Bone resorption mechanisms on LPS in human osteoclast-like cells formation system

脂多糖（LPS）在牙周病的发生和牙槽骨的骨吸收中起着重要的作用。然而，目前还没有关于LPS诱导人细胞破骨细胞形成的研究报道。最近，我们已经证明，长期的人类脐带血培养可以适应形成表达破骨细胞表型的多核细胞（MNC）（多核，存在抗酒石酸酸性磷酸酶活性，对降钙素，降钙素受体的反应收缩，在钙化基质上形成吸收腔隙以及与mAb 23C6（CD-51）的交叉反应性，后者优先结合骨活检标本中的破骨细胞）。该培养提示CFU-GM（粒细胞-巨噬细胞祖细胞）是破骨细胞的前祖细胞。本实验中，我们研究了LPS对破骨细胞形成的影响。在这些培养物中添加LPS （10-100ng/ml）可显著增加MNC的形成，其中50%的MNC表达一种与mAb 23C6交叉反应的抗原。在LPS处理的培养物中添加抗人IL-1完全抑制LPS刺激的MNC形成的增加。此外，与对照培养中5pg/ml的水平相比，暴露于LPS的培养基中il -1 α和β的水平升高（il -1 α为47pg/ml， il -1 β为31pg/ml）。添加LPS后)。这些结果强烈提示LPS显著刺激人脐带血培养中MNC的形成，并且优先刺激表达23C6 mAb识别抗原的MNC的形成。我们进一步指出，LPS在该系统中的作用似乎是通过诱导破骨细胞形成的强效刺激剂if -1介导的。

Lipopolysaccharides(LPS) has very important roles in occuring periodontal disease and bone resorption of alveoral bone. However, no studies have been reported in which LPS induce osteoclasts formation in human cells. Recently we have shown that long term human umbilical cord blood cultures can be adapted to form multinucleated cell(MNC) that express an osteoclast phenotype (multinucleated, presence of tartrate resistant acid phosphatase activity, contraction in response to calcitonin, calcitonin receptor, formation of resorption lacunae on calcified matrices and cross-reactivity with the mAb 23C6(CD-51), which preferentially binds osteoclasts in bone biopsy specimens). This culture suggested that the CFU-GM (the granulocyte-macrophage progentor cells) is the pro-genitor cell for osteoclast. In this experiment, we studied the effect of LPS on osteoclasts formation. Addition of LPS (10-100ng/ml) to these cultures significantly increase MNC formation, with 50% of the MNC expressing an antigen which cross-reacts with the mAb 23C6. Addition of anti-human IL-1 to cultures treated with LPS totally inhibited the increase in MNC formation stimulated by LPS. Further, conditiond madia from these cultures exposed to LPS contained elevated levels of IL-1alphaand beta (47pg/ml of IL-1alpha and 31pg/ml of IL-1beta compared to under 5pg/ml in control cultures 12h. after LPS addition). These results strongly suggested that LPS significantly stimulated MNC formation in human cord blood cultures, and preferentially stimulated formation of MNC expressing the antigen recognized by 23C6 mAb. We further indicate that the effects of LPS in this system appear to be mediated by induction ofIL-1, a potent stimulator of osteoclasts formation.