Expression of Heat Shock Proteins in Response to Mild Short-term Heat Shock in Human Deciduous Dental Pulp Fibroblast-like Cells

Appropriate heat shock results in the production of heat shock proteins (HSPs) whose expression and phosphorylation contribute to repair of damaged proteins, cell proliferation, and cell recovery from shock stimuli. However, there is no information regarding the expression of HSPs in human deciduous dental pulp fibroblast-like cells (hDDPF) in response to mild short-term heat shock. The aim of this study was to investigate the cellular effects of mild short-term heat shock on hDDPF. Cells were subjected to heat shock at 43°C–49°C for 15 min, and cell proliferation was assessed by 3-(4,5-dimethylthiazol-2yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay. mRNA and protein expressions of HSP27, 70, and 90 were detected by reverse transcription PCR and western blot analysis, respectively. Phosphorylation of the AKT and ERK signaling pathways of HSP production was evaluated by western blotting. Heat shock at 43°C for 15 min increased the cell proliferation rate and the mRNA expressions of HSP27, 70, and 90 in hDDPF. Moreover, protein expression of HSP70 was significantly enhanced 24 h after heat shock, and the phosphorylation of AKT was also confirmed. Because HSP70 is critical in tissue repair and regeneration, mild short-term heat shock may enhance tissue repair in hDDPF.