as Alzheimer's disease (AD) and non-AD dementia. The aim of the present study was to investigate whether there are any differences between PIB-positive and PIB-negative patients in a mixed cohort of patients with neurodegenerative dementia of mild severity regarding neuropsychological test performance and regional cerebral glucose metabolism measured with [18F]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET). Methods: Eighteen patients clinically diagnosed as probable AD or frontotemporal dementia were examined with PIB PET, FDG PET and neuropsychological tests and followed for 5-9 years in a clinical setting. Results: The PIB-positive patients (7 out of 18) had slower psychomotor speed and more impaired visual episodic memory than the PIB-negative patients; otherwise performance did not differ between the groups. The initial clinical diagnoses were changed in one third of the patients (6 out of 18) during follow-up. Conclusions: The subtle differences in neuropsychological performance, the overlap of hypometabolic patterns and clinical features between AD and non-AD dementia highlight the need for amyloid biomarkers and a readiness to re-evaluate the initial diagnosis.
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| 6. |
- Ekmark-Lewén, Sara, et al.
(författare)
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Reduction of brain stem pathology and transient amelioration of early cognitive symptoms in transgenic mice treated with a monoclonal antibody against α-synuclein oligomers/protofibrils
- 2023
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Ingår i: AGING BRAIN. - : Elsevier. - 2589-9589. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Immunotherapy against alpha-synuclein (alpha-syn) is a promising novel treatment strategy for Parkinson's disease (PD) and related alpha-synucleinopathies. We have previously shown that systemic treatment with the monoclonal oligomer/protofibril-selective antibody mAb47 targeting cytotoxic alpha-syn leads to reduced central nervous system levels of such species as well as an indication of reduced late-stage symptoms in aged (Thy-1)-h[A30P] alpha-syn transgenic mice. Here, we performed an early-onset long-term treatment study with this antibody to evaluate effects on brain pathology and behavioral outcomes in the same mouse model. Compared to the placebo group, the treatment strongly reduced phosphorylated alpha-syn (pS129 alpha-syn) pathology in the upper brain stem. Moreover, a preserved recognition memory and risk assessment behavior could be seen in antibody-treated mice at six months of age, even although these effects were no longer significant at eleven months of age. Importantly, no evidence of inflammatory responses or other potential toxic effects was seen with the treatment. Taken together, this study supports the strategy to target alpha-syn oligomers/protofibrils with monoclonal antibodies to counteract early symptoms and slow down the progression of PD and other alpha-synucleinopathies.
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| 7. |
- Emami Khoonsari, Payam, et al.
(författare)
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Analysis of the Cerebrospinal Fluid Proteome in Alzheimer's Disease
- 2016
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:3
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimer's disease is a neurodegenerative disorder accounting for more than 50% of cases of dementia. Diagnosis of Alzheimer's disease relies on cognitive tests and analysis of amyloid beta, protein tau, and hyperphosphorylated tau in cerebrospinal fluid. Although these markers provide relatively high sensitivity and specificity for early disease detection, they are not suitable for monitor of disease progression. In the present study, we used label-free shotgun mass spectrometry to analyse the cerebrospinal fluid proteome of Alzheimer's disease patients and non-demented controls to identify potential biomarkers for Alzheimer's disease. We processed the data using five programs (DecyderMS, Maxquant, OpenMS, PEAKS, and Sieve) and compared their results by means of reproducibility and peptide identification, including three different normalization methods. After depletion of high abundant proteins we found that Alzheimer's disease patients had lower fraction of low-abundance proteins in cerebrospinal fluid compared to healthy controls (p<0.05). Consequently, global normalization was found to be less accurate compared to using spiked-in chicken ovalbumin for normalization. In addition, we determined that Sieve and OpenMS resulted in the highest reproducibility and PEAKS was the programs with the highest identification performance. Finally, we successfully verified significantly lower levels (p<0.05) of eight proteins (A2GL, APOM, C1QB, C1QC, C1S, FBLN3, PTPRZ, and SEZ6) in Alzheimer's disease compared to controls using an antibody-based detection method. These proteins are involved in different biological roles spanning from cell adhesion and migration, to regulation of the synapse and the immune system.
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| 8. |
- Emami Khoonsari, Payam, et al.
(författare)
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Improved Differential Diagnosis of Alzheimer's Disease by Integrating ELISA and Mass Spectrometry-Based Cerebrospinal Fluid Biomarkers
- 2019
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Ingår i: Journal of Alzheimer's Disease. - : IOS PRESS. - 1387-2877 .- 1875-8908. ; 67:2, s. 639-651
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Tidskriftsartikel (refereegranskat)abstract
- Background: Alzheimer's disease (AD) is diagnosed based on a clinical evaluation as well as analyses of classical biomarkers: A beta(42), total tau (t-tau), and phosphorylated tau (p-tau) in cerebrospinal fluid (CSF). Although the sensitivities and specificities of the classical biomarkers are fairly good for detection of AD, there is still a need to develop novel biochemical markers for early detection of AD. Objective: We explored if integration of novel proteins with classical biomarkers in CSF can better discriminate AD from non-AD subjects. Methods: We applied ELISA, mass spectrometry, and multivariate modeling to investigate classical biomarkers and the CSF proteome in subjects (n = 206) with 76 AD patients, 74 mild cognitive impairment (MCI) patients, 11 frontotemporal dementia (FTD) patients, and 45 non-dementia controls. The MCI patients were followed for 4-9 years and 21 of these converted to AD, whereas 53 remained stable. Results: By combining classical CSF biomarkers with twelve novel markers, the area of the ROC curves (AUROCS) of distinguishing AD and MCl/AD converters from non-AD were 93% and 96%, respectively. The FTDs and non-dementia controls were identified versus all other groups with AUROCS of 96% and 87%, respectively. Conclusions: Integration of new and classical CSF biomarkers in a model-based approach can improve the identification of AD, FTD, and non-dementia control subjects.
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| 9. |
- Sravani, Musunuri, 1987-, et al.
(författare)
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Increased Levels of Extracellular Microvesicle Markers and Decreased Levels of Endocytic/Exocytic Proteins in the Alzheimer's Disease Brain
- 2016
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Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 54:4, s. 1671-1686
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Tidskriftsartikel (refereegranskat)abstract
- Background: Alzheimer's disease (AD) is a chronic neurodegenerative disorder accounting for more than 50% of all dementia cases. AD neuropathology is characterized by the formation of extracellular plaques and intracellular neurofibrillary tangles consisting of aggregated amyloid-beta and tau, respectively. The disease mechanism has only been partially elucidated and is believed to also involve many other proteins. Objective: This study intended to perform a proteomic profiling of post mortem AD brains and compare it with control brains as well as brains from other neurological diseases to gain insight into the disease pathology. Methods: Here we used label-free shotgun mass spectrometry to analyze temporal neocortex samples from AD, other neurological disorders, and non-demented controls, in order to identify additional proteins that are altered in AD. The mass spectrometry results were verified by antibody suspension bead arrays. Results: We found 50 proteins with altered levels between AD and control brains. The majority of these proteins were found at lower levels in AD. Pathway analyses revealed that several of the decreased proteins play a role in exocytic and endocytic pathways, whereas several of the increased proteins are related to extracellular vesicles. Using antibody-based analysis, we verified the mass spectrometry results for five representative proteins from this group of proteins (CD9, HSP72, PI42A, TALDO, and VAMP2) and GFAP, a marker for neuroinflammation. Conclusions: Several proteins involved in exo-endocytic pathways and extracellular vesicle functions display altered levels in the AD brain. We hypothesize that such changes may result in disturbed cellular clearance and a perturbed cell-to-cell communication that may contribute to neuronal dysfunction and cell death in AD.
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| 10. |
- Degerman Gunnarsson, Malin, et al.
(författare)
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High Tau Levels in Cerebrospinal Fluid Predict Rapid Decline and Increased Dementia Mortality in Alzheimer's Disease
- 2014
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Ingår i: Dementia and Geriatric Cognitive Disorders. - : S. Karger AG. - 1420-8008 .- 1421-9824. ; 37:3-4, s. 196-206
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Cerebrospinal fluid (CSF) amyloid beta(42) (A beta(42)), total tau (t-tau) and phosphorylated tau (p-tau) are useful as predictors of conversion from mild cognitive impairment (MCI) to Alzheimer's disease (AD) dementia. However, results are contradictory as to whether these biomarkers reflect the future rate of clinical decline. Methods: This is a retrospective study on 196 patients with AD [mild/moderate AD (n = 72) or AD-MCI (n = 124) at baseline] with a follow-up period of 2-9 years' duration (median 6 years). Lumbar punctures were performed at baseline as a part of the diagnostic procedure. Results: We found an increased risk of rapid cognitive decline defined as a drop in the Mini-Mental State Examination score of = 4 points/year in patients with CSF t-tau concentrations above the median (OR 3.31, 95% CI 1.53-7.16) and CSF p-tau above the median (OR 2.53, 95% CI 1.21-5.26). Patients with CSF t-tau in the highest quartile had a higher risk of dying in severe dementia (HR 4.67, 95% CI 1.16-18.82). Conclusions: In this large AD cohort, we found an association between high levels of CSF t-tau and p-tau and a more aggressive course of the disease, measured as a rapid cognitive decline and a higher risk of dying in severe dementia.
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