Mehraban F, Lark M W, Ahmed F N, Xu F, Moskowitz R W
Case Western Reserve University, Department of Medicine, Cleveland, Ohio 44106-4946, USA.
Osteoarthritis Cartilage. 1998 Jul;6(4):286-94. doi: 10.1053/joca.1998.0122.
The aim of this study was to define the relative regulation of matrix metalloproteinase-3 (MMP-3), and tissue inhibitor of metalloproteinases-1 (TIMP-1), in chondrocytes and synovium in experimental osteoarthritis (EOA).
Partial-meniscectomized (PM) rabbits, surgical sham controls (SH), and normal non-surgical controls (N) were killed at times corresponding to early degenerative lesions (4 weeks) and increasingly progressive stages of EOA at 8 and 12 weeks post-PM. MMP-3 activity was measured in conditioned media from chondrocytes and synovium using a peptide cleavage assay with substance P (SP) as the substrate. TIMP-1 was quantitated using an enzyme-linked immunosorbent assay (ELISA).
Early degenerative lesions (4 weeks post-PM) were characterized by inflammatory responses in the synovium accompanied by a significant rise of MMP-3 activity in synovial cultures (P < 0.05). At 8 weeks there was no discernible inflammation, and MMP-3 activity in EOA synovial cultures was comparable to that in the controls; this was followed by a second increase in MMP-3 activity in EOA samples at 12 weeks. MMP-3 activity was significantly elevated in EOA chondrocyte cultures at 8 weeks post-PM relative to N controls, corresponding to the most destructive phase of EOA, but not in the early phase (4 weeks) or 'late' degenerative phase (12 weeks). Medium derived from chondrocytes contained little or no TIMP-1. Synovia secreted relatively higher amounts of TIMP-1, and this was elevated at 8 weeks post-PM relative to the SH controls. The majority (approximately 90%) of MMP-3 activity could be inhibited using recombinant TIMP-1 or a hydroxamate MMP inhibitor. Complete inhibition was achieved with EDTA or 1,10 phenanthroline.
Together, these data indicate that in EOA, MMP-3 is initially upregulated in the synovium which may play a pivotal role in the pathogenesis of cartilage lesions. In contrast, chondrocyte-derived MMP-3 is upregulated in the later phases of EOA, contributing further to progression of cartilage lesions.
本研究旨在明确实验性骨关节炎（EOA）中软骨细胞和滑膜内基质金属蛋白酶-3（MMP-3）及金属蛋白酶组织抑制剂-1（TIMP-1）的相对调控情况。
对部分半月板切除（PM）的兔子、手术假手术对照组（SH）以及正常非手术对照组（N），在与早期退行性病变相对应的时间点（4周）以及PM后8周和12周EOA进展程度不断增加的阶段处死。使用以P物质（SP）为底物的肽裂解试验，测定软骨细胞和滑膜条件培养基中的MMP-3活性。使用酶联免疫吸附测定（ELISA）对TIMP-1进行定量。
早期退行性病变（PM后4周）的特征是滑膜出现炎症反应，同时滑膜培养物中MMP-3活性显著升高（P < 0.05）。8周时无明显炎症，EOA滑膜培养物中的MMP-3活性与对照组相当；随后在12周时EOA样本中的MMP-3活性再次升高。与N对照组相比，PM后8周时EOA软骨细胞培养物中的MMP-3活性显著升高，这与EOA最具破坏性的阶段相对应，但在早期阶段（4周）或“晚期”退行性阶段（12周）则未升高。软骨细胞来源的培养基中TIMP-1含量很少或没有。滑膜分泌相对较高量的TIMP-1，并且与SH对照组相比，PM后8周时TIMP-1升高。使用重组TIMP-1或羟肟酸MMP抑制剂可抑制大部分（约90%）的MMP-3活性。使用EDTA或1,10菲咯啉可实现完全抑制。
总之，这些数据表明，在EOA中，MMP-3最初在滑膜中上调，这可能在软骨损伤的发病机制中起关键作用。相比之下，软骨细胞来源的MMP-3在EOA后期上调，进一步促进软骨损伤的进展。
