Dental pulp stem cell transplants: potential for peripheral nerve regeneration?

Written by Alexandra Thompson

Mobilized dental pulp stem cells shown to stimulate residual Schwann cells after peripheral nerve damage in a mouse model

Whether caused by peripheral nerve disorders or injuries, damage to peripheral nerves distorts or interrupts the sensory and motor messages between the brain and the rest of the body, resulting in symptoms such as pain and muscle weakness, and in some cases severe disabilities.

Autologous nerve grafts are used to repair damaged peripheral nerves, but as it requires a functional nerve to be removed from somewhere else in the body it can result in loss of sensation in the location it was removed from.

A team of researchers has been investigating the effectiveness of mobilized dental pulp stem cell (MDPSC) transplants in regenerating damaged peripheral nerves (sciatic nerve defects) in rats, compared with autologous nerve grafts and a control (collagen implants). The dental pulp was obtained from discarded extracted teeth.

Study coauthor Dr Misako Nakashima (National Center for Geriatrics and Gerontology Research Institute, Obu, Japan), explains the results of the investigation: “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 team concluded that “MDPSCs can contribute to peripheral nerve regeneration by the secretion of neurotrophic and angiogenic factors (factors that promote the formation of new blood vessels) when in close proximity to newly migrated Schwann cells” by regulating apoptosis and proliferation — the MDPSCs have had a stimulatory effect on residual Schwann cells, thereby encouraging regeneration. MDPSCs have also demonstrated a beneficial effect on Schwann cells in vitro.

Speculating on the future, the researchers stated: “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.”