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- Bereczki, E., et al.
(författare)
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Synaptic proteins predict cognitive decline in Alzheimer's disease andLewy body dementia
- 2016
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Ingår i: Alzheimer's & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 12:11, s. 1149-1158
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Tidskriftsartikel (refereegranskat)abstract
- Introduction Our objective was to compare the levels of three synaptic proteins involved in different steps of the synaptic transmission: Rab3A, SNAP25, and neurogranin, in three common forms of dementia: Alzheimer's disease (AD), dementia with Lewy bodies (DLB), and Parkinson's disease dementia. Methods A total of 129 postmortem human brain samples were analyzed in brain regional specific manner exploring their associations with morphologic changes and cognitive decline. Results We have observed robust changes reflecting synaptic dysfunction in all studied dementia groups. There were significant associations between the rate of cognitive decline and decreased levels of Rab3 in DLB in the inferior parietal lobe and SNAP25 in AD in the prefrontal cortex. Of particular note, synaptic proteins significantly discriminated between dementia cases and controls with over 90% sensitivity and specificity. Discussion Our findings suggest that the proposition that synaptic markers can predict cognitive decline in AD, should be extended to Lewy body diseases. © 2016 The Alzheimer's Association
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- Bereczki, E., et al.
(författare)
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Synaptic proteins in CSF relate to Parkinson's disease stage markers
- 2017
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Ingår i: Npj Parkinsons Disease. - : Springer Science and Business Media LLC. - 2373-8057. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- Recent findings of morphological and functional changes in Parkinson's disease brains have shown altered synapse formation, but their role in cognitive decline is still an area under exploration. Here we measured the concentration of three key synaptic proteins, Rab3A, SNAP25 and neurogranin by enzyme-linked immunosorbent assay, in cerebrospinal fluid from a total of 139 participants (87 controls and 52 Parkinson's disease patients out of which 30 were drug-naive) and explored their associations with motor and cognitive symptoms. Associations with motor disease stage (assessed by Hoehn and Yahr scale) and cognitive performance (assessed by the Montreal Cognitive Assessment scores) were explored. An overall increase in the concentration of SNAP25 was found in Parkinson's disease patients (p = 0.032). Increased neurogranin levels were found in the drug naive patients subgroup (p = 0.023). Significant associations were observed between increased concentration of neurogranin and cognitive impairment in total Parkinson's disease group (p = 0.017), as well as in the drug naive (p = 0.021) and with motor disease stage (p = 0.041). There were no significant disease-driven changes observed in the concentration of Rab3a. Concentrations SNAP25 and neurogranin were increased in cerebrospinal fluid of Parkinson's disease patients in a disease specific manner and related to cognitive and motor symptom severity. Future longitudinal studies should explore whether cerebrospinal fluid synaptic proteins can predict cognitive decline in Parkinson's disease.
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- Bogstedt, A., et al.
(författare)
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Development of Immunoassays for the Quantitative Assessment of Amyloid-β in the Presence of Therapeutic Antibody: Application to Pre-Clinical Studies
- 2015
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 46:4, s. 1091-1101
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Tidskriftsartikel (refereegranskat)abstract
- Utilizing decision making biomarkers in drug development requires thorough assay validation. Special considerations need to be taken into account when monitoring biomarkers using immunoassays in the presence of therapeutic antibodies. We have developed robust and sensitive assays to assess target engagement and proof of mechanism to support the clinical progression of a human monoclonal antibody against the neurotoxic amyloid-β (Aβ)42 peptide. Here we present the introduction of novel pre-treatment steps to ensure drug-tolerant immunoassays and describe the validation of the complete experimental procedures to measure total Aβ42 concentration (bound and unbound) in cerebrospinal fluid (CSF) and plasma, free Aβ42 concentration (unbound) in CSF, and Aβ40 concentration in CSF. The difference in composition of the matrices (CSF and plasma) and antigen levels therein, in combination with the hydrophobic properties of Aβ protein, adds to the complexity of validation. Monitoring pharmacodynamics of an Aβ42 specific monoclonal antibody in a non-human primate toxicology study using these assays, we demonstrated a 1500-fold and a 3000-fold increase in total Aβ42 in plasma, a 4-fold and 8-fold increase in total Aβ42 in CSF together with a 95% and 96% reduction of free Aβ42 in CSF following weekly intravenous injections of 10 mg/kg and 100 mg/kg, respectively. Levels of Aβ40 were unchanged. The accuracy of these data is supported by previous pre-clinical studies as well as predictive pharmacokinetic/pharmacodynamics modeling. In contrast, when analyzing the same non-human primate samples excluding the pre-treatment steps, we were not able to distinguish between free and total Aβ42. Our data clearly demonstrate the importance of thorough evaluation of antibody interference and appropriate validation to monitor different types of biomarkers in the presence of a therapeutic antibody. © 2015-IOS Press and the authors. All rights reserved.
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- Eketjäll, Susanna, et al.
(författare)
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AZD3293: A Novel, Orally Active BACE1 Inhibitor with High Potency and Permeability and Markedly Slow Off-Rate Kinetics
- 2016
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 50:4, s. 1109-1123
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Tidskriftsartikel (refereegranskat)abstract
- A growing body of pathological, biomarker, genetic, and mechanistic data suggests that amyloid accumulation, as a result of changes in production, processing, and/or clearance of brain amyloid-beta peptide (A beta) concentrations, plays a key role in the pathogenesis of Alzheimer's disease (AD). Beta-secretase 1 (BACE1) mediates the first step in the processing of amyloid-beta protein precursor (A beta PP) to A beta peptides, with the soluble N terminal fragment of A beta PP (sA beta PP beta) as a direct product, and BACE1 inhibition is an attractive target for therapeutic intervention to reduce the production of A beta. Here, we report the in vitro and in vivo pharmacological profile of AZD3293, a potent, highly permeable, orally active, blood-brain barrier (BBB) penetrating, BACE1 inhibitor with unique slow off-rate kinetics. The in vitro potency of AZD3293 was demonstrated in several cellular models, including primary cortical neurons. In vivo in mice, guinea pigs, and dogs, AZD3293 displayed significant dose-and time-dependent reductions in plasma, cerebrospinal fluid, and brain concentrations of A beta(40), A beta(42), and sA beta PP beta. The in vitro potency of AZD3293 in mouse and guinea pig primary cortical neuronal cells was correlated to the in vivo potency expressed as free AZD3293 concentrations in mouse and guinea pig brains. In mice and dogs, the slow off-rate from BACE1 may have translated into a prolongation of the observed effect beyond the turnover rate of A beta. The preclinical data strongly support the clinical development of AZD3293, and patients with AD are currently being recruited into a combined Phase 2/3 study to test the disease-modifying properties of AZD3293.
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