Involvement of PIN1 pathway on effects of melatonin in EtOH-induced cellular senescence of PDLCs and cementoblasts. Cells are pretreated with juglone or PIN1 siRNA and then incubated with melatonin (100 μM) and EtOH (25 mM) for 3 days (A–F). mRNA and protein expression were accessed by Western blot and RT-PCR (A,B,E,F), respectively. Senescence was examined by β-gal activity (C), ROS production (D,E) and expression of senescence-associated proteins (E) and mRNAs (F). These data are representative of three independent experiments. * statistically significant difference compared to the control groups (p < 0.05). # statistically significant difference in each group.