miR-146 a/27 a在SD大鼠OA软骨、滑膜组织中的表达及意义

目的：观察切断前交叉韧带( ACLT)构建SD大鼠骨性关节炎( OA)模型的病理特点,并检测 miR-146a和 miR-27a在OA动物模型软骨、滑膜组织中的表达情况。方法120只SD大鼠随机分为实验组和对照组,实验组行左膝前交叉韧带切断术,对照组只打开关节腔不切断前交叉韧带,分别于术后2、4、8周获取关节软骨、滑膜组织,对软骨情况进行大体及组织学评分,应用RT-PCR检测软骨和滑膜组织中miR-146a、miR-27a的表达情况。结果实验组术后2周软骨表面粗糙,色泽灰暗,4周和8周病变程度加重,对照组关节软骨无明显退变；实验组不同时间段Mankin评分与对照组比较差异有统计学意义( P<0．01)。实验组和对照组2、4、8周时软骨组织中miR-146a的相对表达量分别为(0．58±0．13)vs(0．66±0．14)、(0．43±0．08) vs (0．68±0．12)、(0．18±0．06)vs(0．61±0．07),各个时间点差异均有统计学意义(P<0．01)；同期检测到软骨组织中miR-27a、滑膜组织中miR-146a和miR-27a在实验组和对照组各时间点的表达量差异有统计学意义( P<0．01)。应用Pearson相关分析显示,miR-146a、miR-27a在软骨组织中的表达情况与 Mankin评分呈显著负相关(r=-0．92、-0．89,P<0．05),而滑膜、软骨中miR-146a和miR-27a的表达呈线性正相关(r=0．78、0．80,P<0．05)。结论 miR-146a 和 miR-27a 在 SD 大鼠OA模型软骨组织、滑膜组织中呈低表达,且与OA软骨病变程度呈负相关。

Expression and significance of miR-146a,miR-27a in the cartilage and synovial of SD rat model of osteoarthritis

Objective To observe anterior cruciate ligament transection( ACLT) to build clinical pathological fea-tures of SD rat model of osteoarthritis(OA),and to examine the expression of miR-146a and miR-27a in joint carti-lage and synovial of SD rat model of OA. Methods Experimental groups received unilateral ACLT, the treatment of control groups was similar to the experrnental groups,but no transction ACL, and they were sacrificed at 2,4 and 8 weeks after surgery respectively. Knees were harvested to observe the pathologic change of cartilage macroscopi-cally and histologically, histopathological grading OA was performed according to a Mankin 's scoring system. The expression levels of miR-146 a and miR-27 a in joint cartilage and synovial were detected by real-time fluorescent quantitative polymerase chain reaction. Results Two weeks after ACLT cartilage surface roughness and color gloomy were seen, and became more severe at 4 and 8 weeks after operation, while cartilage still remained normal after pseudo operation. Mankin score of the experimental groups in different time periods were significant differences with the control groups. In the experimental and control groups ,the relative expression levels of miR-146a at 2,4, 8 weeks in joint cartilage were ( 0. 58 ± 0. 13 ) vs ( 0. 66 ± 0. 14 ) , ( 0. 43 ± 0. 08 ) vs ( 0. 68 ± 0. 12 ) , ( 0. 18 ± 0. 06) vs (0. 61 ± 0. 07), and each time point that had statistically significant differences(P<0. 01). At the same period detected cartilage tissue miR-27a, synovial tissue miR-146a and miR-27a, there were statistically significant differences at each time point between the expression of the experimental groups and the control groups(P<0. 01). Application pearson correlation analysis showed that the expression levels of miR-146 a and miR-27 a in cartilage tis-sue were significantly negatively correlated to Mankin score (r= -0. 92,-0. 89,P<0. 05), while the expression levels of miR-146a,miR-27a in synovium and cartilage were significantly positive correlation(r=0. 78, 0. 80,P<0. 05 ) . Conclusion The expression levels of miR-146 a and miR-27 a decreased in joint cartilage and synovial in SD rat model of OA, and that were negatively related to the severity of OA.