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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.


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Journal ArticleDOI
TL;DR: The role of galectins in microbial infection is discussed, with particular emphasis on adaptations of pathogens to evasion or subversion of host galectin-mediated immune responses.
Abstract: Galectins, which were first characterized in the mid-1970s, were assigned a role in the recognition of endogenous ('self') carbohydrate ligands in embryogenesis, development and immune regulation. Recently, however, galectins have been shown to bind glycans on the surface of potentially pathogenic microorganisms, and function as recognition and effector factors in innate immunity. Some parasites subvert the recognition roles of the vector or host galectins to ensure successful attachment or invasion. This Review discusses the role of galectins in microbial infection, with particular emphasis on adaptations of pathogens to evasion or subversion of host galectin-mediated immune responses.

485 citations

Journal ArticleDOI
TL;DR: Crystallographic studies revealed that galectins and legume lectins such as concanavalin A have a common topology in spite of the absence of sequence homology, which suggests a possible relationship between animal and plant lectins, and the existence of a lectin super family.
Abstract: Galectins, animal lectins exhibiting specificity for galactosides, are now known to be widely distributed from lower invertebrates, such as sponges and nematodes, to higher vertebrates. The origin of the family can be traced back to the Precambrian era. They are classified into proto-, chimera-, and tandem-repeat types on the basis of protein architecture. The molecular functions of these types should be different because they can cross-link pairs of biomolecules of different combinations. Their biological significance, however, is not yet fully understood because they are involved in too many phenomena, such as differentiation, morphogenesis, metastasis, etc., and too many problems remain unsolved, such as those regarding their controversial cellular localization, mechanism of externalization, etc. Nevertheless, such difficulties seem to indicate their importance as household equipment and their common roles throughout the animal kingdom. They are likely to be responsible for recognizing the N-acetyllactosamine (LacNAc) structure, which is included in various glycoconjugates and considered to be an important glycocode, and then carry out appropriate tasks under given circumstances. Recently, crystallographic studies revealed that galectins and legume lectins such as concanavalin A have a common topology in spite of the absence of sequence homology. This suggests a possible relationship between animal and plant lectins, and the existence of a lectin super family. Studies on the galectin family are becoming increasingly important for glycobiology.

473 citations

Journal ArticleDOI
TL;DR: There is potential for the development of acellular therapeutic interventions for autoimmune, inflammatory, and malignant diseases and tissue regeneration from cellular secretions derived from MSCs cultured under the appropriate conditions.
Abstract: The mesenchymal stem cell (MSC) is being broadly studied in clinical trials. Contrary to the early paradigm of cell replacement and differentiation as a therapeutic mechanism of action, evidence is mounting that the secretions of the cells are responsible for their therapeutic effects. These secretions include molecules and extracellular vesicles that have both local and distant effects. This review summarizes the up- and down-regulation of MSC anti-inflammatory, immune modulating, anti-tumor, and regenerative secretions resulting from different stimuli including: a) hypoxia, which increases the production of growth factors and anti-inflammatory molecules; b) pro-inflammatory stimuli that induce the secretion of immune modulating and anti-inflammatory factors; and c) 3 dimensional growth which up regulates the production of anti-cancer factors and anti-inflammatory molecules compared to monolayer culture. Finally we review in detail the most important factors present in conditioned medium of MSC that can be considered protagonists of MSC physiological effects including HGF, TGF-b, VEGF, TSG-6, PGE2 and galectins 1, and 9. We conclude that there is potential for the development of acellular therapeutic interventions for autoimmune, inflammatory, and malignant diseases and tissue regeneration from cellular secretions derived from MSCs cultured under the appropriate conditions.

469 citations

Journal ArticleDOI
TL;DR: It is demonstrated that extracellular galectin-3 directly induces death of human thymocytes and T cells through distinct cell surface events and that the two death pathways may converge inside the cell.
Abstract: Galectins are a family of mammalian β-galactoside-binding proteins that positively and negatively regulate T cell death. Extracellular galectin-1 directly induces death of T cells and thymocytes, while intracellular galectin-3 blocks T cell death. In contrast to the antiapoptotic function of intracellular galectin-3, we demonstrate that extracellular galectin-3 directly induces death of human thymocytes and T cells. However, events in galectin-3- and galectin-1-induced cell death differ in a number of ways. Thymocyte subsets demonstrate different susceptibility to the two galectins: whereas galectin-1 kills double-negative and double-positive human thymocytes with equal efficiency, galectin-3 preferentially kills double-negative thymocytes. Galectin-3 binds to a complement of T cell surface glycoprotein receptors distinct from that recognized by galectin-1. Of these glycoprotein receptors, CD45 and CD71, but not CD29 and CD43, appear to be involved in galectin-3-induced T cell death. In addition, CD7 that is required for galectin-1-induced death is not required for death triggered by galectin-3. Following galectin-3 binding, CD45 remains uniformly distributed on the cell surface, in contrast to the CD45 clustering induced by galectin-1. Thus, extracellular galectin-3 and galectin-1 induce death of T cells through distinct cell surface events. However, as galectin-3 and galectin-1 cell death are neither additive nor synergistic, the two death pathways may converge inside the cell.

436 citations

Journal ArticleDOI
TL;DR: The findings point toward a mechanism by which galectin-3 may serve in the assembly of AGE-R components and in the efficient cell surface attachment and endocytosis by macrophages of a heterogenous pool of A GE moieties with diverse affinities, thus contributing to the elimination of these pathogenic substances.
Abstract: Advanced glycation end products (AGE), the reactive derivatives of nonenzymatic glucose-protein condensation reactions, are implicated in the multiorgan complications of diabetes and aging. An AGE-specific cellular receptor complex (AGE-R) mediating AGE removal as well as multiple biological responses has been identified. By screening an expression library using antibody against a previously identified component of the AGE-R complex p90, a known partial cDNA clone was isolated with homology to galectin-3, a protein of diverse identity, and member of the galectin family. To explore this unexpected finding, the nature of the interactions between galectin-3 and AGE was studied using intact macrophage-like RAW 264.7 cells, membrane-associated and recombinant galectin-1 through -4, and model AGE-ligands (AGE-BSA, FFI-BSA). Among the members of this family (galectin-1 through 4), recombinant rat galectin-3 was found to exhibit high-affinity 125I-AGE-BSA binding with saturable kinetics (kD 3.5 × 107 M−1) that was fully blocked by excess unlabeled naturally formed AGE-BSA or synthetic FFI-BSA, but only weakly inhibited by several known galectin-3 ligands, such as lactose. In addition to the p90, immunoprecipitation with anti-galectin-3, followed by 125I-AGE-BSA ligand blot analysis of RAW 264.7 cell extracts, revealed galectin-3 (28 and 32 kD), as well as galectin-3-associated proteins (40 and 50 kD) with AGE-binding activity. Interaction of galectin-3 with AGE-BSA or FFI-BSA resulted in formation of SDS-, and β-mercaptoethanol-insoluble, but hydroxylamine-sensitive high-molecular weight complexes between AGE-ligand, galectin-3, and other membrane components. The findings point toward a mechanism by which galectin-3 may serve in the assembly of AGE-R components and in the efficient cell surface attachment and endocytosis by macrophages of a heterogenous pool of AGE moieties with diverse affinities, thus contributing to the elimination of these pathogenic substances.

410 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023182
2022176
2021107
2020120
201995
2018119