Document Detail


DEK in the synovium of patients with juvenile idiopathic arthritis: characterization of DEK antibodies and posttranslational modification of the DEK autoantigen.
MedLine Citation:
PMID:  21280010     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVE: DEK is a nuclear phosphoprotein and autoantigen in a subset of children with juvenile idiopathic arthritis (JIA). Autoantibodies to DEK are also found in a broad spectrum of disorders associated with abnormal immune activation. We previously demonstrated that DEK is secreted by macrophages, is released by apoptotic T cells, and attracts leukocytes. Since DEK has been identified in the synovial fluid (SF) of patients with JIA, this study was undertaken to investigate how DEK protein and/or autoantibodies may contribute to the pathogenesis of JIA.
METHODS: DEK autoantibodies, immune complexes (ICs), and synovial macrophages were purified from the SF of patients with JIA. DEK autoantibodies and ICs were purified by affinity-column chromatography and analyzed by 2-dimensional gel electrophoresis, immunoblotting, and enzyme-linked immunosorbent assay. DEK in supernatants and exosomes was purified by serial centrifugation and immunoprecipitation with magnetic beads, and posttranslational modifications of DEK were identified by nano-liquid chromatography tandem mass spectrometry (nano-LC-MS/MS).
RESULTS: DEK autoantibodies and protein were found in the SF of patients with JIA. Secretion of DEK by synovial macrophages was observed both in a free form and via exosomes. DEK autoantibodies (IgG2) may activate the complement cascade, primarily recognize the C-terminal portion of DEK protein, and exhibit higher affinity for acetylated DEK. Consistent with these observations, DEK underwent acetylation on an unprecedented number of lysine residues, as demonstrated by nano-LC-MS/MS.
CONCLUSION: These results indicate that DEK can contribute directly to joint inflammation in JIA by generating ICs through high-affinity interaction between DEK and DEK autoantibodies, a process enhanced by acetylation of DEK in the inflamed joint.
Authors:
Nirit Mor-Vaknin; Ferdinand Kappes; Amalie E Dick; Maureen Legendre; Catalina Damoc; Seagal Teitz-Tennenbaum; Roland Kwok; Elisa Ferrando-May; Barbara S Adams; David M Markovitz
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Arthritis and rheumatism     Volume:  63     ISSN:  1529-0131     ISO Abbreviation:  Arthritis Rheum.     Publication Date:  2011 Feb 
Date Detail:
Created Date:  2011-01-31     Completed Date:  2011-03-08     Revised Date:  2012-04-27    
Medline Journal Info:
Nlm Unique ID:  0370605     Medline TA:  Arthritis Rheum     Country:  United States    
Other Details:
Languages:  eng     Pagination:  556-67     Citation Subset:  AIM; IM    
Copyright Information:
Copyright © 2011 by the American College of Rheumatology.
Affiliation:
University of Michigan, Ann Arbor, MI 48109-5640, USA. morvak@umich.edu
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Acetylation
Antigen-Antibody Complex / immunology,  metabolism
Arthritis, Juvenile Rheumatoid / immunology,  metabolism*,  pathology
Autoantibodies / blood
Autoantigens / immunology,  metabolism*
Child
Chromosomal Proteins, Non-Histone / immunology,  metabolism*
Humans
Joints / metabolism,  pathology
Macrophages / metabolism,  pathology
Oncogene Proteins / immunology,  metabolism*
Protein Processing, Post-Translational*
Synovial Fluid / chemistry,  metabolism
Synovial Membrane / metabolism*,  pathology
Grant Support
ID/Acronym/Agency:
5-P30-AR-048310-07/AR/NIAMS NIH HHS; K01 AR055620-01A2/AR/NIAMS NIH HHS; K01-AR-055620/AR/NIAMS NIH HHS; P30 AR048310-07/AR/NIAMS NIH HHS; R01 AI062248-05/AI/NIAID NIH HHS; R01 AI087128-01/AI/NIAID NIH HHS; R01 DK067102-01A3/DK/NIDDK NIH HHS; R01-AI-062248/AI/NIAID NIH HHS; R01-AI-087128/AI/NIAID NIH HHS; R01-DK-067102/DK/NIDDK NIH HHS; R03 AR056748-01/AR/NIAMS NIH HHS; R03-AR-056748-01/AR/NIAMS NIH HHS; T32 CA088784-03/CA/NCI NIH HHS; T32-CA-88784-03/CA/NCI NIH HHS; UL1 RR024986-02/RR/NCRR NIH HHS; UL1-RR-024986/RR/NCRR NIH HHS
Chemical
Reg. No./Substance:
0/Antigen-Antibody Complex; 0/Autoantibodies; 0/Autoantigens; 0/Chromosomal Proteins, Non-Histone; 0/Dek protein, human; 0/Oncogene Proteins

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Anakinra as first-line disease-modifying therapy in systemic juvenile idiopathic arthritis: Report o...
Next Document:  The molecular structure and solution conformation of an acidic heteropolysaccharide from Auricularia...