title: The influence of conditioned medium from mouse intestinal epithelial cells on the proliferative activity of crypt cells: role of granulocyte-macrophage colony-stimulating factor.
abstract: BACKGROUND
  The aim of this work was to study the influence of soluble factors produced by native mouse intestinal epithelial cells (IECs) on the proliferative activity of freshly isolated intestinal crypt cells.
  
  
  METHODS
  The crypt cells were cultured with either conditioned medium and its ultrafiltrates or recombinant mouse granulocyte-macrophage colony-stimulating factor (GM-CSF) in the presence or absence of neutralizing anti-GM-CSF antibodies. GM-CSF in culture medium was identified by the electrochemiluminescence method.
  
  
  RESULTS
  It was demonstrated that the IEC conditioned medium contained GM-CSF. This cytokine led to both the upregulation and downregulation of crypt cell proliferative activity, depending on its concentration in the culture medium. The effect of native GM-CSF was reproduced with recombinant mouse GM-CSF: 25 and 5 ng/ml inhibited the proliferative activity, whereas 1 ng/ml led to its significant stimulation.
  
  
  CONCLUSIONS
  Freshly isolated murine IECs produce GM-CSF, which plays a critical role in crypt cell proliferative activity in vitro. These results suggest the involvement of this factor in the regulation of the crypt proliferative zone, in an autocrine and/or paracrine manner.
authors.affiliation: Group of Molecular Immunology, Institute of Clinical Immunology, SB RAMS, 14 Yadrintsevskaya Str., Novosibirsk 630099, Russia.
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Sennikov
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Temchura
authors.forename: Vladimir A
authors.initials: VA
authors.lastname: Kozlov
authors.forename: Valeriy A
authors.initials: VA
authors.lastname: Trufakin
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects / Q000502:physiology*; D017077:Culture Media, Conditioned; D004847:Epithelial Cells / Q000187:drug effects* / Q000502:physiology*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000378:metabolism* / Q000494:pharmacology; D007413:Intestinal Mucosa / Q000166:cytology; D051379:Mice; D012016:Reference Values; D012680:Sensitivity and Specificity
chemical_list: D017077:Culture Media, Conditioned; D016178:Granulocyte-Macrophage Colony-Stimulating Factor