| 1. |
- Alic, I., et al.
(författare)
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Patient-specific Alzheimer-like pathology in trisomy 21 cerebral organoids reveals BACE2 as a gene dose-sensitive AD suppressor in human brain
- 2021
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Ingår i: Molecular Psychiatry. - : Springer Science and Business Media LLC. - 1359-4184 .- 1476-5578. ; 26:10, s. 5766-5788
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Tidskriftsartikel (refereegranskat)abstract
- A population of more than six million people worldwide at high risk of Alzheimer's disease (AD) are those with Down Syndrome (DS, caused by trisomy 21 (T21)), 70% of whom develop dementia during lifetime, caused by an extra copy of beta-amyloid-(A beta)-precursor-protein gene. We report AD-like pathology in cerebral organoids grown in vitro from non-invasively sampled strands of hair from 71% of DS donors. The pathology consisted of extracellular diffuse and fibrillar A beta deposits, hyperphosphorylated/pathologically conformed Tau, and premature neuronal loss. Presence/absence of AD-like pathology was donor-specific (reproducible between individual organoids/iPSC lines/experiments). Pathology could be triggered in pathology-negative T21 organoids by CRISPR/Cas9-mediated elimination of the third copy of chromosome 21 gene BACE2, but prevented by combined chemical beta and gamma-secretase inhibition. We found that T21 organoids secrete increased proportions of A beta-preventing (A beta 1-19) and A beta-degradation products (A beta 1-20 and A beta 1-34). We show these profiles mirror in cerebrospinal fluid of people with DS. We demonstrate that this protective mechanism is mediated by BACE2-trisomy and cross-inhibited by clinically trialled BACE1 inhibitors. Combined, our data prove the physiological role of BACE2 as a dose-sensitive AD-suppressor gene, potentially explaining the dementia delay in similar to 30% of people with DS. We also show that DS cerebral organoids could be explored as pre-morbid AD-risk population detector and a system for hypothesis-free drug screens as well as identification of natural suppressor genes for neurodegenerative diseases.
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| 2. |
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| 3. |
- de Rojas, I., et al.
(författare)
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Common variants in Alzheimer’s disease and risk stratification by polygenic risk scores
- 2021
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Genetic discoveries of Alzheimer’s disease are the drivers of our understanding, and together with polygenetic risk stratification can contribute towards planning of feasible and efficient preventive and curative clinical trials. We first perform a large genetic association study by merging all available case-control datasets and by-proxy study results (discovery n = 409,435 and validation size n = 58,190). Here, we add six variants associated with Alzheimer’s disease risk (near APP, CHRNE, PRKD3/NDUFAF7, PLCG2 and two exonic variants in the SHARPIN gene). Assessment of the polygenic risk score and stratifying by APOE reveal a 4 to 5.5 years difference in median age at onset of Alzheimer’s disease patients in APOE ɛ4 carriers. Because of this study, the underlying mechanisms of APP can be studied to refine the amyloid cascade and the polygenic risk score provides a tool to select individuals at high risk of Alzheimer’s disease. © 2021, The Author(s).
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| 4. |
- Hendrix, S. B., et al.
(författare)
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Alzheimer's Disease Composite Score: a Post-Hoc Analysis Using Data from the LipiDiDiet Trial in Prodromal Alzheimer's Disease
- 2019
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Ingår i: Jpad-Journal of Prevention of Alzheimers Disease. - : SERDI. - 2274-5807 .- 2426-0266. ; 6:4, s. 232-236
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Tidskriftsartikel (refereegranskat)abstract
- As research evolves in prodromal AD, the need to validate sufficiently sensitive outcome measures, e.g. the Alzheimer's Disease Composite Score (ADCOMS) is clear. In the LipiDiDiet randomized trial in prodromal AD, cognitive decline in the study population was much less than expected in the timeframe studied. While the primary composite endpoint was insufficiently sensitive to detect a difference in the modified intention to treat population, the per-protocol population showed less decline in the active than the control group, indicating better treatment effects with regular product intake. These results were further strengthened by significant benefits on secondary endpoints of cognition and function, and brain atrophy. The present post-hoc analysis investigated whether ADCOMS could detect a difference between groups in the LipiDiDiet population (138 active, 140 control). The estimated mean change in ADCOMS from baseline (standard error) was 0.085 (0.018) in the active and 0.133 (0.018) in the control group; estimated mean treatment difference -0.048 (95% confidence intervals -0.090, -0.007; p=0.023), or 36% less decline in the active group. This suggests ADCOMS identified the cognitive and functional benefits observed previously, confirming the sensitivity of this composite measure.
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| 5. |
- Hendrix, S. B., et al.
(författare)
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Combined Evidence for a Long-Term, Clinical Slowing Effect of Multinutrient Intervention in Prodromal Alzheimer's Disease: Post-Hoc Analysis of 3-Year Data from the LipiDiDiet Trial
- 2023
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Ingår i: Jpad-Journal of Prevention of Alzheimers Disease. - : SERDI. - 2274-5807 .- 2426-0266. ; 10:3, s. 464-70
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Tidskriftsartikel (refereegranskat)abstract
- The LipiDiDiet randomized clinical trial is evaluating the long term effects of a multinutrient intervention (Fortasyn Connect) compared with control in participants with prodromal AD. In this post-hoc analysis we used the Alzheimer's Disease Composite Score (ADCOMS) as a measure of cognition and global function, together with a global statistical test (GST) and Bayesian hierarchical modelling (BHM) to evaluate the totality of evidence for an effect of the intervention over 36 months. The analysis includes 67 participants (39 active, 28 control) with change from baseline data after 36 months intervention. All outcome measures showed a statistically significant effect for the intervention: ADCOMS (P =0.045), GST (P <0.001), and BHM (P =0.008 based on 3 outcomes and P <0.001 including all primary and secondary quantitative clinical outcomes). Fortasyn Connect was associated with significantly less clinical decline over 36 months, suggesting the long-lasting beneficial effects of the multinutrient in prodromal AD.
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| 6. |
- Morris, J. C., et al.
(författare)
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Harmonized diagnostic criteria for Alzheimer's disease: recommendations
- 2014
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Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 275:3, s. 204-213
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundTwo major sets of criteria for the clinical diagnosis of Alzheimer's disease (AD) recently have been published, one from an International Working Group (IWG) and the other from working groups convened by the National Institute on Aging (NIA) and the Alzheimer's Association (AA) in the United States. These criteria both aim to support a clinical diagnosis with in vivo evidence of AD pathology, using imaging methods and detection of biofluid biomarkers, and emphasize an aetiological diagnosis even in the prodromal stages of the disorder. Nonetheless, there are substantial differences in these two sets of criteria. MethodsAn international group of investigators with experience in the clinical diagnosis of AD met at the Key Symposium in Stockholm, Sweden on 6 & 7 December 2012, to develop recommendations to harmonize these criteria. The group was led by individuals who were integral to the development of both the IWG and the NIA-AA criteria. The similarities and differences between the two sets of criteria were identified and open discussion focused on ways to resolve the differences and thus yield a harmonized set of criteria. ResultsBased on both published evidence as well as the group's collective clinical experience, the group was tasked with achieving consensus, if not unanimity, as it developed recommendations for harmonized clinical diagnostic criteria for AD. ConclusionThe recommendations are to: (i) define AD as a brain disorder, regardless of clinical status; (ii) refer to the clinically expressed disorder, including its prodromal stages, as symptomatic AD; (iii) after the successful completion of standardization efforts, consider incorporating biomarkers into diagnostic algorithms for AD; and (iv) allow nonamnestic, atypical presentations to be included as symptomatic AD, especially when there is supportive biomarker evidence.
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| 7. |
- Portelius, Erik, 1977, et al.
(författare)
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Altered Cerebrospinal Fluid Levels of Amyloid beta and Amyloid Precursor-Like Protein 1 Peptides in Down's Syndrome
- 2014
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Ingår i: Neuromolecular medicine. - : Springer Science and Business Media LLC. - 1535-1084 .- 1559-1174. ; 16:2, s. 510-516
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Tidskriftsartikel (refereegranskat)abstract
- Down's syndrome (DS) patients develop early Alzheimer's disease pathology with abundant cortical amyloid plaques, likely due to overproduction of the amyloid precursor protein (APP), which subsequently leads to amyloid beta (A beta) aggregation. This is reflected in cerebrospinal fluid (CSF) levels of the 42-amino acid long A beta peptide (A beta 1-42), which are increased in young DS patients and decreases with age. However, it is unclear whether DS also affects other aspects of A beta metabolism, including production of shorter C- and N-terminal truncated A beta peptides, and production of peptides from the amyloid precursor-like protein 1 (APLP1), which is related to APP, and cleaved by the same enzymatic processing machinery. APLP1-derived peptides may be surrogate markers for A beta 1-42 production in the brain. Here, we used hybrid immunoaffinity-mass spectrometry and enzyme-linked immunosorbent assays to monitor several A beta and APLP1 peptides in CSF from DS patients (n = 12) and healthy controls (n = 20). CSF levels of A beta 1-42 and three endogenous peptides derived from APLP1 (APL1 beta 25, APL1 beta 27 and APL1 beta 28) were decreased in DS compared with controls, while a specific A beta peptide, A beta 1-28, was increased in a majority of the DS individuals. This study indicates that DS causes previously unknown specific alterations of APP and APLP1 metabolism.
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| 8. |
- Ramakers, I. H. G. B., et al.
(författare)
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Anxiety is related to Alzheimer cerebrospinal fluid markers in subjects with mild cognitive impairment
- 2013
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Ingår i: Psychological Medicine. - 0033-2917 .- 1469-8978. ; 43:5, s. 911-920
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Tidskriftsartikel (refereegranskat)abstract
- Background Anxiety, apathy and depression are common in subjects with mild cognitive impairment (MCI) and may herald Alzheimer's disease (AD). We investigated whether these symptoms correlated with cerebrospinal fluid (CSF) markers for AD in subjects with MCI. Method Subjects with MCI (n=268) were selected from the 'Development of screening guidelines and criteria for pre-dementia Alzheimer's disease' (DESCRIPA) and Alzheimer's Disease Neuroimaging Initiative (ADNI) studies. We measured amyloid β(1-42) protein (Aβ42) and total tau (t-tau) in CSF. Neuropsychiatric symptoms were measured with the Neuropsychiatric Inventory. Results Depressive symptoms were reported by 55 subjects (21%), anxiety by 35 subjects (13%) and apathy by 49 subjects (18%). The presence of anxiety was associated with abnormal CSF Aβ42 [odds ratio (OR) 2.3, 95% confidence interval (CI) 1.6-3.3] and t-tau (OR 2.6, 95% CI 1.9-3.6) concentrations and with the combination of abnormal concentrations of both Aβ42 and t-tau (OR 3.1, 95% CI 2.0-4.7). The presence of agitation and irritability was associated with abnormal concentrations of Aβ42 (agitation: OR 1.6, 95% CI 1.1-2.3; irritability: OR 2.2, 95% CI 1.5-3.3). Symptoms of depression and apathy were not related to any of the CSF markers. Conclusions In subjects with MCI, symptoms of anxiety, agitation and irritability may reflect underlying AD pathology, whereas symptoms of depression and apathy do not. © 2012 Cambridge University Press.
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| 9. |
- van Doorn, Ljcv, et al.
(författare)
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Improved Cerebrospinal Fluid-Based Discrimination between Alzheimer's Disease Patients and Controls after Correction for Ventricular Volumes
- 2017
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Ingår i: Journal of Alzheimers Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 56:2, s. 543-555
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Tidskriftsartikel (refereegranskat)abstract
- Cerebrospinal fluid (CSF) biomarkers may support the diagnosis of Alzheimer's disease (AD). We studied if the diagnostic power of AD CSF biomarker concentrations, i.e., A beta(42), total tau (t-tau), and phosphorylated tau (p-tau), is affected by differences in lateral ventricular volume (VV), using CSF biomarker data and magnetic resonance imaging (MRI) scans of 730 subjects, from 13 European Memory Clinics. We developed a Matlab-algorithm for standardized automated segmentation analysis of T1 weighted MRI scans in SPM8 for determining VV, and computed its ratio with total intracranial volume (TIV) as proxy for total CSF volume. The diagnostic power of CSF biomarkers (and their combination), either corrected for VV/TIV ratio or not, was determined by ROC analysis. CSF A beta(42) levels inversely correlated to VV/TIV in the whole study population (A beta(42): r = -0.28; p < 0.0001). For CSF t-tau and p-tau, this association only reached statistical significance in the combined MCI and AD group (t-tau: r = -0.15; p-tau: r = -0.13; both p < 0.01). Correction for differences in VV/TIV improved the differentiation of AD versus controls based on CSF A beta(42) alone (AUC: 0.75 versus 0.81) or in combination with t-tau (AUC: 0.81 versus 0.91). In conclusion, differences in VV may be an important confounder in interpreting CSF A beta(42) levels.
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| 10. |
- Vermunt, L., et al.
(författare)
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Duration of preclinical, prodromal, and dementia stages of Alzheimer's disease in relation to age, sex, and APOE genotype
- 2019
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Ingår i: Alzheimers & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 15:7, s. 888-898
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: We estimated the age-specific duration of the preclinical, prodromal, and dementia stages of Alzheimer's disease (AD) and the influence of sex, setting, apolipoprotein E (APOE) genotype, and cerebrospinal fluid tau on disease duration. Methods: We performed multistate modeling in a combined sample of 6 cohorts (n = 3268) with death as the end stage and estimated the preclinical, prodromal, and dementia stage duration. Results: The overall AD duration varied between 24 years (age 60) and 15 years (age 80). For individuals presenting with preclinical AD, age 70, the estimated preclinical AD duration was 10 years, prodromal AD 4 years, and dementia 6 years. Male sex, clinical setting, APOE epsilon 4 allele carriership, and abnormal cerebrospinal fluid tau were associated with a shorter duration, and these effects depended on disease stage. Discussion: Estimates of AD disease duration become more accurate if age, sex, setting, APOE, and cerebrospinal fluid tau are taken into account. This will be relevant for clinical practice and trial design. (C) 2019 the Alzheimer's Association. Published by Elsevier Inc. All rights reserved.
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