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Various secretory phospholipase A 2 enzymes are expressed in rheumatoid arthritis and augment prostaglandin production in cultured synovial cells
Author(s) -
Masuda Seiko,
Murakami Makoto,
Komiyama Kazuo,
Ishihara Motoko,
Ishikawa Yukio,
Ishii Toshiharu,
Kudo Ichiro
Publication year - 2005
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2004.04489.x
Subject(s) - prostaglandin e2 , synovial fluid , phospholipase a2 , prostaglandin , chemistry , biology , immunology , endocrinology , medicine , pathology , osteoarthritis , enzyme , biochemistry , alternative medicine
Although group IIA secretory phospholipase A 2 (sPLA 2 ‐IIA) is known to be abundantly present in the joints of patients with rheumatoid arthritis (RA), expression of other sPLA 2 s in this disease has remained unknown. In this study, we examined the expression and localization of six sPLA 2 s (groups IIA, IID, IIE, IIF, V and X) in human RA. Immunohistochemistry of RA sections revealed that sPLA 2 ‐IIA was generally located in synovial lining and sublining cells and cartilage chondrocytes, sPLA 2 ‐IID in lymph follicles and capillary endothelium, sPLA 2 ‐IIE in vascular smooth muscle cells, and sPLA 2 ‐V in interstitial fibroblasts. Expression levels of these group II subfamily sPLA 2 s appeared to be higher in severe RA than in inactive RA. sPLA 2 ‐X was detected in synovial lining cells and interstitial fibers in both active and inactive RA sections. Expression of sPLA 2 ‐IIF was partially positive, yet its correlation with disease states was unclear. Expression of sPLA 2 transcripts was also evident in cultured normal human synoviocytes, in which sPLA 2 ‐IIA and ‐V were induced by interleukin‐1 and sPLA 2 ‐X was expressed constitutively. Adenovirus‐mediated expression of sPLA 2 s in cultured synoviocytes resulted in increased prostaglandin E 2 production at low ng·mL −1 concentrations. Thus, multiple sPLA 2 s are expressed in human RA, in which they may play a role in the augmentation of arachidonate metabolism or exhibit other cell type‐specific functions.