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Sánchez-Muniz FJ, Macho-González A, Garcimartín A, Santos-López JA, Benedí J, Bastida S, González-Muñoz MJ. The Nutritional Components of Beer and Its Relationship with Neurodegeneration and Alzheimer's Disease. Nutrients 2019; 11:nu11071558. [PMID: 31295866 PMCID: PMC6682961 DOI: 10.3390/nu11071558] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 07/04/2019] [Accepted: 07/08/2019] [Indexed: 02/07/2023] Open
Abstract
The prevalence of degenerative diseases has risen in western countries. Growing evidence suggests that demenia and other cognition affectations are associated with ambient factors including specific nutrients, food ingredients or specific dietary patterns. Mediterranean diet adherence has been associated with various health benefits and decreased risk of many diseases, including neurodegenerative disorders. Beer, as part of this protective diet, contains compounds such as silicon and hops that could play a major role in preventing brain disorders. In this review, different topics regarding Mediterranean diet, beer and the consumption of their main compounds and their relation to neurological health have been addressed. Taking into account published results from our group and other studies, the hypothesis linking aluminum intoxication with dementia and/or Alzheimer’s disease and the potential role of regular beer has also been considered. Beer, in spite of its alcohol content, may have some health benefits; nonetheless, its consumption is not adequate for all subjects. Thus, this review analyzed some promising results of non-alcoholic beer on several mechanisms engaged in neurodegeneration such as inflammation, oxidation, and cholinesterase activity, and their contribution to the behavioral modifications induced by aluminum intoxication. The review ends by giving conclusions and suggesting future topics of research related to moderate beer consumption and/or the consumption of its major compounds as a potential instrument for protecting against neurodegenerative disease progression and the need to develop nutrigenetic and nutrigenomic studies in aged people and animal models.
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Affiliation(s)
- Francisco José Sánchez-Muniz
- Departamento de Nutrición y Ciencia de los Alimentos, Facultad de Farmacia. Universidad Complutense de Madrid, 28040 Madrid, Spain.
- AFUSAN Research Group. Universidad Complutense de Madrid and Instituto de Investigación Sanitaria from Hospital Clínico San Carlos (IdISSC), 28040 Madrid, Spain.
| | - Adrián Macho-González
- Departamento de Nutrición y Ciencia de los Alimentos, Facultad de Farmacia. Universidad Complutense de Madrid, 28040 Madrid, Spain
- AFUSAN Research Group. Universidad Complutense de Madrid and Instituto de Investigación Sanitaria from Hospital Clínico San Carlos (IdISSC), 28040 Madrid, Spain
| | - Alba Garcimartín
- AFUSAN Research Group. Universidad Complutense de Madrid and Instituto de Investigación Sanitaria from Hospital Clínico San Carlos (IdISSC), 28040 Madrid, Spain
- Departamento de Farmacología, Farmacognosia y Botánica, Facultad de Farmacia. Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Jorge Arturo Santos-López
- AFUSAN Research Group. Universidad Complutense de Madrid and Instituto de Investigación Sanitaria from Hospital Clínico San Carlos (IdISSC), 28040 Madrid, Spain
- Departamento de Farmacología, Farmacognosia y Botánica, Facultad de Farmacia. Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Juana Benedí
- AFUSAN Research Group. Universidad Complutense de Madrid and Instituto de Investigación Sanitaria from Hospital Clínico San Carlos (IdISSC), 28040 Madrid, Spain
- Departamento de Farmacología, Farmacognosia y Botánica, Facultad de Farmacia. Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Sara Bastida
- Departamento de Nutrición y Ciencia de los Alimentos, Facultad de Farmacia. Universidad Complutense de Madrid, 28040 Madrid, Spain
- AFUSAN Research Group. Universidad Complutense de Madrid and Instituto de Investigación Sanitaria from Hospital Clínico San Carlos (IdISSC), 28040 Madrid, Spain
| | - María José González-Muñoz
- AFUSAN Research Group. Universidad Complutense de Madrid and Instituto de Investigación Sanitaria from Hospital Clínico San Carlos (IdISSC), 28040 Madrid, Spain
- Departamento de Ciencias Biomédicas, Unidad Docente de Toxicología, Facultad de Farmacia, Universidad de Alcalá, 28805 Alcalá de Henares, Spain
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Hedges DW, Berrett AN, Erickson LD, Brown BL, Thacker EL, Gale SD. Cardiovascular factors moderate the association of infection burden with cognitive function in young to middle-aged U.S. adults. PLoS One 2019; 14:e0218476. [PMID: 31194855 PMCID: PMC6564032 DOI: 10.1371/journal.pone.0218476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 06/03/2019] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Infectious diseases might affect cognitive aging and dementia risk, possibly via neuroinflammation. Similarly, risk factors for cardiovascular and cerebrovascular diseases are associated with cognitive function and dementia. We hypothesized that cardiovascular risk factors moderate the association of exposure to infectious diseases with cognitive function. METHODS We studied 5662 participants aged 20 to 59 years from the third National Health and Nutrition Examination Survey (1988-1994) in the United States. We used linear regression to investigate whether the Framingham general cardiovascular risk index moderated the association of infection burden based on exposure to eight different infectious diseases with cognitive functioning as measured by the Symbol Digit Substitution, Serial Digit Learning, and Reaction Time tests. RESULTS The multiplicative interaction between the infection-burden index and the cardiovascular-risk index was associated with performance on the Symbol Digit Substitution (B = .019 [95% CI: .008, .031], p < .001) but not on the Serial Digit Learning (B = .034 [95% CI: -.025, .094]) or for Reaction Time (B = -.030 [95% CI: -.848, .787]). Participants with a lower cardiovascular risk appeared to be more resilient against the potential adverse effects of higher infection burden on the Symbol Digit Substitution task. CONCLUSIONS Participants at zero risk for a cardiovascular event in the next 10 years had no differences in processing speed with increasing exposure to infectious disease, whereas participants with higher risk for a cardiovascular event had worse processing speed with increased exposure to infectious disease.
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Affiliation(s)
- Dawson W. Hedges
- Department of Psychology, Brigham Young University, Provo, Utah, United States of America
- The Neuroscience Center, Brigham Young University, Provo, Utah, United States of America
| | - Andrew N. Berrett
- Department of Psychology, Brigham Young University, Provo, Utah, United States of America
| | - Lance D. Erickson
- Department of Sociology, Brigham Young University, Provo, Utah, United States of America
| | - Bruce L. Brown
- Department of Psychology, Brigham Young University, Provo, Utah, United States of America
| | - Evan L. Thacker
- Department of Public Health, Brigham Young University, Provo, Utah, United States of America
| | - Shawn D. Gale
- Department of Psychology, Brigham Young University, Provo, Utah, United States of America
- The Neuroscience Center, Brigham Young University, Provo, Utah, United States of America
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53
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Giridharan VV, Masud F, Petronilho F, Dal-Pizzol F, Barichello T. Infection-Induced Systemic Inflammation Is a Potential Driver of Alzheimer's Disease Progression. Front Aging Neurosci 2019; 11:122. [PMID: 31191296 PMCID: PMC6546917 DOI: 10.3389/fnagi.2019.00122] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 05/07/2019] [Indexed: 12/18/2022] Open
Affiliation(s)
- Vijayasree V Giridharan
- Department of Psychiatry and Behavioral Sciences, Translational Psychiatry Program, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Faisal Masud
- Department of Anesthesiology, Houston Methodist Hospital, Houston, TX, United States
| | - Fabricia Petronilho
- Health Sciences Unit, Laboratory of Neurobiology of Inflammatory and Metabolic Processes, Graduate Program in Health Sciences, University of South Santa Catarina, Tubarão, Brazil
| | - Felipe Dal-Pizzol
- Laboratory of Experimental Pathophysiology, Graduate Program in Health Sciences, University of Southern Santa Catarina, Criciúma, Brazil
| | - Tatiana Barichello
- Department of Psychiatry and Behavioral Sciences, Translational Psychiatry Program, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States.,Laboratory of Experimental Pathophysiology, Graduate Program in Health Sciences, University of Southern Santa Catarina, Criciúma, Brazil.,Graduate Program in Health Sciences, Laboratory of Neurosciences, Health Sciences Unit, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
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54
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Syk and Hrs Regulate TLR3-Mediated Antiviral Response in Murine Astrocytes. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:6927380. [PMID: 31089414 PMCID: PMC6476135 DOI: 10.1155/2019/6927380] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 12/22/2018] [Accepted: 01/13/2019] [Indexed: 12/02/2022]
Abstract
Toll-like receptors (TLRs) sense the presence of pathogen-associated molecular patterns. Nevertheless, the mechanisms modulating TLR-triggered innate immune responses are not yet fully understood. Complex regulatory systems exist to appropriately direct immune responses against foreign or self-nucleic acids, and a critical role of hepatocyte growth factor-regulated tyrosine kinase substrate (HRS), endosomal sorting complex required for transportation-0 (ESCRT-0) subunit, has recently been implicated in the endolysosomal transportation of TLR7 and TLR9. We investigated the involvement of Syk, Hrs, and STAM in the regulation of the TLR3 signaling pathway in a murine astrocyte cell line C8-D1A following cell stimulation with a viral dsRNA mimetic. Our data uncover a relationship between TLR3 and ESCRT-0, point out Syk as dsRNA-activated kinase, and suggest the role for Syk in mediating TLR3 signaling in murine astrocytes. We show molecular events that occur shortly after dsRNA stimulation of astrocytes and result in Syk Tyr-342 phosphorylation. Further, TLR3 undergoes proteolytic processing; the resulting TLR3 N-terminal form interacts with Hrs. The knockdown of Syk and Hrs enhances TLR3-mediated antiviral response in the form of IFN-β, IL-6, and CXCL8 secretion. Understanding the role of Syk and Hrs in TLR3 immune responses is of high importance since activation and precise execution of the TLR3 signaling pathway in the brain seem to be particularly significant in mounting an effective antiviral defense. Infection of the brain with herpes simplex type 1 virus may increase the secretion of amyloid-β by neurons and astrocytes and be a causal factor in degenerative diseases such as Alzheimer's disease. Errors in TLR3 signaling, especially related to the precise regulation of the receptor transportation and degradation, need careful observation as they may disclose foundations to identify novel or sustain known therapeutic targets.
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de Waal GM, Engelbrecht L, Davis T, de Villiers WJS, Kell DB, Pretorius E. Correlative Light-Electron Microscopy detects lipopolysaccharide and its association with fibrin fibres in Parkinson's Disease, Alzheimer's Disease and Type 2 Diabetes Mellitus. Sci Rep 2018; 8:16798. [PMID: 30429533 PMCID: PMC6235901 DOI: 10.1038/s41598-018-35009-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 10/27/2018] [Indexed: 02/06/2023] Open
Abstract
Many chronic diseases, including those classified as cardiovascular, neurodegenerative, or autoimmune, are characterized by persistent inflammation. The origin of this inflammation is mostly unclear, but it is typically mediated by inflammatory biomarkers, such as cytokines, and affected by both environmental and genetic factors. Recently circulating bacterial inflammagens such as lipopolysaccharide (LPS) have been implicated. We used a highly selective mouse monoclonal antibody to detect bacterial LPS in whole blood and/or platelet poor plasma of individuals with Parkinson’s Disease, Alzheimer’s type dementia, or Type 2 Diabetes Mellitus. Our results showed that staining is significantly enhanced (P < 0.0001) compared to healthy controls. Aberrant blood clots in these patient groups are characterized by amyloid formation as shown by the amyloid-selective stains thioflavin T and Amytracker™ 480 or 680. Correlative Light-Electron Microscopy (CLEM) illustrated that the LPS antibody staining is located in the same places as where amyloid fibrils may be observed. These data are consistent with the Iron Dysregulation and Dormant Microbes (IDDM) hypothesis in which bacterial inflammagens such as LPS are responsible for anomalous blood clotting as part of the aetiology of these chronic inflammatory diseases.
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Affiliation(s)
- Greta M de Waal
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa
| | - Lize Engelbrecht
- Central Analytical Facilities, Fluorescence Microscopy Unit, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa
| | - Tanja Davis
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa
| | - Willem J S de Villiers
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa.,Department of Internal Medicine, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa
| | - Douglas B Kell
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa.,School of Chemistry, The University of Manchester, 131 Princess St, Manchester, Lancs, M1 7DN, UK.,Manchester Institute of Biotechnology, The University of Manchester, 131 Princess St, Manchester, Lancs, M1 7DN, UK
| | - Etheresia Pretorius
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa.
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Solana C, Tarazona R, Solana R. Immunosenescence of Natural Killer Cells, Inflammation, and Alzheimer's Disease. Int J Alzheimers Dis 2018; 2018:3128758. [PMID: 30515321 PMCID: PMC6236558 DOI: 10.1155/2018/3128758] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Accepted: 10/08/2018] [Indexed: 02/07/2023] Open
Abstract
Alzheimer's disease (AD) represents the most common cause of dementia in the elderly. AD is a neurodegenerative disorder characterized by progressive memory loss and cognitive decline. Although the aetiology of AD is not clear, both environmental factors and heritable predisposition may contribute to disease occurrence. In addition, inflammation and immune system alterations have been linked to AD. The prevailing hypothesis as cause of AD is the deposition in the brain of amyloid beta peptides (Aβ). Although Aβ have a role in defending the brain against infections, their accumulation promotes an inflammatory response mediated by microglia and astrocytes. The production of proinflammatory cytokines and other inflammatory mediators such as prostaglandins and complement factors favours the recruitment of peripheral immune cells further promoting neuroinflammation. Age-related inflammation and chronic infection with herpes virus such as cytomegalovirus may also contribute to inflammation in AD patients. Natural killer (NK) cells are innate lymphoid cells involved in host defence against viral infections and tumours. Once activated NK cells secrete cytokines such as IFN-γ and TNF-α and chemokines and exert cytotoxic activity against target cells. In the elderly, changes in NK cell compartment have been described which may contribute to the lower capacity of elderly individuals to respond to pathogens and tumours. Recently, the role of NK cells in the immunopathogenesis of AD is discussed. Although in AD patients the frequency of NK cells is not affected, a high NK cell response to cytokines has been described together with NK cell dysregulation of signalling pathways which is in part involved in this altered behaviour.
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Affiliation(s)
| | | | - Rafael Solana
- Instituto Maimónides de Investigación Biomédica (IMIBIC), Córdoba, Spain
- Reina Sofia University Hospital, Córdoba, Spain
- University of Cordoba, Córdoba, Spain
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58
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Ashraf GM, Tarasov VV, Makhmutovа A, Chubarev VN, Avila-Rodriguez M, Bachurin SO, Aliev G. The Possibility of an Infectious Etiology of Alzheimer Disease. Mol Neurobiol 2018; 56:4479-4491. [DOI: 10.1007/s12035-018-1388-y] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 09/27/2018] [Indexed: 12/26/2022]
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59
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Fülöp T, Itzhaki RF, Balin BJ, Miklossy J, Barron AE. Role of Microbes in the Development of Alzheimer's Disease: State of the Art - An International Symposium Presented at the 2017 IAGG Congress in San Francisco. Front Genet 2018; 9:362. [PMID: 30250480 PMCID: PMC6139345 DOI: 10.3389/fgene.2018.00362] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 08/21/2018] [Indexed: 12/17/2022] Open
Abstract
This article reviews research results and ideas presented at a special symposium at the International Association of Gerontology and Geriatrics (IAGG) Congress held in July 2017 in San Francisco. Five researchers presented their results related to infection and Alzheimer's disease (AD). Prof. Itzhaki presented her work on the role of viruses, specifically HSV-1, in the pathogenesis of AD. She maintains that although it is true that most people harbor HSV-1 infection, either latent or active, nonetheless aspects of herpes infection can play a role in the pathogenesis of AD, based on extensive experimental evidence from AD brains and infected cell cultures. Dr. Miklossy presented research on the high prevalence of bacterial infections that correlate with AD, specifically spirochete infections, which have been known for a century to be a significant cause of dementia (e.g., in syphilis). She demonstrated how spirochetes drive senile plaque formation, which are in fact biofilms. Prof. Balin then described the involvement of brain tissue infection by the Chlamydia pneumoniae bacterium, with its potential to use the innate immune system in its spread, and its initiation of tissue damage characteristic of AD. Prof. Fülöp described the role of AD-associated amyloid beta (Aβ) peptide as an antibacterial, antifungal and antiviral innate immune effector produced in reaction to microorganisms that attack the brain. Prof. Barron put forward the novel hypothesis that, according to her experiments, there is strong sequence-specific binding between the AD-associated Aβ and another ubiquitous and important human innate immune effector, the cathelicidin peptide LL-37. Given this binding, LL-37 expression in the brain will decrease Aβ deposition via formation of non-toxic, soluble Aβ/LL-37 complexes. Therefore, a chronic underexpression of LL-37 could be the factor that simultaneously permits chronic infections in brain tissue and allows for pathological accumulation of Aβ. This first-of-its-kind symposium opened the way for a paradigm shift in studying the pathogenesis of AD, from the "amyloid cascade hypothesis," which so far has been quite unsuccessful, to a new "infection hypothesis," or perhaps more broadly, "innate immune system dysregulation hypothesis," which may well permit and lead to the discovery of new treatments for AD patients.
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Affiliation(s)
- Tamàs Fülöp
- Department of Medicine, Division of Geriatrics, Research Center on Aging, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Ruth F. Itzhaki
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Brian J. Balin
- Department of Bio-Medical Sciences, Center for Chronic Disorders of Aging, Philadelphia College of Osteopathic Medicine, Philadelphia, PA, United States
| | - Judith Miklossy
- International Alzheimer Research Centre, Prevention Alzheimer International Foundation, Martigny-Croix, Switzerland
| | - Annelise E. Barron
- Department of Bioengineering, Stanford University, Stanford, CA, United States
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60
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Pretorius E, Bester J, Page MJ, Kell DB. The Potential of LPS-Binding Protein to Reverse Amyloid Formation in Plasma Fibrin of Individuals With Alzheimer-Type Dementia. Front Aging Neurosci 2018; 10:257. [PMID: 30186156 PMCID: PMC6113936 DOI: 10.3389/fnagi.2018.00257] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 08/03/2018] [Indexed: 12/28/2022] Open
Abstract
Many studies indicate that there is a (mainly dormant) microbial component in the progressive development of Alzheimer-type dementias (ADs); and that in the case of Gram-negative organisms, a chief culprit might be the shedding of the highly inflammagenic lipopolysaccharide (LPS) from their cell walls. We have recently shown that a highly sensitive assay for the presence of free LPS [added to platelet poor plasma (PPP)] lies in its ability (in healthy individuals) to induce blood to clot into an amyloid form. This may be observed in a SEM or in a confocal microscope when suitable amyloid stains (such as thioflavin T) are added. This process could be inhibited by human lipopolysaccharide-binding protein (LBP). In the current paper, we show using scanning electron microscopy and confocal microscopy with amyloid markers, that PPP taken from individuals with AD exhibits considerable amyloid structure when clotting is initiated with thrombin but without added LPS. Furthermore, we could show that this amyloid structure may be reversed by the addition of very small amounts of LBP. This provides further evidence for a role of microbes and their inflammagenic cell wall products and that these products may be involved in pathological clotting in individuals with AD.
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Affiliation(s)
- Etheresia Pretorius
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
| | - Janette Bester
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Martin J Page
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
| | - Douglas B Kell
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa.,School of Chemistry, The University of Manchester, Manchester, United Kingdom.,The Manchester Institute of Biotechnology, The University of Manchester, Manchester, United Kingdom
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Kell DB, Pretorius E. No effects without causes: the Iron Dysregulation and Dormant Microbes hypothesis for chronic, inflammatory diseases. Biol Rev Camb Philos Soc 2018; 93:1518-1557. [PMID: 29575574 PMCID: PMC6055827 DOI: 10.1111/brv.12407] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 02/12/2018] [Accepted: 02/15/2018] [Indexed: 12/11/2022]
Abstract
Since the successful conquest of many acute, communicable (infectious) diseases through the use of vaccines and antibiotics, the currently most prevalent diseases are chronic and progressive in nature, and are all accompanied by inflammation. These diseases include neurodegenerative (e.g. Alzheimer's, Parkinson's), vascular (e.g. atherosclerosis, pre-eclampsia, type 2 diabetes) and autoimmune (e.g. rheumatoid arthritis and multiple sclerosis) diseases that may appear to have little in common. In fact they all share significant features, in particular chronic inflammation and its attendant inflammatory cytokines. Such effects do not happen without underlying and initially 'external' causes, and it is of interest to seek these causes. Taking a systems approach, we argue that these causes include (i) stress-induced iron dysregulation, and (ii) its ability to awaken dormant, non-replicating microbes with which the host has become infected. Other external causes may be dietary. Such microbes are capable of shedding small, but functionally significant amounts of highly inflammagenic molecules such as lipopolysaccharide and lipoteichoic acid. Sequelae include significant coagulopathies, not least the recently discovered amyloidogenic clotting of blood, leading to cell death and the release of further inflammagens. The extensive evidence discussed here implies, as was found with ulcers, that almost all chronic, infectious diseases do in fact harbour a microbial component. What differs is simply the microbes and the anatomical location from and at which they exert damage. This analysis offers novel avenues for diagnosis and treatment.
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Affiliation(s)
- Douglas B. Kell
- School of ChemistryThe University of Manchester, 131 Princess StreetManchesterLancsM1 7DNU.K.
- The Manchester Institute of BiotechnologyThe University of Manchester, 131 Princess StreetManchesterLancsM1 7DNU.K.
- Department of Physiological SciencesStellenbosch University, Stellenbosch Private Bag X1Matieland7602South Africa
| | - Etheresia Pretorius
- Department of Physiological SciencesStellenbosch University, Stellenbosch Private Bag X1Matieland7602South Africa
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Fulop T, Witkowski JM, Bourgade K, Khalil A, Zerif E, Larbi A, Hirokawa K, Pawelec G, Bocti C, Lacombe G, Dupuis G, Frost EH. Can an Infection Hypothesis Explain the Beta Amyloid Hypothesis of Alzheimer's Disease? Front Aging Neurosci 2018; 10:224. [PMID: 30087609 PMCID: PMC6066504 DOI: 10.3389/fnagi.2018.00224] [Citation(s) in RCA: 128] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 07/02/2018] [Indexed: 12/19/2022] Open
Abstract
Alzheimer's disease (AD) is the most frequent type of dementia. The pathological hallmarks of the disease are extracellular senile plaques composed of beta-amyloid peptide (Aβ) and intracellular neurofibrillary tangles composed of pTau. These findings led to the "beta-amyloid hypothesis" that proposes that Aβ is the major cause of AD. Clinical trials targeting Aβ in the brain have mostly failed, whether they attempted to decrease Aβ production by BACE inhibitors or by antibodies. These failures suggest a need to find new hypotheses to explain AD pathogenesis and generate new targets for intervention to prevent and treat the disease. Many years ago, the "infection hypothesis" was proposed, but received little attention. However, the recent discovery that Aβ is an antimicrobial peptide (AMP) acting against bacteria, fungi, and viruses gives increased credence to an infection hypothesis in the etiology of AD. We and others have shown that microbial infection increases the synthesis of this AMP. Here, we propose that the production of Aβ as an AMP will be beneficial on first microbial challenge but will become progressively detrimental as the infection becomes chronic and reactivates from time to time. Furthermore, we propose that host measures to remove excess Aβ decrease over time due to microglial senescence and microbial biofilm formation. We propose that this biofilm aggregates with Aβ to form the plaques in the brain of AD patients. In this review, we will develop this connection between Infection - Aβ - AD and discuss future possible treatments based on this paradigm.
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Affiliation(s)
- Tamas Fulop
- Division of Geriatrics, Department of Medicine, Research Center on Aging, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Jacek M. Witkowski
- Department of Pathophysiology, Medical University of Gdańsk, Gdańsk, Poland
| | - Karine Bourgade
- Division of Geriatrics, Department of Medicine, Research Center on Aging, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Abdelouahed Khalil
- Division of Geriatrics, Department of Medicine, Research Center on Aging, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Echarki Zerif
- Division of Geriatrics, Department of Medicine, Research Center on Aging, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Anis Larbi
- Singapore Immunology Network, ASTAR, Biopolis, Singapore, Singapore
| | - Katsuiku Hirokawa
- Department of Pathology, Nitobe Memorial Nakano General Hospital, Tokyo, Japan
| | - Graham Pawelec
- Department of Internal Medicine II, Center for Medical Research, University of Tübingen, Tübingen, Germany
- Health Sciences North Research Institute, Greater Sudbury, ON, Canada
| | - Christian Bocti
- Division of Geriatrics, Department of Medicine, Research Center on Aging, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Guy Lacombe
- Division of Geriatrics, Department of Medicine, Research Center on Aging, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Gilles Dupuis
- Department of Biochemistry, Graduate Programme of Immunology, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Eric H. Frost
- Department of Microbiology and Infectious Diseases, University of Sherbrooke, Sherbrooke, QC, Canada
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Yashin AI, Fang F, Kovtun M, Wu D, Duan M, Arbeev K, Akushevich I, Kulminski A, Culminskaya I, Zhbannikov I, Yashkin A, Stallard E, Ukraintseva S. Hidden heterogeneity in Alzheimer's disease: Insights from genetic association studies and other analyses. Exp Gerontol 2018; 107:148-160. [PMID: 29107063 PMCID: PMC5920782 DOI: 10.1016/j.exger.2017.10.020] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 10/20/2017] [Accepted: 10/22/2017] [Indexed: 02/08/2023]
Abstract
Despite evident success in clarifying many important features of Alzheimer's disease (AD) the efficient methods of its prevention and treatment are not yet available. The reasons are likely to be the fact that AD is a multifactorial and heterogeneous health disorder with multiple alternative pathways of disease development and progression. The availability of genetic data on individuals participated in longitudinal studies of aging health and longevity, as well as on participants of cross-sectional case-control studies allow for investigating genetic and non-genetic connections with AD and to link the results of these analyses with research findings obtained in clinical, experimental, and molecular biological studies of this health disorder. The objective of this paper is to perform GWAS of AD in several study populations and investigate possible roles of detected genetic factors in developing AD hallmarks and in other health disorders. The data collected in the Framingham Heart Study (FHS), Cardiovascular Health Study (CHS), Health and Retirement Study (HRS) and Late Onset Alzheimer's Disease Family Study (LOADFS) were used in these analyses. The logistic regression and Cox's regression were used as statistical models in GWAS. The results of analyses confirmed strong associations of genetic variants from well-known genes APOE, TOMM40, PVRL2 (NECTIN2), and APOC1 with AD. Possible roles of these genes in pathological mechanisms resulting in development of hallmarks of AD are described. Many genes whose connection with AD was detected in other studies showed nominally significant associations with this health disorder in our study. The evidence on genetic connections between AD and vulnerability to infection, as well as between AD and other health disorders, such as cancer and type 2 diabetes, were investigated. The progress in uncovering hidden heterogeneity in AD would be substantially facilitated if common mechanisms involved in development of AD, its hallmarks, and AD related chronic conditions were investigated in their mutual connection.
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Affiliation(s)
- Anatoliy I Yashin
- Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, 2024 W. Main Street, Durham, NC 27705, USA.
| | - Fang Fang
- Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, 2024 W. Main Street, Durham, NC 27705, USA
| | - Mikhail Kovtun
- Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, 2024 W. Main Street, Durham, NC 27705, USA
| | - Deqing Wu
- Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, 2024 W. Main Street, Durham, NC 27705, USA
| | - Matt Duan
- Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, 2024 W. Main Street, Durham, NC 27705, USA
| | - Konstantin Arbeev
- Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, 2024 W. Main Street, Durham, NC 27705, USA
| | - Igor Akushevich
- Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, 2024 W. Main Street, Durham, NC 27705, USA
| | - Alexander Kulminski
- Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, 2024 W. Main Street, Durham, NC 27705, USA
| | - Irina Culminskaya
- Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, 2024 W. Main Street, Durham, NC 27705, USA
| | - Ilya Zhbannikov
- Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, 2024 W. Main Street, Durham, NC 27705, USA
| | - Arseniy Yashkin
- Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, 2024 W. Main Street, Durham, NC 27705, USA
| | - Eric Stallard
- Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, 2024 W. Main Street, Durham, NC 27705, USA
| | - Svetlana Ukraintseva
- Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, 2024 W. Main Street, Durham, NC 27705, USA.
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64
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Xin Y, Diling C, Jian Y, Ting L, Guoyan H, Hualun L, Xiaocui T, Guoxiao L, Ou S, Chaoqun Z, Jun Z, Yizhen X. Effects of Oligosaccharides From Morinda officinalis on Gut Microbiota and Metabolome of APP/PS1 Transgenic Mice. Front Neurol 2018; 9:412. [PMID: 29962999 PMCID: PMC6013575 DOI: 10.3389/fneur.2018.00412] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 05/18/2018] [Indexed: 12/20/2022] Open
Abstract
Alzheimer's disease (AD), a progressive neurodegenerative disorder, lacks preclinical diagnostic biomarkers and therapeutic drugs. Thus, earlier intervention in AD is a top priority. Studies have shown that the gut microbiota influences central nervous system disorders and that prebiotics can improve the cognition of hosts with AD, but these effects are not well understood. Preliminary research has shown that oligosaccharides from Morinda officinalis (OMO) are a useful prebiotic and cause substantial memory improvements in animal models of AD; however, the mechanism is still unclear. Therefore, this study was conducted to investigate whether OMO are clinically effective in alleviating AD by improving gut microbiota. OMO were administered to APP/PS1 transgenic mice, and potential clinical biomarkers of AD were identified with metabolomics and bioinformatics. Behavioral experiments demonstrated that OMO significantly ameliorated the memory of the AD animal model. Histological changes indicated that OMO ameliorated brain tissue swelling and neuronal apoptosis and downregulated the expression of the intracellular AD marker Aβ1−42. 16S rRNA sequencing analyses indicated that OMO maintained the diversity and stability of the microbial community. The data also indicated that OMO are an efficacious prebiotic in an animal model of AD, regulating the composition and metabolism of the gut microbiota. A serum metabolomics assay was performed using UHPLC-LTQ Orbitrap mass spectrometry to delineate the metabolic changes and potential early biomarkers in APP/PS1 transgenic mice. Multivariate statistical analysis showed that 14 metabolites were significantly upregulated, and 8 metabolites were downregulated in the model animals compared to the normal controls. Thus, key metabolites represent early indicators of the development of AD. Overall, we report a drug and signaling pathway with therapeutic potential, including proteins associated with cognitive deficits in normal mice or gene mutations that cause AD.
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Affiliation(s)
- Yang Xin
- Department of Pharmacy, The Fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,The Fifth Clinical School of Guangzhou Medical University, Guangzhou, China
| | - Chen Diling
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China
| | - Yang Jian
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China
| | - Liu Ting
- The Fifth Clinical School of Guangzhou Medical University, Guangzhou, China
| | - Hu Guoyan
- The Fifth Clinical School of Guangzhou Medical University, Guangzhou, China
| | - Liang Hualun
- Department of Pharmacy, The Second Clinical Medical College of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Tang Xiaocui
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China
| | - Lai Guoxiao
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China.,College of Pharmacy, Guangxi University of Traditional Chinese Medicine, Nanning, China
| | - Shuai Ou
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China
| | - Zheng Chaoqun
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China
| | - Zhao Jun
- Department of Obstetrics, Guangdong Women and Children Hospital, Guangzhou, China
| | - Xie Yizhen
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China
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65
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Hunter S, Smailagic N, Brayne C. Dementia Research: Populations, Progress, Problems, and Predictions. J Alzheimers Dis 2018; 64:S119-S143. [DOI: 10.3233/jad-179927] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Sally Hunter
- Institute of Public Health, University of Cambridge, Cambridge, UK
| | - Nadja Smailagic
- Institute of Public Health, University of Cambridge, Cambridge, UK
| | - Carol Brayne
- Institute of Public Health, University of Cambridge, Cambridge, UK
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66
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Spitzer P, Lang R, Oberstein TJ, Lewczuk P, Ermann N, Huttner HB, Masouris I, Kornhuber J, Ködel U, Maler JM. A Specific Reduction in Aβ 1-42 vs. a Universal Loss of Aβ Peptides in CSF Differentiates Alzheimer's Disease From Meningitis and Multiple Sclerosis. Front Aging Neurosci 2018; 10:152. [PMID: 29881343 PMCID: PMC5976781 DOI: 10.3389/fnagi.2018.00152] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 05/04/2018] [Indexed: 11/23/2022] Open
Abstract
A reduced concentration of Aβ1−42 in CSF is one of the established biomarkers of Alzheimer's disease. Reduced CSF concentrations of Aβ1−42 have also been shown in multiple sclerosis, viral encephalitis and bacterial meningitis. As neuroinflammation is one of the neuropathological hallmarks of Alzheimer's disease, an infectious origin of the disease has been proposed. According to this hypothesis, amyloid pathology is a consequence of a microbial infection and the resulting immune defense. Accordingly, changes in CSF levels of amyloid-β peptides should be similar in AD and inflammatory brain diseases. Aβ1−42 and Aβ1−40 levels were measured in cerebrospinal fluid by ELISA and Western blotting in 34 patients with bacterial meningitis (n = 9), multiple sclerosis (n = 5) or Alzheimer's disease (n = 9) and in suitable controls (n = 11). Reduced concentrations of Aβ1−42 were detected in patients with bacterial meningitis, multiple sclerosis and Alzheimer's disease. However, due to a concurrent reduction in Aβ1−40 in multiple sclerosis and meningitis patients, the ratio of Aβ1−42/Aβ1−40 was reduced only in the CSF of Alzheimer's disease patients. Urea-SDS-PAGE followed by Western blotting revealed that all Aβ peptide variants are reduced in bacterial meningitis, whereas in Alzheimer's disease, only Aβ1−42 is reduced. These results have two implications. First, they confirm the discriminatory diagnostic power of the Aβ1−42/Aβ1−40 ratio. Second, the differential pattern of Aβ peptide reductions suggests that the amyloid pathology in meningitis and multiple sclerosis differs from that in AD and does not support the notion of AD as an infection-triggered immunopathology.
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Affiliation(s)
- Philipp Spitzer
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, University Hospital Erlangen, Erlangen, Germany
| | - Roland Lang
- Institute of Clinical Microbiology, Immunology and Hygiene, Friedrich-Alexander-University Erlangen-Nuremberg, University Hospital Erlangen, Erlangen, Germany
| | - Timo J Oberstein
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, University Hospital Erlangen, Erlangen, Germany
| | - Piotr Lewczuk
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, University Hospital Erlangen, Erlangen, Germany.,Department of Neurodegeneration Diagnostics, Medical University of Bialystok, Bialystok, Poland
| | - Natalia Ermann
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, University Hospital Erlangen, Erlangen, Germany
| | - Hagen B Huttner
- Department of Neurology, Friedrich-Alexander-University Erlangen-Nuremberg, University Hospital Erlangen, Erlangen, Germany
| | - Ilias Masouris
- Department of Neurology, Ludwig-Maximilian-University, Munich, Germany
| | - Johannes Kornhuber
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, University Hospital Erlangen, Erlangen, Germany
| | - Uwe Ködel
- Department of Neurology, Ludwig-Maximilian-University, Munich, Germany
| | - Juan M Maler
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, University Hospital Erlangen, Erlangen, Germany
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67
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Andreadou E, Pantazaki AA, Daniilidou M, Tsolaki M. Rhamnolipids, Microbial Virulence Factors, in Alzheimer's Disease. J Alzheimers Dis 2018; 59:209-222. [PMID: 28598837 DOI: 10.3233/jad-161020] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Alzheimer's disease (AD) has been attributed to chronic bacterial infections. The recognition of human microbiota as a substantial contributor to health and disease is relatively recent and growing. During evolution, mammals live in a symbiotic state with myriads of microorganisms that survive at a diversity of tissue micro-surroundings. Microbes produce a plethora of secretory products [amyloids, lipopolysaccharides, virulence factors rhamnolipids (RLs), toxins, and a great number of neuroactive compounds]. The contribution of infectious microbial components to the pathophysiology of the human central nervous system including AD is considered potentially substantial, but the involvement of the RLs has never been reported. Here, RLs were isolated from serum and identified through various conventional methods including the colorimetric orcinol method, thin-layer chromatography, attenuated total reflection Fourier transform infrared (ATR-FTIR), and dot blot using antibodies against RLs. Dot blot demonstrated elevated RL levels in sera of AD patients compared to controls (p = 0.014). Moreover, ELISA showed similarly elevated RL levels in cerebrospinal fluid of both AD (0.188 versus 0.080) (p = 0.04) and mild cognitive impairment (0.188 versus 0.129) (p = 0.088) patients compared to healthy, and are well-correlated with the AD stages severity assessed using the Mini-Mental State Examination. These results provide conclusive evidence for the newly-reported implication of RLs in AD, adding it to the list of bacterial components, opening new avenues for AD investigation. Moreover, they strengthen and vindicate the divergence of research toward the exploration of bacterial involvement in AD generation and progression.
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Affiliation(s)
- Eleni Andreadou
- Department of Chemistry, Laboratory of Biochemistry, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Anastasia A Pantazaki
- Department of Chemistry, Laboratory of Biochemistry, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Makrina Daniilidou
- Department of Chemistry, Laboratory of Biochemistry, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Magda Tsolaki
- 3rd Department of Neurology, "G. Papanikolaou" General Hospital of Thessaloniki, Aristotle University of Thessaloniki, Greece
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68
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Harris SA, Harris EA. Molecular Mechanisms for Herpes Simplex Virus Type 1 Pathogenesis in Alzheimer's Disease. Front Aging Neurosci 2018; 10:48. [PMID: 29559905 PMCID: PMC5845560 DOI: 10.3389/fnagi.2018.00048] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Accepted: 02/12/2018] [Indexed: 12/12/2022] Open
Abstract
This review focuses on research in the areas of epidemiology, neuropathology, molecular biology and genetics that implicates herpes simplex virus type 1 (HSV-1) as a causative agent in the pathogenesis of sporadic Alzheimer’s disease (AD). Molecular mechanisms whereby HSV-1 induces AD-related pathophysiology and pathology, including neuronal production and accumulation of amyloid beta (Aβ), hyperphosphorylation of tau proteins, dysregulation of calcium homeostasis, and impaired autophagy, are discussed. HSV-1 causes additional AD pathologies through mechanisms that promote neuroinflammation, oxidative stress, mitochondrial damage, synaptic dysfunction, and neuronal apoptosis. The AD susceptibility genes apolipoprotein E (APOE), phosphatidylinositol binding clathrin assembly protein (PICALM), complement receptor 1 (CR1) and clusterin (CLU) are involved in the HSV lifecycle. Polymorphisms in these genes may affect brain susceptibility to HSV-1 infection. APOE, for example, influences susceptibility to certain viral infections, HSV-1 viral load in the brain, and the innate immune response. The AD susceptibility gene cholesterol 25-hydroxylase (CH25H) is upregulated in the AD brain and is involved in the antiviral immune response. HSV-1 interacts with additional genes to affect cognition-related pathways and key enzymes involved in Aβ production, Aβ clearance, and hyperphosphorylation of tau proteins. Aβ itself functions as an antimicrobial peptide (AMP) against various pathogens including HSV-1. Evidence is presented supporting the hypothesis that Aβ is produced as an AMP in response to HSV-1 and other brain infections, leading to Aβ deposition and plaque formation in AD. Epidemiologic studies associating HSV-1 infection with AD and cognitive impairment are discussed. Studies are reviewed supporting subclinical chronic reactivation of latent HSV-1 in the brain as significant in the pathogenesis of AD. Finally, the rationale for and importance of clinical trials treating HSV-1-infected MCI and AD patients with antiviral medication is discussed.
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Affiliation(s)
- Steven A Harris
- St. Vincent Medical Group, Northside Internal Medicine, Indianapolis, IN, United States
| | - Elizabeth A Harris
- Department of Neurology, University of Chicago Medical Center, Chicago, IL, United States
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69
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Doulberis M, Kotronis G, Thomann R, Polyzos SA, Boziki M, Gialamprinou D, Deretzi G, Katsinelos P, Kountouras J. Review: Impact of Helicobacter pylori on Alzheimer's disease: What do we know so far? Helicobacter 2018; 23. [PMID: 29181894 DOI: 10.1111/hel.12454] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Helicobacter pylori has changed radically gastroenterologic world, offering a new concept in patients' management. Over time, more medical data gave rise to diverse distant, extragastric manifestations and interactions of the "new" discovered bacterium. Special interest appeared within the field of neurodegenerative diseases and particularly Alzheimer's disease, as the latter and Helicobacter pylori infection are associated with a large public health burden and Alzheimer's disease ranks as the leading cause of disability. However, the relationship between Helicobacter pylori infection and Alzheimer's disease remains uncertain. METHODS We performed a narrative review regarding a possible connection between Helicobacter pylori and Alzheimer's disease. All accessible relevant (pre)clinical studies written in English were included. Both affected pathologies were briefly analyzed, and relevant studies are discussed, trying to focus on the possible pathogenetic role of this bacterium in Alzheimer's disease. RESULTS Data stemming from both epidemiologic studies and animal experiments seem to be rather encouraging, tending to confirm the hypothesis that Helicobacter pylori infection might influence the course of Alzheimer's disease pleiotropically. Possible main mechanisms may include the bacterium's access to the brain via the oral-nasal-olfactory pathway or by circulating monocytes (infected with Helicobacter pylori due to defective autophagy) through disrupted blood-brain barrier, thereby possibly triggering neurodegeneration. CONCLUSIONS Current data suggest that Helicobacter pylori infection might influence the pathophysiology of Alzheimer's disease. However, further large-scale randomized controlled trials are mandatory to clarify a possible favorable effect of Helicobacter pylori eradication on Alzheimer's disease pathophysiology, before the recommendation of short-term and cost-effective therapeutic regimens against Helicobacter pylori-related Alzheimer's disease.
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Affiliation(s)
- Michael Doulberis
- Department of Internal Medicine, Bürgerspital Hospital, Solothurn, Switzerland
| | - Georgios Kotronis
- Department of Internal Medicine, Agios Pavlos General Hospital, Thessaloniki, Macedonia, Greece
| | - Robert Thomann
- Department of Internal Medicine, Bürgerspital Hospital, Solothurn, Switzerland
| | - Stergios A Polyzos
- Department of Internal Medicine, Ippokration Hospital, Second Medical Clinic, Aristotle University of Thessaloniki, Thessaloniki, Macedonia, Greece
| | - Marina Boziki
- Department of Internal Medicine, Ippokration Hospital, Second Medical Clinic, Aristotle University of Thessaloniki, Thessaloniki, Macedonia, Greece
| | - Dimitra Gialamprinou
- Department of Pediatrics, Papageorgiou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Macedonia, Greece
| | - Georgia Deretzi
- Department of Neurology, Papageorgiou General Hospital, Multiple Sclerosis Unit, Aristotle University of Thessaloniki, Thessaloniki, Macedonia, Greece
| | - Panagiotis Katsinelos
- Department of Internal Medicine, Ippokration Hospital, Second Medical Clinic, Aristotle University of Thessaloniki, Thessaloniki, Macedonia, Greece
| | - Jannis Kountouras
- Department of Internal Medicine, Ippokration Hospital, Second Medical Clinic, Aristotle University of Thessaloniki, Thessaloniki, Macedonia, Greece
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70
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Miklossy J. Bacterial Amyloid and DNA are Important Constituents of Senile Plaques: Further Evidence of the Spirochetal and Biofilm Nature of Senile Plaques. J Alzheimers Dis 2018; 53:1459-73. [PMID: 27314530 PMCID: PMC4981904 DOI: 10.3233/jad-160451] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
It has long been known that spirochetes form clumps or micro colonies in vitro and in vivo. Cortical spirochetal colonies in syphilitic dementia were considered as reproductive centers for spirochetes. Historic and recent data demonstrate that senile plaques in Alzheimer’s disease (AD) are made up by spirochetes. Spirochetes, are able to form biofilm in vitro. Senile plaques are also reported to contain elements of biofilm constituents. We expected that AβPP and Aβ (the main components of senile plaques) also occur in pure spirochetal biofilms, and bacterial DNA (an important component of biofilm) is also present in senile plaques. Histochemical, immunohistochemical, and in situ hybridization techniques and the TUNEL assay were used to answer these questions. The results obtained demonstrate that Aβ and DNA, including spirochete-specific DNA, are key components of both pure spirochetal biofilms and senile plaques in AD and confirm the biofilm nature of senile plaques. These results validate validate previous observations that AβPP and/or an AβPP-like amyloidogenic protein are an integral part of spirochetes, and indicate that bacterial and host derived Aβ are both constituents of senile plaques. DNA fragmentation in senile plaques further confirms their bacterial nature and provides biochemical evidence for spirochetal cell death. Spirochetes evade host defenses, locate intracellularly, form more resistant atypical forms and notably biofilms, which contribute to sustain chronic infection and inflammation and explain the slowly progressive course of dementia in AD. To consider co-infecting microorganisms is equally important, as multi-species biofilms result in a higher resistance to treatments and a more severe dementia.
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Affiliation(s)
- Judith Miklossy
- Correspondence to: Judith Miklossy, Prevention Alzheimer International Foundation, International Alzheimer Research Centre, Martigny-Croix, CP 16, 1921, Switzerland. Tel.: +41 79 207 4442/27 722 0652; E-mail:
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71
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Pretorius E, Bester J, Kell DB. A Bacterial Component to Alzheimer's-Type Dementia Seen via a Systems Biology Approach that Links Iron Dysregulation and Inflammagen Shedding to Disease. J Alzheimers Dis 2018; 53:1237-56. [PMID: 27340854 PMCID: PMC5325058 DOI: 10.3233/jad-160318] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The progression of Alzheimer's disease (AD) is accompanied by a great many observable changes, both molecular and physiological. These include oxidative stress, neuroinflammation, and (more proximal to cognitive decline) the death of neuronal and other cells. A systems biology approach seeks to organize these observed variables into pathways that discriminate those that are highly involved (i.e., causative) from those that are more usefully recognized as bystander effects. We review the evidence that iron dysregulation is one of the central causative pathway elements here, as this can cause each of the above effects. In addition, we review the evidence that dormant, non-growing bacteria are a crucial feature of AD, that their growth in vivo is normally limited by a lack of free iron, and that it is this iron dysregulation that is an important factor in their resuscitation. Indeed, bacterial cells can be observed by ultrastructural microscopy in the blood of AD patients. A consequence of this is that the growing cells can shed highly inflammatory components such as lipopolysaccharides (LPS). These too are known to be able to induce (apoptotic and pyroptotic) neuronal cell death. There is also evidence that these systems interact with elements of vitamin D metabolism. This integrative systems approach has strong predictive power, indicating (as has indeed been shown) that both natural and pharmaceutical iron chelators might have useful protective roles in arresting cognitive decline, and that a further assessment of the role of microbes in AD development is more than highly warranted.
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Affiliation(s)
- Etheresia Pretorius
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia, South Africa
| | - Janette Bester
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia, South Africa
| | - Douglas B Kell
- School of Chemistry, The University of Manchester, Manchester, Lancs, UK.,The Manchester Institute of Biotechnology, The University of Manchester, Manchester, Lancs, UK.,Centre for Synthetic Biology of Fine and Speciality Chemicals, The University of Manchester, Manchester, Lancs, UK
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72
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Itzhaki RF. Herpes and Alzheimer's Disease: Subversion in the Central Nervous System and How It Might Be Halted. J Alzheimers Dis 2018; 54:1273-1281. [PMID: 27497484 DOI: 10.3233/jad-160607] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The last 8 or so years have seen a large increase in the number of studies supporting the concept of a major role for herpes simplex virus type 1 (HSV1) in Alzheimer's disease (AD). The main advances have been made through studies in humans and in mice, investigating the likelihood of reactivation of the latent virus in brain. Others have aimed to explain the mechanisms in cells whereby the increase in amyloid-beta (Aβ) production on HSV1 infection of cells and mouse brains occurs, and the reason that infected cells make this increase. The possibility that other herpesviruses are involved in the development of AD has been explored, and human herpesvirus type 6, Epstein-Barr virus, and cytomegalovirus, in particular, have been implicated. Epidemiological studies have further supported the role specifically of HSV1 and its reactivation in the disease. Antiviral studies have continued, comparing those acting by different mechanisms, such as restricting viral replication, or blocking viral entry into cells, to treat HSV1-infected cell cultures, and then examining the extent to which the virus-induced increases in Aβ and AD-like tau are reduced. All the studies support the usage of antiviral treatment to slow or halt the progression of AD.
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73
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Scannapieco FA, Cantos A. Oral inflammation and infection, and chronic medical diseases: implications for the elderly. Periodontol 2000 2018; 72:153-75. [PMID: 27501498 DOI: 10.1111/prd.12129] [Citation(s) in RCA: 172] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/15/2015] [Indexed: 12/12/2022]
Abstract
Oral diseases, such as caries and periodontitis, not only have local effects on the dentition and on tooth-supporting tissues but also may impact a number of systemic conditions. Emerging evidence suggests that poor oral health influences the initiation and/or progression of diseases such as atherosclerosis (with sequelae including myocardial infarction and stoke), diabetes mellitus and neurodegenerative diseases (such as Alzheimer's disease, rheumatoid arthritis and others). Aspiration of oropharyngeal (including periodontal) bacteria causes pneumonia, especially in hospitalized patients and the elderly, and may influence the course of chronic obstructive pulmonary disease. This article addresses several pertinent aspects related to the medical implications of periodontal disease in the elderly. There is moderate evidence that improved oral hygiene may help prevent aspiration pneumonia in high-risk patients. For other medical conditions, because of the absence of well-designed randomized clinical trials in elderly patients, no specific guidance can be provided regarding oral hygiene or periodontal interventions that enhance the medical management of older adults.
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Kumar DKV, Choi SH, Washicosky KJ, Eimer WA, Tucker S, Ghofrani J, Lefkowitz A, McColl G, Goldstein LE, Tanzi RE, Moir RD. Amyloid-β peptide protects against microbial infection in mouse and worm models of Alzheimer's disease. Sci Transl Med 2017; 8:340ra72. [PMID: 27225182 DOI: 10.1126/scitranslmed.aaf1059] [Citation(s) in RCA: 684] [Impact Index Per Article: 97.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 05/10/2016] [Indexed: 12/19/2022]
Abstract
The amyloid-β peptide (Aβ) is a key protein in Alzheimer's disease (AD) pathology. We previously reported in vitro evidence suggesting that Aβ is an antimicrobial peptide. We present in vivo data showing that Aβ expression protects against fungal and bacterial infections in mouse, nematode, and cell culture models of AD. We show that Aβ oligomerization, a behavior traditionally viewed as intrinsically pathological, may be necessary for the antimicrobial activities of the peptide. Collectively, our data are consistent with a model in which soluble Aβ oligomers first bind to microbial cell wall carbohydrates via a heparin-binding domain. Developing protofibrils inhibited pathogen adhesion to host cells. Propagating β-amyloid fibrils mediate agglutination and eventual entrapment of unatttached microbes. Consistent with our model, Salmonella Typhimurium bacterial infection of the brains of transgenic 5XFAD mice resulted in rapid seeding and accelerated β-amyloid deposition, which closely colocalized with the invading bacteria. Our findings raise the intriguing possibility that β-amyloid may play a protective role in innate immunity and infectious or sterile inflammatory stimuli may drive amyloidosis. These data suggest a dual protective/damaging role for Aβ, as has been described for other antimicrobial peptides.
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Affiliation(s)
- Deepak Kumar Vijaya Kumar
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Se Hoon Choi
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Kevin J Washicosky
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - William A Eimer
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Stephanie Tucker
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Jessica Ghofrani
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Aaron Lefkowitz
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Gawain McColl
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Lee E Goldstein
- Department of Psychiatry, Boston University, Boston, MA 02215, USA
| | - Rudolph E Tanzi
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA.
| | - Robert D Moir
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA.
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75
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Frost GR, Li YM. The role of astrocytes in amyloid production and Alzheimer's disease. Open Biol 2017; 7:170228. [PMID: 29237809 PMCID: PMC5746550 DOI: 10.1098/rsob.170228] [Citation(s) in RCA: 248] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 11/16/2017] [Indexed: 12/18/2022] Open
Abstract
Alzheimer's disease (AD) is marked by the presence of extracellular amyloid beta (Aβ) plaques, intracellular neurofibrillary tangles (NFTs) and gliosis, activated glial cells, in the brain. It is thought that Aβ plaques trigger NFT formation, neuronal cell death, neuroinflammation and gliosis and, ultimately, cognitive impairment. There are increased numbers of reactive astrocytes in AD, which surround amyloid plaques and secrete proinflammatory factors and can phagocytize and break down Aβ. It was thought that neuronal cells were the major source of Aβ. However, mounting evidence suggests that astrocytes may play an additional role in AD by secreting significant quantities of Aβ and contributing to overall amyloid burden in the brain. Astrocytes are the most numerous cell type in the brain, and therefore even minor quantities of amyloid secretion from individual astrocytes could prove to be substantial when taken across the whole brain. Reactive astrocytes have increased levels of the three necessary components for Aβ production: amyloid precursor protein, β-secretase (BACE1) and γ-secretase. The identification of environmental factors, such as neuroinflammation, that promote astrocytic Aβ production, could redefine how we think about developing therapeutics for AD.
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Affiliation(s)
- Georgia R Frost
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
- Programs of Neurosciences, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
- Programs of Neurosciences, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
- Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
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76
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Eiser AR. Why does Finland have the highest dementia mortality rate? Environmental factors may be generalizable. Brain Res 2017; 1671:14-17. [DOI: 10.1016/j.brainres.2017.06.032] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 06/28/2017] [Accepted: 06/30/2017] [Indexed: 12/12/2022]
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77
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Polymicrobial Infections In Brain Tissue From Alzheimer's Disease Patients. Sci Rep 2017; 7:5559. [PMID: 28717130 PMCID: PMC5514053 DOI: 10.1038/s41598-017-05903-y] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 06/05/2017] [Indexed: 01/10/2023] Open
Abstract
Several studies have advanced the idea that the etiology of Alzheimer’s disease (AD) could be microbial in origin. In the present study, we tested the possibility that polymicrobial infections exist in tissue from the entorhinal cortex/hippocampus region of patients with AD using immunohistochemistry (confocal laser scanning microscopy) and highly sensitive (nested) PCR. We found no evidence for expression of early (ICP0) or late (ICP5) proteins of herpes simplex virus type 1 (HSV-1) in brain sections. A polyclonal antibody against Borrelia detected structures that appeared not related to spirochetes, but rather to fungi. These structures were not found with a monoclonal antibody. Also, Borrelia DNA was undetectable by nested PCR in the ten patients analyzed. By contrast, two independent Chlamydophila antibodies revealed several structures that resembled fungal cells and hyphae, and prokaryotic cells, but most probably were unrelated to Chlamydophila spp. Finally, several structures that could belong to fungi or prokaryotes were detected using peptidoglycan and Clostridium antibodies, and PCR analysis revealed the presence of several bacteria in frozen brain tissue from AD patients. Thus, our results show that polymicrobial infections consisting of fungi and bacteria can be revealed in brain tissue from AD patients.
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78
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Emery DC, Shoemark DK, Batstone TE, Waterfall CM, Coghill JA, Cerajewska TL, Davies M, West NX, Allen SJ. 16S rRNA Next Generation Sequencing Analysis Shows Bacteria in Alzheimer's Post-Mortem Brain. Front Aging Neurosci 2017; 9:195. [PMID: 28676754 PMCID: PMC5476743 DOI: 10.3389/fnagi.2017.00195] [Citation(s) in RCA: 209] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 05/31/2017] [Indexed: 12/13/2022] Open
Abstract
The neurological deterioration associated with Alzheimer's disease (AD), involving accumulation of amyloid-beta peptides and neurofibrillary tangles, is associated with evident neuroinflammation. This is now seen to be a significant contributor to pathology. Recently the tenet of the privileged status of the brain, regarding microbial compromise, has been questioned, particularly in terms of neurodegenerative diseases. It is now being considered that microbiological incursion into the central nervous system could be either an initiator or significant contributor to these. This is a novel study using 16S ribosomal gene-specific Next generation sequencing (NGS) of extracted brain tissue. A comparison was made of the bacterial species content of both frozen and formaldehyde fixed sections of a small cohort of Alzheimer-affected cases with those of cognitively unimpaired (normal). Our findings suggest an increase in bacterial populations in Alzheimer brain tissue compared with normal.
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Affiliation(s)
- David C. Emery
- School of Clinical Sciences, Faculty of Health Sciences, University of BristolBristol, United Kingdom
| | | | - Tom E. Batstone
- School of Biological Sciences, Life Sciences, University of BristolBristol, United Kingdom
| | - Christy M. Waterfall
- School of Biological Sciences, Life Sciences, University of BristolBristol, United Kingdom
| | - Jane A. Coghill
- School of Biological Sciences, Life Sciences, University of BristolBristol, United Kingdom
| | | | - Maria Davies
- School of Oral and Dental SciencesBristol, United Kingdom
| | - Nicola X. West
- School of Oral and Dental SciencesBristol, United Kingdom
| | - Shelley J. Allen
- School of Clinical Sciences, Faculty of Health Sciences, University of BristolBristol, United Kingdom
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79
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Holmstrup P, Damgaard C, Olsen I, Klinge B, Flyvbjerg A, Nielsen CH, Hansen PR. Comorbidity of periodontal disease: two sides of the same coin? An introduction for the clinician. J Oral Microbiol 2017; 9:1332710. [PMID: 28748036 PMCID: PMC5508374 DOI: 10.1080/20002297.2017.1332710] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 01/07/2017] [Indexed: 12/14/2022] Open
Abstract
Increasing evidence has suggested an independent association between periodontitis and a range of comorbidities, for example cardiovascular disease, type 2 diabetes, rheumatoid arthritis, osteoporosis, Parkinson’s disease, Alzheimer’s disease, psoriasis, and respiratory infections. Shared inflammatory pathways are likely to contribute to this association, but distinct causal mechanisms remain to be defined. Some of these comorbid conditions may improve by periodontal treatment, and a bidirectional relationship may exist, where, for example, treatment of diabetes can improve periodontal status. The present article presents an overview of the evidence linking periodontitis with selected systemic diseases and calls for increased cooperation between dentists and medical doctors to provide optimal screening, treatment, and prevention of both periodontitis and its comorbidities.
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Affiliation(s)
- Palle Holmstrup
- Section for Periodontology, Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Christian Damgaard
- Section for Periodontology, Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Institute for Inflammation Research, Center for Rheumatology and Spine Diseases, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Ingar Olsen
- Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway
| | - Björn Klinge
- Department of Periodontology, Faculty of Odontology, Malmö University, Malmö, Sweden.,Division of Periodontology, Department of Dental Medicine, Karolinska Institutet, Stockholm, Sweden
| | | | - Claus Henrik Nielsen
- Section for Periodontology, Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Institute for Inflammation Research, Center for Rheumatology and Spine Diseases, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Peter Riis Hansen
- Section for Periodontology, Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Cardiology Department, Herlev and Gentofte Hospital, Hellerup, Denmark
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80
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Abstract
Over the last 10 years there have been only a handful of publications dealing with the oral virome, which is in contrast to the oral microbiome, an area that has seen considerable interest. Here, we survey viral infections in general and then focus on those viruses that are found in and/or are transmitted via the oral cavity; norovirus, rabies, human papillomavirus, Epstein‐Barr virus, herpes simplex viruses, hepatitis C virus, and HIV. Increasingly, viral infections have been diagnosed using an oral sample (e.g. saliva mucosal transudate or an oral swab) instead of blood or urine. The results of two studies using a rapid and semi‐quantitative lateral flow assay format demonstrating the correlation of HIV anti‐IgG/sIgA detection with saliva and serum samples are presented. When immediate detection of infection is important, point‐of‐care devices that obtain a non‐invasive sample from the oral cavity can be used to provide a first line diagnosis to assist in determining appropriate counselling and therapeutic path for an increasing number of diseases.
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81
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Santos CY, Snyder PJ, Wu WC, Zhang M, Echeverria A, Alber J. Pathophysiologic relationship between Alzheimer's disease, cerebrovascular disease, and cardiovascular risk: A review and synthesis. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2017; 7:69-87. [PMID: 28275702 PMCID: PMC5328683 DOI: 10.1016/j.dadm.2017.01.005] [Citation(s) in RCA: 235] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
As the population ages due to demographic trends and gains in life expectancy, the incidence and prevalence of dementia increases, and the need to understand the etiology and pathogenesis of dementia becomes ever more urgent. Alzheimer's disease (AD), the most common form of dementia, is a complex disease, the mechanisms of which are poorly understood. The more we learn about AD, the more questions are raised about our current conceptual models of disease. In the absence of a cure or the means by which to slow disease progress, it may be prudent to apply our current knowledge of the intersection between AD, cardiovascular disease, and cerebrovascular disease to foster efforts to delay or slow the onset of AD. This review discusses our current understanding of the epidemiology, genetics, and pathophysiology of AD, the intersection between AD and vascular causes of dementia, and proposes future directions for research and prevention.
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Affiliation(s)
- Cláudia Y. Santos
- Lifespan Clinical Research Center, Rhode Island Hospital, Providence, RI, USA
- Interdisciplinary Neuroscience Program, University of Rhode Island, Kingston, RI, USA
| | - Peter J. Snyder
- Lifespan Clinical Research Center, Rhode Island Hospital, Providence, RI, USA
- Interdisciplinary Neuroscience Program, University of Rhode Island, Kingston, RI, USA
- Department of Neurology, Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Wen-Chih Wu
- Division of Cardiology, Department of Medicine, Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Mia Zhang
- Griffith University School of Medicine, Gold Coast, Queensland, Australia
| | - Ana Echeverria
- University of Puerto Rico School of Medicine, San Juan, Puerto Rico
| | - Jessica Alber
- Lifespan Clinical Research Center, Rhode Island Hospital, Providence, RI, USA
- Department of Neurology, Warren Alpert Medical School of Brown University, Providence, RI, USA
- Department of Psychiatry and Human Behavior, Warren Alpert Medical School of Brown University, Providence, RI, USA
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82
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83
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Kepp KP. Ten Challenges of the Amyloid Hypothesis of Alzheimer’s Disease. J Alzheimers Dis 2016; 55:447-457. [DOI: 10.3233/jad-160550] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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84
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Shim SM, Cheon HS, Jo C, Koh YH, Song J, Jeon JP. Elevated Epstein-Barr Virus Antibody Level is Associated with Cognitive Decline in the Korean Elderly. J Alzheimers Dis 2016; 55:293-301. [DOI: 10.3233/jad-160563] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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85
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Bourgade K, Dupuis G, Frost EH, Fülöp T. Anti-Viral Properties of Amyloid-β Peptides. J Alzheimers Dis 2016; 54:859-878. [DOI: 10.3233/jad-160517] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Karine Bourgade
- Research Center on Aging, Graduate Program in Immunology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Gilles Dupuis
- Department of Biochemistry, Graduate Program in Immunology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Eric H. Frost
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Tamàs Fülöp
- Department of Medicine, Research Center on Aging, Graduate Program in Immunology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada
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86
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Uchoa MF, Moser VA, Pike CJ. Interactions between inflammation, sex steroids, and Alzheimer's disease risk factors. Front Neuroendocrinol 2016; 43:60-82. [PMID: 27651175 PMCID: PMC5123957 DOI: 10.1016/j.yfrne.2016.09.001] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 09/10/2016] [Accepted: 09/14/2016] [Indexed: 12/19/2022]
Abstract
Alzheimer's disease (AD) is an age-related neurodegenerative disorder for which there are no effective strategies to prevent or slow its progression. Because AD is multifactorial, recent research has focused on understanding interactions among the numerous risk factors and mechanisms underlying the disease. One mechanism through which several risk factors may be acting is inflammation. AD is characterized by chronic inflammation that is observed before clinical onset of dementia. Several genetic and environmental risk factors for AD increase inflammation, including apolipoprotein E4, obesity, and air pollution. Additionally, sex steroid hormones appear to contribute to AD risk, with age-related losses of estrogens in women and androgens in men associated with increased risk. Importantly, sex steroid hormones have anti-inflammatory actions and can interact with several other AD risk factors. This review examines the individual and interactive roles of inflammation and sex steroid hormones in AD, as well as their relationships with the AD risk factors apolipoprotein E4, obesity, and air pollution.
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Affiliation(s)
- Mariana F Uchoa
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA
| | - V Alexandra Moser
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA
| | - Christian J Pike
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA; Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA.
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87
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Olsson J, Lövheim H, Honkala E, Karhunen PJ, Elgh F, Kok EH. HSV presence in brains of individuals without dementia: the TASTY brain series. Dis Model Mech 2016; 9:1349-1355. [PMID: 27664135 PMCID: PMC5117234 DOI: 10.1242/dmm.026674] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 09/20/2016] [Indexed: 12/28/2022] Open
Abstract
Herpes simplex virus (HSV) type 1 affects a majority of the population and recent evidence suggests involvement in Alzheimer's disease aetiology. We investigated the prevalence of HSV type 1 and 2 in the Tampere Autopsy Study (TASTY) brain samples using PCR and sero-positivity in plasma, and associations with Alzheimer's disease neuropathology. HSV was shown to be present in human brain tissue in 11/584 (1.9%) of samples in the TASTY cohort, of which six had Alzheimer's disease neuropathological amyloid beta (Aβ) aggregations. Additionally, serological data revealed 86% of serum samples tested were IgG-positive for HSV. In conclusion, we report epidemiological evidence of the presence of HSV in brain tissue free from encephalitis symptoms in a cohort most closely representing the general population (a minimum prevalence of 1.9%). Whereas 6/11 samples with HSV DNA in the brain tissue had Aβ aggregations, most of those with Aβ aggregations did not have HSV present in the brain tissue. Summary: We assessed the presence of HSV types 1 and 2 in the brain tissue of a large non-institutionalised autopsy cohort, providing evidence of asymptomatic access of HSV to the brain.
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Affiliation(s)
- Jan Olsson
- Department of Clinical Microbiology, Virology, Umeå University, Umeå 90185, Sweden
| | - Hugo Lövheim
- Department of Community Medicine and Rehabilitation, Geriatric Medicine, Umeå University, Umeå 90185, Sweden
| | - Emma Honkala
- Department of Clinical Microbiology, Virology, Umeå University, Umeå 90185, Sweden
| | - Pekka J Karhunen
- Department of Forensic Medicine, University of Tampere, Tampere 33520, Finland
| | - Fredrik Elgh
- Department of Clinical Microbiology, Virology, Umeå University, Umeå 90185, Sweden
| | - Eloise H Kok
- Department of Forensic Medicine, University of Tampere, Tampere 33520, Finland
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88
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Spitzer P, Condic M, Herrmann M, Oberstein TJ, Scharin-Mehlmann M, Gilbert DF, Friedrich O, Grömer T, Kornhuber J, Lang R, Maler JM. Amyloidogenic amyloid-β-peptide variants induce microbial agglutination and exert antimicrobial activity. Sci Rep 2016; 6:32228. [PMID: 27624303 PMCID: PMC5021948 DOI: 10.1038/srep32228] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 08/04/2016] [Indexed: 11/09/2022] Open
Abstract
Amyloid-β (Aβ) peptides are the main components of the plaques found in the brains of patients with Alzheimer's disease. However, Aβ peptides are also detectable in secretory compartments and peripheral blood contains a complex mixture of more than 40 different modified and/or N- and C-terminally truncated Aβ peptides. Recently, anti-infective properties of Aβ peptides have been reported. Here, we investigated the interaction of Aβ peptides of different lengths with various bacterial strains and the yeast Candida albicans. The amyloidogenic peptides Aβ1-42, Aβ2-42, and Aβ3p-42 but not the non-amyloidogenic peptides Aβ1-40 and Aβ2-40 bound to microbial surfaces. As observed by immunocytochemistry, scanning electron microscopy and Gram staining, treatment of several bacterial strains and Candida albicans with Aβ peptide variants ending at position 42 (Aβx-42) caused the formation of large agglutinates. These aggregates were not detected after incubation with Aβx-40. Furthermore, Aβx-42 exerted an antimicrobial activity on all tested pathogens, killing up to 80% of microorganisms within 6 h. Aβ1-40 only had a moderate antimicrobial activity against C. albicans. Agglutination of Aβ1-42 was accelerated in the presence of microorganisms. These data demonstrate that the amyloidogenic Aβx-42 variants have antimicrobial activity and may therefore act as antimicrobial peptides in the immune system.
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Affiliation(s)
- Philipp Spitzer
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen, Germany
| | - Mateja Condic
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen, Germany
| | - Martin Herrmann
- Department of Medicine III, Institute for Clinical Immunology, Friedrich-Alexander-University Erlangen-Nuremberg, Gluecksstraße 4a, D-91054 Erlangen, Germany
| | - Timo Jan Oberstein
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen, Germany
| | - Marina Scharin-Mehlmann
- Electron Devices, Friedrich-Alexander-University Erlangen-Nuremberg, Cauerstraße 6, D-91058 Erlangen, Germany
| | - Daniel F Gilbert
- Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nuremberg, Paul-Gordan-Str. 3, D-91052 Erlangen, Germany
| | - Oliver Friedrich
- Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nuremberg, Paul-Gordan-Str. 3, D-91052 Erlangen, Germany
| | - Teja Grömer
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen, Germany
| | - Johannes Kornhuber
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen, Germany
| | - Roland Lang
- Institute of Clinical Microbiology, Immunology and Hygiene, Friedrich-Alexander-University Erlangen-Nuremberg, Wasserturmstr. 3/5, D-91054 Erlangen, Germany
| | - Juan Manuel Maler
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen, Germany
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89
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Kell DB, Pretorius E. On the translocation of bacteria and their lipopolysaccharides between blood and peripheral locations in chronic, inflammatory diseases: the central roles of LPS and LPS-induced cell death. Integr Biol (Camb) 2016; 7:1339-77. [PMID: 26345428 DOI: 10.1039/c5ib00158g] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We have recently highlighted (and added to) the considerable evidence that blood can contain dormant bacteria. By definition, such bacteria may be resuscitated (and thus proliferate). This may occur under conditions that lead to or exacerbate chronic, inflammatory diseases that are normally considered to lack a microbial component. Bacterial cell wall components, such as the endotoxin lipopolysaccharide (LPS) of Gram-negative strains, are well known as potent inflammatory agents, but should normally be cleared. Thus, their continuing production and replenishment from dormant bacterial reservoirs provides an easy explanation for the continuing, low-grade inflammation (and inflammatory cytokine production) that is characteristic of many such diseases. Although experimental conditions and determinants have varied considerably between investigators, we summarise the evidence that in a great many circumstances LPS can play a central role in all of these processes, including in particular cell death processes that permit translocation between the gut, blood and other tissues. Such localised cell death processes might also contribute strongly to the specific diseases of interest. The bacterial requirement for free iron explains the strong co-existence in these diseases of iron dysregulation, LPS production, and inflammation. Overall this analysis provides an integrative picture, with significant predictive power, that is able to link these processes via the centrality of a dormant blood microbiome that can resuscitate and shed cell wall components.
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Affiliation(s)
- Douglas B Kell
- School of Chemistry and The Manchester Institute of Biotechnology, The University of Manchester, 131, Princess St, Manchester M1 7DN, Lancs, UK.
| | - Etheresia Pretorius
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia 0007, South Africa.
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90
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Hu X, Wang T, Jin F. Alzheimer’s disease and gut microbiota. SCIENCE CHINA-LIFE SCIENCES 2016; 59:1006-1023. [DOI: 10.1007/s11427-016-5083-9] [Citation(s) in RCA: 146] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 07/10/2016] [Indexed: 12/13/2022]
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91
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Wang J, Ye F, Cheng X, Zhang X, Liu F, Liu G, Ni M, Qiao S, Zhou W, Zhang Y. The Effects of LW-AFC on Intestinal Microbiome in Senescence-Accelerated Mouse Prone 8 Strain, a Mouse Model of Alzheimer’s Disease. J Alzheimers Dis 2016; 53:907-19. [DOI: 10.3233/jad-160138] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Jianhui Wang
- Department of TCM and Neuroimmunopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Fuqiang Ye
- Department of Biotechnology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Xiaorui Cheng
- Department of TCM and Neuroimmunopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Xiaorui Zhang
- Department of TCM and Neuroimmunopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Feng Liu
- Department of TCM and Neuroimmunopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Gang Liu
- Department of TCM and Neuroimmunopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Ming Ni
- Department of Biotechnology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Shanyi Qiao
- Department of TCM and Neuroimmunopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Wenxia Zhou
- Department of TCM and Neuroimmunopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Yongxiang Zhang
- Department of TCM and Neuroimmunopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
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92
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Licastro F, Porcellini E. Persistent infections, immune-senescence and Alzheimer's disease. Oncoscience 2016; 3:135-42. [PMID: 27489858 PMCID: PMC4965253 DOI: 10.18632/oncoscience.309] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 05/15/2016] [Indexed: 12/22/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder and the most common cause of dementia. Classical hallmarks of AD such as amyloid deposition and neurofibrillary tangles do not completely explain AD pathogenesis. Recent investigations proposed Aβ peptide as an anti-microbial factor. Our previous works suggested that the concomitant presence of single nucleotide polymorphisms (SNPs) from AD genetic studies might impair antiviral defenses and increase the individual susceptibility to herpes virus infection. Viruses of herpes family by inducing frequent cycles of reactivation and latency constantly challenge the immune response and drive the accumulation of memory T cells. However, the immune system is not able to completely eradicate these viruses. The continuous antigen stimulation activates chronic inflammatory responses that may progressively induce neurodegenerative mechanisms in genetically susceptible elderly. The aim of this paper is to suggest new perspectives in clinical pathogenesis of AD with potential prevention and new medical treatment of the age associated cognitive decline.
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Affiliation(s)
- Federico Licastro
- Department of Experimental, Diagnostic and Specialty Medicine, School of Medicine, University of Bologna, Bologna 40126, Italy
| | - Elisa Porcellini
- Department of Experimental, Diagnostic and Specialty Medicine, School of Medicine, University of Bologna, Bologna 40126, Italy
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93
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Harris SA, Harris EA. Herpes Simplex Virus Type 1 and Other Pathogens are Key Causative Factors in Sporadic Alzheimer's Disease. J Alzheimers Dis 2016; 48:319-53. [PMID: 26401998 PMCID: PMC4923765 DOI: 10.3233/jad-142853] [Citation(s) in RCA: 162] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This review focuses on research in epidemiology, neuropathology, molecular biology, and genetics regarding the hypothesis that pathogens interact with susceptibility genes and are causative in sporadic Alzheimer's disease (AD). Sporadic AD is a complex multifactorial neurodegenerative disease with evidence indicating coexisting multi-pathogen and inflammatory etiologies. There are significant associations between AD and various pathogens, including Herpes simplex virus type 1 (HSV-1), Cytomegalovirus, and other Herpesviridae, Chlamydophila pneumoniae, spirochetes, Helicobacter pylori, and various periodontal pathogens. These pathogens are able to evade destruction by the host immune system, leading to persistent infection. Bacterial and viral DNA and RNA and bacterial ligands increase the expression of pro-inflammatory molecules and activate the innate and adaptive immune systems. Evidence demonstrates that pathogens directly and indirectly induce AD pathology, including amyloid-β (Aβ) accumulation, phosphorylation of tau protein, neuronal injury, and apoptosis. Chronic brain infection with HSV-1, Chlamydophila pneumoniae, and spirochetes results in complex processes that interact to cause a vicious cycle of uncontrolled neuroinflammation and neurodegeneration. Infections such as Cytomegalovirus, Helicobacter pylori, and periodontal pathogens induce production of systemic pro-inflammatory cytokines that may cross the blood-brain barrier to promote neurodegeneration. Pathogen-induced inflammation and central nervous system accumulation of Aβ damages the blood-brain barrier, which contributes to the pathophysiology of AD. Apolipoprotein E4 (ApoE4) enhances brain infiltration by pathogens including HSV-1 and Chlamydophila pneumoniae. ApoE4 is also associated with an increased pro-inflammatory response by the immune system. Potential antimicrobial treatments for AD are discussed, including the rationale for antiviral and antibiotic clinical trials.
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Affiliation(s)
- Steven A Harris
- St. Vincent Medical Group, Northside Internal Medicine, Indianapolis, IN, USA
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94
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Miklossy J, McGeer PL. Common mechanisms involved in Alzheimer's disease and type 2 diabetes: a key role of chronic bacterial infection and inflammation. Aging (Albany NY) 2016; 8:575-88. [PMID: 26961231 PMCID: PMC4925815 DOI: 10.18632/aging.100921] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Accepted: 02/20/2016] [Indexed: 12/30/2022]
Abstract
Strong epidemiologic evidence and common molecular mechanisms support an association between Alzheimer's disease (AD) and type 2-diabetes. Local inflammation and amyloidosis occur in both diseases and are associated with periodontitis and various infectious agents. This article reviews the evidence for the presence of local inflammation and bacteria in type 2 diabetes and discusses host pathogen interactions in chronic inflammatory disorders. Chlamydophyla pneumoniae, Helicobacter pylori and spirochetes are demonstrated in association with dementia and brain lesions in AD and islet lesions in type 2 diabetes. The presence of pathogens in host tissues activates immune responses through Toll-like receptor signaling pathways. Evasion of pathogens from complement-mediated attack results in persistent infection, inflammation and amyloidosis. Amyloid beta and the pancreatic amyloid called amylin bind to lipid bilayers and produce Ca(2+) influx and bacteriolysis. Similarly to AD, accumulation of amylin deposits in type 2 diabetes may result from an innate immune response to chronic bacterial infections, which are known to be associated with amyloidosis. Further research based on an infectious origin of both AD and type 2 diabetes may lead to novel treatment strategies.
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Affiliation(s)
- Judith Miklossy
- International Alzheimer Research Centre, Prevention Alzheimer International Foundation, Martigny-Croix, Switzerland
| | - Patrick L. McGeer
- Kinsmen Laboratory of Neurological Research, The University of British Columbia, Vancouver, B.C, Canada
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95
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Möhle L, Israel N, Paarmann K, Krohn M, Pietkiewicz S, Müller A, Lavrik IN, Buguliskis JS, Schott BH, Schlüter D, Gundelfinger ED, Montag D, Seifert U, Pahnke J, Dunay IR. Chronic Toxoplasma gondii infection enhances β-amyloid phagocytosis and clearance by recruited monocytes. Acta Neuropathol Commun 2016; 4:25. [PMID: 26984535 PMCID: PMC4793516 DOI: 10.1186/s40478-016-0293-8] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 02/19/2016] [Indexed: 01/02/2023] Open
Abstract
INTRODUCTION Alzheimer's disease (AD) is associated with the accumulation of β-amyloid (Aβ) as senile plaques in the brain, thus leading to neurodegeneration and cognitive impairment. Plaque formation depends not merely on the amount of generated Aβ peptides, but more importantly on their effective removal. Chronic infections with neurotropic pathogens, most prominently the parasite Toxoplasma (T.) gondii, are frequent in the elderly, and it has been suggested that the resulting neuroinflammation may influence the course of AD. In the present study, we investigated how chronic T. gondii infection and resulting neuroinflammation affect plaque deposition and removal in a mouse model of AD. RESULTS Chronic infection with T. gondii was associated with reduced Aβ and plaque load in 5xFAD mice. Upon infection, myeloid-derived CCR2(hi) Ly6C(hi) monocytes, CCR2(+) Ly6C(int), and CCR2(+) Ly6C(low) mononuclear cells were recruited to the brain of mice. Compared to microglia, these recruited mononuclear cells showed highly increased phagocytic capacity of Aβ ex vivo. The F4/80(+) Ly6C(low) macrophages expressed high levels of Triggering Receptor Expressed on Myeloid cells 2 (TREM2), CD36, and Scavenger Receptor A1 (SCARA1), indicating phagocytic activity. Importantly, selective ablation of CCR2(+) Ly6C(hi) monocytes resulted in an increased amount of Aβ in infected mice. Elevated insulin-degrading enzyme (IDE), matrix metalloproteinase 9 (MMP9), as well as immunoproteasome subunits β1i/LMP2, β2i/MECL-1, and β5i/LMP7 mRNA levels in the infected brains indicated increased proteolytic Aβ degradation. Particularly, LMP7 was highly expressed by the recruited mononuclear cells in the brain, suggesting a novel mechanism of Aβ clearance. CONCLUSIONS Our results indicate that chronic Toxoplasma infection ameliorates β-amyloidosis in a murine model of AD by activation of the immune system, specifically by recruitment of Ly6C(hi) monocytes and by enhancement of phagocytosis and degradation of soluble Aβ. Our findings provide evidence for a modulatory role of inflammation-induced Aβ phagocytosis and degradation by newly recruited peripheral immune cells in the pathophysiology of AD.
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Affiliation(s)
- Luisa Möhle
- Institute for Medical Microbiology and Hospital Hygiene, University of Magdeburg, Leipziger Str. 44, 39120, Magdeburg, Germany
| | - Nicole Israel
- Institute for Molecular and Clinical Immunology, University of Magdeburg, Magdeburg, Germany
| | - Kristin Paarmann
- Department of Pathology (PAT), Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo (UiO) and Oslo University Hospital (OUS), Oslo, Norway
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
- Neurogenetics, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Markus Krohn
- Department of Pathology (PAT), Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo (UiO) and Oslo University Hospital (OUS), Oslo, Norway
| | - Sabine Pietkiewicz
- Department of Translational Inflammation Research, Institute of Experimental Internal Medicine, University of Magdeburg, Magdeburg, Germany
| | - Andreas Müller
- Institute for Molecular and Clinical Immunology, University of Magdeburg, Magdeburg, Germany
- Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Inna N Lavrik
- Department of Translational Inflammation Research, Institute of Experimental Internal Medicine, University of Magdeburg, Magdeburg, Germany
| | | | - Björn H Schott
- Center for Behavioral Brain Sciences (CBBS), University of Magdeburg, Magdeburg, Germany
- Department of Behavioral Neurology, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Department of Psychiatry and Psychotherapy, Campus Mitte, Charité Universitätsmedizin, Berlin, Germany
| | - Dirk Schlüter
- Institute for Medical Microbiology and Hospital Hygiene, University of Magdeburg, Leipziger Str. 44, 39120, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), University of Magdeburg, Magdeburg, Germany
| | - Eckart D Gundelfinger
- Center for Behavioral Brain Sciences (CBBS), University of Magdeburg, Magdeburg, Germany
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Medical Faculty, University of Magdeburg, Magdeburg, Germany
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
| | - Dirk Montag
- Neurogenetics, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Ulrike Seifert
- Institute for Molecular and Clinical Immunology, University of Magdeburg, Magdeburg, Germany
| | - Jens Pahnke
- Department of Pathology (PAT), Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo (UiO) and Oslo University Hospital (OUS), Oslo, Norway
- University of Lübeck (UzL), LIED, Lübeck, Germany
- Leibniz Institute of Plant Biochemistry (IPB), Halle, Germany
| | - Ildiko Rita Dunay
- Institute for Medical Microbiology and Hospital Hygiene, University of Magdeburg, Leipziger Str. 44, 39120, Magdeburg, Germany.
- Center for Behavioral Brain Sciences (CBBS), University of Magdeburg, Magdeburg, Germany.
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96
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Bourgade K, Le Page A, Bocti C, Witkowski JM, Dupuis G, Frost EH, Fülöp T. Protective Effect of Amyloid-β Peptides Against Herpes Simplex Virus-1 Infection in a Neuronal Cell Culture Model. J Alzheimers Dis 2016; 50:1227-41. [DOI: 10.3233/jad-150652] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Karine Bourgade
- Research Center on Aging, Graduate Program in Immunology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Aurélie Le Page
- Research Center on Aging, Graduate Program in Immunology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Christian Bocti
- Department of Medicine, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, QC, Canada
| | | | - Gilles Dupuis
- Department of Biochemistry, Graduate Program in Immunology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Eric H. Frost
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Tamás Fülöp
- Department of Medicine, Research Center on Aging, Graduate Program in Immunology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, QC, Canada
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97
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Kamer AR, Fortea JO, Videla S, Mayoral A, Janal M, Carmona-Iragui M, Benejam B, Craig RG, Saxena D, Corby P, Glodzik L, Annam KRC, Robbins M, de Leon MJ. Periodontal disease's contribution to Alzheimer's disease progression in Down syndrome. ALZHEIMER'S & DEMENTIA: DIAGNOSIS, ASSESSMENT & DISEASE MONITORING 2016; 2:49-57. [PMID: 27239536 PMCID: PMC4879643 DOI: 10.1016/j.dadm.2016.01.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
People with Down syndrome (DS) are at an increased risk for Alzheimer's disease (AD). After 60 years of age, >50% of DS subjects acquire dementia. Nevertheless, the age of onset is highly variable possibly because of both genetic and environmental factors. Genetics cannot be modified, but environmental risk factors present a potentially relevant intervention for DS persons at risk for AD. Among them, inflammation, important in AD of DS type, is potential target. Consistent with this hypothesis, chronic peripheral inflammation and infections may contribute to AD pathogenesis in DS. People with DS have an aggressive form of periodontitis characterized by rapid progression, significant bacterial and inflammatory burden, and an onset as early as 6 years of age. This review offers a hypothetical mechanistic link between periodontitis and AD in the DS population. Because periodontitis is a treatable condition, it may be a readily modifiable risk factor for AD.
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Affiliation(s)
- Angela R Kamer
- Department of Periodontology and Implant Dentistry, College of Dentistry, New York University, New York, NY, USA; Department of Psychiatry, Center for Brain Health, School of Medicine, New York, NY, USA
| | - Juan O Fortea
- Department of Neurology, Hospital de la Santa Creu i Sant Pau, Universitat Autónoma de Barcelona, Barcelona, Spain; Down Medical Center, Fundació Catalana Síndrome de Down, Barcelona, Spain
| | - Sebastià Videla
- Down Medical Center, Fundació Catalana Síndrome de Down, Barcelona, Spain
| | - Angela Mayoral
- Down Medical Center, Fundació Catalana Síndrome de Down, Barcelona, Spain; Dentistry School Universitat Internacional de Catalunya, Sant Cugat del Vallés, Barcelona, Spain
| | - Malvin Janal
- Department of Epidemiology, College of Dentistry, New York University, New York, NY, USA
| | - Maria Carmona-Iragui
- Department of Neurology, Hospital de la Santa Creu i Sant Pau, Universitat Autónoma de Barcelona, Barcelona, Spain; Down Medical Center, Fundació Catalana Síndrome de Down, Barcelona, Spain
| | - Bessy Benejam
- Down Medical Center, Fundació Catalana Síndrome de Down, Barcelona, Spain
| | - Ronald G Craig
- Department of Basic Sciences and Craniofacial Biology, College of Dentistry, New York University, New York, NY, USA
| | - Deepak Saxena
- Department of Basic Sciences and Craniofacial Biology, College of Dentistry, New York University, New York, NY, USA
| | - Patricia Corby
- Department of Psychiatry, Center for Brain Health, School of Medicine, New York, NY, USA
| | - Lidia Glodzik
- Department of Psychiatry, Center for Brain Health, School of Medicine, New York, NY, USA
| | - Kumar Raghava Chowdary Annam
- Department of Periodontology and Implant Dentistry, College of Dentistry, New York University, New York, NY, USA
| | - Miriam Robbins
- Department of Dental Medicine, Winthrop University Hospital, Mineola, NY, USA
| | - Mony J de Leon
- Department of Psychiatry, Center for Brain Health, School of Medicine, New York, NY, USA
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98
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Genetic and Transcriptomic Profiles of Inflammation in Neurodegenerative Diseases: Alzheimer, Parkinson, Creutzfeldt-Jakob and Tauopathies. Int J Mol Sci 2016; 17:206. [PMID: 26861289 PMCID: PMC4783939 DOI: 10.3390/ijms17020206] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Revised: 01/21/2016] [Accepted: 01/25/2016] [Indexed: 01/02/2023] Open
Abstract
Polymorphisms in certain inflammatory-related genes have been identified as putative differential risk factors of neurodegenerative diseases with abnormal protein aggregates, such as sporadic Alzheimer’s disease (AD) and sporadic Parkinson’s disease (sPD). Gene expression studies of cytokines and mediators of the immune response have been made in post-mortem human brain samples in AD, sPD, sporadic Creutzfeldt-Jakob disease (sCJD) subtypes MM1 and VV2, Pick’s disease (PiD), progressive supranuclear palsy (PSP) and frontotemporal lobar degeneration linked to mutation P301L in MAPT Frontotemporal lobar degeneration-tau (FTLD-tau). The studies have disclosed variable gene regulation which is: (1) disease-dependent in the frontal cortex area 8 in AD, sPD, sCJD MM1 and VV2, PiD, PSP and FTLD-tau; (2) region-dependent as seen when comparing the entorhinal cortex, orbitofrontal cortex, and frontal cortex area 8 (FC) in AD; the substantia nigra, putamen, FC, and angular gyrus in PD, as well as the FC and cerebellum in sCJD; (3) genotype-dependent as seen considering sCJD MM1 and VV2; and (4) stage-dependent as seen in AD at different stages of disease progression. These observations show that regulation of inflammation is much more complicated and diverse than currently understood, and that new therapeutic approaches must be designed in order to selectively act on specific targets in particular diseases and at different time points of disease progression.
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100
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Underly R, Song MS, Dunbar GL, Weaver CL. Expression of Alzheimer-Type Neurofibrillary Epitopes in Primary Rat Cortical Neurons Following Infection with Enterococcus faecalis. Front Aging Neurosci 2016; 7:259. [PMID: 26834627 PMCID: PMC4720002 DOI: 10.3389/fnagi.2015.00259] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 12/24/2015] [Indexed: 11/13/2022] Open
Abstract
The neurofibrillary tau pathology and amyloid deposits seen in Alzheimer’s disease (AD) also have been seen in bacteria-infected brains. However, few studies have examined the role of these bacteria in the generation of tau pathology. One suggested link between infection and AD is edentulism, the complete loss of teeth. Edentulism can result from chronic periodontal disease due to infection by Enterococcus faecalis. The current study assessed the ability to generate early Alzheimer-like neurofibrillary epitopes in primary rat cortical neurons through bacterial infection by E. faecalis. Seven-day old cultured neurons were infected with E. faecalis for 24 and 48 h. An upward molecular weight shift in tau by Western blotting (WB) and increased appearance of tau reactivity in cell bodies and degenerating neurites was found in the 48 h infection group for the antibody CP13 (phospho-Serine 202). A substantial increase in reactivity of Alz-50 was seen at 24 and 48 h after infection. Furthermore, extensive microtubule-associated protein 2 (MAP2) reactivity also was seen at 24 and 48 h post-infection. Our preliminary findings suggest a potential link between E. faecalis infection and intracellular changes that may help facilitate early AD-like neurofibrillary pathology.
Highlights Enterococcus faecalis used in the generation of AD neurofibrillary epitopes in rat. Infection increases Alz-50, phospho-Serine 202 tau, and MAP2 expression. Infection by Enterococcus may play a role in early Alzheimer neurofibrillary changes.
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Affiliation(s)
- Robert Underly
- Department of Psychology, Saginaw Valley State University University Center, MI, USA
| | | | - Gary L Dunbar
- Field Neurosciences InstituteSaginaw, MI, USA; Department of Psychology, Central Michigan UniversityMount Pleasant, MI, USA
| | - Charles L Weaver
- Department of Health Sciences, Saginaw Valley State University University Center, MI, USA
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