Genes associated with sodium fluoride-induced human osteoblast apoptosis

This study aims to explore the potential pathways and molecular characteristics of fluorine-induced osteoblast apoptosis. In vitro fluorine-induced model was established with an osteogenesis sarcoma cell line Saos-2. Then flow cytometry was used to determine the mitochondrial membrane potential at 24 h after the intervention. 84 apoptosis-related genes in the cells were determined using the functional polymerase chain reaction (PCR) chip and part of the differentially expressed genes was verified with immune blotting. When the stimulated concentration of sodium fluoride were 20 mg/L, 40 mg/L and 80 mg/L, the mitochondrial membrane potential of the osteoblast cells were 27.0%, 28.8% and 38.6%, respectively, significantly higher than that in the blank control group (P<0.05). The PCR chip detection found 13 up-regulating genes and 15 down-regulating genes, among which the expression of Bim, Caspase 9, Caspase 14, B-cell lymphoma-2 (BCL2) and BAX increased with the doses of sodium fluoride, while the expression of Caspase 3 down-regulated in 5 mg/L sodium fluoride but up-regulated at the concentration of sodium fluoride more than 10 mg/L. Caspase 7 expression showed no obvious difference between the different concentration groups. However, Caspase 10 decreased with the increasing doses of sodium fluoride. Fluoride-induced osteoblast apoptosis may be through the mitochondrial pathway (including endoplasmic reticulum stress pathway) and death receptor pathway.