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Graßhoff H, Fourlakis K, Comdühr S, Riemekasten G. Autoantibodies as Biomarker and Therapeutic Target in Systemic Sclerosis. Biomedicines 2022; 10:biomedicines10092150. [PMID: 36140251 PMCID: PMC9496142 DOI: 10.3390/biomedicines10092150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 08/21/2022] [Accepted: 08/23/2022] [Indexed: 12/03/2022] Open
Abstract
Systemic sclerosis (SSc) is a rare connective tissue disorder characterized by immune dysregulation evoking the pathophysiological triad of inflammation, fibrosis and vasculopathy. In SSc, several alterations in the B-cell compartment have been described, leading to polyclonal B-cell hyperreactivity, hypergammaglobulinemia and autoantibody production. Autoreactive B cells and autoantibodies promote and maintain pathologic mechanisms. In addition, autoantibodies in SSc are important biomarkers for predicting clinical phenotype and disease progression. Autoreactive B cells and autoantibodies represent potentially promising targets for therapeutic approaches including B-cell-targeting therapies, as well as strategies for unselective and selective removal of autoantibodies. In this review, we present mechanisms of the innate immune system leading to the generation of autoantibodies, alterations of the B-cell compartment in SSc, autoantibodies as biomarkers and autoantibody-mediated pathologies in SSc as well as potential therapeutic approaches to target these.
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2
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Chairta P, Nicolaou P, Sokratous K, Galant C, Houssiau F, Oulas A, Spyrou GM, Alarcon-Riquelme ME, Lauwerys BR, Christodoulou K. Comparative analysis of affected and unaffected areas of systemic sclerosis skin biopsies by high-throughput proteomic approaches. Arthritis Res Ther 2020; 22:107. [PMID: 32381114 PMCID: PMC7206756 DOI: 10.1186/s13075-020-02196-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 04/23/2020] [Indexed: 12/19/2022] Open
Abstract
Background Pathogenesis and aetiology of systemic sclerosis (SSc) are currently unclear, thus rendering disease prognosis, diagnosis and treatment challenging. The aim of this study was to use paired skin biopsy samples from affected and unaffected areas of the same patient, in order to compare the proteomes and identify biomarkers and pathways which are associated with SSc pathogenesis. Methods Biopsies were obtained from affected and unaffected skin areas of SSc patients. Samples were cryo-pulverised and proteins were extracted and analysed using mass spectrometry (MS) discovery analysis. Differentially expressed proteins were revealed after analysis with the Progenesis QIp software. Pathway analysis was performed using the Enrichr Web server. Using specific criteria, fifteen proteins were selected for further validation with targeted-MS analysis. Results Proteomic analysis led to the identification and quantification of approximately 2000 non-redundant proteins. Statistical analysis showed that 169 of these proteins were significantly differentially expressed in affected versus unaffected tissues. Pathway analyses showed that these proteins are involved in multiple pathways that are associated with autoimmune diseases (AIDs) and fibrosis. Fifteen of these proteins were further investigated using targeted-MS approaches, and five of them were confirmed to be significantly differentially expressed in SSc affected versus unaffected skin biopsies. Conclusion Using MS-based proteomics analysis of human skin biopsies from patients with SSc, we identified a number of proteins and pathways that might be involved in SSc progression and pathogenesis. Fifteen of these proteins were further validated, and results suggest that five of them may serve as potential biomarkers for SSc.
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Affiliation(s)
- Paraskevi Chairta
- Cyprus School of Molecular Medicine, 6 Iroon Avenue, 2371, Nicosia, Cyprus.,Neurogenetics Department, Cyprus Institute of Neurology & Genetics, 6 Iroon Avenue, 2371, Nicosia, Cyprus
| | - Paschalis Nicolaou
- Cyprus School of Molecular Medicine, 6 Iroon Avenue, 2371, Nicosia, Cyprus.,Neurogenetics Department, Cyprus Institute of Neurology & Genetics, 6 Iroon Avenue, 2371, Nicosia, Cyprus
| | - Kleitos Sokratous
- Cyprus School of Molecular Medicine, 6 Iroon Avenue, 2371, Nicosia, Cyprus.,Bioinformatics ERA Chair, Cyprus Institute of Neurology & Genetics, 6 Iroon Avenue, 2371, Nicosia, Cyprus.,Present Address: OMass Therapeutics, The Schrödinger Building, Heatley Road, The Oxford Science Park, Oxford, OX4 4GE, UK
| | - Christine Galant
- Department of Pathology, Université catholique de Louvain, Bruxelles, Belgium
| | - Frédéric Houssiau
- Rheumatology Department, Cliniques Universitaires Saint-Luc, Pôle de Pathologies Rhumatismales Inflammatoires et Systémiques, Université catholique de Louvain, Bruxelles, Belgium
| | - Anastasis Oulas
- Cyprus School of Molecular Medicine, 6 Iroon Avenue, 2371, Nicosia, Cyprus.,Bioinformatics ERA Chair, Cyprus Institute of Neurology & Genetics, 6 Iroon Avenue, 2371, Nicosia, Cyprus
| | - George M Spyrou
- Cyprus School of Molecular Medicine, 6 Iroon Avenue, 2371, Nicosia, Cyprus.,Bioinformatics ERA Chair, Cyprus Institute of Neurology & Genetics, 6 Iroon Avenue, 2371, Nicosia, Cyprus
| | - Marta E Alarcon-Riquelme
- Area of Medical Genomics, Pfizer-Universidad de Granada-Junta de Andalucía de Genómica e Investigación Oncológica (GENyO), Parque Tenológico de la Salud Fundación (PTS) Granada, Spain; Arthritis and Clinical Immunology, Oklahoma Medical Research Foundation, Oklahoma City, USA
| | - Bernard R Lauwerys
- Department of Pathology, Université catholique de Louvain, Bruxelles, Belgium
| | - Kyproula Christodoulou
- Cyprus School of Molecular Medicine, 6 Iroon Avenue, 2371, Nicosia, Cyprus. .,Neurogenetics Department, Cyprus Institute of Neurology & Genetics, 6 Iroon Avenue, 2371, Nicosia, Cyprus.
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3
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Affandi AJ, Carvalheiro T, Radstake TRDJ, Marut W. Dendritic cells in systemic sclerosis: Advances from human and mice studies. Immunol Lett 2017; 195:18-29. [PMID: 29126878 DOI: 10.1016/j.imlet.2017.11.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 11/05/2017] [Accepted: 11/06/2017] [Indexed: 12/20/2022]
Abstract
Systemic sclerosis (SSc) is a complex heterogeneous fibrotic autoimmune disease with an unknown exact etiology, and characterized by three hallmarks: fibrosis, vasculopathy, and immune dysfunction. Dendritic cells (DCs) are specialized cells in pathogen sensing with high potency of antigen presentation and capable of releasing mediators to shape the immune response. Altered DCs distributions and their impaired functions may account for their role in breaking the immune tolerance and driving inflammation in SSc, and the direct contribution of DCs in promoting endothelial dysfunction and fibrotic process has only begun to be understood. Plasmacytoid dendritic cells in particular have been implicated due to their high production of type I interferon as well as other cytokines and chemokines, including the pro-inflammatory and anti-angiogenic CXCL4. Furthermore, a deeper understanding of human and mouse DC biology has clarified their identification and function in different tissues, and novel DC subsets have only recently been discovered. In this review, we highlight key findings and recent advances exploring DC role in the pathogenesis of SSc and other related autoimmune diseases, and consideration of their potential use as targeted therapy in SSc.
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Affiliation(s)
- Alsya J Affandi
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands; Department of Rheumatology and Clinical Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Tiago Carvalheiro
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands; Department of Rheumatology and Clinical Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Timothy R D J Radstake
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands; Department of Rheumatology and Clinical Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Wioleta Marut
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands; Department of Rheumatology and Clinical Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.
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4
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Mehta H, Goulet PO, Nguyen V, Pérez G, Koenig M, Senécal JL, Sarfati M. Topoisomerase I peptide-loaded dendritic cells induce autoantibody response as well as skin and lung fibrosis. Autoimmunity 2016; 49:503-513. [DOI: 10.1080/08916934.2016.1230848] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
| | | | | | - Gemma Pérez
- Laboratory for Research in Autoimmunity, Center de Recherche du Center Hospitalier de l’Université de Montréal (CRCHUM), Montréal, Québec, Canada
| | - Martial Koenig
- Laboratory for Research in Autoimmunity, Center de Recherche du Center Hospitalier de l’Université de Montréal (CRCHUM), Montréal, Québec, Canada
| | - Jean-Luc Senécal
- Laboratory for Research in Autoimmunity, Center de Recherche du Center Hospitalier de l’Université de Montréal (CRCHUM), Montréal, Québec, Canada
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Abstract
In aging societies increasing cases of neurodegenerative protein deposit diseases urge for the identification of the underlying mechanisms. Expectations are that in 2050 the percentage of population over age 60 is 42% in Japan, 34% in China, and 27% in the US. The cell nucleus is a major target of amyloid-like protein fibrillation in a variety of disorders that are characterized by widespread aggregation of proteins with instable homopolymeric amino acid repeats, ubiquitin, and other proteinaceous components. Additionally, accumulation of insoluble, SDS-resistant proteins has been identified as an intrinsic property of organismal aging. This review collects current knowledge about the composition and function of insoluble, nuclear protein inclusions from the protein homeostasis perspective. It discusses the occurrence and role of nuclear amyloid in the diseased as well as the healthy cell. Features of nuclear inclusions such as protein composition and locally active protein degradation may predict neural fitness and survival in a variety of health or disease settings.
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Affiliation(s)
- Anna von Mikecz
- a IUF - Leibniz Research Institute for Environmental Medicine at Heinrich-Heine-University; Duesseldorf, Germany
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6
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Hopp AK, Rupp A, Lukacs-Kornek V. Self-antigen presentation by dendritic cells in autoimmunity. Front Immunol 2014; 5:55. [PMID: 24592266 PMCID: PMC3923158 DOI: 10.3389/fimmu.2014.00055] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Accepted: 01/30/2014] [Indexed: 11/13/2022] Open
Abstract
The operation of both central and peripheral tolerance ensures the prevention of autoimmune diseases. The maintenance of peripheral tolerance requires self-antigen presentation by professional antigen presenting cells (APCs). Dendritic cells (DCs) are considered as major APCs involved in this process. The current review discusses the role of DCs in autoimmune diseases, the various factors involved in the induction and maintenance of tolerogenic DC phenotype, and pinpoints their therapeutic capacity as well as potential novel targets for future clinical studies.
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Affiliation(s)
- Ann-Katrin Hopp
- Department of Medicine II, Saarland University Medical Center , Homburg , Germany
| | - Anne Rupp
- Department of Medicine II, Saarland University Medical Center , Homburg , Germany
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Zhou X, Lin W, Tan FK, Assassi S, Fritzler MJ, Guo X, Sharif R, Xia T, Lai S, Arnett FC. Decreased catalytic function with altered sumoylation of DNA topoisomerase I in the nuclei of scleroderma fibroblasts. Arthritis Res Ther 2011; 13:R128. [PMID: 21827649 PMCID: PMC3239368 DOI: 10.1186/ar3435] [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: 11/12/2010] [Revised: 06/18/2011] [Accepted: 08/09/2011] [Indexed: 11/10/2022] Open
Abstract
Introduction Sumoylation is involved in nucleolus-nucleoplasm transport of DNA topoisomerase I (topo I), which may associate with changes of cellular and topo I functions. Skin fibroblasts of patients with systemic sclerosis (SSc) exhibit profibrotic cellular changes. The aims of this study were to examine the catalytic function and sumoylation of topo I in the nuclei of SSc fibroblasts, a major cell type involved in the fibrotic process. Methods Eleven pairs of fibroblast strains obtained from nonlesional skin biopsies of SSc patients and age/sex/ethnicity-matched normal controls were examined for catalytic function of nuclear topo I. Immunoprecipitation (IP)-Western blots were used to examine sumoylation of fibroblast topo I. Real-time quantitative RT-PCR was used to measure transcript levels of SUMO1 and COL1A2 in the fibroblasts. Results Topo I in nuclear extracts of SSc fibroblasts generally showed a significantly lower efficiency than that of normal fibroblasts in relaxing equivalent amounts of supercoiled DNA. Increased sumoylation of topo I was clearly observed in 7 of 11 SSc fibroblast strains. Inhibition of SUMO1 with SUMO1 siRNA improved the catalytic efficiency of topo I in the SSc fibroblasts. In contrast, sumoylation of recombinant topo I proteins reduced their catalytic function. Conclusions The catalytic function of topo I was decreased in SSc fibroblasts, to which increased sumoylation of topo I may contribute.
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Affiliation(s)
- Xiaodong Zhou
- Division of Rheumatology, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
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Pathogenesis of systemic sclerosis. Rheumatology (Oxford) 2011. [DOI: 10.1016/b978-0-323-06551-1.00139-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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9
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Cooper G, Gilbert K, Greidinger E, James J, Pfau J, Reinlib L, Richardson B, Rose N. Recent advances and opportunities in research on lupus: environmental influences and mechanisms of disease. CIENCIA & SAUDE COLETIVA 2010; 14:1865-76. [PMID: 19851599 DOI: 10.1590/s1413-81232009000500028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Accepted: 03/05/2008] [Indexed: 12/14/2022] Open
Abstract
We summarize research on mechanisms through which environmental agents may affect the pathogenesis of lupus, discuss three exposures that have been the focus of research in this area, and propose recommendations for new research initiatives. We examined studies pertaining to key mechanistic events and specific exposures. Apoptosis leading to increased production or decreased clearance of immunogenic intracellular self-antigens and defective apoptosis of autoreactive immune cells both have been implicated in the loss of self-tolerance. The adjuvant or bystander effect is also needed to produce a sustained autoimmune response. Activation of toll-like receptors is one mechanism through which these effects may occur. Abnormal DNA methylation may contribute to the pathogenesis of lupus. Each of the specific exposures has been shown, in humans or in mice, to act upon one or more of these pathogenic steps. Specific recommendations for the continued advancement of our understanding of environmental influences on lupus and other autoimmune diseases include the development and use of mouse models with varying degrees of penetrance and manifestations of disease, identification of molecular or physiologic targets of specific exposures, development and use of improved exposure assessment methodologies, and multisite collaborations designed to examine understudied environmental exposures in humans.
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Affiliation(s)
- Glinda Cooper
- National Center for Environmental Assessment, U.S. EnvironmentalProtection Agency, Washington, DC 20460 USA.
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10
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Slobodin G, Pavlotzky E, Panov J, Rosner I, Kessel A, Toubi E. Endothelin-1 Does Not Change the Function of Monocyte-Derived Dendritic Cells Grown from Patients with Systemic Sclerosis. Immunol Invest 2009; 37:841-8. [DOI: 10.1080/08820130802438016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Abstract
Dendritic cells (DC) have been implicated both in initiation of immunity and in immune tolerance. The mechanisms whereby tolerogenic DC may induce and maintain peripheral tolerance include the generation or expansion of regulatory T cells (Treg) and the promotion of T-cell anergy or deletion. A wide spectrum of hematopoietic growth factors and cytokines are endowed with the ability to differentiate tolerogenic DC both in vitro and in vivo. Based on this knowledge, therapeutic vaccination with cytokine-modulated tolerogenic DC has been applied to animal models of autoimmune disorders. This article will review the current experimental evidence underpinning DC dysfunction in rheumatic autoimmune diseases and will discuss how the manipulation of DC and Treg number and function may control undesired T-cell responses.
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12
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Tokumura A, Carbone LD, Yoshioka Y, Morishige J, Kikuchi M, Postlethwaite A, Watsky MA. Elevated serum levels of arachidonoyl-lysophosphatidic acid and sphingosine 1-phosphate in systemic sclerosis. Int J Med Sci 2009; 6:168-76. [PMID: 19521548 PMCID: PMC2695151 DOI: 10.7150/ijms.6.168] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Accepted: 06/02/2009] [Indexed: 12/12/2022] Open
Abstract
Systemic sclerosis (SSc) is an often fatal disease characterized by autoimmunity and inflammation, leading to widespread vasculopathy and fibrosis. Lysophosphatidic acid (LPA), a bioactive phospholipid in serum, is generated from lysophospholipids secreted from activated platelets in part by the action of lysophospholipase D (lysoPLD). Sphingosine 1-phosphate (S1P), a member of the bioactive lysophospholipid family, is also released from activated platelets. Because activated platelets are a hallmark of SSc, we wanted to determine whether subjects with SSc have altered serum lysophospholipid levels or lysoPLD activity. Lysophospholipid levels were measured using mass spectrometric analysis. LysoPLD activity was determined by quantifying choline released from exogenous lysophosphatidylcholine (LPC). The major results were that serum levels of arachidonoyl (20:4)-LPA and S1P were significantly higher in SSc subjects versus controls. Furthermore, serum LPA:LPC ratios of two different polyunsaturated phospholipid molecular species, and also the ratio of all species combined, were significantly higher in SSc subjects versus controls. No significant differences were found between other lysophospholipid levels or lysoPLD activities. Elevated 20:4 LPA, S1P levels and polyunsaturated LPA:LPC ratios may be markers for and/or play a significant role in the etiology of SSc and may be future pharmacological targets for SSc treatment.
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Affiliation(s)
- Akira Tokumura
- Department of Health Chemistry, Institute of Health Bioscience, The University of Tokushima Graduate School, 1-78-1 Shomachi, Tokushima 770-8505, Japan
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13
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Cooper GS, Gilbert KM, Greidinger EL, James JA, Pfau JC, Reinlib L, Richardson BC, Rose NR. Recent advances and opportunities in research on lupus: environmental influences and mechanisms of disease. ENVIRONMENTAL HEALTH PERSPECTIVES 2008; 116:695-702. [PMID: 18560522 PMCID: PMC2430222 DOI: 10.1289/ehp.11092] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Accepted: 03/05/2008] [Indexed: 05/26/2023]
Abstract
OBJECTIVES In this review we summarize research on mechanisms through which environmental agents may affect the pathogenesis of lupus, discuss three exposures that have been the focus of research in this area, and propose recommendations for new research initiatives. DATA SOURCES AND SYNTHESIS We examined studies pertaining to key mechanistic events and specific exposures. Apoptosis leading to increased production or decreased clearance of immunogenic intracellular self-antigens and defective apoptosis of autoreactive immune cells both have been implicated in the loss of self-tolerance. The adjuvant or bystander effect is also needed to produce a sustained autoimmune response. Activation of toll-like receptors is one mechanism through which these effects may occur. Abnormal DNA methylation may also contribute to the pathogenesis of lupus. Each of the specific exposures we examined--Epstein-Barr virus, silica, and trichloroethylene--has been shown, in humans or in mice, to act upon one or more of these pathogenic steps. Specific recommendations for the continued advancement of our understanding of environmental influences on lupus and other autoimmune diseases include the development and use of mouse models with varying degrees of penetrance and manifestations of disease, identification of molecular or physiologic targets of specific exposures, development and use of improved exposure assessment methodologies, and multisite collaborations designed to examine understudied environmental exposures in humans. CONCLUSIONS The advances made in the past decade concerning our understanding of mechanisms involved in the development of lupus and the influence of environmental agents on this process provide a strong foundation for further developments in this field.
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Affiliation(s)
- Glinda S Cooper
- National Center for Environmental Assessment, US Environmental Protection Agency, Washington, DC 20460, USA.
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14
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Abstract
Systemic sclerosis (SSc) is a systemic autoimmune disease characterized by extensive fibrotic changes in various organs, including skin and lung. Although the etiology of SSc remains unknown, three major abnormalities, abnormal humoral immunity, microvasculature, and fibroblast dysfunctions are considered to play important roles. Significant progress has been made in understanding the pathogenesis on SSc, and has been also providing clues to the treatment for this disease. This review summarizes recent advances on the pathogenesis and new therapeutic strategy for SSc.
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Fonseca C, Lindahl GE, Ponticos M, Sestini P, Renzoni EA, Holmes AM, Spagnolo P, Pantelidis P, Leoni P, McHugh N, Stock CJ, Shi-Wen X, Denton CP, Black CM, Welsh KI, du Bois RM, Abraham DJ. A polymorphism in the CTGF promoter region associated with systemic sclerosis. N Engl J Med 2007; 357:1210-20. [PMID: 17881752 DOI: 10.1056/nejmoa067655] [Citation(s) in RCA: 139] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Systemic sclerosis (scleroderma) is a life-threatening autoimmune disease that is characterized by the presence of specific autoantibodies and fibrosis of the skin and major internal organs. METHODS We genotyped a polymorphism (G-945C) in the promoter of the connective-tissue growth factor (CTGF) gene in 1000 subjects in two groups: group 1, consisting of 200 patients with systemic sclerosis and 188 control subjects; and group 2, consisting of 300 patients with systemic sclerosis and 312 control subjects. The combined groups represented an estimated 10% of patients with systemic sclerosis in the United Kingdom. We tested the effect of the polymorphism on the transcription of CTGF. RESULTS The GG genotype was significantly more common in patients with systemic sclerosis than in control subjects in both groups, with an odds ratio for the combined group of 2.2 (95% confidence interval [CI], 1.5 to 3.2; P<0.001 for trend). Analysis of the combined group of patients with systemic sclerosis showed a significant association between homozygosity for the G allele and the presence of anti-topoisomerase I antibodies (odds ratio, 3.3; 95% CI, 2.0 to 5.6; P<0.001) and fibrosing alveolitis (odds ratio, 3.1; 95% CI, 1.9 to 5.0; P<0.001). We observed that the substitution of cytosine for guanine created a binding site of the transcriptional regulators Sp1 and Sp3. The C allele has high affinity for Sp3 and is associated with severely reduced transcriptional activity. A chromatin immunoprecipitation assay showed a marked shift in the ratio of Sp1 to Sp3 binding at this region, demonstrating functional relevance in vivo. CONCLUSIONS The G-945C substitution represses CTGF transcription, and the -945G allele is significantly associated with susceptibility to systemic sclerosis.
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Affiliation(s)
- Carmen Fonseca
- Centre for Rheumatology, Royal Free and University College Medical School, London, United Kingdom
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Tanaka T, Grusby MJ, Kaisho T. PDLIM2-mediated termination of transcription factor NF-kappaB activation by intranuclear sequestration and degradation of the p65 subunit. Nat Immunol 2007; 8:584-91. [PMID: 17468759 DOI: 10.1038/ni1464] [Citation(s) in RCA: 242] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Accepted: 04/05/2007] [Indexed: 11/08/2022]
Abstract
Activation of transcription factor NF-kappaB in the innate immune system is tightly regulated to prevent excessive inflammatory responses. How NF-kappaB activation is terminated, however, is not fully understood. Here we report that PDLIM2 negatively regulated NF-kappaB activity, acting as a nuclear ubiquitin E3 ligase targeting the p65 subunit of NF-kappaB. PDLIM2 bound to p65 and promoted p65 polyubiquitination. In addition, PDLIM2 targeted p65 to discrete intranuclear compartments where polyubiquitinated p65 was degraded by the proteasome. PDLIM2 deficiency resulted in larger amounts of nuclear p65, defective p65 ubiquitination and augmented production of proinflammatory cytokines in response to innate stimuli. Our findings delineate a pathway by which PDLIM2 terminates NF-kappaB activation through intranuclear sequestration and subsequent degradation.
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Affiliation(s)
- Takashi Tanaka
- Laboratory for Host Defense, RIKEN Research Center for Allergy and Immunology, Yokohama, Kanagawa 230-0045, Japan
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17
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Codullo V, Bardoni A, Salvini R, Montecucco C. Antinuclear antibodies in systemic sclerosis. ACTA ACUST UNITED AC 2006. [DOI: 10.2217/17460816.1.3.365] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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18
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Abstract
In eukaryotes, thousands of genes have to be organized and expressed in the cell nucleus. Conformational and kinetic instability of nuclear structure and components appear to enable cells to use the encoded information selectively. The ubiquitin-proteasome system is active in distinct nuclear domains and plays a major role controlling the initial steps of gene expression, DNA repair and nuclear quality-control mechanisms. Recent work indicates that a tuned balance of ubiquitylation and proteasome-dependent protein degradation of nuclear proteins is instrumental in nuclear function and, when deregulated, leads to the development of diseases such as polyQ disorders and other neurodegenerative conditions.
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Affiliation(s)
- Anna von Mikecz
- Institut für umweltmedizinische Forschung, Heinrich-Heine-Universität Düsseldorf, Auf'm Hennekamp 50, 40225 Düsseldorf, Germany.
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Chen M, von Mikecz A. Xenobiotic-Induced Recruitment of Autoantigens to Nuclear Proteasomes Suggests a Role for Altered Antigen Processing in Scleroderma. Ann N Y Acad Sci 2005; 1051:382-9. [PMID: 16126980 DOI: 10.1196/annals.1361.080] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The cell nucleus is a prominent target of autoantibodies in systemic autoimmune disorders. Approximately 2% of the population in Europe and North America suffers from systemic rheumatic diseases, such as rheumatoid arthritis, systemic lupus erythematosus (SLE), and scleroderma. The molecular mechanisms of systemic autoimmunity are largely unknown despite its high prevalence. Contributing factors that have been considered include (1) genetic predisposition, (2) influence of hormones, and (3) environmental factors. The latter are mainly correlated with the generation of scleroderma, as xenobiotic-induced subsets of this disease have been observed in individuals exposed to silica (SiO(2)) dusts, organic solvents, heavy metals, and certain drugs. In addition to the epidemiological relevance, animal models of xenobiotic-induced autoimmunity serve as elegant tools for controlled induction of antigen-driven autoimmune responses. Because antigen processing and presentation constitute the basis for every antigen-driven autoimmune response, effects of xenobiotics on degradation of nuclear autoantigens have been characterized to elucidate molecular mechanisms of autoimmunity that target the cell nucleus. By means of a cell-based disease model, it has been shown that xenobiotics such as mercuric chloride, platinum salts, and silica (nano)particles specifically alter structure, function, and proteolysis in the cell nucleus. Signature proteins of the cell nucleus redistribute to aberrant, nucleoplasmic clusters, where they colocalize with proteasomes and are subjected to proteasomal proteolysis. Recruitment of nuclear autoantigens to proteasomal degradation is correlated with autoimmune responses that specifically target these antigens in both animal models of xenobiotic-induced autoimmunity and patients with idiopathic scleroderma.
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Affiliation(s)
- Min Chen
- Institut für umweltmedizinische Forschung at Heinrich-Heine-University Duesseldorf, Auf'm Hennekamp 50, D-40225 Duesseldorf, Germany.
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von Mikecz A. Xenobiotic-induced autoimmunity and protein aggregation diseases share a common subnuclear pathology. Autoimmun Rev 2005; 4:214-8. [PMID: 15893714 DOI: 10.1016/j.autrev.2004.11.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2004] [Accepted: 11/21/2004] [Indexed: 11/18/2022]
Abstract
The cell nucleus constitutes a prime target of idiopathic and xenobiotic-induced autoimmunity. Despite of the high prevalence of rheumatic autoimmune diseases, the molecular mechanisms inducing systemic autoimmunity are largely unknown. In appreciation of Rudolf Virchow's cellularpathology, this review introduces the new concept of subnuclear pathology to autoimmune responses against the cell nucleus. Aberrant nucleoplasmic clusters consisting of nuclear autoantigens and proteasomes are observed in xenobiotic-treated cell lines, splenic cells from animal models of xenobiotic-induced autoimmunity, and dendritic cells of scleroderma patients. Aggregation of nuclear proteins in clusters inhibits nuclear functions such as replication and transcription, and induces altered proteasomal degradation of nuclear autoantigens and cellular senescence. Since these modifications of nuclear structure, function and proteolysis resemble the pathology of neurodegenerative protein aggregation diseases, the hypothesis is put forward that xenobiotic-induced autoimmunity may also be a consequence of protein aggregation.
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Affiliation(s)
- Anna von Mikecz
- Institut für umweltmedizinische Forschung at Heinrich-Heine-University Düsseldorf, Auf'm Hennekamp 50, D-40225 Düsseldorf, Germany.
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