RT Journal Article
SR Electronic
T1 Enhanced local production of osteopontin in rheumatoid joints.
JF The Journal of Rheumatology
JO J Rheumatol
FD The Journal of Rheumatology
SP 2061
OP 2067
VO 29
IS 10
A1 Shiro Ohshima
A1 Norihiko Yamaguchi
A1 Katsuhiro Nishioka
A1 Toru Mima
A1 Taeko Ishii
A1 Mitsuko Umeshita-Sasai
A1 Hideyuki Kobayashi
A1 Masatoshi Shimizu
A1 Yoshinori Katada
A1 Shigeyuki Wakitani
A1 Norikazu Murata
A1 Shintaro Nomura
A1 Hiroaki Matsuno
A1 Rie Katayama
A1 Shigeyuki Kon
A1 Manabu Inobe
A1 Toshimitsu Uede
A1 Ichiro Kawase
A1 Yukihiko Saeki
YR 2002
UL http://www.jrheum.org/content/29/10/2061.abstract
AB OBJECTIVE: To investigate the involvement of osteopontin (OPN) in the pathogenesis of rheumatoid arthritis (RA), localization and production of OPN were examined in patients with RA. METHODS: Localization of OPN in the rheumatoid synovium was examined by immunohistochemistry. In vitro OPN production by cultured synovial cells from patients with RA (n = 5) and with osteoarthritis (OA) (n = 5) was assessed by ELISA. OPN concentrations in plasma and synovium were quantified in patients with RA (n = 23) by 2 distinct ELISA systems to measure both thrombin cleaved and non-cleaved OPN. The same experiments were done in patients with OA (n = 15) and healthy volunteers (n = 10) as a control. RESULTS: OPN was highly detected by immunohistochemistry predominantly in the RA synovial lining cells, while less and scattered OPN was detected in OA synovial tissues. ELISA revealed that cultured RA synovial cells secreted significantly more OPN than OA cells. ELISA also showed a marked increase of OPN levels in synovial fluid (SF) of patients with RA and with OA compared to the control plasma OPN levels, although OPN levels were not increased in RA and OA plasma compared to healthy controls. SF OPN levels of patients with RA were significantly higher than those of patients with OA, and correlated with serum C-reactive protein levels. The ratios of thrombin cleaved versus non-cleaved OPN were significantly increased in RA plasma and SF compared with OA plasma and SF and plasma from healthy controls. CONCLUSION: Our results revealed enhanced local production of OPN in rheumatoid joints, suggesting involvement of OPN in the pathogenesis of RA.