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Yasuda H, Uno A, Tanaka Y, Koda S, Saito M, Sato EF, Matsumoto K, Kato S. Neutrophil extracellular trap induction through peptidylarginine deiminase 4 activity is involved in 2,4,6-trinitrobenzenesulfonic acid-induced colitis. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2024; 397:3127-3140. [PMID: 37878044 DOI: 10.1007/s00210-023-02800-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 10/16/2023] [Indexed: 10/26/2023]
Abstract
Neutrophil extracellular traps (NETs) are induced in the innate immune response against infectious agents and are also implicated in the pathogenesis of various cancers and autoimmune diseases. Peptidylarginine deiminase 4 (PAD4), an enzyme that converts arginine to citrulline, is also involved in NET formation. In this study, we investigated the pathogenic effect of PAD4 on NETs in inflammatory bowel disease using a trinitrobenzene sulfonic acid (TNBS)-induced murine colitis model. PAD4-deficient (PAD4KO) mice were generated by CRISPR-Cas9-mediated genomic editing. NETs were triggered in peritoneal neutrophils obtained from wild-type mice by A23187 (a calcium ionophore), but these responses were completely abolished in the PAD4KO mice. Experimental colitis was induced in wild-type and PAD4KO mice via an intrarectal injection of TNBS. TNBS injection resulted in body weight loss, extensive colonic erosion, and ulceration in wildtype mice. However, these responses were significantly attenuated following the administration of Cl-amidine (an inhibitor of pan-PADs) and DNase I (an inhibitor of NET formation), in combination with PAD4KO in mice. TNBS-induced increases in myeloperoxidase activity, inflammatory cytokine expression, and NET formation in the colon were significantly reduced following the administration of Cl-amidine, DNase I injection, and PAD4KO. These findings suggest that NET formation contributes to the pathogenesis of TNBS-induced colitis via PAD4. Thus, PAD4 is a promising target for the treatment of inflammatory bowel disease.
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Affiliation(s)
- Hiroyuki Yasuda
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University, Kyoto, 6078414, Japan.
| | - Ayaka Uno
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University, Kyoto, 6078414, Japan
| | - Yoshiya Tanaka
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University, Kyoto, 6078414, Japan
| | - Saya Koda
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University, Kyoto, 6078414, Japan
| | - Michiko Saito
- Bio-Science Research Center, Kyoto Pharmaceutical University, Kyoto, 6078414, Japan
| | - Eisuke F Sato
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, 3500-3, Minamitamagaki, Suzuka-City, Mie, 513-8670, Japan
| | - Kenjiro Matsumoto
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University, Kyoto, 6078414, Japan
| | - Shinichi Kato
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University, Kyoto, 6078414, Japan
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Nie H, Kong X, Song X, Guo X, Li Z, Fan C, Zhai B, Yang X, Wang Y. Roles of histone post-translational modifications in meiosis†. Biol Reprod 2024; 110:648-659. [PMID: 38224305 DOI: 10.1093/biolre/ioae011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 01/09/2024] [Accepted: 01/11/2024] [Indexed: 01/16/2024] Open
Abstract
Histone post-translational modifications, such as phosphorylation, methylation, acetylation, and ubiquitination, play vital roles in various chromatin-based cellular processes. Meiosis is crucial for organisms that depend on sexual reproduction to produce haploid gametes, during which chromatin undergoes intricate conformational changes. An increasing body of evidence is clarifying the essential roles of histone post-translational modifications during meiotic divisions. In this review, we concentrate on the post-translational modifications of H2A, H2B, H3, and H4, as well as the linker histone H1, that are required for meiosis, and summarize recent progress in understanding how these modifications influence diverse meiotic events. Finally, challenges and exciting open questions for future research in this field are discussed. Summary Sentence Diverse histone post-translational modifications exert important effects on the meiotic cell cycle and these "histone codes" in meiosis might lead to the development of novel therapeutic strategies against reproductive diseases.
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Affiliation(s)
- Hui Nie
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University, Jinan, Shandong, China
| | - Xueyu Kong
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University, Jinan, Shandong, China
| | - Xiaoyu Song
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University, Jinan, Shandong, China
| | - Xiaoyu Guo
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University, Jinan, Shandong, China
| | - Zhanyu Li
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University, Jinan, Shandong, China
| | - Cunxian Fan
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University, Jinan, Shandong, China
| | - Binyuan Zhai
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University, Jinan, Shandong, China
| | - Xiao Yang
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University, Jinan, Shandong, China
| | - Ying Wang
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University, Jinan, Shandong, China
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3
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Wang B, Li Z, Shi Y, Zhu Z, Fields L, Shelef MA, Li L. Mass Spectrometry-Based Precise Identification of Citrullinated Histones via Limited Digestion and Biotin Derivative Tag Enrichment. Anal Chem 2024; 96:2309-2317. [PMID: 38285917 DOI: 10.1021/acs.analchem.3c02646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2024]
Abstract
Histone citrullination is an essential epigenetic post-translational modification (PTM) that affects many important physiological and pathological processes, but effective tools to study histone citrullination are greatly limited due to several challenges, including the small mass shift caused by this PTM and its low abundance in biological systems. Although previous studies have reported frequent occurrences of histone citrullination, these methods failed to provide a high-throughput and site-specific strategy to detect histone citrullination. Recently, we developed a biotin thiol tag that enabled precise identification of protein citrullination coupled with mass spectrometry. However, very few histone citrullination sites were identified, likely due to the highly basic nature of these proteins. In this study, we develop a novel method utilizing limited digestion and biotin derivative tag enrichment to facilitate direct in vivo identification of citrullination sites on histones. We achieve improved coverage of histone identification via partial enzymatic digestion and lysine block by dimethylation. With biotin tag-assisted chemical derivatization and enrichment, we also achieve precise annotation of histone citrullination sites with high confidence. We further compare different fragmentation methods and find that the electron-transfer-dissociation-based approach enables the most in-depth analysis and characterization. In total, we unambiguously identify 18 unique citrullination sites on histones in human astrocytoma U87 cells, including 15 citrullinated sites being detected for the first time. Some of these citrullination sites are observed to exhibit noticeable alterations in response to DNA damage, which demonstrates the superiority of our strategy in understanding the roles of histone citrullination in critical biological processes.
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Affiliation(s)
- Bin Wang
- School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Zihui Li
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Yatao Shi
- School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Zexin Zhu
- School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Lauren Fields
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Miriam A Shelef
- Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
- William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705, United States
| | - Lingjun Li
- School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Lachman Institute for Pharmaceutical Development, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
- Wisconsin Center for NanoBioSystems, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
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4
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Lerner A, Benzvi C, Vojdani A. Cross-reactivity and sequence similarity between microbial transglutaminase and human tissue antigens. Sci Rep 2023; 13:17526. [PMID: 37845267 PMCID: PMC10579360 DOI: 10.1038/s41598-023-44452-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 10/09/2023] [Indexed: 10/18/2023] Open
Abstract
Microbial transglutaminase (mTG) is a bacterial survival factor, frequently used as a food additive to glue processed nutrients. As a result, new immunogenic epitopes are generated that might drive autoimmunity. Presently, its contribution to autoimmunity through epitope similarity and cross-reactivity was investigated. Emboss Matcher was used to perform sequence alignment between mTG and various antigens implicated in many autoimmune diseases. Monoclonal and polyclonal antibodies made specifically against mTG were applied to 77 different human tissue antigens using ELISA. Six antigens were detected to share significant homology with mTG immunogenic sequences, representing major targets of common autoimmune conditions. Polyclonal antibody to mTG reacted significantly with 17 out of 77 tissue antigens. This reaction was most pronounced with mitochondrial M2, ANA, and extractable nuclear antigens. The results indicate that sequence similarity and cross-reactivity between mTG and various tissue antigens are possible, supporting the relationship between mTG and the development of autoimmune disorders 150W.
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Affiliation(s)
- Aaron Lerner
- Chaim Sheba Medical Center, The Zabludowicz Research Center for Autoimmune Diseases, Tel Hashomer, Israel.
- Ariel University, Ariel, Israel.
| | - Carina Benzvi
- Chaim Sheba Medical Center, The Zabludowicz Research Center for Autoimmune Diseases, Tel Hashomer, Israel
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Green RM, Thompson PR. Current insights into the role of citrullination in thrombosis. Curr Opin Chem Biol 2023; 75:102313. [PMID: 37148643 PMCID: PMC10523988 DOI: 10.1016/j.cbpa.2023.102313] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 03/22/2023] [Accepted: 04/01/2023] [Indexed: 05/08/2023]
Abstract
Protein citrullination is a post-translational modification of arginine that controls a diverse array of cellular processes, including gene regulation, protein stability, and neutrophil extracellular trap (NET) formation. Histone citrullination promotes chromatin decondensation and NET formation, a pro-inflammatory form of cell death that is aberrantly increased in numerous immune disorders. This review will provide insights into NETosis and how this novel form of cell death contributes to inflammatory diseases, with a particular emphasis on its role in thrombosis. We will also discuss recent efforts to develop PAD-specific inhibitors.
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Affiliation(s)
- R Madison Green
- Program in Chemical Biology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA; Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Paul R Thompson
- Program in Chemical Biology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA; Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA.
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6
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Moustakas AK, Nguyen H, James EA, Papadopoulos GK. Autoimmune susceptible HLA class II motifs facilitate the presentation of modified neoepitopes to potentially autoreactive T cells. Cell Immunol 2023; 390:104729. [PMID: 37301094 DOI: 10.1016/j.cellimm.2023.104729] [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: 01/30/2023] [Revised: 03/27/2023] [Accepted: 05/11/2023] [Indexed: 06/12/2023]
Abstract
Rheumatoid arthritis (RA), multiple sclerosis (MS), type 1 diabetes (T1D), and celiac disease (CD), are strongly associated with susceptible HLA class II haplotypes. The peptide-binding pockets of these molecules are polymorphic, thus each HLA class II protein presents a distinct set of peptides to CD4+ T cells. Peptide diversity is increased through post-translational modifications, generating non-templated sequences that enhance HLA binding and/or T cell recognition. The high-risk HLA-DR alleles that confer susceptibility to RA are notable for their ability to accommodate citrulline, promoting responses to citrullinated self-antigens. Likewise, HLA-DQ alleles associated with T1D and CD favor the binding of deamidated peptides. In this review, we discuss structural features that promote modified self-epitope presentation, provide evidence supporting the relevance of T cell recognition of such antigens in disease processes, and make a case that interrupting the pathways that generate such epitopes and reprogramming neoepitope-specific T cells are key strategies for effective therapeutic intervention.
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Affiliation(s)
- Antonis K Moustakas
- Department of Food Science and Technology, Faculty of Environmental Sciences, Ionian University, GR26100 Argostoli, Cephalonia, Greece
| | - Hai Nguyen
- Center for Translational Immunology, Benaroya Research Institute at Virginia Mason, Seattle, WA, USA
| | - Eddie A James
- Center for Translational Immunology, Benaroya Research Institute at Virginia Mason, Seattle, WA, USA.
| | - George K Papadopoulos
- Laboratory of Biophysics, Biochemistry, Bioprocessing and Bioproducts, Faculty of Agricultural Technology, Technological Educational Institute of Epirus, GR47100 Arta, Greece
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7
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Zhu D, Lu Y, Wang Y, Wang Y. PAD4 and Its Inhibitors in Cancer Progression and Prognosis. Pharmaceutics 2022; 14:2414. [PMID: 36365233 PMCID: PMC9699117 DOI: 10.3390/pharmaceutics14112414] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 10/28/2022] [Accepted: 11/06/2022] [Indexed: 07/24/2023] Open
Abstract
The systemic spread of malignancies and the risk of cancer-associated thrombosis are major clinical challenges in cancer therapy worldwide. As an important post-translational modification enzyme, peptidyl arginine deiminase 4 (PAD4) could mediate the citrullination of protein in different components (including nucleus and cytoplasm, etc.) of a variety of cells (tumor cells, neutrophils, macrophages, etc.), thus participating in gene regulation, neutrophil extracellular trap (NET) and macrophage extracellular trap (MET). Thereby, PAD4 plays an important role in enhancing the growth of primary tumors and facilitating the distant metastasis of cancer cells. In addition, it is related to the formation of cancer-associated thrombosis. Therefore, the development of PAD4-specific inhibitors may be a promising strategy for treating cancer, and it may improve patient prognosis. In this review, we describe PAD4 involvement in gene regulation, protein citrullination, and NET formation. We also discuss its potential role in cancer and cancer-associated thrombosis, and we summarize the development and application of PAD4 inhibitors.
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Affiliation(s)
- Di Zhu
- Department of Medicinal Chemistry, College of Pharmaceutical Sciences of Capital Medical University, Beijing 100069, China
- Beijing Area Major Laboratory of Peptide and Small Molecular Drugs, Engineering Research Center of Endogenous Prophylactic of Ministry of Education of China, Beijing Laboratory of Biomedical Materials, Beijing 100069, China
| | - Yu Lu
- Department of Medicinal Chemistry, College of Pharmaceutical Sciences of Capital Medical University, Beijing 100069, China
- Beijing Area Major Laboratory of Peptide and Small Molecular Drugs, Engineering Research Center of Endogenous Prophylactic of Ministry of Education of China, Beijing Laboratory of Biomedical Materials, Beijing 100069, China
| | - Yanming Wang
- School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Yuji Wang
- Department of Medicinal Chemistry, College of Pharmaceutical Sciences of Capital Medical University, Beijing 100069, China
- Beijing Area Major Laboratory of Peptide and Small Molecular Drugs, Engineering Research Center of Endogenous Prophylactic of Ministry of Education of China, Beijing Laboratory of Biomedical Materials, Beijing 100069, China
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8
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Christophorou MA. The virtues and vices of protein citrullination. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220125. [PMID: 35706669 PMCID: PMC9174705 DOI: 10.1098/rsos.220125] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 05/16/2022] [Indexed: 05/03/2023]
Abstract
The post-translational modification of proteins expands the regulatory scope of the proteome far beyond what is achievable through genome regulation. The field of protein citrullination has seen significant progress in the last two decades. The small family of peptidylarginine deiminase (PADI or PAD) enzymes, which catalyse citrullination, have been implicated in virtually all facets of molecular and cell biology, from gene transcription and epigenetics to cell signalling and metabolism. We have learned about their association with a remarkable array of disease states and we are beginning to understand how they mediate normal physiological functions. However, while the biochemistry of PADI activation has been worked out in exquisite detail in vitro, we still lack a clear mechanistic understanding of the processes that regulate PADIs within cells, under physiological and pathophysiological conditions. This review summarizes and discusses the current knowledge, highlights some of the unanswered questions of immediate importance and gives a perspective on the outlook of the citrullination field.
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9
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Karmakar U, Vermeren S. Crosstalk between B cells and neutrophils in rheumatoid arthritis. Immunology 2021; 164:689-700. [PMID: 34478165 PMCID: PMC8561113 DOI: 10.1111/imm.13412] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 08/30/2021] [Indexed: 12/13/2022] Open
Abstract
Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease without known cure that primarily affects synovial joints. RA has a prevalence of approximately 1% of the population worldwide. A vicious circle between two critical immune cell types, B cells and neutrophils, develops and promotes disease. Pathogenic anti‐citrullinated protein antibodies (ACPA) directed against a range of citrullinated epitopes are abundant in both plasma and synovial fluid of RA patients. In addition to stimulating numerous cell types, ACPA and other autoantibodies, notably rheumatoid factor, form immune complexes (ICs) that potently activate neutrophils. Attracted to the synovium by abundant chemokines, neutrophils are locally stimulated by ICs. They generate cytokines and release cytotoxic compounds including neutrophil extracellular traps (NETs), strands of decondensed chromatin decorated with citrullinated histones and granule‐derived neutrophil proteins, which are particularly abundant in the synovial fluid. In this way, neutrophils generate citrullinated epitopes and release peptidylarginine deiminase (PAD) enzymes capable of citrullinating extracellular proteins in the rheumatic joint, contributing to renewed ACPA generation. This review article focusses on the central function of citrullination, a post‐translational modification of arginine residues in RA. The discussion includes ACPA and related autoantibodies, somatic hypermutation‐mediated escape from negative selection by autoreactive B cells, promotion of the dominance of citrullinated antigens by genetic and lifestyle susceptibility factors and the vicious circle between ACPA‐producing pathogenic B cells and NET‐producing neutrophils in RA.
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Affiliation(s)
- Utsa Karmakar
- Centre for Inflammation Research, Institute for Regeneration and Repair, The University of Edinburgh, Edinburgh, UK
| | - Sonja Vermeren
- Centre for Inflammation Research, Institute for Regeneration and Repair, The University of Edinburgh, Edinburgh, UK
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10
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Yang ML, Sodré FMC, Mamula MJ, Overbergh L. Citrullination and PAD Enzyme Biology in Type 1 Diabetes - Regulators of Inflammation, Autoimmunity, and Pathology. Front Immunol 2021; 12:678953. [PMID: 34140951 PMCID: PMC8204103 DOI: 10.3389/fimmu.2021.678953] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 05/11/2021] [Indexed: 02/06/2023] Open
Abstract
The generation of post-translational modifications (PTMs) in human proteins is a physiological process leading to structural and immunologic variety in proteins, with potentially altered biological functions. PTMs often arise through normal responses to cellular stress, including general oxidative changes in the tissue microenvironment and intracellular stress to the endoplasmic reticulum or immune-mediated inflammatory stresses. Many studies have now illustrated the presence of 'neoepitopes' consisting of PTM self-proteins that induce robust autoimmune responses. These pathways of inflammatory neoepitope generation are commonly observed in many autoimmune diseases including systemic lupus erythematosus, rheumatoid arthritis, multiple sclerosis, and type 1 diabetes (T1D), among others. This review will focus on one specific PTM to self-proteins known as citrullination. Citrullination is mediated by calcium-dependent peptidylarginine deiminase (PAD) enzymes, which catalyze deimination, the conversion of arginine into the non-classical amino acid citrulline. PADs and citrullinated peptides have been associated with different autoimmune diseases, notably with a prominent role in the diagnosis and pathology of rheumatoid arthritis. More recently, an important role for PADs and citrullinated self-proteins has emerged in T1D. In this review we will provide a comprehensive overview on the pathogenic role for PADs and citrullination in inflammation and autoimmunity, with specific focus on evidence for their role in T1D. The general role of PADs in epigenetic and transcriptional processes, as well as their crucial role in histone citrullination, neutrophil biology and neutrophil extracellular trap (NET) formation will be discussed. The latter is important in view of increasing evidence for a role of neutrophils and NETosis in the pathogenesis of T1D. Further, we will discuss the underlying processes leading to citrullination, the genetic susceptibility factors for increased recognition of citrullinated epitopes by T1D HLA-susceptibility types and provide an overview of reported autoreactive responses against citrullinated epitopes, both of T cells and autoantibodies in T1D patients. Finally, we will discuss recent observations obtained in NOD mice, pointing to prevention of diabetes development through PAD inhibition, and the potential role of PAD inhibitors as novel therapeutic strategy in autoimmunity and in T1D in particular.
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Affiliation(s)
- Mei-Ling Yang
- Section of Rheumatology, Allergy and Clinical Immunology, Department of Internal Medicine, Yale University, New Haven, CT, United States
| | - Fernanda M C Sodré
- Department of Chronic Diseases, Metabolism and Ageing, Laboratory of Clinical and Experimental Endocrinology (CEE), KU Leuven, Leuven, Belgium
| | - Mark J Mamula
- Section of Rheumatology, Allergy and Clinical Immunology, Department of Internal Medicine, Yale University, New Haven, CT, United States
| | - Lut Overbergh
- Department of Chronic Diseases, Metabolism and Ageing, Laboratory of Clinical and Experimental Endocrinology (CEE), KU Leuven, Leuven, Belgium
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11
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Bruggeman Y, Sodré FMC, Buitinga M, Mathieu C, Overbergh L, Kracht MJL. Targeting citrullination in autoimmunity: insights learned from preclinical mouse models. Expert Opin Ther Targets 2021; 25:269-281. [PMID: 33896351 DOI: 10.1080/14728222.2021.1918104] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Aberrant citrullination and excessive peptidylarginine deiminase (PAD) activity are detected in numerous challenging autoimmune diseases such as rheumatoid arthritis, inflammatory bowel diseases, systemic lupus erythematosus, multiple sclerosis, and type 1 diabetes. Because excessive PAD activity is a common denominator in these diseases, PADs are interesting potential therapeutic targets for future therapies. AREAS COVERED This review summarizes the advances made in the design of PAD inhibitors, their utilization and therapeutic potential in preclinical mouse models of autoimmunity. Relevant literature encompasses studies from 1994 to 2021 that are available on PubMed.gov. EXPERT OPINION Pan-PAD inhibition is a promising therapeutic strategy for autoimmune diseases. Drugs achieving pan-PAD inhibition were capable of ameliorating, reversing, and preventing clinical symptoms in preclinical mouse models. However, the implications for PADs in key biological processes potentially present a high risk for clinical complications and could hamper the translation of PAD inhibitors to the clinic. We envisage that PAD isozyme-specific inhibitors will improve the understanding the role of PAD isozymes in disease pathology, reduce the risk of side-effects and enhance prospects for future clinical translation.
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Affiliation(s)
- Ylke Bruggeman
- Department of Chronic Diseases and Metabolism, Laboratory for Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Fernanda M C Sodré
- Department of Chronic Diseases and Metabolism, Laboratory for Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Mijke Buitinga
- Department of Chronic Diseases and Metabolism, Laboratory for Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium.,Department of Nutrition and Movement Sciences, Maastricht University, Maastricht, The Netherlands.,Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Chantal Mathieu
- Department of Chronic Diseases and Metabolism, Laboratory for Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Lut Overbergh
- Department of Chronic Diseases and Metabolism, Laboratory for Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Maria J L Kracht
- Department of Chronic Diseases and Metabolism, Laboratory for Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
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Histone H1 Post-Translational Modifications: Update and Future Perspectives. Int J Mol Sci 2020; 21:ijms21165941. [PMID: 32824860 PMCID: PMC7460583 DOI: 10.3390/ijms21165941] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/07/2020] [Accepted: 08/08/2020] [Indexed: 12/12/2022] Open
Abstract
Histone H1 is the most variable histone and its role at the epigenetic level is less characterized than that of core histones. In vertebrates, H1 is a multigene family, which can encode up to 11 subtypes. The H1 subtype composition is different among cell types during the cell cycle and differentiation. Mass spectrometry-based proteomics has added a new layer of complexity with the identification of a large number of post-translational modifications (PTMs) in H1. In this review, we summarize histone H1 PTMs from lower eukaryotes to humans, with a particular focus on mammalian PTMs. Special emphasis is made on PTMs, whose molecular function has been described. Post-translational modifications in H1 have been associated with the regulation of chromatin structure during the cell cycle as well as transcriptional activation, DNA damage response, and cellular differentiation. Additionally, PTMs in histone H1 that have been linked to diseases such as cancer, autoimmune disorders, and viral infection are examined. Future perspectives and challenges in the profiling of histone H1 PTMs are also discussed.
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13
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DNA demethylation increases NETosis. Arch Biochem Biophys 2020; 689:108465. [PMID: 32561201 DOI: 10.1016/j.abb.2020.108465] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 04/27/2020] [Accepted: 06/06/2020] [Indexed: 12/28/2022]
Abstract
Neutrophil extracellular traps (NETs) occur during the development of autoimmune diseases, cancer and diabetes. A novel form of cell death that is induced by NETs is called NETosis. Although these diseases are known to have an epigenetic component, epigenetic regulation of NETosis has not previously been explored. In the present study, we investigated the effects of epigenetic change, especially DNA demethylation, on NETosis in neutrophil-like cells differentiated from HL-60 cells, which were incubated for 72 h in the presence of 1.25% DMSO. DMSO-differentiated neutrophil-like cells tended to have increased methylation of genomic DNA. NETosis in the neutrophil-like cells was induced by the treatment with A23187, calcium ionophore, and increased by the addition of the DNMT inhibitor 5-azacytidine (Aza) during differentiation. Interestingly, Aza-stimulated neutrophil-like cell induced NETosis without treatment with A23187. Although reactive oxygen species (ROS), especially superoxide and hypochlorous acid, are important in NETosis induction, treatment with Aza decreased production of ROS, while mitochondria ROS scavenger tended to decrease Aza-induced NETosis. Moreover, the genomic DNA in Aza-stimulated neutrophil-like cell was demethylated, and the expression of peptidylarginine deiminase4 (PAD4) and citrullinated histone H3 (R2+R8+R17) was increased, but myeloperoxidase expression was unaffected. Additionally, PAD4 inhibition tended to decrease Aza-induced NETosis. The DNA demethylation induced by the DNMT inhibitor in neutrophil-like cells enhanced spontaneous NETosis through increasing PAD4 expression and histone citrullination. This study establishes a relationship between NETosis and epigenetics for the first time, and indicates that various diseases implicated to have an epigenetic component might be exacerbated by excessive NETosis also under epigenetic control.
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Innate and Autoimmunity in the Pathogenesis of Inherited Retinal Dystrophy. Cells 2020; 9:cells9030630. [PMID: 32151065 PMCID: PMC7140441 DOI: 10.3390/cells9030630] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 02/26/2020] [Accepted: 03/03/2020] [Indexed: 12/14/2022] Open
Abstract
Inherited retinal dystrophies (RDs) are heterogenous in many aspects including genes involved, age of onset, rate of progression, and treatments. While RDs are caused by a plethora of different mutations, all result in the same outcome of blindness. While treatments, both gene therapy-based and drug-based, have been developed to slow or halt disease progression and prevent further blindness, only a small handful of the forms of RDs have treatments available, which are primarily for recessively inherited forms. Using immunohistochemical methods coupled with electroretinography, optical coherence tomography, and fluorescein angiography, we show that in rhodopsin mutant mice, the involvement of both the innate and the autoimmune systems could be a strong contributing factor in disease progression and pathogenesis. Herein, we show that monocytic phagocytosis and inflammatory cytokine release along with protein citrullination, a major player in forms of autoimmunity, work to enhance the progression of RD associated with a rhodopsin mutation.
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Galkina SI, Fedorova NV, Golenkina EA, Stadnichuk VI, Sud’ina GF. Cytonemes Versus Neutrophil Extracellular Traps in the Fight of Neutrophils with Microbes. Int J Mol Sci 2020; 21:ijms21020586. [PMID: 31963289 PMCID: PMC7014225 DOI: 10.3390/ijms21020586] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 12/11/2022] Open
Abstract
Neutrophils can phagocytose microorganisms and destroy them intracellularly using special bactericides located in intracellular granules. Recent evidence suggests that neutrophils can catch and kill pathogens extracellularly using the same bactericidal agents. For this, live neutrophils create a cytoneme network, and dead neutrophils provide chromatin and proteins to form neutrophil extracellular traps (NETs). Cytonemes are filamentous tubulovesicular secretory protrusions of living neutrophils with intact nuclei. Granular bactericides are localized in membrane vesicles and tubules of which cytonemes are composed. NETs are strands of decondensed DNA associated with histones released by died neutrophils. In NETs, bactericidal neutrophilic agents are adsorbed onto DNA strands and are not covered with a membrane. Cytonemes and NETs occupy different places in protecting the body against infections. Cytonemes can develop within a few minutes at the site of infection through the action of nitric oxide or actin-depolymerizing alkaloids of invading microbes. The formation of NET in vitro occurs due to chromatin decondensation resulting from prolonged activation of neutrophils with PMA (phorbol 12-myristate 13-acetate) or other stimuli, or in vivo due to citrullination of histones with peptidylarginine deiminase 4. In addition to antibacterial activity, cytonemes are involved in cell adhesion and communications. NETs play a role in autoimmunity and thrombosis.
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Affiliation(s)
- Svetlana I. Galkina
- Lomonosov Moscow State University, A. N. Belozersky Institute of Physico-Chemical Biology, 119991 Moscow, Russia; (N.V.F.); (E.A.G.)
- Correspondence: (S.I.G.); (G.F.S.); Tel.: +7-495-939-5408 (S.I.G.)
| | - Natalia V. Fedorova
- Lomonosov Moscow State University, A. N. Belozersky Institute of Physico-Chemical Biology, 119991 Moscow, Russia; (N.V.F.); (E.A.G.)
| | - Ekaterina A. Golenkina
- Lomonosov Moscow State University, A. N. Belozersky Institute of Physico-Chemical Biology, 119991 Moscow, Russia; (N.V.F.); (E.A.G.)
| | | | - Galina F. Sud’ina
- Lomonosov Moscow State University, A. N. Belozersky Institute of Physico-Chemical Biology, 119991 Moscow, Russia; (N.V.F.); (E.A.G.)
- Correspondence: (S.I.G.); (G.F.S.); Tel.: +7-495-939-5408 (S.I.G.)
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Jablonska E, Garley M, Surazynski A, Grubczak K, Iwaniuk A, Borys J, Moniuszko M, Ratajczak-Wrona W. Neutrophil extracellular traps (NETs) formation induced by TGF-β in oral lichen planus - Possible implications for the development of oral cancer. Immunobiology 2019; 225:151901. [PMID: 31882256 DOI: 10.1016/j.imbio.2019.151901] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 12/17/2019] [Accepted: 12/17/2019] [Indexed: 12/15/2022]
Abstract
Oral Potentially Malignant Disorders (OPMDs) including Oral Lichen Planus (OLP) are associated with risk of transformation to oral squamous cell carcinoma (OSCC). Available data show that innate immune cells involving polymorphonuclear neutrophils (PMNs) with their ability to neutrophil extracellular traps (NETs) formation are likely to be directly involved in development of cancer. Examination of NETs generation by TGF-β - induced neutrophils of OLP patients showed increased amounts of traps with MPO, H3Cit and cfDNA, known to be released with NETs. The presence of excessive amounts of NETs components may lead to numerous adverse consequences associated with potential transformation to OSCC. Bacterial-related infection may enhance the NETs formation and lead to consequences resulting from the excessive number of individual elements of these networks. It is likely that regulating NETs release by the flavonoids presented herein may be beneficial not only for inhibiting OLP development, but also in reducing risk of transformation to OSCC.
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Affiliation(s)
- Ewa Jablonska
- Department of Immunology Medical University of Bialystok, Poland.
| | - Marzena Garley
- Department of Immunology Medical University of Bialystok, Poland.
| | | | - Kamil Grubczak
- Department of Regenerative Medicine and Immune Regulation Medical University of Bialystok, Poland.
| | | | - Jan Borys
- Department of Maxillofacial and Plastic Surgery Medical University of Bialystok, Poland.
| | - Marcin Moniuszko
- Department of Regenerative Medicine and Immune Regulation Medical University of Bialystok, Poland.
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Qiu CC, Caricchio R, Gallucci S. Triggers of Autoimmunity: The Role of Bacterial Infections in the Extracellular Exposure of Lupus Nuclear Autoantigens. Front Immunol 2019; 10:2608. [PMID: 31781110 PMCID: PMC6857005 DOI: 10.3389/fimmu.2019.02608] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 10/21/2019] [Indexed: 12/12/2022] Open
Abstract
Infections are considered important environmental triggers of autoimmunity and can contribute to autoimmune disease onset and severity. Nucleic acids and the complexes that they form with proteins—including chromatin and ribonucleoproteins—are the main autoantigens in the autoimmune disease systemic lupus erythematosus (SLE). How these nuclear molecules become available to the immune system for recognition, presentation, and targeting is an area of research where complexities remain to be disentangled. In this review, we discuss how bacterial infections participate in the exposure of nuclear autoantigens to the immune system in SLE. Infections can instigate pro-inflammatory cell death programs including pyroptosis and NETosis, induce extracellular release of host nuclear autoantigens, and promote their recognition in an immunogenic context by activating the innate and adaptive immune systems. Moreover, bacterial infections can release bacterial DNA associated with other bacterial molecules, complexes that can elicit autoimmunity by acting as innate stimuli of pattern recognition receptors and activating autoreactive B cells through molecular mimicry. Recent studies have highlighted SLE disease activity-associated alterations of the gut commensals and the expansion of pathobionts that can contribute to chronic exposure to extracellular nuclear autoantigens. A novel field in the study of autoimmunity is the contribution of bacterial biofilms to the pathogenesis of autoimmunity. Biofilms are multicellular communities of bacteria that promote colonization during chronic infections. We review the very recent literature highlighting a role for bacterial biofilms, and their major components, amyloid/DNA complexes, in the generation of anti-nuclear autoantibodies and their ability to stimulate the autoreactive immune response. The best studied bacterial amyloid is curli, produced by enteric bacteria that commonly cause infections in SLE patients, including Escherichia coli and Salmonella spps. Evidence suggests that curli/DNA complexes can trigger autoimmunity by acting as danger signals, molecular mimickers, and microbial chaperones of nucleic acids.
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Affiliation(s)
- Connie C Qiu
- Laboratory of Dendritic Cell Biology, Department of Microbiology and Immunology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Roberto Caricchio
- Division of Rheumatology, Department of Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Stefania Gallucci
- Laboratory of Dendritic Cell Biology, Department of Microbiology and Immunology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
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Hamam HJ, Palaniyar N. Post-Translational Modifications in NETosis and NETs-Mediated Diseases. Biomolecules 2019; 9:E369. [PMID: 31416265 PMCID: PMC6723044 DOI: 10.3390/biom9080369] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 07/31/2019] [Accepted: 08/01/2019] [Indexed: 12/19/2022] Open
Abstract
: Neutrophils undergo a unique form of cell death that generates neutrophil extracellular traps (NETs) that may help to neutralize invading pathogens and restore homeostasis. However, uncontrolled NET formation (NETosis) can result in numerous diseases that adversely affect health. Recent studies further elucidate the mechanistic details of the different forms of NETosis and their common end structure, as NETs were constantly found to contain DNA, modified histones and cytotoxic enzymes. In fact, emerging evidence reveal that the post translational modifications (PTMs) of histones in neutrophils have a critical role in regulating neutrophil death. Histone citrullination is shown to promote a rapid form of NET formation independent of NADPH oxidase (NOX), which relies on calcium influx. Interestingly, few studies suggest an association between histone citrullination and other types of PTMs to control cell survival and death, such as histone methylation. Even more exciting is the finding that histone acetylation has a biphasic effect upon NETosis, where histone deacetylase (HDAC) inhibitors promote baseline, NOX-dependent and -independent NETosis. However, increasing levels of histone acetylation suppresses NETosis, and to switch neutrophil death to apoptosis. Interestingly, in the presence of NETosis-promoting stimuli, high levels of HDACis limit both NETosis and apoptosis, and promote neutrophil survival. Recent studies also reveal the importance of the PTMs of neutrophils in influencing numerous pathologies. Histone modifications in NETs can act as a double-edged sword, as they are capable of altering multiple types of neutrophil death, and influencing numerous NET-mediated diseases, such as acute lung injury (ALI), thrombosis, sepsis, systemic lupus erythematosus, and cancer progression. A clear understanding of the role of different PTMs in neutrophils would be important for an understanding of the molecular mechanisms of NETosis, and to appropriately treat NETs-mediated diseases.
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Affiliation(s)
- Hussein J Hamam
- Program in Translational Medicine, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Nades Palaniyar
- Program in Translational Medicine, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada.
- Institute of Medical Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada.
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Rekvig OP. The dsDNA, Anti-dsDNA Antibody, and Lupus Nephritis: What We Agree on, What Must Be Done, and What the Best Strategy Forward Could Be. Front Immunol 2019; 10:1104. [PMID: 31156647 PMCID: PMC6529578 DOI: 10.3389/fimmu.2019.01104] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 04/30/2019] [Indexed: 12/19/2022] Open
Abstract
This study aims to understand what lupus nephritis is, its origin, clinical context, and its pathogenesis. Truly, we encounter many conceptual and immanent tribulations in our attempts to search for the pathogenesis of this disease—and how to explain its assumed link to SLE. Central in the present landscape stay a short history of the early studies that substantiated the structures of isolated or chromatin-assembled mammalian dsDNA, and its assumed, highly controversial role in induction of anti-dsDNA antibodies. Arguments discussed here may provoke the view that anti-dsDNA antibodies are not what we think they are, as they may be antibodies operational in quite different biological contexts, although they bind dsDNA by chance. This may not mean that these antibodies are not pathogenic but they do not inform how they are so. This theoretical study centers the content around the origin and impact of extra-cellular DNA, and if dsDNA has an effect on the adaptive immune system. The pathogenic potential of chromatin-anti-dsDNA antibody interactions is limited to incite lupus nephritis and dermatitis which may be linked in a common pathogenic process. These are major criteria in SLE classification systems but are not shared with other defined manifestations in SLE, which may mean that they are their own disease entities, and not integrated in SLE. Today, the models thought to explain lupus nephritis are divergent and inconsistent. We miss a comprehensive perspective to try the different models against each other. To do this, we need to take all elements of the syndrome SLE into account. This can only be achieved by concentrating on the interactions between autoimmunity, immunopathology, deviant cell death and necrotic chromatin in context of elements of system science. System science provides a framework where data generated by experts can be compared, and tested against each other. This approach open for consensus on central elements making up “lupus nephritis” to separate what we agree on and how to understand the basis for conflicting models. This has not been done yet in a systematic context.
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Affiliation(s)
- Ole Petter Rekvig
- Department of Medical Biology, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway
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20
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Challenges and Advances in SLE Autoantibody Detection and Interpretation. CURRENT TREATMENT OPTIONS IN RHEUMATOLOGY 2019. [DOI: 10.1007/s40674-019-00122-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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21
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Hollingsworth TJ, Radic MZ, Beranova-Giorgianni S, Giorgianni F, Wang Y, Iannaccone A. Murine Retinal Citrullination Declines With Age and is Mainly Dependent on Peptidyl Arginine Deiminase 4 (PAD4). Invest Ophthalmol Vis Sci 2019; 59:3808-3815. [PMID: 30073354 PMCID: PMC6074612 DOI: 10.1167/iovs.18-24118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Purpose Citrullination is a post-translational modification (PTM) that serves many normal physiological functions. Studies have shown that this PTM—along with expression of the catalyzing enzymes, peptidyl arginine deiminases (PADs)—are increased in autoimmune and age-related pathologies. PAD2 retinal expression has been previously documented in rat and human. Herein, we report on the expression levels and patterns of PAD2, PAD4, and retinal citrullination in the murine retina with age. Methods Wild-type (WT) and Pad4-/- (PAD4KO) mice ages 0.5, 0.75, 1, 3, 6, and 9 months were investigated after euthanasia and eye enucleation. Retinal lysates from 3-month-old mice were probed for PAD4 by western blot. Whole eyes were fixed, cryosectioned, and probed using an anti-PAD2/4 antibody (Ab), a specific anti-PAD4 Ab, and F95 anti-citrullinated peptide Ab. Fluorescent intensities were quantified with ImageJ. Results WT retinas show different levels of PAD4 expression in distinct retinal layers, with the most intense labeling in inner retinal layers, while PAD4KO mice lacked retinal PAD4. Using a nonspecific anti-PAD2/4 Ab, PAD reactivity observed in PAD4KO mice was attributed to PAD2. In WT, both PAD2 and PAD4 expression levels decrease significantly with age while low-level residual PAD2 expression was seen in PAD4KO mice. Citrullination levels in WT retinas paralleled PAD4 expression, with PAD4KO mice exhibiting consistently minimal citrullination. Conclusions Both PAD2 and PAD4 expression and citrullination decrease with age in the murine retina. However, in the absence of PAD4, retinal citrullination is nearly abolished, indicating that PAD4 is a main effector for retinal citrullination under physiological conditions.
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Affiliation(s)
- T J Hollingsworth
- Neuroscience Institute, University of Tennessee Health Science Center, Memphis, Tennessee, United States
| | - Marko Z Radic
- Department of Microbiology, Biochemistry and Immunology, University of Tennessee Health Science Center, Memphis, Tennessee, United States
| | - Sarka Beranova-Giorgianni
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, Tennessee, United States
| | - Francesco Giorgianni
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, Tennessee, United States
| | - Yanming Wang
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, United States
| | - Alessandro Iannaccone
- Duke University School of Medicine, Duke Eye Center, Department of Ophthalmology, Durham, North Carolina, United States
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Chapman EA, Lyon M, Simpson D, Mason D, Beynon RJ, Moots RJ, Wright HL. Caught in a Trap? Proteomic Analysis of Neutrophil Extracellular Traps in Rheumatoid Arthritis and Systemic Lupus Erythematosus. Front Immunol 2019; 10:423. [PMID: 30915077 PMCID: PMC6421309 DOI: 10.3389/fimmu.2019.00423] [Citation(s) in RCA: 127] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 02/18/2019] [Indexed: 12/22/2022] Open
Abstract
Neutrophil Extracellular Traps (NETs) are implicated in the development of auto-immunity in diseases such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) through the externalization of intracellular neoepitopes e.g., dsDNA and nuclear proteins in SLE and citrullinated peptides in RA. The aim of this work was to use quantitative proteomics to identify and measure NET proteins produced by neutrophils from healthy controls, and from patients with RA and SLE to determine if NETs can be differentially-generated to expose different sets of neoepitopes. Ultra-pure neutrophils (>99%) from healthy individuals (n = 3) and patients with RA or SLE (n = 6 each) were incubated ± PMA (50 nM, PKC super-activator) or A23187 (3.8 μM, calcium ionophore) for 4 h. NETs were liberated by nuclease digestion and concentrated onto Strataclean beads prior to on-bead digestion with trypsin. Data-dependent LC-MS/MS analyses were conducted on a QExactive HF quadrupole-Orbitrap mass spectrometer, and label-free protein quantification was carried out using Progenesis QI. PMA-induced NETs were decorated with annexins, azurocidin and histone H3, whereas A23187-induced NETs were decorated with granule proteins including CAMP/LL37, CRISP3, lipocalin and MMP8, histones H1.0, H1.4, and H1.5, interleukin-8, protein-arginine deiminase-4 (PADI4), and α-enolase. Four proteins were significantly different between PMA-NETs from RA and SLE neutrophils (p < 0.05): RNASE2 was higher in RA, whereas MPO, leukocyte elastase inhibitor and thymidine phosphorylase were higher in SLE. For A23187-NETs, six NET proteins were higher in RA (p < 0.05), including CAMP/LL37, CRISP3, interleukin-8, MMP8; Thirteen proteins were higher in SLE, including histones H1.0, H2B, and H4. This work provides the first, direct comparison of NOX2-dependent (PMA) and NOX2-independent (A23187) NETs using quantitative proteomics, and the first direct comparison of RA and SLE NETs using quantitative proteomics. We show that it is the nature of the stimulant rather than neutrophil physiology that determines NET protein profiles in disease, since stimulation of NETosis in either a NOX2-dependent or a NOX2-independent manner generates broadly similar NET proteins irrespective of the disease background. We also use our proteomics pipeline to identify an extensive range of post-translationally modified proteins in RA and SLE, including histones and granule proteins, many of which are known targets of auto-antibodies in each disease.
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Affiliation(s)
- Elinor A Chapman
- Department of Musculoskeletal Biology I, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Max Lyon
- Department of Musculoskeletal Biology I, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Deborah Simpson
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom.,Centre for Proteome Research, University of Liverpool, Liverpool, United Kingdom
| | - David Mason
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom.,Centre for Cell Imaging, University of Liverpool, Liverpool, United Kingdom
| | - Robert J Beynon
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom.,Centre for Proteome Research, University of Liverpool, Liverpool, United Kingdom
| | - Robert J Moots
- Department of Musculoskeletal Biology I, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom.,University of Liverpool and Aintree University Hospital, Members of Liverpool Health Partners, Liverpool, United Kingdom
| | - Helen L Wright
- Department of Musculoskeletal Biology I, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
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Nakabo S. Clinical and etiological meaning of anti-carbamylated protein antibodies in rheumatoid arthritis. Immunol Med 2019; 41:147-153. [PMID: 30714481 DOI: 10.1080/25785826.2018.1556017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Several autoantibodies against proteins with post-translational modifications have been detected in patients with rheumatoid arthritis (RA) and are called anti-modified protein antibodies (AMPAs). Anti-carbamylated protein antibodies (Anti-CarP Ab) are the second most vigorously researched AMPAs following anti-citrullinated protein/peptide antibodies (ACPA). Anti-CarP Ab and ACPA show cross-reactivity to some extent and frequently co-exist with each other in RA, but are two distinct antibodies. Although the diagnostic efficacy of anti-CarP Ab is inferior to that of ACPA, the diagnostic specificity of RA may improve when used in combination with ACPA and rheumatoid factor. Anti-CarP Ab and ACPA are also useful for identifying patients at high risk of more severe joint destruction and cardiovascular diseases. The high prevalence of the co-existence of both antibodies suggests a common factor in their production, and this is important for the development of RA because both antibodies emerge before the onset of clinical symptoms. Neutrophils may also be crucially involved. It is important to distinguish citrullinated antigens from carbamylated antigens because the methods commonly used to detect the former are now known to be cross-reactive with the latter. Research on anti-CarP Ab will provide novel insights into the pathology and etiology of RA.
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Affiliation(s)
- Shuichiro Nakabo
- a Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases , National Institutes of Health , Bethesda , MD , USA
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25
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17-β-estradiol enhances neutrophil extracellular trap formation by interaction with estrogen membrane receptor. Arch Biochem Biophys 2018; 663:64-70. [PMID: 30590021 DOI: 10.1016/j.abb.2018.12.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 12/14/2018] [Accepted: 12/23/2018] [Indexed: 12/13/2022]
Abstract
Cell death-associated neutrophil extracellular trap formation (NETosis) occurs during various autoimmune diseases including systemic lupus erythematosus and rheumatoid arthritis, as well as during gestation. Although increasing estrogen concentrations associated with pregnancy might induce NETosis via nuclear estrogen receptor (ERα/ERβ), little is known about the mechanisms associated with estrogen-induced NETosis. Here, we investigated the effects of estrogen (17-β-estradiol; E2) on NETosis, focusing on mechanisms associated with estrogen membrane receptor (GPR30) in neutrophil-like HL-60 cells. Our results show that E2 and the GPR30 agonist G-1 increases level of NETosis and NET formation. Moreover, NETosis-associated intracellular and extracellular histone citrullination and peptidyl arginine deiminase 4 (PAD4) expression were also increased by E2 or G-1 treatment. Furthermore, GPR30 antagonist pre-treatment inhibited increases in NETosis and PAD4 expression mediated by G-1 and partially inhibited these effects mediated by E2. These results demonstrate that E2 treatment induces NETosis via not only ERα/ERβ but also GPR30 in neutrophil-like HL-60 cells.
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Dwivedi N, Radic M. Burning controversies in NETs and autoimmunity: The mysteries of cell death and autoimmune disease. Autoimmunity 2018; 51:267-280. [PMID: 30417698 DOI: 10.1080/08916934.2018.1523395] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The causes and mechanisms of autoimmune disease pose continuing challenges to the scientific community. Recent clues implicate a peculiar feature of neutrophils, their ability to release nuclear chromatin in the form of neutrophil extracellular traps (NETs), in the induction or progression of autoimmune disease. Efforts to define the beneficial versus detrimental effects of NET release have, as yet, only partially revealed mechanisms that guide this process. Evidence suggests that the process of NET release is highly regulated, but the details of regulation remain controversial and obscure. Without a better understanding of the factors that initiate and control NET formation, the judicious modification of neutrophil behaviour for medically useful purposes appears remote. We highlight gaps and inconsistencies in published work, which make NETs and their role in health and disease a puzzle that deserves more focused attention.
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Affiliation(s)
- Nishant Dwivedi
- a TIP Immunology , EMD Serono Research and Development Institute, Inc , Billerica , MA , USA
| | - Marko Radic
- b Department of Microbiology, Immunology and Biochemistry , University of Tennessee Health Science Center , Memphis , TN , USA
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Dong X, Zheng Z, Zhai Y, Zheng Y, Ding J, Jiang J, Zhu P. ACPA mediates the interplay between innate and adaptive immunity in rheumatoid arthritis. Autoimmun Rev 2018; 17:845-853. [DOI: 10.1016/j.autrev.2018.02.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 02/20/2018] [Indexed: 01/17/2023]
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Dąbrowska D, Jabłońska E, Garley M, Sawicka-Powierza J, Nowak K. The Phenomenon of Neutrophil Extracellular Traps in Vascular Diseases. Arch Immunol Ther Exp (Warsz) 2018; 66:273-281. [PMID: 29404659 PMCID: PMC6061175 DOI: 10.1007/s00005-018-0505-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Accepted: 01/02/2018] [Indexed: 01/04/2023]
Abstract
Vascular diseases constitute a global health issue due to the increasing number of cases of patients with these diseases. The pathogenesis of the majority of these diseases, including atherosclerosis and thrombosis, is complex and not yet fully understood. One of the major causes for their occurrence can be immune disorders resulting in the development of a chronic inflammation within the vessels. In recent years, studies have placed emphasis on the role of neutrophils in the development of these diseases, i.e., the discovery of neutrophil extracellular traps (NETs) demonstrated that the structures released by the cells may contribute to the enhancement of inflammatory reactions and cell damage. This article summarizes current knowledge on the role of NETs during atherosclerosis, thrombosis and small-vessel vasculitis, especially in antineutrophil cytoplasmic antibody (ANCA)-associated small-vessel vasculitis (AAV).
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Affiliation(s)
- Dorota Dąbrowska
- Department of Immunology, Medical University of Bialystok, J. Waszyngtona 15A, 15-269, Bialystok, Poland.
| | - Ewa Jabłońska
- Department of Immunology, Medical University of Bialystok, J. Waszyngtona 15A, 15-269, Bialystok, Poland
| | - Marzena Garley
- Department of Immunology, Medical University of Bialystok, J. Waszyngtona 15A, 15-269, Bialystok, Poland
| | - Jolanta Sawicka-Powierza
- Department of Family Medicine, Medical University of Bialystok, Mieszka I 4B, 15-054, Bialystok, Poland
| | - Karolina Nowak
- Department of Immunology, Medical University of Bialystok, J. Waszyngtona 15A, 15-269, Bialystok, Poland
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Abstract
Neutrophils are essential to the homeostatic mission of safeguarding host tissues, responding rapidly and diversely to breaches of the host's barriers to infection, and returning tissues to a sterile state. In response to specific stimuli, neutrophils extrude modified chromatin structures decorated with specific cytoplasmic and granular proteins called neutrophil extracellular traps (NETs). Several pathways lead to this unique form of cell death (NETosis). Extracellular chromatin may have evolved to defend eukaryotic organisms against infection, and its release has at least three functions: trapping and killing of microbes, amplifying immune responses, and inducing coagulation. Here we review neutrophil development and heterogeneity with a focus on NETs, NET formation, and their relevance in host defense and disease.
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Rekvig OP. Systemic Lupus Erythematosus: Definitions, Contexts, Conflicts, Enigmas. Front Immunol 2018; 9:387. [PMID: 29545801 PMCID: PMC5839091 DOI: 10.3389/fimmu.2018.00387] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 02/12/2018] [Indexed: 12/15/2022] Open
Abstract
Systemic lupus erythematosus (SLE) is an inadequately defined syndrome. Etiology and pathogenesis remain largely unknown. SLE is on the other hand a seminal syndrome that has challenged immunologists, biologists, genetics, and clinicians to solve its nature. The syndrome is characterized by multiple, etiologically unlinked manifestations. Unexpectedly, they seem to occur in different stochastically linked clusters, although single gene defects may promote a smaller spectrum of symptoms/criteria typical for SLE. There is no known inner coherence of parameters (criteria) making up the disease. These parameters are, nevertheless, implemented in The American College of Rheumatology (ACR) and The Systemic Lupus Collaborating Clinics (SLICC) criteria to classify SLE. Still, SLE is an abstraction since the ACR or SLICC criteria allow us to define hundreds of different clinical SLE phenotypes. This is a major point of the present discussion and uses "The anti-dsDNA antibody" as an example related to the problematic search for biomarkers for SLE. The following discussion will show how problematic this is: the disease is defined through non-coherent classification criteria, its complexity is recognized and accepted, its pathogenesis is plural and poorly understood. Therapy is focused on dominant symptoms or organ manifestations, and not on the syndrome itself. From basic scientific evidences, we can add substantial amount of data that are not sufficiently considered in clinical medicine, which may change the paradigms linked to what "The Anti-DNA antibody" is-and is not-in context of the imperfectly defined syndrome SLE.
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Affiliation(s)
- Ole Petter Rekvig
- Department of Medical Biology, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway
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Harbige J, Eichmann M, Peakman M. New insights into non-conventional epitopes as T cell targets: The missing link for breaking immune tolerance in autoimmune disease? J Autoimmun 2017; 84:12-20. [PMID: 28803690 DOI: 10.1016/j.jaut.2017.08.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 07/29/2017] [Accepted: 08/01/2017] [Indexed: 12/15/2022]
Abstract
The mechanism by which immune tolerance is breached in autoimmune disease is poorly understood. One possibility is that post-translational modification of self-antigens leads to peripheral recognition of neo-epitopes against which central and peripheral tolerance is inadequate. Accumulating evidence points to multiple mechanisms through which non-germline encoded sequences can give rise to these non-conventional epitopes which in turn engage the immune system as T cell targets. In particular, where these modifications alter the rules of epitope engagement with MHC molecules, such non-conventional epitopes offer a persuasive explanation for associations between specific HLA alleles and autoimmune diseases. In this review article, we discuss current understanding of mechanisms through which non-conventional epitopes may be generated, focusing on several recently described pathways that can transpose germline-encoded sequences. We contextualise these discoveries around type 1 diabetes, the prototypic organ-specific autoimmune disease in which specific HLA-DQ molecules confer high risk. Non-conventional epitopes have the potential to act as tolerance breakers or disease drivers in type 1 diabetes, prompting a timely re-evaluation of models of a etiopathogenesis. Future studies are required to elucidate the disease-relevance of a range of potential non-germline epitopes and their relationship to the natural peptide repertoire.
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Affiliation(s)
- James Harbige
- Department of Immunobiology, Faculty of Life Sciences & Medicine, King's College London, UK.
| | - Martin Eichmann
- Department of Immunobiology, Faculty of Life Sciences & Medicine, King's College London, UK
| | - Mark Peakman
- Department of Immunobiology, Faculty of Life Sciences & Medicine, King's College London, UK; Division of Diabetes and Nutritional Sciences, King's College London, UK; Institute of Diabetes, Endocrinology and Obesity, King's Health Partners, London, UK.
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Dwivedi N, Hedberg A, Zheng YY, Neeli I, Satoh M, Morel L, Rekvig OP, Radic M. B Cell Tolerance to Deiminated Histones in BALB/c, C57BL/6, and Autoimmune-Prone Mouse Strains. Front Immunol 2017; 8:362. [PMID: 28424695 PMCID: PMC5371714 DOI: 10.3389/fimmu.2017.00362] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 03/14/2017] [Indexed: 12/03/2022] Open
Abstract
Deimination, a posttranslational modification of arginine to citrulline carried out by peptidylarginine deiminases, may compromise tolerance of self-antigens. Patients with connective tissue autoimmunity, particularly rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), or Felty’s syndrome, present with autoantibodies to deiminated histones (dH), which thus form a category of antibodies to citrullinated protein antigens (ACPA). In general, ACPA are a sensitive diagnostic for RA and may form in response to the release of nuclear chromatin (DNA plus dH) from granulocytes, usually referred to as neutrophil extracellular traps. The aim of this study was to examine spontaneously autoimmune mice for autoantibodies and T cell responses to dH. We compared IgG binding to deiminated and non-deiminated histones (nH) by ELISA and Western blotting in spontaneously autoimmune strains of (NZB × NZW) F1 and NZM2410 together with their derivative congenic strains, C57BL/6.Sle1 and C57BL/6.Sle1.Sle3, which display profound autoreactivity against nuclear self-antigens. The splenocyte proliferation against the two antigens was determined in the spontaneously autoimmune (NZB × NZW) F1 strain from which other autoimmune strains used in the study were derived. Immunizations with dH and nH were attempted in BALB/c mice to assess their splenocyte response. Splenocytes from BALB/c mice and from autoimmune mice at the time of conversion to autoimmunity proliferated strongly in response to dH, yet serum IgG from autoimmune (NZB × NZW) F1, NZM2410, and C57BL/6.Sle1.Sle3 mice displayed a remarkable bias against binding to dH. At the time of seroconversion, the antibodies already exhibited preference for nH, and only nH were recovered from circulating immune complexes. Analysis of histone deimination showed constitutive deimination in thymic extracts from C57BL/6 and C57BL/6.Sle1.Sle2.Sle3 triply congenic mice and in spleens of autoimmune triply congenic mice. Our study demonstrates that tolerance mechanisms against dH are intact in BALB/c and C57BL/6 mice and continue to be effective in mice with overt autoimmunity to nH. We conclude that, in contrast to human RA and SLE patients, where we frequently observe autoantibodies against dH, autoimmune mice maintain strong tolerance mechanisms to prevent the development of autoantibodies to dH.
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Affiliation(s)
- Nishant Dwivedi
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Annica Hedberg
- Medical Faculty, Department of RNA and Molecular Pathology, Institute of Medical Biology, University of Tromsø, Tromsø, Norway
| | - Ying Yi Zheng
- Department of Medicine, University of Florida, Gainesville, FL, USA
| | - Indira Neeli
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Minoru Satoh
- Department of Clinical Nursing, University of Occupational and Environmental Health, Fukuoka, Japan
| | - Laurence Morel
- Department of Medicine, University of Florida, Gainesville, FL, USA
| | - Ole Petter Rekvig
- Medical Faculty, Department of RNA and Molecular Pathology, Institute of Medical Biology, University of Tromsø, Tromsø, Norway
| | - Marko Radic
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, USA
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Khan MA, Palaniyar N. Transcriptional firing helps to drive NETosis. Sci Rep 2017; 7:41749. [PMID: 28176807 PMCID: PMC5296899 DOI: 10.1038/srep41749] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 12/28/2016] [Indexed: 12/20/2022] Open
Abstract
Neutrophils are short-lived innate immune cells. These cells respond quickly to stimuli, and die within minutes to hours; the relevance of DNA transcription in dying neutrophils remains an enigma for several decades. Here we show that the transcriptional activity reflects the degree of DNA decondensation occurring in both NADPH oxidase 2 (Nox)-dependent and Nox-independent neutrophil extracellular trap (NET) formation or NETosis. Transcriptomics analyses show that transcription starts at multiple loci in all chromosomes earlier in the rapid Nox-independent NETosis (induced by calcium ionophore A23187) than Nox-dependent NETosis (induced by PMA). NETosis-specific kinase cascades differentially activate transcription of different sets of genes. Inhibitors of transcription, but not translation, suppress both types of NETosis. In particular, promoter melting step is important to drive NETosis (induced by PMA, E. coli LPS, A23187, Streptomyces conglobatus ionomycin). Extensive citrullination of histones in multiple loci occurs only during calcium-mediated NETosis, suggesting that citrullination of histone contributes to the rapid DNA decondensation seen in Nox-independent NETosis. Furthermore, blocking transcription suppresses both types of NETosis, without affecting the reactive oxygen species production that is necessary for antimicrobial functions. Therefore, we assign a new function for transcription in neutrophils: Transcriptional firing, regulated by NETosis-specific kinases, helps to drive NETosis.
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Affiliation(s)
- Meraj A Khan
- Innate Immunity Research Lab, Physiology and Experimental Medicine, PGCRL, The Hospital for Sick Children Research Institute, 686 Bay St, Toronto M5G 0A4, Canada.,Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Nades Palaniyar
- Innate Immunity Research Lab, Physiology and Experimental Medicine, PGCRL, The Hospital for Sick Children Research Institute, 686 Bay St, Toronto M5G 0A4, Canada.,Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Canada.,Institute of Medical Sciences, Faculty of Medicine, University of Toronto, Toronto, Canada
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Corsiero E, Pratesi F, Prediletto E, Bombardieri M, Migliorini P. NETosis as Source of Autoantigens in Rheumatoid Arthritis. Front Immunol 2016; 7:485. [PMID: 27895639 PMCID: PMC5108063 DOI: 10.3389/fimmu.2016.00485] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 10/21/2016] [Indexed: 12/29/2022] Open
Abstract
In neutrophils (but also in eosinophils and in mast cells), different inflammatory stimuli induce histone deimination, chromatin decondensation, and NET formation. These web-like structures that trap and kill microbes contain DNA, cationic granule proteins, and antimicrobial peptides, but the most abundant proteins are core histones. Histones contained in NETs have been deiminated, and arginines are converted in citrullines. While deimination is a physiological process amplified in inflammatory conditions, only individuals carrying genetic predisposition to develop rheumatoid arthritis (RA) make antibodies to deiminated proteins. These antibodies, collectively identified as anti-citrullinated proteins/peptides antibodies (ACPA), react with different deiminated proteins and display partially overlapping specificities. In this paper, we will summarize current evidence supporting the role of NETosis as critical mechanism in the breach of tolerance to self-antigens and in supporting expansion and differentiation of autoreactive cells. In fact, several lines of evidence connect NETosis with RA: RA unstimulated synovial fluid neutrophils display enhanced NETosis; sera from RA patients with Felty's syndrome bind deiminated H3 and NETs; a high number of RA sera bind deiminated H4 contained in NETs; human monoclonal antibodies generated from RA synovial B cells decorate NETs and bind deiminated histones. In RA, NETs represent on one side an important source of autoantigens bearing posttranslational modifications and fueling the production of ACPA. On the other side, NETs deliver signals that maintain an inflammatory milieu and contribute to the expansion and differentiation of ACPA-producing B cells.
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Affiliation(s)
- Elisa Corsiero
- Centre for Experimental Medicine and Rheumatology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London , London , UK
| | - Federico Pratesi
- Clinical Immunology and Allergy Unit, Department of Clinical and Experimental Medicine, University of Pisa , Pisa , Italy
| | - Edoardo Prediletto
- Centre for Experimental Medicine and Rheumatology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London , London , UK
| | - Michele Bombardieri
- Centre for Experimental Medicine and Rheumatology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London , London , UK
| | - Paola Migliorini
- Clinical Immunology and Allergy Unit, Department of Clinical and Experimental Medicine, University of Pisa , Pisa , Italy
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35
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Nguyen H, James EA. Immune recognition of citrullinated epitopes. Immunology 2016; 149:131-8. [PMID: 27531825 DOI: 10.1111/imm.12640] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 06/17/2016] [Accepted: 06/19/2016] [Indexed: 12/27/2022] Open
Abstract
Conversion of arginine into citrulline is a post-translational modification that is observed in normal physiological processes. However, abnormal citrullination can provoke autoimmunity by generating altered self-epitopes that are specifically targeted by autoantibodies and T cells. In this review we discuss the recognition of citrullinated antigens in human autoimmune diseases and the role that this modification plays in increasing antigenic diversity and circumventing tolerance mechanisms. Early published work demonstrated that citrullinated proteins are specifically targeted by autoantibodies in rheumatoid arthritis and that citrullinated peptides are more readily presented to T cells by arthritis-susceptible HLA class II 'shared epitope' proteins. Emerging data support the relevance of citrullinated epitopes in other autoimmune diseases, including type 1 diabetes and multiple sclerosis, whose susceptible HLA haplotypes also preferentially present citrullinated peptides. In these settings, autoimmune patients have been shown to have elevated responses to citrullinated epitopes derived from tissue-specific antigens. Contrasting evidence implicates autophagy or perforin and complement-mediated membrane attack as inducers of ectopic citrullination. In either case, the peptidyl deiminases responsible for citrullination are activated in response to inflammation or insult, providing a mechanistic link between this post-translational modification and interactions with the environment and infection. As such, it is likely that immune recognition of citrullinated epitopes also plays a role in pathogen clearance. Indeed, our recent data suggest that responses to citrullinated peptides facilitate recognition of novel influenza strains. Therefore, increased understanding of responses to citrullinated epitopes may provide important insights about the initiation of autoimmunity and recognition of heterologous viruses.
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Affiliation(s)
- Hai Nguyen
- Benaroya Research Institute at Virginia Mason, Seattle, WA, USA
| | - Eddie A James
- Benaroya Research Institute at Virginia Mason, Seattle, WA, USA
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36
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Muller S, Radic M. Citrullinated Autoantigens: From Diagnostic Markers to Pathogenetic Mechanisms. Clin Rev Allergy Immunol 2016; 49:232-9. [PMID: 25355199 DOI: 10.1007/s12016-014-8459-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The conversion of an arginine residue in a protein to a citrulline residue, a reaction carried out by enzymes called peptidylarginine deiminases (PADs), is rather subtle. One of the terminal imide groups in arginine is replaced by oxygen in citrulline, thus resulting in the loss of positive charge and the gain of 1 dalton. This post-translational modification by PAD enzymes is conserved in vertebrates and affects specific substrates during development and in various mature cell lineages. Citrullination offers a unique perspective on autoimmunity because PAD activity is stringently regulated, yet autoantibodies to citrullinated proteins predictably arise. Autoantigens recognized by anti-citrullinated protein antibodies (ACPA) include extracellular proteins such as filaggrin, collagen II, fibrinogen, and calreticulin; membrane-associated proteins such as myelin basic protein; cytoplasmic proteins such as vimentin and enolase; and even nuclear proteins such as histones. Some ACPA are remarkably effective as diagnostics in autoimmune disorders, most notably rheumatoid arthritis (RA). Several ACPA can be observed before other clinical RA manifestations are apparent. In patients with RA, ACPA may attain a sensitivity that exceeds 70 % and specificity that approaches 96-98 %. The biological context that may account for the induction of ACPA emerges from studies of the cellular response of the innate immune system to acute or chronic stimuli. In response to infections or inflammation, neutrophil granulocytes activate PAD, citrullinate multiple autoantigens, and expel chromatin from the cell. The externalized chromatin is called a neutrophil extracellular "trap" (NET). Citrullination of core and linker histones occurs prior to the release of chromatin from neutrophils, thus implicating the regulation of citrullinated chromatin release in the development of autoreactivity. The citrullination of extracellular autoantigens likely follows the release of NETs and associated PADs. Autoantibodies to citrullinated histones arise in RA, systemic lupus erythematosus, and Felty's syndrome patients. The citrullination of linker histone H1 may play a key role in NET release because the H1 histone regulates the entry and exit of DNA from the nucleosome. Juxtaposition of citrullinated histones with infectious pathogens and complement and immune complexes may compromise tolerance of nuclear autoantigens and promote autoimmunity.
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Affiliation(s)
- Sylviane Muller
- Immunopathology and Therapeutic Chemistry/Laboratory of Excellence MEDALIS, CNRS, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France
| | - Marko Radic
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, USA.
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Mistry P, Kaplan MJ. Cell death in the pathogenesis of systemic lupus erythematosus and lupus nephritis. Clin Immunol 2016; 185:59-73. [PMID: 27519955 DOI: 10.1016/j.clim.2016.08.010] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 08/05/2016] [Accepted: 08/08/2016] [Indexed: 12/12/2022]
Abstract
Nephritis is one of the most severe complications of systemic lupus erythematosus (SLE). One key characteristic of lupus nephritis (LN) is the deposition of immune complexes containing nucleic acids and/or proteins binding to nucleic acids and autoantibodies recognizing these molecules. A variety of cell death processes are implicated in the generation and externalization of modified nuclear autoantigens and in the development of LN. Among these processes, apoptosis, primary and secondary necrosis, NETosis, necroptosis, pyroptosis, and autophagy have been proposed to play roles in tissue damage and immune dysregulation. Cell death occurs in healthy individuals during conditions of homeostasis yet autoimmunity does not develop, at least in part, because of rapid clearance of dying cells. In SLE, accelerated cell death combined with a clearance deficiency may lead to the accumulation and externalization of nuclear autoantigens and to autoantibody production. In addition, specific types of cell death may modify autoantigens and alter their immunogenicity. These modified molecules may then become novel targets of the immune system and promote autoimmune responses in predisposed hosts. In this review, we examine various cell death pathways and discuss how enhanced cell death, impaired clearance, and post-translational modifications of proteins could contribute to the development of lupus nephritis.
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Affiliation(s)
- Pragnesh Mistry
- Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mariana J Kaplan
- Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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Abstract
PURPOSE OF REVIEW Recent discoveries implicate neutrophils as important regulators of innate and adaptive immunity and in the development of organ damage in systemic autoimmune diseases, including systemic lupus erythematosus (SLE). RECENT FINDINGS Various putative SLE biomarkers are neutrophil-related, including neutrophil granular proteins and histones undergoing post-translational modifications during neutrophil extracellular trap (NET) formation. In the bone marrow, lupus neutrophils can drive B and T cell abnormalities, at least in part, by their enhanced production of type-I interferons, tumor necrosis factor-alpha (TNFα) and the B-cell stimulating factors B-cell activating factor (BAFF) and a proliferation-inducing ligand (APRIL). Lupus neutrophils and, in particular, lupus low-density granulocytes (a distinct pathogenic subset) display epigenetic modifications and genomic alterations that may be relevant to their deleterious roles in SLE. Proteins and enzymes externalized by lupus NETs can affect vascular health by inducing endothelial apoptosis and oxidizing lipoproteins. Hampering NET formation through peptidylarginine deiminase inhibitors abrogates lupus phenotype and atherosclerosis in murine studies. SUMMARY Recent discoveries support the notion that neutrophils, low-density granulocytes and aberrant NET formation and clearance play important roles in lupus pathogenesis. Future studies should focus on how to selectively target these immunostimulatory pathways in this disease.
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Saijo S, Nagai A, Kinjo S, Mashimo R, Akimoto M, Kizawa K, Yabe-Wada T, Shimizu N, Takahara H, Unno M. Monomeric Form of Peptidylarginine Deiminase Type I Revealed by X-ray Crystallography and Small-Angle X-ray Scattering. J Mol Biol 2016; 428:3058-73. [DOI: 10.1016/j.jmb.2016.06.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 06/20/2016] [Accepted: 06/28/2016] [Indexed: 02/01/2023]
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40
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McLaughlin RJ, Spindler MP, van Lummel M, Roep BO. Where, How, and When: Positioning Posttranslational Modification Within Type 1 Diabetes Pathogenesis. Curr Diab Rep 2016; 16:63. [PMID: 27168063 PMCID: PMC4863913 DOI: 10.1007/s11892-016-0752-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Autoreactive T cells specific for islet autoantigens develop in type 1 diabetes (T1D) by escaping central as well as peripheral tolerance. The current paradigm for development of islet autoimmunity is just beginning to include the contribution of posttranslationally modified (PTM) islet autoantigens, for which the immune system may be ignorant rather than tolerant. As a result, PTM is the latest promising lead in the quest to understand how the break in peripheral tolerance occurs in T1D. However, it is not completely clear how, where, or when these modifications take place. Currently, only a few PTM antigens have been well-thought-out or identified in T1D, and methods for identifying and characterizing new PTM antigens are rapidly improving. This review will address both reported and potential new sources of modified islet autoantigens and discuss how islet neo-autoantigen generation may contribute to the development and progression of T1D.
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Affiliation(s)
- Rene J McLaughlin
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, E3-Q, PO Box 9600, 2300 RC, Leiden, The Netherlands
| | - Matthew P Spindler
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, E3-Q, PO Box 9600, 2300 RC, Leiden, The Netherlands
| | - Menno van Lummel
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, E3-Q, PO Box 9600, 2300 RC, Leiden, The Netherlands
| | - Bart O Roep
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, E3-Q, PO Box 9600, 2300 RC, Leiden, The Netherlands.
- Department of Diabetes Immunology, Diabetes & Metabolism Research Institute, Beckman Research Institute of City of Hope, Duarte, CA, 91010, USA.
- Danish Diabetes Academy, Søndre Blvd. 29, 5000, Odense, Denmark.
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41
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Oxidation and mitochondrial origin of NET DNA in the pathogenesis of lupus. Nat Med 2016; 22:126-7. [PMID: 26845404 DOI: 10.1038/nm.4044] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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42
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Domingo-Gonzalez R, Martínez-Colón GJ, Smith AJ, Smith CK, Ballinger MN, Xia M, Murray S, Kaplan MJ, Yanik GA, Moore BB. Inhibition of Neutrophil Extracellular Trap Formation after Stem Cell Transplant by Prostaglandin E2. Am J Respir Crit Care Med 2016; 193:186-97. [PMID: 26417909 DOI: 10.1164/rccm.201501-0161oc] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
RATIONALE Autologous and allogeneic hematopoietic stem cell transplant (HSCT) patients are susceptible to pulmonary infections, including bacterial pathogens, even after hematopoietic reconstitution. We previously reported that murine bone marrow transplant (BMT) neutrophils overexpress cyclooxygenase-2, overproduce prostaglandin E2 (PGE2), and exhibit defective intracellular bacterial killing. Neutrophil extracellular traps (NETs) are DNA structures that capture and kill extracellular bacteria and other pathogens. OBJECTIVES To determine whether NETosis was defective after transplant and if so, whether this was regulated by PGE2 signaling. METHODS Neutrophils isolated from mice and humans (both control and HSCT subjects) were analyzed for NETosis in response to various stimuli in the presence or absence of PGE2 signaling modifiers. MEASUREMENTS AND MAIN RESULTS NETs were visualized by immunofluorescence or quantified by Sytox Green fluorescence. Treatment of BMT or HSCT neutrophils with phorbol 12-myristate 13-acetate or rapamycin resulted in reduced NET formation relative to control cells. NET formation after BMT was rescued both in vitro and in vivo with cyclooxygenase inhibitors. Additionally, the EP2 receptor antagonist (PF-04418948) or the EP4 antagonist (AE3-208) restored NET formation in neutrophils isolated from BMT mice or HSCT patients. Exogenous PGE2 treatment limited NETosis of neutrophils collected from normal human volunteers and naive mice in an exchange protein activated by cAMP- and protein kinase A-dependent manner. CONCLUSIONS Our results suggest blockade of the PGE2-EP2 or EP4 signaling pathway restores NETosis after transplantation. Furthermore, these data provide the first description of a physiologic inhibitor of NETosis.
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Affiliation(s)
| | | | | | - Carolyne K Smith
- 1 Immunology Graduate Program.,3 Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland; and
| | - Megan N Ballinger
- 4 Pulmonary, Allergy, Critical Care and Sleep Division, Department of Internal Medicine, The Ohio State University, Columbus, Ohio
| | - Meng Xia
- 5 Biostatistics Department, School of Public Health
| | - Susan Murray
- 5 Biostatistics Department, School of Public Health
| | - Mariana J Kaplan
- 3 Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland; and
| | - Gregory A Yanik
- 6 Department of Pediatrics, Division of Hematology-Oncology, Medical School
| | - Bethany B Moore
- 7 Pulmonary and Critical Care Medicine Division, Department of Internal Medicine, and.,8 Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan
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43
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Comparative analysis of novel autoantibody isotypes against citrullinated-inter-alpha-trypsin inhibitor heavy chain 3 (ITIH3)542–556 peptide in serum from Taiwanese females with rheumatoid arthritis, primary Sjögren's syndrome and secondary Sjögren's syndrome in rheumatoid arthritis. J Proteomics 2016; 141:1-11. [DOI: 10.1016/j.jprot.2016.03.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Revised: 03/10/2016] [Accepted: 03/16/2016] [Indexed: 12/29/2022]
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44
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Berezin A. Is the neutrophil extracellular trap-driven microvascular inflammation essential for diabetes vasculopathy? BIOMEDICAL RESEARCH AND THERAPY 2016. [DOI: 10.7603/s40730-016-0021-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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45
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Sørensen OE, Borregaard N. Neutrophil extracellular traps - the dark side of neutrophils. J Clin Invest 2016; 126:1612-20. [PMID: 27135878 DOI: 10.1172/jci84538] [Citation(s) in RCA: 318] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Neutrophil extracellular traps (NETs) were discovered as extracellular strands of decondensed DNA in complex with histones and granule proteins, which were expelled from dying neutrophils to ensnare and kill microbes. NETs are formed during infection in vivo by mechanisms different from those originally described in vitro. Citrullination of histones by peptidyl arginine deiminase 4 (PAD4) is central for NET formation in vivo. NETs may spur formation of autoantibodies and may also serve as scaffolds for thrombosis, thereby providing a link among infection, autoimmunity, and thrombosis. In this review, we present the mechanisms by which NETs are formed and discuss the physiological and pathophysiological consequences of NET formation. We conclude that NETs may be of more importance in autoimmunity and thrombosis than in innate immune defense.
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46
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Hoeksema M, van Eijk M, Haagsman HP, Hartshorn KL. Histones as mediators of host defense, inflammation and thrombosis. Future Microbiol 2016; 11:441-53. [PMID: 26939619 DOI: 10.2217/fmb.15.151] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Histones are known for their ability to bind to and regulate expression of DNA. However, histones are also present in cytoplasm and extracellular fluids where they serve host defense functions and promote inflammatory responses. Histones are a major component of neutrophil extracellular traps that contribute to bacterial killing but also to inflammatory injury. Histones can act as antimicrobial peptides and directly kill bacteria, fungi, parasites and viruses, in vitro and in a variety of animal hosts. In addition, histones can trigger inflammatory responses in some cases acting through Toll-like receptors or inflammasome pathways. Extracellular histones mediate organ injury (lung, liver), sepsis physiology, thrombocytopenia and thrombin generation and some proteins can bind histones and reduce these potentially harmful effects.
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Affiliation(s)
- Marloes Hoeksema
- Department of Medicine, Boston University School of Medicine, Boston, MA, USA.,Department of Infectious Diseases & Immunology, Faculty of Veterinary Medicine, Utrecht University, The Netherlands
| | - Martin van Eijk
- Department of Infectious Diseases & Immunology, Faculty of Veterinary Medicine, Utrecht University, The Netherlands
| | - Henk P Haagsman
- Department of Infectious Diseases & Immunology, Faculty of Veterinary Medicine, Utrecht University, The Netherlands
| | - Kevan L Hartshorn
- Department of Medicine, Boston University School of Medicine, Boston, MA, USA
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47
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Fattahi F, Ward PA. Anti-inflammatory interventions-what has worked, not worked, and what may work in the future. Transl Res 2016; 167:1-6. [PMID: 26323016 PMCID: PMC5062739 DOI: 10.1016/j.trsl.2015.08.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 08/06/2015] [Accepted: 08/07/2015] [Indexed: 12/31/2022]
Abstract
Our Introductory Commentary relates to many topics that are linked to inflammatory responses and how these responses are regulated in order to promote healing of damaged tissues and bring about effective clearance of infectious agents. In non-infectious situations, cells and tissues release products (danger associated molecular patterns) that can trigger damaging inflammatory responses. These products must be effectively dealt with in order to avoid serious tissue injury. We provide a perspective about many decades of research into the inflammatory response and describe strategies that have achieved success in restraining inflammatory responses, as well as many approaches that have not been clinically effective. With development of new technologies such as advanced genomic analysis, highly sensitive and sophisticated mass spectrometry and related approaches, as well as the ability to employ mutagenesis induction, we are beginning to define highly sophisticated molecular pathways that previously were opaque. This progress may well have clinical relevance, and we may be on the edge of a scientific revolution in the broad area of inflammation.
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Affiliation(s)
- Fatemeh Fattahi
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Mich
| | - Peter A Ward
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Mich.
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48
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Roque A, Ponte I, Suau P. Interplay between histone H1 structure and function. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2015; 1859:444-54. [PMID: 26415976 DOI: 10.1016/j.bbagrm.2015.09.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 09/21/2015] [Accepted: 09/22/2015] [Indexed: 01/10/2023]
Abstract
H1 linker histones are involved both in the maintenance of higher-order chromatin structure and in gene regulation. Histone H1 exists in multiple isoforms, is evolutionarily variable and undergoes a large variety of post-translational modifications. We review recent progress in the understanding of the folding and structure of histone H1 domains with an emphasis on the interactions with DNA. The importance of intrinsic disorder and hydrophobic interactions in the folding and function of the carboxy-terminal domain (CTD) is discussed. The induction of a molten globule-state in the CTD by macromolecular crowding is also considered. The effects of phosphorylation by cyclin-dependent kinases on the structure of the CTD, as well as on chromatin condensation and oligomerization, are described. We also address the extranuclear functions of histone H1, including the interaction with the β-amyloid peptide.
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Affiliation(s)
- Alicia Roque
- Departamento de Bioquímica y Biología Molecular, Facultad de Biociencias, Universidad Autónoma de Barcelona, Spain
| | - Inma Ponte
- Departamento de Bioquímica y Biología Molecular, Facultad de Biociencias, Universidad Autónoma de Barcelona, Spain
| | - Pedro Suau
- Departamento de Bioquímica y Biología Molecular, Facultad de Biociencias, Universidad Autónoma de Barcelona, Spain.
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49
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Fuhrmann J, Clancy K, Thompson PR. Chemical biology of protein arginine modifications in epigenetic regulation. Chem Rev 2015; 115:5413-61. [PMID: 25970731 PMCID: PMC4463550 DOI: 10.1021/acs.chemrev.5b00003] [Citation(s) in RCA: 206] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Indexed: 01/10/2023]
Affiliation(s)
- Jakob Fuhrmann
- Department
of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United States
| | - Kathleen
W. Clancy
- Department of Biochemistry and Molecular Pharmacology and Program in Chemical
Biology, University of Massachusetts Medical
School, 364 Plantation
Street, Worcester, Massachusetts 01605, United States
| | - Paul R. Thompson
- Department of Biochemistry and Molecular Pharmacology and Program in Chemical
Biology, University of Massachusetts Medical
School, 364 Plantation
Street, Worcester, Massachusetts 01605, United States
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50
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Slade DJ, Fang P, Dreyton CJ, Zhang Y, Fuhrmann J, Rempel D, Bax BD, Coonrod SA, Lewis HD, Guo M, Gross ML, Thompson PR. Protein arginine deiminase 2 binds calcium in an ordered fashion: implications for inhibitor design. ACS Chem Biol 2015; 10:1043-53. [PMID: 25621824 PMCID: PMC4569063 DOI: 10.1021/cb500933j] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
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Protein
arginine deiminases (PADs) are calcium-dependent histone-modifying
enzymes whose activity is dysregulated in inflammatory diseases and
cancer. PAD2 functions as an Estrogen Receptor (ER) coactivator in
breast cancer cells via the citrullination of histone tail arginine
residues at ER binding sites. Although an attractive therapeutic target,
the mechanisms that regulate PAD2 activity are largely unknown, especially
the detailed role of how calcium facilitates enzyme activation. To
gain insights into these regulatory processes, we determined the first
structures of PAD2 (27 in total), and through calcium-titrations by
X-ray crystallography, determined the order of binding and affinity
for the six calcium ions that bind and activate this enzyme. These
structures also identified several PAD2 regulatory elements, including
a calcium switch that controls proper positioning of the catalytic
cysteine residue, and a novel active site shielding mechanism. Additional
biochemical and mass-spectrometry-based hydrogen/deuterium exchange
studies support these structural findings. The identification of multiple
intermediate calcium-bound structures along the PAD2 activation pathway
provides critical insights that will aid the development of allosteric
inhibitors targeting the PADs.
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Affiliation(s)
- Daniel J. Slade
- Department
of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, United States
- Department
of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, United States
| | - Pengfei Fang
- Department
of Cancer Biology, The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Christina J. Dreyton
- Department
of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, United States
- Department
of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
| | - Ying Zhang
- Department
of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Jakob Fuhrmann
- Department
of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Don Rempel
- Department
of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Benjamin D. Bax
- Molecular
Discovery Research, GlaxoSmithKline, Medicines Research Centre, Gunnels
Wood Road, Stevenage, Herts., SG1 2NY, United Kingdom
| | - Scott A. Coonrod
- Department
of Biomedical Sciences, Baker Institute for Animal Health, Cornell University, Ithaca, New York 14853, United States
| | - Huw D. Lewis
- EpiNova DPU,
Immuno-Inflammation Therapy Area, GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Stevenage, Herts., SG1 2NY, United Kingdom
| | - Min Guo
- Department
of Cancer Biology, The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Michael L. Gross
- Department
of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Paul R. Thompson
- Department
of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, United States
- Department
of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
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