title: Current insights into the role of transforming growth factor-beta in bone resorption.
abstract: Transforming growth factor-beta (TGF-beta) elicits a variety of effects on cellular proliferation and differentiation. The major repository for TGF-beta is bone, where it possesses separate facilitative and suppressive actions on osteoclast differentiation and bone resorption. Without a direct enabling stimulus from TGF-beta monocytes cannot form osteoclasts but instead follow macrophage differentiation pathways. This facilitative action depends on an ability to promote a state in which precursors are resistant to anti-osteoclastic inflammatory signals. Following the initiation of resorption TGF-beta is released from bone matrix. This acts on osteoblasts to reduce the availability of the osteoclast differentiation factor, RANKL (receptor activator of NFkappaB ligand) and thereby indirectly limits further osteoclast formation. Thus TGF-beta has a fundamental role in the control of bone resorption having actions that first allow monocytes to develop into osteoclasts then subsequently limiting the extent and duration of resorption after its release from the bone matrix.
authors.affiliation: Ecotoxicology and Stress Biology Research Group, Room A413 Portland Square, School of Biological Science, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK. simon.fox@plymouth.ac.uk
authors.forename: Simon W
authors.initials: SW
authors.lastname: Fox
authors.forename: Alison C
authors.initials: AC
authors.lastname: Lovibond
mesh_terms: D000818:Animals; D001862:Bone Resorption / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism; D002454:Cell Differentiation; D006801:Humans; D008562:Membrane Glycoproteins / Q000378:metabolism; D009000:Monocytes / Q000378:metabolism / Q000473:pathology; D010006:Osteoblasts / Q000378:metabolism; D010010:Osteoclasts / Q000378:metabolism / Q000473:pathology; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D015398:Signal Transduction; D016212:Transforming Growth Factor beta / Q000502:physiology*
chemical_list: D002352:Carrier Proteins; D008562:Membrane Glycoproteins; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; C505686:TNFRSF11A protein, human; C505688:TNFSF11 protein, human; D016212:Transforming Growth Factor beta