MMP3在早期骨关节炎模型软骨下骨的表达及其意义

Expression of MMP3 in subchondral bones in early experimental osteoarthritis

目的:研究早期骨关节炎软骨下骨基质金属蛋白酶3(MMP3)的表达情况,为阐述其在骨关节炎致病中的重要作用提供依据。方法:大鼠分为实验组(n=30)和对照组(n=30)。实验组切除右膝内侧半月板并切断内侧副韧带,对照组仅切开关节囊。于术后1、2、4周取右膝关节标本,病理检查验证造模成功后,采用qPCR技术及免疫组化技术从基因水平及蛋白水平全面分析软骨下骨MMP3的表达情况。结果:(1)术后1周,软骨下骨的MMP3在实验组的表达量明显升高,是对照组的8.34倍(P<0.05);术后2周,MMP3在实验组的表达量也升高,是对照组的4.85倍(P<0.05),但相对于术后1周,表达量有所下降;术后4周,2组的MMP3表达量无显著差异;(2)术后1周与术后2周,实验组软骨下骨区检测到大量的MMP3阳性细胞,以小单核细胞及多核巨细胞为主,术后4周实验组、对照组及阴性对照组织切片均未检测到MMP3阳性细胞。结论:软骨下骨MMP3表达在早期骨关节炎致病机制中起了重要作用。

AIM： To demonstrate that matrix metalloproteinase 3（MMP3）plays MMP3 play an important role in the pathogenesis of osteoarthritis by studying the expression of MMP3 in subchondral bones in early experimental osteoarthritis at gene and protein levels.METHODS： The SD rats were randomly divided into 2 groups： experimental group and control group,each containing 30 rats with similar body weight.The right knee joints of the rats in experimental group underwent surgery,which involved in both medial collateral ligament（MCL） transection and medial meniscectomy,while the animals in control group were only carried out a sham operation.The rats were killed at the 1st,2nd and 4th weeks post-surgery to obtain the right knee joints.Pathological analysis was performed to validate this early osteoarthritic rat model.The expression of MMP3 in subchondral bones at mRNA and protein levels was evaluated by real-time polymerase chain reaction and immunohistochemical staining,respectively.RESULTS： The expression of MMP3 in subchondral bones was significantly increased at both the 1st and 2nd weeks post-surgery in experimental group,with the fold changes of 8.34（P0.05） and 4.85（P0.05）,respectively,as compared with control group.No differentially expression of MMP3 was observed at the 4th week post-surgery between these 2 groups.A lot of MMP3 positive cells,including small mononuclear cells and bigger polynuclear giant cells,were found in subchondral bones in experimental group at the 1st and 2nd weeks post-surgery,but not in control group.At the 4th week post-surgery,no MMP3 positive cells were found in subchondral bones of both groups.CONCLUSION： MMP3 plays an important role in the pathogenesis of early experimental osteoarthritis.