Tumor necrosis factor alpha enhances the bone-resorptive capabilities of osteoclasts by improving the expression and activity of vocuolar-type ATPase / 中国组织工程研究

ABSTRACT

BACKGROUND:Vocuolar-type ATPase (V-ATPase) is highly expressed in osteoclasts and especial y plays an important role in osteoclastic bone resorption. Tumor necrosis factor-αis a potent stimulator of bone resorption. However, the effect of tumor necrosis factor-αon expression and activity of V-ATPase is stil not clear. OBJECTIVE:To investigate the mechanism of tumor necrosis factor-αto promote osteoclastic bone resorption by observing expression and activity of V-ATPase. METHODOsteoclasts cultured in vitro were intervened by different concentrations of tumor necrosis factor-α(5, 10, 30μg/L) in order to observe the changes in expression and enzyme activity of V-ATPase and its effects on bone resorption of osteoclasts. Under an inverted microscope, we observed the formation of resorption lacunas, and bone resorption area was analyzed using Image J software. RESULTS AND CONCLUSION:The expression and activity of V-ATPase increased significantly after 48 hours of tumor necrosis factor-αintervention and the increase of tumor necrosis factor-αconcentration might enhance this effect. In addition, osteoclastic bone resorption was promoted after intervention with tumor necrosis factor-α. The bone-resorbing capabilities of osteoclasts increased in paral el with the concentration of tumor necrosis factor-α.The results suggested that tumor necrosis factor-α, as a significant inflammatory mediator involved in the pathological process of bone resorption, not only promotes formation of osteoclasts but also enhances bone-resorbing capabilities of osteoclasts by increasing V-ATPase expression and activity.