Human neural stem cells survive long term in the midbrain of dopamine-depleted monkeys after GDNF overexpression and project neurites toward an appropriate target

Stem Cells Transl Med. 2014 Jun;3(6):692-701. doi: 10.5966/sctm.2013-0208. Epub 2014 Apr 17.

Abstract

Transplanted multipotent human fetal neural stem cells (hfNSCs) significantly improved the function of parkinsonian monkeys in a prior study primarily by neuroprotection, with only 3%-5% of cells expressing a dopamine (DA) phenotype. In this paper, we sought to determine whether further manipulation of the neural microenvironment by overexpression of a developmentally critical molecule, glial cell-derived neurotrophic factor (GDNF), in the host striatum could enhance DA differentiation of hfNSCs injected into the substantia nigra and elicit growth of their axons to the GDNF-expressing target. hfNSCs were transplanted into the midbrain of 10 green monkeys exposed to 1-methyl-4-phenyl-1,2,3,6-tetrahydro-pyridine. GDNF was delivered concomitantly to the striatum via an adeno-associated virus serotype 5 vector, and the fate of grafted cells was assessed after 11 months. Donor cells remained predominantly within the midbrain at the injection site and sprouted numerous neurofilament-immunoreactive fibers that appeared to course rostrally toward the striatum in parallel with tyrosine hydroxylase-immunoreactive fibers from the host substantia nigra but did not mature into DA neurons. This work suggests that hfNSCs can generate neurons that project long fibers in the adult primate brain. However, in the absence of region-specific signals and despite GDNF overexpression, hfNSCs did not differentiate into mature DA neurons in large numbers. It is encouraging, however, that the adult primate brain appeared to retain axonal guidance cues. We believe that transplantation of stem cells, specifically instructed ex vivo to yield DA neurons, could lead to reconstruction of some portion of the nigrostriatal pathway and prove beneficial for the parkinsonian condition.

Keywords: GDNF; MPTP; Neural stem cells; Parkinson; Primate; Stem cell; Transplantation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine
  • Animals
  • Cell Line
  • Cell Lineage
  • Cell Shape
  • Cell Survival
  • Chlorocebus aethiops
  • Dependovirus / genetics
  • Disease Models, Animal
  • Genetic Therapy / methods*
  • Genetic Vectors
  • Glial Cell Line-Derived Neurotrophic Factor / genetics
  • Glial Cell Line-Derived Neurotrophic Factor / metabolism*
  • Humans
  • MPTP Poisoning / chemically induced
  • MPTP Poisoning / genetics
  • MPTP Poisoning / metabolism
  • MPTP Poisoning / pathology
  • MPTP Poisoning / therapy*
  • Mesencephalon / metabolism
  • Mesencephalon / pathology
  • Mesencephalon / surgery*
  • Neural Stem Cells / metabolism
  • Neural Stem Cells / pathology
  • Neural Stem Cells / transplantation*
  • Neurites / metabolism
  • Neurites / pathology
  • Neurites / transplantation*
  • Neurogenesis*
  • Regenerative Medicine / methods*
  • Stem Cell Niche
  • Time Factors
  • Transduction, Genetic
  • Transfection
  • Up-Regulation

Substances

  • Glial Cell Line-Derived Neurotrophic Factor
  • 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine