Davies Y, Lewis D, Fullwood N J, Nieduszynski I A, Marcyniuk B, Albon J, Tullo A
Department of Biological Sciences, Institute of Environmental and Natural Sciences, Lancaster University, Lancaster, LA1 4YQ, U.K.
Exp Eye Res. 1999 Mar;68(3):303-11. doi: 10.1006/exer.1998.0609.
Proteoglycans are of fundamental importance to the normal functioning of the cornea. They consist of a core protein to which one or more glycosaminoglycan chains are attached. Cell surface proteoglycans are known to mediate many aspects of cell behaviour including cell adhesion, control of extracellular matrix deposition, cell proliferation, cell migration, leukocyte adhesion and modulation of growth factor activity. This paper describes the first investigation into the distribution and function of the three main classes of proteoglycans on human corneal endothelium. Immuno-gold labelling techniques were used at the light, scanning and transmission electron microscope level to localise heparan sulphate, chondroitin sulphate and keratan sulphate proteoglycans on human corneal endothelium. Human corneas were freeze-wounded and kept in organ culture for 3 days in order to study the distribution of proteoglycans on migrating corneal endothelium. An Optimas image analysis system was used to quantify the change in proteoglycan labelling during cell migration. Labelling for chondroitin sulphate and heparan sulphate was at very low levels on normal corneal endothelium while keratan sulphate labelling was at high levels. The wound healing experiments showed that migrating cells had increased labelling for heparan sulphate and chondroitin sulphate with greatly decreased labelling for keratan sulphate. Statistical analysis showed these changes were highly significant (P<0.001). Transmission electron microscopy revealed that chondroitin sulphate and keratan sulphate were present throughout Descemet's membrane while heparan sulphate was concentrated at the interface of Descemet's membrane and the migrating corneal endothelial cells. The pattern of occurrence of chondroitin sulphate, heparan sulphate and keratan sulphate on the human endothelium in normal and wounded cornea suggests that these proteoglycans are linked to the process of cell migration.
蛋白聚糖对于角膜的正常功能至关重要。它们由一个核心蛋白和连接在其上的一条或多条糖胺聚糖链组成。已知细胞表面蛋白聚糖介导细胞行为的许多方面，包括细胞黏附、细胞外基质沉积的控制、细胞增殖、细胞迁移、白细胞黏附以及生长因子活性的调节。本文描述了对人角膜内皮上三类主要蛋白聚糖的分布和功能的首次研究。在光学显微镜、扫描电子显微镜和透射电子显微镜水平上使用免疫金标记技术，以定位人角膜内皮上的硫酸乙酰肝素、硫酸软骨素和硫酸角质素蛋白聚糖。将人角膜冷冻损伤并在器官培养中保存3天，以研究蛋白聚糖在迁移的角膜内皮上的分布。使用Optimas图像分析系统量化细胞迁移过程中蛋白聚糖标记的变化。在正常角膜内皮上，硫酸软骨素和硫酸乙酰肝素的标记水平非常低，而硫酸角质素的标记水平很高。伤口愈合实验表明，迁移的细胞硫酸乙酰肝素和硫酸软骨素的标记增加，而硫酸角质素的标记大大减少。统计分析表明这些变化非常显著（P<0.001）。透射电子显微镜显示，硫酸软骨素和硫酸角质素存在于整个后弹力层，而硫酸乙酰肝素集中在后弹力层与迁移的角膜内皮细胞的界面处。正常和受伤角膜中硫酸软骨素、硫酸乙酰肝素和硫酸角质素在人内皮上的出现模式表明，这些蛋白聚糖与细胞迁移过程有关。
