TRAIL is involved in human osteoclast apoptosis.

Control of osteoclast (OC) apoptosis has been recognized as a critical regulatory factor in bone remodeling. TRAIL, a member of the TNF superfamily, induces apoptosis in neoplastic and normal cells. However, few data are available on the effects of TRAIL on bone cells, thus in the present study we investigated TRAIL role on the apoptosis of human mature OCs. We show that TRAIL treatment causes reduced cell viability, loss of nuclei integrity, and derangement of the actin microfilament in OCs. We also demonstrated that the death receptor DR5, upregulated by TRAIL, could be the mediator of TRAIL-induced OC apoptosis.