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.

Galectin 3 aggravates joint inflammation and destruction in antigen‐induced arthritis

Abstract: Objective Galectin 3, an endogenous β-galactoside–binding lectin, plays an important role in the modulation of immune responses. The finding that galectin 3 is present in the inflamed synovium in patients with rheumatoid arthritis suggests that the protein is associated with the pathogenesis of this disease. We undertook this study to investigate the influence of galectin 3 deficiency in a murine model of arthritis. Methods Wild-type (WT) and galectin 3–deficient (galectin 3−/−) mice were subjected to antigen-induced arthritis (AIA) through immunization with methylated bovine serum albumin. The concentration of serum cytokines (interleukin-6 [IL-6] and tumor necrosis factor α [TNFα]) and antigen-specific antibodies was evaluated using a cytometric bead array platform and enzyme-linked immunosorbent assay (ELISA). Cellular IL-17 responses were examined by flow cytometry, ELISA, and enzyme-linked immunospot assay. Results The joint inflammation and bone erosion of AIA were markedly suppressed in galectin 3−/− mice as compared with WT mice. The reduced arthritis in galectin 3−/− mice was accompanied by decreased levels of antigen-specific IgG and proinflammatory cytokines. The frequency of IL-17–producing cells in the spleen was reduced in galectin 3−/− mice as compared with WT mice. Exogenously added recombinant galectin 3 could partially restore the reduced arthritis and cytokines in galectin 3−/− mice. Conclusion Our findings show that galectin 3 plays a pathogenic role in the development and progression of AIA and that the disease severity is accompanied by alterations of antigen-specific IgG levels, systemic levels of TNFα and IL-6, and frequency of IL-17–producing T cells. To our knowledge, this is the first report of in vivo evidence that galectin 3 plays a crucial role in the development of arthritis.

Diversified carbohydrate-binding lectins from marine resources.

Abstract: Marine bioresources produce a great variety of specific and potent bioactive molecules including natural organic compounds such as fatty acids, polysaccharides, polyether, peptides, proteins, and enzymes. Lectins are also one of the promising candidates for useful therapeutic agents because they can recognize the specific carbohydrate structures such as proteoglycans, glycoproteins, and glycolipids, resulting in the regulation of various cells via glycoconjugates and their physiological and pathological phenomenon through the host-pathogen interactions and cell-cell communications. Here, we review the multiple lectins from marine resources including fishes and sea invertebrate in terms of their structure-activity relationships and molecular evolution. Especially, we focus on the unique structural properties and molecular evolution of C-type lectins, galectin, F-type lectin, and rhamnose-binding lectin families.

Identification and tissue expression analysis of C-type lectin and galectin in the Pacific oyster, Crassostrea gigas.

Abstract: As an initial step in the functional analysis of lectins in the Pacific oyster, Crassostrea gigas, we attempted to obtain the full coding sequences of C. gigas lectins and conduct tissue expression analyses. To obtain lectin genes quickly, we identified C. gigas expressed sequence tags that coded for lectins in GenBank, and selected three encoding partial sequences of C-type lectin 1 (CgCLec-1), galectin (CgGal) and fucolectin. We obtained full open reading frames of CgCLec-1 and CgGal cDNAs by RACE-PCR. CgCLec-1 is a typical C-type lectin with a signal peptide and C-type lectin domain. CgCLec-1 mRNA was expressed only in specialized basophilic cells involved with digestive enzyme secretion in the digestive gland, suggesting that CgCLec-1 is secreted into the lumen of the digestive diverticula. CgGal is a prototype galectin with a single galactose-binding domain that was expressed in all of the tissues examined. As suggested for vertebrate galectin-1 (prototype galectin), CgGal may function in general cell activities such as cell adhesion. Fucolectin in C. gigas was expressed specifically in the gonads, indicating a possible function in gonadal development. CgCLec-1 and CgGal expression in hemocytes was not upregulated after injecting Vibrio tubiashii into adductor muscle, suggesting that bacterial infection does not induce synthesis of these lectins. Of the three lectins examined, CgCLec-1 is an interesting target for future investigations of innate immunity in the digestive system of C. gigas.

Homology modelling and molecular dynamics studies of human placental tissue protein 13 (galectin-13).

Abstract: The primary structure of the newly sequence analysed placental tissue protein 13 (PP13) was highly homologous to several members of the beta-galactoside-binding S-type lectin (galectin) family. By homology modelling, the three-dimensional structure of PP13 was built based on high-resolution crystal structures of homologues and also their characteristic 'jellyroll' fold was found in the case of PP13. Our model has been deposited in the Brookhaven Protein Data Bank. By multiple sequence alignment and structure-based secondary structure prediction, we underlined the structural similarity of PP13 with its homologues. The secondary structure of PP13 was identical with 'proto-type' galectins consisting of a five- and a six-stranded beta-sheet, joined by two alpha-helices, and galectins' highly conserved carbohydrate-recognition domain (CRD) was also present in PP13. Of the eight consensus residues in the CRD, four identical and three conservatively substituted were shared by PP13. By docking simulations PP13 possessed sugar-binding activity with highest affinity to N-acetyllactosamine and lactose typical of most galectins. All ligands were docked into the putative CRD of PP13. Based on several lines of evidence discussed in this paper demonstrating that PP13 is a novel galectin, PP13 was also designated galectin-13. These computational results provide some new insights into the possible role and importance of PP13 in various processes of the human body and can be of help in the initial steps of further functional research.