人工关节无菌性松动动物模型中EphB4-EphrinB2的表达

目的：建立并评价聚甲基丙烯酸甲酯（PMMA）微粒诱导的小鼠air-pouch人工关节无菌性松动模型，并且分析核激活因子受体配体（RANKL）与EphB4-EphrinB2在此模型中表达及意义。方法：在10周大小的雌性近交系BALB／c小鼠背部皮下单点注射无菌空气形成气囊，后将气囊中植入同种系小鼠颅骨骨片。术后实验组和对照组小鼠气囊内分别注射PMMA微粒溶液和生理盐水，15d后处死小鼠，将气囊和植入颅骨骨片一并取出，进行组织学观察。并行RANKL及EphB4-EphrinB2免疫组化检测。结果：HE染色实验组标本囊壁增厚、炎性细胞浸润增多，颅骨表面有明显的骨吸收；免疫组化显示实验组中RANKL的表达增高，EphrinB2-EphB4的表达降低。结论：小鼠air—pouch模型能方便、经济、有效的模拟人工关节松动的病理过程；实验组中RANKL的高表达显示骨溶解效应增强，EphB4-EphrinB2双向信号蛋白的低表达显示骨形成作用被抑制，验证了骨稳态的失衡是导致关节松动发生的重要机制。

Expression of EphB4-EphrinB2 in the Animal Model of Aseptic Loosening for Artificial Joint

Objective： To establish and evaluate the PMMA -particles induced air-pouch model, and analyze the significance of RANKL and EphB4-EphrinB2 expression in this model. Methods ： Air pouches were established on the back of the 10 - week - old female BALB / c mice by injecting sterile air subcutaneously. A part of calvaria from the syngeneic mouse was implanted in the air pouch. Postoperative experimental group and control group of air pouches were injected with PMMA particles and saline solutions respectively. All mice were killed at 15 days after the implantation. The tissues of air pouches with implanted calvaria were harvested for histological and immunohistochemical analysis. Results：Compared with the control group in histological, inflammatory responses, and bone resorption were much obvious in the experimental group; Immunohistochemistry showed that RANKL expression in the experimental group increased （ P 〈 0.05 ）, and the expression of EphBd- EphrinB2 decreased （P 〈 0.05 ）. Conclusions ： Air-pouch model is a convenient, economic and effective animal model to mimic the pathological process of aseptic loosening. High expression of RANKL in the experimental group shows osteolysis effect increases and the low expression of EphlM-EphrinB2 bidirectional signaling protein shows bone formation is inhibited. The results verify that the imbalance of bone metabolism is an important mechanism leading to aseptic loosening.