Cleavage of cartilage oligomeric matrix protein (thrombospondin-5) by matrix metalloproteinases and a disintegrin and metalloproteinase with thrombospondin motifs
Cleavage of cartilage oligomeric matrix protein (thrombospondin-5) by matrix metalloproteinases and a disintegrin and metalloproteinase with thrombospondin motifs
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DOI：
10.1016/s0945-053x(03)00034-9
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发表时间：
2003-05-01
期刊：
影响因子：
6.9
通讯作者：
Hollander, AP
中科院分区：
文献类型：
--
作者：
Dickinson, SC;Vankemmelbeke, MN;Hollander, AP
软骨寡聚基质蛋白 (COMP) 是存在于软骨、肌腱和韧带中的五聚体糖蛋白。该分子的片段存在于膝关节损伤、骨关节炎和类风湿性关节炎患者的患病软骨、滑液和血清中。尽管 COMP 是多种基质金属蛋白酶 (MMP) 的底物，但负责体内 COMP 降解的酶尚未确定。在这项研究中，我们利用成熟的牛软骨培养模型来检查在存在和不存在 MMP 抑制剂的情况下 IL-1α 刺激的 COMP 蛋白水解作用。当培养基中可溶性 MMP 水平检测不到时，牛鼻软骨响应 IL-1α，在蛋白聚糖和 11 型胶原蛋白之间的中间时间释放 COMP。 IL-1α 刺激后释放的 COMP 主要片段以约 110 kDa 的表观分子量（片段 110）进行迁移，并与人关节炎滑液样品中存在的主要片段以及纯化的 MMP-9 的 COMP 裂解产物共同迁移。然而，广谱MMP和ADAM抑制剂BB94仅部分抑制Fragment-110的形成，未能显着抑制COMP释放。因此，这些研究的结果表明除 MMP 之外的蛋白酶在牛软骨中 COMP 的降解中也发挥着作用。进一步证明纯化的COMP被ADAMTS-4而非ADAMTS-1或-5切割，产生与Fragment-110共迁移的片段。因此，这是首次证明 COMP 作为 ADAMTS-4 的底物，尽管该酶是否在体内 COMP 降解中发挥作用仍有待确定。 (C) 2003 年 Elsevier Science B.V. 和国际基质生物学学会。版权所有。
Cartilage oligomeric matrix protein (COMP) is a pentameric glycoprotein present in cartilage, tendon and ligament. Fragments of the molecule are present in the diseased cartilage, synovial fluid and serum of patients with knee injuries, osteoarthritis and rheumatoid arthritis. Although COMP is a substrate for several matrix metalloprotemases (MMPs), the enzymes responsible for COMP degradation in vivo have yet to be identified. In this study we utilised well-established bovine cartilage culture models to examine IL-1alpha-stimulated COMP proteolysis in the presence and absence of MMP inhibitors. COMP was released from bovine nasal cartilage, in response to IL-1alpha, at an intermediate time between proteoglycans and type 11 collagen, when soluble MMP levels in the culture medium were undetectable. The major fragment of COMP released following IL-1alpha-stimulation migrated with an apparent molecular mass of approximately 110 kDa (Fragment-110) and co-migrated with both the major fragment present in human arthritic synovial fluid samples and the product of COMP cleavage by purified MMP-9. However, the broad-spectrum MMP and ADAM inhibitor BB94 only partially inhibited the formation of Fragment-110 and failed to inhibit COMP release significantly. Therefore the results of these studies indicate a role for proteinases other than MMPs in the degradation of COMP in bovine cartilage. It was further demonstrated that purified COMP was cleaved by ADAMTS-4, but not ADAMTS-I or -5, to yield a fragment which co-migrated with Fragment-110. Therefore this is the first demonstration of COMP as a substrate for ADAMTS-4, although it remains to be determined whether this enzyme plays a role in COMP degradation in vivo. (C) 2003 Elsevier Science B.V. and International Society of Matrix Biology. All rights reserved.