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Municio C, Carro E. Implication of salivary lactoferrin and periodontal-mediated infections in Alzheimer's disease. Neural Regen Res 2023; 18:2691-2692. [PMID: 37449625 DOI: 10.4103/1673-5374.373712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023] Open
Affiliation(s)
- Cristina Municio
- Group of Neurodegenerative Diseases, Hospital Universitario 12 de Octubre Research Institute (imas12), Madrid, Spain; Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | - Eva Carro
- Neurobiology of Alzheimer's disease Unit, Functional Unit for Research into Chronic Diseases, Instituto de Salud Carlos III, Madrid, Spain; Network Centre for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
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Hu H, Leung WK. Mass Spectrometry-Based Proteomics for Discovering Salivary Biomarkers in Periodontitis: A Systematic Review. Int J Mol Sci 2023; 24:14599. [PMID: 37834046 PMCID: PMC10572407 DOI: 10.3390/ijms241914599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/07/2023] [Accepted: 09/08/2023] [Indexed: 10/15/2023] Open
Abstract
Periodontitis is one of the primary causes of tooth loss, and is also related to various systemic diseases. Early detection of this condition is crucial when it comes to preventing further oral damage and the associated health complications. This study offers a systematic review of the literature published up to April 2023, and aims to clearly explain the role of proteomics in identifying salivary biomarkers for periodontitis. Comprehensive searches were conducted on PubMed and Web of Science to shortlist pertinent studies. The inclusion criterion was those that reported on mass spectrometry-driven proteomic analyses of saliva samples from periodontitis cohorts, while those on gingivitis or other oral diseases were excluded. An assessment for risk of bias was carried out using the Newcastle-Ottawa Scale and Quality Assessment of Diagnostic Accuracy Studies or the NIH quality assessment tool, and a meta-analysis was performed for replicable candidate biomarkers, i.e., consistently reported candidate biomarkers (in specific saliva samples, and periodontitis subgroups, reported in ≥2 independent cohorts/reports) were identified. A Gene Ontology enrichment analysis was conducted using the Database for Annotation, Visualization, and Integrated Discovery bioinformatics resources, which consistently expressed candidate biomarkers, to explore the predominant pathway wherein salivary biomarkers consistently manifested. Of the 15 studies included, 13 were case-control studies targeting diagnostic biomarkers for periodontitis participants (periodontally healthy/diseased, n = 342/432), while two focused on biomarkers responsive to periodontal treatment (n = 26 participants). The case-control studies were considered to have a low risk of bias, while the periodontitis treatment studies were deemed fair. Summary estimate and confidence/credible interval, etc. determination for the identified putative salivary biomarkers could not be ascertained due to the low number of studies in each case. The results from the included case-control studies identified nine consistently expressed candidate biomarkers (from nine studies with 230/297 periodontally healthy/diseased participants): (i) those that were upregulated: alpha-amylase, serum albumin, complement C3, neutrophil defensin, profilin-1, and S100-P; and (ii) those that were downregulated: carbonic anhydrase 6, immunoglobulin J chain, and lactoferrin. All putative biomarkers exhibited consistent regulation patterns. The implications of the current putative marker proteins identified were reviewed, with a focus on their potential roles in periodontitis diagnosis and pathogenesis, and as putative therapeutic targets. Although in its early stages, mass spectrometry-based salivary periodontal disease biomarker proteomics detection appeared promising. More mass spectrometry-based proteomics studies, with or without the aid of already available clinical biochemical approaches, are warranted to aid the discovery, identification, and validation of periodontal health/disease indicator molecule(s). Protocol registration number: CRD42023447722; supported by RD-02-202410 and GRF17119917.
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Affiliation(s)
- Hongying Hu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Oral Medical Imaging, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China;
| | - Wai Keung Leung
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
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Fulop T, Ramassamy C, Lévesque S, Frost EH, Laurent B, Lacombe G, Khalil A, Larbi A, Hirokawa K, Desroches M, Rodrigues S, Bourgade K, Cohen AA, Witkowski JM. Viruses - a major cause of amyloid deposition in the brain. Expert Rev Neurother 2023; 23:775-790. [PMID: 37551672 DOI: 10.1080/14737175.2023.2244162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 07/31/2023] [Indexed: 08/09/2023]
Abstract
INTRODUCTION Clinically, Alzheimer's disease (AD) is a syndrome with a spectrum of various cognitive disorders. There is a complete dissociation between the pathology and the clinical presentation. Therefore, we need a disruptive new approach to be able to prevent and treat AD. AREAS COVERED In this review, the authors extensively discuss the evidence why the amyloid beta is not the pathological cause of AD which makes therefore the amyloid hypothesis not sustainable anymore. They review the experimental evidence underlying the role of microbes, especially that of viruses, as a trigger/cause for the production of amyloid beta leading to the establishment of a chronic neuroinflammation as the mediator manifesting decades later by AD as a clinical spectrum. In this context, the emergence and consequences of the infection/antimicrobial protection hypothesis are described. The epidemiological and clinical data supporting this hypothesis are also analyzed. EXPERT OPINION For decades, we have known that viruses are involved in the pathogenesis of AD. This discovery was ignored and discarded for a long time. Now we should accept this fact, which is not a hypothesis anymore, and stimulate the research community to come up with new ideas, new treatments, and new concepts.
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Affiliation(s)
- Tamas Fulop
- Research Center on Aging, Centre Intégré Universitaire de Santé Et Services Sociaux de l'Estrie-Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
- Department of Medicine, Division of Geriatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | | | - Simon Lévesque
- CIUSSS de l'Estrie - CHUS, Sherbrooke, QC, Canada
- Département de Microbiologie Et Infectiologie, Faculté de Médecine Et des Sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Eric H Frost
- Département de Microbiologie Et Infectiologie, Faculté de Médecine Et des Sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Benoit Laurent
- Research Center on Aging, Centre Intégré Universitaire de Santé Et Services Sociaux de l'Estrie-Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
- Department of Biochemistry and Functional Genomics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Guy Lacombe
- Research Center on Aging, Centre Intégré Universitaire de Santé Et Services Sociaux de l'Estrie-Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
- Department of Medicine, Division of Geriatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Abedelouahed Khalil
- Research Center on Aging, Centre Intégré Universitaire de Santé Et Services Sociaux de l'Estrie-Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
- Department of Medicine, Division of Geriatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Anis Larbi
- Department of Medicine, Division of Geriatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Katsuiku Hirokawa
- Department of Pathology, Institute of Health and Life Science, Tokyo Medical Dental University, Tokyo and Nito-Memory Nakanosogo Hospital, Tokyo, Japan
| | - Mathieu Desroches
- MathNeuro Team, Inria Sophia Antipolis Méditerranée, Biot, France
- Université Côte d'Azur, Nice, France
| | - Serafim Rodrigues
- Ikerbasque, BCAM, the Basque Foundation for Science and BCAM - The Basque Center for Applied Mathematics, Bilbao, Spain
| | - Karine Bourgade
- Research Center on Aging, Centre Intégré Universitaire de Santé Et Services Sociaux de l'Estrie-Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Alan A Cohen
- Department of Environmental Health Sciences, Butler Columbia Aging Center, Mailman School of Public Health, Columbia University, New York, NY, USA
| | - Jacek M Witkowski
- Department of Pathophysiology, Medical University of Gdansk, Gdansk, Poland
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Municio C, Carro E. Aquaporin 5 in Alzheimer's disease: a link between oral and brain pathology? Neural Regen Res 2023; 18:1491-1492. [PMID: 36571348 PMCID: PMC10075123 DOI: 10.4103/1673-5374.361545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Cristina Municio
- Group of Neurodegenerative Diseases, Hospital Universitario 12 de Octubre Research Institute (imas12); Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | - Eva Carro
- Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED); Neurobiology of Alzheimer's Disease Unit, Functional Unit for Research into Chronic Diseases, Instituto de Salud Carlos III, Madrid, Spain
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Weber C, Dilthey A, Finzer P. The role of microbiome-host interactions in the development of Alzheimer´s disease. Front Cell Infect Microbiol 2023; 13:1151021. [PMID: 37333848 PMCID: PMC10272569 DOI: 10.3389/fcimb.2023.1151021] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 05/16/2023] [Indexed: 06/20/2023] Open
Abstract
Alzheimer`s disease (AD) is the most prevalent cause of dementia. It is often assumed that AD is caused by an aggregation of extracellular beta-amyloid and intracellular tau-protein, supported by a recent study showing reduced brain amyloid levels and reduced cognitive decline under treatment with a beta-amyloid-binding antibody. Confirmation of the importance of amyloid as a therapeutic target notwithstanding, the underlying causes of beta-amyloid aggregation in the human brain, however, remain to be elucidated. Multiple lines of evidence point towards an important role of infectious agents and/or inflammatory conditions in the etiology of AD. Various microorganisms have been detected in the cerebrospinal fluid and brains of AD-patients and have thus been hypothesized to be linked to the development of AD, including Porphyromonas gingivalis (PG) and Spirochaetes. Intriguingly, these microorganisms are also found in the oral cavity under normal physiological conditions, which is often affected by multiple pathologies like caries or tooth loss in AD patients. Oral cavity pathologies are mostly accompanied by a compositional shift in the community of oral microbiota, mainly affecting commensal microorganisms and referred to as 'dysbiosis'. Oral dysbiosis seems to be at least partly mediated by key pathogens such as PG, and it is associated with a pro-inflammatory state that promotes the destruction of connective tissue in the mouth, possibly enabling the translocation of pathogenic microbiota from the oral cavity to the nervous system. It has therefore been hypothesized that dysbiosis of the oral microbiome may contribute to the development of AD. In this review, we discuss the infectious hypothesis of AD in the light of the oral microbiome and microbiome-host interactions, which may contribute to or even cause the development of AD. We discuss technical challenges relating to the detection of microorganisms in relevant body fluids and approaches for avoiding false-positives, and introduce the antibacterial protein lactoferrin as a potential link between the dysbiotic microbiome and the host inflammatory reaction.
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Chen Z, Du J, Song Q, Yang J, Wu Y. A prediction model of cognitive impairment risk in elderly illiterate Chinese women. Front Aging Neurosci 2023; 15:1148071. [PMID: 37181625 PMCID: PMC10169753 DOI: 10.3389/fnagi.2023.1148071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 04/05/2023] [Indexed: 05/16/2023] Open
Abstract
Objective To establish and validate a targeted model for the prediction of cognitive impairment in elderly illiterate Chinese women. Methods 1864 participants in the 2011-2014 cohort and 1,060 participants in the 2014-2018 cohort from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) were included in this study. The Chinese version of the Mini-Mental State Examination (MMSE) was used to measure cognitive function. Demographics and lifestyle information were collected to construct a risk prediction model by a restricted cubic spline Cox regression. The discrimination and accuracy of the model were assessed by the area under the curve (AUC) and the concordance index, respectively. Results A total of seven critical variables were included in the final prediction model for cognitive impairment risk, including age, MMSE score, waist-to-height ratio (WHtR), psychological score, activities of daily living (ADL), instrumental abilities of daily living (IADL), and frequency of tooth brushing. The internal and external validation AUCs were 0.8 and 0.74, respectively; and the receiver operating characteristic (ROC) curves indicated good performance ability of the constructed model. Conclusion A feasible model to explore the factors influencing cognitive impairment in elderly illiterate women in China and to identify the elders at high risk was successfully constructed.
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Affiliation(s)
- Zhaojing Chen
- Department of Epidemiology and Health Statistics, School of Public Health, Hangzhou Normal University, Hangzhou, China
| | - Jiaolan Du
- Department of Epidemiology and Health Statistics, School of Public Health, Hangzhou Normal University, Hangzhou, China
| | - Qin Song
- Department of Occupational and Environmental Health, School of Public Health, Hangzhou Normal University, Hangzhou, China
| | - Jun Yang
- Department of Nutrition and Toxicology, School of Public Health, Hangzhou Normal University, Hangzhou, China
| | - Yinyin Wu
- Department of Epidemiology and Health Statistics, School of Public Health, Hangzhou Normal University, Hangzhou, China
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Kondaveeti SN, Thekkekkara D, T LN, Manjula SN, Tausif YM, Babu A, Meheronnisha SK. A Deep Insight into the Correlation Between Gut Dysbiosis and Alzheimer’s Amyloidopathy. J Pharmacol Pharmacother 2023. [DOI: 10.1177/0976500x221150310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
Abstract
Background Recent research has shown a strong correlation between gut dysbiosis and Alzheimer’s disease (AD). Purpose To investigate the relationship between gut dysbiosis, immune system activation, and the onset of AD and to examine current breakthroughs in microbiota-targeted AD therapeutics. Methods A review of scientific literature was conducted to assess the correlation between gut dysbiosis and AD and the various factors associated. Results Gut dysbiosis produces an increase in harmful substances, such as bacterial amyloids, which makes the gut barrier and blood-brain barrier more permeable. This leads to the stimulation of immunological responses and an increase in cytokines such as interleukin-1β (IL-1β). As a result, gut dysbiosis accelerates the progression of AD. Conclusion The review highlights the connection between gut dysbiosis and AD and the potential for microbiota-targeted therapies in AD treatment. Pictorial Abstract
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Affiliation(s)
| | - Dithu Thekkekkara
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education and Research, Mysuru, India
| | - Lakshmi Narayanan T
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education and Research, Mysuru, India
| | - S. N. Manjula
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education and Research, Mysuru, India
| | - Y Mohammed Tausif
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education and Research, Mysuru, India
| | - Amrita Babu
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education and Research, Mysuru, India
| | - SK Meheronnisha
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education and Research, Mysuru, India
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Naidu SAG, Wallace TC, Davies KJA, Naidu AS. Lactoferrin for Mental Health: Neuro-Redox Regulation and Neuroprotective Effects across the Blood-Brain Barrier with Special Reference to Neuro-COVID-19. J Diet Suppl 2023; 20:218-253. [PMID: 33977807 DOI: 10.1080/19390211.2021.1922567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Overall mental health depends in part on the blood-brain barrier, which regulates nutrient transfer in-and-out of the brain and its central nervous system. Lactoferrin, an innate metal-transport protein, synthesized in the substantia nigra, particularly in dopaminergic neurons and activated microglia is vital for brain physiology. Lactoferrin rapidly crosses the blood-brain barrier via receptor-mediated transcytosis and accumulates in the brain capillary endothelial cells. Lactoferrin receptors are additionally present on glioma cells, brain micro-vessels, and neurons. As a regulator of neuro-redox, microglial lactoferrin is critical for protection/repair of neurons and healthy brain function. Iron imbalance and oxidative stress are common among patients with neurodegenerative disorders such as Parkinson's disease, Alzheimer's disease, dementia, depression, and multiple sclerosis. As an endogenous iron-chelator, lactoferrin prevents iron accumulation and dopamine depletion in Parkinson's disease patients. Oral lactoferrin supplementation could modulate the p-Akt/PTEN pathway, reduce Aβ deposition, and ameliorate cognitive decline in Alzheimer's disease. Novel lactoferrin-based nano-therapeutics have emerged as effective drug-delivery systems for clinical management of neurodegenerative disorders. Recent emergence of the Coronavirus disease-2019 (COVID-19) pandemic, initially considered a respiratory illness, demonstrated a broader virulence spectrum with the ability to cross the blood-brain barrier and inflict a plethora of neuropathological manifestations in the brain - the Neuro-COVID-19. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections are widely reported in Parkinson's disease, Alzheimer's disease, dementia, and multiple sclerosis patients with aggravated clinical outcomes. Lactoferrin, credited with several neuroprotective benefits in the brain could serve as a potential adjuvant in the clinical management of Neuro-COVID-19.
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Affiliation(s)
- Sreus A G Naidu
- N-terminus Research Laboratory, Yorba Linda, California, USA
| | - Taylor C Wallace
- Department of Nutrition and Food Studies, George Mason University, Fairfax, Virginia, USA
- Think Healthy Group, Washington, District of Columbia, USA
| | - Kelvin J A Davies
- Division of Biogerontology, Leonard Davis School of Gerontology, The University of Southern California, Los Angeles, California, USA
- Division of Molecular & Computational Biology, Dornsife College of Letters, Arts, and Sciences, The University of Southern California, Los Angeles, California, USA
- Department Biochemistry & Molecular Medicine, Keck School of Medicine of USC, The University of Southern California, Los Angeles, California, USA
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The Mechanistic Pathways of Periodontal Pathogens Entering the Brain: The Potential Role of Treponema denticola in Tracing Alzheimer’s Disease Pathology. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19159386. [PMID: 35954742 PMCID: PMC9368682 DOI: 10.3390/ijerph19159386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/26/2022] [Accepted: 07/27/2022] [Indexed: 11/20/2022]
Abstract
Alzheimer’s Disease (AD) is a complex neurodegenerative disease and remains the most common form of dementia. The pathological features include amyloid (Aβ) accumulation, neurofibrillary tangles (NFTs), neural and synaptic loss, microglial cell activation, and an increased blood–brain barrier permeability. One longstanding hypothesis suggests that a microbial etiology is key to AD initiation. Among the various periodontal microorganisms, Porphyromonas gingivalis has been considered the keystone agent to potentially correlate with AD, due to its influence on systemic inflammation. P. gingivalis together with Treponema denticola and Tannerella forsythia belong to the red complex consortium of bacteria advocated to sustain periodontitis within a local dysbiosis and a host response alteration. Since the implication of P. gingivalis in the pathogenesis of AD, evidence has emerged of T. denticola clusters in some AD brain tissue sections. This narrative review explored the potential mode of spirochetes entry into the AD brain for tracing pathology. Spirochetes are slow-growing bacteria, which can hide within ganglia for many years. It is this feature in combination with the ability of these bacteria to evade the hosts’ immune responses that may account for a long lag phase between infection and plausible AD disease symptoms. As the locus coeruleus has direct connection between the trigeminal nuclei to periodontal free nerve endings and proprioceptors with the central nervous system, it is plausible that they could initiate AD pathology from this anatomical region.
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Bartolomé F, Rosa L, Valenti P, Lopera F, Hernández-Gallego J, Cantero JL, Orive G, Carro E. Lactoferrin as Immune-Enhancement Strategy for SARS-CoV-2 Infection in Alzheimer's Disease Patients. Front Immunol 2022; 13:878201. [PMID: 35547737 PMCID: PMC9083828 DOI: 10.3389/fimmu.2022.878201] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 03/28/2022] [Indexed: 12/25/2022] Open
Abstract
Coronavirus 2 (SARS-CoV2) (COVID-19) causes severe acute respiratory syndrome. Severe illness of COVID-19 largely occurs in older people and recent evidence indicates that demented patients have higher risk for COVID-19. Additionally, COVID-19 further enhances the vulnerability of older adults with cognitive damage. A balance between the immune and inflammatory response is necessary to control the infection. Thus, antimicrobial and anti-inflammatory drugs are hopeful therapeutic agents for the treatment of COVID-19. Accumulating evidence suggests that lactoferrin (Lf) is active against SARS-CoV-2, likely due to its potent antiviral and anti-inflammatory actions that ultimately improves immune system responses. Remarkably, salivary Lf levels are significantly reduced in different Alzheimer's disease (AD) stages, which may reflect AD-related immunological disturbances, leading to reduced defense mechanisms against viral pathogens and an increase of the COVID-19 susceptibility. Overall, there is an urgent necessity to protect AD patients against COVID-19, decreasing the risk of viral infections. In this context, we propose bovine Lf (bLf) as a promising preventive therapeutic tool to minimize COVID-19 risk in patients with dementia or AD.
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Affiliation(s)
- Fernando Bartolomé
- Group of Neurodegenerative Diseases, Hospital Universitario 12 de Octubre Research Institute (imas12), Madrid, Spain
- Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Luigi Rosa
- Department of Public Health and Infectious Diseases, University of Rome “La Sapienza”, Rome, Italy
| | - Piera Valenti
- Department of Public Health and Infectious Diseases, University of Rome “La Sapienza”, Rome, Italy
| | - Francisco Lopera
- Neuroscience Group of Antioquia, Faculty of Medicine, University of Antioquia, Medellín, Colombia
| | - Jesús Hernández-Gallego
- Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
- Department of Neurology, Hospital Universitario 12 de Octubre, Madrid, Spain
- Department of Medicine, Faculty of Medicine, Complutense University of Madrid, Madrid, Spain
| | - José Luis Cantero
- Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
- Laboratory of Functional Neuroscience, Pablo de Olavide University, Seville, Spain
| | - Gorka Orive
- Laboratory of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, University of the Basque Country, Vitoria, Spain
- Bioaraba, NanoBioCel Research Group, Vitoria-Gasteiz, Spain
- Networked Center for Biomedical Research in Bioengineering Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain
| | - Eva Carro
- Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
- Neurobiology of Alzheimer’s Disease Unit, Chronic Disease Programme, Instituto de Salud Carlos III, Madrid, Spain
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Bazarnyi VV, Sidenkova AP, Sosnin DY. Lactoferrin of oral fluid is normal and in Alzheimer's disease: laboratory and diagnostic aspects (review of literature). Klin Lab Diagn 2022; 67:207-212. [PMID: 35575393 DOI: 10.51620/0869-2084-2022-67-4-207-212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The article discusses the clinical value of determining the lactoferrin protein in oral fluid - one of the representatives of the saliva proteome. The review is based on the analysis of modern literature, including systematic reviews, the results of multicenter prospective studies, review and original articles by leading experts in this field, presented in the databases PubMed, Scopus, CyberLeninka. The problems of the preanalytical stage, methods for determining lactoferrin are highlighted and information about its content in mixed saliva according to various authors is provided. Special attention is paid to the clinical and diagnostic value of the level of salivary lactoferrin in Alzheimer's disease. According to most authors, the diagnostic sensitivity of this parameter ranges from 87 to 100%. Some mechanisms of the relationship between this protein and the central nervous system (CNS) are shown. In conclusion, it is concluded that salivary lactoferrin can be an "indicator" of the formation of amyloid plaques and can be considered as one of the reliable biomarkers of Alzheimer's disease. This opinion is based both on fundamental ideas about the global relationship between innate immunity and the central nervous system, and on clinical data. The special advantage of this laboratory test is its non-invasiveness, which makes it more preferable in comparison with the determination of amyloid and tau proteins in the cerebrospinal fluid and blood.
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Seymour T, Zhang J. Porphyromonas Gingivalis in the Pathogenesis of Alzheimer’s Disease and Its Therapeutic Target. JOURNAL OF EXPLORATORY RESEARCH IN PHARMACOLOGY 2022; 7:45-53. [DOI: 10.14218/jerp.2021.00030] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Varesi A, Pierella E, Romeo M, Piccini GB, Alfano C, Bjørklund G, Oppong A, Ricevuti G, Esposito C, Chirumbolo S, Pascale A. The Potential Role of Gut Microbiota in Alzheimer’s Disease: from Diagnosis to Treatment. Nutrients 2022; 14:nu14030668. [PMID: 35277027 PMCID: PMC8840394 DOI: 10.3390/nu14030668] [Citation(s) in RCA: 70] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 02/02/2022] [Accepted: 02/03/2022] [Indexed: 12/04/2022] Open
Abstract
Gut microbiota is emerging as a key regulator of many disease conditions and its dysregulation is implicated in the pathogenesis of several gastrointestinal and extraintestinal disorders. More recently, gut microbiome alterations have been linked to neurodegeneration through the increasingly defined gut microbiota brain axis, opening the possibility for new microbiota-based therapeutic options. Although several studies have been conducted to unravel the possible relationship between Alzheimer’s Disease (AD) pathogenesis and progression, the diagnostic and therapeutic potential of approaches aiming at restoring gut microbiota eubiosis remain to be fully addressed. In this narrative review, we briefly summarize the role of gut microbiota homeostasis in brain health and disease, and we present evidence for its dysregulation in AD patients. Based on these observations, we then discuss how dysbiosis might be exploited as a new diagnostic tool in early and advanced disease stages, and we examine the potential of prebiotics, probiotics, fecal microbiota transplantation, and diets as complementary therapeutic interventions on disease pathogenesis and progression, thus offering new insights into the diagnosis and treatment of this devastating and progressive disease.
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Affiliation(s)
- Angelica Varesi
- Department of Biology and Biotechnology, University of Pavia, 27100 Pavia, Italy;
- Almo Collegio Borromeo, 27100 Pavia, Italy
- Correspondence: (A.V.); (G.R.)
| | - Elisa Pierella
- School of Medicine, Faculty of Clinical and Biomedical Sciences, University of Central Lancashire, Preston PR1 2HE, UK; (E.P.); (A.O.)
| | - Marcello Romeo
- Department of Biology and Biotechnology, University of Pavia, 27100 Pavia, Italy;
| | | | - Claudia Alfano
- Department of Emergency Medicine and Surgery, IRCCS Fondazione Policlinico San Matteo, 27100 Pavia, Italy;
| | - Geir Bjørklund
- Council for Nutritional and Environmental Medicine (CONEM), 8610 Mo i Rana, Norway;
| | - Abigail Oppong
- School of Medicine, Faculty of Clinical and Biomedical Sciences, University of Central Lancashire, Preston PR1 2HE, UK; (E.P.); (A.O.)
| | - Giovanni Ricevuti
- Department of Drug Sciences, University of Pavia, 27100 Pavia, Italy
- Correspondence: (A.V.); (G.R.)
| | - Ciro Esposito
- Unit of Nephrology and Dialysis, ICS Maugeri, University of Pavia, 27100 Pavia, Italy;
| | - Salvatore Chirumbolo
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37121 Verona, Italy;
| | - Alessia Pascale
- Section of Pharmacology, Department of Drug Sciences, University of Pavia, 27100 Pavia, Italy;
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Krog MC, Madsen ME, Bliddal S, Bashir Z, Vexø LE, Hartwell D, Hugerth LW, Fransson E, Hamsten M, Boulund F, Wannerberger K, Engstrand L, Schuppe-Koistinen I, Nielsen HS. OUP accepted manuscript. Hum Reprod Open 2022; 2022:hoac015. [PMID: 35441092 PMCID: PMC9014536 DOI: 10.1093/hropen/hoac015] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 01/11/2022] [Indexed: 11/23/2022] Open
Abstract
STUDY QUESTION What is the microbiome profile across different body sites in relation to the normal menstrual cycle (with and without hormonal contraception), recurrent pregnancy loss (RPL) (before and during pregnancy, pregnancy loss or birth) and endometriosis (before, during and after surgery)? How do these profiles interact with genetics, environmental exposures, immunological and endocrine biomarkers? WHAT IS KNOWN ALREADY The microbiome is a key factor influencing human health and disease in areas as diverse as immune functioning, gastrointestinal disease and mental and metabolic disorders. There is mounting evidence to suggest that the reproductive microbiome may be influential in general and reproductive health, fertility and pregnancy outcomes. STUDY DESIGN, SIZE, DURATION This is a prospective, longitudinal, observational study using a systems biology approach in three cohorts totalling 920 participants. Since microbiome profiles by shot-gun sequencing have never been investigated in healthy controls during varying phases of the menstrual cycle, patients with RPL and patients with endometriosis, no formal sample size calculation can be performed. The study period is from 2017 to 2024 and allows for longitudinal profiling of study participants to enable deeper understanding of the role of the microbiome and of host–microbe interactions in reproductive health. PARTICIPANTS/MATERIALS, SETTING, METHODS Participants in each cohort are as follows: Part 1 MiMens—150 healthy women with or without hormonal contraception; Part 2 MiRPL—200 couples with RPL, 50 healthy couples with prior uncomplicated pregnancy and 150 newborns; Part 3 MiEndo—120 patients with endometriosis requiring surgery with or without hormonal treatment. Microbiome profiles from saliva, faeces, rectal mucosa, vaginal fluid and endometrium will be studied, as well as the Omics profile, endocrine disrupting chemicals and endocrine and immune factors in blood, hair, saliva and urine. Pregnancy loss products, seminal microbiome, HLA types, endometriotic tissue and genetic risk and comprehensive questionnaire data will also be studied, where appropriate. Correlations with mental and physical health will be evaluated. STUDY FUNDING/COMPETING INTEREST(S) This work is supported by funding from Ferring Pharmaceuticals ([#MiHSN01] to H.S.N., M.C.K., M.E.M., L.E.V., L.E., I.S.-K., F.B., L.W.H., E.F. and M.H.), Rigshospitalet’s Research Funds ([#E-22614-01 and #E-22614-02] to M.C.K. and [#E-22222-06] to S.B.), Niels and Desiree Yde’s Foundation (S.B., endocrine analyses [#2015-2784]), the Musikforlæggerne Agnes and Knut Mørk’s Foundation (S.B., endocrine and immune analyses [#35108-001]) and Oda and Hans Svenningsen’s Foundation ([#F-22614-08] to H.S.N.). Medical writing assistance with this manuscript was provided by Caroline Loat, PhD, and funded by Ferring Pharmaceuticals. H.S.N. reports personal fees from Ferring Pharmaceuticals, Merck Denmark A/S, Ibsa Nordic, Astra Zeneca and Cook Medical outside the submitted work. K.W. is a full-time employee of Ferring Pharmaceuticals. No other conflicts are reported. TRIAL REGISTRATION NUMBER N/A TRIAL REGISTRATION DATE N/A DATE OF FIRST PATIENT’S ENROLMENT N/A
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Affiliation(s)
- Maria Christine Krog
- Correspondence address. The Recurrent Pregnancy Loss Unit, The Fertility Clinic 4071, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen Ø, Denmark. E-mail:
| | | | - Sofie Bliddal
- The Department of Medical Endocrinology and Metabolism, Rigshospitalet, Copenhagen University Hospital, Copenhagen Ø, Denmark
- Institute for Inflammation Research, Center for Rheumatology and Spine Diseases, Rigshospitalet, Copenhagen University Hospital, Copenhagen Ø, Denmark
| | - Zahra Bashir
- The Recurrent Pregnancy Loss Unit, The Capital Region, The Fertility Clinic, Copenhagen University Hospitals Rigshospitalet and Hvidovre, Copenhagen, Denmark
- Department of Obstetrics and Gynecology, Slagelse Hospital, Slagelse, Denmark
| | - Laura Emilie Vexø
- The Recurrent Pregnancy Loss Unit, The Capital Region, The Fertility Clinic, Copenhagen University Hospitals Rigshospitalet and Hvidovre, Copenhagen, Denmark
- Department of Gynecology, The Endometriosis Unit, Rigshospitalet, Copenhagen University Hospital, Copenhagen Ø, Denmark
| | - Dorthe Hartwell
- Department of Gynecology, The Endometriosis Unit, Rigshospitalet, Copenhagen University Hospital, Copenhagen Ø, Denmark
| | - Luisa W Hugerth
- Centre for Translational Microbiome Research (CTMR), Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Emma Fransson
- Centre for Translational Microbiome Research (CTMR), Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Marica Hamsten
- Centre for Translational Microbiome Research (CTMR), Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Fredrik Boulund
- Centre for Translational Microbiome Research (CTMR), Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | | | - Lars Engstrand
- Centre for Translational Microbiome Research (CTMR), Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Ina Schuppe-Koistinen
- Centre for Translational Microbiome Research (CTMR), Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Henriette Svarre Nielsen
- The Recurrent Pregnancy Loss Unit, The Capital Region, The Fertility Clinic, Copenhagen University Hospitals Rigshospitalet and Hvidovre, Copenhagen, Denmark
- Department of Clinical Medicine, Copenhagen University, Copenhagen N, Denmark
- Department of Obstetrics and Gynecology, Copenhagen University Hospital, Hvidovre, Denmark
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Antequera D, Moneo D, Carrero L, Bartolome F, Ferrer I, Proctor G, Carro E. Salivary Lactoferrin Expression in a Mouse Model of Alzheimer's Disease. Front Immunol 2021; 12:749468. [PMID: 34659251 PMCID: PMC8514982 DOI: 10.3389/fimmu.2021.749468] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 09/14/2021] [Indexed: 12/24/2022] Open
Abstract
In the last few years, microbial infection and innate immune theories have been proposed as an alternative approach explaining the etiopathogenesis and origin of Alzheimer's disease (AD). Lactoferrin, one of the main antimicrobial proteins in saliva, is an important modulator of immune response and inflammation, and represents an important defensive element by inducing a broad spectrum of antimicrobial effects against microbial infections. We demonstrated that lactoferrin levels in saliva are decreased in prodromal and dementia stages of AD compared with healthy subjects. That finding seems to be specific to cerebral amyloid-β (Aβ) load as such observation was not observed in healthy elderly controls or those subjects with frontotemporal dementia. In the present study, we analysed salivary lactoferrin levels in a mouse model of AD. We observed robust and early reduction of lactoferrin levels in saliva from 6- and 12-month-old APP/PS1 mice. Because saliva is secreted by salivary glands, we presume that deregulation in salivary glands resulting in reduced salivary lactoferrin levels may occur in AD. To test this hypothesis, we collected submandibular glands from APP/PS1 mice, as well as submandibular gland tissue from AD patients and we analysed the expression levels of key components of the salivary protein signalling pathway. A significant reduction in M3 receptor levels was found along with decreased acetylcholine (Ach) levels in submandibular glands from APP/PS1 mice. Similarly, a reduction in M3 receptor levels was observed in human submandibular glands from AD patients but in that case, the Ach levels were found increased. Our data suggest that the ACh-mediated M3 signalling pathway is impaired in salivary glands in AD, resulting in salivary gland dysfunction and reduced salivary lactoferrin secretion.
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Affiliation(s)
- Desiree Antequera
- Network Centre for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Alzheimer’s Disease and Other Degenerative Dementias, Madrid, Spain
- Group of Neurodegenerative Diseases, Hospital Universitario 12 de Octubre Research Institute (imas12), Madrid, Spain
| | - Diego Moneo
- Group of Neurodegenerative Diseases, Hospital Universitario 12 de Octubre Research Institute (imas12), Madrid, Spain
| | - Laura Carrero
- Network Centre for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Alzheimer’s Disease and Other Degenerative Dementias, Madrid, Spain
- Group of Neurodegenerative Diseases, Hospital Universitario 12 de Octubre Research Institute (imas12), Madrid, Spain
| | - Fernando Bartolome
- Network Centre for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Alzheimer’s Disease and Other Degenerative Dementias, Madrid, Spain
- Group of Neurodegenerative Diseases, Hospital Universitario 12 de Octubre Research Institute (imas12), Madrid, Spain
| | - Isidro Ferrer
- Network Centre for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Alzheimer’s Disease and Other Degenerative Dementias, Madrid, Spain
- Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Barcelona, Spain
- Department of Pathology and Experimental Therapeutics, University of Barcelona, Hospitalet de Llobregat, Barcelona, Spain
- Institute of Neurosciences, University of Barcelona, Barcelona, Spain
| | - Gordon Proctor
- Centre for Host Microbiome Interactions, King’s College London, London, United Kingdom
| | - Eva Carro
- Network Centre for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Alzheimer’s Disease and Other Degenerative Dementias, Madrid, Spain
- Group of Neurodegenerative Diseases, Hospital Universitario 12 de Octubre Research Institute (imas12), Madrid, Spain
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16
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Bartolome F, Orive G, Carro E. Standardizing salivary lactoferrin measurements to obtain a robust diagnostic biomarker for Alzheimer's disease. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2021; 13:e12173. [PMID: 33969170 PMCID: PMC8088590 DOI: 10.1002/dad2.12173] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 02/01/2021] [Accepted: 02/18/2021] [Indexed: 12/13/2022]
Abstract
The search for new, robust, and reproducible biomarkers for Alzheimer's disease (AD) diagnosis is a challenge. We recently reported that salivary lactoferrin (Lf) could be presented as new biomarker candidate for AD, being both non-invasive and cost-effective, as well as having appropriate diagnostic performance for the clinical detection of AD subjects. Saliva is an attractive sample type for biomarker-based testing approaches for several other diseases; however, its composition may change under certain circumstances. It is therefore critical to maintain a consistent salivary handling protocol, considering possible extrinsic factors that may influence salivary Lf concentration. In this work, we analyzed salivary Lf concentration under different handling conditions and donor-dependent factors including age, inter-diurnal variations, physical activity, and pharmacological treatments. Our aim was to evaluate the influence of such conditions on salivary Lf concentration. In conclusion, we found that most of these extrinsic factors should be considered in the future when using Lf as a predictive biomarker for AD.
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Affiliation(s)
- Fernando Bartolome
- Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED)CordobaSpain
- Group of Neurodegenerative DiseasesHospital Universitario 12 de Octubre Research Institute (imas12)MadridSpain
| | - Gorka Orive
- Laboratory of Pharmacy and Pharmaceutical TechnologyFaculty of PharmacyUniversity of the Basque CountryVitoriaSpain
- Bioaraba, NanoBioCel Research GroupVitoria‐GasteizSpain
- Networked Center for Biomedical Research in BioengineeringBiomaterials and Nanomedicine (CIBER‐BBN)BarcelonaSpain
| | - Eva Carro
- Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED)CordobaSpain
- Group of Neurodegenerative DiseasesHospital Universitario 12 de Octubre Research Institute (imas12)MadridSpain
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Ficiarà E, Munir Z, Boschi S, Caligiuri ME, Guiot C. Alteration of Iron Concentration in Alzheimer's Disease as a Possible Diagnostic Biomarker Unveiling Ferroptosis. Int J Mol Sci 2021; 22:4479. [PMID: 33923052 PMCID: PMC8123284 DOI: 10.3390/ijms22094479] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/23/2021] [Accepted: 04/23/2021] [Indexed: 12/14/2022] Open
Abstract
Proper functioning of all organs, including the brain, requires iron. It is present in different forms in biological fluids, and alterations in its distribution can induce oxidative stress and neurodegeneration. However, the clinical parameters normally used for monitoring iron concentration in biological fluids (i.e., serum and cerebrospinal fluid) can hardly detect the quantity of circulating iron, while indirect measurements, e.g., magnetic resonance imaging, require further validation. This review summarizes the mechanisms involved in brain iron metabolism, homeostasis, and iron imbalance caused by alterations detectable by standard and non-standard indicators of iron status. These indicators for iron transport, storage, and metabolism can help to understand which biomarkers can better detect iron imbalances responsible for neurodegenerative diseases.
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Affiliation(s)
- Eleonora Ficiarà
- Department of Neurosciences, University of Turin, 10124 Turin, Italy; (Z.M.); (S.B.); (C.G.)
| | - Zunaira Munir
- Department of Neurosciences, University of Turin, 10124 Turin, Italy; (Z.M.); (S.B.); (C.G.)
| | - Silvia Boschi
- Department of Neurosciences, University of Turin, 10124 Turin, Italy; (Z.M.); (S.B.); (C.G.)
| | - Maria Eugenia Caligiuri
- Neuroscience Research Center, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy;
| | - Caterina Guiot
- Department of Neurosciences, University of Turin, 10124 Turin, Italy; (Z.M.); (S.B.); (C.G.)
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Olsen I. Can Porphyromonas gingivalis Contribute to Alzheimer's Disease Already at the Stage of Gingivitis? J Alzheimers Dis Rep 2021; 5:237-241. [PMID: 34113781 PMCID: PMC8150255 DOI: 10.3233/adr-210006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Alzheimer's disease (AD) has been associated with periodontitis, which starts as gingivitis. Similar to periodontitis, gingivitis bacteria, bacterial products, and inflammatory mediators can travel to the brain via the blood stream and promote brain inflammation. Periodontal pathogens such as Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, both associated with AD, have been found in dental plaque of children already at the age of 3. It is suggested that these bacteria during long-term exposure may drive microglia (brain resident macrophage cells) into a pro-inflammatory M1 phase where they contribute to AD rather than protect against it. This notion comes from studies in mice showing that microglia actually can "remember" previous inflammatory challenge and become "trained" or "tolerant" to toxins like lipopolysaccharide. If gingivitis has an impact on AD, which should be verified, AD prophylaxis should start already at this pre-periodontitis stage with removal of supragingival plaque.
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Affiliation(s)
- Ingar Olsen
- Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway
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19
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Olsen I. Porphyromonas Gingivalis May Seek the Alzheimer's Disease Brain to Acquire Iron from Its Surplus. J Alzheimers Dis Rep 2021; 5:79-86. [PMID: 33681719 PMCID: PMC7903007 DOI: 10.3233/adr-200272] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Iron accumulates in the brain of subjects with Alzheimer’s disease (AD). Here it promotes the aggregation of amyloid-β plaques in which it is abundant. Iron induces amyloid-β neurotoxicity by damaging free radicals and causing oxidative stress in brain areas with neurodegeneration. It can also bind to tau in AD and enhance the toxicity of tau through co-localization with neurofibrillary tangles and induce accumulation of these tangles. Porphyromonas gingivalis is a key oral pathogen in the widespread biofilm-induced disease “chronic” periodontitis, and recently, has been suggested to have an important role in the pathogenesis of AD. P. gingivalis has an obligate requirement for iron. The current paper suggests that P. gingivalis seeks the AD brain, where it has been identified, to satisfy this need. If this is correct, iron chelators binding iron could have beneficial effects in the treatment of AD. Indeed, studies from both animal AD models and humans with AD have indicated that iron chelators, e.g., lactoferrin, can have such effects. Lactoferrin can also inhibit P. gingivalis growth and proteinases and its ability to form biofilm.
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Affiliation(s)
- Ingar Olsen
- Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway
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20
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Nara PL, Sindelar D, Penn MS, Potempa J, Griffin WST. Porphyromonas gingivalis Outer Membrane Vesicles as the Major Driver of and Explanation for Neuropathogenesis, the Cholinergic Hypothesis, Iron Dyshomeostasis, and Salivary Lactoferrin in Alzheimer's Disease. J Alzheimers Dis 2021; 82:1417-1450. [PMID: 34275903 PMCID: PMC8461682 DOI: 10.3233/jad-210448] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/27/2021] [Indexed: 12/22/2022]
Abstract
Porphyromonas gingivalis (Pg) is a primary oral pathogen in the widespread biofilm-induced "chronic" multi-systems inflammatory disease(s) including Alzheimer's disease (AD). It is possibly the only second identified unique example of a biological extremophile in the human body. Having a better understanding of the key microbiological and genetic mechanisms of its pathogenesis and disease induction are central to its future diagnosis, treatment, and possible prevention. The published literature around the role of Pg in AD highlights the bacteria's direct role within the brain to cause disease. The available evidence, although somewhat adopted, does not fully support this as the major process. There are alternative pathogenic/virulence features associated with Pg that have been overlooked and may better explain the pathogenic processes found in the "infection hypothesis" of AD. A better explanation is offered here for the discrepancy in the relatively low amounts of "Pg bacteria" residing in the brain compared to the rather florid amounts and broad distribution of one or more of its major bacterial protein toxins. Related to this, the "Gingipains Hypothesis", AD-related iron dyshomeostasis, and the early reduced salivary lactoferrin, along with the resurrection of the Cholinergic Hypothesis may now be integrated into one working model. The current paper suggests the highly evolved and developed Type IX secretory cargo system of Pg producing outer membrane vesicles may better explain the observed diseases. Thus it is hoped this paper can provide a unifying model for the sporadic form of AD and guide the direction of research, treatment, and possible prevention.
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Affiliation(s)
| | | | - Marc S. Penn
- Summa Heart Health and Vascular Institute, Akron, OH, USA
| | - Jan Potempa
- Department of Oral Immunology and Infectious Diseases in the School of Dentistry, University of Louisville, Louisville, KY, USA
| | - W. Sue T. Griffin
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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