Blondal J A, Dick J E, Wright J A
Mech Ageing Dev. 1985 May 31;30(3):273-83. doi: 10.1016/0047-6374(85)90117-4.
The plasma membrane is intimately involved in a variety of cellular phenomena and may play an important role in the aging of human cells in culture. Significant differences in human diploid fibroblast surface glycoproteins were observed with in vitro aging. Senescent cells bound more concanavalin A (Con A) than young cells and exhibited two distinct classes of binding sites. Cell surfaces of senescent cells incorporated less labelled mannose and more labelled fucose and glucosamine than young cell surfaces. Membranes prepared from older cells were also less effective than membrane preparations from young cells in incorporating mannose from GDP-mannose into a group of oligolipid intermediates, required for the synthesis of glycoproteins with asparagine-linked oligosaccharides. These results demonstrate novel quantitative changes in membrane structure and lectin reactivity in aging human diploid fibroblasts, which must reflect the fundamental physiological modifications in the cell that occur during senescence.
质膜密切参与各种细胞现象，并且可能在体外培养的人类细胞衰老过程中发挥重要作用。随着体外老化，观察到人类二倍体成纤维细胞表面糖蛋白存在显著差异。衰老细胞比年轻细胞结合更多的伴刀豆球蛋白A（Con A），并表现出两类不同的结合位点。与年轻细胞表面相比，衰老细胞表面掺入的标记甘露糖较少，而掺入的标记岩藻糖和葡糖胺较多。从老龄细胞制备的膜在将GDP-甘露糖中的甘露糖掺入一组寡脂中间体方面也不如从年轻细胞制备的膜有效，这些寡脂中间体是合成具有天冬酰胺连接寡糖的糖蛋白所必需的。这些结果表明，衰老的人类二倍体成纤维细胞的膜结构和凝集素反应性发生了新的定量变化，这必然反映了细胞在衰老过程中发生的基本生理改变。
