title: Impact of metabolic regulators on the expression of the obesity associated genes FTO and NAMPT in human preadipocytes and adipocytes.
abstract: BACKGROUND
  FTO and NAMPT/PBEF/visfatin are thought to play a role in obesity but their transcriptional regulation in adipocytes is not fully understood. In this study, we evaluated the transcriptional regulation of FTO and NAMPT in preadipocytes and adipocytes by metabolic regulators.
  
  
  RESULTS
  We assessed FTO mRNA expression during human adipocyte differentiation of Simpson-Golabi-Behmel syndrome (SGBS) cells and primary subcutaneous preadipocytes in vitro and evaluated the effect of the metabolic regulators glucose, insulin, dexamethasone, IGF-1 and isoproterenol on FTO and NAMPT mRNA expression in SGBS preadipocytes and adipocytes. FTO mRNA levels were not significantly modulated during adipocyte differentiation. Also, metabolic regulators had no impact on FTO expression in preadipocytes or adipocytes. In SGBS preadipocytes NAMPT expression was more than 3fold induced by dexamethasone and isoproterenol and 1.6fold by dexamethasone in adipocytes. Complete glucose restriction caused an increase in NAMPT mRNA expression by more than 5fold and 1.4fold in SGBS preadipocytes and adipocytes, respectively.
  
  
  CONCLUSIONS
  FTO mRNA expression is not significantly affected by differentiation or metabolic regulators in human adipocytes. The stimulation of NAMPT expression by dexamethasone, isoproterenol and complete glucose restriction may indicate a regulation of NAMPT by metabolic stress, which was more pronounced in preadipocytes compared to mature adipocytes.
authors.affiliation: University Hospital for Children and Adolescents, University of Leipzig, Leipzig, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Friebe
authors.forename: Dennis
authors.initials: D
authors.lastname: Löffler
authors.forename: Maria
authors.initials: M
authors.lastname: Schönberg
authors.forename: Falk
authors.initials: F
authors.lastname: Bernhard
authors.forename: Petra
authors.initials: P
authors.lastname: Büttner
authors.forename: Kathrin
authors.initials: K
authors.lastname: Landgraf
authors.forename: Wieland
authors.initials: W
authors.lastname: Kiess
authors.forename: Antje
authors.initials: A
authors.lastname: Körner
mesh_terms: D017667:Adipocytes / Q000166:cytology* / Q000201:enzymology / Q000378:metabolism*; D050156:Adipogenesis / Q000235:genetics; D000328:Adult; D000071516:Alpha-Ketoglutarate-Dependent Dioxygenase FTO; D002454:Cell Differentiation; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D008297:Male; D008875:Middle Aged; D054409:Nicotinamide Phosphoribosyltransferase / Q000235:genetics*; D009765:Obesity / Q000235:genetics*; D011506:Proteins / Q000235:genetics*; D014158:Transcription, Genetic; D055815:Young Adult
chemical_list: D011506:Proteins; D000071516:Alpha-Ketoglutarate-Dependent Dioxygenase FTO; C526492:FTO protein, human; D054409:Nicotinamide Phosphoribosyltransferase