Bonassar L J, Stinn J L, Paguio C G, Frank E H, Moore V L, Lark M W, Sandy J D, Hollander A P, Poole A R, Grodzinsky A J
Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge 02139, USA.
Arch Biochem Biophys. 1996 Sep 15;333(2):359-67. doi: 10.1006/abbi.1996.0402.
Bovine cartilage explants were cultured with 1 mM 4-aminophenylmercuric acetate (APMA) to activate endogenous matrix metalloproteinases (MMPs) and changes in biochemical, biomechanical, and physicochemical properties were assessed. Additionally, graded levels of either rhTIMP-1 (recombinant human tissue inhibitor of metalloproteinases-1) or L-696-418 (a synthetic metalloproteinase inhibitor) were used to inhibit degradation induced by APMA. Treatment with APMA resulted in as much as 80% loss in tissue GAG content, a greater than threefold increase in denatured type II collagen as determined by the presence of CB11B epitope, and complete loss of biosynthetic activity after 3 days in culture. Physicochemical studies revealed that APMA treatment resulted in a significant increase in tissue swelling response, consistent with damage to the collagen network. Activation of MMPs by APMA also resulted in > 80% decrease in equilibrium modulus, dynamic stiffness, and streaming potential and > 50% decrease in electrokinetic coupling coefficient. The addition of 4 microM, 400 nM, and 40 nM TIMP inhibited PG loss by 95, 50, and 20%, respectively, and all doses effectively inhibited swelling response. The addition of 4 microM and 400 nM L-696-418 inhibited PG loss by 95% while 40 nM L-696-418 inhibited PG loss by 60%, and all doses effectively inhibited swelling response. The inhibition of APMA-induced GAG loss by 4 microM TIMP was accompanied by maintenance of streaming potential, electrokinetic coupling coefficient, dynamic stiffness, and equilibrium modulus.
牛软骨外植体用1 mM乙酸对氨基苯汞（APMA）培养以激活内源性基质金属蛋白酶（MMPs），并评估其生化、生物力学和物理化学性质的变化。此外，使用不同梯度水平的重组人金属蛋白酶组织抑制剂-1（rhTIMP-1）或L-696-418（一种合成金属蛋白酶抑制剂）来抑制APMA诱导的降解。用APMA处理导致组织糖胺聚糖（GAG）含量损失高达80%，由CB11B表位的存在确定的变性II型胶原增加超过三倍，并且在培养3天后生物合成活性完全丧失。物理化学研究表明，APMA处理导致组织肿胀反应显著增加，这与胶原网络受损一致。APMA激活MMPs还导致平衡模量、动态刚度和流动电位降低>80%，电动耦合系数降低>50%。添加4 μM、400 nM和40 nM的TIMP分别抑制蛋白聚糖损失95%、50%和20%，并且所有剂量均有效抑制肿胀反应。添加4 μM和400 nM的L-696-418抑制蛋白聚糖损失95%，而40 nM的L-696-418抑制蛋白聚糖损失60%，并且所有剂量均有效抑制肿胀反应。4 μM的TIMP抑制APMA诱导的GAG损失伴随着流动电位、电动耦合系数、动态刚度和平衡模量的维持。
