J Rheumatol
-
To determine the effects of synovial fluids (SF) on DNA binding activity of transcription factor nuclear factor-kappaB (NF-kappaB) in the Mono Mac 6 monocytic/macrophage cell line as a model for the interaction between SF and synovial tissue macrophages in arthritis. ⋯ Biological activity of TNF-alpha in SF from RA and OA subjects is capable of inducing p65/p50 NF-kappaB DNA binding activity in macrophages. A property of SF that is independent of TNF-alpha and other cytokines is responsible for the induction of a novel slowly migrating NF-kappaB-binding complex. Soluble mediators in SF of subjects with RA and OA can therefore modulate binding of nuclear proteins to the NF-kappaB binding site in macrophages and may play a role in inflammatory gene expression in arthritis.