1
|
Adler GL, Le K, Fu Y, Kim WS. Human Endogenous Retroviruses in Neurodegenerative Diseases. Genes (Basel) 2024; 15:745. [PMID: 38927681 PMCID: PMC11202925 DOI: 10.3390/genes15060745] [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: 05/10/2024] [Revised: 05/25/2024] [Accepted: 06/04/2024] [Indexed: 06/28/2024] Open
Abstract
Human endogenous retroviruses (HERVs) are DNA transposable elements that have integrated into the human genome via an ancestral germline infection. The potential importance of HERVs is underscored by the fact that they comprise approximately 8% of the human genome. HERVs have been implicated in the pathogenesis of neurodegenerative diseases, a group of CNS diseases characterized by a progressive loss of structure and function of neurons, resulting in cell death and multiple physiological dysfunctions. Much evidence indicates that HERVs are initiators or drivers of neurodegenerative processes in multiple sclerosis and amyotrophic lateral sclerosis, and clinical trials have been designed to target HERVs. In recent years, the role of HERVs has been explored in other major neurodegenerative diseases, including frontotemporal dementia, Alzheimer's disease and Parkinson's disease, with some interesting discoveries. This review summarizes and evaluates the past and current research on HERVs in neurodegenerative diseases. It discusses the potential role of HERVs in disease manifestation and neurodegeneration. It critically reviews antiretroviral strategies used in the therapeutic intervention of neurodegenerative diseases.
Collapse
Affiliation(s)
- Gabrielle L. Adler
- Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- School of Medical Sciences, The University of Sydney, Sydney, NSW 2050, Australia
| | - Kelvin Le
- Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- School of Medical Sciences, The University of Sydney, Sydney, NSW 2050, Australia
| | - YuHong Fu
- Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- School of Medical Sciences, The University of Sydney, Sydney, NSW 2050, Australia
| | - Woojin Scott Kim
- Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- School of Medical Sciences, The University of Sydney, Sydney, NSW 2050, Australia
- School of Biomedical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| |
Collapse
|
2
|
Pribac M, Motataianu A, Andone S, Mardale E, Nemeth S. Bridging the Gap: Harnessing Plant Bioactive Molecules to Target Gut Microbiome Dysfunctions in Amyotrophic Lateral Sclerosis. Curr Issues Mol Biol 2024; 46:4471-4488. [PMID: 38785539 PMCID: PMC11120375 DOI: 10.3390/cimb46050271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 04/30/2024] [Accepted: 05/03/2024] [Indexed: 05/25/2024] Open
Abstract
The correlation between neurodegenerative diseases and the gut microbiome is increasingly evident, with amyotrophic lateral sclerosis (ALS) being particularly notable for its severity and lack of therapeutic options. The gut microbiota, implicated in the pathogenesis and development of ALS, plays a crucial role in the disease. Bioactive plant molecules, specifically volatile compounds in essential oils, offer a promising therapeutic avenue due to their anti-inflammatory properties and gut-modulating effects. Our narrative review aimed to identify microbiota-associated bacteria in ALS and analyze the benefits of administering bioactive plant molecules as much-needed therapeutic options in the management of this disease. A comprehensive search of PubMed database articles published before December 2023, encompassing research on cell, human, and animal ALS models, was conducted. After selecting, analyzing, and discussing key articles, bacteria linked to ALS pathogenesis and physiopathology were identified. Notably, positively highlighted bacteria included Akkermansia muciniphila (Verrucomicrobia phylum), Faecalibacterium prausnitzii, and Butyrivibrio spp. (Firmicutes phylum). Conversely, members of the Escherichia coli spp. (Proteobacteria phylum) and Ruminococcus spp. (Firmicutes phylum) stood out negatively in respect to ALS development. These bacteria were associated with molecular changes linked to ALS pathogenesis and evolution. Bioactive plant molecules can be directly associated with improvements in the microbiome, due to their role in reducing inflammation and oxidative stress, emerging as one of the most promising natural agents for enriching present-day ALS treatments.
Collapse
Affiliation(s)
- Mirela Pribac
- Doctoral School of Biomedical Sciences, University of Oradea, 410087 Oradea, Romania
| | - Anca Motataianu
- Ist Neurology Clinic, Mures County Clinical Emergency Hospital, 540136 Targu Mures, Romania
- Department of Neurology, University of Medicine, Pharmacy, Science and Technology, 540142 Targu Mures, Romania
| | - Sebastian Andone
- Ist Neurology Clinic, Mures County Clinical Emergency Hospital, 540136 Targu Mures, Romania
- Department of Neurology, University of Medicine, Pharmacy, Science and Technology, 540142 Targu Mures, Romania
| | | | - Sebastian Nemeth
- Doctoral School of Biomedical Sciences, University of Oradea, 410087 Oradea, Romania
| |
Collapse
|
3
|
da Silva AL, Guedes BLM, Santos SN, Correa GF, Nardy A, Nali LHDS, Bachi ALL, Romano CM. Beyond pathogens: the intriguing genetic legacy of endogenous retroviruses in host physiology. Front Cell Infect Microbiol 2024; 14:1379962. [PMID: 38655281 PMCID: PMC11035796 DOI: 10.3389/fcimb.2024.1379962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 03/22/2024] [Indexed: 04/26/2024] Open
Abstract
The notion that viruses played a crucial role in the evolution of life is not a new concept. However, more recent insights suggest that this perception might be even more expansive, highlighting the ongoing impact of viruses on host evolution. Endogenous retroviruses (ERVs) are considered genomic remnants of ancient viral infections acquired throughout vertebrate evolution. Their exogenous counterparts once infected the host's germline cells, eventually leading to the permanent endogenization of their respective proviruses. The success of ERV colonization is evident so that it constitutes 8% of the human genome. Emerging genomic studies indicate that endogenous retroviruses are not merely remnants of past infections but rather play a corollary role, despite not fully understood, in host genetic regulation. This review presents some evidence supporting the crucial role of endogenous retroviruses in regulating host genetics. We explore the involvement of human ERVs (HERVs) in key physiological processes, from their precise and orchestrated activities during cellular differentiation and pluripotency to their contributions to aging and cellular senescence. Additionally, we discuss the costs associated with hosting a substantial amount of preserved viral genetic material.
Collapse
Affiliation(s)
- Amanda Lopes da Silva
- Instituto de Medicina Tropical de São Paulo, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Bruno Luiz Miranda Guedes
- Instituto de Medicina Tropical de São Paulo, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Samuel Nascimento Santos
- UNISA Research Center, Universidade Santo Amaro, Post-Graduation in Health Sciences, São Paulo, Brazil
| | - Giovanna Francisco Correa
- Instituto de Medicina Tropical de São Paulo, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Ariane Nardy
- UNISA Research Center, Universidade Santo Amaro, Post-Graduation in Health Sciences, São Paulo, Brazil
| | | | - Andre Luis Lacerda Bachi
- UNISA Research Center, Universidade Santo Amaro, Post-Graduation in Health Sciences, São Paulo, Brazil
| | - Camila Malta Romano
- Instituto de Medicina Tropical de São Paulo, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
- Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brazil
| |
Collapse
|
4
|
Dopkins N, Singh B, Michael S, Zhang P, Marston JL, Fei T, Singh M, Feschotte C, Collins N, Bendall ML, Nixon DF. Ribosomal profiling of human endogenous retroviruses in healthy tissues. BMC Genomics 2024; 25:5. [PMID: 38166631 PMCID: PMC10759522 DOI: 10.1186/s12864-023-09909-x] [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: 06/05/2023] [Accepted: 12/14/2023] [Indexed: 01/05/2024] Open
Abstract
Human endogenous retroviruses (HERVs) are the germline embedded proviral fragments of ancient retroviral infections that make up roughly 8% of the human genome. Our understanding of HERVs in physiology primarily surrounds their non-coding functions, while their protein coding capacity remains virtually uncharacterized. Therefore, we applied the bioinformatic pipeline "hervQuant" to high-resolution ribosomal profiling of healthy tissues to provide a comprehensive overview of translationally active HERVs. We find that HERVs account for 0.1-0.4% of all translation in distinct tissue-specific profiles. Collectively, our study further supports claims that HERVs are actively translated throughout healthy tissues to provide sequences of retroviral origin to the human proteome.
Collapse
Affiliation(s)
- Nicholas Dopkins
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine, New York, NY, 10021, USA.
| | - Bhavya Singh
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Stephanie Michael
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Panpan Zhang
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14850, USA
| | - Jez L Marston
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Tongyi Fei
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Manvendra Singh
- Clinical Neuroscience, Max Planck Institute for Multidisciplinary Sciences, City Campus, Göttingen, Germany
| | - Cedric Feschotte
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14850, USA
| | - Nicholas Collins
- Jill Roberts Institute for Research in Inflammatory Bowel Disease, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Matthew L Bendall
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Douglas F Nixon
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine, New York, NY, 10021, USA
| |
Collapse
|
5
|
Dubowsky M, Theunissen F, Carr JM, Rogers ML. The Molecular Link Between TDP-43, Endogenous Retroviruses and Inflammatory Neurodegeneration in Amyotrophic Lateral Sclerosis: a Potential Target for Triumeq, an Antiretroviral Therapy. Mol Neurobiol 2023; 60:6330-6345. [PMID: 37450244 PMCID: PMC10533598 DOI: 10.1007/s12035-023-03472-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 06/30/2023] [Indexed: 07/18/2023]
Abstract
Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease (MND), is a progressive neurological disorder, characterised by the death of upper and lower motor neurons. The aetiology of ALS remains unknown, and treatment options are limited. Endogenous retroviruses (ERVs), specifically human endogenous retrovirus type K (HERV-K), have been proposed to be involved in the propagation of neurodegeneration in ALS. ERVs are genomic remnants of ancient viral infection events, with most being inactive and not retaining the capacity to encode a fully infectious virus. However, some ERVs retain the ability to be activated and transcribed, and ERV transcripts have been found to be elevated within the brain tissue of MND patients. A hallmark of ALS pathology is altered localisation of the transactive response (TAR) DNA binding protein 43 kDa (TDP-43), which is normally found within the nucleus of neuronal and glial cells and is involved in RNA regulation. In ALS, TDP-43 aggregates within the cytoplasm and facilitates neurodegeneration. The involvement of ERVs in ALS pathology is thought to occur through TDP-43 and neuroinflammatory mediators. In this review, the proposed involvement of TDP-43, HERV-K and immune regulators on the onset and progression of ALS will be discussed. Furthermore, the evidence supporting a therapy based on targeting ERVs in ALS will be reviewed.
Collapse
Affiliation(s)
- Megan Dubowsky
- College of Medicine and Public Health and Flinders Health and Medical Research Institute, Flinders University, Bedford Park, SA, Australia.
| | - Frances Theunissen
- Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Murdoch, WA, Australia
| | - Jillian M Carr
- College of Medicine and Public Health and Flinders Health and Medical Research Institute, Flinders University, Bedford Park, SA, Australia
| | - Mary-Louise Rogers
- College of Medicine and Public Health and Flinders Health and Medical Research Institute, Flinders University, Bedford Park, SA, Australia
| |
Collapse
|
6
|
Kyriakou E, Magiorkinis G. Interplay between endogenous and exogenous human retroviruses. Trends Microbiol 2023; 31:933-946. [PMID: 37019721 DOI: 10.1016/j.tim.2023.03.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 03/09/2023] [Accepted: 03/13/2023] [Indexed: 04/07/2023]
Abstract
In humans, retroviruses thrive more as symbionts than as parasites. Apart from the only two modern exogenous human retroviruses (human T-cell lymphotropic and immunodeficiency viruses; HTLV and HIV, respectively), ~8% of the human genome is occupied by ancient retroviral DNA [human endogenous retroviruses (HERVs)]. Here, we review the recent discoveries about the interactions between the two groups, the impact of infection by exogenous retroviruses on the expression of HERVs, the effect of HERVs on the pathogenicity of HIV and HTLV and on the severity of the diseases caused by them, and the antiviral protection that HERVs can allegedly provide to the host. Tracing the crosstalk between contemporary retroviruses and their endogenized ancestors will provide better understanding of the retroviral world.
Collapse
Affiliation(s)
- Eleni Kyriakou
- Department of Hygiene, Epidemiology and Medical Statistics, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Gkikas Magiorkinis
- Department of Hygiene, Epidemiology and Medical Statistics, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece.
| |
Collapse
|
7
|
Interplay between activation of endogenous retroviruses and inflammation as common pathogenic mechanism in neurological and psychiatric disorders. Brain Behav Immun 2023; 107:242-252. [PMID: 36270439 DOI: 10.1016/j.bbi.2022.10.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 09/21/2022] [Accepted: 10/13/2022] [Indexed: 12/05/2022] Open
Abstract
Human endogenous retroviruses (ERVs) are ancestorial retroviral elements that were integrated into our genome through germline infections and insertions during evolution. They have repeatedly been implicated in the aetiology and pathophysiology of numerous human disorders, particularly in those that affect the central nervous system. In addition to the known association of ERVs with multiple sclerosis and amyotrophic lateral sclerosis, a growing number of studies links the induction and expression of these retroviral elements with the onset and severity of neurodevelopmental and psychiatric disorders. Although these disorders differ in terms of overall disease pathology and causalities, a certain degree of (subclinical) chronic inflammation can be identified in all of them. Based on these commonalities, we discuss the bidirectional relationship between ERV expression and inflammation and highlight that numerous entry points to this reciprocal sequence of events exist, including initial infections with ERV-activating pathogens, exposure to non-infectious inflammatory stimuli, and conditions in which epigenetic silencing of ERV elements is disrupted.
Collapse
|
8
|
Mazumder S, Kiernan MC, Halliday GM, Timmins HC, Mahoney CJ. The contribution of brain banks to knowledge discovery in amyotrophic lateral sclerosis: A systematic review. Neuropathol Appl Neurobiol 2022; 48:e12845. [PMID: 35921237 PMCID: PMC9804699 DOI: 10.1111/nan.12845] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 06/17/2022] [Accepted: 07/23/2022] [Indexed: 01/09/2023]
Abstract
Over the past decade, considerable efforts have been made to accelerate pathophysiological understanding of fatal neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) with brain banks at the forefront. In addition to exploratory disease mechanisms, brain banks have aided our understanding with regard to clinical diagnosis, genetics and cell biology. Across neurodegenerative disorders, the impact of brain tissue in ALS research has yet to be quantified. This review aims to outline (i) how postmortem tissues from brain banks have influenced our understanding of ALS over the last 15 years, (ii) correlate the location of dedicated brain banks with the geographical prevalence of ALS, (iii) identify the frequency of features reported from postmortem studies and (iv) propose common reporting standards for materials obtained from dedicated brain banks. A systematic review was conducted using PubMed and Web of Science databases using key words. From a total of 1439 articles, 73 articles were included in the final review, following PRISMA guidelines. Following a thematic analysis, articles were categorised into five themes; clinico-pathological (13), genetic (20), transactive response DNA binding protein 43 (TDP-43) pathology (12), non-TDP-43 neuronal pathology (nine) and extraneuronal pathology (19). Research primarily focused on the genetics of ALS, followed by protein pathology. About 63% of the brain banks were in the United States of America and United Kingdom. The location of brain banks overall aligned with the incidence of ALS worldwide with 88% of brain banks situated in Europe and North America. An overwhelming lack of consistency in reporting and replicability was observed, strengthening the need for a standardised reporting system. Overall, postmortem material from brain banks generated substantial new knowledge in areas of genetics and proteomics and supports their ongoing role as an important research tool.
Collapse
Affiliation(s)
- Srestha Mazumder
- ForeFront Clinic, Brain and Mind CentreUniversity of SydneySydneyNew South WalesAustralia
| | - Matthew C. Kiernan
- ForeFront Clinic, Brain and Mind CentreUniversity of SydneySydneyNew South WalesAustralia
| | - Glenda M. Halliday
- Frontier, Brain and Mind CentreUniversity of SydneySydneyNew South WalesAustralia
| | - Hannah C. Timmins
- ForeFront Clinic, Brain and Mind CentreUniversity of SydneySydneyNew South WalesAustralia
| | - Colin J. Mahoney
- ForeFront Clinic, Brain and Mind CentreUniversity of SydneySydneyNew South WalesAustralia
| |
Collapse
|
9
|
Garcia-Montojo M, Simula ER, Fathi S, McMahan C, Ghosal A, Berry JD, Cudkowicz M, Elkahloun A, Johnson K, Norato G, Jensen P, James T, Sechi LA, Nath A. Antibody Response to HML-2 May Be Protective in Amyotrophic Lateral Sclerosis. Ann Neurol 2022; 92:782-792. [PMID: 36053951 DOI: 10.1002/ana.26466] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 07/28/2022] [Accepted: 07/28/2022] [Indexed: 01/07/2023]
Abstract
OBJECTIVES Reactivation of HERV-K(HML-2) has been found in subsets of individuals with amyotrophic lateral sclerosis (ALS). This study examines the antibody response against HML-2 in ALS and analyzes its clinical relevance. METHODS Antibodies to HML-2 envelope (env) were analyzed using a peptide array for epitope mapping and by a peptide enzyme-linked immunosorbent assay (ELISA) in 242 healthy donors, and 243 ALS and 85 multiple sclerosis (MS) individuals. Extracellular levels of HML-2 were analyzed by digital polymerase chain reaction (PCR). RESULTS Antibodies in the sera of ALS individuals recognized more HML-2 env peptides compared to healthy controls (p < 0.0001). ALS individuals had higher levels of HML-2 than healthy donors (p = 0.02) and higher antibody levels against a select HML-2 env peptide compared to healthy donors or individuals with multiple sclerosis (p < 0.0001). 55.14% of ALS compared to 21.16% of healthy donors and 13.10% of MS individuals had antibodies against the HML-2 peptide (AUC = 0.769, p < 0.0001). Levels of extracellular HML-2 DNA in serum (p = 0.02) and the number of HML-2 env peptides recognized by ALS sera (p = 0.02) correlated with disease duration. Among ALS individuals, lower levels of HML-2 antibodies were associated with a definite diagnosis per EL Escorial criteria (p = 0.03), and with a lower predicted (p = 0.02) and observed survival (p = 0.03). INTERPRETATION There is a differential antibody response against specific epitopes of HML-2 env in ALS and controls, suggesting epitope spreading, likely due to persistent antigenic exposure following reactivation of the viral genes. Low levels of antibodies to HML-2 env in ALS are associated with poor prognosis and decreased survival probability. ANN NEUROL 2022;92:782-792.
Collapse
Affiliation(s)
- Marta Garcia-Montojo
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Elena Rita Simula
- Department of Biomedical Sciences, Division of Microbiology and Virology, University of Sassari, Sassari, Italy
| | - Saeed Fathi
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Cynthia McMahan
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Anubrata Ghosal
- Sean M. Healey & AMG Center for ALS and the Neurology Clinical Research Institute, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - James D Berry
- Sean M. Healey & AMG Center for ALS and the Neurology Clinical Research Institute, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Merit Cudkowicz
- Sean M. Healey & AMG Center for ALS and the Neurology Clinical Research Institute, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Abdel Elkahloun
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Kory Johnson
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Gina Norato
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Peter Jensen
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Tony James
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Leonardo A Sechi
- Department of Biomedical Sciences, Division of Microbiology and Virology, University of Sassari, Sassari, Italy.,Struttura Complessa Microbiologia e Virologia, Azienda Ospedaliera Universitaria Sassari, Sassari, Italy
| | - Avindra Nath
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| |
Collapse
|
10
|
Li W, Pandya D, Pasternack N, Garcia-Montojo M, Henderson L, Kozak CA, Nath A. Retroviral Elements in Pathophysiology and as Therapeutic Targets for Amyotrophic Lateral Sclerosis. Neurotherapeutics 2022; 19:1085-1101. [PMID: 35415778 PMCID: PMC9587200 DOI: 10.1007/s13311-022-01233-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/03/2022] [Indexed: 10/18/2022] Open
Abstract
The study of the role of retroviruses in amyotrophic lateral sclerosis (ALS) dates back to the 1960s shortly after transposable elements themselves were first discovered. It was quickly realized that in wild mice both horizontal and vertical transmissions of retroviral elements were key to the development of an ALS-like syndrome leading to the postulate that endogenous retroviruses (ERVs) contribute significantly to the pathogenicity of this disease. Subsequent studies identified retroviral reverse transcriptase activity in brains of individuals with ALS from Guam. However, except for a single study from the former Soviet Union, ALS could not be transmitted to rhesus macaques. The discovery of an ALS-like syndrome in human immunodeficiency virus (HIV) and human T cell leukemia virus infected individuals led to renewed interest in the field and reverse transcriptase activity was found in the blood and cerebrospinal fluid of individuals with sporadic ALS. However, exogenous retroviruses could not be found in individuals with ALS which further reinforced the possibility of involvement of a human ERV (HERV). The first demonstration of the involvement of a HERV was the discovery of the activation of human endogenous retrovirus-K subtype HML-2 in the brains of individuals with ALS. The envelope protein of HML-2 is neurotoxic and transgenic animals expressing the envelope protein develop an ALS-like syndrome. Activation of HML-2 occurs in the context of generalized transposable element activation and is not specific for ALS. Individuals with HIV-associated ALS show a remarkable response to antiretroviral therapy; however, antiretroviral trials in ALS down-regulate HML-2 without ameliorating the disease. This highlights the need for specific drugs to be developed against HML-2 as a novel therapeutic target for ALS. Other approaches might include antisense oligonucleotides, shRNA targeted against the envelope gene or antibodies that can target the extracellular envelope protein. Future clinical trials in ALS should consider combination therapies to control these ERVs.
Collapse
Affiliation(s)
- Wenxue Li
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Darshan Pandya
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Nicholas Pasternack
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Marta Garcia-Montojo
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Lisa Henderson
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Christine A Kozak
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Avindra Nath
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA.
| |
Collapse
|
11
|
Ma G, Babarinde IA, Zhou X, Hutchins AP. Transposable Elements in Pluripotent Stem Cells and Human Disease. Front Genet 2022; 13:902541. [PMID: 35719395 PMCID: PMC9201960 DOI: 10.3389/fgene.2022.902541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 05/20/2022] [Indexed: 11/18/2022] Open
Abstract
Transposable elements (TEs) are mobile genetic elements that can randomly integrate into other genomic sites. They have successfully replicated and now occupy around 40% of the total DNA sequence in humans. TEs in the genome have a complex relationship with the host cell, being both potentially deleterious and advantageous at the same time. Only a tiny minority of TEs are still capable of transposition, yet their fossilized sequence fragments are thought to be involved in various molecular processes, such as gene transcriptional activity, RNA stability and subcellular localization, and chromosomal architecture. TEs have also been implicated in biological processes, although it is often hard to reveal cause from correlation due to formidable technical issues in analyzing TEs. In this review, we compare and contrast two views of TE activity: one in the pluripotent state, where TEs are broadly beneficial, or at least mechanistically useful, and a second state in human disease, where TEs are uniformly considered harmful.
Collapse
|
12
|
A retrotransposon storm marks clinical phenoconversion to late-onset Alzheimer's disease. GeroScience 2022; 44:1525-1550. [PMID: 35585302 PMCID: PMC9213607 DOI: 10.1007/s11357-022-00580-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 04/26/2022] [Indexed: 12/03/2022] Open
Abstract
Recent reports have suggested that the reactivation of otherwise transcriptionally silent transposable elements (TEs) might induce brain degeneration, either by dysregulating the expression of genes and pathways implicated in cognitive decline and dementia or through the induction of immune-mediated neuroinflammation resulting in the elimination of neural and glial cells. In the work we present here, we test the hypothesis that differentially expressed TEs in blood could be used as biomarkers of cognitive decline and development of AD. To this aim, we used a sample of aging subjects (age > 70) that developed late-onset Alzheimer’s disease (LOAD) over a relatively short period of time (12–48 months), for which blood was available before and after their phenoconversion, and a group of cognitive stable subjects as controls. We applied our developed and validated customized pipeline that allows the identification, characterization, and quantification of the differentially expressed (DE) TEs before and after the onset of manifest LOAD, through analyses of RNA-Seq data. We compared the level of DE TEs within more than 600,000 TE-mapping RNA transcripts from 25 individuals, whose specimens we obtained before and after their phenotypic conversion (phenoconversion) to LOAD, and discovered that 1790 TE transcripts showed significant expression differences between these two timepoints (logFC ± 1.5, logCMP > 5.3, nominal p value < 0.01). These DE transcripts mapped both over- and under-expressed TE elements. Occurring before the clinical phenoconversion, this TE storm features significant increases in DE transcripts of LINEs, LTRs, and SVAs, while those for SINEs are significantly depleted. These dysregulations end with signs of manifest LOAD. This set of highly DE transcripts generates a TE transcriptional profile that accurately discriminates the before and after phenoconversion states of these subjects. Our findings suggest that a storm of DE TEs occurs before phenoconversion from normal cognition to manifest LOAD in risk individuals compared to controls, and may provide useful blood-based biomarkers for heralding such a clinical transition, also suggesting that TEs can indeed participate in the complex process of neurodegeneration.
Collapse
|
13
|
Li Y, Chen Y, Zhang N, Fan D. Human endogenous retrovirus K (HERV-K) env in neuronal extracellular vesicles: a new biomarker of motor neuron disease. Amyotroph Lateral Scler Frontotemporal Degener 2022; 23:100-107. [PMID: 34151656 DOI: 10.1080/21678421.2021.1936061] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 05/18/2021] [Accepted: 05/24/2021] [Indexed: 10/21/2022]
Abstract
Objective: Human endogenous retroviruses (HERVs) have been gradually confirmed to be involved in the onset and progression of motor neuron disease(MND). However, noninvasive detection of HERVs in the central nervous system is lacking. The aim of this study is to verify the relationship between the level of HERV-K env in neuronal extracellular vesicles in plasma and the onset and severity of MND. Methods: We extracted neuronal extracellular vesicles from plasma of 39 MND patients and 30 age- and sex-matched controls, and detected HERV-K env in extracellular vesicles by an enzyme-linked immunosorbent assay (ELISA). Results: Levels of HERV-K env in neuronal extracellular vesicles positively associated with range of lower motor neurons (LMNs) involved (1.66 ± 0.37 vs. 1.35 ± 0.34, p = 0.041), ALS phenotype (1.52 ± 0.31 vs. 1.24 ± 0.37, p = 0.013) and course of disease (1.83 ± 0.35 vs. 1.42 ± 0.22, p = 0.003), and increased in advanced-phase MND (definite and probable according to revised EI Escorial criteria) compared with early-phase MND (possible and lab-supported probable), albeit without very profound significance (1.52 ± 0.34 vs. 1.29 ± 0.36, p = 0.048). Conclusions: In conclusion, levels of HERV-K env in neuronal extracellular vesicles extracted from plasma can be used as a noninvasive biomarker of severity of MND.
Collapse
Affiliation(s)
- Yuan Li
- Department of Neurology, Peking University Third Hospital, Beijing, China
- Beijing Municipal Key Laboratory of Biomarker and Translational Research in Neurodegenerative Diseases, Beijing, China, and
| | - Yong Chen
- Department of Neurology, Peking University Third Hospital, Beijing, China
- Beijing Municipal Key Laboratory of Biomarker and Translational Research in Neurodegenerative Diseases, Beijing, China, and
| | - Nan Zhang
- Department of Neurology, Peking University Third Hospital, Beijing, China
- Beijing Municipal Key Laboratory of Biomarker and Translational Research in Neurodegenerative Diseases, Beijing, China, and
| | - Dongsheng Fan
- Department of Neurology, Peking University Third Hospital, Beijing, China
- Beijing Municipal Key Laboratory of Biomarker and Translational Research in Neurodegenerative Diseases, Beijing, China, and
- Key Laboratory for Neuroscience, National Health Commission/Ministry of Education, Peking University, Beijing, China
| |
Collapse
|
14
|
Cordeiro PAS, Assone T, Prates G, Tedeschi MRM, Fonseca LAM, Casseb J. The role of IFN-γ production during retroviral infections: an important cytokine involved in chronic inflammation and pathogenesis. Rev Inst Med Trop Sao Paulo 2022; 64:e64. [PMID: 36197425 PMCID: PMC9528752 DOI: 10.1590/s1678-9946202264064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 08/09/2022] [Indexed: 11/23/2022] Open
Abstract
Interferon-gamma (IFN-γ) plays a crucial role in viral infections by preventing viral replication and in the promotion of innate and adaptive immune responses. However, IFN-gamma can exert distinct effects in different persistent viral infections. The long-term overproduction of IFN-γ in retroviral infections, such as the human immunodeficiency virus (HIV), human T-lymphotropic virus type 1 (HTLV-1), and human endogenous retroviruses (HERVs), resulting in inflammation, may cause neuronal damage. This review is provocative about the role of IFN-γ during persistent retroviral infections and its relationship with the causation of some neurological disorders that are important for public health.
Collapse
|
15
|
Traiffort E, Morisset-Lopez S, Moussaed M, Zahaf A. Defective Oligodendroglial Lineage and Demyelination in Amyotrophic Lateral Sclerosis. Int J Mol Sci 2021; 22:ijms22073426. [PMID: 33810425 PMCID: PMC8036314 DOI: 10.3390/ijms22073426] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/15/2021] [Accepted: 03/24/2021] [Indexed: 01/23/2023] Open
Abstract
Motor neurons and their axons reaching the skeletal muscle have long been considered as the best characterized targets of the degenerative process observed in amyotrophic lateral sclerosis (ALS). However, the involvement of glial cells was also more recently reported. Although oligodendrocytes have been underestimated for a longer time than other cells, they are presently considered as critically involved in axonal injury and also conversely constitute a target for the toxic effects of the degenerative neurons. In the present review, we highlight the recent advances regarding oligodendroglial cell involvement in the pathogenesis of ALS. First, we present the oligodendroglial cells, the process of myelination, and the tight relationship between axons and myelin. The histological abnormalities observed in ALS and animal models of the disease are described, including myelin defects and oligodendroglial accumulation of pathological protein aggregates. Then, we present data that establish the existence of dysfunctional and degenerating oligodendroglial cells, the chain of events resulting in oligodendrocyte degeneration, and the most recent molecular mechanisms supporting oligodendrocyte death and dysfunction. Finally, we review the arguments in support of the primary versus secondary involvement of oligodendrocytes in the disease and discuss the therapeutic perspectives related to oligodendrocyte implication in ALS pathogenesis.
Collapse
Affiliation(s)
- Elisabeth Traiffort
- Diseases and Hormones of the Nervous System U1195 INSERM, Paris Saclay University, 80 Rue du Général Leclerc, 94276 Le Kremlin-Bicêtre, France;
- Correspondence:
| | - Séverine Morisset-Lopez
- Centre de Biophysique Moléculaire, UPR 4301 CNRS, Orléans University, INSERM, rue Charles Sadron, CEDEX 02, 45071 Orleans, France; (S.M.-L.); (M.M.)
| | - Mireille Moussaed
- Centre de Biophysique Moléculaire, UPR 4301 CNRS, Orléans University, INSERM, rue Charles Sadron, CEDEX 02, 45071 Orleans, France; (S.M.-L.); (M.M.)
| | - Amina Zahaf
- Diseases and Hormones of the Nervous System U1195 INSERM, Paris Saclay University, 80 Rue du Général Leclerc, 94276 Le Kremlin-Bicêtre, France;
| |
Collapse
|
16
|
Inhibition of HERV-K (HML-2) in amyotrophic lateral sclerosis patients on antiretroviral therapy. J Neurol Sci 2021; 423:117358. [PMID: 33653604 DOI: 10.1016/j.jns.2021.117358] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 01/20/2021] [Accepted: 02/17/2021] [Indexed: 11/21/2022]
Abstract
Reactivation of Human Endogenous Retrovirus K (HERV-K), subtype HML-2, has been associated with pathophysiology of amyotrophic lateral sclerosis (ALS). We aimed to assess the efficacy of antiretroviral therapy in inhibiting HML-2 in patients with ALS and a possible association between the change in HML-2 levels and clinical outcomes. We studied the effect of 24-weeks antiretroviral combination therapy with abacavir, lamivudine, and dolutegravir on HML-2 levels in 29 ALS patients. HML-2 levels decreased progressively over 24 weeks (P = 0.001) and rebounded within a week of stopping medications (P = 0.02). The majority of participants (82%), defined as "responders", experienced a decrease in HML-2 at week 24 of treatment compared to the pre-treatment levels. Differences in the evolution of some of the clinical outcomes could be seen between responders and non-responders: FVC decreased 23.69% (SE = 11.34) in non-responders and 12.71% (SE = 8.28) in responders. NPI score decreased 91.95% (SE = 6.32) in non-responders and 53.05% (SE = 10.06) in responders (P = 0.01). Thus, participants with a virological response to treatment showed a trend for slower progression of the illness. These findings further support the possible involvement of HML-2 in the clinical course of the disease.
Collapse
|