Bone loss. Factors that regulate osteoclast differentiation: an update.
Osteoclast activation is a critical cellular process for pathological bone resorption, such as erosions in rheumatoid arthritis (RA) or generalized bone loss. Among many factors triggering excessive osteoclast activity, cytokines such as IL-1 or tumour necrosis factor (TNF)-alpha play a central role. New members of the TNF receptor ligand family (namely receptor activator of nuclear factor-kappa B [RANK] and RANK ligand [RANKL]) have been discovered whose cross-interaction is mandatory for the differentiation of osteoclasts from hemopoietic precursors, in both physiological and pathological situations. Osteoprotegerin, a decoy receptor which blocks this interaction, decreases osteoclast activity and could have a fascinating therapeutic potential in conditions associated with upregulated bone resorption.
Roux
S
S
INSERM U349, Lariboisière Hospital, Paris, France.
Orcel
P
P
D002454:Cell Differentiation / Q000502:physiology*; D006801:Humans; D010010:Osteoclasts / Q000473:pathology*; D010024:Osteoporosis / Q000473:pathology* / Q000503:physiopathology