title: Human mesenchymal stem cells as an in vitro model for human adipogenesis.
abstract: OBJECTIVE
  To validate the human mesenchymal stem cells (hMSCs) as a new in vitro model for the study of human adipogenesis, to develop the optimal protocol for the differentiation of hMSCs into adipocytes, and to describe effect of mitogen-activated protein kinase on hMSC differentiation into adipocytes.
  
  
  METHODS
  hMSCs, obtained commercially, were differentiated by exposure to insulin, dexamethasone, indomethacin, and 3-isobutyl-1-methylxanthine three times for 3 days each. Various differentiation conditions were examined to optimize differentiation as measured by Oil Red O staining. The gene expression during adipogenic conversion was assessed by reverse-transcription polymerase chain reaction, real-time reverse-transcription polymerase chain reaction, and Western blotting.
  
  
  RESULTS
  hMSCs differentiated into adipocytes to a different extent depending on the experimental conditions. We have found that differentiation medium based on medium 199 and containing 170 nM insulin, 0.5 mM 3-isobutyl-1-methylxanthine, 0.2 mM indomethacin, 1 microM dexamethasone, and 5% fetal bovine serum was optimal. However, the replacement of fetal bovine serum with rabbit serum (15%) led to further enhancement of differentiation. Inhibition of mitogen-activated protein kinase activation also facilitated adipogenic conversion of hMSCs. The pattern of genes expressed during hMSC differentiation into adipocytes (adipsin, peroxisome proliferator-activated receptor-gamma, CCAAT/enhancer-binding protein-beta, GLUT4, and leptin) was similar to that observed in other in vitro adipocyte models.
  
  
  CONCLUSIONS
  hMSCs are renewable sources of noncommitted precursors that are able to differentiate into mature adipocytes under the proper hormonal and pharmacological stimuli. Thus, hMSCs represent a new model for the study of human adipogenesis.
authors.affiliation: Pennington Biomedical Research Center 6400 Perkins Road, Baton Rouge, LA 70808, USA.
authors.forename: Lenka
authors.initials: L
authors.lastname: Janderová
authors.forename: Michele
authors.initials: M
authors.lastname: McNeil
authors.forename: Angela N
authors.initials: AN
authors.lastname: Murrell
authors.forename: Randall L
authors.initials: RL
authors.lastname: Mynatt
authors.forename: Steven R
authors.initials: SR
authors.lastname: Smith
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D017667:Adipocytes / Q000166:cytology*; D000818:Animals; D001769:Blood; D015153:Blotting, Western; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D002999:Clone Cells / Q000166:cytology; D003470:Culture Media; D019938:Cyclin D1 / Q000235:genetics; D003907:Dexamethasone / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005938:Glucocorticoids / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology; D008648:Mesoderm / Q000166:cytology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D018809:Proliferating Cell Nuclear Antigen / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D011817:Rabbits; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells / Q000166:cytology*
chemical_list: D003470:Culture Media; D004791:Enzyme Inhibitors; D005938:Glucocorticoids; D007328:Insulin; D018809:Proliferating Cell Nuclear Antigen; D012333:RNA, Messenger; D019938:Cyclin D1; D003907:Dexamethasone; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D005947:Glucose; D015056:1-Methyl-3-isobutylxanthine; D007213:Indomethacin