Molecular mechanism of bone destruction by rheumatoid synovium and its treatment

破骨细胞可能参与类风湿骨破坏的过程。为了验证这一假设，我们在不使用任何诱导剂的情况下，开发了一种体外模型，由培养的类风湿性滑膜组织中获得的破骨细胞样细胞破坏骨。从类风湿关节炎和骨关节炎患者获得滑膜组织，培养约2 mm^3的滑膜衬里组织块。从培养的滑膜组织中提取多核细胞进行细胞化学和形态学研究，寻找破骨细胞特异性标志物。来自组织块的成纤维细胞样和巨噬细胞样细胞在淋巴细胞共存中增殖。培养14天后，出现了具有抗酒石酸酸性磷酸酶活性的多核细胞。这些细胞表达空泡H^+ - atp酶、玻璃体粘连素受体和组织蛋白酶k。尽管[^<125>l]-鲑鱼降钙素结合非常低，但细胞含有f -肌动蛋白的环状结构，并表现出较强的骨性。在6个月的培养过程中，巨噬细胞样细胞的增殖和多核细胞的形成在成纤维细胞样细胞的存在下继续进行。类风湿滑膜组织多核细胞的骨吸收活性远高于骨关节炎滑膜组织细胞，并与类风湿关节炎的疾病活动性有关。我们的培养系统在体外复制了类风湿滑膜破坏骨的过程，包括前体细胞的增殖、融合、极化、活化和骨组织吸收。为了阐明滑膜细胞向破骨细胞分化的分子机制，我们测试了RNAKL/ rank依赖或独立通路的参与。骨保护素（RANKL的诱饵受体）阻断RANKL/ rank依赖信号可显著降低培养的类风湿性滑膜的骨吸收。通过tnf受体II介导的TNFα作用阻断也降低了体外骨吸收。我们的数据表明，在体外骨破坏模型中，依赖rankl和独立的信号都可能参与破骨细胞的形成。少

Osteoclasts may be involved in the process of rheumatoid bone destruction. To test this hypothesis, we developed an in vitro model of bone destruction by osteoclast-like cells derived from cultured rheumatoid synovial tissue without using any inducers. Synovial tissues were obtained from rheumatoid arthritis and osteoarthritis patients and tissue pieces of about 2 mm^3 that contained synovial lining were cultured. Multinucleated cells derived from cultured synovial tissues were studied cytochemically and morphologically for osteoclast-specific markers. Fibroblast-like and macrophage-like cells from the tissue pieces proliferated in the coexistence of lymphocytes. After 14 days of culture, multinucleated cells with tartrate-resistant acid phosphatase activity appeared. These cells expressed vacuolar H^+ -ATPase, the vitronectin receptor, and cathepsin K. Although [^<125>l]-salmon calcitonin binding was very low, the cells contained ringed structures of F-actin and showed strong bone res … More orbing activity on ivory slices. Proliferation of macrophage-like cells and formation of multinucleated cells continued during 6 months of culture in the presence of fibroblast-like cells. The bone-resorbing activity of multinucleated cells derived from rheumatoid synovial tissue was much higher than that of cells from osteoarthritis synovial tissue, and was related to the disease activity of rheumatoid arthritis Our culture system reproduced in vitro the process of bone destruction by rheumatoid synovium, including the proliferation and fusion of precursor cells, polarization, activation, and bone tissue resorption. To clarify the molecular mechanism of the differentiation from synovial cells to osteoclasts, we tested the involvement of RNAKL/RANK-dependent or independent pathway. Blocking of RANKL/RANK-dependent signals by osteoprotergrin, a decoy receptor of RANKL significantly reduced bone resorption by cultured rheumatoid synovium. Blockade of TNFα action mediated through TNF-recptor II also decreased in vitrop bone resorption. Our data suggest that both RANKL-dependent and independent signals might be involved in the formation of osteoclasts in the in vitro model of bone derstruction. Less