Trabelsi N, Greffard A, Pairon J C, Bignon J, Zanetti G, Fubini B, Pilatte Y
INSERM, U139, IM3, Faculté de Médecine 8, Créteil, France.
Environ Health Perspect. 1997 Sep;105 Suppl 5(Suppl 5):1153-8. doi: 10.1289/ehp.97105s51153.
Carbohydrate moieties of cell glycoconjugates play a pivotal role in molecular recognition phenomena involved in the regulation of most biological systems and the changes observed in cell surface carbohydrates during cell activation or differentiation frequently modulate certain cell functions. Consequently, some aspects of macrophage response to particle exposure might conceivably result from alterations in glycosylation. Therefore, the effect of mineral particles on protein glycosylation was investigated in phorbol myristate acetate (PMA)-differentiated U-937. Jacalin, a lectin specific for O-glycosylated structures, showed a global increase in O-glycosylation in particle-treated cells. In contrast, no significant modifications were observed with concanavalin A, a lectin that recognizes certain N-glycosylated structures. The sialic acid-specific lectins Sambucus nigra agglutinin and Maackia amurensis agglutinin and the galactose-specific lectin Ricinus communis agglutinin revealed a complex pattern of alterations in glycoprotein glycosylation after crystalline silica or manganese dioxide treatments. Expression of sialyl Lewis(x), a glycosylated structure implicated in leukocyte trafficking, could not be detected in control or treated cells. This finding was consistent with the decrease in sialyl Lewis(x) expression observed during PMA-induced differentiation. In conclusion, various treatments used in this study induced quantitative as well as qualitative changes in protein glycosylation. Whether these changes are due to glycosidase release or to an alteration in glycosyltransferase expression remains to be determined. The potential functional implications of these changes are currently under investigation.
细胞糖缀合物中的碳水化合物部分在涉及大多数生物系统调节的分子识别现象中起关键作用，并且在细胞激活或分化过程中细胞表面碳水化合物的变化经常调节某些细胞功能。因此，可以想象巨噬细胞对颗粒暴露的某些反应可能是由糖基化改变引起的。因此，在佛波酯肉豆蔻酸酯乙酸盐（PMA）分化的U-937细胞中研究了矿物颗粒对蛋白质糖基化的影响。红豆蔻凝集素是一种对O-糖基化结构具有特异性的凝集素，在颗粒处理的细胞中显示O-糖基化总体增加。相比之下，对于识别某些N-糖基化结构的凝集素伴刀豆球蛋白A，未观察到明显的修饰。唾液酸特异性凝集素黑接骨木凝集素和山嵛凝集素以及半乳糖特异性凝集素蓖麻凝集素显示，在结晶二氧化硅或二氧化锰处理后糖蛋白糖基化存在复杂的变化模式。在对照细胞或处理细胞中未检测到与白细胞运输有关的糖基化结构唾液酸路易斯（x）的表达。这一发现与在PMA诱导的分化过程中观察到的唾液酸路易斯（x）表达降低一致。总之，本研究中使用的各种处理诱导了蛋白质糖基化的定量和定性变化。这些变化是由于糖苷酶释放还是糖基转移酶表达改变尚待确定。这些变化的潜在功能影响目前正在研究中。
