title: Conditions that support long-term production of osteoclast progenitors in vitro.
abstract: To better understand the mechanisms of osteoclast precursor development from hematopoietic stem cells, we examined the conditions that support the production of osteoclast progenitors, osteoclast colony-forming units (CFU-O), from long-term bone marrow cultures established under myeloid (Dexter's) and lymphoid (Whitlock and Witte's) conditions. Nonadherent cells harvested weekly from myeloid or lymphoid long-term cultures were assayed for CFU-O-derived colony formation in agar in the presence of a murine osteoclast colony-stimulating factor. The myeloid system supported CFU-O production for weeks, but the system produced many other types of myeloid colonies and cells as well, and quantification of CFU-O-derived colonies was difficult. The lymphoid long-term culture system also produced CFU-O; however, CFU-O production in the lymphoid system appeared more selective than in the myeloid system, but was transient. Interestingly, the addition of medium containing G-CSF to these cultures greatly enhanced (> 200%) the CFU-O production. This enhanced CFU-O production was confirmed using bone marrow cultures established on a defined marrow stromal cell line under lymphoid conditions and supplemented with recombinant murine G-CSF. Thus, G-CSF facilitates the development of clonogenic osteoclast progenitors from hematopoietic stem cells in lymphoid long-term culture conditions. This culture system may serve as a useful model for ex vivo generation of osteoclast progenitors.
authors.affiliation: Department of Biological Structure, University of Washington School of Medicine, Seattle 98195, USA.
authors.forename: M Y
authors.initials: MY
authors.lastname: Lee
authors.forename: K L
authors.initials: KL
authors.lastname: Fevold
authors.forename: Y
authors.initials: Y
authors.lastname: Muguruma
authors.forename: J L
authors.initials: JL
authors.lastname: Lottsfeldt
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology; D002478:Cells, Cultured / Q000187:drug effects; D003114:Colony-Forming Units Assay; D003115:Colony-Stimulating Factors / Q000494:pharmacology; D017077:Culture Media, Conditioned / Q000737:chemistry / Q000494:pharmacology; D005260:Female; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects*; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008815:Mice, Inbred Strains; D010010:Osteoclasts / Q000166:cytology / Q000187:drug effects*; D017154:Stromal Cells; D013997:Time Factors
chemical_list: D003115:Colony-Stimulating Factors; D017077:Culture Media, Conditioned; D016179:Granulocyte Colony-Stimulating Factor; D016173:Macrophage Colony-Stimulating Factor