Cell-density-dependent changes in cell-surface glycopeptides and in adhesion of cultured intestinal epithelial cells.
Cell-density-dependent changes in cell-surface glycopeptides and in adhesion of cultured intestinal epithelial cells.
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细胞表面糖肽和培养的肠上皮细胞粘附的细胞密度依赖性变化。
DOI：
10.1042/bj2010359
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
Quaroni,A
中科院分区：
文献类型：
--
作者：
Sasak,W;Herscovics,A;Quaroni,A
我们研究了培养的亚融合和融合肠上皮细胞中含有甘露糖的糖肽和糖蛋白。用d-[2-~3H]甘露糖标记细胞24小时，用Pronase或胰酶处理细胞表面成分。细胞表面和细胞残基部分用Pronase完全消化，所得糖肽在Bio-Gel P-6上分级，用Endo-β-N-乙酰氨基葡萄糖苷酶H处理前后，以区分高甘露糖和复杂低聚糖。细胞表面糖肽富含复合低聚糖，而残基糖肽主要含有高甘露糖低聚糖。融合细胞的细胞表面糖肽比亚融合细胞的糖肽含有更高比例的复合寡糖。在培养至5天时，细胞与[~3H]刀豆蛋白A结合的能力随细胞密度的增加而线性下降，然后保持不变。当细胞生长被维甲酸或皮质醇完全抑制时，亚融合细胞细胞表面糖肽中复合糖与高甘露糖寡糖的比例没有显著差异。二维凝胶分析发现，融合细胞和亚融合细胞的甘露糖标记的总糖蛋白只有很小的差异。在不同的生长阶段和细胞密度下，测量细胞与基质的粘附力。亚汇合体细胞具有较弱的粘附性，随着细胞密度的增加，粘附性明显增强，直到培养6d。这表明，细胞表面糖蛋白碳水化合物结构的变化取决于细胞密度，而不是细胞生长。糖肽的这些变化与细胞与底物粘附性的变化有关。
We studied mannose-containing glycopeptides and glycoproteins of subconfluent and confluent intestinal epithelial cells in culture. Cells were labelled withd-[2-3H]mannose for 24h and treated with Pronase or trypsin to release cell-surface components. The cell-surface and cell-residue fractions were then exhaustively digested with Pronase and the resulting glycopeptides were fractionated on Bio-Gel P-6, before and after treatment with endo-β-N-acetylglucosaminidase H to distinguish between high-mannose and complex oligosaccharides. The cell-surface glycopeptides were enriched in complex oligosaccharides as compared with residue glycopeptides, which contained predominantly high-mannose oligosaccharides. Cell-surface glycopeptides of confluent cells contained a much higher proportion of complex oligosaccharides than did glycopeptides from subconfluent cells. The ability of the cells to bind [3H]concanavalin A decreased linearly with increasing cell density up to 5 days in culture and then remained constant. When growth of the cells was completely inhibited by either retinoic acid or cortisol, no significant difference was observed in the ratio of complex to high-mannose oligosaccharides in the cell-surface glycopeptides of subconfluent cells. Only minor differences were found in total mannose-labelled glycoproteins between subconfluent and confluent cells by two-dimensional gel analysis. The adhesion of the cells to the substratum was measured at different stages of growth and cell density. Subconfluent cells displayed a relatively weak adhesion, which markedly increased with increased cell density up to 6 days in culture. It is suggested that alterations in the structure of the carbohydrates of the cell-surface glycoproteins are dependent on cell density rather than on cell growth. These changes in the glycopeptides are correlated with the changes in adhesion of the cells to the substratum.