201
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de la Torre JC, Olmo AD, Valles S. Can mild cognitive impairment be stabilized by showering brain mitochondria with laser photons? Neuropharmacology 2019; 171:107841. [PMID: 31704275 DOI: 10.1016/j.neuropharm.2019.107841] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 10/30/2019] [Accepted: 11/03/2019] [Indexed: 11/17/2022]
Abstract
There is now substantial evidence that cerebral blood flow (CBF) declines with age. From age 20 to 60, CBF is estimated to dip about 16% and continues to drop at a rate of 0.4%/year. This CBF dip will slowly reduce oxygen/glucose delivery to brain thus lowering ATP energy production needed by brain cells to perform normal activities. Reduced ATP production from mitochondrial loss or damage in the wear-and-tear of aging worsens when vascular risk factors (VRF) to Alzheimer's disease develop that can accelerate both age-decline CBF and mitochondrial deficiency to a level where mild cognitive impairment (MCI) develops. To date, no pharmacological or any other treatment has been successful in reversing, stabilizing or delaying MCI. For the first time in medical interventions, a non-pharmacological, non-invasive, well-tolerated, easy to perform, free of significant side effects and cost-effective treatment may achieve what virtually all AD treatments in the past have been unable to accomplish. This intervention uses transcranial infrared brain stimulation (TIBS), a form of photobiomodulation (PBM). PBM is a bioenergetic non-ionizing, therapeutic approach using low level light emission from laser or light emitting diodes. PBM has been used in a number of neurological conditions including Parkinson's disease, depression, traumatic brain injury, and stroke with diverse reported benefits. This brief review examines the impact of reduced energy supply stemming from chronic brain hypoperfusion in the aging brain. In this context, the use of TIBS is planned in a randomized, placebo-controlled study of MCI patients to be done at our University Clinic. This article is part of the special issue entitled 'The Quest for Disease-Modifying Therapies for Neurodegenerative Disorders'.
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Affiliation(s)
- Jack C de la Torre
- Department of Psychology, University of Texas at Austin, Austin, TX, 78712, USA; Department of Physiology, University of Valencia, Valencia, 46010, Spain.
| | - Antonio Del Olmo
- Neurology Section, Hospital Universitario Dr. Peset, Valencia, 46017, Spain
| | - Soraya Valles
- Department of Physiology, University of Valencia, Valencia, 46010, Spain
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202
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Yasuno F, Kajimoto K, Ihara M, Taguchi A, Yamamoto A, Fukuda T, Kazui H, Iida H, Nagatsuka K. Amyloid β deposition in subcortical stroke patients and effects of educational achievement: A pilot study. Int J Geriatr Psychiatry 2019; 34:1651-1657. [PMID: 31328305 DOI: 10.1002/gps.5178] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 07/17/2019] [Indexed: 02/05/2023]
Abstract
OBJECTIVE A direct causal relationship of cerebrovascular risk factors/stroke to amyloid β (Aβ) deposition has yet to be shown. We conducted [11 C] Pittsburgh compound B (PiB)-positron emission tomography (PET) analysis on subacute ischemic stroke patients and healthy controls. We hypothesized that subacute ischemic stroke patients would show focal Aβ accumulation in cortical regions, which would increase and extend over time during the chronic phase after stroke onset. METHODS Patients were recruited 14 to 28 days after acute subcortical ischemic stroke and examined with [11 C]PiB-PET scans. Regional time-activity data were analyzed with the Logan graphical method. Whole brain voxel-based analysis was conducted to compare stroke patients with healthy controls. We also performed longitudinal comparison of patients with successive [11 C]PiB-PET scans 1 year after stroke. RESULTS Voxel-based analysis revealed a significant increase of [11 C]PiB-BPND of the precuneus/posterior cingulate cortex (PCu/PCC) in stroke patients at the subacute stage. Based on stepwise multiple regression analysis of [11 C]PiB-BP changes during follow-up as the dependent variable, years of education was the best independent correlate. There was a significant negative relationship between changes in [11 C]PiB-BP and years of education. CONCLUSIONS Our results suggest that processes before and after the onset of ischemic stroke may trigger Aβ deposition in the PCu/PCC, whereby amyloid deposition begins at an early stage of Alzheimer's disease (AD). Our findings support the existence of a cooperative association between vascular risk factors/stroke and AD progression. Further, educational achievement had a protective effect against the increase in Aβ accumulation.
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Affiliation(s)
- Fumihiko Yasuno
- Department of Psychiatry, National Center for Geriatrics and Gerontology, Japan.,Department of Neurology, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Katsufumi Kajimoto
- Department of Neurology, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Masafumi Ihara
- Department of Neurology, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Akihiko Taguchi
- Department of Neurology, National Cerebral and Cardiovascular Center, Suita, Japan.,Department of Regenerative Medicine Research, Institute of Biomedical Research and Innovation, Kobe, Japan
| | - Akihide Yamamoto
- Department of Investigative Radiology, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Tetsyuta Fukuda
- Department of Radiology, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Hiroaki Kazui
- Department of Psychiatry, Kochi Medical School, Kochi University, Nankoku, Japan
| | - Hidehiro Iida
- Department of Investigative Radiology, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Kazuyuki Nagatsuka
- Department of Neurology, National Cerebral and Cardiovascular Center, Suita, Japan
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203
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Butterfield DA, Boyd-Kimball D. Redox proteomics and amyloid β-peptide: insights into Alzheimer disease. J Neurochem 2019; 151:459-487. [PMID: 30216447 PMCID: PMC6417976 DOI: 10.1111/jnc.14589] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 08/15/2018] [Accepted: 09/07/2018] [Indexed: 12/12/2022]
Abstract
Alzheimer disease (AD) is a progressive neurodegenerative disorder associated with aging and characterized pathologically by the presence of senile plaques, neurofibrillary tangles, and neurite and synapse loss. Amyloid beta-peptide (1-42) [Aβ(1-42)], a major component of senile plaques, is neurotoxic and induces oxidative stress in vitro and in vivo. Redox proteomics has been used to identify proteins oxidatively modified by Aβ(1-42) in vitro and in vivo. In this review, we discuss these proteins in the context of those identified to be oxidatively modified in animal models of AD, and human studies including familial AD, pre-clinical AD (PCAD), mild cognitive impairment (MCI), early AD, late AD, Down syndrome (DS), and DS with AD (DS/AD). These redox proteomics studies indicate that Aβ(1-42)-mediated oxidative stress occurs early in AD pathogenesis and results in altered antioxidant and cellular detoxification defenses, decreased energy yielding metabolism and mitochondrial dysfunction, excitotoxicity, loss of synaptic plasticity and cell structure, neuroinflammation, impaired protein folding and degradation, and altered signal transduction. Improved access to biomarker imaging and the identification of lifestyle interventions or treatments to reduce Aβ production could be beneficial in preventing or delaying the progression of AD. This article is part of the special issue "Proteomics".
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Affiliation(s)
- D. Allan Butterfield
- Department of Chemistry and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506
| | - Debra Boyd-Kimball
- Department of Chemistry and Biochemistry, University of Mount Union, Alliance, OH 44601
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204
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Kepp KP, Squitti R. Copper imbalance in Alzheimer’s disease: Convergence of the chemistry and the clinic. Coord Chem Rev 2019. [DOI: 10.1016/j.ccr.2019.06.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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205
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Hu H, Chen KL, Ou YN, Cao XP, Chen SD, Cui M, Dong Q, Tan L, Yu JT. Neurofilament light chain plasma concentration predicts neurodegeneration and clinical progression in nondemented elderly adults. Aging (Albany NY) 2019; 11:6904-6914. [PMID: 31514172 PMCID: PMC6756875 DOI: 10.18632/aging.102220] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Accepted: 08/13/2019] [Indexed: 01/31/2023]
Abstract
Previous studies demonstrated that plasma neurofilament light chain (NFL) played important predictive roles in disease progression and neurodegeneration in the preclinical phase of familial Alzheimer’s disease (AD). However, whether plasma NFL has the same predictive roles in sporadic AD is still unclear. In this study, 243 cognitively normal (CN) participants from the ADNI database were divided into two subgroups (CN- and CN+) according to CSF Aβ or AV45-PET. Associations of baseline plasma NFL concentrations or rate of change in plasma NFL with longitudinal data on other biomarkers were tested by multivariate linear mixed effects models (LMEMs). Results showed that plasma NFL concentration and its rate of change were already abnormally high in the preclinical phase of AD. Plasma NFL was associated with three core AD-related biomarkers in preclinical phase. Baseline plasma NFL, but not its rate of change, played predictive roles in both cognitive decline (β = -0.0349, p = 0.0274) and hippocampal atrophy (β = -0.0351, p = 0.0088), especially for preclinical AD participants. In summary, these results indicated that baseline plasma NFL, but not its rate of change, may be a valuable noninvasive tool to assess neurodegeneration and predict longitudinal disease progression in preclinical AD individuals.
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Affiliation(s)
- Hao Hu
- Department of Neurology, Qingdao Municipal Hospital, Qingdao University, Qingdao, China
| | - Ke-Liang Chen
- Department of Neurology and Institute of Neurology, WHO Collaborating Center for Research and Training in Neurosciences, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Ya-Nan Ou
- Department of Neurology, Qingdao Municipal Hospital, Qingdao University, Qingdao, China
| | - Xi-Peng Cao
- Clinical Research Center, Qingdao Municipal Hospital, Qingdao University, Qingdao, China
| | - Shi-Dong Chen
- Department of Neurology and Institute of Neurology, WHO Collaborating Center for Research and Training in Neurosciences, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Mei Cui
- Department of Neurology and Institute of Neurology, WHO Collaborating Center for Research and Training in Neurosciences, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Qiang Dong
- Department of Neurology and Institute of Neurology, WHO Collaborating Center for Research and Training in Neurosciences, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Lan Tan
- Department of Neurology, Qingdao Municipal Hospital, Qingdao University, Qingdao, China
| | - Jin-Tai Yu
- Department of Neurology and Institute of Neurology, WHO Collaborating Center for Research and Training in Neurosciences, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
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206
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Matsuda H, Shigemoto Y, Sato N. Neuroimaging of Alzheimer's disease: focus on amyloid and tau PET. Jpn J Radiol 2019; 37:735-749. [PMID: 31493197 DOI: 10.1007/s11604-019-00867-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 08/28/2019] [Indexed: 12/14/2022]
Abstract
Although the diagnosis of dementia is still largely a clinical one, based on history and disease course, neuroimaging has dramatically increased our ability to accurately diagnose it. Neuroimaging modalities now play a wider role in dementia beyond their traditional role of excluding neurosurgical lesions and are recommended in most clinical guidelines for dementia. In addition, new neuroimaging methods facilitate the diagnosis of most neurodegenerative conditions after symptom onset and show diagnostic promise even in the very early or presymptomatic phases of some diseases. In the case of Alzheimer's disease (AD), extracellular amyloid-β (Aβ) aggregates and intracellular tau neurofibrillary tangles are the two neuropathological hallmarks of the disease. Recent molecular imaging techniques using amyloid and tau PET ligands have led to preclinical diagnosis and improved differential diagnosis as well as narrowed subject selection and treatment monitoring in clinical trials aimed at delaying or preventing the symptomatic phase of AD. This review discusses the recent progress in amyloid and tau PET imaging and the key findings achieved by the use of this molecular imaging modality related to the respective roles of Aβ and tau in AD, as well as its specific limitations.
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Affiliation(s)
- Hiroshi Matsuda
- Integrative Brain Imaging Center, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo, 187-8551, Japan.
| | - Yoko Shigemoto
- Department of Radiology, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo, 187-8551, Japan
| | - Noriko Sato
- Department of Radiology, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo, 187-8551, Japan
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207
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Wahl AS, Löffler M, Hausner L, Ruttorf M, Nees F, Frölich L. Case report: a giant arachnoid cyst masking Alzheimer's disease. BMC Psychiatry 2019; 19:274. [PMID: 31488095 PMCID: PMC6728996 DOI: 10.1186/s12888-019-2247-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 08/19/2019] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Intracranial arachnoid cysts are usually benign congenital findings of neuroimaging modalities, sometimes however, leading to focal neurological and psychiatric comorbidities. Whether primarily clinically silent cysts may become causally involved in cognitive decline in old age is neither well examined nor understood. CASE PRESENTATION A 66-year old caucasian man presenting with a giant left-hemispheric frontotemporal cyst without progression of size, presented with slowly progressive cognitive decline. Neuropsychological assessment revealed an amnestic mild cognitive impairment (MCI) without further neurological or psychiatric symptoms. The patient showed mild medio-temporal lobe atrophy on structural MRI. Diffusion tensor and functional magnetic resonance imaging depicted a rather sustained function of the strongly suppressed left hemisphere. Amyloid-PET imaging was positive for increased amyloid burden and he was homozygous for the APOEε3-gene. A diagnosis of MCI due to Alzheimer's disease was given and a co-morbidity with a silent arachnoid cyst was assumed. To investigate, if a potentially reduced CSF flow due to the giant arachnoid cyst contributed to the early manifestation of AD, we reviewed 15 case series of subjects with frontotemporal arachnoid cysts and cognitive decline. However, no increased manifestation of neurodegenerative disorders was reported. CONCLUSIONS With this case report, we illustrate the necessity of a systematic work-up for neurodegenerative disorders in patients with arachnoid cysts and emerging cognitive decline. We finally propose a modus operandi for the stratification and management of patients with arachnoid cysts potentially susceptive for cognitive dysfunction.
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Affiliation(s)
- Anna-Sophia Wahl
- Department of Geriatric Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, J5, 68159, Mannheim, Germany.
| | - Martin Löffler
- 0000 0001 2190 4373grid.7700.0Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Lucrezia Hausner
- 0000 0001 2190 4373grid.7700.0Department of Geriatric Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, J5, 68159 Mannheim, Germany
| | - Michaela Ruttorf
- 0000 0001 2190 4373grid.7700.0Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Frauke Nees
- 0000 0001 2190 4373grid.7700.0Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Lutz Frölich
- 0000 0001 2190 4373grid.7700.0Department of Geriatric Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, J5, 68159 Mannheim, Germany
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208
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Zhao Y, Tudorascu DL, Lopez OL, Cohen AD, Mathis CA, Aizenstein HJ, Price JC, Kuller LH, Kamboh MI, DeKosky ST, Klunk WE, Snitz BE. Amyloid β Deposition and Suspected Non-Alzheimer Pathophysiology and Cognitive Decline Patterns for 12 Years in Oldest Old Participants Without Dementia. JAMA Neurol 2019; 75:88-96. [PMID: 29114732 DOI: 10.1001/jamaneurol.2017.3029] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Importance The prevalence of pathologic conditions of the brain associated with Alzheimer disease increases strongly with age. Little is known about the distribution and clinical significance of preclinical biomarker staging in the oldest old, when most individuals without dementia are likely to have positive biomarkers. Objective To compare the patterns of long-term cognitive decline in multiple domains by preclinical biomarker status in the oldest old without dementia. Design, Setting, and Participants A longitudinal observational study with a mean (SD) of 12.2 (2.2) years (range 7.2-15.1 years) of follow-up was conducted in an academic medical center from August 24, 2000, to January 14, 2016, including and extending observations from the Ginkgo Evaluation of Memory study. A total of 197 adults who had completed the Ginkgo Evaluation of Memory study, were free of dementia, and were able to undergo magnetic resonance imaging were eligible for a neuroimaging study in 2009. Of these patients, 175 were included in the present analyses; 140 (80%) were cognitively normal and 35 (20%) had mild cognitive impairment. Main Outcomes and Measures Biomarker groups included amyloid β negative (Aβ-)/neurodegeneration negative (ND-), amyloid β positive (Aβ+)/ND-, Aβ-/neurodegeneration positive (ND+), and Aβ+/ND+ based on Pittsburgh Compound B retention and hippocampal volume in 2009. Participants completed baseline neuropsychological testing from 2000 to 2002 and annual testing from 2004 to 2016. Domains included memory, executive function, language, visual-spatial reasoning, and attention and psychomotor speed. Slopes of decline were evaluated with linear mixed models adjusted for age, sex, and years of education. Results Of the 175 participants (71 women and 104 men), at imaging, mean (SD) age was 86.0 (2.9) years (range, 82-95 years). A total of 42 participants (24.0%) were Aβ-/ND-, 32 (18.3%) were Aβ+/ND-, 35 (20.0%) were Aβ-/ND+, and 66 (37.7%) were Aβ+/ND+. On all cognitive measures, the Aβ+/ND+ group showed the steepest decline. Compared with the Aβ-/ND- group, the amyloid deposition alone (Aβ+/ND-) group showed faster decline on tests of verbal and visual memory (-0.3513; 95% CI, -0.5269 to -0.1756), executive function (0.0158; 95% CI, 0.0013-0.0303), and language (-0.1934; 95% CI, -0.3520 to -0.0348). The Aβ-/ND+ group showed faster visual memory decline than the Aβ-/ND- reference group (-0.3007; 95% CI, -0.4736 to -0.1279). Conclusions and Relevance In the oldest old without dementia, presence of either or both Aβ and hippocampal atrophy is typical (>75%). Isolated hippocampal volume atrophy is associated only with greater decline in memory. However, isolated Aβ is associated with decline in memory plus language and executive functions. These findings suggest different underlying pathophysiologic processes in the Aβ+/ND- and Aβ-/ND+ groups.
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Affiliation(s)
- Yujing Zhao
- School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Dana L Tudorascu
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Oscar L Lopez
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Ann D Cohen
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Chester A Mathis
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Howard J Aizenstein
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Julie C Price
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania.,now with the Department of Radiology, Massachusetts General Hospital, Boston
| | - Lewis H Kuller
- Department of Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - M Ilyas Kamboh
- Department of Human Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania
| | | | - William E Klunk
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Beth E Snitz
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania
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209
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Lowe AJ, Paquola C, Vos de Wael R, Girn M, Lariviere S, Tavakol S, Caldairou B, Royer J, Schrader DV, Bernasconi A, Bernasconi N, Spreng RN, Bernhardt BC. Targeting age-related differences in brain and cognition with multimodal imaging and connectome topography profiling. Hum Brain Mapp 2019; 40:5213-5230. [PMID: 31444896 PMCID: PMC6864903 DOI: 10.1002/hbm.24767] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 07/29/2019] [Accepted: 08/05/2019] [Indexed: 02/06/2023] Open
Abstract
Aging is characterized by accumulation of structural and metabolic changes in the brain. Recent studies suggest transmodal brain networks are especially sensitive to aging, which, we hypothesize, may be due to their apical position in the cortical hierarchy. Studying an open‐access healthy cohort (n = 102, age range = 30–89 years) with MRI and Aβ PET data, we estimated age‐related cortical thinning, hippocampal atrophy and Aβ deposition. In addition to carrying out surface‐based morphological and metabolic mapping experiments, we stratified effects along neocortical and hippocampal resting‐state functional connectome gradients derived from independent datasets. The cortical gradient depicts an axis of functional differentiation from sensory‐motor regions to transmodal regions, whereas the hippocampal gradient recapitulates its long‐axis. While age‐related thinning and increased Aβ deposition occurred across the entire cortical topography, increased Aβ deposition was especially pronounced toward higher‐order transmodal regions. Age‐related atrophy was greater toward the posterior end of the hippocampal long‐axis. No significant effect of age on Aβ deposition in the hippocampus was observed. Imaging markers correlated with behavioral measures of fluid intelligence and episodic memory in a topography‐specific manner, confirmed using both univariate as well as multivariate analyses. Our results strengthen existing evidence of structural and metabolic change in the aging brain and support the use of connectivity gradients as a compact framework to analyze and conceptualize brain‐based biomarkers of aging.
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Affiliation(s)
- Alexander J Lowe
- Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Casey Paquola
- Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Reinder Vos de Wael
- Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Manesh Girn
- Laboratory of Brain and Cognition, Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, Canada
| | - Sara Lariviere
- Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Shahin Tavakol
- Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Benoit Caldairou
- Neuroimaging of Epilepsy Lab, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Jessica Royer
- Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Dewi V Schrader
- Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Andrea Bernasconi
- Neuroimaging of Epilepsy Lab, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Neda Bernasconi
- Neuroimaging of Epilepsy Lab, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - R Nathan Spreng
- Laboratory of Brain and Cognition, Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, Canada.,Department of Psychiatry and Psychology, McGill University, Montreal, Canada
| | - Boris C Bernhardt
- Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
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210
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Khosravi M, Peter J, Wintering NA, Serruya M, Shamchi SP, Werner TJ, Alavi A, Newberg AB. 18F-FDG Is a Superior Indicator of Cognitive Performance Compared to 18F-Florbetapir in Alzheimer’s Disease and Mild Cognitive Impairment Evaluation: A Global Quantitative Analysis. J Alzheimers Dis 2019; 70:1197-1207. [DOI: 10.3233/jad-190220] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Mohsen Khosravi
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Jonah Peter
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Nancy A. Wintering
- Marcus Institute of Integrative Health, Thomas Jefferson University, Philadelphia, PA, USA
| | - Mijail Serruya
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA, USA
| | | | - Thomas J. Werner
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Abass Alavi
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Andrew B. Newberg
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA, USA
- Marcus Institute of Integrative Health, Thomas Jefferson University, Philadelphia, PA, USA
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211
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Zolochevska O, Bjorklund N, Woltjer R, Wiktorowicz JE, Taglialatela G. Postsynaptic Proteome of Non-Demented Individuals with Alzheimer's Disease Neuropathology. J Alzheimers Dis 2019; 65:659-682. [PMID: 30103319 PMCID: PMC6130411 DOI: 10.3233/jad-180179] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Some individuals, here referred to as Non-Demented with Alzheimer’s Neuropathology (NDAN), retain their cognitive function despite the presence of amyloid plaques and tau tangles typical of symptomatic Alzheimer’s disease (AD). In NDAN, unlike AD, toxic amyloid-β oligomers do not localize to the postsynaptic densities (PSDs). Synaptic resistance to amyloid-β in NDAN may thus enable these individuals to remain cognitively intact despite the AD-like pathology. The mechanism(s) responsible for this resistance remains unresolved and understanding such protective biological processes could reveal novel targets for the development of effective treatments for AD. The present study uses a proteomic approach to compare the hippocampal postsynaptic densities of NDAN, AD, and healthy age-matched persons to identify protein signatures characteristic for these groups. Subcellular fractionation followed by 2D gel electrophoresis and mass spectrometry were used to analyze the PSDs. We describe fifteen proteins which comprise the unique proteomic signature of NDAN PSDs, thus setting them apart from control subjects and AD patients.
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Affiliation(s)
- Olga Zolochevska
- Department of Neurology, University of Texas Medical Branch, Galveston, TX, USA
| | - Nicole Bjorklund
- Department of Neurology, University of Texas Medical Branch, Galveston, TX, USA
| | - Randall Woltjer
- Department of Pathology, Oregon Health and Science University, Portland, OR, USA
| | - John E Wiktorowicz
- Department of Biochemistry and Molecular Biology, Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, TX, USA
| | - Giulio Taglialatela
- Department of Neurology, University of Texas Medical Branch, Galveston, TX, USA
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212
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Piri R, Naghavi-Behzad M, Gerke O, Høilund-Carlsen PF, Vafaee MS. Investigations of possible links between Alzheimer’s disease and type 2 diabetes mellitus by positron emission tomography: a systematic review. Clin Transl Imaging 2019. [DOI: 10.1007/s40336-019-00339-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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213
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Meyer PF, Savard M, Poirier J, Morgan D, Breitner J. Hypothesis: cerebrospinal fluid protein markers suggest a pathway toward symptomatic resilience to AD pathology. Alzheimers Dement 2019; 15:1160-1171. [PMID: 31405825 DOI: 10.1016/j.jalz.2019.05.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 05/14/2019] [Accepted: 05/20/2019] [Indexed: 01/22/2023]
Abstract
INTRODUCTION We sought biological pathways that explained discordance between Alzheimer's disease (AD) pathology and symptoms. METHODS In 306 Alzheimer's Disease Neuroimaging Initiative (ADNI)-1 participants across the AD clinical spectrum, we investigated association between cognitive outcomes and 23 cerebrospinal fluid (CSF) analytes associated with abnormalities in the AD biomarkers amyloid β1-42 and total-tau. In a 200-person "training" set, Least Absolute Shrinkage and Selection Operator regression estimated model weights for the 23 proteins, and for the AD biomarkers themselves, as predictors of ADAS-Cog11 scores. In the remaining 106 participants ("validation" set), fully adjusted regression models then tested the Least Absolute Shrinkage and Selection Operator-derived models and a related protein marker summary score as predictors of ADAS-Cog11, ADNI diagnostic category, and longitudinal cognitive trajectory. RESULTS AD biomarkers alone explained 26% of the variance in validation set cognitive scores. Surprisingly, the 23 AD-related proteins explained 31% of this variance. The biomarkers and protein markers appeared independent in this respect, jointly explaining 42% of test score variance. The composite protein marker score also predicted ADNI diagnosis and subsequent cognitive trajectory. Cognitive outcome prediction redounded principally to ten markers related to lipid or vascular functions or to microglial activation or chemotaxis. In each analysis, apoE protein and four markers in the latter immune-activation group portended better outcomes. DISCUSSION CSF markers of vascular, lipid-metabolic and immune-related functions may explain much of the disjunction between AD biomarker abnormality and symptom severity. In particular, our results suggest the hypothesis that innate immune activation improves cognitive outcomes in persons with AD pathology. This hypothesis should be tested by further study of cognitive outcomes related to CSF markers of innate immune activation.
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Affiliation(s)
- Pierre-François Meyer
- Faculty of Medicine, McGill University, Montréal, QC, Canada; Center for Studies on the Prevention of Alzheimer's Disease (StoP-AD), Douglas Mental Health University Institute, Montréal, QC, Canada
| | - Melissa Savard
- McGill Center for Studies on Aging, Douglas Mental Health University Institute, Montréal, QC, Canada
| | - Judes Poirier
- Faculty of Medicine, McGill University, Montréal, QC, Canada; Center for Studies on the Prevention of Alzheimer's Disease (StoP-AD), Douglas Mental Health University Institute, Montréal, QC, Canada; Douglas Mental Health University Institute Research Centre, Montréal, QC, Canada
| | - David Morgan
- College of Human Medicine, Michigan State University, Grand Rapids, MI, USA
| | - John Breitner
- Faculty of Medicine, McGill University, Montréal, QC, Canada; Center for Studies on the Prevention of Alzheimer's Disease (StoP-AD), Douglas Mental Health University Institute, Montréal, QC, Canada; Douglas Mental Health University Institute Research Centre, Montréal, QC, Canada.
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214
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Svenningsson AL, Stomrud E, Insel PS, Mattsson N, Palmqvist S, Hansson O. β-amyloid pathology and hippocampal atrophy are independently associated with memory function in cognitively healthy elderly. Sci Rep 2019; 9:11180. [PMID: 31371787 PMCID: PMC6671981 DOI: 10.1038/s41598-019-47638-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 07/11/2019] [Indexed: 11/25/2022] Open
Abstract
The independent effects of different brain pathologies on age-dependent cognitive decline are unclear. We examined this in 300 cognitively unimpaired elderly individuals from the BioFINDER study. Using cognition as outcome we studied the effects of cerebrospinal fluid biomarkers for amyloid-β (Aβ42/40), neuroinflammation (YKL-40), and neurodegeneration and tau pathology (T-tau and P-tau) as well as MRI measures of white-matter lesions, hippocampal volume (HV), and regional cortical thickness. We found that Aβ positivity and HV were independently associated with memory. Results differed depending on age, with memory being associated with HV (but not Aβ) in older participants (73.3–88.4 years), and with Aβ (but not HV) in relatively younger participants (65.2–73.2 years). This indicates that Aβ and atrophy are independent contributors to memory variability in cognitively healthy elderly and that Aβ mainly affects memory in younger elderly individuals. With advancing age, the effect of brain atrophy overshadows the effect of Aβ on memory function.
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Affiliation(s)
- Anna L Svenningsson
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Lund/Malmö, Sweden. .,Memory Clinic, Skåne University Hospital, Malmö, Sweden.
| | - Erik Stomrud
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Lund/Malmö, Sweden.,Memory Clinic, Skåne University Hospital, Malmö, Sweden
| | - Philip S Insel
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Lund/Malmö, Sweden
| | - Niklas Mattsson
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Lund/Malmö, Sweden.,Department of Neurology, Skåne University Hospital, Lund University, Lund, Sweden
| | - Sebastian Palmqvist
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Lund/Malmö, Sweden.,Department of Neurology, Skåne University Hospital, Lund University, Lund, Sweden
| | - Oskar Hansson
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Lund/Malmö, Sweden.,Memory Clinic, Skåne University Hospital, Malmö, Sweden
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215
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Pignataro A, Meli G, Pagano R, Fontebasso V, Battistella R, Conforto G, Ammassari-Teule M, Middei S. Activity-Induced Amyloid-β Oligomers Drive Compensatory Synaptic Rearrangements in Brain Circuits Controlling Memory of Presymptomatic Alzheimer's Disease Mice. Biol Psychiatry 2019; 86:185-195. [PMID: 30528194 DOI: 10.1016/j.biopsych.2018.10.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 10/02/2018] [Accepted: 10/22/2018] [Indexed: 12/17/2022]
Abstract
BACKGROUND A consistent proportion of individuals at risk for Alzheimer's disease show intact cognition regardless of the extensive accumulation of amyloid-β (Aβ) peptide in their brain. Several pieces of evidence indicate that overactivation of brain regions negative for Aβ can compensate for the underactivation of Aβ-positive ones to preserve cognition, but the underlying synaptic changes are still unexplored. METHODS Using Golgi staining, we investigate how dendritic spines rearrange following contextual fear conditioning (CFC) in the hippocampus and amygdala of presymptomatic Tg2576 mice, a genetic model for Aβ accumulation. A molecular biology approach combined with intrahippocampal injection of a γ-secretase inhibitor evaluates the impact of Aβ fluctuations on spine rearrangements. RESULTS Encoding of CFC increases Aβ oligomerization in the hippocampus but not in the amygdala of Tg2576 mice. The presence of Aβ oligomers predicts vulnerability to network dysfunctions, as low c-Fos activation and spine maturation are detected in the hippocampus of Tg2576 mice upon recall of CFC memory. Rather, enhanced c-Fos activation and new spines are evident in the amygdala of Tg2576 mice compared with wild-type control mice. Preventing Aβ increase in the hippocampus of Tg2576 mice restores CFC-associated spine changes to wild-type levels in both the hippocampus and amygdala. CONCLUSIONS Our study provides the first evidence of neural compensation consisting of enhanced synaptic activity in brain regions spared by Aβ load. Furthermore, it unravels an activity-mediated feedback loop through which neuronal activation during CFC encoding favors Aβ oligomerization in the hippocampus and prevents synaptic rearrangements in this region.
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Affiliation(s)
- Annabella Pignataro
- Laboratory of Psychobiology, Department of Experimental Neurology, Santa Lucia Foundation, Rome, Italy; Institute of Cell Biology and Neurobiology, National Research Council, Rome, Italy
| | - Giovanni Meli
- European Brain Research Institute-Fondazione Rita Levi Montalcini, Rome, Italy.
| | - Roberto Pagano
- Department of Molecular and Cellular Neurobiology Laboratory of Molecular Basis of Behavior, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Veronica Fontebasso
- Department of Pharmacology & Toxicology and Center for Chemistry and Biomedicine, University of Innsbruck, Innsbruck, Austria
| | - Roberta Battistella
- Department of Experimental Biomedical Sciences, Lund University, Lund, Sweden
| | - Giulia Conforto
- Laboratory of Psychobiology, Department of Experimental Neurology, Santa Lucia Foundation, Rome, Italy
| | - Martine Ammassari-Teule
- Laboratory of Psychobiology, Department of Experimental Neurology, Santa Lucia Foundation, Rome, Italy; Institute of Cell Biology and Neurobiology, National Research Council, Rome, Italy
| | - Silvia Middei
- Institute of Cell Biology and Neurobiology, National Research Council, Rome, Italy.
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216
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Gulisano W, Melone M, Ripoli C, Tropea MR, Li Puma DD, Giunta S, Cocco S, Marcotulli D, Origlia N, Palmeri A, Arancio O, Conti F, Grassi C, Puzzo D. Neuromodulatory Action of Picomolar Extracellular Aβ42 Oligomers on Presynaptic and Postsynaptic Mechanisms Underlying Synaptic Function and Memory. J Neurosci 2019; 39:5986-6000. [PMID: 31127002 PMCID: PMC6650983 DOI: 10.1523/jneurosci.0163-19.2019] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Revised: 04/09/2019] [Accepted: 04/28/2019] [Indexed: 01/01/2023] Open
Abstract
Failure of anti-amyloid-β peptide (Aβ) therapies against Alzheimer's disease (AD), a neurodegenerative disorder characterized by high amounts of the peptide in the brain, raised the question of the physiological role of Aβ released at low concentrations in the healthy brain. To address this question, we studied the presynaptic and postsynaptic mechanisms underlying the neuromodulatory action of picomolar amounts of oligomeric Aβ42 (oAβ42) on synaptic glutamatergic function in male and female mice. We found that 200 pm oAβ42 induces an increase of frequency of miniature EPSCs and a decrease of paired pulse facilitation, associated with an increase in docked vesicle number, indicating that it augments neurotransmitter release at presynaptic level. oAβ42 also produced postsynaptic changes as shown by an increased length of postsynaptic density, accompanied by an increased expression of plasticity-related proteins such as cAMP-responsive element binding protein phosphorylated at Ser133, calcium-calmodulin-dependent kinase II phosphorylated at Thr286, and brain-derived neurotrophic factor, suggesting a role for Aβ in synaptic tagging. These changes resulted in the conversion of early into late long-term potentiation through the nitric oxide/cGMP/protein kinase G intracellular cascade consistent with a cGMP-dependent switch from short- to long-term memory observed in vivo after intrahippocampal administration of picomolar amounts of oAβ42 These effects were present upon extracellular but not intracellular application of the peptide and involved α7 nicotinic acetylcholine receptors. These observations clarified the physiological role of oAβ42 in synaptic function and memory formation providing solid fundamentals for investigating the pathological effects of high Aβ levels in the AD brains.SIGNIFICANCE STATEMENT High levels of oligomeric amyloid-β42 (oAβ42) induce synaptic dysfunction leading to memory impairment in Alzheimer's disease (AD). However, at picomolar concentrations, the peptide is needed to ensure long-term potentiation (LTP) and memory. Here, we show that extracellular 200 pm oAβ42 concentrations increase neurotransmitter release, number of docked vesicles, postsynaptic density length, and expression of plasticity-related proteins leading to the conversion of early LTP into late LTP and of short-term memory into long-term memory. These effects require α7 nicotinic acetylcholine receptors and are mediated through the nitric oxide/cGMP/protein kinase G pathway. The knowledge of Aβ function in the healthy brain might be useful to understand the causes leading to its increase and detrimental effect in AD.
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Affiliation(s)
- Walter Gulisano
- Department Biomedical and Biotechnological Sciences, University of Catania, Catania 95123, Italy
| | - Marcello Melone
- Section of Neuroscience and Cell Biology, Department Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona 60020, Italy
- Center for Neurobiology of Aging, IRCCS Istituto Nazionale Ricovero e Cura Anziani (INRCA), Ancona 60020, Italy
| | - Cristian Ripoli
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome 00168, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome 00168, Italy
| | - Maria Rosaria Tropea
- Department Biomedical and Biotechnological Sciences, University of Catania, Catania 95123, Italy
| | - Domenica D Li Puma
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome 00168, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome 00168, Italy
| | - Salvatore Giunta
- Department Biomedical and Biotechnological Sciences, University of Catania, Catania 95123, Italy
| | - Sara Cocco
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome 00168, Italy
| | - Daniele Marcotulli
- Section of Neuroscience and Cell Biology, Department Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona 60020, Italy
| | - Nicola Origlia
- Neuroscience Institute, Italian National Research Council, Pisa 56100, Italy
| | - Agostino Palmeri
- Department Biomedical and Biotechnological Sciences, University of Catania, Catania 95123, Italy
| | - Ottavio Arancio
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, New York 10032
| | - Fiorenzo Conti
- Section of Neuroscience and Cell Biology, Department Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona 60020, Italy
- Center for Neurobiology of Aging, IRCCS Istituto Nazionale Ricovero e Cura Anziani (INRCA), Ancona 60020, Italy
- Foundation for Molecular Medicine, Università Politecnica delle Marche, Ancona 60020, Italy, and
| | - Claudio Grassi
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome 00168, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome 00168, Italy
| | - Daniela Puzzo
- Department Biomedical and Biotechnological Sciences, University of Catania, Catania 95123, Italy,
- Oasi Research Institute-IRCCS, Troina, 94018, Italy
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217
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Wolf D, Fischer FU, Fellgiebel A. Impact of Resilience on the Association Between Amyloid-β and Longitudinal Cognitive Decline in Cognitively Healthy Older Adults. J Alzheimers Dis 2019; 70:361-370. [DOI: 10.3233/jad-190370] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Dominik Wolf
- Department of Psychiatry and Psychotherapy, University Medical Center Mainz, Mainz, Germany
- Center for Mental Health in Old Age, Mainz, Germany
| | - Florian U. Fischer
- Department of Psychiatry and Psychotherapy, University Medical Center Mainz, Mainz, Germany
- Center for Mental Health in Old Age, Mainz, Germany
| | - Andreas Fellgiebel
- Department of Psychiatry and Psychotherapy, University Medical Center Mainz, Mainz, Germany
- Center for Mental Health in Old Age, Mainz, Germany
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218
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Ye C, Albert M, Brown T, Bilgel M, Hsu J, Ma T, Caffo B, Miller MI, Mori S, Oishi K. Extended multimodal whole-brain anatomical covariance analysis: detection of disrupted correlation networks related to amyloid deposition. Heliyon 2019; 5:e02074. [PMID: 31372540 PMCID: PMC6656959 DOI: 10.1016/j.heliyon.2019.e02074] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 04/22/2019] [Accepted: 07/08/2019] [Indexed: 01/27/2023] Open
Abstract
Background An anatomical covariance analysis (ACA) enables to elucidate inter-regional connections on a group basis, but little is known about the connections among white matter structures or among gray and white matter structures. Effect of including multiple magnetic resonance imaging (MRI) modalities into ACA framework in detecting white-to-white or gray-to-white connections is yet to be investigated. New method Proposed extended anatomical covariance analysis (eACA), analyzes correlations among gray and white matter structures (multi-structural) in various types of imaging modalities (T1-weighted images, T2 maps obtained from dual-echo sequences, and diffusion tensor images (DTI)). To demonstrate the capability to detect a disruption of the correlation network affected by pathology, we applied the eACA to two groups of cognitively-normal elderly individuals, one with (PiB+) and one without (PiB-) amyloid deposition in their brains. Results The volume of each anatomical structure was symmetric and functionally related structures formed a cluster. The pseudo-T2 value was highly homogeneous across the entire cortex in the PiB- group, while a number of physiological correlations were altered in the PiB + group. The DTI demonstrated unique correlation network among structures within the same phylogenetic portions of the brain that were altered in the PiB + group. Comparison with Existing Method The proposed eACA expands the concept of existing ACA to the connections among the white matter structures. The extension to other image modalities expands the way in which connectivity may be detected. Conclusion The eACA has potential to evaluate alterations of the anatomical network related to pathological processes.
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Affiliation(s)
- Chenfei Ye
- Department of Electronics and Information, Harbin Institute of Technology at Shenzhen, Shenzhen, Guangdong Province, China.,The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Peng Cheng Laboratory, Shenzhen, Guangdong, China
| | - Marilyn Albert
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.,The Johns Hopkins Alzheimer's Disease Research Center, Baltimore, MD, USA
| | - Timothy Brown
- Center for Imaging Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Murat Bilgel
- Laboratory of Behavioral Neuroscience, Intramural Research Program, National Institute on Aging, Baltimore, MD, USA
| | - Johnny Hsu
- Peng Cheng Laboratory, Shenzhen, Guangdong, China
| | - Ting Ma
- Department of Electronics and Information, Harbin Institute of Technology at Shenzhen, Shenzhen, Guangdong Province, China.,Peng Cheng Laboratory, Shenzhen, Guangdong, China
| | - Brian Caffo
- Department of Biostatistics, Johns Hopkins University, Baltimore, MD, USA
| | - Michael I Miller
- Center for Imaging Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Susumu Mori
- The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Kenichi Oishi
- The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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219
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Sabri O, Meyer PM, Gräf S, Hesse S, Wilke S, Becker GA, Rullmann M, Patt M, Luthardt J, Wagenknecht G, Hoepping A, Smits R, Franke A, Sattler B, Tiepolt S, Fischer S, Deuther-Conrad W, Hegerl U, Barthel H, Schönknecht P, Brust P. Cognitive correlates of α4β2 nicotinic acetylcholine receptors in mild Alzheimer's dementia. Brain 2019; 141:1840-1854. [PMID: 29672680 PMCID: PMC5972585 DOI: 10.1093/brain/awy099] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 02/19/2018] [Indexed: 12/22/2022] Open
Abstract
In early Alzheimer's dementia, there is a need for PET biomarkers of disease progression with close associations to cognitive dysfunction that may aid to predict further cognitive decline and neurodegeneration. Amyloid biomarkers are not suitable for that purpose. The α4β2 nicotinic acetylcholine receptors (α4β2-nAChRs) are widely abundant in the human brain. As neuromodulators they play an important role in cognitive functions such as attention, learning and memory. Post-mortem studies reported lower expression of α4β2-nAChRs in more advanced Alzheimer's dementia. However, there is ongoing controversy whether α4β2-nAChRs are reduced in early Alzheimer's dementia. Therefore, using the recently developed α4β2-nAChR-specific radioligand (-)-18F-flubatine and PET, we aimed to quantify the α4β2-nAChR availability and its relationship to specific cognitive dysfunction in mild Alzheimer's dementia. Fourteen non-smoking patients with mild Alzheimer's dementia, drug-naïve for cholinesterase therapy, were compared with 15 non-smoking healthy controls matched for age, sex and education by applying (-)-18F-flubatine PET together with a neuropsychological test battery. The one-tissue compartment model and Logan plot method with arterial input function were used for kinetic analysis to obtain the total distribution volume (VT) as the primary, and the specific binding part of the distribution volume (VS) as the secondary quantitative outcome measure of α4β2-nAChR availability. VS was determined by using a pseudo-reference region. Correlations between VT within relevant brain regions and Z-scores of five cognitive functions (episodic memory, executive function/working memory, attention, language, visuospatial function) were calculated. VT (and VS) were applied for between-group comparisons. Volume of interest and statistical parametric mapping analyses were carried out. Analyses revealed that in patients with mild Alzheimer's dementia compared to healthy controls, there was significantly lower VT, especially within the hippocampus, fronto-temporal cortices, and basal forebrain, which was similar to comparisons of VS. VT decline in Alzheimer's dementia was associated with distinct domains of impaired cognitive functioning, especially episodic memory and executive function/working memory. Using (-)-18F-flubatine PET in patients with mild Alzheimer's dementia, we show for the first time a cholinergic α4β2-nAChR deficiency mainly present within the basal forebrain-cortical and septohippocampal cholinergic projections and a relationship between lower α4β2-nAChR availability and impairment of distinct cognitive domains, notably episodic memory and executive function/working memory. This shows the potential of (-)-18F-flubatine as PET biomarker of cholinergic α4β2-nAChR dysfunction and specific cognitive decline. Thus, if validated by longitudinal PET studies, (-)-18F-flubatine might become a PET biomarker of progression of neurodegeneration in Alzheimer's dementia.
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Affiliation(s)
- Osama Sabri
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany
| | - Philipp M Meyer
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany
| | - Susanne Gräf
- Department of Psychiatry and Psychotherapy, University of Leipzig, Leipzig, Germany.,Max-Planck-Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Swen Hesse
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany.,Integrated Research and Treatment Centre (IFB) Adiposity Diseases, University of Leipzig, Leipzig, Germany
| | - Stephan Wilke
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany
| | | | - Michael Rullmann
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany.,Max-Planck-Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.,Integrated Research and Treatment Centre (IFB) Adiposity Diseases, University of Leipzig, Leipzig, Germany
| | - Marianne Patt
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany
| | - Julia Luthardt
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany
| | - Gudrun Wagenknecht
- Central Institute for Engineering, Electronics and Analytics-Electronic Systems (ZEA-2), Forschungszentrum Jülich, Jülich, Germany
| | | | - Rene Smits
- ABX Advanced Biochemical Compounds GmbH, Radeberg, Germany
| | - Annegret Franke
- Centre for Clinical Trials Leipzig, University of Leipzig, Leipzig, Germany
| | - Bernhard Sattler
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany
| | - Solveig Tiepolt
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany
| | - Steffen Fischer
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Research Site Leipzig, Leipzig, Germany
| | - Winnie Deuther-Conrad
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Research Site Leipzig, Leipzig, Germany
| | - Ulrich Hegerl
- Department of Psychiatry and Psychotherapy, University of Leipzig, Leipzig, Germany
| | - Henryk Barthel
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany
| | - Peter Schönknecht
- Department of Psychiatry and Psychotherapy, University of Leipzig, Leipzig, Germany
| | - Peter Brust
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Research Site Leipzig, Leipzig, Germany
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220
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Mihaila I, Handen BL, Christian BT, Lao PJ, Cody KA, Klunk WE, Tudorascu DL, Cohen AD, Okonkwo OC, Hartley SL. Leisure Activity, Brain β-amyloid, and Episodic Memory in Adults with Down Syndrome. Dev Neurobiol 2019; 79:738-749. [PMID: 30912871 PMCID: PMC7063586 DOI: 10.1002/dneu.22677] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 03/04/2019] [Accepted: 03/05/2019] [Indexed: 02/03/2023]
Abstract
The present study provided an investigation of associations between leisure activity and early Alzheimer's disease neuropathology (i.e., brain β-amyloid) and episodic memory in a sample of 65 adults with Down syndrome (aged 30-53 years), at baseline and follow-up, approximately three years apart. Findings indicated that leisure activity at baseline was not associated with brain β-amyloid at baseline or change in brain β-amyloid from baseline to follow-up. Greater cognitively stimulating leisure activity at baseline was associated with better episodic memory at baseline, and greater social leisure activity at baseline was associated with less decline in episodic memory from baseline to follow-up. High (as opposed to low) levels of social and overall leisure activity at baseline moderated the association between increase in brain β-amyloid and decline in episodic memory, from baseline to follow-up. Findings suggest that cognitively stimulating and social leisure activity could protect against the effect of Alzheimer's disease neuropathology on episodic memory in adults with Down syndrome.
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Affiliation(s)
- Iulia Mihaila
- University of Illinois at Chicago Department of Disability and Human Development
| | | | - Bradley T. Christian
- University of Wisconsin-Madison Waisman Center,,University of Wisconsin-Madison Department of Medical Physics
| | | | | | | | | | | | - Ozioma C. Okonkwo
- University of Wisconsin-Madison School of Medicine and Public Health
| | - Sigan L. Hartley
- University of Wisconsin-Madison Waisman Center,,University of Wisconsin-Madison Department of Human Development and Family Studies
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221
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Kaide S, Watanabe H, Shimizu Y, Tatsumi H, Iikuni S, Nakamoto Y, Togashi K, Ihara M, Saji H, Ono M. 18F-labeled benzimidazopyridine derivatives for PET imaging of tau pathology in Alzheimer's disease. Bioorg Med Chem 2019; 27:3587-3594. [PMID: 31285098 DOI: 10.1016/j.bmc.2019.06.039] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 05/11/2019] [Accepted: 06/25/2019] [Indexed: 11/29/2022]
Abstract
Hyperphosphorylated tau proteins are one of the neuropathological hallmarks in the Alzheimer's disease (AD) brain. The in vivo imaging of tau aggregates with nuclear medical imaging probes is helpful for the further comprehension of and medical intervention in the AD pathology. For tau-selective PET imaging, we newly designed and synthesized 18F-labeled benzimidazopyridine (BIP) derivatives with fluoroalkylamino groups, [18F]IBIPF1 and [18F]IBIPF2, and evaluated their utilities as tau imaging probes. They both bound selectively to tau against amyloid β (Aβ) aggregates in AD brain sections in vitro, and showed good pharmacokinetics in mouse brains in vivo. Notably, [18F]IBIPF1 exhibited high tau-selectivity (Tau/Aβ ratio = 34.8), high brain uptake (6.22% ID/g at 2 min postinjection), and subsequent washout (2.77% ID/g at 30 min postinjection). In vivo analysis of radiometabolites indicated that [18F]IBIPF1 was stable against metabolism in the mouse brain. These encouraging preclinical results suggest that further structural optimization based on the BIP scaffold may lead to the development of more useful tau imaging probes.
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Affiliation(s)
- Sho Kaide
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Hiroyuki Watanabe
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yoichi Shimizu
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan; Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Haruka Tatsumi
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Shimpei Iikuni
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yuji Nakamoto
- Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Kaori Togashi
- Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Masafumi Ihara
- Department of Stroke and Cerebrovascular Diseases, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, Osaka 565-8565, Japan
| | - Hideo Saji
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Masahiro Ono
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan.
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222
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Cordone S, Annarumma L, Rossini PM, De Gennaro L. Sleep and β-Amyloid Deposition in Alzheimer Disease: Insights on Mechanisms and Possible Innovative Treatments. Front Pharmacol 2019; 10:695. [PMID: 31281257 PMCID: PMC6595048 DOI: 10.3389/fphar.2019.00695] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 05/28/2019] [Indexed: 02/05/2023] Open
Abstract
The growing interest in the preclinical stage of Alzheimer's disease (AD) led investigators to identify modifiable risk and predictive factors useful to design early intervention strategies. The preclinical stage of AD is characterized by β-amyloid (Aβ) aggregation into amyloid plaques and tau phosphorylation and aggregation into neurofibrillary tangles. There is a consensus on the importance of sleep within this context: the bidirectional relationship between sleep and AD pathology is supported by growing evidence that proved that the occurrence of sleep changes starting from the preclinical stage of AD, many years before the onset of cognitive decline. Hence, we review the most recent studies on sleep disturbances related to Aβ and the effects of sleep deprivation on Aβ accumulation in animal and human models. We also discuss evidence on the role of sleep in clearing the brain of toxic metabolic by-products, with original findings of the clearance activity of the glymphatic system stimulated by sleep. Furthermore, starting from new recent advances about the relationship between slow-wave sleep (SWS) and Aβ burden, we review the results of recent electroencephalographic (EEG) studies in order to clarify the possible role of SWS component disruption as a novel mechanistic pathway through which Aβ pathology may contribute to cognitive decline and, conversely, the eventual useful role of SWS in facilitating Aβ clearance. Finally, we discuss some promising innovative, effective, low-risk, non-invasive interventions, although empirical evidence on the efficacy of sleep interventions in improving the course of AD is at the very beginning.
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Affiliation(s)
- Susanna Cordone
- Department of Psychology, University of Rome "Sapienza," Rome, Italy
| | | | - Paolo Maria Rossini
- Department of Neurological, Motor and Sensory Sciences, IRCCS San Raffaele Pisana, Rome, Italy.,Institute of Neurology, Catholic University of The Sacred Heart, Rome, Italy
| | - Luigi De Gennaro
- Department of Psychology, University of Rome "Sapienza," Rome, Italy
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223
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Mormino EC, Papp KV. Amyloid Accumulation and Cognitive Decline in Clinically Normal Older Individuals: Implications for Aging and Early Alzheimer's Disease. J Alzheimers Dis 2019; 64:S633-S646. [PMID: 29782318 DOI: 10.3233/jad-179928] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The aberrant accumulation of the amyloid protein is a critical and early event in the Alzheimer's disease (AD) cascade. Given the early involvement of this pathological process, it is not surprising that many clinically normal (CN) older individuals demonstrate evidence of abnormal Aβ at postmortem examination and in vivo using either CSF or PET imaging. Converging evidence across multiple research groups suggests that the presence of abnormal Aβ among CN individuals is associated with elevated risk of future clinical impairment and cognitive decline. Amyloid positivity in conjunction with biomarkers of neuronal injury offers further insight into which CN are most at risk for short-term decline. Although in its infancy, tau PET has demonstrated early increases among Aβ+ that will likely be an important indicator of risk among CN. Overall, the detection of early Aβ among CN individuals has provided an important opportunity to understand the contributions of this pathology to age-related cognitive decline and to explore early intervention with disease modifying strategies.
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Affiliation(s)
- Elizabeth C Mormino
- Department of Neurology and Neurological Sciences, Stanford University, Palo Alto, CA, USA
| | - Kathryn V Papp
- Department of Neurology, Center for Alzheimer Research and Treatment, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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224
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Ryan L, Hay M, Huentelman MJ, Duarte A, Rundek T, Levin B, Soldan A, Pettigrew C, Mehl MR, Barnes CA. Precision Aging: Applying Precision Medicine to the Field of Cognitive Aging. Front Aging Neurosci 2019; 11:128. [PMID: 31231204 PMCID: PMC6568195 DOI: 10.3389/fnagi.2019.00128] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 05/16/2019] [Indexed: 12/13/2022] Open
Abstract
The current "one size fits all" approach to our cognitive aging population is not adequate to close the gap between cognitive health span and lifespan. In this review article, we present a novel model for understanding, preventing, and treating age-related cognitive impairment (ARCI) based on concepts borrowed from precision medicine. We will discuss how multiple risk factors can be classified into risk categories because of their interrelatedness in real life, the genetic variants that increase sensitivity to, or ameliorate, risk for ARCI, and the brain drivers or common mechanisms mediating brain aging. Rather than providing a definitive model of risk for ARCI and cognitive decline, the Precision Aging model is meant as a starting point to guide future research. To that end, after briefly discussing key risk categories, genetic risks, and brain drivers, we conclude with a discussion of steps that must be taken to move the field forward.
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Affiliation(s)
- Lee Ryan
- Department of Psychology, College of Science, University of Arizona, Tucson, AZ, United States
| | - Meredith Hay
- Department of Physiology, University of Arizona, Tucson, AZ, United States
| | - Matt J. Huentelman
- Neurobehavioral Research Unit, Division of Neurological Disorders, Translational Genomics Research Institute (TGen), Phoenix, AZ, United States
| | - Audrey Duarte
- Center for Advanced Brain Imaging, School of Psychology, Georgia Institute of Technology, Atlanta, GA, United States
| | - Tatjana Rundek
- Clinical and Translational Research Division, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Bonnie Levin
- Neuropsychology Division, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Anja Soldan
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Corinne Pettigrew
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Matthias R. Mehl
- Department of Psychology, College of Science, University of Arizona, Tucson, AZ, United States
| | - Carol A. Barnes
- Department of Psychology, College of Science, University of Arizona, Tucson, AZ, United States
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225
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NIA-AA Research Framework: Toward a biological definition of Alzheimer's disease. Alzheimers Dement 2019; 14:535-562. [PMID: 29653606 PMCID: PMC5958625 DOI: 10.1016/j.jalz.2018.02.018] [Citation(s) in RCA: 5623] [Impact Index Per Article: 1124.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 02/21/2018] [Accepted: 02/27/2018] [Indexed: 02/06/2023]
Abstract
In 2011, the National Institute on Aging and Alzheimer’s Association created separate diagnostic recommendations for the preclinical, mild cognitive impairment, and dementia stages of Alzheimer’s disease. Scientific progress in the interim led to an initiative by the National Institute on Aging and Alzheimer’s Association to update and unify the 2011 guidelines. This unifying update is labeled a “research framework” because its intended use is for observational and interventional research, not routine clinical care. In the National Institute on Aging and Alzheimer’s Association Research Framework, Alzheimer’s disease (AD) is defined by its underlying pathologic processes that can be documented by postmortem examination or in vivo by biomarkers. The diagnosis is not based on the clinical consequences of the disease (i.e., symptoms/signs) in this research framework, which shifts the definition of AD in living people from a syndromal to a biological construct. The research framework focuses on the diagnosis of AD with biomarkers in living persons. Biomarkers are grouped into those of β amyloid deposition, pathologic tau, and neurodegeneration [AT(N)]. This ATN classification system groups different biomarkers (imaging and biofluids) by the pathologic process each measures. The AT(N) system is flexible in that new biomarkers can be added to the three existing AT(N) groups, and new biomarker groups beyond AT(N) can be added when they become available. We focus on AD as a continuum, and cognitive staging may be accomplished using continuous measures. However, we also outline two different categorical cognitive schemes for staging the severity of cognitive impairment: a scheme using three traditional syndromal categories and a six-stage numeric scheme. It is important to stress that this framework seeks to create a common language with which investigators can generate and test hypotheses about the interactions among different pathologic processes (denoted by biomarkers) and cognitive symptoms. We appreciate the concern that this biomarker-based research framework has the potential to be misused. Therefore, we emphasize, first, it is premature and inappropriate to use this research framework in general medical practice. Second, this research framework should not be used to restrict alternative approaches to hypothesis testing that do not use biomarkers. There will be situations where biomarkers are not available or requiring them would be counterproductive to the specific research goals (discussed in more detail later in the document). Thus, biomarker-based research should not be considered a template for all research into age-related cognitive impairment and dementia; rather, it should be applied when it is fit for the purpose of the specific research goals of a study. Importantly, this framework should be examined in diverse populations. Although it is possible that β-amyloid plaques and neurofibrillary tau deposits are not causal in AD pathogenesis, it is these abnormal protein deposits that define AD as a unique neurodegenerative disease among different disorders that can lead to dementia. We envision that defining AD as a biological construct will enable a more accurate characterization and understanding of the sequence of events that lead to cognitive impairment that is associated with AD, as well as the multifactorial etiology of dementia. This approach also will enable a more precise approach to interventional trials where specific pathways can be targeted in the disease process and in the appropriate people.
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226
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Bischof GN, Jacobs HIL. Subthreshold amyloid and its biological and clinical meaning: Long way ahead. Neurology 2019; 93:72-79. [PMID: 31167933 DOI: 10.1212/wnl.0000000000007747] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 03/26/2019] [Indexed: 01/22/2023] Open
Abstract
The development of in vivo imaging of the pathologic hallmark of Alzheimer disease (AD), β-amyloid (Aβ), altered the framing of its pathophysiology and formulation of inclusion criteria for clinical trials. Recent evidence suggests that in vivo measures of Aβ deposition below a threshold indicative of Aβ positivity carry critical information on future cognitive decline and accumulation of AD pathology, potentially already at a younger age. Here, we integrate the existing literature on histopathology of Aβ and its convergence and divergence with in vivo Aβ imaging. The evidence presented amounts to a reconceptualization, in which we advocate for a closer look into Aβ accumulation rates in earlier life, the factors that promote accumulation, comparative studies with different markers of Aβ, and longitudinal designs to elucidate when AD pathology rises and how it shifts from benign to malignant stages that ultimately define AD. These efforts open a new window of opportunity for disease-modifying interventions.
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Affiliation(s)
- Gérard N Bischof
- From the Multimodal Imaging Group (G.N.B.), Department of Nuclear Medicine, University Hospital Cologne, Germany; Cognitive Neuroscience (H.I.L.J.), Faculty of Psychology and Neuroscience, and School for Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Alzheimer Centre Limburg, Maastricht University, the Netherlands; and Department of Radiology, Division of Nuclear Medicine and Molecular Imaging, Harvard Medical School, Massachusetts General Hospital, Boston.
| | - Heidi I L Jacobs
- From the Multimodal Imaging Group (G.N.B.), Department of Nuclear Medicine, University Hospital Cologne, Germany; Cognitive Neuroscience (H.I.L.J.), Faculty of Psychology and Neuroscience, and School for Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Alzheimer Centre Limburg, Maastricht University, the Netherlands; and Department of Radiology, Division of Nuclear Medicine and Molecular Imaging, Harvard Medical School, Massachusetts General Hospital, Boston
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227
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Yoon SP, Grewal DS, Thompson AC, Polascik BW, Dunn C, Burke JR, Fekrat S. Retinal Microvascular and Neurodegenerative Changes in Alzheimer's Disease and Mild Cognitive Impairment Compared with Control Participants. Ophthalmol Retina 2019; 3:489-499. [PMID: 31174670 PMCID: PMC6586560 DOI: 10.1016/j.oret.2019.02.002] [Citation(s) in RCA: 135] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Revised: 12/30/2018] [Accepted: 02/11/2019] [Indexed: 10/27/2022]
Abstract
PURPOSE Evaluate and compare the retinal microvasculature in the superficial capillary plexus (SCP) in Alzheimer's disease (AD), mild cognitive impairment (MCI), and cognitively intact controls using OCT angiography. OCT parameters were also compared. DESIGN Cross-sectional study. PARTICIPANTS Seventy eyes from 39 AD participants, 72 eyes from 37 MCI participants, and 254 eyes from 133 control participants were enrolled. METHODS Participants were imaged using Zeiss Cirrus HD-5000 with AngioPlex (Carl Zeiss Meditec, Dublin, CA) and underwent cognitive evaluation with Mini-Mental State Examination. MAIN OUTCOME MEASURES Vessel density (VD) and perfusion density (PD) in the SCP within the Early Treatment Diabetic Retinopathy Study 6-mm circle, 3-mm circle, and 3-mm ring were compared between groups. Foveal avascular zone (FAZ) area, central subfield thickness (CST), macular ganglion cell-inner plexiform layer (GC-IPL) thickness, and peripapillary retinal nerve fiber layer (RNFL) thickness were also compared. RESULTS Alzheimer's participants showed significantly decreased SCP VD and PD in the 3-mm ring (P = 0.001 and P = 0.002, respectively) and 3-mm circle (P = 0.003 and P = 0.004, respectively) and decreased SCP VD in the 6-mm circle (P = 0.047) compared with MCI and significantly decreased SCP VD and PD in the 3-mm ring (P = 0.008 and P = 0.004, respectively) and 3-mm circle (P = 0.015 and P = 0.009, respectively) and SCP PD in the 6-mm circle (P = 0.033) when compared with cognitively intact controls. There was no difference in SCP VD or PD between MCI and controls (P > 0.05). FAZ area and CST did not differ significantly between groups (P > 0.05). Alzheimer's participants showed significantly decreased GC-IPL thickness over the inferior (P = 0.032) and inferonasal (P = 0.025) sectors compared with MCI and significantly decreased GC-IPL thickness over the entire (P = 0.012), superonasal (P = 0.041), inferior (P = 0.004), and inferonasal (P = 0.006) sectors compared to controls. MCI participants showed significantly decreased temporal RNFL thickness (P = 0.04) compared with controls. CONCLUSIONS Alzheimer's participants showed significantly reduced macular VD, PD, and GC-IPL thickness compared with MCI and controls. Changes in the retinal microvasculature may mirror small vessel cerebrovascular changes in AD.
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Affiliation(s)
- Stephen P Yoon
- Department of Ophthalmology, Duke University, Durham, North Carolina
| | - Dilraj S Grewal
- Department of Ophthalmology, Duke University, Durham, North Carolina
| | - Atalie C Thompson
- Department of Ophthalmology, Duke University, Durham, North Carolina
| | - Bryce W Polascik
- Department of Ophthalmology, Duke University, Durham, North Carolina
| | - Cynthia Dunn
- Department of Neurology, Duke University, Durham, North Carolina
| | - James R Burke
- Department of Neurology, Duke University, Durham, North Carolina
| | - Sharon Fekrat
- Department of Ophthalmology, Duke University, Durham, North Carolina.
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228
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Marciani DJ. Promising Results from Alzheimer's Disease Passive Immunotherapy Support the Development of a Preventive Vaccine. RESEARCH 2019; 2019:5341375. [PMID: 31549066 PMCID: PMC6750119 DOI: 10.34133/2019/5341375] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 04/18/2019] [Indexed: 12/23/2022]
Abstract
The apparently near-term effects of the monoclonal antibody BAN2401 in slowing the progression of prodromal Alzheimer's disease (AD) has created cautious optimism about the therapeutic use of antibodies that neutralize cytotoxic soluble amyloid-β aggregates, rather than removing plaque. Plaque being protective, as it immobilizes cytotoxic amyloid-β, rather than AD's causative agent. The presence of natural antibodies against cytotoxic amyloid-β implies the existence of a protective anti-AD immunity. Hence, for vaccines to induce a similar immunoresponse that prevents and/or delays the onset of AD, they must have adjuvants that stimulate a sole anti-inflammatory Th2 immunity, plus immunogens that induce a protective immunoresponse against diverse cytotoxic amyloid-β conformers. Indeed, amyloid-β pleomorphism may explain the lack of long-term protection by monoclonal antibodies that neutralize single conformers, like aducanumab. A situation that would allow new cytotoxic conformers to escape neutralization by previously effective monoclonal antibodies. Stimulation of a vaccine's effective immunoresponse would require the concurrent delivery of immunogen to dendritic cells and their priming, to induce a polarized Th2 immunity. An immunoresponse that would produce besides neutralizing antibodies against neurotoxic amyloid-β oligomers, anti-inflammatory cytokines; preventing inflammation that aggravates AD. Because of age-linked immune decline, vaccines would be significantly more effective in preventing, rather than treating AD. Considering the amyloid-β's role in tau's pathological hyperphosphorylation and their synergism in AD, the development of preventive vaccines against both amyloid-β and tau should be considered. Due to convenience and cost, vaccines may be the only option available to many countries to forestall the impending AD epidemic.
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Affiliation(s)
- D J Marciani
- Qantu Therapeutics, Inc., 612 E. Main Street, Lewisville, TX 75057, USA
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229
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Summers KL, Schilling KM, Roseman G, Markham KA, Dolgova NV, Kroll T, Sokaras D, Millhauser GL, Pickering IJ, George GN. X-ray Absorption Spectroscopy Investigations of Copper(II) Coordination in the Human Amyloid β Peptide. Inorg Chem 2019; 58:6294-6311. [PMID: 31013069 DOI: 10.1021/acs.inorgchem.9b00507] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Alzheimer's disease (AD) is the main cause of age-related dementia and currently affects approximately 5.7 million Americans. Major brain changes associated with AD pathology include accumulation of amyloid beta (Aβ) protein fragments and formation of extracellular amyloid plaques. Redox-active metals mediate oligomerization of Aβ, and the resultant metal-bound oligomers have been implicated in the putative formation of harmful, reactive species that could contribute to observed oxidative damage. In isolated plaque cores, Cu(II) is bound to Aβ via histidine residues. Despite numerous structural studies of Cu(II) binding to synthetic Aβ in vitro, there is still uncertainty surrounding Cu(II) coordination in Aβ. In this study, we used X-ray absorption spectroscopy (XAS) and high energy resolution fluorescence detected (HERFD) XAS to investigate Cu(II) coordination in Aβ(1-42) under various solution conditions. We found that the average coordination environment in Cu(II)Aβ(1-42) is sensitive to X-ray photoreduction, changes in buffer composition, peptide concentration, and solution pH. Fitting of the extended X-ray absorption fine structure (EXAFS) suggests Cu(II) is bound in a mixture of coordination environments in monomeric Aβ(1-42) under all conditions studied. However, it was evident that on average only a single histidine residue coordinates Cu(II) in monomeric Aβ(1-42) at pH 6.1, in addition to 3 other oxygen or nitrogen ligands. Cu(II) coordination in Aβ(1-42) at pH 7.4 is similarly 4-coordinate with oxygen and nitrogen ligands, although an average of 2 histidine residues appear to coordinate at this pH. At pH 9.0, the average Cu(II) coordination environment in Aβ(1-42) appears to be 5-coordinate with oxygen and nitrogen ligands, including two histidine residues.
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Affiliation(s)
- Kelly L Summers
- Molecular and Environmental Sciences Group, Department of Geological Sciences , University of Saskatchewan , 114 Science Place , Saskatoon , Saskatchewan S7N 5E2 , Canada.,Department of Chemistry , University of Saskatchewan , 110 Science Place , Saskatoon , Saskatchewan S7N 5C9 , Canada
| | - Kevin M Schilling
- Department of Chemistry and Biochemistry , University of California , Santa Cruz , California 95064 , United States
| | - Graham Roseman
- Department of Chemistry and Biochemistry , University of California , Santa Cruz , California 95064 , United States
| | - Kate A Markham
- Department of Chemistry and Biochemistry , University of California , Santa Cruz , California 95064 , United States
| | - Natalia V Dolgova
- Molecular and Environmental Sciences Group, Department of Geological Sciences , University of Saskatchewan , 114 Science Place , Saskatoon , Saskatchewan S7N 5E2 , Canada
| | - Thomas Kroll
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory , Stanford University , Menlo Park , California 94025 , United States
| | - Dimosthenis Sokaras
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory , Stanford University , Menlo Park , California 94025 , United States
| | - Glenn L Millhauser
- Department of Chemistry and Biochemistry , University of California , Santa Cruz , California 95064 , United States
| | - Ingrid J Pickering
- Molecular and Environmental Sciences Group, Department of Geological Sciences , University of Saskatchewan , 114 Science Place , Saskatoon , Saskatchewan S7N 5E2 , Canada.,Department of Chemistry , University of Saskatchewan , 110 Science Place , Saskatoon , Saskatchewan S7N 5C9 , Canada
| | - Graham N George
- Molecular and Environmental Sciences Group, Department of Geological Sciences , University of Saskatchewan , 114 Science Place , Saskatoon , Saskatchewan S7N 5E2 , Canada.,Department of Chemistry , University of Saskatchewan , 110 Science Place , Saskatoon , Saskatchewan S7N 5C9 , Canada
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230
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Kim Y, Yoo YK, Kim HY, Roh JH, Kim J, Baek S, Lee JC, Kim HJ, Chae MS, Jeong D, Park D, Lee S, Jang H, Kim K, Lee JH, Byun BH, Park SY, Ha JH, Lee KC, Cho WW, Kim JS, Koh JY, Lim SM, Hwang KS. Comparative analyses of plasma amyloid-β levels in heterogeneous and monomerized states by interdigitated microelectrode sensor system. SCIENCE ADVANCES 2019; 5:eaav1388. [PMID: 31001580 PMCID: PMC6469948 DOI: 10.1126/sciadv.aav1388] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 02/25/2019] [Indexed: 05/31/2023]
Abstract
Detection of amyloid-β (Aβ) aggregates contributes to the diagnosis of Alzheimer disease (AD). Plasma Aβ is deemed a less invasive and more accessible hallmark of AD, as Aβ can penetrate blood-brain barriers. However, correlations between biofluidic Aβ concentrations and AD progression has been tenuous. Here, we introduce a diagnostic technique that compares the heterogeneous and the monomerized states of Aβ in plasma. We used a small molecule, EPPS [4-(2-hydroxyethyl)-1-piperazinepropanesulfonic acid], to dissociate aggregated Aβ into monomers to enhance quantification accuracy. Subsequently, Aβ levels of EPPS-treated plasma were compared to those of untreated samples to minimize inter- and intraindividual variations. The interdigitated microelectrode sensor system was used to measure plasma Aβ levels on a scale of 0.1 pg/ml. The implementation of this self-standard blood test resulted in substantial distinctions between patients with AD and individuals with normal cognition (NC), with selectivity and sensitivity over 90%.
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Affiliation(s)
- YoungSoo Kim
- Integrated Science and Engineering Division, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Department of Pharmacy, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
| | - Yong Kyoung Yoo
- Department of Clinical Pharmacology and Therapeutics, College of Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Republic of Korea
- Department of Electrical Engineering, Kwangwoon University, 20 Kwangwoon-ro, Nowon-gu, Seoul 01897, Republic of Korea
| | - Hye Yun Kim
- Department of Pharmacy, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
| | - Jee Hoon Roh
- Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Republic of Korea
| | - Jinsik Kim
- Department of Medical Biotechnology, Dongguk University, 30 Pildong-ro 1-gil, Jung-gu, Seoul 04620, Republic of Korea
| | - Seungyeop Baek
- Department of Pharmacy, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Department of Biotechnology, Yonsei University, 50 Yonsei-ro Seodaemun-gu, Seoul 03722, Republic of Korea
- Brain Science Institute, Korea Institute of Science and Technology, 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea
| | - Jinny Claire Lee
- Integrated Science and Engineering Division, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Department of Pharmacy, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
| | - Hye Jin Kim
- Department of Clinical Pharmacology and Therapeutics, College of Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Republic of Korea
| | - Myung-Sic Chae
- Department of Clinical Pharmacology and Therapeutics, College of Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Republic of Korea
| | - Dahye Jeong
- Department of Clinical Pharmacology and Therapeutics, College of Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Republic of Korea
| | - Dongsung Park
- Department of Clinical Pharmacology and Therapeutics, College of Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Republic of Korea
| | - Sejin Lee
- Department of Pharmacy, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Brain Science Institute, Korea Institute of Science and Technology, 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea
| | - HoChung Jang
- Department of Pharmacy, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Brain Science Institute, Korea Institute of Science and Technology, 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea
| | - Kyeonghwan Kim
- Department of Pharmacy, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
| | - Jeong Hoon Lee
- Department of Electrical Engineering, Kwangwoon University, 20 Kwangwoon-ro, Nowon-gu, Seoul 01897, Republic of Korea
| | - Byung Hyun Byun
- Department of Nuclear Medicine, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul 01812, Republic of Korea
| | - Su Yeon Park
- Department of Neurology of Korea Cancer Center Hospital, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul 01812, Republic of Korea
| | - Jeong Ho Ha
- Department of Neurology of Korea Cancer Center Hospital, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul 01812, Republic of Korea
| | - Kyo Chul Lee
- Division of RI-Convergence Research, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul 01812, Republic of Korea
| | - Won Woo Cho
- Cantis, Sangnok-gu, Ansan-si, Gyeonggi-do 15588, Republic of Korea
| | - Jae-Seung Kim
- Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Republic of Korea
| | - Jae-Young Koh
- Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Republic of Korea
| | - Sang Moo Lim
- Department of Neurology of Korea Cancer Center Hospital, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul 01812, Republic of Korea
| | - Kyo Seon Hwang
- Department of Clinical Pharmacology and Therapeutics, College of Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Republic of Korea
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231
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Wu M, Thurston RC, Tudorascu DL, Karim HT, Mathis CA, Lopresti BJ, Kamboh MI, Cohen AD, Snitz BE, Klunk WE, Aizenstein HJ. Amyloid deposition is associated with different patterns of hippocampal connectivity in men versus women. Neurobiol Aging 2019; 76:141-150. [PMID: 30711677 PMCID: PMC6584958 DOI: 10.1016/j.neurobiolaging.2018.11.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 10/04/2018] [Accepted: 11/18/2018] [Indexed: 01/26/2023]
Abstract
Compared to men, women are disproportionally affected by Alzheimer's disease (AD) and have an accelerated trajectory of cognitive decline and disease progression. Neurobiological factors underlying gender differences in AD remain unclear. This study investigated brain beta-amyloid (Aβ)-related neural system differences in cognitively normal older men and women (N = 61; 41 females, 65-93 years old). We found that men and women showed different associations between Aβ load and hippocampal functional connectivity. During associative memory encoding, in men greater Aβ burden was accompanied by greater hippocampus-prefrontal connectivity (i.e., more synchronized activities), whereas in women hippocampal connectivity did not vary by Aβ burden. For resting-state data, the interaction of gender × Aβ on hippocampal connectivity did not survive multiple comparison in the whole-brain analyses. In the region of interest-based analyses, resting-state hippocampal-prefrontal connectivity was positively correlated with Aβ load in men and was negatively correlated with Aβ load in women. The observed Aβ-related neural differences may explain the accelerated trajectory of cognitive decline and AD progression in women.
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Affiliation(s)
- Minjie Wu
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Rebecca C Thurston
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA; Departments of Epidemiology and Psychology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Dana L Tudorascu
- Departments of Medicine and Biostatistics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Helmet T Karim
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Chester A Mathis
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Brian J Lopresti
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - M Ilyas Kamboh
- Department of Human Genetics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Ann D Cohen
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Beth E Snitz
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - William E Klunk
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Howard J Aizenstein
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA.
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232
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Arenaza-Urquijo EM, Przybelski SA, Lesnick TL, Graff-Radford J, Machulda MM, Knopman DS, Schwarz CG, Lowe VJ, Mielke MM, Petersen RC, Jack CR, Vemuri P. The metabolic brain signature of cognitive resilience in the 80+: beyond Alzheimer pathologies. Brain 2019; 142:1134-1147. [PMID: 30851100 PMCID: PMC6439329 DOI: 10.1093/brain/awz037] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 12/04/2018] [Accepted: 12/21/2018] [Indexed: 11/14/2022] Open
Abstract
Research into cognitive resilience imaging markers may help determine the clinical significance of Alzheimer's disease pathology among older adults over 80 years (80+). In this study, we aimed to identify a fluorodeoxyglucose (FDG)-PET based imaging marker of cognitive resilience. We identified 457 participants ≥ 80 years old (357 cognitively unimpaired, 118 cognitively impaired at baseline, mean age of 83.5 ± 3.2 years) from the population-based Mayo Clinic Study of Aging (MCSA) with baseline MRI, Pittsburgh compound B-PET and FDG-PET scans and neuropsychological evaluation. We identified a subset of 'resilient' participants (cognitively stable 80+, n = 192) who maintained normal cognition for an average of 5 years (2-10 years). Global PIB ratio, FDG-PET ratio and cortical thickness from Alzheimer's disease signature regions were used as Alzheimer's disease imaging biomarker outcomes and global cognitive z-score was used as a cognitive outcome. First, using voxel-wise multiple regression analysis, we identified the metabolic areas underlying cognitive resilience in cognitively stable 80+ participants, which we call the 'resilience signature'. Second, using multivariate linear regression models, we evaluated the association of risk and protective factors with the resilience signature and its added value for predicting global cognition beyond established Alzheimer's disease imaging biomarkers in the full 80+ sample. Third, we evaluated the utility of the resilience signature in conjunction with amyloidosis in predicting longitudinal cognition using linear mixed effect models. Lastly, we assessed the utility of the resilience signature in an independent cohort using ADNI (n = 358, baseline mean age of 80 ± 3.8). Our main findings were: (i) FDG-PET uptake in the bilateral anterior cingulate cortex and anterior temporal pole was associated with baseline global cognition in cognitively stable 80+ (the resilience signature); (ii) established Alzheimer's disease imaging biomarkers did not predict baseline global cognition in this subset of participants; (iii) in the full MCSA 80+ and ADNI cohorts, amyloid burden and FDG-PET in the resilience signature were the stronger predictors of baseline global cognition; (iv) sex and systemic vascular health predicted FDG-PET in the resilience signature, suggesting vascular health maintenance as a potential pathway to preserve the metabolism of these areas; and (v) the resilience signature provided significant information about global longitudinal cognitive change even when considering amyloid status in both the MCSA and ADNI cohorts. The FDG-PET resilience signature may be able to provide important information in conjunction with other Alzheimer's disease biomarkers for the determination of clinical prognosis. It may also facilitate identification of disease targeting modifiable risk factors such as vascular health maintenance.
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Affiliation(s)
| | | | | | | | - Mary M Machulda
- Department of Psychiatry and Psychology, Mayo Clinic, Rochester, Minnesota, USA
| | - David S Knopman
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Val J Lowe
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
| | - Michelle M Mielke
- Health Science Research, Mayo Clinic, Rochester, Minnesota, USA
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Clifford R Jack
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
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233
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Bransby L, Lim YY, Ames D, Fowler C, Roberston J, Harrington K, Snyder PJ, Villemagne VL, Salvado O, Masters CL, Maruff P. Sensitivity of a Preclinical Alzheimer's Cognitive Composite (PACC) to amyloid β load in preclinical Alzheimer's disease. J Clin Exp Neuropsychol 2019; 41:591-600. [PMID: 30924399 DOI: 10.1080/13803395.2019.1593949] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Introduction: Preclinical Alzheimer's disease (AD) is characterized by amyloid-related cognitive decline. Reduction in this decline is used to determine the efficacy of drug therapies designed to forestall the disease in preclinical AD clinical trials, measured by a Preclinical Alzheimer's Cognitive Composite (PACC). Most studies estimate rates of cognitive change by comparing cognitively normal (CN) older adults with abnormally high beta-amyloid (Aβ+) to those with low levels (Aβ-). However, participants of preclinical AD clinical trials must be Aβ+ for entry. Therefore, we estimated the effect of very high amyloid (Aβ++) and Aβ+ on cognitive change over three years measured by different versions of the PACC in individuals with preclinical AD. Method: CN older adults underwent Aβ neuroimaging and neuropsychological assessments over three years as part of the Australian Imaging, Biomarkers and Lifestyle (AIBL) study. Three cognitive composite scores were computed: the Alzheimer's Disease Cooperative Study (ADCS)-PACC, the ADCS-PACC with no Mini-Mental State Examination (MMSE), and the z-scores of Attention, Verbal Fluency and Episodic Memory for Nondemented Older Adults (ZAVEN) composite. Results: Compared to the Aβ++ group, the Aβ+ group showed a slower rate of cognitive decline with the largest magnitude of difference reflected by the ADCS-PACC (d = 0.85). The ADCS-PACC excluding the MMSE and the ZAVEN also reflected a moderate to large magnitude of difference between groups (d = 0.62, d = 0.72, respectively). Conclusions: When all individuals have abnormal Aβ, the level of Aβ at baseline is associated with the rate of subsequent decline. The ADCS-PACC was the most sensitive composite score in showing that lower Aβ is associated with a slower rate of cognitive decline; however, there are limitations to the use of the MMSE. These results provide a benchmark of comparison for preclinical AD clinical trials aiming to slow cognitive deterioration.
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Affiliation(s)
- Lisa Bransby
- a The Florey Institute of Neuroscience and Mental Health , The University of Melbourne , Melbourne , VIC , Australia
| | - Yen Ying Lim
- a The Florey Institute of Neuroscience and Mental Health , The University of Melbourne , Melbourne , VIC , Australia
| | - David Ames
- b National Ageing Research Institute , Melbourne , VIC , Australia.,c Academic Unit for Psychiatry of Old Age, St. Vincent's Health , The University of Melbourne , Melbourne , VIC , Australia
| | - Christopher Fowler
- a The Florey Institute of Neuroscience and Mental Health , The University of Melbourne , Melbourne , VIC , Australia
| | - Joanne Roberston
- a The Florey Institute of Neuroscience and Mental Health , The University of Melbourne , Melbourne , VIC , Australia
| | - Karra Harrington
- a The Florey Institute of Neuroscience and Mental Health , The University of Melbourne , Melbourne , VIC , Australia.,d Cooperative Research Centre for Mental Health , Parkville , Australia
| | - Peter J Snyder
- e Ryan Institute for Neuroscience , University of Rhode Island , Kingston , RI , USA
| | - Victor L Villemagne
- a The Florey Institute of Neuroscience and Mental Health , The University of Melbourne , Melbourne , VIC , Australia.,f Department of Nuclear Medicine and Centre for PET , Austin Health , Melbourne , VIC , Australia.,g Department of Medicine, Austin Health , The University of Melbourne , Melbourne , VIC , Australia
| | - Olivier Salvado
- h Commonwealth Scientific Industrial Research Organization (CSIRO) Preventative Health National Research Flagship , Australian e-Health Research Centre-BiaMedIA , Brisbane , QLD , Australia
| | - Colin L Masters
- a The Florey Institute of Neuroscience and Mental Health , The University of Melbourne , Melbourne , VIC , Australia
| | - Paul Maruff
- a The Florey Institute of Neuroscience and Mental Health , The University of Melbourne , Melbourne , VIC , Australia.,i CogState Ltd ., Melbourne , VIC , Australia
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234
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Duara R, Loewenstein DA, Lizarraga G, Adjouadi M, Barker WW, Greig-Custo MT, Rosselli M, Penate A, Shea YF, Behar R, Ollarves A, Robayo C, Hanson K, Marsiske M, Burke S, Ertekin-Taner N, Vaillancourt D, De Santi S, Golde T, St D. Effect of age, ethnicity, sex, cognitive status and APOE genotype on amyloid load and the threshold for amyloid positivity. NEUROIMAGE-CLINICAL 2019; 22:101800. [PMID: 30991618 PMCID: PMC6447735 DOI: 10.1016/j.nicl.2019.101800] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 02/08/2019] [Accepted: 03/26/2019] [Indexed: 11/30/2022]
Abstract
The threshold for amyloid positivity by visual assessment on PET has been validated by comparison to amyloid load measured histopathologically and biochemically at post mortem. As such, it is now feasible to use qualitative visual assessment of amyloid positivity as an in-vivo gold standard to determine those factors which can modify the quantitative threshold for amyloid positivity. We calculated quantitative amyloid load, measured as Standardized Uptake Value Ratios (SUVRs) using [18-F]florbetaben PET scans, for 159 Hispanic and non-Hispanic participants, who had been classified clinically as Cognitively Normal (CN), Mild Cognitive Impairment (MCI) or Dementia (DEM). PET scans were visually rated as amyloid positive (A+) or negative (A-), and these judgments were used as the gold standard with which to determine (using ROC analyses) the SUVR threshold for amyloid positivity considering factors such as age, ethnicity (Hispanic versus non-Hispanic), gender, cognitive status, and apolipoprotein E ε4 carrier status. Visually rated scans were A+ for 11% of CN, 39.0% of MCI and 70% of DEM participants. The optimal SUVR threshold for A+ among all participants was 1.42 (sensitivity = 94%; specificity = 92.5%), but this quantitative threshold was higher among E4 carriers (SUVR = 1.52) than non-carriers (SUVR = 1.31). While mean SUVRs did not differ between Hispanic and non-Hispanic participants;, a statistically significant interaction term indicated that the effect of E4 carrier status on amyloid load was greater among non-Hispanics than Hispanics. Visual assessment, as the gold standard for A+, facilitates determination of the effects of various factors on quantitative thresholds for amyloid positivity. A continuous relationship was found between amyloid load and global cognitive scores, suggesting that any calculated threshold for the whole group, or a subgroup, is artefactual and that the lowest calculated threshold may be optimal for the purposes of early diagnosis and intervention. Demographic factors did not affect the threshold for amyloid positivity. Cognitive status did not affect this threshold for amyloid positivity. APOE4 carriers had a higher threshold for amyloid positivity than non-carriers. Among APOE4 carriers, non-Hispanics had higher amyloid load than non- Hispanics. There was a continuous relationship between amyloid load and cognitive status.
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Affiliation(s)
- R Duara
- Florida ADRC, USA; Mount Sinai Medical Center, Miami Beach, USA; College of Engineering and Computing, Florida International University, Miami, FL, USA; University of Florida College of Medicine, Gainesville, FL, USA.
| | - D A Loewenstein
- Florida ADRC, USA; Mount Sinai Medical Center, Miami Beach, USA; Miller School of Medicine, University of Miami, Miami, FL, USA
| | - G Lizarraga
- Florida ADRC, USA; College of Engineering and Computing, Florida International University, Miami, FL, USA
| | - M Adjouadi
- Florida ADRC, USA; College of Engineering and Computing, Florida International University, Miami, FL, USA
| | - W W Barker
- Florida ADRC, USA; Mount Sinai Medical Center, Miami Beach, USA
| | - M T Greig-Custo
- Florida ADRC, USA; Mount Sinai Medical Center, Miami Beach, USA
| | - M Rosselli
- Florida ADRC, USA; Florida Atlantic University, USA
| | - A Penate
- Florida ADRC, USA; Mount Sinai Medical Center, Miami Beach, USA
| | - Y F Shea
- Mount Sinai Medical Center, Miami Beach, USA; Department of Medicine, University of Hong Kong, Hong Kong
| | - R Behar
- Florida ADRC, USA; Mount Sinai Medical Center, Miami Beach, USA
| | - A Ollarves
- Florida ADRC, USA; Mount Sinai Medical Center, Miami Beach, USA
| | - C Robayo
- Florida ADRC, USA; Mount Sinai Medical Center, Miami Beach, USA
| | - K Hanson
- Florida ADRC, USA; University of Florida College of Medicine, Gainesville, FL, USA
| | - M Marsiske
- Florida ADRC, USA; University of Florida College of Medicine, Gainesville, FL, USA; University of Florida, College of Public Health and Health Professions, USA
| | - S Burke
- Florida ADRC, USA; Robert Stempel College of Public Health & Social Work, Florida International University, Miami, FL, USA
| | - N Ertekin-Taner
- Mayo Clinic Florida, Department of Neurology, Jacksonville, FL, USA; Mayo Clinic Florida, Department of Neuroscience, Jacksonville, FL, USA
| | - D Vaillancourt
- Florida ADRC, USA; University of Florida College of Medicine, Gainesville, FL, USA
| | | | - T Golde
- Florida ADRC, USA; University of Florida College of Medicine, Gainesville, FL, USA
| | - DeKosky St
- Florida ADRC, USA; University of Florida College of Medicine, Gainesville, FL, USA
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235
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Discovering deviance: The visibility mechanisms through which one becomes a person with dementia in interaction. J Aging Stud 2019; 48:33-39. [DOI: 10.1016/j.jaging.2018.12.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 12/12/2018] [Accepted: 12/17/2018] [Indexed: 11/20/2022]
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236
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Wilson H, Pagano G, Politis M. Dementia spectrum disorders: lessons learnt from decades with PET research. J Neural Transm (Vienna) 2019; 126:233-251. [PMID: 30762136 PMCID: PMC6449308 DOI: 10.1007/s00702-019-01975-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 01/21/2019] [Indexed: 02/07/2023]
Abstract
The dementia spectrum encompasses a range of disorders with complex diagnosis, pathophysiology and limited treatment options. Positron emission tomography (PET) imaging provides insights into specific neurodegenerative processes underlying dementia disorders in vivo. Here we focus on some of the most common dementias: Alzheimer's disease, Parkinsonism dementias including Parkinson's disease with dementia, dementia with Lewy bodies, progressive supranuclear palsy and corticobasal syndrome, and frontotemporal lobe degeneration. PET tracers have been developed to target specific proteinopathies (amyloid, tau and α-synuclein), glucose metabolism, cholinergic system and neuroinflammation. Studies have shown distinct imaging abnormalities can be detected early, in some cases prior to symptom onset, allowing disease progression to be monitored and providing the potential to predict symptom onset. Furthermore, advances in PET imaging have identified potential therapeutic targets and novel methods to accurately discriminate between different types of dementias in vivo. There are promising imaging markers with a clinical application on the horizon, however, further studies are required before they can be implantation into clinical practice.
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Affiliation(s)
- Heather Wilson
- Neurodegeneration Imaging Group, Maurice Wohl Clinical Neuroscience Institute, 125 Coldharbour Lane, Camberwell, London, SE5 9NU, UK
| | - Gennaro Pagano
- Neurodegeneration Imaging Group, Maurice Wohl Clinical Neuroscience Institute, 125 Coldharbour Lane, Camberwell, London, SE5 9NU, UK
| | - Marios Politis
- Neurodegeneration Imaging Group, Maurice Wohl Clinical Neuroscience Institute, 125 Coldharbour Lane, Camberwell, London, SE5 9NU, UK.
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237
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Mullane K, Williams M. The de-Alzheimerization of age-related dementias: implications for drug targets and approaches to effective therapeutics. Curr Opin Pharmacol 2019; 44:62-75. [PMID: 30795894 DOI: 10.1016/j.coph.2019.01.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 01/10/2019] [Indexed: 12/20/2022]
Abstract
Alzheimer's disease (AD) was differentiated from senile dementia (SD) in 1910 due to its early onset and pathological severity. In 1976, this distinction was upended when SD was redesignated as AD to focus efforts and funding in dementia-related research. AD then became conflated with amyloid plaques and, to a lesser degree, neurofibrillary tangles complicating efforts in understanding dementia causality and its treatment. The resultant four-decade search for therapies-based almost exclusively on amyloid was an exercise in futility. While dementia is a complex, multifactorial syndrome, AD is viewed as a homogeneous, linear disease. An amyloid-agnostic approach is necessary to discover therapeutics for age-related dementias.
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Affiliation(s)
- Kevin Mullane
- Gladstone Institutes, San Francisco, CA, United States
| | - Michael Williams
- Department of Biological Chemistry and Pharmacology, College of Medicine, Ohio State University, Columbus, OH, United States.
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238
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Actual memory as a mediator of the amyloid-subjective cognitive decline relationship. ALZHEIMER'S & DEMENTIA: DIAGNOSIS, ASSESSMENT & DISEASE MONITORING 2019; 11:151-160. [PMID: 30809586 PMCID: PMC6376166 DOI: 10.1016/j.dadm.2018.12.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Introduction Amyloid pathology in cognitively normal adults is associated with subjective cognitive decline, potentially reflecting awareness of Alzheimer's-related memory deficits. To clarify the mechanism underlying this relationship, we used mediational analyses to determine the role of depression, anxiety, and actual memory performance. Methods To assess amyloid deposition, we imaged 85 cognitively normal adults with florbetapir positron emission tomography imaging. Subjective cognitive decline was measured using a multidimensional instrument that assessed seven subjective memory domains. Mediational measures included assessments of actual memory performance (current and retrospective longitudinal change), depression, and anxiety. Results The relationship between amyloid and subjective cognitive decline was mediated by poorer memory performance and greater retrospective memory decline, not depression or anxiety. The mediational roles were significant for domains associated with memory function and memory-related anxiety. Discussion In individuals harboring amyloid, self-reported beliefs of declining memory likely indicate early self-awareness of actual worsening function rather than depression or anxiety.
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239
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James BD, Bennett DA. Causes and Patterns of Dementia: An Update in the Era of Redefining Alzheimer's Disease. Annu Rev Public Health 2019; 40:65-84. [PMID: 30642228 DOI: 10.1146/annurev-publhealth-040218-043758] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The burden of dementia continues to increase as the population ages, with no disease-modifying treatments available. However, dementia risk appears to be decreasing, and progress has been made in understanding its multifactorial etiology. The 2018 National Institute on Aging-Alzheimer's Association (NIA-AA) research framework for Alzheimer's disease (AD) defines AD as a biological process measured by brain pathology or biomarkers, spanning the cognitive spectrum from normality to dementia. This framework facilitates interventions in the asymptomatic space and accommodates knowledge that many additional pathologies (e.g., cerebrovascular) contribute to the Alzheimer's dementia syndrome. The framework has implications for how we think about risk factors for "AD": Many commonly accepted risk factors are not related to AD pathology and would no longer be considered risk factors for AD. They may instead be related to other pathologies or resilience to pathology. This review updates what is known about causes, risk factors, and changing patterns of dementia, addressing whether they are related to AD pathology/biomarkers, other pathologies, or resilience.
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Affiliation(s)
- Bryan D James
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, Illinois 60612, USA; .,Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois 60612, USA
| | - David A Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, Illinois 60612, USA; .,Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois 60612, USA
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240
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Quantitative proteomics reveals distinct composition of amyloid plaques in Alzheimer's disease. Alzheimers Dement 2019; 15:429-440. [PMID: 30502339 DOI: 10.1016/j.jalz.2018.10.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 10/29/2018] [Indexed: 11/22/2022]
Abstract
INTRODUCTION We investigated the proteomic profiles of amyloid plaques (APs) from Alzheimer's disease (AD) and age-matched non-AD brains and APP/PS1 transgenic model mice. METHODS APs and adjacent control regions were collected from fresh-frozen brain sections using laser capture dissection. Proteins were quantitated using tag-labeling coupled high-throughput mass spectra. RESULTS Over 4000 proteins were accurately quantified, and more than 40 were identified as highly enriched in both AD and non-AD APs, including apoE, midkine, VGFR1, and complement C4. Intriguingly, proteins including synaptic structural proteins and complement C1r, C5, and C9 were found to be upregulated in AD APs but not non-AD APs. Moreover, the proteomic pattern of AD APs was distinct from APP/PS1 APs and exhibited correlation with aging hippocampus. DISCUSSION Our results provide new insight into AP composition. We demonstrate unexpected differences between AD, non-AD, and APP/PS1 mouse APs, which may relate to different pathological processes.
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241
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Abstract
The most common neurodegenerative diseases are Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease, frontotemporal lobar degeneration, and the motor neuron diseases, with AD affecting approximately 6% of people aged 65 years and older, and PD affecting approximately 1% of people aged over 60 years. Specific proteins are associated with these neurodegenerative diseases, as determined by both immunohistochemical studies on post-mortem tissue and genetic screening, where protein misfolding and aggregation are key hallmarks. Many of these proteins are shown to misfold and aggregate into soluble non-native oligomers and large insoluble protein deposits (fibrils and plaques), both of which may exert a toxic gain of function. Proteotoxicity has been examined intensively in cell culture and in in vivo models, and clinical trials of methods to attenuate proteotoxicity are relatively new. Therapies to enhance cellular protein quality control mechanisms such as upregulation of chaperones and clearance/degradation pathways, as well as immunotherapies against toxic protein conformations, are being actively pursued. In this article, we summarize the common pathophysiology of neurodegenerative disease, and review therapies in early-phase clinical trials that target the proteotoxic component of several neurodegenerative diseases.
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Affiliation(s)
- Luke McAlary
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada.
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, V6T 2B5, Canada.
| | - Steven S Plotkin
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada.
- Genome Sciences and Technology Program, University of British Columbia, Vancouver, BC, V6T 1Z2, Canada.
| | - Neil R Cashman
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, V6T 2B5, Canada.
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242
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Alm KH, Bakker A. Relationships Between Diffusion Tensor Imaging and Cerebrospinal Fluid Metrics in Early Stages of the Alzheimer's Disease Continuum. J Alzheimers Dis 2019; 70:965-981. [PMID: 31306117 PMCID: PMC6860011 DOI: 10.3233/jad-181210] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Recently, the field of Alzheimer's disease (AD) research has adopted a new framework that places the progression of AD along a continuum consisting of a preclinical stage, followed by conversion to mild cognitive impairment, and ultimately dementia. Important neuropathological changes occur in the preclinical phase, necessitating the identification of metrics that can detect such early changes. While cerebrospinal fluid (CSF) measures of amyloid and tau are generally accepted as biomarkers of AD pathology, neuroimaging measures used to index white matter alterations throughout the brain remain less widely endorsed as candidate biomarkers. To explore the relationship between white matter alterations and AD pathology, we review the literature on multimodal studies that assessed both CSF markers and white matter indices, derived from diffusion tensor imaging (DTI) methods, across cohorts primarily in the early phases of AD. Our review indicates that abnormal CSF measures of Aβ42 and tau are associated with widespread alterations in white matter microstructure throughout the brain. Furthermore, white matter variability is related to individual differences in behavior and can aid in tracking longitudinal changes in cognition. Our review advocates for the utilization of DTI metrics in investigations of early AD and suggests that the combined use of DTI and CSF markers may better explain individual differences in cognition and disease progression. However, further research is needed to resolve certain mixed findings.
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Affiliation(s)
- Kylie H. Alm
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Arnold Bakker
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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243
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Tudorascu DL, Anderson SJ, Minhas DS, Yu Z, Comer D, Lao P, Hartley S, Laymon CM, Snitz BE, Lopresti BJ, Johnson S, Price JC, Mathis CA, Aizenstein HJ, Klunk WE, Handen BL, Christian BT, Cohen AD. Comparison of longitudinal Aβ in nondemented elderly and Down syndrome. Neurobiol Aging 2019; 73:171-176. [PMID: 30359879 PMCID: PMC6251757 DOI: 10.1016/j.neurobiolaging.2018.09.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 09/21/2018] [Accepted: 09/23/2018] [Indexed: 12/31/2022]
Abstract
Down syndrome (DS) predisposes individuals to early Alzheimer's disease (AD). Using Pittsburgh Compound B ([11C]PiB), a pattern of striatal amyloid beta (Aβ) that is elevated relative to neocortical binding has been reported, similar to that of nondemented autosomal dominant AD mutation carriers. However, it is not known whether changes in striatal and neocortical [11C]PiB retention differ over time in a nondemented DS population when compared to changes in a nondemented elderly (NDE) population. The purpose of this work was to assess longitudinal changes in trajectories of Aβ in a nondemented DS compared to an NDE cohort. The regional trajectories for anterior ventral striatum (AVS), frontal cortex, and precuneus [11C]PiB retention were explored over time using linear mixed effects models with fixed effects of time, cohort, and time-by-cohort interactions and subject as random effects. Significant differences between DS and NDE cohort trajectories for all 3 region of interests were observed (p < 0.05), with the DS cohort showing a faster accumulation in the AVS and slower accumulation in the frontal cortex and precuneus compared to the NDE cohort. These data add to the previously reported distinct pattern of early striatal deposition not commonly seen in sporadic AD by demonstrating that individuals with DS may also accumulate Aβ at a rate faster in the AVS when compared to NDE subjects.
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Affiliation(s)
- Dana L Tudorascu
- Department of Medicine, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA; Department of Biostatistics, University of Pittsburgh, Graduate School of Public Health, Pittsburgh, PA, USA
| | - Stewart J Anderson
- Department of Biostatistics, University of Pittsburgh, Graduate School of Public Health, Pittsburgh, PA, USA
| | - Davneet S Minhas
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Zheming Yu
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Diane Comer
- Department of Medicine, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA
| | - Patrick Lao
- Department of Medical Physics, University of Wisconsin, Madison School of Medicine, Madison, WI, USA; Department of Waisman Center, University of Wisconsin, Madison School of Medicine, Madison, WI, USA
| | - Sigan Hartley
- Department of Waisman Center, University of Wisconsin, Madison School of Medicine, Madison, WI, USA; Departments of Human Development and Family Studies, University of Wisconsin, Madison School of Medicine, Madison, WI, USA
| | - Charles M Laymon
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Department of Biongeenering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Beth E Snitz
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Brian J Lopresti
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Sterling Johnson
- Department of Medical Physics, University of Wisconsin, Madison School of Medicine, Madison, WI, USA; Department of Medicine and Geriatrics, University of Wisconsin, Madison School of Medicine, Madison, WI, USA
| | - Julie C Price
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Massachusetts General Hospital, A. A. Martinos Center for Biomedical Imaging, Cambridge, MA, USA
| | - Chester A Mathis
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Howard J Aizenstein
- Department of Psychiatry, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA
| | - William E Klunk
- Department of Psychiatry, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA
| | - Benjamin L Handen
- Department of Psychiatry, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA
| | - Brad T Christian
- Department of Medical Physics, University of Wisconsin, Madison School of Medicine, Madison, WI, USA; Department of Waisman Center, University of Wisconsin, Madison School of Medicine, Madison, WI, USA
| | - Ann D Cohen
- Department of Psychiatry, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA.
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244
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Biochemical deficits and cognitive decline in brain aging: Intervention by dietary supplements. J Chem Neuroanat 2019; 95:70-80. [DOI: 10.1016/j.jchemneu.2018.04.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 02/28/2018] [Accepted: 04/13/2018] [Indexed: 01/23/2023]
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245
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Risacher SL, Saykin AJ. Neuroimaging in aging and neurologic diseases. HANDBOOK OF CLINICAL NEUROLOGY 2019; 167:191-227. [PMID: 31753134 DOI: 10.1016/b978-0-12-804766-8.00012-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Neuroimaging biomarkers for neurologic diseases are important tools, both for understanding pathology associated with cognitive and clinical symptoms and for differential diagnosis. This chapter explores neuroimaging measures, including structural and functional measures from magnetic resonance imaging (MRI) and molecular measures primarily from positron emission tomography (PET), in healthy aging adults and in a number of neurologic diseases. The spectrum covers neuroimaging measures from normal aging to a variety of dementias: late-onset Alzheimer's disease [AD; including mild cognitive impairment (MCI)], familial and nonfamilial early-onset AD, atypical AD syndromes, posterior cortical atrophy (PCA), logopenic aphasia (lvPPA), cerebral amyloid angiopathy (CAA), vascular dementia (VaD), sporadic and familial behavioral-variant frontotemporal dementia (bvFTD), semantic dementia (SD), progressive nonfluent aphasia (PNFA), frontotemporal dementia with motor neuron disease (FTD-MND), frontotemporal dementia with amyotrophic lateral sclerosis (FTD-ALS), corticobasal degeneration (CBD), progressive supranuclear palsy (PSP), dementia with Lewy bodies (DLB), Parkinson's disease (PD) with and without dementia, and multiple systems atrophy (MSA). We also include a discussion of the appropriate use criteria (AUC) for amyloid imaging and conclude with a discussion of differential diagnosis of neurologic dementia disorders in the context of neuroimaging.
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Affiliation(s)
- Shannon L Risacher
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Andrew J Saykin
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States.
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246
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Li H, Liu CC, Zheng H, Huang TY. Amyloid, tau, pathogen infection and antimicrobial protection in Alzheimer's disease -conformist, nonconformist, and realistic prospects for AD pathogenesis. Transl Neurodegener 2018; 7:34. [PMID: 30603085 PMCID: PMC6306008 DOI: 10.1186/s40035-018-0139-3] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 12/02/2018] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is a fatal disease that threatens the quality of life of an aging population at a global scale. Various hypotheses on the etiology of AD have been developed over the years to guide efforts in search of therapeutic strategies. MAIN BODY In this review, we focus on four AD hypotheses currently relevant to AD onset: the prevailing amyloid cascade hypothesis, the well-recognized tau hypothesis, the increasingly popular pathogen (viral infection) hypothesis, and the infection-related antimicrobial protection hypothesis. In briefly reviewing the main evidence supporting each hypothesis and discussing the questions that need to be addressed, we hope to gain a better understanding of the complicated multi-layered interactions in potential causal and/or risk factors in AD pathogenesis. As a defining feature of AD, the existence of amyloid deposits is likely fundamental to AD onset but is insufficient to wholly reproduce many complexities of the disorder. A similar belief is currently also applied to hyperphosphorylated tau aggregates within neurons, where tau has been postulated to drive neurodegeneration in the presence of pre-existing Aβ plaques in the brain. Although infection of the central nerve system by pathogens such as viruses may increase AD risk, it is yet to be determined whether this phenomenon is applicable to all cases of sporadic AD and whether it is a primary trigger for AD onset. Lastly, the antimicrobial protection hypothesis provides insight into a potential physiological role for Aβ peptides, but how Aβ/microbial interactions affect AD pathogenesis during aging awaits further validation. Nevertheless, this hypothesis cautions potential adverse effects in Aβ-targeting therapies by hindering potential roles for Aβ in anti-viral protection. CONCLUSION AD is a multi-factor complex disorder, which likely requires a combinatorial therapeutic approach to successfully slow or reduce symptomatic memory decline. A better understanding of how various causal and/or risk factors affecting disease onset and progression will enhance the likelihood of conceiving effective treatment paradigms, which may involve personalized treatment strategies for individual patients at varying stages of disease progression.
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Affiliation(s)
- Hongmei Li
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL USA
| | - Chia-Chen Liu
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL USA
| | - Hui Zheng
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX USA
| | - Timothy Y. Huang
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, San Diego, CA USA
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247
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Gabelle A, Jaussent I, Bouallègue FB, Lehmann S, Lopez R, Barateau L, Grasselli C, Pesenti C, de Verbizier D, Béziat S, Mariano-Goulart D, Carlander B, Dauvilliers Y. Reduced brain amyloid burden in elderly patients with narcolepsy type 1. Ann Neurol 2018; 85:74-83. [PMID: 30387527 DOI: 10.1002/ana.25373] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 10/26/2018] [Accepted: 10/26/2018] [Indexed: 12/24/2022]
Abstract
OBJECTIVE To determine whether brain amyloid burden in elderly patients with narcolepsy type 1 (NT1) is lower than in controls, and to assess in patients with NT1 the relationships between amyloid burden, cerebral spinal fluid (CSF) markers of Alzheimer disease (AD), CSF orexin-A, and cognitive profile. METHODS Cognitive and 18 F-florbetapir positron emission tomography (PET) data were compared in patients with NT1 aged ≥ 65 years (n = 23) and in age- and sex-matched controls free of clinical dementia selected from the Alzheimer's Disease Neuroimaging Initiative (ADNI; n = 69) and the Multi-Domain Intervention Alzheimer's Prevention Trial (MAPT-18F AV45-PET; n = 23) cohorts. The standardized uptake values (SUVs) of the cortical retention index for 6 regions of interest were computed and averaged to create a mean SUV ratio normalized to 3 subcortical reference regions (cerebellum, pons, and a composite region). A cortical/cerebellum SUV ratio ≥ 1.17 defined positive PET amyloid. RESULTS Lower cortical amyloid burden was observed in the NT1 than in the ADNI and MAPT-AV45 groups (mean cortical/cerebellum SUV ratios = 0.95 ± 0.15, 1.11 ± 0.18 [p < 0.0001], and 1.14 ± 0.17 [p = 0.0005], respectively). Similar results were obtained with all subcortical reference regions and for all cortical regions of interest, except cingulum. Only 1 patient with NT1 (4.4%) had positive PET amyloid compared with 27.5% in the ADNI and 30.4% in the MAPT-AV45 group. In the NT1 group, cortical or regional amyloid load was not associated with CSF orexin-A, CSF AD biomarkers, or neuropsychological profile. INTERPRETATION Lower brain amyloid burden, assessed by 18 F-florbetapir PET, in patients with NT1 suggests delayed appearance of amyloid plaques. ANN NEUROL 2019;85:74-83.
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Affiliation(s)
- Audrey Gabelle
- Memory Research and Resources Center, Department of Neurology, Gui de Chauliac University Hospital Center.,University of Montpellier.,National Institute of Health and Medical Research U1061, Neuropsychiatry: Epidemiological and Clinical Research
| | - Isabelle Jaussent
- University of Montpellier.,National Institute of Health and Medical Research U1061, Neuropsychiatry: Epidemiological and Clinical Research
| | - Fayçal Ben Bouallègue
- University of Montpellier.,Department of Nuclear Medicine, Montpellier University Hospital.,PhyMedExp, National Institute of Health and Medical Research, National Center for Scientific Research
| | - Sylvain Lehmann
- University of Montpellier.,National Institute of Health and Medical Research U1183, Saint Eloi Hospital
| | - Régis Lopez
- University of Montpellier.,National Institute of Health and Medical Research U1061, Neuropsychiatry: Epidemiological and Clinical Research.,Narcolepsy National Reference Center, Sleep Center, Department of Neurology, Montpellier University Hospital Center, Montpellier, France
| | - Lucie Barateau
- University of Montpellier.,National Institute of Health and Medical Research U1061, Neuropsychiatry: Epidemiological and Clinical Research.,Narcolepsy National Reference Center, Sleep Center, Department of Neurology, Montpellier University Hospital Center, Montpellier, France
| | - Caroline Grasselli
- Memory Research and Resources Center, Department of Neurology, Gui de Chauliac University Hospital Center
| | - Carole Pesenti
- Narcolepsy National Reference Center, Sleep Center, Department of Neurology, Montpellier University Hospital Center, Montpellier, France
| | | | - Séverine Béziat
- University of Montpellier.,National Institute of Health and Medical Research U1061, Neuropsychiatry: Epidemiological and Clinical Research
| | - Denis Mariano-Goulart
- University of Montpellier.,Department of Nuclear Medicine, Montpellier University Hospital.,PhyMedExp, National Institute of Health and Medical Research, National Center for Scientific Research
| | - Bertrand Carlander
- Narcolepsy National Reference Center, Sleep Center, Department of Neurology, Montpellier University Hospital Center, Montpellier, France
| | - Yves Dauvilliers
- University of Montpellier.,National Institute of Health and Medical Research U1061, Neuropsychiatry: Epidemiological and Clinical Research.,Narcolepsy National Reference Center, Sleep Center, Department of Neurology, Montpellier University Hospital Center, Montpellier, France
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248
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Han Q, Sun YA, Zong Y, Chen C, Wang HF, Tan L. Common Variants in PLXNA4 and Correlation to CSF-related Phenotypes in Alzheimer's Disease. Front Neurosci 2018; 12:946. [PMID: 30618575 PMCID: PMC6305543 DOI: 10.3389/fnins.2018.00946] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 11/29/2018] [Indexed: 01/21/2023] Open
Abstract
The Plexin-A 4 (PLXNA4) gene, has recently been identified in genome wide association studies (GWAS), as a novel genetic player associated with Alzheimer's disease (AD). Additionally, PLXNA4 genetic variations were also found to increase AD risk by tau pathology in vitro. However, the potential roles of PLXNA4 variants in the amyloid-β (Aβ) pathology, were not evaluated. Five targeted loci capturing the top common variations in PLXNA4, were extracted using tagger methods. Multiple linear regression models were used to explore whether these variations can affect the cerebrospinal fluid (CSF) (Aβ1−42, T-tau, and P-tau) phenotypes in the Alzheimer's disease Neuroimaging Initiative (ADNI) dataset. We detected that two loci (rs6467431, rs67468325) were significantly associated with CSF Aβ1−42 levels in the hybrid population (rs6467431: P = 0.01376, rs67468325: P = 0.006536) and the significance remained after false discovery rate (FDR) correction (rs6467431: Pc = 0.03441, rs67468325: Pc = 0.03268). In the subgroup analysis, we further confirmed the association of rs6467431 in the cognitively normal (CN) subgroup (P = 0.01904, Pc = 0.04761). Furthermore, rs6467431-A carriers and rs67468325-G carriers showed higher CSF Aβ1−42 levels than non-carriers. Nevertheless, we did not detect any significant relationships between the levels of T-tau, P-tau and these PLXNA4 loci. Our findings provided preliminary evidence that PLXNA4 variants can confer AD risk through modulating the Aβ deposition.
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Affiliation(s)
- Qiu Han
- Department of Neurology, Qingdao Clinical Medical School, Qingdao Municipal Hospital, Nanjing Medical University, Qingdao, China.,Department of Neurology, The Affiliated Huaian Hosipital of Xuzhou Medical University, Huai'an, China
| | - Yong-An Sun
- Department of Neurology, Qingdao Clinical Medical School, Qingdao Municipal Hospital, Nanjing Medical University, Qingdao, China.,Department of Neurology, First Affiliated Hospital of Kangda School, Nanjing Medical University, Lianyungang, China
| | - Yu Zong
- Department of Neurology, School of Medicine, Qingdao Municipal Hospital, Qingdao University, Qingdao, China
| | - Chun Chen
- Department of Neurology, Qingdao Clinical Medical School, Qingdao Municipal Hospital, Nanjing Medical University, Qingdao, China.,Department of Neurology, Hongze Huai'an District People's Hospital, Huai'an, China
| | - Hui-Fu Wang
- Department of Neurology, School of Medicine, Qingdao Municipal Hospital, Qingdao University, Qingdao, China
| | - Lan Tan
- Department of Neurology, Qingdao Clinical Medical School, Qingdao Municipal Hospital, Nanjing Medical University, Qingdao, China
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249
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Abstract
β-amyloid is regarded by some scientists to be the cause of Alzheimer’s disease (AD). One of the strongest arguments against this hypothesis is the presence of hundreds of AD-causing mutations in presenilin, but none in the other three components of γ-secretase. This observation implies a γ-secretase–independent function of presenilin. To understand such a putative function, discovery of presenilin-binding proteins represents an important first step. In this study, we report the identification of Bax-inhibitor 1 (BI1) as a stable interacting partner of presenilin 1 (PS1), but not the intact γ-secretase. Our results link PS1 to BI1, a protein thought to play a role in apoptosis and calcium channel regulation. This finding opens a range of possibilities for the investigation of PS1 function and AD genesis. Presenilin is the catalytic subunit of γ-secretase, a four-component intramembrane protease responsible for the generation of β-amyloid (Aβ) peptides. Over 200 Alzheimer’s disease-related mutations have been identified in presenilin 1 (PS1) and PS2. Here, we report that Bax-inhibitor 1 (BI1), an evolutionarily conserved transmembrane protein, stably associates with PS1. BI1 specifically interacts with PS1 in isolation, but not with PS1 in the context of an assembled γ-secretase. The PS1–BI1 complex exhibits no apparent proteolytic activity, as judged by the inability to produce Aβ40 and Aβ42 from the substrate APP-C99. At an equimolar concentration, BI1 has no impact on the proteolytic activity of γ-secretase; at a 200-fold molar excess, BI1 reduces γ-secretase activity nearly by half. Our biochemical study identified BI1 as a PS1-interacting protein, suggesting additional functions of PS1 beyond its involvement in γ-secretase.
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250
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Kelly ÁM. Exercise-Induced Modulation of Neuroinflammation in Models of Alzheimer's Disease. Brain Plast 2018; 4:81-94. [PMID: 30564548 PMCID: PMC6296260 DOI: 10.3233/bpl-180074] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/11/2018] [Indexed: 12/17/2022] Open
Abstract
Alzheimer's disease (AD), a progressive, neurodegenerative condition characterised by accumulation of toxic βeta-amyloid (Aβ) plaques, is one of the leading causes of dementia globally. The cognitive impairment that is a hallmark of AD may be caused by inflammation in the brain triggered and maintained by the presence of Aβ protein, ultimately leading to neuronal dysfunction and loss. Since there is a significant inflammatory component to AD, it is postulated that anti-inflammatory strategies may be of prophylactic or therapeutic benefit in AD. One such strategy is that of regular physical activity, which has been shown in epidemiological studies to be protective against various forms of dementia including AD. Exercise induces an anti-inflammatory environment in peripheral organs and also increases expression of anti-inflammatory molecules within the brain. Here we review the evidence, mainly from animal models of AD, supporting the hypothesis that exercise can reduce or slow the cellular and cognitive impairments associated with AD by modulating neuroinflammation.
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Affiliation(s)
- Áine M. Kelly
- Department of Physiology, School of Medicine & Trinity College Institute of Neuroscience & Trinity Biomedical Sciences Institute, Trinity College Dublin, University of Dublin, Dublin, Ireland
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