骨保护素基因敲除对老年小鼠关节软骨的影响

Effect of Osteoprotegerin Knockout in Aged Mice on the Articular Cartilage

目的:研究骨保护素(osteoprotegerin,OPG)在老年小鼠关节软骨增龄性变化中的作用及意义。方法 :取鼠龄为1年的骨保护素基因敲除(opg-knockout,Opg-KO)型小鼠和野生型(wildtype,WT)小鼠的长骨组织,分别进行X-ray、micro-CT检查,并行组织学染色观察关节软骨组织形态学的改变;行甲苯胺蓝染色,观察关节软骨蛋白聚糖的改变;行免疫组化染色,观察关节软骨Ⅱ型胶原表达情况。结果:与WT小鼠相比,Opg-KO小鼠关节表面粗糙,边缘性骨赘增多,软骨下骨的骨密度增高,关节软骨表面扁平塌陷,软骨细胞明显减少,排列紊乱,蛋白聚糖显著丢失,Ⅱ型胶原表达明显减少。结论:Opg-KO小鼠发生了严重骨关节炎,骨保护素对于维持老年小鼠关节软骨结构的完整有重要作用。

Objective： To investigate the roles of osteoprotegerin （OPG） in the age related changes of articular cartilage in old mice. Methods： The long bone tissues of one-year-old Opg-Knockout （Opg-KO） mice and wildtype mice （WT mice） were examed by X-ray, micro-CT, HE staining to observe the histological changes of articular cartilage; toluidine blue staining was used to exam the changes of proteoglycan in articular cartilage; immunohistochemistry was used to observe the expression level of collagen Ⅱ in articular cartilage. Results： Compared with WT mice, specific changes in Opg-KO mice articular cartilage included rough joint surface, increased marginal osteophytes, increased bone density of the subchondral bone, flattened and collapsed articular cartilage surface, decreased number of chondrocytes, disorganized chondrocytes, loss of proteoglycan, decreased expression of collagen Ⅱ. Conclusion： Opg-KO mice develope severe osteoarthritis, and osteoprotegerin is important for maintaining the structural integrity of articular cartilage in aged mice.