Galectin

About: Galectin is a research topic. Over the lifetime, 2076 publications have been published within this topic receiving 103409 citations. The topic is also known as: IPR001079 & Galectin.

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

Abstract: 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, ie the linkage type of sialylation We first mapped the expression profile of the type of sialylation (alpha2,3- or alpha2,6-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 alpha2,6-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

Structural and functional studies of galectin-1: a novel axonal regeneration-promoting activity for oxidized galectin-1.

Abstract: Recently, we discovered oxidized galectin-1 as a factor that regulates initial axonal growth in the peripheral nerve after axotomy. Galectin-1 is a member of the galectins, a family of animal lectins ranging from Caenorhabditis elegans to humans, which is defined by their affinity for beta-galactosides and by significant sequence similarity in the carbohydrate-binding site. Galectin-1 is a homodimer with a subunit molecular mass of 14.5 kDa, which contains six cysteine residues per subunit. The cysteine residues should be in a free state in order to maintain a molecular structure that is capable of showing lectin activity. However, our structural analysis revealed that the axonal regeneration-promoting factor exists as an oxidized form of galectin-1, containing three intramolecular disulfide bonds. The oxidized galectin-1 exhibited marked peripheral nerve regeneration-promoting activity, although it showed no lectin activity. It was also revealed that oxidized galectin-1 exists as a monomer in a physiological solution. Galectin-1 seems to have a variety of biological functions. These functions could vary according to the time at which a biological function is taking place, as well as the site in which a biological function is taking place. In addition, these functions could vary according to the structure of galectin-1 by which a particular biological function is taking place. Disulfide bond formation alters the structure of galectin-1, so as to confer the novel ability to promote axonal regeneration. Oxidized galectin-1 likely acts as an autocrine or paracrine factor to promote axonal regeneration, functioning more like a cytokine than as a lectin.

Open Wound Healing In Vivo: Monitoring Binding and Presence of Adhesion/Growth-Regulatory Galectins in Rat Skin during the Course of Complete Re-Epithelialization.

Abstract: Galectins are a family of carbohydrate-binding proteins that modulate inflammation and immunity. This functional versatility prompted us to perform a histochemical study of their occurrence during wound healing using rat skin as an in vivo model. Wound healing is a dynamic process that exhibits three basic phases: inflammation, proliferation, and maturation. In this study antibodies against keratins-10 and -14, wide-spectrum cytokeratin, vimentin, and fibronectin, and non-cross-reactive antibodies to galectins-1, -2, and -3 were applied to frozen sections of skin specimens two days (inflammatory phase), seven days (proliferation phase), and twenty-one days (maturation phase) after wounding. The presence of binding sites for galectins-1, -2, -3, and -7 as a measure for assessing changes in reactivity was determined using labeled proteins as probes. Our study detected a series of alterations in galectin parameters during the different phases of wound healing. Presence of galectin-1, for example, increased during the early phase of healing, whereas galectin-3 rapidly decreased in newly formed granulation tissue. In addition, nuclear reactivity of epidermal cells for galectin-2 occurred seven days post-trauma. The dynamic regulation of galectins during re-epithelialization intimates a role of these proteins in skin wound healing, most notably for galectin-1 increasing during the early phases and galectin-3 then slightly increasing during later phases of healing. Such changes may identify a potential target for the development of novel drugs to aid in wound repair and patients' care.