Johnson-Green P C, Dow K E, Riopelle R J
Department of Medicine, Queen's University, Kingston, Ontario, Canada.
Glia. 1991;4(3):314-21. doi: 10.1002/glia.440040309.
Quantitative biosynthetic studies with cultures highly enriched for glial fibrillary acidic protein (GFAP+) cells of neonatal mammalian brain demonstrated production of four proteoglycans: hyaluronate (HA), heparan sulphate (HS), chondroitin sulphate (CS), and dermatan sulphate (DS). The glycosaminoglycans were present in cell conditioned medium and in the cellular compartment. There were qualitative differences in the subcellular disposition of the various proteoglycans. The ratio of HS to CS/DS in cell extracts was 1:1, while in medium this ratio was 1:6. All of the glycosaminoglycans were associated with core proteins that were integral to the cell membrane and associated with the cell surface by non-covalent interactions involving glycosaminoglycans. Less than 20% of the HS was non-covalently associated with the astrocyte cell surface reflecting in part the proportionately smaller amounts of this proteoglycan released to astrocyte conditioned medium. HS released to medium was undersulphated relative to that associated with cells. The astrocyte can contribute proteoglycans to the extracellular milieu and displays cell surface proteoglycans that have the potential to provide appropriate substrates for neuron adhesion, process extension, and other cell-cell interactions.
对新生哺乳动物大脑中富含胶质纤维酸性蛋白（GFAP+）细胞的培养物进行的定量生物合成研究表明，产生了四种蛋白聚糖：透明质酸（HA）、硫酸乙酰肝素（HS）、硫酸软骨素（CS）和硫酸皮肤素（DS）。这些糖胺聚糖存在于细胞条件培养基和细胞区室中。各种蛋白聚糖在亚细胞分布上存在质的差异。细胞提取物中HS与CS/DS的比例为1:1，而在培养基中该比例为1:6。所有糖胺聚糖都与核心蛋白相关，这些核心蛋白是细胞膜不可或缺的一部分，并通过涉及糖胺聚糖的非共价相互作用与细胞表面相关联。不到20%的HS与星形胶质细胞表面非共价结合，这部分反映了释放到星形胶质细胞条件培养基中的这种蛋白聚糖数量相对较少。释放到培养基中的HS相对于与细胞结合的HS硫酸化不足。星形胶质细胞可以向细胞外环境贡献蛋白聚糖，并展示细胞表面蛋白聚糖，这些蛋白聚糖有可能为神经元黏附、突起延伸和其他细胞间相互作用提供合适的底物。
