Barrett A J
Agents Actions. 1978 Jan;8(1-2):11-8. doi: 10.1007/BF01972396.
The proteolytic degradation of articular cartilage that is seen in the arthritides affects both of the major structural components of the tissue, proteoglycan and collagen. Neutrophil leucocytes are abundant in the synovial fluid of the inflamed joints, and we have considered whether the large quantities of neutral proteinases carried by these cells could contribute to the cartilage degradation. The two neutrophil serine proteinases have been isolated, and shown to break down both proteoglycan and collagen in articular cartilage. The enzymes attacked the non-helical terminal peptides of the collagen, eliminating the cross-links, thus destabilizing and solubilizing, the fibres. The soluble collagen then denatured spontaneously, and was further degraded. Although large quantities of the neutrophil proteinases are probably released in the synovial fluid each day, the inhibitory capacity of the fluid is seldom, if ever, saturated. Nevertheless, immunologically mediated release of the neutrophil enzymes in 'frustrated endocytosis' at the cartilage surface could give rise to the generalized damage that has been reported by others.
在关节炎中所见的关节软骨蛋白水解降解会影响该组织的两个主要结构成分，即蛋白聚糖和胶原蛋白。中性粒细胞在炎症关节的滑液中大量存在，我们曾思考这些细胞所携带的大量中性蛋白酶是否会导致软骨降解。两种中性粒细胞丝氨酸蛋白酶已被分离出来，并显示它们能分解关节软骨中的蛋白聚糖和胶原蛋白。这些酶攻击胶原蛋白的非螺旋末端肽，消除交联，从而使纤维不稳定并溶解。可溶性胶原蛋白随后自发变性，并被进一步降解。尽管每天可能有大量中性粒细胞蛋白酶释放入滑液中，但滑液的抑制能力很少（如果有的话）会饱和。然而，在软骨表面通过“受阻内吞作用”免疫介导释放中性粒细胞酶可能会导致其他人所报道的广泛性损伤。
