A group of researchers at Karolinska Institutet including our compatriot Igor Adameyko, the research partner of the Extreme Biology OpenLab of the KFU Institute of Fundamental Medicine and Biology, assert that a significant population of mesenchymal stem cells during development, self-renewal, and repair of a tooth is derived from peripheral nerve-associated glia. The results of the study appeared July 27 in Nature, in an article entitled, "Glial origin of mesenchymal stem cells in a tooth model system."
"We have identified a previously unknown type of stem cells that surprisingly enough belong to the nerves of the tooth; these are nerves that would normally be associated with the tooth's extreme sensitivity to pain," says Kaj Fried at the Department of Neuroscience of Karolinska Institutet, one of the head researchers responsible for the study.
The researchers discovered that young cells, which at first are part of the neural support cells, or the glial cells, leave the nerves at an early stage of the foetal development. The cells change their identity and become both connective tissues in the tooth pulp and odontoblasts, i.e., the cells that produce the hard dentin underneath the enamel. Today we do not have the possibility of growing new teeth in adults, but the discovery of this new type of stem cells is an important step towards the knowledge and technology that is required to make it a future possibility.
"The fact that stem cells are available inside the nerves is highly significant, and this is in no way unique for the tooth. Our results indicate that peripheral nerves, which are found basically everywhere, may function as important stem cell reserves. From such reserves, multipotent stem cells can depart from the nerves and contribute to the healing and reformation of tissues in different parts of the body," says Igor Adameyko, who has headed the study along with Kaj Fried.