Control of osteoclast activity and bone loss by IKK subunits: new targets for therapy.

Transcription factor NF-kappaB has been well recognized as a pivotal player in osteclastogenesis and inflammation-induced bone loss. Here, we discuss our recent results obtained using a genetic approach in mice that indicate the importance of IKKbeta, and not IKKalpha, as a transducer of signals from receptor activator of NF-kappaB (RANK) to NF-kappaB. Ablation of IKKbeta results in lack of osteoclastogenesis and unresponsiveness of IKKbeta-deficient mice to inflammation-induced bone loss. In the need of a more effective therapy for the treatment of inflammatory diseases causing bone resorption, specific inhibition of IKKbeta represents a logical alternative strategy to the current therapies.