title: Expression of the anaphylatoxin receptor C5aR (CD88) by human articular chondrocytes.
abstract: Although the complement system is implicated in the inflammatory process in arthritic diseases, a direct interaction between chondrocytes and complement has not been demonstrated. In this study, we investigated expression of the C5a receptor (C5aR) on chondrocytes of cartilage from patients with rheumatoid arthritis (RA), osteoarthritis (OA), and bone fracture as normal controls by reverse transcriptase polymerase chain reaction (RT-PCR), flow cytometry, and immunohistochemistry. The RT-PCR detected mRNA for C5aR in most or all of the tested samples (73% in OA, 100% in RA, 89% in normal). The FACS analysis revealed different expression ratios between individuals varying from 0.7% to 77.1%; however, expression ratios of C5aR were significantly higher in RA than in controls (26.0% in RA, 9.0% in OA, 6.9% in normal). The expression of C5aR was upregulated significantly by addition of IL-1beta in RA and normal samples but not in OA. In addition, the C5aR-positive chondrocytes were confirmed by immunohistochemistry. In conclusion, expression of C5aR and the effect of IL-1beta on the expression were different between RA and OA. The C5aR may contribute to chondrocyte metabolism and the pathogenesis of arthritis differently between in RA and OA.
authors.affiliation: Department of Orthopedic Surgery, St. Marianna University School of Medicine, 2-16-1 Sugao, Kawasaki-shi, Kanagawa, 216-8511, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Onuma
authors.forename: Kayo
authors.initials: K
authors.lastname: Masuko-Hongo
authors.forename: Guohua
authors.initials: G
authors.lastname: Yuan
authors.forename: Masahiro
authors.initials: M
authors.lastname: Sakata
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakamura
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Kato
authors.forename: Haruhito
authors.initials: H
authors.lastname: Aoki
authors.forename: Kusuki
authors.initials: K
authors.lastname: Nishioka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000096:biosynthesis* / Q000235:genetics; D001172:Arthritis, Rheumatoid / Q000378:metabolism / Q000473:pathology; D002358:Cartilage, Articular / Q000166:cytology*; D019902:Chondrocytes / Q000187:drug effects / Q000378:metabolism*; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D007375:Interleukin-1 / Q000494:pharmacology; D008875:Middle Aged; D010003:Osteoarthritis / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics; D044087:Receptor, Anaphylatoxin C5a; D011951:Receptors, Complement / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation
chemical_list: D015703:Antigens, CD; D007375:Interleukin-1; D012333:RNA, Messenger; D044087:Receptor, Anaphylatoxin C5a; D011951:Receptors, Complement