SYNOPSIS
The cell-therapy for the tooth root tissue regeneration combined with tissue-stem cells and tissue-engineering technology would be a very powerful tool in the future, but there is not enough accumulation of basic knowledge about tooth root development. In fact, several signalling molecules in the Shh, FGF, BMP and Wnt families appear to regulate the developmantal steps of tooth morphogenesis via sequential and reciprocal interactions between the oral epithelium and cranial neural crest cells (CNCCs). Recent findings that non-odontogenic mesenchyme, bone marrow derived mesenchymal stem cells (MSCs), can construct tooth structure with the help of odontogenic epithelium. We improved the tissue culture techniques to isolate the cell populations of CNCCs and MSCs. Next, we examined CNCC culture of Wnt1-Cre/R26R to confirm the specificity of the cultured CNCCs by lacZ staining. For understanding the molecular basis of the odontogenic poten-tiality of CNCCs and MSCs, we did the DNA microarray analysis with a small amount of cultured CNCCs and MSCs to compare the genome-wide expression pattern between CNCCs and MSCs. In addition, we examined the biological effects for the root development of typical signaling molecules, SHH, BMP, FGF family and found that FGFs were most stimulative for root development. It is expected that the further studies involved in mechanisms of tooth root development and tissue-stem cell biology could lead to the innovation of tooth regenerative therapy based on the biological evidence.

Key words: neural crest cells, mesenchymal stem cells, gene networks, signalling molecules, tooth regeneration