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Fotuhi SN, Khalaj-Kondori M. Imbalanced clearance of Aβ peptide cause presynaptic plaque formation. Int J Neurosci 2024; 134:66-70. [PMID: 35639020 DOI: 10.1080/00207454.2022.2085099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 05/26/2022] [Indexed: 10/18/2022]
Abstract
Alzheimer's disease is characterized by abnormal increase of Aβ peptide which is likely as the result of imbalanced homeostasis of its production and clearance mechanisms. Here, we briefly review that the uncleaned extracellular Aβ peptides are loaded into presynaptic neurons. The Aβ oligomers desperately affect pre- and post-synapse neuron activity and turn into plaques inside the presynaptic neurons over the time passes.
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Affiliation(s)
- Seyedeh Nahid Fotuhi
- Department of Animal Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran
| | - Mohammad Khalaj-Kondori
- Department of Animal Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran
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2
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L'esperance OJ, McGhee J, Davidson G, Niraula S, Smith AS, Sosunov A, Yan SS, Subramanian J. Functional connectivity favors aberrant visual network c-Fos expression accompanied by cortical synapse loss in a mouse model of Alzheimer's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.01.05.522900. [PMID: 36712054 PMCID: PMC9881957 DOI: 10.1101/2023.01.05.522900] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
While Alzheimer's disease (AD) has been extensively studied with a focus on cognitive networks, sensory network dysfunction has received comparatively less attention despite compelling evidence of its significance in both Alzheimer's disease patients and mouse models. We recently found that neurons in the primary visual cortex of an AD mouse model expressing human amyloid protein precursor with the Swedish and Indiana mutations (hAPP mutations) exhibit aberrant c-Fos expression and altered synaptic structures at a pre-amyloid plaque stage. However, it is unclear whether aberrant c-Fos expression and synaptic pathology vary across the broader visual network and to what extent c-Fos abnormality in the cortex is inherited through functional connectivity. Using both sexes of 4-6-month AD model mice with hAPP mutations (J20[PDGF-APPSw, Ind]), we found that cortical regions of the visual network show aberrant c-Fos expression and impaired experience-dependent modulation while subcortical regions do not. Interestingly, the average network-wide functional connectivity strength of a brain region in wild type (WT) mice significantly predicts its aberrant c-Fos expression, which in turn correlates with impaired experience-dependent modulation in the AD model. Using in vivo two-photon and ex vivo imaging of presynaptic termini, we observed a subtle yet selective weakening of excitatory cortical synapses in the visual cortex. Intriguingly, the change in the size distribution of cortical boutons in the AD model is downscaled relative to those in WT mice, suggesting that synaptic weakening may reflect an adaptation to aberrant activity. Our observations suggest that cellular and synaptic abnormalities in the AD model represent a maladaptive transformation of the baseline physiological state seen in WT conditions rather than entirely novel and unrelated manifestations.
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Zoltowska KM, Das U, Lismont S, Enzlein T, Maesako M, Houser MCQ, Franco ML, Özcan B, Moreira DG, Karachentsev D, Becker A, Hopf C, Vilar M, Berezovska O, Mobley W, Chávez-Gutiérrez L. Alzheimer's disease linked Aβ42 exerts product feedback inhibition on γ-secretase impairing downstream cell signaling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.02.551596. [PMID: 37577527 PMCID: PMC10418207 DOI: 10.1101/2023.08.02.551596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Amyloid β (Aβ) peptides accumulating in the brain are proposed to trigger Alzheimer's disease (AD). However, molecular cascades underlying their toxicity are poorly defined. Here, we explored a novel hypothesis for Aβ42 toxicity that arises from its proven affinity for γ-secretases. We hypothesized that the reported increases in Aβ42, particularly in the endolysosomal compartment, promote the establishment of a product feedback inhibitory mechanism on γ-secretases, and thereby impair downstream signaling events. We show that human Aβ42 peptides, but neither murine Aβ42 nor human Aβ17-42 (p3), inhibit γ-secretases and trigger accumulation of unprocessed substrates in neurons, including C-terminal fragments (CTFs) of APP, p75 and pan-cadherin. Moreover, Aβ42 treatment dysregulated cellular -homeostasis, as shown by the induction of p75-dependent neuronal death in two distinct cellular systems. Our findings raise the possibility that pathological elevations in Aβ42 contribute to cellular toxicity via the γ-secretase inhibition, and provide a novel conceptual framework to address Aβ toxicity in the context of γ-secretase-dependent homeostatic signaling.
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Affiliation(s)
| | - Utpal Das
- Department of Neurosciences, University of California San Diego, La Jolla, CA, United States of America
| | - Sam Lismont
- VIB-KU Leuven Center for Brain & Disease Research, VIB, Leuven, Belgium
| | - Thomas Enzlein
- VIB-KU Leuven Center for Brain & Disease Research, VIB, Leuven, Belgium
- Center for Mass Spectrometry and Optical Spectroscopy (CeMOS), Mannheim University of Applied Sciences, Mannheim, Germany
| | - Masato Maesako
- Department of Neurology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA, United States of America
| | - Mei CQ Houser
- Department of Neurology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA, United States of America
| | - María Luisa Franco
- Molecular Basis of Neurodegeneration Unit, Institute of Biomedicine of València (IBV-CSIC), València, Spain
| | - Burcu Özcan
- VIB-KU Leuven Center for Brain & Disease Research, VIB, Leuven, Belgium
| | | | - Dmitry Karachentsev
- Department of Neurosciences, University of California San Diego, La Jolla, CA, United States of America
| | - Ann Becker
- Department of Neurosciences, University of California San Diego, La Jolla, CA, United States of America
| | - Carsten Hopf
- Center for Mass Spectrometry and Optical Spectroscopy (CeMOS), Mannheim University of Applied Sciences, Mannheim, Germany
- Medical Faculty, Heidelberg University, Heidelberg, Germany
- Mannheim Center for Translational Neuroscience (MCTN), Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Marçal Vilar
- Molecular Basis of Neurodegeneration Unit, Institute of Biomedicine of València (IBV-CSIC), València, Spain
| | - Oksana Berezovska
- Department of Neurology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA, United States of America
| | - William Mobley
- Department of Neurosciences, University of California San Diego, La Jolla, CA, United States of America
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4
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Kumar A, Scarpa M, Nordberg A. Tracing synaptic loss in Alzheimer's brain with SV2A PET-tracer UCB-J. Alzheimers Dement 2024; 20:2589-2605. [PMID: 38363009 PMCID: PMC11032538 DOI: 10.1002/alz.13720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 01/04/2024] [Accepted: 01/05/2024] [Indexed: 02/17/2024]
Abstract
INTRODUCTION Synaptic loss is an early prominent feature of Alzheimer's disease (AD). The recently developed novel synaptic vesicle 2A protein (SV2A) PET-tracer UCB-J has shown great promise in tracking synaptic loss in AD. However, there have been discrepancies between the findings and a lack of mechanistic insight. METHODS Here we report the first extensive pre-clinical validation studies for UCB-J in control (CN; n = 11) and AD (n = 11) brains using a multidimensional approach of post-mortem brain imaging techniques, radioligand binding, and biochemical studies. RESULTS AND DISCUSSION We demonstrate that UCB-J could target SV2A protein with high specificity and depict synaptic loss at synaptosome levels in AD brain regions compared to CNs. UCB-J showed highest synaptic loss in AD hippocampus followed in descending order by frontal cortex, temporal cortex, parietal cortex, and cerebellum. 3H-UCB-J large brain-section autoradiography and cellular/subcellular fractions binding studies indicated potential off-target interaction with phosphorylated tau (p-tau) species in AD brains, which could have subsequent clinical implications for imaging studies. HIGHLIGHTS Synaptic positron emission tomography (PET)-tracer UCB-J could target synaptic vesicle 2A protein (SV2A) with high specificity in Alzheimer's disease (AD) and control brains. Synaptic PET-tracer UCB-J could depict synaptic loss at synaptosome levels in AD brain regions compared to control. Potential off-target interaction of UCB-J with phosphorylated tau (p-tau) species at cellular/subcellular levels could have subsequent clinical implications for imaging studies, warranting further investigations.
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Affiliation(s)
- Amit Kumar
- Division of Clinical GeriatricsCenter for Alzheimer ResearchDepartment of NeurobiologyCare Sciences and SocietyKarolinska InstitutetStockholmSweden
| | - Miriam Scarpa
- Division of Clinical GeriatricsCenter for Alzheimer ResearchDepartment of NeurobiologyCare Sciences and SocietyKarolinska InstitutetStockholmSweden
| | - Agneta Nordberg
- Division of Clinical GeriatricsCenter for Alzheimer ResearchDepartment of NeurobiologyCare Sciences and SocietyKarolinska InstitutetStockholmSweden
- Theme Inflammation and AgingKarolinska University HospitalStockholmSweden
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5
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Tolar M, Hey JA, Power A, Abushakra S. The Single Toxin Origin of Alzheimer's Disease and Other Neurodegenerative Disorders Enables Targeted Approach to Treatment and Prevention. Int J Mol Sci 2024; 25:2727. [PMID: 38473975 PMCID: PMC10932387 DOI: 10.3390/ijms25052727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 02/20/2024] [Accepted: 02/23/2024] [Indexed: 03/14/2024] Open
Abstract
New data suggest that the aggregation of misfolded native proteins initiates and drives the pathogenic cascade that leads to Alzheimer's disease (AD) and other age-related neurodegenerative disorders. We propose a unifying single toxin theory of brain neurodegeneration that identifies new targets and approaches to the development of disease-modifying treatments. An extensive body of genetic evidence suggests soluble aggregates of beta-amyloid (Aβ) as the primary neurotoxin in the pathogenesis of AD. New insights from fluid biomarkers, imaging, and clinical studies provide further evidence for the decisive impact of toxic Aβ species in the initiation and progression of AD. Understanding the distinct roles of soluble and insoluble amyloid aggregates on AD pathogenesis has been the key missing piece of the Alzheimer's puzzle. Data from clinical trials with anti-amyloid agents and recent advances in the diagnosis of AD demonstrate that the driving insult in biologically defined AD is the neurotoxicity of soluble Aβ aggregates, called oligomers and protofibrils, rather than the relatively inert insoluble mature fibrils and amyloid plaques. Amyloid oligomers appear to be the primary factor causing the synaptic impairment, neuronal stress, spreading of tau pathology, and eventual cell death that lead to the clinical syndrome of AD dementia. All other biochemical effects and neurodegenerative changes in the brain that are observed in AD are a response to or a downstream effect of this initial toxic insult by oligomers. Other neurodegenerative disorders follow a similar pattern of pathogenesis, in which normal brain proteins with important biological functions become trapped in the aging brain due to impaired clearance and then misfold and aggregate into neurotoxic species that exhibit prion-like behavior. These aggregates then spread through the brain and cause disease-specific neurodegeneration. Targeting the inhibition of this initial step in neurodegeneration by blocking the misfolding and aggregation of healthy proteins has the potential to slow or arrest disease progression, and if treatment is administered early in the course of AD and other neurodegenerative disorders, it may delay or prevent the onset of clinical symptoms.
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Sun S, Ma Q, Sheng Q, Huang S, Wu C, Liu J, Xu J. Amyloid-β Oligomer-Induced Electrophysiological Mechanisms and Electrical Impedance Changes in Neurons. SENSORS (BASEL, SWITZERLAND) 2024; 24:1211. [PMID: 38400369 PMCID: PMC10892449 DOI: 10.3390/s24041211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 02/04/2024] [Accepted: 02/10/2024] [Indexed: 02/25/2024]
Abstract
Amyloid plays a critical role in the pathogenesis of Alzheimer's disease (AD) and can aggregate to form oligomers and fibrils in the brain. There is increasing evidence that highly toxic amyloid-β oligomers (AβOs) lead to tau protein aggregation, hyperphosphorylation, neuroinflammation, neuronal loss, synaptic loss, and dysfunction. Although the effects of AβOs on neurons have been investigated using conventional biochemical experiments, there are no established criteria for electrical evaluation. To this end, we explored electrophysiological changes in mouse hippocampal neurons (HT22) following exposure to AβOs and/or naringenin (Nar, a flavonoid compound) using electrical impedance spectroscopy (EIS). AβO-induced HT22 showed a decreased impedance amplitude and increased phase angle, and the addition of Nar reversed these changes. The characteristic frequency was markedly increased with AβO exposure, which was also reversed by Nar. The AβOs decreased intranuclear and cytoplasmic resistance and increased nucleus resistance and extracellular capacitance. Overall, the innovative construction of the eight-element CPE-equivalent circuit model further reflects that the pseudo-capacitance of the cell membrane and cell nucleus was increased in the AβO-induced group. This study conclusively revealed that AβOs induce cytotoxic effects by disrupting the resistance characteristics of unit membranes. The results further support that EIS is an effective technique for evaluating AβO-induced neuronal damage and microscopic electrical distinctions in the sub-microscopic structure of reactive cells.
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Affiliation(s)
- Shimeng Sun
- Department of Physiology and Pharmacology, Health Science Center, Ningbo University, Ningbo 315211, China; (S.S.); (Q.M.); (Q.S.); (S.H.); (C.W.)
| | - Qing Ma
- Department of Physiology and Pharmacology, Health Science Center, Ningbo University, Ningbo 315211, China; (S.S.); (Q.M.); (Q.S.); (S.H.); (C.W.)
| | - Qiyu Sheng
- Department of Physiology and Pharmacology, Health Science Center, Ningbo University, Ningbo 315211, China; (S.S.); (Q.M.); (Q.S.); (S.H.); (C.W.)
| | - Shangwei Huang
- Department of Physiology and Pharmacology, Health Science Center, Ningbo University, Ningbo 315211, China; (S.S.); (Q.M.); (Q.S.); (S.H.); (C.W.)
| | - Chenxia Wu
- Department of Physiology and Pharmacology, Health Science Center, Ningbo University, Ningbo 315211, China; (S.S.); (Q.M.); (Q.S.); (S.H.); (C.W.)
| | - Junsong Liu
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China
| | - Jia Xu
- Department of Physiology and Pharmacology, Health Science Center, Ningbo University, Ningbo 315211, China; (S.S.); (Q.M.); (Q.S.); (S.H.); (C.W.)
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7
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Chen J, Chen JS, Li S, Zhang F, Deng J, Zeng LH, Tan J. Amyloid Precursor Protein: A Regulatory Hub in Alzheimer's Disease. Aging Dis 2024; 15:201-225. [PMID: 37307834 PMCID: PMC10796103 DOI: 10.14336/ad.2023.0308] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 03/08/2023] [Indexed: 06/14/2023] Open
Abstract
Decades of research have demonstrated an incontrovertible role of amyloid-β (Aβ) in the etiology of Alzheimer's disease (AD). However, the overemphasis on the pathological impacts of Aβ may obscure the role of its metabolic precursor, amyloid precursor protein (APP), as a significant hub in the occurrence and progression of AD. The complicated enzymatic processing, ubiquitous receptor-like properties, and abundant expression of APP in the brain, as well as its close links with systemic metabolism, mitochondrial function and neuroinflammation, imply that APP plays multifaceted roles in AD. In this review, we briefly describe the evolutionarily conserved biological characteristics of APP, including its structure, functions and enzymatic processing. We also discuss the possible involvement of APP and its enzymatic metabolites in AD, both detrimental and beneficial. Finally, we describe pharmacological agents or genetic approaches with the capability to reduce APP expression or inhibit its cellular internalization, which can ameliorate multiple aspects of AD pathologies and halt disease progression. These approaches provide a basis for further drug development to combat this terrible disease.
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Affiliation(s)
- Jiang Chen
- Key Laboratory of Endemic and Ethnic Diseases, Laboratory of Molecular Biology, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou, China.
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou, China.
| | - Jun-Sheng Chen
- Key Laboratory of Endemic and Ethnic Diseases, Laboratory of Molecular Biology, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou, China.
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou, China.
| | - Song Li
- The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China.
| | - Fengning Zhang
- Key Laboratory of Endemic and Ethnic Diseases, Laboratory of Molecular Biology, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou, China.
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou, China.
| | - Jie Deng
- Key Laboratory of Endemic and Ethnic Diseases, Laboratory of Molecular Biology, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou, China.
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou, China.
| | - Ling-Hui Zeng
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Jun Tan
- Key Laboratory of Endemic and Ethnic Diseases, Laboratory of Molecular Biology, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou, China.
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou, China.
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
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8
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Kreutzer AG, Parrocha CMT, Haerianardakani S, Guaglianone G, Nguyen JT, Diab MN, Yong W, Perez-Rosendahl M, Head E, Nowick JS. Antibodies Raised Against an Aβ Oligomer Mimic Recognize Pathological Features in Alzheimer's Disease and Associated Amyloid-Disease Brain Tissue. ACS CENTRAL SCIENCE 2024; 10:104-121. [PMID: 38292607 PMCID: PMC10823522 DOI: 10.1021/acscentsci.3c00592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 11/27/2023] [Accepted: 11/27/2023] [Indexed: 02/01/2024]
Abstract
Antibodies that target the β-amyloid peptide (Aβ) and its associated assemblies are important tools in Alzheimer's disease research and have emerged as promising Alzheimer's disease therapies. This paper reports the creation and characterization of a triangular Aβ trimer mimic composed of Aβ17-36 β-hairpins and the generation and study of polyclonal antibodies raised against the Aβ trimer mimic. The Aβ trimer mimic is covalently stabilized by three disulfide bonds at the corners of the triangular trimer to create a homogeneous oligomer. Structural, biophysical, and cell-based studies demonstrate that the Aβ trimer mimic shares characteristics with oligomers of full-length Aβ. X-ray crystallography elucidates the structure of the trimer and reveals that four copies of the trimer assemble to form a dodecamer. SDS-PAGE, size exclusion chromatography, and dynamic light scattering reveal that the trimer also forms higher-order assemblies in solution. Cell-based toxicity assays show that the trimer elicits LDH release, decreases ATP levels, and activates caspase-3/7 mediated apoptosis. Immunostaining studies on brain slices from people who lived with Alzheimer's disease and people who lived with Down syndrome reveal that the polyclonal antibodies raised against the Aβ trimer mimic recognize pathological features including different types of Aβ plaques and cerebral amyloid angiopathy.
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Affiliation(s)
- Adam G. Kreutzer
- Department
of Chemistry, University of California Irvine, Irvine, California 92697, United States
| | - Chelsea Marie T. Parrocha
- Department
of Pharmaceutical Sciences, University of
California Irvine, Irvine, California 92697, United States
| | - Sepehr Haerianardakani
- Department
of Chemistry, University of California Irvine, Irvine, California 92697, United States
| | - Gretchen Guaglianone
- Department
of Chemistry, University of California Irvine, Irvine, California 92697, United States
| | - Jennifer T. Nguyen
- Department
of Pharmaceutical Sciences, University of
California Irvine, Irvine, California 92697, United States
| | - Michelle N. Diab
- Department
of Chemistry, University of California Irvine, Irvine, California 92697, United States
| | - William Yong
- Department
of Pathology and Laboratory Medicine, University
of California Irvine, Irvine, California 92697, United States
| | - Mari Perez-Rosendahl
- Department
of Pathology and Laboratory Medicine, University
of California Irvine, Irvine, California 92697, United States
| | - Elizabeth Head
- Department
of Pathology and Laboratory Medicine, University
of California Irvine, Irvine, California 92697, United States
| | - James S. Nowick
- Department
of Chemistry, University of California Irvine, Irvine, California 92697, United States
- Department
of Pharmaceutical Sciences, University of
California Irvine, Irvine, California 92697, United States
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9
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Zhang C, Wang J, Wang W. Wnt signaling in synaptogenesis of Alzheimer's disease. IBRAIN 2023; 9:316-325. [PMID: 37786762 PMCID: PMC10527795 DOI: 10.1002/ibra.12130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 08/25/2023] [Accepted: 08/26/2023] [Indexed: 10/04/2023]
Abstract
Alzheimer's disease (AD), recognized as the leading cause of dementia, occupies a prominent position on the list of significant neurodegenerative disorders, representing a significant global health concern with far-reaching implications at both individual and societal levels. The primary symptom of Alzheimer's disease is a decrease in synaptic potency along with synaptic connection loss. Synapses, which act as important linkages between neuronal units within the cerebral region, are critical in signal transduction processes essential to orchestrating cognitive tasks. Synaptic connections act as critical interconnections between neuronal cells inside the cerebral environment, facilitating critical signal transduction processes required for cognitive functions. The confluence of axonal and dendritic filopodial extensions culminates in the creation of intercellular connections, coordinated by various signals and molecular mechanisms. The progression of synaptic maturation and plasticity is a critical determinant in maintaining mental well-being, and abnormalities in these processes have been linked to the development of neurodegenerative diseases. Wnt signaling pathways are important to the orchestration of synapse development. This review examines the complicated interplay between Wnt signaling and dendritic filopodia, including an examination of the regulatory complexities and molecular machinations involved in synaptogenesis progression. Then, these findings are contextualized within the context of AD pathology, allowing for the consideration of prospective therapeutic approaches based on the findings and development of novel avenues for future scientific research.
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Affiliation(s)
| | - Joy Wang
- Winchester High SchoolWinchesterMassachusettsUSA
| | - Wen‐Yuan Wang
- Interdisciplinary Research Center on Biology and ChemistryShanghai Institute of Organic Chemistry, Chinese Academy of ScienceShanghaiChina
- Huashan HospitalFudan UniversityShanghaiChina
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10
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Ondrejcak T, Klyubin I, Hu NW, O'Malley TT, Corbett GT, Winters R, Perkinton MS, Billinton A, Prenderville JA, Walsh DM, Rowan MJ. Tau and Amyloid β Protein in Patient-Derived Aqueous Brain Extracts Act Concomitantly to Disrupt Long-Term Potentiation in Vivo. J Neurosci 2023; 43:5870-5879. [PMID: 37491315 PMCID: PMC10423043 DOI: 10.1523/jneurosci.0082-23.2023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 06/07/2023] [Accepted: 07/05/2023] [Indexed: 07/27/2023] Open
Abstract
Amyloid β protein (Aβ) and tau, the two main proteins implicated in causing Alzheimer's disease (AD), are posited to trigger synaptic dysfunction long before significant synaptic loss occurs in vulnerable circuits. Whereas soluble Aβ aggregates from AD brain are well recognized potent synaptotoxins, less is known about the synaptotoxicity of soluble tau from AD or other tauopathy patient brains. Minimally manipulated patient-derived aqueous brain extracts contain the more diffusible native forms of these proteins. Here, we explore how intracerebral injection of Aβ and tau present in such aqueous extracts of patient brain contribute to disruption of synaptic plasticity in the CA1 area of the male rat hippocampus. Aqueous extracts of certain AD brains acutely inhibited long-term potentiation (LTP) of synaptic transmission in a manner that required both Aβ and tau. Tau-containing aqueous extracts of a brain from a patient with Pick's disease (PiD) also impaired LTP, and diffusible tau from either AD or PiD brain lowered the threshold for AD brain Aβ to inhibit LTP. Remarkably, the disruption of LTP persisted for at least 2 weeks after a single injection. These findings support a critical role for diffusible tau in causing rapid onset, persistent synaptic plasticity deficits, and promoting Aβ-mediated synaptic dysfunction.SIGNIFICANCE STATEMENT The microtubule-associated protein tau forms relatively insoluble fibrillar deposits in the brains of people with neurodegenerative diseases including Alzheimer's and Pick's diseases. More soluble aggregates of disease-associated tau may diffuse between cells and could cause damage to synapses in vulnerable circuits. We prepared aqueous extracts of diseased cerebral cortex and tested their ability to interfere with synaptic function in the brains of live rats. Tau in these extracts rapidly and persistently disrupted synaptic plasticity and facilitated impairments caused by amyloid β protein, the other major pathologic protein in Alzheimer's disease. These findings show that certain diffusible forms of tau can mediate synaptic dysfunction and may be a target for therapy.
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Affiliation(s)
- Tomas Ondrejcak
- Department of Pharmacology & Therapeutics, School of Medicine and Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Igor Klyubin
- Department of Pharmacology & Therapeutics, School of Medicine and Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Neng-Wei Hu
- Department of Pharmacology & Therapeutics, School of Medicine and Institute of Neuroscience, Trinity College, Dublin 2, Ireland
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Tiernan T O'Malley
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, and Harvard Medical School, Hale Building for Transformative Medicine, 60 Fenwood Road, Boston, Massachusetts 02115
| | - Grant T Corbett
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, and Harvard Medical School, Hale Building for Transformative Medicine, 60 Fenwood Road, Boston, Massachusetts 02115
| | - Róisín Winters
- Transpharmation Ireland, Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Michael S Perkinton
- Neuroscience, BioPharmaceuticals R&D, AstraZeneca UK, Cambridge, CB21 6GH, United Kingdom
| | - Andy Billinton
- Neuroscience, BioPharmaceuticals R&D, AstraZeneca UK, Cambridge, CB21 6GH, United Kingdom
| | - Jack A Prenderville
- Transpharmation Ireland, Institute of Neuroscience, Trinity College, Dublin 2, Ireland
- Department of Physiology, School of Medicine, Trinity College, Dublin 2, Ireland
| | - Dominic M Walsh
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, and Harvard Medical School, Hale Building for Transformative Medicine, 60 Fenwood Road, Boston, Massachusetts 02115
| | - Michael J Rowan
- Department of Pharmacology & Therapeutics, School of Medicine and Institute of Neuroscience, Trinity College, Dublin 2, Ireland
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11
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Cai W, Li L, Sang S, Pan X, Zhong C. Physiological Roles of β-amyloid in Regulating Synaptic Function: Implications for AD Pathophysiology. Neurosci Bull 2023; 39:1289-1308. [PMID: 36443453 PMCID: PMC10387033 DOI: 10.1007/s12264-022-00985-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 09/02/2022] [Indexed: 11/29/2022] Open
Abstract
The physiological functions of endogenous amyloid-β (Aβ), which plays important role in the pathology of Alzheimer's disease (AD), have not been paid enough attention. Here, we review the multiple physiological effects of Aβ, particularly in regulating synaptic transmission, and the possible mechanisms, in order to decipher the real characters of Aβ under both physiological and pathological conditions. Some worthy studies have shown that the deprivation of endogenous Aβ gives rise to synaptic dysfunction and cognitive deficiency, while the moderate elevation of this peptide enhances long term potentiation and leads to neuronal hyperexcitability. In this review, we provide a new view for understanding the role of Aβ in AD pathophysiology from the perspective of physiological meaning.
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Affiliation(s)
- Wenwen Cai
- Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Linxi Li
- Basic Medical College, Nanchang University, Nanchang, 330031, China
| | - Shaoming Sang
- Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Xiaoli Pan
- Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.
| | - Chunjiu Zhong
- Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science & Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China.
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12
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Boeddrich A, Haenig C, Neuendorf N, Blanc E, Ivanov A, Kirchner M, Schleumann P, Bayraktaroğlu I, Richter M, Molenda CM, Sporbert A, Zenkner M, Schnoegl S, Suenkel C, Schneider LS, Rybak-Wolf A, Kochnowsky B, Byrne LM, Wild EJ, Nielsen JE, Dittmar G, Peters O, Beule D, Wanker EE. A proteomics analysis of 5xFAD mouse brain regions reveals the lysosome-associated protein Arl8b as a candidate biomarker for Alzheimer's disease. Genome Med 2023; 15:50. [PMID: 37468900 PMCID: PMC10357615 DOI: 10.1186/s13073-023-01206-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 06/22/2023] [Indexed: 07/21/2023] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is characterized by the intra- and extracellular accumulation of amyloid-β (Aβ) peptides. How Aβ aggregates perturb the proteome in brains of patients and AD transgenic mouse models, remains largely unclear. State-of-the-art mass spectrometry (MS) methods can comprehensively detect proteomic alterations, providing relevant insights unobtainable with transcriptomics investigations. Analyses of the relationship between progressive Aβ aggregation and protein abundance changes in brains of 5xFAD transgenic mice have not been reported previously. METHODS We quantified progressive Aβ aggregation in hippocampus and cortex of 5xFAD mice and controls with immunohistochemistry and membrane filter assays. Protein changes in different mouse tissues were analyzed by MS-based proteomics using label-free quantification; resulting MS data were processed using an established pipeline. Results were contrasted with existing proteomic data sets from postmortem AD patient brains. Finally, abundance changes in the candidate marker Arl8b were validated in cerebrospinal fluid (CSF) from AD patients and controls using ELISAs. RESULTS Experiments revealed faster accumulation of Aβ42 peptides in hippocampus than in cortex of 5xFAD mice, with more protein abundance changes in hippocampus, indicating that Aβ42 aggregate deposition is associated with brain region-specific proteome perturbations. Generating time-resolved data sets, we defined Aβ aggregate-correlated and anticorrelated proteome changes, a fraction of which was conserved in postmortem AD patient brain tissue, suggesting that proteome changes in 5xFAD mice mimic disease-relevant changes in human AD. We detected a positive correlation between Aβ42 aggregate deposition in the hippocampus of 5xFAD mice and the abundance of the lysosome-associated small GTPase Arl8b, which accumulated together with axonal lysosomal membranes in close proximity of extracellular Aβ plaques in 5xFAD brains. Abnormal aggregation of Arl8b was observed in human AD brain tissue. Arl8b protein levels were significantly increased in CSF of AD patients. CONCLUSIONS We report a comprehensive biochemical and proteomic investigation of hippocampal and cortical brain tissue derived from 5xFAD transgenic mice, providing a valuable resource to the neuroscientific community. We identified Arl8b, with significant abundance changes in 5xFAD and AD patient brains. Arl8b might enable the measurement of progressive lysosome accumulation in AD patients and have clinical utility as a candidate biomarker.
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Affiliation(s)
- Annett Boeddrich
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Christian Haenig
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Nancy Neuendorf
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Eric Blanc
- Core Unit Bioinformatics, Berlin Institute of Health at Charité - University Medicine Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Andranik Ivanov
- Core Unit Bioinformatics, Berlin Institute of Health at Charité - University Medicine Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Marieluise Kirchner
- Core Unit Proteomics, Berlin Institute of Health at Charité - University Medicine Berlin, Lindenberger Weg 80, 13125, Berlin, Germany
| | - Philipp Schleumann
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Irem Bayraktaroğlu
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Matthias Richter
- Advanced Light Microscopy, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Christine Mirjam Molenda
- Advanced Light Microscopy, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Anje Sporbert
- Advanced Light Microscopy, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Martina Zenkner
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Sigrid Schnoegl
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Christin Suenkel
- Systems Biology of Gene Regulatory Elements, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Luisa-Sophie Schneider
- Department of Psychiatry, Charité - University Medicine Berlin, Hindenburgdamm 30, 12203, Berlin, Germany
| | - Agnieszka Rybak-Wolf
- Systems Biology of Gene Regulatory Elements, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Bianca Kochnowsky
- Department of Psychiatry, Charité - University Medicine Berlin, Hindenburgdamm 30, 12203, Berlin, Germany
| | - Lauren M Byrne
- UCL Huntington's Disease Centre, UCL Queen Square Institute of Neurology, Queen Square, London, WC1N 3BG, UK
| | - Edward J Wild
- UCL Huntington's Disease Centre, UCL Queen Square Institute of Neurology, Queen Square, London, WC1N 3BG, UK
- National Hospital for Neurology & Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Jørgen E Nielsen
- Neurogenetics Clinic & Research Lab, Danish Dementia Research Centre, Rigshospitalet, University of Copenhagen, Section 8008, Inge Lehmanns Vej 8, 2100, Copenhagen, Denmark
| | - Gunnar Dittmar
- Core Unit Proteomics, Berlin Institute of Health at Charité - University Medicine Berlin, Lindenberger Weg 80, 13125, Berlin, Germany
- Proteomics of Cellular Signalling, Luxembourg Institute of Health, 1a Rue Thomas Edison, 1445, Strassen, Luxembourg
| | - Oliver Peters
- Department of Psychiatry, Charité - University Medicine Berlin, Hindenburgdamm 30, 12203, Berlin, Germany
- German Center for Neurodegenerative Diseases (DZNE), Charitéplatz 1, 10117, Berlin, Germany
| | - Dieter Beule
- Core Unit Bioinformatics, Berlin Institute of Health at Charité - University Medicine Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Erich E Wanker
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany.
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13
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Kreutzer AG, Guaglianone G, Yoo S, Parrocha CMT, Ruttenberg SM, Malonis RJ, Tong K, Lin YF, Nguyen JT, Howitz WJ, Diab MN, Hamza IL, Lai JR, Wysocki VH, Nowick JS. Probing differences among Aβ oligomers with two triangular trimers derived from Aβ. Proc Natl Acad Sci U S A 2023; 120:e2219216120. [PMID: 37216514 PMCID: PMC10235986 DOI: 10.1073/pnas.2219216120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 04/17/2023] [Indexed: 05/24/2023] Open
Abstract
The assembly of the β-amyloid peptide (Aβ) to form oligomers and fibrils is closely associated with the pathogenesis and progression of Alzheimer's disease. Aβ is a shape-shifting peptide capable of adopting many conformations and folds within the multitude of oligomers and fibrils the peptide forms. These properties have precluded detailed structural elucidation and biological characterization of homogeneous, well-defined Aβ oligomers. In this paper, we compare the structural, biophysical, and biological characteristics of two different covalently stabilized isomorphic trimers derived from the central and C-terminal regions Aβ. X-ray crystallography reveals the structures of the trimers and shows that each trimer forms a ball-shaped dodecamer. Solution-phase and cell-based studies demonstrate that the two trimers exhibit markedly different assembly and biological properties. One trimer forms small soluble oligomers that enter cells through endocytosis and activate capase-3/7-mediated apoptosis, while the other trimer forms large insoluble aggregates that accumulate on the outer plasma membrane and elicit cellular toxicity through an apoptosis-independent mechanism. The two trimers also exhibit different effects on the aggregation, toxicity, and cellular interaction of full-length Aβ, with one trimer showing a greater propensity to interact with Aβ than the other. The studies described in this paper indicate that the two trimers share structural, biophysical, and biological characteristics with oligomers of full-length Aβ. The varying structural, assembly, and biological characteristics of the two trimers provide a working model for how different Aβ trimers can assemble and lead to different biological effects, which may help shed light on the differences among Aβ oligomers.
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Affiliation(s)
- Adam G. Kreutzer
- Department of Chemistry, University of California Irvine, Irvine, CA92697
| | | | - Stan Yoo
- Department of Chemistry, University of California Irvine, Irvine, CA92697
| | | | | | - Ryan J. Malonis
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY10461
| | - Karen Tong
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY10461
| | - Yu-Fu Lin
- Resource for Native Mass Spectrometry Guided Structural Biology, The Ohio State University, Columbus, OH43210
| | - Jennifer T. Nguyen
- Department of Pharmaceutical Sciences, University of California Irvine, Irvine, CA92697
| | - William J. Howitz
- Department of Chemistry, University of California Irvine, Irvine, CA92697
| | - Michelle N. Diab
- Department of Chemistry, University of California Irvine, Irvine, CA92697
| | - Imane L. Hamza
- Department of Chemistry, University of California Irvine, Irvine, CA92697
| | - Jonathan R. Lai
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY10461
| | - Vicki H. Wysocki
- Resource for Native Mass Spectrometry Guided Structural Biology, The Ohio State University, Columbus, OH43210
| | - James S. Nowick
- Department of Chemistry, University of California Irvine, Irvine, CA92697
- Department of Pharmaceutical Sciences, University of California Irvine, Irvine, CA92697
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14
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Wang Z, Jin M, Hong W, Liu W, Reczek D, Lagomarsino VN, Hu Y, Weeden T, Frosch MP, Young-Pearse TL, Pradier L, Selkoe D, Walsh DM. Learnings about Aβ from human brain recommend the use of a live-neuron bioassay for the discovery of next generation Alzheimer's disease immunotherapeutics. Acta Neuropathol Commun 2023; 11:39. [PMID: 36899414 PMCID: PMC10007750 DOI: 10.1186/s40478-023-01511-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 01/10/2023] [Indexed: 03/12/2023] Open
Abstract
Despite ongoing debate, the amyloid β-protein (Aβ) remains the prime therapeutic target for the treatment of Alzheimer's disease (AD). However, rational drug design has been hampered by a lack of knowledge about neuroactive Aβ. To help address this deficit, we developed live-cell imaging of iPSC-derived human neurons (iNs) to study the effects of the most disease relevant form of Aβ-oligomeric assemblies (oAβ) extracted from AD brain. Of ten brains studied, extracts from nine caused neuritotoxicity, and in eight cases this was abrogated by Aβ immunodepletion. Here we show that activity in this bioassay agrees relatively well with disruption of hippocampal long-term potentiation, a correlate of learning and memory, and that measurement of neurotoxic oAβ can be obscured by more abundant non-toxic forms of Aβ. These findings indicate that the development of novel Aβ targeting therapeutics may benefit from unbiased activity-based discovery. To test this principle, we directly compared 5 clinical antibodies (aducanumab, bapineuzumab, BAN2401, gantenerumab, and SAR228810) together with an in-house aggregate-preferring antibody (1C22) and established relative EC50s in protecting human neurons from human Aβ. The results yielded objective numerical data on the potency of each antibody in neutralizing human oAβ neuritotoxicity. Their relative efficacies in this morphological assay were paralleled by their functional ability to rescue oAβ-induced inhibition of hippocampal synaptic plasticity. This novel paradigm provides an unbiased, all-human system for selecting candidate antibodies for advancement to human immunotherapy.
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Affiliation(s)
- Zemin Wang
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Hale Building for Transformative Medicine, 60 Fenwood Road, Boston, MA, 02115, USA
| | - Ming Jin
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Wei Hong
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Hale Building for Transformative Medicine, 60 Fenwood Road, Boston, MA, 02115, USA
- The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences; Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, Guangdong, China
| | - Wen Liu
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Hale Building for Transformative Medicine, 60 Fenwood Road, Boston, MA, 02115, USA
| | - David Reczek
- Sanofi-Genzyme Corporation, Framingham, MA, 01701, USA
| | - Valentina N Lagomarsino
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Yuan Hu
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Hale Building for Transformative Medicine, 60 Fenwood Road, Boston, MA, 02115, USA
| | - Tim Weeden
- Sanofi-Genzyme Corporation, Framingham, MA, 01701, USA
| | - Matthew P Frosch
- Massachusetts General Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Tracy L Young-Pearse
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | | | - Dennis Selkoe
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
| | - Dominic M Walsh
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Hale Building for Transformative Medicine, 60 Fenwood Road, Boston, MA, 02115, USA.
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15
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Chen LL, Fan YG, Zhao LX, Zhang Q, Wang ZY. The metal ion hypothesis of Alzheimer's disease and the anti-neuroinflammatory effect of metal chelators. Bioorg Chem 2023; 131:106301. [PMID: 36455485 DOI: 10.1016/j.bioorg.2022.106301] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 11/13/2022] [Accepted: 11/22/2022] [Indexed: 11/26/2022]
Abstract
Alzheimer's disease (AD), characterized by the β-amyloid protein (Aβ) deposition and tau hyperphosphorylation, is the most common dementia with uncertain etiology. The clinical trials of Aβ monoclonal antibody drugs have almost failed, giving rise to great attention on the other etiologic hypothesis regarding AD such as metal ions dysmetabolism and chronic neuroinflammation. Mounting evidence revealed that the metal ions (iron, copper, and zinc) were dysregulated in the susceptible brain regions of AD patients, which was highly associated with Aβ deposition, tau hyperphosphorylation, neuronal loss, as well as neuroinflammation. Further studies uncovered that iron, copper and zinc could not only enhance the production of Aβ but also directly bind to Aβ and tau to promote their aggregations. In addition, the accumulation of iron and copper could respectively promote ferroptosis and cuproptosis. Therefore, the metal ion chelators were recognized as promising agents for treating AD. This review comprehensively summarized the effects of metal ions on the Aβ dynamics and tau phosphorylation in the progression of AD. Furthermore, taking chronic neuroinflammation contributes to the progression of AD, we also provided a summary of the mechanisms concerning metal ions on neuroinflammation and highlighted the metal ion chelators may be potential agents to alleviate neuroinflammation under the condition of AD. Nevertheless, more investigations regarding metal ions on neuroinflammation should be taken into practice, and the effects of metal ion chelators on neuroinflammation should gain more attention. Running title: Metal chelators against neuroinflammation.
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Affiliation(s)
- Li-Lin Chen
- Key Laboratory of Medical Cell Biology of Ministry of Education, Key Laboratory of Major Chronic Diseases of Nervous System of Liaoning Province, Health Sciences Institute of China Medical University, Shenyang 110122, China
| | - Yong-Gang Fan
- Key Laboratory of Medical Cell Biology of Ministry of Education, Key Laboratory of Major Chronic Diseases of Nervous System of Liaoning Province, Health Sciences Institute of China Medical University, Shenyang 110122, China
| | - Ling-Xiao Zhao
- Key Laboratory of Medical Cell Biology of Ministry of Education, Key Laboratory of Major Chronic Diseases of Nervous System of Liaoning Province, Health Sciences Institute of China Medical University, Shenyang 110122, China
| | - Qi Zhang
- Key Laboratory of Medical Cell Biology of Ministry of Education, Key Laboratory of Major Chronic Diseases of Nervous System of Liaoning Province, Health Sciences Institute of China Medical University, Shenyang 110122, China
| | - Zhan-You Wang
- Key Laboratory of Medical Cell Biology of Ministry of Education, Key Laboratory of Major Chronic Diseases of Nervous System of Liaoning Province, Health Sciences Institute of China Medical University, Shenyang 110122, China.
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16
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Niraula S, Doderer JJ, Indulkar S, Berry KP, Hauser WL, L'Esperance OJ, Deng JZ, Keeter G, Rouse AG, Subramanian J. Excitation-inhibition imbalance disrupts visual familiarity in amyloid and non-pathology conditions. Cell Rep 2023; 42:111946. [PMID: 36640331 PMCID: PMC9939293 DOI: 10.1016/j.celrep.2022.111946] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 09/14/2022] [Accepted: 12/15/2022] [Indexed: 01/06/2023] Open
Abstract
Neuronal hyperactivity induces memory deficits in Alzheimer's disease. However, how hyperactivity disrupts memory is unclear. Using in vivo synaptic imaging in the mouse visual cortex, we show that structural excitatory-inhibitory synapse imbalance in the apical dendrites favors hyperactivity in early amyloidosis. Consistent with this, natural images elicit neuronal hyperactivity in these mice. Compensatory changes that maintain activity homeostasis disrupt functional connectivity and increase population sparseness such that a small fraction of neurons dominates population activity. These properties reduce the selectivity of neural response to natural images and render visual recognition memory vulnerable to interference. Deprivation of non-specific visual experiences improves the neural representation and behavioral expression of visual familiarity. In contrast, in non-pathological conditions, deprivation of non-specific visual experiences induces disinhibition, increases excitability, and disrupts visual familiarity. We show that disrupted familiarity occurs when the fraction of high-responsive neurons and the persistence of neural representation of a memory-associated stimulus are not constrained.
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Affiliation(s)
- Suraj Niraula
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA
| | - Julia J Doderer
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA
| | - Shreya Indulkar
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA
| | - Kalen P Berry
- Division of Experimental Hematology and Cancer Biology, Brain Tumor Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - William L Hauser
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA
| | - Oliver J L'Esperance
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA
| | - Jasmine Z Deng
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA
| | - Griffin Keeter
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA
| | - Adam G Rouse
- Department of Neurosurgery, University of Kansas Medical Center, Kansas City, KS 66103, USA
| | - Jaichandar Subramanian
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA.
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17
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Ribarič S. Detecting Early Cognitive Decline in Alzheimer's Disease with Brain Synaptic Structural and Functional Evaluation. Biomedicines 2023; 11:biomedicines11020355. [PMID: 36830892 PMCID: PMC9952956 DOI: 10.3390/biomedicines11020355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 01/22/2023] [Accepted: 01/24/2023] [Indexed: 01/28/2023] Open
Abstract
Early cognitive decline in patients with Alzheimer's (AD) is associated with quantifiable structural and functional connectivity changes in the brain. AD dysregulation of Aβ and tau metabolism progressively disrupt normal synaptic function, leading to loss of synapses, decreased hippocampal synaptic density and early hippocampal atrophy. Advances in brain imaging techniques in living patients have enabled the transition from clinical signs and symptoms-based AD diagnosis to biomarkers-based diagnosis, with functional brain imaging techniques, quantitative EEG, and body fluids sampling. The hippocampus has a central role in semantic and episodic memory processing. This cognitive function is critically dependent on normal intrahippocampal connections and normal hippocampal functional connectivity with many cortical regions, including the perirhinal and the entorhinal cortex, parahippocampal cortex, association regions in the temporal and parietal lobes, and prefrontal cortex. Therefore, decreased hippocampal synaptic density is reflected in the altered functional connectivity of intrinsic brain networks (aka large-scale networks), including the parietal memory, default mode, and salience networks. This narrative review discusses recent critical issues related to detecting AD-associated early cognitive decline with brain synaptic structural and functional markers in high-risk or neuropsychologically diagnosed patients with subjective cognitive impairment or mild cognitive impairment.
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Affiliation(s)
- Samo Ribarič
- Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Zaloška 4, SI-1000 Ljubljana, Slovenia
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18
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Hong W, Liu W, Desousa AO, Young-Pearse T, Walsh DM. Methods for the isolation and analysis of Aβ from postmortem brain. Front Neurosci 2023; 17:1108715. [PMID: 36777642 PMCID: PMC9909698 DOI: 10.3389/fnins.2023.1108715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Accepted: 01/09/2023] [Indexed: 01/27/2023] Open
Abstract
Amyloid β-protein (Aβ) plays an initiating role in Alzheimer's disease (AD), but only a small number of groups have studied Aβ extracted from human brain. Most prior studies have utilized synthetic Aβ peptides, but the relevance of these test tube experiments to the conditions that prevail in AD is uncertain. Here, we describe three distinct methods for studying Aβ from cortical tissue. Each method allows the analysis of different ranges of species thus enabling the examination of different questions. The first method allows the study of readily diffusible Aβ with a relatively high specific activity. The second enables the analysis of readily solubilized forms of Aβ the majority of which are inactive. The third details the isolation of true Aβ dimers which have disease-related activity. We also describe a bioassay to study the effects of Aβ on the neuritic integrity of iPSC-derived human neurons. The combined use of this bioassay and the described extraction procedures provides a platform to investigate the activity of different forms and mixtures of Aβ species, and offers a tractable system to identify strategies to mitigate Aβ mediated neurotoxicity.
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Affiliation(s)
- Wei Hong
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, United States,The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China
| | - Wen Liu
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, United States
| | - Alexandra O. Desousa
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, United States
| | - Tracy Young-Pearse
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, United States
| | - Dominic M. Walsh
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, United States,*Correspondence: Dominic M. Walsh,
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19
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Paschou M, Liaropoulou D, Kalaitzaki V, Efthimiopoulos S, Papazafiri P. Knockdown of Amyloid Precursor Protein Increases Ion Channel Expression and Alters Ca 2+ Signaling Pathways. Int J Mol Sci 2023; 24:ijms24032302. [PMID: 36768625 PMCID: PMC9917207 DOI: 10.3390/ijms24032302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/17/2023] [Accepted: 01/20/2023] [Indexed: 01/27/2023] Open
Abstract
Although the physiological role of the full-length Amyloid Precursor Protein (APP) and its proteolytic fragments remains unclear, they are definitively crucial for normal synaptic function. Herein, we report that the downregulation of APP in SH-SY5Y cells, using short hairpin RNA (shRNA), alters the expression pattern of several ion channels and signaling proteins that are involved in synaptic and Ca2+ signaling. Specifically, the levels of GluR2 and GluR4 subunits of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid glutamate receptors (AMPAR) were significantly increased with APP knockdown. Similarly, the expression of the majority of endoplasmic reticulum (ER) residing proteins, such as the ER Ca2+ channels IP3R (Inositol 1,4,5-triphosphate Receptor) and RyR (Ryanodine Receptor), the Ca2+ pump SERCA2 (Sarco/endoplasmic reticulum Ca2+ ATPase 2) and the ER Ca2+ sensor STIM1 (Stromal Interaction Molecule 1) was upregulated. A shift towards the upregulation of p-AKT, p-PP2A, and p-CaMKIV and the downregulation of p-GSK, p-ERK1/2, p-CaMKII, and p-CREB was observed, interconnecting Ca2+ signal transduction from the plasma membrane and ER to the nucleus. Interestingly, we detected reduced responses to several physiological stimuli, with the most prominent being the ineffectiveness of SH-SY5Y/APP- cells to mobilize Ca2+ from the ER upon carbachol-induced Ca2+ release through IP3Rs and RyRs. Our data further support an emerging yet perplexing role of APP within a functional molecular network of membrane and cytoplasmic proteins implicated in Ca2+ signaling.
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Affiliation(s)
- Maria Paschou
- Division of Animal and Human Physiology, Department of Biology, National and Kapodistrian University of Athens, 15784 Athens, Greece
| | - Danai Liaropoulou
- Division of Animal and Human Physiology, Department of Biology, National and Kapodistrian University of Athens, 15784 Athens, Greece
| | - Vasileia Kalaitzaki
- Division of Animal and Human Physiology, Department of Biology, National and Kapodistrian University of Athens, 15784 Athens, Greece
- Institute of Laboratory Animal Science, University of Zurich, 8952 Schlieren, Switzerland
| | - Spiros Efthimiopoulos
- Division of Animal and Human Physiology, Department of Biology, National and Kapodistrian University of Athens, 15784 Athens, Greece
- Correspondence: (S.E.); (P.P.)
| | - Panagiota Papazafiri
- Division of Animal and Human Physiology, Department of Biology, National and Kapodistrian University of Athens, 15784 Athens, Greece
- Correspondence: (S.E.); (P.P.)
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20
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Huang Z. A Function of Amyloid-β in Mediating Activity-Dependent Axon/Synapse Competition May Unify Its Roles in Brain Physiology and Pathology. J Alzheimers Dis 2023; 92:29-57. [PMID: 36710681 PMCID: PMC10023438 DOI: 10.3233/jad-221042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Amyloid-β protein precursor (AβPP) gives rise to amyloid-β (Aβ), a peptide at the center of Alzheimer's disease (AD). AβPP, however, is also an ancient molecule dating back in evolution to some of the earliest forms of metazoans. This suggests a possible ancestral function that may have been obscured by those that evolve later. Based on literature from the functions of Aβ/AβPP in nervous system development, plasticity, and disease, to those of anti-microbial peptides (AMPs) in bacterial competition as well as mechanisms of cell competition uncovered first by Drosophila genetics, I propose that Aβ/AβPP may be part of an ancient mechanism employed in cell competition, which is subsequently co-opted during evolution for the regulation of activity-dependent neural circuit development and plasticity. This hypothesis is supported by foremost the high similarities of Aβ to AMPs, both of which possess unique, opposite (i.e., trophic versus toxic) activities as monomers and oligomers. A large body of data further suggests that the different Aβ oligomeric isoforms may serve as the protective and punishment signals long predicted to mediate activity-dependent axonal/synaptic competition in the developing nervous system and that the imbalance in their opposite regulation of innate immune and glial cells in the brain may ultimately underpin AD pathogenesis. This hypothesis can not only explain the diverse roles observed of Aβ and AβPP family molecules, but also provide a conceptual framework that can unify current hypotheses on AD. Furthermore, it may explain major clinical observations not accounted for and identify approaches for overcoming shortfalls in AD animal modeling.
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Affiliation(s)
- Zhen Huang
- Departments of Neuroscience and Neurology, University of Wisconsin-Madison, Madison, WI, USA
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21
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Varshavskaya KB, Mitkevich VA, Makarov AA, Barykin EP. Synthetic, Cell-Derived, Brain-Derived, and Recombinant β-Amyloid: Modelling Alzheimer's Disease for Research and Drug Development. Int J Mol Sci 2022; 23:ijms232315036. [PMID: 36499362 PMCID: PMC9738609 DOI: 10.3390/ijms232315036] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 11/26/2022] [Accepted: 11/29/2022] [Indexed: 12/02/2022] Open
Abstract
Alzheimer's disease (AD) is the most common cause of dementia in the elderly, characterised by the accumulation of senile plaques and tau tangles, neurodegeneration, and neuroinflammation in the brain. The development of AD is a pathological cascade starting according to the amyloid hypothesis with the accumulation and aggregation of the β-amyloid peptide (Aβ), which induces hyperphosphorylation of tau and promotes the pro-inflammatory activation of microglia leading to synaptic loss and, ultimately, neuronal death. Modelling AD-related processes is important for both studying the molecular basis of the disease and the development of novel therapeutics. The replication of these processes is often achieved with the use of a purified Aβ peptide. However, Aβ preparations obtained from different sources can have strikingly different properties. This review aims to compare the structure and biological effects of Aβ oligomers and aggregates of a higher order: synthetic, recombinant, purified from cell culture, or extracted from brain tissue. The authors summarise the applicability of Aβ preparations for modelling Aβ aggregation, neurotoxicity, cytoskeleton damage, receptor toxicity in vitro and cerebral amyloidosis, synaptic plasticity disruption, and cognitive impairment in vivo and ex vivo. Further, the paper discusses the causes of the reported differences in the effect of Aβ obtained from the sources mentioned above. This review points to the importance of the source of Aβ for AD modelling and could help researchers to choose the optimal way to model the Aβ-induced abnormalities.
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22
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Vijayaragavan K, Cannon BJ, Tebaykin D, Bossé M, Baranski A, Oliveria JP, Bukhari SA, Mrdjen D, Corces MR, McCaffrey EF, Greenwald NF, Sigal Y, Marquez D, Khair Z, Bruce T, Goldston M, Bharadwaj A, Montine KS, Angelo RM, Montine TJ, Bendall SC. Single-cell spatial proteomic imaging for human neuropathology. Acta Neuropathol Commun 2022; 10:158. [PMID: 36333818 PMCID: PMC9636771 DOI: 10.1186/s40478-022-01465-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 10/18/2022] [Indexed: 11/06/2022] Open
Abstract
Neurodegenerative disorders are characterized by phenotypic changes and hallmark proteopathies. Quantifying these in archival human brain tissues remains indispensable for validating animal models and understanding disease mechanisms. We present a framework for nanometer-scale, spatial proteomics with multiplex ion beam imaging (MIBI) for capturing neuropathological features. MIBI facilitated simultaneous, quantitative imaging of 36 proteins on archival human hippocampus from individuals spanning cognitively normal to dementia. Customized analysis strategies identified cell types and proteopathies in the hippocampus across stages of Alzheimer's disease (AD) neuropathologic change. We show microglia-pathologic tau interactions in hippocampal CA1 subfield in AD dementia. Data driven, sample independent creation of spatial proteomic regions identified persistent neurons in pathologic tau neighborhoods expressing mitochondrial protein MFN2, regardless of cognitive status, suggesting a survival advantage. Our study revealed unique insights from multiplexed imaging and data-driven approaches for neuropathologic analysis and serves broadly as a methodology for spatial proteomic analysis of archival human neuropathology. TEASER: Multiplex Ion beam Imaging enables deep spatial phenotyping of human neuropathology-associated cellular and disease features.
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Affiliation(s)
| | - Bryan J Cannon
- Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Dmitry Tebaykin
- Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Marc Bossé
- Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Alex Baranski
- Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA
| | - J P Oliveria
- Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Syed A Bukhari
- Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Dunja Mrdjen
- Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA
| | | | - Erin F McCaffrey
- Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Noah F Greenwald
- Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA
| | | | - Diana Marquez
- Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Zumana Khair
- Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Trevor Bruce
- Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Mako Goldston
- Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Anusha Bharadwaj
- Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Kathleen S Montine
- Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA
| | - R Michael Angelo
- Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Thomas J Montine
- Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Sean C Bendall
- Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA.
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23
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Zhou B, Lu JG, Siddu A, Wernig M, Südhof TC. Synaptogenic effect of APP-Swedish mutation in familial Alzheimer's disease. Sci Transl Med 2022; 14:eabn9380. [PMID: 36260691 PMCID: PMC9894682 DOI: 10.1126/scitranslmed.abn9380] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Mutations in β-amyloid (Aβ) precursor protein (APP) cause familial Alzheimer's disease (AD) probably by enhancing Aβ peptides production from APP. An antibody targeting Aβ (aducanumab) was approved as an AD treatment; however, some Aβ antibodies have been reported to accelerate, instead of ameliorating, cognitive decline in individuals with AD. Using conditional APP mutations in human neurons for perfect isogenic controls and translational relevance, we found that the APP-Swedish mutation in familial AD increased synapse numbers and synaptic transmission, whereas the APP deletion decreased synapse numbers and synaptic transmission. Inhibition of BACE1, the protease that initiates Aβ production from APP, lowered synapse numbers, suppressed synaptic transmission in wild-type neurons, and occluded the phenotype of APP-Swedish-mutant neurons. Modest elevations of Aβ, conversely, elevated synapse numbers and synaptic transmission. Thus, the familial AD-linked APP-Swedish mutation under physiologically relevant conditions increased synaptic connectivity in human neurons via a modestly enhanced production of Aβ. These data are consistent with the relative inefficacy of BACE1 and anti-Aβ treatments in AD and the chronic nature of AD pathogenesis, suggesting that AD pathogenesis is not simply caused by overproduction of toxic Aβ but rather by a long-term effect of elevated Aβ concentrations.
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Affiliation(s)
- Bo Zhou
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
- Department of Pathology, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
| | - Jacqueline G. Lu
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
- Department of Pathology, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
| | - Alberto Siddu
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
| | - Marius Wernig
- Department of Pathology, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
| | - Thomas C. Südhof
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
- Howard Hughes Medical Institute, Stanford University School of Medicine; Stanford 94305, USA
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24
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Baerends E, Soud K, Folke J, Pedersen AK, Henmar S, Konrad L, Lycas MD, Mori Y, Pakkenberg B, Woldbye DPD, Dmytriyeva O, Pankratova S. Modeling the early stages of Alzheimer's disease by administering intracerebroventricular injections of human native Aβ oligomers to rats. Acta Neuropathol Commun 2022; 10:113. [PMID: 35974377 PMCID: PMC9380371 DOI: 10.1186/s40478-022-01417-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 07/29/2022] [Indexed: 11/10/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive and irreversible neurodegenerative disease characterized by the accumulation of aggregated amyloid beta (Aβ) and hyperphosphorylated tau along with a slow decline in cognitive functions. Unlike advanced AD, the initial steps of AD pathophysiology have been poorly investigated, partially due to limited availability of animal models focused on the early, plaque-free stages of the disease. The aim of this study was to evaluate the early behavioral, anatomical and molecular alterations in wild-type rats following intracerebroventricular injections of human Aβ oligomers (AβOs). Bioactive human AD and nondemented control brain tissue extracts were characterized using ELISA and proteomics approaches. Following a bilateral infusion, rats underwent behavioral testing, including the elevated plus maze, social recognition test, Morris water maze and Y-maze within 6 weeks postinjection. An analysis of brain structure was performed with manganese-enhanced MRI. Collected brain tissues were analyzed using stereology, immunohistochemistry, ELISA and qPCR. No sensorimotor deficits affecting motor performance on different maze tasks were observed, nor was spatial memory disturbed in AD rats. In contrast, a significant impairment of social memory became evident at 21 days postinjection. This deficit was associated with a significantly decreased volume of the lateral entorhinal cortex and a tendency toward a decrease in the total brain volume. Significant increase of cleaved caspase-3-positive cells, microglial activation and proinflammatory responses accompanied by altered expression of synaptic markers were observed in the hippocampus of AD rats with immunohistochemical and qPCR approaches at 6 weeks postinjection. Our data suggest that the social memory impairment observed in AβO-injected rats might be determined by neuroinflammatory responses and synaptopathy. An infusion of native oligomeric Aβ in the rat brain represents a feasible tool to model early plaque-free events associated with AD.
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Affiliation(s)
- Eva Baerends
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Katia Soud
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Jonas Folke
- Centre for Neuroscience and Stereology, Department of Neurology,, Bispebjerg-Frederiksberg Hospital, Copenhagen University Hospital, Copenhagen, Denmark.,Copenhagen Center for Translational Research, Bispebjerg-Frederiksberg Hospital, Copenhagen University Hospital, Copenhagen, Denmark
| | - Anna-Kathrine Pedersen
- Proteomics Program, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Simon Henmar
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Lisa Konrad
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Matthew D Lycas
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Yuki Mori
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Bente Pakkenberg
- Centre for Neuroscience and Stereology, Department of Neurology,, Bispebjerg-Frederiksberg Hospital, Copenhagen University Hospital, Copenhagen, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - David P D Woldbye
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Oksana Dmytriyeva
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Stanislava Pankratova
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark. .,Comparative Pediatrics and Nutrition, Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark.
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25
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Bioactive human Alzheimer brain soluble Aβ: pathophysiology and therapeutic opportunities. Mol Psychiatry 2022; 27:3182-3191. [PMID: 35484241 DOI: 10.1038/s41380-022-01589-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 04/11/2022] [Accepted: 04/14/2022] [Indexed: 12/16/2022]
Abstract
The accumulation of amyloid-β protein (Aβ) plays an early role in the pathogenesis of Alzheimer's disease (AD). The precise mechanism of how Aβ accumulation leads to synaptic dysfunction and cognitive impairment remains unclear but is likely due to small soluble oligomers of Aβ (oAβ). Most studies have used chemical synthetic or cell-secreted Aβ oligomers to study their pathogenic mechanisms, but the Aβ derived from human AD brain tissue is less well characterized. Here we review updated knowledge on the extraction and characterization of bioactive human AD brain oAβ and the mechanisms by which they cause hippocampal synaptic dysfunction. Human AD brain-derived oAβ can impair hippocampal long-term potentiation (LTP) and enhance long-term depression (LTD). Many studies suggest that oAβ may directly disrupt neuronal NMDA receptors, AMPA receptors and metabotropic glutamate receptors (mGluRs). oAβ also impairs astrocytic synaptic functions, including glutamate uptake, D-serine release, and NMDA receptor function. We also discuss oAβ-induced neuronal hyperexcitation. These results may suggest a multi-target approach for the treatment of AD, including both oAβ neutralization and reversal of glutamate-mediated excitotoxicity.
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26
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Pfundstein G, Nikonenko AG, Sytnyk V. Amyloid precursor protein (APP) and amyloid β (Aβ) interact with cell adhesion molecules: Implications in Alzheimer’s disease and normal physiology. Front Cell Dev Biol 2022; 10:969547. [PMID: 35959488 PMCID: PMC9360506 DOI: 10.3389/fcell.2022.969547] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 07/07/2022] [Indexed: 11/16/2022] Open
Abstract
Alzheimer’s disease (AD) is an incurable neurodegenerative disorder in which dysfunction and loss of synapses and neurons lead to cognitive impairment and death. Accumulation and aggregation of neurotoxic amyloid-β (Aβ) peptides generated via amyloidogenic processing of amyloid precursor protein (APP) is considered to play a central role in the disease etiology. APP interacts with cell adhesion molecules, which influence the normal physiological functions of APP, its amyloidogenic and non-amyloidogenic processing, and formation of Aβ aggregates. These cell surface glycoproteins also mediate attachment of Aβ to the neuronal cell surface and induce intracellular signaling contributing to Aβ toxicity. In this review, we discuss the current knowledge surrounding the interactions of cell adhesion molecules with APP and Aβ and analyze the evidence of the critical role these proteins play in regulating the processing and physiological function of APP as well as Aβ toxicity. This is a necessary piece of the complex AD puzzle, which we should understand in order to develop safe and effective therapeutic interventions for AD.
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Affiliation(s)
- Grant Pfundstein
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | | | - Vladimir Sytnyk
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
- *Correspondence: Vladimir Sytnyk,
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27
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Delport A, Hewer R. The amyloid precursor protein: a converging point in Alzheimer's disease. Mol Neurobiol 2022; 59:4501-4516. [PMID: 35579846 DOI: 10.1007/s12035-022-02863-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 04/30/2022] [Indexed: 11/30/2022]
Abstract
The decades of evidence that showcase the role of amyloid precursor protein (APP), and its fragment amyloidβ (Aβ), in Alzheimer's disease (AD) pathogenesis are irrefutable. However, the absolute focus on the single APP metabolite Aβ as the cause for AD has resulted in APP and its other fragments that possess toxic propensity, to be overlooked as targets for treatment. The complexity of its processing and its association with systematic metabolism suggests that, if misregulated, APP has the potential to provoke an array of metabolic dysfunctions. This review discusses APP and several of its cleaved products with a particular focus on their toxicity and ability to disrupt healthy cellular function, in relation to AD development. We subsequently argue that the reduction of APP, which would result in a concurrent decrease in Aβ as well as all other toxic APP metabolites, would alleviate the toxic environment associated with AD and slow disease progression. A discussion of those drug-like compounds already identified to possess this capacity is also included.
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Affiliation(s)
- Alexandré Delport
- Discipline of Biochemistry, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, 3201, South Africa.
| | - Raymond Hewer
- Discipline of Biochemistry, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, 3201, South Africa
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28
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Krafft GA, Jerecic J, Siemers E, Cline EN. ACU193: An Immunotherapeutic Poised to Test the Amyloid β Oligomer Hypothesis of Alzheimer’s Disease. Front Neurosci 2022; 16:848215. [PMID: 35557606 PMCID: PMC9088393 DOI: 10.3389/fnins.2022.848215] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 03/02/2022] [Indexed: 12/26/2022] Open
Abstract
Alzheimer’s disease (AD) is an age-related neurodegenerative disease that affects 50 million people worldwide, with 10 million new cases occurring each year. The emotional and economic impacts of AD on patients and families are devastating. Approved treatments confer modest improvement in symptoms, and recently one treatment obtained accelerated approval from the United States Food and Drug Administration (FDA) and may have modest disease modifying benefit. Research over the past three decades has established a clear causal linkage between AD and elevated brain levels of amyloid β (Aβ) peptide, and substantial evidence now implicates soluble, non-fibrillar Aβ oligomers (AβOs) as the molecular assemblies directly responsible for AD-associated memory and cognitive failure and accompanying progressive neurodegeneration. The widely recognized linkage of elevated Aβ and AD spawned a comprehensive 20-year therapeutic campaign that focused primarily on two strategies – inhibition of the secretase enzymes responsible for Aβ production and clearance of Aβ peptide or amyloid plaques with Aβ-directed immunotherapeutics. Unfortunately, all clinical trials of secretase inhibitors were unsuccessful. Of the completed phase 3 immunotherapy programs, bapineuzumab (targeting amyloid plaque) and solanezumab (targeting Aβ monomers) were negative, and the crenezumab program (targeting Aβ monomers and to a small extent oligomers) was stopped for futility. Aducanumab (targeting amyloid plaques), which recently received FDA accelerated approval, had one positive and one negative phase 3 trial. More than 25 negative randomized clinical trials (RCTs) have evaluated Aβ-targeting therapeutics, yet none has directly evaluated whether selective blockage of disease-relevant AβOs can stop or reverse AD-associated cognitive decline. Here, we briefly summarize studies that establish the AD therapeutic rationale to target AβOs selectively, and we describe ACU193, the first AβO-selective immunotherapeutic to enter human clinical trials and the first positioned to test the AβO hypothesis of AD.
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29
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Pomilio AB, Vitale AA, Lazarowski AJ. Neuroproteomics Chip-Based Mass Spectrometry and Other Techniques for Alzheimer´S Disease Biomarkers – Update. Curr Pharm Des 2022; 28:1124-1151. [DOI: 10.2174/1381612828666220413094918] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 02/25/2022] [Indexed: 11/22/2022]
Abstract
Background:
Alzheimer's disease (AD) is a progressive neurodegenerative disease of growing interest given that there is cognitive damage and symptom onset acceleration. Therefore, it is important to find AD biomarkers for early diagnosis, disease progression, and discrimination of AD and other diseases.
Objective:
To update the relevance of mass spectrometry for the identification of peptides and proteins involved in AD useful as discriminating biomarkers.
Methods:
Proteomics and peptidomics technologies that show the highest possible specificity and selectivity for AD biomarkers are analyzed, together with the biological fluids used. In addition to positron emission tomography and magnetic resonance imaging, MALDI-TOF mass spectrometry is widely used to identify proteins and peptides involved in AD. The use of protein chips in SELDI technology and electroblotting chips for peptides makes feasible small amounts (L) of samples for analysis.
Results:
Suitable biomarkers are related to AD pathology, such as intracellular neurofibrillary tangles; extraneuronal senile plaques; neuronal and axonal degeneration; inflammation and oxidative stress. Recently, peptides were added to the candidate list, which are not amyloid-b or tau fragments, but are related to coagulation, brain plasticity, and complement/neuroinflammation systems involving the neurovascular unit.
Conclusion:
The progress made in the application of mass spectrometry and recent chip techniques is promising for discriminating between AD, mild cognitive impairment, and matched healthy controls. The application of this technique to blood samples from patients with AD has shown to be less invasive and fast enough to determine the diagnosis, stage of the disease, prognosis, and follow-up of the therapeutic response.
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Affiliation(s)
- Alicia B. Pomilio
- Departamento de Bioquímica Clínica, Área Hematología, Hospital de Clínicas “José de San Martín”, Universidad de Buenos Aires, Av. Córdoba 2351, C1120AAF Buenos Aires, Argentina
| | - Arturo A. Vitale
- Departamento de Bioquímica Clínica, Área Hematología, Hospital de Clínicas “José de San Martín”, Universidad de Buenos Aires, Av. Córdoba 2351, C1120AAF Buenos Aires, Argentina
| | - Alberto J. Lazarowski
- Departamento de Bioquímica Clínica, Facultad de Farmacia y Bioquímica, Instituto de Fisiopatología y Bioquímica Clínica (INFIBIOC), Universidad de Buenos Aires, Córdoba 2351, C1120AAF Buenos Aires, Argentina
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30
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Antonino M, Marmo P, Freites CL, Quassollo GE, Sánchez MF, Lorenzo A, Bignante EA. Aβ Assemblies Promote Amyloidogenic Processing of APP and Intracellular Accumulation of Aβ42 Through Go/Gβγ Signaling. Front Cell Dev Biol 2022; 10:852738. [PMID: 35445022 PMCID: PMC9013780 DOI: 10.3389/fcell.2022.852738] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 03/07/2022] [Indexed: 12/16/2022] Open
Abstract
Alzheimer’s disease (AD) is characterized by the deposition of aggregated species of amyloid beta (Aβ) in the brain, which leads to progressive cognitive deficits and dementia. Aβ is generated by the successive cleavage of the amyloid precursor protein (APP), first by β-site APP cleaving enzyme 1 (BACE1) and subsequently by the γ-secretase complex. Those conditions which enhace or reduce its clearance predispose to Aβ aggregation and the development of AD. In vitro studies have demonstrated that Aβ assemblies spark a feed-forward loop heightening Aβ production. However, the underlying mechanism remains unknown. Here, we show that oligomers and fibrils of Aβ enhance colocalization and physical interaction of APP and BACE1 in recycling endosomes of human neurons derived from induced pluripotent stem cells and other cell types, which leads to exacerbated amyloidogenic processing of APP and intracellular accumulation of Aβ42. In cells that are overexpressing the mutant forms of APP which are unable to bind Aβ or to activate Go protein, we have found that treatment with aggregated Aβ fails to increase colocalization of APP with BACE1 indicating that Aβ-APP/Go signaling is involved in this process. Moreover, inhibition of Gβγ subunit signaling with βARKct or gallein prevents Aβ-dependent interaction of APP and BACE1 in endosomes, β-processing of APP, and intracellular accumulation of Aβ42. Collectively, our findings uncover a signaling mechanism leading to a feed-forward loop of amyloidogenesis that might contribute to Aβ pathology in the early stages of AD and suggest that gallein could have therapeutic potential.
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Affiliation(s)
- Magdalena Antonino
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Paula Marmo
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Carlos Leandro Freites
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina
| | | | | | - Alfredo Lorenzo
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina
- *Correspondence: Elena Anahi Bignante, ; Alfredo Lorenzo,
| | - Elena Anahi Bignante
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina
- Instituto Universitario de Ciencias Biomédicas de Córdoba (IUCBC), Córdoba, Argentina
- *Correspondence: Elena Anahi Bignante, ; Alfredo Lorenzo,
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31
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Eren E, Leoutsakos JM, Troncoso J, Lyketsos CG, Oh ES, Kapogiannis D. Neuronal-Derived EV Biomarkers Track Cognitive Decline in Alzheimer’s Disease. Cells 2022; 11:cells11030436. [PMID: 35159246 PMCID: PMC8834433 DOI: 10.3390/cells11030436] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/16/2022] [Accepted: 01/26/2022] [Indexed: 12/12/2022] Open
Abstract
The hallmarks of Alzheimer’s disease (AD) pathology are senile plaques containing amyloid-beta (Aβ) and neurofibrillary tangles containing hyperphosphorylated tau. Additional pathologies often co-exist, whereas multiple pathogenic mechanisms are involved in AD, especially synaptic degeneration, which necessitate the need for synaptic integrity-related biomarkers alongside Aβ- and tau-related biomarkers. Plasma neuron-derived Extracellular Vesicles EVs (NDEVs) provide biomarkers related to Aβ and tau and synaptic degeneration. Here, to further establish the latter as a “liquid biopsy” for AD, we examined their relationship with ante-mortem cognition in pathologically-confirmed AD cases. We immunoprecipitated NDEVs by targeting neuronal marker L1CAM from ante-mortem plasma samples from 61 autopsy-confirmed cases of pure AD or AD with additional pathologies and measured Aβ42, p181-Tau, total Tau, synaptophysin, synaptopodin and three canonical EV markers, CD63, CD81 and CD9. Higher NDEV Aβ42 levels were consistently associated with better cognitive status, memory, fluency, working memory and executive function. Higher levels of NDEV synaptic integrity-related biomarkers were associated with better performance on executive function tasks. Our findings motivate the hypothesis that releasing Aβ42-laden NDEVs may be an adaptive mechanism in AD.
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Affiliation(s)
- Erden Eren
- Intramural Research Program, Laboratory of Clinical Investigation, National Institute on Aging, Baltimore, MD 21224, USA;
| | - Jeannie-Marie Leoutsakos
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; (J.-M.L.); (C.G.L.)
- Department of Medicine, Division of Geriatric Medicine and Gerontology, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA
| | - Juan Troncoso
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21224, USA;
| | - Constantine G. Lyketsos
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; (J.-M.L.); (C.G.L.)
- Department of Medicine, Division of Geriatric Medicine and Gerontology, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA
| | - Esther S. Oh
- Department of Medicine, Division of Geriatric Medicine and Gerontology, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA
- Richman Family Precision Medicine Center of Excellence in Alzheimer’s Disease, Johns Hopkins School of Medicine, Baltimore, MD 21224, USA
- Correspondence: (E.S.O.); (D.K.)
| | - Dimitrios Kapogiannis
- Intramural Research Program, Laboratory of Clinical Investigation, National Institute on Aging, Baltimore, MD 21224, USA;
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21224, USA;
- Correspondence: (E.S.O.); (D.K.)
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Pelucchi S, Gardoni F, Di Luca M, Marcello E. Synaptic dysfunction in early phases of Alzheimer's Disease. HANDBOOK OF CLINICAL NEUROLOGY 2022; 184:417-438. [PMID: 35034752 DOI: 10.1016/b978-0-12-819410-2.00022-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The synapse is the locus of plasticity where short-term alterations in synaptic strength are converted to long-lasting memories. In addition to the presynaptic terminal and the postsynaptic compartment, a more holistic view of the synapse includes the astrocytes and the extracellular matrix to form a tetrapartite synapse. All these four elements contribute to synapse health and are crucial for synaptic plasticity events and, thereby, for learning and memory processes. Synaptic dysfunction is a common pathogenic trait of several brain disorders. In Alzheimer's Disease, the degeneration of synapses can be detected at the early stages of pathology progression before neuronal degeneration, supporting the hypothesis that synaptic failure is a major determinant of the disease. The synapse is the place where amyloid-β peptides are generated and is the target of the toxic amyloid-β oligomers. All the elements constituting the tetrapartite synapse are altered in Alzheimer's Disease and can synergistically contribute to synaptic dysfunction. Moreover, the two main hallmarks of Alzheimer's Disease, i.e., amyloid-β and tau, act in concert to cause synaptic deficits. Deciphering the mechanisms underlying synaptic dysfunction is relevant for the development of the next-generation therapeutic strategies aimed at modifying the disease progression.
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Affiliation(s)
- Silvia Pelucchi
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Fabrizio Gardoni
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Monica Di Luca
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Elena Marcello
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy.
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Zarhin D, Atsmon R, Ruggiero A, Baeloha H, Shoob S, Scharf O, Heim LR, Buchbinder N, Shinikamin O, Shapira I, Styr B, Braun G, Harel M, Sheinin A, Geva N, Sela Y, Saito T, Saido T, Geiger T, Nir Y, Ziv Y, Slutsky I. Disrupted neural correlates of anesthesia and sleep reveal early circuit dysfunctions in Alzheimer models. Cell Rep 2022; 38:110268. [PMID: 35045289 PMCID: PMC8789564 DOI: 10.1016/j.celrep.2021.110268] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 12/06/2021] [Accepted: 12/22/2021] [Indexed: 11/30/2022] Open
Abstract
Dysregulated homeostasis of neural activity has been hypothesized to drive Alzheimer's disease (AD) pathogenesis. AD begins with a decades-long presymptomatic phase, but whether homeostatic mechanisms already begin failing during this silent phase is unknown. We show that before the onset of memory decline and sleep disturbances, familial AD (fAD) model mice display no deficits in CA1 mean firing rate (MFR) during active wakefulness. However, homeostatic down-regulation of CA1 MFR is disrupted during non-rapid eye movement (NREM) sleep and general anesthesia in fAD mouse models. The resultant hyperexcitability is attenuated by the mitochondrial dihydroorotate dehydrogenase (DHODH) enzyme inhibitor, which tunes MFR toward lower set-point values. Ex vivo fAD mutations impair downward MFR homeostasis, resulting in pathological MFR set points in response to anesthetic drug and inhibition blockade. Thus, firing rate dyshomeostasis of hippocampal circuits is masked during active wakefulness but surfaces during low-arousal brain states, representing an early failure of the silent disease stage.
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Affiliation(s)
- Daniel Zarhin
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Refaela Atsmon
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Antonella Ruggiero
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Halit Baeloha
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Shiri Shoob
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Oded Scharf
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Leore R Heim
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Nadav Buchbinder
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ortal Shinikamin
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ilana Shapira
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Boaz Styr
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Gabriella Braun
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Michal Harel
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Anton Sheinin
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Nitzan Geva
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yaniv Sela
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Takashi Saito
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Saitama 351-0198, Japan; Department of Neurocognitive Science, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi 467-8601, Japan
| | - Takaomi Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Saitama 351-0198, Japan
| | - Tamar Geiger
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Yuval Nir
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Yaniv Ziv
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Inna Slutsky
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel.
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Broussard JI, Redell JB, Maynard ME, Zhao J, Moore A, Mills RW, Hood KN, Underwood E, Roysam B, Dash PK. Impaired Experience-Dependent Refinement of Place Cells in a Rat Model of Alzheimer's Disease. J Alzheimers Dis 2022; 86:1907-1916. [PMID: 35253742 PMCID: PMC9850819 DOI: 10.3233/jad-215023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
BACKGROUND Hippocampal place cells play an integral role in generating spatial maps. Impaired spatial memory is a characteristic pathology of Alzheimer's disease (AD), yet it remains unclear how AD influences the properties of hippocampal place cells. OBJECTIVE To record electrophysiological activity in hippocampal CA1 neurons in freely-moving 18-month-old male TgF344-AD and age-matched wild-type (WT) littermates to examine place cell properties. METHODS We implanted 32-channel electrode arrays into the CA1 subfield of 18-month-old male WT and TgF344-AD (n = 6/group) rats. Ten days after implantation, single unit activity in an open field arena was recorded across days. The spatial information content, in-field firing rate, and stability of each place cell was compared across groups. Pathology was assessed by immunohistochemical staining, and a deep neural network approach was used to count cell profiles. RESULTS Aged TgF344-AD rats exhibited hippocampal amyloid-β deposition, and a significant increase in Iba1 immunoreactivity and microglia cell counts. Place cells from WT and TgF344-AD rat showed equivalent spatial information, in-field firing rates, and place field stability when initially exposed to the arena. However, by day 3, the place cells in aged WT rats showed characteristic spatial tuning as evidenced by higher spatial information content, stability, and in-field firing rates, an effect not seen in TgF344-AD rats. CONCLUSION These findings support the notion that altered electrophysiological properties of place cells may contribute to the learning and memory deficits observed in AD.
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Affiliation(s)
- John I. Broussard
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, Houston, Texas 77030,To whom correspondence should be addressed: JI Broussard, Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, 6431 Fannin, St., Suite 7.011, Houston, TX 77030, Phone: (713) 500-5545,
| | - John B. Redell
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, Houston, Texas 77030
| | - Mark E. Maynard
- Department of Electrical and Computer Engineering, Cullen College of Engineering, University of Houston, Houston, TX, 77204, USA
| | - Jing Zhao
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, Houston, Texas 77030
| | - Anthony Moore
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, Houston, Texas 77030
| | - Rachel W. Mills
- Department of Electrical and Computer Engineering, Cullen College of Engineering, University of Houston, Houston, TX, 77204, USA
| | - Kimberly N. Hood
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, Houston, Texas 77030
| | - Erica Underwood
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, Houston, Texas 77030
| | - Badrinath Roysam
- Department of Electrical and Computer Engineering, Cullen College of Engineering, University of Houston, Houston, TX, 77204, USA
| | - Pramod K. Dash
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, Houston, Texas 77030
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35
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Naomi R, Shafie NH, Kaniappan P, Bahari H. An Interactive Review on the Role of Tocotrienols in the Neurodegenerative Disorders. Front Nutr 2021; 8:754086. [PMID: 34765631 PMCID: PMC8576197 DOI: 10.3389/fnut.2021.754086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 09/21/2021] [Indexed: 12/12/2022] Open
Abstract
Neurodegenerative disorders, such as Parkinson's and Alzheimer's disease, are claimed to be of major concern causing a significant disease burden worldwide. Oxidative stress, mitochondrial dysfunction and nerve damage are the main reasons for the emergence of these diseases. The formation of reactive oxygen species (ROS) is the common chemical molecule that is formed from all these three interdependent mechanisms which is highly reactive toward the neuronal cells. For these reasons, the administration of tocotrienols (T3s), which is a potent antioxidant, is proven to cater to this problem, through in vitro and in vivo investigations. Interestingly, their therapeutic potentials are not only limited to antioxidant property but also to being able to reverse the neuronal damage and act as a shield for mitochondria dysfunction. Thereby, T3s prevents the damage to the neurons. In regards to this statement, in this review, we focused on summarizing and discussing the potential therapeutic role of T3s on Alzheimer's and Parkinson's diseases, and their protective mechanisms based on evidence from the in vitro and in vivo studies. However, there is no clinical trial conducted to prove the efficacy of T3s for Alzheimer's and Parkinson's subjects. As such, the therapeutic role of T3s for these neurodegenerative disorders is still under debate.
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Affiliation(s)
- Ruth Naomi
- Department of Human Anatomy, Universiti Putra Malaysia, Serdang, Malaysia
| | - Nurul Husna Shafie
- Department of Nutrition, Faculty of Medicine & Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia.,UPM-MAKNA Cancer Research Laboratory, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Malaysia
| | - Priyatharisni Kaniappan
- Department of Medical Microbiology & Parasitology, Faculty of Medicine & Health Science, Universiti Putra Malaysia, Serdang, Malaysia
| | - Hasnah Bahari
- Department of Human Anatomy, Universiti Putra Malaysia, Serdang, Malaysia
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36
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Jiang H, Esparza TJ, Kummer TT, Brody DL. Unbiased high-content screening reveals Aβ- and tau-independent synaptotoxic activities in human brain homogenates from Alzheimer's patients and high-pathology controls. PLoS One 2021; 16:e0259335. [PMID: 34748596 PMCID: PMC8575250 DOI: 10.1371/journal.pone.0259335] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 10/19/2021] [Indexed: 11/22/2022] Open
Abstract
Alzheimer’s disease (AD) is tightly correlated with synapse loss in vulnerable brain regions. It is assumed that specific molecular entities such as Aβ and tau cause synapse loss in AD, yet unbiased screens for synaptotoxic activities have not been performed. Here, we performed size exclusion chromatography on soluble human brain homogenates from AD cases, high pathology non-demented controls, and low pathology age-matched controls using our novel high content primary cultured neuron-based screening assay. Both presynaptic and postsynaptic toxicities were elevated in homogenates from AD cases and high pathology non-demented controls to a similar extent, with more modest synaptotoxic activities in homogenates from low pathology normal controls. Surprisingly, synaptotoxic activities were found in size fractions peaking between the 17–44 kDa size standards that did not match well with Aβ and tau immunoreactive species in these homogenates. The fractions containing previously identified high molecular weight soluble amyloid beta aggregates/”oligomers” were non-toxic in this assay. Furthermore, immunodepletion of Aβ and tau did not reduce synaptotoxic activity. This result contrasts with previous findings involving the same methods applied to 3xTg-AD mouse brain extracts. The nature of the synaptotoxic species has not been identified. Overall, our data indicates one or more potential Aβ and tau independent synaptotoxic activities in human AD brain homogenates. This result aligns well with the key role of synaptic loss in the early cognitive decline and may provide new insight into AD pathophysiology.
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Affiliation(s)
- Hao Jiang
- Department of Neurology, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Thomas J. Esparza
- Department of Neurology, Washington University School of Medicine, St Louis, Missouri, United States of America
- Henry M Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, United States of America
- National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, United States of America
| | - Terrance T. Kummer
- Department of Neurology, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - David L. Brody
- Department of Neurology, Washington University School of Medicine, St Louis, Missouri, United States of America
- National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, United States of America
- Department of Neurology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
- * E-mail:
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37
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Robbins M, Clayton E, Kaminski Schierle GS. Synaptic tau: A pathological or physiological phenomenon? Acta Neuropathol Commun 2021; 9:149. [PMID: 34503576 PMCID: PMC8428049 DOI: 10.1186/s40478-021-01246-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 08/12/2021] [Indexed: 12/17/2022] Open
Abstract
In this review, we discuss the synaptic aspects of Tau pathology occurring during Alzheimer's disease (AD) and how this may relate to memory impairment, a major hallmark of AD. Whilst the clinical diagnosis of AD patients is a loss of working memory and long-term declarative memory, the histological diagnosis is the presence of neurofibrillary tangles of hyperphosphorylated Tau and Amyloid-beta plaques. Tau pathology spreads through synaptically connected neurons to impair synaptic function preceding the formation of neurofibrillary tangles, synaptic loss, axonal retraction and cell death. Alongside synaptic pathology, recent data suggest that Tau has physiological roles in the pre- or post- synaptic compartments. Thus, we have seen a shift in the research focus from Tau as a microtubule-stabilising protein in axons, to Tau as a synaptic protein with roles in accelerating spine formation, dendritic elongation, and in synaptic plasticity coordinating memory pathways. We collate here the myriad of emerging interactions and physiological roles of synaptic Tau, and discuss the current evidence that synaptic Tau contributes to pathology in AD.
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38
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Kreis A, Desloovere J, Suelves N, Pierrot N, Yerna X, Issa F, Schakman O, Gualdani R, de Clippele M, Tajeddine N, Kienlen-Campard P, Raedt R, Octave JN, Gailly P. Overexpression of wild-type human amyloid precursor protein alters GABAergic transmission. Sci Rep 2021; 11:17600. [PMID: 34475508 PMCID: PMC8413381 DOI: 10.1038/s41598-021-97144-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 08/13/2021] [Indexed: 02/07/2023] Open
Abstract
The function of the amyloid precursor protein (APP) is not fully understood, but its cleavage product amyloid beta (Aβ) together with neurofibrillary tangles constitute the hallmarks of Alzheimer's disease (AD). Yet, imbalance of excitatory and inhibitory neurotransmission accompanied by loss of synaptic functions, has been reported much earlier and independent of any detectable pathological markers. Recently, soluble APP fragments have been shown to bind to presynaptic GABAB receptors (GABABRs), subsequently decreasing the probability of neurotransmitter release. In this body of work, we were able to show that overexpression of wild-type human APP in mice (hAPPwt) causes early cognitive impairment, neuronal loss, and electrophysiological abnormalities in the absence of amyloid plaques and at very low levels of Aβ. hAPPwt mice exhibited neuronal overexcitation that was evident in EEG and increased long-term potentiation (LTP). Overexpression of hAPPwt did not alter GABAergic/glutamatergic receptor components or GABA production ability. Nonetheless, we detected a decrease of GABA but not glutamate that could be linked to soluble APP fragments, acting on presynaptic GABABRs and subsequently reducing GABA release. By using a specific presynaptic GABABR antagonist, we were able to rescue hyperexcitation in hAPPwt animals. Our results provide evidence that APP plays a crucial role in regulating inhibitory neurotransmission.
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Affiliation(s)
- Anna Kreis
- grid.7942.80000 0001 2294 713XLaboratory of Cell Physiology, Institute of Neuroscience, Université Catholique de Louvain, av. Mounier 53/B1.53.17, 1200 Brussels, Belgium
| | - Jana Desloovere
- grid.5342.00000 0001 2069 7798Faculty of Medicine and Health Sciences, Universiteit Gent, C. Heymanslaan 10, 9000 Gent, Belgium
| | - Nuria Suelves
- grid.7942.80000 0001 2294 713XAlzheimer Dementia Group, Institute of Neuroscience, Université Catholique de Louvain, av. Mounier 53, 1200 Brussels, Belgium
| | - Nathalie Pierrot
- grid.7942.80000 0001 2294 713XAlzheimer Dementia Group, Institute of Neuroscience, Université Catholique de Louvain, av. Mounier 53, 1200 Brussels, Belgium
| | - Xavier Yerna
- grid.7942.80000 0001 2294 713XLaboratory of Cell Physiology, Institute of Neuroscience, Université Catholique de Louvain, av. Mounier 53/B1.53.17, 1200 Brussels, Belgium
| | - Farah Issa
- grid.7942.80000 0001 2294 713XLaboratory of Cell Physiology, Institute of Neuroscience, Université Catholique de Louvain, av. Mounier 53/B1.53.17, 1200 Brussels, Belgium
| | - Olivier Schakman
- grid.7942.80000 0001 2294 713XLaboratory of Cell Physiology, Institute of Neuroscience, Université Catholique de Louvain, av. Mounier 53/B1.53.17, 1200 Brussels, Belgium
| | - Roberta Gualdani
- grid.7942.80000 0001 2294 713XLaboratory of Cell Physiology, Institute of Neuroscience, Université Catholique de Louvain, av. Mounier 53/B1.53.17, 1200 Brussels, Belgium
| | - Marie de Clippele
- grid.7942.80000 0001 2294 713XLaboratory of Cell Physiology, Institute of Neuroscience, Université Catholique de Louvain, av. Mounier 53/B1.53.17, 1200 Brussels, Belgium
| | - Nicolas Tajeddine
- grid.7942.80000 0001 2294 713XLaboratory of Cell Physiology, Institute of Neuroscience, Université Catholique de Louvain, av. Mounier 53/B1.53.17, 1200 Brussels, Belgium
| | - Pascal Kienlen-Campard
- grid.7942.80000 0001 2294 713XAlzheimer Dementia Group, Institute of Neuroscience, Université Catholique de Louvain, av. Mounier 53, 1200 Brussels, Belgium
| | - Robrecht Raedt
- grid.5342.00000 0001 2069 7798Faculty of Medicine and Health Sciences, Universiteit Gent, C. Heymanslaan 10, 9000 Gent, Belgium
| | - Jean-Noël Octave
- grid.7942.80000 0001 2294 713XAlzheimer Dementia Group, Institute of Neuroscience, Université Catholique de Louvain, av. Mounier 53, 1200 Brussels, Belgium
| | - Philippe Gailly
- grid.7942.80000 0001 2294 713XLaboratory of Cell Physiology, Institute of Neuroscience, Université Catholique de Louvain, av. Mounier 53/B1.53.17, 1200 Brussels, Belgium
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Genetic deletion of α7 nicotinic acetylcholine receptors induces an age-dependent Alzheimer's disease-like pathology. Prog Neurobiol 2021; 206:102154. [PMID: 34453977 DOI: 10.1016/j.pneurobio.2021.102154] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 05/29/2021] [Accepted: 08/18/2021] [Indexed: 11/22/2022]
Abstract
The accumulation of amyloid-beta peptide (Aβ) and the failure of cholinergic transmission are key players in Alzheimer's disease (AD). However, in the healthy brain, Aβ contributes to synaptic plasticity and memory acting through α7 subtype nicotinic acetylcholine receptors (α7nAChRs). Here, we hypothesized that the α7nAChR deletion blocks Aβ physiological function and promotes a compensatory increase in Aβ levels that, in turn, triggers an AD-like pathology. To validate this hypothesis, we studied the age-dependent phenotype of α7 knock out mice. We found that α7nAChR deletion caused an impairment of hippocampal synaptic plasticity and memory at 12 months of age, paralleled by an increase of Amyloid Precursor Protein expression and Aβ levels. This was accompanied by other classical AD features such as a hyperphosphorylation of tau at residues Ser 199, Ser 396, Thr 205, a decrease of GSK-3β at Ser 9, the presence of paired helical filaments and neurofibrillary tangles, neuronal loss and an increase of GFAP-positive astrocytes. Our findings suggest that α7nAChR malfunction might precede Aβ and tau pathology, offering a different perspective to interpret the failure of anti-Aβ therapies against AD and to find novel therapeutical approaches aimed at restoring α7nAChRs-mediated Aβ function at the synapse.
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40
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Yang Y, Ji WG, Zhang YJ, Zhou LP, Chen H, Yang N, Zhu ZR. Riluzole ameliorates soluble Aβ 1-42-induced impairments in spatial memory by modulating the glutamatergic/GABAergic balance in the dentate gyrus. Prog Neuropsychopharmacol Biol Psychiatry 2021; 108:110077. [PMID: 32818535 DOI: 10.1016/j.pnpbp.2020.110077] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 08/12/2020] [Accepted: 08/13/2020] [Indexed: 01/21/2023]
Abstract
Soluble amyloid beta (Aβ) is believed to contribute to cognitive deficits in the early stages of Alzheimer's disease (AD). Increased soluble Aβ1-42 in the hippocampus is closely correlated with spatial learning and memory deficits in AD. Riluzole (RLZ), an FDA-approved drug for amyotrophic lateral sclerosis (ALS), has beneficial effects for AD. However, the mechanism underlying the effects remains unclear. In this study, its neuroprotective effect against soluble Aβ1-42-induced spatial cognitive deficits in rats was assessed. We found that intrahippocampal injection of soluble Aβ1-42 impaired spatial cognitive function and suppressed long-term potentiation (LTP) of the DG region, which was relevant to soluble Aβ1-42-induced shift of the hippocampal excitation/inhibition balance toward excitation. Interestingly, RLZ ameliorated Aβ1-42-induced behavioral and LTP impairments through rescuing the soluble Aβ1-42-induced excitation/inhibition imbalance. RLZ attenuated Aβ1-42-mediated facilitation of excitatory synaptic transmission by facilitating glutamate reuptake and decreasing presynaptic glutamate release. Meanwhile, RLZ attenuated the suppression of inhibitory synaptic transmission caused by Aβ1-42 by potentiating postsynaptic GABA receptor function. These results suggest that RLZ exerts a neuroprotective effect against soluble Aβ1-42-related spatial cognitive deficits through rescuing the excitation/inhibition imbalance, and it could be a potential therapy for AD.
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Affiliation(s)
- Yang Yang
- Department of Developmental Neuropsychology, Army Medical University, Chongqing 400038, China; Department of Urology, The Second Affiliated Hospital, Army Medical University, Chongqing 400038, China
| | - Wei-Gang Ji
- Department of Pharmacy, Chongqing Medical and Pharmaceutical College, Chongqing 401331, China
| | - Ying-Jie Zhang
- Department of Developmental Neuropsychology, Army Medical University, Chongqing 400038, China
| | - Li-Ping Zhou
- Department of Developmental Neuropsychology, Army Medical University, Chongqing 400038, China
| | - Hao Chen
- Department of Physiology, Army Medical University, Chongqing 400038, China
| | - Nian Yang
- Department of Physiology, Army Medical University, Chongqing 400038, China
| | - Zhi-Ru Zhu
- Department of Developmental Neuropsychology, Army Medical University, Chongqing 400038, China.
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Hammoud H, Netsyk O, Tafreshiha AS, Korol SV, Jin Z, Li J, Birnir B. Insulin differentially modulates GABA signalling in hippocampal neurons and, in an age-dependent manner, normalizes GABA-activated currents in the tg-APPSwe mouse model of Alzheimer's disease. Acta Physiol (Oxf) 2021; 232:e13623. [PMID: 33559388 DOI: 10.1111/apha.13623] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/29/2021] [Accepted: 02/03/2021] [Indexed: 02/06/2023]
Abstract
AIM We examined if tonic γ-aminobutyric acid (GABA)-activated currents in primary hippocampal neurons were modulated by insulin in wild-type and tg-APPSwe mice, an Alzheimer's disease (AD) model. METHODS GABA-activated currents were recorded in dentate gyrus (DG) granule cells and CA3 pyramidal neurons in hippocampal brain slices, from 8 to 10 weeks old (young) wild-type mice and in dorsal DG granule cells in adult, 5-6 and 10-12 (aged) months old wild-type and tg-APPSwe mice, in the absence or presence of insulin, by whole-cell patch-clamp electrophysiology. RESULTS In young mice, insulin (1 nmol/L) enhanced the total spontaneous inhibitory postsynaptic current (sIPSCT ) density in both dorsal and ventral DG granule cells. The extrasynaptic current density was only increased by insulin in dorsal CA3 pyramidal neurons. In absence of action potentials, insulin enhanced DG granule cells and dorsal CA3 pyramidal neurons miniature IPSC (mIPSC) frequency, consistent with insulin regulation of presynaptic GABA release. sIPSCT densities in DG granule cells were similar in wild-type and tg-APPSwe mice at 5-6 months but significantly decreased in aged tg-APPSwe mice where insulin normalized currents to wild-type levels. The extrasynaptic current density was increased in tg-APPSwe mice relative to wild-type littermates but, only in aged tg-APPSwe mice did insulin decrease and normalize the current. CONCLUSION Insulin effects on GABA signalling in hippocampal neurons are selective while multifaceted and context-based. Not only is the response to insulin related to cell-type, hippocampal axis-location, age of animals and disease but also to the subtype of neuronal inhibition involved, synaptic or extrasynaptic GABAA receptors-activated currents.
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Affiliation(s)
- Hayma Hammoud
- Department of Medical Cell Biology Uppsala University Uppsala Sweden
| | - Olga Netsyk
- Department of Medical Cell Biology Uppsala University Uppsala Sweden
| | | | - Sergiy V. Korol
- Department of Medical Cell Biology Uppsala University Uppsala Sweden
| | - Zhe Jin
- Department of Medical Cell Biology Uppsala University Uppsala Sweden
| | - Jin‐Ping Li
- Department of Medical Biochemistry and Microbiology Uppsala University Uppsala Sweden
| | - Bryndis Birnir
- Department of Medical Cell Biology Uppsala University Uppsala Sweden
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Sciaccaluga M, Megaro A, Bellomo G, Ruffolo G, Romoli M, Palma E, Costa C. An Unbalanced Synaptic Transmission: Cause or Consequence of the Amyloid Oligomers Neurotoxicity? Int J Mol Sci 2021; 22:ijms22115991. [PMID: 34206089 PMCID: PMC8199544 DOI: 10.3390/ijms22115991] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 05/25/2021] [Accepted: 05/26/2021] [Indexed: 12/18/2022] Open
Abstract
Amyloid-β (Aβ) 1-40 and 1-42 peptides are key mediators of synaptic and cognitive dysfunction in Alzheimer's disease (AD). Whereas in AD, Aβ is found to act as a pro-epileptogenic factor even before plaque formation, amyloid pathology has been detected among patients with epilepsy with increased risk of developing AD. Among Aβ aggregated species, soluble oligomers are suggested to be responsible for most of Aβ's toxic effects. Aβ oligomers exert extracellular and intracellular toxicity through different mechanisms, including interaction with membrane receptors and the formation of ion-permeable channels in cellular membranes. These damages, linked to an unbalance between excitatory and inhibitory neurotransmission, often result in neuronal hyperexcitability and neural circuit dysfunction, which in turn increase Aβ deposition and facilitate neurodegeneration, resulting in an Aβ-driven vicious loop. In this review, we summarize the most representative literature on the effects that oligomeric Aβ induces on synaptic dysfunction and network disorganization.
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Affiliation(s)
- Miriam Sciaccaluga
- Neurology Clinic, Department of Medicine and Surgery, University of Perugia, Santa Maria della Misericordia Hospital, 06132 Perugia, Italy; (A.M.); (G.B.)
- Correspondence: (M.S.); (C.C.); Tel.: +39-0755858180 (M.S.); +39-0755784233 (C.C.)
| | - Alfredo Megaro
- Neurology Clinic, Department of Medicine and Surgery, University of Perugia, Santa Maria della Misericordia Hospital, 06132 Perugia, Italy; (A.M.); (G.B.)
| | - Giovanni Bellomo
- Neurology Clinic, Department of Medicine and Surgery, University of Perugia, Santa Maria della Misericordia Hospital, 06132 Perugia, Italy; (A.M.); (G.B.)
| | - Gabriele Ruffolo
- Department of Physiology and Pharmacology, Istituto Pasteur—Fondazione Cenci Bolognetti, University of Rome Sapienza, 00185 Rome, Italy; (G.R.); (E.P.)
- IRCCS San Raffaele Pisana, 00166 Rome, Italy
| | - Michele Romoli
- Neurology Unit, Rimini “Infermi” Hospital—AUSL Romagna, 47923 Rimini, Italy;
| | - Eleonora Palma
- Department of Physiology and Pharmacology, Istituto Pasteur—Fondazione Cenci Bolognetti, University of Rome Sapienza, 00185 Rome, Italy; (G.R.); (E.P.)
| | - Cinzia Costa
- Neurology Clinic, Department of Medicine and Surgery, University of Perugia, Santa Maria della Misericordia Hospital, 06132 Perugia, Italy; (A.M.); (G.B.)
- Correspondence: (M.S.); (C.C.); Tel.: +39-0755858180 (M.S.); +39-0755784233 (C.C.)
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Walker AS, Raliski BK, Karbasi K, Zhang P, Sanders K, Miller EW. Optical Spike Detection and Connectivity Analysis With a Far-Red Voltage-Sensitive Fluorophore Reveals Changes to Network Connectivity in Development and Disease. Front Neurosci 2021; 15:643859. [PMID: 34054405 PMCID: PMC8155641 DOI: 10.3389/fnins.2021.643859] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 03/10/2021] [Indexed: 12/14/2022] Open
Abstract
The ability to optically record dynamics of neuronal membrane potential promises to revolutionize our understanding of neurobiology. In this study, we show that the far-red voltage sensitive fluorophore, Berkeley Red Sensor of Transmembrane potential-1, or BeRST 1, can be used to monitor neuronal membrane potential changes across dozens of neurons at a sampling rate of 500 Hz. Notably, voltage imaging with BeRST 1 can be implemented with affordable, commercially available illumination sources, optics, and detectors. BeRST 1 is well-tolerated in cultures of rat hippocampal neurons and provides exceptional optical recording fidelity, as judged by dual fluorescence imaging and patch-clamp electrophysiology. We developed a semi-automated spike-picking program to reduce user bias when calling action potentials and used this in conjunction with BeRST 1 to develop an optical spike and connectivity analysis (OSCA) for high-throughput dissection of neuronal activity dynamics. The high temporal resolution of BeRST 1 enables dissection of firing rate changes in response to acute, pharmacological interventions with commonly used inhibitors like gabazine and picrotoxin. Over longer periods of time, BeRST 1 also tracks chronic perturbations to neurons exposed to amyloid beta 1-42 (Aβ 1-42), revealing modest changes to spiking frequency but profound changes to overall network connectivity. Finally, we use OSCA to track changes in neuronal connectivity during maturation in culture, providing a functional readout of network assembly. We envision that use of BeRST 1 and OSCA described here will be of use to the broad neuroscience community.
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Affiliation(s)
- Alison S. Walker
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
- Department of Molecular & Cell Biology, University of California, Berkeley, Berkeley, CA, United States
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States
| | - Benjamin K. Raliski
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
| | - Kaveh Karbasi
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
| | - Patrick Zhang
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
| | - Kate Sanders
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
| | - Evan W. Miller
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
- Department of Molecular & Cell Biology, University of California, Berkeley, Berkeley, CA, United States
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States
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Amyloid-Beta Mediates Homeostatic Synaptic Plasticity. J Neurosci 2021; 41:5157-5172. [PMID: 33926999 PMCID: PMC8211553 DOI: 10.1523/jneurosci.1820-20.2021] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 03/02/2021] [Accepted: 03/28/2021] [Indexed: 12/25/2022] Open
Abstract
The physiological role of the amyloid-precursor protein (APP) is insufficiently understood. Recent work has implicated APP in the regulation of synaptic plasticity. Substantial evidence exists for a role of APP and its secreted ectodomain APPsα in Hebbian plasticity. Here, we addressed the relevance of APP in homeostatic synaptic plasticity using organotypic tissue cultures prepared from APP -/- mice of both sexes. In the absence of APP, dentate granule cells failed to strengthen their excitatory synapses homeostatically. Homeostatic plasticity is rescued by amyloid-β and not by APPsα, and it is neither observed in APP+/+ tissue treated with β- or γ-secretase inhibitors nor in synaptopodin-deficient cultures lacking the Ca2+-dependent molecular machinery of the spine apparatus. Together, these results suggest a role of APP processing via the amyloidogenic pathway in homeostatic synaptic plasticity, representing a function of relevance for brain physiology as well as for brain states associated with increased amyloid-β levels.
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Caspase Activation and Caspase-Mediated Cleavage of APP Is Associated with Amyloid β-Protein-Induced Synapse Loss in Alzheimer's Disease. Cell Rep 2021; 31:107839. [PMID: 32610140 DOI: 10.1016/j.celrep.2020.107839] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 01/29/2020] [Accepted: 06/08/2020] [Indexed: 01/09/2023] Open
Abstract
Amyloid β-protein (Aβ) toxicity is hypothesized to play a seminal role in Alzheimer's disease (AD) pathogenesis. However, it remains unclear how Aβ causes synaptic dysfunction and synapse loss. We hypothesize that one mechanism of Aβ-induced synaptic injury is related to the cleavage of amyloid β precursor protein (APP) at position D664 by caspases that release the putatively cytotoxic C31 peptide. In organotypic slice cultures derived from mice with a knock-in mutation in the APP gene (APP D664A) to inhibit caspase cleavage, Aβ-induced synaptic injury is markedly reduced in two models of Aβ toxicity. Loss of dendritic spines is also attenuated in mice treated with caspase inhibitors. Importantly, the time-dependent dendritic spine loss is correlated with localized activation of caspase-3 but is absent in APP D664A cultures. We propose that the APP cytosolic domain plays an essential role in Aβ-induced synaptic damage in the injury pathway mediated by localized caspase activation.
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William CM, Stern MA, Pei X, Saqran L, Ramani M, Frosch MP, Hyman BT. Impairment of visual cortical plasticity by amyloid-beta species. Neurobiol Dis 2021; 154:105344. [PMID: 33766652 DOI: 10.1016/j.nbd.2021.105344] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 03/06/2021] [Accepted: 03/19/2021] [Indexed: 10/21/2022] Open
Abstract
INTRODUCTION A variety of transgenic and knock-in mice that express mutant alleles of Amyloid precursor protein (APP) have been used to model the effects of amyloid-beta (Aβ) on circuit function in Alzheimer's disease (AD); however phenotypes described in these mice may be affected by expression of mutant APP or proteolytic cleavage products independent of Aβ. In addition, the effects of mutant APP expression are attributed to elevated expression of the amyloidogenic, 42-amino acid-long species of Aβ (Aβ42) associated with amyloid plaque accumulation in AD, though elevated concentrations of Aβ40, an Aβ species produced with normal synaptic activity, may also affect neural function. METHODS To explore the effects of elevated expression of Aβ on synaptic function in vivo, we assessed visual system plasticity in transgenic mice that express and secrete Aβ throughout the brain in the absence of APP overexpression. Transgenic mice that express either Aβ40 or Aβ42 were assayed for their ability to appropriately demonstrate ocular dominance plasticity following monocular deprivation. RESULTS Using two complementary approaches to measure the plastic response to monocular deprivation, we find that male and female mice that express either 40- or 42-amino acid-long Aβ species demonstrate a plasticity defect comparable to that elicited in transgenic mice that express mutant alleles of APP and Presenilin 1 (APP/PS1 mice). CONCLUSIONS These data support the hypothesis that mutant APP-driven plasticity impairment in mouse models of AD is mediated by production and accumulation of Aβ. Moreover, these findings suggest that soluble species of Aβ are capable of modulating synaptic plasticity, likely independent of any aggregation. These findings may have implications for the role of soluble species of Aβ in both development and disease settings.
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Affiliation(s)
- Christopher M William
- New York University Grossman School of Medicine, Department of Pathology, 550 First Avenue, New York, NY 10016, United States.
| | - Matthew A Stern
- MassGeneral Institute for Neurodegenerative Disease, Neurology, Massachusetts General Hospital, 114 16th St., Charlestown, MA 02129, United States.
| | - Xuewei Pei
- New York University Grossman School of Medicine, Department of Pathology, 550 First Avenue, New York, NY 10016, United States
| | - Lubna Saqran
- MassGeneral Institute for Neurodegenerative Disease, Neurology, Massachusetts General Hospital, 114 16th St., Charlestown, MA 02129, United States
| | - Margish Ramani
- New York University Grossman School of Medicine, Department of Pathology, 550 First Avenue, New York, NY 10016, United States.
| | - Matthew P Frosch
- Neuropathology Service, Massachusetts General Hospital, 114 16th St., Charlestown, MA 02129, United States; MassGeneral Institute for Neurodegenerative Disease, Neurology, Massachusetts General Hospital, 114 16th St., Charlestown, MA 02129, United States.
| | - Bradley T Hyman
- MassGeneral Institute for Neurodegenerative Disease, Neurology, Massachusetts General Hospital, 114 16th St., Charlestown, MA 02129, United States.
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Kulenkampff K, Wolf Perez AM, Sormanni P, Habchi J, Vendruscolo M. Quantifying misfolded protein oligomers as drug targets and biomarkers in Alzheimer and Parkinson diseases. Nat Rev Chem 2021; 5:277-294. [PMID: 37117282 DOI: 10.1038/s41570-021-00254-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/15/2021] [Indexed: 02/06/2023]
Abstract
Protein misfolding and aggregation are characteristic of a wide range of neurodegenerative disorders, including Alzheimer and Parkinson diseases. A hallmark of these diseases is the aggregation of otherwise soluble and functional proteins into amyloid aggregates. Although for many decades such amyloid deposits have been thought to be responsible for disease progression, it is now increasingly recognized that the misfolded protein oligomers formed during aggregation are, instead, the main agents causing pathological processes. These oligomers are transient and heterogeneous, which makes it difficult to detect and quantify them, generating confusion about their exact role in disease. The lack of suitable methods to address these challenges has hampered efforts to investigate the molecular mechanisms of oligomer toxicity and to develop oligomer-based diagnostic and therapeutic tools to combat protein misfolding diseases. In this Review, we describe methods to quantify misfolded protein oligomers, with particular emphasis on diagnostic applications as disease biomarkers and on therapeutic applications as target biomarkers. The development of these methods is ongoing, and we discuss the challenges that remain to be addressed to establish measurement tools capable of overcoming existing limitations and to meet present needs.
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48
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Liu X, Wang K, Wei X, Xie T, Lv B, Zhou Q, Wang X. Interaction of NF-κB and Wnt/β-catenin Signaling Pathways in Alzheimer's Disease and Potential Active Drug Treatments. Neurochem Res 2021; 46:711-731. [PMID: 33523396 DOI: 10.1007/s11064-021-03227-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 11/24/2020] [Accepted: 01/02/2021] [Indexed: 12/25/2022]
Abstract
The most important neuropathological features of Alzheimer's disease (AD) are extracellular amyloid-β protein (Aβ) deposition, tau protein hyperphosphorylation and activation of neurometabolic reaction in the brain accompanied by neuronal and synaptic damage, and impaired learning and memory function. According to the amyloid cascade hypothesis, increased Aβ deposits in the brain to form the core of the senile plaques that initiate cascade reactions, affecting the synapses and stimulating activation of microglia, resulting in neuroinflammation. A growing number of studies has shown that NF-κB and Wnt/β-catenin pathways play important roles in neurodegenerative diseases, especially AD. In this review, we briefly introduce the connection between neuroinflammation-mediated synaptic dysfunction in AD and elaborated on the mechanism of these two signaling pathways in AD-related pathological changes, as well as their interaction. Based on our interest in natural compounds, we also briefly introduce and conduct preliminary screening of potential therapeutics for AD.
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Affiliation(s)
- Xiao Liu
- State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, China
| | - Kaiyue Wang
- State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, China
| | - Xing Wei
- State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, China
| | - Tian Xie
- State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, China
| | - Bin Lv
- State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, China
| | - Qian Zhou
- Department of Anatomy, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishiku, Kitakyushu, 807-8555, Japan
| | - Xiaoying Wang
- State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, China. .,College of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, China.
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Di Zhang D, Wang YG, Liu CY, Wang ZH, Wang YF. Aminoguanidine ameliorates ovariectomy-induced neuronal deficits in rats by inhibiting AGE-mediated Aβ production. Acta Neurobiol Exp (Wars) 2021; 81:10-20. [PMID: 33949165 DOI: 10.21307/ane-2021-002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 10/08/2020] [Indexed: 11/11/2022]
Abstract
Advanced glycation end products (AGEs) have been reported to cause neurodegeneration, senile plaque formation and spatial learning and memory deficits. There is much evidence describing the beneficial effects of aminoguanidine (AG) on the central nervous system; AG is able to inhibit the receptor for AGEs and beta-amyloid (Aβ) deposition in the brain, thus preventing cognitive decline and neurodegeneration. In this study, we investigated whether AG protects against ovariectomy-induced neuronal deficits and Aβ deposition in rats. Animals in the ovariectomy group (OVX) group, and those in the OVX+AG group were treated with AG (100 mg/kg/day) for 8 weeks. Learning and memory were evaluated using the electric Y maze. AGE and Aβ1-40 biochemical assessments were performed using enzyme-linked immunosorbent assay (ELISA) kits. Furthermore, evaluations of brain amyloid precursor protein 695 (APP695) mRNA expression by RT-PCR and AGE expression by immunohistochemistry were carried out. Ovariectomized rats exhibited memory impairment and Aβ production disorder with upregulated APP695 mRNA and AGE expression levels. AG pretreatment relieved the ovariectomy-induced learning and memory disorder and significantly ameliorated the Aβ production disturbance and AGE generation. Additionally, pathological changes in morphology were also significantly recovered. Our data reveal that AG plays a potentially neuroprotective role against ovariectomy-induced learning and cognitive impairment and Aβ production disorder. Advanced glycation end products (AGEs) have been reported to cause neurodegeneration, senile plaque formation and spatial learning and memory deficits. There is much evidence describing the beneficial effects of aminoguanidine (AG) on the central nervous system; AG is able to inhibit the receptor for AGEs and beta-amyloid (Aβ) deposition in the brain, thus preventing cognitive decline and neurodegeneration. In this study, we investigated whether AG protects against ovariectomy-induced neuronal deficits and Aβ deposition in rats. Animals in the ovariectomy group (OVX) group, and those in the OVX+AG group were treated with AG (100 mg/kg/day) for 8 weeks. Learning and memory were evaluated using the electric Y maze. AGE and Aβ1-40 biochemical assessments were performed using enzyme-linked immunosorbent assay (ELISA) kits. Furthermore, evaluations of brain amyloid precursor protein 695 (APP695) mRNA expression by RT-PCR and AGE expression by immunohistochemistry were carried out. Ovariectomized rats exhibited memory impairment and Aβ production disorder with upregulated APP695 mRNA and AGE expression levels. AG pretreatment relieved the ovariectomy-induced learning and memory disorder and significantly ameliorated the Aβ production disturbance and AGE generation. Additionally, pathological changes in morphology were also significantly recovered. Our data reveal that AG plays a potentially neuroprotective role against ovariectomy-induced learning and cognitive impairment and Aβ production disorder.
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Affiliation(s)
- Dan Di Zhang
- Department of Geriatric Medicine , Beijing Luhe Hospital Affiliated to Capital Medical University , Beijing , China
| | - Yan Gang Wang
- Department of Gastroenterology , Hebei Provincial Hospital of Traditional Chinese Medicine , Hebei , China
| | - Chun Yan Liu
- Department of Rheumatology , The Third Hospital of Hebei Medical University , Hebei , China
| | - Ze Hou Wang
- Department of Chinese Medicine , Beijing University of Chinese Medicine , Beijing , China
| | - Yue Fen Wang
- Department of Nephropathy , Beijing Hospital of Traditional Chinese Medicine , Capital Medical University , Beijing , China
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Pepperberg DR. Amyloid-β-Dependent Inactivation of the Mitochondrial Electron Transport Chain at Low Transmembrane Potential: An Ameliorating Process in Hypoxia-Associated Neurodegenerative Disease? J Alzheimers Dis 2020; 72:663-675. [PMID: 31640091 DOI: 10.3233/jad-190476] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Cerebral hypoperfusion-induced hypoxia, a condition that impairs oxygen utilization and thus ATP production by mitochondrial oxidative phosphorylation (oxphos), is thought to contribute to neural degeneration in Alzheimer's disease. However, hypoxia upregulates the generation of amyloid-β (Aβ), a group of peptides known to impair/inhibit the electron transport chain (ETC) of reactions that support oxphos in the inner mitochondrial membrane (IMM). This is a hypothesis paper that reconciles the hypoxia-induced upregulation of Aβ with Aβ's ETC-inhibiting action and, specifically, posits an oxphos-enhancing effect of this inhibition under conditions of newly developing or otherwise mild hypoxia. This effect is typically transient; that is, under conditions of prolonged or severe hypoxia, the oxphos-enhancing activity is overwhelmed by Aβ's well-known toxic actions on mitochondria and other cellular components. The hypothesis is motivated by evidence that the IMM transmembrane potential Ψm, an important determinant of ETC activity, exhibits heterogeneity, i.e., a range of values, among a given local population of mitochondria. It specifically proposes that during oxygen limitation, Aβ selectively inactivates ETC complexes in mitochondria that exhibit relatively low absolute values of Ψm, thereby suppressing oxygen binding and consumption by complex IV of the ETC in these mitochondria. This effect of Aβ on low-Ψm mitochondria is hypothesized to spare hypoxia-limited oxygen for oxphos-enabling utilization by the ETC of the remaining active, higher-Ψm local mitochondria, and thereby to increase overall ATP generated collectively by the local mitochondrial population, i.e., to ameliorate hypoxia-induced oxphos reduction. The protective action of Aβ hypothesized here may slow the early development of hypoxia-associated cellular deterioration/loss in Alzheimer's disease and perhaps other neurodegenerative diseases.
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Affiliation(s)
- David R Pepperberg
- Lions of Illinois Eye Research Institute, Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, IL, USA
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