BISPHOSPHONATES DIRECTLY INHIBIT THE BONE-RESORPTION ACTIVITY OF ISOLATED AVIAN OSTEOCLASTS INVITRO
BISPHOSPHONATES DIRECTLY INHIBIT THE BONE-RESORPTION ACTIVITY OF ISOLATED AVIAN OSTEOCLASTS INVITRO
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DOI：
10.1172/jci114459
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发表时间：
1990-02-01
影响因子：
15.9
通讯作者：
BLAIR, HC
中科院分区：
文献类型：
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作者：
CARANO, A;TEITELBAUM, SL;BLAIR, HC
双膦酸盐可用于治疗骨代谢活性增加的疾病，但双膦酸盐的作用机制尚不清楚。我们使用鸡破骨细胞的培养物来解决这个问题，发现1-羟基亚乙基二膦酸（EHDP），二氯亚甲基二膦酸（Cl 2 MDP）或3-氨基-1-羟基亚丙基-1，1-二膦酸（APD）都能引起破骨细胞活性的直接剂量依赖性抑制。作用由骨结合药物介导，在500 nM至5 μ M的不同药剂下发生50%的骨降解减少。骨细胞骨结合能力下降了30-40%后，72小时的双膦酸盐治疗，尽管维持细胞活力。仅在治疗24-72小时后观察到每种情况下骨吸收的显著抑制。破骨细胞的活性依赖于ATP依赖的质子转运。使用吖啶橙子作为指示剂，我们发现EHDP减少破骨细胞的质子积累。然而，在高浓度EHDP，Cl 2 MDP或APD中，破骨细胞的内面向外质膜囊泡正常转运H+以响应ATP。这表明双膦酸盐起代谢抑制剂的作用。双磷酸盐减少骨钙蛋白的合成，支持这一假设。此外，EHDP、Cl 2 MDP和APD也会减少不吸收骨的成纤维细胞的（3 H）亮氨酸掺入，但与双膦酸盐结合骨颗粒共培养时除外。 因此，EHDP、Cl 2 MDP和APD的再吸收拮抗能力反映了代谢抑制，对破骨细胞的选择性来自与骨矿物质的高亲和力结合。
Bisphosphonates are useful in treatment of disorders with increased osteoclastic activity, but the mechanism by which bisphosphonates act is unknown. We used cultures of chicken osteoclasts to address this issue, and found that 1-hydroxy-ethylidenediphosphonic acid (EHDP), dichloromethylidene-diphosphonic acid (Cl2MDP), or 3-amino-1-hydroxypropylidene-1,1-diphosphonic acid (APD) all cause direct dose-dependent suppression of osteoclastic activity. Effects are mediated by bone-bound drugs, with 50% reduction of bone degradation occurring at 500 nM to 5 .mu.M of the different agents. Osteoclastic bone-binding capacity decreased by 30-40% after 72 h of bisphosphonate treatment, despite maintenance of cell viability. Significant inhibition of bone resorption in each case is seen only after 24-72 h of treatment. Osteoclast activity depends on ATP-dependent proton transport. Using acridine orange as an indicator, we found that EHDP reduces proton accumulation by osteoclasts. However, inside-out plasma membrane vesicles from osteoclasts transport H+ normally in response to ATP in high concentrations of EHDP, Cl2MDP, or APD. This suggests that the bisphosphonates act as metabolic inhibitors. Bisphosphonates reduce osteoclastic protein synthesis, supporting this hypothesis. Furthermore, (3H]leucine incorporation by the fibroblast, which does not resorb bone, is also diminished by EHDP, Cl2MDP and APD except when co-cultured with bisphosphonate-binding bone particles. Thus, the resorption-antagonizing capacities of EHDP, Cl2MDP and APD reflect metabolic inhibition, with selectivity for the osteoclast resulting from high affinity binding to bone mineral.