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Jones TB, Chu P, Wilkey B, Lynch L, Jentarra G. Regional Differences in Microbial Infiltration of Brain Tissue from Alzheimer's Disease Patients and Control Individuals. Brain Sci 2024; 14:677. [PMID: 39061418 PMCID: PMC11274863 DOI: 10.3390/brainsci14070677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Revised: 06/29/2024] [Accepted: 07/01/2024] [Indexed: 07/28/2024] Open
Abstract
Alzheimer's disease (AD) is characterized by cognitive decline and neuropathology including amyloid beta (Aβ) plaques and neurofibrillary tangles (tau). Factors initiating or driving these pathologies remain unclear, though microbes have been increasingly implicated. Our data and others' findings indicate that microbes may be common constituents of the brain. It is notable that Aβ and tau have antimicrobial properties, suggesting a response to microbes in the brain. We used 16S rRNA sequencing to compare major bacterial phyla in post-mortem tissues from individuals exhibiting a range of neuropathology and cognitive status in two brain regions variably affected in AD. Our data indicate that strong regional differences exist, driven in part by the varied presence of Proteobacteria and Firmicutes. We confirmed our data using ELISA of bacterial lipopolysaccharide (LPS) and lipoteichoic acid in the same brain tissue. We identified a potential association between the composition of phyla and the presence of neuropathology but not cognitive status. Declining cognition and increasing pathology correlated closely with serum LPS, but not brain levels of LPS, although brain LPS showed a strong negative correlation with cerebral amyloid angiopathy. Collectively, our data suggest a region-specific heterogeneity of microbial populations in brain tissue potentially associated with neurodegenerative pathology.
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Affiliation(s)
- T. Bucky Jones
- College of Graduate Studies, Midwestern University, Glendale, AZ 85308, USA; (T.B.J.); (P.C.); (L.L.)
- Arizona College of Osteopathic Medicine, Midwestern University, Glendale, AZ 85308, USA;
| | - Ping Chu
- College of Graduate Studies, Midwestern University, Glendale, AZ 85308, USA; (T.B.J.); (P.C.); (L.L.)
| | - Brooke Wilkey
- Arizona College of Osteopathic Medicine, Midwestern University, Glendale, AZ 85308, USA;
- School of Medicine, Creighton University, Phoenix, AZ 85012, USA
| | - Leigha Lynch
- College of Graduate Studies, Midwestern University, Glendale, AZ 85308, USA; (T.B.J.); (P.C.); (L.L.)
| | - Garilyn Jentarra
- College of Graduate Studies, Midwestern University, Glendale, AZ 85308, USA; (T.B.J.); (P.C.); (L.L.)
- Arizona College of Osteopathic Medicine, Midwestern University, Glendale, AZ 85308, USA;
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2
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Naik B, Sasikumar J, Das SP. From Skin and Gut to the Brain: The Infectious Journey of the Human Commensal Fungus Malassezia and Its Neurological Consequences. Mol Neurobiol 2024:10.1007/s12035-024-04270-w. [PMID: 38871941 DOI: 10.1007/s12035-024-04270-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 05/27/2024] [Indexed: 06/15/2024]
Abstract
The human mycobiome encompasses diverse communities of fungal organisms residing within the body and has emerged as a critical player in shaping health and disease. While extensive research has focused on the skin and gut mycobiome, recent investigations have pointed toward the potential role of fungal organisms in neurological disorders. Among those fungal organisms, the presence of the commensal fungus Malassezia in the brain has created curiosity because of its commensal nature and primary association with the human skin and gut. This budding yeast is responsible for several diseases, such as Seborrheic dermatitis, Atopic dermatitis, Pityriasis versicolor, Malassezia folliculitis, dandruff, and others. However recent findings surprisingly show the presence of Malassezia DNA in the brain and have been linked to diseases like Alzheimer's disease, Parkinson's disease, Multiple sclerosis, and Amyotrophic lateral sclerosis. The exact role of Malassezia in these disorders is unknown, but its ability to infect human cells, travel through the bloodstream, cross the blood-brain barrier, and reside along with the lipid-rich neuronal cells are potential mechanisms responsible for pathogenesis. This also includes the induction of pro-inflammatory cytokines, disruption of the blood-brain barrier, gut-microbe interaction, and accumulation of metabolic changes in the brain environment. In this review, we discuss these key findings from studies linking Malassezia to neurological disorders, emphasizing the complex and multifaceted nature of these cases. Furthermore, we discuss potential mechanisms through which Malassezia might contribute to the development of neurological conditions. Future investigations will open up new avenues for our understanding of the fungal gut-brain axis and how it influences human behavior. Collaborative research efforts among microbiologists, neuroscientists, immunologists, and clinicians hold promise for unraveling the enigmatic connections between human commensal Malassezia and neurological disorders.
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Affiliation(s)
- Bharati Naik
- Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, 575018, India
| | - Jayaprakash Sasikumar
- Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, 575018, India
| | - Shankar Prasad Das
- Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, 575018, India.
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3
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Subedi L, Gaire BP, Koronyo Y, Koronyo-Hamaoui M, Crother TR. Chlamydia pneumoniae in Alzheimer's disease pathology. Front Neurosci 2024; 18:1393293. [PMID: 38770241 PMCID: PMC11102982 DOI: 10.3389/fnins.2024.1393293] [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: 02/28/2024] [Accepted: 04/22/2024] [Indexed: 05/22/2024] Open
Abstract
While recent advances in diagnostics and therapeutics offer promising new approaches for Alzheimer's disease (AD) diagnosis and treatment, there is still an unmet need for an effective remedy, suggesting new avenues of research are required. Besides many plausible etiologies for AD pathogenesis, mounting evidence supports a possible role for microbial infections. Various microbes have been identified in the postmortem brain tissues of human AD patients. Among bacterial pathogens in AD, Chlamydia pneumoniae (Cp) has been well characterized in human AD brains and is a leading candidate for an infectious involvement. However, no definitive studies have been performed proving or disproving Cp's role as a causative or accelerating agent in AD pathology and cognitive decline. In this review, we discuss recent updates for the role of Cp in human AD brains as well as experimental models of AD. Furthermore, based on the current literature, we have compiled a list of potential mechanistic pathways which may connect Cp with AD pathology.
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Affiliation(s)
- Lalita Subedi
- Department of Pediatrics, Division of Infectious Diseases and Immunology, Guerin Children's at Cedars-Sinai Medical Center, Los Angeles, CA, United States
- Infectious and Immunologic Diseases Research Center (IIDRC), Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Bhakta Prasad Gaire
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Yosef Koronyo
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Maya Koronyo-Hamaoui
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Timothy R. Crother
- Department of Pediatrics, Division of Infectious Diseases and Immunology, Guerin Children's at Cedars-Sinai Medical Center, Los Angeles, CA, United States
- Infectious and Immunologic Diseases Research Center (IIDRC), Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
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4
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Williams ZAP, Lang L, Nicolas S, Clarke G, Cryan J, Vauzour D, Nolan YM. Do microbes play a role in Alzheimer's disease? Microb Biotechnol 2024; 17:e14462. [PMID: 38593310 PMCID: PMC11003713 DOI: 10.1111/1751-7915.14462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 03/19/2024] [Indexed: 04/11/2024] Open
Abstract
Alzheimer's disease is a complex and progressive condition that affects essential neurological functions such as memory and reasoning. In the brain, neuronal loss, synaptic dysfunction, proteinopathy, neurofibrillary tangles, and neuroinflammation are the hallmarks of Alzheimer's disease pathophysiology. In addition, recent evidence has highlighted that microbes, whether commensal or pathogenic, also have the ability to interact with their host and to regulate its immune system, therefore participating in the exchanges that lead to peripheral inflammation and neuropathology. Because of this intimate relationship, bacteria, viruses, fungi, and protozoa have been implicated in the development of Alzheimer's disease. Here, we bring together current and most recent evidence of the role of microbes in Alzheimer's disease, raising burning questions that need to be addressed to guide therapeutic approaches and potential prophylactic strategies.
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Affiliation(s)
- Zoë A. P. Williams
- Department of Anatomy and NeuroscienceUniversity College CorkCorkIreland
- APC Microbiome IrelandUniversity College CorkCorkIreland
| | - Leonie Lang
- Norwich Medical School, Faculty of Medicine and Health SciencesUniversity of East AngliaNorwichUK
| | - Sarah Nicolas
- Department of Anatomy and NeuroscienceUniversity College CorkCorkIreland
- APC Microbiome IrelandUniversity College CorkCorkIreland
| | - Gerard Clarke
- APC Microbiome IrelandUniversity College CorkCorkIreland
- Department of Psychiatry and Neurobehavioural ScienceUniversity College CorkCorkIreland
| | - John Cryan
- Department of Anatomy and NeuroscienceUniversity College CorkCorkIreland
- APC Microbiome IrelandUniversity College CorkCorkIreland
| | - David Vauzour
- Norwich Medical School, Faculty of Medicine and Health SciencesUniversity of East AngliaNorwichUK
| | - Yvonne M. Nolan
- Department of Anatomy and NeuroscienceUniversity College CorkCorkIreland
- APC Microbiome IrelandUniversity College CorkCorkIreland
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5
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Li Z, Wang H, Yin Y. Peripheral inflammation is a potential etiological factor in Alzheimer's disease. Rev Neurosci 2024; 35:99-120. [PMID: 37602685 DOI: 10.1515/revneuro-2023-0049] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 07/27/2023] [Indexed: 08/22/2023]
Abstract
Peripheral inflammation could constitute a risk factor for AD. This review summarizes the research related to peripheral inflammation that appears to have a relationship with Alzheimer's disease. We find there are significant associations between AD and peripheral infection induced by various pathogens, including herpes simplex virus type 1, cytomegalovirus, Epstein-Barr virus, human immunodeficiency virus, severe acute respiratory syndrome coronavirus 2, Porphyromonas gingivalis, Helicobacter pylori, and Toxoplasma gondii. Chronic inflammatory diseases are also reported to contribute to the pathophysiology of AD. The mechanisms by which peripheral inflammation affects the pathophysiology of AD are complex. Pathogen-derived neurotoxic molecule composition, disrupted BBB, and dysfunctional neurogenesis may all play a role in peripheral inflammation, promoting the development of AD. Anti-pathogenic medications and anti-inflammatory treatments are reported to decrease the risk of AD. Studies that could improve understanding the associations between AD and peripheral inflammation are needed. If our assumption is correct, early intervention against inflammation may be a potential method of preventing and treating AD.
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Affiliation(s)
- Ziyuan Li
- Department of Nuclear Medicine, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Kongjiang Road 1665, Yangpu District, Shanghai 200092, China
| | - Hui Wang
- Department of Nuclear Medicine, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Kongjiang Road 1665, Yangpu District, Shanghai 200092, China
| | - Yafu Yin
- Department of Nuclear Medicine, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Kongjiang Road 1665, Yangpu District, Shanghai 200092, China
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6
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Taheri M, Bahrami A, Asadi KK, Mohammadi M, Molaei P, Hashemi M, Nouri F. A review on nonviral, nonbacterial infectious agents toxicity involved in neurodegenerative diseases. Neurodegener Dis Manag 2023; 13:351-369. [PMID: 38357803 DOI: 10.2217/nmt-2023-0004] [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] [Indexed: 02/16/2024] Open
Abstract
Neuronal death, decreased activity or dysfunction of neurotransmitters are some of the pathophysiological reasons for neurodegenerative diseases like Alzheimer's, Parkinson's and multiple sclerosis. Also, there is evidence for the role of infections and infectious agents in neurodegenerative diseases and the effect of some metabolites in microorganisms in the pathophysiology of these diseases. In this study, we intend to evaluate the existing studies on the role of infectious agents and their metabolites on the pathophysiology of neurodegenerative diseases. PubMed, Scopus, Google Scholar and Web of Science search engines were searched. Some infectious agents have been observed in neurodegenerative diseases. Also, isolations of some fungi and microalgae have an improving effect on Parkinson's and Alzheimer's.
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Affiliation(s)
- Mohammad Taheri
- Department of Medical Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Ali Bahrami
- Student Research Committee, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Kiana Kimiaei Asadi
- Student Research Committee, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Mojdeh Mohammadi
- Department of Pharmacology & Toxicology, School of Pharmacy, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Pejman Molaei
- Research Center for Molecular Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Mehrdad Hashemi
- Department of Genetics, Faculty of Advanced Science & Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Fatemeh Nouri
- Research Center for Molecular Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
- Department of Pharmaceutical Biotechnology, School of Pharmacy, Hamadan University of Medical Sciences, Hamadan, Iran
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7
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Meng L, Liu C, Liu M, Chen J, Liu C, Zhang Z, Chen G, Zhang Z. The yeast protein Ure2p triggers Tau pathology in a mouse model of tauopathy. Cell Rep 2023; 42:113342. [PMID: 37897723 DOI: 10.1016/j.celrep.2023.113342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 06/28/2023] [Accepted: 10/10/2023] [Indexed: 10/30/2023] Open
Abstract
The molecular mechanisms that trigger Tau aggregation in Alzheimer's disease (AD) remain elusive. Fungi, especially Saccharomyces cerevisiae (S. cerevisiae), can be found in brain samples from patients with AD. Here, we show that the yeast protein Ure2p from S. cerevisiae interacts with Tau and facilitates its aggregation. The Ure2p-seeded Tau fibrils are more potent in seeding Tau and causing neurotoxicity in vitro. When injected into the hippocampus of Tau P301S transgenic mice, the Ure2p-seeded Tau fibrils show enhanced seeding activity compared with pure Tau fibrils. Strikingly, intracranial injection of Ure2p fibrils promotes the aggregation of Tau and cognitive impairment in Tau P301S mice. Furthermore, intranasal infection of S. cerevisiae in the nasal cavity of Tau P301S mice accelerates the aggregation of Tau. Together, these observations indicate that the yeast protein Ure2p initiates Tau pathology. Our results provide a conceptual advance that non-mammalian prions may cross-seed mammalian prion-like proteins.
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Affiliation(s)
- Lanxia Meng
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Congcong Liu
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Miao Liu
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Jiehui Chen
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Chaoyang Liu
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China; Research Center for Environment and Health, Zhongnan University of Economics and Law, Wuhan 430073, China
| | - Zhaohui Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Guiqin Chen
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China; Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Zhentao Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China; TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan 430000, China.
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8
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Zhao H, Huang M, Jiang L. Potential Roles and Future Perspectives of Chitinase 3-like 1 in Macrophage Polarization and the Development of Diseases. Int J Mol Sci 2023; 24:16149. [PMID: 38003338 PMCID: PMC10671302 DOI: 10.3390/ijms242216149] [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: 10/16/2023] [Revised: 11/03/2023] [Accepted: 11/05/2023] [Indexed: 11/26/2023] Open
Abstract
Chitinase-3-like protein 1 (CHI3L1), a chitinase-like protein family member, is a secreted glycoprotein that mediates macrophage polarization, inflammation, apoptosis, angiogenesis, and carcinogenesis. Abnormal CHI3L1 expression has been associated with multiple metabolic and neurological disorders, including diabetes, atherosclerosis, and Alzheimer's disease. Aberrant CHI3L1 expression is also reportedly associated with tumor migration and metastasis, as well as contributions to immune escape, playing important roles in tumor progression. However, the physiological and pathophysiological roles of CHI3L1 in the development of metabolic and neurodegenerative diseases and cancer remain unclear. Understanding the polarization relationship between CHI3L1 and macrophages is crucial for disease progression. Recent research has uncovered the complex mechanisms of CHI3L1 in different diseases, highlighting its close association with macrophage functional polarization. In this article, we review recent findings regarding the various disease types and summarize the relationship between macrophages and CHI3L1. Furthermore, this article also provides a brief overview of the various mechanisms and inhibitors employed to inhibit CHI3L1 and disrupt its interaction with receptors. These endeavors highlight the pivotal roles of CHI3L1 and suggest therapeutic approaches targeting CHI3L1 in the development of metabolic diseases, neurodegenerative diseases, and cancers.
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Affiliation(s)
| | - Mingdong Huang
- College of Chemistry, Fuzhou University, Fuzhou 350116, China;
| | - Longguang Jiang
- College of Chemistry, Fuzhou University, Fuzhou 350116, China;
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Seeing Neurodegeneration in a New Light Using Genetically Encoded Fluorescent Biosensors and iPSCs. Int J Mol Sci 2023; 24:ijms24021766. [PMID: 36675282 PMCID: PMC9861453 DOI: 10.3390/ijms24021766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/11/2023] [Accepted: 01/12/2023] [Indexed: 01/18/2023] Open
Abstract
Neurodegenerative diseases present a progressive loss of neuronal structure and function, leading to cell death and irrecoverable brain atrophy. Most have disease-modifying therapies, in part because the mechanisms of neurodegeneration are yet to be defined, preventing the development of targeted therapies. To overcome this, there is a need for tools that enable a quantitative assessment of how cellular mechanisms and diverse environmental conditions contribute to disease. One such tool is genetically encodable fluorescent biosensors (GEFBs), engineered constructs encoding proteins with novel functions capable of sensing spatiotemporal changes in specific pathways, enzyme functions, or metabolite levels. GEFB technology therefore presents a plethora of unique sensing capabilities that, when coupled with induced pluripotent stem cells (iPSCs), present a powerful tool for exploring disease mechanisms and identifying novel therapeutics. In this review, we discuss different GEFBs relevant to neurodegenerative disease and how they can be used with iPSCs to illuminate unresolved questions about causes and risks for neurodegenerative disease.
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10
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Vojtechova I, Machacek T, Kristofikova Z, Stuchlik A, Petrasek T. Infectious origin of Alzheimer’s disease: Amyloid beta as a component of brain antimicrobial immunity. PLoS Pathog 2022; 18:e1010929. [PMCID: PMC9671327 DOI: 10.1371/journal.ppat.1010929] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The amyloid cascade hypothesis, focusing on pathological proteins aggregation, has so far failed to uncover the root cause of Alzheimer’s disease (AD), or to provide an effective therapy. This traditional paradigm essentially explains a mechanism involved in the development of sporadic AD rather than its cause. The failure of an overwhelming majority of clinical studies (99.6%) demonstrates that a breakthrough in therapy would be difficult if not impossible without understanding the etiology of AD. It becomes more and more apparent that the AD pathology might originate from brain infection. In this review, we discuss a potential role of bacteria, viruses, fungi, and eukaryotic parasites as triggers of AD pathology. We show evidence from the current literature that amyloid beta, traditionally viewed as pathological, actually acts as an antimicrobial peptide, protecting the brain against pathogens. However, in case of a prolonged or excessive activation of a senescent immune system, amyloid beta accumulation and aggregation becomes damaging and supports runaway neurodegenerative processes in AD. This is paralleled by the recent study by Alam and colleagues (2022) who showed that alpha-synuclein, the protein accumulating in synucleinopathies, also plays a critical physiological role in immune reactions and inflammation, showing an unforeseen link between the 2 unrelated classes of neurodegenerative disorders. The multiplication of the amyloid precursor protein gene, recently described by Lee and collegues (2018), and possible reactivation of human endogenous retroviruses by pathogens fits well into the same picture. We discuss these new findings from the viewpoint of the infection hypothesis of AD and offer suggestions for future research. More than a century after its discovery, Alzheimer’s disease (AD) remains incurable and mysterious. The dominant hypothesis of amyloid cascade has succeeded in explaining the key pathological mechanism, but not its trigger. Amyloid beta has been traditionally considered a pathological peptide, and its physiological functions remain poorly known. These knowledge gaps have contributed to repeated failures of clinical studies. The emerging infectious hypothesis of AD considers central nervous system (CNS) infection the primary trigger of sporadic AD. A closely connected hypothesis claims that amyloid beta is an antimicrobial peptide. In this review, we discuss the available evidence for the involvement of infections in AD, coming from epidemiological studies, post mortem analyses of brain tissue, and experiments in vitro and in vivo. We argue there is no unique “Alzheimer’s germ,” instead, AD is a general reaction of the CNS to chronic infections, in the milieu of an aged immune system. The pathology may become self-sustained even without continuous presence of microbes in the brain. Importantly, the infectious hypothesis leads to testable predictions. Targeting amyloid beta should be ineffective, unless the triggering pathogen and inflammatory response are addressed as well. Meticulous control of selected infections might be the best near-term strategy for AD prevention.
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Affiliation(s)
- Iveta Vojtechova
- National Institute of Mental Health, Klecany, Czech Republic
- Laboratory of Neurophysiology of Memory, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
- * E-mail: , (IV); , (TP)
| | - Tomas Machacek
- Department of Parasitology, Faculty of Science, Charles University, Prague, Czech Republic
| | | | - Ales Stuchlik
- National Institute of Mental Health, Klecany, Czech Republic
- Laboratory of Neurophysiology of Memory, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Tomas Petrasek
- National Institute of Mental Health, Klecany, Czech Republic
- Laboratory of Neurophysiology of Memory, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
- * E-mail: , (IV); , (TP)
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11
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Implications of Microorganisms in Alzheimer's Disease. Curr Issues Mol Biol 2022; 44:4584-4615. [PMID: 36286029 PMCID: PMC9600878 DOI: 10.3390/cimb44100314] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 09/23/2022] [Accepted: 09/28/2022] [Indexed: 11/20/2022] Open
Abstract
Alzheimer’s disease (AD) is a deadly brain degenerative disorder that leads to brain shrinkage and dementia. AD is manifested with hyperphosphorylated tau protein levels and amyloid beta (Aβ) peptide buildup in the hippocampus and cortex regions of the brain. The nervous tissue of AD patients also contains fungal proteins and DNA which are linked to bacterial infections, suggesting that polymicrobial infections also occur in the brains of those with AD. Both immunohistochemistry and next-generation sequencing (NGS) techniques were employed to assess fungal and bacterial infections in the brain tissue of AD patients and non-AD controls, with the most prevalent fungus genera detected in AD patients being Alternaria, Botrytis, Candida, and Malassezia. Interestingly, Fusarium was the most common genus detected in the control group. Both AD patients and controls were also detectable for Proteobacteria, followed by Firmicutes, Actinobacteria, and Bacteroides for bacterial infection. At the family level, Burkholderiaceae and Staphylococcaceae exhibited higher levels in the brains of those with AD than the brains of the control group. Accordingly, there is thought to be a viscous cycle of uncontrolled neuroinflammation and neurodegeneration in the brain, caused by agents such as the herpes simplex virus type 1 (HSV1), Chlamydophilapneumonia, and Spirochetes, and the presence of apolipoprotein E4 (APOE4), which is associated with an increased proinflammatory response in the immune system. Systemic proinflammatory cytokines are produced by microorganisms such as Cytomegalovirus, Helicobacter pylori, and those related to periodontal infections. These can then cross the blood–brain barrier (BBB) and lead to the onset of dementia. Here, we reviewed the relationship between the etiology of AD and microorganisms (such as bacterial pathogens, Herpesviridae viruses, and periodontal pathogens) according to the evidence available to understand the pathogenesis of AD. These findings might guide a targeted anti-inflammatory therapeutic approach to AD.
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Parker A, James SA, Purse C, Brion A, Goldson A, Telatin A, Baker D, Carding SR. Absence of Bacteria Permits Fungal Gut-To-Brain Translocation and Invasion in Germfree Mice but Ageing Alone Does Not Drive Pathobiont Expansion in Conventionally Raised Mice. Front Aging Neurosci 2022; 14:828429. [PMID: 35923548 PMCID: PMC9339909 DOI: 10.3389/fnagi.2022.828429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 06/20/2022] [Indexed: 11/13/2022] Open
Abstract
Age-associated changes in the structure of the intestinal microbiome and in its interaction with the brain via the gut-brain axis are increasingly being implicated in neurological and neurodegenerative diseases. Intestinal microbial dysbiosis and translocation of microbes and microbial products including fungal species into the brain have been implicated in the development of dementias such as Alzheimer's disease. Using germ-free mice, we investigated if the fungal gut commensal, Candida albicans, an opportunistic pathogen in humans, can traverse the gastrointestinal barrier and disseminate to brain tissue and whether ageing impacts on the gut mycobiome as a pre-disposing factor in fungal brain infection. C. albicans was detected in different regions of the brain of colonised germ-free mice in both yeast and hyphal cell forms, often in close association with activated (Iba-1+) microglial cells. Using high-throughput ITS1 amplicon sequencing to characterise the faecal gut fungal composition of aged and young SPF mice, we identified several putative gut commensal fungal species with pathobiont potential although their abundance was not significantly different between young and aged mice. Collectively, these results suggest that although some fungal species can travel from the gut to brain where they can induce an inflammatory response, ageing alone is not correlated with significant changes in gut mycobiota composition which could predispose to these events. These results are consistent with a scenario in which significant disruptions to the gut microbiota or intestinal barrier, beyond those which occur with natural ageing, are required to allow fungal escape and brain infection.
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Affiliation(s)
- Aimée Parker
- Gut Microbes and Health Research Programme, Quadram Institute, Norwich, United Kingdom
| | - Steve A. James
- Gut Microbes and Health Research Programme, Quadram Institute, Norwich, United Kingdom
| | - Catherine Purse
- Gut Microbes and Health Research Programme, Quadram Institute, Norwich, United Kingdom
| | - Arlaine Brion
- Gut Microbes and Health Research Programme, Quadram Institute, Norwich, United Kingdom
| | - Andrew Goldson
- Gut Microbes and Health Research Programme, Quadram Institute, Norwich, United Kingdom
| | - Andrea Telatin
- Gut Microbes and Health Research Programme, Quadram Institute, Norwich, United Kingdom
| | - David Baker
- Gut Microbes and Health Research Programme, Quadram Institute, Norwich, United Kingdom
| | - Simon R. Carding
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom
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13
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Golan N, Engelberg Y, Landau M. Structural Mimicry in Microbial and Antimicrobial Amyloids. Annu Rev Biochem 2022; 91:403-422. [PMID: 35729071 DOI: 10.1146/annurev-biochem-032620-105157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The remarkable variety of microbial species of human pathogens and microbiomes generates significant quantities of secreted amyloids, which are structured protein fibrils that serve diverse functions related to virulence and interactions with the host. Human amyloids are associated largely with fatal neurodegenerative and systemic aggregation diseases, and current research has put forward the hypothesis that the interspecies amyloid interactome has physiological and pathological significance. Moreover, functional and molecular-level connections between antimicrobial activity and amyloid structures suggest a neuroimmune role for amyloids that are otherwise known to be pathological. Compared to the extensive structural information that has been accumulated for human amyloids, high-resolution structures of microbial and antimicrobial amyloids are only emerging. These recent structures reveal both similarities and surprising departures from the typical amyloid motif, in accordance with their diverse activities, and advance the discovery of novel antivirulence and antimicrobial agents. In addition, the structural information has led researchers to postulate that amyloidogenic sequences are natural targets for structural mimicry, for instance in host-microbe interactions. Microbial amyloid research could ultimately be used to fight aggressive infections and possibly processes leading to autoimmune and neurodegenerative diseases.
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Affiliation(s)
- Nimrod Golan
- Department of Biology, Technion-Israel Institute of Technology, Haifa, Israel;
| | - Yizhaq Engelberg
- Department of Biology, Technion-Israel Institute of Technology, Haifa, Israel;
| | - Meytal Landau
- Department of Biology, Technion-Israel Institute of Technology, Haifa, Israel; .,European Molecular Biology Laboratory (EMBL) and Center for Structural Systems Biology (CSSB), Hamburg, Germany
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14
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Abstract
The potential contribution of pathogenic microbes to dementia-inducing disease is a subject of considerable importance. Alzheimer’s disease (AD) is a neurocognitive disease that slowly destroys brain function, leading to cognitive decline and behavioral and psychiatric disorders. The histopathology of AD is associated with neuronal loss and progressive synaptic dysfunction, accompanied by the deposition of amyloid-β (Aβ) peptide in the form of parenchymal plaques and abnormal aggregated tau protein in the form of neurofibrillary tangles. Observational, epidemiological, experimental, and pathological studies have generated evidence for the complexity and possible polymicrobial causality in dementia-inducing diseases. The AD pathogen hypothesis states that pathogens and microbes act as triggers, interacting with genetic factors to initiate the accumulation of Aβ, hyperphosphorylated tau protein (p-tau), and inflammation in the brain. Evidence indicates that Borrelia sp., HSV-1, VZV (HHV-2), HHV-6/7, oral pathogens, Chlamydophila pneumoniae, and Candida albicans can infect the central nervous system (CNS), evade the immune system, and consequently prevail in the AD brain. Researchers have made significant progress in understanding the multifactorial and overlapping factors that are thought to take part in the etiopathogenesis of dementia; however, the cause of AD remains unclear.
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15
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Wiatrak B, Balon K, Jawień P, Bednarz D, Jęśkowiak I, Szeląg A. The Role of the Microbiota-Gut-Brain Axis in the Development of Alzheimer's Disease. Int J Mol Sci 2022; 23:ijms23094862. [PMID: 35563253 PMCID: PMC9104401 DOI: 10.3390/ijms23094862] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/16/2022] [Accepted: 04/21/2022] [Indexed: 02/06/2023] Open
Abstract
Along with the increase in life expectancy in the populations of developed and developing countries resulting from better access and improved health care, the number of patients with dementia, including Alzheimer’s disease (AD), is growing. The disease was first diagnosed and described at the beginning of the 20th century. However, to this day, there is no effective causal therapy, and symptomatic treatment often improves patients’ quality of life only for a short time. The current pharmacological therapies are based mainly on the oldest hypotheses of the disease—cholinergic (drugs affecting the cholinergic system are available), the hypothesis of amyloid-β aggregation (an anti-amyloid drug was conditionally approved by the FDA in 2020), and one drug is an N-methyl-D-aspartate receptor (NMDAR) antagonist (memantine). Hypotheses about AD pathogenesis focus on the nervous system and the brain. As research progresses, it has become known that AD can be caused by diseases that have been experienced over the course of a lifetime, which could also affect other organs. In this review, we focus on the potential association of AD with the digestive system, primarily the gut microbiota. The role of diet quality in preventing and alleviating Alzheimer’s disease is also discussed. The problem of neuroinflammation, which may be the result of microbiota disorders, is also described. An important aspect of the work is the chapter on the treatment strategies for changing the microbiota, potentially protecting against the disease and alleviating its course in the initial stages.
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Affiliation(s)
- Benita Wiatrak
- Department of Pharmacology, Wroclaw Medical University, Mikulicza-Radeckiego 2, 50-345 Wroclaw, Poland; (D.B.); (I.J.); (A.S.)
- Correspondence: (B.W.); (P.J.)
| | - Katarzyna Balon
- Laboratory of Genomics & Bioinformatics, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wroclaw, Poland;
| | - Paulina Jawień
- Department of Biostructure and Animal Physiology, Wroclaw University of Environmental and Life Sciences, Norwida 25/27, 50-375 Wroclaw, Poland
- Correspondence: (B.W.); (P.J.)
| | - Dominika Bednarz
- Department of Pharmacology, Wroclaw Medical University, Mikulicza-Radeckiego 2, 50-345 Wroclaw, Poland; (D.B.); (I.J.); (A.S.)
| | - Izabela Jęśkowiak
- Department of Pharmacology, Wroclaw Medical University, Mikulicza-Radeckiego 2, 50-345 Wroclaw, Poland; (D.B.); (I.J.); (A.S.)
| | - Adam Szeląg
- Department of Pharmacology, Wroclaw Medical University, Mikulicza-Radeckiego 2, 50-345 Wroclaw, Poland; (D.B.); (I.J.); (A.S.)
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16
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Kong G, Lê Cao KA, Hannan AJ. Alterations in the Gut Fungal Community in a Mouse Model of Huntington's Disease. Microbiol Spectr 2022; 10:e0219221. [PMID: 35262396 PMCID: PMC9045163 DOI: 10.1128/spectrum.02192-21] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 02/14/2022] [Indexed: 12/26/2022] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disorder caused by a trinucleotide expansion in the HTT gene, which is expressed throughout the brain and body, including the gut epithelium and enteric nervous system. Afflicted individuals suffer from progressive impairments in motor, psychiatric, and cognitive faculties, as well as peripheral deficits, including the alteration of the gut microbiome. However, studies characterizing the gut microbiome in HD have focused entirely on the bacterial component, while the fungal community (mycobiome) has been overlooked. The gut mycobiome has gained recognition for its role in host homeostasis and maintenance of the gut epithelial barrier. We aimed to characterize the gut mycobiome profile in HD using fecal samples collected from the R6/1 transgenic mouse model (and wild-type littermate controls) from 4 to 12 weeks of age, corresponding to presymptomatic through to early disease stages. Shotgun sequencing was performed on fecal DNA samples, followed by metagenomic analyses. The HD gut mycobiome beta diversity was significantly different from that of wild-type littermates at 12 weeks of age, while no genotype differences were observed at the earlier time points. Similarly, greater alpha diversity was observed in the HD mice by 12 weeks of age. Key taxa, including Malassezia restricta, Yarrowia lipolytica, and Aspergillus species, were identified as having a negative association with HD. Furthermore, integration of the bacterial and fungal data sets at 12 weeks of age identified negative correlations between the HD-associated fungal species and Lactobacillus reuteri. These findings provide new insights into gut microbiome alterations in HD and may help identify novel therapeutic targets. IMPORTANCE Huntington's disease (HD) is a fatal neurodegenerative disorder affecting both the mind and body. We have recently discovered that gut bacteria are disrupted in HD. The present study provides the first evidence of an altered gut fungal community (mycobiome) in HD. The genomes of many thousands of gut microbes were sequenced and used to assess "metagenomics" in particular the different types of fungal species in the HD versus control gut, in a mouse model. At an early disease stage, before the onset of symptoms, the overall gut mycobiome structure (array of fungi) in HD mice was distinct from that of their wild-type littermates. Alterations of multiple key fungi species were identified as being associated with the onset of disease symptoms, some of which showed strong correlations with the gut bacterial community. This study highlights the potential role of gut fungi in HD and may facilitate the development of novel therapeutic approaches.
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Affiliation(s)
- Geraldine Kong
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne Brain Centre, Parkville, Australia
| | - Kim-Anh Lê Cao
- Melbourne Integrative Genomics, School of Mathematics and Statistics, University of Melbourne, Parkville, Australia
| | - Anthony J. Hannan
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne Brain Centre, Parkville, Australia
- Department of Anatomy and Physiology, University of Melbourne, Parkville, Australia
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17
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Nafady MH, Sayed ZS, Abdelkawy DA, Shebl ME, Elsayed RA, Ashraf GM, Perveen A, Attia MS, Bahbah EI. The Effect of Gut Microbe Dysbiosis on the Pathogenesis of Alzheimer's Disease (AD) and related conditions. Curr Alzheimer Res 2022; 19:274-284. [PMID: 35440296 DOI: 10.2174/1567205019666220419101205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/17/2022] [Accepted: 03/09/2022] [Indexed: 11/22/2022]
Abstract
It has been hypothesized that the shift in gut microbiota composition, known as gut microbe dysbiosis, may be correlated with the onset of Alzheimer's disease (AD), which is the most common cause of dementia characterized by a gradual deterioration in cognitive function associated with the development of amyloid-beta (Aβ) plaques. The gut microbiota dysbiosis induces the release of significant amounts of amyloids, lipopolysaccharides, and neurotoxins, which might play a role in modulating signaling pathways and immune activation, leading to the production of proinflammatory cytokines related to the pathogenesis of AD. The dysbiosis of gut microbe is associated with various diseases such as type 2 diabetes, obesity, hypertension, and some neuropsychiatric disorders like depression, anxiety, and stress. It is conceivable that these diseases trigger the onset of AD. Thus, modifying the gut microbiota composition with probiotic and prebiotic supplementation can reduce depression and anxiety symptoms, lower stress reactivity, and improve memory. This narrative review aimed to examine the possible role of gut microbe dysbiosis in AD's pathogenesis.
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Affiliation(s)
- Mohamed H Nafady
- Radiological Imaging Technology Department, Faculty of Applied Medical Science, Misr university for science and technology (MUST), Cairo, Egypt.,Radiation Science Department, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Zeinab S Sayed
- Faculty of Applied Medical Science (AMS), Misr university for science and technology (MUST), Cairo, Egypt
| | - Dalia A Abdelkawy
- Faculty of Applied Medical Science (AMS), Misr university for science and technology (MUST), Cairo, Egypt
| | - Mostafa E Shebl
- Faculty of Applied Medical Science (AMS), Misr university for science and technology (MUST), Cairo, Egypt
| | - Reem A Elsayed
- Faculty of Applied Medical Science (AMS), Misr university for science and technology (MUST), Cairo, Egypt
| | - Ghulam Md Ashraf
- Pre-Clinical Research Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia.,Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Asma Perveen
- Glocal School of Life Sciences, Glocal University, Mirzapur Pole, Saharanpur, Uttar Pradesh, India
| | - Mohamed S Attia
- Department of Pharmaceutics, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt
| | - Eshak I Bahbah
- Faculty of Medicine, Al-Azhar University, Damietta, Egypt.,Medical Research Group of Egypt (MRGE), Cairo, Egypt.,SevoClin Research Group, Cairo, Egypt
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18
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Pritchard AB, Fabian Z, Lawrence CL, Morton G, Crean S, Alder JE. An Investigation into the Effects of Outer Membrane Vesicles and Lipopolysaccharide of Porphyromonas gingivalis on Blood-Brain Barrier Integrity, Permeability, and Disruption of Scaffolding Proteins in a Human in vitro Model. J Alzheimers Dis 2022; 86:343-364. [PMID: 35034897 DOI: 10.3233/jad-215054] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND The effects of the key pathogens and virulence factors associated with gum disease such as Porphyromonas gingivalis (P. gingivalis) on the central nervous system is of great interest with respect to development of neuropathologies and hence therapeutics and preventative strategies. Chronic infections and associated inflammation are known to weaken the first line of defense for the brain, the blood-brain barrier (BBB). OBJECTIVE The focus of this study is to utilize an established human in vitro BBB model to evaluate the effects of P. gingivalis virulence factors lipopolysaccharide (LPS) and outer membrane vesicles (OMVs) on a primary-derived human model representing the neurovascular unit of the BBB. METHODS Changes to the integrity of the BBB after application of P. gingivalis LPS and OMVs were investigated and correlated with transport of LPS. Additionally, the effect of P. gingivalis LPS and OMVs on human brain microvascular endothelial cells in monolayer was evaluated using immunofluorescence microscopy. RESULTS The integrity of the BBB model was weakened by application of P. gingivalis LPS and OMVs, as measured by a decrease in electrical resistance and a recovery deficit was seen in comparison to the controls. Application of P. gingivalis OMVs to a monoculture of human brain microvascular endothelial cells showed disruption of the tight junction zona occludens protein (ZO-1) compared to controls. CONCLUSION These findings show that the integrity of tight junctions of the human BBB could be weakened by association with P. gingivalis virulence factors LPS and OMVs containing proteolytic enzymes (gingipains).
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Affiliation(s)
- Anna Barlach Pritchard
- Brain and Behaviour Centre, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, UK
| | - Zsolt Fabian
- School of Medicine, University of Central Lancashire, Preston, UK
| | - Clare L Lawrence
- Brain and Behaviour Centre, Faculty of Clinical and Biomedical Sciences, School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston, UK
| | - Glyn Morton
- School of Forensic and Investigative Science, University of Central Lancashire, Preston, UK
| | - StJohn Crean
- Brain and Behaviour Centre, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, UK
| | - Jane E Alder
- Brain and Behaviour Centre, Faculty of Clinical and Biomedical Sciences, School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston, UK
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19
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Phuna ZX, Madhavan P. A CLOSER LOOK AT THE MYCOBIOME IN ALZHEIMER'S DISEASE: FUNGAL SPECIES, PATHOGENESIS AND TRANSMISSION. Eur J Neurosci 2022; 55:1291-1321. [DOI: 10.1111/ejn.15599] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 11/30/2022]
Affiliation(s)
- Zhi Xin Phuna
- School of Medicine, Faculty of Health & Medical Sciences, Taylor’s University Malaysia Subang Jaya Selangor
| | - Priya Madhavan
- School of Medicine, Faculty of Health & Medical Sciences, Taylor’s University Malaysia Subang Jaya Selangor
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20
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Blázquez E, Hurtado-Carneiro V, LeBaut-Ayuso Y, Velázquez E, García-García L, Gómez-Oliver F, Ruiz-Albusac J, Ávila J, Pozo MÁ. Significance of Brain Glucose Hypometabolism, Altered Insulin Signal Transduction, and Insulin Resistance in Several Neurological Diseases. Front Endocrinol (Lausanne) 2022; 13:873301. [PMID: 35615716 PMCID: PMC9125423 DOI: 10.3389/fendo.2022.873301] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 03/23/2022] [Indexed: 12/14/2022] Open
Abstract
Several neurological diseases share pathological alterations, even though they differ in their etiology. Neuroinflammation, altered brain glucose metabolism, oxidative stress, mitochondrial dysfunction and amyloidosis are biological events found in those neurological disorders. Altered insulin-mediated signaling and brain glucose hypometabolism are characteristic signs observed in the brains of patients with certain neurological diseases, but also others such as type 2 diabetes mellitus and vascular diseases. Thus, significant reductions in insulin receptor autophosphorylation and Akt kinase activity, and increased GSK-3 activity and insulin resistance, have been reported in these neurological diseases as contributing to the decline in cognitive function. Supporting this relationship is the fact that nasal and hippocampal insulin administration has been found to improve cognitive function. Additionally, brain glucose hypometabolism precedes the unmistakable clinical manifestations of some of these diseases by years, which may become a useful early biomarker. Deficiencies in the major pathways of oxidative energy metabolism have been reported in patients with several of these neurological diseases, which supports the hypothesis of their metabolic background. This review remarks on the significance of insulin and brain glucose metabolism alterations as keystone common pathogenic substrates for certain neurological diseases, highlighting new potential targets.
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Affiliation(s)
- Enrique Blázquez
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Complutense University, Madrid, Spain
- *Correspondence: Enrique Blázquez,
| | | | - Yannick LeBaut-Ayuso
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Complutense University, Madrid, Spain
| | - Esther Velázquez
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Complutense University, Madrid, Spain
| | - Luis García-García
- Pluridisciplinary Institute, Complutense University, IdISSC, Madrid, Spain
- Department of Pharmacology, Pharmacognosy and Botany, Faculty of Pharmacy, Complutense University, Madrid, Spain
| | - Francisca Gómez-Oliver
- Pluridisciplinary Institute, Complutense University, IdISSC, Madrid, Spain
- Department of Pharmacology, Pharmacognosy and Botany, Faculty of Pharmacy, Complutense University, Madrid, Spain
| | - Juan Miguel Ruiz-Albusac
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Complutense University, Madrid, Spain
| | - Jesús Ávila
- Center of Molecular Biology “Severo Ochoa”, CSIC-UAM, Madrid, Spain
| | - Miguel Ángel Pozo
- Department of Physiology, Faculty of Medicine, Complutense University, Madrid, Spain
- Pluridisciplinary Institute, Complutense University, IdISSC, Madrid, Spain
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21
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Begum N, Harzandi A, Lee S, Uhlen M, Moyes DL, Shoaie S. Host-mycobiome metabolic interactions in health and disease. Gut Microbes 2022; 14:2121576. [PMID: 36151873 PMCID: PMC9519009 DOI: 10.1080/19490976.2022.2121576] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 08/31/2022] [Accepted: 08/31/2022] [Indexed: 02/04/2023] Open
Abstract
Fungal communities (mycobiome) have an important role in sustaining the resilience of complex microbial communities and maintenance of homeostasis. The mycobiome remains relatively unexplored compared to the bacteriome despite increasing evidence highlighting their contribution to host-microbiome interactions in health and disease. Despite being a small proportion of the total species, fungi constitute a large proportion of the biomass within the human microbiome and thus serve as a potential target for metabolic reprogramming in pathogenesis and disease mechanism. Metabolites produced by fungi shape host niches, induce immune tolerance and changes in their levels prelude changes associated with metabolic diseases and cancer. Given the complexity of microbial interactions, studying the metabolic interplay of the mycobiome with both host and microbiome is a demanding but crucial task. However, genome-scale modelling and synthetic biology can provide an integrative platform that allows elucidation of the multifaceted interactions between mycobiome, microbiome and host. The inferences gained from understanding mycobiome interplay with other organisms can delineate the key role of the mycobiome in pathophysiology and reveal its role in human disease.
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Affiliation(s)
- Neelu Begum
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King’s College London, London, UK
| | - Azadeh Harzandi
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King’s College London, London, UK
| | - Sunjae Lee
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King’s College London, London, UK
| | - Mathias Uhlen
- Science for Life Laboratory, KTH–Royal Institute of Technology, Stockholm, Sweden
| | - David L. Moyes
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King’s College London, London, UK
| | - Saeed Shoaie
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King’s College London, London, UK
- Science for Life Laboratory, KTH–Royal Institute of Technology, Stockholm, Sweden
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22
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Yan C, Wang C, Shao X, Shu Q, Hu X, Guan P, Teng Y, Cheng Y. Dual-targeted carbon-dot-drugs nanoassemblies for modulating Alzheimer's related amyloid- β aggregation and inhibiting fungal infection. Mater Today Bio 2021; 12:100167. [PMID: 34901820 PMCID: PMC8639470 DOI: 10.1016/j.mtbio.2021.100167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 11/15/2021] [Accepted: 11/23/2021] [Indexed: 12/11/2022] Open
Abstract
Amyloid aggregation and fungal infection, especially amyloid beta (Aβ) peptide and Candida albicans are considered as two of the crucial pathogenic agents in Alzheimer's disease (AD). In this work, we propose an innovative treatment strategy for AD, targeting at not only Aβ aggregation but also Candida albicans infection. Here, a high-performance nanomaterial, namely gCDs-E, have been prepared by self-assembled of glycosylated carbon dots (gCDs) and epigallocatechin-3-gallate (EGCG). Surprisingly, gCDs-E can not only suppress the fibrillation of Aβ and disaggregate Aβ fibrils, but also effectively inhibit the activity of Candida albicans. More importantly, the prepared gCDs-E can effectively cut down the cytotoxicity of amyloid aggregations, and the cell viability reached to 99.2%. In addition, the capability of the gCDs-E for blood brain barrier (BBB) penetration was also observed using a normal mice model. Above all, the gCDs-E greatly cleaned Aβ deposition and improved memory impairment in APP/PS1 transgenic AD model mice, confirming its potential as therapeutic agent for AD treatment.
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Affiliation(s)
- Chaoren Yan
- Department of Chemistry, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an, 710072, PR China
| | - Chaoli Wang
- Department of Pharmaceutical Analysis, School of Pharmacy, Air Force Medical University, Xi'an, 710032, PR China
| | - Xu Shao
- Department of Chemistry, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an, 710072, PR China
| | - Qi Shu
- Department of Chemistry, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an, 710072, PR China
| | - Xiaoling Hu
- Department of Chemistry, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an, 710072, PR China
| | - Ping Guan
- Department of Chemistry, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an, 710072, PR China
| | - Yonggang Teng
- Department of Thoracic Surgery, The Second Affiliated Hospital of Air Force Medical University, Xi'an, China
| | - Yuan Cheng
- Monash Suzhou Research Institute, Suzhou, 215123, PR China
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton Victoria, 3800, Melbourne, Australia
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23
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Shinjyo N, Kagaya W, Pekna M. Interaction Between the Complement System and Infectious Agents - A Potential Mechanistic Link to Neurodegeneration and Dementia. Front Cell Neurosci 2021; 15:710390. [PMID: 34408631 PMCID: PMC8365172 DOI: 10.3389/fncel.2021.710390] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 07/09/2021] [Indexed: 12/24/2022] Open
Abstract
As part of the innate immune system, complement plays a critical role in the elimination of pathogens and mobilization of cellular immune responses. In the central nervous system (CNS), many complement proteins are locally produced and regulate nervous system development and physiological processes such as neural plasticity. However, aberrant complement activation has been implicated in neurodegeneration, including Alzheimer's disease. There is a growing list of pathogens that have been shown to interact with the complement system in the brain but the short- and long-term consequences of infection-induced complement activation for neuronal functioning are largely elusive. Available evidence suggests that the infection-induced complement activation could be protective or harmful, depending on the context. Here we summarize how various infectious agents, including bacteria (e.g., Streptococcus spp.), viruses (e.g., HIV and measles virus), fungi (e.g., Candida spp.), parasites (e.g., Toxoplasma gondii and Plasmodium spp.), and prion proteins activate and manipulate the complement system in the CNS. We also discuss the potential mechanisms by which the interaction between the infectious agents and the complement system can play a role in neurodegeneration and dementia.
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Affiliation(s)
- Noriko Shinjyo
- Laboratory of Immune Homeostasis, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
| | - Wataru Kagaya
- Department of Parasitology and Research Center for Infectious Disease Sciences, Graduate School of Medicine, Osaka City University, Osaka, Japan
| | - Marcela Pekna
- Laboratory of Regenerative Neuroimmunology, Center for Brain Repair, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
- Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
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24
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Shi M, Li C, Tian X, Chu F, Zhu J. Can Control Infections Slow Down the Progression of Alzheimer's Disease? Talking About the Role of Infections in Alzheimer's Disease. Front Aging Neurosci 2021; 13:685863. [PMID: 34366826 PMCID: PMC8339924 DOI: 10.3389/fnagi.2021.685863] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 06/24/2021] [Indexed: 01/07/2023] Open
Abstract
Alzheimer’s disease as the most common age-related dementia affects more than 40 million people in the world, representing a global public health priority. However, the pathogenesis of Alzheimer’s disease (AD) is complex, and it remains unclear. Over the past decades, all efforts made in the treatments of AD, with targeting the pathogenic amyloid β (Aβ), neurofibrillary tangles, and misfolded tau protein, were failed. Recently, many studies have hinted that infection, and chronic inflammation that caused by infection are crucial risk factors for AD development and progress. In the review, we analyzed the role of infections caused by bacteria, viruses, and other pathogens in the pathogenesis of AD and its animal models, and explored the therapeutic possibility with anti-infections for AD. However, based on the published data, it is still difficult to determine their causal relationship between infection and AD due to contradictory results. We think that the role of infection in the pathogenesis of AD should not be ignored, even though infection does not necessarily cause AD, it may act as an accelerator in AD at least. It is essential to conduct the longitudinal studies and randomized controlled trials in humans, which can determine the role of infection in AD and clarify the links between infection and the pathological features of AD. Finding targeting infection drugs and identifying the time window for applying antibacterial or antiviral intervention may be more promising for future clinical therapeutic strategies in AD.
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Affiliation(s)
- Mingchao Shi
- Department of Neurology, Neuroscience Center, The First Hospital of Jilin University, Changchun, China.,Division of Neurogeriatrcs, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Karolinska University Hospital, Solna, Sweden
| | - Chunrong Li
- Department of Neurology, Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Xiaoping Tian
- Cognitive Impairment Ward of Neurology Department, The Third Affiliated Hospital of Shenzhen University Medical College, Shenzhen, China
| | - Fengna Chu
- Department of Neurology, Neuroscience Center, The First Hospital of Jilin University, Changchun, China.,Division of Neurogeriatrcs, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Karolinska University Hospital, Solna, Sweden
| | - Jie Zhu
- Department of Neurology, Neuroscience Center, The First Hospital of Jilin University, Changchun, China.,Division of Neurogeriatrcs, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Karolinska University Hospital, Solna, Sweden
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25
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Zhang Y, Liu Y, Tang Y, Zhang D, He H, Wu J, Zheng J. Antimicrobial α-defensins as multi-target inhibitors against amyloid formation and microbial infection. Chem Sci 2021; 12:9124-9139. [PMID: 34276942 PMCID: PMC8261786 DOI: 10.1039/d1sc01133b] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 05/27/2021] [Indexed: 12/22/2022] Open
Abstract
Amyloid aggregation and microbial infection are considered as pathological risk factors for developing amyloid diseases, including Alzheimer's disease (AD), type II diabetes (T2D), Parkinson's disease (PD), and medullary thyroid carcinoma (MTC). Due to the multifactorial nature of amyloid diseases, single-target drugs and treatments have mostly failed to inhibit amyloid aggregation and microbial infection simultaneously, thus leading to marginal benefits for amyloid inhibition and medical treatments. Herein, we proposed and demonstrated a new "anti-amyloid and antimicrobial hypothesis" to discover two host-defense antimicrobial peptides of α-defensins containing β-rich structures (human neutrophil peptide of HNP-1 and rabbit neutrophil peptide of NP-3A), which have demonstrated multi-target, sequence-independent functions to (i) prevent the aggregation and misfolding of different amyloid proteins of amyloid-β (Aβ, associated with AD), human islet amyloid polypeptide (hIAPP, associated with T2D), and human calcitonin (hCT, associated with MTC) at sub-stoichiometric concentrations, (ii) reduce amyloid-induced cell toxicity, and (iii) retain their original antimicrobial activity upon the formation of complexes with amyloid peptides. Further structural analysis showed that the sequence-independent amyloid inhibition function of α-defensins mainly stems from their cross-interactions with amyloid proteins via β-structure interactions. The discovery of antimicrobial peptides containing β-structures to inhibit both microbial infection and amyloid aggregation greatly expands the new therapeutic potential of antimicrobial peptides as multi-target amyloid inhibitors for better understanding pathological causes and treatments of amyloid diseases.
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Affiliation(s)
- Yanxian Zhang
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron Ohio USA
| | - Yonglan Liu
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron Ohio USA
| | - Yijing Tang
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron Ohio USA
| | - Dong Zhang
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron Ohio USA
| | - Huacheng He
- College of Chemistry and Materials Engineering, Wenzhou University Zhejiang China
| | - Jiang Wu
- School of Pharmaceutical Sciences, Wenzhou Medical University Zhejiang China
| | - Jie Zheng
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron Ohio USA
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26
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Qian XH, Song XX, Liu XL, Chen SD, Tang HD. Inflammatory pathways in Alzheimer's disease mediated by gut microbiota. Ageing Res Rev 2021; 68:101317. [PMID: 33711509 DOI: 10.1016/j.arr.2021.101317] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 02/25/2021] [Accepted: 03/08/2021] [Indexed: 12/14/2022]
Abstract
In the past decade, numerous studies have demonstrated the close relationship between gut microbiota and the occurrence and development of Alzheimer's disease (AD). However, the specific mechanism is still unclear. Both the neuroinflammation and systemic inflammation serve as the key hubs to accelerate the process of AD by promoting pathology and damaging neuron. What's more, the gut microbiota is also crucial for the regulation of inflammation. Therefore, this review focused on the role of gut microbiota in AD through inflammatory pathways. Firstly, this review summarized the relationship and interaction among gut microbiota, inflammation, and AD. Secondly, the direct and indirect regulatory effects of gut microbiota on AD through inflammatory pathways were described. These effects were mainly mediated by the component of the gut microbiota (lipopolysaccharides (LPS) and amyloid peptides), the metabolites of bacteria (short-chain fatty acids, branched amino acids, and neurotransmitters) and functional by-products (bile acids). In addition, potential treatments (fecal microbiota transplantation, antibiotics, probiotics, prebiotics, and dietary interventions) for AD were also discussed through these mechanisms. Finally, according to the current research status, the key problems to be solved in the future studies were proposed.
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Affiliation(s)
- Xiao-Hang Qian
- Department of Neurology and Institute of Neurology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
| | - Xiao-Xuan Song
- Department of Neurology and Institute of Neurology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
| | - Xiao-Li Liu
- Department of Neurology, Shanghai Fengxian District Central Hospital, Shanghai Jiao Tong University Affiliated Sixth People's Hospital South Campus, Shanghai, 201406, China.
| | - Sheng-di Chen
- Department of Neurology and Institute of Neurology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
| | - Hui-Dong Tang
- Department of Neurology and Institute of Neurology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
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27
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Nayeri T, Sarvi S, Sharif M, Daryani A. Toxoplasma gondii: A possible etiologic agent for Alzheimer's disease. Heliyon 2021; 7:e07151. [PMID: 34141920 PMCID: PMC8187970 DOI: 10.1016/j.heliyon.2021.e07151] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/03/2021] [Accepted: 05/24/2021] [Indexed: 01/03/2023] Open
Abstract
Toxoplasma gondii (T. gondii) is one of the most pervasive neurotropic pathogens causing different lesions in a wide variety of mammals as intermediate hosts, including humans. It is estimated that one-third of the world population is infected with T. gondii; however, for a long time, there has been much interest in the examination of the possible role of this parasite in the development of mental disorders, such as Alzheimer's disease (AD). T. gondii may play a role in the progression of AD using mechanisms, such as the induction of the host's immune responses, inflammation of the central nervous system (CNS), alteration in the levels of neurotransmitters, and activation of indoleamine-2,3-dyoxigenase. This paper presents an appraisal of the literature, reports, and studies that seek to the possible role of T. gondii in the development of AD. For achieving the purpose of the current study, a search of six English databases (PubMed, ScienceDirect, Web of Science, Scopus, ProQuest, and Google Scholar) was performed. The results support the involvement of T. gondii in the induction and development of AD. Indeed, T. gondii can be considered a risk factor for the development of AD and requires the special attention of specialists and patients. Furthermore, the results of this study may contribute to prevent or delay the progress of AD worldwide. Therefore, it is required to carry out further studies in order to better perceive the parasitic mechanisms in the progression of AD.
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Affiliation(s)
- Tooran Nayeri
- Toxoplasmosis Research Center, Mazandaran University of Medical Sciences, Sari, Iran
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
- Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
| | - Shahabeddin Sarvi
- Toxoplasmosis Research Center, Mazandaran University of Medical Sciences, Sari, Iran
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mehdi Sharif
- Toxoplasmosis Research Center, Mazandaran University of Medical Sciences, Sari, Iran
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Ahmad Daryani
- Toxoplasmosis Research Center, Mazandaran University of Medical Sciences, Sari, Iran
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
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28
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Contini C, Olianas A, Serrao S, Deriu C, Iavarone F, Boroumand M, Bizzarro A, Lauria A, Faa G, Castagnola M, Messana I, Manconi B, Masullo C, Cabras T. Top-Down Proteomics of Human Saliva Highlights Anti-inflammatory, Antioxidant, and Antimicrobial Defense Responses in Alzheimer Disease. Front Neurosci 2021; 15:668852. [PMID: 34121996 PMCID: PMC8189262 DOI: 10.3389/fnins.2021.668852] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 04/06/2021] [Indexed: 12/13/2022] Open
Abstract
Alzheimer disease (AD) is the most prevalent neurodegenerative disease in the elderly, characterized by accumulation in the brain of misfolded proteins, inflammation, and oxidative damage leading to neuronal cell death. By considering the viewpoint that AD onset and worsening may be influenced by environmental factors causing infection, oxidative stress, and inflammatory reaction, we investigated the changes of the salivary proteome in a population of patients with respect to that in healthy controls (HCs). Indeed, the possible use of saliva as a diagnostic tool has been explored in several oral and systemic diseases. Moreover, the oral cavity continuously established adaptative and protective processes toward exogenous stimuli. In the present study, qualitative/quantitative variations of 56 salivary proteoforms, including post-translationally modified derivatives, have been analyzed by RP-HPLC-ESI-IT-MS and MS/MS analyses, and immunological methods were applied to validate MS results. The salivary protein profile of AD patients was characterized by significantly higher levels of some multifaceted proteins and peptides that were either specific to the oral cavity or also expressed in other body districts: (i) peptides involved in the homeostasis of the oral cavity; (ii) proteins acting as ROS/RNS scavengers and with a neuroprotective role, such as S100A8, S100A9, and their glutathionylated and nitrosylated proteoforms; cystatin B and glutathionylated and dimeric derivatives; (iii) proteins with antimicrobial activity, such as α-defensins, cystatins A and B, histatin 1, statherin, and thymosin β4, this last with a neuroprotective role at the level of microglia. These results suggested that, in response to injured conditions, Alzheimer patients established defensive mechanisms detectable at the oral level. Data are available via ProteomeXchange with identifier PXD021538.
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Affiliation(s)
- Cristina Contini
- Dipartimento di Scienze della Vita e dell'Ambiente, Università di Cagliari, Cagliari, Italy
| | - Alessandra Olianas
- Dipartimento di Scienze della Vita e dell'Ambiente, Università di Cagliari, Cagliari, Italy
| | - Simone Serrao
- Dipartimento di Scienze della Vita e dell'Ambiente, Università di Cagliari, Cagliari, Italy
| | - Carla Deriu
- Dipartimento di Scienze della Vita e dell'Ambiente, Università di Cagliari, Cagliari, Italy
| | - Federica Iavarone
- Dipartimento di Scienze Biotecnologiche di Base, Cliniche Intensivologiche e Perioperatorie, Università Cattolica del Sacro Cuore, Rome, Italy.,Fondazione Policlinico Universitario "A. Gemelli" - IRCCS, Rome, Italy
| | - Mozhgan Boroumand
- Laboratorio di Proteomica, Centro Europeo di Ricerca sul Cervello, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Alessandra Bizzarro
- UOC Continuità Assistenziale, Fondazione Policlinico Universitario "A. Gemelli" - IRCCS, Rome, Italy
| | - Alessandra Lauria
- UOC Continuità Assistenziale, Fondazione Policlinico Universitario "A. Gemelli" - IRCCS, Rome, Italy
| | - Gavino Faa
- Dipartimento di Scienze Mediche e Sanità Pubblica, University of Cagliari, Cagliari, Italy
| | - Massimo Castagnola
- Laboratorio di Proteomica, Centro Europeo di Ricerca sul Cervello, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Irene Messana
- Istituto di Scienze e Tecnologie Chimiche "Giulio Natta", Consiglio Nazionale delle Ricerche, Rome, Italy
| | - Barbara Manconi
- Dipartimento di Scienze della Vita e dell'Ambiente, Università di Cagliari, Cagliari, Italy
| | - Carlo Masullo
- Dipartimento di Neuroscienze, Sez. Neurologia, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Tiziana Cabras
- Dipartimento di Scienze della Vita e dell'Ambiente, Università di Cagliari, Cagliari, Italy
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29
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Li F, Hearn M, Bennett LE. The role of microbial infection in the pathogenesis of Alzheimer's disease and the opportunity for protection by anti-microbial peptides. Crit Rev Microbiol 2021; 47:240-253. [PMID: 33555958 DOI: 10.1080/1040841x.2021.1876630] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Alzheimer's disease (AD) is the most common cause of dementia. Its pathology is primarily characterized by extracellular deposits of amyloid β peptide and intracellular neurofibrillary tangles. Current rationales to explain the pathogenesis of AD include amyloid cascade, inflammation, infection defense and anti-microbial protection hypotheses. This review focuses on recent advances in the infection hypothesis, in particular on those pathogenic microbes that act systemically, via periodontal and gastro-intestinal infection routes. It is proposed that the evidence convincingly supports that pathogenic microbial infection is associated with, and is likely a causative trigger for, AD pathology. Microbes can drive AD pathology by two main pathways: either by directly infecting the brain and stimulating amyloid-mediated defence (causative trigger) or indirectly, by stimulating the pro-inflammatory effects of infection. In this context, it follows that anti-microbial/anti-infection therapies could be effective for regulating the pathology and symptoms of AD, depending on the stage of disease. As long-term administration of traditional antibiotic therapy is not recommended, alternative antibiotic agents such as anti-microbial peptides (AMPs), could be preferred for intervention and disease management of AD.
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Affiliation(s)
- Feijie Li
- School of Chemistry, Monash University, Clayton, Victoria, Australia
| | - Milton Hearn
- School of Chemistry, Monash University, Clayton, Victoria, Australia
| | - Louise E Bennett
- School of Chemistry, Monash University, Clayton, Victoria, Australia
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30
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Ling Z, Zhu M, Yan X, Cheng Y, Shao L, Liu X, Jiang R, Wu S. Structural and Functional Dysbiosis of Fecal Microbiota in Chinese Patients With Alzheimer's Disease. Front Cell Dev Biol 2021; 8:634069. [PMID: 33614635 PMCID: PMC7889981 DOI: 10.3389/fcell.2020.634069] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 12/28/2020] [Indexed: 12/13/2022] Open
Abstract
Increasing evidence suggests that gut dysbiosis plays vital roles in a variety of gut–brain disorders, such as Alzheimer's disease (AD). However, alterations of the gut microbiota as well as their correlations with cognitive scores and host immunity have remained unclear in well-controlled trials on Chinese AD patients. In this study, samples from 100 AD patients, and 71 age- and gender-matched, cognitively normal controls were obtained to explore the structural and functional alterations of the fecal microbiota targeting the V3–V4 region of the 16S rRNA gene by MiSeq sequencing, and to analyze their associations with clinical characteristics. Our data demonstrated a remarkably reduction in the bacterial diversity and alterations in the taxonomic composition of the fecal microbiota of the AD patients. Interestingly, the abundant butyrate-producing genera such as Faecalibacterium decreased significantly, where this was positively correlated with such clinical indicators as the MMSE, WAIS, and Barthel scores in the AD patients. On the contrary, abundant lactate-producing genera, such as Bifidobacterium, increased prominently, and were inversely correlated with these indicators. This shift in the gut dysbiosis of the microbiota, from being butyrate producers to lactate producers, contributed to immune disturbances in the host that could be used as non-invasive biomarkers to distinguish the controls from the AD patients. Moreover, several predicted functional modules, including the biosynthesis and the metabolism of fatty acids, that were altered in the microbiota of the AD patients could be utilized by the bacteria to produce immunomodulatory metabolites. Our study established the structural and functional dysbiosis of fecal microbiota in AD patients, and the results suggest the potential for use of gut bacteria for the early, non-invasive diagnosis of AD, personalized treatment, and the development of tailor-made probiotics designed for Chinese AD patients.
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Affiliation(s)
- Zongxin Ling
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, School of Medicine, The First Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Manlian Zhu
- Department of Geriatrics, Lishui Second People's Hospital, Lishui, China
| | - Xiumei Yan
- Department of Geriatrics, Lishui Second People's Hospital, Lishui, China
| | - Yiwen Cheng
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, School of Medicine, The First Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Li Shao
- Institute of Hepatology and Metabolic Diseases, Hangzhou Normal University, Hangzhou, China.,Department of Liver Diseases, Institute of Translational Medicine, The Affiliated Hospital of Hangzhou Normal University, Hangzhou, China
| | - Xia Liu
- Department of Intensive Care Unit, School of Medicine, The First Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Ruilai Jiang
- Department of Geriatrics, Lishui Second People's Hospital, Lishui, China
| | - Shaochang Wu
- Department of Geriatrics, Lishui Second People's Hospital, Lishui, China
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31
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Vigasova D, Nemergut M, Liskova B, Damborsky J. Multi-pathogen infections and Alzheimer's disease. Microb Cell Fact 2021; 20:25. [PMID: 33509204 PMCID: PMC7844946 DOI: 10.1186/s12934-021-01520-7] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Accepted: 01/16/2021] [Indexed: 02/06/2023] Open
Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative disease associated with the overproduction and accumulation of amyloid-β peptide and hyperphosphorylation of tau proteins in the brain. Despite extensive research on the amyloid-based mechanism of AD pathogenesis, the underlying cause of AD is not fully understood. No disease-modifying therapies currently exist, and numerous clinical trials have failed to demonstrate any benefits. The recent discovery that the amyloid-β peptide has antimicrobial activities supports the possibility of an infectious aetiology of AD and suggests that amyloid-β plaque formation might be induced by infection. AD patients have a weakened blood-brain barrier and immune system and are thus at elevated risk of microbial infections. Such infections can cause chronic neuroinflammation, production of the antimicrobial amyloid-β peptide, and neurodegeneration. Various pathogens, including viruses, bacteria, fungi, and parasites have been associated with AD. Most research in this area has focused on individual pathogens, with herpesviruses and periodontal bacteria being most frequently implicated. The purpose of this review is to highlight the potential role of multi-pathogen infections in AD. Recognition of the potential coexistence of multiple pathogens and biofilms in AD's aetiology may stimulate the development of novel approaches to its diagnosis and treatment. Multiple diagnostic tests could be applied simultaneously to detect major pathogens, followed by anti-microbial treatment using antiviral, antibacterial, antifungal, and anti-biofilm agents.
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Affiliation(s)
- Dana Vigasova
- International Clinical Research Center, St. Anne’s University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
- Department of Experimental Biology and RECETOX, Faculty of Science, Loschmidt Laboratories, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Michal Nemergut
- Department of Experimental Biology and RECETOX, Faculty of Science, Loschmidt Laboratories, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Barbora Liskova
- Department of Experimental Biology and RECETOX, Faculty of Science, Loschmidt Laboratories, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Jiri Damborsky
- International Clinical Research Center, St. Anne’s University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
- Department of Experimental Biology and RECETOX, Faculty of Science, Loschmidt Laboratories, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
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32
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Lee EY, Chan LC, Wang H, Lieng J, Hung M, Srinivasan Y, Wang J, Waschek JA, Ferguson AL, Lee KF, Yount NY, Yeaman MR, Wong GCL. PACAP is a pathogen-inducible resident antimicrobial neuropeptide affording rapid and contextual molecular host defense of the brain. Proc Natl Acad Sci U S A 2021; 118:e1917623117. [PMID: 33372152 PMCID: PMC7817161 DOI: 10.1073/pnas.1917623117] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Defense of the central nervous system (CNS) against infection must be accomplished without generation of potentially injurious immune cell-mediated or off-target inflammation which could impair key functions. As the CNS is an immune-privileged compartment, inducible innate defense mechanisms endogenous to the CNS likely play an essential role in this regard. Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide known to regulate neurodevelopment, emotion, and certain stress responses. While PACAP is known to interact with the immune system, its significance in direct defense of brain or other tissues is not established. Here, we show that our machine-learning classifier can screen for immune activity in neuropeptides, and correctly identified PACAP as an antimicrobial neuropeptide in agreement with previous experimental work. Furthermore, synchrotron X-ray scattering, antimicrobial assays, and mechanistic fingerprinting provided precise insights into how PACAP exerts antimicrobial activities vs. pathogens via multiple and synergistic mechanisms, including dysregulation of membrane integrity and energetics and activation of cell death pathways. Importantly, resident PACAP is selectively induced up to 50-fold in the brain in mouse models of Staphylococcus aureus or Candida albicans infection in vivo, without inducing immune cell infiltration. We show differential PACAP induction even in various tissues outside the CNS, and how these observed patterns of induction are consistent with the antimicrobial efficacy of PACAP measured in conditions simulating specific physiologic contexts of those tissues. Phylogenetic analysis of PACAP revealed close conservation of predicted antimicrobial properties spanning primitive invertebrates to modern mammals. Together, these findings substantiate our hypothesis that PACAP is an ancient neuro-endocrine-immune effector that defends the CNS against infection while minimizing potentially injurious neuroinflammation.
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Affiliation(s)
- Ernest Y Lee
- Department of Bioengineering, University of California, Los Angeles, CA 90095
- UCLA-Caltech Medical Scientist Training Program, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095
| | - Liana C Chan
- Lundquist Institute for Biomedical Innovation, Harbor-UCLA Medical Center, Torrance, CA 90509
- Division of Molecular Medicine, Los Angeles County, Harbor-UCLA Medical Center, Torrance, CA 90509
- Division of Infectious Diseases, Los Angeles County, Harbor-UCLA Medical Center, Torrance, CA 90509
| | - Huiyuan Wang
- Lundquist Institute for Biomedical Innovation, Harbor-UCLA Medical Center, Torrance, CA 90509
- Division of Molecular Medicine, Los Angeles County, Harbor-UCLA Medical Center, Torrance, CA 90509
| | - Juelline Lieng
- Department of Bioengineering, University of California, Los Angeles, CA 90095
| | - Mandy Hung
- Department of Bioengineering, University of California, Los Angeles, CA 90095
| | - Yashes Srinivasan
- Department of Bioengineering, University of California, Los Angeles, CA 90095
| | - Jennifer Wang
- Department of Bioengineering, University of California, Los Angeles, CA 90095
| | - James A Waschek
- Semel Institute for Neuroscience and Human Behavior, Intellectual Development and Disabilities Research Center, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Andrew L Ferguson
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637
| | - Kuo-Fen Lee
- Peptide Biology Laboratories, Salk Institute for Biological Studies, La Jolla, CA 92037
| | - Nannette Y Yount
- Lundquist Institute for Biomedical Innovation, Harbor-UCLA Medical Center, Torrance, CA 90509
- Division of Molecular Medicine, Los Angeles County, Harbor-UCLA Medical Center, Torrance, CA 90509
| | - Michael R Yeaman
- Division of Molecular Medicine, Los Angeles County, Harbor-UCLA Medical Center, Torrance, CA 90509;
- Division of Infectious Diseases, Los Angeles County, Harbor-UCLA Medical Center, Torrance, CA 90509
- Semel Institute for Neuroscience and Human Behavior, Intellectual Development and Disabilities Research Center, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Gerard C L Wong
- Department of Bioengineering, University of California, Los Angeles, CA 90095;
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095
- California NanoSystems Institute, University of California, Los Angeles, CA 90095
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33
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Wouk J, Rechenchoski DZ, Rodrigues BCD, Ribelato EV, Faccin-Galhardi LC. Viral infections and their relationship to neurological disorders. Arch Virol 2021; 166:733-753. [PMID: 33502593 PMCID: PMC7838016 DOI: 10.1007/s00705-021-04959-6] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/27/2020] [Indexed: 01/26/2023]
Abstract
The chronic dysfunction of neuronal cells, both central and peripheral, a characteristic of neurological disorders, may be caused by irreversible damage and cell death. In 2016, more than 276 million cases of neurological disorders were reported worldwide. Moreover, neurological disorders are the second leading cause of death. Generally, the etiology of neurological diseases is not fully understood. Recent studies have related the onset of neurological disorders to viral infections, which may cause neurological symptoms or lead to immune responses that trigger these pathological signs. Currently, this relationship is mostly based on epidemiological data on infections and seroprevalence of patients who present with neurological disorders. The number of studies aiming to elucidate the mechanism of action by which viral infections may directly or indirectly contribute to the development of neurological disorders has been increasing over the years but these studies are still scarce. Comprehending the pathogenesis of these diseases and exploring novel theories may favor the development of new strategies for diagnosis and therapy in the future. Therefore, the objective of the present study was to review the main pieces of evidence for the relationship between viral infection and neurological disorders such as Alzheimer's disease, Parkinson's disease, Guillain-Barré syndrome, multiple sclerosis, and epilepsy. Viruses belonging to the families Herpesviridae, Orthomyxoviridae, Flaviviridae, and Retroviridae have been reported to be involved in one or more of these conditions. Also, neurological symptoms and the future impact of infection with SARS-CoV-2, a member of the family Coronaviridae that is responsible for the COVID-19 pandemic that started in late 2019, are reported and discussed.
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Affiliation(s)
- Jéssica Wouk
- Post-Graduation Program of Pharmaceutical Science, Midwest State University, CEDETEG Campus, Guarapuava, Paraná Brazil
| | | | | | - Elisa Vicente Ribelato
- Department of Microbiology, Biological Science Center, Londrina State University, Londrina, Paraná Brazil
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34
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Ren J, Wei D, An H, Zhang J, Zhang Z. Shenqi Yizhi granules protect hippocampus of AD transgenic mice by modulating on multiple pathological processes. JOURNAL OF ETHNOPHARMACOLOGY 2020; 263:112869. [PMID: 32315734 DOI: 10.1016/j.jep.2020.112869] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 04/09/2020] [Accepted: 04/09/2020] [Indexed: 06/11/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Chinese herbal medicine (CHM) draws more attention to explore effective therapeutic strategy for Alzheimer's disease (AD). CHM usually uses combinations of herbs or herbal ingredients to treat diseases, with the components targeting different disease processes. CHM might improve cognition in AD and MCI patients by optimizing network activity, promoting neural plasticity and repairing damaged neurons. Shenqi Yizhi granules (SQYG), a CHM prescription, are mainly consists of Panax ginseng C.A.Mey, Astragalus membranaceus (Fisch.) Bunge, and Scutellaria baicalensis Georgi and have been used to ameliorate cognitive impairment in mild-to-moderate dementia patients. AIM OF THE STUDY To investigate the neuroprotection effect and pharmacological mechanism of SQYG in the hippocampus of 5XFAD transgenic mice. MATERIALS AND METHODS The immunofluorescence detection, 2DE-gels, mass spectrum identification, biological information analysis and Western blot were performed after SQYG treatment. RESULTS SQYG treatment significantly decreased the fluorescence intensities of anti-GFAP and anti-Iba1 in the hippocampus of 5XFAD mice. The expression levels of 31 proteins in the hippocampus were significantly influenced by SQYG, approximately 65% of these proteins are related to energy metabolism, stress response and cytoskeleton, whereas others are related to synaptic transmission, signal transduction, antioxidation, amino acid metabolism, and DNA repair. The expression of these proteins were increased. The changes in the expression levels of malate dehydrogenase (cytoplasmic) and pyruvate kinase M were confirmed by Western blot. CONCLUSIONS The pharmacological mechanism of SQYG on the hippocampus may be related to modulation of multiple pathological processes, including energy metabolism, stress response, cytoskeleton, synaptic transmission, signal transduction, and amino acid metabolism in 5XFAD mice.
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Affiliation(s)
- Jianting Ren
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875, China; BABRI Centre, Beijing Normal University, Beijing, 100875, China
| | - Dongfeng Wei
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
| | - Haiting An
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875, China; BABRI Centre, Beijing Normal University, Beijing, 100875, China
| | - Junying Zhang
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Zhanjun Zhang
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875, China; BABRI Centre, Beijing Normal University, Beijing, 100875, China.
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González-Sanmiguel J, Schuh CMAP, Muñoz-Montesino C, Contreras-Kallens P, Aguayo LG, Aguayo S. Complex Interaction between Resident Microbiota and Misfolded Proteins: Role in Neuroinflammation and Neurodegeneration. Cells 2020; 9:E2476. [PMID: 33203002 PMCID: PMC7697492 DOI: 10.3390/cells9112476] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 11/02/2020] [Accepted: 11/10/2020] [Indexed: 12/13/2022] Open
Abstract
Neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD) and Creutzfeldt-Jakob disease (CJD) are brain conditions affecting millions of people worldwide. These diseases are associated with the presence of amyloid-β (Aβ), alpha synuclein (α-Syn) and prion protein (PrP) depositions in the brain, respectively, which lead to synaptic disconnection and subsequent progressive neuronal death. Although considerable progress has been made in elucidating the pathogenesis of these diseases, the specific mechanisms of their origins remain largely unknown. A body of research suggests a potential association between host microbiota, neuroinflammation and dementia, either directly due to bacterial brain invasion because of barrier leakage and production of toxins and inflammation, or indirectly by modulating the immune response. In the present review, we focus on the emerging topics of neuroinflammation and the association between components of the human microbiota and the deposition of Aβ, α-Syn and PrP in the brain. Special focus is given to gut and oral bacteria and biofilms and to the potential mechanisms associating microbiome dysbiosis and toxin production with neurodegeneration. The roles of neuroinflammation, protein misfolding and cellular mediators in membrane damage and increased permeability are also discussed.
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Affiliation(s)
| | - Christina M. A. P. Schuh
- Centro de Medicina Regenerativa, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago 7710162, Chile; (C.M.A.P.S.); (P.C.-K.)
| | - Carola Muñoz-Montesino
- Department of Physiology, Universidad de Concepción, Concepción 4070386, Chile; (J.G.-S.); (C.M.-M.)
| | - Pamina Contreras-Kallens
- Centro de Medicina Regenerativa, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago 7710162, Chile; (C.M.A.P.S.); (P.C.-K.)
| | - Luis G. Aguayo
- Department of Physiology, Universidad de Concepción, Concepción 4070386, Chile; (J.G.-S.); (C.M.-M.)
- Program on Neuroscience, Psychiatry and Mental Health, Universidad de Concepción, Concepción 4070386, Chile
| | - Sebastian Aguayo
- School of Dentistry, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago 7820436, Chile
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Vasefi M, Ghaboolian-Zare E, Abedelwahab H, Osu A. Environmental toxins and Alzheimer's disease progression. Neurochem Int 2020; 141:104852. [PMID: 33010393 DOI: 10.1016/j.neuint.2020.104852] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 09/05/2020] [Accepted: 09/18/2020] [Indexed: 12/29/2022]
Abstract
Alzheimer's disease (AD) is the most common form of dementia, which causes progressive memory loss and cognitive decline. Effective strategies to treat or prevent remains one of the most challenging undertakings in the medical field. AD is a complex and multifactorial disease that involves several risk factors. Aging and genetic factors both play important roles in the onset of the AD, however; certain environmental factors have been reported to increase the risk of AD. Chronic exposure to toxins has been seen as an environmental factor that may increase the risk of developing a neurodegenerative disease such as AD. Exposure to metals and biotoxins produced by bacteria, molds, and viruses may contribute to the cognitive decline and pathophysiology associated with AD. Toxins may contribute to the pathology of the disease through various mechanisms such as deposition of amyloid-beta (Aβ) plaques and tangles in the brain, induction of apoptosis, inflammation, or oxidative damage. Here, we will review how toxins affect brain physiology with a focus on mechanisms by which toxins may contribute to the development and progression of AD. A better understanding of these mechanisms may help contribute towards the development of an effective strategy to slow the progression of AD.
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Affiliation(s)
- Maryam Vasefi
- Department Biology, Lamar University, Beaumont, TX, United States.
| | | | | | - Anthony Osu
- Department Biology, Lamar University, Beaumont, TX, United States
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Stojković D, Kostić M, Smiljković M, Aleksić M, Vasiljević P, Nikolić M, Soković M. Linking Antimicrobial Potential of Natural Products Derived from Aquatic Organisms and Microbes Involved in Alzheimer's Disease - A Review. Curr Med Chem 2020. [PMID: 29521212 DOI: 10.2174/0929867325666180309103645] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The following review is oriented towards microbes linked to Alzheimer's disease (AD) and antimicrobial effect of compounds and extracts derived from aquatic organisms against specific bacteria, fungi and viruses which were found previously in patients suffering from AD. Major group of microbes linked to AD include bacteria: Chlamydia pneumoniae, Helicobacter pylori, Porphyromonas gingivalis, Fusobacterium nucleatum, Prevotella intermedia, Actinomyces naeslundii, spirochete group; fungi: Candida sp., Cryptococcus sp., Saccharomyces sp., Malassezia sp., Botrytis sp., and viruses: herpes simplex virus type 1 (HSV-1), Human cytomegalovirus (CMV), hepatitis C virus (HCV). In the light of that fact, this review is the first to link antimicrobial potential of aquatic organisms against these sorts of microbes. This literature review might serve as a starting platform to develop novel supportive therapy for patients suffering from AD and to possibly prevent escalation of the disease in patients already having high-risk factors for AD occurrence.
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Affiliation(s)
- Dejan Stojković
- Department of Plant Physiology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, Bulevar Despota Stefana 142, 11000 Belgrade, Serbia
| | - Marina Kostić
- Department of Plant Physiology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, Bulevar Despota Stefana 142, 11000 Belgrade, Serbia
| | - Marija Smiljković
- Department of Plant Physiology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, Bulevar Despota Stefana 142, 11000 Belgrade, Serbia
| | - Milena Aleksić
- Department of Biology and Ecology, Faculty of Science and Mathematics, University of Nis, Visegradska 33, 18000 Nis, Serbia
| | - Perica Vasiljević
- Department of Biology and Ecology, Faculty of Science and Mathematics, University of Nis, Visegradska 33, 18000 Nis, Serbia
| | - Miloš Nikolić
- Department of Plant Physiology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, Bulevar Despota Stefana 142, 11000 Belgrade, Serbia
| | - Marina Soković
- Department of Plant Physiology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, Bulevar Despota Stefana 142, 11000 Belgrade, Serbia
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Ennerfelt HE, Lukens JR. The role of innate immunity in Alzheimer's disease. Immunol Rev 2020; 297:225-246. [PMID: 32588460 PMCID: PMC7783860 DOI: 10.1111/imr.12896] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 05/23/2020] [Accepted: 05/28/2020] [Indexed: 12/12/2022]
Abstract
The amyloid hypothesis has dominated Alzheimer's disease (AD) research for almost 30 years. This hypothesis hinges on the predominant clinical role of the amyloid beta (Aβ) peptide in propagating neurofibrillary tangles (NFTs) and eventual cognitive impairment in AD. Recent research in the AD field has identified the brain-resident macrophages, known as microglia, and their receptors as integral regulators of both the initiation and propagation of inflammation, Aβ accumulation, neuronal loss, and memory decline in AD. Emerging studies have also begun to reveal critical roles for distinct innate immune pathways in AD pathogenesis, which has led to great interest in harnessing the innate immune response as a therapeutic strategy to treat AD. In this review, we will highlight recent advancements in our understanding of innate immunity and inflammation in AD onset and progression. Additionally, there has been mounting evidence suggesting pivotal contributions of environmental factors and lifestyle choices in AD pathogenesis. Therefore, we will also discuss recent findings, suggesting that many of these AD risk factors influence AD progression via modulation of microglia and immune responses.
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Affiliation(s)
- Hannah E. Ennerfelt
- Center for Brain Immunology and Glia (BIG), Department of Neuroscience, University of Virginia, Charlottesville, VA 22908, USA
- Neuroscience Graduate Program, University of Virginia, Charlottesville, VA 22908, USA
- Cell and Molecular Biology Training Program, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - John R. Lukens
- Center for Brain Immunology and Glia (BIG), Department of Neuroscience, University of Virginia, Charlottesville, VA 22908, USA
- Neuroscience Graduate Program, University of Virginia, Charlottesville, VA 22908, USA
- Cell and Molecular Biology Training Program, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
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The neurotoxicity of trichothecenes T-2 toxin and deoxynivalenol (DON): Current status and future perspectives. Food Chem Toxicol 2020; 145:111676. [PMID: 32805342 DOI: 10.1016/j.fct.2020.111676] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 08/01/2020] [Accepted: 08/04/2020] [Indexed: 12/14/2022]
Abstract
During the last decade, the neurotoxicity of the trichothecenes T-2 toxin and deoxynivalenol (DON) has been a major concern, and many important findings have been reported on this topic. Through a summary of relevant research reports in recent years, we discuss the potential neurotoxic mechanisms of T-2 toxin and DON. In neuronal cells, T-2 toxin induces mitochondrial dysfunction and oxidative stress through a series of signalling pathways, including Nrf2/HO-1 and p53. This toxin crosses the blood-brain barrier (BBB) by altering permeability and induces oxidative stress responses, including ROS generation, lipid peroxidation, and protein carbonyl formation. Cellular metabolites (for example, HT-2 toxin) further promote neurotoxic effects. The type B trichothecene DON induces neuronal cell apoptosis via the MAPK and mitochondrial apoptosis pathways. This molecule induces inflammation of the central nervous system, increasing the expression of proinflammatory molecules. DON directly affects brain neurons and glial cells after passing through the BBB and affects the vitality and function of astrocytes and microglia. Exposure to trichothecenes alters brain dopamine levels, decreases ganglion area, and further induces brain damage. In this review, we mainly discuss the neurotoxicity of T-2 toxin and DON. However, our main goal was to reveal the potential mechanism(s) and offer new topics, including the potential of hypoxia-inducible factors, immune evasion, and exosomes, for future research in this context. This review should help elucidate the neurotoxic mechanism of trichothecenes and provides some potential inspiration for the follow-up study of neurotoxicity of mycotoxins.
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Vigezzi C, Riera FO, Rodriguez E, Icely PA, Miró MS, Figueredo CM, Caeiro JP, Sotomayor CE. [Invasive candidiasis: A view to central nervous system infection]. Rev Argent Microbiol 2020; 53:171-178. [PMID: 32768262 DOI: 10.1016/j.ram.2020.06.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 04/24/2020] [Accepted: 06/01/2020] [Indexed: 10/23/2022] Open
Abstract
Candidemia is the most frequent invasive mycosis in hospitalized patients worldwide. Fungal infection in central nervous system is a life-threatening complication which aggravates patients' prognosis. This article summarizes relevant aspects on the clinical characteristics of this pathology, mechanisms of fungus invasion, local immune response to Candida albicans and the impact of genetic defects on innate immune receptors that increase susceptibility to the acquisition of this form of mycosis.
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Affiliation(s)
- Cecilia Vigezzi
- Laboratorio de Inmunidad Innata a Patógenos Fúngicos, Departamento de Bioquímica Clínica, Córdoba, Argentina; Centro de Investigaciones en Bioquímica Clínica e Inmunología, CIBICI-CONICET, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina; Servicio de Infectología, Hospital Privado Universitario de Córdoba, Córdoba, Argentina; Research Group of Immunology and Mycology, Córdoba, Argentina
| | - Fernando Oscar Riera
- Servicio de Infectología, Hospital Privado Universitario de Córdoba, Córdoba, Argentina; Research Group of Immunology and Mycology, Córdoba, Argentina; Servicio de Infectología, Sanatorio Allende, Córdoba, Argentina
| | - Emilse Rodriguez
- Laboratorio de Inmunidad Innata a Patógenos Fúngicos, Departamento de Bioquímica Clínica, Córdoba, Argentina; Centro de Investigaciones en Bioquímica Clínica e Inmunología, CIBICI-CONICET, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina; Servicio de Infectología, Hospital Privado Universitario de Córdoba, Córdoba, Argentina; Research Group of Immunology and Mycology, Córdoba, Argentina
| | - Paula Alejandra Icely
- Laboratorio de Inmunidad Innata a Patógenos Fúngicos, Departamento de Bioquímica Clínica, Córdoba, Argentina; Centro de Investigaciones en Bioquímica Clínica e Inmunología, CIBICI-CONICET, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina; Servicio de Infectología, Hospital Privado Universitario de Córdoba, Córdoba, Argentina; Research Group of Immunology and Mycology, Córdoba, Argentina
| | - María Soledad Miró
- Laboratorio de Inmunidad Innata a Patógenos Fúngicos, Departamento de Bioquímica Clínica, Córdoba, Argentina; Centro de Investigaciones en Bioquímica Clínica e Inmunología, CIBICI-CONICET, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina; Servicio de Infectología, Hospital Privado Universitario de Córdoba, Córdoba, Argentina; Research Group of Immunology and Mycology, Córdoba, Argentina
| | - Carlos Mauricio Figueredo
- Laboratorio de Inmunidad Innata a Patógenos Fúngicos, Departamento de Bioquímica Clínica, Córdoba, Argentina; Centro de Investigaciones en Bioquímica Clínica e Inmunología, CIBICI-CONICET, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina; Servicio de Infectología, Hospital Privado Universitario de Córdoba, Córdoba, Argentina
| | - Juan Pablo Caeiro
- Servicio de Infectología, Hospital Privado Universitario de Córdoba, Córdoba, Argentina; Servicio de Infectología, Sanatorio Allende, Córdoba, Argentina
| | - Claudia Elena Sotomayor
- Laboratorio de Inmunidad Innata a Patógenos Fúngicos, Departamento de Bioquímica Clínica, Córdoba, Argentina; Centro de Investigaciones en Bioquímica Clínica e Inmunología, CIBICI-CONICET, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina; Servicio de Infectología, Hospital Privado Universitario de Córdoba, Córdoba, Argentina; Research Group of Immunology and Mycology, Córdoba, Argentina.
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The Viral Hypothesis in Alzheimer's Disease: Novel Insights and Pathogen-Based Biomarkers. J Pers Med 2020; 10:jpm10030074. [PMID: 32751069 PMCID: PMC7563893 DOI: 10.3390/jpm10030074] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 07/27/2020] [Accepted: 07/28/2020] [Indexed: 02/07/2023] Open
Abstract
Early diagnosis of Alzheimer’s disease (AD) and the identification of significant risk factors are necessary to better understand disease progression, and to develop intervention-based therapies prior to significant neurodegeneration. There is thus a critical need to establish biomarkers which can predict the risk of developing AD before the onset of cognitive decline. A number of studies have indicated that exposure to various microbial pathogens can accelerate AD pathology. Additionally, several studies have indicated that amyloid-β possess antimicrobial properties and may act in response to infection as a part of the innate immune system. These findings have led some to speculate that certain types of infections may play a significant role in AD pathogenesis. In this review, we will provide an overview of studies which suggest pathogen involvement in AD. Additionally, we will discuss a number of pathogen-associated biomarkers which may be effective in establishing AD risk. Infections that increase the risk of AD represent a modifiable risk factor which can be treated with therapeutic intervention. Pathogen-based biomarkers may thus be a valuable tool for evaluating and decreasing AD risk across the population.
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Iqbal UH, Zeng E, Pasinetti GM. The Use of Antimicrobial and Antiviral Drugs in Alzheimer's Disease. Int J Mol Sci 2020; 21:E4920. [PMID: 32664669 PMCID: PMC7404195 DOI: 10.3390/ijms21144920] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/09/2020] [Accepted: 07/10/2020] [Indexed: 12/15/2022] Open
Abstract
The aggregation and accumulation of amyloid-β plaques and tau proteins in the brain have been central characteristics in the pathophysiology of Alzheimer's disease (AD), making them the focus of most of the research exploring potential therapeutics for this neurodegenerative disease. With success in interventions aimed at depleting amyloid-β peptides being limited at best, a greater understanding of the physiological role of amyloid-β peptides is needed. The development of amyloid-β plaques has been determined to occur 10-20 years prior to AD symptom manifestation, hence earlier interventions might be necessary to address presymptomatic AD. Furthermore, recent studies have suggested that amyloid-β peptides may play a role in innate immunity as an antimicrobial peptide. These findings, coupled with the evidence of pathogens such as viruses and bacteria in AD brains, suggests that the buildup of amyloid-β plaques could be a response to the presence of viruses and bacteria. This has led to the foundation of the antimicrobial hypothesis for AD. The present review will highlight the current understanding of amyloid-β, and the role of bacteria and viruses in AD, and will also explore the therapeutic potential of antimicrobial and antiviral drugs in Alzheimer's disease.
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Affiliation(s)
| | | | - Giulio M. Pasinetti
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (U.H.I.); (E.Z.)
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Matsushita K, Yamada-Furukawa M, Kurosawa M, Shikama Y. Periodontal Disease and Periodontal Disease-Related Bacteria Involved in the Pathogenesis of Alzheimer's Disease. J Inflamm Res 2020; 13:275-283. [PMID: 32636667 PMCID: PMC7335281 DOI: 10.2147/jir.s255309] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 05/29/2020] [Indexed: 12/11/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common cause of dementia, and it exhibits pathological properties such as deposition of extracellular amyloid β (Aβ) and abnormally phosphorylated Tau in nerve cells and a decrease of synapses. Conventionally, drugs targeting Aβ and its related molecules have been developed on the basis of the amyloid cascade hypothesis, but sufficient effects on the disease have not been obtained in past clinical trials. On the other hand, it has been pointed out that chronic inflammation and microbial infection in the brain may be involved in the pathogenesis of AD. Recently, attention has been focused on the relationship between the periodontopathic bacterium Porphylomonas gingivalis and AD. P. gingivalis and its toxins have been detected in autopsy brain tissues from patients with AD. In addition, pathological conditions of AD are formed or exacerbated in mice infected with P. gingivalis. Compounds that target the toxins of P. gingivalis ameliorate the pathogenesis of AD triggered by P. gingivalis infection. These findings indicate that the pathological condition of AD may be regulated by controlling the bacteria in the oral cavity and the body. In the current aging society, the importance of oral and periodontal care for preventing the onset of AD will increase.
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Affiliation(s)
- Kenji Matsushita
- Department of Oral Disease Research, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan
| | - Masae Yamada-Furukawa
- Department of Oral Disease Research, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan
| | - Mie Kurosawa
- Department of Oral Disease Research, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan
| | - Yosuke Shikama
- Department of Oral Disease Research, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan
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Panza F, Lozupone M, Solfrizzi V, Watling M, Imbimbo BP. Time to test antibacterial therapy in Alzheimer's disease. Brain 2020; 142:2905-2929. [PMID: 31532495 DOI: 10.1093/brain/awz244] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 05/24/2019] [Accepted: 06/14/2019] [Indexed: 12/19/2022] Open
Abstract
Alzheimer's disease is associated with cerebral accumulation of amyloid-β peptide and hyperphosphorylated tau. In the past 28 years, huge efforts have been made in attempting to treat the disease by reducing brain accumulation of amyloid-β in patients with Alzheimer's disease, with no success. While anti-amyloid-β therapies continue to be tested in prodromal patients with Alzheimer's disease and in subjects at risk of developing Alzheimer's disease, there is an urgent need to provide therapeutic support to patients with established Alzheimer's disease for whom current symptomatic treatment (acetylcholinesterase inhibitors and N-methyl d-aspartate antagonist) provide limited help. The possibility of an infectious aetiology for Alzheimer's disease has been repeatedly postulated over the past three decades. Infiltration of the brain by pathogens may act as a trigger or co-factor for Alzheimer's disease, with Herpes simplex virus type 1, Chlamydia pneumoniae, and Porphyromonas gingivalis being most frequently implicated. These pathogens may directly cross a weakened blood-brain barrier, reach the CNS and cause neurological damage by eliciting neuroinflammation. Alternatively, pathogens may cross a weakened intestinal barrier, reach vascular circulation and then cross blood-brain barrier or cause low grade chronic inflammation and subsequent neuroinflammation from the periphery. The gut microbiota comprises a complex community of microorganisms. Increased permeability of the gut and blood-brain barrier induced by microbiota dysbiosis may impact Alzheimer's disease pathogenesis. Inflammatory microorganisms in gut microbiota are associated with peripheral inflammation and brain amyloid-β deposition in subjects with cognitive impairment. Oral microbiota may also influence Alzheimer's disease risk through circulatory or neural access to the brain. At least two possibilities can be envisaged to explain the association of suspected pathogens and Alzheimer's disease. One is that patients with Alzheimer's disease are particularly prone to microbial infections. The other is that microbial infection is a contributing cause of Alzheimer's disease. Therapeutic trials with antivirals and/or antibacterials could resolve this dilemma. Indeed, antiviral agents are being tested in patients with Alzheimer's disease in double-blind placebo-controlled studies. Although combined antibiotic therapy was found to be effective in animal models of Alzheimer's disease, antibacterial drugs are not being widely investigated in patients with Alzheimer's disease. This is because it is not clear which bacterial populations in the gut of patients with Alzheimer's disease are overexpressed and if safe, selective antibacterials are available for them. On the other hand, a bacterial protease inhibitor targeting P. gingivalis toxins is now being tested in patients with Alzheimer's disease. Clinical studies are needed to test if countering bacterial infection may be beneficial in patients with established Alzheimer's disease.
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Affiliation(s)
- Francesco Panza
- Unit of Epidemiological Research on Aging, National Institute of Gastroenterology 'Saverio de Bellis', Research Hospital, Castellana Grotte, Bari, Italy
| | - Madia Lozupone
- Unit of Epidemiological Research on Aging, National Institute of Gastroenterology 'Saverio de Bellis', Research Hospital, Castellana Grotte, Bari, Italy
- Neurodegenerative Disease Unit, Department of Basic Medicine, Neuroscience, and Sense Organs, University of Bari Aldo Moro, Bari, Italy
| | - Vincenzo Solfrizzi
- 'C. Frugoni' Internal and Geriatric Medicine and Memory Unit, University of Bari Aldo Moro, Bari, Italy
| | - Mark Watling
- Department of Research and Development, Chiesi Farmaceutici, Parma, Italy
| | - Bruno P Imbimbo
- Department of Research and Development, Chiesi Farmaceutici, Parma, Italy
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Epstein AL. [Alzheimer's disease, neuro-inflammation, and herpes viruses, a path that traces its way]. Med Sci (Paris) 2020; 36:479-486. [PMID: 32452370 DOI: 10.1051/medsci/2020090] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Infection of the brain with various types of pathogens, and the resulting inflammatory response, is becoming increasingly important in our understanding of the etiology of Alzheimer's disease (AD). The fact that several genes identified as risk factors are actually involved in the modulation of the immune response, as well as the very diversity of the infectious agents identified as possible actors in the evolution of this disease, argue in favor of the neuro-inflammatory hypothesis, as does the demonstration that the protein Aβ, one of the most important markers of AD, is an antimicrobial peptide. Among others, herpes viruses (mainly, but not only, HSV-1), which can establish latent infections in brain neurons, especially in the elder population, punctuated by episodes of reactivation following stress or immunosuppression, appear as very strong candidates to play an etiological role, if only as cofactors, of AD. Recent results show that, in human and rat neurons, infection with HSV-1 increases the formation of Aβ along the amyloidogenic pathway, as well as the phosphorylation of Tau proteins, another essential marker of AD. The growing evidence that chronic infections and defense mechanisms, including inflammatory processes, are at the heart of AD, warrants reviewing antiviral drugs such as acyclovir, and possibly vaccination, as potential avenues for AD control.
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Affiliation(s)
- Alberto L Epstein
- UMR Inserm U1179 - UVSQ - UFR des sciences de la santé Simone Veil, Université de Versailles-Saint-Quentin-en-Yvelines, 2 avenue de la source de la Bièvre, 78180 Montigny-le-Bretonneux, France
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46
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Carrasco L, Pisa D, Alonso R. Polymicrobial Infections and Neurodegenerative Diseases. CURRENT CLINICAL MICROBIOLOGY REPORTS 2020. [DOI: 10.1007/s40588-020-00139-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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47
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Ardura JA, Gutiérrez-Rojas I, Álvarez-Carrión L, Rodríguez-Ramos MR, Pozuelo JM, Alonso V. The secreted matrix protein mindin increases prostate tumor progression and tumor-bone crosstalk via ERK 1/2 regulation. Carcinogenesis 2020; 40:828-839. [PMID: 31168562 DOI: 10.1093/carcin/bgz105] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 05/03/2019] [Accepted: 06/04/2019] [Indexed: 12/15/2022] Open
Abstract
Advanced prostate cancer cells preferentially metastasize to bone by acquiring a bone phenotype that allows metastatic cells to thrive in the skeletal environment. Identification of factors that promote the expression of ectopic bone genes-process known as osteomimicry-leading to tumor progression is crucial to prevent and treat metastatic prostate cancer and prolong life expectancy for patients. Here, we identify the extracelular matrix protein mindin in the secretome of prostate adenocarcinoma cells and show that mindin overexpression in human and mouse TRAMP-C1-induced prostate tumors correlates with upregulated levels of bone-related genes in the tumorigenic prostate tissues. Moreover, mindin silencing decreased osteomimicry in adenocarcinoma cells and in the prostate tumor mice model, as well as reduced tumor cell proliferation, migration and adhesion to bone cells. Inhibition of the extracellular signal-regulated kinase 1/2 (ERK 1/2) phosphorylation decreased the proliferative, migratory and pro-adhesion actions of mindin on prostate tumor cells. In addition, conditioned media obtained by crosstalk stimulation of either osteocytes or osteoblasts with the secretome of TRAMP-C1 cells promoted osteomimicry in prostate tumor cells; an effect inhibited by mindin silencing of TRAMP-C1 cells. In vivo, tibiae of primary tumor-bearing mice overexpressed the pro-angiogenic and pro-metastattic factor vascular endothelial growth factor receptor 2 (VEGFR2) in a mindin-dependent manner. Our findings indicate that mindin is a novel regulator of osteomimicry in prostate tumors and potentially mediates tumor-bone cell crosstalk, suggesting its promising role as a target to inhibit bone metastases.
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Affiliation(s)
- Juan A Ardura
- Bone Physiopathology laboratory, Applied Molecular Medicine Institute (IMMA).,Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad San Pablo-CEU, CEU Universities, Campus Monteprincipe, Alcorcón, Madrid, Spain
| | | | | | - M Rosario Rodríguez-Ramos
- Bone Physiopathology laboratory, Applied Molecular Medicine Institute (IMMA).,Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad San Pablo-CEU, CEU Universities, Campus Monteprincipe, Alcorcón, Madrid, Spain
| | - José M Pozuelo
- Bone Physiopathology laboratory, Applied Molecular Medicine Institute (IMMA).,Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad San Pablo-CEU, CEU Universities, Campus Monteprincipe, Alcorcón, Madrid, Spain
| | - Verónica Alonso
- Bone Physiopathology laboratory, Applied Molecular Medicine Institute (IMMA).,Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad San Pablo-CEU, CEU Universities, Campus Monteprincipe, Alcorcón, Madrid, Spain
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48
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Itzhaki RF, Golde TE, Heneka MT, Readhead B. Do infections have a role in the pathogenesis of Alzheimer disease? Nat Rev Neurol 2020; 16:193-197. [PMID: 32152461 DOI: 10.1038/s41582-020-0323-9] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/07/2020] [Indexed: 12/21/2022]
Abstract
The idea that infectious agents in the brain have a role in the pathogenesis of Alzheimer disease (AD) was proposed nearly 30 years ago. However, this theory failed to gain substantial traction and was largely disregarded by the AD research community for many years. Several recent discoveries have reignited interest in the infectious theory of AD, culminating in a debate on the topic at the Alzheimer's Association International Conference (AAIC) in July 2019. In this Viewpoint article, experts who participated in the AAIC debate weigh up the evidence for and against the infectious theory of AD and suggest avenues for future research and drug development.
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Affiliation(s)
- Ruth F Itzhaki
- School of Biological Sciences, University of Manchester, Manchester, UK. .,Institute of Population Ageing, University of Oxford, Oxford, UK.
| | - Todd E Golde
- Center for Translational Research in Neurodegenerative Disease, Department of Neuroscience, McKnight Brain Institute, Gainesville, FL, USA.
| | - Michael T Heneka
- Department of Neurodegenerative Diseases and Geriatric Psychiatry, University Hospital of Bonn, Bonn, Germany. .,German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany. .,Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA, USA.
| | - Ben Readhead
- ASU-Banner Neurodegenerative Disease Research Center, Arizona State University, Tempe, AZ, USA.
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49
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Giannoni P, Claeysen S, Noe F, Marchi N. Peripheral Routes to Neurodegeneration: Passing Through the Blood-Brain Barrier. Front Aging Neurosci 2020; 12:3. [PMID: 32116645 PMCID: PMC7010934 DOI: 10.3389/fnagi.2020.00003] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 01/08/2020] [Indexed: 12/21/2022] Open
Abstract
A bidirectional crosstalk between peripheral players of immunity and the central nervous system (CNS) exists. Hence, blood-brain barrier (BBB) breakdown is emerging as a participant mechanism of dysregulated peripheral-CNS interplay, promoting diseases. Here, we examine the implication of BBB damage in neurodegeneration, linking it to peripheral brain-directed autoantibodies and gut-brain axis mechanisms. As BBB breakdown is a factor contributing to, or even anticipating, neuronal dysfunction(s), we here identify contemporary pharmacological strategies that could be exploited to repair the BBB in disease conditions. Developing neurovascular, add on, therapeutic strategies may lead to a more efficacious pre-clinical to clinical transition with the goal of curbing the progression of neurodegeneration.
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Affiliation(s)
| | - Sylvie Claeysen
- CNRS, INSERM U1191, Institut de Génomique Fonctionnelle, University of Montpellier, Montpellier, France
| | - Francesco Noe
- HiLIFE – Neuroscience Center, University of Helsinki, Helsinki, Finland
| | - Nicola Marchi
- CNRS, INSERM U1191, Institut de Génomique Fonctionnelle, University of Montpellier, Montpellier, France
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50
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Frost GR, Jonas LA, Li YM. Friend, Foe or Both? Immune Activity in Alzheimer's Disease. Front Aging Neurosci 2019; 11:337. [PMID: 31920620 PMCID: PMC6916654 DOI: 10.3389/fnagi.2019.00337] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 11/21/2019] [Indexed: 12/18/2022] Open
Abstract
Alzheimer's disease (AD) is marked by the presence of amyloid beta (Aβ) plaques, neurofibrillary tangles (NFT), neuronal death and synaptic loss, and inflammation in the brain. AD research has, in large part, been dedicated to the understanding of Aβ and NFT deposition as well as to the pharmacological reduction of these hallmarks. However, recent GWAS data indicates neuroinflammation plays a critical role in AD development, thereby redirecting research efforts toward unveiling the complexities of AD-associated neuroinflammation. It is clear that the innate immune system is intimately associated with AD progression, however, the specific roles of glia and neuroinflammation in AD pathology remain to be described. Moreover, inflammatory processes have largely been painted as detrimental to AD pathology, when in fact, many immune mechanisms such as phagocytosis aid in the reduction of AD pathologies. In this review, we aim to outline the delicate balance between the beneficial and detrimental aspects of immune activation in AD as a more thorough understanding of these processes is critical to development of effective therapeutics for AD.
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Affiliation(s)
- Georgia R. Frost
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, Manhattan, NY, United States
| | - Lauren A. Jonas
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, Manhattan, NY, United States
- Pharmacology Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, Ithaca, NY, United States
| | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, Manhattan, NY, United States
- Pharmacology Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, Ithaca, NY, United States
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