title: Valproic acid induces differentiation and inhibition of proliferation in neural progenitor cells via the beta-catenin-Ras-ERK-p21Cip/WAF1 pathway.
abstract: BACKGROUND
  Valproic acid (VPA), a commonly used mood stabilizer that promotes neuronal differentiation, regulates multiple signaling pathways involving extracellular signal-regulated kinase (ERK) and glycogen synthase kinase3beta (GSK3beta). However, the mechanism by which VPA promotes differentiation is not understood.
  
  
  RESULTS
  We report here that 1 mM VPA simultaneously induces differentiation and reduces proliferation of basic fibroblast growth factor (bFGF)-treated embryonic day 14 (E14) rat cerebral cortex neural progenitor cells (NPCs). The effects of VPA on the regulation of differentiation and inhibition of proliferation occur via the ERK-p21Cip/WAF1 pathway. These effects, however, are not mediated by the pathway involving the epidermal growth factor receptor (EGFR) but via the pathway which stabilizes Ras through beta-catenin signaling. Stimulation of differentiation and inhibition of proliferation in NPCs by VPA occur independently and the beta-catenin-Ras-ERK-p21Cip/WAF1 pathway is involved in both processes. The independent regulation of differentiation and proliferation in NPCs by VPA was also demonstrated in vivo in the cerebral cortex of developing rat embryos.
  
  
  CONCLUSIONS
  We propose that this mechanism of VPA action may contribute to an explanation of its anti-tumor and neuroprotective effects, as well as elucidate its role in the independent regulation of differentiation and inhibition of proliferation in the cerebral cortex of developing rat embryos.
authors.affiliation: Department of Biotechnology, Yonsei University, Seoul, Korea. assam76@gmail.com
authors.forename: Gyung-Ah
authors.initials: GA
authors.lastname: Jung
authors.forename: Ju-Yong
authors.initials: JY
authors.lastname: Yoon
authors.forename: Byoung-San
authors.initials: BS
authors.lastname: Moon
authors.forename: Dong-Hwa
authors.initials: DH
authors.lastname: Yang
authors.forename: Hyun-Yi
authors.initials: HY
authors.lastname: Kim
authors.forename: Sang-Hun
authors.initials: SH
authors.lastname: Lee
authors.forename: Vitezslav
authors.initials: V
authors.lastname: Bryja
authors.forename: Ernest
authors.initials: E
authors.lastname: Arenas
authors.forename: Kang-Yell
authors.initials: KY
authors.lastname: Choi
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects*; D002540:Cerebral Cortex / Q000196:embryology / Q000502:physiology; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D004622:Embryo, Mammalian; D066246:ErbB Receptors / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D016222:Fibroblast Growth Factor 2 / Q000037:antagonists & inhibitors / Q000494:pharmacology; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects; D013234:Stem Cells / Q000166:cytology / Q000502:physiology*; D014635:Valproic Acid / Q000494:pharmacology*; D051176:beta Catenin / Q000378:metabolism*; D018631:ras Proteins / Q000378:metabolism
chemical_list: C493958:Cdkn1a protein, rat; D050759:Cyclin-Dependent Kinase Inhibitor p21; D051176:beta Catenin; D016222:Fibroblast Growth Factor 2; D014635:Valproic Acid; D066246:ErbB Receptors; D000071679:Glycogen Synthase Kinase 3 beta; C000605508:Gsk3b protein, rat; D048049:Extracellular Signal-Regulated MAP Kinases; D038362:Glycogen Synthase Kinase 3; D018631:ras Proteins