title: Interferon-γ inhibits ghrelin expression and secretion via a somatostatin-mediated mechanism.
abstract: OBJECTIVE
  To investigate if and how the proinflammatory cytokine interferon γ (IFNγ) affects ghrelin expression in mice.
  
  
  METHODS
  The plasma concentration of ghrelin, and gastric ghrelin and somatostatin expression, were examined in wild-type mice and mice infected with Helicobacter pylori (H. pylori). Furthermore, ghrelin expression was examined in two achlorhydric mouse models with varying degrees of gastritis due to bacterial overgrowth. To study the effect of IFNγ alone, mice were given a subcutaneous infusion of IFNγ for 7 d. Finally, the influence of IFNγ and somatostatin on the ghrelin promoter was characterized.
  
  
  RESULTS
  H. pylori infection was associated with a 50% reduction in ghrelin expression and plasma concentration. Suppression of ghrelin expression was inversely correlated with gastric inflammation in achlorhdyric mouse models. Subcutaneous infusion of IFNγ suppressed fundic ghrelin mRNA expression and plasma ghrelin concentrations. Finally, we showed that the ghrelin promoter operates under the control of somatostatin but not under that of IFNγ.
  
  
  CONCLUSIONS
  Gastric infection and inflammation is associated with increased IFNγ expression and reduced ghrelin expression. IFNγ does not directly control ghrelin expression but inhibits it indirectly via somatostatin.
authors.affiliation: Genomic Medicine, Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Jesper A B
authors.initials: JA
authors.lastname: Strickertsson
authors.forename: Kristina B V
authors.initials: KB
authors.lastname: Døssing
authors.forename: Anna J M
authors.initials: AJ
authors.lastname: Aabakke
authors.forename: Hans-Olof
authors.initials: HO
authors.lastname: Nilsson
authors.forename: Thomas V O
authors.initials: TV
authors.lastname: Hansen
authors.forename: Ulrich
authors.initials: U
authors.lastname: Knigge
authors.forename: Andreas
authors.initials: A
authors.lastname: Kjær
authors.forename: Torkel
authors.initials: T
authors.lastname: Wadström
authors.forename: Lennart
authors.initials: L
authors.lastname: Friis-Hansen
mesh_terms: D000818:Animals; D002460:Cell Line; D005260:Female; D005755:Gastrins / Q000235:genetics / Q000378:metabolism; D005756:Gastritis / Q000188:drug therapy / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D054439:Ghrelin / Q000235:genetics / Q000378:metabolism*; D016481:Helicobacter Infections / Q000188:drug therapy / Q000378:metabolism; D016480:Helicobacter pylori / Q000378:metabolism; D006640:Histidine Decarboxylase / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism* / Q000627:therapeutic use; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011401:Promoter Regions, Genetic; D013004:Somatostatin / Q000378:metabolism*; D013270:Stomach / Q000382:microbiology / Q000473:pathology / Q000502:physiology
chemical_list: D005755:Gastrins; D054439:Ghrelin; D013004:Somatostatin; D007371:Interferon-gamma; D006640:Histidine Decarboxylase