title: Macrophage colony stimulating factor (M-CSF) is essential for osteoclast formation in vitro.
abstract: The op/op mouse, in which the M-CSF gene is mutated, has greatly reduced numbers of macrophages and osteoclasts. We assessed the ability of M-CSF to induce osteoclast and macrophage formation in op/op hemopoietic cells in vitro. Osteoclast production was undetectable in op/op cell cultures, but was restored by M-CSF at concentrations approximately an order of magnitude higher than those that induced macrophages. In normal hemopoietic tissue M-CSF similarly increased macrophage numbers, but inhibited osteoclast formation. Despite cure of the macrophage defect, neither interleukin 3 nor granulocyte-macrophage CSF were able to induce osteoclastic differentiation in op/op cells. The results suggest that M-CSF induces osteoclastic differentiation but that macrophages, which are also induced by M-CSF, suppress osteoclast differentiation. Macrophages induced by other cytokines seem unable to contribute to osteoclast-formation.
authors.affiliation: Dept. of Histopathology, St George's Hospital Medical School, London, UK.
authors.forename: G
authors.initials: G
authors.lastname: Hattersley
authors.forename: J
authors.initials: J
authors.lastname: Owens
authors.forename: A M
authors.initials: AM
authors.lastname: Flanagan
authors.forename: T J
authors.initials: TJ
authors.lastname: Chambers
mesh_terms: D000818:Animals; D002117:Calcitriol / Q000494:pharmacology; D002450:Cell Communication; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects; D007377:Interleukin-3 / Q000494:pharmacology; D007700:Kinetics; D016173:Macrophage Colony-Stimulating Factor / Q000235:genetics / Q000494:pharmacology*; D008264:Macrophages / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D051379:Mice; D008817:Mice, Mutant Strains; D010010:Osteoclasts / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D013154:Spleen / Q000166:cytology / Q000187:drug effects / Q000502:physiology
chemical_list: D007377:Interleukin-3; D016173:Macrophage Colony-Stimulating Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D002117:Calcitriol