Citrullination of synovial proteins in murine models of rheumatoid arthritis

作者：Erik R Vossenaar, Suzanne Nijenhuis, Monique M. Helsen, Annemarie van der Heijden, Tatsuo Senshu, Wim B. van den Berg, Walther J. van Venrooij, Leo A. B. Joosten · 发表于：Arthritis & Rheumatism · 年份：2003 · DOI：10.1002/art.11229 · 被引用次数：244 · 研究领域：Rheumatoid Arthritis Research and Therapies、Interstitial Lung Diseases and Idiopathic Pulmonary Fibrosis、Immunotoxicology and immune responses

OBJECTIVE: Antibodies directed to citrulline-containing proteins are highly specific for rheumatoid arthritis (RA) and can be detected in up to 80% of patients with RA. Citrulline is a nonstandard amino acid that can be incorporated into proteins only by posttranslational modification of arginine by peptidylarginine deiminase (PAD) enzymes. The objective of this study was to investigate the presence of anticitrulline antibodies, PAD enzymes, and citrullinated antigens in mouse models of both acute and chronic destructive arthritis: streptococcal cell wall (SCW)-induced arthritis and collagen-induced arthritis (CIA), respectively. METHODS: Synovial tissue biopsy specimens were obtained from naive mice, mice with CIA, and mice with SCW-induced arthritis. The expression of messenger RNA (mRNA) for PAD enzymes was analyzed by reverse transcriptase-polymerase chain reaction; the presence of PAD proteins and their products (citrullinated proteins) was analyzed by Western blotting and by immunolocalization. The presence of anticitrullinated protein antibodies was investigated by an anti-cyclic citrullinated peptide (anti-CCP) enzyme-linked immunosorbent assay (ELISA) and an ELISA using in vitro citrullinated fibrinogen. RESULTS: In both mouse models, PAD type 2 (PAD2) mRNA was present in the synovium but was not translated into PAD2 protein. In contrast, PAD4 mRNA, although absent from healthy synovium, was readily transcribed and translated by polymorphonuclear neutrophils infiltra...