Abstract
The purpose of this study was to evaluate the effects of nicotine on Malassez' epithelial rest (MER) cells which are thought to maintain the homeostasis of the periodontal ligament. MER cells obtained from porcine periodontal ligament were cultured for 7 days, after which nicotine was added to the culture medium at concentrations of 0.03 μM, 0.15 μM or 0.2 μM. Cells cultured without nicotine were used as controls. Cell proliferation and expression of mRNAs encoding heat shock protein 70 (HSP70) and vascular endothelial growth factor (VEGF) were analyzed to evaluate the effects of nicotine. The cell proliferation ratios of all nicotine-treated groups were significantly lower than the control group on day 7. The expression of HSP70 mRNA in all nicotine-treated groups was higher than in the control group. The expression of VEGF mRNA in all nicotine-treated groups at all times examined tended to be lower than in the control groups. In conclusion, nicotine affects MER cells by increasing mRNA expression of HSP70, but decreasing that of VEGF.
