title: Dexamethasone in osteogenic medium strongly induces adipocyte differentiation of mouse bone marrow stromal cells and increases osteoblast differentiation.
abstract: BACKGROUND
  Osteoblasts and adipocytes share a common mesenchymal stem cell origin. Therefore, it has been suggested that the accumulation of marrow adipocytes observed in bone loss is caused by a shift in the commitment of mesenchymal stem cells from the osteogenic pathway to the adipogenic pathway. Supporting this hypothesis the competition between adipogenic and osteogenic lineages was widely demonstrated on partially homogeneous cell populations. However, some data from mouse models showed the existence of an independent relationship between bone mineral content and bone marrow adiposity. Therefore, the combination of adipogenesis and osteogenesis in primary culture would be helpful to determine if this competition would be observed on a whole bone marrow stromal cell population in a culture medium allowing both lineages. In this aim, mouse bone marrow stromal cells were cultured in a standard osteogenic medium added with different concentrations of Dexamethasone, known to be an important regulator of mesenchymal progenitor cell differentiation.
  
  
  RESULTS
  Gene expression of osteoblast and adipocyte markers, biochemical and physical analyses demonstrated the presence of both cell types when Dexamethasone was used at 100 nM. Overall, our data showed that in this co-differentiation medium both differentiation lineages were enhanced compared to classical adipogenic or osteogenic culture medium. This suggests that in this model, adipocyte phenotype does not seem to increase at the expense of the osteoblast lineage.
  
  
  CONCLUSIONS
  This model appears to be a promising tool to study osteoblast and adipocyte differentiation capabilities and the interactions between these two processes.
authors.affiliation: Lille2-ULCO, PMOI, F-62200, Boulogne-sur-Mer, France. olfa.ghali@univ-littoral.fr.
authors.forename: Olfa
authors.initials: O
authors.lastname: Ghali
authors.affiliation: Lille2-ULCO, PMOI, F-62200, Boulogne-sur-Mer, France. odile.broux@univ-littoral.fr.
authors.forename: Odile
authors.initials: O
authors.lastname: Broux
authors.affiliation: Lille2-ULCO, PMOI, F-62200, Boulogne-sur-Mer, France. guillaume.falgayrac@univ-lille2.fr.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Falgayrac
authors.affiliation: Lille2-ULCO, PMOI, F-62200, Boulogne-sur-Mer, France. nathalie.haren@univ-littoral.fr.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Haren
authors.affiliation: Department of Internal Medicine, Erasmus MC, 3000 CA, Rotterdam, The Netherlands. j.vanleeuwen@erasmusmc.nl.
authors.forename: Johannes P T M
authors.initials: JP
authors.lastname: van Leeuwen
authors.affiliation: Lille2-ULCO, PMOI, F-62200, Boulogne-sur-Mer, France. guillaume.penel@univ-lille2.fr.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Penel
authors.affiliation: Lille2-ULCO, PMOI, F-62200, Boulogne-sur-Mer, France. pierre.hardouin@univ-littoral.fr.
authors.forename: Pierre
authors.initials: P
authors.lastname: Hardouin
authors.affiliation: Lille2-ULCO, PMOI, F-62200, Boulogne-sur-Mer, France. christophe.chauveau@univ-littoral.fr.|PMOI, ULCO, Boulevard Napoléon, BP 120, 62327, Boulogne-sur-mer, Cedex, France. christophe.chauveau@univ-littoral.fr.
authors.forename: Christophe
authors.initials: C
authors.lastname: Chauveau
mesh_terms: D017667:Adipocytes / Q000166:cytology* / Q000378:metabolism; D050156:Adipogenesis / Q000187:drug effects; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D001854:Bone Marrow Cells / Q000166:cytology; D002454:Cell Differentiation / Q000187:drug effects*; D019070:Cell Lineage; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics / Q000378:metabolism; D017077:Culture Media, Conditioned / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology*; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism; D015675:Osteocalcin / Q000235:genetics / Q000378:metabolism; D010012:Osteogenesis / Q000187:drug effects
chemical_list: D000893:Anti-Inflammatory Agents; D050659:Core Binding Factor Alpha 1 Subunit; D017077:Culture Media, Conditioned; C493716:Runx2 protein, mouse; D015675:Osteocalcin; D003907:Dexamethasone