Influência da vitamina D na atividade osteoclástica em um modelo de cultura de órgãos ósseos

Abstract

Introduction: Bone remodeling is controlled by various cytokines and hormones, such as vitamin D3, which regulates receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG) expression levels positively and negatively. It is also used as an inducer of osteoclast formation in vitro. Objective: To evaluate the effect of vitamin D (VitD) on osteoclastic activity in cultured calvariae. Material and method: Fragments of mice calvaria were cultured in basic medium (control) or VitD-containing medium (10 nM: low dose; 100 nM: high dose). After intervals of 24, 48 and 72 hours, the culture medium was collected for calcium measurement and the fragments were fixed for confocal microscopy. Results: It was observed that the addition of vitamin D in both concentrations promoted an increase of calcium levels in the medium. Nonetheless, statistically significant differences between high and low doses were detected only in the 24-hour interval. In the microscopic analysis, areas of demineralization were more extensive among calvariae cultured with high doses of VitD. Conclusion: VitD increases osteoclastic activity in vitro in a dose-dependent effect.