title: The effects of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) on human osteoblast-like cells.
abstract: The activity of human osteoblast-like cells cultured in vitro is regulated by a number of factors, which include systemic hormones as well as agents that can be produced locally within bone. Several cytokines and growth factors have been demonstrated to be produced by osteoblasts themselves, and this includes granulocyte-macrophage colony-stimulating factor (GM-CSF). In this report we show that recombinant human GM-CSF (rhGM-CSF) modulates the activities of osteoblast-like cells derived from human trabecular bone in vitro. rhGM-CSF stimulated the proliferation of the cultured human osteoblast-like cells, but antagonised the induction by 1,25(OH)2D3 of osteocalcin synthesis and alkaline phosphatase activity, two characteristic products of osteoblasts. rhGM-CSF however, had no appreciable effect on the production of prostaglandin E2, or on the plasminogen activator activity associated with human osteoblast-like cells. These results are the first report of which we are aware of an apparently direct action of GM-CSF on cells of the osteoblast phenotype. These studies indicate that GM-CSF represents another haematological factor that can potentially exert regulatory actions on human osteoblast-like cells. GM-CSF may therefore be a potential paracrine/autocrine regulator of osteoblast activity.
authors.affiliation: Department of Human Metabolism and Clinical Biochemistry, University of Sheffield Medical School, UK.
authors.forename: D B
authors.initials: DB
authors.lastname: Evans
authors.forename: R A
authors.initials: RA
authors.lastname: Bunning
authors.forename: R G
authors.initials: RG
authors.lastname: Russell
mesh_terms: D000469:Alkaline Phosphatase / Q000037:antagonists & inhibitors; D002135:Calcium-Binding Proteins / Q000096:biosynthesis; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003115:Colony-Stimulating Factors / Q000494:pharmacology*; D015232:Dinoprostone / Q000096:biosynthesis; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006133:Growth Substances / Q000494:pharmacology*; D006801:Humans; D010006:Osteoblasts / Q000187:drug effects* / Q000201:enzymology / Q000502:physiology; D015675:Osteocalcin; D010960:Plasminogen Activators / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology*
chemical_list: D002135:Calcium-Binding Proteins; D003115:Colony-Stimulating Factors; D006133:Growth Substances; D011994:Recombinant Proteins; D015675:Osteocalcin; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D000469:Alkaline Phosphatase; D010960:Plasminogen Activators; D015232:Dinoprostone