Methods: Wild type and Clcn5 gene knockout mice and odontoblast like MDPC23 cells were used in this study. HE staining, TEM analysis, western blot were used to compare the changes of tooth in Clcn5 gene knockout mice. ClC-5 RNAi was used to block ClC-5 function in odontoblast like MDPC23 cells and mRNA level of different genes were detected with real time PCR method.
Results: We have found the abundant ClC chloride channel gene expression in tooth germ. Some of these chloride channels may regulate tooth development through effects on cell proliferation and cell cycle signal pathway. Further detail studies demonstrated that Clcn5 gene knockout mice displayed abnormal dentin construction. There was a positive relationship between ClC-5 and TGF-beta1. The mRNA level Dspp and dmp1 were afftected through TGF-beta1 pathway.
Conclusions: ClC-5 has a role in regulating dentin formation through TGF-beta1 pathway. All these research data shed light on the new physiological aspect of tooth development.