151
|
Garcia-Montojo M, Dominguez-Mozo M, Arias-Leal A, Garcia-Martinez Á, De las Heras V, Casanova I, Faucard R, Gehin N, Madeira A, Arroyo R, Curtin F, Alvarez-Lafuente R, Perron H. The DNA copy number of human endogenous retrovirus-W (MSRV-type) is increased in multiple sclerosis patients and is influenced by gender and disease severity. PLoS One 2013; 8:e53623. [PMID: 23308264 PMCID: PMC3538585 DOI: 10.1371/journal.pone.0053623] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 11/30/2012] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Multiple sclerosis is an autoimmune disease more prevalent in women than in men. Multiple Sclerosis Associated Retrovirus element (MSRV) is a member of type-W endogenous retrovirus family (HERV-W), known to be associated to MS. Most HERVs are unable to replicate but MSRV expression associated with reverse-transcriptase activity in MS would explain reported DNA copy number increase in MS patients. A potential link between HERV-W copies on chromosome X and gender differential prevalence has been suggested. The present study addresses MSRV-type DNA load in relation with the gender differences and clinical status in MS and healthy controls. RESULTS 178 MS patients (62.9% women) and 124 controls (56.5% women) were included. MSRV env load (copies/pg of DNA) was analyzed by real time qPCR with specific primers and probe for its env gene, in DNA from peripheral blood mononuclear cells (PBMCs). MSRV load was more elevated in MS patients than in controls (p = 4.15e-7). MS women presented higher MSRV load than control women (p = 0.009) and MS men also had higher load than control men (p = 2.77e-6). Besides, women had higher levels than men, both among patients (p = 0.007) and controls (p = 1.24e-6). Concordantly, EDSS and MSSS scores were higher among female patients with an elevated MSRV load (p = 0.03 and p = 0.04, respectively). CONCLUSIONS MSRV increases its copy number in PBMC of MS patients and particularly in women with high clinical scores. This may explain causes underlying the higher prevalence of MS in women. The association with the clinical severity calls for further investigations on MSRV load in PBMCs as a biomarker for MS.
Collapse
Affiliation(s)
- Marta Garcia-Montojo
- Multiple Sclerosis Unit, Hospital Clínico San Carlos, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Madrid, Spain.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
152
|
|
153
|
Campos JC, Queliconi BB, Dourado PMM, Cunha TF, Zambelli VO, Bechara LRG, Kowaltowski AJ, Brum PC, Mochly-Rosen D, Ferreira JCB. Exercise training restores cardiac protein quality control in heart failure. PLoS One 2012; 7:e52764. [PMID: 23300764 PMCID: PMC3531365 DOI: 10.1371/journal.pone.0052764] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Accepted: 11/22/2012] [Indexed: 12/16/2022] Open
Abstract
Exercise training is a well-known coadjuvant in heart failure treatment; however, the molecular mechanisms underlying its beneficial effects remain elusive. Despite the primary cause, heart failure is often preceded by two distinct phenomena: mitochondria dysfunction and cytosolic protein quality control disruption. The objective of the study was to determine the contribution of exercise training in regulating cardiac mitochondria metabolism and cytosolic protein quality control in a post-myocardial infarction-induced heart failure (MI-HF) animal model. Our data demonstrated that isolated cardiac mitochondria from MI-HF rats displayed decreased oxygen consumption, reduced maximum calcium uptake and elevated H₂O₂ release. These changes were accompanied by exacerbated cardiac oxidative stress and proteasomal insufficiency. Declined proteasomal activity contributes to cardiac protein quality control disruption in our MI-HF model. Using cultured neonatal cardiomyocytes, we showed that either antimycin A or H₂O₂ resulted in inactivation of proteasomal peptidase activity, accumulation of oxidized proteins and cell death, recapitulating our in vivo model. Of interest, eight weeks of exercise training improved cardiac function, peak oxygen uptake and exercise tolerance in MI-HF rats. Moreover, exercise training restored mitochondrial oxygen consumption, increased Ca²⁺-induced permeability transition and reduced H₂O₂ release in MI-HF rats. These changes were followed by reduced oxidative stress and better cardiac protein quality control. Taken together, our findings uncover the potential contribution of mitochondrial dysfunction and cytosolic protein quality control disruption to heart failure and highlight the positive effects of exercise training in re-establishing cardiac mitochondrial physiology and protein quality control, reinforcing the importance of this intervention as a non-pharmacological tool for heart failure therapy.
Collapse
Affiliation(s)
- Juliane C. Campos
- Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Bruno B. Queliconi
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Sao Paulo, Brazil
| | | | - Telma F. Cunha
- School of Physical Education and Sport, University of Sao Paulo, Sao Paulo, Brazil
| | | | - Luiz R. G. Bechara
- School of Physical Education and Sport, University of Sao Paulo, Sao Paulo, Brazil
| | - Alicia J. Kowaltowski
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Sao Paulo, Brazil
| | - Patricia C. Brum
- School of Physical Education and Sport, University of Sao Paulo, Sao Paulo, Brazil
| | - Daria Mochly-Rosen
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Julio C. B. Ferreira
- Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California, United States of America
- * E-mail:
| |
Collapse
|
154
|
Leboyer M, Soreca I, Scott J, Frye M, Henry C, Tamouza R, Kupfer DJ. Can bipolar disorder be viewed as a multi-system inflammatory disease? J Affect Disord 2012; 141:1-10. [PMID: 22497876 PMCID: PMC3498820 DOI: 10.1016/j.jad.2011.12.049] [Citation(s) in RCA: 310] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 12/31/2011] [Accepted: 12/31/2011] [Indexed: 12/19/2022]
Abstract
BACKGROUND Patients with bipolar disorder are known to be at high risk of premature death. Comorbid cardio-vascular diseases are a leading cause of excess mortality, well above the risk associated with suicide. In this review, we explore comorbid medical disorders, highlighting evidence that bipolar disorder can be effectively conceptualized as a multi-systemic inflammatory disease. METHODS We conducted a systematic PubMed search of all English-language articles recently published with bipolar disorder cross-referenced with the following terms: mortality and morbidity, cardio-vascular, diabetes, obesity, metabolic syndrome, inflammation, auto-antibody, retro-virus, stress, sleep and circadian rhythm. RESULTS Evidence gathered so far suggests that the multi-system involvement is present from the early stages, and therefore requires proactive screening and diagnostic procedures, as well as comprehensive treatment to reduce progression and premature mortality. Exploring the biological pathways that could account for the observed link show that dysregulated inflammatory background could be a common factor underlying cardio-vascular and bipolar disorders. Viewing bipolar disorder as a multi-system disorder should help us to re-conceptualize disorders of the mind as "disorders of the brain and the body". LIMITATIONS The current literature substantially lacks longitudinal and mechanistic studies, as well as comparison studies to explore the magnitude of the medical burden in bipolar disorder compared to major mood disorders as well as psychotic disorders. It is also necessary to look for subgroups of bipolar disorder based on their rates of comorbid disorders. CONCLUSIONS Comorbid medical illnesses in bipolar disorder might be viewed not only as the consequence of health behaviors and of psychotropic medications, but rather as an early manifestation of a multi-systemic disorder. Medical monitoring is thus a critical component of case assessment. Exploring common biological pathways of inflammation should help biomarkers discovery, ultimately leading to innovative diagnostic tools, new methods of prevention and personalized treatments.
Collapse
Affiliation(s)
- Marion Leboyer
- INSERM U955, University Paris-Est, FondaMental Fondation, Fondation de Coopération Scientifique, AP-HP, Groupe Hospitalier Mondor, 40, Rue de Mesly, Creteil, F-94000, France.
| | - Isabella Soreca
- Department of Psychiatry, University of Pittsburgh School of Medicine, USA
| | - Jan Scott
- INSERM U955, University Paris-Est, FondaMental Fondation, Fondation de Coopération Scientifique, AP-HP, Groupe Hospitalier Mondor, 40, Rue de Mesly, Creteil, F-94000, France,Academic Psychiatry, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Mark Frye
- Department of Psychiatry, Mayo Clinic, Rochester, MN, USA
| | - Chantal Henry
- INSERM U955, University Paris-Est, FondaMental Fondation, Fondation de Coopération Scientifique, AP-HP, Groupe Hospitalier Mondor, 40, Rue de Mesly, Creteil, F-94000, France,Department of Psychiatry, University of Pittsburgh School of Medicine, USA
| | - Ryad Tamouza
- Immunology and Histocompatibility Department and INSERM, U 940, Saint-Louis Hospital, F-75010 Paris, France
| | - David J. Kupfer
- Department of Psychiatry, University of Pittsburgh School of Medicine, USA
| |
Collapse
|
155
|
Virtanen JO, Jacobson S. Viruses and multiple sclerosis. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2012; 11:528-44. [PMID: 22583435 DOI: 10.2174/187152712801661220] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 04/13/2012] [Accepted: 04/20/2012] [Indexed: 11/22/2022]
Abstract
Multiple sclerosis (MS) is a heterogeneous disease that develops as an interplay between the immune system and environmental stimuli in genetically susceptible individuals. There is increasing evidence that viruses may play a role in MS pathogenesis acting as these environmental triggers. However, it is not known if any single virus is causal, or rather several viruses can act as triggers in disease development. Here, we review the association of different viruses to MS with an emphasis on two herpesviruses, Epstein-Barr virus (EBV) and human herpesvirus 6 (HHV-6). These two agents have generated the most impact during recent years as possible co-factors in MS disease development. The strongest argument for association of EBV with MS comes from the link between symptomatic infectious mononucleosis and MS and from seroepidemiological studies. In contrast to EBV, HHV-6 has been found significantly more often in MS plaques than in MS normal appearing white matter or non-MS brains and HHV-6 re-activation has been reported during MS clinical relapses. In this review we also suggest new strategies, including the development of new infectious animal models of MS and antiviral MS clinical trials, to elucidate roles of different viruses in the pathogenesis of this disease. Furthermore, we introduce the idea of using unbiased sequence-independent pathogen discovery methodologies, such as next generation sequencing, to study MS brain tissue or body fluids for detection of known viral sequences or potential novel viral agents.
Collapse
Affiliation(s)
- Jussi Oskari Virtanen
- Viral Immunology Section, Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | | |
Collapse
|
156
|
Mameli G, Poddighe L, Mei A, Uleri E, Sotgiu S, Serra C, Manetti R, Dolei A. Expression and activation by Epstein Barr virus of human endogenous retroviruses-W in blood cells and astrocytes: inference for multiple sclerosis. PLoS One 2012; 7:e44991. [PMID: 23028727 PMCID: PMC3459916 DOI: 10.1371/journal.pone.0044991] [Citation(s) in RCA: 122] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 08/15/2012] [Indexed: 11/20/2022] Open
Abstract
Background Proposed co-factors triggering the pathogenesis of multiple sclerosis (MS) are the Epstein Barr virus (EBV), and the potentially neuropathogenic MSRV (MS-associated retrovirus) and syncytin-1, of the W family of human endogenous retroviruses. Methodology/Principal Findings In search of links, the expression of HERV-W/MSRV/syncytin-1, with/without exposure to EBV or to EBV glycoprotein350 (EBVgp350), was studied on peripheral blood mononuclear cells (PBMC) from healthy volunteers and MS patients, and on astrocytes, by discriminatory env-specific RT-PCR assays, and by flow cytometry. Basal expression of HERV-W/MSRV/syncytin-1 occurs in astrocytes and in monocytes, NK, and B, but not in T cells. This uneven expression is amplified in untreated MS patients, and dramatically reduced during therapy. In astrocytes, EBVgp350 stimulates the expression of HERV-W/MSRV/syncytin-1, with requirement of the NF-κB pathway. In EBVgp350-treated PBMC, MSRVenv and syncytin-1 transcription is activated in B cells and monocytes, but not in T cells, nor in the highly expressing NK cells. The latter cells, but not the T cells, are activated by proinflammatory cytokines. Conclusions/Significance In vitro EBV activates the potentially immunopathogenic and neuropathogenic HERV-W/MSRV/syncytin-1, in cells deriving from blood and brain. In vivo, pathogenic outcomes would depend on abnormal situations, as in late EBV primary infection, that is often symptomatic, or/and in the presence of particular host genetic backgrounds. In the blood, HERV-Wenv activation might induce immunopathogenic phenomena linked to its superantigenic properties. In the brain, toxic mechanisms against oligodendrocytes could be established, inducing inflammation, demyelination and axonal damage. Local stimulation by proinflammatory cytokines and other factors might activate further HERV-Ws, contributing to the neuropathogenity. In MS pathogenesis, a possible model could include EBV as initial trigger of future MS, years later, and HERV-W/MSRV/syncytin-1 as actual contributor to MS pathogenicity, in striking parallelism with disease behaviour.
Collapse
Affiliation(s)
- Giuseppe Mameli
- Department of Biomedical Sciences and Centre of Excellence for Biotechnology Development and Biodiversity Research, University of Sassari, Sassari, Italy
| | - Luciana Poddighe
- Department of Biomedical Sciences and Centre of Excellence for Biotechnology Development and Biodiversity Research, University of Sassari, Sassari, Italy
| | - Alessandra Mei
- Department of Biomedical Sciences and Centre of Excellence for Biotechnology Development and Biodiversity Research, University of Sassari, Sassari, Italy
| | - Elena Uleri
- Department of Biomedical Sciences and Centre of Excellence for Biotechnology Development and Biodiversity Research, University of Sassari, Sassari, Italy
| | - Stefano Sotgiu
- Department of Neurosciences and MIS, University of Sassari, Sassari, Italy
| | - Caterina Serra
- Department of Biomedical Sciences and Centre of Excellence for Biotechnology Development and Biodiversity Research, University of Sassari, Sassari, Italy
| | - Roberto Manetti
- Department of Clinical, Experimental and Oncological Medicine, University of Sassari, Sassari, Italy
| | - Antonina Dolei
- Department of Biomedical Sciences and Centre of Excellence for Biotechnology Development and Biodiversity Research, University of Sassari, Sassari, Italy
- * E-mail:
| |
Collapse
|
157
|
Ryan FP. Human endogenous retroviruses in multiple sclerosis: potential for novel neuro-pharmacological research. Curr Neuropharmacol 2012; 9:360-9. [PMID: 22131944 PMCID: PMC3131726 DOI: 10.2174/157015911795596568] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Revised: 11/29/2010] [Accepted: 12/13/2010] [Indexed: 01/30/2023] Open
Abstract
There is growing evidence that the env genes of two or more human endogenous retroviruses (HERVs) of the W family are contributing to the inflammatory processes, and thus to the pathogenesis, of multiple sclerosis (MS). Increasing understanding of the human endogenous retroviral locus, ERVWE1, and the putative multiple sclerosis associated retrovirus, or MSRV, and in particular of the HERV-W env sequences associated with these, offers the potential of new lines of pharmacological research that might assist diagnosis, prognosis and therapy of multiple sclerosis.
Collapse
Affiliation(s)
- F P Ryan
- Department of Animal and Plant Sciences, Sheffield University, UK
| |
Collapse
|
158
|
Holder BS, Tower CL, Forbes K, Mulla MJ, Aplin JD, Abrahams VM. Immune cell activation by trophoblast-derived microvesicles is mediated by syncytin 1. Immunology 2012; 136:184-91. [PMID: 22348442 DOI: 10.1111/j.1365-2567.2012.03568.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Envelope glycoproteins of human endogenous retrovirus (HERV), such as syncytin 1 (HERV-W), are highly expressed in the placenta and some family members have immunomodulatory properties. Placental microvesicles (MV), which are shed into the maternal circulation during pregnancy, have been demonstrated to induce immune cell activation. Therefore, the aim of this study was to investigate the immunological properties of the highly expressed placental HERV-W protein, syncytin 1, and its potential involvement in placental MV modulation of immune cell activity. The MV shed from first trimester, normal term and pre-eclamptic term placentas, and from the BeWo trophoblast cell line, all contain syncytin 1. Recombinant syncytin 1 and syncytin 1-positive BeWo trophoblast MV both induced peripheral blood mononuclear cell (PBMC) activation, indicated through production of cytokines and chemokines. Reducing syncytin 1 content in BeWo MV inhibited PBMC activation. Recombinant syncytin 1 and syncytin-1-positive BeWo MV dampened PBMC responses to lipopolysaccharide challenge. Our findings suggest that syncytin 1 is shed from the placenta into the maternal circulation in association with MV, and modulates immune cell activation and the responses of immune cells to subsequent lipopolysaccharide stimulation. These studies implicate placental MV-associated HERV in fetal regulation of the maternal immune system.
Collapse
Affiliation(s)
- Beth S Holder
- Maternal and Fetal Health Research Group, Academic Health Sciences Centre, University of Manchester, St Mary's Hospital, Manchester, UK
| | | | | | | | | | | |
Collapse
|
159
|
Kao D, Hsu K, Chiu S, Tu V, Chew A, Lee KH, Lee YK, Kwon DN, Greenhalgh DG, Cho K. ERE database: a database of genomic maps and biological properties of endogenous retroviral elements in the C57BL/6J mouse genome. Genomics 2012; 100:157-61. [PMID: 22691267 DOI: 10.1016/j.ygeno.2012.06.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 05/31/2012] [Accepted: 06/04/2012] [Indexed: 10/28/2022]
Abstract
Endogenous retroviral elements (EREs), a family of transposable elements, constitute a substantial fraction of mammalian genomes. It is expected that profiles of the ERE sequences and their genomic locations are unique for each individual. Comprehensive characterization of the EREs' genomic locations and their biological properties is essential for understanding their roles in the pathophysiology of the host. In this study, we identified and mapped putative EREs (a total of 111 endogenous retroviruses [ERVs] and 488 solo long terminal repeats [sLTRs]) within the C57BL/6J mouse genome. The biological properties of individual ERE isolates (both ERVs and sLTRs) were then characterized in the following aspects: transcription potential, tropism trait, coding potential, recombination event, integration age, and primer binding site for replication. In addition, a suite of database management system programs was developed to organize and update the data acquired from current and future studies and to make the data accessible via internet.
Collapse
Affiliation(s)
- Damian Kao
- Burn Research, Shriners Hospitals for Children Northern California, Sacramento, CA 95817, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
160
|
Petersen T, Møller-Larsen A, Ellermann-Eriksen S, Thiel S, Christensen T. Effects of interferon-beta therapy on elements in the antiviral immune response towards the human herpesviruses EBV, HSV, and VZV, and to the human endogenous retroviruses HERV-H and HERV-W in multiple sclerosis. J Neuroimmunol 2012; 249:105-8. [PMID: 22608883 DOI: 10.1016/j.jneuroim.2012.04.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Revised: 04/23/2012] [Accepted: 04/24/2012] [Indexed: 12/22/2022]
Abstract
Effects of treatment of multiple sclerosis patients with IFN-β on elements of the antiviral immune response to herpesviruses were analysed in a longitudinal study. We found significantly increased seroreactivity to EBV EBNA-1, and to VZV, in patients who did not respond to IFN-β therapy. We found no significant changes in seroreactivity to EBV EA, or to HSV. For the same patient cohort, we have previously demonstrated significant decreases in seroreactivities to envelope antigens for the two human endogenous retroviruses HERV-H and HERV-W, closely linked to efficacy of therapy. We further searched for correlations between seroreactivities to EBV, HSV, and VZV, and levels of mannan-binding lectin (MBL), and MBL-associated serine protease 3. We found no such correlations. Our results are in accord with recent reports of increased seroreactivity to EBV EBNA-1, and to VZV in active MS, and they support that the herpesviruses EBV and VZV together with HERV-H/HERV-W and the antiviral immune response may play a role in MS development.
Collapse
Affiliation(s)
- Thor Petersen
- Department of Neurology, Aarhus University Hospital, Nørrebrogade 44, Aarhus C, Denmark
| | | | | | | | | |
Collapse
|
161
|
Aagaard L, Bjerregaard B, Kjeldbjerg AL, Pedersen FS, Larsson LI, Rossi JJ. Silencing of endogenous envelope genes in human choriocarcinoma cells shows that envPb1 is involved in heterotypic cell fusions. J Gen Virol 2012; 93:1696-1699. [PMID: 22573740 DOI: 10.1099/vir.0.041764-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Syncytin-1 and envPb1 are two conserved envelope genes in the human genome encoded by single loci from the HERV-W and -Pb families, respectively. To characterize the role of these envelope proteins in cell-cell fusion, we have developed lentiviral vectors that express short hairpin RNAs for stable knockdown of syncytin-1 and envPb1. Analysis of heterotypic fusion activity between trophoblast-derived choriocarcinoma BeWo cells, in which syncytin-1 and envPb1 are specifically silenced, and endothelial cells demonstrated that both syncytin-1 and envPb1 are important to fusion. The ability to fuse cells makes syncytin-1 and envPb1 attractive candidate molecules in therapy against cancer. Our available vectors may help eventually to decipher roles for these genes in human health and/or disease.
Collapse
Affiliation(s)
- Lars Aagaard
- Department of Biomedicine, Aarhus University, Aarhus DK-8000, Denmark.,Division of Molecular Biology, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA
| | - Bolette Bjerregaard
- Department of Anatomy and Cell Biology, Institute of Animal and Veterinary Basic Sciences, Copenhagen University, Frederiksberg DK-1870, Denmark.,Division of Molecular Biology, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA
| | - Anders L Kjeldbjerg
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus DK-8000, Denmark
| | - Finn Skou Pedersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus DK-8000, Denmark
| | - Lars-Inge Larsson
- Department of Anatomy and Cell Biology, Institute of Animal and Veterinary Basic Sciences, Copenhagen University, Frederiksberg DK-1870, Denmark
| | - John J Rossi
- Division of Molecular Biology, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA
| |
Collapse
|
162
|
Activation of the long terminal repeat of human endogenous retrovirus K by melanoma-specific transcription factor MITF-M. Neoplasia 2012; 13:1081-92. [PMID: 22131883 DOI: 10.1593/neo.11794] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Revised: 09/21/2011] [Accepted: 09/23/2011] [Indexed: 12/20/2022] Open
Abstract
The human and Old World primate genomes possess conserved endogenous retrovirus sequences that have been implicated in evolution, reproduction, and carcinogenesis. Human endogenous retrovirus (HERV)-K with 5'LTR-gag-pro-pol-env-rec/np9-3'LTR sequences represents the newest retrovirus family that integrated into the human genome 1 to 5 million years ago. Although a high-level expression of HERV-K in melanomas, breast cancers, and teratocarcinomas has been demonstrated, the mechanism of the lineage-specific activation of the long terminal repeat (LTR) remains obscure. We studied chromosomal HERV-K expression in MeWo melanoma cells in comparison with the basal expression in human embryonic kidney 293 (HEK293) cells. Cloned LTR of HERV-K (HML-2.HOM) was also characterized by mutation and transactivation experiments. We detected multiple transcriptional initiator (Inr) sites in the LTR by rapid amplification of complementary DNA ends (5' RACE). HEK293 and MeWo showed different Inr usage. The most potent Inr was associated with a TATA box and three binding motifs of microphthalmia-associated transcription factor (MITF). Both chromosomal HERV-K expression and the cloned LTR function were strongly activated in HEK293 by transfection with MITF-M, a melanocyte/melanoma-specific isoform of MITF. Coexpression of MITF and the HERV-K core antigen was detected in retinal pigmented epithelium by an immunofluorescence analysis. Although malignant melanoma lines MeWo, G361, and SK-MEL-28 showed enhanced HERV-K transcription compared with normal melanocytes, the level of MITF-M messenger RNA persisted from normal to transformed melanocytes. Thus, MITF-M may be a prerequisite for the pigmented cell lineage-specific function of HERV-K LTR, leading to the high-level expression in malignant melanomas.
Collapse
|
163
|
Ferulic acid attenuates ischemia/reperfusion-induced hepatocyte apoptosis via inhibition of JNK activation. Eur J Pharm Sci 2012; 45:708-15. [DOI: 10.1016/j.ejps.2012.01.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 12/27/2011] [Accepted: 01/24/2012] [Indexed: 11/22/2022]
|
164
|
Ferreira JCB, Boer BN, Grinberg M, Brum PC, Mochly-Rosen D. Protein quality control disruption by PKCβII in heart failure; rescue by the selective PKCβII inhibitor, βIIV5-3. PLoS One 2012; 7:e33175. [PMID: 22479367 PMCID: PMC3316563 DOI: 10.1371/journal.pone.0033175] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Accepted: 02/05/2012] [Indexed: 11/18/2022] Open
Abstract
Myocardial remodeling and heart failure (HF) are common sequelae of many forms of cardiovascular disease and a leading cause of mortality worldwide. Accumulation of damaged cardiac proteins in heart failure has been described. However, how protein quality control (PQC) is regulated and its contribution to HF development are not known. Here, we describe a novel role for activated protein kinase C isoform βII (PKCβII) in disrupting PQC. We show that active PKCβII directly phosphorylated the proteasome and inhibited proteasomal activity in vitro and in cultured neonatal cardiomyocytes. Importantly, inhibition of PKCβII, using a selective PKCβII peptide inhibitor (βIIV5-3), improved proteasomal activity and conferred protection in cultured neonatal cardiomyocytes. We also show that sustained inhibition of PKCβII increased proteasomal activity, decreased accumulation of damaged and misfolded proteins and increased animal survival in two rat models of HF. Interestingly, βIIV5-3-mediated protection was blunted by sustained proteasomal inhibition in HF. Finally, increased cardiac PKCβII activity and accumulation of misfolded proteins associated with decreased proteasomal function were found also in remodeled and failing human hearts, indicating a potential clinical relevance of our findings. Together, our data highlights PKCβII as a novel inhibitor of proteasomal function. PQC disruption by increased PKCβII activity in vivo appears to contribute to the pathophysiology of heart failure, suggesting that PKCβII inhibition may benefit patients with heart failure. (218 words).
Collapse
Affiliation(s)
- Julio C B Ferreira
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California, United States of America
| | | | | | | | | |
Collapse
|
165
|
Perron H, Germi R, Bernard C, Garcia-Montojo M, Deluen C, Farinelli L, Faucard R, Veas F, Stefas I, Fabriek BO, Van-Horssen J, Van-der-Valk P, Gerdil C, Mancuso R, Saresella M, Clerici M, Marcel S, Creange A, Cavaretta R, Caputo D, Arru G, Morand P, Lang AB, Sotgiu S, Ruprecht K, Rieckmann P, Villoslada P, Chofflon M, Boucraut J, Pelletier J, Hartung HP. Human endogenous retrovirus type W envelope expression in blood and brain cells provides new insights into multiple sclerosis disease. Mult Scler 2012; 18:1721-36. [PMID: 22457345 PMCID: PMC3573672 DOI: 10.1177/1352458512441381] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Background: The envelope protein from multiple sclerosis (MS) associated retroviral element (MSRV), a member of the Human Endogenous Retroviral family ‘W’ (HERV-W), induces dysimmunity and inflammation. Objective: The objective of this study was to confirm and specify the association between HERV-W/MSRV envelope (Env) expression and MS. Methods: 103 MS, 199 healthy controls (HC) and controls with other neurological diseases (28), chronic infections (30) or autoimmunity (30) were analysed with an immunoassay detecting Env in serum. Env RNA or DNA copy numbers in peripheral blood mononuclear cells (PBMC) were determined by a quantitative polymerase chain reaction (PCR). Env was detected by immunohistology in the brains of patients with MS with three specific monoclonals. Results: Env antigen was detected in a serum of 73% of patients with MS with similar prevalence in all clinical forms, and not in chronic infection, systemic lupus, most other neurological diseases and healthy donors (p<0.01). Cases with chronic inflammatory demyelinating polyneuropathy (5/8) and rare HC (4/103) were positive. RNA expression in PBMC and DNA copy numbers were significantly elevated in patients with MS versus HC (p<0.001). In patients with MS, DNA copy numbers were significantly increased in chronic progressive MS (secondary progressive MS vs relapsing–remitting MS (RRMS) p<0.001; primary progressive MS vs RRMS –<0.02). Env protein was evidenced in macrophages within MS brain lesions with particular concentrations around vascular elements. Conclusion: The association between MS disease and the MSRV-type HERV-W element now appears quite strong, as evidenced ex-vivo from serum and PBMC with post-mortem confirmation in brain lesions. Chronic progressive MS, RRMS and clinically isolated syndrome show different ELISA (Enzyme-Linked Immunosorbent Assay) and/or PCR profiles suggestive of an increase with disease evolution, and amplicon sequencing confirms the association with particular HERV-W elements.
Collapse
|
166
|
Gene coexpression networks in human brain identify epigenetic modifications in alcohol dependence. J Neurosci 2012; 32:1884-97. [PMID: 22302827 DOI: 10.1523/jneurosci.3136-11.2012] [Citation(s) in RCA: 298] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Alcohol abuse causes widespread changes in gene expression in human brain, some of which contribute to alcohol dependence. Previous microarray studies identified individual genes as candidates for alcohol phenotypes, but efforts to generate an integrated view of molecular and cellular changes underlying alcohol addiction are lacking. Here, we applied a novel systems approach to transcriptome profiling in postmortem human brains and generated a systemic view of brain alterations associated with alcohol abuse. We identified critical cellular components and previously unrecognized epigenetic determinants of gene coexpression relationships and discovered novel markers of chromatin modifications in alcoholic brain. Higher expression levels of endogenous retroviruses and genes with high GC content in alcoholics were associated with DNA hypomethylation and increased histone H3K4 trimethylation, suggesting a critical role of epigenetic mechanisms in alcohol addiction. Analysis of cell-type-specific transcriptomes revealed remarkable consistency between molecular profiles and cellular abnormalities in alcoholic brain. Based on evidence from this study and others, we generated a systems hypothesis for the central role of chromatin modifications in alcohol dependence that integrates epigenetic regulation of gene expression with pathophysiological and neuroadaptive changes in alcoholic brain. Our results offer implications for epigenetic therapeutics in alcohol and drug addiction.
Collapse
|
167
|
Activation of LTRs from different human endogenous retrovirus (HERV) families by the HTLV-1 tax protein and T-cell activators. Viruses 2011; 3:2146-59. [PMID: 22163338 PMCID: PMC3230845 DOI: 10.3390/v3112146] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 10/22/2011] [Indexed: 11/16/2022] Open
Abstract
Human endogenous retroviruses (HERVs) represent approximately 8% of our genome. HERVs influence cellular gene expression and contribute to normal physiological processes such as cellular differentiation and morphogenesis. HERVs have also been associated with certain pathological conditions, including cancer and neurodegenerative diseases. As HTLV-1 causes adult T-cell leukemia and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and has been shown to modulate host gene expression mainly through the expression of the powerful Tax transactivator, herein we were interested in looking at the potential modulation capacity of HTLV-1 Tax on HERV expression. In order to evaluate the promoter activity of different HERV LTRs, pHERV-LTR-luc constructs were co-transfected in Jurkat T-cells with a Tax expression vector. Tax expression potently increased the LTR activity of HERV-W8 and HERV-H (MC16). In parallel, Jurkat cells were also stimulated with different T-cell-activating agents and HERV LTRs were observed to respond to different combination of Forskolin, bpV[pic] a protein tyrosine phosphatase inhibitor, and PMA. Transfection of expression vectors for different Tax mutants in Jurkat cells showed that several transcription factors including CREB appeared to be important for HERV-W8 LTR activation. Deletion mutants were derived from the HERV-W8 LTR and the region from −137 to −123 was found to be important for LTR response following Tax expression in Jurkat cells, while a different region was shown to be required in cells treated with activators. Our results thus demonstrated that HTLV-1 Tax activates several HERV LTRs. This raises the possibility that upregulated HERV expression could be involved in diseases associated with HTLV-1 infection.
Collapse
|
168
|
Kapadia M, Sakic B. Autoimmune and inflammatory mechanisms of CNS damage. Prog Neurobiol 2011; 95:301-33. [DOI: 10.1016/j.pneurobio.2011.08.008] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2011] [Revised: 08/18/2011] [Accepted: 08/19/2011] [Indexed: 12/13/2022]
|
169
|
Sultana R. Ferulic acid ethyl ester as a potential therapy in neurodegenerative disorders. Biochim Biophys Acta Mol Basis Dis 2011; 1822:748-52. [PMID: 22064438 DOI: 10.1016/j.bbadis.2011.10.015] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 10/21/2011] [Accepted: 10/22/2011] [Indexed: 12/11/2022]
Abstract
Oxidative stress is involved in the onset, progression and pathogenesis of a number of diseases including neurodegenerative diseases. It is critical to develop a pharmacological approach to combat oxidative stress which may reduce the risk of diseases and help in promoting healthy life. In an attempt to reduce the side effects associated with allopathic medicines a number of studies are now focusing on developing treatment regimens from naturally occurring plant products. In this review, the protective role of ferulic acid (4-hydroxy-3-methoxycinnamic acid) (FA), a naturally occurring antioxidant compound found in fruit, some vegetables, and grains, and its ethyl ester derivative are discussed with respect to neurodegeneration. This article is part of a Special Issue entitled: Antioxidants and Antioxidant Treatment in Disease.
Collapse
Affiliation(s)
- Rukhsana Sultana
- Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA.
| |
Collapse
|
170
|
Deslauriers AM, Afkhami-Goli A, Paul AM, Bhat RK, Acharjee S, Ellestad KK, Noorbakhsh F, Michalak M, Power C. Neuroinflammation and endoplasmic reticulum stress are coregulated by crocin to prevent demyelination and neurodegeneration. THE JOURNAL OF IMMUNOLOGY 2011; 187:4788-99. [PMID: 21964030 DOI: 10.4049/jimmunol.1004111] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Endoplasmic reticulum (ER) stress is a homeostatic mechanism, which is used by cells to adapt to intercellular and intracellular changes. Moreover, ER stress is closely linked to inflammatory pathways. We hypothesized that ER stress is an integral component of neuroinflammation and contributes to the development of neurological diseases. In autopsied brain specimens from multiple sclerosis (MS) and non-MS patients, XBP-1 spliced variant (XBP-1/s) was increased in MS brains (p < 0.05) and was correlated with the expression of the human endogenous retrovirus-W envelope transcript, which encodes the glycoprotein, Syncytin-1 (p < 0.05). In primary human fetal astrocytes transfected with a Syncytin-1-expressing plasmid, XBP-1/s, BiP, and NOS2 were induced, which was suppressed by crocin treatment (p < 0.05). Crocin also protected oligodendrocytes exposed to cytotoxic supernatants derived from Syncytin-1-expressing astrocytes (p < 0.05) and NO-mediated oligodendrocytotoxicity (p < 0.05). During experimental autoimmune encephalomyelitis (EAE), the transcript levels of the ER stress genes XBP-1/s, BiP, PERK, and CHOP were increased in diseased spinal cords compared with healthy littermates (p < 0.05), although CHOP expression was not involved in the EAE disease phenotype. Daily treatment with crocin starting on day 7 post-EAE induction suppressed ER stress and inflammatory gene expression in spinal cords (p < 0.05), which was accompanied by preserved myelination and axonal density, together with reduced T cell infiltration and macrophage activation. EAE-associated neurobehavioral deficits were also ameliorated by crocin treatment (p < 0.05). These findings underscored the convergent roles of pathogenic ER stress and immune pathways in neuroinflammatory disease and point to potential therapeutic applications for crocin.
Collapse
Affiliation(s)
- André M Deslauriers
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2S2, Canada
| | | | | | | | | | | | | | | | | |
Collapse
|
171
|
Kim S, Steelman AJ, Zhang Y, Kinney HC, Li J. Aberrant upregulation of astroglial ceramide potentiates oligodendrocyte injury. Brain Pathol 2011; 22:41-57. [PMID: 21615590 DOI: 10.1111/j.1750-3639.2011.00501.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Oligodendroglial injury is a pathological hallmark of many human white matter diseases, including multiple sclerosis (MS) and periventricular leukomalacia (PVL). Critical regulatory mechanisms of oligodendroglia destruction, however, remain incompletely understood. Ceramide, a bioactive sphingolipid pivotal to sphingolipid metabolism pathways, regulates cell death in response to diverse stimuli and has been implicated in neurodegenerative disorders. We report here that ceramide accumulates in reactive astrocytes in active lesions of MS and PVL, as well as in animal models of demyelination. Serine palmitoyltransferase, the rate-limiting enzyme for ceramide de novo biosynthesis, was consistently upregulated in reactive astrocytes in the cuprizone mouse model of demyelination. Mass spectrometry confirmed the upregulation of specific ceramides during demyelination, and revealed a concomitant increase of sphingosine and a suppression of sphingosine-1-phosphate, a potent signaling molecule with key roles in cell survival and mitogenesis. Importantly, this altered sphingolipid metabolism during demyelination was restored upon active remyelination. In culture, ceramide acted synergistically with tumor necrosis factor, leading to apoptotic death of oligodendroglia in an astrocyte-dependent manner. Taken together, our findings implicate that disturbed sphingolipid pathways in reactive astrocytes may indirectly contribute to oligodendroglial injury in cerebral white matter disorders.
Collapse
Affiliation(s)
- SunJa Kim
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX 77843, USA
| | | | | | | | | |
Collapse
|
172
|
Trejbalová K, Blazková J, Matousková M, Kucerová D, Pecnová L, Vernerová Z, Herácek J, Hirsch I, Hejnar J. Epigenetic regulation of transcription and splicing of syncytins, fusogenic glycoproteins of retroviral origin. Nucleic Acids Res 2011; 39:8728-39. [PMID: 21771862 PMCID: PMC3203578 DOI: 10.1093/nar/gkr562] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Syncytin-1 and -2, human fusogenic glycoproteins encoded by the env genes of the endogenous retroviral loci ERVWE1 and ERVFRDE1, respectively, contribute to the differentiation of multinucleated syncytiotrophoblast in chorionic villi. In non-trophoblastic cells, however, the expression of syncytins has to be suppressed to avoid potential pathogenic effects. We studied the epigenetic suppression of ERVWE1 and ERVFRDE1 5′-long terminal repeats by DNA methylation and chromatin modifications. Immunoprecipitation of the provirus-associated chromatin revealed the H3K9 trimethylation at transcriptionally inactivated syncytins in HeLa cells. qRT-PCR analysis of non-spliced ERVWE1 and ERVFRDE1 mRNAs and respective env mRNAs detected efficient splicing of endogenously expressed RNAs in trophoblastic but not in non-placental cells. Pointing to the pathogenic potential of aberrantly expressed syncytin-1, we have found deregulation of transcription and splicing of the ERVWE1 in biopsies of testicular seminomas. Finally, ectopic expression experiments suggest the importance of proper chromatin context for the ERVWE1 splicing. Our results thus demonstrate that cell-specific retroviral splicing represents an additional epigenetic level controling the expression of endogenous retroviruses.
Collapse
Affiliation(s)
- Katerina Trejbalová
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Vídeňská 1083, CZ-14220, Prague 4, Czech Republic
| | | | | | | | | | | | | | | | | |
Collapse
|
173
|
Sato F, Tanaka H, Hasanovic F, Tsunoda I. Theiler's virus infection: Pathophysiology of demyelination and neurodegeneration. ACTA ACUST UNITED AC 2011; 18:31-41. [PMID: 20537875 DOI: 10.1016/j.pathophys.2010.04.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 02/28/2010] [Accepted: 04/08/2010] [Indexed: 02/08/2023]
Abstract
Multiple sclerosis (MS) has been suggested to be an autoimmune demyelinating disease of the central nervous system (CNS), whose primary target is either myelin itself, or myelin-forming cells, the oligodendrocytes. Although axonal damage occurs in MS, it is regarded as a secondary event to the myelin damage. Here, the lesion develops from the myelin (outside) to the axons (inside) "Outside-In model". The Outside-In model has been supported by an autoimmune model for MS, experimental autoimmune (allergic) encephalomyelitis (EAE). However, recently, (1) EAE-like disease has also been shown to be induced by immune responses against axons, and (2) immune responses against axons and neurons as well as neurodegeneration independent of inflammatory demyelination have been reported in MS, which can not be explained by the Outside-In model. Theiler's murine encephalomyelitis virus (TMEV)-induced demyelinating disease (TMEV-IDD) is a viral model for MS. In TMEV infection, axonal injury precedes demyelination, where the lesion develops from the axons (inside) to the myelin (outside) "Inside-Out model". The initial axonal damage could result in the release of neuroantigens, inducing autoimmune responses against myelin antigens, which potentially attack the myelin from outside the nerve fiber. Thus, the Inside-Out and Outside-In models can make a "vicious" immunological cycle or initiate an immune cascade.
Collapse
Affiliation(s)
- Fumitaka Sato
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center, School of Medicine in Shreveport, Shreveport, LA 71130, USA
| | | | | | | |
Collapse
|
174
|
Niller HH, Wolf H, Ay E, Minarovits J. Epigenetic dysregulation of epstein-barr virus latency and development of autoimmune disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 711:82-102. [PMID: 21627044 DOI: 10.1007/978-1-4419-8216-2_7] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Epstein-Barr virus (EBV) is ahumanherpesvirus thatpersists in the memory B-cells of the majority of the world population in a latent form. Primary EBV infection is asymptomatic or causes a self-limiting disease, infectious mononucleosis. Virus latency is associated with a wide variety of neoplasms whereof some occur in immune suppressed individuals. Virus production does not occur in strict latency. The expression of latent viral oncoproteins and nontranslated RNAs is under epigenetic control via DNA methylation and histone modifications that results either in a complete silencing of the EBV genome in memory B cells, or in a cell-type dependent usage of a couple of latency promoters in tumor cells, germinal center B cells and lymphoblastoid cells (LCL, transformed by EBV in vitro). Both, latent and lytic EBV proteins elicit a strong immune response. In immune suppressed and infectious mononucleosis patients, an increased viral load can be detected in the blood. Enhanced lytic replication may result in new infection- and transformation-events and thus is a risk factor both for malignant transformation and the development of autoimmune diseases. An increased viral load or a changed presentation of a subset of lytic or latent EBV proteins that cross-react with cellular antigens may trigger pathogenic processes through molecular mimicry that result in multiple sclerosis (MS), systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA).
Collapse
Affiliation(s)
- Hans Helmut Niller
- Institute for Medical Microbiology and Hygiene of the University of Regensburg, Regensburg, Germany.
| | | | | | | |
Collapse
|
175
|
Tropism, cytotoxicity, and inflammatory properties of two envelope genes of murine leukemia virus type-endogenous retroviruses of C57BL/6J mice. Mediators Inflamm 2011; 2011:509604. [PMID: 21772664 PMCID: PMC3134291 DOI: 10.1155/2011/509604] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2011] [Accepted: 03/09/2011] [Indexed: 12/16/2022] Open
Abstract
Envelope (env) proteins of certain endogenous retroviruses (ERVs) participate in various pathophysiological processes. In this study, we characterized pathophysiologic properties of two murine leukemia virus-type ERV (MuLV-ERV) env genes cloned from the ovary of C57BL/6J mice. The two env genes (named ENVOV1 and ENVOV2), with 1,926 bp coding region, originated from two MuLV-ERV loci on chromosomes 8 and 18, respectively. ENVOV1 and ENVOV2 were ~75 kDa and predominantly expressed on the cell membrane. They were capable of producing pseudotype murine leukemia virus virions. Tropism trait and infectivity of ENVOV2 were similar to the polytropic env; however, ENVOV1 had very low level of infectivity. Overexpression of ENVOV2, but not ENVOV1, exerted cytotoxic effects and induced expression of COX-2, IL-1β, IL-6, and iNOS. These findings suggest that the ENVOV1 and ENVOV2 are capable of serving as an env protein for virion assembly, and they exert differential cytotoxicity and modulation of inflammatory mediators.
Collapse
|
176
|
Krone B, Grange JM. Paradigms in multiple sclerosis: time for a change, time for a unifying concept. Inflammopharmacology 2011; 19:187-95. [PMID: 21547536 PMCID: PMC3127006 DOI: 10.1007/s10787-011-0084-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2011] [Accepted: 04/09/2011] [Indexed: 12/12/2022]
Abstract
It has recently been suggested that, rather than being an autoimmune disease, multiple sclerosis (MS) is an example of a neurocristopathy, a pathological process resulting from a faulty development of the neural crest. Whilst several characteristics of the disease suggest a neurocristopathy, other aetiological factors require consideration, including hygiene-related factors that alter the immune responses to common pathogens resulting in an eclipse of immune reactivity that could protect against MS, the possible role of human endogenous retroviruses (HERVs) in pathogenesis and autoimmune phenomena, HLA polymorphism, vitamin D levels before and after birth and immune repair mechanisms. A postulated aetiological factor in MS, associated with altered vitamin D metabolism and abnormal HERV expression, is a long-lasting disturbed redox regulation in the biosynthesis of a melanoma-like melanin pigment. Although intensive further studies on melanin pigments in nerve tissue in MS are required, the known properties of a pathological form of such pigments in melanoma could explain a number of observations in MS, including the impact of light, UV-light, and vitamin D, and could explain the clinical manifestations of MS on the basis of an oscillating process of oxidative charge and discharge of the pigments and a threshold phenomenon with a change of the quasi-catalytic function of the pigment from destroying reactive oxygen radicals or species to transforming them to more harmful long-persisting highly reactive species. Taken together with the consequences of an adaptive process in partly demyelinated neurons, resulting in an increase in number of mitochondria, and the impact of stressful life events, these conditions are necessary and sufficient to explain the disease process of MS with its spatial (plaques) and temporal (attacks and remissions) characteristics. This suggested unifying concept of the pathogenesis of MS may open perspectives for prevention, diagnosis and therapy. In particular, prevention may be achieved by vaccinating against Epstein-Barr virus in early childhood.
Collapse
Affiliation(s)
- Bernd Krone
- Institute of Virology, Centre for Hygiene and Human Genetics, University of Göttingen, Kreuzbergring 57, 37075 Göttingen, Germany
| | | |
Collapse
|
177
|
Age- and disease-dependent HERV-W envelope allelic variation in brain: association with neuroimmune gene expression. PLoS One 2011; 6:e19176. [PMID: 21559469 PMCID: PMC3084769 DOI: 10.1371/journal.pone.0019176] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Accepted: 03/22/2011] [Indexed: 12/27/2022] Open
Abstract
Background The glycoprotein, Syncytin-1, is encoded by a human endogenous retrovirus (HERV)-W env gene and is capable of inducing neuroinflammation. The specific allele(s) responsible for Syncytin-1 expression in the brain is uncertain. Herein, HERV-W env diversity together with Syncytin-1 abundance and host immune gene profiles were examined in the nervous system using a multiplatform approach. Results HERV-W env sequences were encoded by multiple chromosomal encoding loci in primary human neurons compared with less chromosomal diversity in astrocytes and microglia (p<0.05). HERV-W env RNA sequences cloned from brains of patients with systemic or neurologic diseases were principally derived from chromosomal locus 7q21.2. Within the same specimens, HERV-W env transcript levels were correlated with the expression of multiple proinflammatory genes (p<0.05). Deep sequencing of brain transcriptomes disclosed the env transcripts to be the most abundant HERV-W transcripts, showing greater expression in fetal compared with healthy adult brain specimens. Syncytin-1's expression in healthy brain specimens was derived from multiple encoding loci and linked to distinct immune and developmental gene profiles. Conclusions Syncytin-1 expression in the brain during disease was associated with neuroinflammation and was principally encoded by a full length provirus. The present studies also highlighted the diversity in HERV gene expression within the brain and reinforce the potential contributions of HERV expression to neuroinflammatory diseases.
Collapse
|
178
|
Miljković D, Timotijević G, Stojković MM. Astrocytes in the tempest of multiple sclerosis. FEBS Lett 2011; 585:3781-8. [DOI: 10.1016/j.febslet.2011.03.047] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2011] [Revised: 03/21/2011] [Accepted: 03/23/2011] [Indexed: 12/11/2022]
|
179
|
Improved integration time estimation of endogenous retroviruses with phylogenetic data. PLoS One 2011; 6:e14745. [PMID: 21394200 PMCID: PMC3048862 DOI: 10.1371/journal.pone.0014745] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Accepted: 09/25/2010] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Endogenous retroviruses (ERVs) are genetic fossils of ancient retroviral integrations that remain in the genome of many organisms. Most loci are rendered non-functional by mutations, but several intact retroviral genes are known in mammalian genomes. Some have been adopted by the host species, while the beneficial roles of others remain unclear. Besides the obvious possible immunogenic impact from transcribing intact viral genes, endogenous retroviruses have also become an interesting and useful tool to study phylogenetic relationships. The determination of the integration time of these viruses has been based upon the assumption that both 5' and 3' Long Terminal Repeats (LTRs) sequences are identical at the time of integration, but evolve separately afterwards. Similar approaches have been using either a constant evolutionary rate or a range of rates for these viral loci, and only single species data. Here we show the advantages of using different approaches. RESULTS We show that there are strong advantages in using multiple species data and state-of-the-art phylogenetic analysis. We incorporate both simple phylogenetic information and Monte Carlo Markov Chain (MCMC) methods to date the integrations of these viruses based on a relaxed molecular clock approach over a Bayesian phylogeny model and applied them to several selected ERV sequences in primates. These methods treat each ERV locus as having a distinct evolutionary rate for each LTR, and make use of consensual speciation time intervals between primates to calibrate the relaxed molecular clocks. CONCLUSIONS The use of a fixed rate produces results that vary considerably with ERV family and the actual evolutionary rate of the sequence, and should be avoided whenever multi-species phylogenetic data are available. For genome-wide studies, the simple phylogenetic approach constitutes a better alternative, while still being computationally feasible.
Collapse
|
180
|
The human microbiome in multiple sclerosis: pathogenic or protective constituents? Can J Neurol Sci 2011; 37 Suppl 2:S24-33. [PMID: 21246932 DOI: 10.1017/s031716710002240x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The human microbiome is comprised of commensal and pathogenic microorganisms, which exert diverse effects in close proximity to the site of intection as well as in remote tissues through immune-mediated mechanisms. Multiple infectious agents have been implicated in the pathogenesis of multiple sclerosis (MS) with variable findings depending on the agent, techniques, and disease phenotype. Herein, the contributions of individual infectious agents to MS and their effects on the immune and nervous systems are reviewed, focusing on herpes viruses, coronaviruses, retroviruses, and synchronic infections. While infectious agents are often assumed to be pathogenic, their effects might also be beneficial to the host in the long-term, depending on age and the type of immunogen/pathogen exposure, as proposed by the hygiene hypothesis. The human microbiome has potential impact on future diagnostic and therapeutic issues in MS.
Collapse
|
181
|
Li F, Nellåker C, Yolken RH, Karlsson H. A systematic evaluation of expression of HERV-W elements; influence of genomic context, viral structure and orientation. BMC Genomics 2011; 12:22. [PMID: 21226900 PMCID: PMC3031232 DOI: 10.1186/1471-2164-12-22] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Accepted: 01/12/2011] [Indexed: 12/19/2022] Open
Abstract
Background One member of the W family of human endogenous retroviruses (HERV) appears to have been functionally adopted by the human host. Nevertheless, a highly diversified and regulated transcription from a range of HERV-W elements has been observed in human tissues and cells. Aberrant expression of members of this family has also been associated with human disease such as multiple sclerosis (MS) and schizophrenia. It is not known whether this broad expression of HERV-W elements represents transcriptional leakage or specific transcription initiated from the retroviral promoter in the long terminal repeat (LTR) region. Therefore, potential influences of genomic context, structure and orientation on the expression levels of individual HERV-W elements in normal human tissues were systematically investigated. Results Whereas intronic HERV-W elements with a pseudogene structure exhibited a strong anti-sense orientation bias, intronic elements with a proviral structure and solo LTRs did not. Although a highly variable expression across tissues and elements was observed, systematic effects of context, structure and orientation were also observed. Elements located in intronic regions appeared to be expressed at higher levels than elements located in intergenic regions. Intronic elements with proviral structures were expressed at higher levels than those elements bearing hallmarks of processed pseudogenes or solo LTRs. Relative to their corresponding genes, intronic elements integrated on the sense strand appeared to be transcribed at higher levels than those integrated on the anti-sense strand. Moreover, the expression of proviral elements appeared to be independent from that of their corresponding genes. Conclusions Intronic HERV-W provirus integrations on the sense strand appear to have elicited a weaker negative selection than pseudogene integrations of transcripts from such elements. Our current findings suggest that the previously observed diversified and tissue-specific expression of elements in the HERV-W family is the result of both directed transcription (involving both the LTR and internal sequence) and leaky transcription of HERV-W elements in normal human tissues.
Collapse
Affiliation(s)
- Fang Li
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | | | | | | |
Collapse
|
182
|
The cellular prion protein in multiple sclerosis: A potential target for neurotherapeutics? Transl Neurosci 2011. [DOI: 10.2478/s13380-011-0042-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractMultiple sclerosis (MS) is a debilitating disease that affects millions. There is no known cure for the disease and neither is the cause of the disease known. Recent studies have indicated that it is a multi-factorial disease with several genes involved. Importantly, sunlight and vitamin D have been implicated in the progression of the disease. The pathogenesis of MS chiefly involves loss of oligodendrocytes, which in addition to being killed by inflammatory mediators in the CNS, also succumbs to loss of trophic support from astrocytes. Neurotrophins play an important role in myelination and the cellular prion protein (PrPC) is a key player in this process. Although the physiological roles of PrPC remain to be fully understood, increasing evidence suggests multiple roles for PrPC in regulation of cellular immunity and for its interaction with several neurotrophins that are necessary for homeostasis of the nervous system. This mini-review focuses on the findings establishing a crucial role for PrPC in the neuropathogenesis of MS, emphasizing its neuroprotective role. Since MS is a multi-factorial disease with unknown etiology and no cure, this review aims to highlight endogenous repair mechanisms mediated by PrPC that might contribute to functional recovery in MS patients.
Collapse
|
183
|
Krone B, Grange JM. Multiple sclerosis: are protective immune mechanisms compromised by a complex infectious background? Autoimmune Dis 2010; 2011:708750. [PMID: 21197482 PMCID: PMC3010623 DOI: 10.4061/2011/708750] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Revised: 10/07/2010] [Accepted: 11/18/2010] [Indexed: 11/20/2022] Open
Abstract
The immunological background of multiple sclerosis (MS) manifests as an altered reactivity against a diverse range of infections, particularly with the Epstein-Barr virus. Although this could be only an epiphenomenon of a more generalised dysfunction of the immune system in MS, it is also possible that a complex infectious background forms the basis of a specific immune dysregulation finally causing the disease. It is thus suggested that the complex infectious background bears the key for an understanding of the immune pathogenesis of the disease. It appears probable that improved standards of hygiene cause regulatory defects in the immune system, allowing the abnormal expression of human endogenous retroviral (HERV) genes. On the basis of epidemiological observations we describe how a failure of expansion or an eclipse of a subfraction of self-antigen-specific CD8(+) T cells mediating immune repair, and a deleterious mode of action of HERV gene products, could underlie the pathogenesis of MS.
Collapse
Affiliation(s)
- Bernd Krone
- Institute of Virology, Centre for Hygiene and Human Genetics, University of Göttingen, Kreuzbergring 57, 37075 Göttingen, Germany
| | | |
Collapse
|
184
|
Perron H, Lang A. The human endogenous retrovirus link between genes and environment in multiple sclerosis and in multifactorial diseases associating neuroinflammation. Clin Rev Allergy Immunol 2010; 39:51-61. [PMID: 19697163 DOI: 10.1007/s12016-009-8170-x] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Endogenous retroviruses represent about 8% of the human genome and belong to the superfamily of transposable and retrotransposable genetic elements. Altogether, these mobile genetic elements and their numerous inactivated "junk" sequences represent nearly one half of the human DNA. Nonetheless, a significant part of this "non-conventional" genome has retained potential activity. Epigenetic control is notably involved in silencing most of these genetic elements but certain environmental factors such as viruses are known to dysregulate their expression in susceptible cells. More particularly, embryonal cells with limited gene methylation are most susceptible to uncontrolled activation of these mobile genetic elements by, e.g., viral infections. In particular, certain viruses transactivate promoters from endogenous retroviral family type W (HERV-W). HERV-W RNA was first isolated in circulating viral particles (Multiple Sclerosis-associated RetroViral element, MSRV) that have been associated with the evolution and prognosis of multiple sclerosis. HERV-W elements encode a powerful immunopathogenic envelope protein (ENV) that activates a pro-inflammatory and autoimmune cascade through interaction with Toll-like receptor 4 on immune cells. This ENV protein has repeatedly been detected in MS brain lesions and may be involved in other diseases. Epigenetic factors controlling HERV-W ENV protein expression then reveal critical. This review addresses the gene-environment epigenetic interface of such HERV-W elements and its potential involvement in disease.
Collapse
Affiliation(s)
- Hervé Perron
- GeNeuro, 18, Chemin des Aulx, 1228, Plan-Les Ouates, Geneva, Switzerland.
| | | |
Collapse
|
185
|
Yang G, Meng Y, Li W, Yong Y, Fan Z, Ding H, Wei Y, Luo J, Ke ZJ. Neuronal MCP-1 mediates microglia recruitment and neurodegeneration induced by the mild impairment of oxidative metabolism. Brain Pathol 2010; 21:279-97. [PMID: 21029241 DOI: 10.1111/j.1750-3639.2010.00445.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Chemokines are implicated in the neuroinflammation of several chronic neurodegenerative disorders. However, the precise role of chemokines in neurodegeneration is unknown. Thiamine deficiency (TD) causes abnormal oxidative metabolism in the brain as well as a well-defined microglia activation and neurodegeneration in the submedial thalamus nucleus (SmTN), which are common features of neurodegenerative diseases. We evaluated the role of chemokines in neurodegeneration and the underlying mechanism in a TD model. Among the chemokines examined, TD selectively induced neuronal expression of monocyte chemoattractant protein-1 (MCP-1) in the SmTN prior to microglia activation and neurodegeneration. The conditioned medium collected from TD-induced neurons caused microglia activation. With a neuron/microglia co-culture system, we showed that MCP-1-induced neurotoxicity required the presence of microglia, and exogenous MCP-1 was able to activate microglia and stimulated microglia to produce cytokines. A MCP-1 neutralizing antibody inhibited MCP-1-induced microglia activation and neuronal death in culture and in the thalamus. MCP-1 knockout mice were resistant to TD-induced neuronal death in SmTN. TD selectively induced the accumulation of reactive oxygen species in neurons, and antioxidants blocked TD-induced MCP-1 expression. Together, our results indicated an induction of neuronal MCP-1 during mild impairment of oxidative metabolism caused by microglia recruitment/activation, which exacerbated neurodegeneration.
Collapse
Affiliation(s)
- Guang Yang
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, China
| | | | | | | | | | | | | | | | | |
Collapse
|
186
|
Kuang X, Hu W, Yan M, Wong PKY. Phenylbutyric acid suppresses protein accumulation-mediated ER stress in retrovirus-infected astrocytes and delays onset of paralysis in infected mice. Neurochem Int 2010; 57:738-48. [PMID: 20813146 DOI: 10.1016/j.neuint.2010.08.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Revised: 07/20/2010] [Accepted: 08/06/2010] [Indexed: 12/15/2022]
Abstract
Many neurodegenerative diseases are associated with accumulation of misfolded proteins in cells of the central nervous system (CNS). We have previously reported that accumulation of the precursor envelope protein gPr80(env) of ts1, a mutant of Moloney murine leukemia virus (MoMuLV), in the endoplasmic reticulum (ER) of infected astrocytes, results in ER stress, oxidative stress and cell death, subsequently leading to ts1-mediated neurodegeneration in infected mice. In the present study, we assessed whether treatments that reduce the accumulation of gPr80(env) in the ER of ts1-infected astrocytes provided a protective effect against ER stress and cell death. We show that treatment with phenylbutyric acid (PBA) can prevent the unfolded protein response (UPR), ER stress and cell death in cultured ts1-infected astrocytes. The protective effect of PBA is associated with its ability to reduce gPr80(env) accumulation and to increase the expression of proteins involved in protein folding in the ER, such as protein disulfide isomerase (PDI) and ERp44, rather than by decrease mRNA levels of gPr80(env) or alter the proteasomal degradation process for gPr80(env). In infected mice treated with PBA we also noted a reduction in the severity of the neuropathology in brainstem tissues and a delayed onset of paralysis. These results show that PBA is a potentially effective drug for the treatment of neurodegeneration caused by protein accumulation in cells of the CNS.
Collapse
Affiliation(s)
- Xianghong Kuang
- Department of Carcinogenesis, The University of Texas, MD Anderson Cancer Center, Science Park-Research Division, Smithville, TX 78957, USA
| | | | | | | |
Collapse
|
187
|
Roebke C, Wahl S, Laufer G, Stadelmann C, Sauter M, Mueller-Lantzsch N, Mayer J, Ruprecht K. An N-terminally truncated envelope protein encoded by a human endogenous retrovirus W locus on chromosome Xq22.3. Retrovirology 2010; 7:69. [PMID: 20735848 PMCID: PMC2936387 DOI: 10.1186/1742-4690-7-69] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2010] [Accepted: 08/24/2010] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND We previously showed that the envelope (env) sequence of a human endogenous retrovirus (HERV)-W locus on chromosome Xq22.3 is transcribed in human peripheral blood mononuclear cells. The env open reading frame (ORF) of this locus is interrupted by a premature stop at codon 39, but otherwise harbors a long ORF for an N-terminally truncated 475 amino acid Env protein, starting at an in-frame ATG at codon 68. We set out to characterize the protein encoded by that ORF. RESULTS Transient expression of the 475 amino acid Xq22.3 HERV-W env ORF produced an N-terminally truncated HERV-W Env protein, as detected by the monoclonal anti-HERV-W Env antibodies 6A2B2 and 13H5A5. Remarkably, reversion of the stop at codon 39 in Xq22.3 HERV-W env reconstituted a full-length HERV-W Xq22.3 Env protein. Similar to the full-length HERV-W Env protein Syncytin-1, reconstituted full-length Xq22.3 HERV-W Env is glycosylated, forms oligomers, and is expressed at the cell surface. In contrast, Xq22.3 HERV-W Env is unglycosylated, does not form oligomers, and is located intracellularly, probably due to lack of a signal peptide. Finally, we reconfirm by immunohistochemistry that monoclonal antibody 6A2B2 detects an antigen expressed in placenta and multiple sclerosis brain lesions. CONCLUSIONS A partially defective HERV-W env gene located on chromosome Xq22.3, which we propose to designate ERVWE2, has retained coding capacity and can produce ex vivo an N-terminally truncated Env protein, named N-Trenv. Detection of an antigen by 6A2B2 in placenta and multiple sclerosis lesions opens the possibility that N-Trenv could be expressed in vivo. More generally, our findings are compatible with the idea that defective HERV elements may be capable of producing incomplete HERV proteins that, speculatively, may exert functions in human physiology or pathology.
Collapse
Affiliation(s)
- Christina Roebke
- Institut für Virologie, Gebäude 47, Universitätsklinikum des Saarlandes, 66421 Homburg, Germany
| | | | | | | | | | | | | | | |
Collapse
|
188
|
Antony JM, Deslauriers AM, Bhat RK, Ellestad KK, Power C. Human endogenous retroviruses and multiple sclerosis: innocent bystanders or disease determinants? Biochim Biophys Acta Mol Basis Dis 2010; 1812:162-76. [PMID: 20696240 PMCID: PMC7172332 DOI: 10.1016/j.bbadis.2010.07.016] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Revised: 07/14/2010] [Accepted: 07/26/2010] [Indexed: 12/21/2022]
Abstract
Human endogenous retroviruses (HERVs) constitute 5–8% of human genomic DNA and are replication incompetent despite expression of individual HERV genes from different chromosomal loci depending on the specific tissue. Several HERV genes have been detected as transcripts and proteins in the central nervous system, frequently in the context of neuroinflammation. The HERV-W family has received substantial attention in large part because of associations with diverse syndromes including multiple sclerosis (MS) and several psychiatric disorders. A HERV-W-related retroelement, multiple sclerosis retrovirus (MSRV), has been reported in MS patients to be both a biomarker as well as an effector of aberrant immune responses. HERV-H and HERV-K have also been implicated in MS and other neurological diseases but await delineation of their contributions to disease. The HERV-W envelope-encoded glycosylated protein, syncytin-1, is encoded by chromosome 7q21 and exhibits increased glial expression within MS lesions. Overexpression of syncytin-1 in glia induces endoplasmic reticulum stress leading to neuroinflammation and the induction of free radicals, which damage proximate cells. Syncytin-1's receptor, ASCT1 is a neutral amino acid transporter expressed on glia and is suppressed in white matter of MS patients. Of interest, antioxidants ameliorate syncytin-1's neuropathogenic effects raising the possibility of using these agents as therapeutics for neuroinflammatory diseases. Given the multiple insertion sites of HERV genes as complete and incomplete open reading frames, together with their differing capacity to be expressed and the complexities of individual HERVs as both disease markers and bioactive effectors, HERV biology is a compelling area for understanding neuropathogenic mechanisms and developing new therapeutic strategies.
Collapse
|
189
|
Balada E, Vilardell-Tarrés M, Ordi-Ros J. Implication of Human Endogenous Retroviruses in the Development of Autoimmune Diseases. Int Rev Immunol 2010; 29:351-70. [DOI: 10.3109/08830185.2010.485333] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
|
190
|
Post-injury stress signals alter epigenetic profile of cytosine methylation in the proviral genome of endogenous retroviruses. Exp Mol Pathol 2010; 89:291-300. [PMID: 20609362 DOI: 10.1016/j.yexmp.2010.06.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2010] [Accepted: 06/29/2010] [Indexed: 11/22/2022]
Abstract
The majority of epigenetic methylation events at cytosine residues of the genome are reported to occur in transposable elements, as a result, it contributes to genome stability by repressing their transposition activity. Our recent studies demonstrated that the expression of certain murine endogenous retroviruses (MuERVs), a family of retrotransposons, is modulated in the liver after burn injury and sepsis. In this study, we investigated whether burn-elicited stress signals alter epigenetic methylation profile of cytosine residues of the MuERV proviral genome. Female C57BL/6J mice were subjected to ~18% total body surface area burn. The genomic DNAs from the livers, which were collected at 3 and 24 h after burn, were treated with bisulfite to convert unmethylated cytosines (C) to thymines (T). From four experimental groups (no burn-3h, burn-3h, no burn-24h, and burn-24h), 91, 98, 94, and 86 unique U3 sequences (from sense or antisense strand) were cloned, respectively and a total of 16 different U3 sizes were identified among them. The survey of C to T conversions in these U3 sequences revealed that the epigenetic profiles of cytosine methylation are differentially affected (increase or decrease in demethylated cytosine residues) by stress signals from burn and/or anesthesia-resuscitation in a position of cytosine residue and/or size of U3 sequence-specific manner. In addition, the methylation characteristics of the majority of cytosine residues of the different U3 sequences within each size group were conserved. The findings from this study suggest that burn-elicited stress signals contribute to a transient or permanent alteration in cytosine methylation characteristics of certain MuERV loci in the genome, potentially modulating transcription activity of their own as well as neighboring genes.
Collapse
|
191
|
Abstract
In humans, exogenous retroviruses are known to cause immunodeficiency and neurological disease. While endogenous retroviruses are firmly established pathogens in other species, the human endogenous retroviruses (HERVs) may well be considered as emerging pathogens. HERVs also exhibit complex interactions with exogenous retroviruses and herpesviruses. Two neurological disorders in particular are associated with HERVs: multiple sclerosis (MS) and schizophrenia. HERV-H/F and HERV-W are specifically activated both in the circulation and the central nervous system (CNS) in a majority of MS patients, and particularly, the envelopes (env transcription and Env proteins) appear strongly associated with disease activity. Interferon beta (IFN-beta) therapy is well-established for MS. IFN-beta is also known to have anti-retroviral activities toward exogenous retroviruses (HIV and HTLV-I). New reports show that IFN-beta also mediate down-regulation of HERV-H/F and HERV-W in MS patients. HERV-W and HERV-K transcription (gag and pol) appears, to some extent, to be up-regulated in the circulation and the CNS of patients with schizophrenia. The expression of anti-HERV-W Gag reactive epitopes is reported to be down-regulated in the brain but up-regulated in the blood from schizophrenia patients. The pathogenic potential of HERVs certainly merits further studies.
Collapse
|
192
|
Sun Y, Ouyang DY, Pang W, Tu YQ, Li YY, Shen XM, Tam SC, Yang HY, Zheng YT. Expression of syncytin in leukemia and lymphoma cells. Leuk Res 2010; 34:1195-202. [PMID: 20362331 DOI: 10.1016/j.leukres.2010.03.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Revised: 03/07/2010] [Accepted: 03/08/2010] [Indexed: 11/15/2022]
Abstract
Syncytin is a placenta-specific protein and generally believed to play a pivotal role in syncytiotrophoblast morphogenesis. In this study, transcripts of this gene were quantified by real-time RT-PCR and the translated products were measured by an indirect immunofluorescence assay. Results showed that syncytin was found to be expressed in all nine leukemia and lymphoma cell lines studied albeit at different levels and in 43 peripheral blood samples of 57 leukemia or lymphoma patients. Neither the transcripts nor the translated syncytin was detected in blood samples of normal individuals. In conclusion, peripheral blood syncytin may serve as a marker for leukemia and lymphoma.
Collapse
Affiliation(s)
- Yi Sun
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, 32 Jiaochang Donglu, Kunming 650223, China
| | | | | | | | | | | | | | | | | |
Collapse
|
193
|
Bradl M, Lassmann H. Progressive multiple sclerosis. Semin Immunopathol 2010; 31:455-65. [PMID: 19730864 DOI: 10.1007/s00281-009-0182-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Accepted: 08/13/2009] [Indexed: 12/13/2022]
Abstract
Multiple sclerosis (MS) is a chronic inflammatory, demyelinating disease of the central nervous system, which starts in the majority of patients with a relapsing/remitting MS (RRMS) course , which after several years of disease duration converts into a progressive disease. Since anti-inflammatory therapies and immune modulation exert a beneficial effect at the relapsing/remitting stage of the disease, but not in the progressive stage, the question was raised whether inflammation drives tissue damage in progressive MS at all. We show here that also in progressive MS, inflammation is the driving force for brain injury and that the discrepancy between inflammation-driven tissue injury and response to immunomodulatory therapies can be explained by different pathomechanisms acting in RRMS and progressive MS.
Collapse
Affiliation(s)
- Monika Bradl
- Department of Neuroimmunology, Medical University Vienna, Center for Brain Research, Vienna, Austria.
| | | |
Collapse
|
194
|
Makri G, Lavdas AA, Katsimpardi L, Charneau P, Thomaidou D, Matsas R. Transplantation of embryonic neural stem/precursor cells overexpressing BM88/Cend1 enhances the generation of neuronal cells in the injured mouse cortex. Stem Cells 2010; 28:127-39. [PMID: 19911428 DOI: 10.1002/stem.258] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The intrinsic inability of the central nervous system to efficiently repair traumatic injuries renders transplantation of neural stem/precursor cells (NPCs) a promising approach towards repair of brain lesions. In this study, NPCs derived from embryonic day 14.5 mouse cortex were genetically modified via transduction with a lentiviral vector to overexpress the neuronal lineage-specific regulator BM88/Cend1 that coordinates cell cycle exit and differentiation of neuronal precursors. BM88/Cend1-overexpressing NPCs exhibiting enhanced differentiation into neurons in vitro were transplanted in a mouse model of acute cortical injury and analyzed in comparison with control NPCs. Immunohistochemical analysis revealed that a smaller proportion of BM88/Cend1-overexpressing NPCs, as compared with control NPCs, expressed the neural stem cell marker nestin 1 day after transplantation, while the percentage of nestin-positive cells was significantly reduced thereafter in both types of cells, being almost extinct 1 week post-grafting. Both types of cells did not proliferate up to 4 weeks in vivo, thus minimizing the risk of tumorigenesis. In comparison with control NPCs, Cend1-overexpressing NPCs generated more neurons and less glial cells 1 month after transplantation in the lesioned cortex whereas the majority of graft-derived neurons were identified as GABAergic interneurons. Furthermore, transplantation of Cend1-overexpressing NPCs resulted in a marked reduction of astrogliosis around the lesioned area as compared to grafts of control NPCs. Our results suggest that transplantation of Cend1-overexpressing NPCs exerts beneficial effects on tissue regeneration by enhancing the number of generated neurons and restricting the formation of astroglial scar, in a mouse model of cortical brain injury.
Collapse
Affiliation(s)
- Georgia Makri
- Laboratory of Cellular and Molecular Neurobiology, Hellenic Pasteur Institute, 11521 Athens, Greece
| | | | | | | | | | | |
Collapse
|
195
|
Yabe T, Hirahara H, Harada N, Ito N, Nagai T, Sanagi T, Yamada H. Ferulic acid induces neural progenitor cell proliferation in vitro and in vivo. Neuroscience 2010; 165:515-24. [PMID: 19837139 DOI: 10.1016/j.neuroscience.2009.10.023] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 09/28/2009] [Accepted: 10/12/2009] [Indexed: 10/20/2022]
Abstract
Ferulic acid (4-hydroxy-3-methoxycinnamic acid; FA) is a plant constituent and is contained in several medicinal plants for clinical use. In this paper, we investigated the effects of FA on the proliferation of neural stem/progenitor cells (NSC/NPCs) in vitro and in vivo. FA significantly increased the proliferation of NSC/NPCs cultured from the telencephalon of embryonic day-14 rats, and increased the number and size of secondary formed neurospheres. An in vitro differentiation assay showed that FA did not affect the percentage of either neuron-specific class III beta-tubulin (Tuj-1)-positive cells or glial fibrillary acidic protein (GFAP)-positive cells in the total cell population. Oral administration of FA increased the number of newly generated cells in the dentate gyrus (DG) of the hippocampus of corticosterone (CORT)-treated mice, indicating that FA enhances the proliferation of adult NSC/NPCs in vivo. We also found that oral administration of FA increased cAMP response element binding protein (CREB) phosphorylation and brain-derived neurotrophic factor (BDNF) mRNA level in the hippocampus of CORT-treated mice, and ameliorated the stress-induced depression-like behavior of mice. These novel pharmacological effects of FA may be useful for the treatment of mood disorders such as depression.
Collapse
Affiliation(s)
- T Yabe
- Kitasato Institute for Life Sciences, Kitasato University, Tokyo, Japan.
| | | | | | | | | | | | | |
Collapse
|
196
|
The prevalence of human endogenous retroviruses in cerebrospinal fluids from patients with sporadic Creutzfeldt–Jakob disease. J Clin Virol 2010; 47:136-42. [DOI: 10.1016/j.jcv.2009.11.016] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Revised: 11/03/2009] [Accepted: 11/11/2009] [Indexed: 11/21/2022]
|
197
|
Gimenez J, Montgiraud C, Pichon JP, Bonnaud B, Arsac M, Ruel K, Bouton O, Mallet F. Custom human endogenous retroviruses dedicated microarray identifies self-induced HERV-W family elements reactivated in testicular cancer upon methylation control. Nucleic Acids Res 2010; 38:2229-46. [PMID: 20053729 PMCID: PMC2853125 DOI: 10.1093/nar/gkp1214] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Endogenous retroviruses (ERVs) are an inherited part of the eukaryotic genomes, and represent ∼400 000 loci in the human genome. Human endogenous retroviruses (HERVs) can be divided into distinct families, composed of phylogenetically related but structurally heterogeneous elements. The majority of HERVs are silent in most physiological contexts, whereas a significant expression is observed in pathological contexts, such as cancers. Owing to their repetitive nature, few of the active HERV elements have been accurately identified. In addition, there are no criteria defining the active promoters among HERV long-terminal repeats (LTRs). Hence, it is difficult to understand the HERV (de)regulation mechanisms and their implication on the physiopathology of the host. We developed a microarray to specifically detect the LTR-containing transcripts from the HERV-H, HERV-E, HERV-W and HERV-K(HML-2) families. HERV transcriptome was analyzed in the placenta and seven normal/tumoral match-pair samples. We identified six HERV-W loci overexpressed in testicular cancer, including a usually placenta-restricted transcript of ERVWE1. For each locus, specific overexpression was confirmed by quantitative RT-PCR, and comparison of the activity of U3 versus U5 regions suggested a U3-promoted transcription coupled with 5′R initiation. The analysis of DNA from tumoral versus normal tissue revealed that hypomethylation of U3 promoters in tumors is a prerequisite for their activation.
Collapse
Affiliation(s)
- Juliette Gimenez
- Laboratoire Commun de Recherche Hospices Civils de Lyon-bioMérieux, Cancer Biomarkers Research Group, Centre Hospitalier Lyon Sud, bâtiment 3F, 69495 Pierre Bénite Cedex, France
| | | | | | | | | | | | | | | |
Collapse
|
198
|
Adibhatla RM, Hatcher JF. Lipid oxidation and peroxidation in CNS health and disease: from molecular mechanisms to therapeutic opportunities. Antioxid Redox Signal 2010; 12:125-69. [PMID: 19624272 DOI: 10.1089/ars.2009.2668] [Citation(s) in RCA: 317] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Reactive oxygen species (ROS) are produced at low levels in mammalian cells by various metabolic processes, such as oxidative phosphorylation by the mitochondrial respiratory chain, NAD(P)H oxidases, and arachidonic acid oxidative metabolism. To maintain physiological redox balance, cells have endogenous antioxidant defenses regulated at the transcriptional level by Nrf2/ARE. Oxidative stress results when ROS production exceeds the cell's ability to detoxify ROS. Overproduction of ROS damages cellular components, including lipids, leading to decline in physiological function and cell death. Reaction of ROS with lipids produces oxidized phospholipids, which give rise to 4-hydroxynonenal, 4-oxo-2-nonenal, and acrolein. The brain is susceptible to oxidative damage due to its high lipid content and oxygen consumption. Neurodegenerative diseases (AD, ALS, bipolar disorder, epilepsy, Friedreich's ataxia, HD, MS, NBIA, NPC, PD, peroxisomal disorders, schizophrenia, Wallerian degeneration, Zellweger syndrome) and CNS traumas (stroke, TBI, SCI) are problems of vast clinical importance. Free iron can react with H(2)O(2) via the Fenton reaction, a primary cause of lipid peroxidation, and may be of particular importance for these CNS injuries and disorders. Cholesterol is an important regulator of lipid organization and the precursor for neurosteroid biosynthesis. Atherosclerosis, the major risk factor for ischemic stroke, involves accumulation of oxidized LDL in the arteries, leading to foam cell formation and plaque development. This review will discuss the role of lipid oxidation/peroxidation in various CNS injuries/disorders.
Collapse
Affiliation(s)
- Rao Muralikrishna Adibhatla
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53792-3232, USA.
| | | |
Collapse
|
199
|
Ryan FP. An alternative approach to medical genetics based on modern evolutionary biology. Part 3: HERVs in diseases. J R Soc Med 2009; 102:415-24. [PMID: 19797599 DOI: 10.1258/jrsm.2009.090221] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Affiliation(s)
- Frank P Ryan
- Sheffield Primary Care Trust and Department of Animal and Plant Sciences, Sheffield University UK.
| |
Collapse
|
200
|
Perron H, Bernard C, Bertrand JB, Lang AB, Popa I, Sanhadji K, Portoukalian J. Endogenous retroviral genes, Herpesviruses and gender in Multiple Sclerosis. J Neurol Sci 2009; 286:65-72. [DOI: 10.1016/j.jns.2009.04.034] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2009] [Revised: 04/02/2009] [Accepted: 04/14/2009] [Indexed: 01/13/2023]
|