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Azargoonjahromi A. The duality of amyloid-β: its role in normal and Alzheimer's disease states. Mol Brain 2024; 17:44. [PMID: 39020435 PMCID: PMC11256416 DOI: 10.1186/s13041-024-01118-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Accepted: 07/14/2024] [Indexed: 07/19/2024] Open
Abstract
Alzheimer's disease (AD) is a degenerative neurological condition that gradually impairs cognitive abilities, disrupts memory retention, and impedes daily functioning by impacting the cells of the brain. A key characteristic of AD is the accumulation of amyloid-beta (Aβ) plaques, which play pivotal roles in disease progression. These plaques initiate a cascade of events including neuroinflammation, synaptic dysfunction, tau pathology, oxidative stress, impaired protein clearance, mitochondrial dysfunction, and disrupted calcium homeostasis. Aβ accumulation is also closely associated with other hallmark features of AD, underscoring its significance. Aβ is generated through cleavage of the amyloid precursor protein (APP) and plays a dual role depending on its processing pathway. The non-amyloidogenic pathway reduces Aβ production and has neuroprotective and anti-inflammatory effects, whereas the amyloidogenic pathway leads to the production of Aβ peptides, including Aβ40 and Aβ42, which contribute to neurodegeneration and toxic effects in AD. Understanding the multifaceted role of Aβ, particularly in AD, is crucial for developing effective therapeutic strategies that target Aβ metabolism, aggregation, and clearance with the aim of mitigating the detrimental consequences of the disease. This review aims to explore the mechanisms and functions of Aβ under normal and abnormal conditions, particularly in AD, by examining both its beneficial and detrimental effects.
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Puzzo D. Beyond Amyloid-β: Reevaluating Its Physiological Role to Find Safe Therapies Against Alzheimer's Disease. J Alzheimers Dis 2024:JAD240406. [PMID: 38943395 DOI: 10.3233/jad-240406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/01/2024]
Abstract
This commentary critically examines the long-standing emphasis on amyloid-β (Aβ)-based therapies in Alzheimer's disease (AD), despite numerous clinical trial failures. It highlights the urgency to reassess research methodologies and challenges the initiation of anti-Aβ trials in preclinical stages of the disease without conclusive proofs of their safety and efficacy. Instead, a comprehensive approach that considers Aβ's physiological roles and addresses AD complex nature is suggested, encouraging the idea that clinical trial failures may result from targeting the wrong mechanism. Evidence-based scientific research is needed to advance with AD treatment, moving beyond the current conception of Aβ hypothesis.
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Affiliation(s)
- Daniela Puzzo
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
- Oasi Research Institute-IRCCS, Troina, Italy
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3
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Stone J, Mitrofanis J, Johnstone DM, Robinson SR. The Catastrophe of Intracerebral Hemorrhage Drives the Capillary-Hemorrhage Dementias, Including Alzheimer's Disease. J Alzheimers Dis 2024; 97:1069-1081. [PMID: 38217606 DOI: 10.3233/jad-231202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2024]
Abstract
This review advances an understanding of several dementias, based on four premises. One is that capillary hemorrhage is prominent in the pathogenesis of the dementias considered (dementia pugilistica, chronic traumatic encephalopathy, traumatic brain damage, Alzheimer's disease). The second premise is that hemorrhage introduces four neurotoxic factors into brain tissue: hypoxia of the tissue that has lost its blood supply, hemoglobin and its breakdown products, excitotoxic levels of glutamate, and opportunistic pathogens that can infect brain cells and induce a cytotoxic immune response. The third premise is that where organisms evolve molecules that are toxic to itself, like the neurotoxicity ascribed to hemoglobin, amyloid- (A), and glutamate, there must be some role for the molecule that gives the organism a selection advantage. The fourth is the known survival-advantage roles of hemoglobin (oxygen transport), of A (neurotrophic, synaptotrophic, detoxification of heme, protective against pathogens) and of glutamate (a major neurotransmitter). From these premises, we propose 1) that the brain has evolved a multi-factor response to intracerebral hemorrhage, which includes the expression of several protective molecules, including haptoglobin, hemopexin and A; and 2) that it is logical, given these premises, to posit that the four neurotoxic factors set out above, which are introduced into the brain by hemorrhage, drive the progression of the capillary-hemorrhage dementias. In this view, A expressed at the loci of neuronal death in these dementias functions not as a toxin but as a first responder, mitigating the toxicity of hemoglobin and the infection of the brain by opportunistic pathogens.
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Affiliation(s)
- Jonathan Stone
- Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - John Mitrofanis
- Université Grenoble Alpes, Fonds de Dotation, Clinatec, Grenoble, France
- Institute of Ophthalmology, University College London, London, UK
| | - Daniel M Johnstone
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, Australia
- School of Medical Sciences, The University of Sydney, Sydney, Australia
| | - Stephen R Robinson
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Australia
- Institute for Breathing and Sleep, Austin Health, Heidelberg, Australia
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4
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Haut F, Argyrousi EK, Arancio O. Re-Arranging the Puzzle between the Amyloid-Beta and Tau Pathology: An APP-Centric Approach. Int J Mol Sci 2023; 25:259. [PMID: 38203429 PMCID: PMC10779219 DOI: 10.3390/ijms25010259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 12/04/2023] [Accepted: 12/20/2023] [Indexed: 01/12/2024] Open
Abstract
After several years of research in the field of Alzheimer's disease (AD), it is still unclear how amyloid-beta (Aβ) and Tau, two key hallmarks of the disease, mediate the neuropathogenic events that lead to AD. Current data challenge the "Amyloid Cascade Hypothesis" that has prevailed in the field of AD, stating that Aβ precedes and triggers Tau pathology that will eventually become the toxic entity in the progression of the disease. This perspective also led the field of therapeutic approaches towards the development of strategies that target Aβ or Tau. In the present review, we discuss recent literature regarding the neurotoxic role of both Aβ and Tau in AD, as well as their physiological function in the healthy brain. Consequently, we present studies suggesting that Aβ and Tau act independently of each other in mediating neurotoxicity in AD, thereafter, re-evaluating the "Amyloid Cascade Hypothesis" that places Tau pathology downstream of Aβ. More recent studies have confirmed that both Aβ and Tau could propagate the disease and induce synaptic and memory impairments via the amyloid precursor protein (APP). This finding is not only interesting from a mechanistic point of view since it provides better insights into the AD pathogenesis but also from a therapeutic point of view since it renders APP a common downstream effector for both Aβ and Tau. Subsequently, therapeutic strategies that act on APP might provide a more viable and physiologically relevant approach for targeting AD.
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Affiliation(s)
- Florence Haut
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, 630 West 168th Street, P&S, New York, NY 10032, USA; (F.H.); (E.K.A.)
| | - Elentina K. Argyrousi
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, 630 West 168th Street, P&S, New York, NY 10032, USA; (F.H.); (E.K.A.)
| | - Ottavio Arancio
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, 630 West 168th Street, P&S, New York, NY 10032, USA; (F.H.); (E.K.A.)
- Department of Medicine, Columbia University, New York, NY 10032, USA
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
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Rodriguez-Jimenez FJ, Ureña-Peralta J, Jendelova P, Erceg S. Alzheimer's disease and synapse Loss: What can we learn from induced pluripotent stem Cells? J Adv Res 2023; 54:105-118. [PMID: 36646419 DOI: 10.1016/j.jare.2023.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 12/21/2022] [Accepted: 01/08/2023] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Synaptic dysfunction is a major contributor to Alzheimeŕs disease (AD) pathogenesis in addition to the formation of neuritic β-amyloid plaques and neurofibrillary tangles of hyperphosphorylated Tau protein. However, how these features contribute to synaptic dysfunction and axonal loss remains unclear. While years of considerable effort have been devoted to gaining an improved understanding of this devastating disease, the unavailability of patient-derived tissues, considerable genetic heterogeneity, and lack of animal models that faithfully recapitulate human AD have hampered the development of effective treatment options. Ongoing progress in human induced pluripotent stem cell (hiPSC) technology has permitted the derivation of patient- and disease-specific stem cells with unlimited self-renewal capacity. These cells can differentiate into AD-affected cell types, which support studies of disease mechanisms, drug discovery, and the development of cell replacement therapies in traditional and advanced cell culture models. AIM OF REVIEW To summarize current hiPSC-based AD models, highlighting the associated achievements and challenges with a primary focus on neuron and synapse loss. KEY SCIENTIFIC CONCEPTS OF REVIEW We aim to identify how hiPSC models can contribute to understanding AD-associated synaptic dysfunction and axonal loss. hiPSC-derived neural cells, astrocytes, and microglia, as well as more sophisticated cellular organoids, may represent reliable models to investigate AD and identify early markers of AD-associated neural degeneration.
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Affiliation(s)
- Francisco Javier Rodriguez-Jimenez
- Stem Cell Therapies in Neurodegenerative Diseases Lab., Centro de Investigación Principe Felipe (CIPF), c/ Eduardo Primo Yúfera 3, 46012 Valencia, Spain.
| | - Juan Ureña-Peralta
- Stem Cell Therapies in Neurodegenerative Diseases Lab., Centro de Investigación Principe Felipe (CIPF), c/ Eduardo Primo Yúfera 3, 46012 Valencia, Spain.
| | - Pavla Jendelova
- Institute of Experimental Medicine, Department of Neuroregeneration, Czech Academy of Science, Prague, Czech Republic.
| | - Slaven Erceg
- Stem Cell Therapies in Neurodegenerative Diseases Lab., Centro de Investigación Principe Felipe (CIPF), c/ Eduardo Primo Yúfera 3, 46012 Valencia, Spain; Institute of Experimental Medicine, Department of Neuroregeneration, Czech Academy of Science, Prague, Czech Republic; National Stem Cell Bank-Valencia Node, Centro de Investigacion Principe Felipe, c/ Eduardo Primo Yúfera 3, 46012 Valencia, Spain.
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Stone J, Mitrofanis J, Johnstone DM, Robinson SR. Twelve protections evolved for the brain, and their roles in extending its functional life. Front Neuroanat 2023; 17:1280275. [PMID: 38020212 PMCID: PMC10657866 DOI: 10.3389/fnana.2023.1280275] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2023] [Accepted: 10/20/2023] [Indexed: 12/01/2023] Open
Abstract
As human longevity has increased, we have come to understand the ability of the brain to function into advanced age, but also its vulnerability with age, apparent in the age-related dementias. Against that background of success and vulnerability, this essay reviews how the brain is protected by (by our count) 12 mechanisms, including: the cranium, a bony helmet; the hydraulic support given by the cerebrospinal fluid; the strategically located carotid body and sinus, which provide input to reflexes that protect the brain from blood-gas imbalance and extremes of blood pressure; the blood brain barrier, an essential sealing of cerebral vessels; the secretion of molecules such as haemopexin and (we argue) the peptide Aβ to detoxify haemoglobin, at sites of a bleed; autoregulation of the capillary bed, which stabilises metabolites in extracellular fluid; fuel storage in the brain, as glycogen; oxygen storage, in the haemoprotein neuroglobin; the generation of new neurones, in the adult, to replace cells lost; acquired resilience, the stress-induced strengthening of cell membranes and energy production found in all body tissues; and cognitive reserve, the ability of the brain to maintain function despite damage. Of these 12 protections, we identify 5 as unique to the brain, 3 as protections shared with all body tissues, and another 4 as protections shared with other tissues but specialised for the brain. These protections are a measure of the brain's vulnerability, of its need for protection. They have evolved, we argue, to maintain cognitive function, the ability of the brain to function despite damage that accumulates during life. Several can be tools in the hands of the individual, and of the medical health professional, for the lifelong care of our brains.
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Affiliation(s)
- Jonathan Stone
- Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, Australia
| | - John Mitrofanis
- Grenoble and Institute of Ophthalmology, Fonds de Dotation Clinatec, Université Grenoble Alpes, University College London, London, United Kingdom
| | - Daniel M. Johnstone
- School of Biomedical Sciences and Pharmacy, University of Newcastle and School of Medical Sciences, The University of Sydney, Camperdown, NSW, Australia
| | - Stephen R. Robinson
- School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, Australia
- Institute for Breathing and Sleep, Austin Health, Heidelberg, VIC, Australia
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Bai X, Liu CM, Li HJ, Zhang ZP, Cui WB, An FL, Zhang ZX, Wang DS, Fei DQ. Ethyl caffeate attefnuates Aβ-induced toxicity in Caenorhabditis elegans AD models via the insulin/insulin-like growth factor-1 signaling pathway. Bioorg Chem 2023; 139:106714. [PMID: 37454496 DOI: 10.1016/j.bioorg.2023.106714] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 06/21/2023] [Accepted: 07/05/2023] [Indexed: 07/18/2023]
Abstract
The pathogenesis of Alzheimer's disease (AD), a multifactorial progressive neurodegenerative disease associated with aging, is unclear. Ethyl caffeate is a plant polyphenol that has been reported to have neuroprotective effects, but the mechanisms by which it acts are unclear. In this study, for the first time, we investigated the molecular mechanism of its anti-AD properties using the Caernorhabditis elegans model. The results of our experiments showed that ethyl caffeate delayed the paralysis symptoms of CL4176 to a different extent and reduced the exogenous 5-hydroxytryptophan-induced paralysis phenotype. Further studies revealed that ethyl caffeate lowered Aβ plaques and depressed the expression of Aβ monomers and oligomers, but did not influence the mRNA levels of Aβ. Moreover, it was able to bring paraquat-induced ROS levels down to near-standard conditions. Real-time quantitative PCR experiment showed a significant upregulation of the transcript abundance of daf-16, skn-1 and hsf-1, key factors associated with the insulin/insulin-like growth factor 1 (IGF-1) signaling pathway (IIS), and their downstream genes sod-3, gst-4 and hsp-16.2. It was further shown that ethyl caffeate activated the translocation of DAF-16 and SKN-1 from the cytoplasm to the nucleus and enhanced the expression of sod-3::GFP, gst-4::GFP and hsp-16.2::GFP in transgenic nematodes. This meant that the protection against Aβ toxicity by ethyl caffeate may be partly through the IIS signaling pathway. In addition, ethyl caffeate suppressed the aggregation of polyglutamine proteins in AM141, which indicated a potential protective effect against neurodegenerative diseases based on abnormal folding and aggregation of amyloid proteins. Taken together, ethyl caffeate is expected to develop as a potential drug for the management of AD.
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Affiliation(s)
- Xue Bai
- School of Pharmacy and State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, PR China
| | - Chun-Min Liu
- School of Pharmacy and State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, PR China
| | - Hui-Jie Li
- School of Pharmacy and State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, PR China
| | - Zong-Ping Zhang
- School of Pharmacy and State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, PR China
| | - Wen-Bo Cui
- School of Pharmacy and State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, PR China
| | - Feng-Li An
- School of Pharmacy and State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, PR China
| | - Zhan-Xin Zhang
- School of Pharmacy and State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, PR China.
| | - Dong-Sheng Wang
- School of Pharmacy and State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, PR China.
| | - Dong-Qing Fei
- School of Pharmacy and State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, PR China.
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Fedele E. Anti-Amyloid Therapies for Alzheimer's Disease and the Amyloid Cascade Hypothesis. Int J Mol Sci 2023; 24:14499. [PMID: 37833948 PMCID: PMC10578107 DOI: 10.3390/ijms241914499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 09/22/2023] [Accepted: 09/22/2023] [Indexed: 10/15/2023] Open
Abstract
Over the past 30 years, the majority of (pre)clinical efforts to find an effective therapy for Alzheimer's disease (AD) focused on clearing the β-amyloid peptide (Aβ) from the brain since, according to the amyloid cascade hypothesis, the peptide was (and it is still considered by many) the pathogenic determinant of this neurodegenerative disorder. However, as reviewed in this article, results from the numerous clinical trials that have tested anti-Aβ therapies to date indicate that this peptide plays a minor role in the pathogenesis of AD. Indeed, even Aducanumab and Lecanemab, the two antibodies recently approved by the FDA for AD therapy, as well as Donanemab showed limited efficacy on cognitive parameters in phase III clinical trials, despite their capability of markedly lowering Aβ brain load. Furthermore, preclinical evidence demonstrates that Aβ possesses several physiological functions, including memory formation, suggesting that AD may in part be due to a loss of function of this peptide. Finally, it is generally accepted that AD could be the result of many molecular dysfunctions, and therefore, if we keep chasing only Aβ, it means that we cannot see the forest for the trees.
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Affiliation(s)
- Ernesto Fedele
- Pharmacology and Toxicology Unit, Department of Pharmacy, School of Medical and Pharmaceutical Sciences, University of Genoa, Viale Cembrano 4, 16148 Genoa, Italy;
- IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
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9
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Cai W, Li L, Sang S, Pan X, Zhong C. Physiological Roles of β-amyloid in Regulating Synaptic Function: Implications for AD Pathophysiology. Neurosci Bull 2023; 39:1289-1308. [PMID: 36443453 PMCID: PMC10387033 DOI: 10.1007/s12264-022-00985-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 09/02/2022] [Indexed: 11/29/2022] Open
Abstract
The physiological functions of endogenous amyloid-β (Aβ), which plays important role in the pathology of Alzheimer's disease (AD), have not been paid enough attention. Here, we review the multiple physiological effects of Aβ, particularly in regulating synaptic transmission, and the possible mechanisms, in order to decipher the real characters of Aβ under both physiological and pathological conditions. Some worthy studies have shown that the deprivation of endogenous Aβ gives rise to synaptic dysfunction and cognitive deficiency, while the moderate elevation of this peptide enhances long term potentiation and leads to neuronal hyperexcitability. In this review, we provide a new view for understanding the role of Aβ in AD pathophysiology from the perspective of physiological meaning.
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Affiliation(s)
- Wenwen Cai
- Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Linxi Li
- Basic Medical College, Nanchang University, Nanchang, 330031, China
| | - Shaoming Sang
- Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Xiaoli Pan
- Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.
| | - Chunjiu Zhong
- Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science & Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China.
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10
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Zhang Y, Chen H, Li R, Sterling K, Song W. Amyloid β-based therapy for Alzheimer's disease: challenges, successes and future. Signal Transduct Target Ther 2023; 8:248. [PMID: 37386015 PMCID: PMC10310781 DOI: 10.1038/s41392-023-01484-7] [Citation(s) in RCA: 73] [Impact Index Per Article: 73.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 05/05/2023] [Accepted: 05/09/2023] [Indexed: 07/01/2023] Open
Abstract
Amyloid β protein (Aβ) is the main component of neuritic plaques in Alzheimer's disease (AD), and its accumulation has been considered as the molecular driver of Alzheimer's pathogenesis and progression. Aβ has been the prime target for the development of AD therapy. However, the repeated failures of Aβ-targeted clinical trials have cast considerable doubt on the amyloid cascade hypothesis and whether the development of Alzheimer's drug has followed the correct course. However, the recent successes of Aβ targeted trials have assuaged those doubts. In this review, we discussed the evolution of the amyloid cascade hypothesis over the last 30 years and summarized its application in Alzheimer's diagnosis and modification. In particular, we extensively discussed the pitfalls, promises and important unanswered questions regarding the current anti-Aβ therapy, as well as strategies for further study and development of more feasible Aβ-targeted approaches in the optimization of AD prevention and treatment.
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Affiliation(s)
- Yun Zhang
- National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital, Capital Medical University, Beijing, China.
| | - Huaqiu Chen
- National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Ran Li
- The Second Affiliated Hospital and Yuying Children's Hospital, Institute of Aging, Key Laboratory of Alzheimer's Disease of Zhejiang Province, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Keenan Sterling
- Townsend Family Laboratories, Department of Psychiatry, The University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - Weihong Song
- National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital, Capital Medical University, Beijing, China.
- The Second Affiliated Hospital and Yuying Children's Hospital, Institute of Aging, Key Laboratory of Alzheimer's Disease of Zhejiang Province, Wenzhou Medical University, Wenzhou, Zhejiang, China.
- Townsend Family Laboratories, Department of Psychiatry, The University of British Columbia, Vancouver, BC, V6T 1Z3, Canada.
- Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou, Zhejiang, China.
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Lantz MJ, Roberts AM, Delgado DD, Nichols RA. The neuroprotective N-terminal amyloid-β core hexapeptide reverses reactive gliosis and gliotoxicity in Alzheimer's disease pathology models. J Neuroinflammation 2023; 20:129. [PMID: 37245024 DOI: 10.1186/s12974-023-02807-9] [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: 12/27/2022] [Accepted: 05/16/2023] [Indexed: 05/29/2023] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by accumulation of extracellular amyloid beta (Aβ) and intracellular neurofibrillary tangles, leading to chronic activation of astrocytes and microglia and persistent neuroinflammation. Aβ-linked activation of microglia and astrocytes leads to increased intracellular calcium and production of proinflammatory cytokines, impacting the progression of neurodegeneration. An N-terminal Aβ fragment (Aβ1-15) and a shorter hexapeptide core sequence within the N-Aβ fragment (N-Aβcore: Aβ10-15) have previously been shown to protect against Aβ-induced mitochondrial dysfunction, oxidative stress and apoptosis in neurons and rescue synaptic and spatial memory deficits in an APP/PSEN1 mouse model. Here, we hypothesized that the N-Aβ fragment and N-Aβcore are protective against Aβ-induced gliotoxicity, promoting a neuroprotective environment and potentially alleviating the characteristically persistent neuroinflammation present in AD. METHODS We treated ex vivo organotypic brain slice cultures from an aged familial AD mouse model, 5xFAD, with the N-Aβcore and used immunocytochemistry to assess the impact on astrogliosis and microgliosis and alterations in synaptophysin-positive puncta engulfed by microglia. Isolated neuron/glia cultures, mixed glial cultures or a microglial cell line were treated with oligomeric human Aβ at concentrations mimicking the pathogenic concentrations (μM) observed in AD in the absence or presence of the non-toxic N-terminal Aβ fragments. Resultant changes in synaptic density, gliosis, oxidative stress, mitochondrial dysfunction, apoptosis, and the expression and release of proinflammatory markers were then determined. RESULTS We demonstrate that the N-terminal Aβ fragments mitigated the phenotypic switch leading to astrogliosis and microgliosis induced by pathological concentrations of Aβ in mixed glial cultures and organotypic brain slice cultures from the transgenic 5xFAD mouse model, while protecting against Aβ-induced oxidative stress, mitochondrial dysfunction and apoptosis in isolated astrocytes and microglia. Moreover, the addition of the N-Aβcore attenuated the expression and release of proinflammatory mediators in microglial cells activated by Aβ and rescued microglia-mediated loss of synaptic elements induced by pathological levels of Aβ. CONCLUSIONS Together, these findings indicate the protective functions of the N-terminal Aβ fragments extend to reactive gliosis and gliotoxicity induced by Aβ, by preventing or reversing glial reactive states indicative of neuroinflammation and synaptic loss central to AD pathogenesis.
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Affiliation(s)
- Megan J Lantz
- Department of Cell and Molecular Biology, University of Hawai'i at Mānoa, Honolulu, HI, USA
| | - Alyssa M Roberts
- Department of Cell and Molecular Biology, University of Hawai'i at Mānoa, Honolulu, HI, USA
| | - Donovan D Delgado
- Department of Cell and Molecular Biology, University of Hawai'i at Mānoa, Honolulu, HI, USA
| | - Robert A Nichols
- Department of Cell and Molecular Biology, University of Hawai'i at Mānoa, Honolulu, HI, USA.
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12
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Whiteaker P, George AA. Discoveries and future significance of research into amyloid-beta/α7-containing nicotinic acetylcholine receptor (nAChR) interactions. Pharmacol Res 2023; 191:106743. [PMID: 37084859 DOI: 10.1016/j.phrs.2023.106743] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 03/13/2023] [Accepted: 03/21/2023] [Indexed: 04/23/2023]
Abstract
Initiated by findings that Alzheimer's disease is associated with a profound loss of cholinergic markers in human brain, decades of studies have examined the interactions between specific subtypes of nicotinic acetylcholine receptors and amyloid-β [derive from the amyloid precursor protein (APP), which is cleaved to yield variable isoforms of amyloid-β]. We review the evolving understanding of amyloid-β's roles in Alzheimer's disease and pioneering studies that highlighted a role of nicotinic acetylcholine receptors in mediating important aspects of amyloid-β's effects. This review also surveys the current state of research into amyloid-β / nicotinic acetylcholine receptor interactions. The field has reached an exciting point in which common themes are emerging from the wide range of prior research and a range of accessible, relevant model systems are available to drive further progress. We highlight exciting new areas of inquiry and persistent challenges that need to be considered while conducting this research. Studies of amyloid-β and nicotinic acetylcholine receptor populations that it interacts with provide opportunities for innovative basic and translational scientific breakthroughs related to nicotinic receptors biology, Alzheimer's disease, and cholinergic contributions to cognition more broadly.
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Affiliation(s)
- Paul Whiteaker
- Virginia Commonwealth University School of Medicine, Department of Pharmacology and Toxicology, VCU Health Sciences Research Building, Box 980613, Richmond, VA 23298-0613, USA
| | - Andrew A George
- Virginia Commonwealth University School of Medicine, Department of Pharmacology and Toxicology, VCU Health Sciences Research Building, Box 980613, Richmond, VA 23298-0613, USA.
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13
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Perez SM, Boley AM, McCoy AM, Lodge DJ. Aberrant Dopamine System Function in the Ferrous Amyloid Buthionine (FAB) Rat Model of Alzheimer's Disease. Int J Mol Sci 2023; 24:7196. [PMID: 37108357 PMCID: PMC10138591 DOI: 10.3390/ijms24087196] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 04/06/2023] [Accepted: 04/11/2023] [Indexed: 04/29/2023] Open
Abstract
Antipsychotics increase the risk of death in elderly patients with Alzheimer's disease (AD). Thus, there is an immediate need for novel therapies to treat comorbid psychosis in AD. Psychosis has been attributed to a dysregulation of the dopamine system and is associated with aberrant regulation by the hippocampus. Given that the hippocampus is a key site of pathology in AD, we posit that aberrant regulation of the dopamine system may contribute to comorbid psychosis in AD. A ferrous amyloid buthionine (FAB) rodent model was used to model a sporadic form of AD. FAB rats displayed functional hippocampal alterations, which were accompanied by decreases in spontaneous, low-frequency oscillations and increases in the firing rates of putative pyramidal neurons. Additionally, FAB rats exhibited increases in dopamine neuron population activity and augmented responses to the locomotor-inducing effects of MK-801, as is consistent with rodent models of psychosis-like symptomatology. Further, working memory deficits in the Y-maze, consistent with an AD-like phenotype, were observed in FAB rats. These data suggest that the aberrant hippocampal activity observed in AD may contribute to dopamine-dependent psychosis, and that the FAB model may be useful for the investigation of comorbid psychosis related to AD. Understanding the pathophysiology that leads to comorbid psychosis in AD will ultimately lead to the discovery of novel targets for the treatment of this disease.
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Affiliation(s)
- Stephanie M. Perez
- Department of Pharmacology and Center for Biomedical Neuroscience, UT Health San Antonio, San Antonio, TX 78229, USA; (A.M.B.); (D.J.L.)
- South Texas Veterans Health Care System, Audie L. Murphy Division, San Antonio, TX 78229, USA
| | - Angela M. Boley
- Department of Pharmacology and Center for Biomedical Neuroscience, UT Health San Antonio, San Antonio, TX 78229, USA; (A.M.B.); (D.J.L.)
- South Texas Veterans Health Care System, Audie L. Murphy Division, San Antonio, TX 78229, USA
| | - Alexandra M. McCoy
- Department of Pharmacology and Center for Biomedical Neuroscience, UT Health San Antonio, San Antonio, TX 78229, USA; (A.M.B.); (D.J.L.)
- South Texas Veterans Health Care System, Audie L. Murphy Division, San Antonio, TX 78229, USA
| | - Daniel J. Lodge
- Department of Pharmacology and Center for Biomedical Neuroscience, UT Health San Antonio, San Antonio, TX 78229, USA; (A.M.B.); (D.J.L.)
- South Texas Veterans Health Care System, Audie L. Murphy Division, San Antonio, TX 78229, USA
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14
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Huffels CFM, Middeldorp J, Hol EM. Aß Pathology and Neuron-Glia Interactions: A Synaptocentric View. Neurochem Res 2023; 48:1026-1046. [PMID: 35976488 PMCID: PMC10030451 DOI: 10.1007/s11064-022-03699-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 06/30/2022] [Accepted: 07/15/2022] [Indexed: 10/15/2022]
Abstract
Alzheimer's disease (AD) causes the majority of dementia cases worldwide. Early pathological hallmarks include the accumulation of amyloid-ß (Aß) and activation of both astrocytes and microglia. Neurons form the building blocks of the central nervous system, and astrocytes and microglia provide essential input for its healthy functioning. Their function integrates at the level of the synapse, which is therefore sometimes referred to as the "quad-partite synapse". Increasing evidence puts AD forward as a disease of the synapse, where pre- and postsynaptic processes, as well as astrocyte and microglia functioning progressively deteriorate. Here, we aim to review the current knowledge on how Aß accumulation functionally affects the individual components of the quad-partite synapse. We highlight a selection of processes that are essential to the healthy functioning of the neuronal synapse, including presynaptic neurotransmitter release and postsynaptic receptor functioning. We further discuss how Aß affects the astrocyte's capacity to recycle neurotransmitters, release gliotransmitters, and maintain ion homeostasis. We additionally review literature on how Aß changes the immunoprotective function of microglia during AD progression and conclude by summarizing our main findings and highlighting the challenges in current studies, as well as the need for further research.
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Affiliation(s)
- Christiaan F M Huffels
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Jinte Middeldorp
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
- Department of Neurobiology & Aging, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Elly M Hol
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands.
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15
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Robinson J, Sarangi NK, Keyes TE. Role of phosphatidylserine in amyloid-beta oligomerization at asymmetric phospholipid bilayers. Phys Chem Chem Phys 2023; 25:7648-7661. [PMID: 36317678 DOI: 10.1039/d2cp03344e] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Amyloid-beta (Aβ1-42) aggregation triggers neurotoxicity and is linked to Alzheimer's disease. Aβ1-42 oligomers, rather than extended fibrils, adhere to the cell membrane, causing cell death. Phosphatidylserine (PS), an anionic phospholipid, is prevalent in neuronal membranes (< 20 molar percentage) and, while isolated to the cytoplasmic leaflet of the membrane in healthy cells, its exposure in apoptotic cells and migration to exoplasmic leaflet is triggered by oxidative damage to the membrane. It is widely believed that PS plays a crucial role in the Aβ peptide interaction in the membranes of neuronal cells. However, due to the complexity of the cell membrane, it can be challenging to address molecular level understanding of the PS-Aβ binding and oligomerization processes. Herein, we use microcavity supported lipid bilayers (MSLBs) to analyse PS and Aβ1-42 binding, oligomer formation, and membrane damage. MSLBs are a useful model to evaluate protein-membrane interactions because of their cell-like dual aspect fluidity, their addressability and compositional versatility. We used electrochemical impedance spectroscopy (EIS) and confocal fluorescence microscopy to compare the impact of Aβ1-42 on simple zwitterioinic membrane, dioleoylphosphatidylcholine (DOPC), with MSLBs comprised of transversally asymmetric binary DOPC and dioleoylphosphatidylserine (DOPS). Monomeric Aβ1-42 adsorbs weakly to the pristine zwitterionic DOPC membrane without aggregation. Using a membrane integrity test, with pyranine trapped within the cavities beneath the membrane, Aβ1-42 exposure did not result in pyranine leakage, indicating that DOPC membranes were intact. When 10 mol% DOPS was doped asymmetrically into the membrane's outer leaflet, oligomerization of Aβ1-42 monomer was evident in EIS and atomic force microscopy (AFM), and confocal imaging revealed that membrane damage, resulted in extensive pyranine leakage from the pores. The effects were time, and DOPS and Aβ1-42 concentration-dependent. Membrane pore formation was visible within 30 minutes, and oligomerization, membrane-oligomer multilayer, and Aβ1-42 fibril formation evident over 3 to 18 hours. In asymmetric membranes with DOPS localized to the lower leaflet, optothermally (laser induced) damage increased local DOPS concentrations at the distal leaflet, promoting Aβ1-42 aggregation.
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Affiliation(s)
- Jack Robinson
- School of Chemical Sciences, Dublin City University, Dublin 9, Ireland
| | - Nirod Kumar Sarangi
- School of Chemical Sciences, Dublin City University, Dublin 9, Ireland.,National Center for Sensor Research, Dublin City University, Dublin 9, Ireland.
| | - Tia E Keyes
- School of Chemical Sciences, Dublin City University, Dublin 9, Ireland.,National Center for Sensor Research, Dublin City University, Dublin 9, Ireland.
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16
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Ezzat K, Sturchio A, Espay AJ. The shift to a proteinopenia paradigm in neurodegeneration. HANDBOOK OF CLINICAL NEUROLOGY 2023; 193:23-32. [PMID: 36803814 DOI: 10.1016/b978-0-323-85555-6.00001-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
The toxic proteinopathy paradigm has defined neurodegenerative disorders for over a century. This gain-of-function (GOF) framework posited that proteins become toxic when turned into amyloids (pathology), predicting that lowering its levels would translate into clinical benefits. Genetic observations used to support a GOF framework are equally compatible with a loss-of-function (LOF) framework, as the soluble pool of proteins rendered unstable by these mutations (e.g., APP in Alzheimer's disease, SNCA in Parkinson's disease) aggregate, becoming depleted. In this review, we highlight misconceptions that have prevented LOF from gaining currency. Some of these misconceptions include no phenotype in knock-out animals (there is neurodegenerative phenotype in knock-out animals) and high levels of proteins in patients (patients have lower levels of the proteins involved in neurodegeneration than healthy age-matched controls). We also expose the internal contradictions within the GOF framework, namely that (1) pathology can have both pathogenic and protective roles; (2) the neuropathology gold standard for diagnosis can be present in normal individuals and absent in those affected; (3) oligomers are the toxic species even if they are ephemeral and decrease over time. We therefore advocate for a paradigm shift from proteinopathy (GOF) to proteinopenia (LOF) based on the universal depletion of soluble functional proteins in neurodegenerative diseases (low amyloid-β 42 in Alzheimer's disease, low α-synuclein in Parkinson's disease, and low tau in progressive supranuclear palsy) and supported by the confluence of biologic, thermodynamic, and evolutionary principles with proteins having evolved to perform a function, not to become toxic, and where protein depletion is consequential. Such shift to a Proteinopenia paradigm is necessary to examining the safety and efficacy of protein replacement strategies instead of perpetuating a therapeutic paradigm with further antiprotein permutations.
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Affiliation(s)
- Kariem Ezzat
- Department of Laboratory Medicine, Biomolecular and Cellular Medicine, Karolinska Institutet, Stockholm, Sweden.
| | - Andrea Sturchio
- Department of Clinical Neuroscience, Neuro Svenningsson, Karolinska Institutet, Stockholm, Sweden; James J. and Joan A. Gardner Family Center for Parkinson's Disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH, United States
| | - Alberto J Espay
- James J. and Joan A. Gardner Family Center for Parkinson's Disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH, United States
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17
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Phospholipase D1 Attenuation Therapeutics Promotes Resilience against Synaptotoxicity in 12-Month-Old 3xTg-AD Mouse Model of Progressive Neurodegeneration. Int J Mol Sci 2023; 24:ijms24043372. [PMID: 36834781 PMCID: PMC9967100 DOI: 10.3390/ijms24043372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 02/02/2023] [Accepted: 02/03/2023] [Indexed: 02/11/2023] Open
Abstract
Abrogating synaptotoxicity in age-related neurodegenerative disorders is an extremely promising area of research with significant neurotherapeutic implications in tauopathies including Alzheimer's disease (AD). Our studies using human clinical samples and mouse models demonstrated that aberrantly elevated phospholipase D1 (PLD1) is associated with amyloid beta (Aβ) and tau-driven synaptic dysfunction and underlying memory deficits. While knocking out the lipolytic PLD1 gene is not detrimental to survival across species, elevated expression is implicated in cancer, cardiovascular conditions and neuropathologies, leading to the successful development of well-tolerated mammalian PLD isoform-specific small molecule inhibitors. Here, we address the importance of PLD1 attenuation, achieved using repeated 1 mg/kg of VU0155069 (VU01) intraperitoneally every alternate day for a month in 3xTg-AD mice beginning only from ~11 months of age (with greater influence of tau-driven insults) compared to age-matched vehicle (0.9% saline)-injected siblings. A multimodal approach involving behavior, electrophysiology and biochemistry corroborate the impact of this pre-clinical therapeutic intervention. VU01 proved efficacious in preventing in later stage AD-like cognitive decline affecting perirhinal cortex-, hippocampal- and amygdala-dependent behaviors. Glutamate-dependent HFS-LTP and LFS-LTD improved. Dendritic spine morphology showed the preservation of mushroom and filamentous spine characteristics. Differential PLD1 immunofluorescence and co-localization with Aβ were noted.
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18
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Amyloid-β in Alzheimer's disease - front and centre after all? Neuronal Signal 2023; 7:NS20220086. [PMID: 36687366 PMCID: PMC9829960 DOI: 10.1042/ns20220086] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 12/07/2022] [Accepted: 12/08/2022] [Indexed: 12/13/2022] Open
Abstract
The amyloid hypothesis, which proposes that accumulation of the peptide amyloid-β at synapses is the key driver of Alzheimer's disease (AD) pathogenesis, has been the dominant idea in the field of Alzheimer's research for nearly 30 years. Recently, however, serious doubts about its validity have emerged, largely motivated by disappointing results from anti-amyloid therapeutics in clinical trials. As a result, much of the AD research effort has shifted to understanding the roles of a variety of other entities implicated in pathogenesis, such as microglia, astrocytes, apolipoprotein E and several others. All undoubtedly play an important role, but the nature of this has in many cases remained unclear, partly due to their pleiotropic functions. Here, we propose that all of these AD-related entities share at least one overlapping function, which is the local regulation of amyloid-β levels, and that this may be critical to their role in AD pathogenesis. We also review what is currently known of the actions of amyloid-β at the synapse in health and disease, and consider in particular how it might interact with the key AD-associated protein tau in the disease setting. There is much compelling evidence in support of the amyloid hypothesis; rather than detract from this, the implication of many disparate AD-associated cell types, molecules and processes in the regulation of amyloid-β levels may lend further support.
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19
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Huang Z. A Function of Amyloid-β in Mediating Activity-Dependent Axon/Synapse Competition May Unify Its Roles in Brain Physiology and Pathology. J Alzheimers Dis 2023; 92:29-57. [PMID: 36710681 PMCID: PMC10023438 DOI: 10.3233/jad-221042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Amyloid-β protein precursor (AβPP) gives rise to amyloid-β (Aβ), a peptide at the center of Alzheimer's disease (AD). AβPP, however, is also an ancient molecule dating back in evolution to some of the earliest forms of metazoans. This suggests a possible ancestral function that may have been obscured by those that evolve later. Based on literature from the functions of Aβ/AβPP in nervous system development, plasticity, and disease, to those of anti-microbial peptides (AMPs) in bacterial competition as well as mechanisms of cell competition uncovered first by Drosophila genetics, I propose that Aβ/AβPP may be part of an ancient mechanism employed in cell competition, which is subsequently co-opted during evolution for the regulation of activity-dependent neural circuit development and plasticity. This hypothesis is supported by foremost the high similarities of Aβ to AMPs, both of which possess unique, opposite (i.e., trophic versus toxic) activities as monomers and oligomers. A large body of data further suggests that the different Aβ oligomeric isoforms may serve as the protective and punishment signals long predicted to mediate activity-dependent axonal/synaptic competition in the developing nervous system and that the imbalance in their opposite regulation of innate immune and glial cells in the brain may ultimately underpin AD pathogenesis. This hypothesis can not only explain the diverse roles observed of Aβ and AβPP family molecules, but also provide a conceptual framework that can unify current hypotheses on AD. Furthermore, it may explain major clinical observations not accounted for and identify approaches for overcoming shortfalls in AD animal modeling.
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Affiliation(s)
- Zhen Huang
- Departments of Neuroscience and Neurology, University of Wisconsin-Madison, Madison, WI, USA
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20
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Vilella A, Romoli B, Bodria M, Pons S, Maskos U, Zoli M. Evidence for a protective effect of the loss of α4-containing nicotinic acetylcholine receptors on Aβ-related neuropathology in Tg2576 mice. Front Neurosci 2023; 17:1097857. [PMID: 37113156 PMCID: PMC10126303 DOI: 10.3389/fnins.2023.1097857] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 03/15/2023] [Indexed: 04/29/2023] Open
Abstract
Introduction Loss of cholinergic neurons as well as α4β2* (* = containing) nicotinic acetylcholine receptors (nAChRs) is a prominent feature of Alzheimer's disease (AD). Specifically, amyloid β (Aβ), the principal pathogenic factor of AD, is a high affinity ligand for nAChRs. Yet, the pathophysiological role of nAChRs in AD is not well established. Methods In the present study, we have investigated the effects of the loss of α4* nAChRs on the histological alterations of the Tg2576 mouse model of AD (APPswe) crossing hemizygous APPswe mice with mice carrying the genetic inactivation of α4 nAChR subunit (α4KO). Results A global decrease in Aβ plaque load was observed in the forebrain of APPswe/α4KO mice in comparison with APPswe mice, that was particularly marked in neocortex of 15 month-old mice. At the same age, several alterations in synaptophysin immunoreactivity were observed in cortico-hippocampal regions of APPswe mice that were partially counteracted by α4KO. The analysis of the immunoreactivity of specific astroglia (glial fibrillary acidic protein, GFAP) and microglia (ionized calcium-binding adapter molecule, Iba1) markers showed an increase in the number as well as in the area occupied by these cells in APPswe mice that were partially counteracted by α4KO. Conclusion Overall, the present histological study points to a detrimental role of α4* nAChRs that may be specific for Aβ-related neuropathology.
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Affiliation(s)
- Antonietta Vilella
- Department of Biomedical, Metabolic and Neural Sciences, Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena, Italy
- *Correspondence: Antonietta Vilella,
| | - Benedetto Romoli
- Department of Biomedical, Metabolic and Neural Sciences, Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena, Italy
| | - Martina Bodria
- Department of Biomedical, Metabolic and Neural Sciences, Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena, Italy
| | - Stéphanie Pons
- Institut Pasteur, Université Paris Cité, Neurobiologie Intégrative des Systèmes Cholinergiques, CNRS UMR 3571, Département de Neuroscience, Paris, France
| | - Uwe Maskos
- Institut Pasteur, Université Paris Cité, Neurobiologie Intégrative des Systèmes Cholinergiques, CNRS UMR 3571, Département de Neuroscience, Paris, France
| | - Michele Zoli
- Department of Biomedical, Metabolic and Neural Sciences, Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena, Italy
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21
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Varshavskaya KB, Mitkevich VA, Makarov AA, Barykin EP. Synthetic, Cell-Derived, Brain-Derived, and Recombinant β-Amyloid: Modelling Alzheimer's Disease for Research and Drug Development. Int J Mol Sci 2022; 23:ijms232315036. [PMID: 36499362 PMCID: PMC9738609 DOI: 10.3390/ijms232315036] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 11/26/2022] [Accepted: 11/29/2022] [Indexed: 12/02/2022] Open
Abstract
Alzheimer's disease (AD) is the most common cause of dementia in the elderly, characterised by the accumulation of senile plaques and tau tangles, neurodegeneration, and neuroinflammation in the brain. The development of AD is a pathological cascade starting according to the amyloid hypothesis with the accumulation and aggregation of the β-amyloid peptide (Aβ), which induces hyperphosphorylation of tau and promotes the pro-inflammatory activation of microglia leading to synaptic loss and, ultimately, neuronal death. Modelling AD-related processes is important for both studying the molecular basis of the disease and the development of novel therapeutics. The replication of these processes is often achieved with the use of a purified Aβ peptide. However, Aβ preparations obtained from different sources can have strikingly different properties. This review aims to compare the structure and biological effects of Aβ oligomers and aggregates of a higher order: synthetic, recombinant, purified from cell culture, or extracted from brain tissue. The authors summarise the applicability of Aβ preparations for modelling Aβ aggregation, neurotoxicity, cytoskeleton damage, receptor toxicity in vitro and cerebral amyloidosis, synaptic plasticity disruption, and cognitive impairment in vivo and ex vivo. Further, the paper discusses the causes of the reported differences in the effect of Aβ obtained from the sources mentioned above. This review points to the importance of the source of Aβ for AD modelling and could help researchers to choose the optimal way to model the Aβ-induced abnormalities.
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22
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Circulating Small Extracellular Vesicle-Derived miR-342-5p Ameliorates Beta-Amyloid Formation via Targeting Beta-site APP Cleaving Enzyme 1 in Alzheimer's Disease. Cells 2022; 11:cells11233830. [PMID: 36497090 PMCID: PMC9741225 DOI: 10.3390/cells11233830] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 11/12/2022] [Accepted: 11/26/2022] [Indexed: 12/03/2022] Open
Abstract
Alzheimer's disease (AD) is a common neurodegenerative disorder with progressive cognitive impairment in the elderly. Beta-amyloid (Aβ) formation and its accumulation in the brain constitute one of the pathological hallmarks of AD. Until now, how to modulate Aβ formation in hippocampal neurons remains a big challenge. Herein, we investigated whether the exosomal transfer of microRNA (miR) relates to amyloid pathology in the recipient neuron cells. We isolated circulating small extracellular vesicles (sEVs) from AD patients and healthy controls, determined the miR-342-5p level in the sEVs by RT-PCR, and evaluated its diagnostic performance in AD. Then, we took advantage of biomolecular assays to estimate the role of miR-342-5p in modulating the amyloid pathway, including amyloid precursor protein (APP), beta-site APP cleaving enzyme 1 (BACE1), and Aβ42. Furthermore, we subjected HT22 cells to the sEVs from the hippocampal tissues of transgenic APP mice (Exo-APP) or C57BL/6 littermates (Exo-CTL), and the Exo-APP enriched with miR-342-5p mimics or the control to assess the effect of the sEVs' delivery of miR-342-5p on Aβ formation. We observed a lower level of miR-342-5p in the circulating sEVs from AD patients compared with healthy controls. MiR-342-5p participated in Aβ formation by modulating BACE1 expression, specifically binding its 3'-untranslated region (UTR) sequence. Exo-APP distinctly promoted Aβ42 formation in the recipient cells compared to Exo-CTL. Intriguingly, miR-342-5p enrichment in Exo-APP ameliorated amyloid pathology in the recipient cells. Our study indicated that miR-342-5p was dysregulated in human circulating sEVs from AD patients; sEV transfer of miR-342-5p ameliorates Aβ formation by modulating BACE1 expression. These findings highlight the promising potential of exosomal miRNAs in AD clinical therapy.
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23
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Tropea MR, Gulisano W, Vacanti V, Arancio O, Puzzo D, Palmeri A. Nitric oxide/cGMP/CREB pathway and amyloid-beta crosstalk: From physiology to Alzheimer's disease. Free Radic Biol Med 2022; 193:657-668. [PMID: 36400326 DOI: 10.1016/j.freeradbiomed.2022.11.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/30/2022] [Accepted: 11/12/2022] [Indexed: 11/17/2022]
Abstract
The nitric oxide (NO)/cGMP pathway has been extensively studied for its pivotal role in synaptic plasticity and memory processes, resulting in an increase of cAMP response element-binding (CREB) phosphorylation, and consequent synthesis of plasticity-related proteins. The NO/cGMP/CREB signaling is downregulated during aging and neurodegenerative disorders and is affected by Amyloid-β peptide (Aβ) and tau protein, whose increase and deposition is considered the key pathogenic event of Alzheimer's disease (AD). On the other hand, in physiological conditions, the crosstalk between the NO/cGMP/PKG/CREB pathway and Aβ ensures long-term potentiation and memory formation. This review summarizes the current knowledge on the interaction between the NO/cGMP/PKG/CREB pathway and Aβ in the healthy and diseased brain, offering a new perspective to shed light on AD pathophysiology. We will focus on the synaptic mechanisms underlying Aβ physiological interplay with cGMP pathway and how this balance is corrupted in AD, as high levels of Aβ interfere with NO production and cGMP molecular signaling leading to cognitive impairment. Finally, we will discuss results from preclinical and clinical studies proposing the increase of cGMP signaling as a therapeutic strategy in the treatment of AD.
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Affiliation(s)
- Maria Rosaria Tropea
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, 95123, Italy
| | - Walter Gulisano
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, 95123, Italy
| | - Valeria Vacanti
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, 95123, Italy
| | - Ottavio Arancio
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, USA; Department of Pathology & Cell Biology and Department of Medicine, Columbia University, New York, NY, 10032, USA
| | - Daniela Puzzo
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, 95123, Italy; Oasi Research Institute-IRCCS, Troina (EN), 94018, Italy.
| | - Agostino Palmeri
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, 95123, Italy
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24
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Fišar Z. Linking the Amyloid, Tau, and Mitochondrial Hypotheses of Alzheimer's Disease and Identifying Promising Drug Targets. Biomolecules 2022; 12:1676. [PMID: 36421690 PMCID: PMC9687482 DOI: 10.3390/biom12111676] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 10/23/2022] [Accepted: 11/09/2022] [Indexed: 08/27/2023] Open
Abstract
Damage or loss of brain cells and impaired neurochemistry, neurogenesis, and synaptic and nonsynaptic plasticity of the brain lead to dementia in neurodegenerative diseases, such as Alzheimer's disease (AD). Injury to synapses and neurons and accumulation of extracellular amyloid plaques and intracellular neurofibrillary tangles are considered the main morphological and neuropathological features of AD. Age, genetic and epigenetic factors, environmental stressors, and lifestyle contribute to the risk of AD onset and progression. These risk factors are associated with structural and functional changes in the brain, leading to cognitive decline. Biomarkers of AD reflect or cause specific changes in brain function, especially changes in pathways associated with neurotransmission, neuroinflammation, bioenergetics, apoptosis, and oxidative and nitrosative stress. Even in the initial stages, AD is associated with Aβ neurotoxicity, mitochondrial dysfunction, and tau neurotoxicity. The integrative amyloid-tau-mitochondrial hypothesis assumes that the primary cause of AD is the neurotoxicity of Aβ oligomers and tau oligomers, mitochondrial dysfunction, and their mutual synergy. For the development of new efficient AD drugs, targeting the elimination of neurotoxicity, mutual potentiation of effects, and unwanted protein interactions of risk factors and biomarkers (mainly Aβ oligomers, tau oligomers, and mitochondrial dysfunction) in the early stage of the disease seems promising.
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Affiliation(s)
- Zdeněk Fišar
- Department of Psychiatry, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 11, 120 00 Prague, Czech Republic
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25
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Trebesova H, Olivero G, Marchi M, Grilli M. The Anti-Aggregative Peptide KLVFF Mimics Aβ1-40 in the Modulation of Nicotinic Receptors: Implications for Peptide-Based Therapy. Biomedicines 2022; 10:biomedicines10092231. [PMID: 36140331 PMCID: PMC9496455 DOI: 10.3390/biomedicines10092231] [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: 07/28/2022] [Revised: 08/31/2022] [Accepted: 09/05/2022] [Indexed: 12/02/2022] Open
Abstract
In recent years, the inhibition of beta-amyloid (Aβ) aggregation has emerged as a potential strategy for Alzheimer’s disease. KLVFF, a small peptide corresponding to the aminoacidic sequence 16-20 of Aβ, reduces Aβ fibrillation dose dependently. Therefore, the toxic and functional characterization of its brain activity is fundamental for clarifying its potential therapeutic role. Accordingly, we studied the modulatory role of KLVFF on the cholinergic receptors regulating dopamine and noradrenaline release in rat synaptosomes. Nicotinic receptors on dopaminergic nerve terminals in the nucleus acccumbens are inhibited by KLVFF, which closely resembles full-length Aβ1-40. Moreover, KLVFF entrapped in synaptosomes does not modify the nicotinic receptor’s function, suggesting that external binding to the receptor is required for its activity. The cholinergic agent desformylflustrabromine counteracts the KLVFF effect. Remarkably, muscarinic receptors on dopaminergic terminals and nicotinic receptors regulating noradrenaline release in the hippocampus are completely insensitive to KLVFF. Based on our findings, KLVFF mimics Aβ1-40 as a negative modulator of specific nicotinic receptor subtypes affecting dopamine transmission in the rat brain. Therefore, new pharmacological strategies using the anti-aggregative properties of KLVFF need to be evaluated for potential interference with nicotinic receptor-mediated transmission.
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Na,K-ATPase Acts as a Beta-Amyloid Receptor Triggering Src Kinase Activation. Cells 2022; 11:cells11172753. [PMID: 36078160 PMCID: PMC9455167 DOI: 10.3390/cells11172753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 08/29/2022] [Accepted: 09/01/2022] [Indexed: 11/17/2022] Open
Abstract
Beta-amyloid (Aβ) has a dual role, both as an important factor in the pathology of Alzheimer's disease and as a regulator in brain physiology. The inhibitory effect of Aβ42 oligomers on Na,K-ATPase contributes to neuronal dysfunction in Alzheimer's disease. Still, the physiological role of the monomeric form of Aβ42 interaction with Na,K-ATPase remains unclear. We report that Na,K-ATPase serves as a receptor for Aβ42 monomer, triggering Src kinase activation. The co-localization of Aβ42 with α1- and β1-subunits of Na,K-ATPase, and Na,K-ATPase with Src kinase in SH-SY5Y neuroblastoma cells, was observed. Treatment of cells with 100 nM Aβ42 causes Src kinase activation, but does not alter Na,K-ATPase transport activity. The interaction of Aβ42 with α1β1 Na,K-ATPase isozyme leads to activation of Src kinase associated with the enzyme. Notably, prevention of Na,K-ATPase:Src kinase interaction by a specific inhibitor pNaKtide disrupts the Aβ-induced Src kinase activation. Stimulatory effect of Aβ42 on Src kinase was lost under hypoxic conditions, which was similar to the effect of specific Na,K-ATPase ligands, the cardiotonic steroids. Our findings identify Na,K-ATPase as a Aβ42 receptor, thus opening a prospect on exploring the physiological and pathological Src kinase activation caused by Aβ42 in the nervous system.
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Pfundstein G, Nikonenko AG, Sytnyk V. Amyloid precursor protein (APP) and amyloid β (Aβ) interact with cell adhesion molecules: Implications in Alzheimer’s disease and normal physiology. Front Cell Dev Biol 2022; 10:969547. [PMID: 35959488 PMCID: PMC9360506 DOI: 10.3389/fcell.2022.969547] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 07/07/2022] [Indexed: 11/16/2022] Open
Abstract
Alzheimer’s disease (AD) is an incurable neurodegenerative disorder in which dysfunction and loss of synapses and neurons lead to cognitive impairment and death. Accumulation and aggregation of neurotoxic amyloid-β (Aβ) peptides generated via amyloidogenic processing of amyloid precursor protein (APP) is considered to play a central role in the disease etiology. APP interacts with cell adhesion molecules, which influence the normal physiological functions of APP, its amyloidogenic and non-amyloidogenic processing, and formation of Aβ aggregates. These cell surface glycoproteins also mediate attachment of Aβ to the neuronal cell surface and induce intracellular signaling contributing to Aβ toxicity. In this review, we discuss the current knowledge surrounding the interactions of cell adhesion molecules with APP and Aβ and analyze the evidence of the critical role these proteins play in regulating the processing and physiological function of APP as well as Aβ toxicity. This is a necessary piece of the complex AD puzzle, which we should understand in order to develop safe and effective therapeutic interventions for AD.
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Affiliation(s)
- Grant Pfundstein
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | | | - Vladimir Sytnyk
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
- *Correspondence: Vladimir Sytnyk,
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Antman-Passig M, Wong E, Frost GR, Cupo C, Shah J, Agustinus A, Chen Z, Mancinelli C, Kamel M, Li T, Jonas LA, Li YM, Heller DA. Optical Nanosensor for Intracellular and Intracranial Detection of Amyloid-Beta. ACS NANO 2022; 16:7269-7283. [PMID: 35420796 PMCID: PMC9710299 DOI: 10.1021/acsnano.2c00054] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Amyloid-beta (Aβ) deposition occurs in the early stages of Alzheimer's disease (AD), but the early detection of Aβ is a persistent challenge. Herein, we engineered a near-infrared optical nanosensor capable of detecting Aβ intracellularly in live cells and intracranially in vivo. The sensor is composed of single-walled carbon nanotubes functionalized with Aβ wherein Aβ-Aβ interactions drive the response. We found that the Aβ nanosensors selectively responded to Aβ via solvatochromic modulation of the near-infrared emission of the nanotube. The sensor tracked Aβ accumulation in live cells and, upon intracranial administration in a genetic model of AD, signaled distinct responses in aged mice. This technology enables the interrogation of molecular mechanisms underlying Aβ neurotoxicity in the development of AD in living systems.
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Affiliation(s)
- Merav Antman-Passig
- Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
| | - Eitan Wong
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
| | - Georgia R Frost
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
| | - Christian Cupo
- Department of Mechanical Engineering, Columbia University, New York, New York 10027, United States
| | - Janki Shah
- Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
| | - Albert Agustinus
- Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, New York 10065, United States
| | - Ziyu Chen
- Program of Physiology, Biophysics, & Systems Biology, Weill Graduate School of Medical Sciences of Cornell University, New York, New York 10065, United States
| | - Chiara Mancinelli
- Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, New York 10065, United States
| | - Maikel Kamel
- Sophie Davis School of Biomedical Education, CUNY School of Medicine, New York, New York 10031, United States
| | - Thomas Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
- Program of Neurosciences, Weill Graduate School of Medical Sciences of Cornell University, New York, New York 10065, United States
| | - Lauren A Jonas
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
- Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, New York 10065, United States
| | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
- Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, New York 10065, United States
- Program of Neurosciences, Weill Graduate School of Medical Sciences of Cornell University, New York, New York 10065, United States
| | - Daniel A Heller
- Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
- Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, New York 10065, United States
- Program of Physiology, Biophysics, & Systems Biology, Weill Graduate School of Medical Sciences of Cornell University, New York, New York 10065, United States
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Natural Products from Plants and Algae for Treatment of Alzheimer’s Disease: A Review. Biomolecules 2022; 12:biom12050694. [PMID: 35625622 PMCID: PMC9139049 DOI: 10.3390/biom12050694] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 05/05/2022] [Accepted: 05/06/2022] [Indexed: 12/14/2022] Open
Abstract
Neurodegenerative disorders including Parkinson’s disease (PD), Huntington’s disease (HD) and the most frequent, Alzheimer’s disease (AD), represent one of the most urgent medical needs worldwide. Despite a significantly developed understanding of disease development and pathology, treatments that stop AD progression are not yet available. The recent approval of sodium oligomannate (GV-971) for AD treatment in China emphasized the potential value of natural products for the treatment of neurodegenerative disorders. Many current clinical studies include the administration of a natural compound as a single and combination treatment. The most prominent mechanisms of action are anti-inflammatory and anti-oxidative activities, thus preserving cellular survival. Here, we review current natural products that are either approved or are in testing for a treatment of neurodegeneration in AD. In addition to the most important compounds of plant origin, we also put special emphasis on compounds from algae, given their neuroprotective activity and their underlying mechanisms of neuroprotection.
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30
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Jeong H, Shin H, Hong S, Kim Y. Physiological Roles of Monomeric Amyloid-β and Implications for Alzheimer's Disease Therapeutics. Exp Neurobiol 2022; 31:65-88. [PMID: 35673997 PMCID: PMC9194638 DOI: 10.5607/en22004] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 03/26/2022] [Accepted: 03/30/2022] [Indexed: 12/23/2022] Open
Abstract
Alzheimer's disease (AD) progressively inflicts impairment of synaptic functions with notable deposition of amyloid-β (Aβ) as senile plaques within the extracellular space of the brain. Accordingly, therapeutic directions for AD have focused on clearing Aβ plaques or preventing amyloidogenesis based on the amyloid cascade hypothesis. However, the emerging evidence suggests that Aβ serves biological roles, which include suppressing microbial infections, regulating synaptic plasticity, promoting recovery after brain injury, sealing leaks in the blood-brain barrier, and possibly inhibiting the proliferation of cancer cells. More importantly, these functions were found in in vitro and in vivo investigations in a hormetic manner, that is to be neuroprotective at low concentrations and pathological at high concentrations. We herein summarize the physiological roles of monomeric Aβ and current Aβ-directed therapies in clinical trials. Based on the evidence, we propose that novel therapeutics targeting Aβ should selectively target Aβ in neurotoxic forms such as oligomers while retaining monomeric Aβ in order to preserve the physiological functions of Aβ monomers.
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Affiliation(s)
- Hyomin Jeong
- Division of Integrated Science and Engineering, Underwood International College, Yonsei University, Incheon 21983, Korea
- Department of Pharmacy, College of Pharmacy, Yonsei University, Incheon 21983, Korea
- Yonsei Institute of Pharmaceutical Sciences, College of Pharmacy, Yonsei University, Incheon 21983, Korea
| | - Heewon Shin
- Department of Pharmacy, College of Pharmacy, Yonsei University, Incheon 21983, Korea
- Yonsei Institute of Pharmaceutical Sciences, College of Pharmacy, Yonsei University, Incheon 21983, Korea
| | - Seungpyo Hong
- Department of Pharmacy, College of Pharmacy, Yonsei University, Incheon 21983, Korea
- Yonsei Frontier Lab, Yonsei University, Seoul 03722, Korea
- Division of Pharmaceutical Sciences, School of Pharmacy, University of Wisconsin-Madison, Madison, WI 53705, USA
- Wisconsin Center for NanoBioSystems, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - YoungSoo Kim
- Division of Integrated Science and Engineering, Underwood International College, Yonsei University, Incheon 21983, Korea
- Department of Pharmacy, College of Pharmacy, Yonsei University, Incheon 21983, Korea
- Yonsei Institute of Pharmaceutical Sciences, College of Pharmacy, Yonsei University, Incheon 21983, Korea
- Yonsei Frontier Lab, Yonsei University, Seoul 03722, Korea
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31
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Roy M, Nath AK, Pal I, Dey SG. Second Sphere Interactions in Amyloidogenic Diseases. Chem Rev 2022; 122:12132-12206. [PMID: 35471949 DOI: 10.1021/acs.chemrev.1c00941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Amyloids are protein aggregates bearing a highly ordered cross β structural motif, which may be functional but are mostly pathogenic. Their formation, deposition in tissues and consequent organ dysfunction is the central event in amyloidogenic diseases. Such protein aggregation may be brought about by conformational changes, and much attention has been directed toward factors like metal binding, post-translational modifications, mutations of protein etc., which eventually affect the reactivity and cytotoxicity of the associated proteins. Over the past decade, a global effort from different groups working on these misfolded/unfolded proteins/peptides has revealed that the amino acid residues in the second coordination sphere of the active sites of amyloidogenic proteins/peptides cause changes in H-bonding pattern or protein-protein interactions, which dramatically alter the structure and reactivity of these proteins/peptides. These second sphere effects not only determine the binding of transition metals and cofactors, which define the pathology of some of these diseases, but also change the mechanism of redox reactions catalyzed by these proteins/peptides and form the basis of oxidative damage associated with these amyloidogenic diseases. The present review seeks to discuss such second sphere modifications and their ramifications in the etiopathology of some representative amyloidogenic diseases like Alzheimer's disease (AD), type 2 diabetes mellitus (T2Dm), Parkinson's disease (PD), Huntington's disease (HD), and prion diseases.
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Affiliation(s)
- Madhuparna Roy
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Arnab Kumar Nath
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Ishita Pal
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Somdatta Ghosh Dey
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
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32
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Cho E, Youn K, Kwon H, Jeon J, Cho WS, Park SJ, Son SH, Jang DS, Shin CY, Moon M, Jun M, Kim NJ, Kim DH. Eugenitol ameliorates memory impairments in 5XFAD mice by reducing Aβ plaques and neuroinflammation. Biomed Pharmacother 2022; 148:112763. [PMID: 35240526 DOI: 10.1016/j.biopha.2022.112763] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 02/12/2022] [Accepted: 02/24/2022] [Indexed: 11/18/2022] Open
Abstract
Alzheimer's disease (AD) is caused by various pathological mechanisms; therefore, it is necessary to develop drugs that simultaneously act on multiple targets. In this study, we investigated the effects of eugenitol, which has anti-amyloid β (Aβ) and anti-neuroinflammatory effects, in an AD mouse model. We found that eugenitol potently inhibited Aβ plaque and oligomer formation. Moreover, eugenitol dissociated the preformed Aβ plaques and reduced Aβ-induced nero2a cell death. An in silico docking simulation study showed that eugenitol may interact with Aβ1-42 monomers and fibrils. Eugenitol showed radical scavenging effects and potently reduced the release of proinflammatory cytokines from lipopolysaccharide-treated BV2 cells. Systemic administration of eugenitol blocked Aβ aggregate-induced memory impairment in the Morris water maze test in a dose-dependent manner. In 5XFAD mice, prolonged administration of eugenitol ameliorated memory and hippocampal long-term potentiation impairment. Moreover, eugenitol significantly reduced Aβ deposits and neuroinflammation in the hippocampus of 5XFAD mice. These results suggest that eugenitol, which has anti-Aβ aggregation, Aβ fibril dissociation, and anti-inflammatory effects, potently modulates AD-like pathologies in 5XFAD mice, and could be a promising candidate for AD therapy.
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Affiliation(s)
- Eunbi Cho
- Department of Pharmacology and Department of Advanced Translational Medicine, School of Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Kumju Youn
- Department of Food Science and Nutrition, Dong-A University, Busan 49315, Republic of Korea
| | - Huiyoung Kwon
- Department of Health Sciences, The Graduate School of Dong-A University, Dong-A University, Busan 49315, Republic of Korea
| | - Jieun Jeon
- Department of Pharmacology and Department of Advanced Translational Medicine, School of Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Wan-Seob Cho
- Department of Health Sciences, The Graduate School of Dong-A University, Dong-A University, Busan 49315, Republic of Korea
| | - Se Jin Park
- School of Natural Resources and Environmental Sciences, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Seung Hwan Son
- Department of Pharmacy, College of Pharmacy, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Republic of Korea
| | - Dae Sik Jang
- Department of Life and Nanopharmaceutical Science, Republic of Korea, Kyung Hee East-West Pharmaceutical Research Institute, College of Pharmacy, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Chan Young Shin
- Department of Pharmacology and Department of Advanced Translational Medicine, School of Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Minho Moon
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon 35365, Republic of Korea
| | - Mira Jun
- Department of Health Sciences, The Graduate School of Dong-A University, Dong-A University, Busan 49315, Republic of Korea.
| | - Nam-Jung Kim
- Department of Pharmacy, College of Pharmacy, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Republic of Korea.
| | - Dong Hyun Kim
- Department of Pharmacology and Department of Advanced Translational Medicine, School of Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea; Department of Pharmacology, School of Medicine, Konkuk University, Seoul 05029, Republic of Korea; Institute of Biomedical Sciences & Technology, Konkuk University, Seoul 05029, Republic of Korea.
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Kaushik M, Kaushik P, Parvez S. Memory related molecular signatures: The pivots for memory consolidation and Alzheimer's related memory decline. Ageing Res Rev 2022; 76:101577. [PMID: 35104629 DOI: 10.1016/j.arr.2022.101577] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 12/23/2021] [Accepted: 01/27/2022] [Indexed: 12/31/2022]
Abstract
Age-related cognitive decline is the major cause of concern due to its 70% more incidence than dementia cases worldwide. Moreover, aging is also the major risk factor of Alzheimer's disease (AD), associated with progressive memory loss. Approx. 13 million people will have Alzheimer-related memory decline by 2050. Learning and memory is the fundamental process of brain functions. However, the mechanism for the same is still under investigation. Thus, it is critical to understand the process of memory consolidation in the brain and extrapolate its understanding to the memory decline mechanism. Research on learning and memory has identified several molecular signatures such as Protein kinase M zeta (PKMζ), Calcium/calmodulin-dependent protein kinase II (CaMKII), Brain-derived neurotrophic factor (BDNF), cAMP-response element binding protein (CREB) and Activity-regulated cytoskeleton-associated protein (Arc) crucial for the maintenance and stabilization of long-term memory in the brain. Interestingly, memory decline in AD has also been linked to the abnormality in expressing these memory-related molecular signatures. Hence, in the present consolidated review, we explored the role of these memory-related molecular signatures in long-term memory consolidation. Additionally, the effect of amyloid-beta toxicity on these molecular signatures is discussed in detail.
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Affiliation(s)
- Medha Kaushik
- Department of Toxicology, School of Chemical & Life Sciences, Jamia Hamdard, New Delhi 110062, India
| | - Pooja Kaushik
- Department of Toxicology, School of Chemical & Life Sciences, Jamia Hamdard, New Delhi 110062, India
| | - Suhel Parvez
- Department of Toxicology, School of Chemical & Life Sciences, Jamia Hamdard, New Delhi 110062, India.
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Ezzat K, Sturchio A, Espay AJ. Proteins Do Not Replicate, They Precipitate: Phase Transition and Loss of Function Toxicity in Amyloid Pathologies. BIOLOGY 2022; 11:biology11040535. [PMID: 35453734 PMCID: PMC9031251 DOI: 10.3390/biology11040535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 03/27/2022] [Accepted: 03/29/2022] [Indexed: 12/11/2022]
Abstract
Protein aggregation into amyloid fibrils affects many proteins in a variety of diseases, including neurodegenerative disorders, diabetes, and cancer. Physicochemically, amyloid formation is a phase transition process, where soluble proteins are transformed into solid fibrils with the characteristic cross-β conformation responsible for their fibrillar morphology. This phase transition proceeds via an initial, rate-limiting nucleation step followed by rapid growth. Several well-defined nucleation pathways exist, including homogenous nucleation (HON), which proceeds spontaneously; heterogeneous nucleation (HEN), which is catalyzed by surfaces; and seeding via preformed nuclei. It has been hypothesized that amyloid aggregation represents a protein-only (nucleic-acid free) replication mechanism that involves transmission of structural information via conformational templating (the prion hypothesis). While the prion hypothesis still lacks mechanistic support, it is also incompatible with the fact that proteins can be induced to form amyloids in the absence of a proteinaceous species acting as a conformational template as in the case of HEN, which can be induced by lipid membranes (including viral envelopes) or polysaccharides. Additionally, while amyloids can be formed from any protein sequence and via different nucleation pathways, they invariably adopt the universal cross-β conformation; suggesting that such conformational change is a spontaneous folding event that is thermodynamically favorable under the conditions of supersaturation and phase transition and not a templated replication process. Finally, as the high stability of amyloids renders them relatively inert, toxicity in some amyloid pathologies might be more dependent on the loss of function from protein sequestration in the amyloid state rather than direct toxicity from the amyloid plaques themselves.
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Affiliation(s)
- Kariem Ezzat
- Clinical Research Center, Department of Laboratory Medicine, Karolinska Institutet, 141 57 Stockholm, Sweden
- Correspondence:
| | - Andrea Sturchio
- Department of Clinical Neuroscience, Neuro Svenningsson, Karolinska Institutet, 171 76 Stockholm, Sweden;
- James J. and Joan A. Gardner Family Center for Parkinson’s Disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH 45221, USA;
| | - Alberto J. Espay
- James J. and Joan A. Gardner Family Center for Parkinson’s Disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH 45221, USA;
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Duan Y, Lv J, Zhang Z, Chen Z, Wu H, Chen J, Chen Z, Yang J, Wang D, Liu Y, Chen F, Tian Y, Cao X. Exogenous Aβ 1-42 monomers improve synaptic and cognitive function in Alzheimer's disease model mice. Neuropharmacology 2022; 209:109002. [PMID: 35196539 DOI: 10.1016/j.neuropharm.2022.109002] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/28/2022] [Accepted: 02/15/2022] [Indexed: 01/16/2023]
Abstract
Growing evidence has suggested the poor correlation between brain amyloid plaque and Alzheimer's disease (AD). Presenilin1 (PS1) and presenilin2 (PS2) conditional double knockout (cDKO) mice exhibited the reduced 42-amino acid amyloid-β peptide (Aβ1-42) level and AD-like symptoms, indicating a different pathological mechanism from the amyloid cascade hypothesis for AD. Here we found that exogenous synthetic Aβ1-42 monomers could improve the impaired memory not only in cDKO mice without Aβ1-42 deposition but also in the APP/PS1/Tau triple transgenic 3 × Tg-AD mice with Aβ1-42 deposition, which were mediated by α7-nAChR. Our findings demonstrate for the first time that reduced soluble Aβ1-42 level is the main cause of cognitive dysfunction in cDKO mice, and support the opinions that low soluble Aβ1-42 level due to Aβ1-42 deposition may also cause cognitive deficits in 3 × Tg-AD mice. Therefore, "loss-of-function" of Aβ1-42 should be avoided when designing therapies aimed at reducing Aβ1-42 burden in AD.
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Affiliation(s)
- Yanhong Duan
- Key Laboratory of Brain Functional Genomics, Ministry of Education, School of Life Sciences, East China Normal University, 3663 N. Zhongshan Rd., Shanghai, 200062, China
| | - Junyan Lv
- Key Laboratory of Brain Functional Genomics, Ministry of Education, School of Life Sciences, East China Normal University, 3663 N. Zhongshan Rd., Shanghai, 200062, China
| | - Zhonghui Zhang
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, 3663 N. Zhongshan Rd., Shanghai, 200062, China
| | - Zhenzhen Chen
- Key Laboratory of Brain Functional Genomics, Ministry of Education, School of Life Sciences, East China Normal University, 3663 N. Zhongshan Rd., Shanghai, 200062, China
| | - Hao Wu
- Key Laboratory of Brain Functional Genomics, Ministry of Education, School of Life Sciences, East China Normal University, 3663 N. Zhongshan Rd., Shanghai, 200062, China
| | - Jinnan Chen
- Key Laboratory of Brain Functional Genomics, Ministry of Education, School of Life Sciences, East China Normal University, 3663 N. Zhongshan Rd., Shanghai, 200062, China
| | - Zhidong Chen
- Key Laboratory of Brain Functional Genomics, Ministry of Education, School of Life Sciences, East China Normal University, 3663 N. Zhongshan Rd., Shanghai, 200062, China
| | - Jiarun Yang
- Key Laboratory of Brain Functional Genomics, Ministry of Education, School of Life Sciences, East China Normal University, 3663 N. Zhongshan Rd., Shanghai, 200062, China
| | - Dasheng Wang
- Key Laboratory of Brain Functional Genomics, Ministry of Education, School of Life Sciences, East China Normal University, 3663 N. Zhongshan Rd., Shanghai, 200062, China
| | - Yamei Liu
- School of Life Sciences, Shanghai University, No. 99 Shangda Rd., Shanghai, 200444, PR China
| | - Fuxue Chen
- School of Life Sciences, Shanghai University, No. 99 Shangda Rd., Shanghai, 200444, PR China
| | - Yang Tian
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, 3663 N. Zhongshan Rd., Shanghai, 200062, China
| | - Xiaohua Cao
- Key Laboratory of Brain Functional Genomics, Ministry of Education, School of Life Sciences, East China Normal University, 3663 N. Zhongshan Rd., Shanghai, 200062, China.
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Jaragh-Alhadad LA, Falahati M. Tin oxide nanoparticles trigger the formation of amyloid β oligomers/protofibrils and underlying neurotoxicity as a marker of Alzheimer's diseases. Int J Biol Macromol 2022; 204:154-160. [PMID: 35124024 DOI: 10.1016/j.ijbiomac.2022.01.190] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/11/2022] [Accepted: 01/29/2022] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease (AD) is known as one of the most common forms of dementia, and oligomerization of amyloid β (Aβ42) peptides can result in the onset of AD. Tin oxide nanoparticles (SnO2 NPs) showed several applications in biomedical fields can trigger unwanted interaction with proteins and inducing protein aggregation. Herein, we synthesized SnO2 NPs via the hydrothermal method and characterized by UV-visible, XRD, FTIR, TEM, and DLS techniques. Afterward, the formation of Aβ42 amyloid oligomers/protofibrils treated alone and with SnO2 NPs was explored by ThT and Nile red fluorescence and CD spectroscopic methods along with TEM imaging. The neurotoxicity of different spices of Aβ42 samples against PC-12 cells was then explored by MTT and caspase-3 activity assays. The characterization of SnO2 NPs confirmed the successful synthesis of crystalline NPs (20-30 nm). Different biophysical and cellular analyses indicated that SnO2 NPs accelerated Aβ42 fibrillogenesis and promoted amyloid oligomers/protofibrils cytotoxicity. As compared to the Aβ42 samples grown alone, the ThT and ANS fluorescence intensity along with ellipticity results indicated the promotory effect of SnO2 NPs on the formation of oligomers/protofibrils. Also, the cellular results showed that the treated Aβ42 samples with SnO2 NPs further reduced cell viability through activation of caspase-3. In conclusion, SnO2 NPs greatly accelerate the fibrillation of Aβ42 peptides and lead to the formation of more toxic species. The present data may offer further warrants into nano-based systems for biomedical applications in the central nervous system.
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Affiliation(s)
- Laila Abdulmohsen Jaragh-Alhadad
- Department of Chemistry, College of Science, Kuwait University, Safat 13060, Kuwait; Cardiovascular and Metabolic Sciences Department, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio 44195, USA.
| | - Mojtaba Falahati
- Laboratory Experimental Oncology and Nanomedicine Innovation Center Erasmus (NICE), Department of Pathology, Erasmus Medical Center, Rotterdam, the Netherlands; Department of Nanotechnology, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.
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Wang R, Chopra N, Nho K, Maloney B, Obukhov AG, Nelson PT, Counts SE, Lahiri DK. Human microRNA (miR-20b-5p) modulates Alzheimer's disease pathways and neuronal function, and a specific polymorphism close to the MIR20B gene influences Alzheimer's biomarkers. Mol Psychiatry 2022; 27:1256-1273. [PMID: 35087196 PMCID: PMC9054681 DOI: 10.1038/s41380-021-01351-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 09/30/2021] [Accepted: 10/04/2021] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder with loss of cognitive, executive, and other mental functions, and is the most common form of age-related dementia. Amyloid-β peptide (Aβ) contributes to the etiology and progression of the disease. Aβ is derived from the amyloid-β precursor protein (APP). Multiple microRNA (miRNA) species are also implicated in AD. We report that human hsa-miR20b-5p (miR-20b), produced from the MIR20B gene on Chromosome X, may play complex roles in AD pathogenesis, including Aβ regulation. Specifically, miR-20b-5p miRNA levels were altered in association with disease progression in three regions of the human brain: temporal neocortex, cerebellum, and posterior cingulate cortex. In cultured human neuronal cells, miR-20b-5p treatment interfered with calcium homeostasis, neurite outgrowth, and branchpoints. A single-nucleotide polymorphism (SNP) upstream of the MIR20B gene (rs13897515) associated with differences in levels of cerebrospinal fluid (CSF) Aβ1-42 and thickness of the entorhinal cortex. We located a miR-20b-5p binding site in the APP mRNA 3'-untranslated region (UTR), and treatment with miR-20b-5p reduced APP mRNA and protein levels. Network analysis of protein-protein interactions and gene coexpression revealed other important potential miR-20b-5p targets among AD-related proteins/genes. MiR-20b-5p, a miRNA that downregulated APP, was paradoxically associated with an increased risk for AD. However, miR-20b-5p also reduced, and the blockade of APP by siRNA likewise reduced calcium influx. As APP plays vital roles in neuronal health and does not exist solely to be the source of "pathogenic" Aβ, the molecular etiology of AD is likely to not just be a disease of "excess" but a disruption of delicate homeostasis.
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Affiliation(s)
- Ruizhi Wang
- Laboratory of Molecular Neurogenetics, Department of Psychiatry, Indiana Alzheimer's Disease Research Center, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Nipun Chopra
- Laboratory of Molecular Neurogenetics, Department of Psychiatry, Indiana Alzheimer's Disease Research Center, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
- DePauw University, Greencastle, IN, 46135, USA
| | - Kwangsik Nho
- Radiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Bryan Maloney
- Laboratory of Molecular Neurogenetics, Department of Psychiatry, Indiana Alzheimer's Disease Research Center, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Alexander G Obukhov
- Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Peter T Nelson
- Sanders-Brown Center on Aging, University of Kentucky, Kentucky Alzheimer's Disease Research Center, Lexington, KY, 40536, USA
| | - Scott E Counts
- Departments of Translational Neuroscience & Family Medicine, Michigan State University, Grand Rapids, and Michigan Alzheimer's Disease Research Center, Ann Arbor, MI, USA
| | - Debomoy K Lahiri
- Laboratory of Molecular Neurogenetics, Department of Psychiatry, Indiana Alzheimer's Disease Research Center, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
- Department of Medical & Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA.
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Pelucchi S, Gardoni F, Di Luca M, Marcello E. Synaptic dysfunction in early phases of Alzheimer's Disease. HANDBOOK OF CLINICAL NEUROLOGY 2022; 184:417-438. [PMID: 35034752 DOI: 10.1016/b978-0-12-819410-2.00022-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The synapse is the locus of plasticity where short-term alterations in synaptic strength are converted to long-lasting memories. In addition to the presynaptic terminal and the postsynaptic compartment, a more holistic view of the synapse includes the astrocytes and the extracellular matrix to form a tetrapartite synapse. All these four elements contribute to synapse health and are crucial for synaptic plasticity events and, thereby, for learning and memory processes. Synaptic dysfunction is a common pathogenic trait of several brain disorders. In Alzheimer's Disease, the degeneration of synapses can be detected at the early stages of pathology progression before neuronal degeneration, supporting the hypothesis that synaptic failure is a major determinant of the disease. The synapse is the place where amyloid-β peptides are generated and is the target of the toxic amyloid-β oligomers. All the elements constituting the tetrapartite synapse are altered in Alzheimer's Disease and can synergistically contribute to synaptic dysfunction. Moreover, the two main hallmarks of Alzheimer's Disease, i.e., amyloid-β and tau, act in concert to cause synaptic deficits. Deciphering the mechanisms underlying synaptic dysfunction is relevant for the development of the next-generation therapeutic strategies aimed at modifying the disease progression.
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Affiliation(s)
- Silvia Pelucchi
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Fabrizio Gardoni
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Monica Di Luca
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Elena Marcello
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy.
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Keshavarzi M, Moradbeygi F, Mobini K, Ghaffarian Bahraman A, Mohammadi P, Ghaedi A, Mohammadi-Bardbori A. The interplay of aryl hydrocarbon receptor/WNT/CTNNB1/Notch signaling pathways regulate amyloid beta precursor mRNA/protein expression and effected the learning and memory of mice. Toxicol Res (Camb) 2021; 11:147-161. [PMID: 35237419 PMCID: PMC8882790 DOI: 10.1093/toxres/tfab120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/22/2021] [Accepted: 12/01/2021] [Indexed: 12/31/2022] Open
Abstract
The amyloid beta precursor protein (APP) plays a pathophysiological role in the development of Alzheimer's disease as well as a physiological role in neuronal growth and synaptogenesis. The aryl hydrocarbon receptor (AhR)/WNT/Catenin Beta 1 (CTNNB1)/Notch signaling pathways stamp in many functions, including development and growth of neurons. However, the regulatory role of AhR-/WNT-/CTNNB1-/Notch-induced APP expression and its influence on hippocampal-dependent learning and memory deficits is not clear. Male BALB/C mice received 6-formylindolo[3,2-b]carbazole (an AhR agonist), CH223191(an AhR antagonist), DAPT (an inhibitor of Notch signaling), and XAV-939 (a WNT pathway inhibitor) at a single dose of 100 μg/kg, 1, 5 , and 5 mg/kg of body weight, respectively, via intraperitoneal injection alone or in combination. Gene expression analyses and protein assay were performed on the 7th and 29th days. To assess the hippocampal-dependent memory, all six mice also underwent contextual fear conditioning on the 28th day after treatments. Our results showed that endogenous ligand of AhR has a regulatory effect on APP gene. Also, the interaction of AhR/WNT/CTNNB1 has a positive regulatory effect, but Notch has a negative regulatory effect on the mRNA and protein expression of APP, which have a correlation with mice's learning skills and memory.
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Affiliation(s)
- Majid Keshavarzi
- Department of Pharmacology and Toxicology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz 7146864685, Iran,Department of Environmental Health, Faculty of Health, Sabzevar University of Medical Sciences, Sabzevar 7146864685, Iran
| | - Fatemeh Moradbeygi
- Department of Pharmacology and Toxicology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz 7146864685, Iran
| | - Keivan Mobini
- Department of Pharmacology and Toxicology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz 7146864685, Iran
| | - Ali Ghaffarian Bahraman
- Department of Pharmacology and Toxicology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz 7146864685, Iran,Occupational Environment Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Parisa Mohammadi
- Department of Environmental Health, Faculty of Health, Sabzevar University of Medical Sciences, Sabzevar 7146864685, Iran
| | - Afsaneh Ghaedi
- Department of Pharmacology and Toxicology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz 7146864685, Iran
| | - Afshin Mohammadi-Bardbori
- Correspondence address. Department of Pharmacology and Toxicology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz 7146864685, Iran. Tel.: +98(71)32425374; Fax: +98(71)32424326; E-mail:
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Guglielmotto M, Manassero G, Vasciaveo V, Venezia M, Tabaton M, Tamagno E. Estrogens Inhibit Amyloid-β-Mediated Paired Helical Filament-Like Conformation of Tau Through Antioxidant Activity and miRNA 218 Regulation in hTau Mice. J Alzheimers Dis 2021; 77:1339-1351. [PMID: 32804095 DOI: 10.3233/jad-200707] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND The risk of developing Alzheimer's disease as well as its progression and severity are known to be different in men and women, and cognitive decline is greater in women than in men at the same stage of disease and could be correlated at least in part on estradiol levels. OBJECTIVE In our work we found that biological sex influences the effect of amyloid-β42 (Aβ42) monomers on pathological tau conformational change. METHODS In this study we used transgenic mice expressing the wild-type human tau (hTau) which were subjected to intraventricular (ICV) injections of Aβ peptides in nanomolar concentration. RESULTS We found that Aβ42 produces pathological conformational changes and hyperphosphorylation of tau protein in male or ovariectomized female mice but not in control females. The treatment of ovariectomized females with estradiol replacement protects against the pathological conformation of tau and seems to be mediated by antioxidant activity as well as the ability to modulate the expression of miRNA 218 linked to tau phosphorylation. CONCLUSION Our study indicates that factors as age, reproductive stage, hormone levels, and the interplay with other risk factors should be considered in women, in order to identify the best appropriate therapeutic approach in prevention of cognitive impairment.
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Affiliation(s)
- Michela Guglielmotto
- Department of Neuroscience, University of Torino, Torino, Italy.,Neuroscience Institute of Cavalieri Ottolenghi Foundation (NICO), University of Torino, Orbassano, Torino, Italy
| | - Giusi Manassero
- Department of Neuroscience, University of Torino, Torino, Italy.,Neuroscience Institute of Cavalieri Ottolenghi Foundation (NICO), University of Torino, Orbassano, Torino, Italy
| | - Valeria Vasciaveo
- Department of Neuroscience, University of Torino, Torino, Italy.,Neuroscience Institute of Cavalieri Ottolenghi Foundation (NICO), University of Torino, Orbassano, Torino, Italy
| | - Marika Venezia
- Department of Neuroscience, University of Torino, Torino, Italy.,Neuroscience Institute of Cavalieri Ottolenghi Foundation (NICO), University of Torino, Orbassano, Torino, Italy
| | - Massimo Tabaton
- Unit of Geriatric Medicine, Department of Internal Medicine and Medical Specialties (DIMI), University of Genova, Genova, Italy
| | - Elena Tamagno
- Department of Neuroscience, University of Torino, Torino, Italy.,Neuroscience Institute of Cavalieri Ottolenghi Foundation (NICO), University of Torino, Orbassano, Torino, Italy
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Cuestas Torres DM, Cardenas FP. Synaptic plasticity in Alzheimer's disease and healthy aging. Rev Neurosci 2021; 31:245-268. [PMID: 32250284 DOI: 10.1515/revneuro-2019-0058] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 11/01/2019] [Indexed: 12/17/2022]
Abstract
The strength and efficiency of synaptic connections are affected by the environment or the experience of the individual. This property, called synaptic plasticity, is directly related to memory and learning processes and has been modeled at the cellular level. These types of cellular memory and learning models include specific stimulation protocols that generate a long-term strengthening of the synapses, called long-term potentiation, or a weakening of the said long-term synapses, called long-term depression. Although, for decades, researchers have believed that the main cause of the cognitive deficit that characterizes Alzheimer's disease (AD) and aging was the loss of neurons, the hypothesis of an imbalance in the cellular and molecular mechanisms of synaptic plasticity underlying this deficit is currently widely accepted. An understanding of the molecular and cellular changes underlying the process of synaptic plasticity during the development of AD and aging will direct future studies to specific targets, resulting in the development of much more efficient and specific therapeutic strategies. In this review, we classify, discuss, and describe the main findings related to changes in the neurophysiological mechanisms of synaptic plasticity in excitatory synapses underlying AD and aging. In addition, we suggest possible mechanisms in which aging can become a high-risk factor for the development of AD and how its development could be prevented or slowed.
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Affiliation(s)
- Diana Marcela Cuestas Torres
- Departamento de Psicología and Departamento de Biología, Laboratorio de Neurociencia y Comportamiento, Universidad de los Andes, Cra 1 N° 18A-12, CP 111711, Bogotá, Colombia
| | - Fernando P Cardenas
- Departamento de Psicología, Laboratorio de Neurociencia y Comportamiento, Universidad de los Andes, Cra 1 N° 18A-12, CP 111711, Bogotá, Colombia
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Genetic deletion of α7 nicotinic acetylcholine receptors induces an age-dependent Alzheimer's disease-like pathology. Prog Neurobiol 2021; 206:102154. [PMID: 34453977 DOI: 10.1016/j.pneurobio.2021.102154] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 05/29/2021] [Accepted: 08/18/2021] [Indexed: 11/22/2022]
Abstract
The accumulation of amyloid-beta peptide (Aβ) and the failure of cholinergic transmission are key players in Alzheimer's disease (AD). However, in the healthy brain, Aβ contributes to synaptic plasticity and memory acting through α7 subtype nicotinic acetylcholine receptors (α7nAChRs). Here, we hypothesized that the α7nAChR deletion blocks Aβ physiological function and promotes a compensatory increase in Aβ levels that, in turn, triggers an AD-like pathology. To validate this hypothesis, we studied the age-dependent phenotype of α7 knock out mice. We found that α7nAChR deletion caused an impairment of hippocampal synaptic plasticity and memory at 12 months of age, paralleled by an increase of Amyloid Precursor Protein expression and Aβ levels. This was accompanied by other classical AD features such as a hyperphosphorylation of tau at residues Ser 199, Ser 396, Thr 205, a decrease of GSK-3β at Ser 9, the presence of paired helical filaments and neurofibrillary tangles, neuronal loss and an increase of GFAP-positive astrocytes. Our findings suggest that α7nAChR malfunction might precede Aβ and tau pathology, offering a different perspective to interpret the failure of anti-Aβ therapies against AD and to find novel therapeutical approaches aimed at restoring α7nAChRs-mediated Aβ function at the synapse.
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Mather M. Noradrenaline in the aging brain: Promoting cognitive reserve or accelerating Alzheimer's disease? Semin Cell Dev Biol 2021; 116:108-124. [PMID: 34099360 PMCID: PMC8292227 DOI: 10.1016/j.semcdb.2021.05.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 05/04/2021] [Accepted: 05/05/2021] [Indexed: 12/19/2022]
Abstract
Many believe that engaging in novel and mentally challenging activities promotes brain health and prevents Alzheimer's disease in later life. However, mental stimulation may also have risks as well as benefits. As neurons release neurotransmitters, they often also release amyloid peptides and tau proteins into the extracellular space. These by-products of neural activity can aggregate into the tau tangle and amyloid plaque signatures of Alzheimer's disease. Over time, more active brain regions accumulate more pathology. Thus, increasing brain activity can have a cost. But the neuromodulator noradrenaline, released during novel and mentally stimulating events, may have some protective effects-as well as some negative effects. Via its inhibitory and excitatory effects on neurons and microglia, noradrenaline sometimes prevents and sometimes accelerates the production and accumulation of amyloid-β and tau in various brain regions. Both α2A- and β-adrenergic receptors influence amyloid-β production and tau hyperphosphorylation. Adrenergic activity also influences clearance of amyloid-β and tau. Furthermore, some findings suggest that Alzheimer's disease increases noradrenergic activity, at least in its early phases. Because older brains clear the by-products of synaptic activity less effectively, increased synaptic activity in the older brain risks accelerating the accumulation of Alzheimer's pathology more than it does in the younger brain.
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Affiliation(s)
- Mara Mather
- Leonard Davis School of Gerontology, Department of Psychology, & Department of Biomedical Engineering, University of Southern California, 3715 McClintock Ave, Los Angeles, CA 90089, United States.
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Sturchio A, Dwivedi AK, Young CB, Malm T, Marsili L, Sharma JS, Mahajan A, Hill EJ, Andaloussi SEL, Poston KL, Manfredsson FP, Schneider LS, Ezzat K, Espay AJ. High cerebrospinal amyloid-β 42 is associated with normal cognition in individuals with brain amyloidosis. EClinicalMedicine 2021; 38:100988. [PMID: 34505023 PMCID: PMC8413261 DOI: 10.1016/j.eclinm.2021.100988] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 06/09/2021] [Accepted: 06/10/2021] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Brain amyloidosis does not invariably predict dementia. We hypothesized that high soluble 42-amino acid β amyloid (Aβ42) peptide levels are associated with normal cognition and hippocampal volume despite increasing brain amyloidosis. METHODS This cross-sectional study of 598 amyloid-positive participants in the Alzheimer's Disease Neuroimaging Initiative cohort examined whether levels of soluble Aβ42 are higher in amyloid-positive normal cognition (NC) individuals compared to mild cognitive impairment (MCI) and Alzheimer's disease (AD) and whether this relationship applies to neuropsychological assessments and hippocampal volume measured within the same year. All subjects were evaluated between June 2010 and February 2019. Brain amyloid positivity was defined as positron emission tomography-based standard uptake value ratio (SUVR) ≥1.08 for [18] F-florbetaben or 1.11 for [18]F-florbetapir, with higher SUVR indicating more brain amyloidosis. Analyses were adjusted for age, sex, education, APOE4, p-tau, t-tau, and centiloids levels. FINDINGS Higher soluble Aβ42 levels were observed in NC (864.00 pg/ml) than in MCI (768.60 pg/ml) or AD (617.46 pg/ml), with the relationship between NC, MCI, and AD maintained across all amyloid tertiles. In adjusted analysis, there was a larger absolute effect size of soluble Aβ42 than SUVR for NC (0.82 vs. 0.40) and MCI (0.60 vs. 0.26) versus AD. Each standard deviation increase in Aβ42 was associated with greater odds of NC than AD (adjusted odds ratio, 6.26; p < 0.001) or MCI (1.42; p = 0.006). Higher soluble Aβ42 levels were also associated with better neuropsychological function and larger hippocampal volume. INTERPRETATION Normal cognition and hippocampal volume are associated with preservation of high soluble Aβ42 levels despite increasing brain amyloidosis. FUNDING Please refer to the Funding section at the end of the article.
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Affiliation(s)
- Andrea Sturchio
- James J. and Joan A. Gardner Family Center for Parkinson's disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH, USA
- Department of Clinical Neuroscience, Neuro Svenningsson, Karolinska Institute, 171 76 Stockholm, Sweden
| | - Alok K. Dwivedi
- Division of Biostatistics & Epidemiology, Department of Molecular and Translational Medicine, Texas Tech University Health Sciences Center, El Paso, TX, USA
| | - Christina B. Young
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Tarja Malm
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Luca Marsili
- James J. and Joan A. Gardner Family Center for Parkinson's disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH, USA
| | - Jennifer S. Sharma
- James J. and Joan A. Gardner Family Center for Parkinson's disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH, USA
| | - Abhimanyu Mahajan
- James J. and Joan A. Gardner Family Center for Parkinson's disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH, USA
| | - Emily J. Hill
- James J. and Joan A. Gardner Family Center for Parkinson's disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH, USA
| | - Samir EL Andaloussi
- Department of Laboratory Medicine, Clinical Research Center, Karolinska Institutet, Stockholm, Sweden
| | - Kathleen L. Poston
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | | | - Lon S. Schneider
- University of Southern California Keck School of Medicine, Los Angeles, CA, USA
| | - Kariem Ezzat
- Department of Laboratory Medicine, Clinical Research Center, Karolinska Institutet, Stockholm, Sweden
| | - Alberto J. Espay
- James J. and Joan A. Gardner Family Center for Parkinson's disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH, USA
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Zhi D, Yang W, Yue J, Xu S, Ma W, Zhao C, Wang X, Wang D. HSF-1 mediated combined ginsenosides ameliorating Alzheimer's disease like symptoms in Caernorhabditis elegans. Nutr Neurosci 2021; 25:2136-2148. [PMID: 34263695 DOI: 10.1080/1028415x.2021.1949791] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
There are few effective medications to treat Alzheimer's disease (AD). It has been suggested that several ginsenosides possess mild or moderate anti-AD activity. In our present work, a preferred combined ginsenosides was shown to have a more significant benefit effect on AD-like symptoms of worm paralysis and hypersensitivity to exogenous 5-HT in C. elegans. The combined ginsenosides can suppress Aβ deposits and Aβ oligomers, alleviating the toxicity induced by Aβ overexpression more effectively than used alone. Its anti-AD effect was partially abolished by hsf-1 RNAi knocked down or hsf-1 inactivation by point mutation, but not by daf-16 or skn-1 RNAi knocked down. Furthermore, it markedly activated hsp-16.2 gene expression downstream of HSF-1. Our results demonstrated that HSF-1 signaling pathway exerts an important role in mediating the therapeutic effect of combined ginsenosides on AD worms. These results provided powerful evidences and theoretical foundation for reshaping medicinal products of ginsenosides and ginseng on prevention of neurodegenerative diseases.
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Affiliation(s)
- Dejuan Zhi
- School of Pharmacy, Lanzhou University, Lanzhou, People's Republic of China
| | - Wenqi Yang
- School of Pharmacy, Lanzhou University, Lanzhou, People's Republic of China
| | - Juan Yue
- School of Pharmacy, Lanzhou University, Lanzhou, People's Republic of China
| | - Shuaishuai Xu
- School of Pharmacy, Lanzhou University, Lanzhou, People's Republic of China
| | - Wenjuan Ma
- School of Pharmacy, Lanzhou University, Lanzhou, People's Republic of China
| | - Chengmu Zhao
- School of Pharmacy, Lanzhou University, Lanzhou, People's Republic of China
| | - Xin Wang
- School of Pharmacy, Lanzhou University, Lanzhou, People's Republic of China
| | - Dongsheng Wang
- School of Pharmacy, Lanzhou University, Lanzhou, People's Republic of China
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Back MK, Ruggieri S, Jacobi E, von Engelhardt J. Amyloid Beta-Mediated Changes in Synaptic Function and Spine Number of Neocortical Neurons Depend on NMDA Receptors. Int J Mol Sci 2021; 22:ijms22126298. [PMID: 34208315 PMCID: PMC8231237 DOI: 10.3390/ijms22126298] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/07/2021] [Accepted: 06/09/2021] [Indexed: 11/16/2022] Open
Abstract
Onset and progression of Alzheimer's disease (AD) pathophysiology differs between brain regions. The neocortex, for example, is a brain region that is affected very early during AD. NMDA receptors (NMDARs) are involved in mediating amyloid beta (Aβ) toxicity. NMDAR expression, on the other hand, can be affected by Aβ. We tested whether the high vulnerability of neocortical neurons for Aβ-toxicity may result from specific NMDAR expression profiles or from a particular regulation of NMDAR expression by Aβ. Electrophysiological analyses suggested that pyramidal cells of 6-months-old wildtype mice express mostly GluN1/GluN2A NMDARs. While synaptic NMDAR-mediated currents are unaltered in 5xFAD mice, extrasynaptic NMDARs seem to contain GluN1/GluN2A and GluN1/GluN2A/GluN2B. We used conditional GluN1 and GluN2B knockout mice to investigate whether NMDARs contribute to Aβ-toxicity. Spine number was decreased in pyramidal cells of 5xFAD mice and increased in neurons with 3-week virus-mediated Aβ-overexpression. NMDARs were required for both Aβ-mediated changes in spine number and functional synapses. Thus, our study gives novel insights into the Aβ-mediated regulation of NMDAR expression and the role of NMDARs in Aβ pathophysiology in the somatosensory cortex.
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Prikhodko O, Rynearson KD, Sekhon T, Mante MM, Nguyen PD, Rissman RA, Tanzi RE, Wagner SL. The GSM BPN-15606 as a Potential Candidate for Preventative Therapy in Alzheimer's Disease. J Alzheimers Dis 2021; 73:1541-1554. [PMID: 31958080 DOI: 10.3233/jad-190442] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND In the amyloid hypothesis of Alzheimer's disease (AD), the dysregulation of amyloid-β protein (Aβ) production and clearance leads to amyloid deposits, tau tangles, neuronal loss, and cognitive dysfunction. Thus far, therapies targeting the enzymes responsible for Aβ production have been found ineffective or having significant side effects. OBJECTIVE To test whether a γ-secretase modulator, BPN-15606, is an effective disease-modifying or preventative treatment in the PSAPP mouse model of AD. METHODS We treated pre-plaque (3-month-old) and post-plaque (6-month-old) PSAPP AD transgenic mice for 3 months and examined behavioral, biochemical, and pathological end points. RESULTS BPN-15606 attenuated cognitive impairment and reduced amyloid plaque load, microgliosis, and astrogliosis associated with the AD phenotype of PSAPP mice when administered to pre-plaque (3-month-old) but was ineffective when administered to post-plaque (6-month-old) mice. No treatment-related toxicity was observed. CONCLUSION BPN-15606 appears efficacious when administered prior to significant pathology.
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Affiliation(s)
- Olga Prikhodko
- Department of Neurosciences, University of California San Diego, La Jolla, CA USA.,Present Address: Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Kevin D Rynearson
- Department of Neurosciences, University of California San Diego, La Jolla, CA USA.,VA San Diego Healthcare System, La Jolla, CA, USA
| | - Travis Sekhon
- Genetics and Aging Research Unit, Massachusetts General Hospital, Charlestown, MA, USA
| | - Mike M Mante
- Department of Neurosciences, University of California San Diego, La Jolla, CA USA.,VA San Diego Healthcare System, La Jolla, CA, USA
| | - Phuong D Nguyen
- Department of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - Robert A Rissman
- Department of Neurosciences, University of California San Diego, La Jolla, CA USA.,VA San Diego Healthcare System, La Jolla, CA, USA
| | - Rudolph E Tanzi
- Genetics and Aging Research Unit, Massachusetts General Hospital, Charlestown, MA, USA
| | - Steven L Wagner
- Department of Neurosciences, University of California San Diego, La Jolla, CA USA.,VA San Diego Healthcare System, La Jolla, CA, USA
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48
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Amyloid-Beta Mediates Homeostatic Synaptic Plasticity. J Neurosci 2021; 41:5157-5172. [PMID: 33926999 PMCID: PMC8211553 DOI: 10.1523/jneurosci.1820-20.2021] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 03/02/2021] [Accepted: 03/28/2021] [Indexed: 12/25/2022] Open
Abstract
The physiological role of the amyloid-precursor protein (APP) is insufficiently understood. Recent work has implicated APP in the regulation of synaptic plasticity. Substantial evidence exists for a role of APP and its secreted ectodomain APPsα in Hebbian plasticity. Here, we addressed the relevance of APP in homeostatic synaptic plasticity using organotypic tissue cultures prepared from APP -/- mice of both sexes. In the absence of APP, dentate granule cells failed to strengthen their excitatory synapses homeostatically. Homeostatic plasticity is rescued by amyloid-β and not by APPsα, and it is neither observed in APP+/+ tissue treated with β- or γ-secretase inhibitors nor in synaptopodin-deficient cultures lacking the Ca2+-dependent molecular machinery of the spine apparatus. Together, these results suggest a role of APP processing via the amyloidogenic pathway in homeostatic synaptic plasticity, representing a function of relevance for brain physiology as well as for brain states associated with increased amyloid-β levels.
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49
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Anni D, Weiss EM, Guhathakurta D, Akdas YE, Klueva J, Zeitler S, Andres-Alonso M, Huth T, Fejtova A. Aβ1-16 controls synaptic vesicle pools at excitatory synapses via cholinergic modulation of synapsin phosphorylation. Cell Mol Life Sci 2021; 78:4973-4992. [PMID: 33864480 PMCID: PMC8233295 DOI: 10.1007/s00018-021-03835-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 03/12/2021] [Accepted: 04/02/2021] [Indexed: 02/06/2023]
Abstract
Amyloid beta (Aβ) is linked to the pathology of Alzheimer’s disease (AD). At physiological concentrations, Aβ was proposed to enhance neuroplasticity and memory formation by increasing the neurotransmitter release from presynapse. However, the exact mechanisms underlying this presynaptic effect as well as specific contribution of endogenously occurring Aβ isoforms remain unclear. Here, we demonstrate that Aβ1-42 and Aβ1-16, but not Aβ17-42, increased size of the recycling pool of synaptic vesicles (SV). This presynaptic effect was driven by enhancement of endogenous cholinergic signalling via α7 nicotinic acetylcholine receptors, which led to activation of calcineurin, dephosphorylation of synapsin 1 and consequently resulted in reorganization of functional pools of SV increasing their availability for sustained neurotransmission. Our results identify synapsin 1 as a molecular target of Aβ and reveal an effect of physiological concentrations of Aβ on cholinergic modulation of glutamatergic neurotransmission. These findings provide new mechanistic insights in cholinergic dysfunction observed in AD.
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Affiliation(s)
- Daniela Anni
- Department of Psychiatry and Psychotherapy, University Hospital, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Eva-Maria Weiss
- Department of Psychiatry and Psychotherapy, University Hospital, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Debarpan Guhathakurta
- Department of Psychiatry and Psychotherapy, University Hospital, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Yagiz Enes Akdas
- Department of Psychiatry and Psychotherapy, University Hospital, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Julia Klueva
- RG Presynaptic Plasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Stefanie Zeitler
- Department of Psychiatry and Psychotherapy, University Hospital, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Maria Andres-Alonso
- RG Presynaptic Plasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Tobias Huth
- Institute of Physiology and Pathophysiology, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Anna Fejtova
- Department of Psychiatry and Psychotherapy, University Hospital, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany.
- RG Presynaptic Plasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany.
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50
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García-Viñuales S, Sciacca MFM, Lanza V, Santoro AM, Grasso G, Tundo GR, Sbardella D, Coletta M, Grasso G, La Rosa C, Milardi D. The interplay between lipid and Aβ amyloid homeostasis in Alzheimer's Disease: risk factors and therapeutic opportunities. Chem Phys Lipids 2021; 236:105072. [PMID: 33675779 DOI: 10.1016/j.chemphyslip.2021.105072] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 02/15/2021] [Accepted: 03/01/2021] [Indexed: 12/19/2022]
Abstract
Alzheimer's Diseases (AD) is characterized by the accumulation of amyloid deposits of Aβ peptide in the brain. Besides genetic background, the presence of other diseases and an unhealthy lifestyle are known risk factors for AD development. Albeit accumulating clinical evidence suggests that an impaired lipid metabolism is related to Aβ deposition, mechanistic insights on the link between amyloid fibril formation/clearance and aberrant lipid interactions are still unavailable. Recently, many studies have described the key role played by membrane bound Aβ assemblies in neurotoxicity. Moreover, it has been suggested that a derangement of the ubiquitin proteasome pathway and autophagy is significantly correlated with toxic Aβ aggregation and dysregulation of lipid levels. Thus, studies focusing on the role played by lipids in Aβ aggregation and proteostasis could represent a promising area of investigation for the design of valuable treatments. In this review we examine current knowledge concerning the effects of lipids in Aβ aggregation and degradation processes, focusing on the therapeutic opportunities that a comprehensive understanding of all biophysical, biochemical, and biological processes involved may disclose.
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Affiliation(s)
| | - Michele F M Sciacca
- Consiglio Nazionale delle Ricerche, Istituto di Cristallografia, Catania, Italy
| | - Valeria Lanza
- Consiglio Nazionale delle Ricerche, Istituto di Cristallografia, Catania, Italy
| | - Anna Maria Santoro
- Consiglio Nazionale delle Ricerche, Istituto di Cristallografia, Catania, Italy
| | - Giulia Grasso
- Consiglio Nazionale delle Ricerche, Istituto di Cristallografia, Catania, Italy
| | - Grazia R Tundo
- Department of Clinical Sciences and Translational Medicine, University of Rome Tor Vergata, Rome, Italy
| | | | - Massimiliano Coletta
- Department of Clinical Sciences and Translational Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Giuseppe Grasso
- Department of Chemistry, University of Catania, Catania, Italy
| | - Carmelo La Rosa
- Department of Chemistry, University of Catania, Catania, Italy
| | - Danilo Milardi
- Consiglio Nazionale delle Ricerche, Istituto di Cristallografia, Catania, Italy.
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