Platt D, Bird J L, Bayliss M T
Royal Veterinary College, University of London, London, UK.
Equine Vet J. 1998 Jan;30(1):43-52. doi: 10.1111/j.2042-3306.1998.tb04087.x.
In order to identify the pathological processes involved in the destruction of articular cartilage in arthritic diseases, it is first necessary to characterise the normal homeostasis of cartilage in a healthy joint. In particular, normal age-related changes in the biochemistry of cartilage complicate any comparisons that are made between diseased and healthy tissue. There are, however, no reports in the literature detailing the influence of ageing on the biochemistry of proteoglycans in equine articular cartilage. This study addresses the absence of such information by investigating the structure of aggrecan and decorin extracted from a wide age-range of full thickness equine tissue. The total glycosaminoglycan content of articular cartilage from the metacarpophalangeal joint remained relatively constant throughout life. In contrast, specific components such as hyaluronan increased in concentration with advancing age as did the content of a structural epitope present on keratan sulphate chains. There were also significant age-related changes in the sulphation pattern of chondroitin sulphate chains. The structure of the large aggregating proteoglycan (aggrecan) became more heterogeneous in size with increasing age and each of the subspecies of aggrecan identified in the extracts was shown to carry a hyaluronan binding region (G1) domain. All subspecies of aggrecan also expressed specific epitopes to keratan sulphate, chondroitin-4-sulphate and chondroitin-6-sulphate glycosaminoglycan chains. The structure of the small nonaggregating proteoglycan decorin and the aggrecan stabilising molecule link protein were demonstrated to be similar in size and charge to that reported for other species.
为了确定关节炎疾病中关节软骨破坏所涉及的病理过程，首先需要描述健康关节中软骨的正常稳态。特别是，软骨生物化学中与年龄相关的正常变化使患病组织和健康组织之间的任何比较都变得复杂。然而，文献中没有报告详细说明衰老对马关节软骨中蛋白聚糖生物化学的影响。本研究通过研究从广泛年龄范围的马全层组织中提取的聚集蛋白聚糖和核心蛋白聚糖的结构，解决了此类信息的缺失问题。掌指关节的关节软骨总糖胺聚糖含量在整个生命过程中保持相对恒定。相比之下，透明质酸等特定成分的浓度随着年龄的增长而增加，硫酸角质素链上存在的结构表位含量也增加。硫酸软骨素链的硫酸化模式也有显著的年龄相关变化。随着年龄的增长，大型聚集蛋白聚糖（聚集蛋白聚糖）的结构在大小上变得更加异质，提取物中鉴定出的聚集蛋白聚糖的每个亚种类都显示带有透明质酸结合区域（G1）结构域。聚集蛋白聚糖的所有亚种类也表达了针对硫酸角质素、硫酸软骨素-4-硫酸酯和硫酸软骨素-6-硫酸酯糖胺聚糖链的特定表位。小型非聚集蛋白聚糖核心蛋白聚糖和聚集蛋白聚糖稳定分子连接蛋白的结构在大小和电荷方面与其他物种报道的相似。
