Browsing by Subject "Galectin"

Now showing 1 - 4 of 4
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    Galectin fingerprinting in Warthin`s tumors: lectin-based approach to trace its origin?
    (Murcia : F. Hernández, 2010) Saussez, Sven; Leval, Laurence de; Decaestecker, Christine; Sirtaine, Nicolas; Cludts, Stéphanie; Duray, Anaelle; Chevallier, Dominique; André, S.; Gabius, H.J.; Remmelink, Myriam; Leroy, Xavier
    Warthin’s tumor of the parotid gland is assumed to originate from the proliferation of epithelial inclusions within parotid lymph nodes. In that case, these cells are supposed to retain characteristics similar to common salivary gland ductal cells. Using immunohistochemical fingerprinting with four members of the family of adhesion/growth-regulatory galectins and comparison to intra- and interlobular ducts, marked similarities were noted for presence of galectins-3, -7 and -8. Notably, profiles of lectin binding, determined by applying human lectins as probes, were also similar when testing biotinylated galectins-3 and -8. Besides defining the galectin histochemical parameters in Warthin’s tumors this study adds support to the hypothesis of heterotopia
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    Open Access
    Galectin-7, will the lectinrsquos activity establish clinical correlations in head and neck squamous cell and basal cell carcinomas?
    (Murcia : F. Hernández, 2009) Câda, Z.; Chovanec, M.; Smetana, K. Jr.; Betka, J.; Lacina, L.; Plzák, J.; Kodet, R.; Stork, J.; Lensch, M.; Kaltner, H.; André, S.; Gabius, H.J.
    The human lectin galectin-7 (Gal-7; p53- induced gene-1) has anti- and pro-malignant features in different in vitro models. We tried to clarify relation of its expression to cellular and clinical parameters in head and neck squamous and basal cell carcinomas. Using a non-cross-reactive antibody, immunohistochemical staining in squamous cell epithelia (epidermis, epithelium of oropharynx and larynx) (n = 57), squamous cell carcinomas (n = 47) and lymph node metastases (n = 25), as well as basal cell carcinomas (n = 10) were studied. This monitoring was flanked by processing to assess the level of differentiation (cytokeratins 10 and 14), proliferation (Ki67) and basal lamina formation (collagen IV). The results were correlated with clinical and pathological findings (grading, TNM-staging, extracapsular spread, angio- and lymphangioinvasion, perineural invasion, recurrence and survival). Gal-7 resides in all layers of epithelia with cytoplasmic and nuclear localization in normal specimens. Basal cell carcinomas were devoid of the Gal-7 respective signal. Squamous cell carcinomas were positive, presenting different staining profiles. Intense staining was predominantly found in squamous cell cancers with high degrees of differentiation and keratinization. Fittingly, poor level of differentiation (P = 0.0009), absence of keratinization (P = 0.0105) and significant discontinuity or absence of collagen IV expression in the peritumoral basal lamina (P = 0.0024). was found in Gal-7-negative tumors. Gal-7 presence was not related to gender, primary tumor site, T-stage, Nstage, clinical stage, extracapsular spread, angio- and lymphangioinvasion, perineural spread or treatment outcome at a statistically significant level. Immunohistochemical analysis revealed a positive correlation for differentiation and keratinization to Gal-7 presence in squamous cell carcinomas. Absence of Gal-7 expression was detected in basal cell carcinomas. These clinical data delineate Gal-7 influence on differentiation in vivo, without evidence for a role in dissemination reported for lymphoma.
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    Open Access
    Quantitation and histochemical localization of galectin-1 and galectin-1 -reactive glycoconjugates in fetal development of bovine organs
    (Murcia : F. Hernández, 1997) Kaltner, H.; Lips, K.S.; Reuter, G.; Lippert, S.; Sinowatz, F.; Gabius, H.J.
    The display of cellular oligosaccharide chains is known to undergo marked developmental changes, as monitored histochemically with plant lectins. In conjunction with endogenous lectins respective ligand structures may have a functional role during fetal development. The assumption of a recognitive, functionally productive interplay prompts the study of the expression of a tissue lectin and of lectin-reactive glycoconjugates concomitantiy. Focusing on comrnon Bgalactosides as constituents of oligosaccharide chains and the predominant member of the farnily of galectins in marnrnals, namely galectin-1, the question therefore is addressed as to whether expression of lectin and lectinreactive glycoconjugates exhibits alterations, assessed in three morphologically defined fetal stages and in adult bovine organs. Using a sandwich ELISA, the leve1 of the rather ubiquitous galectin-1 is mostly increased in adult organs relative to respective fetal stages, except for the case of kidney. This developmental course is seen rather seldom, when the amounts of lectin-reactive glycoproteins or glycolipids are quantitated in solid-phase assays after tissue homogenization. Western blotting, combined with probing by labeled galectin-1, discloses primarily quantitative changes in the reactivity of individual glycoproteins. Perforrning the same assays on extract aliquots with a plant agglutinin, namely the galactoside-binding mistletoe lectin, whose fine specificity is different @m galectin-1, its reduced extent of binding in solid-phase assays and the disparate profile of lectin-reactive glycoproteins reveal a non-uniform developmental alteration within the group of stmctural variants of B-galactosides. Although sample preparation can affect ligand preservation andlor presentation and thus restricts the comparability of biochemical and histochemical results, especially for soluble reactants, the histochemical studies on frozen and paraffinembedded sections of bovine heart, kidney and liver demonstrate that the localization of the galectin and of lectin-reactive epitopes can show a sirnilar distribution, as seen in liver and heart, with organ-typical quantitative changes of a rather similar staining profile (heart, kidney) or notable changes in the spatial distribution (liver) in the course of development. This report emphasizes the potential value of combined monitoring of the lectin and its potential in vivo ligands to contribute to eventually unravel organ-related function(s) of a tissue lectin.
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    Open Access
    Sertoli cell expression of galectin-l and -3 and accessible binding sites in normal human testis and Sertoli cell only-syndrome
    (Murcia : F. Hernández, 1999) Wollina, U.; Schreiber, G.; Görnig, M.; Feldrappe, S.; Burchert, M.; Gabius, H.J.
    Galectins are vertebrate lectins interacting with B-galactosides and derivates thereof such as blood group A, B and H determinants. The expression of galectin-l and -3 and galectin-specific binding sites by human Sertoli cells was analyzed in normal human testis and Sertoli cell only-syndrome (SCOS). Staining intensity was scored semiquantitatively on a 4-grade scale. Sertoli cells in normal testes displayed a moderate cytoplasmic and weak nuclear staining for galectin-lspecific binding sites. Galectin-3-specific binding sites were expressed in Sertoli cells less intensely than accessible ligands for galectin-l (mean score 2.25 for galectin-l and 1.50 for galectin-3). Germ cells were only weakly reactive. Tubular walls were negative for both classes of galectin-specific binding sites. In SCOS, galectin-l binding was moderate to strong and more pronounced than galectin-3 binding by Sertoli cells (mean scores 4.00 and 2.25). Tubular walls were negative for galectin-staining. The ratio for galectin-1-1 galectin-3-specific binding (staining score ratio) was 1.50 form normal testis and 1.78 for SCOS disclosing a relative increase of galectin-3 binding sites in the latter. Staining with galectin-l- and -3-specific antisera showed a strong cytoplasmic galectin-l immunoreactivity in Sertoli cells of normal and SCOS testis (score 4.00 for both). Anti-galectin-3 did not stain Sertoli cells or germ cells in normal testis. Only Leydig cells were labeled (score 3.00). In SCOS a weak to moderate nuclear staining of Sertoli cells was noted (score 2.00). Galectin-3 expression and galectin-l-specific binding sites were found to be increased in Sertoli cells of SCOS. This modulation of reactivity can have implications for Sertoli cell interactions with galectinreactive extracellular matrix components like laminin and for anti-apoptotic effects.