title: Improved neurite outgrowth on central nervous system myelin substrate by siRNA-mediated knockdown of Nogo receptor.
abstract: OBJECTIVE
  To investigate the in vitro effect of short interfering RNAs (siRNAs) against Nogo receptor (NgR) on neurite outgrowth under an inhibitory substrate of central nervous system (CNS) myelin.
  
  
  METHODS
  Three siRNA sequences against NgR were designed and transfected into cerebellar granule cells (CGCs) to screen for the most effcient sequence of NgR siRNA by using reverse transcription polymerase chain reaction (RT-PCR) and immunofluorescence staining. NgR siRNA sequence 1 was found the most efficient which was then transfected into the CGCs grown on CNS myelin substrate to observe its disinhibition for neurite outgrowth.
  
  
  RESULTS
  Compared with the scrambled control sequence of siRNA, the NgR siRNA sequence 1 significantly decreased NgR mRNA level at 24 h and 48 h (p <0.05), which was recovered by 96 h after transfection. NgR immunoreactivity was also markedly reduced at 24 and 48 h after the transfection of siRNA sequence 1 compared with that before transfection (p<0.05). The NgR immunoreactivity was recovered after 72 h post-transfection. Moreover, the neurite outgrowth on the myelin substrate was greatly improved within 72 h after the transfection with siRNA sequence 1 compared with the scrambled sequence-transfected group or non-transfected group (p<0.05).
  
  
  CONCLUSIONS
  siRNA-mediated knockdown of NgR expression contributes to neurite outgrowth in vitro.
authors.affiliation: Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China.
authors.forename: Sheng-Hao
authors.initials: SH
authors.lastname: Ding
authors.forename: Ying-Hui
authors.initials: YH
authors.lastname: Bao
authors.forename: Jian-Hong
authors.initials: JH
authors.lastname: Shen
authors.forename: Guo-Yi
authors.initials: GY
authors.lastname: Gao
authors.forename: Yao-Hua
authors.initials: YH
authors.lastname: Pan
authors.forename: Qi-Zhong
authors.initials: QZ
authors.lastname: Luo
authors.forename: Ji-Yao
authors.initials: JY
authors.lastname: Jiang
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D009186:Myelin Sheath / Q000502:physiology*; D000071446:Neuronal Outgrowth / Q000502:physiology*; D000070816:Nogo Receptor 1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D034741:RNA, Small Interfering; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000070816:Nogo Receptor 1; D034741:RNA, Small Interfering; C486581:Rtn4r protein, rat