title: Differentiation potential of conditionally immortalized mesenchymal progenitor cells from adult marrow of a H-2Kb-tsA58 transgenic mouse.
abstract: Primary cultures were initiated from marrow, spleen, and bone explants of an adult H-2Kb-tsA58 transgenic mouse (immortomouse). All cultures were initiated in immortalizing conditions, and an additional marrow culture was first incubated for 1 week in standard conditions and then switched to immortalizing conditions. Marrow cells immediately immortalized were designated the marrow immediate population (MIP); those immortalized after 1 week were termed the marrow delayed population (MDP). MIP and MDP cells both contained a mixture of fibroblastic or flattened cells, and the MIP cells contained an additional subpopulation of adipocytic (Oil Red-O positive) cells. Alkaline phosphatase expression was induced by dexamethasone (10(-7) M) in MDP cells while MIP, spleen, and bone explant cells had only a low level of expression. MDP and MIP cells differentiated into bone when combined with porous calcium phosphate ceramics and implanted subcutaneously into nude mice while bone- and spleen-derived cells did not. Clones were isolated from the MDP and MIP cell populations and tested for differentiated phenotypes. Some MIP-derived clones exhibited adipocytic characteristics while MDP-derived subclones were negative. Histologic examination of porous ceramic implanted clones showed that all of the clones had osteogenic potential. Clones exposed to either dexamethasone, human recombinant bone morphogenetic protein-2, or horse serum plus hydrocortisone showed differences in expression of adipocytic or osteogenic markers. These immortalized cultures have retained both adipocytic and osteogenic potential even after 1 year of continuous culture, and provide a model system for clonal analysis of the developmental potential of marrow-derived mesenchymal precursor cells.
authors.affiliation: Department of Biology, Case Western Reserve University, Cleveland, Ohio 44106, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Dennis
authors.forename: A I
authors.initials: AI
authors.lastname: Caplan
mesh_terms: D017667:Adipocytes / Q000166:cytology; D000469:Alkaline Phosphatase / Q000096:biosynthesis; D000818:Animals; D001853:Bone Marrow / Q000378:metabolism; D001854:Bone Marrow Cells; D019485:Bone Morphogenetic Proteins; D002454:Cell Differentiation; D002455:Cell Division / Q000187:drug effects / Q000235:genetics; D048429:Cell Size; D002478:Cells, Cultured; D002999:Clone Cells / Q000378:metabolism; D003907:Dexamethasone / Q000494:pharmacology; D008648:Mesoderm / Q000166:cytology; D051379:Mice; D008822:Mice, Transgenic; D010012:Osteogenesis; D011506:Proteins / Q000494:pharmacology; D011994:Recombinant Proteins / Q000494:pharmacology; D013154:Spleen / Q000166:cytology / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism
chemical_list: D019485:Bone Morphogenetic Proteins; D011506:Proteins; D011994:Recombinant Proteins; D003907:Dexamethasone; D000469:Alkaline Phosphatase