Bone Marrow Mesenchymal Stem Cells Differentiate Into Odontoblasts In Vivo

It is important for related stem cells to differentiate into odontoblasts in the repair of dentin defects.. In the control of niche, the bone marrow mesenchymal stem cells as a type of adult stem cells can differentiate into cells of mesoderm and ectoderm origin. But there is no report that the stem cells from other origins repair the dentin defects by differentiating into odontoblasts. The experiments aims to disclose if the bone marrow mesenchymal stem cells of transgenic GFP-gene mice can differentiate into odontoblasts for the repair of dentin defects in vivo and in vitro. It will provide seed cells for the dental tissue engineering.Methods: (1) The whole marrow of transgenic GFP-gene mice was gained. After ACK splited the erythrocytes, the bone marrow mesenchymal stem cells were cultured and proliferated by adherence way in vitro. The molecules on the cells were identified by flow cytometer and then the cells was induced to differentiated into the osteoblastic and adipogenic lineage. (2) The C57BL/6 mice model jointed with green fluorescence bone marrow mesenchymal stem cells was established by intravenous injection. (3) The mice model of dentin defects was established. The immunofluorescence observation was used to see if the bone marrow mesenchymal stem cells with immunofluorescence took part in the dentin defects and study the possibility of the bone marrow mesenchymal stem cell as the seed cells for repair of dentin defects.Results: (1) The bone marrow mesenchymal stem cells of transgenic GFP-gene mice had ability to proliferate and passage continually. The molecules on the cells of P3 generation were identified positive by flow cytometer and the expression of green fluorescence was steady. The cells could be induced to differentiate into the osteoblastic and adipogenic lineage. (2) The whole marrow of the jointed model was cultured. Large amount of cells with green fluorescence were found and the cells also existed in the multiple tissues and organs. (3) Many cells with green fluorescence appeared in the pulp of the jointed mice model with dentin defects. The cells with green fluorescence especially expressed DSP and DMP-1 in the dentin defects.Conclusion: Through the culture of the bone marrow mesenchymal stem cells of transgenic GFP-gene mice and establishing the jointed mice fluorescence model, the differentiation ability of the bone marrow mesenchymal stem cells into odontoblasts was proved and this was induced by special cell niche. BMMSCs differentiating into odontoblasts took part in the repair of dentin defects. It could be a new type of stem cells resource for teeth tissue engineering.