Overexpression of septin-7 inhibits melatonin-induced cell apoptosis in human fetal osteoblastic cells via suppression of endoplasmic reticulum stress.

Our previous study demonstrated that melatonin could induce apoptosis in the human fetal osteoblastic (hFOB) 1.19 cell line via induction of endoplasmic reticulum stress (ERS), and recent studies have demonstrated that the expression of septin-7 (SEPT7) exhibits a positive correlation with the concentration of melatonin. Western blotting demonstrated the expression level of SEPT7 was significantly upregulated in a dose-dependent manner following treatment with differing concentrations of melatonin compared with the control groups, which did not receive any treatment. The expression of proteins associated with cell apoptosis and endoplasmic reticulum stress (ERS; pro-caspase-3, cleaved caspase-3, C/EBP-homologous protein, 78 kDa glucose-regulated protein and phosphorylated-eukaryotic translation initiation factor 2) were decreased following transfection with SEPT7 overexpression plasmid and increased following transfection with SEPT7 small interfering RNA compared with the control groups. The results of the present study suggest that SEPT7 inhibits melatonin-induced cell apoptosis via suppression of ERS.