Expression Of Caveolin-1, CD147 And MMP-2 In The Mouse Molar Lower First Tooth Germ And Ameloblast

The tooth is an organ that develops as a result of mutual induction and reciprocal interactions between the dental epithelium and the neural crest-derived mesenchyme with a large number of signaling molecules involved which constitutes a complex signaling network. The correct understanding of a number of mechanisms for the occurrence of tooth development will play a decisive role for the advances in dental tissue engineering. Cell signal transduction is one of the most important physiological functions of Cavealae / Caveolin-1. Matrix metalloproteinase-2(MMP-2) and extracellular matrix metalloproteinase inducer(EMMPRIN / CD147) may be involved in the degradation of the basement membrane during the tooth development, which facilitates the cross-talking between epithelial cells and mesenchymal cells and signals transmition to induce the development of dental hard tissue. Our previous study have found that Caveolin-1、CD147 and MMP-2 Immunohistochemically expressed in mouse tooth germ at different developmental stages suggesting that they make function in tooth development. However, the morphology of caveolae in enamel-forming cells; the spatiotemporal expression of Caveolin-1, CD147 and MMP-2 at transcriptional level and the relationships among the three factors are largely unknown. Objective1. To observe the morphology chang of Caveolae in enamel-forming cells with the tooth germ development.2. To detect the transcriptional expression of Caveolin-1, CD147 and MMP-2 in mouse developing tooth germ.3. To investigate the relationships among Caveolin-1,CD147 and MMP-2 by silencing the Caveolin-1 expression in the enamel cells in vitro. Method1. Under the stereomicroscope,we separated the mandibular first molar tooth germ of E14.5,E16.5, E18.5 and PN2 mouse, and used electron microscopy and immune electron microscopy to observe of the shape and location of caveolae in tooth germ epithelium.2. Collecting the mandibular first molar tooth germ of E14.5, e16.5, E18.5 and PN2, we used real-time quantitative PCR technique to detect the expression of Caveolin-1 mRNA, CD147 mRNA and MMP-2mRNA in mouse tooth germ at different developmental stages, and made a statistical analysis.3. Culturing the ameloblasts line, and using small interfering RNA to transfect the cells, the expression of caveolin-1 was silence. Using real-time PCR and Western blot to detect the interference effects, and the change of CD147 and MMP-2.The results were statistically analyzed. Result1. The inner enamel cell and ameloblast of E14.5, E16.5, E18.5 and PN2 of the mandibular first molar tooth germ can be observed the cave-like appearance of Caveolae, and the expression of Caveolin-1 in the cytoplasm of the cells was located by immunoelectron microscopic.2. The Caveolin-1mRNA expression of the E14.5, E16.5, E18.5 and PN2 mandibular first molar tooth germs increased gradually. The expression of CD147 and MMP-2mRNA from the bud stage to the early bell stage had no obvious changes, but in the late bell stage the expression significantly increased. And there was a positive correlation among them.3. After transfection, the expression of Caveolin-1mRNA and MMP-2mRNA by Real-Time PCR detection significantly decreased, the expression of CD147 mRNA did not change significantly. The expression of Caveolin-1, high glucose CD147 and MMP-2 were decreased by Western blot. Conclusion1. Caveolae existed in the cell membrane and cytoplasm in enamel-forming cells, and has the individually cave-like appearance.2. Caveolin-1、CD147 and MMP-2 Immunohistochemically expressed in mouse tooth germ at different developmental stages suggesting that they make function in tooth development.3. During the development of tooth germ, Caveolin-1 may affect the production of MMP-2 by regulating the degree of glycosylation of CD147.