title: Voltage-gated K+ channels in adipogenic differentiation of bone marrow-derived human mesenchymal stem cells.
abstract: OBJECTIVE
  To determine the presence of voltage-gated K(+) (Kv) channels in bone marrow-derived human mesenchymal stem cells (hMSCs) and their impact on differentiation of hMSCs into adipocytes.
  
  
  METHODS
  For adipogenic differentiation, hMSCs were cultured in adipogenic medium for 22 d. The degrees of adipogenic differentiation were examined using Western blot, Oil Red O staining and Alamar assay. The expression levels of Kv channel subunits Kv1.1, Kv1.2, Kv1.3, Kv1.4, Kv2.1, Kv3.1, Kv3.3, Kv4.2, Kv4.3, and Kv9.3 in the cells were detected using RT-PCR and Western blot analysis.
  
  
  RESULTS
  The expression levels of Kv2.1 and Kv3.3 subunits were markedly increased on d 16 and 22. In contrast, the expression levels of other Kv channel subunits, including Kv1.1, Kv1.2, Kv1.3, Kv1.4, Kv4.2, Kv4.3, and Kv9.3, were decreased as undifferentiated hMSCs differentiated into adipocytes. Addition of the Kv channel blocker tetraethylammonium (TEA, 10 mmol/L) into the adipogenic medium for 6 or 12 d caused a significant decrease, although not complete, in lipid droplet formation and adipocyte fatty acid-binding protein 2 (aP(2)) expressions. Addition of the selective Kv2.1 channel blocker guangxitoxin (GxTX-1, 40 nmol/L) into the adipogenic medium for 21 d also suppressed adipogenic differentiation of the cells.
  
  
  CONCLUSIONS
  The results demonstrate that subsets of Kv channels including Kv2.1 and Kv3.3 may play an important role in the differentiation of hMSCs into adipocytes.
authors.affiliation: Laboratory of Veterinary Pathology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea.
authors.forename: Mi-hyeon
authors.initials: MH
authors.lastname: You
authors.forename: Min Seok
authors.initials: MS
authors.lastname: Song
authors.forename: Seul Ki
authors.initials: SK
authors.lastname: Lee
authors.forename: Pan Dong
authors.initials: PD
authors.lastname: Ryu
authors.forename: So Yeong
authors.initials: SY
authors.lastname: Lee
authors.forename: Dae-yong
authors.initials: DY
authors.lastname: Kim
mesh_terms: D017667:Adipocytes / Q000166:cytology*; D050156:Adipogenesis / Q000187:drug effects; D001854:Bone Marrow Cells / Q000166:cytology; D002478:Cells, Cultured; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D008564:Membrane Potentials; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D026902:Potassium Channel Blockers / Q000494:pharmacology; D024642:Potassium Channels, Voltage-Gated / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D019789:Tetraethylammonium / Q000494:pharmacology
chemical_list: D026902:Potassium Channel Blockers; D024642:Potassium Channels, Voltage-Gated; D012333:RNA, Messenger; D019789:Tetraethylammonium