MODIFIED EXPRESSION OF C-FOS AND C-JUN PROTEINS AND PRODUCTION OF INTERLEUKIN-1-BETA IN PATIENTS WITH RHEUMATOID-ARTHRITIS

Objective. To examine the relationship between the expression of c-Fos and c-Jun proteins and the production of IL-1 beta in the PBMC of RA patients. Methods. The expression of c-Fos and c-Jun proteins and the production of IL-1 beta in the PBMC of 11 patients with active RA was determine by Western blots and ELISA techniques, respectively. Results . The spontaneous expression of c-Fos protein and the production of IL -1 beta was higher in RA patients. Under LPS treatment, the PBMC of bo th RA patients and healthy subjects produced similar high levels of IL -1 beta without any significant changes in the expression of c-Fos and c-Jun proteins. By contrast, PMA-induced production of IL-1 beta was impaired in RA patients and was preceded by the disregulated expressio n of c-Fos and c-Jun proteins when compared with healthy donors. Concl usion. It can be postulated that in some RA patients the spontaneously high production of IL-1 beta may be associated with the up-regulated expression of c-Fos protein in PBMC. On the other hand the impairment of IL-1 beta production in RA induced by the PKC-dependent pathway, ma y be related to disturbances in c-Fos and c-Jun protein expression. Th is dysfunction seems to be compensated by some unknown mechanisms impl icated in LPS signalling which is known to involve not only the PKC-me diated pathway.