高脱乙酰度羧甲基壳聚糖对兔膝骨关节炎软骨诱导型一氧化氮合酶表达的影响

Effect of the high deacetylating carboxymethychitosan on iNOS of cartilage of osteoarthritis rabbits

目的观察高脱乙酰度羧甲基壳聚糖(HD-CMC)经关节腔注射后对兔膝骨关节炎(OA)软骨诱导型一氧化氮合酶(iNOS)的mRNA和蛋白表达的影响,探讨其用于OA防治的机制及可能性。方法36只日本大耳白兔,行右侧膝关节前交叉韧带切断术(ACLT),术后随机分为2组,实验组于术后当天开始关节腔内注射2%HD-CMC 0．15mg/kg,每2周给药1次,对照组同一时间点关节腔内注射0．9%生理盐水0．15mg/kg。实验组与对照组于第6周分别随机处死大白兔各9只,剩余大白兔于第12周处死,对比两组大白兔股骨髁关节软骨的大体改变,用反转录聚合酶链反应(RT-PCR)及免疫组织化学的方法检测iNOS在软骨中的mRNA和蛋白的表达。结果实验组退变软骨的大体评分轻于对照组,NOS的mRNA和蛋白表达水平均低于对照组。结论HD-CMC能够降低OA退变软骨iNOS的表达,并延缓软骨的退行性变,对OA退变软骨具有修复保护作用。

Objective To observe the influence of intra-articular injection of the high deacetylating carboxymethychitosan （HD-CMC） on mRNA and protein expression of iNOS in cartilage of osteoarthritis （OA） rabbits and to explore the mechanisms and the possibility of using HD-CMC in treating OA. Methods OA was induced in 36 rabbits by rabbit unilateral anterior cruciate ligament transaction （ACLT）. Eighteen divided into the rabbits were randomly experimental group and intra-articular injection of 0.15 mg/kg of 2 g/L high deacetylating of carboxymethychitosan were initiated every two weeks since the 0th week. The other 18 rabbits of the control group received intra-articular injection of 0.15 mg/kg normal saline at the same time. Nine rabbits in each group were randomly selected and sacrificed at the 6th week. The other 18 rabbits were killed at the 12th week. Cartilage degradation of femoral condyles was evaluated macroscopically, mRNA expression level and protein expression level of iNOS were documented by reverse transcription-polymerase chain reaction （RT-PCR） and immunohistochemistry. Results Cartilage degradation in the control group was more severe than that in the experimental group at the macroscopical level. RT-PCR and immunohistochemistry study showed that the expression of iNOS in the control group was significantly more severe than that in the experimental group. Conclusion It is suggested that the high deacetylating carboxymethychitosan may reduce the severity of cartilage degaradation and the expression of iNOS in cartilage at mRNA and protein level. So it is proposed that the high deacetylating carboxymethychitosan would be a potential potion for the treatment of OA and is worthy of further study.