The odontogenic ameloblast‐associated protein (ODAM) cooperates with RUNX2 and modulates enamel mineralization via regulation of MMP‐20

Abstract

We have previously reported that the odontogenic ameloblast-associated protein (ODAM) plays important roles in enamel mineralization through the regulation of matrix metalloproteinase-20 (MMP-20). However, the precise function of ODAM in MMP-20 regulation remains largely unknown. The aim of the present study was to uncover the molecular mechanisms responsible for MMP-20 regulation. The subcellular localization of ODAM varies in a stage-specific fashion during ameloblast differentiation. During the secretory stage of amelogenesis ODAM was localized to both the nucleus and cytoplasm of ameloblasts. However, during the maturation stage of amelogenesis, ODAM was observed in the cytoplasm and at the interface between ameloblasts and the enamel layer, but not in the nucleus. Secreted ODAM was detected in the conditioned medium of ameloblast-lineage cell line (ALC) from days 14 to 21, which coincided with the maturation stage of amelogenesis. Interestingly, the expression of Runx2 and nuclear ODAM correlated with MMP-20 expression in ALC. We therefore examined whether ODAM cooperates with Runx2 to regulate MMP-20 and modulate enamel mineralization. Increased expression of ODAM and Runx2 augmented MMP-20 expression, and Runx2 expression enhanced expression of ODAM, although overexpression of ODAM did not influence Runx2 expression. Conversely, loss of Runx2 in ALC decreased ODAM expression, resulting in down-regulation of MMP-20 expression. Increased MMP-20 expression accelerated amelogenin processing during enamel mineralization. Our data suggest that Runx2 regulates the expression of ODAM and that nuclear ODAM serves an important regulatory function in the mineralization of enamel through the regulation of MMP-20 apart from a different, currently unidentified, function of extracellular ODAM.

CPNE7, a preameloblast-derived factor, regulates odontoblastic differentiation of mesenchymal stem cells

“…Odam and Mmp-20, ameloblast differentiation markers, were expressed during ameloblast differentiation ( Fig. 1(A and B)), as expected [12]. Furthermore, secretory Cpne7 was clearly detected in ameloblast conditioned medium (CM) from day 4 (preameloblast stage) and then decreased thereafter ( Fig.…”

“…Briefly, proteins (30 mg) were separated by 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and transferred to nitrocellulose membranes. Rabbit and affinity-purified polyclonal anti-Odam, anti-Cpne7, and anti-Dsp antibodies were produced as described previously [6,12]. The Flag (F3165) antibody was purchased from SigmaeAldrich (St. Louis, MO).…”

El papel de la enamelisina (MMP-20) en el desarrollo dentario. Revisión sistemática

“…En el 2010, Lee y colaboradores 22 estudiaron los mecanismos moleculares responsables de la regulación de la MMP-20, encontrando que la fase secretora de la amelogénesis ODAM (proteína asociada a ameloblastos odontogénicos) se localizó en el núcleo y citoplasma de los ameloblastos, y la etapa de maduración se observó en el citoplasma y en la interfaz entre los ameloblastos y la capa de esmalte, pero no en el núcleo. Se sugiere que Runx2 regula la expresión de ODAM nuclear que tiene una función reguladora importante en la mineralización del esmalte a través de la regulación de la MMP-20.…”

“…In 2010, Lee et al, 22 studied the molecular mechanisms responsible for the regulation of MMP-20, finding out that the secretory phase of amelogenesis ODAM (odontogenic-ameloblast-associated protein) was located in the nucleus and cytoplasm of ameloblasts, and maturation stage was observed in the cytoplasm and at the interface between the ameloblasts and enamel coating, but not in the nucleus. It is suggested that Runx2 regulates the expression of nuclear ODAM playing an important regulatory role in the mineralization of enamel through regulation of MMP-20.…”

An evolutionarily conserved non-coding element in casein locus acts as transcriptional repressor

“…During tooth development, this protein is involved in matrix protein production (Lee et al, 2012b). In ameloblasts, nuclear Odam has been reported as a regulator of the expression of matrix metalloproteinase-20 (MMP-20), a gene that is responsible for the mineralization of enamel (Lee et al, 2010a). Also, Odam is expressed in malignant ameloblasts and other types of human neoplastic cells, including those of gastric, lung, and breast origins but the precise function of Odam in these cancers is not known (Kestler et al, 2011).…”