Liu H, McKenna L A, Dean M F
Department of Veterinary Basic Sciences, The Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK.
Biochim Biophys Acta. 1999 Aug 5;1428(2-3):191-200. doi: 10.1016/s0304-4165(99)00074-4.
Previous studies have shown that a synthetic, unglycosylated analogue of the N-terminal peptide from link protein can function as a growth factor and up-regulate proteoglycan biosynthesis in explant cultures of normal human articular cartilage from a wide age range of subjects (McKenna et al., Arthritis Rheum. 41 (1998) 157-162). The present work further shows that link peptide increased proteoglycan synthesis by cartilage cultured in both the presence and absence of serum, suggesting that the mechanism of up-regulation may be different from that of insulin-like growth factors. The proteoglycans synthesised during stimulation with link peptide were of normal hydrodynamic size and the ratio of core protein to glycosaminoglycan side chains and the proportions of the large proteoglycan aggrecan to the small proteoglycans, decorin and biglycan, remained constant. Aggrecan molecules were equally capable of forming aggregates as those from control tissues and the relative proportions of decorin and biglycan were unchanged showing that both were co-ordinately up-regulated. These results confirmed that this novel peptide is a potent stimulator of proteoglycan synthesis by articular cartilage and showed that the newly synthesised proteoglycans were of normal composition.
先前的研究表明，连接蛋白N端肽的一种合成的、未糖基化类似物可作为一种生长因子，上调来自广泛年龄范围受试者的正常人关节软骨外植体培养物中蛋白聚糖的生物合成（麦肯纳等人，《关节炎与风湿病》41（1998年）157 - 162）。目前的工作进一步表明，连接肽在有血清和无血清培养的情况下均能增加软骨中蛋白聚糖的合成，这表明上调机制可能与胰岛素样生长因子的上调机制不同。在用连接肽刺激过程中合成的蛋白聚糖具有正常的流体动力学大小，核心蛋白与糖胺聚糖侧链的比例以及大蛋白聚糖聚集蛋白聚糖与小蛋白聚糖（饰胶蛋白聚糖和双糖链蛋白聚糖）的比例保持恒定。聚集蛋白聚糖分子与对照组织中的分子一样能够形成聚集体，饰胶蛋白聚糖和双糖链蛋白聚糖的相对比例没有变化，表明两者是协同上调的。这些结果证实，这种新型肽是关节软骨蛋白聚糖合成的有效刺激剂，并表明新合成的蛋白聚糖具有正常的组成。
