title: Daidzein induces neuritogenesis in DRG neuronal cultures.
abstract: BACKGROUND
  Daidzein, a phytoestrogen found in isoflavone, is known to exert neurotrophic and neuroprotective effects on the nervous system. Using primary rat dorsal root ganglion (DRG) neuronal cultures, we have examined the potential neurite outgrowth effect of daidzein.
  
  
  METHODS
  Dissociated dorsal root ganglia (DRG) cultures were used to study the signaling mechanism of daidzein-induced neuritogenesis by immunocytochemistry and Western blotting.
  
  
  RESULTS
  In response to daidzein treatment, DRG neurons showed a significant increase in total neurite length and in tip number per neuron. The neuritogenic effect of daidzein was significantly hampered by specific blockers for Src, protein kinase C delta (PKCδ) and mitogen-activated protein kinase/extracellular signal-regulated kinase kinases (MEK/ERK), but not by those for estrogen receptor (ER). Moreover, daidzein induced phosphorylation of Src, PKCδ and ERK. The activation of PKCδ by daidzein was attenuated in the presence of a Src kinase inhibitor, and that of ERK by daidzein was diminished in the presence of either a Src or PKCδ inhibitor.
  
  
  CONCLUSIONS
  Daidzein may stimulate neurite outgrowth of DRG neurons depending on Src kinase, PKCδ and ERK signaling pathway.
authors.affiliation: Division of Neurosurgery, Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Shih-Hung
authors.initials: SH
authors.lastname: Yang
authors.forename: Chih-Chen
authors.initials: CC
authors.lastname: Liao
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.forename: Jhih-Pu
authors.initials: JP
authors.lastname: Syu
authors.forename: Chung-Jiuan
authors.initials: CJ
authors.lastname: Jeng
authors.forename: Seu-Mei
authors.initials: SM
authors.lastname: Wang
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D005727:Ganglia, Spinal / Q000166:cytology / Q000187:drug effects / Q000254:growth & development; D005786:Gene Expression Regulation / Q000187:drug effects; D066298:In Vitro Techniques; D007529:Isoflavones / Q000494:pharmacology*; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D016501:Neurites / Q000187:drug effects / Q000502:physiology; D018696:Neuroprotective Agents / Q000494:pharmacology*; D015688:Oncogene Protein pp60(v-src) / Q000037:antagonists & inhibitors / Q000378:metabolism; D051745:Protein Kinase C-delta / Q000037:antagonists & inhibitors / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction
chemical_list: D007529:Isoflavones; D018696:Neuroprotective Agents; C004742:daidzein; D015688:Oncogene Protein pp60(v-src); D051745:Protein Kinase C-delta; D020929:Mitogen-Activated Protein Kinase Kinases