Fernandez-Teran M, Bayliss M, Archer C W
Department of Anatomy and Cell Biology, University of Cantabria, Faculty of Medicine, Santander, Spain.
Anat Embryol (Berl). 1993 Aug;188(2):189-99. doi: 10.1007/BF00186252.
Proteoglycans are ubiquitous extracellular matrix molecules whose role in development remains poorly understood. In the developing chick limb, the nature and possible roles of a number of extracellular matrix proteins is well documented. Much less is known of the biochemical nature, and more importantly, the roles of proteoglycans. Using a panel of monoclonal antibodies (Mabs) which recognise specific epitopes on the constituent chondroitin/dermatan sulphate chains, we show that distinct sub-populations of proteoglycans are dynamically expressed within the limb ectoderm, the ectodermal basement membrane and the limb mesenchyme. In particular, prior to chondrogenesis, chondroitin-6-sulphate-rich proteoglycans containing over-sulphated domains residue predominantly within the mesenchymal extracellular matrix ECM, whilst chondroitin-4-sulphate (C-4-S) is associated with the ectodermal basement membrane and subjacent mesenchymal ECM. At stage 24, C-4-S is also localized in the prechondrogenic condensation. Concomitantly with overt chondrogenesis, the epitopes recognized by the Mabs become restricted to the chondrifying skeletal elements and the undifferentiated distal mesenchyme. The significance of these findings has yet to be elucidated.
蛋白聚糖是普遍存在的细胞外基质分子，其在发育过程中的作用仍知之甚少。在发育中的鸡胚肢体中，许多细胞外基质蛋白的性质和可能的作用已有充分记录。而对于蛋白聚糖的生化性质，更重要的是其作用，人们了解得更少。我们使用一组能识别组成型硫酸软骨素/硫酸皮肤素链上特定表位的单克隆抗体，发现蛋白聚糖的不同亚群在肢体外胚层、外胚层基底膜和肢体间充质中动态表达。特别是在软骨形成之前，富含硫酸软骨素-6-硫酸酯且含有过度硫酸化结构域的蛋白聚糖主要存在于间充质细胞外基质（ECM）中，而硫酸软骨素-4-硫酸酯（C-4-S）则与外胚层基底膜及相邻的间充质ECM相关。在第24阶段，C-4-S也定位于软骨形成前的细胞凝聚处。随着明显的软骨形成，这些单克隆抗体识别的表位局限于正在软骨化的骨骼成分和未分化的远端间充质。这些发现的意义尚待阐明。
