The binding of human galectins by glycomimetic inhibitors is a promising therapeutic approach. The structurally distinct group of tandem-repeat galectins has scarcely been studied so far, and there is hardly any knowledge on their ligand specificity or their inhibitory potential, particularly concerning non-natural carbohydrates. Here, we present the synthesis of a library of seven 3-O-disubstituted thiodigalactoside-derived glycomimetics and their affinity to two tandem-repeat galectins, Gal-8 and Gal-9. The straightforward synthesis of these glycomimetics involved dibutyltin oxide-catalyzed 3,3́-O-disubstitution of commercially available unprotected thiodigalactoside, and conjugation of various aryl substituents by copper-catalyzed Huisgen azide-alkyne cycloaddition (CuAAC). The inhibitory potential of the prepared glycomimetics for Gal-8 and Gal-9 was assessed, and compared with the established galectins Gal-1 and Gal-3. The introduction of C-3 substituents resulted in an over 40-fold increase in affinity compared with unmodified TDG. The structure-affinity relations within the studied series were discussed using molecular modeling. Furthermore, the prepared glycomimetics were shown to scavenge Gal-8 and Gal-9 from the surface of cancer cells. This pioneering study on the synthetic inhibitors especially of Gal-9 identified lead compounds that may be used in further biomedical research.
- MeSH
- galektiny * metabolismus MeSH
- lidé MeSH
- sacharidy chemie MeSH
- thiogalaktosidy * chemie MeSH
- vazba proteinů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Elevated levels of galectin-3 are associated with tumorigenesis. Its inhibition with high-affinity carbohydrate ligands opens new therapeutic routes. Targeting of intracellular galectin-3 is challenging for polar inhibitors like carbohydrates. We demonstrate the potential of novel biomedical research tools, glycocalix[4]arenes, to enter epithelial cells, which may allow their interaction with galectin-3.
- MeSH
- buněčná membrána MeSH
- galektin 3 * MeSH
- galektiny MeSH
- glykokalyx * MeSH
- sacharidy farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
Galectin-3 (Gal-3) participates in many cancer-related metabolic processes. The inhibition of overexpressed Gal-3 by, e.g., β-galactoside-derived inhibitors is hence promising for cancer treatment. The multivalent presentation of such inhibitors on a suitable biocompatible carrier can enhance the overall affinity to Gal-3 and favorably modify the interaction with Gal-3-overexpressing cells. We synthesized a library of C-3 aryl-substituted thiodigalactoside inhibitors and their multivalent N-(2-hydroxypropyl)methacrylamide (HPMA)-based counterparts with two different glycomimetic contents. Glycopolymers with a higher content of glycomimetic exhibited a higher affinity to Gal-3 as assessed by ELISA and biolayer interferometry. Among them, four candidates (with 4-acetophenyl, 4-cyanophenyl, 4-fluorophenyl, and thiophen-3-yl substitution) were selected for further evaluation in cancer-related experiments in cell cultures. These glycopolymers inhibited Gal-3-induced processes in cancer cells. The cyanophenyl-substituted glycopolymer exhibited the strongest antiproliferative, antimigratory, antiangiogenic, and immunoprotective properties. The prepared glycopolymers appear to be prospective modulators of the tumor microenvironment applicable in the therapy of Gal-3-associated cancers.
Galectin-3 (Gal-3) is a β-galactoside-binding protein that influences various cell functions, including cell adhesion. We focused on the role of Gal-3 as an extracellular ligand mediating cell-matrix adhesion. We used human adipose tissue-derived stem cells and human umbilical vein endothelial cells that are promising for vascular tissue engineering. We found that these cells naturally contained Gal-3 on their surface and inside the cells. Moreover, they were able to associate with exogenous Gal-3 added to the culture medium. This association was reduced with a β-galactoside LacdiNAc (GalNAcβ1,4GlcNAc), a selective ligand of Gal-3, which binds to the carbohydrate recognition domain (CRD) in the Gal-3 molecule. This ligand was also able to detach Gal-3 newly associated with cells but not Gal-3 naturally present on cells. In addition, Gal-3 preadsorbed on plastic surfaces acted as an adhesion ligand for both cell types, and the cell adhesion was resistant to blocking with LacdiNAc. This result suggests that the adhesion was mediated by a binding site different from the CRD. The blocking of integrin adhesion receptors on cells with specific antibodies revealed that the cell adhesion to the preadsorbed Gal-3 was mediated, at least partially, by β1 and αV integrins-namely α5β1, αVβ3, and αVβ1 integrins.
- MeSH
- buněčná adheze * MeSH
- endoteliální buňky pupečníkové žíly (lidské) cytologie fyziologie MeSH
- galektiny metabolismus MeSH
- integriny metabolismus MeSH
- krevní proteiny metabolismus MeSH
- kultivované buňky MeSH
- lidé MeSH
- mezenchymální kmenové buňky cytologie fyziologie MeSH
- spoje buňka-matrix metabolismus MeSH
- vazba proteinů MeSH
- vazebná místa MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Galectin-3 plays a crucial role in cancerogenesis; its targeting is a prospective pathway in cancer diagnostics and therapy. Multivalent presentation of glycans was shown to strongly increase the affinity of glycoconjugates to galectin-3. Further strengthening of interaction with galectin-3 may be accomplished using artificial glycomimetics with apt aryl substitutions. We established a new, as yet undescribed chemoenzymatic method to produce selective C-3-substituted N,N'-diacetyllactosamine glycomimetics and coupled them to human serum albumin. From a library of enzymes, only β-N-acetylhexosaminidase from Talaromyces flavus was able to efficiently synthesize the C-3-propargylated disaccharide. Various aryl residues were attached to the functionalized N,N'-diacetyllactosamine via click chemistry to assess the impact of the aromatic substitution. In ELISA-type assays with galectin-3, free glycomimetics exhibited up to 43-fold stronger inhibitory potency to Gal-3 than the lactose standard. Coupling to human serum albumin afforded multivalent neo-glycoproteins with up to 4209-fold increased inhibitory potency per glycan compared to the monovalent lactose standard. Surface plasmon resonance brought further information on the kinetics of galectin-3 inhibition. The potential of prepared neo-glycoproteins to target galectin-3 was demonstrated on colorectal adenocarcinoma DLD-1 cells. We investigated the uptake of neo-glycoproteins into cells and observed limited non-specific transport into the cytoplasm. Therefore, neo-glycoproteins primarily act as efficient scavengers of exogenous galectin-3 of cancer cells, inhibiting its interaction with the cell surface, and protecting T-lymphocytes against galectin-3-induced apoptosis. The present neo-glycoproteins combine the advantage of a straightforward synthesis, selectivity, non-toxicity, and high efficiency for targeting exogenous galectin-3, with possible application in the immunomodulatory treatment of galectin-3-overexpressing cancers.
- MeSH
- biomimetické materiály chemická syntéza chemie farmakologie MeSH
- galektiny antagonisté a inhibitory genetika metabolismus MeSH
- glykoproteiny chemie metabolismus MeSH
- kinetika MeSH
- krevní proteiny antagonisté a inhibitory genetika metabolismus MeSH
- lidé MeSH
- molekulární struktura MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
AIM: To determine whether the promoter polymorphism -203A>C of cholesterol-7α-hydroxylase encoding gene (CYP7A1) affects diurnal variation in CYP7A1 enzyme activity. METHODS: The study included 16 healthy male volunteers - 8 homozygous for -203A and 8 homozygous for the -203C allele of CYP7A1. Three 15-hour examinations (from 7am to 10pm) were carried out for each of the participants: after one-day treatment with cholestyramine; after one-day treatment with chenodeoxycholic acid (CDCA); and a control examination without any treatment. The plasma concentration of 7α-hydroxy-4-cholesten-3-one (C4), a marker of CYP7A1 activity, was determined in all the experiments at 90-min intervals. RESULTS: CYP7A1 activity was up-regulated after treatment with cholestyramine and suppressed after treatment with CDCA. There were no differences between -203A and -203C allele carriers in the response of enzyme activity to both drugs. In the control experiment, -203A allele carriers displayed diurnal variation in enzyme activity, whereas CYP7A1 activity did not change in -203C allele carriers. These results were confirmed by modeling the dynamics of C4 using polynomial regression. CONCLUSION: The promoter polymorphism of the CYP7A1 gene has a pronounced impact on diurnal variation in CYP7A1 activity.
- MeSH
- aktivace enzymů MeSH
- cholestenony krev MeSH
- cholesterol-7-alfa-hydroxylasa genetika metabolismus MeSH
- cholesterol krev MeSH
- cirkadiánní rytmus fyziologie MeSH
- dospělí MeSH
- lidé MeSH
- plocha pod křivkou MeSH
- polymorfismus genetický * MeSH
- promotorové oblasti (genetika) MeSH
- upregulace MeSH
- žlučové kyseliny a soli biosyntéza MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
