The localization of Fos B, a member of transcription factor AP-1 family, in rat odontoblasts and pulpal undifferentiated ectomesenchymal cells.

It has been proposed that cellular proliferation and differentiation are accomplished by AP-1 components but different components can be responsible for different functions. The aim of this study was to compare the localization of Fos B, which is a component of AP-1, in postmitotic differentiated and undifferentiated cells via Fos B immunoreactivity. For this purpose, maxillary incisor teeth from 10 Wistar rats were obtained and Fos-B was investigated immunohistochemically in formalin-fixed, paraffin-embedded tooth sections containing odontoblasts, which are postmitotic differentiated cells, and pulpal undifferentiated ectomesenchymal cells. No significant differences in percentage of Fos B-positive cells were observed between the two cell types (p>0.05). These findings suggest that Fos B, a component of AP-1 family, seems to have a negligible effect on differentiation and proliferation in odontoblasts and pulpal undifferentiated ectomesenchymal cells.