In vivo expression of inflammatory cytokine receptors in the joint compartments of patients with arthritis.
To test a hypothesis of compartmentalized pathogenesis of different types of arthritis, namely inflammatory arthritis (IA) and osteoarthritis (OA), synovial and cartilage biopsies were examined for the expression of TNF and IL-1 receptors. In cartilage, we found constitutive expression of all receptors in normal tissues, and decreased expression of signal-transducing receptors in pathological chondrocytes. In synovium, there was a lower expression of signal-transducing receptors in cases of OA compared to those of IA. In OA, the three signal-transducing receptors were more abundantly expressed in cartilage, while in IA they were mainly present in synovial tissue (TNFRp75 being expressed more than p55). IL-1 decoy receptor type II was low or absent in synovial tissues, but present in cartilage. The increased expression of TNFRp75 and IL-1RI in OA cartilage, compared to IA, in addition to the abundant local cytokine production, strengthens the hypothesis of autocrine/paracrine action by inflammatory cytokines in the pathogenesis of cartilage damage.
Silvestri
Tania
T
Laboratorio di Immunologia e Genetica, Istituto Codivilla-Putti, Istituti Ortopedici Rizzoli, Via di Barbiano 1/10, Bologna, Italy. tsilve@ior.it
Pulsatelli
Lia
L
Dolzani
Paolo
P
Frizziero
Luigi
L
Facchini
Andrea
A
Meliconi
Riccardo
R
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000378:metabolism* / Q000473:pathology; D002358:Cartilage, Articular / Q000378:metabolism* / Q000473:pathology; D019902:Chondrocytes / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000378:metabolism* / Q000473:pathology; D017472:Receptors, Interleukin-1 / Q000378:metabolism*; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D013583:Synovial Membrane / Q000378:metabolism* / Q000473:pathology
D017472:Receptors, Interleukin-1; D018124:Receptors, Tumor Necrosis Factor