Abstract:

Objective　To studythe roles of the Notch2-Delta signaling in the differentiation of dental pulp cells into odon- toblastsin vitro.Methods　A long-term culture system was used as a model for the study of proliferation and differentiation of pulp cells into preodontoblasts. The expression patterns ofNotch2and its ligand Delta in different phases of long-term cultured den- tal pulp cellswere studied by immunohistochemistry andwestern blotting. Furthermore, the effects of rhBMP-2 on the expression of Notch signaling members were studied.Results　Notch2and its ligand Delta expressed in all phases of dental pulp cells and the sites and levels of their expression changed with different phases. rhBMP-2 could significantly up-regulated the expression of Delta in the phase of later cell nodule formation.Conclusion　This study demonstrated that Notch signaling pathway played roles in the differentiation of long-term cultured human dental pulp cells which formed nudules that were slightly mineralized and had ul- trastructural features reminiscient of preodontoblasts, and it may be the mechanism that control pulpal cell’s responsiveness to sig- naling molecules in the healing of wound pulp.

Key words: signaling reduction, pulp cell, cell culture, Notch, Delta