Fluoride effect in matrix vesicules of osteblasts in vitro: comparative analysis in two straight with differents fluoride susceptibilidade

Abstract

Bone is a specialized connective tissue that is mineralized over a deposition by osteoblasts, matrix organic non-mineralized, mainly collagen type I, with its subsequent mineralization by release of matrix vesicles, responsible for the maturation of hydroxyapatite crystals. It is known that fluoride causes cellular and chemical changes in bone tissue, depending on dosage and duration of exposure to this element. Several studies have demonstrated that clinically important changes, such as osteoporosis, osteopenia and bone sclerosis may be influenced by fluoride. In response, we seek to assess whether the fluoride influences the mineralization process mediated by osteoblasts, through the release of extracellular matrix vesicles (MV). We use pre-osteoblastic cells derived from 2 strains of mice with different bone densities and known, C3H/HeJ (high density) and C57BL/6J (low density), undergoing treatment with different concentrations of NaF (10-3, 10-4 , 10-5, and 0 M) for 24, 48, 72, 96 and 120 h. After the experimental period, we will test corroborating the osteoblast differentiation and mineralization. By ultracentrifugation, isolated the VM that will be compared with vesicles isolated from the control group (0M NaF) on the protein content (Bradford Assay and protein expression by Western blotting for alkaline phosphatase, Annexin; Osterix; Runx-2 and BSP ) and change the gene expression of annexin V, osterix, collagen type I, LRP-5, osteocalcin,, bone sialoprotein and Runx2. The data are expressed as mean ± standard deviation and will be subjected to analysis of variance (ANOVA) and Tukey's test for individual comparisons and the Kruskal-Wallis test for multiple comparisons (p <0.05). (AU)