Molecular Pathology of Cartilage destruction in Rheumatoid Arthritis

细胞外基质（ECM）的降解是类风湿性关节炎（RA）关节软骨破坏的重要步骤，基质金属蛋白酶（MMP）基因家族成员参与了降解。在本研究中，我们描述了一些MMP物种的生化特性，并研究了它们在RA关节软骨破坏中的作用。此外，与制药公司合作开发了合成的MMP抑制剂和金属蛋白酶3组织抑制剂（TIMP-3）诱导药物。主要研究结果如下：(1)。TIMP-2存在时，膜型MMP （MT1-MMP）介导的proMMP-2的激活被加速，因此TIMP-2被认为是细胞膜上proMMP-2有效激活的必要条件。我们还证明MT1-MMP在球间结构域的三个位点切割聚集蛋白，MT3-MMP降解ECM成分，如III型胶原和聚集蛋白。另一方面，MT1-MMP和MT3-MMP的活性不受TIMP-1的抑制。经concanvalin a处理后，MT-MMP可从肿瘤细胞的细胞膜上脱落(2)。ProMMP-2在RA滑膜组织中被有效激活，其激活率与MT1、2,3 - mmps中MT1- mmp的表达水平直接相关。MT1-MMP在RA滑膜衬里细胞中表达，通过原位酶谱法检测衬里细胞层的明胶溶解活性(3)。采用夹心酶免疫法检测滑液中MMP-1、2、3、7、8、9、13和TIMP-1、2的稳态水平，RA组的MMP-1、2、3、8、9和TIMP-1水平明显高于OA组。RA的摩尔比明显高于OA，并且检测到金属蛋白酶活性与MMP/TIMP摩尔比直接相关，表明不平衡有利于蛋白酶(4)。通过与一家制药公司合作，我们开发了对MT1-MMP更具选择性的合成抑制剂，我们还证明了聚硫酸戊聚糖通过转录后水平刺激RA滑膜成纤维细胞产生TIMP-3。少

Degradation of the extracellular matrix (ECM) is an essential step to the destruction of articular cartilage in rheumatoid athritis (RA), and members of the matrix metalloproteinase (MMP) gene family are involved in the degradation. In the present studies, we characterized the biochemical properties of some MMP species and examined their functions in the destruction of the cartilage in RA joints. In addition, synthetic MMP inhibitors and tissue inhibitor of metalloproteinases 3 (TIMP-3)-inducible drug were developed by collaboration with pharmaceutical companies. The major results are as follows:(1). Activation of proMMP-2 mediated by membrane-type1 MMP (MT1-MMP) was accelerated in the presence of TIMP-2, and thus TIMP-2 was considered to be essential to the efficient activation of proMMP-2 on the cell membranes. We also demonstrated that MT1-MMP cleaves aggrecan at three sites in the interglobular domain and MT3-MMP degrades the ECM components such as type III collagen and aggrecan. O … More n the other hand, the activities of MT1-MMP and MT3-MMP were not inhibited by TIMP-1. MT-MMP was shown to be shed from the cell membranes of tumor cells treated with concanvalin A.(2). ProMMP-2 was efficiently activated in RA synovial tissues and its activation ratio directly correlated with the expression levels of MT1-MMP among MT1, 2, 3-MMPs. MT1-MMP was expressed in the lining cells of RA synovial membrane and gelatinolytic activity was detected by in situ zymography in the lining cell layer.(3). When steady state levels of MMP-1, 2, 3, 7, 8, 9, 13 and TIMP-1, 2 in synovial fluids were assayed by sandwich enzyme immunoassays, the levels of MMP 1, 2, 3, 8, 9 and TIMP-1 were significantly higher in RA than in OA. The molar ratio was significantly higher in RA than in OA, and metalloproteinase activity was detected with a direct correlation to MMP/TIMP molar ratio, suggesting an imbalance in favor of proteinase.(4). By collaboration with a pharmaceutical company, we developed synthetic inhibitors more selective to MT1-MMP, We also demonstrated that pentosan polysulfate stimulates RA synovial fibroblasts to produce TIMP-3 by the posttranscriptional level. Less