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Defining the glycophenotype of squamous epithelia using plant and mammalian lectins. Differentiation‐dependent expression of α2,6‐ and α2,3‐linked N‐acetylneuraminic acid in squamous epithelia and carcinomas, and its differential effect on binding of the endogenous lectins galectins‐1 and ‐3
Author(s) -
HOLÍKOVÁ ZUZANA,
HRDLIČKOVÁCELA ENKELA,
PLZÁK JAN,
SMETA JR. KAREL,
BETKA JAN,
DVOŘÁNKOVÁ BARBORA,
ESNER MILAN,
WASANO KOJIRO,
ANDRÉ SABINE,
KALTNER HERBERT,
MOTLÍK JAN,
HERCOGOVÁ JANA,
KODET ROMAN,
GABIUS HANSJOACHIM
Publication year - 2002
Publication title -
apmis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0903-4641
DOI - 10.1034/j.1600-0463.2002.1101202.x
Subject(s) - galectin , lectin , glycoconjugate , epitope , biology , sialic acid , glycan , glycoprotein , endogeny , glycosylation , biochemistry , receptor , microbiology and biotechnology , antigen , immunology
A thorough characterization of the properties of squamous epithelial cells is necessary in order to improve our understanding of the functional aspects of normal development and malignant aberrations. Up to now, studies have focused almost exclusively on monitoring distinct protein markers. With our growing awareness of the coding function of glycan chains of cellular glycoconjugates and their interaction with receptors (lectins) in situ, defining the glycophenotype of these cells has become an important issue. Whereas the commonly applied plant lectins are tools used to map the presence and localization of biochemically defined saccharide epitopes, the introduction of endogenous (mammalian) lectins to this analysis enables us to take the step from monitoring the presence of glycan to understanding the functional implications by revealing ligand properties of the detected epitope for tissue lectin. Thus, in this study we investigated a distinct aspect of glycosylation using plant and mammalian lectins, i.e. the linkage type of sialylation. We first mapped the expression profile of the type of sialylation (α2,3‐ or α2,6‐linked) by plant lectins. Based on the hypothesis that this factor regulates accessibility of ligands for endogenous lectins we introduced two labeled galectins to this study. Galectin‐3 (but not galectin‐1) binding was related to cell differentiation in normal adult and developing epithelia, cultured epidermal cells, and carcinomas derived from these epithelia. The presented data suggest that α2,6‐linked N‐acetyl‐ D ‐neuraminic acid moieties could serve to mask galectin‐3‐reactive glycoepitopes. As a consequence, monitoring of the linkage type of sialic acid in glycans by plant lectins therefore has implications for the extent of glycan reactivity with endogenous lectins, pointing to a potential function of changes in sialylation type beyond these cell and lectin systems.