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1.
Biotechnol Adv ; 68: 108209, 2023 11.
Article in English | MEDLINE | ID: mdl-37467868

ABSTRACT

Glycoconjugates are the ubiquitous components of mammalian cells, mainly synthesized by covalent bonds of carbohydrates to other biomolecules such as proteins and lipids, with a wide range of potential applications in novel vaccines, therapeutic peptides and antibodies (Ab). Considering the emerging developments in glycoscience, renewable production of glycoconjugates is of importance and lignocellulosic biomass (LCB) is a potential source of carbohydrates to produce synthetic glycoconjugates in a sustainable pathway. In this review, recent advances in glycobiology aiming on glycoconjugates production is presented together with the recent and cutting-edge advances in the therapeutic properties and application of glycoconjugates, including therapeutic glycoproteins, glycosaminoglycans (GAGs), and nutraceuticals, emphasizing the integral role of glycosylation in their function and efficacy. Special emphasis is given towards the potential exploration of carbon neutral feedstocks, in which LCB has an emerging role. Techniques for extraction and recovery of mono- and oligosaccharides from LCB are critically discussed and influence of the heterogeneous nature of the feedstocks and different methods for recovery of these sugars in the development of the customized glycoconjugates is explored. Although reports on the use of LCB for the production of glycoconjugates are scarce, this review sets clear that the potential of LCB as a source for the production of valuable glycoconjugates cannot be underestimated and encourages that future research should focus on refining the existing methodologies and exploring new approaches to fully realize the potential of LCB in glycoconjugate production.


Subject(s)
Glycoconjugates , Glycoproteins , Animals , Biomass , Glycoconjugates/chemistry , Glycoconjugates/metabolism , Glycoproteins/chemistry , Glycoproteins/metabolism , Carbohydrates/chemistry , Mammals
2.
Int J Mol Sci ; 23(17)2022 Aug 30.
Article in English | MEDLINE | ID: mdl-36077240

ABSTRACT

Sialic acids and heparan sulfates make up the outermost part of the cell membrane and the extracellular matrix. Both structures are characterized by being negatively charged, serving as receptors for various pathogens, and are highly expressed in the respiratory and digestive tracts. Numerous viruses use heparan sulfates as receptors to infect cells; in this group are HSV, HPV, and SARS-CoV-2. Other viruses require the cell to express sialic acids, as is the case in influenza A viruses and adenoviruses. This review aims to present, in a general way, the participation of glycoconjugates in viral entry, and therapeutic strategies focused on inhibiting the interaction between the virus and the glycoconjugates. Interestingly, there are few studies that suggest the participation of both glycoconjugates in the viruses addressed here. Considering the biological redundancy that exists between heparan sulfates and sialic acids, we propose that it is important to jointly evaluate and design strategies that contemplate inhibiting the interactions of both glycoconjugates. This approach will allow identifying new receptors and lead to a deeper understanding of interspecies transmission.


Subject(s)
COVID-19 , Viruses , Glycoconjugates/metabolism , Heparitin Sulfate/metabolism , Humans , N-Acetylneuraminic Acid/metabolism , Receptors, Virus/metabolism , SARS-CoV-2 , Sialic Acids/metabolism , Sulfates , Virus Attachment , Viruses/metabolism
3.
J Mol Recognit ; 34(10): e2922, 2021 10.
Article in English | MEDLINE | ID: mdl-34132435

ABSTRACT

Using a rat model of peritonitis, we herein report the inflammatory effect induced by the lectin isolated from Vatairea guianensis (VGL) seeds in the context of interactions between VGL and both toll-like receptor 4 (TLR4) and tumor necrosis factor receptor 1 (TNFR1). Peritoneal macrophages were stimulated with VGL for dose-dependent gene expression and release of TNF-α. In vivo results showed that VGL (1 mg/kg; intraperitoneal) induced peritonitis in female Wistar rats. Leukocyte migration, macrophage activation, and protein leakage were measured 3 and 6 hours after induction. In vitro, peritoneal macrophages were stimulated with VGL for gene expression and TNF-α dosage (mean ± SEM (n = 6), analysis of variance, and Bonferroni's test (P < .05)). In silico, VGL structure was applied in molecular docking with representative glycans. It was found that (a) VGL increases vascular permeability and stimulates leukocyte migration, both rolling and adhesion; (b) lectin-induced neutrophil migration occurs via macrophage stimulation, both in vitro and in vivo; (c) lectin interacts with TLR4 and TNFR1; and (d) stimulates TNF-α gene expression (RT-PCR) and release from peritoneal macrophages. Thus, upon lectin-glycan binding on the cell surface, our results suggest that VGL induces an acute inflammatory response, in turn activating the release of peritoneal macrophages via TNF-α and TLR and/or TNFR receptor pathways.


Subject(s)
Fabaceae/chemistry , Glycoconjugates/metabolism , Macrophages, Peritoneal/drug effects , Plant Lectins/pharmacology , Animals , Cell Movement/drug effects , Cells, Cultured , Disease Models, Animal , Female , Gene Expression Regulation/drug effects , Glycoconjugates/chemistry , Leukocytes/drug effects , Macrophages, Peritoneal/metabolism , Peritonitis/chemically induced , Peritonitis/metabolism , Peritonitis/pathology , Plant Lectins/chemistry , Plant Lectins/metabolism , Rats, Wistar , Receptors, Tumor Necrosis Factor, Type I/chemistry , Receptors, Tumor Necrosis Factor, Type I/metabolism , Toll-Like Receptor 4/metabolism , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolism
4.
J Morphol ; 281(6): 578-590, 2020 06.
Article in English | MEDLINE | ID: mdl-32271483

ABSTRACT

The Argentine hake Merluccius hubbsi is an important fishery resource of the Southwestern Atlantic Ocean and it is also a potential species for cultivation. In this work, the digestive system development in field-caught hake larvae was studied using histological and histochemical approaches. The digestive tract of larvae was divided into: oropharyngeal cavity (OPC), esophagus, stomach (that develops in the preflexion stage), and intestine. The annexed digestive glands consisted of the liver and the exocrine pancreas. At the beginning of the preflexion stage, teeth were developed in the OPC. There were mucous cells in the esophagus secreting different glycoconjugates from hatching. The enterocytes in the posterior intestine exhibited supranuclear vesicles associated with protein absorption. Mucous cells were observed in the posterior intestine in the preflexion stage and, in the anterior region, ending the flexion stage. Each type of glycoconjugates has a specific role. Acidic mucins lubricate and protect from mechanical damage, sialomucines protect from bacterial infections and neutral mucins regulate the acidity of mucus secretion, protect against abrasion and participate in the formation of the chyme, indicating a pregastric digestion. The liver was present since hatching with pancreatic tissue inside and increased in size acquiring the typical structure with hepatocyte cords, sinusoids, vacuoles, and hepatic duct. The hepatocytes vacuolization increased with larval development. The pancreas became extra-hepatic, with basophilic acinar cells and acidophilic zymogen granules. Throughout the ontogeny, the increased structural and functional complexity of the digestive system reflected the transition to exogenous feeding and nutritional increasing needs.


Subject(s)
Gadiformes/growth & development , Gastrointestinal Tract/growth & development , Animals , Gastrointestinal Tract/anatomy & histology , Gastrointestinal Tract/cytology , Glycoconjugates/metabolism , Larva/cytology , Larva/growth & development , Mucus/metabolism
5.
J Cell Physiol ; 234(8): 13387-13402, 2019 08.
Article in English | MEDLINE | ID: mdl-30624780

ABSTRACT

We have previously demonstrated that kidney embryonic structures are present in rats, and are still developing until postnatal Day 20. Consequently, at postnatal Day 10, the rat renal papilla contains newly formed collecting duct (CD) cells and others in a more mature stage. Performing primary cultures, combined with immunocytochemical and time-lapse analysis, we investigate the cellular mechanisms that mediate the postnatal CD formation. CD cells acquired a greater degree of differentiation, as we observed that they gradually lose the ability to bind BSL-I lectin, and acquire the capacity to bind Dolichos biflorus. Because CD cells retain the same behavior in culture than in vivo, and by using DBA and BSL-I as markers of cellular lineage besides specific markers of epithelial/mesenchymal phenotype, the experimental results strongly suggest the existence of mesenchymal cell insertion into the epithelial CD sheet. We propose such a mechanism as an alternative strategy for CD growing and development.


Subject(s)
Kidney Tubules, Collecting/cytology , Kidney Tubules, Collecting/growth & development , Animals , Aquaporin 2/metabolism , Cell Differentiation , Cell Movement , Cells, Cultured , Epithelial Cells/cytology , Epithelial Cells/metabolism , Glycoconjugates/metabolism , Imaging, Three-Dimensional , Kidney Medulla/cytology , Kidney Medulla/growth & development , Kidney Medulla/metabolism , Kidney Tubules, Collecting/metabolism , Male , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/metabolism , Plant Lectins/metabolism , Rats , Rats, Wistar , Receptor, Bradykinin B2/metabolism , Time-Lapse Imaging
6.
Parasit Vectors ; 11(1): 536, 2018 Oct 03.
Article in English | MEDLINE | ID: mdl-30285837

ABSTRACT

Leishmania spp. depend on effective macrophage infection to establish and develop in mammalian hosts. Both metacyclic promastigotes and amastigotes are able to infect host cells, and thus they rely on several ligands that, when recognized by macrophage receptors, mediate parasite uptake. During macrophage primary infection with metacyclic forms from the insect vector and during amastigote dissemination via macrophage rupture, both infective stages have to cope with the host extracellular microenvironment, including extracellular matrix molecules. Glycosaminoglycans are abundant in the extracellular matrix and many of these molecules are able to interact with the parasite and the host cell, mediating positive and negative effects for the infection, depending on their structure and/or location. In addition, glycosaminoglycans are present at the surface of macrophages as proteoglycans, playing important roles for parasite recognition and uptake. In this review, we discuss glycosaminoglycans in the context of Leishmania infection as well as the possible applications of the current knowledge regarding these molecules for the development of new therapeutic strategies to control parasite dissemination.


Subject(s)
Glycosaminoglycans/pharmacology , Glycosaminoglycans/therapeutic use , Leishmania/drug effects , Leishmania/physiology , Leishmaniasis/drug therapy , Leishmaniasis/parasitology , Animals , Cell Adhesion Molecules/metabolism , Glycoconjugates/metabolism , Glycosaminoglycans/metabolism , Host-Parasite Interactions/drug effects , Humans , Leishmaniasis/metabolism , Macrophages/metabolism , Macrophages/parasitology , Proteoglycans/metabolism
7.
Methods Mol Biol ; 1674: 183-191, 2018.
Article in English | MEDLINE | ID: mdl-28921437

ABSTRACT

The bacterial expression of glycoproteins has experienced significant progress in recent years, particularly in regard to the production of conjugate vaccines against pathogens. In this case, a protein carrier conjugated with glycosides is used to produce intense stimulation of the immune system. Glycoconjugate vaccines account for 35% of the global vaccine market, and consequently, several biotechnological companies have developed products for the purification of glycosylated proteins to attain homogeneity. In this chapter we present a general process for glycoprotein production in Escherichia coli and a practice method for purification of glycosylated proteins, using affinity chromatography.


Subject(s)
Escherichia coli Proteins/metabolism , Escherichia coli/metabolism , Glycoconjugates/metabolism , Glycoproteins/metabolism , Vaccines, Conjugate/metabolism , Chromatography, Affinity/methods , Glycosylation
8.
Sci Rep ; 7: 46748, 2017 Apr 24.
Article in English | MEDLINE | ID: mdl-28436457

ABSTRACT

Dendritic cell-specific ICAM-3 grabbing non-integrin (DC-SIGN) expressed on a variety of DCs, is a C-type lectin receptor that recognizes glycans on a diverse range of pathogens, including parasites. The interaction of DC-SIGN with pathogens triggers specific signaling events that modulate DC-maturation and activity and regulate T-cell activation by DCs. In this work we evaluate whether F. hepatica glycans can immune modulate DCs via DC-SIGN. We demonstrate that DC-SIGN interacts with F. hepatica glycoconjugates through mannose and fucose residues. We also show that mannose is present in high-mannose structures, hybrid and trimannosyl N-glycans with terminal GlcNAc. Furthermore, we demonstrate that F. hepatica glycans induce DC-SIGN triggering leading to a strong production of TLR-induced IL-10 and IL-27p28. In addition, parasite glycans induced regulatory DCs via DC-SIGN that decrease allogeneic T cell proliferation, via the induction of anergic/regulatory T cells, highlighting the role of DC-SIGN in the regulation of innate and adaptive immune responses by F. hepatica. Our data confirm the immunomodulatory properties of DC-SIGN triggered by pathogen-derived glycans and contribute to the identification of immunomodulatory glyans of helminths that might eventually be useful for the design of vaccines against fasciolosis.


Subject(s)
Dendritic Cells/immunology , Fasciola hepatica/chemistry , Fasciola hepatica/immunology , Glycoconjugates/metabolism , Host-Pathogen Interactions , Immunologic Factors/metabolism , T-Lymphocytes/immunology , Animals , Cell Adhesion Molecules , Clonal Anergy , Dendritic Cells/drug effects , Glycoconjugates/isolation & purification , Humans , Immunologic Factors/isolation & purification , Lectins, C-Type , Receptors, Cell Surface
9.
Exp Parasitol ; 168: 31-8, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27264642

ABSTRACT

Leishmaniasis are worldwide diseases that occur in 98 countries including Brazil, transmitted by the bite of female phlebotomines during blood feeding. In Brazil it is known that some species of sand flies as Lutzomyia longipalpis sensun latum (vector of Leishmania infantum chagasi), Lutzomyia flaviscutellata (vector of Leishmania (Leishmania) amazonensis) and Lutzomyia antunesi [suspected vector of Leishmania (Viannia) lindenbergi] are incriminated of transmitting the parasite Leishmania for the vertebrate host. The phlebotomine-parasite is mediated by the attachment of the promastigote lipophosphoglycan (LPG) to the midgut epithelium. However, another mechanism that is LPG-independent and mediated by N-acetyl-galactosamine (GalNAc) seems to occur in some species of phlebotomines that are classified as permissive. The aim of this study was to characterize the carbohydrate residues that, probably, play a role in parasite attachment to the midgut of phlebotomine from colony and field populations from the Brazilian Amazonian region. We observed the presence of GalNAc, mannose, galactose and GlcNAc in all phlebotomine species. A binding assay between L. (L.) amazonensis and L. i.chagasi to the midguts of different species of phlebotomines was performed. The attachment of both Leishmania and vector species suggests the presence of GalNAc on the midgut surfaces. Thus, these results suggested that GalNAc is a possible binding sites of Leishmania in sand flies from the Brazilian Amazonian region.


Subject(s)
Acetylgalactosamine/metabolism , Carbohydrates/analysis , Glycoconjugates/metabolism , Glycosphingolipids/metabolism , Leishmania/physiology , Psychodidae/parasitology , Acetylglucosamine/metabolism , Animals , Brazil , Female , Galactose/metabolism , Mannose/metabolism , Psychodidae/chemistry , Psychodidae/physiology
10.
Eur J Med Chem ; 99: 67-81, 2015 Jun 24.
Article in English | MEDLINE | ID: mdl-26046314

ABSTRACT

The stereoselective preparation of diosgenin-derived thio(seleno)ureas and glycomimetics bearing a 1,2,3-triazolyl tether on C-3 has been accomplished. The key steps in the synthetic pathway are the incorporation of an amino moiety and its further transformation into thio- and selenoureas, and also a click chemistry reaction involving a propargyl residue and an azido moiety to afford carbohydrate-derived 1,2,3-triazoles; subsequent BF3-promoted acetolysis of the spiranic moiety afforded the corresponding 22-oxocholestanic structure. The N-phenyl selenourea, an hitherto unknown steroidal derivative, turned out to be a potent ROS scavenger, in particular against free radicals (EC50 = 29.47 ± 2.33 µM, DPPH method), and as a glutathione peroxidase mimic in the elimination of H2O2 (t1/2 = 4.8 min, 1% molar ratio). 22-Oxocholestane structures bearing a C-3 azido, propargyl, thioureido, and particularly selenoureido moiety behaved as strong antiproliferative agents against HeLa cells (IC50 1.87-11.80 µM). N-phenyl selenourea also exhibited IC50 values lower than 6.50 µM for MDA-MB-231, MCF-7 and HepG2 cancer cells; apoptosis was found to be involved in its mode of action. Such compound was also capable of efficiently eliminating ROS endogenously produced by HeLa cells. Antiproliferative properties of thioxo and selenoxo derivatives were stronger than diosgenin.


Subject(s)
Diosgenin/chemistry , Diosgenin/pharmacology , Drug Design , Glycoconjugates/chemistry , Glycoconjugates/pharmacology , Organoselenium Compounds/chemistry , Triazoles/chemistry , Urea/analogs & derivatives , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/metabolism , Antineoplastic Agents/pharmacology , Biomimetic Materials/chemistry , Biomimetic Materials/metabolism , Biomimetic Materials/pharmacology , Biphenyl Compounds/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Diosgenin/metabolism , Drug Screening Assays, Antitumor , Free Radical Scavengers/chemistry , Free Radical Scavengers/pharmacology , Glutathione Peroxidase/metabolism , Glycoconjugates/metabolism , Humans , Mice , Picrates/metabolism , Reactive Oxygen Species/metabolism , Urea/chemistry
11.
Biomed Res Int ; 2015: 615865, 2015.
Article in English | MEDLINE | ID: mdl-25664320

ABSTRACT

C-type lectins are multifunctional sugar-binding molecules expressed on dendritic cells (DCs) and macrophages that internalize antigens for processing and presentation. Macrophage galactose-type lectin 1 (MGL1) recognizes glycoconjugates expressing Lewis X structures which contain galactose residues, and it is selectively expressed on immature DCs and macrophages. Helminth parasites contain large amounts of glycosylated components, which play a role in the immune regulation induced by such infections. Macrophages from MGL1(-/-) mice showed less binding ability toward parasite antigens than their wild-type (WT) counterparts. Exposure of WT macrophages to T. crassiceps antigens triggered tyrosine phosphorylation signaling activity, which was diminished in MGL1(-/-) macrophages. Following T. crassiceps infection, MGL1(-/-) mice failed to produce significant levels of inflammatory cytokines early in the infection compared to WT mice. In contrast, MGL1(-/-) mice developed a Th2-dominant immune response that was associated with significantly higher parasite loads, whereas WT mice were resistant. Flow cytometry and RT-PCR analyses showed overexpression of the mannose receptors, IL-4Rα, PDL2, arginase-1, Ym1, and RELM-α on MGL1(-/-) macrophages. These studies indicate that MGL1 is involved in T. crassiceps recognition and subsequent innate immune activation and resistance.


Subject(s)
Antigens, Helminth/immunology , Asialoglycoproteins/metabolism , Disease Resistance/immunology , Lectins, C-Type/metabolism , Macrophages, Peritoneal/metabolism , Membrane Proteins/metabolism , Signal Transduction , Taenia/immunology , Taeniasis/immunology , Acetylgalactosamine/metabolism , Animals , Asialoglycoproteins/deficiency , Cytokines/biosynthesis , Female , Galactose/metabolism , Glycoconjugates/metabolism , Immunity , Intracellular Space/metabolism , Kinetics , Lectins, C-Type/deficiency , Macrophage Activation/immunology , Membrane Proteins/deficiency , Mice, Inbred BALB C , Mice, Inbred C57BL , Phosphorylation , Phosphotyrosine/metabolism , Protein Binding , Solubility , Taeniasis/parasitology
12.
Article in English | MEDLINE | ID: mdl-25401093

ABSTRACT

Dematiaceous fungi constitute a large and heterogeneous group, characterized by having a dark pigment, the dihydroxynaftalen melanin-DHN, inside their cell walls. In nature they are found mainly as soil microbiota or decomposing organic matter, and are spread in tropical and subtropical regions. The fungus Fonsecaea monophora causes chromoblastomycosis in humans, and possesses essential mechanisms that may enhance pathogenicity, proliferation and dissemination inside the host. Glycoconjugates confer important properties to these pathogenic microorganisms. In this work, structural characterization of glycan structures present in two different strains of F. monophora MMHC82 and FE5p4, from clinical and environmental origins, respectively, was performed. Each one were grown on Minimal Medium (MM) and Czapeck-Dox (CD) medium, and the water soluble cell wall glycoconjugates and exopolysaccharides (EPS) were evaluated by NMR, methylation and principal component analysis (PCA). By combining the methylation and 2D NMR analyses, it was possible to visualize the glycosidic profiles of the complex carbohydrate mixtures. Significant differences were observed in ß-D-Galf-(1→5) and (1→6) linkages, α- and ß-D-Glcp-(1→3), (1→4), and (1→6) units, as well as in α-D-Manp. PCA from (1)H-NMR data showed that MMHC82 from CD medium showed a higher variation in the cell wall carbohydrates, mainly related to O-2 substituted ß-D-Galf (δ 106.0/5.23 and δ 105.3/5.23) units. In order to investigate the antigenic response of the glycoconjugates, these were screened against serum from chromoblastomycosis patients. The antigen which contained the cell wall of MMHC82 grown in MM had ß-D-Manp units that promoted higher antigenic response. The distribution of these fungal species in nature and the knowledge of how cell wall polysaccharides and glycoconjugates structure vary, may contribute to the better understanding and the elucidation of the pathology caused by this fungus.


Subject(s)
Antigens, Fungal/chemistry , Antigens, Fungal/immunology , Ascomycota/immunology , Fungal Polysaccharides/chemistry , Fungal Polysaccharides/immunology , Mycoses/immunology , Mycoses/microbiology , Antibodies, Fungal/blood , Antibodies, Fungal/immunology , Ascomycota/growth & development , Ascomycota/isolation & purification , Ascomycota/metabolism , Cell Wall/metabolism , Chromoblastomycosis/immunology , Chromoblastomycosis/microbiology , Environmental Microbiology , Glycoconjugates/metabolism , Humans , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular
13.
Article in English | MEDLINE | ID: mdl-25353009

ABSTRACT

Polysaccharides such as α- and ß-glucans, chitin, and glycoproteins extensively modified with both N- and O-linked carbohydrates are the major components of fungal surfaces. The fungal cell wall is an excellent target for the action of antifungal agents, since most of its components are absent from mammalian cells. Recognition of these carbohydrate-containing molecules by the innate immune system triggers inflammatory responses and activation of microbicidal mechanisms by leukocytes. This review will discuss the structure of surface fungal glycoconjugates and polysaccharides and their recognition by innate immune receptors.


Subject(s)
Fungal Polysaccharides/metabolism , Fungi/immunology , Fungi/metabolism , Host-Pathogen Interactions , Immunity, Innate , Mycoses/immunology , Animals , Carbohydrate Metabolism , Chitin/metabolism , Glycoconjugates/metabolism , Host-Pathogen Interactions/immunology , Humans , Mycoses/metabolism , Protein Binding , Receptors, Pattern Recognition/metabolism
14.
Carbohydr Res ; 397: 31-6, 2014 Oct 09.
Article in English | MEDLINE | ID: mdl-25193382

ABSTRACT

Here we report the preparation and physico-chemical characterization of carbohydrate-decorated micelles and their interaction with lectins. A library of biosourced amphiphiles was prepared by copper-catalyzed azide-alkyne cycloaddition (CuAAC) between alkynyl sugars (lactose, N-acetyl-D-glucosamine) and azido-functionalized poly(ethylene glycol) esters (N3-PEG900-decanoate (C10) and -dodecanoate (C12)). In water, these glycoconjugates self-assemble into micelles of homogeneous nanometric size (11 nm) as evidenced by scattering techniques (DLS for light, and SAXS for X-ray). A comparative study with previously synthesized octadecanoate counterparts pointed out that that nature of the fatty acid has no significant influence on the particle size but only affects their compactness. These findings are in favor of a possible bulk preparation from lipid mixtures such as those encountered in renewable vegetable oils. The presence of the carbohydrate epitopes on the surface of the micelles and their bioavailability for lectin targeting were also evidenced by light scattering measurements using wheat germ agglutinin (WGA) and peanut (Arachis hypogaea) (PNA) lectins, supporting possible application as targeted drug nanocarriers.


Subject(s)
Glycoconjugates/chemistry , Glycoconjugates/metabolism , Lectins/metabolism , Chemistry Techniques, Synthetic , Epitopes , Fatty Acids/chemistry , Glycoconjugates/chemical synthesis , Glycoconjugates/immunology , Lactose/chemistry , Micelles , Nanoparticles , Polyethylene Glycols/chemistry , Scattering, Small Angle , Thermodynamics , Wheat Germ Agglutinins/immunology
15.
Acta Trop ; 137: 161-73, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24879929

ABSTRACT

Sulfation, a post-translational modification which plays a key role in various biological processes, is inhibited by competition with chlorate. In Trypanosoma cruzi, the agent of Chagas' disease, sulfated structures have been described as part of glycolipids and we have reported sulfated high-mannose type oligosaccharides in the C-T domain of the cruzipain (Cz) glycoprotein. However, sulfation pathways have not been described yet in this parasite. Herein, we studied the effect of chlorate treatment on T. cruzi with the aim to gain some knowledge about sulfation metabolism and the role of sulfated molecules in this parasite. In chlorate-treated epimastigotes, immunoblotting with anti-sulfates enriched Cz IgGs (AS-enriched IgGs) showed Cz undersulfation. Accordingly, a Cz mobility shift toward higher isoelectric points was observed in 2D-PAGE probed with anti-Cz antibodies. Ultrastructural membrane abnormalities and a significant decrease of dark lipid reservosomes were shown by electron microscopy and a significant decrease in sulfatide levels was confirmed by TLC/UV-MALDI-TOF-MS analysis. Altogether, these results suggest T. cruzi sulfation occurs via PAPS. Sulfated epitopes in trypomastigote and amastigote forms were evidenced using AS-enriched IgGs by immunoblotting. Their presence on trypomastigotes surface was demonstrated by flow cytometry and IF with Cz/dCz specific antibodies. Interestingly, the percentage of infected cardiac HL-1 cells decreased 40% when using chlorate-treated trypomastigotes, suggesting sulfates are involved in the invasion process. The same effect was observed when cells were pre-incubated with dCz, dC-T or an anti-high mannose receptor (HMR) antibody, suggesting Cz sulfates and HMR are also involved in the infection process by T. cruzi.


Subject(s)
Chlorates/metabolism , Cysteine Endopeptidases/metabolism , Endocytosis/drug effects , Glycoconjugates/metabolism , Metabolic Networks and Pathways/drug effects , Sulfates/metabolism , Trypanosoma cruzi/drug effects , Animals , Cell Line , Electrophoresis, Gel, Two-Dimensional , Humans , Immunoblotting , Isoelectric Point , Microscopy, Electron , Myocytes, Cardiac/parasitology , Protein Processing, Post-Translational , Protozoan Proteins , Rabbits , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Trypanosoma cruzi/metabolism , Trypanosoma cruzi/physiology
16.
Int J Nanomedicine ; 8: 4623-9, 2013.
Article in English | MEDLINE | ID: mdl-24324334

ABSTRACT

Cell surface glycoconjugates play an important role in differentiation/dedifferentiation processes and lectins are employed to evaluate them by several methodologies. Fluorescent probes are considered a valuable tool because of their ability to provide a particular view, and are more detailed and sensitive in terms of cell structure and molecular content. The aim of this study was to evaluate and compare the expression and distribution of glycoconjugates in normal human breast tissue, and benign (fibroadenoma), and malignantly transformed (invasive ductal carcinoma) breast tissues. For this, we used mercaptosuccinic acid-coated Cadmium Telluride (CdTe) quantum dots (QDs) conjugated with concanavalin A (Con A) or Ulex europaeus agglutinin I (UEA I) lectins to detect α-D-glucose/mannose and L-fucose residues, respectively. The QD-lectin conjugates were evaluated by hemagglutination activity tests and carbohydrate inhibition assays, and were found to remain functional, keeping their fluorescent properties and carbohydrate recognition ability. Fluorescence images showed that different regions of breast tissue expressed particular types of carbohydrates. While the stroma was preferentially and intensely stained by QD-Con A, ductal cells were preferentially labeled by QD-UEA I. These results indicate that QD-lectin conjugates can be used as molecular probes and can help to elucidate the glycoconjugate profile in biological processes.


Subject(s)
Breast Neoplasms/chemistry , Breast/chemistry , Concanavalin A/metabolism , Glycoconjugates/analysis , Histocytochemistry/methods , Quantum Dots , Concanavalin A/chemistry , Female , Glycoconjugates/chemistry , Glycoconjugates/metabolism , Humans , Microscopy, Fluorescence
17.
Parasitol Res ; 112(10): 3615-25, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23922203

ABSTRACT

We analyzed the possible role of glycoconjugates containing α-D-mannose and α-D-glucose residues in adherence of trophozoites to mouse nasal epithelium. Trophozoites incubated with 20 µg of one of three different lectins which preferentially recognized these residues were inoculated intranasally in Balb/c mice. Mouse survival was 40% with Pisum sativum and Canavalia ensiformis and 20% with Galanthus nivalis amebic pretreatment, compared with 0% survival for control animals administered trophozoites without pretreatment. Possibly some of the glycoproteins found in Naegleria fowleri represent an adherence factor. Differences in the saccharide sequences of the Naegleria species, even on the same glycoconjugate structure, could explain the different results corresponding to the distinct pretreatments (C. ensiformis, G. nivalis, and P. sativum). We found a higher expression of glycoconjugates recognized by P. sativum in Naegleria lovaniensis than N. fowleri, probably due to the higher number of oligosaccharides containing an α-1,6-linked fucose moiety expressed on the former species.


Subject(s)
Cell Adhesion/physiology , Glycoconjugates/metabolism , Mannose/chemistry , Naegleria/physiology , Nasal Mucosa/metabolism , Trophozoites/physiology , Animals , Flow Cytometry , Glucose , Glycoconjugates/chemistry , Lectins/chemistry , Lectins/metabolism , Male , Mice , Mice, Inbred BALB C
18.
Biotech Histochem ; 87(2): 81-94, 2012 Feb.
Article in English | MEDLINE | ID: mdl-21351822

ABSTRACT

The aim of the present work was to describe the morphology of the vagina in Lagostomus maximus and to characterize its epithelial cells using morphometric and histochemical techniques (variations of PAS, Alcian blue and lectin histochemistry). Thirty-five sexually mature adult females were captured in their natural environment during four periods of the year and their genital organs were dissected. The vaginal wall of the viscacha has three tunics: mucosa, muscularis and adventitia or serosa according to the region. The epithelium is stratified in both cranial and caudal regions, but its characteristics vary depending on the physiological state. In anestrous, nonpregnant females have a stratified epithelium of two to three cellular layers with columnar PAS-positive superficial mucous cells. During the follicular phase, the epithelium of the vagina is stratified squamous and cornified. Females at early, middle and term pregnancy have a columnar stratified epithelium with mucous cells. Glycoproteins in the mucous cells were detected using PAS, PA*S, KOH/PA*/BH/PAS; and Alcian blue, pH 0.5, pH 1, pH 2.5 and 0.006 M). Lectin histochemistry showed that UEA-I and RCA-1 lectins reacted strongly or moderately with epithelial cells in all stages analyzed. These results indicate the presence of L-fucose and ß-galactose. Binding with other lectins was variable.


Subject(s)
Lectins/metabolism , Mucous Membrane/cytology , Mucous Membrane/metabolism , Pregnancy, Animal/metabolism , Vagina/cytology , Vagina/metabolism , Animals , Epithelial Cells/metabolism , Epithelium/metabolism , Female , Glycoconjugates/metabolism , Histocytochemistry , Lectins/analysis , Mucus/cytology , Mucus/metabolism , Pregnancy , Rodentia , Staining and Labeling
19.
Carbohydr Res ; 346(12): 1389-93, 2011 Sep 06.
Article in English | MEDLINE | ID: mdl-21645882

ABSTRACT

A dense glycocalix covers the surface of Trypanosoma cruzi, the agent of Chagas disease. Sialic acid in the surface of the parasite plays an important role in the infectious process, however, T. cruzi is unable to synthesize sialic acid or the usual donor CMP-sialic acid. Instead, T. cruzi expresses a unique enzyme, the trans-sialidase (TcTS) involved in the transfer of sialic acid from host glycoconjugates to mucins of the parasite. The mucins are the major glycoproteins in the insect stage epimastigotes and in the infective trypomastigotes. Both, the mucins and the TcTS are anchored to the plasma membrane by a glycosylphosphatidylinositol anchor. Thus, TcTS may be shed into the bloodstream of the mammal host by the action of a parasite phosphatidylinositol-phospholipase C, affecting the immune system. The composition and structure of the sugars in the parasite mucins is characteristic of each differentiation stage, also, interstrain variations were described for epimastigote mucins. This review focus on the characteristics of the interplay between the trans-sialidase and the mucins of T. cruzi and summarizes the known carbohydrate structures of the mucins.


Subject(s)
Chagas Disease , Enzyme Inhibitors/pharmacology , Glycoproteins/antagonists & inhibitors , Mucins/metabolism , Neuraminidase/antagonists & inhibitors , Sialic Acids/metabolism , Trypanosoma cruzi/enzymology , Animals , Carbohydrate Sequence , Chagas Disease/metabolism , Chagas Disease/parasitology , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/therapeutic use , Glycoconjugates/chemistry , Glycoconjugates/metabolism , Glycoproteins/metabolism , Glycosylphosphatidylinositols/metabolism , Humans , Life Cycle Stages , Molecular Sequence Data , Mucins/chemistry , Neuraminidase/metabolism , Protein Binding , Species Specificity , Type C Phospholipases/metabolism
20.
Acta Biochim Pol ; 58(1): 95-100, 2011.
Article in English | MEDLINE | ID: mdl-21403918

ABSTRACT

Recently, glyco-therapy is proposed to prevent the interaction of bacterial lectins with host ligands (glycoconjugates). This interaction represents the first step in infection. Neoglycans referred to as PSA-Lac (PSA-Glu (ß1-4) Gal) were obtained by conjugation of porcine serum albumin (PSA) with lactose at 80 °C, 100 °C and 120 ºC. Characterization studies of the products showed that PSA could contain 1, 38 or 41 added lactoses, depending on the reaction temperature. These neoglycans were approximately 10 times more glycated than PSA-Lac obtained in previous work. Lactose conjugation occurred only at lysines and PSA-Lac contained terminal galactoses as confirmed by Ricinus communis lectin recognition. Furthermore, Escherichia coli K88+, K88ab, K88ac and K88ad adhesins showed affinity toward all PSA-Lac neoglycans, and the most effective was the PSA-Lac obtained after 100 ºC treatment. In vitro, this neoglycan partially inhibited the adhesion of E. coli K88+ to piglet mucin (its natural ligand). These results provide support for the hypothesis that glycated proteins can be used as an alternative for bioactive compounds for disease prevention.


Subject(s)
Glycoconjugates/metabolism , Lactose/chemistry , Serum Albumin/chemistry , Serum Albumin/metabolism , Adhesins, Escherichia coli/chemistry , Adhesins, Escherichia coli/metabolism , Animals , Bacterial Adhesion/drug effects , Bacterial Adhesion/physiology , Bacterial Infections/prevention & control , Enzyme-Linked Immunosorbent Assay , Escherichia coli/chemistry , Escherichia coli/metabolism , Glycoconjugates/chemistry , Glycoconjugates/therapeutic use , Glycosylation , Mucins/chemistry , Plant Lectins/chemistry , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Swine , Temperature
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