Gene Brings Teeth In Shape

[Anonymous]

No healthy teeth without this gene: if during tooth formation (odontogenesis) the so-called Jagged2 gene is inactivated, and hence the Notch signalling pathway interrupted, tooth crowns will be malformed and enamel will be lacking. As this signalling pathway is involved in the formation of all tissues and organs, the new insights from the University of Zurich research team have wider implications.

Through the means of signaling pathways cells react to signals from their environment. One of the most important signalling pathways is the Notch signalling pathway. It is evolutionary conserved to a very high degree and it is involved in the development of all organs and tissues in animal and human embryos. The Notch signaling pathway enables neighboring cells to adopt different fates. By this mechanism signals exchanged via Notch receptors between neighboring cells control formation, development and differentiation of organs. Similarly, formation and differentiation of teeth is controlled by Notch signalling.

The research team of Thimios Mitsiadis, Professor for Oral Biology at the University of Zurich, has now shown that in mice the Jagged2 gene is required for the healthy development of teeth. Inactivation of this gene interrupts the Notch signalling pathway resulting in serious tooth malformations: The tooth crowns of the molars were deformed, additional cusps were formed. In incisors cell growth and enamel formation was blocked.

Bioteeth: one aim of stem-cell research

Understanding the Notch signalling pathway and knowing the genes that direct form and shape of tissues is important for many areas of biology. Within the field of dentistry these findings make an important contribution to our knowledge, particularly for the field of stem cell research, as Mitsiadis points out. Because there, the aim is to use the potential of stem cells not only for tooth repair, but ultimately for the generation of completely new teeth, called bioteeth. Therefore we require the knowledge of the precise genetic mechanisms that control tooth shape. To generate a new tooth whose shape suits a patient’s individual requirements is not possible today. A combined solution, however, is already thinkable with our current knowledge, Mitsiadis explains: «A combination of stem cells with an artificial scaffold could constitute a solution for this problem.

Source: Zurich University

        

[drsnehamaheshwari]

King’s researchers are one step closer to developing a method to replace missing teeth with bioengineered teeth generated from a person’s own gum cells.

Current implant methods to replace missing teeth mean that there is no natural root structure in the gum. As a consequence of the friction from eating and other jaw movement, loss of jaw bone can occur around the implant. Bioengineered teeth, or bioteeth, would mean a whole new tooth, complete with a root structure, grows from cells transplanted into a person’s gum.

The new research is being led by Professor Paul Sharpe, an expert in craniofacial development and stem cell biology at King’s College London’s Dental Institute. His team have been building on the bioteeth research done so far, which has focused on generating immature teeth that could then be transplanted into an adult jaw to develop into fully functional teeth. However, the cells used to form the immature teeth were sourced from embryos – thereby meaning the method cannot be widely used. The challenge in developing bioteeth that grow from a human jaw is finding adult sources of both human gum cells and human cells that are able to produce teeth.

Professor Sharpe and his team are half-way there. They took human gum tissue from patients at the Dental Institute at King’s College London, grew more of it in the lab, and then combined it with tooth-forming cells from mice. By transplanting this combination of cells into mice the researchers were able to grow hybrid human/mouse teeth containing dentine and enamel, as well as viable roots.

The next challenge in the development of bioteeth is to find a source of adult human tooth-forming cells that can be combined with human gum cells. If successful, it will revolutionise tooth replacement methods.

 

        

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