Brown C J, Rahman S, Morton A C, Beauchamp C L, Bramwell H, Buttle D J
Institute for Bone and Joint Medicine, Department of Human Metabolism and Clinical Biochemistry, University of Sheffield Medical School, Beech Hill Road, Sheffield S10 2RX.
Clin Mol Pathol. 1996 Dec;49(6):M331-9. doi: 10.1136/mp.49.6.m331.
Aims-To investigate the level of matrix metalloproteinase activity during the time-course of cartilage explant proteoglycan breakdown; to determine the effects of selective small-molecule inhibitors of matrix metalloproteinases on proteoglycan degradation.Methods-The levels of matrix metalloproteinase activity in cartilage explant cultures and conditioned media were monitored by use of a quenched fluorescent substrate. The constants for inhibition of certain matrix metalloproteinases by a series of synthetic inhibitors were determined. Bovine and human cartilage explant cultures were treated with interleukin-1, tumor necrosis factor or retinoic acid and the amount of proteoglycan released into the culture medium in the absence and presence of the inhibitors was quantified. Control experiments, examining the inhibition of other proteinases, and investigating possible toxic or non-specific effects of the inhibitors, were carried out.Results-The profile of inhibition of proteoglycan release suggested the involvement of interstitial collagenase-like, rather than gelatinase- or possibly stromelysin-like, proteinases. No evidence was found for toxic or non-specific mechanisms of inhibition. Very low levels of activity of the known matrix metalloproteinases were present during the time-course of aggrecan breakdown.Conclusions-A novel collagenase-like proteinase(s) may be involved in cartilage proteoglycan breakdown. Gelatinase-type matrix metalloproteinases do not seem to be involved in this process. Specific collagenase inhibitors may be therapeutically efficacious in the treatment of arthritis.
目的——研究软骨外植体蛋白聚糖降解过程中基质金属蛋白酶活性水平；确定基质金属蛋白酶选择性小分子抑制剂对蛋白聚糖降解的影响。方法——通过使用淬灭荧光底物监测软骨外植体培养物和条件培养基中基质金属蛋白酶的活性水平。测定了一系列合成抑制剂对某些基质金属蛋白酶的抑制常数。用白细胞介素-1、肿瘤坏死因子或视黄酸处理牛和人软骨外植体培养物，并在有无抑制剂的情况下对释放到培养基中的蛋白聚糖量进行定量。进行了对照实验，检测其他蛋白酶的抑制情况，并研究抑制剂可能的毒性或非特异性作用。结果——蛋白聚糖释放抑制情况表明，间质胶原酶样蛋白酶而非明胶酶或可能的基质溶解素样蛋白酶参与其中。未发现毒性或非特异性抑制机制的证据。在聚集蛋白聚糖降解过程中，已知基质金属蛋白酶的活性水平非常低。结论——一种新型胶原酶样蛋白酶可能参与软骨蛋白聚糖的降解。明胶酶型基质金属蛋白酶似乎不参与此过程。特异性胶原酶抑制剂在关节炎治疗中可能具有治疗效果。
