Nuclear factor κB (NF-κB) pathway as a therapeutic target in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by persistent joint swelling and progressive destruction of cartilage and bone. Current RA treatments are largely empirical in origin and their precise mechanism of action is uncertain. Increasing evidence shows that chronic inflammatory diseases such as RA are caused by prolonged production of proinflammatory cytokines including tumor necrosis factor (TNF) and interleukin 1 (IL-1). The nuclear factor κB (NF-κB) plays an essential role in transcriptional activation of TNF and IL-1. NF-κB is induced by many stimuli including TNF and IL-1, forming a positive regulatory cycle that may amplify and maintain RA disease process. NF-κB and enzymes involved in its activation can be a target for anti-inflammatory treatment. Aspirin and sodium salicylate inhibit activation of NF-κB by blocking IκB kinase, a key enzyme in NF-κB activation. Glucocorticoids suppress expression of inflammatory genes by binding glucocorticoid receptor with NF-κB, and increasing expression of inhibitory protein of NF-κB, IκBα. Sulfasalazine and gold compounds also inhibit NF-κB activation. Continuing advances in our understanding of action mechanism of antirheumatic agents will benefit the future development of RA regimens with greater efficacy and less toxicity.