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Singh R, Panghal A, Jadhav K, Thakur A, Verma RK, Singh C, Goyal M, Kumar J, Namdeo AG. Recent Advances in Targeting Transition Metals (Copper, Iron, and Zinc) in Alzheimer's Disease. Mol Neurobiol 2024:10.1007/s12035-024-04256-8. [PMID: 38809370 DOI: 10.1007/s12035-024-04256-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 05/21/2024] [Indexed: 05/30/2024]
Abstract
Changes in the transition metal homeostasis in the brain are closely linked with Alzheimer's disease (AD), including intraneuronal iron accumulation and extracellular copper and zinc pooling in the amyloid plague. The brain copper, zinc, and iron surplus are commonly acknowledged characteristics of AD, despite disagreements among some. This has led to the theory that oxidative stress resulting from abnormal homeostasis of these transition metals may be a causative explanation behind AD. In the nervous system, the interaction of metals with proteins appears to be an essential variable in the development or suppression of neurodegeneration. Chelation treatment may be an option for treating neurodegeneration induced by transition metal ion dyshomeostasis. Some clinicians even recommend using chelating agents as an adjunct therapy for AD. The current review also looks at the therapeutic strategies that have been attempted, primarily with metal-chelating drugs. Metal buildup in the nervous system, as reported in the AD, could be the result of compensatory mechanisms designed to improve metal availability for physiological functions.
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Affiliation(s)
- Raghuraj Singh
- Pharmaceutical Nanotechnology Lab, Institutes of Nano Science and Technology (INST), Sector 81. Mohali, Punjab, 140306, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, 201002, India
| | - Archna Panghal
- Department of Pharmacology and Toxicology, Facility for Risk Assessment and Intervention Studies, National Institute of Pharmaceutical Education and Research, S.A.S Nagar, Punjab, India
| | - Krishna Jadhav
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, 201002, India
| | - Ashima Thakur
- Faculty of Pharmaceutical Sciences, ICFAI University, Baddi, Distt. Solan, Himachal Pradesh, 174103, India
| | - Rahul Kumar Verma
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, 201002, India
| | - Charan Singh
- Department of Pharmaceutical Sciences Hemwati, Nandan Bahuguna Garhwal University (A Central University), Srinagar, Dist. Garhwal (Uttarakhand), 246174, India
| | - Manoj Goyal
- Department of Pharmaceutical Sciences Hemwati, Nandan Bahuguna Garhwal University (A Central University), Srinagar, Dist. Garhwal (Uttarakhand), 246174, India
| | - Jayant Kumar
- Department of Pharmaceutical Sciences Hemwati, Nandan Bahuguna Garhwal University (A Central University), Srinagar, Dist. Garhwal (Uttarakhand), 246174, India.
| | - Ajay G Namdeo
- Department of Pharmaceutical Sciences Hemwati, Nandan Bahuguna Garhwal University (A Central University), Srinagar, Dist. Garhwal (Uttarakhand), 246174, India
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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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Blume T, Filser S, Sgobio C, Peters F, Neumann U, Shimshek D, Saito T, Saido TC, Brendel M, Herms J. β-secretase inhibition prevents structural spine plasticity deficits in AppNL-G-F mice. Front Aging Neurosci 2022; 14:909586. [PMID: 35936777 PMCID: PMC9354544 DOI: 10.3389/fnagi.2022.909586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 06/29/2022] [Indexed: 11/23/2022] Open
Abstract
All clinical BACE1-inhibitor trials for the treatment of Alzheimer's Disease (AD) have failed due to insufficient efficacy or side effects like worsening of cognitive symptoms. However, the scientific evidence to date suggests that BACE1-inhibition could be an effective preventative measure if applied prior to the accumulation of amyloid-beta (Aβ)-peptide and resultant impairment of synaptic function. Preclinical studies have associated BACE1-inhibition-induced cognitive deficits with decreased dendritic spine density. Therefore, we investigated dose-dependent effects of BACE1-inhibition on hippocampal dendritic spine dynamics in an APP knock-in mouse line for the first time. We conducted in vivo two-photon microscopy in the stratum oriens layer of hippocampal CA1 neurons in 3.5-month-old AppNL-G-FGFP-M mice over 6 weeks to monitor the effect of potential preventive treatment with a high and low dose of the BACE1-inhibitor NB-360 on dendritic spine dynamics. Structural spine plasticity was severely impaired in untreated AppNL-G-FGFP-M mice, although spines were not yet showing signs of degeneration. Prolonged high-dose BACE1-inhibition significantly enhanced spine formation, improving spine dynamics in the AD mouse model. We conclude that in an early AD stage characterized by low Aβ-accumulation and no irreversible spine loss, BACE1-inhibition could hold the progressive synapse loss and cognitive decline by improving structural spine dynamics.
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Affiliation(s)
- Tanja Blume
- German Center for Neurodegenerative Diseases, Munich, Germany
- Center for Neuropathology and Prion Research, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Severin Filser
- Institute for Stroke and Dementia Research, University Hospital, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Carmelo Sgobio
- German Center for Neurodegenerative Diseases, Munich, Germany
- Center for Neuropathology and Prion Research, Ludwig-Maximilians-University of Munich, Munich, Germany
| | | | - Ulf Neumann
- Department of Neuroscience, Novartis Institutes for BioMedical Research, Basel, Switzerland
| | - Derya Shimshek
- Department of Neuroscience, Novartis Institutes for BioMedical Research, Basel, Switzerland
| | - Takashi Saito
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Saitama, Japan
- Department of Neurocognitive Science, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Aichi, Japan
| | - Takaomi C. Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Saitama, Japan
| | - Matthias Brendel
- Munich Cluster for Systems Neurology, Munich, Germany
- Department of Nuclear Medicine, University Hospital of Munich, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Jochen Herms
- German Center for Neurodegenerative Diseases, Munich, Germany
- Center for Neuropathology and Prion Research, Ludwig-Maximilians-University of Munich, Munich, Germany
- Munich Cluster for Systems Neurology, Munich, Germany
- *Correspondence: Jochen Herms
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4
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Blume T, Deussing M, Biechele G, Peters F, Zott B, Schmidt C, Franzmeier N, Wind K, Eckenweber F, Sacher C, Shi Y, Ochs K, Kleinberger G, Xiang X, Focke C, Lindner S, Gildehaus FJ, Beyer L, von Ungern-Sternberg B, Bartenstein P, Baumann K, Adelsberger H, Rominger A, Cumming P, Willem M, Dorostkar MM, Herms J, Brendel M. Chronic PPARγ Stimulation Shifts Amyloidosis to Higher Fibrillarity but Improves Cognition. Front Aging Neurosci 2022; 14:854031. [PMID: 35431893 PMCID: PMC9007038 DOI: 10.3389/fnagi.2022.854031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 02/25/2022] [Indexed: 11/30/2022] Open
Abstract
We undertook longitudinal β-amyloid positron emission tomography (Aβ-PET) imaging as a translational tool for monitoring of chronic treatment with the peroxisome proliferator-activated receptor gamma (PPARγ) agonist pioglitazone in Aβ model mice. We thus tested the hypothesis this treatment would rescue from increases of the Aβ-PET signal while promoting spatial learning and preservation of synaptic density. Here, we investigated longitudinally for 5 months PS2APP mice (N = 23; baseline age: 8 months) and AppNL–G–F mice (N = 37; baseline age: 5 months) using Aβ-PET. Groups of mice were treated with pioglitazone or vehicle during the follow-up interval. We tested spatial memory performance and confirmed terminal PET findings by immunohistochemical and biochemistry analyses. Surprisingly, Aβ-PET and immunohistochemistry revealed a shift toward higher fibrillary composition of Aβ-plaques during upon chronic pioglitazone treatment. Nonetheless, synaptic density and spatial learning were improved in transgenic mice with pioglitazone treatment, in association with the increased plaque fibrillarity. These translational data suggest that a shift toward higher plaque fibrillarity protects cognitive function and brain integrity. Increases in the Aβ-PET signal upon immunomodulatory treatments targeting Aβ aggregation can thus be protective.
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Affiliation(s)
- Tanja Blume
- DZNE – German Center for Neurodegenerative Diseases, Munich, Germany
| | - Maximilian Deussing
- Department of Nuclear Medicine, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany
| | - Gloria Biechele
- Department of Radiology, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany
| | - Finn Peters
- DZNE – German Center for Neurodegenerative Diseases, Munich, Germany
| | - Benedikt Zott
- Institute of Neuroscience, Technical University of Munich, Munich, Germany
- Department of Diagnostic and Interventional Neuroradiology, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Claudio Schmidt
- Department of Nuclear Medicine, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany
| | - Nicolai Franzmeier
- Institute for Stroke and Dementia Research, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany
| | - Karin Wind
- DZNE – German Center for Neurodegenerative Diseases, Munich, Germany
- Department of Nuclear Medicine, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany
| | - Florian Eckenweber
- Department of Nuclear Medicine, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany
| | - Christian Sacher
- Department of Nuclear Medicine, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany
| | - Yuan Shi
- DZNE – German Center for Neurodegenerative Diseases, Munich, Germany
| | - Katharina Ochs
- DZNE – German Center for Neurodegenerative Diseases, Munich, Germany
| | - Gernot Kleinberger
- Metabolic Biochemistry, Faculty of Medicine, Biomedical Center (BMC), Ludwig Maximilian University of Munich, Munich, Germany
- ISAR Bioscience GmbH, Planegg, Germany
| | - Xianyuan Xiang
- Metabolic Biochemistry, Faculty of Medicine, Biomedical Center (BMC), Ludwig Maximilian University of Munich, Munich, Germany
| | - Carola Focke
- Department of Nuclear Medicine, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany
| | - Simon Lindner
- Department of Nuclear Medicine, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany
| | - Franz-Josef Gildehaus
- Department of Nuclear Medicine, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany
| | - Leonie Beyer
- Department of Nuclear Medicine, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany
| | - Barbara von Ungern-Sternberg
- Department of Nuclear Medicine, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany
| | - Karlheinz Baumann
- Roche Pharma Research and Early Development, Neuroscience Discovery, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Helmuth Adelsberger
- Department of Radiology, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany
| | - Axel Rominger
- SyNergy, Ludwig Maximilian University of Munich, Munich, Germany
- Department of Nuclear Medicine, Inselspital Bern, Bern, Switzerland
| | - Paul Cumming
- Department of Nuclear Medicine, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany
- School of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia
| | - Michael Willem
- Metabolic Biochemistry, Faculty of Medicine, Biomedical Center (BMC), Ludwig Maximilian University of Munich, Munich, Germany
| | - Mario M. Dorostkar
- DZNE – German Center for Neurodegenerative Diseases, Munich, Germany
- Center for Neuropathology and Prion Research, Ludwig Maximilian University of Munich, Munich, Germany
| | - Jochen Herms
- DZNE – German Center for Neurodegenerative Diseases, Munich, Germany
- SyNergy, Ludwig Maximilian University of Munich, Munich, Germany
- Center for Neuropathology and Prion Research, Ludwig Maximilian University of Munich, Munich, Germany
| | - Matthias Brendel
- DZNE – German Center for Neurodegenerative Diseases, Munich, Germany
- Department of Nuclear Medicine, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany
- SyNergy, Ludwig Maximilian University of Munich, Munich, Germany
- *Correspondence: Matthias Brendel,
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Alipour HR, Yaghmaei P, Ahmadian S, Ghobeh M, Ebrahim-Habibi A. A study on alpha-terpineol in Alzheimer’s disease with the use of rodent in vivo model, restraint stress effect and in vitro Amyloid beta fibrils. BRAZ J PHARM SCI 2022. [DOI: 10.1590/s2175-97902022e19090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
| | | | | | | | - Azadeh Ebrahim-Habibi
- Tehran University of Medical Sciences, Iran; Tehran University of Medical Sciences, Iran
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Zhang H, Ben Zablah Y, Liu A, Lee D, Zhang H, Meng Y, Zhou C, Liu X, Wang Y, Jia Z. Overexpression of LIMK1 in hippocampal excitatory neurons improves synaptic plasticity and social recognition memory in APP/PS1 mice. Mol Brain 2021; 14:121. [PMID: 34315506 PMCID: PMC8314529 DOI: 10.1186/s13041-021-00833-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 07/16/2021] [Indexed: 01/22/2023] Open
Abstract
Accumulating evidence indicates that the actin regulator cofilin is overactivated in Alzheimer's Disease (AD), but whether this abnormality contributes to synaptic and cognitive impairments in AD is unclear. In addition, the brain region and cell types involved remain unknown. In this study, we specifically manipulate LIMK1, the key protein kinase that phosphorylates and inactivates cofilin, in the hippocampus of APP/PS1 transgenic mice. Using local injections of the AAV virus containing LIMK1 under the control of the CaMKIIα promoter, we show that expression of LIMK1 in hippocampal excitatory neurons increases cofilin phosphorylation (i.e., decreases cofilin activity), rescues impairments in long-term potentiation, and improves social memory in APP/PS1 mice. Our results suggest that deficits in LIMK1/cofilin signaling in the hippocampal excitatory neurons contribute to AD pathology and that manipulations of LIMK1/cofilin activity provide a potential therapeutic strategy to treat AD.
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Affiliation(s)
- Haiwang Zhang
- Guizhou Medical University, Guiyang, 550000, Guizhou, China.,Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, M5S 1A8, Canada.,Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Youssif Ben Zablah
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, M5S 1A8, Canada.,Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - An Liu
- The Key Laboratory of Developmental Genes and Human Disease, Ministry of Education, School of Life Science and Technology, Southeast University, Nanjing, China
| | - Dongju Lee
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, M5S 1A8, Canada.,Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Haorui Zhang
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, M5S 1A8, Canada.,Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Yanghong Meng
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, M5S 1A8, Canada.,Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Changxi Zhou
- Department of Geriatrics, The Second Medical Center and National Clinical Research Center for Geriatric Diseases, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, China
| | - Xingde Liu
- Department of Cardiovascular Medicine, The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, 550001, Guizhou, China
| | - Yiming Wang
- Department of Psychiatry, Affiliated Hospital of Guizhou Medical University, Guiyang, 550004, Guizhou, China. .,Mental Health Education and Counseling Center for College Students, Guizhou Medical University, Guiyang, 550004, Guizhou, China.
| | - Zhengping Jia
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, M5S 1A8, Canada. .,Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
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Morgese MG, Schiavone S, Bove M, Colia AL, Dimonte S, Tucci P, Trabace L. N-3 PUFA Prevent Oxidative Stress in a Rat Model of Beta-Amyloid-Induced Toxicity. Pharmaceuticals (Basel) 2021; 14:ph14040339. [PMID: 33917814 PMCID: PMC8068120 DOI: 10.3390/ph14040339] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 03/31/2021] [Accepted: 04/04/2021] [Indexed: 12/11/2022] Open
Abstract
Polyunsaturated fatty acids (PUFA) are involved in brain disorders associated to amyloid beta (Aβ) toxicity for which oxidative stress, neurochemical dysfunctions, and neuroinflammation are underlying mechanisms. Here, mechanisms through which lifelong exposure to n-3 PUFA-enriched or n-6/n-3 balanced diets could elicit a protective role in a rat model of Aβ-induced toxicity were investigated. To this aim, we quantified hippocampal reactive oxygen species (ROS) amount, 8-hydroxy-2'-deoxyguanosine and interleukin-10 levels, NADPH oxidase (NOX) 1, NOX2, superoxide dismutase 1, and glutathione contents, as well as plasmatic malondialdehyde. Moreover, in the same experimental groups, we assessed tryptophan, serotonin, and its turnover, kynurenine, and noradrenaline amounts. Results showed increased hippocampal ROS and NOX2 levels, serotonin turnover, kynurenine, and noradrenaline contents in Aβ-treated rats. Both n-6/n-3 balanced and n-3 PUFA enriched diets reduced ROS production, NOX1 and malondialdehyde levels, serotonin turnover, and kynurenine amount in Aβ-injected rats, while increasing NOX2, superoxide dismutase 1, and serotonin contents. No differences in plasmatic coenzyme Q10, reduced glutathione (GSH) and tryptophan levels were detected among different experimental groups, whereas GSH + oxidized glutathione (GSSG) levels were increased in sham animals fed with n-3 PUFA enriched diet and in Aβ-treated rats exposed to both n-6/n-3 balanced and n-3 enriched diets. In addition, Aβ-induced decrease of interleukin-10 levels was prevented by n-6/n-3 PUFA balanced diet. N-3 PUFA enriched diet further increased interleukin-10 and 8-hydroxy-2'-deoxyguanosine levels. In conclusion, our data highlight the possible neuroprotective role of n-3 PUFA in perturbation of oxidative equilibrium induced by Aβ-administration.
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Seifi-Nahavandi B, Yaghmaei P, Ahmadian S, Ghobeh M, Ebrahim-Habibi A. Cymene consumption and physical activity effect in Alzheimer's disease model: an in vivo and in vitro study. J Diabetes Metab Disord 2021; 19:1381-1389. [PMID: 33520841 DOI: 10.1007/s40200-020-00658-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Accepted: 10/07/2020] [Indexed: 12/17/2022]
Abstract
Purpose Alzheimer's disease (AD) is one of the most important neurodegenerative diseases and accompanied by the production of free radicals and inflammatory factors. Studies have shown that p-cymene has anti-inflammatory and anti-oxidant effects. Here, the effects of this compound were investigated on a rat model of AD. Methods In order to create Alzheimer's rat model, bilateral injection of Amyloid β1-42 (Aβ1-42) into rats hippocampus was performed. Both therapeutic (post-AD induction) and preventive effects of p-cymene consumption with doses of 50 and 100 mg/kg were investigated. In addition, the effects of adding short-term exercise to the process were also observed. In vitro, Aβ1-42 peptide was driven toward fibril formation and effect of p-cymene was observed on the resulting fibrils. Results Learning and memory indices in the AD rats were significantly reduced compared to the Sham group, while p-cymene consumption with both doses, as well as performing exercise counteracted AD consequences. Moreover, increased neurogenesis and reduced amyloid plaques counts were observed in treated rats. In vitro formed fibrils of Aβ1-42 were partially disaggregated in the presence of p-cymene. Discussion p-Cymene could act on this AD model via antioxidant and anti-inflammatory properties as well as direct anti-fibril effect. Conclusion p-cymene can improve AD-related disorders including memory impairment.
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Affiliation(s)
| | - Parichehreh Yaghmaei
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Shahin Ahmadian
- Department of Biochemistry, Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
| | - Maryam Ghobeh
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Azadeh Ebrahim-Habibi
- Biosensor Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.,Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
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9
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Rezvani Boroujeni E, Hosseini SM, Fani G, Cecchi C, Chiti F. Soluble Prion Peptide 107-120 Protects Neuroblastoma SH-SY5Y Cells against Oligomers Associated with Alzheimer's Disease. Int J Mol Sci 2020; 21:E7273. [PMID: 33019683 PMCID: PMC7582777 DOI: 10.3390/ijms21197273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/27/2020] [Accepted: 09/28/2020] [Indexed: 12/20/2022] Open
Abstract
Alzheimer's disease (AD) is the most prevalent form of dementia and soluble amyloid β (Aβ) oligomers are thought to play a critical role in AD pathogenesis. Cellular prion protein (PrPC) is a high-affinity receptor for Aβ oligomers and mediates some of their toxic effects. The N-terminal region of PrPC can interact with Aβ, particularly the region encompassing residues 95-110. In this study, we identified a soluble and unstructured prion-derived peptide (PrP107-120) that is external to this region of the sequence and was found to successfully reduce the mitochondrial impairment, intracellular ROS generation and cytosolic Ca2+ uptake induced by oligomeric Aβ42 ADDLs in neuroblastoma SH-SY5Y cells. PrP107-120 was also found to rescue SH-SY5Y cells from Aβ42 ADDL internalization. The peptide did not change the structure and aggregation pathway of Aβ42 ADDLs, did not show co-localization with Aβ42 ADDLs in the cells and showed a partial colocalization with the endogenous cellular PrPC. As a sequence region that is not involved in Aβ binding but in PrP self-recognition, the peptide was suggested to protect against the toxicity of Aβ42 oligomers by interfering with cellular PrPC and/or activating a signaling that protected the cells. These results strongly suggest that PrP107-120 has therapeutic potential for AD.
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Affiliation(s)
- Elham Rezvani Boroujeni
- Department of Microbiology and Microbial Biotechnology, Faculty of Life Science and Biotechnology, Shahid Beheshti University, Tehran 1983969411, Iran;
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Viale G.B Morgagni 50, 50134 Florence, Italy; (G.F.); (C.C.)
| | - Seyed Masoud Hosseini
- Department of Microbiology and Microbial Biotechnology, Faculty of Life Science and Biotechnology, Shahid Beheshti University, Tehran 1983969411, Iran;
| | - Giulia Fani
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Viale G.B Morgagni 50, 50134 Florence, Italy; (G.F.); (C.C.)
| | - Cristina Cecchi
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Viale G.B Morgagni 50, 50134 Florence, Italy; (G.F.); (C.C.)
| | - Fabrizio Chiti
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Viale G.B Morgagni 50, 50134 Florence, Italy; (G.F.); (C.C.)
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10
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Li S, Selkoe DJ. A mechanistic hypothesis for the impairment of synaptic plasticity by soluble Aβ oligomers from Alzheimer's brain. J Neurochem 2020; 154:583-597. [PMID: 32180217 DOI: 10.1111/jnc.15007] [Citation(s) in RCA: 137] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/28/2020] [Accepted: 03/02/2020] [Indexed: 12/18/2022]
Abstract
It is increasingly accepted that early cognitive impairment in Alzheimer's disease results in considerable part from synaptic dysfunction caused by the accumulation of a range of oligomeric assemblies of amyloid β-protein (Aβ). Most studies have used synthetic Aβ peptides to explore the mechanisms of memory deficits in rodent models, but recent work suggests that Aβ assemblies isolated from human (AD) brain tissue are far more potent and disease-relevant. Although reductionist experiments show Aβ oligomers to impair synaptic plasticity and neuronal viability, the responsible mechanisms are only partly understood. Glutamatergic receptors, GABAergic receptors, nicotinic receptors, insulin receptors, the cellular prion protein, inflammatory mediators, and diverse signaling pathways have all been suggested. Studies using AD brain-derived soluble Aβ oligomers suggest that only certain bioactive forms (principally small, diffusible oligomers) can disrupt synaptic plasticity, including by binding to plasma membranes and changing excitatory-inhibitory balance, perturbing mGluR, PrP, and other neuronal surface proteins, down-regulating glutamate transporters, causing glutamate spillover, and activating extrasynaptic GluN2B-containing NMDA receptors. We synthesize these emerging data into a mechanistic hypothesis for synaptic failure in Alzheimer's disease that can be modified as new knowledge is added and specific therapeutics are developed.
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Affiliation(s)
- Shaomin Li
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Dennis J Selkoe
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
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11
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Mohd Lazaldin MA, Iezhitsa I, Agarwal R, Bakar NS, Agarwal P, Mohd Ismail N. Neuroprotective effects of brain-derived neurotrophic factor against amyloid beta 1-40-induced retinal and optic nerve damage. Eur J Neurosci 2020; 51:2394-2411. [PMID: 31883161 DOI: 10.1111/ejn.14662] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 12/09/2019] [Accepted: 12/12/2019] [Indexed: 01/17/2023]
Abstract
Brain-derived neurotrophic factor (BDNF) could be considered a potential neuroprotective therapy in amyloid beta (Aβ)-associated retinal and optic nerve degeneration. Hence, in this study we investigated the neuroprotective effect of BDNF against Aβ1-40-induced retinal and optic nerve injury. In this study, exposure to Aβ1-40 was associated with retinal and optic nerve injury. TUNEL staining showed significant reduction in the apoptotic cell count in the BDNF-treated group compared with Aβ1-40 group. H&E-stained retinal sections also showed a striking reduction in neuronal cells in the ganglion cell layer (GCL) of retinas fourteen days after Aβ1-40 exposure. By contrast, number of retinal cells was preserved in the retinas of BDNF-treated animals. After Aβ1-40 exposure, visible axonal swelling was observed in optic nerve sections. However, the BDNF-treated group showed fewer changes in optic nerve; axonal swelling was less frequent and less marked. In the present study, exposure to Aβ was associated with oxidative stress, whereas levels of retinal glutathione (GSH), superoxide dismutase (SOD) and catalase were significantly increased in BDNF-treated than in Aβ1-40-treated rats. Both visual object recognition tests using an open-field arena and a Morris water maze showed that BDNF improved rats' ability to recognise visual cues (objects with different shapes) after Aβ1-40 exposure, thus demonstrating that the visual performance of rats was relatively preserved following BDNF treatment. In conclusion, intravitreal treatment with BDNF prevents Aβ1-40-induced retinal cell apoptosis and axon loss in the optic nerve of rats by reducing retinal oxidative stress and restoring retinal BDNF levels.
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Affiliation(s)
- Mohd Aizuddin Mohd Lazaldin
- Centre for Neuroscience Research (NeuRon), Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh, Malaysia
| | - Igor Iezhitsa
- Centre for Neuroscience Research (NeuRon), Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh, Malaysia.,Institute for Pathology, Laboratory and Forensic Medicine (I-PPerForM), Universiti Teknologi MARA, Sungai Buloh, Malaysia.,Research Centre for Innovative Medicines, Volgograd State Medical University, Volgograd, Russia
| | - Renu Agarwal
- School of Medicine, International Medical University, Kuala Lumpur, Malaysia
| | - Nor Salmah Bakar
- Centre for Neuroscience Research (NeuRon), Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh, Malaysia
| | - Puneet Agarwal
- School of Medicine, International Medical University, Kuala Lumpur, Malaysia
| | - Nafeeza Mohd Ismail
- School of Medicine, International Medical University, Kuala Lumpur, Malaysia
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12
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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] [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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13
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Development of novel theranostic agents for in vivo amyloid imaging and protective effects on human neuroblastoma cells. Eur J Med Chem 2019; 181:111585. [PMID: 31404860 DOI: 10.1016/j.ejmech.2019.111585] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 08/01/2019] [Accepted: 08/03/2019] [Indexed: 11/21/2022]
Abstract
Brain amyloid deposits have been identified as the main neuropathological hallmarks of Alzheimer's diseases (AD) and intensive efforts have been devoted to develop aggregation inhibitors preventing the formation of toxic oligomeric Aβ for therapeutic. In addition, evidence indicates that the formation and accumulation of β-amyloid plaques probably precede clinical symptoms by around 20 years and imaging of such plaques would be beneficial for early-stage AD detection. In this study, we investigated phenothiazine-based compounds as novel promising theranostic agents for AD. These multifunctional agents exhibited BBB permeability, low neurotoxicity, good bio-stability as well as strong turn-on fluorescence with a Stokes shift upon binding to Aβ aggregates. They had metal-chelating property which could delay Aβ aggregation and displayed high binding affinity for β-amyloid aggregates. Moreover, they have been simultaneously applied to perform in vivo near-infrared fluorescence imaging of β-amyloid plaques in double transgenic AD mouse model, to prevent self-aggregation of Aβ monomer from forming toxic oligomers and to protect human neuroblastoma SH-SY5Y cells against Aβ-induced toxicity and oxidative stress.
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14
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Huang Y, Guo B, Shi B, Gao Q, Zhou Q. Chinese Herbal Medicine Xueshuantong Enhances Cerebral Blood Flow and Improves Neural Functions in Alzheimer's Disease Mice. J Alzheimers Dis 2019; 63:1089-1107. [PMID: 29710701 PMCID: PMC6004915 DOI: 10.3233/jad-170763] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Reduced cerebral blood flow in Alzheimer's disease (AD) may occur in early AD, which contributes to the pathogenesis and/or pathological progression of AD. Reversing this deficit may have therapeutic potential. Certain traditional Chinese herbal medicines (e.g., Saponin and its major component Xueshuantong [XST]) increase blood flow in humans, but whether they could be effective in treating AD patients has not been tested. We found that systemic XST injection elevated cerebral blood flow in APP/PS1 transgenic mice using two-photon time-lapse imaging in the same microvessels before and after injection. Subchronic XST treatment led to improved spatial learning and memory and motor performance in the APP/PS1 mice, suggesting improved neural plasticity and functions. Two-photon time lapse imaging of the same plaques revealed a reduction in plaque size after XST treatment. In addition, western blots experiments showed that XST treatment led to reduced processing of amyloid-β protein precursor (AβPP) and enhanced clearance of amyloid-β (Aβ) without altering the total level of AβPP. We also found increased synapse density in the immediate vicinity of amyloid plaques, suggesting enhanced synaptic function. We conclude that targeting cerebral blood flow can be an effective strategy in treating AD.
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Affiliation(s)
- Yangmei Huang
- School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Baihong Guo
- School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Bihua Shi
- School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Qingtao Gao
- School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Qiang Zhou
- School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China
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15
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Avants BB, Hutchison RM, Mikulskis A, Salinas-Valenzuela C, Hargreaves R, Beaver J, Chiao P. Amyloid beta-positive subjects exhibit longitudinal network-specific reductions in spontaneous brain activity. Neurobiol Aging 2018; 74:191-201. [PMID: 30471630 DOI: 10.1016/j.neurobiolaging.2018.10.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 09/06/2018] [Accepted: 10/02/2018] [Indexed: 12/20/2022]
Abstract
Amyloid beta (Aβ) deposition and cognitive decline are key features of Alzheimer's disease. The relationship between Aβ status and changes in neuronal function over time, however, remains unclear. We evaluated the effect of baseline Aβ status on reference region spontaneous brain activity (SBA-rr) using resting-state functional magnetic resonance imaging and fluorodeoxyglucose positron emission tomography in patients with mild cognitive impairment. Patients (N = 62, [43 Aβ-positive]) from the Alzheimer's Disease Neuroimaging Initiative were divided into Aβ-positive and Aβ-negative groups via prespecified cerebrospinal fluid Aβ42 or 18F-florbetapir positron emission tomography standardized uptake value ratio cutoffs measured at baseline. We analyzed interaction of biomarker-confirmed Aβ status with SBA-rr change over a 2-year period using mixed-effects modeling. SBA-rr differences between Aβ-positive and Aβ-negative subjects increased significantly over time within subsystems of the default and visual networks. Changes exhibit an interaction with memory performance over time but were independent of glucose metabolism. Results reinforce the value of resting-state functional magnetic resonance imaging in evaluating Alzheimer''s disease progression and suggest spontaneous neuronal activity changes are concomitant with cognitive decline.
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Affiliation(s)
- Brian B Avants
- Biogen employee while completing work, 225 Binney Street, Cambridge, Massachusetts, 02142, USA.
| | | | - Alvydas Mikulskis
- Biogen employee while completing work, 225 Binney Street, Cambridge, Massachusetts, 02142, USA
| | | | | | - John Beaver
- Biogen, 225 Binney Street, Cambridge, Massachusetts, 02142, USA
| | - Ping Chiao
- Biogen, 225 Binney Street, Cambridge, Massachusetts, 02142, USA
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16
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Klein CP, Hoppe JB, Saccomori AB, Dos Santos BG, Sagini JP, Crestani MS, August PM, Hözer RM, Grings M, Parmeggiani B, Leipnitz G, Navas P, Salbego CG, Matté C. Physical Exercise During Pregnancy Prevents Cognitive Impairment Induced by Amyloid-β in Adult Offspring Rats. Mol Neurobiol 2018; 56:2022-2038. [PMID: 29982984 DOI: 10.1007/s12035-018-1210-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 06/26/2018] [Indexed: 12/24/2022]
Abstract
Alzheimer's disease (AD) is the main aging-associated neurodegenerative disorder and is characterized by mitochondrial dysfunction, oxidative stress, synaptic failure, and cognitive decline. It has been a challenge to find disease course-modifying treatments. However, several studies demonstrated that regular physical activity and exercise are capable of promoting brain health by improving the cognitive function. Maternal lifestyle, including regular exercise during pregnancy, has also been shown to influence fetal development and disease susceptibility in adulthood through fetal metabolism programming. Here, we investigated the potential neuroprotective role of regular maternal swimming, before and during pregnancy, against amyloid-β neurotoxicity in the adult offspring. Behavioral and neurochemical analyses were performed 14 days after male offspring received a single, bilateral, intracerebroventricular (icv) injection of amyloid-β oligomers (AβOs). AβOs-injected rats of the sedentary maternal group exhibited learning and memory deficits, along with reduced synaptophysin, brain-derived neurotrophic factor (BDNF) levels, and alterations of mitochondrial function. Strikingly, the offspring of the sedentary maternal group had AβOs-induced behavioral alterations that were prevented by maternal exercise. This effect was accompanied by preventing the alteration of synaptophysin levels in the offspring of exercised dams. Additionally, offspring of the maternal exercise group exhibited an augmentation of functional mitochondria, as indicated by increases in mitochondrial mass and membrane potential, α-ketoglutarate dehydrogenase, and cytochrome c oxidase enzymes activities. Moreover, maternal exercise during pregnancy induced long-lasting modulation of fusion and fission proteins, Mfn1 and Drp1, respectively. Overall, our data demonstrates a potential protective effect of exercise during pregnancy against AβOs-induced neurotoxicity in the adult offspring brain, by mitigating the neurodegenerative process triggered by Alzheimer-associated AβOs through programming the brain metabolism.
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Affiliation(s)
- Caroline Peres Klein
- Programa de Pós-Graduação em Ciências Biológicas - Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035-003, Brazil
| | - Juliana Bender Hoppe
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - André Brum Saccomori
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Bernardo Gindri Dos Santos
- Programa de Pós-Graduação em Ciências Biológicas - Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035-003, Brazil
| | - João Pedro Sagini
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Mariana Scortegagna Crestani
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Pauline Maciel August
- Programa de Pós-Graduação em Ciências Biológicas - Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035-003, Brazil
| | - Régis Mateus Hözer
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Mateus Grings
- Programa de Pós-Graduação em Ciências Biológicas - Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035-003, Brazil
| | - Belisa Parmeggiani
- Programa de Pós-Graduação em Ciências Biológicas - Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035-003, Brazil
| | - Guilhian Leipnitz
- Programa de Pós-Graduação em Ciências Biológicas - Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035-003, Brazil.,Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Plácido Navas
- Centro Andaluz de Biología del Desarrollo and CIBERER, Instituto de Salud Carlos III, Universidad Pablo de Olavide-CSIC-JA, 41013, Sevilla, Spain
| | - Christianne Gazzana Salbego
- Programa de Pós-Graduação em Ciências Biológicas - Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035-003, Brazil.,Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Cristiane Matté
- Programa de Pós-Graduação em Ciências Biológicas - Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035-003, Brazil. .,Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
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17
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Mohd Lazaldin MA, Iezhitsa I, Agarwal R, Bakar NS, Agarwal P, Mohd Ismail N. Time- and dose-related effects of amyloid beta1-40 on retina and optic nerve morphology in rats. Int J Neurosci 2018; 128:952-965. [PMID: 29488424 DOI: 10.1080/00207454.2018.1446953] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
PURPOSE Amyloid beta (Aβ) is known to contribute to the pathophysiology of retinal neurodegenerative diseases such as glaucoma. Effects of intravitreal Aβ(1-42) on retinal and optic nerve morphology in animal models have widely been studied but not those of Aβ(1-40). Hence, we evaluated the time- and dose-related effects of intravitreal Aβ(1-40) on retinal and optic nerve morphology. Since oxidative stress and brain derived neurotrophic factor (BDNF) are associated with Aβ-induced neuronal damage, we also studied dose and time-related effects of Aβ(1-40) on retinal oxidative stress and BDNF levels. MATERIALS AND METHODS Five groups of rats were intravitreally administered with vehicle or Aβ(1-40) in doses of 1.0, 2.5, 5 and 10 nmol. Animals were sacrificed and eyes were enucleated at weeks 1, 2 and 4 post-injection. The retinae were subjected to morphometric analysis and TUNEL staining. Optic nerve sections were stained with toluidine blue and were graded for neurodegenerative effects. The estimation of BDNF and markers of oxidative stress in retina were done using ELISA technique. RESULTS AND CONCLUSIONS It was observed that intravitreal Aβ(1-40) causes significant retinal and optic nerve damage up to day 14 post-injection and there was increasing damage with increase in dose. However, on day 30 post-injection both the retinal and optic nerve morphology showed a trend towards normalization. The observations made for retinal cell apoptosis, retinal glutathione, superoxide dismutase activity and BDNF were in accordance with those of morphological changes with deterioration till day 14 and recovery by day 30 post-injection. The findings of this study may provide a guide for selection of appropriate experimental conditions for future studies.
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Affiliation(s)
- Mohd Aizuddin Mohd Lazaldin
- a Centre For Neuroscience Research, Faculty of Medicine , Universiti Teknologi MARA, Sungai Buloh Campus, Selangor , Malaysia
| | - Igor Iezhitsa
- a Centre For Neuroscience Research, Faculty of Medicine , Universiti Teknologi MARA, Sungai Buloh Campus, Selangor , Malaysia.,b Research Institute of Pharmacology, Volgograd State Medical University , Volgograd , Russia
| | - Renu Agarwal
- a Centre For Neuroscience Research, Faculty of Medicine , Universiti Teknologi MARA, Sungai Buloh Campus, Selangor , Malaysia
| | - Nor Salmah Bakar
- a Centre For Neuroscience Research, Faculty of Medicine , Universiti Teknologi MARA, Sungai Buloh Campus, Selangor , Malaysia
| | - Puneet Agarwal
- c IMU Clinical School, International Medical University , Seremban , Malaysia
| | - Nafeeza Mohd Ismail
- a Centre For Neuroscience Research, Faculty of Medicine , Universiti Teknologi MARA, Sungai Buloh Campus, Selangor , Malaysia
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18
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O'Riordan KJ, Hu NW, Rowan MJ. Physiological activation of mGlu5 receptors supports the ion channel function of NMDA receptors in hippocampal LTD induction in vivo. Sci Rep 2018. [PMID: 29535352 PMCID: PMC5849730 DOI: 10.1038/s41598-018-22768-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Synaptic long-term depression (LTD) is believed to underlie critical mnemonic processes in the adult hippocampus. The roles of the metabotropic and ionotropic actions of glutamate in the induction of synaptic LTD by electrical low-frequency stimulation (LFS) in the living adult animal is poorly understood. Here we examined the requirement for metabotropic glutamate (mGlu) and NMDA receptors in LTD induction in anaesthetized adult rats. LTD induction was primarily dependent on NMDA receptors and required the involvement of both the ion channel function and GluN2B subunit of the receptor. Endogenous mGlu5 receptor activation necessitated the local application of relatively high doses of either competitive or non-competitive NMDA receptor antagonists to block LTD induction. Moreover, boosting endogenous glutamate activation of mGlu5 receptors with a positive allosteric modulator lowered the threshold for NMDA receptor-dependent LTD induction by weak LFS. The present data provide support in the living animal that NMDA receptor-dependent LTD is boosted by endogenously released glutamate activation of mGlu5 receptors. Given the predominant perisynaptic location of mGlu5 receptors, the present findings emphasize the need to further evaluate the contribution and mechanisms of these receptors in NMDA receptor-dependent synaptic plasticity in the adult hippocampus in vivo.
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Affiliation(s)
- Kenneth J O'Riordan
- Department of Pharmacology and Therapeutics and Institute of Neuroscience, Watts Building, Trinity College, Dublin, 2, Ireland
| | - Neng-Wei Hu
- Department of Pharmacology and Therapeutics and Institute of Neuroscience, Watts Building, Trinity College, Dublin, 2, Ireland. .,Department of Gerontology, Yijishan Hospital, Wannan Medical College, Wuhu, China. .,Department of Physiology and Neurobiology, Zhengzhou University School of Medicine, Zhengzhou, 450001, China.
| | - Michael J Rowan
- Department of Pharmacology and Therapeutics and Institute of Neuroscience, Watts Building, Trinity College, Dublin, 2, Ireland.
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19
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Hadipour M, Kaka G, Bahrami F, Meftahi GH, Pirzad Jahromi G, Mohammadi A, Sahraei H. Crocin improved amyloid beta induced long-term potentiation and memory deficits in the hippocampal CA1 neurons in freely moving rats. Synapse 2018; 72:e22026. [DOI: 10.1002/syn.22026] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 01/17/2018] [Accepted: 01/18/2018] [Indexed: 01/15/2023]
Affiliation(s)
| | - Gholamreza Kaka
- Neuroscience Research Center, Baqiyatallah University of Medical Sciences; Tehran Iran
| | - Farideh Bahrami
- Department of Physiology and Biophysics, Faculty of Medicine; Baqiyatallah University of Medical Sciences; Tehran Iran
| | | | - Gila Pirzad Jahromi
- Neuroscience Research Center, Baqiyatallah University of Medical Sciences; Tehran Iran
| | - Alireza Mohammadi
- Neuroscience Research Center, Baqiyatallah University of Medical Sciences; Tehran Iran
| | - Hedayat Sahraei
- Neuroscience Research Center, Baqiyatallah University of Medical Sciences; Tehran Iran
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20
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Alzheimer's disease as oligomeropathy. Neurochem Int 2017; 119:57-70. [PMID: 28821400 DOI: 10.1016/j.neuint.2017.08.010] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 07/30/2017] [Accepted: 08/13/2017] [Indexed: 12/21/2022]
Abstract
Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder and is characterized by pathological aggregates of amyloid β-protein (Aβ) and tau protein. On the basis of genetic evidence, biochemical data, and animal models, Aβ has been suggested to be responsible for the pathogenesis of AD (the amyloid hypothesis). Aβ molecules tend to aggregate to form oligomers, protofibrils, and mature fibrils. Although mature fibrils in the final stage have been thought to be the cause of AD pathogenesis, recent studies using synthetic Aβ peptides, a cell culture model, Aβ precursor protein transgenic mice models, and human samples, such as cerebrospinal fluids and postmortem brains of AD patients, suggest that pre-fibrillar forms (oligomers of Aβ) are more deleterious than are extracellular fibril forms. Based on this recent evidence showing that oligomers have a central role in the pathogenesis of AD, the term "oligomeropathy" could be used to define AD and other protein-misfolding diseases. In this review, I discuss recent developments in the "oligomer hypothesis" including our research findings regarding the pathogenesis of AD.
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21
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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] [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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22
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Farrell JS, Gaxiola-Valdez I, Wolff MD, David LS, Dika HI, Geeraert BL, Rachel Wang X, Singh S, Spanswick SC, Dunn JF, Antle MC, Federico P, Teskey GC. Postictal behavioural impairments are due to a severe prolonged hypoperfusion/hypoxia event that is COX-2 dependent. eLife 2016; 5:e19352. [PMID: 27874832 PMCID: PMC5154758 DOI: 10.7554/elife.19352] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 11/21/2016] [Indexed: 12/26/2022] Open
Abstract
Seizures are often followed by sensory, cognitive or motor impairments during the postictal phase that show striking similarity to transient hypoxic/ischemic attacks. Here we show that seizures result in a severe hypoxic attack confined to the postictal period. We measured brain oxygenation in localized areas from freely-moving rodents and discovered a severe hypoxic event (pO2 < 10 mmHg) after the termination of seizures. This event lasted over an hour, is mediated by hypoperfusion, generalizes to people with epilepsy, and is attenuated by inhibiting cyclooxygenase-2 or L-type calcium channels. Using inhibitors of these targets we separated the seizure from the resulting severe hypoxia and show that structure specific postictal memory and behavioral impairments are the consequence of this severe hypoperfusion/hypoxic event. Thus, epilepsy is much more than a disease hallmarked by seizures, since the occurrence of postictal hypoperfusion/hypoxia results in a separate set of neurological consequences that are currently not being treated and are preventable.
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Affiliation(s)
- Jordan S Farrell
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Ismael Gaxiola-Valdez
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Marshal D Wolff
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Laurence S David
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Haruna I Dika
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
- Department of Physiology, Catholic University of Health and Allied Sciences, Mwanza, Tanzania
| | - Bryce L Geeraert
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - X Rachel Wang
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Shaily Singh
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Simon C Spanswick
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Jeff F Dunn
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Michael C Antle
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Paolo Federico
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - G Campbell Teskey
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
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Ge YX, Tian XZ, Lin YY, Liu XY. Chronic treatment with levetiracetam reverses deficits in hippocampal LTP in vivo in experimental temporal lobe epilepsy rats. Neurosci Lett 2016; 628:194-200. [PMID: 27345386 DOI: 10.1016/j.neulet.2016.06.043] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Revised: 06/10/2016] [Accepted: 06/21/2016] [Indexed: 12/21/2022]
Abstract
Temporal lobe epilepsy (TLE), the common form of epilepsy in adults, often displays complex partial seizures and cognitive deficits. The underlying mechanisms of such deficits are not yet well understood. Many contributing factors, such as initial epileptogenic lesion, seizure type, age of onset, and treatment side effects have been proposed. Levetiracetam (LEV) is a novel anti-epileptic drug (AED) used to treat partial seizures and idiopathic generalized epilepsy. It has been suggested that LEV exerts antiepileptic properties by modulation of synaptic release of neurotransmitters. However, its neuroprotective effects on learning and memory are not yet well demonstrated. Here we showed the impairment of spatial memory in the pilocarpine-induced experimental TLE rats, which can be improved by LEV. Furthermore, we found chronic LEV treatment partially reversed the SE-induced synaptic dysfunction in hippocampal LTP induction in vivo. In addition, LEV treatment can alleviate the SE-induced abnormal GluR1 phosphorylation at Ser(831) site, which may contribute to the rescue of synaptic transmission. These results indicate the neuroprotective role for LEV while it exhibits an antiseizure effect on experimental epileptic models.
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Affiliation(s)
- Yu-Xing Ge
- Department of Neurology, Tongji University Affiliated Tenth People's Hospital, 200072 Shanghai, PR China
| | - Xiang-Zhu Tian
- Department of Neurology, Tongji University Affiliated Tenth People's Hospital, 200072 Shanghai, PR China
| | - Ying-Ying Lin
- Department of Neurology, Tongji University Affiliated Tenth People's Hospital, 200072 Shanghai, PR China
| | - Xue-Yuan Liu
- Department of Neurology, Tongji University Affiliated Tenth People's Hospital, 200072 Shanghai, PR China.
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24
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Mutated tau, amyloid and neuroinflammation in Alzheimer disease—A brief review. ACTA ACUST UNITED AC 2016; 51:1-8. [PMID: 26851150 DOI: 10.1016/j.proghi.2016.01.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 01/14/2016] [Accepted: 01/14/2016] [Indexed: 01/08/2023]
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25
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Montgomery KS, Edwards G, Levites Y, Kumar A, Myers CE, Gluck MA, Setlow B, Bizon JL. Deficits in hippocampal-dependent transfer generalization learning accompany synaptic dysfunction in a mouse model of amyloidosis. Hippocampus 2016; 26:455-71. [PMID: 26418152 PMCID: PMC4803574 DOI: 10.1002/hipo.22535] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 09/11/2015] [Accepted: 09/17/2015] [Indexed: 11/08/2022]
Abstract
Elevated β-amyloid and impaired synaptic function in hippocampus are among the earliest manifestations of Alzheimer's disease (AD). Most cognitive assessments employed in both humans and animal models, however, are insensitive to this early disease pathology. One critical aspect of hippocampal function is its role in episodic memory, which involves the binding of temporally coincident sensory information (e.g., sights, smells, and sounds) to create a representation of a specific learning epoch. Flexible associations can be formed among these distinct sensory stimuli that enable the "transfer" of new learning across a wide variety of contexts. The current studies employed a mouse analog of an associative "transfer learning" task that has previously been used to identify risk for prodromal AD in humans. The rodent version of the task assesses the transfer of learning about stimulus features relevant to a food reward across a series of compound discrimination problems. The relevant feature that predicts the food reward is unchanged across problems, but an irrelevant feature (i.e., the context) is altered. Experiment 1 demonstrated that C57BL6/J mice with bilateral ibotenic acid lesions of hippocampus were able to discriminate between two stimuli on par with control mice; however, lesioned mice were unable to transfer or apply this learning to new problem configurations. Experiment 2 used the APPswe PS1 mouse model of amyloidosis to show that robust impairments in transfer learning are evident in mice with subtle β-amyloid-induced synaptic deficits in the hippocampus. Finally, Experiment 3 confirmed that the same transfer learning impairments observed in APPswePS1 mice were also evident in the Tg-SwDI mouse, a second model of amyloidosis. Together, these data show that the ability to generalize learned associations to new contexts is disrupted even in the presence of subtle hippocampal dysfunction and suggest that, across species, this aspect of hippocampal-dependent learning may be useful for early identification of AD-like pathology.
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Affiliation(s)
- Karienn S. Montgomery
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, Bryan, TX
| | - George Edwards
- Mitchell Center for Alzheimer’s Disease and Related Brain Disorders, Department of Neurology, University of Texas Health Science Center in Houston, Houston, TX
| | - Yona Levites
- Department of Neuroscience, University of Florida, Gainesville, FL
| | - Ashok Kumar
- Department of Neuroscience, University of Florida, Gainesville, FL
| | - Catherine E. Myers
- VA New Jersey Health Care System, East Orange, NJ 07018
- Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ
| | - Mark A. Gluck
- Center for Molecular & Behavioral Neuroscience, Rutgers University, Newark, NJ
| | - Barry Setlow
- Department of Psychiatry, University of Florida, Gainesville, FL
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26
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Guntupalli S, Widagdo J, Anggono V. Amyloid-β-Induced Dysregulation of AMPA Receptor Trafficking. Neural Plast 2016; 2016:3204519. [PMID: 27073700 PMCID: PMC4814684 DOI: 10.1155/2016/3204519] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 02/28/2016] [Indexed: 01/22/2023] Open
Abstract
Evidence from neuropathological, genetic, animal model, and biochemical studies has indicated that the accumulation of amyloid-beta (Aβ) is associated with, and probably induces, profound neuronal changes in brain regions critical for memory and cognition in the development of Alzheimer's disease (AD). There is considerable evidence that synapses are particularly vulnerable to AD, establishing synaptic dysfunction as one of the earliest events in pathogenesis, prior to neuronal loss. It is clear that excessive Aβ levels can disrupt excitatory synaptic transmission and plasticity, mainly due to dysregulation of the AMPA and NMDA glutamate receptors in the brain. Importantly, AMPA receptors are the principal glutamate receptors that mediate fast excitatory neurotransmission. This is essential for synaptic plasticity, a cellular correlate of learning and memory, which are the cognitive functions that are most disrupted in AD. Here we review recent advances in the field and provide insights into the molecular mechanisms that underlie Aβ-induced dysfunction of AMPA receptor trafficking. This review focuses primarily on NMDA receptor- and metabotropic glutamate receptor-mediated signaling. In particular, we highlight several mechanisms that underlie synaptic long-term depression as common signaling pathways that are hijacked by the neurotoxic effects of Aβ.
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Affiliation(s)
- Sumasri Guntupalli
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Jocelyn Widagdo
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Victor Anggono
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
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27
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Michels L, Warnock G, Buck A, Macauda G, Leh SE, Kaelin AM, Riese F, Meyer R, O'Gorman R, Hock C, Kollias S, Gietl AF. Arterial spin labeling imaging reveals widespread and Aβ-independent reductions in cerebral blood flow in elderly apolipoprotein epsilon-4 carriers. J Cereb Blood Flow Metab 2016; 36:581-95. [PMID: 26661143 PMCID: PMC4794091 DOI: 10.1177/0271678x15605847] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2014] [Accepted: 10/07/2015] [Indexed: 12/11/2022]
Abstract
Changes in cerebral blood flow are an essential feature of Alzheimer's disease and have been linked to apolipoprotein E-genotype and cerebral amyloid-deposition. These factors could be interdependent or influence cerebral blood flow via different mechanisms. We examined apolipoprotein E-genotype, amyloid beta-deposition, and cerebral blood flow in amnestic mild cognitive impairment using pseudo-continuous arterial spin labeling MRI in 27 cognitively normal elderly and 16 amnestic mild cognitive impairment participants. Subjects underwent Pittsburgh Compound B (PiB) positron emission tomography and apolipoprotein E-genotyping. Global cerebral blood flow was lower in apolipoprotein E ɛ4-allele carriers (apolipoprotein E4+) than in apolipoprotein E4- across all subjects (including cognitively normal participants) and within the group of cognitively normal elderly. Global cerebral blood flow was lower in subjects with mild cognitive impairment compared with cognitively normal. Subjects with elevated cerebral amyloid-deposition (PiB+) showed a trend for lower global cerebral blood flow. Apolipoprotein E-status exerted the strongest effect on global cerebral blood flow. Regional analysis indicated that local cerebral blood flow reductions were more widespread for the contrasts apolipoprotein E4+ versus apolipoprotein E4- compared with the contrasts PiB+ versus PiB- or mild cognitive impairment versus cognitively normal. These findings suggest that apolipoprotein E-genotype exerts its impact on cerebral blood flow at least partly independently from amyloid beta-deposition, suggesting that apolipoprotein E also contributes to cerebral blood flow changes outside the context of Alzheimer's disease.
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Affiliation(s)
- Lars Michels
- Institute of Neuroradiology, University Hospital Zurich, Zurich, Switzerland Center of MR-Research, University Children's Hospital Zurich, Zurich, Switzerland
| | - Geoffrey Warnock
- Clinic of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Alfred Buck
- Clinic of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Gianluca Macauda
- Institute of Neuroradiology, University Hospital Zurich, Zurich, Switzerland Neuropsychology Unit, Department of Neurology, University Hospital Zurich, Zurich, Switzerland
| | - Sandra E Leh
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Andrea M Kaelin
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Florian Riese
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Rafael Meyer
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Ruth O'Gorman
- Center of MR-Research, University Children's Hospital Zurich, Zurich, Switzerland
| | - Christoph Hock
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Spyros Kollias
- Institute of Neuroradiology, University Hospital Zurich, Zurich, Switzerland
| | - Anton F Gietl
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
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28
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Comparison of the Effect of Exercise on Late-Phase LTP of the Dentate Gyrus and CA1 of Alzheimer's Disease Model. Mol Neurobiol 2015; 53:6859-6868. [PMID: 26660327 DOI: 10.1007/s12035-015-9612-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Accepted: 12/03/2015] [Indexed: 01/15/2023]
Abstract
We investigated the neuroprotective effect of regular treadmill exercise training on long-term memory and its correlate: the late-phase long-term potentiation (L-LTP) and plasticity- and memory-related signaling molecules in the DG and CA1 areas of a rat model of Alzheimer's disease (AD) (i.c.v. infusion of Aβ1-42 peptides, 2 weeks, 250 pmol/day). Testing in the radial arm water maze revealed severe impairment of spatial long-term memory in Aβ-infused sedentary rats but not in exercised Aβ-infused rats. The L-LTP, measured as changes in the field (f)EPSP and in the amplitude of population spike (pspike), was induced by multiple high-frequency stimulation in the CA1 and DG areas of anesthetized rats. The L-LTP of fEPSP in both areas was severely impaired in the sedentary Aβ rats but not in exercised Aβ rats. However, L-LTP of the pspike was severely suppressed in the CA1 area but not in the DG of sedentary Aβ rats. Immunoblot analysis revealed no increase in the levels of phosphorylated (p)-CREB, CaMKIV, and brain-derived neurotrophic factor (BDNF) in both CA1 and DG areas of sedentary Aβ rats during L-LTP, whereas the levels of these molecules were robustly increased in exercised Aβ rats. Impairment of synaptic function may be due to deleterious changes in the molecular signaling cascades that mediate synaptic structural and functional changes. The protective effect of regular exercise can be a promising therapeutic measure for countering or delaying the AD-like pathology.
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29
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Müller-Schiffmann A, Herring A, Abdel-Hafiz L, Chepkova AN, Schäble S, Wedel D, Horn AHC, Sticht H, de Souza Silva MA, Gottmann K, Sergeeva OA, Huston JP, Keyvani K, Korth C. Amyloid-β dimers in the absence of plaque pathology impair learning and synaptic plasticity. Brain 2015; 139:509-25. [DOI: 10.1093/brain/awv355] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 10/17/2015] [Indexed: 11/12/2022] Open
Abstract
Abstract
Despite amyloid plaques, consisting of insoluble, aggregated amyloid-β peptides, being a defining feature of Alzheimer’s disease, their significance has been challenged due to controversial findings regarding the correlation of cognitive impairment in Alzheimer’s disease with plaque load. The amyloid cascade hypothesis defines soluble amyloid-β oligomers, consisting of multiple amyloid-β monomers, as precursors of insoluble amyloid-β plaques. Dissecting the biological effects of single amyloid-β oligomers, for example of amyloid-β dimers, an abundant amyloid-β oligomer associated with clinical progression of Alzheimer’s disease, has been difficult due to the inability to control the kinetics of amyloid-β multimerization. For investigating the biological effects of amyloid-β dimers, we stabilized amyloid-β dimers by an intermolecular disulphide bridge via a cysteine mutation in the amyloid-β peptide (Aβ-S8C) of the amyloid precursor protein. This construct was expressed as a recombinant protein in cells and in a novel transgenic mouse, termed tgDimer mouse. This mouse formed constant levels of highly synaptotoxic soluble amyloid-β dimers, but not monomers, amyloid-β plaques or insoluble amyloid-β during its lifespan. Accordingly, neither signs of neuroinflammation, tau hyperphosphorylation or cell death were observed. Nevertheless, these tgDimer mice did exhibit deficits in hippocampal long-term potentiation and age-related impairments in learning and memory, similar to what was observed in classical Alzheimer’s disease mouse models. Although the amyloid-β dimers were unable to initiate the formation of insoluble amyloid-β aggregates in tgDimer mice, after crossbreeding tgDimer mice with the CRND8 mouse, an amyloid-β plaque generating mouse model, Aβ-S8C dimers were sequestered into amyloid-β plaques, suggesting that amyloid-β plaques incorporate neurotoxic amyloid-β dimers that by themselves are unable to self-assemble. Our results suggest that within the fine interplay between different amyloid-β species, amyloid-β dimer neurotoxic signalling, in the absence of amyloid-β plaque pathology, may be involved in causing early deficits in synaptic plasticity, learning and memory that accompany Alzheimer’s disease.
10.1093/brain/awv355_video_abstract awv355_video_abstract
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Affiliation(s)
| | - Arne Herring
- 2 Institute of Neuropathology, University of Duisburg-Essen, Germany
| | - Laila Abdel-Hafiz
- 3 Centre for Behavioural Neuroscience, Heinrich Heine University, Düsseldorf, Germany
| | - Aisa N. Chepkova
- 4 Institute for Neuro- and Sensory Physiology, Heinrich Heine University, Düsseldorf, Germany
| | - Sandra Schäble
- 3 Centre for Behavioural Neuroscience, Heinrich Heine University, Düsseldorf, Germany
- *Present address: Comparative Psychology, Institute of Experimental Psychology, Heinrich Heine University, Düsseldorf, Germany
| | - Diana Wedel
- 1 Department Neuropathology, Heinrich Heine University, Düsseldorf, Germany
| | - Anselm H. C. Horn
- 5 Institute for Biochemistry, Friedrich Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Heinrich Sticht
- 5 Institute for Biochemistry, Friedrich Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | | | - Kurt Gottmann
- 4 Institute for Neuro- and Sensory Physiology, Heinrich Heine University, Düsseldorf, Germany
| | - Olga A. Sergeeva
- 4 Institute for Neuro- and Sensory Physiology, Heinrich Heine University, Düsseldorf, Germany
| | - Joseph P. Huston
- 3 Centre for Behavioural Neuroscience, Heinrich Heine University, Düsseldorf, Germany
| | - Kathy Keyvani
- 2 Institute of Neuropathology, University of Duisburg-Essen, Germany
| | - Carsten Korth
- 1 Department Neuropathology, Heinrich Heine University, Düsseldorf, Germany
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30
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Ferreira ST, Lourenco MV, Oliveira MM, De Felice FG. Soluble amyloid-β oligomers as synaptotoxins leading to cognitive impairment in Alzheimer's disease. Front Cell Neurosci 2015; 9:191. [PMID: 26074767 PMCID: PMC4443025 DOI: 10.3389/fncel.2015.00191] [Citation(s) in RCA: 236] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 04/30/2015] [Indexed: 12/22/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common form of dementia in the elderly, and affects millions of people worldwide. As the number of AD cases continues to increase in both developed and developing countries, finding therapies that effectively halt or reverse disease progression constitutes a major research and public health challenge. Since the identification of the amyloid-β peptide (Aβ) as the major component of the amyloid plaques that are characteristically found in AD brains, a major effort has aimed to determine whether and how Aβ leads to memory loss and cognitive impairment. A large body of evidence accumulated in the past 15 years supports a pivotal role of soluble Aβ oligomers (AβOs) in synapse failure and neuronal dysfunction in AD. Nonetheless, a number of basic questions, including the exact molecular composition of the synaptotoxic oligomers, the identity of the receptor(s) to which they bind, and the signaling pathways that ultimately lead to synapse failure, remain to be definitively answered. Here, we discuss recent advances that have illuminated our understanding of the chemical nature of the toxic species and the deleterious impact they have on synapses, and have culminated in the proposal of an Aβ oligomer hypothesis for Alzheimer’s pathogenesis. We also highlight outstanding questions and challenges in AD research that should be addressed to allow translation of research findings into effective AD therapies.
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Affiliation(s)
- Sergio T Ferreira
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro Rio de Janeiro, RJ, Brazil ; Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro Rio de Janeiro, RJ, Brazil
| | - Mychael V Lourenco
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro Rio de Janeiro, RJ, Brazil
| | - Mauricio M Oliveira
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro Rio de Janeiro, RJ, Brazil
| | - Fernanda G De Felice
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro Rio de Janeiro, RJ, Brazil
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31
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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] [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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32
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Aβ dimers differ from monomers in structural propensity, aggregation paths and population of synaptotoxic assemblies. Biochem J 2014; 461:413-26. [PMID: 24785004 DOI: 10.1042/bj20140219] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Dimers of Aβ (amyloid β-protein) are believed to play an important role in Alzheimer's disease. In the absence of sufficient brain-derived dimers, we studied one of the only possible dimers that could be produced in vivo, [Aβ](DiY) (dityrosine cross-linked Aβ). For comparison, we used the Aβ monomer and a design dimer cross-linked by replacement of Ser²⁶ with cystine [AβS26C]₂. We showed that similar to monomers, unaggregated dimers lack appreciable structure and fail to alter long-term potentiation. Importantly, dimers exhibit subtly different structural propensities from monomers and each other, and can self-associate to form larger assemblies. Although [Aβ](DiY) and [AβS26C]₂ have distinct aggregation pathways, they both populate bioactive soluble assemblies for longer durations than Aβ monomers. Our results indicate that the link between Aβ dimers and Alzheimer's disease results from the ability of dimers to further assemble and form synaptotoxic assemblies that persist for long periods of time.
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Goure WF, Krafft GA, Jerecic J, Hefti F. Targeting the proper amyloid-beta neuronal toxins: a path forward for Alzheimer's disease immunotherapeutics. ALZHEIMERS RESEARCH & THERAPY 2014; 6:42. [PMID: 25045405 PMCID: PMC4100318 DOI: 10.1186/alzrt272] [Citation(s) in RCA: 126] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Levels of amyloid-beta monomer and deposited amyloid-beta in the Alzheimer’s
disease brain are orders of magnitude greater than soluble amyloid-beta oligomer
levels. Monomeric amyloid-beta has no known direct toxicity. Insoluble fibrillar
amyloid-beta has been proposed to be an in vivo mechanism for removal of
soluble amyloid-beta and exhibits relatively low toxicity. In contrast, soluble
amyloid-beta oligomers are widely reported to be the most toxic amyloid-beta form,
both causing acute synaptotoxicity and inducing neurodegenerative processes. None of
the amyloid-beta immunotherapies currently in clinical development selectively target
soluble amyloid-beta oligomers, and their lack of efficacy is not unexpected
considering their selectivity for monomeric or fibrillar amyloid-beta (or both)
rather than soluble amyloid-beta oligomers. Because they exhibit acute,
memory-compromising synaptic toxicity and induce chronic neurodegenerative toxicity
and because they exist at very low in vivo levels in the Alzheimer’s
disease brain, soluble amyloid-beta oligomers constitute an optimal immunotherapeutic
target that should be pursued more aggressively.
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Affiliation(s)
- William F Goure
- Acumen Pharmaceuticals, Inc., 4453 North First Street, #360, Livermore, CA 94551, USA
| | - Grant A Krafft
- Acumen Pharmaceuticals, Inc., 4453 North First Street, #360, Livermore, CA 94551, USA
| | - Jasna Jerecic
- Acumen Pharmaceuticals, Inc., 4453 North First Street, #360, Livermore, CA 94551, USA
| | - Franz Hefti
- Acumen Pharmaceuticals, Inc., 4453 North First Street, #360, Livermore, CA 94551, USA
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34
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Mild cognitive impairment and asymptomatic Alzheimer disease subjects: equivalent β-amyloid and tau loads with divergent cognitive outcomes. J Neuropathol Exp Neurol 2014; 73:295-304. [PMID: 24607960 DOI: 10.1097/nen.0000000000000052] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Older adults with intact cognition before death and substantial Alzheimer disease (AD) lesions at autopsy have been termed "asymptomatic AD subjects" (ASYMAD). We previously reported hypertrophy of neuronal cell bodies, nuclei, and nucleoli in the CA1 of the hippocampus (CA1), anterior cingulate gyrus, posterior cingulate gyrus, and primary visual cortex of ASYMAD versus age-matched Control and mild cognitive impairment (MCI) subjects. However, it was unclear whether the neuronal hypertrophy could be attributed to differences in the severity of AD pathology. Here, we performed quantitative analyses of the severity of β-amyloid (Aβ) and phosphorylated tau (tau) loads in the brains of ASYMAD, Control, MCI, and AD subjects (n = 15 per group) from the Baltimore Longitudinal Study of Aging. Tissue sections from CA1, anterior cingulate gyrus, posterior cingulate gyrus, and primary visual cortex were immunostained for Aβ and tau; the respective loads were assessed using unbiased stereology by measuring the fractional areas of immunoreactivity for each protein in each region. The ASYMAD and MCI groups did not differ in Aβ and tau loads. These data confirm that ASYMAD and MCI subjects have comparable loads of insoluble Aβ and tau in regions vulnerable to AD pathology despite divergent cognitive outcomes. These findings imply that cognitive impairment in AD may be caused or modulated by factors other than insoluble forms of Aβ and tau.
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Hu NW, Nicoll AJ, Zhang D, Mably AJ, O'Malley T, Purro SA, Terry C, Collinge J, Walsh DM, Rowan MJ. mGlu5 receptors and cellular prion protein mediate amyloid-β-facilitated synaptic long-term depression in vivo. Nat Commun 2014; 5:3374. [PMID: 24594908 PMCID: PMC4354159 DOI: 10.1038/ncomms4374] [Citation(s) in RCA: 136] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 02/04/2014] [Indexed: 11/12/2022] Open
Abstract
NMDA-type glutamate receptors (NMDARs) are currently regarded as paramount in the
potent and selective disruption of synaptic plasticity by Alzheimer’s
disease amyloid β-protein
(Aβ). Non-NMDAR
mechanisms remain relatively unexplored. Here we describe how Aβ facilitates NMDAR-independent
long-term depression of synaptic transmission in the hippocampus in vivo.
Synthetic Aβ and
Aβ in soluble
extracts of Alzheimer’s disease brain usurp endogenous acetylcholine
muscarinic receptor-dependent long-term depression, to enable long-term depression
that required metabotropic glutamate-5
receptors (mGlu5Rs). We also find that mGlu5Rs are essential for Aβ-mediated inhibition of NMDAR-dependent long-term
potentiation in vivo. Blocking Aβ binding to cellular prion protein with antibodies prevents the facilitation
of long-term depression. Our findings uncover an overarching role for Aβ-PrPC-mGlu5R interplay in mediating both LTD
facilitation and LTP inhibition, encompassing NMDAR-mediated processes that were
previously considered primary. In Alzheimer's disease, the soluble amyloid beta peptide is
known to modulate synaptic function by forming a complex with prion proteins and
metabotropic glutamate receptors. Here, Hu et al. show that amyloid beta
signalling via this complex facilitates the induction of long-term depression at
synapses.
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Affiliation(s)
- Neng-Wei Hu
- Department of Pharmacology and Therapeutics, and Trinity College Institute of Neuroscience, Biotechnology Building, Trinity College Dublin, Dublin 2, Ireland
| | - Andrew J Nicoll
- Medical Research Council Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Dainan Zhang
- Department of Pharmacology and Therapeutics, and Trinity College Institute of Neuroscience, Biotechnology Building, Trinity College Dublin, Dublin 2, Ireland
| | - Alexandra J Mably
- Laboratory for Neurodegenerative Research, Center for Neurologic Diseases, Brigham & Women's Hospital, Harvard Institute of Medicine, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, USA
| | - Tiernan O'Malley
- Laboratory for Neurodegenerative Research, Center for Neurologic Diseases, Brigham & Women's Hospital, Harvard Institute of Medicine, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, USA
| | - Silvia A Purro
- Medical Research Council Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Cassandra Terry
- Medical Research Council Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - John Collinge
- Medical Research Council Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Dominic M Walsh
- Laboratory for Neurodegenerative Research, Center for Neurologic Diseases, Brigham & Women's Hospital, Harvard Institute of Medicine, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, USA
| | - Michael J Rowan
- Department of Pharmacology and Therapeutics, and Trinity College Institute of Neuroscience, Biotechnology Building, Trinity College Dublin, Dublin 2, Ireland
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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] [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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Sindi IA, Tannenberg RK, Dodd PR. Role for the neurexin-neuroligin complex in Alzheimer's disease. Neurobiol Aging 2013; 35:746-56. [PMID: 24211009 DOI: 10.1016/j.neurobiolaging.2013.09.032] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 09/20/2013] [Accepted: 09/22/2013] [Indexed: 11/29/2022]
Abstract
Synaptic damage is a critical hallmark of Alzheimer's disease, and the best correlate with cognitive impairment ante mortem. Synapses, the loci of communication between neurons, are characterized by signature protein combinations arrayed at tightly apposed pre- and post-synaptic sites. The most widely studied trans-synaptic junctional complexes, which direct synaptogenesis and foster the maintenance and stability of the mature terminal, are conjunctions of presynaptic neurexins and postsynaptic neuroligins. Fluctuations in the levels of neuroligins and neurexins can sway the balance between excitatory and inhibitory neurotransmission in the brain, and could lead to damage of synapses and dendrites. This review summarizes current understanding of the roles of neurexins and neuroligins proteolytic processing in synaptic plasticity in the human brain, and outlines their possible roles in β-amyloid metabolism and function, which are central pathogenic events in Alzheimer's disease progression.
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Affiliation(s)
- Ikhlas A Sindi
- Centre for Psychiatry and Clinical Neuroscience, School of Medicine, The University of Queensland, Brisbane, Australia
| | - Rudolph K Tannenberg
- Centre for Psychiatry and Clinical Neuroscience, School of Medicine, The University of Queensland, Brisbane, Australia; School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - Peter R Dodd
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia.
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Cecchi C, Stefani M. The amyloid-cell membrane system. The interplay between the biophysical features of oligomers/fibrils and cell membrane defines amyloid toxicity. Biophys Chem 2013; 182:30-43. [PMID: 23820236 DOI: 10.1016/j.bpc.2013.06.003] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 06/03/2013] [Accepted: 06/03/2013] [Indexed: 12/14/2022]
Abstract
Amyloid cytotoxicity, structure and polymorphisms are themes of increasing importance. Present knowledge considers any peptide/protein able to undergo misfolding and aggregation generating intrinsically cytotoxic amyloids. It also describes growth and structure of amyloid fibrils and their possible disassembly, whereas reduced information is available on oligomer structure. Recent research has highlighted the importance of the environmental conditions as determinants of the amyloid polymorphisms and cytotoxicity. Another body of evidence describes chemical or biological surfaces as key sites of protein misfolding and aggregation or of interaction with amyloids and the resulting biochemical modifications inducing cell functional/viability impairment. In particular, the membrane lipid composition appears to modulate cell response to toxic amyloids, thus contributing to explain the variable vulnerability to the same amyloids of different cell types. Finally, a recent view describes amyloid toxicity as an emerging property dependent on a complex interplay between the biophysical features of early aggregates and the interacting cell membranes taken as a whole system.
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Affiliation(s)
- Cristina Cecchi
- Department of Biomedical Experimental and Clinical Sciences and Research Centre on the Molecular Basis of Neurodegeneration, University of Florence, Florence, Italy
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39
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Lithner CU, Lacor PN, Zhao WQ, Mustafiz T, Klein WL, Sweatt JD, Hernandez CM. Disruption of neocortical histone H3 homeostasis by soluble Aβ: implications for Alzheimer's disease. Neurobiol Aging 2013; 34:2081-90. [PMID: 23582659 DOI: 10.1016/j.neurobiolaging.2012.12.028] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Accepted: 12/28/2012] [Indexed: 01/08/2023]
Abstract
Amyloid-β peptide (Aβ) fragment misfolding may play a crucial role in the progression of Alzheimer's disease (AD) pathophysiology as well as epigenetic mechanisms at the DNA and histone level. We hypothesized that histone H3 homeostasis is disrupted in association with the appearance of soluble Aβ at an early stage in AD progression. We identified, localized, and compared histone H3 modifications in multiple model systems (neural-like SH-SY5Y, primary neurons, Tg2576 mice, and AD neocortex), and narrowed our focus to investigate 3 key motifs associated with regulating transcriptional activation and inhibition: acetylated lysine 14, phosphorylated serine 10 and dimethylated lysine 9. Our results in vitro and in vivo indicate that multimeric soluble Aβ may be a potent signaling molecule indirectly modulating the transcriptional activity of DNA by modulating histone H3 homeostasis. These findings reveal potential loci of transcriptional disruption relevant to AD. Identifying genes that undergo significant epigenetic alterations in response to Aβ could aid in the understanding of the pathogenesis of AD, as well as suggesting possible new treatment strategies.
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Affiliation(s)
- Christina Unger Lithner
- Alzheimer Neurobiology Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
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40
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Yang T, Hong S, O'Malley T, Sperling RA, Walsh DM, Selkoe DJ. New ELISAs with high specificity for soluble oligomers of amyloid β-protein detect natural Aβ oligomers in human brain but not CSF. Alzheimers Dement 2013; 9:99-112. [PMID: 23375565 DOI: 10.1016/j.jalz.2012.11.005] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 10/16/2012] [Accepted: 11/21/2012] [Indexed: 10/27/2022]
Abstract
BACKGROUND Soluble oligomers of amyloid ß-protein (Aß) have been increasingly linked to synaptic dysfunction, tau alteration, and neuritic dystrophy in Alzheimer's disease (AD) and mouse models. There is a great need for assays that quantify Aß oligomers with high specificity and sensitivity. METHODS We designed and validated two oligomer-specific (o-) enzyme-linked immunoassays (ELISAs) using either an Aß aggregate-selective monoclonal for capture and a monoclonal to the free N-terminus for detection, or the latter antibody for both capture and detection. RESULTS The o-ELISAs specifically quantified pure oligomers of synthetic Aß with sizes from dimers up to much larger assemblies and over a wide dynamic range of concentrations, whereas Aß monomers were undetectable. Natural Aß oligomers of similarly wide size and concentration ranges were measured in extracts of AD and control brains, revealing >1000-fold higher concentrations of Aß oligomers than monomers in the soluble fraction of AD cortex. The assays quantified the age-related rise in oligomers in hAPP transgenic mice. Unexpectedly, none of 90 human cerebrospinal fluid (CSF) samples gave a specific signal in either o-ELISA. CONCLUSIONS These new o-ELISAs with rigorously confirmed specificity can quantify oligomer burden in human and mouse brains for diagnostic and mechanistic studies and for AD biomarker development. However, our data raise the likelihood that the hydrophobicity of Aß oligomers makes them very low in number or absent in aqueous CSF.
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Affiliation(s)
- Ting Yang
- Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
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41
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Alzheimer's disease Aβ assemblies mediating rapid disruption of synaptic plasticity and memory. Mol Brain 2012; 5:25. [PMID: 22805374 PMCID: PMC3502131 DOI: 10.1186/1756-6606-5-25] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 06/22/2012] [Indexed: 01/24/2023] Open
Abstract
Alzheimer’s disease (AD) is characterized by episodic memory impairment that often precedes clinical diagnosis by many years. Probing the mechanisms of such impairment may provide much needed means of diagnosis and therapeutic intervention at an early, pre-dementia, stage. Prior to the onset of significant neurodegeneration, the structural and functional integrity of synapses in mnemonic circuitry is severely compromised in the presence of amyloidosis. This review examines recent evidence evaluating the role of amyloid-ß protein (Aβ) in causing rapid disruption of synaptic plasticity and memory impairment. We evaluate the relative importance of different sizes and conformations of Aβ, including monomer, oligomer, protofibril and fibril. We pay particular attention to recent controversies over the relevance to the pathophysiology of AD of different water soluble Aβ aggregates and the importance of cellular prion protein in mediating their effects. Current data are consistent with the view that both low-n oligomers and larger soluble assemblies present in AD brain, some of them via a direct interaction with cellular prion protein, cause synaptic memory failure. At the two extremes of aggregation, monomers and fibrils appear to act in vivo both as sources and sinks of certain metastable conformations of soluble aggregates that powerfully disrupt synaptic plasticity. The same principle appears to apply to other synaptotoxic amyloidogenic proteins including tau, α-synuclein and prion protein.
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42
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Invernizzi G, Papaleo E, Sabate R, Ventura S. Protein aggregation: mechanisms and functional consequences. Int J Biochem Cell Biol 2012; 44:1541-54. [PMID: 22713792 DOI: 10.1016/j.biocel.2012.05.023] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Revised: 05/09/2012] [Accepted: 05/27/2012] [Indexed: 12/31/2022]
Abstract
Understanding the mechanisms underlying protein misfolding and aggregation has become a central issue in biology and medicine. Compelling evidence show that the formation of amyloid aggregates has a negative impact in cell function and is behind the most prevalent human degenerative disorders, including Alzheimer's Parkinson's and Huntington's diseases or type 2 diabetes. Surprisingly, the same type of macromolecular assembly is used for specialized functions by different organisms, from bacteria to human. Here we address the conformational properties of these aggregates, their formation pathways, their role in human diseases, their functional properties and how bioinformatics tools might be of help to study these protein assemblies.
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Affiliation(s)
- Gaetano Invernizzi
- Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, Milan, Italy
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43
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Critical role of soluble amyloid-β for early hippocampal hyperactivity in a mouse model of Alzheimer's disease. Proc Natl Acad Sci U S A 2012; 109:8740-5. [PMID: 22592800 DOI: 10.1073/pnas.1206171109] [Citation(s) in RCA: 480] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Alzheimer's disease (AD) is characterized by a progressive dysfunction of central neurons. Recent experimental evidence indicates that in the cortex, in addition to the silencing of a fraction of neurons, other neurons are hyperactive in amyloid-β (Aβ) plaque-enriched regions. However, it has remained unknown what comes first, neuronal silencing or hyperactivity, and what mechanisms might underlie the primary neuronal dysfunction. Here we examine the activity patterns of hippocampal CA1 neurons in a mouse model of AD in vivo using two-photon Ca(2+) imaging. We found that neuronal activity in the plaque-bearing CA1 region of older mice is profoundly altered. There was a marked increase in the fractions of both silent and hyperactive neurons, as previously also found in the cortex. Remarkably, in the hippocampus of young mice, we observed a selective increase in hyperactive neurons already before the formation of plaques, suggesting that soluble species of Aβ may underlie this impairment. Indeed, we found that acute treatment with the γ-secretase inhibitor LY-411575 reduces soluble Aβ levels and rescues the neuronal dysfunction. Furthermore, we demonstrate that direct application of soluble Aβ can induce neuronal hyperactivity in wild-type mice. Thus, our study identifies hippocampal hyperactivity as a very early functional impairment in AD transgenic mice and provides direct evidence that soluble Aβ is crucial for hippocampal hyperactivity.
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44
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Fändrich M. Oligomeric intermediates in amyloid formation: structure determination and mechanisms of toxicity. J Mol Biol 2012; 421:427-40. [PMID: 22248587 DOI: 10.1016/j.jmb.2012.01.006] [Citation(s) in RCA: 281] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Revised: 01/03/2012] [Accepted: 01/05/2012] [Indexed: 11/30/2022]
Abstract
Oligomeric intermediates are non-fibrillar polypeptide assemblies that occur during amyloid fibril formation and that are thought to underlie the aetiology of amyloid diseases, such as Alzheimer's disease, Parkinson's disease and Huntington's disease. Focusing primarily on the oligomeric states formed from Alzheimer's disease β-amyloid (Aβ) peptide, this review will make references to other polypeptide systems, highlighting common principles or sequence-specific differences. The covered topics include the structural properties and polymorphism of oligomers, the biophysical mechanism of peptide self-assembly and its role for pathogenicity in amyloid disease. Oligomer-dependent toxicity mechanisms will be explained along with recently emerging possibilities of interference.
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Affiliation(s)
- Marcus Fändrich
- Max-Planck Research Unit for Enzymology of Protein Folding and Martin Luther University Halle-Wittenberg, Weinbergweg 22, 01620 Halle (Saale), Germany.
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45
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Uttner I, Schurig N, von Arnim CAF, Lange-Asschenfeldt C, Brettschneider J, Riepe MW, Tumani H. Amyloid beta 1-42 in cerebrospinal fluid is associated with cognitive plasticity. Psychiatry Res 2011; 190:132-6. [PMID: 21620485 DOI: 10.1016/j.psychres.2011.04.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 02/19/2011] [Accepted: 04/14/2011] [Indexed: 12/13/2022]
Abstract
Cerebrospinal fluid (CSF) total tau-protein (t-tau) and amyloid-beta 1-42 (Abeta(1-42)) have been increasingly included in the diagnostic process of Alzheimer's disease (AD). We aimed to analyze whether these CSF biomarkers correlate with cognitive plasticity as measured by a dynamic recognition test strategy. We assessed 29 elderly individuals (15 with incipient and 14 without AD) from an outpatient memory clinic at a university hospital by a Testing-the-Limits (TtL) based recognition paradigm consisting of a pre-test (baseline) and two post-test conditions with an interposed encoding instruction. We identified a negative association between Abeta(1-42) and the two post-test failure rates, but not with that of the pre-test. Also, none of the standard tests correlates with Abeta 42-1 level. T-tau does not correlate with recognition performance. Our results suggest that Abeta(1-42) could be useful as a state marker for cognitive plasticity.
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Affiliation(s)
- Ingo Uttner
- Neurologische Klinik der Universität Ulm, Oberer Eselsberg 45, 89081 Ulm, Germany.
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46
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Petzold GC, Murthy VN. Role of astrocytes in neurovascular coupling. Neuron 2011; 71:782-97. [PMID: 21903073 DOI: 10.1016/j.neuron.2011.08.009] [Citation(s) in RCA: 285] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2011] [Indexed: 10/17/2022]
Abstract
Neural activity is intimately tied to blood flow in the brain. This coupling is specific enough in space and time that modern imaging methods use local hemodynamics as a measure of brain activity. In this review, we discuss recent evidence indicating that neuronal activity is coupled to local blood flow changes through an intermediary, the astrocyte. We highlight unresolved issues regarding the role of astrocytes and propose ways to address them using novel techniques. Our focus is on cellular level analysis in vivo, but we also relate mechanistic insights gained from ex vivo experiments to native tissue. We also review some strategies to harness advances in optical and genetic methods to study neurovascular coupling in the intact brain.
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Affiliation(s)
- Gabor C Petzold
- German Center for Neurodegenerative Diseases (DZNE), Ludwig-Erhard-Allee 2, 53175 Bonn, Germany.
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47
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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] [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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48
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Chambon C, Wegener N, Gravius A, Danysz W. Behavioural and cellular effects of exogenous amyloid-β peptides in rodents. Behav Brain Res 2011; 225:623-41. [PMID: 21884730 DOI: 10.1016/j.bbr.2011.08.024] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 08/10/2011] [Accepted: 08/16/2011] [Indexed: 12/29/2022]
Abstract
A better understanding of Alzheimer's disease (AD) and the development of disease modifying therapies are some of the biggest challenges of the 21st century. One of the core features of AD are amyloid plaques composed of amyloid-beta (Aβ) peptides. The first hypothesis proposed that cognitive deficits are linked to plaque-development and transgenic mice have been generated to study this link, thereby providing a good model to develop new therapeutic approaches. Since later it was recognised that in AD patients the cognitive deficit is rather correlated to soluble amyloid levels, consequently, a new hypothesis appeared associating the earliest amyloid toxicity to these soluble species. The purpose of this review is to give a summary of behavioural and cellular data obtained after soluble Aβ peptide administration into rodents' brain, thereby showing that this model is a valid tool to investigate AD pathology when no plaques are present. Additionally, this method offers an excellent, efficient model to test compounds which could act at such early stages of the disease.
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Affiliation(s)
- Caroline Chambon
- In Vivo Pharmacology, Merz Pharmaceuticals GmbH, Eckenheimer Landstrasse 100, D-60318 Frankfurt am Main, Germany.
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49
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Soluble Aβ oligomers inhibit long-term potentiation through a mechanism involving excessive activation of extrasynaptic NR2B-containing NMDA receptors. J Neurosci 2011; 31:6627-38. [PMID: 21543591 DOI: 10.1523/jneurosci.0203-11.2011] [Citation(s) in RCA: 465] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
In Alzheimer's disease (AD), dementia severity correlates strongly with decreased synapse density in hippocampus and cortex. Numerous studies report that hippocampal long-term potentiation (LTP) can be inhibited by soluble oligomers of amyloid β-protein (Aβ), but the synaptic elements that mediate this effect remain unclear. We examined field EPSPs and whole-cell recordings in wild-type mouse hippocampal slices. Soluble Aβ oligomers from three distinct sources (cultured cells, AD cortex, or synthetic peptide) inhibited LTP, and this was prevented by the selective NR2B inhibitors ifenprodil and Ro 25-6981. Soluble Aβ enhanced NR2B-mediated NMDA currents and extrasynaptic responses; these effects were mimicked by the glutamate reuptake inhibitor dl-threo-β-benzyloxyaspartic acid. Downstream, an Aβ-mediated rise in p38 mitogen-activated protein kinase (MAPK) activation was followed by downregulation of cAMP response element-binding protein, and LTP impairment was prevented by inhibitors of p38 MAPK or calpain. Thus, soluble Aβ oligomers at low nanomolar levels present in AD brain increase activation of extrasynaptic NR2B-containing receptors, thereby impairing synaptic plasticity.
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Abstract
The ability of the brain to locally augment glucose delivery and blood flow during neuronal activation, termed neurometabolic and neurovascular coupling, respectively, is compromised in Alzheimer's disease (AD). Since perfusion deficits may hasten clinical deterioration and have been correlated with negative treatment outcome, strategies to improve the cerebral circulation should form an integral element of AD therapeutic efforts. These efforts have yielded several experimental models, some of which constitute AD models proper, others which specifically recapture the AD cerebrovascular pathology, characterized by anatomical alterations in brain vessel structure, as well as molecular changes within vascular smooth muscle cells and endothelial cells forming the blood-brain barrier. The following paper will present the elements of AD neurovascular dysfunction and review the in vitro and in vivo model systems that have served to deepen our understanding of it. It will also critically evaluate selected groups of compounds, the FDA-approved cholinesterase inhibitors and thiazolidinediones, for their ability to correct neurovascular dysfunction in AD patients and models. These and several others are emerging as compounds with pleiotropic actions that may positively impact dysfunctional cerebrovascular, glial, and neuronal networks in AD.
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