Arthritogenicity of annexin VII revealed by phosphoproteomics of rheumatoid synoviocytes.

Objective: To identify novel proteins involved in the pathogenesis of rheumatoid arthritis (RA) and to characterise the identified proteins based on pathogenic and therapeutic aspects.

Methods: The authors applied differential phosphoproteomic analysis to articular synoviocytes between RA and osteoarthritis (OA) to identify proteins differently phosphorylated between RA and OA. Focusing on annexin VII (Anx7), one of the highly phosphorylated proteins in RA, the authors prepared Anx7-transgenic C57BL/6 (Anx7-Tg-B6) mice to evaluate their susceptibility to collagen-induced arthritis (CIA).

Identification of novel citrullinated autoantigens of synovium in rheumatoid arthritis using a proteomic approach.

Recently, autoantibodies to some citrullinated autoantigens have been reported to be specific for rheumatoid arthritis (RA). However, an entire profile of and autoimmunity of the citrullinated proteins have been poorly understood. To understand the profile, we examined citrullinated autoantigens by a proteomic approach and further investigated the significance of citrullination in antigenicity of one of the autoantigens.

Regulatory role of heme oxygenase 1 in inflammation of rheumatoid arthritis.

Objective: To examine the expression and pathogenetic roles of heme oxygenase 1 (HO-1), an inducible heme-degrading enzyme with antiinflammatory properties, in rheumatoid arthritis (RA).

Methods: HO-1 expression in synovial tissue from patients with RA, patients with osteoarthritis, and patients with noninflammatory joint diseases was determined by immunoblotting and immunohistochemistry. Effects of various agents, such as hemin (a chemical inducer of HO-1), small interfering RNA (siRNA) specific for HO-1, HO-1 expression vector, and antirheumatic agents, on HO-1 expression in RA synovial cell lines were analyzed by real-time reverse transcription-polymerase chain reaction (PCR) and immunoblotting.