To examine the relationship between the expression of c-Fos and c-Jun proteins and the
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.
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 both 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 expression of c-Fos and c-Jun proteins when compared with healthy donors.
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, may be related to disturbances in c-Fos and c-Jun protein expression. This dysfunction seems to be compensated by some unknown mechanisms implicated in LPS signalling, which is known to involve not only the PKC-mediated pathway.