법랑질 형성과정에서 MMP-20의 조절을 통한 ODAM의 법랑질 석회화 조절

Abstract

It was previously hypothesized that odontogenic ameloblast？]associated protein (ODAM) plays a functional role in the maturation of enamel for proper mine- ralization. Therefore, it was examined whether ODAM modulates enamel mine- ralization through the regulation of MMP？]20 expression in this study. We investigated the expression of ODAM and MMP？]20 during amelogenesis in normal and MMP？]20？]deficient mice in vivo and in vitro. ODAM is weakly expressed in secretory ameloblasts and strongly expressed in maturation？]stage ameloblasts. The expression level of ODAM does not differ between wild？]type and MMP？]20？]deficient ameloblasts. In ameloblast？]lineage cells (ALCs), the expression of ODAM correlates with MMP？]20 expression between four and seven days in culture. This time frame overlaps with the secretory stage of amelogenesis. ODAM mRNA was found in various cancer cells including gastric cancer. However, ODAM mRNA was not expressed in normal oral epithelial cells. The overexpression of ODAM in ameloblasts resulted in up？]regulation of the MMP？]20 gene. In contrast, inactivation of ODAM by siRNA abrogated MMP？]20 expression. Calcium binding property of rODAM revealed that rODAM clearly bound 45Ca by a dot blot technique. Here, it was also demonstrated the entry of exogenous rODAM into the nucleus and cytoplasm of ALCs. These results suggest that ODAM serves an important regulatory function in the mineralization of enamel through the regulation of MMP？]20.

Keywords Ameloblast, ODAM, MMP？]20, Mineralization, Regulation