The differentiation-inducing effect of conditioned media obtained from dental pulp cells.

Objective: Conditioned media (CM) from human dental pulp cells (HDPC) was investigated for its effects on the proliferation and differentiation of HDPC and MG63 cells.

Study Design: CM prepared from the primary culture of HDPC was used for the culture of HDPC and MG63. Cell growth, alkaline phosphatase (ALPase) activity, mRNA expression of differentiation-related genes, and mineralization of the HDPC and MG63 cells in the media containing CM were assessed.

Results: HDPC CM increased the cell growth of HDPC but decreased MG63 cell growth. ALPase activity and the mineralization of both HDPC and MG63 were enhanced by HDPC CM. The CM also up-regulated the expressions of DSPP, DMP-1, and OCN mRNA in HDPC. Pretreatment of HDPC CM with a neutralizing antibody against TGF-beta completely eliminated the effect of CM on ALPase activity in HDPC.

Conclusion: HDPC was able to secrete odontogenic differentiation-inducing factors, in which TGF-beta seems to a key element of the CM effects.