Regulatory role of heme oxygenase 1 in inflammation of rheumatoid arthritis
Article first published online: 29 MAR 2006
Copyright © 2006 by the American College of Rheumatology
Arthritis & Rheumatism
Volume 54, Issue 4, pages 1132–1142, April 2006
How to Cite
Kobayashi, H., Takeno, M., Saito, T., Takeda, Y., Kirino, Y., Noyori, K., Hayashi, T., Ueda, A. and Ishigatsubo, Y. (2006), Regulatory role of heme oxygenase 1 in inflammation of rheumatoid arthritis. Arthritis & Rheumatism, 54: 1132–1142. doi: 10.1002/art.21754
- Issue published online: 29 MAR 2006
- Article first published online: 29 MAR 2006
- Manuscript Accepted: 5 JAN 2006
- Manuscript Received: 19 MAY 2005
- Yokohama City University Center of Excellence Program of the Ministry of Education, Culture, Sports, Science and Technology of Japan
- Ministry of Health, Labour, and Welfare
- Ministry of Education, Culture, Sports, and Technology of Japan. Grant Number: 16590991
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).
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. Cytokine synthesis was evaluated by real-time PCR and enzyme-linked immunosorbent assay.
HO-1 was expressed more abundantly in the lesions of synovial tissue from patients with RA than in those from the other patient groups. Hemin, auranofin, and HO-1 expression vector induced HO-1 and reduced expression of tumor necrosis factor α (TNFα) messenger RNA, lipopolysaccharide (LPS)–induced secretion of interleukin-6 (IL-6) and IL-8, and expression of cyclooxygenase 2 in the synovial cell lines. Treatment with HO-1–specific siRNA augmented the synthesis of TNFα, IL-6, and IL-8 and canceled the suppressive effects of auranofin on TNFα secretion. When hemoglobin, as a scavenger of carbon monoxide, was added to auranofin-treated synovial cell lines, LPS-dependent production of IL-6 and IL-8 was increased.
Our data demonstrate that HO-1 is expressed in RA synovial tissues and plays a regulatory role in the development of inflammation. The pharmacologic effects of auranofin depend, in part, on the levels of HO-1, suggesting that HO-1 induction is a novel therapeutic strategy for RA.