601
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Illes S. More than a drainage fluid: the role of CSF in signaling in the brain and other effects on brain tissue. HANDBOOK OF CLINICAL NEUROLOGY 2018; 146:33-46. [PMID: 29110778 DOI: 10.1016/b978-0-12-804279-3.00003-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Current progress in neuroscience demonstrates that the brain is not an isolated organ and is influenced by the systemic environment and extracerebral processes within the body. In view of this new concept, blood and cerebrospinal fluid (CSF) are important body fluids linking extracerebral and intracerebral processes. For decades, substantial evidence has been accumulated indicating that CSF modulates brain states and influences behavior as well as cognition. This chapter provides an overview of how CSF directly modulates the function of different types of brain cells, such as neurons, neural stem cells, and CSF-contacting cells. Alterations in CSF content occur in most pathologic central nervous system (CNS) conditions. In a classic view, the function of CSF is to drain waste products and detrimental factors derived from diseased brain parenchyma. This chapter presents examples for how intra- and extracerebral pathologic processes lead to alterations in the CSF content. Current knowledge about how pathologically altered CSF influences the functionality of brain cells will be presented. Thereby, it becomes evident that CSF has more than a drainage function and has a causal role for the etiology and pathogenesis of different CNS diseases.
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Affiliation(s)
- Sebastian Illes
- Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
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602
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Buckley RF, Hanseeuw B, Schultz AP, Vannini P, Aghjayan SL, Properzi MJ, Jackson JD, Mormino EC, Rentz DM, Sperling RA, Johnson KA, Amariglio RE. Region-Specific Association of Subjective Cognitive Decline With Tauopathy Independent of Global β-Amyloid Burden. JAMA Neurol 2017; 74:1455-1463. [PMID: 28973551 DOI: 10.1001/jamaneurol.2017.2216] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Importance The ability to explore associations between reports of subjective cognitive decline (SCD) and biomarkers of early Alzheimer disease (AD) pathophysiologic processes (accumulation of neocortical β-amyloid [Aβ] and tau) provides an important opportunity to understand the basis of SCD and AD risk. Objective To examine associations between SCD and global Aβ and tau burdens in regions of interest in clinically healthy older adults. Design, Setting, and Participants This imaging substudy of the Harvard Aging Brain Study included 133 clinically healthy older participants (Clinical Dementia Rating Scale global scores of 0) participating in the Harvard Aging Brain Study who underwent cross-sectional flortaucipir F 18 (previously known as AV 1451, T807) positron emission tomography (FTP-PET) imaging for tau and Pittsburgh compound B carbon 11-labeled PET (PiB-PET) imaging for Aβ. The following 2 regions for tau burden were identified: the entorhinal cortex, which exhibits early signs of tauopathy, and the inferior temporal region, which is more closely associated with AD-related pathologic mechanisms. Data were collected from June 11, 2012, through April 7, 2016. Main Outcomes and Measures Subjective cognitive decline was measured using a previously published method of z-transforming subscales from the Memory Functioning Questionnaire, the Everyday Cognition battery, and a 7-item questionnaire. The Aβ level was measured according to a summary distribution volume ratio of frontal, lateral temporal and parietal, and retrosplenial PiB-PET tracer uptake. The FTP-PET measures were computed as standardized uptake value ratios. Linear regression models focused on main and interactive effects of Aβ, entorhinal cortical, and inferior temporal tau on SCD, controlling for age, sex, educational attainment, and Geriatric Depression Scale score. Results Of the 133 participants, 75 (56.3%) were women and 58 (43.6%) were men; mean (SD) age was 76 (6.9) years (range, 55-90 years). Thirty-nine participants (29.3%) exhibited a high Aβ burden. Greater SCD was associated with increasing entorhinal cortical tau burden (β = 0.35; 95% CI, 0.19-.52; P < .001) and Aβ burden (β = 0.24; 95% CI, 0.08-.40; P = .005), but not inferior temporal tau burden (β = 0.10; 95% CI, -0.08 to 0.28; P = .27). This association between entorhinal cortical tau burden and SCD was largely unchanged after accounting for Aβ burden (β = 0.36; 95% CI, 0.15-.58; P = .001), and no interaction influenced SCD (β = -0.36; 95% CI, -0.34 to 0.09; P = .25). An exploratory post hoc whole-brain analysis also indicated that SCD was predominantly associated with greater tau burden in the entorhinal cortex. Conclusions and Relevance Subjective cognitive decline is indicative of accumulation of early tauopathy in the medial temporal lobe, specifically in the entorhinal cortex, and to a lesser extent, elevated global levels of Aβ. Our findings suggest multiple underlying pathways that motivate SCD that do not necessarily interact to influence SCD endorsement. As such, multiple biological factors must be considered when assessing SCD in clinically healthy older adults.
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Affiliation(s)
- Rachel F Buckley
- Florey Institutes of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia.,Melbourne School of Psychological Science, University of Melbourne, Australia.,Athinoula A. Martinos Center for Biomedical Imaging, Department of Neurology, Massachusetts General Hospital, Charlestown.,Department of Radiology, Harvard Medical School, Boston, Massachusetts
| | - Bernard Hanseeuw
- Department of Radiology, Harvard Medical School, Boston, Massachusetts.,Department of Radiology, Massachusetts General Hospital, Boston.,now affiliated with Department of Neurology, Cliniques Universitaires Saint-Luc, Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium
| | - Aaron P Schultz
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Neurology, Massachusetts General Hospital, Charlestown.,Department of Radiology, Massachusetts General Hospital, Boston.,Department of Psychiatry, Massachusetts General Hospital, Boston
| | - Patrizia Vannini
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Neurology, Massachusetts General Hospital, Charlestown.,Department of Radiology, Harvard Medical School, Boston, Massachusetts.,Department of Radiology, Massachusetts General Hospital, Boston
| | - Sarah L Aghjayan
- Center for Alzheimer Research and Treatment, Department of Neurology, Brigham and Women's Hospital, Boston, Massachusetts
| | - Michael J Properzi
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Neurology, Massachusetts General Hospital, Charlestown
| | - Jonathan D Jackson
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Neurology, Massachusetts General Hospital, Charlestown.,Department of Radiology, Harvard Medical School, Boston, Massachusetts.,Center for Alzheimer Research and Treatment, Department of Neurology, Brigham and Women's Hospital, Boston, Massachusetts
| | - Elizabeth C Mormino
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Neurology, Massachusetts General Hospital, Charlestown.,Department of Radiology, Harvard Medical School, Boston, Massachusetts
| | - Dorene M Rentz
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Neurology, Massachusetts General Hospital, Charlestown.,Department of Radiology, Harvard Medical School, Boston, Massachusetts.,Center for Alzheimer Research and Treatment, Department of Neurology, Brigham and Women's Hospital, Boston, Massachusetts
| | - Reisa A Sperling
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Neurology, Massachusetts General Hospital, Charlestown.,Department of Radiology, Harvard Medical School, Boston, Massachusetts.,Center for Alzheimer Research and Treatment, Department of Neurology, Brigham and Women's Hospital, Boston, Massachusetts
| | - Keith A Johnson
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Neurology, Massachusetts General Hospital, Charlestown.,Department of Radiology, Harvard Medical School, Boston, Massachusetts.,Department of Radiology, Massachusetts General Hospital, Boston.,Center for Alzheimer Research and Treatment, Department of Neurology, Brigham and Women's Hospital, Boston, Massachusetts.,Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston
| | - Rebecca E Amariglio
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Neurology, Massachusetts General Hospital, Charlestown.,Department of Radiology, Harvard Medical School, Boston, Massachusetts.,Center for Alzheimer Research and Treatment, Department of Neurology, Brigham and Women's Hospital, Boston, Massachusetts
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603
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Rajasekhar K, Narayanaswamy N, Murugan NA, Viccaro K, Lee HG, Shah K, Govindaraju T. Aβ plaque-selective NIR fluorescence probe to differentiate Alzheimer's disease from tauopathies. Biosens Bioelectron 2017; 98:54-61. [PMID: 28649025 PMCID: PMC6370041 DOI: 10.1016/j.bios.2017.06.030] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 06/01/2017] [Accepted: 06/15/2017] [Indexed: 10/19/2022]
Abstract
Selective detection and staining of toxic amyloid plaques, a potential biomarker present in the Alzheimer's disease (AD) brain is crucial for both clinical diagnosis and monitoring AD disease progression. Herein, we report a coumarin-quinoline (CQ) conjugate-based turn-on near-infrared (NIR) fluorescence probe for specific detection of β-amyloid (Aβ) aggregates. CQ probe is highly sensitive and exhibits ~100-fold fluorescence enhancement in vitro upon binding Aβ aggregates with enhanced quantum yield. Furthermore, the probe has ~10-fold higher binding affinity towards Aβ aggregates (86nM) compared to commonly used Thioflavin T. Most importantly, CQ probe displays unambiguous selectivity towards Aβ aggregates compared to other toxic protein aggregates such as tau, α-synuclein (α-Syn) and islet amyloid polypeptide (IAPP). In addition, CQ is nontoxic to neuronal cells and shows significant blood brain barrier permeability. Remarkably, CQ stains Aβ plaques in human brain tissue over co-existing tau aggregates and neurofibrillary tangles (NFTs), which are associated in AD and tauopathies. This is a highly desirable attribute to distinguish AD from tau pathology and mixed dementia.
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Affiliation(s)
- K Rajasekhar
- Bioorganic Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bengaluru 560064, Karnataka, India
| | - Nagarjun Narayanaswamy
- Bioorganic Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bengaluru 560064, Karnataka, India
| | - N Arul Murugan
- Division of Theoretical Chemistry and Biology, School of Biotechnology, KTH Royal Institute of Technology, S-106 91 Stockholm, Sweden
| | - Keith Viccaro
- Department of Chemistry, Purdue University Center for Cancer Research, 560 Oval Drive, West Lafayette, IN 47907, USA
| | - Hyoung-Gon Lee
- Department of Biology, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA
| | - Kavita Shah
- Department of Chemistry, Purdue University Center for Cancer Research, 560 Oval Drive, West Lafayette, IN 47907, USA
| | - Thimmaiah Govindaraju
- Bioorganic Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bengaluru 560064, Karnataka, India.
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604
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Bejanin A, Schonhaut DR, La Joie R, Kramer JH, Baker SL, Sosa N, Ayakta N, Cantwell A, Janabi M, Lauriola M, O'Neil JP, Gorno-Tempini ML, Miller ZA, Rosen HJ, Miller BL, Jagust WJ, Rabinovici GD. Tau pathology and neurodegeneration contribute to cognitive impairment in Alzheimer's disease. Brain 2017; 140:3286-3300. [PMID: 29053874 DOI: 10.1093/brain/awx243] [Citation(s) in RCA: 426] [Impact Index Per Article: 60.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Accepted: 08/03/2017] [Indexed: 12/13/2022] Open
Abstract
Neuropathological and in vivo studies have revealed a tight relationship between tau pathology and cognitive impairment across the Alzheimer's disease spectrum. However, tau pathology is also intimately associated with neurodegeneration and amyloid pathology. The aim of the present study was therefore to assess whether grey matter atrophy and amyloid pathology contribute to the relationship between tau pathology, as measured with 18F-AV-1451-PET imaging, and cognitive deficits in Alzheimer's disease. We included 40 amyloid-positive patients meeting criteria for mild cognitive impairment due to Alzheimer's disease (n = 5) or probable Alzheimer's disease dementia (n = 35). Twelve patients additionally fulfilled the diagnostic criteria for posterior cortical atrophy and eight for logopenic variant primary progressive aphasia. All participants underwent 3 T magnetic resonance imaging, amyloid (11C-PiB) positron emission tomography and tau (18F-AV-1451) positron emission tomography, and episodic and semantic memory, language, executive and visuospatial functions assessment. Raw cognitive scores were converted to age-adjusted Z-scores (W-scores) and averaged to compute composite scores for each cognitive domain. Independent regressions were performed between 18F-AV-1451 binding and each cognitive domain, and we used the Biological Parametric Mapping toolbox to further control for local grey matter volumes, 11C-PiB uptake, or both. Partial correlations and causal mediation analyses (mediation R package) were then performed in brain regions showing an association between cognition and both 18F-AV-1451 uptake and grey matter volume. Our results showed that decreased cognitive performance in each domain was related to increased 18F-AV-1451 binding in specific brain regions conforming to established brain-behaviour relationships (i.e. episodic memory: medial temporal lobe and angular gyrus; semantic memory: left anterior temporal regions; language: left posterior superior temporal lobe and supramarginal gyrus; executive functions: bilateral frontoparietal regions; visuospatial functions: right more than left occipitotemporal regions). This pattern of regional associations remained essentially unchanged-although less spatially extended-when grey matter volume or 11C-PiB uptake maps were added as covariates. Mediation analyses revealed both direct and grey matter-mediated effects of 18F-AV-1451 uptake on cognitive performance. Together, these results show that tau pathology is related in a region-specific manner to cognitive impairment in Alzheimer's disease. These regional relationships are weakly related to amyloid burden, but are in part mediated by grey matter volumes. This suggests that tau pathology may lead to cognitive deficits through a variety of mechanisms, including, but not restricted to, grey matter loss. These results might have implications for future therapeutic trials targeting tau pathology.
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Affiliation(s)
- Alexandre Bejanin
- Memory and Aging Center, University of California San Francisco, San Francisco, CA, USA
| | - Daniel R Schonhaut
- Memory and Aging Center, University of California San Francisco, San Francisco, CA, USA
| | - Renaud La Joie
- Memory and Aging Center, University of California San Francisco, San Francisco, CA, USA
| | - Joel H Kramer
- Memory and Aging Center, University of California San Francisco, San Francisco, CA, USA
| | - Suzanne L Baker
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Natasha Sosa
- Memory and Aging Center, University of California San Francisco, San Francisco, CA, USA
| | - Nagehan Ayakta
- Memory and Aging Center, University of California San Francisco, San Francisco, CA, USA
| | - Averill Cantwell
- Memory and Aging Center, University of California San Francisco, San Francisco, CA, USA
| | - Mustafa Janabi
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Mariella Lauriola
- Memory and Aging Center, University of California San Francisco, San Francisco, CA, USA
| | - James P O'Neil
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Maria L Gorno-Tempini
- Memory and Aging Center, University of California San Francisco, San Francisco, CA, USA
| | - Zachary A Miller
- Memory and Aging Center, University of California San Francisco, San Francisco, CA, USA
| | - Howard J Rosen
- Memory and Aging Center, University of California San Francisco, San Francisco, CA, USA
| | - Bruce L Miller
- Memory and Aging Center, University of California San Francisco, San Francisco, CA, USA
| | - William J Jagust
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA, USA
| | - Gil D Rabinovici
- Memory and Aging Center, University of California San Francisco, San Francisco, CA, USA.,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA, USA
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605
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Myeku N, Duff KE. Targeting the 26S Proteasome To Protect Against Proteotoxic Diseases. Trends Mol Med 2017; 24:18-29. [PMID: 29233753 DOI: 10.1016/j.molmed.2017.11.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 11/21/2017] [Accepted: 11/21/2017] [Indexed: 12/16/2022]
Abstract
Aggregates of misfolded proteins can compromise the function of the 26S proteasome complex, leaving neurons susceptible to accelerated and impaired protein homeostasis, thereby contributing to the pathogenesis of neurodegeneration. Strategies aimed at enhancing the function of the 26S proteasome via phosphorylation of key subunit epitopes have been effective in reducing protein aggregates in mouse models of disease. We discuss how phosphodiesterase (PDE) inhibitors and G protein-coupled receptor (GPCR)-targeted drugs might be considered as candidate therapeutics, acting on second messenger signal transduction. The range of candidates might address the need for region-, cell-, or even cellular compartment-specific modulation. Given the array of clinical and experimental drugs targeting cAMP/cGMP signaling, we propose that proteasome activators targeting secondary messengers might be exploited as novel agents for the treatment or prevention of some neurodegenerative diseases.
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Affiliation(s)
- Natura Myeku
- Department of Pathology and Cell Biology, The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY, USA.
| | - Karen E Duff
- Department of Pathology and Cell Biology, The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY, USA; Division of Integrative Neuroscience, New York State Psychiatric Institute, New York, NY, USA.
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606
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Ottoy J, Verhaeghe J, Niemantsverdriet E, Engelborghs S, Stroobants S, Staelens S. A simulation study on the impact of the blood flow-dependent component in [18F]AV45 SUVR in Alzheimer's disease. PLoS One 2017; 12:e0189155. [PMID: 29211812 PMCID: PMC5718604 DOI: 10.1371/journal.pone.0189155] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 11/20/2017] [Indexed: 01/04/2023] Open
Abstract
Background Increased brain uptake on [18F]AV45 PET is a biomarker for Alzheimer’s disease (AD). The standardised uptake value ratio (SUVR) is widely used for quantification but is subject to variability. Here we evaluate how SUVR of a cortical target region is affected by blood flow changes in the target and two frequently used reference regions. Methods Regional baseline time-activity curves (TACs) were simulated based on metabolite-corrected plasma input functions and pharmacokinetic parameters obtained from our previously acquired data in healthy control (HC; n = 10), amnestic mild cognitive impairment (aMCI; n = 15) and AD cohorts (n = 9). Blood flow changes were simulated by altering the regional tracer delivery rate K1 (and clearance rate k2) between -40% and +40% from its regional baseline value in the target region and/or cerebellar grey (CB) or subcortical white matter (WM) reference regions. The corresponding change in SUVR was calculated at 50–60 min post-injection. Results A -40% blood flow reduction in the target resulted in an increased SUVRtarget (e.g. SUVRprecuneus: +10.0±5% in HC, +2.5±2% in AD), irrespective of the used reference region. A -40% blood flow reduction in the WM reference region increased SUVRWM (+11.5±4% in HC, +13.5±3% in AD) while a blood flow reduction in CB decreased SUVRCB (-9.5±6% in HC, -5.5±2% in AD), irrespective of the used target region. A -40% flow reduction in both the precuneus and reference WM (i.e., global flow change) induced an increased SUVR (+22.5±8% in HC, +16.0±4% in AD). When considering reference CB instead, SUVR was decreased by less than -5% (both in HC and AD). Conclusion Blood flow changes introduce alterations in [18F]AV45 PET SUVR. Flow reductions in the CB and WM reference regions resulted in a decreased and increased SUVR of the target, respectively. SUVR was more affected by global blood flow changes when considering WM instead of CB normalization.
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Affiliation(s)
- Julie Ottoy
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Ellis Niemantsverdriet
- Reference Center for Biological Markers of Dementia (BIODEM), University of Antwerp, Antwerp, Belgium
| | - Sebastiaan Engelborghs
- Reference Center for Biological Markers of Dementia (BIODEM), University of Antwerp, Antwerp, Belgium
- Department of Neurology and Memory Clinic, Hospital Network Antwerp (ZNA) Hoge Beuken en Middelheim, Antwerp, Belgium
| | - Sigrid Stroobants
- Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Steven Staelens
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
- * E-mail:
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607
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Smith LA, McMahon LL. Deficits in synaptic function occur at medial perforant path-dentate granule cell synapses prior to Schaffer collateral-CA1 pyramidal cell synapses in the novel TgF344-Alzheimer's Disease Rat Model. Neurobiol Dis 2017; 110:166-179. [PMID: 29199135 DOI: 10.1016/j.nbd.2017.11.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 11/21/2017] [Accepted: 11/29/2017] [Indexed: 12/23/2022] Open
Abstract
Alzheimer's disease (AD) pathology begins decades prior to onset of clinical symptoms, and the entorhinal cortex and hippocampus are among the first and most extensively impacted brain regions. The TgF344-AD rat model, which more fully recapitulates human AD pathology in an age-dependent manner, is a next generation preclinical rodent model for understanding pathophysiological processes underlying the earliest stages of AD (Cohen et al., 2013). Whether synaptic alterations occur in hippocampus prior to reported learning and memory deficit is not known. Furthermore, it is not known if specific hippocampal synapses are differentially affected by progressing AD pathology, or if synaptic deficits begin to appear at the same age in males and females in this preclinical model. Here, we investigated the time-course of synaptic changes in basal transmission, paired-pulse ratio, as an indirect measure of presynaptic release probability, long-term potentiation (LTP), and dendritic spine density at two hippocampal synapses in male and ovariectomized female TgF344-AD rats and wildtype littermates, prior to reported behavioral deficits. Decreased basal synaptic transmission begins at medial perforant path-dentate granule cell (MPP-DGC) synapses prior to Schaffer-collateral-CA1 (CA3-CA1) synapses, in the absence of a change in paired-pulse ratio (PPR) or dendritic spine density. N-methyl-d-aspartate receptor (NMDAR)-dependent LTP magnitude is unaffected at CA3-CA1 synapses at 6, 9, and 12months of age, but is significantly increased at MPP-DGC synapses in TgF344-AD rats at 6months only. Sex differences were only observed at CA3-CA1 synapses where the decrease in basal transmission occurs at a younger age in males versus females. These are the first studies to define presymptomatic alterations in hippocampal synaptic transmission in the TgF344-AD rat model. The time course of altered synaptic transmission mimics the spread of pathology through hippocampus in human AD and provides support for this model as a valuable preclinical tool in elucidating pathological mechanisms of early synapse dysfunction in AD.
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Affiliation(s)
- Lindsey A Smith
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, USA
| | - Lori L McMahon
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, USA.
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608
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Jones DT, Graff-Radford J, Lowe VJ, Wiste HJ, Gunter JL, Senjem ML, Botha H, Kantarci K, Boeve BF, Knopman DS, Petersen RC, Jack CR. Tau, amyloid, and cascading network failure across the Alzheimer's disease spectrum. Cortex 2017; 97:143-159. [PMID: 29102243 PMCID: PMC5773067 DOI: 10.1016/j.cortex.2017.09.018] [Citation(s) in RCA: 141] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 08/02/2017] [Accepted: 09/26/2017] [Indexed: 01/18/2023]
Abstract
Functionally related brain regions are selectively vulnerable to Alzheimer's disease pathophysiology. However, molecular markers of this pathophysiology (i.e., beta-amyloid and tau aggregates) have discrepant spatial and temporal patterns of progression within these selectively vulnerable brain regions. Existing reductionist pathophysiologic models cannot account for these large-scale spatiotemporal inconsistencies. Within the framework of the recently proposed cascading network failure model of Alzheimer's disease, however, these large-scale patterns are to be expected. This model postulates the following: 1) a tau-associated, circumscribed network disruption occurs in brain regions specific to a given phenotype in clinically normal individuals; 2) this disruption can trigger phenotype independent, stereotypic, and amyloid-associated compensatory brain network changes indexed by changes in the default mode network; 3) amyloid deposition marks a saturation of functional compensation and portends an acceleration of the inciting phenotype specific, and tau-associated, network failure. With the advent of in vivo molecular imaging of tau pathology, combined with amyloid and functional network imaging, it is now possible to investigate the relationship between functional brain networks, tau, and amyloid across the disease spectrum within these selectively vulnerable brain regions. In a large cohort (n = 218) spanning the Alzheimer's disease spectrum from young, amyloid negative, cognitively normal subjects to Alzheimer's disease dementia, we found several distinct spatial patterns of tau deposition, including 'Braak-like' and 'non-Braak-like', across functionally related brain regions. Rather than arising focally and spreading sequentially, elevated tau signal seems to occur system-wide based on inferences made from multiple cross-sectional analyses we conducted looking at regional patterns of tau signal. Younger age-of-disease-onset was associated with 'non-Braak-like' patterns of tau, suggesting an association with atypical clinical phenotypes. As predicted by the cascading network failure model of Alzheimer's disease, we found that amyloid is a partial mediator of the relationship between functional network failure and tau deposition in functionally connected brain regions. This study implicates large-scale brain networks in the pathophysiology of tau deposition and offers support to models incorporating large-scale network physiology into disease models linking tau and amyloid, such as the cascading network failure model of Alzheimer's disease.
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Affiliation(s)
- David T Jones
- Department of Neurology, Mayo Clinic, Rochester, MN, USA; Department of Radiology, Mayo Clinic, Rochester, MN, USA.
| | | | - Val J Lowe
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
| | - Heather J Wiste
- Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA
| | - Jeffrey L Gunter
- Department of Radiology, Mayo Clinic, Rochester, MN, USA; Department of Information Technology, Mayo Clinic, Rochester, MN, USA
| | - Matthew L Senjem
- Department of Radiology, Mayo Clinic, Rochester, MN, USA; Department of Information Technology, Mayo Clinic, Rochester, MN, USA
| | - Hugo Botha
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Kejal Kantarci
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
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609
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Merlo S, Spampinato SF, Sortino MA. Estrogen and Alzheimer's disease: Still an attractive topic despite disappointment from early clinical results. Eur J Pharmacol 2017; 817:51-58. [DOI: 10.1016/j.ejphar.2017.05.059] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 04/13/2017] [Accepted: 05/30/2017] [Indexed: 01/06/2023]
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610
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Kusne Y, Wolf AB, Townley K, Conway M, Peyman GA. Visual system manifestations of Alzheimer's disease. Acta Ophthalmol 2017; 95:e668-e676. [PMID: 27864881 DOI: 10.1111/aos.13319] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 10/07/2016] [Indexed: 12/13/2022]
Abstract
Alzheimer's disease (AD) is an increasingly common disease with massive personal and economic costs. While it has long been known that AD impacts the visual system, there has recently been an increased focus on understanding both pathophysiological mechanisms that may be shared between the eye and brain and how related biomarkers could be useful for AD diagnosis. Here, were review pertinent cellular and molecular mechanisms of AD pathophysiology, the presence of AD pathology in the visual system, associated functional changes, and potential development of diagnostic tools based on the visual system. Additionally, we discuss links between AD and visual disorders, including possible pathophysiological mechanisms and their relevance for improving our understanding of AD.
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Affiliation(s)
- Yael Kusne
- University of Arizona College of Medicine; Phoenix Arizona USA
| | - Andrew B. Wolf
- University of Colorado School of Medicine; Aurora Colorado USA
| | - Kate Townley
- University of Arizona College of Medicine; Phoenix Arizona USA
| | - Mandi Conway
- University of Arizona College of Medicine; Phoenix Arizona USA
- Arizona Retinal Specialists; Sun City Arizona USA
| | - Gholam A. Peyman
- University of Arizona College of Medicine; Phoenix Arizona USA
- Arizona Retinal Specialists; Sun City Arizona USA
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611
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Eclalbasaponin II Ameliorates the Cognitive Impairment Induced by Cholinergic Blockade in Mice. Neurochem Res 2017; 43:351-362. [DOI: 10.1007/s11064-017-2430-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 10/26/2017] [Accepted: 10/30/2017] [Indexed: 10/18/2022]
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612
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Stefanova NA, Muraleva NA, Maksimova KY, Rudnitskaya EA, Kiseleva E, Telegina DV, Kolosova NG. An antioxidant specifically targeting mitochondria delays progression of Alzheimer's disease-like pathology. Aging (Albany NY) 2017; 8:2713-2733. [PMID: 27750209 PMCID: PMC5191865 DOI: 10.18632/aging.101054] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 09/18/2016] [Indexed: 12/29/2022]
Abstract
Mitochondrial aberrations are observed in human Alzheimer's disease (AD) and in medical conditions that increase the risk of this disorder, suggesting that mitochondrial dysfunction may contribute to pathophysiology of AD. Here, using OXYS rats that simulate key characteristics of sporadic AD, we set out to determine the role of mitochondria in the pathophysiology of this disorder. OXYS rats were treated with a mitochondria-targeted antioxidant SkQ1 from age 12 to 18 months, that is, during active progression of AD-like pathology in these animals. Dietary supplementation with SkQ1 caused this compound to accumulate in various brain regions, and it was localized mostly to neuronal mitochondria. Via improvement of structural and functional state of mitochondria, treatment with SkQ1 alleviated the structural neurodegenerative alterations, prevented the neuronal loss and synaptic damage, increased the levels of synaptic proteins, enhanced neurotrophic supply, and decreased amyloid-β1-42 protein levels and tau hyperphosphorylation in the hippocampus of OXYS rats, resulting in improvement of the learning ability and memory. Collectively, these data support that mitochondrial dysfunction may play a key role in the pathophysiology of AD and that therapies with target mitochondria are potent to normalize a wide range of cellular signaling processes and therefore slow the progression of AD.
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Affiliation(s)
| | | | | | | | - Elena Kiseleva
- Institute of Cytology and Genetics SB RAS, 630090, Novosibirsk, Russia
| | - Darya V Telegina
- Institute of Cytology and Genetics SB RAS, 630090, Novosibirsk, Russia
| | - Nataliya G Kolosova
- Institute of Cytology and Genetics SB RAS, 630090, Novosibirsk, Russia.,Novosibirsk State University, 630090, Novosibirsk, Russia
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613
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Near infrared light decreases synaptic vulnerability to amyloid beta oligomers. Sci Rep 2017; 7:15012. [PMID: 29118388 PMCID: PMC5678170 DOI: 10.1038/s41598-017-15357-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 10/25/2017] [Indexed: 02/07/2023] Open
Abstract
Synaptic dysfunction due to the disrupting binding of amyloid beta (Aβ) and tau oligomers is one of the earliest impairments in Alzheimer’s Disease (AD), driving initial cognitive deficits and clinical manifestation. Consequently, there is ample consensus that preventing early synaptic dysfunction would be an effective therapeutic strategy for AD. With this goal in mind, we investigated the effect of a treatment of mice with near infrared (NIR) light on synaptic vulnerability to Aβ oligomers. We found that Aβ oligomer binding to CNS synaptosomes isolated from wild type (wt) mice treated with NIR light was significantly reduced and the resulting suppression of long term potentiation (LTP) by Aβ oligomers was prevented. Similarly, APP transgenic mice treated with NIR showed a significant reduction of endogenous Aβ at CNS synapses. We further found that these phenomena were accompanied by increased synaptic mitochondrial membrane potential in both wt and Tg2576 mice. This study provides evidence that NIR light can effectively reduce synaptic vulnerability to damaging Aβ oligomers, thus furthering NIR light therapy as a viable treatment for AD.
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614
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Brody AH, Strittmatter SM. Synaptotoxic Signaling by Amyloid Beta Oligomers in Alzheimer's Disease Through Prion Protein and mGluR5. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2017; 82:293-323. [PMID: 29413525 PMCID: PMC5835229 DOI: 10.1016/bs.apha.2017.09.007] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Alzheimer's disease (AD) represents an impending global health crisis, yet the complexity of AD pathophysiology has so far precluded the development of any interventions to successfully slow or halt AD progression. It is clear that accumulation of Amyloid-beta (Aβ) peptide triggers progressive synapse loss to cause AD symptoms. Once initiated by Aβ, disease progression is complicated and accelerated by inflammation and by tau pathology. The recognition that Aβ peptide assumes multiple distinct states and that soluble oligomeric species (Aβo) are critical for synaptic damage is central to molecular understanding of AD. This knowledge has led to the identification of specific Aβo receptors, such as cellular prion protein (PrPC), mediating synaptic toxicity and neuronal dysfunction. The identification of PrPC as an Aβo receptor has illuminated an Aβo-induced signaling cascade involving mGluR5, Fyn, and Pyk2 that links Aβ and tau pathologies. This pathway provides novel potential therapeutic targets for disease-modifying AD therapy. Here, we discuss the methods by which several putative Aβo receptors were identified. We also offer an in-depth examination of the known molecular mechanisms believed to mediate Aβo-induced synaptic dysfunction, toxicity, and memory dysfunction.
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Affiliation(s)
- A Harrison Brody
- Program in Cellular Neuroscience, Neurodegeneration & Repair, Yale University School of Medicine, New Haven, CT, United States; Yale University, New Haven, CT, United States
| | - Stephen M Strittmatter
- Program in Cellular Neuroscience, Neurodegeneration & Repair, Yale University School of Medicine, New Haven, CT, United States; Yale University, New Haven, CT, United States.
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615
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Tian L, Hui CW, Bisht K, Tan Y, Sharma K, Chen S, Zhang X, Tremblay ME. Microglia under psychosocial stressors along the aging trajectory: Consequences on neuronal circuits, behavior, and brain diseases. Prog Neuropsychopharmacol Biol Psychiatry 2017; 79:27-39. [PMID: 28095309 DOI: 10.1016/j.pnpbp.2017.01.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 12/30/2016] [Accepted: 01/13/2017] [Indexed: 12/18/2022]
Abstract
Mounting evidence indicates the importance of microglia for proper brain development and function, as well as in complex stress-related neuropsychiatric disorders and cognitive decline along the aging trajectory. Considering that microglia are resident immune cells of the brain, a homeostatic maintenance of their effector functions that impact neuronal circuitry, such as phagocytosis and secretion of inflammatory factors, is critical to prevent the onset and progression of these pathological conditions. However, the molecular mechanisms by which microglial functions can be properly regulated under healthy and pathological conditions are still largely unknown. We aim to summarize recent progress regarding the effects of psychosocial stress and oxidative stress on microglial phenotypes, leading to neuroinflammation and impaired microglia-synapse interactions, notably through our own studies of inbred mouse strains, and most importantly, to discuss about promising therapeutic strategies that take advantage of microglial functions to tackle such brain disorders in the context of adult psychosocial stress or aging-induced oxidative stress.
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Affiliation(s)
- Li Tian
- Neuroscience Center, University of Helsinki, Viikinkaari 4, Helsinki FIN-00014, Finland; Psychiatry Research Center, Beijing Huilongguan Hospital, Peking University, Beijing, China.
| | - Chin Wai Hui
- Axe Neurosciences, Centre de recherche du CHU de Québec, Québec, Canada
| | - Kanchan Bisht
- Axe Neurosciences, Centre de recherche du CHU de Québec, Québec, Canada
| | - Yunlong Tan
- Psychiatry Research Center, Beijing Huilongguan Hospital, Peking University, Beijing, China
| | - Kaushik Sharma
- Axe Neurosciences, Centre de recherche du CHU de Québec, Québec, Canada
| | - Song Chen
- Psychiatry Research Center, Beijing Huilongguan Hospital, Peking University, Beijing, China; Beijing Key Laboratory of Mental Disorders and Center of Schizophrenia, Beijing Institute for Brain Disorders, Beijing Anding Hospital, Capital Medical University, China
| | - Xiangyang Zhang
- Psychiatry Research Center, Beijing Huilongguan Hospital, Peking University, Beijing, China; Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Marie-Eve Tremblay
- Axe Neurosciences, Centre de recherche du CHU de Québec, Québec, Canada.
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616
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Wang C, Saar V, Leung KL, Chen L, Wong G. Human amyloid β peptide and tau co-expression impairs behavior and causes specific gene expression changes in Caenorhabditis elegans. Neurobiol Dis 2017; 109:88-101. [PMID: 28982592 DOI: 10.1016/j.nbd.2017.10.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 09/11/2017] [Accepted: 10/01/2017] [Indexed: 01/20/2023] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by the presence of extracellular amyloid plaques consisting of Amyloid-β peptide (Aβ) aggregates and neurofibrillary tangles formed by aggregation of hyperphosphorylated microtubule-associated protein tau. We generated a novel invertebrate model of AD by crossing Aβ1-42 (strain CL2355) with either pro-aggregating tau (strain BR5270) or anti-aggregating tau (strain BR5271) pan-neuronal expressing transgenic Caenorhabditis elegans. The lifespan and progeny viability of the double transgenic strains were significantly decreased compared with wild type N2 (P<0.0001). In addition, co-expression of these transgenes interfered with neurotransmitter signaling pathways, caused deficits in chemotaxis associative learning, increased protein aggregation visualized by Congo red staining, and increased neuronal loss. Global transcriptomic RNA-seq analysis revealed 248 up- and 805 down-regulated genes in N2 wild type versus Aβ1-42+pro-aggregating tau animals, compared to 293 up- and 295 down-regulated genes in N2 wild type versus Aβ1-42+anti-aggregating tau animals. Gene set enrichment analysis of Aβ1-42+pro-aggregating tau animals uncovered up-regulated annotation clusters UDP-glucuronosyltransferase (5 genes, P<4.2E-4), protein phosphorylation (5 genes, P<2.60E-02), and aging (5 genes, P<8.1E-2) while the down-regulated clusters included nematode cuticle collagen (36 genes, P<1.5E-21). RNA interference of 13 available top up-regulated genes in Aβ1-42+pro-aggregating tau animals revealed that F-box family genes and nep-4 could enhance life span deficits and chemotaxis deficits while Y39G8C.2 (TTBK2) could suppress these behaviors. Comparing the list of regulated genes from C. elegans to the top 60 genes related to human AD confirmed an overlap of 8 genes: patched homolog 1, PTCH1 (ptc-3), the Rab GTPase activating protein, TBC1D16 (tbc-16), the WD repeat and FYVE domain-containing protein 3, WDFY3 (wdfy-3), ADP-ribosylation factor guanine nucleotide exchange factor 2, ARFGEF2 (agef-1), Early B-cell Factor, EBF1 (unc-3), d-amino-acid oxidase, DAO (daao-1), glutamate receptor, metabotropic 1, GRM1 (mgl-2), prolyl 4-hydroxylase subunit alpha 2, P4HA2 (dpy-18 and phy-2). Taken together, our C. elegans double transgenic model provides insight on the fundamental neurobiologic processes underlying human AD and recapitulates selected transcriptomic changes observed in human AD brains.
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Affiliation(s)
- Chenyin Wang
- Faculty of Health Sciences, University of Macau, 999078, Macau
| | - Valeria Saar
- Faculty of Health Sciences, University of Macau, 999078, Macau
| | - Ka Lai Leung
- Faculty of Health Sciences, University of Macau, 999078, Macau
| | - Liang Chen
- Faculty of Health Sciences, University of Macau, 999078, Macau
| | - Garry Wong
- Faculty of Health Sciences, University of Macau, 999078, Macau.
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617
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Hu Y, Zeng Z, Wang B, Guo S. Trans-caryophyllene inhibits amyloid β (Aβ) oligomer-induced neuroinflammation in BV-2 microglial cells. Int Immunopharmacol 2017; 51:91-98. [DOI: 10.1016/j.intimp.2017.07.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 06/23/2017] [Accepted: 07/11/2017] [Indexed: 10/18/2022]
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618
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Jeong S. Molecular and Cellular Basis of Neurodegeneration in Alzheimer's Disease. Mol Cells 2017; 40:613-620. [PMID: 28927263 PMCID: PMC5638769 DOI: 10.14348/molcells.2017.0096] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 08/06/2017] [Accepted: 08/16/2017] [Indexed: 12/25/2022] Open
Abstract
The most common form of senile dementia is Alzheimer's disease (AD), which is characterized by the extracellular deposition of amyloid β-peptide (Aβ) plaques and the intracellular formation of neurofibrillary tangles (NFTs) in the cerebral cortex. Tau abnormalities are commonly observed in many neurodegenerative diseases including AD, Parkinson's disease, and Pick's disease. Interestingly, tau-mediated formation of NFTs in AD brains shows better correlation with cognitive impairment than Aβ plaque accumulation; pathological tau alone is sufficient to elicit frontotemporal dementia, but it does not cause AD. A growing amount of evidence suggests that soluble Aβ oligomers in concert with hyperphosphorylated tau (pTau) serve as the major pathogenic drivers of neurodegeneration in AD. Increased Aβ oligomers trigger neuronal dysfunction and network alternations in learning and memory circuitry prior to clinical onset of AD, leading to cognitive decline. Furthermore, accumulated damage to mitochondria in the course of aging, which is the best-known nongenetic risk factor for AD, may collaborate with soluble Aβ and pTau to induce synapse loss and cognitive impairment in AD. In this review, I summarize and discuss the current knowledge of the molecular and cellular biology of AD and also the mechanisms that underlie Aβ-mediated neurodegeneration.
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Affiliation(s)
- Sangyun Jeong
- Department of Molecular Biology, Chonbuk National University, Jeonju 54896,
Korea
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619
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Iaccarino L, Tammewar G, Ayakta N, Baker SL, Bejanin A, Boxer AL, Gorno-Tempini ML, Janabi M, Kramer JH, Lazaris A, Lockhart SN, Miller BL, Miller ZA, O'Neil JP, Ossenkoppele R, Rosen HJ, Schonhaut DR, Jagust WJ, Rabinovici GD. Local and distant relationships between amyloid, tau and neurodegeneration in Alzheimer's Disease. NEUROIMAGE-CLINICAL 2017; 17:452-464. [PMID: 29159058 PMCID: PMC5684433 DOI: 10.1016/j.nicl.2017.09.016] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 09/08/2017] [Accepted: 09/22/2017] [Indexed: 12/11/2022]
Abstract
The relationships between β-amyloid (Aβ), tau and neurodegeneration within Alzheimer's Disease pathogenesis are not fully understood. To explore these associations in vivo, we evaluated 30 Aβ PET-positive patients (mean ± sd age 62.4 ± 8.3) with mild probable AD and 12 Aβ PET-negative healthy controls (HC) (mean ± sd age 77.3 ± 6.9) as comparison. All participants underwent 3 T MRI, 11C-PiB (Aβ) PET and 18F-AV1451 (tau) PET. Multimodal correlation analyses were run at both voxel- and region-of-interest levels. 11C-PiB retention in AD showed the most diffuse uptake pattern throughout association neocortex, whereas 18F-AV1451 and gray matter volume reduction (GMR) showed a progressive predilection for posterior cortices (p<0.05 Family-Wise Error-[FWE]-corrected). Voxel-level analysis identified negative correlations between 18F-AV1451 and gray matter peaking in medial and infero-occipital regions (p<0.01 False Discovery Rate-[FDR]-corrected). 18F-AV1451 and 11C-PiB were positively correlated in right parietal and medial/inferior occipital regions (p<0.001 uncorrected). 11C-PiB did not correlate with GMR at the voxel-level. Regionally, 18F-AV1451 was largely associated with local/adjacent GMR whereas frontal 11C-PiB correlated with GMR in posterior regions. These findings suggest that, in mild AD, tau aggregation drives local neurodegeneration, whereas the relationships between Aβ and neurodegeneration are not region specific and may be mediated by the interaction between Aβ and tau. Tau tangles show tight and local associations with gray matter volume. Amyloid plaques show long-distance and indirect effects on gray matter volume. Local relationships between tau and amyloid may evolve and vary by disease stage. Amyloid accumulates homogeneously and uniformly across association cortices. Tau accumulation begins locally and spreads to functionally connected regions.
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Affiliation(s)
- Leonardo Iaccarino
- Memory and Aging Center, Sandler Neurosciences Center, University of California, San Francisco, CA 94158, United States; Vita-Salute San Raffaele University, Milan 20132, Italy; In Vivo Human Molecular and Structural Neuroimaging Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan 20132, Italy.
| | - Gautam Tammewar
- Memory and Aging Center, Sandler Neurosciences Center, University of California, San Francisco, CA 94158, United States
| | - Nagehan Ayakta
- Memory and Aging Center, Sandler Neurosciences Center, University of California, San Francisco, CA 94158, United States
| | - Suzanne L Baker
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, United States; Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States
| | - Alexandre Bejanin
- Memory and Aging Center, Sandler Neurosciences Center, University of California, San Francisco, CA 94158, United States
| | - Adam L Boxer
- Memory and Aging Center, Sandler Neurosciences Center, University of California, San Francisco, CA 94158, United States
| | - Maria Luisa Gorno-Tempini
- Memory and Aging Center, Sandler Neurosciences Center, University of California, San Francisco, CA 94158, United States
| | - Mustafa Janabi
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States
| | - Joel H Kramer
- Memory and Aging Center, Sandler Neurosciences Center, University of California, San Francisco, CA 94158, United States
| | - Andreas Lazaris
- Memory and Aging Center, Sandler Neurosciences Center, University of California, San Francisco, CA 94158, United States; Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, United States
| | - Samuel N Lockhart
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, United States
| | - Bruce L Miller
- Memory and Aging Center, Sandler Neurosciences Center, University of California, San Francisco, CA 94158, United States
| | - Zachary A Miller
- Memory and Aging Center, Sandler Neurosciences Center, University of California, San Francisco, CA 94158, United States
| | - James P O'Neil
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States
| | - Rik Ossenkoppele
- Memory and Aging Center, Sandler Neurosciences Center, University of California, San Francisco, CA 94158, United States; Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, United States; Department of Neurology and Alzheimer Center, VU University Medical Center, Amsterdam 1081 HV, The Netherlands
| | - Howard J Rosen
- Memory and Aging Center, Sandler Neurosciences Center, University of California, San Francisco, CA 94158, United States
| | - Daniel R Schonhaut
- Memory and Aging Center, Sandler Neurosciences Center, University of California, San Francisco, CA 94158, United States; Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, United States
| | - William J Jagust
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, United States; Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States
| | - Gil D Rabinovici
- Memory and Aging Center, Sandler Neurosciences Center, University of California, San Francisco, CA 94158, United States; Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, United States; Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States
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620
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Yamazaki Y, Kanekiyo T. Blood-Brain Barrier Dysfunction and the Pathogenesis of Alzheimer's Disease. Int J Mol Sci 2017; 18:ijms18091965. [PMID: 28902142 PMCID: PMC5618614 DOI: 10.3390/ijms18091965] [Citation(s) in RCA: 258] [Impact Index Per Article: 36.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 09/06/2017] [Accepted: 09/07/2017] [Indexed: 01/22/2023] Open
Abstract
Brain capillary endothelial cells form the blood-brain barrier (BBB), which is covered with basement membranes and is also surrounded by pericytes and astrocyte end-feet in the neurovascular unit. The BBB tightly regulates the molecular exchange between the blood flow and brain parenchyma, thereby regulating the homeostasis of the central nervous system (CNS). Thus, dysfunction of the BBB is likely involved in the pathogenesis of several neurological diseases, including Alzheimer’s disease (AD). While amyloid-β (Aβ) deposition and neurofibrillary tangle formation in the brain are central pathological hallmarks in AD, cerebrovascular lesions and BBB alteration have also been shown to frequently coexist. Although further clinical studies should clarify whether BBB disruption is a specific feature of AD pathogenesis, increasing evidence indicates that each component of the neurovascular unit is significantly affected in the presence of AD-related pathologies in animal models and human patients. Conversely, since some portions of Aβ are eliminated along the neurovascular unit and across the BBB, disturbing the pathways may result in exacerbated Aβ accumulation in the brain. Thus, current evidence suggests that BBB dysfunction may causatively and consequently contribute to AD pathogenesis, forming a vicious cycle between brain Aβ accumulation and neurovascular unit impairments during disease progression.
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Affiliation(s)
- Yu Yamazaki
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
| | - Takahisa Kanekiyo
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
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621
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Salta E, De Strooper B. microRNA-132: a key noncoding RNA operating in the cellular phase of Alzheimer's disease. FASEB J 2017; 31:424-433. [PMID: 28148775 DOI: 10.1096/fj.201601308] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 12/12/2016] [Indexed: 12/20/2022]
Abstract
With the consideration of the broad involvement of microRNAs (miRNAs) in the regulation of molecular networks in the brain, it is not surprising that miRNA dysregulation causes neurodegeneration in animal models. miRNA profiling in the human brain has revealed miR-132 as one of the most severely down-regulated miRNAs at the intermediate and late Braak stages of Alzheimer's disease (AD), as well as in other neurodegenerative disorders. Suppression of miR-132 aggravates multiple layers of pathology at the molecular and functional level. We describe the potential therapeutic implications of these findings and suggest miRNA targeting or replacement as a realistic multi-hit, therapeutic strategy for AD. Salta, E., De Strooper, B. microRNA-132: a key noncoding RNA operating in the cellular phase of Alzheimer's disease.
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Affiliation(s)
- Evgenia Salta
- Vlaams Instituut voor Biotechnologie (VIB) Center for Brain and Disease, VIB-Leuven, Leuven, Belgium; .,Center for Human Genetics, Universitaire Ziekenhuizen and Leuven Research Institute for Neuroscience and Disease, KU-Leuven, Leuven, Belgium; and
| | - Bart De Strooper
- Vlaams Instituut voor Biotechnologie (VIB) Center for Brain and Disease, VIB-Leuven, Leuven, Belgium; .,Center for Human Genetics, Universitaire Ziekenhuizen and Leuven Research Institute for Neuroscience and Disease, KU-Leuven, Leuven, Belgium; and.,Institute of Neurology, University College London, London, United Kingdom
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622
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Membrane-Accelerated Amyloid-β Aggregation and Formation of Cross-β Sheets. MEMBRANES 2017; 7:membranes7030049. [PMID: 28858214 PMCID: PMC5618134 DOI: 10.3390/membranes7030049] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 07/26/2017] [Accepted: 08/23/2017] [Indexed: 11/17/2022]
Abstract
Amyloid- β aggregates play a causative role in Alzheimer's disease. These aggregates are a product of the physical environment provided by the basic neuronal membrane, composed of a lipid bilayer. The intrinsic properties of the lipid bilayer allow amyloid- β peptides to nucleate and form well-ordered cross- β sheets within the membrane. Here, we correlate the aggregation of the hydrophobic fragment of the amyloid- β protein, A β 25 - 35 , with the hydrophobicity, fluidity, and charge density of a lipid bilayer. We summarize recent biophysical studies of model membranes and relate these to the process of aggregation in physiological systems.
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623
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Bahri MA, Plenevaux A, Aerts J, Bastin C, Becker G, Mercier J, Valade A, Buchanan T, Mestdagh N, Ledoux D, Seret A, Luxen A, Salmon E. Measuring brain synaptic vesicle protein 2A with positron emission tomography and [ 18F]UCB-H. ALZHEIMERS & DEMENTIA-TRANSLATIONAL RESEARCH & CLINICAL INTERVENTIONS 2017; 3:481-486. [PMID: 29124105 PMCID: PMC5671624 DOI: 10.1016/j.trci.2017.08.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Introduction Brain distribution of synaptic vesicle protein 2A was measured with fluorine-18 UCB-H ([18F]UCB-H) and positron emission tomography (PET). Methods Images of synaptic density were acquired in healthy volunteers (two young participants and two seniors). Input function was measured by arterial blood sampling (arterial input function) and derived from PET images using carotid activity (image-derived input function). Logan graphical analysis was used to estimate regional synaptic vesicle protein 2A distribution volume. Results [18F]UCB-H uptake was ubiquitous in cortical and subcortical gray matter. Arterial input function and image-derived input function provided regional distribution volume with a high linear relationship. Discussion The cerebral distribution of [18F]UCB-H is similar to that recently observed with carbon-11 UCB-J ([11C]UCB-J). An accurate [18F]UCB-H quantification can be performed without invasive arterial blood sampling when no suitable reference region is available, using dynamic PET carotid activity. Brain synaptic density can be studied in vivo in normal and pathological aging.
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Affiliation(s)
| | - Alain Plenevaux
- GIGA-Cyclotron Research Center, University of Liège, Liege, Belgium
| | - Joël Aerts
- GIGA-Cyclotron Research Center, University of Liège, Liege, Belgium
| | - Christine Bastin
- GIGA-Cyclotron Research Center, University of Liège, Liege, Belgium
| | - Guillaume Becker
- GIGA-Cyclotron Research Center, University of Liège, Liege, Belgium
| | | | | | | | | | - Didier Ledoux
- Service des soins intensifs généraux, CHU Liege, Liege, Belgium
| | - Alain Seret
- GIGA-Cyclotron Research Center, University of Liège, Liege, Belgium
| | - André Luxen
- GIGA-Cyclotron Research Center, University of Liège, Liege, Belgium
| | - Eric Salmon
- GIGA-Cyclotron Research Center, University of Liège, Liege, Belgium
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624
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Nadjar A, Wigren HKM, Tremblay ME. Roles of Microglial Phagocytosis and Inflammatory Mediators in the Pathophysiology of Sleep Disorders. Front Cell Neurosci 2017; 11:250. [PMID: 28912686 PMCID: PMC5582207 DOI: 10.3389/fncel.2017.00250] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 08/07/2017] [Indexed: 11/13/2022] Open
Abstract
Sleep serves crucial learning and memory functions in both nervous and immune systems. Microglia are brain immune cells that actively maintain health through their crucial physiological roles exerted across the lifespan, including phagocytosis of cellular debris and orchestration of neuroinflammation. The past decade has witnessed an explosive growth of microglial research. Considering the recent developments in the field of microglia and sleep, we examine their possible impact on various pathological conditions associated with a gain, disruption, or loss of sleep in this focused mini-review. While there are extensive studies of microglial implication in a variety of neuropsychiatric and neurodegenerative diseases, less is known regarding their roles in sleep disorders. It is timely to stimulate new research in this emergent and rapidly growing field of investigation.
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Affiliation(s)
- Agnes Nadjar
- Nutrition et Neurobiologie Intégrée, UMR 1286, Institut National de la Recherche AgronomiqueBordeaux, France.,Nutrition et Neurobiologie Intégrée, UMR 1286, Bordeaux UniversityBordeaux, France.,OptiNutriBrain International Associated Laboratory (NutriNeuro France-INAF Canada)Québec, QC, Canada
| | | | - Marie-Eve Tremblay
- Axe Neurosciences, CRCHU de Québec-Université LavalQuébec, QC, Canada.,Département de médecine moléculaire, Université LavalQuébec, QC, Canada
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625
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Spires-Jones TL, Attems J, Thal DR. Interactions of pathological proteins in neurodegenerative diseases. Acta Neuropathol 2017; 134:187-205. [PMID: 28401333 PMCID: PMC5508034 DOI: 10.1007/s00401-017-1709-7] [Citation(s) in RCA: 268] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 03/30/2017] [Accepted: 04/01/2017] [Indexed: 02/06/2023]
Abstract
Neurodegenerative diseases such as Alzheimer's disease (AD), frontotemporal lobar degeneration (FTD), Lewy body disease (LBD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS) have in common that protein aggregates represent pathological hallmark lesions. Amyloid β-protein, τ-protein, α-synuclein, and TDP-43 are the most frequently aggregated proteins in these disorders. Although they are assumed to form disease-characteristic aggregates, such as amyloid plaques and neurofibrillary tangles in AD or Lewy bodies in LBD/PD, they are not restricted to these clinical presentations. They also occur in non-diseased individuals and can co-exist in the same brain without or with a clinical picture of a distinct dementing or movement disorder. In this review, we discuss the co-existence of these pathologies and potential additive effects in the human brain as well as related functional findings on cross-seeding and molecular interactions between these aggregates/proteins. We conclude that there is evidence for interactions at the molecular level as well as for additive effects on brain damage by multiple pathologies occurring in different functionally important neurons. Based upon this information, we hypothesize a cascade of events that may explain general mechanisms in the development of neurodegenerative disorders: (1) distinct lesions are a prerequisite for the development of a distinct disease (e.g., primary age-related tauopathy for AD), (2) disease-specific pathogenic events further trigger the development of a specific disease (e.g., Aβ aggregation in AD that exaggerate further Aβ and AD-related τ pathology), (3) the symptomatic disease manifests, and (4) neurodegenerative co-pathologies may be either purely coincidental or (more likely) have influence on the disease development and/or its clinical presentation.
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Affiliation(s)
- Tara L Spires-Jones
- Centre for Dementia Prevention, and Euan MacDonald Centre for Motor Neurone Disease, The University of Edinburgh Centre for Cognitive and Neural Systems, 1 George Square, Edinburgh, EH8 9JZ, UK.
| | - Johannes Attems
- Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, UK
| | - Dietmar Rudolf Thal
- Departement Neurowetenschappen, Katholieke Universiteit Leuven, Herestraat 49, 3000, Leuven, Belgium
- Departement Pathologische Ontleedkunde, UZ Leuven, Herestraat 49, 3000, Leuven, Belgium
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626
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Fu AKY, Ip NY. Regulation of postsynaptic signaling in structural synaptic plasticity. Curr Opin Neurobiol 2017; 45:148-155. [DOI: 10.1016/j.conb.2017.05.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 04/28/2017] [Accepted: 05/12/2017] [Indexed: 02/05/2023]
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627
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Nasrallah IM, Chen YJ, Hsieh MK, Phillips JS, Ternes K, Stockbower GE, Sheline Y, McMillan CT, Grossman M, Wolk DA. 18F-Flortaucipir PET/MRI Correlations in Nonamnestic and Amnestic Variants of Alzheimer Disease. J Nucl Med 2017; 59:299-306. [PMID: 28747523 DOI: 10.2967/jnumed.117.194282] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Accepted: 07/05/2017] [Indexed: 12/19/2022] Open
Abstract
Nonamnestic Alzheimer disease (AD) variants, including posterior cortical atrophy and the logopenic variant of primary progressive aphasia, differ from amnestic AD in distributions of tau aggregates and neurodegeneration. We evaluated whether 18F-flortaucipir (also called 18F-AV-1451) PET, targeting tau aggregates, detects these differences, and we compared the results with MRI measures of gray matter (GM) atrophy. Methods: Five subjects with posterior cortical atrophy, 4 subjects with the logopenic variant of primary progressive aphasia, 6 age-matched patients with AD, and 6 control subjects underwent 18F-flortaucipir PET and MRI. SUV ratios and GM volumes were compared using regional and voxel-based methods. Results: The subgroups showed the expected 18F-flortaucipir-binding patterns. Group effect sizes were generally stronger with 18F-flortaucipir PET than with MRI volumes. There were moderate-to-high correlations between regional GM atrophy and 18F-flortaucipir uptake. 18F-flortaucipir binding and GM atrophy correlated similarly to cognitive test performance. Conclusion:18F-flortaucipir binding corresponds to the expected neurodegeneration patterns in nonamnestic AD, with potential for earlier detection of pathology than is possible with MRI atrophy measures.
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Affiliation(s)
- Ilya M Nasrallah
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Yin Jie Chen
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Meng-Kang Hsieh
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jeffrey S Phillips
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania; and
| | - Kylie Ternes
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania; and
| | - Grace E Stockbower
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania; and
| | - Yvette Sheline
- Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Corey T McMillan
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania; and
| | - Murray Grossman
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania; and
| | - David A Wolk
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania; and
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628
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Selective Degeneration of Entorhinal-CA1 Synapses in Alzheimer's Disease via Activation of DAPK1. J Neurosci 2017; 36:10843-10852. [PMID: 27798139 DOI: 10.1523/jneurosci.2258-16.2016] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 08/30/2016] [Indexed: 01/13/2023] Open
Abstract
Excitatory pyramidal neurons in the entorhinal cortical layer II region (ECIIPN) form functional excitatory synapses with CA1 parvalbumin inhibitory neurons (CA1PV) and undergo selective degeneration in the early stages of Alzheimer's disease (AD). Here, we show that death-associated protein kinase 1 (DAPK1) is selectively activated in ECIIPN of AD mice. Inhibition of DAPK1 by deleting a catalytic domain or a death domain of DAPK1 rescues the ECIIPN-CA1PV synaptic loss and improves spatial learning and memory in AD mice. This study demonstrates that activation of DAPK1 in ECIIPN contributes to a memory loss in AD and hence warrants a promising target for the treatment of AD. SIGNIFICANCE STATEMENT Our recent study reported that excitatory pyramidal neurons in the entorhinal cortical layer II region (ECIIPN) target to CA1 parvalbumin-type inhibitory neurons (CA1PV) at a direct pathway and are one of the most vulnerable brain cells that are selectively degenerated in the early stage of Alzheimer's disease (AD). Our present study shows that death-associated protein kinase 1 (DAPK1) is selectively activated in ECIIPN of AD mice. Inhibition of DAPK1 by deleting a catalytic domain or a death domain of DAPK1 rescues the ECIIPN-CA1PV synaptic loss and improves spatial learning and memory in the early stage of AD. These data not only demonstrate a crucial molecular event for synaptic degeneration but also provide a therapeutic target for the treatment of AD.
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629
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Lee KH, Lee SJ, Lee HJ, Choi GE, Jung YH, Kim DI, Gabr AA, Ryu JM, Han HJ. Amyloid β1-42 (Aβ1-42) Induces the CDK2-Mediated Phosphorylation of Tau through the Activation of the mTORC1 Signaling Pathway While Promoting Neuronal Cell Death. Front Mol Neurosci 2017; 10:229. [PMID: 28790888 PMCID: PMC5522873 DOI: 10.3389/fnmol.2017.00229] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 07/05/2017] [Indexed: 01/08/2023] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder, characterized by cognitive impairment and memory loss. Amyloid β1-42 (Aβ) and hyper-phosphorylation of microtubule-associated protein tau have been considered as major histological features in AD. However, the mechanism of how Aβ induces the hyper-phosphorylation of tau remains to be clarified. In the present study, we investigated the underlying cellular mechanisms of Aβ with regard to the cell cycle regulatory protein-mediated phosphorylation of tau in promoting neuronal cell death. The oligomer Aβ (5 μM) significantly increased the level of caspase 3 cleavage and has the ability to induce cytotoxicity in human neuroblastoma SK-N-MC cells. Aβ induced the degree of extracellular calcium influx via the L-type channel to facilitate the production of reactive oxygen species (ROS). Aβ signaling through ROS production is uniquely mediated by the activation of PI3K/Akt, which is in turn required for mammalian target of rapamycin complex 1 (mTORC1) phosphorylation. mTORC1 activated by Aβ further increased the phosphorylation of eukaryotic translation initiation factor 4E (eIF4E), a binding protein (4E-BP1) and p70S6K1 to stimulate the HIF1α synthesis responsible for the induction of cyclinD1/cyclin-dependent kinase 4 (CDK4) and cyclinE/CDK2, whereas it significantly attenuated the activation of autophagy. Aβ distinctively induced the CDK2-mediated phosphorylation of tau, which is responsible for microtubule destabilization in promoting neuronal apoptosis. In mouse hippocampal primary neurons, the apoptotic cell death induced by Aβ is highly susceptible to the mTORC1 signaling pathway. These results demonstrate that Aβ efficiently stimulates the mTORC1 signaling pathway to facilitate HIF1α synthesis and autophagy inhibition to promote the expression of cell cycle regulatory proteins, during which CDK2 uniquely stimulates tau phosphorylation for microtubule destabilization-mediated neuronal apoptosis.
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Affiliation(s)
- Ki Hoon Lee
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science and BK21 PLUS Program for Creative Veterinary Science Research Center, Seoul National UniversitySeoul, South Korea
| | - Sei-Jung Lee
- Department of Pharmaceutical Engineering, Daegu Haany UniversityGyeongsan, South Korea
| | - Hyun Jik Lee
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science and BK21 PLUS Program for Creative Veterinary Science Research Center, Seoul National UniversitySeoul, South Korea
| | - Gee Euhn Choi
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science and BK21 PLUS Program for Creative Veterinary Science Research Center, Seoul National UniversitySeoul, South Korea
| | - Young Hyun Jung
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science and BK21 PLUS Program for Creative Veterinary Science Research Center, Seoul National UniversitySeoul, South Korea
| | - Dah Ihm Kim
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science and BK21 PLUS Program for Creative Veterinary Science Research Center, Seoul National UniversitySeoul, South Korea
| | - Amr Ahmed Gabr
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science and BK21 PLUS Program for Creative Veterinary Science Research Center, Seoul National UniversitySeoul, South Korea.,Department of Physiology, Faculty of Veterinary Medicine, Cairo UniversityGiza, Egypt
| | - Jung Min Ryu
- Department of Veterinary Physiology, College of Veterinary Medicine, Chonnam National UniversityGwangju, South Korea
| | - Ho Jae Han
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science and BK21 PLUS Program for Creative Veterinary Science Research Center, Seoul National UniversitySeoul, South Korea
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630
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Hojati S, Ghahghaei A, Lagzian M. The potential inhibitory effect of β-casein on the aggregation and deposition of Aβ1-42 fibrils in Alzheimer’s disease: insight from in-vitro and in-silico studies. J Biomol Struct Dyn 2017. [DOI: 10.1080/07391102.2017.1345326] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Sedighehsadat Hojati
- Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran
| | - Arezou Ghahghaei
- Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran
| | - Milad Lagzian
- Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran
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631
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Du X, West MB, Cai Q, Cheng W, Ewert DL, Li W, Floyd RA, Kopke RD. Antioxidants reduce neurodegeneration and accumulation of pathologic Tau proteins in the auditory system after blast exposure. Free Radic Biol Med 2017; 108:627-643. [PMID: 28438658 DOI: 10.1016/j.freeradbiomed.2017.04.343] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 04/17/2017] [Accepted: 04/21/2017] [Indexed: 12/31/2022]
Abstract
Cochlear neurodegeneration commonly accompanies hair cell loss resulting from aging, ototoxicity, or exposures to intense noise or blast overpressures. However, the precise pathophysiological mechanisms that drive this degenerative response have not been fully elucidated. Our laboratory previously demonstrated that non-transgenic rats exposed to blast overpressures exhibited marked somatic accumulation of neurotoxic variants of the microtubule-associated protein, Tau, in the hippocampus. In the present study, we extended these analyses to examine neurodegeneration and pathologic Tau accumulation in the auditory system in response to blast exposure and evaluated the potential therapeutic efficacy of antioxidants on short-circuiting this pathological process. Blast injury induced ribbon synapse loss and retrograde neurodegeneration in the cochlea in untreated animals. An accompanying perikaryal accumulation of neurofilament light chain and pathologic Tau oligomers were observed in neurons from both the peripheral and central auditory system, spanning from the spiral ganglion to the auditory cortex. Due to its coincident accumulation pattern and well-documented neurotoxicity, our results suggest that the accumulation of pathologic Tau oligomers may actively contribute to blast-induced cochlear neurodegeneration. Therapeutic intervention with a combinatorial regimen of 2,4-disulfonyl α-phenyl tertiary butyl nitrone (HPN-07) and N-acetylcysteine (NAC) significantly reduced both pathologic Tau accumulation and indications of ongoing neurodegeneration in the cochlea and the auditory cortex. These results demonstrate that a combination of HPN-07 and NAC administrated shortly after a blast exposure can serve as a potential therapeutic strategy for preserving auditory function among military personnel or civilians with blast-induced traumatic brain injuries.
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Affiliation(s)
| | | | | | | | | | - Wei Li
- Hough Ear Institute, Oklahoma City, OK, USA
| | - Robert A Floyd
- Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Richard D Kopke
- Hough Ear Institute, Oklahoma City, OK, USA; Oklahoma Medical Research Foundation, Oklahoma City, OK, USA; Departments of Physiology and Otolaryngology, University of Oklahoma Health Sciences Center, Oklahoma City 73014, USA.
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632
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Chen J, Yin W, Tu Y, Wang S, Yang X, Chen Q, Zhang X, Han Y, Pi R. L-F001, a novel multifunctional ROCK inhibitor, suppresses neuroinflammation in vitro and in vivo: Involvement of NF-κB inhibition and Nrf2 pathway activation. Eur J Pharmacol 2017; 806:1-9. [DOI: 10.1016/j.ejphar.2017.03.025] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 03/05/2017] [Accepted: 03/15/2017] [Indexed: 10/20/2022]
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633
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Zhao R, Hu W, Tsai J, Li W, Gan WB. Microglia limit the expansion of β-amyloid plaques in a mouse model of Alzheimer's disease. Mol Neurodegener 2017; 12:47. [PMID: 28606182 PMCID: PMC5468952 DOI: 10.1186/s13024-017-0188-6] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Accepted: 06/02/2017] [Indexed: 11/25/2022] Open
Abstract
Background Microglia are known as resident immune cells in the brain. β-amyloid (Aβ) plaques in the brain of Alzheimer’s disease (AD) are surrounded by microglia, but whether and how microglia affect the formation and maintenance of plaques remains controversial. Methods We depleted microglia by injecting diphtheria toxin (DT) in CX3CR1CreER/+:R26DTR/+ (CX3CR1-iDTR) mice crossed with APPswe/PSEN1dE9 (APP/PS1) mice. Intravital time-lapse imaging was performed to examine changes in the number and size of Congo Red-labeled amyloid plaques over 1–2 weeks. We also examined spine density and shaft diameter of dendrites passing through plaques in a PSAPP mouse model of AD (PS1M146L line 6.2 × Tg2576) crossed with Thy1 YFP H-line mice. Results We found that DT administration to CX3CR1-iDTR mice efficiently ablated microglia within one week and that microglia repopulated in the second week after DT administration. Microglia depletion didn’t affect the number of amyloid plaques, but led to ~13% increase in the size of Aβ plaques within one week. Moreover, microglia repopulation was associated with the stabilization of plaque size during the second week. In addition, we found dendritic spine loss and shaft atrophy in the distal parts of dendrites passing through plaques. Conclusion Our results demonstrate the important role of microglia in limiting the growth of Aβ plaques and plaque-associated disruption of neuronal connection. Electronic supplementary material The online version of this article (doi:10.1186/s13024-017-0188-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ruohe Zhao
- Drug Discovery Center, Peking University Shenzhen Graduate School, Shenzhen, 518055, China.,Skirball Institute, New York University School of Medicine, New York, NY, 10016, USA
| | - Wanling Hu
- Drug Discovery Center, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Julia Tsai
- Skirball Institute, New York University School of Medicine, New York, NY, 10016, USA
| | - Wei Li
- Drug Discovery Center, Peking University Shenzhen Graduate School, Shenzhen, 518055, China. .,Skirball Institute, New York University School of Medicine, New York, NY, 10016, USA.
| | - Wen-Biao Gan
- Drug Discovery Center, Peking University Shenzhen Graduate School, Shenzhen, 518055, China. .,Skirball Institute, New York University School of Medicine, New York, NY, 10016, USA.
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634
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Vossel KA, Tartaglia MC, Nygaard HB, Zeman AZ, Miller BL. Epileptic activity in Alzheimer's disease: causes and clinical relevance. Lancet Neurol 2017; 16:311-322. [PMID: 28327340 DOI: 10.1016/s1474-4422(17)30044-3] [Citation(s) in RCA: 348] [Impact Index Per Article: 49.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 01/10/2017] [Accepted: 01/31/2017] [Indexed: 01/18/2023]
Abstract
Epileptic activity is frequently associated with Alzheimer's disease; this association has therapeutic implications, because epileptic activity can occur at early disease stages and might contribute to pathogenesis. In clinical practice, seizures in patients with Alzheimer's disease can easily go unrecognised because they usually present as non-motor seizures, and can overlap with other symptoms of the disease. In patients with Alzheimer's disease, seizures can hasten cognitive decline, highlighting the clinical relevance of early recognition and treatment. Some evidence indicates that subclinical epileptiform activity in patients with Alzheimer's disease, detected by extended neurophysiological monitoring, can also lead to accelerated cognitive decline. Treatment of clinical seizures in patients with Alzheimer's disease with select antiepileptic drugs (AEDs), in low doses, is usually well tolerated and efficacious. Moreover, studies in mouse models of Alzheimer's disease suggest that certain classes of AEDs that reduce network hyperexcitability have disease-modifying properties. These AEDs target mechanisms of epileptogenesis involving amyloid β and tau. Clinical trials targeting network hyperexcitability in patients with Alzheimer's disease will identify whether AEDs or related strategies could improve their cognitive symptoms or slow decline.
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Affiliation(s)
- Keith A Vossel
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA, USA.
| | | | - Haakon B Nygaard
- Division of Neurology, University of British Columbia, Vancouver, BC, Canada
| | - Adam Z Zeman
- Cognitive Neurology Research Group, University of Exeter Medical School, Exeter, UK
| | - Bruce L Miller
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA, USA
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635
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Kim J, Choi IY, Duff KE, Lee P. Progressive Pathological Changes in Neurochemical Profile of the Hippocampus and Early Changes in the Olfactory Bulbs of Tau Transgenic Mice (rTg4510). Neurochem Res 2017; 42:1649-1660. [PMID: 28523532 DOI: 10.1007/s11064-017-2298-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Revised: 05/08/2017] [Accepted: 05/08/2017] [Indexed: 01/02/2023]
Abstract
Tauopathies such as Alzheimer's disease and frontotemporal lobe degeneration (FTLD-tau) dementia, characterized by pathologic aggregation of the microtubule-associated tau protein and formation of neurofibrillary tangles, have been linked to neurodegeneration and cognitive decline. The early detection of cerebral abnormalities and the identification of biological contributors to the continuous pathologic processes of neurodegeneration in tauopathies critically hinge on sensitive and reliable measures of biomarkers in the living brain. In this study, we measured alterations in a number of key neurochemicals associated with tauopathy-induced neurodegeneration in the hippocampus and the olfactory bulbs of a transgenic mouse model of FTLD-tauopathy, line rTg4510, using in vivo 1H magnetic resonance spectroscopy at 9.4 T. The rTg4510 line develops tauopathy at a young age (4-5 months), reaching a severe stage by 8-12 months of age. Longitudinal measurement of neurochemical concentrations in the hippocampus of mice from 5 to 12 months of age showed significant progressive changes with distinctive disease staging patterns including N-acetylaspartate, myo-inositol, γ-aminobutyric acid, glutathione and glutamine. The accompanying hippocampal volume loss measured using magnetic resonance imaging showed significant correlation (p < 0.01) with neurochemical measurements. Neurochemical alterations in the olfactory bulbs were more pronounced than those in the hippocampus in rTg4510 mice. These results demonstrate progressive neuropathology in the mouse model and provide potential biomarkers of early neuropathological events and effective noninvasive monitoring of the disease progression and treatment efficacy, which can be easily translated to clinical studies.
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Affiliation(s)
- Jieun Kim
- Hoglund Brain Imaging Center, University of Kansas Medical Center, 3901 Rainbow Blvd, Mail Stop 1052, Kansas City, KS, 66160, USA
| | - In-Young Choi
- Hoglund Brain Imaging Center, University of Kansas Medical Center, 3901 Rainbow Blvd, Mail Stop 1052, Kansas City, KS, 66160, USA.,Department of Neurology, University of Kansas Medical Center, Kansas City, KS, 66160, USA.,Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Karen E Duff
- Department of Integrative Neuroscience, Columbia University Medical Center, New York, NY, 10032, USA
| | - Phil Lee
- Hoglund Brain Imaging Center, University of Kansas Medical Center, 3901 Rainbow Blvd, Mail Stop 1052, Kansas City, KS, 66160, USA. .,Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, 66160, USA.
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636
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Forner S, Baglietto-Vargas D, Martini AC, Trujillo-Estrada L, LaFerla FM. Synaptic Impairment in Alzheimer's Disease: A Dysregulated Symphony. Trends Neurosci 2017; 40:347-357. [PMID: 28494972 DOI: 10.1016/j.tins.2017.04.002] [Citation(s) in RCA: 286] [Impact Index Per Article: 40.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 04/13/2017] [Accepted: 04/14/2017] [Indexed: 11/30/2022]
Abstract
Alzheimer's disease (AD) is characterized by memory loss, cognitive decline, and devastating neurodegeneration, not only as a result of the extracellular accumulation of beta-amyloid peptide (Aβ) and intracellular accumulation of tau, but also as a consequence of the dysfunction and loss of synapses. Although significant advances have been made in our understanding of the relationship of the pathological role of Aβ and tau in synapse dysfunction, several questions remain as to how Aβ and tau interdependently cause impairments in synaptic function in AD. Overall, more insight into these questions should enable researchers in this field to develop novel therapeutic targets to mitigate or delay the cognitive deficits associated with this devastating disease.
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Affiliation(s)
- Stefania Forner
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA
| | - David Baglietto-Vargas
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA
| | - Alessandra C Martini
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA
| | - Laura Trujillo-Estrada
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA
| | - Frank M LaFerla
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA; Department of Neurobiology and Behavior, University of California, Irvine, CA 92697, USA.
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637
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Abstract
Early-onset Alzheimer disease (EOAD), with onset in individuals younger than 65 years, although overshadowed by the more common late-onset AD (LOAD), differs significantly from LOAD. EOAD comprises approximately 5% of AD and is associated with delays in diagnosis, aggressive course, and age-related psychosocial needs. One source of confusion is that a substantial percentage of EOAD are phenotypic variants that differ from the usual memory-disordered presentation of typical AD. The management of EOAD is similar to that for LOAD, but special emphasis should be placed on targeting the specific cognitive areas involved and more age-appropriate psychosocial support and education.
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Affiliation(s)
- Mario F Mendez
- Behavioral Neurology Program, David Geffen School of Medicine at UCLA, 300 Westwood Plaza, Suite B-200, Box 956975, Los Angeles, CA 90095, USA; Neurobehavior Unit, VA Greater Los Angeles Healthcare System, 11301 Wilshire Boulevard, Building 206, Los Angeles, CA 90073, USA.
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638
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Jiang S, Bhaskar K. Dynamics of the Complement, Cytokine, and Chemokine Systems in the Regulation of Synaptic Function and Dysfunction Relevant to Alzheimer’s Disease. J Alzheimers Dis 2017; 57:1123-1135. [DOI: 10.3233/jad-161123] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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639
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Lockhart SN, Schöll M, Baker SL, Ayakta N, Swinnerton KN, Bell RK, Mellinger TJ, Shah VD, O'Neil JP, Janabi M, Jagust WJ. Amyloid and tau PET demonstrate region-specific associations in normal older people. Neuroimage 2017; 150:191-199. [PMID: 28232190 PMCID: PMC5391247 DOI: 10.1016/j.neuroimage.2017.02.051] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 01/27/2017] [Accepted: 02/19/2017] [Indexed: 01/22/2023] Open
Abstract
β-amyloid (Aβ) and tau pathology become increasingly prevalent with age, however, the spatial relationship between the two pathologies remains unknown. We examined local (same region) and non-local (different region) associations between these 2 aggregated proteins in 46 normal older adults using [18F]AV-1451 (for tau) and [11C]PiB (for Aβ) positron emission tomography (PET) and 1.5T magnetic resonance imaging (MRI) images. While local voxelwise analyses showed associations between PiB and AV-1451 tracer largely in the temporal lobes, k-means clustering revealed that some of these associations were driven by regions with low tracer retention. We followed this up with a whole-brain region-by-region (local and non-local) partial correlational analysis. We calculated each participant's mean AV-1451 and PiB uptake values within 87 regions of interest (ROI). Pairwise ROI analysis demonstrated many positive PiB-AV-1451 associations. Importantly, strong positive partial correlations (controlling for age, sex, and global gray matter fraction, p<.01) were identified between PiB in multiple regions of association cortex and AV-1451 in temporal cortical ROIs. There were also less frequent and weaker positive associations of regional PiB with frontoparietal AV-1451 uptake. Particularly in temporal lobe ROIs, AV-1451 uptake was strongly predicted by PiB across multiple ROI locations. These data indicate that Aβ and tau pathology show significant local and non-local regional associations among cognitively normal elderly, with increased PiB uptake throughout the cortex correlating with increased temporal lobe AV-1451 uptake. The spatial relationship between Aβ and tau accumulation does not appear to be specific to Aβ location, suggesting a regional vulnerability of temporal brain regions to tau accumulation regardless of where Aβ accumulates.
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Affiliation(s)
- Samuel N Lockhart
- Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA 94720, USA.
| | - Michael Schöll
- Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA 94720, USA; MedTech West and the Department of Psychiatry and Neurochemistry, University of Gothenburg, 413 45 Gothenburg, Sweden.
| | - Suzanne L Baker
- Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA 94720, USA; Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| | - Nagehan Ayakta
- Department of Neurology, Memory and Aging Center, University of California San Francisco, San Francisco, CA 94158, USA.
| | - Kaitlin N Swinnerton
- Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA 94720, USA; Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| | - Rachel K Bell
- Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA 94720, USA.
| | - Taylor J Mellinger
- Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA 94720, USA; Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| | - Vyoma D Shah
- Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA 94720, USA; Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| | - James P O'Neil
- Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| | - Mustafa Janabi
- Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| | - William J Jagust
- Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA 94720, USA; Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
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640
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Hansson O, Grothe MJ, Strandberg TO, Ohlsson T, Hägerström D, Jögi J, Smith R, Schöll M. Tau Pathology Distribution in Alzheimer's disease Corresponds Differentially to Cognition-Relevant Functional Brain Networks. Front Neurosci 2017; 11:167. [PMID: 28408865 PMCID: PMC5374886 DOI: 10.3389/fnins.2017.00167] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Accepted: 03/13/2017] [Indexed: 12/16/2022] Open
Abstract
Neuropathological studies have shown that the typical neurofibrillary pathology of hyperphosphorylated tau protein in Alzheimer's disease (AD) preferentially affects specific brain regions whereas others remain relatively spared. It has been suggested that the distinct regional distribution profile of tau pathology in AD may be a consequence of the intrinsic network structure of the human brain. The spatially distributed brain regions that are most affected by the spread of tau pathology may hence reflect an interconnected neuronal system. Here, we characterized the brain-wide regional distribution profile of tau pathology in AD using 18F-AV 1451 tau-sensitive positron emission tomography (PET) imaging, and studied this pattern in relation to the functional network organization of the human brain. Specifically, we quantified the spatial correspondence of the regional distribution pattern of PET-evidenced tau pathology in AD with functional brain networks characterized by large-scale resting state functional magnetic resonance imaging (rs-fMRI) data in healthy subjects. Regional distribution patterns of increased PET-evidenced tau pathology in AD compared to controls were characterized in two independent samples of prodromal and manifest AD cases (the Swedish BioFINDER study, n = 44; the ADNI study, n = 35). In the BioFINDER study we found that the typical AD tau pattern involved predominantly inferior, medial, and lateral temporal cortical areas, as well as the precuneus/posterior cingulate, and lateral parts of the parietal and occipital cortex. This pattern overlapped primarily with the dorsal attention, and to some extent with higher visual, limbic and parts of the default-mode network. PET-evidenced tau pathology in the ADNI replication sample, which represented a more prodromal group of AD cases, was less pronounced but showed a highly similar spatial distribution profile, suggesting an earlier-stage snapshot of a consistently progressing regional pattern. In conclusion, the present study indicates that the regional deposition of tau aggregates in AD predominantly affects higher-order cognitive over primary sensory-motor networks, but does not appear to be specific for the default-mode or related limbic networks.
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Affiliation(s)
- Oskar Hansson
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund UniversityMalmö, Sweden.,Memory Clinic, Skåne University HospitalMalmö, Sweden
| | - Michel J Grothe
- German Center for Neurodegenerative DiseasesRostock, Germany
| | - Tor Olof Strandberg
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund UniversityMalmö, Sweden
| | - Tomas Ohlsson
- Department of Radiation Physics, Skåne University HospitalLund, Sweden
| | - Douglas Hägerström
- Department of Clinical Neurophysiology, Skåne University HospitalLund, Sweden
| | - Jonas Jögi
- Department of Clinical Physiology and Nuclear Medicine, Skåne University HospitalLund, Sweden
| | - Ruben Smith
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund UniversityMalmö, Sweden.,Department of Neurology, Skåne University HospitalLund, Sweden
| | - Michael Schöll
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund UniversityMalmö, Sweden.,MedTech West and the Department of Psychiatry and Neurochemistry, University of GothenburgGothenburg, Sweden
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641
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Ramos-Miguel A, García-Sevilla JA, Barr AM, Bayer TA, Falkai P, Leurgans SE, Schneider JA, Bennett DA, Honer WG, García-Fuster MJ. Decreased cortical FADD protein is associated with clinical dementia and cognitive decline in an elderly community sample. Mol Neurodegener 2017; 12:26. [PMID: 28320441 PMCID: PMC5360099 DOI: 10.1186/s13024-017-0168-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 03/09/2017] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND FADD (Fas-associated death domain) adaptor is a crucial protein involved in the induction of cell death but also mediates non-apoptotic actions via a phosphorylated form (p-Ser194-FADD). This study investigated the possible association of FADD forms with age-related neuropathologies, cognitive function, and the odds of dementia in an elderly community sample. METHODS FADD forms were quantified by western blot analysis in dorsolateral prefrontal cortex (DLPFC) samples from a large cohort of participants in a community-based aging study (Memory and Aging Project, MAP), experiencing no-(NCI, n = 51) or mild-(MCI, n = 42) cognitive impairment, or dementia (n = 57). RESULTS Cortical FADD was lower in subjects with dementia and lower FADD was associated with a greater load of amyloid-β pathology, fewer presynaptic terminal markers, poorer cognitive function and increased odds of dementia. Together with the observations of FADD redistribution into tangles and dystrophic neurites within plaques in Alzheimer's disease brains, and its reduction in APP23 mouse cortex, the results suggest this multifunctional protein might participate in the mechanisms linking amyloid and tau pathologies during the course of the illness. CONCLUSIONS The present data suggests FADD as a putative biomarker for pathological processes associated with the course of clinical dementia.
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Affiliation(s)
- Alfredo Ramos-Miguel
- BC Mental Health and Addictions Research Institute, Vancouver, Canada
- Department of Psychiatry, University of British Columbia, Vancouver, Canada
| | - Jesús A. García-Sevilla
- IUNICS, University of the Balearic Islands, Ctra. de Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
- Instituto de Investigación Sanitaria de Baleares, Palma de Mallorca, Spain
| | - Alasdair M. Barr
- BC Mental Health and Addictions Research Institute, Vancouver, Canada
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, Canada
| | - Thomas A. Bayer
- Department of Psychiatry, University Medicine Goettingen, Goettingen, Germany
| | - Peter Falkai
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Sue E. Leurgans
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, USA
| | - Julie A. Schneider
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, USA
| | - David A. Bennett
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, USA
| | - William G. Honer
- BC Mental Health and Addictions Research Institute, Vancouver, Canada
- Department of Psychiatry, University of British Columbia, Vancouver, Canada
| | - M. Julia García-Fuster
- IUNICS, University of the Balearic Islands, Ctra. de Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
- Instituto de Investigación Sanitaria de Baleares, Palma de Mallorca, Spain
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642
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Direct Keap1-Nrf2 disruption as a potential therapeutic target for Alzheimer's disease. PLoS Genet 2017; 13:e1006593. [PMID: 28253260 PMCID: PMC5333801 DOI: 10.1371/journal.pgen.1006593] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 01/21/2017] [Indexed: 12/13/2022] Open
Abstract
Nrf2, a transcriptional activator of cell protection genes, is an attractive therapeutic target for the prevention of neurodegenerative diseases, including Alzheimer’s disease (AD). Current Nrf2 activators, however, may exert toxicity and pathway over-activation can induce detrimental effects. An understanding of the mechanisms mediating Nrf2 inhibition in neurodegenerative conditions may therefore direct the design of drugs targeted for the prevention of these diseases with minimal side-effects. Our study provides the first in vivo evidence that specific inhibition of Keap1, a negative regulator of Nrf2, can prevent neuronal toxicity in response to the AD-initiating Aβ42 peptide, in correlation with Nrf2 activation. Comparatively, lithium, an inhibitor of the Nrf2 suppressor GSK-3, prevented Aβ42 toxicity by mechanisms independent of Nrf2. A new direct inhibitor of the Keap1-Nrf2 binding domain also prevented synaptotoxicity mediated by naturally-derived Aβ oligomers in mouse cortical neurons. Overall, our findings highlight Keap1 specifically as an efficient target for the re-activation of Nrf2 in AD, and support the further investigation of direct Keap1 inhibitors for the prevention of neurodegeneration in vivo. As our population ages the incidence of neurodegenerative diseases, including Alzheimer’s disease (AD), is predicted to increase dramatically. Despite providing important symptomatic relief, existing treatments for such conditions do not slow-down disease progression, and this will cause an overwhelming future burden on our healthcare system and immense suffering for many more patients and their families. Nrf2 is a gene that normally protects cells from stressful conditions. Although we don’t know why, Nrf2 is reduced in the brains of AD patients and this may explain the increased susceptibility of neurons to damage in neurodegenerative diseases. Our research, using a fruit fly model, identifies Keap1, a negative regulator of Nrf2, as a valid target for the rescue of AD-related Nrf2 defects and the subsequent prevention of neuronal degeneration. Moreover, we show that a new compound, which directly blocks the binding between Nrf2 and Keap1, can prevent toxicity of the AD-initiating Aβ peptide in mouse neurons. Hence, our study provides strong evidence that direct Keap1-Nrf2 disruptors can specifically target the defects in Nrf2 activity observed in neurodegenerative diseases, and supports the further development of such compounds as potential new drugs to prevent neuronal decline AD and other neurodegenerative conditions.
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643
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Tan FHP, Azzam G. Drosophila melanogaster: Deciphering Alzheimer's Disease. Malays J Med Sci 2017; 24:6-20. [PMID: 28894399 PMCID: PMC5566057 DOI: 10.21315/mjms2017.24.2.2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 02/21/2017] [Indexed: 09/29/2022] Open
Abstract
Alzheimer's disease (AD) is the most widespread neurodegenerative disorder worldwide. Its pathogenesis involves two hallmarks: aggregation of amyloid beta (Aβ) and occurrence of neurofibrillary tangles (NFTs). The mechanism behind the disease is still unknown. This has prompted the use of animal models to mirror the disease. The fruit fly, Drosophila melanogaster has garnered considerable attention as an organism to recapitulate human disorders. With the ability to monopolise a multitude of traditional and novel genetic tools, Drosophila is ideal for studying not only cellular aspects but also physiological and behavioural traits of human neurodegenerative diseases. Here, we discuss the use of the Drosophila model in understanding AD pathology and the insights gained in discovering drug therapies for AD.
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Affiliation(s)
- Florence Hui Ping Tan
- School of Biological Sciences, Universiti Sains Malaysia, 11800 USM, Pulau Pinang, Malaysia
| | - Ghows Azzam
- School of Biological Sciences, Universiti Sains Malaysia, 11800 USM, Pulau Pinang, Malaysia
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644
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Ramos-Miguel A, Sawada K, Jones AA, Thornton AE, Barr AM, Leurgans SE, Schneider JA, Bennett DA, Honer WG. Presynaptic proteins complexin-I and complexin-II differentially influence cognitive function in early and late stages of Alzheimer's disease. Acta Neuropathol 2017; 133:395-407. [PMID: 27866231 PMCID: PMC6542594 DOI: 10.1007/s00401-016-1647-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 11/12/2016] [Accepted: 11/13/2016] [Indexed: 12/14/2022]
Abstract
Progressive accumulation of Alzheimer's disease-related pathology is associated with cognitive dysfunction. Differences in cognitive reserve may contribute to individual differences in cognitive function in the presence of comparable neuropathology. The protective effects of cognitive reserve could contribute differentially in early versus late stages of the disease. We investigated presynaptic proteins as measures of brain reserve (a subset of total cognitive reserve), and used Braak staging to estimate the progression of Alzheimer's disease. Antemortem evaluations of cognitive function, postmortem assessments of pathologic indices, and presynaptic protein analyses, including the complexins I and II as respective measures of inhibitory and excitatory terminal function, were assayed in multiple key brain regions in 418 deceased participants from a community study. After covarying for demographic variables, pathologic indices, and overall synapse density, lower brain complexin-I and -II levels contributed to cognitive dysfunction (P < 0.01). Each complexin appeared to be dysregulated at a different Braak stage. Inhibitory complexin-I explained 14.4% of the variance in global cognition in Braak 0-II, while excitatory complexin-II explained 7.3% of the variance in Braak V-VI. Unlike other presynaptic proteins, complexins did not colocalize with pathologic tau within neuritic plaques, suggesting that these functional components of the synaptic machinery are cleared early from dystrophic neurites. Moreover, complexin levels showed distinct patterns of change related to memory challenges in a rat model, supporting the functional specificity of these proteins. The present results suggest that disruption of inhibitory synaptic terminals may trigger early cognitive impairment, while excitatory terminal disruption may contribute relatively more to later cognitive impairment.
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Affiliation(s)
- Alfredo Ramos-Miguel
- BC Mental Health and Addictions Research Institute, 938 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada
- Department of Psychiatry, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC, V6T 2A1, Canada
| | - Ken Sawada
- Kochi Prefectural Aki General Hospital, 3-33 Hoheicho, Kochi, 784-0027, Japan
| | - Andrea A Jones
- BC Mental Health and Addictions Research Institute, 938 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada
- Department of Psychiatry, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC, V6T 2A1, Canada
| | - Allen E Thornton
- BC Mental Health and Addictions Research Institute, 938 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada
- Department of Psychology, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Alasdair M Barr
- BC Mental Health and Addictions Research Institute, 938 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, 2176 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Sue E Leurgans
- Rush Alzheimer's Disease Center, Rush University Medical Center, 600 S Paulina Street, Chicago, IL, 60612, USA
| | - Julie A Schneider
- Rush Alzheimer's Disease Center, Rush University Medical Center, 600 S Paulina Street, Chicago, IL, 60612, USA
| | - David A Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, 600 S Paulina Street, Chicago, IL, 60612, USA
| | - William G Honer
- BC Mental Health and Addictions Research Institute, 938 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada.
- Department of Psychiatry, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC, V6T 2A1, Canada.
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645
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Amyloid plaque structure and cell surface interactions of β-amyloid fibrils revealed by electron tomography. Sci Rep 2017; 7:43577. [PMID: 28240273 PMCID: PMC5327471 DOI: 10.1038/srep43577] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 01/25/2017] [Indexed: 12/30/2022] Open
Abstract
The deposition of amyloid fibrils as plaques is a key feature of several neurodegenerative diseases including in particular Alzheimer’s. This disease is characterized, if not provoked, by amyloid aggregates formed from Aβ peptide that deposit inside the brain or are toxic to neuronal cells. We here used scanning transmission electron microscopy (STEM) to determine the fibril network structure and interactions of Aβ fibrils within a cell culture model of Alzheimer’s disease. STEM images taken from the formed Aβ amyloid deposits revealed three main types of fibril network structures, termed amorphous meshwork, fibril bundle and amyloid star. All three were infiltrated by different types of lipid inclusions from small-sized exosome-like structures (50–100 nm diameter) to large-sized extracellular vesicles (up to 300 nm). The fibrils also presented strong interactions with the surrounding cells such that fibril bundles extended into tubular invaginations of the plasma membrane. Amyloid formation in the cell model was previously found to have an intracellular origin and we show here that it functionally destroys the integrity of the intracellular membranes as it leads to lysosomal leakage. These data provide a mechanistic link to explain why intracellular fibril formation is toxic to the cell.
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646
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Barber KR, Tanquary J, Bush K, Shaw A, Woodson M, Sherman M, Wairkar YP. Active zone proteins are transported via distinct mechanisms regulated by Par-1 kinase. PLoS Genet 2017; 13:e1006621. [PMID: 28222093 PMCID: PMC5340405 DOI: 10.1371/journal.pgen.1006621] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 03/07/2017] [Accepted: 02/08/2017] [Indexed: 11/24/2022] Open
Abstract
Disruption of synapses underlies a plethora of neurodevelopmental and neurodegenerative disease. Presynaptic specialization called the active zone plays a critical role in the communication with postsynaptic neuron. While the role of many proteins at the active zones in synaptic communication is relatively well studied, very little is known about how these proteins are transported to the synapses. For example, are there distinct mechanisms for the transport of active zone components or are they all transported in the same transport vesicle? Is active zone protein transport regulated? In this report we show that overexpression of Par-1/MARK kinase, a protein whose misregulation has been implicated in Autism spectrum disorders (ASDs) and neurodegenerative disorders, lead to a specific block in the transport of an active zone protein component- Bruchpilot at Drosophila neuromuscular junctions. Consistent with a block in axonal transport, we find a decrease in number of active zones and reduced neurotransmission in flies overexpressing Par-1 kinase. Interestingly, we find that Par-1 acts independently of Tau-one of the most well studied substrates of Par-1, revealing a presynaptic function for Par-1 that is independent of Tau. Thus, our study strongly suggests that there are distinct mechanisms that transport components of active zones and that they are tightly regulated. Synapses consist of pre- and postsynaptic partners. Proper function of active zones, a presynaptic component of synapse, is essential for efficacious neuronal communication. Disruption of neuronal communication is an early sign of both neurodevelopmental as well as neurodegenerative diseases. Since proteins that reside in active zones are used so frequently during the neuronal communication, they must be constantly replenished to maintain active zones. Axonal transport of these proteins plays an important role in replenishing these vital components necessary for the health of active zones. However, the mechanisms that transport components of active zones are not well understood. Our data suggest that there are distinct mechanisms that transport various active zone cargoes and this process is likely regulated by kinases. Further, our data show that disruption in the transport of one such active zone components causes reduced neuronal communication emphasizing the importance of the process of axonal transport of active zone protein(s) for neuronal communication. Understanding the processes that govern the axonal transport of active zone components will help dissect the initial stages of pathogenesis in both neurodevelopmental and neurodegenerative diseases.
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Affiliation(s)
- Kara R. Barber
- George and Cynthia Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch, Galveston, TX, United States of America
- Neuroscience Graduate Program, Department of Neurology, University of Texas Medical Branch, Galveston, TX, United States of America
| | - Julia Tanquary
- Summer Undergraduate Research Program, UTMB, Department of Neurology, University of Texas Medical Branch, Galveston, TX, United States of America
| | - Keegan Bush
- George and Cynthia Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch, Galveston, TX, United States of America
- Neuroscience Graduate Program, Department of Neurology, University of Texas Medical Branch, Galveston, TX, United States of America
| | - Amanda Shaw
- George and Cynthia Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch, Galveston, TX, United States of America
- Neuroscience Graduate Program, Department of Neurology, University of Texas Medical Branch, Galveston, TX, United States of America
| | - Michael Woodson
- Sealy Center for Structural Biology, UTMB, Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, United States of America
| | - Michael Sherman
- Sealy Center for Structural Biology, UTMB, Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, United States of America
| | - Yogesh P. Wairkar
- George and Cynthia Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch, Galveston, TX, United States of America
- Neuroscience Graduate Program, Department of Neurology, University of Texas Medical Branch, Galveston, TX, United States of America
- * E-mail:
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647
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Tau and β-Amyloid Are Associated with Medial Temporal Lobe Structure, Function, and Memory Encoding in Normal Aging. J Neurosci 2017; 37:3192-3201. [PMID: 28213439 DOI: 10.1523/jneurosci.3769-16.2017] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 02/07/2017] [Accepted: 02/12/2017] [Indexed: 12/12/2022] Open
Abstract
Normal aging is associated with a decline in episodic memory and also with aggregation of the β-amyloid (Aβ) and tau proteins and atrophy of medial temporal lobe (MTL) structures crucial to memory formation. Although some evidence suggests that Aβ is associated with aberrant neural activity, the relationships among these two aggregated proteins, neural function, and brain structure are poorly understood. Using in vivo human Aβ and tau imaging, we demonstrate that increased Aβ and tau are both associated with aberrant fMRI activity in the MTL during memory encoding in cognitively normal older adults. This pathological neural activity was in turn associated with worse memory performance and atrophy within the MTL. A mediation analysis revealed that the relationship with regional atrophy was explained by MTL tau. These findings broaden the concept of cognitive aging to include evidence of Alzheimer's disease-related protein aggregation as an underlying mechanism of age-related memory impairment.SIGNIFICANCE STATEMENT Alterations in episodic memory and the accumulation of Alzheimer's pathology are common in cognitively normal older adults. However, evidence of pathological effects on episodic memory has largely been limited to β-amyloid (Aβ). Because Aβ and tau often cooccur in older adults, previous research offers an incomplete understanding of the relationship between pathology and episodic memory. With the recent development of in vivo tau PET radiotracers, we show that Aβ and tau are associated with different aspects of memory encoding, leading to aberrant neural activity that is behaviorally detrimental. In addition, our results provide evidence linking Aβ- and tau-associated neural dysfunction to brain atrophy.
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648
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Postupna N, Latimer CS, Larson EB, Sherfield E, Paladin J, Shively CA, Jorgensen MJ, Andrews RN, Kaplan JR, Crane PK, Montine KS, Craft S, Keene CD, Montine TJ. Human Striatal Dopaminergic and Regional Serotonergic Synaptic Degeneration with Lewy Body Disease and Inheritance of APOE ε4. THE AMERICAN JOURNAL OF PATHOLOGY 2017; 187:884-895. [PMID: 28212814 DOI: 10.1016/j.ajpath.2016.12.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Revised: 12/10/2016] [Accepted: 12/20/2016] [Indexed: 01/22/2023]
Abstract
Cognitive impairment in older individuals is a complex trait that in population-based studies most commonly derives from an individually varying mixture of Alzheimer disease, Lewy body disease, and vascular brain injury. We investigated the molecular composition of synaptic particles from three sources: consecutive rapid autopsy brains from the Adult Changes in Thought Study, a population-based cohort; four aged nonhuman primate brains optimally processed for molecular investigation; and targeted replacement transgenic mice homozygous for APOE ε4. Our major goal was to characterize the molecular composition of human synaptic particles in regions of striatum and prefrontal cortex. We performed flow cytometry to measure six markers of synaptic subtypes, as well as amyloid β 42 and paired helical filament tau. Our results showed selective degeneration of dopaminergic terminals throughout the striatum in individuals with Lewy body disease, and serotonergic degeneration in human ventromedial caudate nucleus from individuals with an APOE ε4 allele. Similar results were seen in mouse caudate nucleus homozygous for APOE ε4 via targeted replacement. Together, extension of these clinical, pathologic, and genetic associations from tissue to the synaptic compartment of cerebral cortex and striatum strongly supports our approach for accurately observing the molecular composition of human synapses by flow cytometry.
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Affiliation(s)
- Nadia Postupna
- Department of Pathology, University of Washington, Seattle, Washington
| | - Caitlin S Latimer
- Department of Pathology, University of Washington, Seattle, Washington
| | - Eric B Larson
- Group Health Research Institute, Seattle, Washington
| | - Emily Sherfield
- Department of Pathology, University of Washington, Seattle, Washington
| | - Julie Paladin
- Department of Pathology, University of Washington, Seattle, Washington
| | - Carol A Shively
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Matthew J Jorgensen
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Rachel N Andrews
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Jay R Kaplan
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Paul K Crane
- Department of Medicine, University of Washington, Seattle, Washington
| | | | - Suzanne Craft
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - C Dirk Keene
- Department of Pathology, University of Washington, Seattle, Washington
| | - Thomas J Montine
- Department of Pathology, University of Washington, Seattle, Washington.
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649
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Cognitive Ameliorating Effect ofAcanthopanax koreanumAgainst Scopolamine-Induced Memory Impairment in Mice. Phytother Res 2017; 31:425-432. [DOI: 10.1002/ptr.5764] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 11/23/2016] [Accepted: 12/11/2016] [Indexed: 11/07/2022]
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650
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Psychosocial stress on neuroinflammation and cognitive dysfunctions in Alzheimer's disease: the emerging role for microglia? Neurosci Biobehav Rev 2017; 77:148-164. [PMID: 28185874 DOI: 10.1016/j.neubiorev.2017.01.046] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 01/20/2017] [Accepted: 01/31/2017] [Indexed: 01/22/2023]
Abstract
Chronic psychosocial stress is increasingly recognized as a risk factor for late-onset Alzheimer's disease (LOAD) and associated cognitive deficits. Chronic stress also primes microglia and induces inflammatory responses in the adult brain, thereby compromising synapse-supportive roles of microglia and deteriorating cognitive functions during aging. Substantial evidence demonstrates that failure of microglia to clear abnormally accumulating amyloid-beta (Aβ) peptide contributes to neuroinflammation and neurodegeneration in AD. Moreover, genome-wide association studies have linked variants in several immune genes, such as TREM2 and CD33, the expression of which in the brain is restricted to microglia, with cognitive dysfunctions in LOAD. Thus, inflammation-promoting chronic stress may create a vicious cycle of aggravated microglial dysfunction accompanied by increased Aβ accumulation, collectively exacerbating neurodegeneration. Surprisingly, however, little is known about whether and how chronic stress contributes to microglia-mediated neuroinflammation that may underlie cognitive impairments in AD. This review aims to summarize the currently available clinical and preclinical data and outline potential molecular mechanisms linking stress, microglia and neurodegeneration, to foster future research in this field.
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