Utilization of M06-G3 Immortalized Odontoblast Cells in Studies Regarding Dentinogenesis

Abstract

Tooth formation is the result of reciprocal instructive interactions between oral epithelium and cranial neural-crest-derived ectomesenchymal tissues. These interactions lead to the cytodifferentiation of highly specialized matrix-forming cell types, the ameloblast, odontoblast, and cementoblast, that produce the mineralized tissues enamel, dentin, and cementum, respectively. Our laboratory has been developing immortalized dental cell lines representative of these various cell types to facilitate studies on gene regulation, cell differentiation, matrix formation, and mineralization. Odontoblasts are solely responsible for the synthesis and secretion of the dentin extracellular matrix bilayer that consists of non-mineralized predentin and mineralized dentin. The mouse immortalized M06-G3 cell line expresses the major matrix proteins associated with the odontoblast phenotype, producing a matrix that is capable of mineralization. This cell line serves as a useful tool in studies designed to explore the various processes of dentinogenesis. In this paper, we present studies using the mouse odontoblast cell line M06-G3 as examples of the various research applications. Studies highlighted are: in vitro promoter studies investigating the tooth-specific gene regulation of the major noncollagenous dentin matrix protein, dentin sialophosphoprotein; regulation of tertiary dentin formation by cytokines, such as transforming growth factor-Beta 1; and the utilization of dentally relevant cells in dental material biocompatibility testing