Xue Ruyue, Yang Li, Tang Zhenyu, Zhang Jin, Wang Yequan, Tang Xinyan, Jiang Jiahuan, Wu Yupeng, Yang Ruifang, Chen Peter, Sung K L Paul
111 project Laboratory of Biomechanics and Tissue Repair, College of Bioengineering, Chongqing University, Chongqing 400044, China.
Mol Cell Biomech. 2010 Jun;7(2):115-24.
Human anterior cruciate ligament (ACL) has poor healing ability after injury. The devastating effects of matrix metalloproteinases (MMPs) excess expression are regarded as the main reason. Tissue inhibitor metalloproteinases (TIMPs) may be independent of MMPs inhibition. In this paper, a rat ACL rotating injury apparatus was designed to produce ACL injury. After inducing injury, joint fluids and ACL tissue total proteins were immediately extracted. In addition, ACL tissue was isolated in a culture plate with 1%FBS medium for the ex vivo study. We found MMP-2 in joint fluids increased significantly by 4 folds after ACL injury as a function of time. Ex vivo study showed MMP-2 in the medium and ACL cultured tissue increased significantly respectively to 3 folds and to 6 folds. The joint fluids global MMP increased to 3.5 folds with non-treatment and APMA-treatment in day three. On the gene expression level, the changes in MMP-1 and CD147 have the similar tendency. The ratio of MMP-1/TIMP-1 increased with time after ACL injury. We conclude that MMP-2 increased significantly in the early phase in the joint cavity after ACL injury. The ex vivo study demonstrated the same tendency. Generic MMP Activity Assay (global MMP assay) an dzymography also showed significant increase in MMP activity in joint fluids. These results showed ACL having poor healing ability after injury may not be only due to ACL release of large quantities of MMPs. The important factor may be the alterations in the whole joint cavity's internal environment.
人类前交叉韧带（ACL）损伤后愈合能力较差。基质金属蛋白酶（MMPs）过度表达的破坏性影响被认为是主要原因。组织金属蛋白酶抑制剂（TIMPs）可能独立于对MMPs的抑制作用。本文设计了一种大鼠ACL旋转损伤装置来造成ACL损伤。诱导损伤后，立即提取关节液和ACL组织总蛋白。此外，将ACL组织分离到含有1%胎牛血清培养基的培养板中进行体外研究。我们发现，ACL损伤后，关节液中的MMP-2随时间显著增加了4倍。体外研究表明，培养基和培养的ACL组织中的MMP-2分别显著增加到3倍和6倍。在第三天，未经处理和经APMA处理的关节液中总MMP增加到3.5倍。在基因表达水平上，MMP-1和CD147的变化趋势相似。ACL损伤后，MMP-1/TIMP-1的比值随时间增加。我们得出结论，ACL损伤后关节腔内早期MMP-2显著增加。体外研究也显示了相同的趋势。通用MMP活性测定（总MMP测定）和酶谱分析也表明关节液中MMP活性显著增加。这些结果表明，ACL损伤后愈合能力较差可能不仅仅是由于ACL释放大量MMPs。重要因素可能是整个关节腔内环境的改变。
