Melrose J, Ghosh P, Taylor T K
Institute of Bone and Joint Research, Royal North Shore Hospital, University of Sydney (Department of Surgery), St Leonards, NSW, Australia.
J Anat. 2001 Jan;198(Pt 1):3-15. doi: 10.1046/j.1469-7580.2001.19810003.x.
This study provides a comparative analysis of the temporal and spatial distribution of 5 intervertebral disc (IVD) proteoglycans (PGs) in sheep. The main PGs in the 2 and 10 y old sheep groups were polydisperse chondroitin sulphate and keratan sulphate substituted species. Their proportions did not differ markedly either with spinal level or disc zone. In contrast, the fetal discs contained 2 slow migrating (by composite agarose polyacrylamide gel electrophoresis, CAPAGE), relatively monodisperse chondroitin sulphate-rich aggrecan species which were also identified by monoclonal antibody 7-D-4 to an atypical chondroitin sulphate isomer presentation previously found in chick limb bud, and shark cartilage. The main small PG detectable in the fetal discs was biglycan, whereas decorin predominated in the 2 and 10 y old IVD samples; its levels were highest in the outer annulus fibrosus (AF). Versican was most abundant in the AF of the fetal sheep group; it was significantly less abundant in the 2 and 10 y old groups. Furthermore, versican was immunolocalised between adjacent layers of annular lamellae suggesting that it may have some role in the provision of the viscoelastic properties to this tissue. Versican was also diffusely distributed throughout the nucleus pulposus of fetal IVDs, and its levels were significantly lower in adult IVD specimens. This is the first study to identify versican in ovine IVD tissue sections and confirmed an earlier study which demonstrated that ovine IVD cells synthesised versican in culture (Melrose et al. 2000). The variable distribution of the PGs identified in this study provides further evidence of differences in phenotypic expression of IVD cell populations during growth and development and further demonstrates the complexity of the PGs in this heterogeneous but intricately organised connective tissue.
本研究对绵羊5种椎间盘（IVD）蛋白聚糖（PGs）的时空分布进行了比较分析。2岁和10岁绵羊组中的主要PGs是多分散硫酸软骨素和硫酸角质素取代物。它们的比例在脊柱节段或椎间盘区域上没有明显差异。相比之下，胎儿椎间盘含有2种迁移缓慢的（通过复合琼脂糖聚丙烯酰胺凝胶电泳，CAPAGE）、相对单分散的富含硫酸软骨素的聚集蛋白聚糖种类，它们也被单克隆抗体7-D-4鉴定为先前在鸡肢芽和鲨鱼软骨中发现的一种非典型硫酸软骨素异构体呈现形式。在胎儿椎间盘中可检测到的主要小PG是双糖链蛋白聚糖，而核心蛋白聚糖在2岁和10岁的IVD样本中占主导；其水平在外层纤维环（AF）中最高。多功能蛋白聚糖在胎儿绵羊组的AF中最为丰富；在2岁和10岁组中其含量明显较少。此外，多功能蛋白聚糖免疫定位在环形板层的相邻层之间，表明它可能在为该组织提供粘弹性特性方面发挥一定作用。多功能蛋白聚糖也广泛分布于胎儿IVD的髓核中，并且其水平在成年IVD标本中显著降低。这是首次在绵羊IVD组织切片中鉴定出多功能蛋白聚糖，并证实了一项早期研究，该研究表明绵羊IVD细胞在培养中合成多功能蛋白聚糖（Melrose等人，2000年）。本研究中鉴定出的PGs的可变分布进一步证明了IVD细胞群体在生长和发育过程中表型表达的差异，并进一步证明了这种异质性但组织复杂的结缔组织中PGs的复杂性。
