ABSTRACT
Objective To investigate whether 5% strontium-containing brushite bone cements(DCPD) has repair effect on alveolar bone defects in osteoporotic rabbits. Methods Eighteen healthy adult female rabbits were used to establish osteoporosis models and were randomly divided into three groups:the blank control group, DCPD group,doped 5%DCPD group(5%strontium),with 6 rats in each group.In addition to the blank group, rats the other groups were filled with the corresponding bone cements in the bilateral alveolar bone defects. At 4 weeks and 8 weeks after operation,3 rats in each group were killed and given shooting the defect area X-ray.The expression of b-FGF was detected by immunohistochemistry. Results X-ray results showed that the defected of doped 5% DCPD group have been nearly completedat the 8 week,DCPD group partially completed repair,but blank group was not fully repaired. The results of immunohistochemistry showed that the expression of b-FGF was the highest at 4 weeks and decreased at 8 weeks after operation.Expression of b-FGF was significantly different at 4 weeks and 8 weeks among the three groups.Conclusion The 5%strontium-containing brushite bone cements can repair bone defect in osteoporotic rabbits.
ABSTRACT
BACKGROUND:Studies have shown that bisphosphonates inhibit osteoclast resorption, but whether cathepsin K, a key cytokine of bone resorption, plays an effect has rarely been reported. OBJECTIVE:To study the effect of bisphosphonate on capthesin K and bone resorption function during osteoclast differentiation. METHODS:Osteoclasts were cultured by mouse monocyte-macrophage cellline-RAW264.7. The cells were divided into two groups:control group, treated with 100μg/L receptor activator of nuclear factorκB ligand factor;alendronate group, treated with 100μg/L receptor activator of nuclear factorκB ligand factor+10-7 mol/L alendronate. Osteoclastogenesis and resorption function of osteoclasts were examined at 7 days of culture and gene expression of capthesin K was detected by immunofluorescence method at 72 hours of culture. Western blot assay was used to detect capthesin K protein expression at 72 hours of culture. RESULTS AND CONCLUSION:Tartrate-resistant acid phosphatase positive multinuclear cells were observed and resorption lacunae formed in two groups. Control group showed the higher number of tartrate-resistant acid phosphatase positive multinuclear cells and larger size of resorption lacunae than the alendronate group (P<0.01). Immunofluorescence showed expression of capthesin K was higher in the control group than the alendronate group (P<0.01);furthermore, the protein expression of capthesin K was also lower in the alendronate group than the control group (P<0.01). These findings indicate that bisphosphonates could strongly inhibit osteoclastogenesis and its resorption function by inhibiting gene expression of capthesin K.