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

脂多糖在牙周病和牙槽骨骨吸收中起着非常重要的作用。然而，关于脂多糖诱导破骨细胞在人细胞中形成的研究尚未见报道。最近我们发现，长期培养的人脐血可以形成多核细胞(MNC)，表达破骨细胞表型(多核，存在抗酒石酸酸性磷酸酶活性，对降钙素、降钙素受体的收缩反应，钙化基质上形成吸收陷窝，并与23C6单抗(CD-51)交叉反应，后者优先结合骨活检标本中的破骨细胞)。这种培养表明CFU-GM(粒-巨噬细胞前体细胞)是破骨细胞的前体细胞。在本实验中，我们研究了内毒素对破骨细胞形成的影响。在这些培养物中加入内毒素(10-100 ng/ml)显著增加单核细胞的形成，50%的单核细胞表达一种与单抗23C6交叉反应的抗原。加入抗人IL-1可完全抑制内毒素刺激的单核细胞形成。此外，与对照组培养12h相比，暴露于内毒素的这些培养物中的条件基质含有较高水平的IL-1α和IL-1β(47pg/mlIL-1α和31pg/ml IL-1β)。在添加脂多糖之后)。这些结果表明，内毒素能显著刺激人脐血培养物中MNC的形成，并优先刺激表达23C6单抗识别的抗原的MNC的形成。我们进一步指出，内毒素在这个系统中的作用似乎是通过诱导IL-1介导的，IL-1是一种强有力的破骨细胞形成刺激因子。

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.