Autophagy generates citrullinated peptides in human synoviocytes: a possible trigger for anti-citrullinated peptide antibodies
| Autor: | Tina Garofalo, Roberta Misasi, Cristina Iannuccelli, Alessandra Nerviani, Manuela Di Franco, Michele Bombardieri, Guido Valesini, Emanuela Lococo, Maurizio Sorice, Valeria Manganelli, Cristiano Alessandri, Antonella Capozzi |
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| Rok vydání: | 2016 |
| Předmět: |
Male
rheumatoid arthritis 0301 basic medicine autophagy citrullination Hydrolases Immunoprecipitation Filaggrin Proteins Peptides Cyclic Protein citrullination Antibodies Arthritis Rheumatoid anti-CCP antibodies 03 medical and health sciences chemistry.chemical_compound Intermediate Filament Proteins Protein-Arginine Deiminase Type 4 Rheumatology Osteoarthritis Citrulline Humans Vimentin Medicine Pharmacology (medical) Cyclic Citrullinated Peptide Antibody Cells Cultured business.industry Autophagy Citrullination PAD Tunicamycin Fibroblasts Middle Aged Synoviocytes Cell biology 030104 developmental biology chemistry Phosphopyruvate Hydratase Immunology Leukocytes Mononuclear Protein-Arginine Deiminases Female business Filaggrin |
| Zdroj: | Rheumatology. 55:1374-1385 |
| ISSN: | 1462-0332 1462-0324 |
| DOI: | 10.1093/rheumatology/kew178 |
| Popis: | Objectives Autophagy may represent a functional processing event that creates a substrate for autoreactivity. In particular, autophagy may play a role in the pathogenesis of RA, since autophagy is a key cellular event involved in the generation of citrullinated peptides, with consequent breakage of tolerance. Thus, in RA, autophagy may be the common feature in several situations (including smoking, joint injury and infection) that may drive the adaptive responses to citrullinated self-proteins. The aim of this study was the analysis, in vitro, of the role of autophagy in the generation of citrullinated peptides and, in vivo, of the relationship between autophagy and the production of anti-CCP antibodies (Abs). Methods For autophagy induction, fibroblast-like synoviocytes, primary fibroblasts and monocytes were stimulated with tunicamycin or rapamycin. Peptidyl arginine deiminase activity was tested by enzyme-linked immunosorbent assay, and protein citrullination was evaluated by western blotting. The main citrullinated RA candidate antigens, vimentin, α-enolase and filaggrin, were demonstrated by immunoprecipitation. The relationship between autophagy and anti-CCP Abs was analysed in 30 early-active RA patients. Results Our results demonstrated in vitro a role for autophagy in the citrullination process. Cells treated with tunicamycin or rapamycin showed peptidyl arginine deiminase 4 activation, with consequent protein citrullination. Immunoblotting and immunoprecipitation experiments, using specific Abs, identified the main citrullinated proteins: vimentin, α-enolase and filaggrin. In vivo, a significant association between levels of autophagy and anti-CCP Abs was observed in treatment-naive early-active RA patients. Conclusion These findings support the view that the processing of proteins in autophagy generates citrullinated peptides recognized by the immune system in RA. |
| Databáze: | OpenAIRE |
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