Gene Expression of Bovine Dental Pulp Cells In Vitro during Odontoblast-like Cell Differentiation

The expression of developmental stage-specific genes osteocalcin, alkaline phosphatase, thrombospondin (Tsp), transforming growth factor (Tgf) -β, fibroblast growth factor (Fgf), activin (Act) during pulp cell differentiation into odontoblast-like cell was examined using primary cultured pulp cells isolated from bovine adults teeth. The cells slowly became multilayered and clustered to form many nodules. RTPCR amplification demonstrated that Tgf-β1 and Fgf-2 expression were increased whereas osteocalcin, alkaline phosphatase, Tsp-1, and Act-βB expression had declined in relation to cellular differentiation. Mineralization in the nodules was confirmed by Alizarin red and calcein blue staining. These results suggest a role of up-regulation of Tgf-β1 and Fgf-2, and down regulation of osteogenic cell differentiation markers including alkaline phosphatase, Tsp-1 and osteocalcin in the mineralization in bovine dental pulp cells.