[Expression of mineral-associated factors in the mineral stage tooth germ of mice].

PURPOSE: To study the distribution and expression of core binding factor alpha 1(Cbfα1),bone sialoprotein(BSP),osteopontin(OPN),osteocalcin(OC)and alkaline phosphatase(ALP)in mineral stage tooth germ of mice, so as to understand their roles in the development of the mineral stage tooth germ. METHODS: Thirty BALB/c mice in different days were killed, and their bilateral mandibular first molar germs with surrounding alveolar bone were taken out, then the tissues were fixed with 4% paraformaldehyde at 4℃ overnight, dehydrated, embedded in paraffin and serially sectioned at 5μm. Immunohistochemical assay was adopted to determine the tissue distribution and cellular localization of Cbfα1, OPN, BSP, ALP and OC in the mineral stage tooth germ by these sections of BALB/c mice. RESULTS:There were Cbfα1, BSP and OPN expressing in the alveolar bone, and Cbfα1, ALP, OC in predentin, while in other tissues such as dental follicle, pulp cells, stratum intermedium, stellate reticulum, only ALP and OC were detected, but none of them were observed in the dentin. CONCLUSIONS:The formation mechanisms of hard tooth tissues are different. They are controlled by different factors. Cbfα1,ALP and OC are involved in the early formation of dentin, while Cbfα1,OPN and BSP involved in the early formation of alveolar bone, ALP involved in the stratum intermedium. They all play an important role in the start of mineralization.Supported by National Natural Science Foundation of China(Grant No.30371537) and Award Fund for Excellent Young and Middle-Aged Scientists of Shandong Province(Grant No.02BS096).