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 MO6-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 MO6-G3 as examples of the various research applications. Studies highlighted are: in vitro promoter studies investigating the tooth-specific gene regulation of the major non-collagenous 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.

Role of ALK5/Smad2/3 and MEK1/ERK Signaling in Transforming Growth Factor Beta 1–modulated Growth, Collagen Turnover, and Differentiation of Stem Cells from Apical Papilla of Human Tooth

“…Differentiated odontoblasts participating in the repair and regeneration of pulpodentin complex also express TGF-b1. After exposure to TGF-b1 (5 ng/mL), about a 2-fold reduction in dentin sialophosphoprotein (DSPP) promoter activity and a 1.5-to 2-fold reduction in dentin matrix protein-1 (DMP-1) were noted on the mouse odontoblast cell line MO6-G3 (50,51). This implicates the regulatory functions of TGF-b1 on specific stages of odontoblast differentiation and dentin formation.…”

Fluoride at non-toxic dose affects odontoblast gene expression in vitro

“…This line is similar to odontoblasts, as shown by the expression of dentin-specific gene markers and by their polarized morphology (MacDougall et al, 1995(MacDougall et al, , 2001Mesgouez et al, 2005). Our primary question was whether gene expression could be altered by fluoride without effect on cell viability.…”

Human pulp‐derived cells immortalized with Simian Virus 40 T‐antigen

“…Preservation of phenotypic characteristics of SV40 T-Ag-immortalized cell lines has been observed after transfection of murine dental pulp cells (19). Tissuespecific proteins were expressed in cell lines established from mouse dental papilla cells, such as MO6-G3 cells (30), or in MDPC-23 cells (31) from rat pulp cell lines (32) as well as from bovine dental papilla (11). Also, one SV40 T-Ag-transfected human pulp-derived cell line has been established and preliminary characterization has been performed (22).…”