Finnish researchers have recently identified a marker for dental stem cells. They demonstrated that the transcription factor Sox2 is expressed specifically in the stem cells of the anterior teeth of mice. The study of stem cells requires their isolation and a lack of a specific marker has hindered studies so far.
Growing a tooth from stem cells remains a distant goal, even though new bioengineering protocols have been developed. There is a need for bioengineered teeth to replace lost teeth, which affects both oral health and quality of life. The development of a tooth entails a detailed process of cells differentiating into specific lineages to form dental cells. Stem cells are able to differentiate into the specialised cell types required but dental stem cells have not been isolated thus far, as no marker has been identified yet.
Prof. Irma Thesleff, research director at the Institute of Biotechnology in Helsinki, and her research team demonstrated that the transcription factor Sox2 is expressed specifically in the stem cells of the incisors of mice. These anterior teeth grow continuously throughout life and this growth is fuelled by stem cells located at the base of the tooth. These cells offer an excellent model for studying dental stem cells.
The researchers developed a method to record the division, movement and specification of these cells. By tracing the descendants of genetically labelled cells, they demonstrated that Sox2-positive stem cells give rise to enamel-forming ameloblasts and other cell lineages of the tooth.
“Although human teeth don’t grow continuously, the mechanisms that control and regulate their growth are similar to those of mice teeth,” said Emma Juuri, a co-author of the study. “Therefore, the discovery of Sox2 as a marker for dental stem cells is an important step toward developing a complete, bioengineered tooth. In the future, it may be possible to grow new teeth from stem cells to replace lost ones.”
The study “Sox2+ stem cells contribute to all epithelial lineages of the tooth via Sfrp5+ progenitors” was published online on 19 July in the Developmental Cell journal.