Expression of HSP70 in dental pulp fibroblasts from deciduous teeth

Dental pulp plays an important role in tooth vitality. Previous studies have indicated that stem cells can be isolated from dental pulp, and dental pulp exfoliated from deciduous teeth has become a useful alternative in dental tissue engineering because of its higher proliferation rate. However, heat stress can cause irritation in the dentin/pulp complex, and little is known about the thermotolerance of pulp cells and their response to heat stress. Heat shock protein (HSP) is induced by heat and various other stresses. It also reportedly takes part in causing apoptosis when wounded dental pulp cells heal. In this study, we investigated the responses of dental pulp cells to heat stress using reverse transcriptase-polymerase chain reaction and immunoblotting analysis. Cells were subjected to a temperature of 42°C for 1, 2, 7, and 14 h, and HSP70 was determined at each time point. HSP70 expression was weak before heat treatment, but heat shock markedly induced HSP70 expression. This suggests that heat stress raises the wound healing ability of dental pulp cells. The mechanisms by which heat stress induces HSP expression may be an important link between apoptosis and wound healing. Therefore, an understanding of the mechanisms underlying HSP expression in dental pulp is important for the development of new therapeutic strategies.