蛋白酶体抑制剂对骨关节炎大鼠NF—κB信号通路的影响

The effect of proteasome inhibitor on NF-κB signal path in a rat model of knee osteoarthritis

目的观察蛋白酶体抑制剂MG-132对骨关节炎软骨及滑膜组织NF—κB信号通路的影响。方法SD大鼠144只，离断前十字韧带及内侧半月板建立膝关节骨关节炎模型，随机分为四组：MG-132组，造模术后24h于膝关节腔内注射100μl质量浓度为0．007g／L的MG-132溶液；DMSO（二甲基亚砜，Dimethyl sulfoxide）组，造模术后24h于膝关节腔内注射100μl体积分数为0．1％的DMSO溶液；假手术组，仅行关节囊切开；正常对照组，仅于膝关节腔内注射100μl质量浓度为0．007g／L的MG-132溶液。术后2、4和12周处死动物，于膝关节软骨组织及滑膜组织取材，行病理形态学观察，根据Mankin评分标准进行半定量评估；应用RT-PCR法检测NF—κB p65、I-μB、TNF-α、IL-1β等基因mRNA的表达水平；荧光分光光度法检测20S蛋白酶体活性，并行相关性分析。结果MG-132组各时相的Mankin评分均比DMSO组低，假手术组与正常对照组相近且较前两组低，差异有统计学意义。MG-132组各时相的软骨及滑膜组织中NF—κB p65、IL-1β、TNF-α mRNA表达水平均低于DMSO组，除2周滑膜组织NF—κB p65和12周软骨组织IL-1β mRNA外差异均有统计学意义。MG-132组术后2周软骨组织及4周滑膜组织I—κB mRNA表达水平高于DMSO组，差异有统计学意义。结论MG-132具有减轻滑膜炎症、保护关节软骨的作用，从而延缓骨关节炎进程。

To observe the effect of MG-132 on NF—κB signal path of cartilage and synovium in a rat model of knee osteoarthritis. Methods The rat models of knee osteoarthritis were established by performing anterior cruciate ligament amputation and partial medial meniseeetomy. Totally 144 adult SD rats were randomly divided into 4 groups： MG-132 group, 100 ml 0.007 g/L MG-132 solution was injected in to the knee joints of rat model 24 h after surgery; DMSO group, 100 ml 0.1% DMSO solution was injected 24 h after surgery; sham surgery group, merely the knee capsulotomy was performed and no solution was injected; control group, 100 ml 0.007 g/L MG-132 solution was injected into the knee joints. The cartilage and synovium specimens were obtained at 2, 4, 12 weeks postoperatively. Pathomorphological observation was taken. The levels of NF—κB p65, I—κB, TNF-α and IL-1β at mRNA were detected by real-time PCR, and the activity of 20S proteasome was measured by fluorospectrophotometry. Results The Mankin score of MG-132 group was lower than that of DMSO group. The Mankin scores of sham surgery and control groups were lower than those of MG-132 and DMSO groups with significant difference. The mRNA levels of NF—κB p65, IL-1β, TNF-α of cartilage and synovium in MG-132 group were lower than those of DMSO group with significant difference except for NF—κB p65 of synovium at 2 weeks and IL-1β of cartilage at 12 weeks. The mRNA levels of I—κB of cartilage at 2 weeks and I—κB of synovium at 4 weeks in MG-132 group were higher than those in DMSO group with statistical significance. Conclusion MG-132, the proteasome inhibitor, could postpone the progress of osteoarthritis through alleviating synovial inflammation and defending the articular cartilage.