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Nguyen HH, Fritzler MJ, Swain MG. A Review on Biomarkers for the Evaluation of Autoimmune Cholestatic Liver Diseases and Their Overlap Syndromes. FRONTIERS IN MOLECULAR MEDICINE 2022; 2:914505. [PMID: 39086971 PMCID: PMC11285550 DOI: 10.3389/fmmed.2022.914505] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 05/30/2022] [Indexed: 08/02/2024]
Abstract
Autoimmune cholestatic liver disease includes both Primary Biliary Cholangitis (PBC) and Primary Sclerosing Cholangitis (PSC). Both conditions result in impairment of hepatic bile flow ultimately leading to chronic liver injury, liver fibrosis and eventually end stage cirrhosis. Early and accurate diagnosis are important for the risk stratification, follow up and management of these patients. The underlying pathogenesis of these conditions have not been completely resolved and poses a barrier for the development of new diagnostic and prognostics tools. Current research work suggests that the pathogenesis of autoimmune cholestatic liver disease results from environmental, genetic, and a large component of underlying immune dysfunction. While the current available serum biomarkers and imaging modalities showcases progression in precision medicine for the management of autoimmune cholestatic liver disease, development of new biomarkers are still an area of need in this field. In this review, we will discuss the current and emerging biomarkers in patients with PBC, PSC, and a special population that exhibit overlap syndrome with autoimmune hepatitis (AIH). The use of these biomarkers for diagnosis and prognosis of these patients will be reviewed through the lens of the current understanding of the complex immune pathophysiology of these conditions.
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Affiliation(s)
- Henry H. Nguyen
- University of Calgary Liver Unit, Department of Medicine & Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Marvin J. Fritzler
- Department of Medicine, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Mark G. Swain
- University of Calgary Liver Unit, Department of Medicine, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
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Genetic Associations and Differential mRNA Expression Levels of Host Genes Suggest a Viral Trigger for Endemic Pemphigus Foliaceus. Viruses 2022; 14:v14050879. [PMID: 35632621 PMCID: PMC9144834 DOI: 10.3390/v14050879] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 04/11/2022] [Accepted: 04/15/2022] [Indexed: 12/04/2022] Open
Abstract
The long search for the environmental trigger of the endemic pemphigus foliaceus (EPF, fogo selvagem) has not yet resulted in any tangible findings. Here, we searched for genetic associations and the differential expression of host genes involved in early viral infections and innate antiviral defense. Genetic variants could alter the structure, expression sites, or levels of the gene products, impacting their functions. By analyzing 3063 variants of 166 candidate genes in 227 EPF patients and 194 controls, we found 12 variants within 11 genes associated with differential susceptibility (p < 0.005) to EPF. The products of genes TRIM5, TPCN2, EIF4E, EIF4E3, NUP37, NUP50, NUP88, TPR, USP15, IRF8, and JAK1 are involved in different mechanisms of viral control, for example, the regulation of viral entry into the host cell or recognition of viral nucleic acids and proteins. Only two of nine variants were also associated in an independent German cohort of sporadic PF (75 patients, 150 controls), aligning with our hypothesis that antiviral host genes play a major role in EPF due to a specific virus−human interaction in the endemic region. Moreover, CCL5, P4HB, and APOBEC3G mRNA levels were increased (p < 0.001) in CD4+ T lymphocytes of EPF patients. Because there is limited or no evidence that these genes are involved in autoimmunity, their crucial role in antiviral responses and the associations that we observed support the hypothesis of a viral trigger for EPF, presumably a still unnoticed flavivirus. This work opens new frontiers in searching for the trigger of EPF, with the potential to advance translational research that aims for disease prevention and treatment.
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Muñoz-Sánchez G, Pérez-Isidro A, Ortiz de Landazuri I, López-Gómez A, Bravo-Gallego LY, Garcia-Ormaechea M, Julià MR, Viñas O, Ruiz-Ortiz E. Working Algorithms and Detection Methods of Autoantibodies in Autoimmune Liver Disease: A Nationwide Study. Diagnostics (Basel) 2022; 12:diagnostics12030697. [PMID: 35328252 PMCID: PMC8947365 DOI: 10.3390/diagnostics12030697] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 03/09/2022] [Accepted: 03/10/2022] [Indexed: 02/06/2023] Open
Abstract
Autoantibody detection is the cornerstone of autoimmune liver diseases (AILD) diagnosis. Standardisation of working algorithms among autoimmunity laboratories, as well as being aware of the sensitivity and specificity of various commercial techniques in daily practice, are still necessary. The aim of this nationwide study is to report the results of the 2020 Autoimmunity Workshop organised by the Autoimmunity Group of the Spanish Society of Immunology and to provide useful information to clinicians and laboratory specialists to improve the management of autoantibody detection in AILD diagnoses. Serum samples from 17 patients with liver diseases were provided by the organisers of the 2020 Autoimmunity Workshop and were subsequently analysed by the 40 participating laboratories. Each laboratory used different techniques for the detection of autoantibodies in each patients’ serum sample, according to their working algorithm. Thus, almost 680 total complete patient reports were obtained, and the number of results from different autoantibody detection techniques was >3000. Up to eight different working algorithms were employed, including indirect immunofluorescence assays (IFA) and antigen-specific techniques (AgST). The IFA of HEp-2 cells was more sensitive than IFA of rat triple tissue for the study of anti-nuclear autoantibodies (ANA) associated with AILD. The IFA of a human neutrophil study for the analysis of anti-neutrophil cytoplasmic autoantibodies was not carried out systemically in all patients, or by all laboratories. AgSTs were the most sensitive methods for the detection of anti-smooth muscle/F-actin, soluble liver antigen, liver cytosol-1, M2-mitochondrial autoantibodies, and ANA associated with primary biliary cholangitis. The main differences in AMA detection were due to patients with autoantibodies against the non-dominant epitope of pyruvate dehydrogenase complex. Given that they are complementary, IFA and AgST should be performed in parallel. If there is high suspicion of AILD, AgST should always be performed.
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Affiliation(s)
- Guillermo Muñoz-Sánchez
- Department of Immunology, Centre de Diagnòstic Biomèdic, Hospital Clínic de Barcelona, Villarroel 170-Escala 4, Planta 0, 08036 Barcelona, Spain; (G.M.-S.); (A.P.-I.); (I.O.d.L.); (L.Y.B.-G.); (O.V.)
| | - Albert Pérez-Isidro
- Department of Immunology, Centre de Diagnòstic Biomèdic, Hospital Clínic de Barcelona, Villarroel 170-Escala 4, Planta 0, 08036 Barcelona, Spain; (G.M.-S.); (A.P.-I.); (I.O.d.L.); (L.Y.B.-G.); (O.V.)
- Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, 08036 Barcelona, Spain
| | - Iñaki Ortiz de Landazuri
- Department of Immunology, Centre de Diagnòstic Biomèdic, Hospital Clínic de Barcelona, Villarroel 170-Escala 4, Planta 0, 08036 Barcelona, Spain; (G.M.-S.); (A.P.-I.); (I.O.d.L.); (L.Y.B.-G.); (O.V.)
- Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, 08036 Barcelona, Spain
| | - Antonio López-Gómez
- Department of Immunology, Hospital Universitari Son Espases, 07120 Palma de Mallorca, Spain; (A.L.-G.); (M.R.J.)
- Institut d’Investigació Sanitària Illes Balears, 07120 Palma de Mallorca, Spain
| | - Luz Yadira Bravo-Gallego
- Department of Immunology, Centre de Diagnòstic Biomèdic, Hospital Clínic de Barcelona, Villarroel 170-Escala 4, Planta 0, 08036 Barcelona, Spain; (G.M.-S.); (A.P.-I.); (I.O.d.L.); (L.Y.B.-G.); (O.V.)
- Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, 08036 Barcelona, Spain
| | | | - Maria Rosa Julià
- Department of Immunology, Hospital Universitari Son Espases, 07120 Palma de Mallorca, Spain; (A.L.-G.); (M.R.J.)
- Institut d’Investigació Sanitària Illes Balears, 07120 Palma de Mallorca, Spain
| | - Odette Viñas
- Department of Immunology, Centre de Diagnòstic Biomèdic, Hospital Clínic de Barcelona, Villarroel 170-Escala 4, Planta 0, 08036 Barcelona, Spain; (G.M.-S.); (A.P.-I.); (I.O.d.L.); (L.Y.B.-G.); (O.V.)
- Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, 08036 Barcelona, Spain
| | - Estíbaliz Ruiz-Ortiz
- Department of Immunology, Centre de Diagnòstic Biomèdic, Hospital Clínic de Barcelona, Villarroel 170-Escala 4, Planta 0, 08036 Barcelona, Spain; (G.M.-S.); (A.P.-I.); (I.O.d.L.); (L.Y.B.-G.); (O.V.)
- Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, 08036 Barcelona, Spain
- Correspondence:
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Maltez N, Choi MY, Troyanov Y, Wang M, Jantz M, Fritzler MJ, Baron M, Hudson M. Trigeminal neuralgia in systemic sclerosis. Semin Arthritis Rheum 2021; 51:318-323. [PMID: 33461050 DOI: 10.1016/j.semarthrit.2021.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/29/2020] [Accepted: 01/05/2021] [Indexed: 10/22/2022]
Abstract
OBJECTIVES Although trigeminal neuralgia (TN) has been associated with systemic sclerosis (SSc), there is a paucity of evidence and pathophysiological processes remain unknown. We undertook a nested case-control study to identify associations between TN and SSc in a large multi-centered cohort and identify possible pathophysiological links. METHODS Data were derived from a longitudinal cohort of 1652 SSc subjects. Cases with a physician-reported diagnosis of TN were identified at baseline visit (prevalent) and during follow-up (incident). Each case was matched on study visit to four SSc patients without TN. Sociodemographic, clinical and serological characteristics of cases and controls were compared. RESULTS At enrolment, 43/1652 (2.6%) subjects had a history of TN. During follow-up, an additional 36 subjects developed TN over 6193 person-years of observation (incidence rate 5.8 per 1000 person-years). Cases were identified and matched to 172 and 144 controls, respectively. Compared to controls, prevalent cases had more inflammatory myositis (24.4% versus 5.2%, p<0.001) and inflammatory arthritis (46.5% versus 30.2%, p = 0.043). Incident cases also had more inflammatory myositis (19.4% versus. 6.3%, p = 0.033) and inflammatory arthritis (50.0% versus. 16.2%, p<0.001) compared to controls. There was a trend towards more interstitial lung disease in prevalent (32.6% versus 23.8%, p = 0.241) and incident (55.6% versus 40.6%, p = 0.105) cases compared to controls. CONCLUSION This study provides novel evidence for a clinical association linking TN, inflammatory myositis, inflammatory arthritis and possibly interstitial lung disease. In addition to ischemia, we propose that TN in SSc could also be a consequence of inflammatory and possibly fibrotic processes.
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Affiliation(s)
- Nancy Maltez
- Department of Medicine, Division of Rheumatology, The Ottawa Hospital, Ottawa, ON, Canada.
| | - May Y Choi
- Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Yves Troyanov
- Division of Rheumatology, Hôpital Sacré-Coeur de Montréal, Montreal, QC, Canada
| | - Mianbo Wang
- Lady Davis Institute for Medical Research, Montreal, QC, Canada
| | - Mackenzie Jantz
- Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Marvin J Fritzler
- Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Murray Baron
- Division of Rheumatology, Jewish General Hospital, Montreal, QC, Canada; Department of Medicine, McGill University, Montreal, QC, Canada
| | - Marie Hudson
- Lady Davis Institute for Medical Research, Montreal, QC, Canada; Division of Rheumatology, Jewish General Hospital, Montreal, QC, Canada; Department of Medicine, McGill University, Montreal, QC, Canada
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Damoiseaux J, Andrade LEC, Carballo OG, Conrad K, Francescantonio PLC, Fritzler MJ, Garcia de la Torre I, Herold M, Klotz W, Cruvinel WDM, Mimori T, von Muhlen C, Satoh M, Chan EK. Clinical relevance of HEp-2 indirect immunofluorescent patterns: the International Consensus on ANA patterns (ICAP) perspective. Ann Rheum Dis 2019; 78:879-889. [PMID: 30862649 PMCID: PMC6585284 DOI: 10.1136/annrheumdis-2018-214436] [Citation(s) in RCA: 194] [Impact Index Per Article: 38.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 01/23/2019] [Indexed: 12/21/2022]
Abstract
The indirect immunofluorescence assay (IIFA) on HEp-2 cells is widely used for detection of antinuclear antibodies (ANA). The dichotomous outcome, negative or positive, is integrated in diagnostic and classification criteria for several systemic autoimmune diseases. However, the HEp-2 IIFA test has much more to offer: besides the titre or fluorescence intensity, it also provides fluorescence pattern(s). The latter include the nucleus and the cytoplasm of interphase cells as well as patterns associated with mitotic cells. The International Consensus on ANA Patterns (ICAP) initiative has previously reached consensus on the nomenclature and definitions of HEp-2 IIFA patterns. In the current paper, the ICAP consensus is presented on the clinical relevance of the 29 distinct HEp-2 IIFA patterns. This clinical relevance is primarily defined within the context of the suspected disease and includes recommendations for follow-up testing. The discussion includes how this information may benefit the clinicians in daily practice and how the knowledge can be used to further improve diagnostic and classification criteria.
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Affiliation(s)
- Jan Damoiseaux
- Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, The Netherlands
| | | | - Orlando Gabriel Carballo
- Department of Immunology, Instituto Universitario del Hospital Italiano de Buenos Aires, Buenos Aires, Argentina.,Laboratory of Immunology, Hospital General de Agudos Carlos G Durand, Buenos Aires, Argentina
| | - Karsten Conrad
- Immunology, Medical Faculty TU Dresden, Dresden, Germany
| | | | | | | | - Manfred Herold
- Rheumatology Unit, Clinical Department of General Internal Medicine, Innsbruck Medical University, Innsbruck, Austria
| | - Werner Klotz
- Department of Internal Medicine II, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Tsuneyo Mimori
- Department of Rheumatology and Clinical Immunology, Kyoto University Graduate school of Medicine, Kyoto, Japan
| | | | - Minoru Satoh
- Department of Clinical Nursing, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Edward K Chan
- Department of Oral Biology, University of Florida, Gainesville, Florida, USA
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Sakuma S, D'Angelo MA. The roles of the nuclear pore complex in cellular dysfunction, aging and disease. Semin Cell Dev Biol 2017; 68:72-84. [PMID: 28506892 DOI: 10.1016/j.semcdb.2017.05.006] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 05/11/2017] [Indexed: 12/19/2022]
Abstract
The study of the Nuclear Pore Complex (NPC), the proteins that compose it (nucleoporins), and the nucleocytoplasmic transport that it controls have revealed an unexpected layer to pathogenic disease onset and progression. Recent advances in the study of the regulation of NPC composition and function suggest that the precise control of this structure is necessary to prevent diseases from arising or progressing. Here we discuss the role of nucleoporins in a diverse set of diseases, many of which directly or indirectly increase in occurrence and severity as we age, and often shorten the human lifespan. NPC biology has been shown to play a direct role in these diseases and therefore in the process of healthy aging.
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Affiliation(s)
- Stephen Sakuma
- Development, Aging and Regeneration Program (DARe), Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Maximiliano A D'Angelo
- Development, Aging and Regeneration Program (DARe), Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA.
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Ganesan V, Ascherman DP, Minden JS. Immunoproteomics technologies in the discovery of autoantigens in autoimmune diseases. Biomol Concepts 2017; 7:133-43. [PMID: 27115324 DOI: 10.1515/bmc-2016-0007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 03/21/2016] [Indexed: 12/16/2022] Open
Abstract
Proteomics technologies are often used for the identification of protein targets of the immune system. Here, we discuss the immunoproteomics technologies used for the discovery of autoantigens in autoimmune diseases where immune system dysregulation plays a central role in disease onset and progression. These autoantigens and associated autoantibodies can be used as potential biomarkers for disease diagnostics, prognostics and predicting/monitoring drug responsiveness (theranostics). Here, we compare a variety of methods such as mass spectrometry (MS)-based [serological proteome analysis (SERPA), antibody mediated identification of antigens (AMIDA), circulating immune complexome (CIC) analysis, surface enhanced laser desorption/ionization-time of flight (SELDI-TOF)], nucleic acid based serological analysis of antigens by recombinant cDNA expression cloning (SEREX), phage immunoprecipitation sequencing (PhIP-seq) and array-based immunoscreening (proteomic microarrays), luciferase immunoprecipitation systems (LIPS), nucleic acid programmable protein array (NAPPA) methods. We also review the relevance of immunoproteomic data generated in the last 10 years, with a focus on the aforementioned MS based methods.
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Zhang W, Zhang C, Chen P, Yang C, Gan X, Hussain M, Xun Y, Tian Y, Du H. Circulation autoantibody against Lamin A/C in patients with Sjögren's syndrome. Oncotarget 2016; 7:80252-80261. [PMID: 27835913 PMCID: PMC5348317 DOI: 10.18632/oncotarget.13256] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 10/25/2016] [Indexed: 01/17/2023] Open
Abstract
Lamin A/C proteins are major components of nuclear laminae and were encoded by the LMNA gene. Recent studies have found that in addition to provides nuclear-membrane strength; it also regulates the gene expression. Lamin A/C has been confirmed as an autoantigen in RA, SLE and vasculitis. Anti-Lamin A/C antibodies also have been found by indirect immunofluorescence method. In this study, we used various research methods to confirm Lamin A/C is an autoantigen in Han Chinese patients with confirmed Sjögren's syndrome (SS). To further investigate the relationship between the autoimmune disease antigens, we compared the amino acid sequence of Lamin A/C epitope and several common antigens' antigenic determinant. As a result, we found that Lamin A/C has similar epitopes with U1RNP. It means that the potential relationship exist between Lamin A/C and U1RNP. Clinical data we collected also showed that anti-Lamin A/C and anti-U1RNP antibodies always appear in same serum sample. Therefore, we speculated that cross-reaction may take place between antigen and potential antigen, which have similar epitope. Then, by epitope spreading, the potential antigen can be a new autoantigen. Our study provided a new thinking for further research about the relationship between autoantigens and their development mechanism in autoimmune diseases.
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Affiliation(s)
- Wen Zhang
- 112 Lab, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, China
| | - Chunyan Zhang
- Department of Clinical Biochemistry, Chinese PLA General Hospital, Beijing, China
| | - Peng Chen
- 112 Lab, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, China
| | - Chunhe Yang
- 112 Lab, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, China
| | - Xianfeng Gan
- 112 Lab, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, China
| | - Muhammad Hussain
- 112 Lab, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, China
| | - Yiping Xun
- 112 Lab, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, China
| | - Yaping Tian
- Department of Clinical Biochemistry, Chinese PLA General Hospital, Beijing, China
| | - Hongwu Du
- 112 Lab, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, China
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Stinton LM, Barr SG, Tibbles LA, Yilmaz S, Sar A, Benedikttson H, Fritzler MJ. Autoantibodies in lupus nephritis patients requiring renal transplantation. Lupus 2016; 16:394-400. [PMID: 17664229 DOI: 10.1177/0961203307078391] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The goal of this nested case-control study was to compare autoantibody profiles in systemic lupus erythematosus (SLE) patients with lupus nephritis (LN), lupus nephritis patients requiring renal transplantation (LNTP) and a SLE control group without nephritis (CON). Sera were assayed for a variety of autoantibodies by addressable laser bead immunoassay (ALBIA) and enzyme-linked immunoassay (ELISA) and to dsDNA by Crithidia luciliae assay. The frequency of nucleosome autoantibodies was significantly greater in the LNTP group (79%) compared to the LN (18%) and CON (9%) groups ( P < 0.0005). The frequency of other autoantibodies, including anti-dsDNA, did not differ significantly between groups. Among patients with LN, the odds of progressing to renal transplantation was 16-fold higher (OR 16.5 [95% CI 2.5, 125.7], P = 0.0005) in patients testing positive for anti-nucleosome antibodies compared to those who tested negative. Furthermore, the level of anti-nucleosome antibodies was significantly ( P < 0.00005) higher in the LNTP group (3.69 ± 2.79) than the LN (0.51 ± 0.51) and CON (0.34 ± 0.44) groups. Review of 48 renal biopsies from 29 patients indicated that there was no difference in renal histological classification among patients with anti-nucleosome antibodies compared to those who tested negative. Our observations suggest that nucleosome autoantibodies are a biomarker for more severe SLE renal disease requiring transplantation. Lupus (2007) 16, 394—400.
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Affiliation(s)
- L M Stinton
- Department of Medicine, University of Calgary, Calgary, Alberta, Canada
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Autoantibodies in primary biliary cirrhosis: antinuclear envelope autoantibodies. Clin Res Hepatol Gastroenterol 2014; 38:256-8. [PMID: 24268998 DOI: 10.1016/j.clinre.2013.10.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 10/14/2013] [Indexed: 02/04/2023]
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Fritzler MJ, Chan EKL. The Discovery of GW Bodies. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 768:5-21. [DOI: 10.1007/978-1-4614-5107-5_2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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Reflections on ten years of history of, and future prospects for, GW182 and GW/P body research. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 768:261-70. [PMID: 23224975 DOI: 10.1007/978-1-4614-5107-5_15] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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13
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Mehra S, Walker J, Patterson K, Fritzler MJ. Autoantibodies in systemic sclerosis. Autoimmun Rev 2013; 12:340-54. [DOI: 10.1016/j.autrev.2012.05.011] [Citation(s) in RCA: 160] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Accepted: 05/15/2012] [Indexed: 01/06/2023]
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Duarte-Rey C, Bogdanos D, Yang CY, Roberts K, Leung PSC, Anaya JM, Worman HJ, Gershwin ME. Primary biliary cirrhosis and the nuclear pore complex. Autoimmun Rev 2012; 11:898-902. [PMID: 22487189 DOI: 10.1016/j.autrev.2012.03.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 03/19/2012] [Indexed: 12/15/2022]
Abstract
Experimental models of autoimmune diseases have led to the conclusion that an immune response to nuclear antigens is a sentinel marker for loss of tolerance and potential tissue damage. Various proteins are targets of antinuclear antibodies in a variety of autoimmune diseases, ranging from systemic rheumatologic disorders to diseases affecting specific organs such as the liver. Autoantibodies against specific nuclear constituents have also been used as probes to understand the structure and the function of the targeted components and their relevance to disease pathogenesis. Approximately a quarter of patients with primary biliary cirrhosis (PBC) have antibodies targeting proteins of the nuclear pore complex (NPC), a multi-protein structure that mediates molecular transport across the nuclear envelope. Autoantibodies against the integral membrane glycoprotein gp210 and nucleoporin p62 appear to be highly specific for PBC, an autoimmune disease characterized by progressive destruction of intrahepatic biliary epithelial cells. This review discusses the diagnostic and clinical relevance of anti-NPC antibodies in PBC and the possibility that this autoimmune response may arise as a result of molecular mimicry.
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Affiliation(s)
- Carolina Duarte-Rey
- Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis School of Medicine, Davis, CA 95616, USA
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Agarwal S, Yadav SK, Dixit A. Heterologous expression of Translocated promoter region protein, Tpr, identified as a transcription factor from Rattus norvegicus. Protein Expr Purif 2011; 77:112-7. [PMID: 21216290 DOI: 10.1016/j.pep.2011.01.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2010] [Revised: 12/31/2010] [Accepted: 01/03/2011] [Indexed: 11/18/2022]
Abstract
Our earlier studies have demonstrated that the 35 kDa isoform of Translocated promoter region protein (Tpr) of Rattus norvegicus was able to augment c-jun transcription efficiently. Identification of direct targets that may in part downregulate c-jun transcription might prove to be an ideal target to curtail the proliferation of normal cells under pathophysiological conditions. In order to evaluate its potential as a pharmaceutical target, the protein must be produced and purified in sufficiently high yields. In the present study, we report the high level expression of Tpr protein of R. norvegicus employing heterologous host, Escherichia coli, to permit its structural characterization in great detail. We here demonstrate that the Tpr protein was expressed in soluble form and approximately 90 mg/L of the purified protein at the shake flask level could be achieved to near homogeneity using single step-metal chelate affinity chromatography. The amino acid sequence of the protein was confirmed by mass spectroscopic analysis. The highly unstable and disordered Tpr protein was imparted structural and functional stability by the addition of glycerol and it has been shown that the natively unfolded Tpr protein retains DNA binding ability under these conditions only. Thus, the present study emphasizes the significance of an efficient prokaryotic system, which results in a high level soluble expression of a DNA binding protein of eukaryotic origin. Thus, the present strategy employed for purification of the R. norvegicus Tpr protein bypasses the need for the tedious expression strategies associated with the eukaryotic expression systems.
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Affiliation(s)
- Shivani Agarwal
- Gene Regulation Laboratory, School of Biotechnology, Jawaharlal Nehru University, New Delhi 110 067, India
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Kraemer DM, Tony HP. Nuclear Pore Protein p62 Autoantibodies in Systemic Lupus Erythematosus. Open Rheumatol J 2010; 4:24-7. [PMID: 20648220 PMCID: PMC2905771 DOI: 10.2174/1874312901004010024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Revised: 03/12/2010] [Accepted: 04/19/2010] [Indexed: 02/04/2023] Open
Abstract
Systemic lupus erythematosus (SLE) is a systemic autoimmune disease which is classically characterised by a variety of autoantibodies to deoxyribonucleic acid (DNA), ribonucleic acid (RNA), other nuclear and cytoplasmic antigens. Recently several novel autoantibodies against a variety of specific nuclear pore proteins have been described, including the nucleoporin p62. In this paper we evaluate anti-nucleoporin p62 antibodies by western blot analysis in 25 systemic lupus erythematosus patients. Six patients showed antibodies directed against nucleoporin p62. Our data indicate that p62 antibodies could be a useful additional marker in SLE.
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Stalder L, Mühlemann O. Processing bodies are not required for mammalian nonsense-mediated mRNA decay. RNA (NEW YORK, N.Y.) 2009; 15:1265-73. [PMID: 19474145 PMCID: PMC2704072 DOI: 10.1261/rna.1672509] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Accepted: 04/22/2009] [Indexed: 05/18/2023]
Abstract
Nonsense-mediated mRNA decay (NMD) is a eukaryotic quality-control mechanism that recognizes and degrades mRNAs with premature termination codons (PTCs). In yeast, PTC-containing mRNAs are targeted to processing bodies (P-bodies), and yeast strains expressing an ATPase defective Upf1p mutant accumulate P-bodies. Here we show that in human cells, an ATPase-deficient UPF1 mutant and a fraction of UPF2 and UPF3b accumulate in cytoplasmic foci that co-localize with P-bodies. Depletion of the P-body component Ge-1, which prevents formation of microscopically detectable P-bodies, also impairs the localization of mutant UPF1, UPF2, and UPF3b in cytoplasmic foci. However, the accumulation of the ATPase-deficient UPF1 mutant in P-bodies is independent of UPF2, UPF3b, or SMG1, and the ATPase-deficient UPF1 mutant can localize into the P-bodies independent of its phosphorylation status. Most importantly, disruption of P-bodies by depletion of Ge-1 affects neither the mRNA levels of PTC-containing reporter genes nor endogenous NMD substrates. Consistent with the recently reported decapping-independent SMG6-mediated endonucleolytic decay of human nonsense mRNAs, our results imply that microscopically detectable P-bodies are not required for mammalian NMD.
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Affiliation(s)
- Lukas Stalder
- Institute of Cell Biology, University of Berne, 3012 Berne, Switzerland
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Wesierska-Gadek J, Klima A, Ranftler C, Komina O, Hanover J, Invernizzi P, Penner E. Characterization of the antibodies to p62 nucleoporin in primary biliary cirrhosis using human recombinant antigen. J Cell Biochem 2008; 104:27-37. [PMID: 17960595 DOI: 10.1002/jcb.21595] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Reactivity of sera from patients with primary biliary cirrhosis (PBC) with a 60 kDa component of nuclear pore complexes (NPCs), purified by affinity chromatography on wheat-germ agglutinin (WGA)-Sepharose, was previously detected. Recently, clinical significance of the anti-NPC antibodies in PBC became evident. In the light of recent reports, indicating the correlation of the anti-NPC antibodies with severity and progression of the disease, the characterization of the reactive antigens is becoming essential in the clinical management of patients with PBC. Since accurate autoantibody detection represents one of the fundamental requirements for a reliable testing, we have generated a human recombinant p62 protein and validated an immunoprecipitation assay for the detection of anti-p62. We also demonstrated that the generated human recombinant p62 nucleoporin was modified by N-acetylglucosamine residues. More than 50% of tested PBC sera precipitated (35)S-radioactively labeled p62 recombinant nucleoporin and 40% recognized this recombinant antigen by immunoblotting. We compared the reactivity of PBC sera with rat and human nucleoporin. The incidence of anti-p62 nucleoporin positive PBC sera increased by 15% when human recombinant antigen was used. The titer of autoantibodies in p62-positive PBC samples strongly varied. Preadsorption of the PBC sera with p62 recombinant protein completely abolished their reactivity with the antigen. In conclusion, this study unequivocally proves that autoantibodies reacting with the 60 kDa component of NPCs target p62 nucleoporin and, more importantly, provide a better antigen source for future evaluations of the clinical role of anti-p62 in PBC.
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Affiliation(s)
- Józefa Wesierska-Gadek
- Cell Cycle Regulation Group, Institute of Cancer Research, Department of Medicine I, Medical University of Vienna, Vienna, Austria.
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Antimitochondrial antibodies and other antibodies in primary biliary cirrhosis: diagnostic and prognostic value. Clin Liver Dis 2008; 12:261-76; vii. [PMID: 18456179 DOI: 10.1016/j.cld.2008.02.009] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Antimitochondrial antibodies (AMA) are the serologic cornerstone in the diagnosis of primary biliary cirrhosis (PBC), even if they are not detectable in a proportion of patients, notwithstanding the most sensitive and sophisticated technologies used. To fill in the serologic gap in AMA-negative PBC, there is sound evidence to consider antinuclear antibody (ANA) patterns, such as anti-multiple nuclear dots and anti-membranous/rim-like, as PBC-specific surrogate hallmarks of the disease, and their detection can be considered virtually diagnostic. Furthermore, particular ANA specificities, such as anti-gp210, anti-p62, anticentromere antibodies, and anti-dsDNA, may provide additional diagnostic and prognostic information.
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Miyachi K, Miyakawa H, Oda M, Horigome T, Fritzler MJ. Primary biliary cirrhosis and autoantibodies. ACTA ACUST UNITED AC 2008; 31:47-55. [PMID: 18311042 DOI: 10.2177/jsci.31.47] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Fifty years have passed since anti-mitochondrial antibodies were found in patients with primary biliary cirrhosis (PBC). PBC is an autoimmune hepatic disease in which 85-90% of patient antibodies bind to mitochondrial antigens that include pyruvate dehydrogenase complex (PDC)-E2 and other members of the oxaloacid dehydrogenase family. In addition, indirect immunofluorescence (IIF) assays utilizing HEp-2 cell substrates have been used to identify anti-centromere antibodies in 20-30% of PBC sera. These antibodies are generally easily recognized, however, anti-nuclear envelope and anti-multiple nuclear dot antibodies are occasionally more difficult to recognize with certainty by IIF. The use of enzyme linked immunosorbent assays that utilize recombinant gp210 (an autoantigen of the nuclear envelope) and/or sp100 (a protein target represented by multiple nuclear dots) should be particularly considered in anti-mitochondrial antibody negative PBC sera. Although the clinical significance of these antibodies still remains to be determined, there is evidence that the existence of anti-gp210 antibodies are related to poorer prognosis and more aggressive disease progression.
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Affiliation(s)
- K Miyachi
- Keigu Clinic, Department of Internal Medicine
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21
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Jakymiw A, Ikeda K, Fritzler MJ, Reeves WH, Satoh M, Chan EKL. Autoimmune targeting of key components of RNA interference. Arthritis Res Ther 2007; 8:R87. [PMID: 16684366 PMCID: PMC1779426 DOI: 10.1186/ar1959] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2006] [Revised: 04/12/2006] [Accepted: 04/19/2006] [Indexed: 11/10/2022] Open
Abstract
RNA interference (RNAi) is an evolutionarily conserved mechanism that is involved in the post-transcriptional silencing of genes. This process elicits the degradation or translational inhibition of mRNAs based on the complementarity with short interfering RNAs (siRNAs) or microRNAs (miRNAs). Recently, differential expression of specific miRNAs and disruption of the miRNA synthetic pathway have been implicated in cancer; however, their role in autoimmune disease remains largely unknown. Here, we report that anti-Su autoantibodies from human patients with rheumatic diseases and in a mouse model of autoimmunity recognize the human Argonaute (Ago) protein, hAgo2, the catalytic core enzyme in the RNAi pathway. More specifically, 91% (20/22) of the human anti-Su sera were shown to immunoprecipitate the full-length recombinant hAgo2 protein. Indirect immunofluorescence studies in HEp-2 cells demonstrated that anti-Su autoantibodies target cytoplasmic foci identified as GW bodies (GWBs) or mammalian P bodies, structures recently linked to RNAi function. Furthermore, anti-Su sera were also capable of immunoprecipitating additional key components of the RNAi pathway, including hAgo1, -3, -4, and Dicer. Together, these results demonstrate an autoimmune response to components of the RNAi pathway which could potentially implicate the involvement of an innate anti-viral response in the pathogenesis of autoantibody production.
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Affiliation(s)
- Andrew Jakymiw
- Department of Oral Biology, University of Florida, 1600 S.W. Archer Road, Gainesville, FL, 32610, USA
| | - Keigo Ikeda
- Department of Oral Biology, University of Florida, 1600 S.W. Archer Road, Gainesville, FL, 32610, USA
| | - Marvin J Fritzler
- Department of Biochemistry and Molecular Biology, University of Calgary, 3330 Hospital Drive N.W., Calgary, AB, T2N 4N1, Canada
| | - Westley H Reeves
- Division of Rheumatology and Clinical Immunology, Department of Medicine, and Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, 1600 S.W. Archer Road, Gainesville, FL, 32610, USA
| | - Minoru Satoh
- Division of Rheumatology and Clinical Immunology, Department of Medicine, and Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, 1600 S.W. Archer Road, Gainesville, FL, 32610, USA
| | - Edward KL Chan
- Department of Oral Biology, University of Florida, 1600 S.W. Archer Road, Gainesville, FL, 32610, USA
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Tsiakalou V, Tsangaridou E, Polioudaki H, Nifli AP, Koulentaki M, Akoumianaki T, Kouroumalis E, Castanas E, Theodoropoulos PA. Optimized detection of circulating anti-nuclear envelope autoantibodies by immunofluorescence. BMC Immunol 2006; 7:20. [PMID: 16956395 PMCID: PMC1574344 DOI: 10.1186/1471-2172-7-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2006] [Accepted: 09/06/2006] [Indexed: 01/30/2023] Open
Abstract
Background Antinuclear antibodies are useful diagnostic tools in several autoimmune diseases. However, the routine detection of nuclear envelope autoantibodies using immunofluorescence (IF) is not always easy to perform in patients' sera because of the presence of autoantibodies to other nuclear and cytoplasmic components which could mask the characteristic rim-like pattern of nuclear envelope autoantibodies. This is particularly common in sera from patients with primary biliary cirrhosis (PBC), which generaly have high titres of anti-mitochondrial antibodies. Therefore, we have assayed a number of commercial slides and alternative fixation conditions to optimize the detection of anti-nuclear envelope antibodies (ANEA) in PBC sera. Methods We have explored the presence of ANEA in 33 sera from patients with established PBC using three different Hep2 commercial slides and home-made slides with HeLa and Hep2 cells fixed with methanol, ethanol, 1% or 4% formaldehyde. Results We observed that the IF pattern was related to the cell type used (Hep2 or HeLa), the manufacturer and the cell fixation scheme. When both cell lines were fixed with 1% formaldehyde, the intensity of the cytoplasmic staining was considerably decreased regardless to the serum sample, whereas the prevalence of cytoplasmic autoantibodies was significantly lowered, as compared to any of the Hep2 commercial slide and fixation used. In addition, the prevalence of ANEA was importantly increased in formaldehyde-fixed cells. Conclusion Immunofluorescence using appropriately fixed cells represent an easy, no time-consuming and low cost technique for the routine screening of sera for ANEA. Detection of ANEA is shown to be more efficient using formaldehyde-fixed cells instead of commercially available Hep2 cells.
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Affiliation(s)
- Vagia Tsiakalou
- Biochemistry, University of Crete, School of Medicine, P.O. Box 2208, Heraklion 71003, Greece
| | - Elena Tsangaridou
- Biochemistry, University of Crete, School of Medicine, P.O. Box 2208, Heraklion 71003, Greece
| | - Hara Polioudaki
- Biochemistry, University of Crete, School of Medicine, P.O. Box 2208, Heraklion 71003, Greece
| | - Artemissia-Phoebe Nifli
- Experimental Endocrinology, University of Crete, School of Medicine, P.O. Box 2208, Heraklion 71003, Greece
| | - Meri Koulentaki
- Gastroenterology, University of Crete, School of Medicine, P.O. Box 2208, Heraklion 71003, Greece
| | - Tonia Akoumianaki
- Biochemistry, University of Crete, School of Medicine, P.O. Box 2208, Heraklion 71003, Greece
| | - Elias Kouroumalis
- Gastroenterology, University of Crete, School of Medicine, P.O. Box 2208, Heraklion 71003, Greece
| | - Elias Castanas
- Experimental Endocrinology, University of Crete, School of Medicine, P.O. Box 2208, Heraklion 71003, Greece
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Miyachi K, Hosaka H, Nakamura N, Miyakawa H, Mimori T, Shibata M, Matsushima S, Chinoh H, Horigome T, Hankins RW, Zhang M, Fritzler MJ. Anti-p97/VCP antibodies: an autoantibody marker for a subset of primary biliary cirrhosis patients with milder disease? Scand J Immunol 2006; 63:376-82. [PMID: 16640662 DOI: 10.1111/j.1365-3083.2006.01747.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We previously reported that 12.5% of primary biliary cirrhosis (PBC) sera reacted with a 95 kDa cytosol protein (p95c) that was subsequently identified as a p97/valosin-containing protein (VCP). The clinical features and course of the six anti-p97/VCP-positive PBC patients with Scheuer's stage 1 and 2 liver biopsies were monitored for an average of 15 years. This group was compared with 50 PBC patients that did not have detectable anti-VCP. Autoantibodies to a full-length recombinant p97/VCP were assayed by immunoprecipitation. All six PBC patients with anti-VCP had antibodies to the mitochondrial pyruvate dehydrogenase complex-E2 antigen as measured by an addressable laser bead immunoassay. The first was a male with no evidence of liver failure that died of cerebral infarction at the age of 85. The second was a 73-year-old female with Hashimoto's thyroiditis who has remained clinically stable without ursodeoxycolic acid (UDCA) treatment. Although the third had no HCV antibodies, he developed hepatocellular carcinoma at the age of 76 and died of renal failure at 78. The fourth was a 50-year-old female who remained clinically stable during follow-up and the fifth with Hashimoto's thyroiditis and stable liver function following UCDA treatment. The sixth was a male patient presenting a mild clinical course. The clinical course of these patients was in contrast to the 50 comparison group PBC patients who did not have anti-p97/VCP. As the six PBC patients with anti-p97/VCP antibodies had slowly progressive liver disease and no mortality related to autoimmune liver disease, our observations suggest that this autoantibody might be an indicator of a favourable prognosis.
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Affiliation(s)
- K Miyachi
- First Diagnostic Division, Health Sciences Research Institute, Inc., Yokohama, Japan.
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24
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Jakymiw A, Lian S, Eystathioy T, Li S, Satoh M, Hamel JC, Fritzler MJ, Chan EKL. Disruption of GW bodies impairs mammalian RNA interference. Nat Cell Biol 2005; 7:1267-74. [PMID: 16284622 DOI: 10.1038/ncb1334] [Citation(s) in RCA: 321] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2005] [Accepted: 09/24/2005] [Indexed: 01/08/2023]
Abstract
The GW182 RNA-binding protein was initially shown to associate with a specific subset of mRNAs and to reside within discrete cytoplasmic foci named GW bodies (GWBs). GWBs are enriched in proteins that are involved in mRNA degradation. Recent reports have shown that exogenously introduced human Argonaute-2 (Ago2) is also enriched in GWBs, indicating that RNA interference function may be somehow linked to these structures. In this report, we demonstrate that endogenous Ago2 and transfected small interfering RNAs (siRNAs) are also present within these same cytoplasmic bodies and that the GW182 protein interacts with Ago2. Disruption of these cytoplasmic foci in HeLa cells interferes with the silencing capability of a siRNA that is specific to lamin-A/C. Our data support a model in which GW182 and/or the microenvironment of the cytoplasmic GWBs contribute to the RNA-induced silencing complex and to RNA silencing.
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Affiliation(s)
- Andrew Jakymiw
- Department of Oral Biology, University of Florida, Gainesville, FL 32610, USA
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25
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Yang Z, Jakymiw A, Wood MR, Eystathioy T, Rubin RL, Fritzler MJ, Chan EKL. GW182 is critical for the stability of GW bodies expressed during the cell cycle and cell proliferation. J Cell Sci 2004; 117:5567-78. [PMID: 15494374 DOI: 10.1242/jcs.01477] [Citation(s) in RCA: 166] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A novel cytoplasmic compartment referred to as GW bodies was initially identified using human autoantibodies to a 182 kDa protein named GW182. GW bodies are small, generally spherical, cytoplasmic domains that vary in number and size in several mammalian cell types examined to date. Based on our earlier studies, GW bodies were proposed to be cytoplasmic sites for mRNA storage and/or degradation. In the present study, immunogold electron microscopy identified electron dense structures of 100-300 nm diameter devoid of a lipid bilayer membrane. These structures appeared to comprise clusters of electron dense strands of 8-10 nm in diameter. By costaining with CENP-F and PCNA, and employing a double-thymidine block to synchronize HeLa cells, GW bodies were observed to be small in early S phase and larger during late S and G2 phases of the cell cycle. The majority of GW bodies disassembled prior to mitosis and small GW bodies reassembled in early G1. The analysis of GW bodies in two experimental models of cell proliferation using reversal of 3T3/serum-starvation and concanavalin A stimulation of mouse splenocytes and T cells, revealed that proliferating cells contained larger, brighter, and more numerous GW bodies as well as up to a fivefold more total GW182 protein than quiescent cells. In vitro gene knockdown of GW182 led to the disappearance of GW bodies demonstrating that GW182 is a critical component of GW bodies. The incremental expression of the GW182 protein in cells induced to proliferate and the cyclic formation and breakdown of GW bodies during mitosis are intriguing in view of the notion that GW bodies are specialized centers involved in maintaining stability and/or controlling degradation of mRNA.
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Affiliation(s)
- Zheng Yang
- Department of Oral Biology, University of Florida, PO Box 100424, Gainesville, FL 32610-0424, USA
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26
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Enarson P, Rattner JB, Ou Y, Miyachi K, Horigome T, Fritzler MJ. Autoantigens of the nuclear pore complex. J Mol Med (Berl) 2004; 82:423-33. [PMID: 15175862 DOI: 10.1007/s00109-004-0554-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2004] [Accepted: 03/12/2004] [Indexed: 01/27/2023]
Abstract
The nuclear envelope (NE) is one of many intracellular targets of the autoimmune response in patients with autoimmune liver disease, systemic lupus erythematosus, and related conditions. In eukaryotic organisms the NE consists of five interconnected regions: an outer nuclear membrane (ONM) that is continuous with the endoplasmic reticulum, an intermembrane or perinuclear space, an inner nuclear membrane (INM) with a unique set of integral membrane proteins, the underlying nuclear lamina, and the pore domains that are regions where the ONM and INM come together. The pore domains are sites of regulated continuity between the cytoplasm and nucleus that are occupied by supramolecular structures, termed nuclear pore complexes (NPCs). Human autoantibodies identified to date bind to specific components in three of the five NE compartments. Autoantigen targets include the lamins A, B, and C of the nuclear lamina, gp210, p62 complex proteins, Nup153, and Tpr within the NPC, and LBR, MAN1, LAP1, and LAP2 that are integral proteins of the INM. Autoantibodies to these NE targets have been shown to be correlated with various autoimmune diseases such as primary biliary cirrhosis, other autoimmune liver diseases and systemic rheumatic diseases. Now that the proteome of the NE is more clearly defined, other autoantibodies to components in this cell compartment are likely to be defined.
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Affiliation(s)
- P Enarson
- Department of Anatomy and Cell Biology, Faculty of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB, T2N 4N1, Canada
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