Fibroblast Growth Factor-9 for Odontogenic Differentiation of Dental Mesenchymal Stem Cells

Objectives: To investigate the effects of fibroblast growth factor-9 in promoting odontogenic differentiation of dental mesenchymal stem cells.
Methods: Tooth germ stem cells were isolated from lower jaw molars of embryonic day 14^th mouse by using stereo-microscope. Epithelium and mesenchyme stem cells were seperated from the tooth germs by enzyme treatment. The proper concentration of fibroblast growth factor-9 (Fgf-9) was evaluated by MTT assay. Separated tooth germ cells were cultured in TRANSWELL system and experimental groups with Fgf-9 added in the culture medium were compared with the control groups without adding Fgf-9 in the medim. The effects of Fgf-9 were evaluated by comparing the expression of RNA gene expression in the experimental groups of mesenchymal stem cells and the control groups without adding Fgf-9. Organ culture of tooth germs for ten days in the experimental groups were compared with the control groups by observing the paraffin sections with Hematoxylin and eosin (H&E) staining.
Results: Our results demonstrated that Fgf-9 about 25 ng/ml in concentration is proper for investigating the effects on dental mesenchymal stem cells through MTT analysis. Compared with control groups, the expression of mesenchyme calcification-gene mRNA was higher in the experimental groups of dental mesenchymal stem cells cultured with 25 ng/ml Fgf-9 in the medium from first day to sixteenth day. In organ culture, the secretion of enamel-like matter in the experimental groups was also higher than the control groups.
Conclusions: It is concluded that fibroblast growth factor-9 can promote odontogenic differentiation of dental mesenchymal stem cells and also promote tooth development.