Apoptosis-related genes in human osteoblasts induced by sodium fluoride / 中国组织工程研究

ABSTRACT

BACKGROUND:There are no systematic and coherent studies on the mitochondrial apoptotic pathway of fluoride-induced osteoblast apoptosis, and the specific pathways to induce apoptosis in osteoblasts by fluorine are stil unclear. OBJECTIVE:To explore the possible pathways of apoptosis in osteoblasts induced by fluoride and its molecular characteristics. METHODS:A fluorosis model of human osteosarcoma cel line Saos-2 was establishedin vitro. After in vitro culture, the cels were treated with sodium fluoride at different concentrations (0, 5, 10, 20, 40, 80 mg/L). Flow cytometry was used to inspect the mitochondrial membrane potential at 24 hours after intervention; 84 apoptosis-related genes were detected by PCR Array; parts of the differentialy expressed genes were verified by western blot method. RESULTS AND CONCLUSION: When the concentrations of sodium fluoride were 20, 40 and 80 mg/L, the mitochondrial membrane potentials in osteoblasts were 27.0%, 28.8%, 38.6%, respectively (alP < 0.05). PCR array found 13 genes upregulated and 15 genes down-regulated. Immunoblotting results showed Bim, Caspase 9, Caspase 14, BCL2, BAX expressions enhanced with increasing doses of sodium fluoride; Caspase 3 expression was decreased at the concentration of 5 mg/L, but increased gradualy at over 10 mg/L. Caspase 7 expression had no significant difference. The expression of Caspase 10 decreased with the increasing doses of sodium fluoride. These findings indicate that fluoride may induce apoptosis in osteoblasts through the mitochondrial pathway (including the endoplasmic reticulum stress pathway) and death receptor pathway.