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.

Expression profiling of cancer-related galectins in acute myeloid leukemia.

Abstract: Acute myeloid leukemia (AML) is the most common type of leukemia in adults with the lowest survival rate of all the leukemias. It is a heterogeneous disease in which a variety of cytogenetic and molecular alterations have been identified. Some galectins were previously reported to have important roles in cancer-like neoplastic transformation, tumor cell survival, angiogenesis, and tumor metastasis. Previous studies have showed that some galectin family members play a role in various types of leukemia. The present study aims at evaluating and clarifying the diagnostic and prognostic value of the expression of cancer-related galectins in relation to the clinicopathological characters of AML patients. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect expression profile of eight galectin family members (galectin-1, -2, -3, -4, -8, -9, -12, and -13) in 53 newly diagnosed de novo AML patients. The samples were collected from the inpatient clinic at National Cancer Institute (NCI), Cairo University (CU), diagnosed between July 2012 and May 2013. Our results show that patients with lower LGALS12 gene expression have a lower overall survival than those with higher expression (P value <0.026). Moreover, a statistically significant association between the LGALS4 gene expression and patient age is found. Hence, the higher expression of LGALS4 gene is associated with younger age (adjusted P value <0.001). In conclusion, galectin-12 may be a potential prognostic marker for AML.

Prototype and Chimera-Type Galectins in Placentas with Spontaneous and Recurrent Miscarriages

Abstract: Galectins are galactose binding proteins and, in addition, factors for a wide range of pathologies in pregnancy. We have analyzed the expression of prototype (gal-1, -2, -7, -10) and chimera-type (gal-3) galectins in the placenta in cases of spontaneous abortions (SPA) and recurrent abortions (RA) in the first trimester. Fifteen placental samples from healthy pregnancies were used as a control group. Nine placentas were examined for spontaneous abortions, and 12 placentas for recurrent abortions. For differentiation and evaluation of different cell types of galectin-expression in the decidua, immunofluorescence was used. For all investigated prototype galectins (gal-1, -2, -7, -10) in SPA and RA placenta trophoblast cells the expression is significantly decreased. In the decidua/extravillous trophoblast only gal-2 expression was significantly lowered, which could be connected to its role in angiogenesis. In trophoblasts in first-trimester placentas and in cases of SPA and RA, prototype galectins are altered in the same way. We suspect prototype galectins have a similar function in placental tissue because of their common biochemical structure. Expression of galectin 3 as a chimera type galectin was not found to be significantly altered in abortive placentas.

Glycodendrimers and Modified ELISAs: Tools to Elucidate Multivalent Interactions of Galectins 1 and 3.

Abstract: Multivalent protein-carbohydrate interactions that are mediated by sugar-binding proteins, i.e., lectins, have been implicated in a myriad of intercellular recognition processes associated with tumor progression such as galectin-mediated cancer cellular migration/metastatic processes. Here, using a modified ELISA, we show that glycodendrimers bearing mixtures of galactosides, lactosides, and N-acetylgalactosaminosides, galectin-3 ligands, multivalently affect galectin-3 functions. We further demonstrate that lactose functionalized glycodendrimers multivalently bind a different member of the galectin family, i.e., galectin-1. In a modified ELISA, galectin-3 recruitment by glycodendrimers was shown to directly depend on the ratio of low to high affinity ligands on the dendrimers, with lactose-functionalized dendrimers having the highest activity and also binding well to galectin-1. The results depicted here indicate that synthetic multivalent systems and upfront assay formats will improve the understanding of the multivalent function of galectins during multivalent protein carbohydrate recognition/interaction.

Deletion of lec-10, a Galectin-Encoding Gene, Increases Susceptibility to Oxidative Stress in Caenorhabditis elegans

Abstract: Galectins are a family of β-galactoside-binding lectins They are involved in the regulation of a variety of biological phenomena in mammals However, little is known about their roles in invertebrates Caenorhabditis elegans is a well-characterized model organism whose complete genome has been sequenced C elegans is now being studied extensively in various fields of medical sciences In this study, we examined the phenotypes of a mutant strain of C elegans (tm1262) lacking lec-10, a galectin-encoding gene We observed no difference in the rates of embryonic lethality and larval arrest/slow growth between this mutant strain and the wild-type strain No apparent morphological defect was observed in the lec-10-deletion mutant (tm1262) Moreover, the life-spans of this mutant and the wild-type strain were equivalent However, this mutant showed significantly greater susceptibility to paraquat and hydrogen peroxide than the wild type did The lec-10-deletion mutants (tm1262) were as susceptible as the daf-16-deletion mutants (mu86) to paraquat and hydrogen peroxide These results suggest that the deletion of lec-10 does not have a notable effect on the worm's survival under laboratory conditions However, this study indicates that lec-10 does confer some protection against oxidative stress

Molecular basis for intestinal mucin recognition by galectin-3 and C-type lectins

Abstract: Intestinal mucins trigger immune responses upon recognition by dendritic cells via protein-carbohydrate interactions We used a combination of structural, biochemical, biophysical, and cell-based approaches to decipher the specificity of the interaction between mucin glycans and mammalian lectins expressed in the gut, including galectin (Gal)-3 and C-type lectin receptors Gal-3 differentially recognized intestinal mucins with different O-glycosylation profiles, as determined by mass spectrometry (MS) Modification of mucin glycosylation, via chemical treatment leading to a loss of terminal glycans, promoted the interaction of Gal-3 to poly- N-acetyllactosamine Specific interactions were observed between mucins and mouse dendritic cell-associated lectin (mDectin)-2 or specific intercellular adhesion molecule-grabbing nonintegrin-related-1 (SIGN-R1), but not mDectin-1, using a cell-reporter assay, as also confirmed by atomic force spectroscopy We characterized the N-glycosylation profile of mouse colonic mucin (Muc)-2 by MS and showed that the interaction with mDectin-2 was mediated by high-mannose N-glycans Furthermore, we observed Gal-3 binding to the 3 C-type lectins by force spectroscopy We showed that mDectin-1, mDectin-2, and SIGN-R1 are decorated by N-glycan structures that can be recognized by the carbohydrate recognition domain of Gal-3 These findings provide a structural basis for the role of mucins in mediating immune responses and new insights into the structure and function of major mammalian lectins-Leclaire, C, Lecointe, K, Gunning, P A, Tribolo, S, Kavanaugh, D W, Wittmann, A, Latousakis, D, MacKenzie, D A, Kawasaki, N, Juge, N Molecular basis for intestinal mucin recognition by galectin-3 and C-type lectins