持续被动运动通过抑制软骨细胞NO合成下调MMP-1和MMP-13表达

Continuous Passive Motion Downregulated Expression of MMP- 1 and MMP- 13 Via Inhibition of NO Synthesis in Chondrocytes

目的：观察持续被动运动（CPM）和补充一氧化氮（NO）供体——硝酸甘油（NG）对兔骨关节炎（OA）模型中软骨基质金属蛋白酶-1（MMP-1）和MMP-13表达以及NO含量的影响,探讨CPM下调MMPs的可能机制.方法：30只3～4月龄雄性新西兰大白兔,其中6只进行假手术作为正常对照组（NC组）,另外24只建立膝关节OA模型,术后随机分为4组,即OA对照组（OA组）、OA硝酸甘油给药组（NG组）、OA持续被动运动组（CPM组）、OA持续被动运动＋硝酸甘油给药组（CPM＋ NG组）,每组各6只.NC组和OA组不作处理,NG组给予NG软膏膝关节局部涂抹,CMP组在CPM训练仪上进行膝关节持续被动运动,CMP＋ NG组即在运动干预的同时给予NG局部涂抹.4周后取各组软骨组织,硝酸还原酶法测定NO含量,HE染色观察软骨形态学变化并进行Mankin＇s评分,实时荧光定量PCR（RQ-PCR）检测MMP-1和MMP-13 mRNA水平,免疫组织化学法测定MMP-1和MMP-13蛋白表达量.结果：NO含量、Mankin＆#39;s评分以及MMP-1和MMP-13 mRNA和蛋白水平在OA组明显高于NC组（P＜0.01）,NG组高于OA组（P＜0.01）,CPM组低于OA组和NG组（P＜0.01）,CPM＋ NG组低于NG组（P＜0.01）,但高于CPM组（P＜0.01）.结论：CPM通过抑制软骨细胞NO合成下调MMP-1和MMP-13表达,进而对软骨细胞起保护作用.

Objective： To observe the effects of continuous passive motion （CPM） and nitric oxide （NO） donor- nitroglycerin （NG） supplement on matrix metalloproteinase- 1 （MMP- 1 ）, matrix metalloproteinase- 13 （MMP- 13 ） expression and NO content in cartilage of rabbit osteoarthritis （OA） model and investigate the possible mechanism that CPM downregulated MMPs. Methods ： Of thirty male New Zealand white rabbits of 3 - 4 months, six sham operated served as normal control group （NC, not treated） and the other twenty- four animals being created OA model were randomly allocated four group： osteoar- thritis control group （OA, not treated）, nitroglycerin group （NG, treated with NG ointment on knee joint）, continuous pas- sive motion group （ CPM, exercise on CPM training apparatus） and continuous passive motion ＋ nitroglycerin group （ CPM ＋ NG, exercise plus NG supplement）. After four weeks, NO content were measured by nitrate reductase method, cartilage mor- phologic variations by HE stain and Mankin＇s score, MMP - 1 and MMP - 13 mRNA by real -time fluorescent quantitation PCR （RQ -PCR） and the protein level by immunohistochemistry. Results： NO content, Mankin~ score, MMP- 1 and MMP - 13 mRNA and protein level in OA group were higher than those in NC group （ P 〈0.01 ） and in NG group higher than OA group, while the indexes above in CPM group were lower than OA and NG group and in CPM ＋ NG group lower than NG group but higher than CPM group. Conclusion： CPM downregulated expression of MMP - 1 and MMP - 13 via inhibition of NO synthesis in chondroeytes, thus protecting chondroeytes in OA model.