| 31. |
- Lerche, S., et al.
(författare)
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CSF Protein Level of Neurotransmitter Secretion, Synaptic Plasticity, and Autophagy in PD and DLB
- 2021
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Ingår i: Movement Disorders. - : Wiley. - 0885-3185 .- 1531-8257. ; 36:11, s. 2595-2604
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Tidskriftsartikel (refereegranskat)abstract
- Background Molecular pathways associated with alpha-synuclein proteostasis have been detected in genetic studies and in cell models and include autophagy, ubiquitin-proteasome system, mitochondrial homeostasis, and synaptic plasticity. However, we lack biomarkers that are representative for these pathways in human biofluids. Objective The objective of this study was to evaluate CSF protein profiles of pathways related to alpha-synuclein proteostasis. Methods We assessed CSF protein profiles associated with neurotransmitter secretion, synapse plasticity, and autophagy in 2 monocentric cohorts with alpha-synucleinopathy (385 PD patients and 67 DLB patients). We included 80 PD patients and 17 DLB patients with variants in the glucocerebrosidase gene to serve as proxy for accelerated alpha-synuclein pathology with pronounced clinical trajectories. Results (1) Proteins associated with neurotransmitter secretion, synaptic plasticity, and endolysosomal autophagy were lower in PD and DLB patients compared with healthy controls. (2) These patterns were more pronounced in DLB than in PD patients, accentuated by GBA variant status in both entities. (3) CSF levels of these proteins were positively associated with CSF levels of total alpha-synuclein, with lower levels of proteostasis proteins related to lower levels of total alpha-synuclein. (4) These findings could be confirmed longitudinally. PD patients with low CSF profiles of proteostasis proteins showed lower CSF levels of alpha-synuclein longitudinally compared with PD patients with a normal proteostasis profile. Conclusion CSF proteins associated with neurotransmitter secretion, synaptic plasticity, and endolysosomal autophagy might serve as biomarkers related to alpha-synuclein proteostasis in PD and DLB. (c) 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society
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| 32. |
- Mander, B. A., et al.
(författare)
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Inflammation, tau pathology, and synaptic integrity associated with sleep spindles and memory prior to beta-amyloid positivity
- 2022
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Ingår i: Sleep. - : Oxford University Press (OUP). - 0161-8105 .- 1550-9109. ; 45:9
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Tidskriftsartikel (refereegranskat)abstract
- Study Objectives Fast frequency sleep spindles are reduced in aging and Alzheimer's disease (AD), but the mechanisms and functional relevance of these deficits remain unclear. The study objective was to identify AD biomarkers associated with fast sleep spindle deficits in cognitively unimpaired older adults at risk for AD. Methods Fifty-eight cognitively unimpaired, beta-amyloid-negative, older adults (mean +/- SD; 61.4 +/- 6.3 years, 38 female) enriched with parental history of AD (77.6%) and apolipoprotein E (APOE) epsilon 4 positivity (25.9%) completed the study. Cerebrospinal fluid (CSF) biomarkers of central nervous system inflammation, beta-amyloid and tau proteins, and neurodegeneration were combined with polysomnography (PSG) using high-density electroencephalography and assessment of overnight memory retention. Parallelized serial mediation models were used to assess indirect effects of age on fast frequency (13 to <16Hz) sleep spindle measures through these AD biomarkers. Results Glial activation was associated with prefrontal fast frequency sleep spindle expression deficits. While adjusting for sex, APOE epsilon 4 genotype, apnea-hypopnea index, and time between CSF sampling and sleep study, serial mediation models detected indirect effects of age on fast sleep spindle expression through microglial activation markers and then tau phosphorylation and synaptic degeneration markers. Sleep spindle expression at these electrodes was also associated with overnight memory retention in multiple regression models adjusting for covariates. Conclusions These findings point toward microglia dysfunction as associated with tau phosphorylation, synaptic loss, sleep spindle deficits, and memory impairment even prior to beta-amyloid positivity, thus offering a promising candidate therapeutic target to arrest cognitive decline associated with aging and AD.
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| 33. |
- Michno, Wojciech, 1992, et al.
(författare)
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Following spatial Aβ aggregation dynamics in evolving Alzheimer's disease pathology by imaging stable isotope labeling kinetics
- 2021
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 7:25
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Tidskriftsartikel (refereegranskat)abstract
- β-Amyloid (Aβ) plaque formation is the major pathological hallmark of Alzheimer's disease (AD) and constitutes a potentially critical, early inducer driving AD pathogenesis as it precedes other pathological events and cognitive symptoms by decades. It is therefore critical to understand how Aβ pathology is initiated and where and when distinct Aβ species aggregate. Here, we used metabolic isotope labeling in APPNL-G-F knock-in mice together with mass spectrometry imaging to monitor the earliest seeds of Aβ deposition through ongoing plaque development. This allowed visualizing Aβ aggregation dynamics within single plaques across different brain regions. We show that formation of structurally distinct plaques is associated with differential Aβ peptide deposition. Specifically, Aβ1-42 is forming an initial core structure followed by radial outgrowth and late secretion and deposition of Aβ1-38. These data describe a detailed picture of the earliest events of precipitating amyloid pathology at scales not previously possible. Copyright © 2021 The Authors, some rights reserved.
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| 34. |
- Olsson, A, et al.
(författare)
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Measurement of alpha- and beta-secretase cleaved amyloid precursor protein in cerebrospinal fluid from Alzheimer patients
- 2003
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Ingår i: Experimental Neurology. - 0014-4886. ; 183, s. 74-
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Tidskriftsartikel (refereegranskat)abstract
- One of the major histopathological hallmarks of Alzheimer's disease (AD) is redundant senile plaques mainly composed of beta-amyloid (Abeta) aggregates. Alternative cleavage of the amyloid precursor protein (APP), occurring in both normal and AD subjects, results in the generation and secretion of soluble APP (sAPP) and Abeta. We examined the cerebrospinal fluid (CSF) for alpha- and beta-secretase cleaved sAPP (alpha-sAPP and beta-sAPP) in 81 sporadic AD patients, 19 patients with mild cognitive impairment, and 42 healthy controls by using newly developed sandwich enzyme-linked immunosorbent assay methods. We found that neither the level of CSF-alpha-sAPP nor CSF-beta-sAPP differed between sporadic AD patients and healthy controls. These findings further support the conclusion that there is no change in APP expression in sporadic AD. However, the level of CSF-beta-sAPP was significantly increased in patients with mild cognitive impairment compared to controls. We also investigated the relationship between the CSF level of alphabeta-sAPP and Abeta(42) and the apoE epsilon4 (apoFA.) allele. Significantly lower levels of CSF-alpha-sAPP were found in AD patients possessing one or two apoE4 alleles than in those not possessing the apoE4 allele. Neither the levels of CSF-beta-sAPP nor CSF-Abeta(42) differed when comparing ApoE4 allele-positive with allele-negative individuals. (C) 2003 Elsevier Science (USA). All rights reserved.
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| 35. |
- Onatsu, J., et al.
(författare)
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Tau, S100B and NSE as Blood Biomarkers in Acute Cerebrovascular Events
- 2020
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Ingår i: In Vivo. - : Anticancer Research USA Inc.. - 0258-851X .- 1791-7549. ; 34:5, s. 2577-2586
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Tidskriftsartikel (refereegranskat)abstract
- Background/Aim: We aimed to analyze the diagnostic value of total tau (T- tau), S-100 calcium-binding protein B (S100B) and neuron-specific enolase (NSE) as blood-based biomarkers in acute ischemic stroke (AIS) or transient ischemic attack (TIA), and their correlation with symptom severity, infarct size, etiology and outcome. Patients and Methods: A total of 102 patients with stroke and 35 with TIA were analyzed. Subacute (63.8 +/- 50.1 h) plasma T-tau was measured with the single-molecule array (Simoa) method and NSE and S100B were evaluated for comparison. We evaluated biomarkers associations with: (i) diagnosis of AIS or TIA, (ii) cerebral infarction volume in the brain computed tomography, (iii) stroke etiology, (iv) clinical stroke severity and (iv) functional outcome after three months. Results: T-tau was higher in patients with stroke (1.0 pg/ml (IQR=0.3-2 2)] than with TIA (05 pg/ml (IQR=0.2- 1 .0), p=0.02] . The levels of S100B were also increased in stroke [0.082 mu g/l (IQR=0.049-0.157)] patients compared to TIA patients (0.045 mu g/l (IQR=0.03 -0.073 ), p<0.001]. However, when the results were adjusted for confounders, significance was lost. Serum levels of NSE among patients with AIS [11.85 mu g/l (IQR=9.30-16.14)] compared to those with TIA (10.96 mu g/l (IQR=7 .98-15.33), p=0.301 were equal. T-tau and S100B concentrations significantly correlated with cerebral infarction volume (r=0.412, p<0.001) and (r=0.597, p<0.001), also after corrections (p<0.001). mRS scores at three-month follow-up correlated with T-tau (r=0.248, p=0.016) and S100B concentrations (r=0.205, p=0.045). Conclusion: For the diagnosis of TIA vs. AIS, blood T-tau and S100B concentrations discriminated only modestly. Additionally, groups were not separable after measuring of T-tau and S100B levels in the blood. T-tau and S100B concentrations correlated with the infarct size, but were not alone predictive for functional outcome at 3 months.
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| 36. |
- Osborn, K. E., et al.
(författare)
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Adverse Vascular Risk Relates to Cerebrospinal Fluid Biomarker Evidence of Axonal Injury in the Presence of Alzheimer's Disease Pathology
- 2019
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Ingår i: Journal of Alzheimers Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 71:1, s. 281-290
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Tidskriftsartikel (refereegranskat)abstract
- Background: Vascular risk factors promote cerebral small vessel disease and neuropathological changes, particularly in white matter where large-caliber axons are located. How Alzheimer's disease pathology influences the brain's vulnerability in this regard is not well understood. Objective: Systemic vascular risk was assessed in relation to cerebrospinal fluid concentrations of neurofilament light, a biomarker of large-caliber axonal injury, evaluating for interactions by clinical and protein markers of Alzheimer's disease. Methods: Among Alzheimer's Disease Neuroimaging Initiative participants with normal cognition (n = 117), mild cognitive impairment (n = 190), and Alzheimer's disease (n = 95), linear regression related vascular risk (as measured by the modified Framingham Stroke Risk Profile) to neurofilament light, adjusting for age, sex, education, and cognitive diagnosis. Interactions were assessed by cognitive diagnosis, and by cerebrospinal fluid markers of A beta(42), hyperphosphorylated tau, and total tau. Results: Vascular risk and neurofilament light were not related in the main effect model (p = 0.08). However, interactions emerged for total tau (p = 0.01) and hyperphosphorylated tau (p = 0.002) reflecting vascular risk becoming more associated with cerebrospinal fluid neurofilament light in the context of greater concentrations of tau biomarkers. An interaction also emerged for the Alzheimer's disease biomarker profiles (p = 0.046) where in comparison to the referent 'normal' biomarker group, individuals with abnormal levels of both A beta(42) and total tau showed stronger associations between vascular risk and neurofilament light. Conclusion: Older adults may be more vulnerable to axonal injury in response to higher vascular risk burdens in the context of concomitant Alzheimer's disease pathology.
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| 37. |
- Osborn, K. E., et al.
(författare)
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Cerebrospinal fluid beta-amyloid(42) and neurofilament light relate to white matter hyperintensities
- 2018
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Ingår i: Neurobiology of Aging. - : Elsevier BV. - 0197-4580. ; 68, s. 18-25
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Tidskriftsartikel (refereegranskat)abstract
- White matter hyperintensities (WMHs) are associated with poorer brain health, but their pathophysiological substrates remain elusive. To better understand the mechanistic underpinnings of WMHs among older adults, this study examined in vivo cerebrospinal fluid biomarkers of beta-amyloid(42) deposition (A beta(42)), hyperphosphorylated tau pathology, neurodegeneration (total tau), and axonal injury (neurofilament light [NFL]) in relation to log-transformed WMHs volume. Participants free of clinical stroke and dementia were drawn from the Vanderbilt Memory & Aging Project (n = 148, 72 +/- 6 years). Linear regression models adjusted for age, sex, race/ethnicity, education, intracranial volume, modified Framingham Stroke Risk Profile (excluding points assigned for age), cognitive diagnosis, and APOE-epsilon 4 carrier status. A beta(42) (beta = -0.001, p = 0.007) and NFL (beta = 0.0003, p = 0.01) concentrations related to WMHs but neither hyperphosphorylated tau nor total tau associations with WMHs reached statistical significance (p-values > 0.21). In a combined model, NFL accounted for 3.2% of unique variance in WMHs and A beta(42) accounted for an additional 4.3% beyond NFL, providing novel evidence of the co-occurrence of at least 2 distinct pathways for WMHs among older adults, including amyloid deposition and axonal injury. (C) 2018 Elsevier Inc. All rights reserved.
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| 38. |
- Posti, J. P., et al.
(författare)
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Correlation of Blood Biomarkers and Biomarker Panels with Traumatic Findings on Computed Tomography after Traumatic Brain Injury
- 2019
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 0897-7151 .- 1557-9042. ; 36:14, s. 2178-89
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to examine the ability of eight protein biomarkers and their combinations in discriminating computed tomography (CT)-negative and CT-positive patients with traumatic brain injury (TBI), utilizing highly sensitive immunoassays in a well-characterized cohort. Blood samples were obtained from 160 patients with acute TBI within 24 h of admission. Levels of beta-amyloid isoforms 1-40 (A beta 40) and 1-42 (A beta 42), glial fibrillary acidic protein (GFAP), heart fatty-acid binding protein (H-FABP), interleukin 10 (IL-10), neurofilament light (NF-L), S100 calcium-binding protein B (S100B), and tau were measured. Patients were divided into CT-negative (n = 65) and CT-positive (n = 95), and analyses were conducted separately for TBIs of all severities (Glasgow Coma Scale [GCS] score 3-15) and mild TBIs (mTBIs; GCS 13-15). NF-L, GFAP, and tau were the best in discriminating CT-negative and CT-positive patients, both in patients with mTBI and with all severities. In patients with all severities, area under the curve of the receiver operating characteristic (AUC) was 0.822, 0.817, and 0.781 for GFAP, NF-L, and tau, respectively. In patients with mTBI, AUC was 0.720, 0.689, and 0.676, for GFAP, tau, and NF-L, respectively. The best panel of three biomarkers for discriminating CT-negative and CT-positive patients in the group of all severities was a combination of GFAP+H-FABP+IL-10, with a sensitivity of 100% and specificity of 38.5%. In patients with mTBI, the best panel of three biomarkers was H-FABP+S100B+tau, with a sensitivity of 100% and specificity of 46.4%. Panels of biomarkers outperform individual biomarkers in separating CT-negative and CT-positive patients. Panels consisted mainly of different biomarkers than those that performed best as an individual biomarker.
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| 39. |
- Vergallo, A., et al.
(författare)
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Plasma amyloid beta 40/42 ratio predicts cerebral amyloidosis in cognitively normal individuals at risk for Alzheimer's disease
- 2019
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Ingår i: Alzheimers & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 15:6, s. 764-775
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Blood-based biomarkers of pathophysiological brain amyloid beta (A beta) accumulation, particularly for preclinical target and large-scale interventions, are warranted to effectively enrich Alzheimer's disease clinical trials and management. Methods: We investigated whether plasma concentrations of the A beta(1-40)/A beta(1-42) ratio, assessed using the single-molecule array (Simoa) immunoassay, may predict brain A beta positron emission tomography status in a large-scale longitudinal monocentric cohort (N = 276) of older individuals with subjective memory complaints. We performed a hypothesis-driven investigation followed by a no-apriori hypothesis study using machine learning. Results: The receiver operating characteristic curve and machine learning showed a balanced accuracy of 76.5% and 81%, respectively, for the plasma A beta(1-40)/A beta(1-42) ratio. The accuracy is not affected by the apolipoprotein E (APOE) epsilon 4 allele, sex, or age. Discussion: Our results encourage an independent validation cohort study to confirm the indication that the plasma A beta(1-40)/A beta(1-42) ratio, assessed via Simoa, may improve future standard of care and clinical trial design. (C) 2019 the Alzheimer's Association. Published by Elsevier Inc. All rights reserved.
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| 40. |
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