1
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Yang Y, Ondrejcak T, Hu NW, Islam S, O'Rourke E, Reilly RB, Cunningham C, Rowan MJ, Klyubin I. Gamma-patterned sensory stimulation reverses synaptic plasticity deficits in rat models of early Alzheimer's disease. Eur J Neurosci 2023; 58:3402-3411. [PMID: 37655756 DOI: 10.1111/ejn.16129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 06/29/2023] [Accepted: 08/09/2023] [Indexed: 09/02/2023]
Abstract
Non-invasive sensory stimulation in the range of the brain's gamma rhythm (30-100 Hz) is emerging as a new potential therapeutic strategy for the treatment of Alzheimer's disease (AD). Here, we investigated the effect of repeated combined exposure to 40 Hz synchronized sound and light stimuli on hippocampal long-term potentiation (LTP) in vivo in three rat models of early AD. We employed a very complete model of AD amyloidosis, amyloid precursor protein (APP)-overexpressing transgenic McGill-R-Thy1-APP rats at an early pre-plaque stage, systemic treatment of transgenic APP rats with corticosterone modelling certain environmental AD risk factors and, importantly, intracerebral injection of highly disease-relevant AD patient-derived synaptotoxic beta-amyloid and tau in wild-type animals. We found that daily treatment with 40 Hz sensory stimulation for 2 weeks fully abrogated the inhibition of LTP in all three models. Moreover, there was a negative correlation between the magnitude of LTP and the level of active caspase-1 in the hippocampus of transgenic APP animals, which suggests that the beneficial effect of 40 Hz stimulation was dependent on modulation of pro-inflammatory mechanisms. Our findings support ongoing clinical trials of gamma-patterned sensory stimulation in early AD.
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Affiliation(s)
- Yin Yang
- Department of Pharmacology and Therapeutics, Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Tomas Ondrejcak
- Department of Pharmacology and Therapeutics, Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Neng-Wei Hu
- Department of Pharmacology and Therapeutics, Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Sadia Islam
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Eugene O'Rourke
- Department of Electronic and Electrical Engineering, Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Richard B Reilly
- School of Medicine, Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Colm Cunningham
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Michael J Rowan
- Department of Pharmacology and Therapeutics, Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Igor Klyubin
- Department of Pharmacology and Therapeutics, Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
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2
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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3
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Hu Z, Ondrejcak T, Yu P, Zhang Y, Yang Y, Klyubin I, Kennelly SP, Rowan MJ, Hu NW. Do tau-synaptic long-term depression interactions in the hippocampus play a pivotal role in the progression of Alzheimer's disease? Neural Regen Res 2022; 18:1213-1219. [PMID: 36453396 PMCID: PMC9838152 DOI: 10.4103/1673-5374.360166] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Cognitive decline in Alzheimer's disease correlates with the extent of tau pathology, in particular tau hyperphosphorylation that initially appears in the transentorhinal and related regions of the brain including the hippocampus. Recent evidence indicates that tau hyperphosphorylation caused by either amyloid-β or long-term depression, a form of synaptic weakening involved in learning and memory, share similar mechanisms. Studies from our group and others demonstrate that long-term depression-inducing low-frequency stimulation triggers tau phosphorylation at different residues in the hippocampus under different experimental conditions including aging. Conversely, certain forms of long-term depression at hippocampal glutamatergic synapses require endogenous tau, in particular, phosphorylation at residue Ser396. Elucidating the exact mechanisms of interaction between tau and long-term depression may help our understanding of the physiological and pathological functions of tau/tau (hyper)phosphorylation. We first summarize experimental evidence regarding tau-long-term depression interactions, followed by a discussion of possible mechanisms by which this interplay may influence the pathogenesis of Alzheimer's disease. Finally, we conclude with some thoughts and perspectives on future research about these interactions.
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Affiliation(s)
- Zhengtao Hu
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan Province, China,Department of Gerontology, The First Affiliated Hospital of Wannan Medical College, Wuhu, Anhui Province, China
| | - Tomas Ondrejcak
- Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland
| | - Pengpeng Yu
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan Province, China
| | - Yangyang Zhang
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan Province, China
| | - Yin Yang
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan Province, China,Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland
| | - Igor Klyubin
- Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland
| | - Sean P. Kennelly
- Department of Age-Related Healthcare, Tallaght University Hospital, Dublin, Ireland,Department of Medical Gerontology, Trinity College, Dublin, Ireland
| | - Michael J. Rowan
- Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland
| | - Neng-Wei Hu
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan Province, China,Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland,Correspondence to: Neng-Wei Hu, .
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4
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Zhang Y, Yang Y, Hu Z, Zhu M, Qin S, Yu P, Li B, Xu J, Ondrejcak T, Klyubin I, Rowan MJ, Hu NW. Long-Term Depression-Inducing Low Frequency Stimulation Enhances p-Tau181 and p-Tau217 in an Age-Dependent Manner in Live Rats. J Alzheimers Dis 2022; 89:335-350. [PMID: 35871344 PMCID: PMC9484260 DOI: 10.3233/jad-220351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background: Cognitive decline in Alzheimer’s disease (AD) correlates with the extent of tau pathology, in particular tau hyperphosphorylation, which is strongly age-associated. Although elevation of cerebrospinal fluid or blood levels of phosphorylated tau (p-Tau) at residues Thr181 (p-Tau181), Thr217 (p-Tau217), and Thr231 (p-Tau231) are proposed to be particularly sensitive markers of preclinical AD, the generation of p-Tau during brain activity is poorly understood. Objective: To study whether the expression levels of p-Tau181, p-Tau217, and p-Tau231 can be enhanced by physiological synaptic long-term depression (LTD) which has been linked to the enhancement of p-Tau in hippocampus. Methods: In vivo electrophysiology was performed in urethane anesthetized young adult and aged male rats. Low frequency electrical stimulation (LFS) was used to induce LTD at CA3 to CA1 synapses. The expression level of p-Tau and total tau was measured in dorsal hippocampus using immunofluorescent staining and/or western blotting. Results: We found that LFS enhanced p-Tau181 and p-Tau217 in an age-dependent manner in the hippocampus of live rats. In contrast, phosphorylation at residues Thr231, Ser202/Thr205, and Ser396 appeared less sensitive to LFS. Pharmacological antagonism of either N-methyl-D-aspartate or metabotropic glutamate 5 receptors inhibited the elevation of both p-Tau181 and p-Tau217. Targeting the integrated stress response, which increases with aging, using a small molecule inhibitor ISRIB, prevented the enhancement of p-Tau by LFS in aged rats. Conclusion: Together, our data provide a novel in vivo means to uncover brain plasticity-related cellular and molecular processes of tau phosphorylation at key sites in health and aging.
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Affiliation(s)
- Yangyang Zhang
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Yin Yang
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Zhengtao Hu
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
- Department of Gerontology, The First Affiliated Hospital of Wannan Medical College, Wuhu, China
| | - Manyi Zhu
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Shuangying Qin
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Pengpeng Yu
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
- Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland
| | - Bo Li
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Jitian Xu
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Tomas Ondrejcak
- Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland
| | - Igor Klyubin
- Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland
| | - Michael J. Rowan
- Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland
| | - Neng-Wei Hu
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
- Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland
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5
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Sosulina L, Mittag M, Geis HR, Hoffmann K, Klyubin I, Qi Y, Steffen J, Friedrichs D, Henneberg N, Fuhrmann F, Justus D, Keppler K, Cuello AC, Rowan MJ, Fuhrmann M, Remy S. Hippocampal hyperactivity in a rat model of Alzheimer's disease. J Neurochem 2021; 157:2128-2144. [PMID: 33583024 DOI: 10.1111/jnc.15323] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 01/19/2021] [Accepted: 01/31/2021] [Indexed: 12/21/2022]
Abstract
Neuronal network dysfunction is a hallmark of Alzheimer's disease (AD). However, the underlying pathomechanisms remain unknown. We analyzed the hippocampal micronetwork in transgenic McGill-R-Thy1-APP rats (APPtg) at the beginning of extracellular amyloid beta (Aβ) deposition. We established two-photon Ca2+ -imaging in vivo in the hippocampus of rats and found hyperactivity of CA1 neurons. Patch-clamp recordings in brain slices in vitro revealed increased neuronal input resistance and prolonged action potential width in CA1 pyramidal neurons. We did neither observe changes in synaptic inhibition, nor in excitation. Our data support the view that increased intrinsic excitability of CA1 neurons may precede inhibitory dysfunction at an early stage of Aβ-deposition and disease progression.
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Affiliation(s)
- Liudmila Sosulina
- Neuronal Networks Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Department of Cellular Neuroscience, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Manuel Mittag
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Hans-Rüdiger Geis
- Neuronal Networks Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Kerstin Hoffmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Igor Klyubin
- Department of Pharmacology and Therapeutics, Trinity College, Dublin, Ireland
| | - Yingjie Qi
- Department of Pharmacology and Therapeutics, Trinity College, Dublin, Ireland
| | - Julia Steffen
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Detlef Friedrichs
- Neuronal Networks Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Niklas Henneberg
- Neuronal Networks Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Falko Fuhrmann
- Neuronal Networks Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Daniel Justus
- Neuronal Networks Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Kevin Keppler
- Light Microscopy Facility, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - A Claudio Cuello
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada
| | - Michael J Rowan
- Department of Pharmacology and Therapeutics, Trinity College, Dublin, Ireland
| | - Martin Fuhrmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Stefan Remy
- Neuronal Networks Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Department of Cellular Neuroscience, Leibniz Institute for Neurobiology, Magdeburg, Germany
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6
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Madden PW, Klyubin I, Ahearne MJ. Silk fibroin safety in the eye: a review that highlights a concern. BMJ Open Ophthalmol 2020; 5:e000510. [PMID: 33024827 PMCID: PMC7513638 DOI: 10.1136/bmjophth-2020-000510] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 07/15/2020] [Accepted: 08/07/2020] [Indexed: 12/25/2022] Open
Abstract
The biomedical use of silk as a suture dates back to antiquity. Fibroin is the structural element that determines the strength of silk and here we consider the safety of fibroin in its role in ophthalmology. The high mechanical strength of silk meant sufficiently thin threads could be made for eye microsurgery, but such usage was all but superseded by synthetic polymer sutures, primarily because silk in its entirety was more inflammatory. Significant immunological response can normally be avoided by careful manufacturing to provide high purity fibroin, and it has been utilised in this form for tissue engineering an array of fibre and film substrata deployed in research with cells of the eye. Films of fibroin can also be made transparent, which is a required property in the visual pathway. Transparent layers of corneal epithelial, stromal and endothelial cells have all been demonstrated with maintenance of phenotype, as have constructs supporting retinal cells. Fibroin has a lack of demonstrable infectious agent transfer, an ability to be sterilised and prepared with minimal contamination, long-term predictable degradation and low direct cytotoxicity. However, there remains a known ability to be involved in amyloid formation and potential amyloidosis which, without further examination, is enough to currently question whether fibroin should be employed in the eye given its innervation into the brain.
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Affiliation(s)
- Peter W Madden
- Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, the University of Dublin, Dublin, Ireland
- Department of Mechanical, Manufacturing and Biomedical Engineering, School of Engineering, Trinity College Dublin, the University of Dublin, Dublin, Ireland
| | - Igor Klyubin
- Department of Pharmacology Therapeutics, School of Medicine, Trinity College Dublin, the University of Dublin, Dublin, Ireland
- Institute of Neuroscience, Trinity College Dublin, the University of Dublin, Dublin, Ireland
| | - Mark J Ahearne
- Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, the University of Dublin, Dublin, Ireland
- Department of Mechanical, Manufacturing and Biomedical Engineering, School of Engineering, Trinity College Dublin, the University of Dublin, Dublin, Ireland
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7
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Qi Y, Klyubin I, Hu NW, Ondrejcak T, Rowan MJ. Pre-plaque Aß-Mediated Impairment of Synaptic Depotentiation in a Transgenic Rat Model of Alzheimer's Disease Amyloidosis. Front Neurosci 2019; 13:861. [PMID: 31474823 PMCID: PMC6702302 DOI: 10.3389/fnins.2019.00861] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 07/31/2019] [Indexed: 11/13/2022] Open
Abstract
How endogenously produced soluble amyloid ß-protein (Aß) affects synaptic plasticity in vulnerable circuits should provide insight into early Alzheimer's disease pathophysiology. McGill-R-Thy1-APP transgenic rats, modeling Alzheimer's disease amyloidosis, exhibit an age-dependent soluble Aß-mediated impairment of the induction of long-term potentiation (LTP) by 200 Hz conditioning stimulation at apical CA3-to-CA1 synapses. Here, we investigated if synaptic weakening at these synapses in the form of activity-dependent persistent reversal (depotentiation) of LTP is also altered in pre-plaque rats in vivo. In freely behaving transgenic rats strong, 400 Hz, conditioning stimulation induced stable LTP that was NMDA receptor- and voltage-gated Ca2+ channel-dependent. Surprisingly, the ability of novelty exploration to induce depotentiation of 400 Hz-induced LTP was impaired in an Aß-dependent manner in the freely behaving transgenic rats. Moreover, at apical synapses, low frequency conditioning stimulation (1 Hz) did not trigger depotentiation in anaesthetized transgenic rats, with an age-dependence similar to the LTP deficit. In contrast, at basal synapses neither LTP, induced by 100 or 200 Hz, nor novelty exploration-induced depotentiation was impaired in the freely behaving transgenic rats. These findings indicate that activity-dependent weakening, as well as strengthening, is impaired in a synapse- and age-dependent manner in this model of early Alzheimer's disease amyloidosis.
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Affiliation(s)
- Yingjie Qi
- Department of Pharmacology & Therapeutics, Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
| | - Igor Klyubin
- Department of Pharmacology & Therapeutics, Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
| | - Neng-Wei Hu
- Department of Pharmacology & Therapeutics, Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland.,Department of Physiology and Neurobiology, Zhengzhou University School of Medicine, Zhengzhou, China
| | - Tomas Ondrejcak
- Department of Pharmacology & Therapeutics, Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
| | - Michael J Rowan
- Department of Pharmacology & Therapeutics, Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
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8
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Ondrejcak T, Hu NW, Qi Y, Klyubin I, Corbett GT, Fraser G, Perkinton MS, Walsh DM, Billinton A, Rowan MJ. Soluble tau aggregates inhibit synaptic long-term depression and amyloid β-facilitated LTD in vivo. Neurobiol Dis 2019; 127:582-590. [PMID: 30910746 DOI: 10.1016/j.nbd.2019.03.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 03/01/2019] [Accepted: 03/21/2019] [Indexed: 01/29/2023] Open
Abstract
Soluble synaptotoxic aggregates of the main pathological proteins of Alzheimer's disease, amyloid β-protein (Aß) and tau, have rapid and potent inhibitory effects on long-term potentiation (LTP). Although the promotion of synaptic weakening mechanisms, including long-term depression (LTD), is posited to mediate LTP inhibition by Aß, little is known regarding the action of exogenous tau on LTD. The present study examined the ability of different assemblies of full-length human tau to affect LTD in the dorsal hippocampus of the anaesthetized rat. Unlike Aß, intracerebroventricular injection of soluble aggregates of tau (SτAs), but not monomers or fibrils, potently increased the threshold for LTD induction in a manner that required cellular prion protein. However, MTEP, an antagonist of the putative prion protein coreceptor metabotropic glutamate receptor 5, did not prevent the disruption of synaptic plasticity by SτAs. In contrast, systemic treatment with Ro 25-6981, a selective antagonist at GluN2B subunit-containing NMDA receptors, reduced SτA-mediated inhibition of LTD, but not LTP. Intriguingly, SτAs completely blocked Aß-facilitated LTD, whereas a subthreshold dose of SτAs facilitated Aß-mediated inhibition of LTP. Overall, these findings support the importance of cellular prion protein in mediating a range of, sometimes opposing, actions of soluble Aß and tau aggregates with different effector mechanisms on synaptic plasticity.
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Affiliation(s)
- Tomas Ondrejcak
- Department of Pharmacology & Therapeutics, Institute of Neuroscience, Trinity College, Dublin 2, Ireland.
| | - Neng-Wei Hu
- Department of Pharmacology & Therapeutics, Institute of Neuroscience, Trinity College, Dublin 2, Ireland; Department of Physiology and Neurobiology, Zhengzhou University School of Medicine, Zhengzhou 450001, China
| | - Yingjie Qi
- Department of Pharmacology & Therapeutics, Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Igor Klyubin
- Department of Pharmacology & Therapeutics, Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Grant T Corbett
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham & Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Graham Fraser
- Neuroscience, IMED Biotech Unit, AstraZeneca, Cambridge CB21 6GH, UK
| | | | - Dominic M Walsh
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham & Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Andrew Billinton
- Neuroscience, IMED Biotech Unit, AstraZeneca, Cambridge CB21 6GH, UK
| | - Michael J Rowan
- Department of Pharmacology & Therapeutics, Institute of Neuroscience, Trinity College, Dublin 2, Ireland.
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9
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Hu NW, Corbett GT, Moore S, Klyubin I, O'Malley TT, Walsh DM, Livesey FJ, Rowan MJ. Extracellular Forms of Aβ and Tau from iPSC Models of Alzheimer's Disease Disrupt Synaptic Plasticity. Cell Rep 2018; 23:1932-1938. [PMID: 29768194 PMCID: PMC5972225 DOI: 10.1016/j.celrep.2018.04.040] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 02/28/2018] [Accepted: 04/06/2018] [Indexed: 11/18/2022] Open
Abstract
The early stages of Alzheimer's disease are associated with synaptic dysfunction prior to overt loss of neurons. To identify extracellular molecules that impair synaptic plasticity in the brain, we studied the secretomes of human iPSC-derived neuronal models of Alzheimer's disease. When introduced into the rat brain, secretomes from human neurons with either a presenilin-1 mutation, amyloid precursor protein duplication, or trisomy of chromosome 21 all strongly inhibit hippocampal long-term potentiation. Synaptic dysfunction caused by presenilin-1 mutant and amyloid precusor protein duplication secretomes is mediated by Aβ peptides, whereas trisomy of chromosome 21 (trisomy 21) neuronal secretomes induce dysfunction through extracellular tau. In all cases, synaptotoxicity is relieved by antibody blockade of cellular prion protein. These data indicate that human models of Alzheimer's disease generate distinct proteins that converge at the level of cellular prion protein to induce synaptic dysfunction in vivo.
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Affiliation(s)
- Neng-Wei Hu
- Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin 2, Ireland; Department of Physiology and Neurobiology, Zhengzhou University School of Medicine, Zhengzhou 450001, China
| | - Grant T Corbett
- Ann Romney Center for Neurologic Diseases, Brigham & Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Steven Moore
- Gurdon Institute and ARUK Stem Cell Research Centre, University of Cambridge, Cambridge CB2 1QN, UK
| | - Igor Klyubin
- Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Tiernan T O'Malley
- Ann Romney Center for Neurologic Diseases, Brigham & Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Dominic M Walsh
- Ann Romney Center for Neurologic Diseases, Brigham & Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
| | - Frederick J Livesey
- Gurdon Institute and ARUK Stem Cell Research Centre, University of Cambridge, Cambridge CB2 1QN, UK.
| | - Michael J Rowan
- Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin 2, Ireland.
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10
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Qi Y, Klyubin I, Cuello AC, Rowan MJ. NLRP3-dependent synaptic plasticity deficit in an Alzheimer's disease amyloidosis model in vivo. Neurobiol Dis 2018; 114:24-30. [PMID: 29477641 DOI: 10.1016/j.nbd.2018.02.016] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 01/24/2018] [Accepted: 02/21/2018] [Indexed: 01/12/2023] Open
Abstract
Pro-inflammatory mechanisms have recently emerged as an important component of early Alzheimer's disease (AD) pathogenesis. A particularly attractive therapeutic strategy is to selectively prevent the disruptive effects of activation of the innate immune system in the brain at an early transitional stage by reducing the production or directly neutralizing pro-inflammatory cytokines, in particular IL-1β and TNF-α. Here we tested their in vivo effects on synaptic plasticity deficits, which provide sensitive and robust measures of synaptic failure, in a rat model of AD amyloidosis. Using electrophysiological techniques we longitudinally studied the effects of the NLRP3 inflammasome inhibitor Mcc950, the IL-1 receptor antagonist (anakinra) and an anti-TNF-α agent (etanercept) in awake freely moving transgenic rats overexpressing AD associated β-amyloid precursor protein at a pre-plaque stage of amyloidosis. Repeated treatment with Mcc950 reversibly abrogated the inhibition of long-term potentiation. The IL-1 receptor antagonist and etanercept also had a similar beneficial effect on the deficit in synaptic plasticity. Our findings support the clinical development of Mcc950 and clinically available IL-1- and TNF-α-neutralizing agents in early AD.
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Affiliation(s)
- Yingjie Qi
- Department of Pharmacology and Therapeutics, Watts Building, Trinity College Dublin, Dublin 2, Ireland; Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
| | - Igor Klyubin
- Department of Pharmacology and Therapeutics, Watts Building, Trinity College Dublin, Dublin 2, Ireland; Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland.
| | - A Claudio Cuello
- Department of Pharmacology and Therapeutics, McGill University, 3655 Sir-William-Osler Promenade, Room 1210, Montreal, QC H3G1Y6, Canada; Department of Anatomy and Cell Biology, McGill University, Montreal H3G1Y6, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal H3G1Y6, Canada
| | - Michael J Rowan
- Department of Pharmacology and Therapeutics, Watts Building, Trinity College Dublin, Dublin 2, Ireland; Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland.
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11
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Klyubin I, Qi Y, Cuello AC, Rowan MJ. [P1–111]: IMPAIRED REVERSAL OF HIPPOCAMPAL LONG‐TERM POTENTIATION IN APP‐OVEREXPRESSING RATS
IN VIVO. Alzheimers Dement 2017. [DOI: 10.1016/j.jalz.2017.06.178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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12
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Zhang D, Qi Y, Klyubin I, Ondrejcak T, Sarell CJ, Cuello AC, Collinge J, Rowan MJ. Targeting glutamatergic and cellular prion protein mechanisms of amyloid β-mediated persistent synaptic plasticity disruption: Longitudinal studies. Neuropharmacology 2017; 121:231-246. [PMID: 28390893 DOI: 10.1016/j.neuropharm.2017.03.036] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 03/08/2017] [Accepted: 03/30/2017] [Indexed: 01/09/2023]
Abstract
Alzheimer's disease amyloid-β (Aβ) oligomers are synaptotoxic, inappropriately increasing extracellular glutamate concentration and glutamate receptor activation to thereby rapidly disrupt synaptic plasticity. Thus, acutely promoting brain glutamate homeostasis with a blood-based scavenging system, glutamate-oxaloacetate transaminase (GOT), and blocking metabotropic glutamate 5 (mGlu5) receptor or its co-receptor cellular prion protein (PrP), prevent the acute inhibition of long-term potentiation (LTP) by exogenous Aβ. Here, we evaluated the time course of the effects of such interventions in the persistent disruptive effects of Aβ oligomers, either exogenously injected in wild type rats or endogenously generated in transgenic rats that model Alzheimer's disease amyloidosis. We report that repeated, but not acute, systemic administration of recombinant GOT type 1, with or without the glutamate co-substrate oxaloacetate, reversed the persistent deleterious effect of exogenous Aβ on synaptic plasticity. Moreover, similar repetitive treatment reversibly abrogated the inhibition of LTP monitored longitudinally in freely behaving transgenic rats. Remarkably, brief repeated treatment with an mGlu5 receptor antagonist, basimglurant, or an antibody that prevents Aβ oligomer binding to PrP, ICSM35, also had similar reversible ameliorative effects in the transgenic rat model. Overall, the present findings support the ongoing development of therapeutics for early Alzheimer's disease based on these complementary approaches.
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Affiliation(s)
- Dainan Zhang
- Department of Pharmacology & Therapeutics, and Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland; Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China; Center for Neurological Diseases (NCRC-ND), Beijing, China
| | - Yingjie Qi
- Department of Pharmacology & Therapeutics, and Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland.
| | - Igor Klyubin
- Department of Pharmacology & Therapeutics, and Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Tomas Ondrejcak
- Department of Pharmacology & Therapeutics, and Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Claire J Sarell
- MRC Prion Unit, Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - A Claudio Cuello
- Department of Pharmacology and Therapeutics, Department of Neurology and Neurosurgery, Department of Anatomy and Cell Biology, McGill University, Montreal, Canada
| | - John Collinge
- MRC Prion Unit, Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Michael J Rowan
- Department of Pharmacology & Therapeutics, and Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland.
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13
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Harte NP, Klyubin I, McCarthy EK, Min S, Garrahy SA, Xie Y, Davey GP, Boland JJ, Rowan MJ, Mok KH. Amyloid Oligomers and Mature Fibrils Prepared from an Innocuous Protein Cause Diverging Cellular Death Mechanisms. J Biol Chem 2015. [PMID: 26221033 DOI: 10.1074/jbc.m115.676072] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Despite significant advances, the molecular identity of the cytotoxic species populated during in vivo amyloid formation crucial for the understanding of neurodegenerative disorders is yet to be revealed. In this study lysozyme prefibrillar oligomers and fibrils in both mature and sonicated states have been isolated through an optimized ultrafiltration/ultracentrifugation method and characterized with various optical spectroscopic techniques, atomic force microscopy, and transmission electron microscopy. We examined their level and mode of toxicity on rat pheochromocytoma (PC12) cells in both differentiated and undifferentiated states. We find that oligomers and fibrils display cytotoxic capabilities toward cultured cells in vitro, with oligomers producing elevated levels of cellular injury toward undifferentiated PC12 cells (PC12(undiff)). Furthermore, dual flow cytometry staining experiments demonstrate that the oligomers and mature fibrils induce divergent cellular death pathways (apoptosis and secondary necrosis, respectively) in these PC12 cells. We have also shown that oligomers but not sonicated mature fibrils inhibit hippocampal long term potentiation, a form of synaptic plasticity implicated in learning and memory, in vivo. We conclude that our in vitro and in vivo findings confer a level of resistance toward amyloid fibrils, and that the PC 12-based comparative cytotoxicity assay can provide insights into toxicity differences between differently aggregated protein species.
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Affiliation(s)
- Níal P Harte
- Trinity Biomedical Sciences Institute (TBSI), School of Biochemistry and Immunology, Trinity College Dublin, the University of Dublin, Dublin 2, Ireland
| | - Igor Klyubin
- Department of Pharmacology and Therapeutics, Trinity College Institute of Neuroscience (TCIN), Trinity College Dublin, the University of Dublin, Dublin 2, Ireland
| | - Eoin K McCarthy
- School of Chemistry, Trinity College Dublin, the University of Dublin, Dublin 2, Ireland; Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, the University of Dublin, Dublin 2, Ireland
| | - Soyoung Min
- Trinity Biomedical Sciences Institute (TBSI), School of Biochemistry and Immunology, Trinity College Dublin, the University of Dublin, Dublin 2, Ireland
| | - Sarah Ann Garrahy
- TCIN, Trinity College Dublin, the University of Dublin, Dublin 2, Ireland
| | - Yongjing Xie
- Trinity Biomedical Sciences Institute (TBSI), School of Biochemistry and Immunology, Trinity College Dublin, the University of Dublin, Dublin 2, Ireland
| | - Gavin P Davey
- Trinity Biomedical Sciences Institute (TBSI), School of Biochemistry and Immunology, Trinity College Dublin, the University of Dublin, Dublin 2, Ireland; TCIN, Trinity College Dublin, the University of Dublin, Dublin 2, Ireland
| | - John J Boland
- School of Chemistry, Trinity College Dublin, the University of Dublin, Dublin 2, Ireland; Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, the University of Dublin, Dublin 2, Ireland
| | - Michael J Rowan
- Department of Pharmacology and Therapeutics, Trinity College Institute of Neuroscience (TCIN), Trinity College Dublin, the University of Dublin, Dublin 2, Ireland
| | - K Hun Mok
- Trinity Biomedical Sciences Institute (TBSI), School of Biochemistry and Immunology, Trinity College Dublin, the University of Dublin, Dublin 2, Ireland; Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, the University of Dublin, Dublin 2, Ireland.
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14
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Qi Y, Klyubin I, Harney SC, Hu N, Cullen WK, Grant MK, Steffen J, Wilson EN, Do Carmo S, Remy S, Fuhrmann M, Ashe KH, Cuello AC, Rowan MJ. Longitudinal testing of hippocampal plasticity reveals the onset and maintenance of endogenous human Aß-induced synaptic dysfunction in individual freely behaving pre-plaque transgenic rats: rapid reversal by anti-Aß agents. Acta Neuropathol Commun 2014; 2:175. [PMID: 25540024 PMCID: PMC4293804 DOI: 10.1186/s40478-014-0175-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Accepted: 12/04/2014] [Indexed: 11/26/2022] Open
Abstract
Long before synaptic loss occurs in Alzheimer’s disease significant harbingers of disease may be detected at the functional level. Here we examined if synaptic long-term potentiation is selectively disrupted prior to extracellular deposition of Aß in a very complete model of Alzheimer’s disease amyloidosis, the McGill-R-Thy1-APP transgenic rat. Longitudinal studies in freely behaving animals revealed an age-dependent, relatively rapid-onset and persistent inhibition of long-term potentiation without a change in baseline synaptic transmission in the CA1 area of the hippocampus. Thus the ability of a standard 200 Hz conditioning protocol to induce significant NMDA receptor-dependent short- and long-term potentiation was lost at about 3.5 months of age and this deficit persisted for at least another 2–3 months, when plaques start to appear. Consistent with in vitro evidence for a causal role of a selective reduction in NMDA receptor-mediated synaptic currents, the deficit in synaptic plasticity in vivo was associated with a reduction in the synaptic burst response to the conditioning stimulation and was overcome using stronger 400 Hz stimulation. Moreover, intracerebroventricular treatment for 3 days with an N-terminally directed monoclonal anti- human Aß antibody, McSA1, transiently reversed the impairment of synaptic plasticity. Similar brief treatment with the BACE1 inhibitor LY2886721 or the γ-secretase inhibitor MRK-560 was found to have a comparable short-lived ameliorative effect when tracked in individual rats. These findings provide strong evidence that endogenously generated human Aß selectively disrupts the induction of long-term potentiation in a manner that enables potential therapeutic options to be assessed longitudinally at the pre-plaque stage of Alzheimer’s disease amyloidosis.
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15
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Welzel AT, Maggio JE, Shankar GM, Walker DE, Ostaszewski BL, Li S, Klyubin I, Rowan MJ, Seubert P, Walsh DM, Selkoe DJ. Secreted amyloid β-proteins in a cell culture model include N-terminally extended peptides that impair synaptic plasticity. Biochemistry 2014; 53:3908-21. [PMID: 24840308 PMCID: PMC4070750 DOI: 10.1021/bi5003053] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
![]()
Evidence
for a central role of amyloid β-protein (Aβ) in the genesis
of Alzheimer’s disease (AD) has led to
advanced human trials of Aβ-lowering agents. The “amyloid
hypothesis” of AD postulates deleterious effects of small,
soluble forms of Aβ on synaptic form and function. Because selectively
targeting synaptotoxic forms of soluble Aβ could be therapeutically
advantageous, it is important to understand the full range of soluble
Aβ derivatives. We previously described a Chinese hamster ovary (CHO) cell line (7PA2 cells) that stably expresses mutant human amyloid precursor protein (APP). Here, we extend this work by purifying an sodium dodecyl sulfate
(SDS)-stable, ∼8 kDa Aβ species
from the 7PA2 medium. Mass spectrometry confirmed its identity as
a noncovalently bonded Aβ40 homodimer that impaired hippocampal
long-term potentiation (LTP) in vivo. We further report the detection
of Aβ-containing fragments of APP in the 7PA2 medium that extend
N-terminal from Asp1 of Aβ. These N-terminally extended Aβ-containing
monomeric fragments are distinct from soluble Aβ oligomers formed
from Aβ1-40/42 monomers and are bioactive synaptotoxins secreted
by 7PA2 cells. Importantly, decreasing β-secretase processing
of APP elevated these alternative synaptotoxic APP fragments. We conclude
that certain synaptotoxic Aβ-containing species can arise from
APP processing events N-terminal to the classical β-secretase
cleavage site.
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16
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Klyubin I, Ondrejcak T, Hayes J, Cullen WK, Mably AJ, Walsh DM, Rowan MJ. Neurotransmitter receptor and time dependence of the synaptic plasticity disrupting actions of Alzheimer's disease Aβ in vivo. Philos Trans R Soc Lond B Biol Sci 2014; 369:20130147. [PMID: 24298149 PMCID: PMC3843879 DOI: 10.1098/rstb.2013.0147] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Many endogenous factors influence the time course and extent of the detrimental effects of amyloid β-protein (Aβ) on synaptic function. Here, we assessed the impact of varying endogenous glutamatergic and cholinergic transmission by pharmacological means on the disruption of plasticity at hippocampal CA3-to-CA1 synapses in the anaesthetized rat. NMDA receptors (NMDARs) are considered critical in mediating Aβ-induced inhibition of long-term potentiation (LTP). However, intracerebroventricular injection of Aβ1-42 inhibited not only NMDAR-dependent LTP but also voltage-activated Ca(2+)-dependent LTP induced by strong conditioning stimulation during NMDAR blockade. On the other hand, another form of NMDAR-independent synaptic plasticity, endogenous acetylcholine-induced muscarinic receptor-dependent long-term enhancement, was not hindered by Aβ1-42. Interestingly, augmenting endogenous acetylcholine activation of nicotinic receptors prior to the injection of Aβ1-42 prevented the inhibition of NMDAR-dependent LTP, whereas the same intervention when introduced after the infusion of Aβ was ineffective. We also examined the duration of action of Aβ, including water soluble Aβ from Alzheimer's disease (AD) brain. Remarkably, the inhibition of LTP induction caused by a single injection of sodium dodecyl sulfate-stable Aβ dimer-containing AD brain extract persisted for at least a week. These findings highlight the need to increase our understanding of non-NMDAR mechanisms and of developing novel means of overcoming, rather than just preventing, the deleterious synaptic actions of Aβ.
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Affiliation(s)
- Igor Klyubin
- Department of Pharmacology and Therapeutics, Institute of Neuroscience, Trinity College, Biotechnology Building, Dublin 2, Republic ofIreland
| | - Tomas Ondrejcak
- Department of Pharmacology and Therapeutics, Institute of Neuroscience, Trinity College, Biotechnology Building, Dublin 2, Republic ofIreland
| | - Jennifer Hayes
- Department of Pharmacology and Therapeutics, Institute of Neuroscience, Trinity College, Biotechnology Building, Dublin 2, Republic ofIreland
| | - William K. Cullen
- Department of Pharmacology and Therapeutics, Institute of Neuroscience, Trinity College, Biotechnology Building, Dublin 2, Republic ofIreland
| | - Alexandra J. Mably
- Laboratory for Neurodegenerative Research, Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Institute of Medicine, 77-Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Dominic M. Walsh
- Laboratory for Neurodegenerative Research, Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Institute of Medicine, 77-Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Michael J. Rowan
- Department of Pharmacology and Therapeutics, Institute of Neuroscience, Trinity College, Biotechnology Building, Dublin 2, Republic ofIreland
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17
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An K, Klyubin I, Kim Y, Jung JH, Mably AJ, O'Dowd ST, Lynch T, Kanmert D, Lemere CA, Finan GM, Park JW, Kim TW, Walsh DM, Rowan MJ, Kim JH. Exosomes neutralize synaptic-plasticity-disrupting activity of Aβ assemblies in vivo. Mol Brain 2013; 6:47. [PMID: 24284042 PMCID: PMC4222117 DOI: 10.1186/1756-6606-6-47] [Citation(s) in RCA: 130] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 10/31/2013] [Indexed: 12/28/2022] Open
Abstract
Background Exosomes, small extracellular vesicles of endosomal origin, have been suggested to be involved in both the metabolism and aggregation of Alzheimer’s disease (AD)-associated amyloid β-protein (Aβ). Despite their ubiquitous presence and the inclusion of components which can potentially interact with Aβ, the role of exosomes in regulating synaptic dysfunction induced by Aβ has not been explored. Results We here provide in vivo evidence that exosomes derived from N2a cells or human cerebrospinal fluid can abrogate the synaptic-plasticity-disrupting activity of both synthetic and AD brain-derived Aβ. Mechanistically, this effect involves sequestration of synaptotoxic Aβ assemblies by exosomal surface proteins such as PrPC rather than Aβ proteolysis. Conclusions These data suggest that exosomes can counteract the inhibitory action of Aβ, which contributes to perpetual capability for synaptic plasticity.
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Affiliation(s)
- Kyongman An
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, Gyungbuk 790-784, Korea.
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18
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O'Nuallain B, Klyubin I, Mc Donald JM, Foster JS, Welzel A, Barry A, Dykoski RK, Cleary JP, Gebbink MF, Rowan MJ, Walsh DM. A monoclonal antibody against synthetic Aβ dimer assemblies neutralizes brain-derived synaptic plasticity-disrupting Aβ. J Neurochem 2011; 119:189-201. [PMID: 21781116 PMCID: PMC3174526 DOI: 10.1111/j.1471-4159.2011.07389.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Diverse lines of evidence indicate that pre-fibrillar, diffusible assemblies of the amyloid β-protein (Aβ) play an important role in Alzheimer's disease pathogenesis. Although the precise molecular identity of these soluble toxins remains unsettled, recent experiments suggest that sodium dodecyl sulfate (SDS)-stable Aβ dimers may be the basic building blocks of Alzheimer's disease-associated synaptotoxic assemblies and as such present an attractive target for therapeutic intervention. In the absence of sufficient amounts of highly pure cerebral Aβ dimers, we have used synthetic disulfide cross-linked dimers (free of Aβ monomer or fibrils) to generate conformation-specific monoclonal antibodies. These dimers aggregate to form kinetically trapped protofibrils, but do not readily form fibrils. We identified two antibodies, 3C6 and 4B5, which preferentially bind assemblies formed from covalent Aβ dimers, but do not bind to Aβ monomer, amyloid precursor protein, or aggregates formed by other amyloidogenic proteins. Monoclonal antibody 3C6, but not an IgM isotype-matched control antibody, ameliorated the plasticity-disrupting effects of Aβ extracted from the aqueous phase of Alzheimer's disease brain, thus suggesting that 3C6 targets pathogenically relevant Aβ assemblies. These data prove the usefulness of covalent dimers and their assemblies as immunogens and recommend further investigation of the therapeutic and diagnostic utility of monoclonal antibodies raised to such assemblies.
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Affiliation(s)
- Brian O'Nuallain
- Laboratory for Neurodegenerative Research, Conway Institute, University College Dublin, Belfield, Dublin 4
| | - Igor Klyubin
- Trinity College Institute of Neuroscience and Department of Pharmacology and Therapeutics, Trinity College, Dublin 2, Republic of Ireland
| | - Jessica M. Mc Donald
- Laboratory for Neurodegenerative Research, Conway Institute, University College Dublin, Belfield, Dublin 4
| | - James S. Foster
- Human Immunology and Cancer Program, University of Tennessee Graduate School of Medicine, Knoxville, Tennessee 37920
| | - Alfred Welzel
- Laboratory for Neurodegenerative Research, Conway Institute, University College Dublin, Belfield, Dublin 4
| | - Andrew Barry
- Trinity College Institute of Neuroscience and Department of Pharmacology and Therapeutics, Trinity College, Dublin 2, Republic of Ireland
| | - Richard K. Dykoski
- Pathology and GRECC, Minneapolis VA Health Care System, Minneapolis, MN 55417, USA
| | - James P. Cleary
- Pathology and GRECC, Minneapolis VA Health Care System, Minneapolis, MN 55417, USA
| | - Martijn F.B.G. Gebbink
- Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Michael J. Rowan
- Trinity College Institute of Neuroscience and Department of Pharmacology and Therapeutics, Trinity College, Dublin 2, Republic of Ireland
| | - Dominic M. Walsh
- Laboratory for Neurodegenerative Research, Conway Institute, University College Dublin, Belfield, Dublin 4
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19
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Barry AE, Klyubin I, Mc Donald JM, Mably AJ, Farrell MA, Scott M, Walsh DM, Rowan MJ. Alzheimer's disease brain-derived amyloid-β-mediated inhibition of LTP in vivo is prevented by immunotargeting cellular prion protein. J Neurosci 2011; 31:7259-7263. [PMID: 21593310 DOI: 10.1523/jneurosci.6500-10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023] Open
Abstract
Synthetic amyloid-β protein (Aβ) oligomers bind with high affinity to cellular prion protein (PrP(C)), but the role of this interaction in mediating the disruption of synaptic plasticity by such soluble Aβ in vitro is controversial. Here we report that intracerebroventricular injection of Aβ-containing aqueous extracts of Alzheimer's disease (AD) brain robustly inhibits long-term potentiation (LTP) without significantly affecting baseline excitatory synaptic transmission in the rat hippocampus in vivo. Moreover, the disruption of LTP was abrogated by immunodepletion of Aβ. Importantly, intracerebroventricular administration of antigen-binding antibody fragment D13, directed to a putative Aβ-binding site on PrP(C), prevented the inhibition of LTP by AD brain-derived Aβ. In contrast, R1, a Fab directed to the C terminus of PrP(C), a region not implicated in binding of Aβ, did not significantly affect the Aβ-mediated inhibition of LTP. These data support the pathophysiological significance of SDS-stable Aβ dimer and the role of PrP(C) in mediating synaptic plasticity disruption by soluble Aβ.
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Affiliation(s)
- Andrew E Barry
- Department of Pharmacology and Therapeutics and Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
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20
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Adekar SP, Klyubin I, Macy S, Rowan MJ, Solomon A, Dessain SK, O'Nuallain B. Inherent anti-amyloidogenic activity of human immunoglobulin gamma heavy chains. J Biol Chem 2009; 285:1066-74. [PMID: 19889627 DOI: 10.1074/jbc.m109.044321] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
We have previously shown that a subpopulation of naturally occurring human IgGs were cross-reactive against conformational epitopes on pathologic aggregates of Abeta, a peptide that forms amyloid fibrils in the brains of patients with Alzheimer disease, inhibited amyloid fibril growth, and dissociated amyloid in vivo. Here, we describe similar anti-amyloidogenic activity that is a general property of free human Ig gamma heavy chains. A gamma(1) heavy chain, F1, had nanomolar binding to an amyloid fibril-related conformational epitope on synthetic oligomers and fibrils as well as on amyloid-laden tissue sections. F1 did not bind to native Abeta monomers, further indicating the conformational nature of its binding site. The inherent anti-amyloidogenic activity of Ig gamma heavy chains was demonstrated by nanomolar amyloid fibril and oligomer binding by polyclonal and monoclonal human heavy chains that were isolated from inert or weakly reactive antibodies. Most importantly, the F1 heavy chain prevented in vitro fibril growth and reduced in vivo soluble Abeta oligomer-induced impairment of rodent hippocampal long term potentiation, a cellular mechanism of learning and memory. These findings demonstrate that free human Ig gamma heavy chains comprise a novel class of molecules for developing potential therapeutics for Alzheimer disease and other amyloid disorders. Moreover, establishing the molecular basis for heavy chain-amyloidogenic conformer interactions should advance understanding on the types of interactions that these pathologic assemblies have with biological molecules.
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Affiliation(s)
- Sharad P Adekar
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania 19096, USA
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21
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Ondrejcak T, Klyubin I, Hu NW, Barry AE, Cullen WK, Rowan MJ. Alzheimer's disease amyloid beta-protein and synaptic function. Neuromolecular Med 2009; 12:13-26. [PMID: 19757208 DOI: 10.1007/s12017-009-8091-0] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Accepted: 08/25/2009] [Indexed: 12/15/2022]
Abstract
Alzheimer's disease (AD) is characterized neuropathologically by the deposition of different forms of amyloid beta-protein (A beta) including variable amounts of soluble species that correlate with severity of dementia. The extent of synaptic loss in the brain provides the best morphological correlate of cognitive impairment in clinical AD. Animal research on the pathophysiology of AD has therefore focussed on how soluble A beta disrupts synaptic mechanisms in vulnerable brain regions such as the hippocampus. Synaptic plasticity in the form of persistent activity-dependent increases or decreases in synaptic strength provide a neurophysiological substrate for hippocampal-dependent learning and memory. Acute treatment with human-derived or chemically prepared soluble A beta that contains certain oligomeric assemblies, potently and selectively disrupts synaptic plasticity causing inhibition of long-term potentiation (LTP) and enhancement of long-term depression (LTD) of glutamatergic transmission. Over time these and related actions of A beta have been implicated in reducing synaptic integrity. This review addresses the involvement of neurotransmitter intercellular signaling in mediating or modulating the synaptic plasticity disrupting actions of soluble A beta, with particular emphasis on the different roles of glutamatergic and cholinergic mechanisms. There is growing evidence to support the view that NMDA and possibly nicotinic receptors are critically involved in mediating the disruptive effect of A beta and that targeting muscarinic receptors can indirectly modulate A beta's actions. Such studies should help inform ongoing and future clinical trials of drugs acting through the glutamatergic and cholinergic systems.
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Affiliation(s)
- Tomas Ondrejcak
- Department of Pharmacology and Therapeutics, Biotechnology Building and Institute of Neuroscience, Trinity College, Dublin 2, Ireland
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22
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Ryan BK, Vollmayr B, Klyubin I, Gass P, Rowan MJ. Persistent inhibition of hippocampal long-term potentiation in vivo by learned helplessness stress. Hippocampus 2009; 20:758-67. [DOI: 10.1002/hipo.20677] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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23
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Dessain S, Adekar SP, Klyubin I, Macy SD, Rowan MJ, Solomon A, O'Nuallain B. P4‐306: Human Immunoglobulin Heavy Chains Have Novel Fibril‐binding And Anti‐amyloidogenic Activity. Alzheimers Dement 2009. [DOI: 10.1016/j.jalz.2009.07.085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Scott Dessain
- Lankenau Institute for Medical ResearchWynnewoodPAUSA
| | | | - Igor Klyubin
- Institute of NeuroscienceTrinity CollegeDublinIreland
| | - Sally D. Macy
- Human Immunology and Cancer ProgramUniversity of TennesseeKnoxvilleTNUSA
| | | | - Alan Solomon
- Human Immunology and Cancer ProgramUniversity of TennesseeKnoxvilleTNUSA
| | - Brian O'Nuallain
- The Conway Institute of Biomolecular and Biomedical ResearchUniversity CollegeDublinIreland
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24
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Klyubin I, Wang Q, Reed MN, Irving EA, Upton N, Hofmeister J, Cleary JP, Anwyl R, Rowan MJ. Protection against Aβ-mediated rapid disruption of synaptic plasticity and memory by memantine. Neurobiol Aging 2009; 32:614-23. [PMID: 19446369 DOI: 10.1016/j.neurobiolaging.2009.04.005] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Revised: 03/30/2009] [Accepted: 04/06/2009] [Indexed: 12/18/2022]
Abstract
Soluble amyloid-β protein (Aβ) may cause cognitive impairment in Alzheimer's disease in the absence of significant neurodegeneration. Here, the ability of the NMDA receptor (NMDAR) antagonist memantine to prevent synthetic Aβ-mediated rapid functional deficits in learned behavior and synaptic plasticity was assessed in the rat. In vitro, pretreatment with a clinically relevant, NMDAR blocking concentration of memantine partially inhibited the induction of long-term potentiation (LTP) in the dentate gyrus and prevented further inhibition caused by exposure to Aβ(1-42). Whereas systemic injection with memantine alone inhibited LTP in the CA1 area in vivo, a subthreshold dose partially abrogated the inhibition of LTP by intracerebroventricular soluble Aβ(1-42). Similarly, systemic treatment with memantine alone impaired performance of an operant learning task and a subthreshold dose prevented the Aβ(1-42)-mediated increase in perseveration errors. The acute protection afforded by memantine, albeit in a narrow dose range, against the rapid disruptive effects of soluble Aβ(1-42) on synaptic plasticity and learned behavior strongly implicate NMDAR-dependent reversible dysfunction of synaptic mechanisms in Aβ-mediated cognitive impairment.
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Affiliation(s)
- Igor Klyubin
- Department of Pharmacology and Therapeutics, Trinity College, Dublin 2, Ireland
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25
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Wang Q, Klyubin I, Wright S, Griswold-Prenner I, Rowan MJ, Anwyl R. Alpha v integrins mediate beta-amyloid induced inhibition of long-term potentiation. Neurobiol Aging 2007; 29:1485-93. [PMID: 17442458 DOI: 10.1016/j.neurobiolaging.2007.03.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Revised: 03/13/2007] [Accepted: 03/17/2007] [Indexed: 11/22/2022]
Abstract
Beta-amyloid (Abeta) is the principal component of the extracellular plaques present in patients with Alzheimer's disease. Several studies have recently shown that acutely applied Abeta inhibits the induction of LTP in the hippocampus. In the present studies, we have investigated the role of integrins in such Abeta-mediated block of LTP in the dentate gyrus in vitro and in the CA1 in vivo. Selective antibodies to the alpha v integrin subunit were found to prevent the Abeta inhibition of LTP, both in the dentate gyrus in vitro and in the CA1 in vivo. In contrast, two control antibodies did not prevent such action of Abeta. In addition, a small molecule nonpeptide antagonist of alpha v-containing integrins and two other antagonistic ligands of integrins, superfibronectin and the disintegrin echistatin, also prevented the Abeta inhibition of LTP. These studies indicate that alpha v integrins may be important mediators of synaptic dysfunction prior to neurodegeneration in Alzheimer's disease.
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Affiliation(s)
- Qinwen Wang
- Department of Physiology, Trinity College, Dublin 2, Ireland
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26
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Walsh DM, Klyubin I, Shankar GM, Townsend M, Fadeeva JV, Betts V, Podlisny MB, Cleary JP, Ashe KH, Rowan MJ, Selkoe DJ. The role of cell-derived oligomers of Abeta in Alzheimer's disease and avenues for therapeutic intervention. Biochem Soc Trans 2006; 33:1087-90. [PMID: 16246051 DOI: 10.1042/bst20051087] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Burgeoning evidence suggests that soluble oligomers of Abeta (amyloid beta-protein) are the earliest effectors of synaptic compromise in Alzheimer's disease. Whereas most other investigators have employed synthetic Abeta peptides, we have taken advantage of a beta-amyloid precursor protein-overexpressing cell line (referred to as 7PA2) that secretes sub-nanomolar levels of low-n oligomers of Abeta. These are composed of heterogeneous Abeta peptides that migrate on SDS/PAGE as dimers, trimers and tetramers. When injected into the lateral ventricle of rats in vivo, these soluble oligomers inhibit hippocampal long-term potentiation and alter the memory of a complex learned behaviour. Biochemical manipulation of 7PA2 medium including immunodepletion with Abeta-specific antibodies and fractionation by size-exclusion chromatography allowed us to unambiguously attribute these effects to low-n oligomers. Using this paradigm we have tested compounds directed at three prominent amyloid-based therapeutic targets: inhibition of the secretases responsible for Abeta production, inhibition of Abeta aggregation and immunization against Abeta. In each case, compounds capable of reducing oligomer production or antibodies that avidly bind Abeta oligomers also ameliorate the synaptotoxic effects of these natural, cell-derived oligomers.
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Affiliation(s)
- D M Walsh
- Laboratory for Neurodegenerative Research, Conway Institute, University College Dublin, Republic of Ireland.
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27
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Rowan MJ, Klyubin I, Wang Q, Anwyl R. Synaptic plasticity disruption by amyloid beta protein: modulation by potential Alzheimer's disease modifying therapies. Biochem Soc Trans 2005; 33:563-7. [PMID: 16042545 DOI: 10.1042/bst0330563] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
AD (Alzheimer's disease) is characterized by a progressive and devastating mental decline that is usually presaged by impairment of a form of memory dependent on medial temporal lobe structures, including the hippocampus. The severity of clinical dementia correlates positively with the cerebral load of the AD-related protein Abeta (amyloid beta), particularly in its soluble form rather than the insoluble fibrillar Abeta found in amyloid plaques. Recent research in animal models of AD has pointed to a potentially important role for rapid disruptive effects of soluble species of Abeta on neural function in causing a relatively selective impairment of memory early in the disease. Our experiments assessing the mechanisms of Abeta inhibition of LTP (long-term potentiation), a correlate of memory-related synaptic plasticity, in the rodent hippocampus showed that low-n oligomers were the soluble Abeta species primarily responsible for the disruption of synaptic plasticity in vivo. Exogenously applied and endogenously generated anti-Abeta antibodies rapidly neutralized and prevented the synaptic plasticity disrupting effects of these very potent Abeta oligomers. This suggests that active or passive immunotherapeutic strategies for early AD should target Abeta oligomers in the brain. The ability of agents that reduce nitrosative/oxidative stress or antagonize stress-activated kinases to prevent Abeta inhibition of LTP in vitro points to a key role of these cellular mechanisms at very early stages in Abeta-induced neuronal dysfunction. A combination of antibody-mediated inactivation of Abeta oligomers and pharmacological prevention of cellular stress mechanisms underlying their synaptic plasticity disrupting effects provides an attractive strategy in the prevention of early AD.
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Affiliation(s)
- M J Rowan
- Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland.
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28
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Klyubin I, Walsh DM, Lemere CA, Cullen WK, Shankar GM, Betts V, Spooner ET, Jiang L, Anwyl R, Selkoe DJ, Rowan MJ. Amyloid beta protein immunotherapy neutralizes Abeta oligomers that disrupt synaptic plasticity in vivo. Nat Med 2005; 11:556-61. [PMID: 15834427 DOI: 10.1038/nm1234] [Citation(s) in RCA: 374] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2004] [Accepted: 03/09/2005] [Indexed: 11/09/2022]
Abstract
One of the most clinically advanced forms of experimental disease-modifying treatment for Alzheimer disease is immunization against the amyloid beta protein (Abeta), but how this may prevent cognitive impairment is unclear. We hypothesized that antibodies to Abeta could exert a beneficial action by directly neutralizing potentially synaptotoxic soluble Abeta species in the brain. Intracerebroventricular injection of naturally secreted human Abeta inhibited long-term potentiation (LTP), a correlate of learning and memory, in rat hippocampus in vivo but a monoclonal antibody to Abeta completely prevented the inhibition of LTP when injected after Abeta. Size fractionation showed that Abeta oligomers, not monomers or fibrils, were responsible for inhibiting LTP, and an Abeta antibody again prevented such inhibition. Active immunization against Abeta was partially effective, and the effects correlated positively with levels of antibodies to Abeta oligomers. The ability of exogenous and endogenous antibodies to rapidly neutralize soluble Abeta oligomers that disrupt synaptic plasticity in vivo suggests that treatment with such antibodies might show reversible cognitive deficits in early Alzheimer disease.
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Affiliation(s)
- Igor Klyubin
- Trinity College Institute of Neuroscience, Department of Pharmacology and Therapeutics, Trinity College, Dublin 2, Ireland
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29
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Rowan MJ, Klyubin I, Wang Q, Anwyl R. Mechanisms of the inhibitory effects of amyloid β-protein on synaptic plasticity. Exp Gerontol 2004; 39:1661-7. [PMID: 15582282 DOI: 10.1016/j.exger.2004.06.020] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2004] [Accepted: 06/09/2004] [Indexed: 12/29/2022]
Abstract
Alzheimer's disease can be considered a protein misfolding disease. In particular, inappropriate processing of a proteolytic fragment of amyloid precursor protein, amyloid beta-protein (Abeta), in early stages of Alzheimer's disease may lead to stabilization of small oligomers that are highly mobile and have a potential to be extremely toxic assemblies. Recently, the importance of such soluble species of Abeta in triggering synaptic dysfunction, long before neuronal loss occurs, has become apparent. Animal models have revealed that plasticity of hippocampal excitatory synaptic transmission is relatively selectively vulnerable to Abeta both in vitro and in vivo. This review focuses on the mechanisms of Abeta inhibition of long-term potentiation at synapses in the rodent hippocampus from two complimentary perspectives. Firstly, we examine evidence that the synaptic activity of this peptide resides primarily in oligomeric rather than monomeric or fibrillar Abeta species. Secondly, the importance of different oxidative/nitrosative stress-linked cascades including JNK, p38 MAPK and NADPH oxidase/iNOS-generated reactive oxygen/nitrogen free radicals in mediating the inhibition of LTP by Abeta is emphasised. These mechanistic studies provide a plausible explanation for the sensitivity of hippocampus-dependent memory to impairment in the early preclinical stages of Alzheimer's disease.
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Affiliation(s)
- Michael J Rowan
- Trinity College Institute of Neuroscience, Department of Pharmacology and Therapeutics, Trinity College, Biotechnology Building, Dublin 2, Ireland.
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30
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Klyubin I, Walsh DM, Cullen WK, Fadeeva JV, Anwyl R, Selkoe DJ, Rowan MJ. Soluble Arctic amyloid beta protein inhibits hippocampal long-term potentiation in vivo. Eur J Neurosci 2004; 19:2839-46. [PMID: 15147317 DOI: 10.1111/j.1460-9568.2004.03389.x] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Mutations in the amyloid precursor protein that result in substitutions of glutamic acid at residue 22 of the amyloid beta protein (A beta) with glutamine (Q22, Dutch) or glycine (G22, Arctic) cause aggressive familial neurological diseases characterized by cerebrovascular haemorrhages or Alzheimer's-type dementia, respectively. The present study compared the ability of these peptides to block long-term potentiation (LTP) of glutamatergic transmission in the hippocampus in vivo. The effects of intracerebroventricular injection of wild-type, Q22 and G22 A beta(1-40) peptides were examined in the CA1 area of urethane-anaesthetized rats. Both mutant peptides were approximately 100-fold more potent than wild-type A beta at inhibiting LTP induced by high-frequency stimulation when solutions of A beta were freshly prepared. Fibrillar material, as determined by electron microscopy, was obvious in all these peptide solutions and exhibited appreciable Congo Red binding, particularly for A beta(1-40)G22 and A beta(1-40)Q22. A soluble fraction of A beta(1-40)G22, obtained following high-speed centrifugation, retained full activity of the peptide solution to inhibit LTP, providing strong evidence that in the case of the Arctic disease a soluble nonfibrillar form of A beta may represent the primary mediator of A beta-related cognitive deficits, particularly early in the disease. In contrast, nonfibrillar soluble A beta(1-40)Q22 supernatant solution was approximately 10-fold less potent at inhibiting LTP than A beta(1-40)G22, a finding consistent with fibrillar A beta contributing to the inhibition of LTP by the Dutch peptide.
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Affiliation(s)
- Igor Klyubin
- Trinity College Institute of Neuroscience, and Department of Pharmacology and Therapeutics, Trinity College, Dublin 2, Ireland
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31
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Klyubin I, Walsh DM, Fadeeva JV, Anwyl R, Selkoe DJ, Rowan MJ. P2-004 Anti-Aβ antibodies prevention block of long-term potentiation in the CA1 area of rat hippocampus in vivo by naturally produced Aβ oligomers. Neurobiol Aging 2004. [DOI: 10.1016/s0197-4580(04)80752-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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32
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Abstract
Amyloid beta-protein (Abeta) is believed to be a primary cause of Alzheimer's disease (AD). Recent research has examined the potential importance of soluble species of Abeta in synaptic dysfunction, long before fibrillary Abeta is deposited and neurodegenerative changes occur. Hippocampal excitatory synaptic transmission and plasticity are disrupted in transgenic mice overexpressing human amyloid precursor protein with early onset familial AD mutations, and in rats after exogenous application of synthetic Abeta both in vitro and in vivo. Recently, naturally produced soluble Abeta was shown to block the persistence of long-term potentiation (LTP) in the intact hippocampus. Sub-nanomolar concentrations of oligomeric Abeta were sufficient to inhibit late LTP, pointing to a possible reason for the sensitivity of hippocampus-dependent memory to impairment in the early preclinical stages of AD. Having identified the active species of Abeta that can play havoc with synaptic plasticity, it is hoped that new ways of targeting early AD can be developed.
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Affiliation(s)
- Michael J Rowan
- Department of Pharmacology and Therapeutics, Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland.
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33
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Abstract
Despite extensive genetic and animal modelling data that support a central role for the amyloid beta-protein (A beta) in the genesis of Alzheimer's disease, the specific form(s) of A beta which causes injury to neurons in vivo has not been identified. In the present study, we examine the importance of soluble, pre-fibrillar assemblies of A beta as mediators of neurotoxicity. Specifically, we review the role of cell-derived SDS-stable oligomers, their blocking of hippocampal long-term potentiation in vivo and the finding that this blocking can be prevented by prior treatment of oligomer-producing cells with gamma-secretase inhibitors.
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Affiliation(s)
- D M Walsh
- Department of Neurology, Harvard Medical School and Center for Neurologic Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA
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34
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Walsh DM, Klyubin I, Fadeeva JV, Cullen WK, Anwyl R, Wolfe MS, Rowan MJ, Selkoe DJ. Naturally secreted oligomers of amyloid beta protein potently inhibit hippocampal long-term potentiation in vivo. Nature 2002. [PMID: 11932745 DOI: 10.1038/416535a416535a]] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Although extensive data support a central pathogenic role for amyloid beta protein (Abeta) in Alzheimer's disease, the amyloid hypothesis remains controversial, in part because a specific neurotoxic species of Abeta and the nature of its effects on synaptic function have not been defined in vivo. Here we report that natural oligomers of human Abeta are formed soon after generation of the peptide within specific intracellular vesicles and are subsequently secreted from the cell. Cerebral microinjection of cell medium containing these oligomers and abundant Abeta monomers but no amyloid fibrils markedly inhibited hippocampal long-term potentiation (LTP) in rats in vivo. Immunodepletion from the medium of all Abeta species completely abrogated this effect. Pretreatment of the medium with insulin-degrading enzyme, which degrades Abeta monomers but not oligomers, did not prevent the inhibition of LTP. Therefore, Abeta oligomers, in the absence of monomers and amyloid fibrils, disrupted synaptic plasticity in vivo at concentrations found in human brain and cerebrospinal fluid. Finally, treatment of cells with gamma-secretase inhibitors prevented oligomer formation at doses that allowed appreciable monomer production, and such medium no longer disrupted LTP, indicating that synaptotoxic Abeta oligomers can be targeted therapeutically.
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Affiliation(s)
- Dominic M Walsh
- Department of Neurology, Harvard Medical School and Center for Neurologic Diseases, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
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35
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Walsh DM, Klyubin I, Fadeeva JV, Cullen WK, Anwyl R, Wolfe MS, Rowan MJ, Selkoe DJ. Naturally secreted oligomers of amyloid beta protein potently inhibit hippocampal long-term potentiation in vivo. Nature 2002; 416:535-9. [PMID: 11932745 DOI: 10.1038/416535a] [Citation(s) in RCA: 3241] [Impact Index Per Article: 147.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Although extensive data support a central pathogenic role for amyloid beta protein (Abeta) in Alzheimer's disease, the amyloid hypothesis remains controversial, in part because a specific neurotoxic species of Abeta and the nature of its effects on synaptic function have not been defined in vivo. Here we report that natural oligomers of human Abeta are formed soon after generation of the peptide within specific intracellular vesicles and are subsequently secreted from the cell. Cerebral microinjection of cell medium containing these oligomers and abundant Abeta monomers but no amyloid fibrils markedly inhibited hippocampal long-term potentiation (LTP) in rats in vivo. Immunodepletion from the medium of all Abeta species completely abrogated this effect. Pretreatment of the medium with insulin-degrading enzyme, which degrades Abeta monomers but not oligomers, did not prevent the inhibition of LTP. Therefore, Abeta oligomers, in the absence of monomers and amyloid fibrils, disrupted synaptic plasticity in vivo at concentrations found in human brain and cerebrospinal fluid. Finally, treatment of cells with gamma-secretase inhibitors prevented oligomer formation at doses that allowed appreciable monomer production, and such medium no longer disrupted LTP, indicating that synaptotoxic Abeta oligomers can be targeted therapeutically.
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Affiliation(s)
- Dominic M Walsh
- Department of Neurology, Harvard Medical School and Center for Neurologic Diseases, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
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36
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Ischenko A, Shouft M, Zhakhov A, Chan P, Klyubin I, Fontaine M. Expression of C1q phagocytic receptor on cultured astrocytes. Mol Immunol 1998. [DOI: 10.1016/s0161-5890(98)90647-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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