ABSTRACT
<p><b>OBJECTIVE</b>To observe the temporal and spatial expression of Smad7 during human tooth germ development and evaluate the effect of Smad7 on tooth germ development.</p><p><b>METHODS</b>The expression of Smad7 and its changes at different stages of human tooth germ were detected by using immunohistochemical staining.</p><p><b>RESULTS</b>Smad7 was expressed at all stages of tooth germ, but the distribution patterns at various stages were different. It indicated that temporal and spatial expressing mode of Smad7 during human tooth germ development was specific, which was similar to that of TGF-beta its signal transducer Smad2/3.</p><p><b>CONCLUSION</b>Smad7 might play an important role in TGF-beta intracellular signaling for modulating the differentiation of ameloblasts and odontoblasts.</p>
Subject(s)
Humans , Ameloblasts , Cell Biology , Cell Differentiation , DNA-Binding Proteins , Genetics , Metabolism , Physiology , Fetus , Immunohistochemistry , Odontoblasts , Cell Biology , Odontogenesis , Signal Transduction , Smad7 Protein , Tooth , Tooth Germ , Embryology , Trans-Activators , Genetics , Metabolism , Physiology , Transforming Growth Factor beta , Genetics , Metabolism , PhysiologyABSTRACT
Objective: To induce human dental mesenchymal cells to differentiate into odontoblasts in vitro.Methods:The cultured human dental mesenchymal cells were induced in two-dimensional culture model by bFGF(10 ng/ml)+IGF-1(100 ng/ml) or TGF-?1(5 ng/ml) for 4-7 d. Cell growth and morphology after induction were observed. The expression of human DSP protein and DSPP mRNA were detected by immunofluorescent staining and RT-PCR. Mineralization capability of the induced cells was evaluated using Von Kossa staining. Results:In both bFGF+IGF and TGF-?1 groups 20%-30% of the induced cells showed long single process.DSP protein and DSPP mRNA were observed in the induced cells.Mineralized nodules were found in the induction cultures.Conclusion: bFGF+IGF-1 or TGF-?1 can induce dental mesenchymal cells to differentiate into odontoblasts.