A study published in the December 2011 issue of The Journal of Clinical Investigation reports that stem cells taken from tooth pulp are capable of stimulating long-term regeneration of nerves in damaged spinal cords. A team at Nagoya University Graduate School of Medicine, Japan, transplanted human dental-pulp stem cells into adult rats with completely severed spinal cords, which resulted in marked recovery of hind-limb locomotor functions. The results have implications for neuroregenerative activities in humans with spinal cord injuries (SCI).
While results have demonstrated that transplantation of human bone marrow stromal cells or skin-derived fibroblasts can promote varying degrees of functional recovery in spinal cord injury (SCI), they led to substantially less recovery of locomotor function.
The human dental-pulp stem cells, on the other hand, exhibited three major neuroregenerative activities. First, they inhibited the SCI-induced apoptosis, or cell death, of neurons, astrocytes, and oligodendrocytes, which improved the preservation of neuronal filaments and myelin sheaths. Second, they promoted the regeneration of transected axons by directly inhibiting multiple axon-growth inhibitors. Last, they differentiated into mature oligodendrocytes to replace cells that were lost. The onset of regeneration was evident during the acute phase of injury and enabled rats with severed spinal cords to coordinate hind-limb-joint movement and walk without weight support within five weeks.
“To our knowledge, the latter two neuroregenerative activities are unique to tooth-derived stem cells and are not exhibited by any other previously described stem cells,” the researchers stated. “We propose that tooth-derived stem cells may be an excellent and practical cellular resource for the treatment of SCI.”
