中文摘要：

目的研究持续静压力和人牙周膜细胞对体外诱导脐血单核细胞分化为破骨样细胞的影响，初步探讨静压力和牙周膜细胞在正畸性骨改建中的作用机制。方法密度梯度离心法分离脐血，收集单个核细胞。用组织块酶消化法培养获得牙周膜细胞。建立transwell共培养系统，下层接种脐血单个核细胞，上层接种牙周膜细胞。A组为单核细胞与牙周膜细胞共培养加力；B组为单核细胞培养加力，另设不加力对照组A’、B’组。采用倒置相差显微镜观察及TRAP染色，骨磨片染色等方法检测破骨样细胞的形成及功能。结果A组下层细胞在加力后第2天出现细胞融合现象，3d时可见明显的多核破骨样细胞，TRAP染色阳性，骨磨片染色可见典型的骨吸收陷窝。其他组仅有极少量多核细胞形成，未见骨吸收陷窝。结论静压力作用下，牙周膜细胞可以刺激脐血单核细胞分化为破骨样细胞。

英文摘要：

Objective To study the effect of continuously compressive pressure （CCP） and human periodontal ligament cells （HPDLCs） on the differentiation of osteoclast-like cells （OLC） induced from umbilical cord blood cells in vitro, and to investigate the role of continuously compressive pressure and human periodontal ligament cells in alveolar bone rebuilding during orthordontic tooth movement. Methods Mononucleared cells of umbilical cord blood （HCMNCs） were separated by density gradient centrifugation, HPDLCs were isolated from human periodontal ligament by explanting enzymatic digestion with trypsin and collagenase. We also established transwell co-culture system with HCMNCs in the lower layer and HPDLCs in the upper layer. Group A： HCMNCs and HPDLCs were co-cultured with 150 kPa CCP for 1.5 hours on the model. Group 13： only HCMNCs were cultured with the same CCP as Group A. Groups A＇and B＇ were the respective control group of Groups A and B with no CCP exerted. The cell appearance was observed under the phase contrast microscope, and its identification was performed by histochemical analysis of tartrater-resistant acid phosphatase （TRAP）. The capacity of bone resorption of the cell was assessed by lacunae forming ability on bone slice. Results HCMNCs in Group A to fuse on the 2nd day, More positive multinucleated ceils could be seen with TRAP staining and cortical bo formation on the 3rd day. Only a few multinucleated cells formed in the other groups, with no cortical bo began De ne pit pit formation. Conclusion HCMNCs can fuse into multinucleated OLC under CCP with the induction of HPDLCs