Qu Cheng-Juan, Rieppo Jarno, Hyttinen Mika M, Lammi Mikko J, Kiviranta Ilkka, Kurkijärvi Jatta, Jurvelin Jukka S, Töyräs Juha
Institute of Biomedicine, Department of Anatomy, University of Kuopio, Kuopio, Finland.
Connect Tissue Res. 2007;48(1):27-33. doi: 10.1080/03008200601044128.
Chondroitin sulfate is the major constituent of cartilage. Inadequate sulfate availability results in the production of undersulfated proteoglycans. In osteoarthritis, there is a net loss of articular cartilage proteoglycans. Theoretically, it is possible that during the progress of disease undersulfated glycosaminoglycans are synthesized producing proteoglycans with poorer biological properties. In this study, we tested whether in early human osteoarthritic articular cartilage (Mankin's score of 2 and 3) or more advanced disease (Mankin's score over 3), there are proteoglycans that contain a higher relative amount of nonsulfated chondroitin disaccharide isomer in their chondroitin sulfate chains by analyzing the molar ratios of chondroitin sulfate disaccharide isoforms with fluorophore-assisted carbohydrate electrophoresis. Our results indicated that the nonsulfated disaccharide of chondroitin sulfate formed in average only 1-2% of the total chondroitin sulfate. More important, the molar ratio of nonsulfated disaccharide did not appear to be increased in the osteoarthritic articular cartilage. We conclude that undersulfation of articular cartilage proteoglycans is not present in the human osteoarthritic joint.
硫酸软骨素是软骨的主要成分。硫酸盐供应不足会导致生成硫酸化不足的蛋白聚糖。在骨关节炎中，关节软骨蛋白聚糖会出现净损失。从理论上讲，在疾病进展过程中，有可能合成硫酸化不足的糖胺聚糖，从而产生生物学特性较差的蛋白聚糖。在本研究中，我们通过荧光辅助碳水化合物电泳分析硫酸软骨素二糖异构体的摩尔比，来检测在早期人类骨关节炎关节软骨（曼金评分2和3）或更严重的疾病（曼金评分超过3）中，其硫酸软骨素链中是否存在相对含量更高的非硫酸化软骨素二糖异构体的蛋白聚糖。我们的结果表明，硫酸软骨素的非硫酸化二糖平均仅占总硫酸软骨素的1-2%。更重要的是，骨关节炎关节软骨中，非硫酸化二糖的摩尔比似乎并未增加。我们得出结论，人类骨关节炎关节中不存在关节软骨蛋白聚糖硫酸化不足的情况。
