Cole A A, Chubinskaya S, Schumacher B, Huch K, Szabo G, Yao J, Mikecz K, Hasty K A, Kuettner K E
Department of Biochemistry, Rush Medical College, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois 60612, USA.
J Biol Chem. 1996 May 3;271(18):11023-6. doi: 10.1074/jbc.271.18.11023.
This study confirms that normal human articular chondrocytes express neutrophil collagenase or matrix metalloproteinase-8 (MMP-8), a gene product previously thought to be expressed exclusively by neutrophil leukocytes. Both MMP-8 protein and mRNA were present in articular cartilages collected from normal human donors. Cartilage extracts were assayed by immunoblotting and by analysis of enzymatic activity on gelatin-substrate gels. Latent MMP-8 extracted from cartilage has a molecular mass of 55 kDa; active MMP-8 was identified at 46 and 42 kDa. In the absence of a reducing agent, MMP-8 migrated in a high molecular mass complex above 200 kDa. Northern blotting results demonstrated the expression of MMP-8 in chondrocytes, which could be up-regulated by stimulation with interleukin-1 beta. In addition, reverse transcription-polymerase chain reaction using nested primers and in situ hybridization revealed the presence of MMP-8 mRNA in chondrocytes. The presence of both MMP-8 protein and message in cartilage supports the concept that neutrophil collagenase could be the enzyme described as "aggrecanase".
本研究证实，正常人类关节软骨细胞表达中性粒细胞胶原酶或基质金属蛋白酶-8（MMP-8），该基因产物以前被认为仅由中性粒细胞表达。MMP-8蛋白和mRNA均存在于从正常人类供体采集的关节软骨中。通过免疫印迹和明胶底物凝胶上的酶活性分析对软骨提取物进行检测。从软骨中提取的潜伏性MMP-8分子量为55 kDa；在46 kDa和42 kDa处鉴定出活性MMP-8。在没有还原剂的情况下，MMP-8在高于200 kDa的高分子量复合物中迁移。Northern印迹结果证明MMP-8在软骨细胞中表达，其可被白细胞介素-1β刺激上调。此外，使用巢式引物的逆转录-聚合酶链反应和原位杂交显示软骨细胞中存在MMP-8 mRNA。软骨中同时存在MMP-8蛋白和信息支持了中性粒细胞胶原酶可能是被称为“聚集蛋白聚糖酶”的酶这一概念。
