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Elashiry M, Carroll A, Yuan J, Liu Y, Hamrick M, Cutler CW, Wang Q, Elsayed R. Oral Microbially-Induced Small Extracellular Vesicles Cross the Blood-Brain Barrier. Int J Mol Sci 2024; 25:4509. [PMID: 38674094 PMCID: PMC11049816 DOI: 10.3390/ijms25084509] [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: 03/04/2024] [Revised: 04/08/2024] [Accepted: 04/14/2024] [Indexed: 04/28/2024] Open
Abstract
Porphyromonas gingivalis (Pg) and its gingipain proteases contribute to Alzheimer's disease (AD) pathogenesis through yet unclear mechanisms. Cellular secretion of small extracellular vesicles or exosomes (EXO) increases with aging as part of the senescence-associated secretory phenotype (SASP). We have shown that EXO isolated from Pg-infected dendritic cells contain gingipains and other Pg antigens and transmit senescence to bystander gingival cells, inducing alveolar bone loss in mice in vivo. Here, EXO were isolated from the gingiva of mice and humans with/without periodontitis (PD) to determine their ability to penetrate the blood-brain barrier (BBB) in vitro and in vivo. PD was induced by Pg oral gavage for 6 weeks in C57B6 mice. EXO isolated from the gingiva or brain of donor Pg-infected (PD EXO) or control animals (Con EXO) were characterized by NTA, Western blot, and TEM. Gingival PD EXO or Con EXO were labeled and injected into the gingiva of uninfected WT mouse model. EXO biodistribution in brains was tracked by an in vivo imaging system (IVIS) and confocal microscopy. The effect of human PD EXO on BBB integrity and permeability was examined using TEER and FITC dextran assays in a human in vitro 3D model of the BBB. Pg antigens (RGP and Mfa-1) were detected in EXO derived from gingival and brain tissues of donor Pg-infected mice. Orally injected PD EXO from donor mice penetrated the brains of recipient uninfected mice and colocalized with hippocampal microglial cells. IL-1β and IL-6 were expressed in human PD EXO and not in Con EXO. Human PD EXO promoted BBB permeability and penetrated the BBB in vitro. This is the first demonstration that microbial-induced EXO in the oral cavity can disseminate, cross the BBB, and may contribute to AD pathogenesis.
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Affiliation(s)
- Mahmoud Elashiry
- Department of Periodontics, Dental College of Georgia, Augusta University, Augusta, GA 30912, USA; (M.E.); (A.C.); (J.Y.); (C.W.C.)
| | - Angelica Carroll
- Department of Periodontics, Dental College of Georgia, Augusta University, Augusta, GA 30912, USA; (M.E.); (A.C.); (J.Y.); (C.W.C.)
| | - Jessie Yuan
- Department of Periodontics, Dental College of Georgia, Augusta University, Augusta, GA 30912, USA; (M.E.); (A.C.); (J.Y.); (C.W.C.)
| | - Yutao Liu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA; (Y.L.); (M.H.)
| | - Mark Hamrick
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA; (Y.L.); (M.H.)
| | - Christopher W. Cutler
- Department of Periodontics, Dental College of Georgia, Augusta University, Augusta, GA 30912, USA; (M.E.); (A.C.); (J.Y.); (C.W.C.)
| | - Qin Wang
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA;
| | - Ranya Elsayed
- Department of Periodontics, Dental College of Georgia, Augusta University, Augusta, GA 30912, USA; (M.E.); (A.C.); (J.Y.); (C.W.C.)
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Rippee-Brooks MD, Wu W, Dong J, Pappolla M, Fang X, Bao X. Viral Infections, Are They a Trigger and Risk Factor of Alzheimer's Disease? Pathogens 2024; 13:240. [PMID: 38535583 PMCID: PMC10974111 DOI: 10.3390/pathogens13030240] [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: 02/01/2024] [Revised: 03/02/2024] [Accepted: 03/07/2024] [Indexed: 04/01/2024] Open
Abstract
Alzheimer's Disease (AD), a progressive and debilitating condition, is reported to be the most common type of dementia, with at least 55 million people believed to be currently affected. Many causation hypotheses of AD exist, yet the intriguing link between viral infection and its possible contribution to the known etiology of AD has become an attractive focal point of research for the field and a challenging study task. In this review, we will explore the historical perspective and milestones that led the field to investigate the viral connection to AD. Specifically, several viruses such as Herpes Simplex Virus 1 (HSV-1), Zika virus (ZIKV), and severe cute respiratory syndrome coronavirus 2 (SARS-CoV-2), along with several others mentioned, include the various viruses presently considered within the field. We delve into the strong evidence implicating these viruses in the development of AD such as the lytic replication and axonal transport of HSV-1, the various mechanisms of ZIKV neurotropism through the human protein Musashi-1 (MSI1), and the spread of SARS-CoV-2 through the transfer of the virus through the BBB endothelial cells to glial cells and then to neurons via transsynaptic transfer. We will also explore beyond these mere associations by carefully analyzing the potential mechanisms by which these viruses may contribute to AD pathology. This includes but is not limited to direct neuronal infections, the dysregulation of immune responses, and the impact on protein processing (Aβ42 and hyperphosphorylated tau). Controversies and challenges of the virus-AD relationship emerge as we tease out these potential mechanisms. Looking forward, we emphasize future directions, such as distinct questions and proposed experimentations to explore, that the field should take to tackle the remaining unanswered questions and the glaring research gaps that persist. Overall, this review aims to provide a comprehensive survey of the past, present, and future of the potential link between viral infections and their association with AD development while encouraging further discussion.
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Affiliation(s)
- Meagan D. Rippee-Brooks
- Microbiology and Immunology Graduate Program, Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX 77550, USA
| | - Wenzhe Wu
- Department of Pediatrics, The University of Texas Medical Branch, Galveston, TX 77550, USA
| | - Jianli Dong
- Department of Pathology, The University of Texas Medical Branch, Galveston, TX 77550, USA
| | - Miguel Pappolla
- Department of Neurology and Mitchell Center for Neurodegenerative Diseases, The University of Texas Medical Branch, Galveston, TX 77550, USA
| | - Xiang Fang
- Department of Neurology and Mitchell Center for Neurodegenerative Diseases, The University of Texas Medical Branch, Galveston, TX 77550, USA
| | - Xiaoyong Bao
- Microbiology and Immunology Graduate Program, Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX 77550, USA
- Department of Pediatrics, The University of Texas Medical Branch, Galveston, TX 77550, USA
- The Institute of Translational Sciences, The University of Texas Medical Branch, Galveston, TX 77550, USA
- The Institute for Human Infections and Immunity, The University of Texas Medical Branch, Galveston, TX 77550, USA
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3
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Shinde MD, Patil SA, Mukherjee A, Nema V. Revisiting the therapeutic potential of homeopathic medicine Rhus Tox for herpes simplex virus and inflammatory conditions. J Ayurveda Integr Med 2023; 14:100739. [PMID: 37421729 PMCID: PMC10344814 DOI: 10.1016/j.jaim.2023.100739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 04/20/2023] [Accepted: 06/02/2023] [Indexed: 07/10/2023] Open
Abstract
BACKGROUND Herpes simplex virus type-1 and type-2 cause a viral disease named Herpes. Genital herpes is mainly caused by HSV-2 with symptoms of painful and itchy blisters on the vagina, cervix, buttocks, anus, penis, or inner thighs with blisters that rupture and convert into sores. The homeopathic remedy Rhus Tox has been widely used to treat herpes and has shown invitro anti-inflammatory effects in previous studies. PURPOSE The presented review focuses on relapses and harmful effects caused by acyclovir in modern medicine and the probable antiherpetic activity of Rhus Tox on HSV infection based on its pathophysiology, preclinical findings, on primary cultured mouse chondrocytes, mouse cell line MC3T3e1 and a comparative study of Natrum Mur with Rhus Tox on HSV infection. STUDY DESIGN The design of the study focuses mainly on the descriptive data available in various literature articles. METHOD Databases such as PubMed, Google Scholar, Medline and ScienceDirect were used to search the articles. Articles are selected from 1994 to 2022 focusing solely on the competence of Rhus Tox against herpes. Keywords used for the study are antiviral, Herpes, Rhus Tox, in vitro and homeopathy. RESULTS The review includes fifteen articles, including 4 full-text articles on HSV, 6 in vitro studies of homeopathic compounds performed on the herpes virus, and 5 articles based on the pathophysiology and effects of Rhus tox. The review article proposes the anti-inflammatory and antiviral action of the homeopathic remedy Rhus Tox which can be used in crisis conditions when the physician doubts the simillimum, as it prevents further outbreaks of HSV infection. CONCLUSION The homeopathic medicine Rhus Tox has no cytotoxicity observed under in vitro conditions and can be used to treat herpes infection. Further studies are needed to confirm the results under in vitro and in vivo conditions as well as in clinical trials.
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Affiliation(s)
- Mohini D. Shinde
- Homeopathic Materia Medica Department, Bharti Vidyapeeth (Deemed to be University), Homoeopathic Medical College and Hospital, Dept. of Postgraduate & Research Centre, Pune-Satara Road, Dhankawadi, Pune, 411043, India
| | - Sheetal A. Patil
- Homeopathic Materia Medica Department, Bharti Vidyapeeth (Deemed to be University), Homoeopathic Medical College and Hospital, Dept. of Postgraduate & Research Centre, Pune-Satara Road, Dhankawadi, Pune, 411043, India
| | - Anupam Mukherjee
- ICMR-National AIDS Research Institute, 73 G MIDC Bhosari, Pune, India
| | - Vijay Nema
- ICMR-National AIDS Research Institute, 73 G MIDC Bhosari, Pune, India
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4
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Song L, Chen J, Lo CYZ, Guo Q, Feng J, Zhao XM. Impaired type I interferon signaling activity implicated in the peripheral blood transcriptome of preclinical Alzheimer's disease. EBioMedicine 2022; 82:104175. [PMID: 35863293 PMCID: PMC9304603 DOI: 10.1016/j.ebiom.2022.104175] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 07/04/2022] [Accepted: 07/04/2022] [Indexed: 11/16/2022] Open
Abstract
Background Subjective or objective subtle cognitive decline (SCD) is considered the preclinical manifestation of Alzheimer's disease (AD), which is a potentially crucial window for preventing or delaying the progression of the disease. Methods To explore the potential mechanism of disease progression and identify relevant biomarkers, we comprehensively assessed the peripheral blood transcriptomic alterations in SCD, covering lncRNA, mRNA, and miRNA. Findings Dysregulated protein-coding mRNA at both gene and isoform levels implicated impairment in the type I interferon signaling pathway in SCD. Specifically, this pathway was regulated by the transcription factor STAT1 and ncRNAs NRIR and has-miR-146a-5p. The miRNA-mRNA-lncRNA co-expression network revealed hub genes for the interferon module. Individuals with lower interferon signaling activity and lower expression of a hub gene STAT1 exhibited a higher conversion rate to mild cognitive impairment (MCI). Interpretation Our findings illustrated the down-regulation of interferon signaling activity would potentially increase the risk of disease progression and thus serve as a pre-disease biomarker. Funding This work was partly supported by National Key R&D Program of China (2020YFA0712403), National Natural Science Foundation of China (61932008), Shanghai Municipal Science and Technology Major Project (2018SHZDZX01), the 111 Project (No. B18015) of China, Greater Bay Area Institute of Precision Medicine (Guangzhou) (Grand No. IPM21C008), Natural Science Foundation of Shanghai (21ZR1403200), and Shanghai Center for Brain Science and Brain-Inspired Technology.
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Bougakov D, Podell K, Goldberg E. Multiple Neuroinvasive Pathways in COVID-19. Mol Neurobiol 2020; 58:564-575. [PMID: 32990925 PMCID: PMC7523266 DOI: 10.1007/s12035-020-02152-5] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 09/25/2020] [Indexed: 02/06/2023]
Abstract
COVID-19 is a highly infectious viral disease caused by the novel coronavirus SARS-CoV-2. While it was initially regarded as a strictly respiratory illness, the impact of COVID-19 on multiple organs is increasingly recognized. The brain is among the targets of COVID-19, and it can be impacted in multiple ways, both directly and indirectly. Direct brain infection by SARS-CoV-2 may occur via axonal transport via the olfactory nerve, eventually infecting the olfactory cortex and other structures in the temporal lobe, and potentially the brain stem. A hematogenous route, which involves viral crossing of blood-brain barrier, is also possible. Secondary mechanisms involve hypoxia due to respiratory failure, as well as aberrant immune response leading to various forms of encephalopathy, white matter damage, and abnormal blood clotting resulting in stroke. Multiple neurological symptoms of COVID-19 have been described. These involve anosmia/ageusia, headaches, seizures, mental confusion and delirium, and coma. There is a growing concern that in a number of patients, long-term or perhaps even permanent cognitive impairment will persist well after the recovery from acute illness. Furthermore, COVID-19 survivors may be at increased risk for developing neurodegenerative diseases years or decades later. Since COVID-19 is a new disease, it will take months or even years to characterize the exact nature, scope, and temporal extent of its long-term neurocognitive sequelae. To that end, rigorous and systematic longitudinal follow-up will be required. For this effort to succeed, appropriate protocols and patient registries should be developed and put in place without delay now.
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Affiliation(s)
| | - Kenneth Podell
- Houston Methodist Hospital and Weill Cornell Medical College, Houston, TX, USA
| | - Elkhonon Goldberg
- Luria Neuroscience Institute, New York, NY, USA. .,NYU Grossman School of Medicine, New York, NY, USA.
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6
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Guo T, Zhang D, Zeng Y, Huang TY, Xu H, Zhao Y. Molecular and cellular mechanisms underlying the pathogenesis of Alzheimer's disease. Mol Neurodegener 2020; 15:40. [PMID: 32677986 PMCID: PMC7364557 DOI: 10.1186/s13024-020-00391-7] [Citation(s) in RCA: 391] [Impact Index Per Article: 97.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Accepted: 06/17/2020] [Indexed: 12/11/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common neurodegenerative disorder seen in age-dependent dementia. There is currently no effective treatment for AD, which may be attributed in part to lack of a clear underlying mechanism. Studies within the last few decades provide growing evidence for a central role of amyloid β (Aβ) and tau, as well as glial contributions to various molecular and cellular pathways in AD pathogenesis. Herein, we review recent progress with respect to Aβ- and tau-associated mechanisms, and discuss glial dysfunction in AD with emphasis on neuronal and glial receptors that mediate Aβ-induced toxicity. We also discuss other critical factors that may affect AD pathogenesis, including genetics, aging, variables related to environment, lifestyle habits, and describe the potential role of apolipoprotein E (APOE), viral and bacterial infection, sleep, and microbiota. Although we have gained much towards understanding various aspects underlying this devastating neurodegenerative disorder, greater commitment towards research in molecular mechanism, diagnostics and treatment will be needed in future AD research.
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Affiliation(s)
- Tiantian Guo
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Denghong Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Yuzhe Zeng
- Department of Orthopaedics, Orthopaedic Center of People's Liberation Army, The Affiliated Southeast Hospital of Xiamen University, Zhangzhou, China
| | - Timothy Y Huang
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA.
| | - Huaxi Xu
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA.
| | - Yingjun Zhao
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China.
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7
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Liu PP, Xie Y, Meng XY, Kang JS. History and progress of hypotheses and clinical trials for Alzheimer's disease. Signal Transduct Target Ther 2019; 4:29. [PMID: 31637009 PMCID: PMC6799833 DOI: 10.1038/s41392-019-0063-8] [Citation(s) in RCA: 302] [Impact Index Per Article: 60.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 07/07/2019] [Accepted: 07/17/2019] [Indexed: 12/20/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive memory loss along with neuropsychiatric symptoms and a decline in activities of daily life. Its main pathological features are cerebral atrophy, amyloid plaques, and neurofibrillary tangles in the brains of patients. There are various descriptive hypotheses regarding the causes of AD, including the cholinergic hypothesis, amyloid hypothesis, tau propagation hypothesis, mitochondrial cascade hypothesis, calcium homeostasis hypothesis, neurovascular hypothesis, inflammatory hypothesis, metal ion hypothesis, and lymphatic system hypothesis. However, the ultimate etiology of AD remains obscure. In this review, we discuss the main hypotheses of AD and related clinical trials. Wealthy puzzles and lessons have made it possible to develop explanatory theories and identify potential strategies for therapeutic interventions for AD. The combination of hypometabolism and autophagy deficiency is likely to be a causative factor for AD. We further propose that fluoxetine, a selective serotonin reuptake inhibitor, has the potential to treat AD.
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Affiliation(s)
- Pei-Pei Liu
- Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052 Henan China
| | - Yi Xie
- Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052 Henan China
| | - Xiao-Yan Meng
- Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052 Henan China
| | - Jian-Sheng Kang
- Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052 Henan China
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8
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Kong C, Xie H, Gao Z, Shao M, Li H, Shi R, Cai L, Gao S, Sun T, Li C. Binding between Prion Protein and Aβ Oligomers Contributes to the Pathogenesis of Alzheimer's Disease. Virol Sin 2019; 34:475-488. [PMID: 31093882 DOI: 10.1007/s12250-019-00124-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Accepted: 03/26/2019] [Indexed: 12/26/2022] Open
Abstract
A plethora of evidence suggests that protein misfolding and aggregation are underlying mechanisms of various neurodegenerative diseases, such as prion diseases and Alzheimer's disease (AD). Like prion diseases, AD has been considered as an infectious disease in the past decades as it shows strain specificity and transmission potential. Although it remains elusive how protein aggregation leads to AD, it is becoming clear that cellular prion protein (PrPC) plays an important role in AD pathogenesis. Here, we briefly reviewed AD pathogenesis and focused on recent progresses how PrPC contributed to AD development. In addition, we proposed a potential mechanism to explain why infectious agents, such as viruses, conduce AD pathogenesis. Microbe infections cause Aβ deposition and upregulation of PrPC, which lead to high affinity binding between Aβ oligomers and PrPC. The interaction between PrPC and Aβ oligomers in turn activates the Fyn signaling cascade, resulting in neuron death in the central nervous system (CNS). Thus, silencing PrPC expression may turn out be an effective treatment for PrPC dependent AD.
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Affiliation(s)
- Chang Kong
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan, 430070, China.,State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China.,Affiliated Cancer Hospital, Institute of Guangzhou Medical University, Guangzhou, 510095, China
| | - Hao Xie
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan, 430070, China
| | - Zhenxing Gao
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Ming Shao
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Huan Li
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Run Shi
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Lili Cai
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Shanshan Gao
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Taolei Sun
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan, 430070, China
| | - Chaoyang Li
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China. .,Affiliated Cancer Hospital, Institute of Guangzhou Medical University, Guangzhou, 510095, China.
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9
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Sun XW, Liu CM, Teng ZQ. Commentary: Multiscale Analysis of Independent Alzheimer's Cohorts Finds Disruption of Molecular, Genetic, and Clinical Networks by Human Herpesvirus. Front Mol Neurosci 2018; 11:340. [PMID: 30294260 PMCID: PMC6158328 DOI: 10.3389/fnmol.2018.00340] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 08/29/2018] [Indexed: 12/27/2022] Open
Affiliation(s)
- Xiao-Wen Sun
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Chang-Mei Liu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China.,Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
| | - Zhao-Qian Teng
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China.,Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
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10
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Readhead B, Haure-Mirande JV, Funk CC, Richards MA, Shannon P, Haroutunian V, Sano M, Liang WS, Beckmann ND, Price ND, Reiman EM, Schadt EE, Ehrlich ME, Gandy S, Dudley JT. Multiscale Analysis of Independent Alzheimer's Cohorts Finds Disruption of Molecular, Genetic, and Clinical Networks by Human Herpesvirus. Neuron 2018; 99:64-82.e7. [PMID: 29937276 PMCID: PMC6551233 DOI: 10.1016/j.neuron.2018.05.023] [Citation(s) in RCA: 420] [Impact Index Per Article: 70.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 03/05/2018] [Accepted: 05/15/2018] [Indexed: 12/13/2022]
Abstract
Investigators have long suspected that pathogenic microbes might contribute to the onset and progression of Alzheimer's disease (AD) although definitive evidence has not been presented. Whether such findings represent a causal contribution, or reflect opportunistic passengers of neurodegeneration, is also difficult to resolve. We constructed multiscale networks of the late-onset AD-associated virome, integrating genomic, transcriptomic, proteomic, and histopathological data across four brain regions from human post-mortem tissue. We observed increased human herpesvirus 6A (HHV-6A) and human herpesvirus 7 (HHV-7) from subjects with AD compared with controls. These results were replicated in two additional, independent and geographically dispersed cohorts. We observed regulatory relationships linking viral abundance and modulators of APP metabolism, including induction of APBB2, APPBP2, BIN1, BACE1, CLU, PICALM, and PSEN1 by HHV-6A. This study elucidates networks linking molecular, clinical, and neuropathological features with viral activity and is consistent with viral activity constituting a general feature of AD.
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Affiliation(s)
- Ben Readhead
- Departments of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Icahn Institute of Genomic Sciences and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Institute for Next Generation Healthcare, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; ASU-Banner Neurodegenerative Disease Research Center, Arizona State University, Tempe, AZ 85287-5001, USA
| | - Jean-Vianney Haure-Mirande
- Department of Neurology, Alzheimer's Disease Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Cory C Funk
- Institute for Systems Biology, Seattle, WA, 98109-5263, USA
| | | | - Paul Shannon
- Institute for Systems Biology, Seattle, WA, 98109-5263, USA
| | - Vahram Haroutunian
- Departments of Psychiatry and Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; James J. Peters VA Medical Center, 130 West Kingsbridge Road, New York, NY 10468, USA
| | - Mary Sano
- James J. Peters VA Medical Center, 130 West Kingsbridge Road, New York, NY 10468, USA; Department of Psychiatry, Alzheimer's Disease Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Winnie S Liang
- Arizona Alzheimer's Consortium, Phoenix, AZ 85014, USA; Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ 85004, USA
| | - Noam D Beckmann
- Departments of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Icahn Institute of Genomic Sciences and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Nathan D Price
- Institute for Systems Biology, Seattle, WA, 98109-5263, USA
| | - Eric M Reiman
- Arizona Alzheimer's Consortium, Phoenix, AZ 85014, USA; Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ 85004, USA; Department of Psychiatry, University of Arizona, Phoenix, AZ 85721, USA; Banner Alzheimer's Institute, Phoenix, AZ 85006, USA
| | - Eric E Schadt
- Departments of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Icahn Institute of Genomic Sciences and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Sema4, Stamford, CT 06902, USA
| | - Michelle E Ehrlich
- Departments of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Icahn Institute of Genomic Sciences and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Neurology, Alzheimer's Disease Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Sam Gandy
- Department of Neurology, Alzheimer's Disease Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; James J. Peters VA Medical Center, 130 West Kingsbridge Road, New York, NY 10468, USA; Department of Psychiatry, Alzheimer's Disease Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Center for NFL Neurological Care, Department of Neurology, New York, NY 10029, USA
| | - Joel T Dudley
- Departments of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Icahn Institute of Genomic Sciences and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Institute for Next Generation Healthcare, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; ASU-Banner Neurodegenerative Disease Research Center, Arizona State University, Tempe, AZ 85287-5001, USA.
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11
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Tanaka S, Nagashima H. Establishment of an Alzheimer's disease model with latent herpesvirus infection using PS2 and Tg2576 double transgenic mice. Exp Anim 2017; 67:185-192. [PMID: 29187699 PMCID: PMC5955750 DOI: 10.1538/expanim.17-0066] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
A relationship between Alzheimer’s disease and herpes simplex virus infection has been
pointed out. We established a model of Alzheimer’s disease with a latent herpesvirus
infection using a mouse model of Alzheimer’s disease (PS2Tg2576) and examined the changes
in amyloid β (Aβ) in the brain. We crossbred female PS2 mice with male Tg2576 hemi mice
and chose PS2Tg2576 mice. After priming 5-week-old male mice with anti-pseudorabies virus
swine serum, we challenged the mouse with 100 LD50 of YS-81, a wild-type strain
of pseudorabies virus. The viral DNA was detected in nasal swabs by a reactivation test
and in the trigeminal ganglia. At two months after infection, the Aβ40 and Aβ42 levels in
the brains of the mice of the latently infected group were increased; the increase was
greater than that observed in the noninfected group. Latent pseudorabies virus infection
was established in PS2Tg2576 mice and the level of Aβ increased with the reactivation of
the latent virus.
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Affiliation(s)
- Seiichi Tanaka
- Center for Experimental Animals, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka-shi, Fukuoka 814-0180, Japan
| | - Hiroshi Nagashima
- Animal-care Co., Ltd., 5-18-14 Shinjuku, Shinjuku-ku, Tokyo 160-0022, Japan
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12
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Abstract
Late-onset Alzheimer's disease (AD) is the most prevalent cause of dementia among older adults, yet more than a century of research has not determined why this disease develops. One prevailing hypothesis is that late-onset AD is caused by infectious pathogens, an idea widely studied in both humans and experimental animal models. This review examines the infectious AD etiology hypothesis and summarizes existing evidence associating infectious agents with AD in humans. The various mechanisms through which different clinical and subclinical infections could cause or promote the progression of AD are considered, as is the concordance between putative infectious agents and the epidemiology of AD. We searched the PubMed, Web of Science, and EBSCO databases for research articles pertaining to infections and AD and systematically reviewed the evidence linking specific infectious pathogens to AD. The evidence compiled from the literature linking AD to an infectious cause is inconclusive, but the amount of evidence suggestive of an association is too substantial to ignore. Epidemiologic, clinical, and basic science studies that could improve on current understanding of the associations between AD and infections and possibly uncover ways to control this highly prevalent and debilitating disease are suggested.
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Affiliation(s)
| | - Robert Wallace
- Correspondence to Dr. Robert Wallace, Department of Epidemiology, College of Public Health, The University of Iowa, 105 River St. Iowa City, IA 52242 (e-mail: )
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13
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Schmidt C, Karch A, Korth C, Zerr I. On the issue of transmissibility of Alzheimer disease: a critical review. Prion 2012; 6:447-52. [PMID: 23052009 DOI: 10.4161/pri.22502] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Results from recent experiments with rodents imply that Alzheimer disease might be inducible by seeding Aβ peptides into recipient animals. In respect to this new experimental data, public health aspects as well as epidemiological data have to be reevaluated. In this article, the available experimental and epidemiological data are reviewed.
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Affiliation(s)
- Christian Schmidt
- Clinical Dementia Center, Department of Neurology, Georg-August University, Goettingen, Germany.
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14
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Conrady CD, Drevets DA, Carr DJJ. Herpes simplex type I (HSV-1) infection of the nervous system: is an immune response a good thing? J Neuroimmunol 2009; 220:1-9. [PMID: 19819030 DOI: 10.1016/j.jneuroim.2009.09.013] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2009] [Revised: 09/15/2009] [Accepted: 09/15/2009] [Indexed: 02/06/2023]
Abstract
Herpes simplex virus type 1 (HSV-1) can induce a robust immune response initially thru the activation of pattern recognition receptors and subsequent type I interferon production that then shapes, along with other innate immune components, the adaptive immune response to the insult. While this response is necessary to quell virus replication, drive the pathogen into a "latent" state, and likely hinder viral reactivation, collateral damage can ensue with demonstrable cell death and foci of tissue pathology in the central nervous system (CNS) as a result of the release of inflammatory mediators including reactive oxygen species. Although rare, HSV-1 is the leading cause of frank sporadic encephalitis that, if left untreated, can result in death. A greater understanding of the contribution of resident glial cells and infiltrating leukocytes within the CNS in response to HSV-1 invasion is necessary to identify candidate molecules as targets for therapeutic intervention to reduce unwarranted inflammation coinciding with the maintenance of the anti-viral state.
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Affiliation(s)
- Christopher D Conrady
- Department of Microbiology, Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, United States
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15
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Honjo K, van Reekum R, Verhoeff NPLG. Alzheimer's disease and infection: do infectious agents contribute to progression of Alzheimer's disease? Alzheimers Dement 2009; 5:348-60. [PMID: 19560105 DOI: 10.1016/j.jalz.2008.12.001] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2008] [Revised: 11/08/2008] [Accepted: 12/04/2008] [Indexed: 12/31/2022]
Abstract
Infection with several important pathogens could constitute risk factors for cognitive impairment, dementia, and Alzheimer's disease (AD) in particular. This review summarizes the data related to infectious agents that appear to have a relationship with AD. Infections with herpes simplex virus type 1, picornavirus, Borna disease virus, Chlamydia pneumoniae, Helicobacter pylori, and spirochete were reported to contribute to the pathophysiology of AD or to cognitive changes. Based on these reports, it may be hypothesized that central nervous system or systemic infections may contribute to the pathogenesis or pathophysiology of AD, and chronic infection with several pathogens should be considered a risk factor for sporadic AD. If this hypothesis holds true, early intervention against infection may delay or even prevent the future development of AD.
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Affiliation(s)
- Kie Honjo
- L.C. Campbell Cognitive Neurology Research Unit, Heart and Stroke Foundation Centre for Stroke Recovery, Section of Neurology, Department of Medicine, Sunnybrook Health Science Centre and University of Toronto, Toronto, Ontario, Canada
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16
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Hill JM, Bhattacharjee PS, Neumann DM. Apolipoprotein E alleles can contribute to the pathogenesis of numerous clinical conditions including HSV-1 corneal disease. Exp Eye Res 2006; 84:801-11. [PMID: 17007837 PMCID: PMC2217677 DOI: 10.1016/j.exer.2006.08.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2006] [Revised: 07/19/2006] [Accepted: 08/03/2006] [Indexed: 11/18/2022]
Abstract
Apolipoprotein E (ApoE) alleles have been reported to affect the clinical outcome of numerous cardiovascular, neurodegenerative, and viral infectious diseases, including atherosclerosis, Alzheimer's disease (AD), hepatitis C, and HIV. The major alleles of ApoE are 2, 3, and 4. ApoE genotypes have been hypothesized to regulate many biological functions, resulting in significant changes in the onset and/or outcome (severity and duration) of several clinical conditions. Based on genetic analyses in human and animal studies using knockout (ApoE -/-) mice and mice transgenic for human 3 and 4, we present evidence that strongly suggests that the ApoE alleles can regulate the pathogenesis of ocular herpes simplex virus type 1 (HSV-1) infections. This review will summarize the major studies that support this hypothesis. Significant gender based differences in HSV-1 pathogenesis have also been reported, suggesting that hormonal regulation combined with ApoE genotype plays a significant role in HSV-1 pathogenesis. Identification of specific mechanisms in ocular HSV-1 infections related to the ApoE alleles and gender could lead to therapeutic intervention based on the properties of the apoE isoforms. While many clinical investigations have been reported and, to a lesser extent, transgenic mouse studies have been conducted, no specific mechanisms of how ApoE induces or alters clinical disease are known.
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Affiliation(s)
- James M Hill
- Department of Ophthalmology, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA.
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17
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Hill JM, Gebhardt BM, Azcuy AM, Matthews KE, Lukiw WJ, Steiner I, Thompson HW, Ball MJ. Can a herpes simplex virus type 1 neuroinvasive score be correlated to other risk factors in Alzheimer's disease? Med Hypotheses 2005; 64:320-7. [PMID: 15607565 DOI: 10.1016/j.mehy.2003.11.045] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2003] [Accepted: 11/24/2003] [Indexed: 01/05/2023]
Abstract
Herpes simplex virus type 1 (HSV-1) is latent in the nervous system of most humans. Ball [Can J Neurol Sci 9 (1982) 303] first suggested the hypothesis that HSV-1 could be involved in the pathogenesis of Alzheimer's Disease (AD) by noting that regions of the brain particularly and earliest affected in AD were the same as those most damaged during HSV encephalitis. Data from Itzhaki's research suggests that HSV-1 in the brain and the carriage of an apolipoprotein E allele 4 (ApoE e4) together confer risk for AD [J Pathol 97 (2002) 395], [Mol Chem Neuropathol 28 (1996) 135], [Alzheimer's Rep 1 (1998) 173], [Biochem Soc Trans 26 (1998) 273]. Of the two other studies based on Itzhaki's findings, one showed similar results [Lancet 349 (1997) 1102], and the other showed a similar trend [Lancet 351 (1998) 1330], [Lancet 352 (1998) 1312]. To further examine the role of HSV-1 in the etiology of AD, we have formulated a Neuroinvasive Score that quantifies the presence and viral load of HSV-1 in eight brain regions. These regions are: entorhinal cortex, hippocampus, pons, cerebellum, and neocortex (temporal, parietal, occipital, and frontal). We hypothesize that the Neuroinvasive Score that encompasses the presence, amount, and extent of HSV-1 spreading (neuroinvasiveness), will correlate with the genetic risk factor, ApoE e4, in the assessment of autopsy samples from AD patients. If the neuroinvasive score can be directly correlated to the different stages of AD (mild, moderate, severe), this will strengthen the hypothesis that HSV-1 is involved in AD and that ApoE e4 also confers risk for the development and progression of AD.
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Affiliation(s)
- J M Hill
- Departments of Ophthalmology, Neuroscience, Pharmacology, and Microbiology, LSU Health Sciences Center, New Orleans, LA, USA.
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18
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Robinson SR, Dobson C, Lyons J. Challenges and directions for the pathogen hypothesis of Alzheimer's disease. Neurobiol Aging 2004; 25:629-37. [PMID: 15172741 DOI: 10.1016/j.neurobiolaging.2003.12.022] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2003] [Revised: 11/21/2003] [Accepted: 12/02/2003] [Indexed: 10/26/2022]
Abstract
This paper critically reviews the possibility that infiltration of the brain by pathogens (e.g. Herpes simplex virus type 1 (HSV1) or Chlamydophila pneumoniae (Cp)) acts as a trigger or co-factor for Alzheimer's disease (AD). The evidence currently available is limited and in some cases inconsistent, but it does justify the need for more vigorous investigation of this hypothesis. An issue of particular concern is the paucity of experimental evidence showing that pathogens can elicit the neuropathological changes and cognitive deficits that characterise AD. Other weaknesses include a failure to obtain independent confirmation of Cp in AD brains, and a lack of evidence for HSV1 proteins or intact virions in AD brain tissue. Future avenues of investigation that might prove fruitful include epidemiological investigations of the incidence of AD in individuals who are either immunosuppressed or have received chronic antiviral or antibiotic therapy. There is also a need to consider systemic infections as potential contributors to the pathogenesis of AD.
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Affiliation(s)
- Stephen R Robinson
- Department of Psychology, School of Psychology, Psychiatry and Psychological Medicine, Monash University, Clayton, Vic. 3800, Australia.
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19
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Itzhaki RF. The aetiology of Alzheimer's disease. MOLECULAR AND CELL BIOLOGY OF HUMAN DISEASES SERIES 1998; 4:55-91. [PMID: 9439744 DOI: 10.1007/978-94-011-0709-9_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- R F Itzhaki
- Department of Optometry and Vision Sciences, UMIST, Manchester, UK
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20
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Drummond CW, Eglin RP, Esiri MM. Herpes simplex virus encephalitis in a mouse model: PCR evidence for CNS latency following acute infection. J Neurol Sci 1994; 127:159-63. [PMID: 7535840 DOI: 10.1016/0022-510x(94)90068-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We have used a mouse model of herpes simplex encephalitis produced by intranasal inoculation of virus to study the expression of viral immediate early, early and late genes and latency associated transcript (LAT) in trigeminal ganglia and brain at various times after inoculation. A PCR technique was used to detect the viral gene transcripts. All viral genes were expressed between post-inoculation days 1 and 13. On post-inoculation day 42 when the acute infection had subsided only the LAT could be detected, most commonly (70%) in the trigeminal ganglion but also, in 50% of mice, in the brain stem, in 40% in olfactory bulbs and in 20% in cerebrum and cerebellum. These findings suggest that latent infection by HSV-1 may be relatively readily established in the CNS as well as in sensory ganglia. The frequency of establishment of latency appears to be related to the neuroanatomical accessibility of each brain region to the site of entry of the virus.
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Affiliation(s)
- C W Drummond
- Public Health Laboratory, John Radcliffe Hospital, Headington, Oxford, UK
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21
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Abstract
Inherited cases of Alzheimer's disease (AD) comprise only a very small proportion of the total. The remainder are of unknown etiopathogenesis, but they are very probably multifactorial in origin. This article describes studies on four possible factors: aluminum; viruses--in particular, herpes simplex type I virus (HSV1); defective DNA repair; and head trauma. Specific problems associated with aluminum, such as inadvertent contamination and its insolubility, have led to some controversy over its usage. Nonetheless, the effects of aluminum on animals and neuronal cells in culture have been studied intensively. Changes in protein structure and location in the cell are described, including the finding in this laboratory of a change in tau resembling that in AD neurofibrillary tangles, and also the lack of appreciable binding of aluminum to DNA. As for HSV1, there has previously been uncertainty about whether HSV1 DNA is present in human brain. Work in this laboratory using polymerase chain reaction has shown that HSV1 DNA is present in many normal aged brains and AD brains, but is absent in brains from younger people. Studies on DNA damage and repair in AD and normal cells are described, and finally, the possible involvement of head trauma is discussed.
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Affiliation(s)
- R F Itzhaki
- Department of Optometry and Vision Sciences, University of Manchester Institute of Science and Technology, UK
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22
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Nicoll JA, Kinrade E, Love S. PCR-mediated search for herpes simplex virus DNA in sections of brain from patients with multiple sclerosis and other neurological disorders. J Neurol Sci 1992; 113:144-51. [PMID: 1336795 DOI: 10.1016/0022-510x(92)90242-d] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Herpes simplex virus (HSV) has been shown to cause central nervous system demyelination in experimental animals and several studies have implicated HSV in the aetiology of multiple sclerosis (MS). We have used the polymerase chain reaction to look for DNA of both type 1 HSV (HSV-1) and type 2 HSV (HSV-2) in formalin-fixed paraffin-embedded brain tissues from patients with MS and other neurological diseases. Primers which amplify a fragment of the normal cellular gene c-myc were included in the reactions to assess the preservation of DNA in the tissue samples. 77 plaques of demyelination from 23 patients with MS were examined. HSV-1 DNA was amplified from only one plaque. This plaque involved the trigeminal root entry zone in the pons and it is suggested that the presence of viral DNA was related to the site examined rather than to the demyelination per se. HSV-2 DNA was amplified from none of the plaques. As expected, HSV-1 DNA was detected in the brains of 6 patients who died of HSV-1 encephalitis and HSV-2 DNA was amplified from the brain of a neonate with congenital HSV-2 infection. In sections of brain from 39 patients with a wide range of other neurological diseases HSV-1 DNA was detected in the pons of only 1 patient, who had AIDS associated with cytomegalovirus ventriculitis; subsequent investigation confirmed the presence of concomitant HSV-1 brain stem infection.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J A Nicoll
- Department of Neuropathology, Frenchay Hospital, Bristol, UK
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23
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Kittur SD, Hoh JH, Kawas CH, Hayward GS, Endo H, Adler WH. A molecular hybridization study for the presence of Herpes simplex, cytomegalovirus and Epstein-Barr virus in brain and blood of Alzheimer's disease patients. Arch Gerontol Geriatr 1992; 15:35-41. [PMID: 15374379 DOI: 10.1016/0167-4943(92)90038-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/1992] [Accepted: 03/18/1992] [Indexed: 11/16/2022]
Abstract
Among several hypothesis for the development of Alzheimer's disease is a viral hypothesis. The present study was designed to detect nucleic acid sequences for conventional viruses in peripheral blood cells and brain of Alzheimer's disease patients. DNA was isolated from peripheral blood cells and brain tissue from control individuals and Alzheimer's disease patients. Southern blot analysis was performed using radiolabeled probes for various conventional viruses. The results fail to detect the presence of Herpes simplex 1 (HSV-I), Herpes simplex II (HSV-II), Epstein-Barr virus (EBV) and cytomegalo virus (CMV) at a sensitivity level of detecting 1 genome/100 cells. We exclude conventional viruses as a cause of Alzheimer's disease at this level of detection.
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Affiliation(s)
- S D Kittur
- Molecular Neurobiology Unit, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Abstract
Alzheimer's disease (AD) is considered to be the number one health problem and seems to be reaching epidemic proportion in the USA. The cause of AD is not known, a reliable animal model of the disease has not been found and appropriate treatment of this dementia is wanting. The present review focuses on the possibility that a virus or exogenous toxic materials may gain access to the CNS using the olfactory mucosa as a portal of entry. Anterograde and retrograde transport of the virus/zeolites to olfactory forebrain regions, which receive primary and secondary projections from the main olfactory bulb (MOB) and which, in turn, project centrifugal axons to the MOB, may initiate cell degeneration at such loci. Pathological changes may, thus, be initially confined to projecting and intrinsic neurons localized in cortical and subcortical olfactory structures; arguments are advanced which favor the view that excitotoxic phenomena could be mainly responsible for the overall degenerative picture. Neurotoxic activity may follow infection by the virus itself, be facilitated by loss of GABAergic terminals in olfactory cortex, develop following repeated episodes of physiological long term potentiation (which unmasks NMDA receptors) or be due to excessive release, faculty re-uptake or altered glutamate receptor sensitivity. Furthermore, a reduction in central inhibitory inputs to the MOB might then result in disinhibition of mitral/tufted neurons and enhance the excitotoxic phenomena in the MOB projecting field. Within this context, and in line with recent studies, it is believed that pathology begins at cortical (mainly olfactory) regions, basal forebrain neurons being secondarily affected due to retrograde degeneration. In addition, failure to produce a critical level of neurotrophic factors by a damaged MOB and olfactory cortex, could adversely affect survival of basal cholinergic neurons which innervate both regions. Support for these hypothesis is provided, first, by recent reports on pathological findings in AD brains which seem to involve preferentially the olfactory and entorhinal cortices, the olfactory amygdala and the hippocampus, all of which receive primary or secondary projections from the MOB; secondly, by the presence of severe olfactory deficits in the early stages of the disease, mainly of a discriminatory nature, which points to a malfunction of central olfactory structures.
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Affiliation(s)
- H Ferreyra-Moyano
- Instituto de Investigacion Medica M. y M. Ferreyra, Cordoba, Argentina
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25
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Roberts GW, Taylor GR, Carter GI, Johnson JA, Bloxham C, Brown R, Crow TJ. Herpes simplex virus: a role in the aetiology of Alzheimer's disease? J Neurol Neurosurg Psychiatry 1986; 49:216. [PMID: 3005513 PMCID: PMC1028693 DOI: 10.1136/jnnp.49.2.216] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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26
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Mann DM. The neuropathology of Alzheimer's disease: a review with pathogenetic, aetiological and therapeutic considerations. Mech Ageing Dev 1985; 31:213-55. [PMID: 3906293 DOI: 10.1016/0047-6374(85)90092-2] [Citation(s) in RCA: 163] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The neuropathology of Alzheimer's disease is reviewed in this paper emphasizing the morphological and morphometric changes that occur in the disease and their relationship to age and ageing. From this, a new hypothesis of pathogenesis is presented which accounts for the pattern of neuronal damage in Alzheimer's disease. This is that the pathogenesis of Alzheimer's disease begins with a leakage of a neurotoxin through a defective cortical blood brain barrier. This incites development of the senile plaque and later, via a retrograde transport of the same (or different) factors, intracellular neurofibrillary tangle formation and death of neurones within areas of cortex affected by plaques and in subcortical areas such as nucleus basalis of Meynert, locus caeruleus and dorsal raphe nuclei, all of which project to these same areas of cortex. Evidence consistent with this hypothesis is presented and the aetiological and therapeutic implications are discussed.
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Abstract
In the brains of patients with senile dementia of the Alzheimer type (SDAT), the quantitatively pathognomonic neuronal lesions (tangles, plaques, granulovacuolar degeneration, Hirano bodies, and nerve cell loss) are predisposed to occur especially within the limbic system. Anatomical and physiological studies indicate that fibres from the trigeminal ganglia innervate meninges and vessels within the middle and anterior cranial fossae, especially in the same subfrontal and mesial temporal regions preferentially afflicted in acute herpes encephalitis. These limbic regions are critical for normal memory processing and recall. Explantation and cocultivation techniques have recently demonstrated Herpes simplex virus in many humans trigeminal ganglia, which also reveal a life-long lymphocytic infiltration in the absence of any pathological changes in the sensory neurones. These lymphocytes may represent a histological marker of latent herpes virus, which when reactivating is well-established as the ganglionic source of recurrent herpes labialis. It is suggested that reactivation of the same dormant viral material travelling centripetally instead might be the cause of the "degenerative" lesions typical both of Alzheimer's Disease and of the normal aged human brain.
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Abstract
The mechanisms and organelles through which control of protein synthesis within healthy nerve cells is governed are discussed, and the ways in which expression of these biochemical pathways can be related to cell morphology are described. The volumes of the nucleus and nucleolus, and the amount of RNA within the cell body, are all interrelated and seem to be set at genetically predetermined levels which normally match the neurones basal needs for replacement proteins in respect of the size of its' projection field. However, in situations of (induced) hyperactivity or cell damage, or in others where disease may lower nerve cell activity, the protein requirements change, and it is noted that these morphological features also alter in a direction appropriate to the need for greater or lesser amounts of protein. How these alterations in protein synthesis can provide information as to both the basic pathology, or even the pathogenesis, of degenerative disease of the nervous system is illustrated by reference to Alzheimer's disease and motor neurone disease.
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30
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