Expression of core binding factor Osf2/Cbfa-1 and bone sialoprotein in tooth development

Abstract

The transcription factor Osf2/Cbfa1 is a key regulator of osteogenic differentiation while BSP, a major non-collagenous protein, is a marker of osteoblastic differentiation. To determine the relationship between Osf2/Cbfa1 and the formation of mineralized tissues in tooth development we have studied the temporal expression of Osf2/Cbfa1 and BSP mRNA using in situ hybridization. These studies show that Osf2/Cbfa1 is expressed early in mesenchymal and epithelial tissues destined to form the mineralized tissues of the tooth and periodontal tissues, whereas BSP provides a specific marker for the differentiated cells in each of these tissues. Expression of Osf2/Cbfa1, but not BSP, was observed in the periodontal ligament indicating that expression of Osf2/Cbfa1 is not restricted to mineralizing tissues.

A cell line with characteristics of the periodontal ligament fibroblasts is negatively regulated for mineralization and Runx2/Cbfa1/Osf2 activity, part of which can be overcome by bone morphogenetic protein-2

“…1E). Our results were somewhat inconsistent with those of recent studies demonstrating Runx2/Osf2 gene expression in odontoblasts during tooth development, but after completion of tooth development, the principal site of expression of this gene was restricted to the PDL (D'Souz et al, 1999;Jiang et al, 1999). The reason for the discrepancies between those two studies and the present study is not clear at present.…”

“…The reason for the discrepancies between those two studies and the present study is not clear at present. Since the signal detected in our study was clear and consistent with the previous observations concerning the expression of this gene in osteoblasts and PDL cells (D'Souz et al, 1999;Jiang et al, 1999), and since the signal disappeared completely when a sense probe was used, it is unlikely that the signals were non-specific. Differences in the probes used and in the differentiation stage of the animals in these studies may account for the discrepancies.…”

A Case of Calcifying Odontogenic Cyst With Numerous Calcifications: Immunohistochemical Analysis

“…Cbfa-1 is a genetic transcription factor expressed in osteoblasts, and it is related to the expression of osteocalcin and osteopontin, which are known to be involved in the differentiation of osteoblasts with bone formation 3,17) . Recently, the expression of cbfa-1 has been confirmed in the tooth germ, but the mechanism involved remains unclear 4,7,10,13,20) . In this study, positive reactions for cbfa-1 were observed only in mesenchymal cells in the periodontal ligament, but not in cells of the lining epithelium or in odontogenic epithelial islands.…”

Erk Is Essential for Growth, Differentiation, Integrin Expression, and Cell Function in Human Osteoblastic Cells

“…Other transcription factors may also contribute to the Erk/MAPK effects, especially the aforementioned Cbfa1 since the activation of Cbfa1 is dependent on Erk/MAPK (26,44,55). Cbfa1 can regulate the expression of bone sialoprotein, type I collagen, osteocalcin, and osteopontin in osteoblasts (62)(63)(64)(65). Therefore, the inhibition of Erk activity in Erk1DN cells will prevent the activation of Cbfa1 leading to the inhibition of bone matrix protein deposition.…”