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Genchi G, Lauria G, Catalano A, Carocci A, Sinicropi MS. Neuroprotective Effects of Curcumin in Neurodegenerative Diseases. Foods 2024; 13:1774. [PMID: 38891002 PMCID: PMC11172163 DOI: 10.3390/foods13111774] [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: 04/29/2024] [Revised: 05/24/2024] [Accepted: 06/03/2024] [Indexed: 06/20/2024] Open
Abstract
Curcumin, a hydrophobic polyphenol extracted from the rhizome of Curcuma longa, is now considered a candidate drug for the treatment of neurological diseases, including Parkinson's Disease (PD), Alzheimer's Disease (AD), Huntington's Disease (HD), Multiple Sclerosis (MS), Amyotrophic Lateral Sclerosis (ALS), and prion disease, due to its potent anti-inflammatory, antioxidant potential, anticancerous, immunomodulatory, neuroprotective, antiproliferative, and antibacterial activities. Traditionally, curcumin has been used for medicinal and dietary purposes in Asia, India, and China. However, low water solubility, poor stability in the blood, high rate of metabolism, limited bioavailability, and little capability to cross the blood-brain barrier (BBB) have limited the clinical application of curcumin, despite the important pharmacological activities of this drug. A variety of nanocarriers, including liposomes, micelles, dendrimers, cubosome nanoparticles, polymer nanoparticles, and solid lipid nanoparticles have been developed with great success to effectively deliver the active drug to brain cells. Functionalization on the surface of nanoparticles with brain-specific ligands makes them target-specific, which should significantly improve bioavailability and reduce harmful effects. The aim of this review is to summarize the studies on curcumin and/or nanoparticles containing curcumin in the most common neurodegenerative diseases, highlighting the high neuroprotective potential of this nutraceutical.
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Affiliation(s)
- Giuseppe Genchi
- Dipartimento di Farmacia e Scienze della Salute e della Nutrizione, Università della Calabria, Arcavacata di Rende, 87036 Cosenza, Italy; (G.G.); (G.L.); (M.S.S.)
| | - Graziantonio Lauria
- Dipartimento di Farmacia e Scienze della Salute e della Nutrizione, Università della Calabria, Arcavacata di Rende, 87036 Cosenza, Italy; (G.G.); (G.L.); (M.S.S.)
| | - Alessia Catalano
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari “Aldo Moro”, 70125 Bari, Italy;
| | - Alessia Carocci
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari “Aldo Moro”, 70125 Bari, Italy;
| | - Maria Stefania Sinicropi
- Dipartimento di Farmacia e Scienze della Salute e della Nutrizione, Università della Calabria, Arcavacata di Rende, 87036 Cosenza, Italy; (G.G.); (G.L.); (M.S.S.)
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2
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Lathe R, St Clair D. Programmed ageing: decline of stem cell renewal, immunosenescence, and Alzheimer's disease. Biol Rev Camb Philos Soc 2023. [PMID: 37068798 DOI: 10.1111/brv.12959] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 03/27/2023] [Accepted: 03/30/2023] [Indexed: 04/19/2023]
Abstract
The characteristic maximum lifespan varies enormously across animal species from a few hours to hundreds of years. This argues that maximum lifespan, and the ageing process that itself dictates lifespan, are to a large extent genetically determined. Although controversial, this is supported by firm evidence that semelparous species display evolutionarily programmed ageing in response to reproductive and environmental cues. Parabiosis experiments reveal that ageing is orchestrated systemically through the circulation, accompanied by programmed changes in hormone levels across a lifetime. This implies that, like the circadian and circannual clocks, there is a master 'clock of age' (circavital clock) located in the limbic brain of mammals that modulates systemic changes in growth factor and hormone secretion over the lifespan, as well as systemic alterations in gene expression as revealed by genomic methylation analysis. Studies on accelerated ageing in mice, as well as human longevity genes, converge on evolutionarily conserved fibroblast growth factors (FGFs) and their receptors, including KLOTHO, as well as insulin-like growth factors (IGFs) and steroid hormones, as key players mediating the systemic effects of ageing. Age-related changes in these and multiple other factors are inferred to cause a progressive decline in tissue maintenance through failure of stem cell replenishment. This most severely affects the immune system, which requires constant renewal from bone marrow stem cells. Age-related immune decline increases risk of infection whereas lifespan can be extended in germfree animals. This and other evidence suggests that infection is the major cause of death in higher organisms. Immune decline is also associated with age-related diseases. Taking the example of Alzheimer's disease (AD), we assess the evidence that AD is caused by immunosenescence and infection. The signature protein of AD brain, Aβ, is now known to be an antimicrobial peptide, and Aβ deposits in AD brain may be a response to infection rather than a cause of disease. Because some cognitively normal elderly individuals show extensive neuropathology, we argue that the location of the pathology is crucial - specifically, lesions to limbic brain are likely to accentuate immunosenescence, and could thus underlie a vicious cycle of accelerated immune decline and microbial proliferation that culminates in AD. This general model may extend to other age-related diseases, and we propose a general paradigm of organismal senescence in which declining stem cell proliferation leads to programmed immunosenescence and mortality.
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Affiliation(s)
- Richard Lathe
- Division of Infection Medicine, Chancellor's Building, University of Edinburgh Medical School, Little France, Edinburgh, EH16 4SB, UK
| | - David St Clair
- Institute of Medical Sciences, School of Medicine, University of Aberdeen, Aberdeen, AB25 2ZD, UK
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3
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Shafiq M, Da Vela S, Amin L, Younas N, Harris DA, Zerr I, Altmeppen HC, Svergun D, Glatzel M. The prion protein and its ligands: Insights into structure-function relationships. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119240. [PMID: 35192891 DOI: 10.1016/j.bbamcr.2022.119240] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 01/23/2022] [Accepted: 01/28/2022] [Indexed: 06/14/2023]
Abstract
The prion protein is a multifunctional protein that exists in at least two different folding states. It is subject to diverse proteolytic processing steps that lead to prion protein fragments some of which are membrane-bound whereas others are soluble. A multitude of ligands bind to the prion protein and besides proteinaceous binding partners, interaction with metal ions and nucleic acids occurs. Although of great importance, information on structural and functional consequences of prion protein binding to its partners is limited. Here, we will reflect on the structure-function relationship of the prion protein and its binding partners considering the different folding states and prion protein fragments.
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Affiliation(s)
- Mohsin Shafiq
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20251 Hamburg, Germany
| | - Stefano Da Vela
- European Molecular Biology Laboratory (EMBL), Hamburg c/o German Electron Synchrotron (DESY), Notkestraße 85, 22607 Hamburg, Germany
| | - Ladan Amin
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, United States
| | - Neelam Younas
- Department of Neurology, University Medical Center Goettingen, Robert-Koch-str. 40, 37075 Goettingen, Germany
| | - David A Harris
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, United States
| | - Inga Zerr
- Department of Neurology, University Medical Center Goettingen, Robert-Koch-str. 40, 37075 Goettingen, Germany
| | - Hermann C Altmeppen
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20251 Hamburg, Germany
| | - Dmitri Svergun
- European Molecular Biology Laboratory (EMBL), Hamburg c/o German Electron Synchrotron (DESY), Notkestraße 85, 22607 Hamburg, Germany
| | - Markus Glatzel
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20251 Hamburg, Germany.
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4
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Linard M, Ravier A, Mougué L, Grgurina I, Boutillier AL, Foubert-Samier A, Blanc F, Helmer C. Infectious Agents as Potential Drivers of α-Synucleinopathies. Mov Disord 2022; 37:464-477. [PMID: 35040520 DOI: 10.1002/mds.28925] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/10/2021] [Accepted: 12/27/2021] [Indexed: 12/16/2022] Open
Abstract
α-synucleinopathies, encompassing Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy, are devastating neurodegenerative diseases for which available therapeutic options are scarce, mostly because of our limited understanding of their pathophysiology. Although these pathologies are attributed to an intracellular accumulation of the α-synuclein protein in the nervous system with subsequent neuronal loss, the trigger(s) of this accumulation is/are not clearly identified. Among the existing hypotheses, interest in the hypothesis advocating the involvement of infectious agents in the onset of these diseases is renewed. In this article, we aimed to review the ongoing relevant factors favoring and opposing this hypothesis, focusing on (1) the potential antimicrobial role of α-synuclein, (2) potential entry points of pathogens in regard to early symptoms of diverse α-synucleinopathies, (3) pre-existing literature reviews assessing potential associations between infectious agents and Parkinson's disease, (4) original studies assessing these associations for dementia with Lewy bodies and multiple system atrophy (identified through a systematic literature review), and finally (5) potential susceptibility factors modulating the effects of infectious agents on the nervous system. © 2022 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Morgane Linard
- University of Bordeaux, INSERM, Bordeaux Population Health Research Center, UMR U1219, Bordeaux, France
| | - Alix Ravier
- CM2R (Memory Resource and Research Centre), Geriatrics Department, University Hospitals of Strasbourg, Strasbourg, France
| | - Louisa Mougué
- Cognitive-Behavioral Unit and Memory Consultations, Hospital of Sens, Sens, France
| | - Iris Grgurina
- University of Strasbourg, UMR7364 CNRS, LNCA, Strasbourg, France
| | | | - Alexandra Foubert-Samier
- University of Bordeaux, INSERM, Bordeaux Population Health Research Center, UMR U1219, Bordeaux, France.,French Reference Centre for MSA, University Hospital of Bordeaux, Bordeaux, France
| | - Frédéric Blanc
- CM2R (Memory Resource and Research Centre), Geriatrics Department, University Hospitals of Strasbourg, Strasbourg, France.,ICube Laboratory and FMTS (Fédération de Médecine Translationnelle de Strasbourg), Team IMIS, University of Strasbourg, Strasbourg, France
| | - Catherine Helmer
- University of Bordeaux, INSERM, Bordeaux Population Health Research Center, UMR U1219, Bordeaux, France
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5
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Norins LC. Down syndrome and Alzheimer’s disease: Same infectious cause, same preventive? Med Hypotheses 2022. [DOI: 10.1016/j.mehy.2021.110745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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6
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Amyloid-β: A double agent in Alzheimer's disease? Biomed Pharmacother 2021; 139:111575. [PMID: 33845371 DOI: 10.1016/j.biopha.2021.111575] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 03/24/2021] [Accepted: 03/31/2021] [Indexed: 01/23/2023] Open
Abstract
Amyloid-β (Aβ) accumulation is one of the cardinal pathological hallmarks of Alzheimer's disease and plays an important role in its pathogenesis. Although the neurotoxic effects of Aβ has been extensively studied, recent studies have revealed that it may also have protective effects. Here, we review novel findings that have shifted our understanding of the role of Aβ in the pathogenesis of Alzheimer's disease. An in-depth and comprehensive understanding of Aβ will provide us with a broader perspective on the treatment of Alzheimer's disease.
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Monette A, Mouland AJ. Zinc and Copper Ions Differentially Regulate Prion-Like Phase Separation Dynamics of Pan-Virus Nucleocapsid Biomolecular Condensates. Viruses 2020; 12:E1179. [PMID: 33081049 PMCID: PMC7589941 DOI: 10.3390/v12101179] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/05/2020] [Accepted: 10/12/2020] [Indexed: 02/08/2023] Open
Abstract
Liquid-liquid phase separation (LLPS) is a rapidly growing research focus due to numerous demonstrations that many cellular proteins phase-separate to form biomolecular condensates (BMCs) that nucleate membraneless organelles (MLOs). A growing repertoire of mechanisms supporting BMC formation, composition, dynamics, and functions are becoming elucidated. BMCs are now appreciated as required for several steps of gene regulation, while their deregulation promotes pathological aggregates, such as stress granules (SGs) and insoluble irreversible plaques that are hallmarks of neurodegenerative diseases. Treatment of BMC-related diseases will greatly benefit from identification of therapeutics preventing pathological aggregates while sparing BMCs required for cellular functions. Numerous viruses that block SG assembly also utilize or engineer BMCs for their replication. While BMC formation first depends on prion-like disordered protein domains (PrLDs), metal ion-controlled RNA-binding domains (RBDs) also orchestrate their formation. Virus replication and viral genomic RNA (vRNA) packaging dynamics involving nucleocapsid (NC) proteins and their orthologs rely on Zinc (Zn) availability, while virus morphology and infectivity are negatively influenced by excess Copper (Cu). While virus infections modify physiological metal homeostasis towards an increased copper to zinc ratio (Cu/Zn), how and why they do this remains elusive. Following our recent finding that pan-retroviruses employ Zn for NC-mediated LLPS for virus assembly, we present a pan-virus bioinformatics and literature meta-analysis study identifying metal-based mechanisms linking virus-induced BMCs to neurodegenerative disease processes. We discover that conserved degree and placement of PrLDs juxtaposing metal-regulated RBDs are associated with disease-causing prion-like proteins and are common features of viral proteins responsible for virus capsid assembly and structure. Virus infections both modulate gene expression of metalloproteins and interfere with metal homeostasis, representing an additional virus strategy impeding physiological and cellular antiviral responses. Our analyses reveal that metal-coordinated virus NC protein PrLDs initiate LLPS that nucleate pan-virus assembly and contribute to their persistence as cell-free infectious aerosol droplets. Virus aerosol droplets and insoluble neurological disease aggregates should be eliminated by physiological or environmental metals that outcompete PrLD-bound metals. While environmental metals can control virus spreading via aerosol droplets, therapeutic interference with metals or metalloproteins represent additional attractive avenues against pan-virus infection and virus-exacerbated neurological diseases.
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Affiliation(s)
- Anne Monette
- Lady Davis Institute at the Jewish General Hospital, Montréal, QC H3T 1E2, Canada
| | - Andrew J. Mouland
- Lady Davis Institute at the Jewish General Hospital, Montréal, QC H3T 1E2, Canada
- Department of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
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8
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Voth S, Gwin M, Francis CM, Balczon R, Frank DW, Pittet JF, Wagener BM, Moser SA, Alexeyev M, Housley N, Audia JP, Piechocki S, Madera K, Simmons A, Crawford M, Stevens T. Virulent Pseudomonas aeruginosa infection converts antimicrobial amyloids into cytotoxic prions. FASEB J 2020; 34:9156-9179. [PMID: 32413239 PMCID: PMC7383673 DOI: 10.1096/fj.202000051rrr] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 04/19/2020] [Accepted: 04/21/2020] [Indexed: 01/05/2023]
Abstract
Pseudomonas aeruginosa infection elicits the production of cytotoxic amyloids from lung endothelium, yet molecular mechanisms of host‐pathogen interaction that underlie the amyloid production are not well understood. We examined the importance of type III secretion system (T3SS) effectors in the production of cytotoxic amyloids. P aeruginosa possessing a functional T3SS and effectors induced the production and release of cytotoxic amyloids from lung endothelium, including beta amyloid, and tau. T3SS effector intoxication was sufficient to generate cytotoxic amyloid release, yet intoxication with exoenzyme Y (ExoY) alone or together with exoenzymes S and T (ExoS/T/Y) generated the most virulent amyloids. Infection with lab and clinical strains engendered cytotoxic amyloids that were capable of being propagated in endothelial cell culture and passed to naïve cells, indicative of a prion strain. Conversely, T3SS‐incompetent P aeruginosa infection produced non‐cytotoxic amyloids with antimicrobial properties. These findings provide evidence that (1) endothelial intoxication with ExoY is sufficient to elicit self‐propagating amyloid cytotoxins during infection, (2) pulmonary endothelium contributes to innate immunity by generating antimicrobial amyloids in response to bacterial infection, and (3) ExoY contributes to the virulence arsenal of P aeruginosa through the subversion of endothelial amyloid host‐defense to promote a lung endothelial‐derived cytotoxic proteinopathy.
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Affiliation(s)
- Sarah Voth
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, AL, USA.,Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL, USA
| | - Meredith Gwin
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, AL, USA.,Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL, USA
| | - Christopher Michael Francis
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, AL, USA.,Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL, USA
| | - Ron Balczon
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL, USA.,Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, AL, USA
| | - Dara W Frank
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Jean-Francois Pittet
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham School of Medicine, Birmingham, AL, USA
| | - Brant M Wagener
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham School of Medicine, Birmingham, AL, USA
| | - Stephen A Moser
- Department of Pathology, University of Alabama at Birmingham School of Medicine, Birmingham, AL, USA
| | - Mikhail Alexeyev
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, AL, USA.,Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL, USA
| | - Nicole Housley
- Department of Microbiology and Immunology, College of Medicine, University of South Alabama, Mobile, AL, USA
| | - Jonathon P Audia
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL, USA.,Department of Microbiology and Immunology, College of Medicine, University of South Alabama, Mobile, AL, USA
| | - Scott Piechocki
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, AL, USA
| | - Kayla Madera
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, AL, USA
| | - Autumn Simmons
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, AL, USA
| | - Michaela Crawford
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, AL, USA
| | - Troy Stevens
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, AL, USA.,Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL, USA.,Department of Internal Medicine, College of Medicine, University of South Alabama, Mobile, AL, USA
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Lathe R, Darlix JL. Prion protein PrP nucleic acid binding and mobilization implicates retroelements as the replicative component of transmissible spongiform encephalopathy. Arch Virol 2020; 165:535-556. [PMID: 32025859 PMCID: PMC7024060 DOI: 10.1007/s00705-020-04529-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 12/13/2019] [Indexed: 12/21/2022]
Abstract
The existence of more than 30 strains of transmissible spongiform encephalopathy (TSE) and the paucity of infectivity of purified PrPSc, as well as considerations of PrP structure, are inconsistent with the protein-only (prion) theory of TSE. Nucleic acid is a strong contender as a second component. We juxtapose two key findings: (i) PrP is a nucleic-acid-binding antimicrobial protein that is similar to retroviral Gag proteins in its ability to trigger reverse transcription. (ii) Retroelement mobilization is widely seen in TSE disease. Given further evidence that PrP also mediates nucleic acid transport into and out of the cell, a strong case is to be made that a second element – retroelement nucleic acid – bound to PrP constitutes the second component necessary to explain the multiple strains of TSE.
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Affiliation(s)
- Richard Lathe
- Division of Infection Medicine, University of Edinburgh School of Medicine, Edinburgh, UK. .,Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Pushchino, Moscow, Moscow Region, Russia.
| | - Jean-Luc Darlix
- Faculté de Pharmacie, Centre Nationale de la Recherche Scientifique (CNRS) Laboratory of Bioimaging and Pathologies (Unité Mixte de Recherche 7021), Université de Strasbourg, Illkirch, France.
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Zhang B, Shen P, Yin X, Dai Y, Ding M, Cui L. Expression and functions of cellular prion proteins in immunocytes. Scand J Immunol 2019; 91:e12854. [PMID: 31785109 DOI: 10.1111/sji.12854] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 11/21/2019] [Accepted: 11/23/2019] [Indexed: 01/09/2023]
Abstract
Prion diseases are fatal neurodegenerative processes caused by the accumulation of the pathological prion protein, PrPSc . While pathological lesions are limited to the central nervous system (CNS), disease-specific proteins accumulate and replicate in secondary lymphoid organs prior to neuroinvasion, and their replication there depends on the abundance of cellular prion protein (PrPC ). PrPC is expressed in both central and peripheral lymphoid tissues, and up- or downregulates innate and adaptive immune responses. In addition to prion diseases, PrPC is also immunologically involved in other neurological disorders and infectious diseases, including Alzheimer's disease and human immunodeficiency virus infection. Herein, we summarize the expression and functions of PrPC in various immunocytes, as well as its immunological and pathological roles in neurodegeneration and infection.
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Affiliation(s)
- Baizhuo Zhang
- Department of Neurology, Neuroscience Centre, The First Hospital of Jilin University, Jilin University, Changchun, China
| | - Pingping Shen
- Department of Neurology, Neuroscience Centre, The First Hospital of Jilin University, Jilin University, Changchun, China
| | - Xiang Yin
- Department of Neurology, Neuroscience Centre, The First Hospital of Jilin University, Jilin University, Changchun, China
| | - Yanyuan Dai
- Department of Neurology, Neuroscience Centre, The First Hospital of Jilin University, Jilin University, Changchun, China
| | - Mingxuan Ding
- Department of Neurology, Neuroscience Centre, The First Hospital of Jilin University, Jilin University, Changchun, China
| | - Li Cui
- Department of Neurology, Neuroscience Centre, The First Hospital of Jilin University, Jilin University, Changchun, China
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11
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Qin Q, Li Y. Herpesviral infections and antimicrobial protection for Alzheimer's disease: Implications for prevention and treatment. J Med Virol 2019; 91:1368-1377. [PMID: 30997676 DOI: 10.1002/jmv.25481] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 04/04/2019] [Indexed: 02/05/2023]
Abstract
Accumulating evidence suggests that infections by herpesviruses might be closely linked to Alzheimer's disease (AD). Pathological hallmarks of AD brains include senile plaques induced by amyloid β peptide (Aβ) in the extracellular space and intracellular neurofibrillary tangles (NFTs) consisting of phosphorylated tau protein. The prevailing hypothesis for the mechanism of AD is amyloid cascade reaction. Recent studies revealed that infections by herpesviruses induce the similar pathological hallmarks of AD, including Aβ production, phosphorylation of tau (P-tau), oxidative stress, neuroinflammation, etc. Aβ peptide is regarded as one of the antimicrobial peptides, which inhibits HSV-1 replication. In the elderly, reactivation of herpesviruses might act as an initiator for amyloid cascade reaction in vulnerable individuals, triggering the neurofibrillary formation of phosphorylated tau and inducing oxidative stress and neuroinflammation, which can further contribute to the accumulation of Aβ and P-tau by impairing mitochondria and autophagosome. Epidemiological studies have shown AD susceptibility genes, such as APOE-ε4 allele, are highly linked to infections by herpesviruses. Interestingly, anti-herpesviral therapy significantly reduced the risk of AD in a large population study. Given that herpesviruses are arguably the most prevalent opportunistic pathogens and often reactivate in the elderly, it is reasonable to argue reactivation of herpesviruses might be major culprits for initiating AD in individuals carrying AD susceptibility genes. In this review, we summarize epidemiological and molecular evidence that support for a hypothesis of herpesviral infections and antimicrobial protection in the development of AD, and discuss the implications for future prevention and treatment of the disease.
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Affiliation(s)
- Qingsong Qin
- Laboratory of Human Virology and Oncology, Shantou University Medical College, Shantou, Guangdong, China
| | - Yun Li
- Sleep Medicine Center, Shantou University Medical College, Shantou, Guangdong, China
- Mental Health Center, Shantou University Medical College, Shantou, Guangdong, China
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12
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Norins LC. The Beehive Theory: Role of microorganisms in late sequelae of traumatic brain injury and chronic traumatic encephalopathy. Med Hypotheses 2019; 128:1-5. [PMID: 31203899 DOI: 10.1016/j.mehy.2019.04.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 04/25/2019] [Indexed: 12/19/2022]
Abstract
Traumatic brain injury and chronic traumatic encephalopathy are both major health problems, well-publicized for the severe delayed effects attributed to them, including cognitive decline, psychiatric disorders, seizures, impaired motor function, and personality changes. For convenience, the two afflictions are considered together under the rubric traumatic brain injury. Despite the need for neuroprotective agents, no substances have shown efficacy in clinical studies. Thus, a deeper understanding of the neuropathological mechanism of such injury is still needed. Proposed here is a theory that microorganisms from within the brain and elsewhere in the body contribute to the long-term neurological deterioration characteristic of traumatic brain injury. The label, "The Beehive Theory", is drawn from the well-known fact that disturbing a tranquil beehive with a blow can cause a swarm of angry bees to exit their dwelling place and attack nearby humans. Similarly, an impact to the head can initiate dislocations and disruptions in the microbiota present in the brain and body. First, since the normal human brain is not sterile, but is host to a variety of microorganisms, blows to the skull may dislodge them from their accustomed local environments, in which they have been living in quiet equilibrium with neighboring brain cells. Deleterious substances may be released by the displaced microbes, including metabolic products and antigens. Second, upon impact commensal microbes already resident on surfaces of the nose, mouth, and eyes, and potentially harmful organisms from the environment, may gain access to the brain through the distal ends of the olfactory and optic nerves or even a disrupted blood-brain barrier. Third, microbes dwelling in more distant parts of the body may be propelled through the walls of local blood vessels into the bloodstream, and then leak out into damaged areas of the brain that have increased blood-brain barrier permeability. Fourth, the impact may cause dysbiosis in the gastrointestinal microbiome, thereby disrupting signaling via the gut-brain axis. Possible preventatives or therapeutics that would address the adverse contributions of microbes to the late sequelae of traumatic brain injury include anti-inflammatories, antibacterials, antivirals, and probiotics.
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Affiliation(s)
- Leslie C Norins
- Alzheimer's Germ Quest, Inc., 4301 Gulfshore Blvd, Suite 1404, Naples, FL 34103, USA.
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