title: Promoting effects of isobavachin on neurogenesis of mouse embryonic stem cells were associated with protein prenylation.
abstract: OBJECTIVE
  Some small molecules can induce mouse embryonic stem (ES) cells to differentiate into neuronal cells. Here, we explored the effect of isobavachin (IBA), a compound with a prenyl group at position 8 of ring A, on promoting neuronal differentiation and the potential role of its protein prenylation.
  
  
  METHODS
  The hanging drop method was employed for embryonic body (EB) formation to mimic embryo development in vivo. The EBs were treated with IBA at a final concentration of 10(-7) mol/L from EB stage (d 4) to d 8+10. Geranylgeranyltransferase I inhibitor GGTI-298 was subsequently used to disrupt protein prenylation. Neuronal subtypes, including neurons and astrocytes, were observed by fluorescence microscopy. Gene and protein expression levels were detected using RT-PCR and Western blot analysis, respectively.
  
  
  RESULTS
  With IBA treatment, nestin was highly expressed in the neural progenitors generated from EBs (d 4, d 8+0). EBs then further differentiated into neurons (marked by β-tubulin III) and astrocytes (marked by GFAP), which were both up-regulated in a time-dependent manner on d 8+5 and d 8+10. Co-treatment with GGTI-298 selectively abolished the IBA-induced neuronal differentiation. Moreover, in the MAPK pathway, p38 and JNK phosphorylation were down-regulated, while ERK phosphorylation was up-regulated after IBA treatment at different neuronal differentiation passages.
  
  
  CONCLUSIONS
  IBA can facilitate mouse ES cells differentiating into neuronal cells. The mechanism involved protein prenylation and, subsequently, phos-ERK activation and the phos-p38 off pathway.
authors: Division of Cardio-Cerebral Vascular and Hepatic Pharmacology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.
authors: Dan-yin
authors: DY
authors: Wang
authors: Yu-zhe
authors: YZ
authors: Hu
authors: Si-si
authors: SS
authors: Kong
authors: Yong-ping
authors: YP
authors: Yu
authors: Dan-yan
authors: DY
authors: Zhu
authors: Yi-jia
authors: YJ
authors: Lou
mesh_terms: D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D002478:Cells, Cultured; D017931:DNA Primers; D053595:Embryonic Stem Cells / Q000166:cytology / Q000187:drug effects*; D005419:Flavonoids / Q000494:pharmacology*; D007150:Immunohistochemistry; D051379:Mice; D008856:Microscopy, Fluorescence; D055495:Neurogenesis / Q000187:drug effects*; D016133:Polymerase Chain Reaction; D017368:Protein Prenylation
chemical_list: D017931:DNA Primers; D005419:Flavonoids; C468753:isobavachin