Objective: To explore the effect of zoledronate (ZOL) on the osteoclast adhesion and expression of integrin α(v) and β3 in vitro.
Methods: Mice RAW264.7 cells were used for osteoclast differentiation in vitro, and osteoclastogenesis was examined by tartrate-resistant acid phosphatase (TRAP) staining and dentin resorption lacunae examination. The cells were then divided into 2 groups, the control group and ZOL treatment group (treated with 1 x 10(-6) mol · L(-1) ZOL for 2 d). The adhesion ability of osteoclasts and mRNA and the protein expressions of integrin α(v) and β3 were examined by crystal violet staining, real-time fluorescence quantitative polymerase chain reaction, Western blot analysis, and immunofluorescent chemistry.
Results: TRAP staining and dentin resorption lacunae examination revealed the formation of multi-nuclear osteoclasts. ZOL treatment significantly decreased the adhesion ability of osteoclasts (P < 0.01). In the ZOL-treated group, the mRNA levels of integrin α(v) and β3 were 0.66 ± 0.05 and 0.59 ± 0.08, respectively. In the control group, the mRNA levels of integrin α(v) and β3, were 1.01 ± 0.01 and 1.01 ± 0.02, respectively; these values were higher than those in the ZOL-treated group (P < 0.01). The protein level of integrin α(v) and β3 in the ZOL-treated group (31,934.84 ± 112.91 and 18,812.79 ± 194.13) was downregulated by approximately 39.19% and 40.17%, respectively, compared with those in the control group (52,517.81 ± 211.72 and 31,441.93 ± 456.87) (P < 0.01). Immunofluorescent examination showed that the fluorescent intensities of integrin α(v) and β3 in the ZOL-treated group (9.491 ± 0.748 and 4.744 ± 0.759) were also significantly decreased compared with those in the control group (15.159 ± 1.143 and 11.418 ± 1.095) (P < 0.01).
Conclusion: ZOL significantly inhibits osteoclast adhesion and downregulates integrin α(v) and β3, expression, thus contributing to the ZOL-induced inhibition of osteoclast- mediated bone resorption.
目的: 研究唑来膦酸（ZOL）对破骨细胞黏附以及整合素αv和β3基因表达的影响。
方法: 体外诱导小鼠RAW264.7细胞向破骨细胞分化，通过抗酒石酸酸性磷酸酶（TRAP）染色及牙本质吸收陷窝检测以评价破骨细胞生成情况。将细胞分为对照组及ZOL处理组两组，后者用1×10−6 mol·L−1的ZOL处理2 d，用结晶紫染色法检测细胞黏附情况，用实时荧光定量聚合酶链反应、Western blot和免疫荧光化学法检测整合素αv、β3 mRNA及蛋白表达水平。
结果: TRAP染色及牙本质吸收陷窝检测提示有多核破骨细胞生成。ZOL处理组破骨细胞黏附能力较对照组显著降低（P<0.01）。ZOL处理组整合素αv、β3 mRNA水平分别为0.66±0.05、0.59±0.08，显著低于对照组的1.01±0.01和1.01±0.02（P<0.01）；蛋白表达水平分别为31 934.84±112.91、18 812.79±194.13， 较对照组（52 517.81±211.72、31 441.93±456.87）分别下降了39.19%和40.17%（P<0.01）。免疫荧光化学检测显示，ZOL处理使整合素αv、β3荧光强度（9.491±0.748、4.744±0.759）较对照组（15.159±1.143、11.418±1.095）分别降低了37.39% 和58.45%（P<0.01）。
结论: ZOL可抑制破骨细胞黏附并下调整合素αv、β3表达；ZOL的上述作用可能参与对破骨细胞性骨吸收的抑制。