Debilitating nerve injuries can be effectively regenerated using autologous nerve grafts, but that procedure may sacrifice a functional nerve and cause problems elsewhere in the body. A new study by Japanese researchers has found that the use of the dental pulp in extracted teeth could be used as an effective transplant to regenerate nerves without causing problems elsewhere in the body.
Testing on laboratory rats, the team found that the group receiving transplanted mobilised dental pulp stem cells (MDPSCs) demonstrated regeneration of myelinated axons that were significantly higher in density than those resulting for controls that received nerve grafts or collagen.
Study co-author, Dr Misako Nakashima, said: “The total number of myelinated axons was greatest in the autograft group, followed by the MDPSC group and the collagen group. The MDPSC group showed increased blood vessel formation, yet there was no statistical difference between the results found in the MDPSC group and the autograft group.”
The researchers speculated that the MDPSCs may have had a stimulatory effect on residual Schwann cells (cells involved in many important aspects of peripheral nerve cell biology) through their secretion of neurotrophic factors. In in vitro experiments, the researchers found that MDPSCs had a beneficial effect on Schwann cells. That effect was amplified in in vivo studies.
The researchers indicated: “We predict that in the near future dental pulp stem cell transplantation may become a possible candidate for taking the place of autologous nerve grafts in peripheral nerve repair and regeneration.”
Dr John Sladek Jr, analysing the study commented: “The avoidance of potential ethical issues often associated with the derivation of stem cells is also commendable. In this study, although MDPSCs exceeded autografts in axon density, the autografts had the highest total number of myelinated axons. Thus, comparative effectiveness studies should be conducted to compare cells with different lineages that have been proposed for nerve regeneration in order to determine which cell type yields optimal results.”