Yoshihara Y, Nakamura H, Obata K, Yamada H, Hayakawa T, Fujikawa K, Okada Y
Department of Orthopaedic Surgery, National Defence Medical College, Japan.
Ann Rheum Dis. 2000 Jun;59(6):455-61. doi: 10.1136/ard.59.6.455.
Matrix metalloproteinases (MMPs) are expressed in joint tissues of patients with rheumatoid arthritis (RA) and osteoarthritis (OA). The objective of this study was to define the steady state levels of seven different MMPs and two tissue inhibitors of metalloproteinases (TIMPs) as well as the potential metalloproteinase activity in the synovial fluid (SF) to provide more insight into the role of MMPs in cartilage destruction in RA and OA.
Levels of MMP-1, MMP-2, MMP-3, MMP-7, MMP-8, MMP-9, MMP-13, TIMP-1, and TIMP-2 in SF aspirated from knee joints of 97 patients with RA and 103 patients with OA were measured by the corresponding one step sandwich enzyme immunoassays. Proteolytic activity of MMPs in these SFs was examined in an assay using [(3)H]carboxymethylated transferrin substrate in the presence of inhibitors of serine and cysteine proteinases after activation with p-aminophenylmercuric acetate (APMA). Destruction of RA knee joints was radiographically evaluated.
Levels of MMP-1, MMP-2, MMP-3, MMP-8, and MMP-9 were significantly higher in RA SF than in OA SF. MMP-7 and MMP-13 were detectable in more than 45% of RA SFs and in less than 20% of OA SFs, respectively. Among the MMPs examined, MMP-3 levels were extremely high compared with those of other MMPs. Direct correlations were seen between the levels of MMP-1 and MMP-3 and between those of MMP-8 and MMP-9 in RA SF. Although the levels of MMP-1 and MMP-3 increased even in the early stage of RA, those of MMP-8 and MMP-9 were low in the early stage and increased with the progression of RA. Molar ratios of the total amounts of the MMPs to those of the TIMPs were 5.2-fold higher in patients with RA than in OA, which was significant. APMA-activated metalloproteinase activity in SF showed a similar result, and a direct correlation was seen between the molar ratios and the activity in RA SF.
Our results show that high levels of MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, and TIMP-1 are present in RA SF and suggest that once these MMPs are fully activated, they have an imbalance against TIMPs, which may contribute to the cartilage destruction in RA.
基质金属蛋白酶（MMPs）在类风湿关节炎（RA）和骨关节炎（OA）患者的关节组织中表达。本研究的目的是确定七种不同MMPs和两种金属蛋白酶组织抑制剂（TIMPs）的稳态水平以及滑液（SF）中的潜在金属蛋白酶活性，以更深入了解MMPs在RA和OA软骨破坏中的作用。
采用相应的一步夹心酶免疫测定法，检测97例RA患者和103例OA患者膝关节抽取的SF中MMP-1、MMP-2、MMP-3、MMP-7、MMP-8、MMP-9、MMP-13、TIMP-1和TIMP-2的水平。在用对氨基苯基汞乙酸酯（APMA）激活后，在存在丝氨酸和半胱氨酸蛋白酶抑制剂的情况下，使用[³H]羧甲基化转铁蛋白底物的测定法检测这些SF中MMPs的蛋白水解活性。对RA膝关节的破坏进行放射学评估。
RA SF中MMP-1、MMP-2、MMP-3、MMP-8和MMP-9的水平显著高于OA SF。MMP-7和MMP-13分别在超过45%的RA SF和不到20%的OA SF中可检测到。在所检测的MMPs中，MMP-3的水平与其他MMPs相比极高。RA SF中MMP-1和MMP-3的水平之间以及MMP-8和MMP-9的水平之间存在直接相关性。虽然MMP-1和MMP-3的水平在RA早期就升高，但MMP-8和MMP-9的水平在早期较低，并随着RA的进展而升高。RA患者中MMPs总量与TIMPs总量的摩尔比是OA患者的5.2倍，差异显著。SF中APMA激活的金属蛋白酶活性显示出类似的结果，并且RA SF中的摩尔比与活性之间存在直接相关性。
我们的结果表明，RA SF中存在高水平的MMP-1、MMP-2、MMP-3、MMP-8、MMP-9和TIMP-1，并表明一旦这些MMPs被完全激活，它们与TIMPs之间存在失衡，这可能导致RA中的软骨破坏。
