In the shadow of SARS-CoV-2, influenza seems to be an innocent virus, although new zoonotic influenza viruses evolved by mutations may lead to severe pandemics. According to WHO, there is an urgent need for better antiviral drugs. Blocking viral hemagglutinin with multivalent N-acetylneuraminic acid derivatives is a promising approach to prevent influenza infection. Moreover, dual inhibition of both hemagglutinin and neuraminidase may result in a more powerful effect. Since both viral glycoproteins can bind to neuraminic acid, we have prepared three series of amphiphilic self-assembling 2-thio-neuraminic acid derivatives constituting aggregates in aqueous medium to take advantage of their multivalent effect. One of the series was prepared by the azide-alkyne click reaction, and the other two by the thio-click reaction to yield neuraminic acid derivatives containing lipophilic tails of different sizes and an enzymatically stable thioglycosidic bond. Two of the three bis-octyl derivatives produced proved to be active against influenza viruses, while all three octyl derivatives bound to hemagglutinin and neuraminidase from H1N1 and H3N2 influenza types.
- Klíčová slova
- aggregates, hemagglutinin, influenza, neuraminidase, sialic acid,
- MeSH
- chřipka lidská * farmakoterapie MeSH
- hemaglutininové glykoproteiny viru chřipky metabolismus MeSH
- hemaglutininy farmakologie MeSH
- kyselina N-acetylneuraminová farmakologie metabolismus MeSH
- kyseliny neuraminové MeSH
- lidé MeSH
- neuraminidasa metabolismus MeSH
- virus chřipky A, podtyp H1N1 * MeSH
- virus chřipky A, podtyp H3N2 MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- hemaglutininové glykoproteiny viru chřipky MeSH
- hemaglutininy MeSH
- kyselina N-acetylneuraminová MeSH
- kyseliny neuraminové MeSH
- neuraminidasa MeSH
In recent decades, it has become clear that most of human proteins are glycosylated and that protein glycosylation plays an important role in health and diseases. At present, simple, fast and inexpensive methods are sought for clinical applications and particularly for improved diagnostics of various diseases, including cancer. We propose a label- and reagent-free electrochemical method based on chronopotentiometric stripping (CPS) analysis and a hanging mercury drop electrode for the detection of interaction of sialylated protein biomarker a prostate specific antigen (PSA) with two important lectins: Sambucus nigra agglutinin (SNA) and Maackia amurensis agglutinin (MAA). Incubation of PSA-modified electrode with specific SNA lectin resulted in an increase of CPS peak H of the complex as compared to this peak of individual PSA. By adjusting polarization current and temperature, PSA-MAA interaction can be either eliminated or distinguished from the more abundant PSA-SNA complex. CPS data were in a good agreement with the data obtained by complementary methods, namely surface plasmon resonance and fluorescent lectin microarray. It can be anticipated that CPS will find application in glycomics and proteomics.
- Klíčová slova
- A prostate specific antigen, Chronopotentiometric analysis, Lectin-glycoprotein interaction, Mercury electrode, Sialylated glycan isomers,
- MeSH
- aglutininy metabolismus MeSH
- bez černý chemie MeSH
- elektrická vodivost * MeSH
- elektrochemie MeSH
- kyselina N-acetylneuraminová metabolismus MeSH
- Maackia chemie MeSH
- prostatický specifický antigen chemie metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- aglutininy MeSH
- kyselina N-acetylneuraminová MeSH
- prostatický specifický antigen MeSH
Bile acids have been implicated in cholestatic liver damage, primarily due to their detergent effect on membranes and induction of oxidative stress. Gangliosides can counteract these harmful effects by increasing the rigidity of the cytoplasmic membrane. Induction of haem oxygenase (HMOX) has been shown to protect the liver from increased oxidative stress. The aim of this study was to determine the changes in the synthesis and distribution of liver gangliosides following bile duct ligation (BDL), and to assess the effects of HMOX both on cholestatic liver injury and ganglioside metabolism. Compared to controls, BDL resulted in a significant increase in total as well as complex gangliosides and mRNA expression of corresponding glycosyltransferases ST3GalV, ST8SiaI and B3GalTIV. A marked shift of GM1 ganglioside from the intracellular compartment to the cytoplasmic membrane was observed following BDL. Induction of oxidative stress by HMOX inhibition resulted in a further increase of these changes, while HMOX induction prevented this effect. Compared to BDL alone, HMOX inhibition in combination with BDL significantly increased the amount of bile infarcts, while HMOX activation decreased ductular proliferation. We have demonstrated that cholestasis is accompanied by significant changes in the distribution and synthesis of liver gangliosides. HMOX induction results in attenuation of the cholestatic pattern of liver gangliosides, while HMOX inhibition leads to the opposite effect.
- MeSH
- biologické markery metabolismus MeSH
- cholestáza enzymologie genetika metabolismus patologie MeSH
- cytoplazma metabolismus MeSH
- gangliosidy metabolismus MeSH
- hemová oxygenasa (decyklizující) metabolismus MeSH
- intracelulární membrány metabolismus MeSH
- játra enzymologie metabolismus patologie MeSH
- kyselina N-acetylneuraminová metabolismus MeSH
- ligace MeSH
- messenger RNA genetika metabolismus MeSH
- oxidační stres * MeSH
- potkani Wistar MeSH
- proliferace buněk MeSH
- tělesná hmotnost MeSH
- velikost orgánu MeSH
- žlučové cesty patologie MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- biologické markery MeSH
- gangliosidy MeSH
- hemová oxygenasa (decyklizující) MeSH
- kyselina N-acetylneuraminová MeSH
- messenger RNA MeSH
BACKGROUND: Galactose-deficient O-glycans in the hinge region (HR) of immunoglobulin A1 (IgA1) play a key role in the pathogenesis of IgA nephropathy (IgAN). O-Glycans of circulatory IgA1 consist of N-acetylgalactosamine (GalNAc) with a β1,3-linked galactose; both sugars may be sialylated. In patients with IgAN, α2,6-sialylated GalNAc is a frequent form of the galactose-deficient O-glycans. Prior analyses of IgA1-producing cells had indicated that α2,6-sialyltransferase II (ST6GalNAc-II) is likely responsible for sialylation of GalNAc of galactose-deficient IgA1, but direct evidence is missing. METHODS: We produced a secreted variant of recombinant human ST6GalNAc-II and an IgA1 fragment comprised of Cα1-HR-Cα2. This IgA1 fragment and a synthetic HR peptide with enzymatically attached GalNAc residues served as acceptors. ST6GalNAc-II activity was assessed in vitro and the attachment of sialic acid to these acceptors was detected by lectin blot and mass spectrometry. RESULTS: ST6GalNAc-II was active with both acceptors. High-resolution mass spectrometry analysis revealed that up to three sialic acid residues were added to the GalNAc residues of the HR glycopeptide. CONCLUSIONS: Our data provide direct evidence that ST6GalNAc-II can sialylate GalNAc of galactose-deficient IgA1. As serum levels of galactose-deficient IgA1 with sialylated glycoforms are increased in IgAN patients, our data explain the corresponding part of the biosynthetic pathway.
- Klíčová slova
- IgA nephropathy, aberrant O-glycosylation, galactose-deficient IgA1, immunoglobulin A1, α2,6 sialyltransferase ST6GalNAc-II,
- MeSH
- autoantigeny imunologie MeSH
- galaktosa nedostatek MeSH
- glykosylace MeSH
- hmotnostní spektrometrie MeSH
- IgA nefropatie enzymologie imunologie patologie MeSH
- imunoglobulin A metabolismus MeSH
- kultivované buňky MeSH
- kyselina N-acetylneuraminová metabolismus MeSH
- lidé MeSH
- rekombinantní proteiny imunologie metabolismus MeSH
- sialyltransferasy metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Názvy látek
- autoantigeny MeSH
- galactosyl-1-3-N-acetylgalactosaminyl-specific 2,6-sialyltransferase MeSH Prohlížeč
- galaktosa MeSH
- imunoglobulin A MeSH
- kyselina N-acetylneuraminová MeSH
- rekombinantní proteiny MeSH
- sialyltransferasy MeSH
The Rho GTPase Rac1 is a multifunctional protein working through different effector pathways. The emerging physiological significance of glycanlectin recognition gives reason to testing the possibility for an influence of modulation of Rac1 expression on these molecular aspects. Using human colon adenocarcinoma (SW620) cells genetically engineered for its up- and down-regulation (Rac1+ and Rac1- cells) along with wild-type and mock-transfected control cells, the questions are addressed whether the presence of adhesion/growth-regulatory galectins and distinct aspects of cell surface glycosylation are affected. Proceeding from RT-PCR data to Western blotting after two-dimensional gel electrophoresis and flow cytofluorimetry with non-crossreactive antibodies against six members of this lectin family (i.e. galectins-1, -3, -4, -7, -8 and -9), a reduced extent of the presence of galectins-1, -7 and -9 was revealed in the case of Rac1 cells. Application of these six galectins as probes to determination of cell reactivity for human lectins yielded relative increases in surface labelling of Rac1- cells with galectins-1, -3 and -7. Examining distinct aspects of cell surface glycosylation with a panel of 14 plant/fungal lectins disclosed a decrease in α2,6-sialylation of N-glycans and an increase in PNA-reactive sites (i.e. non-sialylated core 1 O-glycans), two alterations known to favour reactivity for galectins-1 and -3. Thus, manipulation of Rac1 expression selectively affects the expression pattern within the galectin network at the level of proteins and distinct aspects of cell surface glycosylation.
- MeSH
- 2D gelová elektroforéza MeSH
- buněčná membrána metabolismus MeSH
- fenotyp MeSH
- galektiny genetika metabolismus MeSH
- glykosylace MeSH
- kyselina N-acetylneuraminová metabolismus MeSH
- lektiny metabolismus MeSH
- lidé MeSH
- messenger RNA genetika metabolismus MeSH
- nádorové buněčné linie MeSH
- nádory tračníku genetika metabolismus MeSH
- polymerázová řetězová reakce s reverzní transkripcí MeSH
- polysacharidy metabolismus MeSH
- průtoková cytometrie MeSH
- rac1 protein vázající GTP metabolismus MeSH
- regulace genové exprese u nádorů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- galektiny MeSH
- kyselina N-acetylneuraminová MeSH
- lektiny MeSH
- messenger RNA MeSH
- polysacharidy MeSH
- rac1 protein vázající GTP MeSH
The presence of sialylated structures in tick organs was observed previously using lectin staining. Recently, we demonstrated the presence of sialylated N-glycans using mass spectrometry in tick salivary glands and the gut. However, we proposed a host (blood) origin for these glycans and mapped the transport of sialylated molecules from the gut to the salivary glands. In this report, we performed quantitation of whole sialic acid and of metabolically incorporated sialic acid (N-azido neuraminic acid) in Ixodes ricinus tick samples. We show that the majority of sialylated molecules in the adult tick originate in the host (blood) and are not synthesized by the tick. Similar results were observed for tick cell cultures. The almost complete absence of tick sialylated molecules and the specific transport and localization of host structures into the tick salivary glands and the saliva raises many questions on the role of these molecules in the physiology and, specifically, the blood-feeding of ticks.
- Klíčová slova
- Click chemistry, Ixodes ricinus, Sialic acid, Thiobarbituric acid assay, Tick, Tick cell line,
- MeSH
- buněčné linie MeSH
- glykoproteiny krev metabolismus MeSH
- interakce hostitele a parazita * MeSH
- klíště metabolismus fyziologie MeSH
- kyselina N-acetylneuraminová metabolismus MeSH
- sliny metabolismus MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- glykoproteiny MeSH
- kyselina N-acetylneuraminová MeSH
We describe the detection of sialylated N-linked glycans in partially fed Ixodes ricinus tick females using matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry. Sialylated glycans were detected in salivary glands as well as in tick guts and we propose the host origin of these structures. In addition, we mapped the transport of sialylated structures from the blood meal through the gut to the salivary glands using electron microscopy. Specific localization of sialylated glycans to basement membranes of salivary glands was observed. Finally, the influence of the sample preparation methods for electron microscopy on ultrastructure and immunogold labeling was evaluated.
- MeSH
- epitopy MeSH
- gastrointestinální trakt metabolismus MeSH
- imunohistochemie MeSH
- klíště metabolismus MeSH
- kyselina N-acetylneuraminová metabolismus MeSH
- malpighické trubice metabolismus MeSH
- polysacharidy metabolismus MeSH
- slinné žlázy metabolismus MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
- transmisní elektronová mikroskopie MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Názvy látek
- epitopy MeSH
- kyselina N-acetylneuraminová MeSH
- polysacharidy MeSH
Erythrocytes (RBC) from untrained male Wistar rats and rat glomerular endothelial cells (EC) were used to investigate the effects of acute exercise (speed: 20 m/min, slope: 0, duration: 1 hour) on RBC membrane protein oxidation and adhesion to cultured EC. Experimental animals were divided into juvenile (age 10 weeks) and adult (age 30 weeks) groups for these studies. Immediately following exercise, juvenile rat RBC membrane protein oxidation was significantly enhanced. Adult rat RBC showed significantly higher basal protein oxidation than juvenile RBC; but the level of adult rat RBC membrane protein oxidation was unaffected by exercise. Prior to exercise, adult rat RBC showed significantly higher adhesion to EC than RBC of juvenile rat. There was no difference in plasma fibronectin or fibrinogen levels following exercise. Only juvenile rat RBC showed a significant decrease in sialic acid residue content following exercise. These experiments show that there are changes in RBC-EC interactions following exercise that are influenced by animal age.
- MeSH
- buněčná adheze fyziologie MeSH
- endoteliální buňky cytologie MeSH
- erytrocytární membrána metabolismus MeSH
- erytrocyty cytologie metabolismus MeSH
- fibrinogen metabolismus MeSH
- fibronektiny krev MeSH
- krysa rodu Rattus MeSH
- kultivované buňky MeSH
- kyselina N-acetylneuraminová metabolismus MeSH
- oxidace-redukce MeSH
- potkani Wistar MeSH
- tělesná námaha fyziologie MeSH
- věkové faktory MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- fibrinogen MeSH
- fibronektiny MeSH
- kyselina N-acetylneuraminová MeSH
An impressive variety of regulatory processes including cell adhesion and migration, proliferation, apoptosis and differentiation folding and routing of glycoproteins have been found to be mediated by specific lectin-carbohydrate interactions. This article summarizes the data on glycobiological aspects of differentiation of squamous epithelia in the head and neck region under physiological conditions and in cancer. The possible function of lectins in tumor development and invasiveness is debated. Introduction of labeled endogenous lectins as a tool for the study of functional glycomics at the cellular level in head and neck squamous epithelia and carcinomas enables a complex interpretation of studied data because these lectins are normally occurring in these tissues. The lectinology of Langerhans cells in head and neck squamous epithelia and carcinoma is also mentioned. Finally, the use of the described data in the diagnosis and prospectively in the treatment of head and neck squamous cell carcinoma is shown.
- MeSH
- bazocelulární karcinom metabolismus patologie MeSH
- buněčná adheze MeSH
- buněčná diferenciace MeSH
- galektiny metabolismus MeSH
- kyselina N-acetylneuraminová metabolismus MeSH
- Langerhansovy buňky metabolismus patologie MeSH
- lektiny metabolismus MeSH
- lidé MeSH
- metabolismus sacharidů * MeSH
- mezibuněčná komunikace MeSH
- nádory hlavy a krku metabolismus patologie MeSH
- rostlinné lektiny metabolismus MeSH
- spinocelulární karcinom metabolismus patologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Názvy látek
- dolichos biflorus agglutinin MeSH Prohlížeč
- galektiny MeSH
- kyselina N-acetylneuraminová MeSH
- lektiny MeSH
- rostlinné lektiny MeSH
BACKGROUND: The splotch (Sp(2H)), Pax-3 mutant mice are characterized by neurulation defects, neural crest deficiencies, and altered somitogenesis. A link connecting all morphological abnormalities in the Pax-3 homozygous embryos is the composition of extracellular matrix and misexpression of cell adhesion molecules. The neural cell adhesion molecule (NCAM) is one of the Pax-3 target genes. Its adhesive properties depend on the attached polysialic acid (PSA). We have studied whether NCAM sialylation has been affected in the Pax-3 mutant embryos. METHODS: Genotyping of embryos was determined using polymerase chain reaction. The periodate-resorcinol method was used for quantitative determination of sialic acid. Immunoblotting was used to detect sialylated NCAM isoforms and sialic acids on the blot. This antibody was also used to detect PSA-NCAM spatial expression. RESULTS: Quantitative determination of sialic acid at days 10.5-13.5 showed decreased sialic acid content in Sp(2H) homozygotes. The results of both techniques used in evaluating the expression of PSA-NCAM isoforms in our study indicate that the 180-kDa isoform is decreased in homozygous Splotch (Sp(2H)) embryos. Immunohistochemistry showed decreased staining in the neural tube, ganglion VIII, (day 13.5), frontal lobe, olfactory bulb, and neuroblastic retinal cells (day 18.5). CONCLUSIONS: PSA-NCAM is present in Sp(2H) embryos of all genotypes, starting on developmental day 9.5. Sialylation of the 180-kDa NCAM isoform begins to decrease on day 12.5 in Sp(2H) homozygotes. Reduced NCAM sialylation could contribute to the decreased migration of cells in the sensory organs.
- MeSH
- DNA primery MeSH
- DNA vazebné proteiny genetika MeSH
- embryo savčí metabolismus MeSH
- homozygot * MeSH
- kyselina N-acetylneuraminová metabolismus MeSH
- molekuly buněčné adheze nervové metabolismus MeSH
- myši MeSH
- sekvence nukleotidů MeSH
- transkripční faktor PAX3 MeSH
- transkripční faktory paired box MeSH
- transkripční faktory genetika MeSH
- western blotting MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- DNA primery MeSH
- DNA vazebné proteiny MeSH
- kyselina N-acetylneuraminová MeSH
- molekuly buněčné adheze nervové MeSH
- Pax3 protein, mouse MeSH Prohlížeč
- transkripční faktor PAX3 MeSH
- transkripční faktory paired box MeSH
- transkripční faktory MeSH
