Human neural stem cells can replace damaged cells and improve function in a mouse model of spinal cord injury, according to the report released Monday.
Reuter reports, that Brian Cummings and colleagues injected human neural stem cells into the site of spinal cord contusion injury in mice and followed their progress. The human cells survived and engrafted extensively within the injured mouse spinal cord, the authors report, with cells persisting 17 weeks after transplantation.
"We set out to find whether these cells would be able to respond to the injury in an appropriate and beneficial way on their own," Cummings was quoted as saying by Science Daily. "We were excited to find that the cells responded to the damage by making appropriate new cells that could assist in repair. This study supports the possibility that formation of new myelin and new neurons may contribute to recovery."
Myelin is the biological insulation for nerve fibers that is critical for maintenance of electrical conduction in the central nervous system. When myelin is stripped away through disease or injury, sensory and motor deficiencies result and, in some cases, paralysis can occur. Previous Reeve-Irvine research has shown that transplantation of oligodendrocyte precursors derived from human embryonic stem cells restores mobility in rats.
Mice injected with human neural stem cells showed evidence of recovering coordinated locomotor function and stepping ability 16 weeks after engraftment, the report indicates.
"To our knowledge," the investigators write, "this is the longest time that mice receiving stem cell grafts of any type have been tracked behaviorally."
Treatment of mice with toxin targeting the human cells resulted in decreased locomotor function, the results indicate. "This suggests that at least some of the recovery was the result of integration between the grafted cells and the host cells," Cummings said.
This study differs from previous work using human embryonic stem cells in spinal cord injury because the human neural stem cells were not coaxed into becoming specific cell types before transplantation, according to Science Daily.