Neural stem cells in regenerative medicine: bridging the gap.

Repair of the chronically injured spinal presents with multiple challenges, including neuronal/axonal loss and demyelination as a result of primary injury (usually a physical insult), as well as secondary damage, which includes ischemia, inflammation, oxidative injury and glutamatergic toxicity. These processes cause neuronal loss, axonal disruption and lead to a cystic degeneration and an inhibitory astroglial scar. A promising therapeutic intervention for SCI is the use of neural stem cells. Cell replacement strategies using neural precursor cells (NPCs) and oligodendroglial precursor cells (OPCs) have been shown to replace lost/damaged cells, secrete trophic factors, regulate gliosis and scar formation, reduce cystic cavity size and axonal dieback, as well as to enhance plasticity, axonal elongation and neuroprotection. These progenitor cells can be obtained through a variety of sources, including adult neural tissue, embryonic blastocysts and adult somatic cells via induced pluripotent stem cell (iPSC) technology. The use of stem cell technology - especially autologous cell transplantation strategies - in regenerative therapy for SCI holds much promise; these therapies show high potential for clinical translation and for future disease treatment.