title: Host induction by transplanted neural stem cells in the spinal cord: further evidence for an adult spinal cord neurogenic niche.
abstract: OBJECTIVE
  To explore the hypothesis that grafts of exogenous stem cells in the spinal cord of athymic rats or rats with transgenic motor neuron disease can induce endogenous stem cells and initiate intrinsic repair mechanisms that can be exploited in amyotrophic lateral sclerosis therapeutics.
  
  
  METHODS
  Human neural stem cells (NSCs) were transplanted into the lower lumbar spinal cord of healthy rats or rats with transgenic motor neuron disease to explore whether signals related to stem cells can initiate intrinsic repair mechanisms in normal and amyotrophic lateral sclerosis subjects. Patterns of migration and differentiation of NSCs in the gray and white matter, with emphasis on the central canal region and ependymal cell-driven neurogenesis, were analyzed.
  
  
  RESULTS
  Findings suggest that there is extensive cross-signaling between transplanted NSCs and a putative neurogenic niche in the ependyma of the lower lumbar cord. The formation of a neuronal cord from NSC-derived cells next to ependyma suggests that this structure may serve a mediating or auxiliary role for ependymal induction.
  
  
  CONCLUSIONS
  These findings raise the possibility that NSCs may stimulate endogenous neurogenesis and initiate intrinsic repair mechanisms in the lower spinal cord.
authors.affiliation: Department of Pathology, Division of Neuropathology, The Johns Hopkins University School of Medicine, Ross Building, Room 558, 720 Rutland Avenue, Baltimore, MD 21205, USA. lxu9@jhmi.edu
authors.forename: Leyan
authors.initials: L
authors.lastname: Xu
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Mahairaki
authors.forename: Vassilis E
authors.initials: VE
authors.lastname: Koliatsos
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000473:pathology / Q000628:therapy; D000818:Animals; D002454:Cell Differentiation; D002465:Cell Movement; D004805:Ependyma / Q000378:metabolism / Q000473:pathology; D006801:Humans; D016472:Motor Neuron Disease / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D058953:Neural Stem Cells / Q000378:metabolism / Q000637:transplantation; D051381:Rats; D055647:Rats, Transgenic; D013116:Spinal Cord / Q000378:metabolism* / Q000473:pathology; D055153:Stem Cell Niche; D014183:Transplantation, Heterologous