兔骨关节炎模型的建立以及关节炎软骨组织中MMP-1/-13的表达

Establishment of rabbit osteoarthritis model and expression of MMP-1 MMP-13 in joint cartilage induced by anterior cruciate ligament transection and excision of partial medial meniscus

目的评价家兔膝关节前交叉韧带切断(ACLT)及内侧半月板前1/3切除制作骨关节炎(OA)模型方法的可行性,同时探索关节炎发病的不同时期,关节软骨中基质金属蛋白酶(MMP)-1,MMP-13的基因表达、蛋白表达水平的变化情况。方法实验组家兔30只行ACLT及内侧半月板前1/3切除术造模,分别于术后4周、8周、12周处死10只,假手术对照组家兔10只于术后12周处死。进行股骨髁关节软骨退变的大体评分;取退变的软骨组织,用实时定量PCR(Real-time PCR)及Western blot印记杂交方法测定软骨组织中MMP-1和MMP-13的mRNA和蛋白表达水平。结果ACLT及内侧半月板前1/3切除术后4周即可见软骨退变,8周和12周时退变进一步加重,对照组无明显软骨退变,不同组动物关节软骨评分有统计学差异。MMP-1的mRNA表达和蛋白表达在正常对照组水平均较低,造模4周开始升高,到第8周及第12周持续升高,且mRNA表达和蛋白表达升高的趋势相同;MMP-13在造模4周时表达开始升高,mRNA表达和蛋白表达趋势相同,造模第8周时持续升高,但在造模第12周时MMP-13mRNA表达和蛋白表达下降。结论家兔膝关节ACLT及内侧半月板前1/3切除制作OA模型的方法简便可行,MMP-1和MMP-13在骨关节炎的发病过程中有不同程度的升高,可以作为OA研究的评价指标。本实验结果提示,在OA发展的过程中,MMP-1和MMP-13的表达不平行,二者调控通路可能存在差异。MMP-13的mRNA表达的变化趋势与其蛋白水平的变化趋势相符合,说明引起MMP-13在OA病程中晚期下降的调控发生在翻译前水平。

Purpose To evaluate the feasibility of animal model of osteoarthritis （OA） by anterior cruciate ligament transaction （ACLT） and excision of partial medial meniscus,and to explore the mRNA and protein expression of matrix metaUoproteinase （MMP）-I and MMP-13 in joint cartilage of rabbit knee at different time after ACLT and partial excision of medial meniscus. Methods Thirty rab- bits in experimental group received unilateral ACLT and partial excision of medial meniscus, another 10 rabbits received unilateral arthrotomy as pseudo-operation control. Ten experimental rabbits were sacrificed at 4,8 and 12 weeks after surgery respectively , and 10 pseudo-operation rabbits were sacrificed at 12 weeks after surgery. Knees were harvested to observe the macropathologic changes of joint cartilage. Cartilage near the lesion were obtained ,and mRNA and protein of MMP-1 and MMP-13 were de-tected by real-time PCR and western blot respectively. Results Cartilage degeneration was obvious at 4 weeks and became more severe at 8 and 12 weeks after operation, while cartilage still remained normal at 12weeks after pseudo-operation. The mRNA and protein expression of MMP-1 and MMP-13 were all lower in normal cartilage, while the mRNA and protein expression of those two proteins increased in 4 and 8 weeks after operation. At 12 weeks after operation,mRNA and protein expression of MMP-1 still remained high,while mRNA and protein expression of MMP-13 decreased respectively. Conclusions Anterior cruciate ligament transaction （ACLT） with partial excision of medial meniscus is a good method to make osteoarthritis model. MMP-1 and MMP-13, especially MMP-1, are good markers in osteoarthritis study. MMP-13 expression was very different from that of MMP-1 at 12 weeks after operation, which suggest that their upstream signaling pathways are different, and the signaling pathway difference may be before translation because the mRNA and protein expression change of MMP-13 are in parallel.