| 1. |
- Chahal, Gurdeep, et al.
(författare)
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A Complex Connection Between the Diversity of Human Gastric Mucin O-Glycans, Helicobacter pylori Binding, Helicobacter Infection and Fucosylation
- 2022
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Ingår i: Molecular & Cellular Proteomics. - : Elsevier BV. - 1535-9476 .- 1535-9484. ; 21:11
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Tidskriftsartikel (refereegranskat)abstract
- Helicobacter pylori colonizes the stomach of half of the human population. Most H. pylori are located in the mucus layer, which is mainly comprised by glycosylated mucins. Using mass spectrometry, we identified 631 glycans (whereof 145 were fully characterized and the remainder assigned as compositions) on mucins isolated from 14 Helicobacter spp.-infected and 14 Helicobacter spp.-noninfected stomachs. Only six identified glycans were common to all individuals, from a total of 60 to 189 glycans in each individual. An increased number of unique glycan structures together with an increased intra-individual diversity and larger interindividual variation were identified among O-glycans from Helicobacter spp.-infected stomachs compared with noninfected stom-achs. H. pylori strain J99, which carries the blood group antigen-binding adhesin (BabA), the sialic acid-binding adhesin (SabA), and the LacdiNAc-binding adhesin, bound both to Lewis b (Leb)-positive and Leb-negative mucins. Among Leb-positive mucins, H. pylori J99 bind-ing was higher to mucins from Helicobacter spp.-infected individuals than noninfected individuals. Statistical corre-lation analysis, binding experiments with J99 wt, and J99 Delta babA Delta sabA and inhibition experiments using syn-thetic glycoconjugates demonstrated that the differences in H. pylori-binding ability among these four groups were governed by BabA-dependent binding to fucosylated structures. LacdiNAc levels were lower in mucins that bound to J99 lacking BabA and SabA than in mucins that did not, suggesting that LacdiNAc did not significantly contribute to the binding. We identified 24 O-glycans from Leb-negative mucins that correlated well with H. pylori binding whereof 23 contained alpha 1,2-linked fucosylation. The large and diverse gastric glycan library identified, including structures that correlated with H. pylori binding, could be used to select glycodeterminants to experimen-tally investigate further for their importance in host- pathogen interactions and as candidates to develop glycan-based therapies.
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| 2. |
- Mthembu, Yolanda H., et al.
(författare)
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Recombinant mucin-type proteins carrying LacdiNAc on differentO-glycan core chains fail to supportH. pyloribinding
- 2020
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Ingår i: Molecular Omics. - : Royal Society of Chemistry (RSC). - 1742-206X .- 1742-2051 .- 2515-4184. ; 16:3, s. 243-257
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Tidskriftsartikel (refereegranskat)abstract
- The beta 4-N-acetylgalactosaminyltransferase 3 (B4GALNT3) transfers GalNAc in a beta 1,4-linkage to GlcNAc forming the LacdiNAc (LDN) determinant on oligosaccharides. The LacdiNAc-binding adhesin (LabA) has been suggested to mediate attachment ofHelicobacter pylorito the gastric mucosaviabinding to the LDN determinant. TheO-glycan core chain specificity of B4GALNT3 is poorly defined. We investigated the specificity of B4GALNT3 on GlcNAc residues carried byO-glycan core 2, core 3 and extended core 1 precursors using transient transfection of CHO-K1 cells and a mucin-type immunoglobulin fusion protein as reporter protein. Binding of the LabA-positiveH. pyloriJ99 and 26695 strains to mucin fusion proteins carrying the LDN determinant on differentO-glycan core chains and human gastric mucins with and without LDN was assessed in a microtiter well-based binding assay, while the binding of(125)I-LDN-BSA to various clinicalH. pyloriisolates was assessed in solution. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) and western blotting confirmed the requirement of a terminal GlcNAc for B4GALNT3 activity. B4GALNT3 added a beta 1,4-linked GalNAc to GlcNAc irrespective of whether the latter was carried by a core 2, core 3 or extended core 1 chain. No LDN-mediated adhesion ofH. pyloristrains 26 695 and J99 to LDN determinants on gastric mucins or a mucin-type fusion protein carrying core 2, 3 and extended core 1O-glycans were detected in a microtiter well-based adhesion assay and no binding of a(125)I-labelled LDN-BSA neoglycoconjugate to clinicalH. pyloriisolates was identified.
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| 3. |
- Padra, Médea, 1986, et al.
(författare)
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Helicobacter suis binding to carbohydrates on human and porcine gastric mucins and glycolipids occurs via two modes
- 2018
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Ingår i: Virulence. - : Informa UK Limited. - 2150-5594 .- 2150-5608. ; 9:1, s. 898-918
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Tidskriftsartikel (refereegranskat)abstract
- Helicobacter suis colonizes the stomach of most pigs and is the most prevalent non-Helicobacter pylori Helicobacter species found in the human stomach. In the human host, H. suis contributes to the development of chronic gastritis, peptic ulcer disease and MALT lymphoma, whereas in pigs it is associated with gastritis, decreased growth and ulcers. Here, we demonstrate that the level of H. pylori and H. suis binding to human and pig gastric mucins varies between individuals with species dependent specificity. The binding optimum of H. pylori is at neutral pH whereas that of H. suis has an acidic pH optimum, and the mucins that H. pylori bind to are different than those that H. suis bind to. Mass spectrometric analysis of mucin O-glycans from the porcine mucin showed that individual variation in binding is reflected by a difference in glycosylation; of 109 oligosaccharide structures identified, only 14 were present in all examined samples. H. suis binding to mucins correlated with glycans containing sulfate, sialic acid and terminal galactose. Among the glycolipids present in pig stomach, binding to lactotetraosylceramide (Gal beta 3GlcNAc beta 3Gal beta 4Glc beta 1Cer) was identified, and adhesion to Gal beta 3GlcNAc beta 3Gal beta 4Glc at both acidic and neutral pH was confirmed using other glycoconjugates. Together with that H. suis bound to DNA (used as a proxy for acidic charge), we conclude that H. suis has two binding modes: one to glycans terminating with Gal beta 3GlcNAc, and one to negatively charged structures. Identification of the glycan structures H. suis interacts with can contribute to development of therapeutic strategies alternative to antibiotics.
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| 4. |
- Padra, Médea, 1986, et al.
(författare)
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Mucin Binding to Moraxella catarrhalis During Airway Inflammation is Dependent on Sialic Acid.
- 2021
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Ingår i: American journal of respiratory cell and molecular biology. - 1535-4989. ; 65:6, s. 593-602
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Tidskriftsartikel (refereegranskat)abstract
- Chronic obstructive pulmonary disease (COPD) is associated with colonization by bacterial pathogens and repeated airway infections, leading to exacerbations and impaired lung function. The highly glycosylated mucins in the mucus lining the airways are an important part of the host defense against pathogens. However, mucus accumulation can contribute to COPD pathology. Here, we examined whether inflammation is associated with glycosylation changes that affect interactions between airway mucins and pathogens. We isolated mucins from lower airway samples (LAS, n=4-9) from long-term smokers with and without COPD and from never-smokers. The most abundant terminal glycan moiety was N-acetylneuraminic acid (Neu5Ac) among smokers with and without COPD and N-acetyl-hexoseamine among never-smokers. Moraxella catarrhalis bound to MUC5 mucins from smokers with and without COPD. M. catarrhalis binding correlated with inflammatory parameters and Neu5Ac content. M. catarrhalis binding was abolished by enzymatic removal of Neu5Ac. Furthermore, M. catarrhalis bound to α2-6 sialyl-lactose suggesting that α2-6 sialic acid contributes to M. catarrhalis binding to mucins. Further, we detected more M. catarrhalis binding to mucins from patients with pneumonia than to those from control subjects (n=8-13) and this binding correlated with C-reactive protein and Neu5Ac levels. These results suggest a key role of inflammation induced Neu5Ac in adhesion of M. catarrhalis to airway mucins. Inflammation induced ability of MUC5 mucins to bind M. catarrhalis is likely a host defense mechanism in the healthy lung, although it cannot be excluded that impaired mucociliary clearance limits the effectiveness of this defense in COPD patients.
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| 5. |
- Quintana-Hayashi, Macarena P, et al.
(författare)
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Mucus-Pathogen Interactions in the Gastrointestinal Tract of Farmed Animals
- 2018
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Ingår i: Microorganisms. - : MDPI AG. - 2076-2607. ; 6:2
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Tidskriftsartikel (refereegranskat)abstract
- Gastrointestinal infections cause significant challenges and economic losses in animal husbandry. As pathogens becoming resistant to antibiotics are a growing concern worldwide, alternative strategies to treat infections in farmed animals are necessary in order to decrease the risk to human health and increase animal health and productivity. Mucosal surfaces are the most common route used by pathogens to enter the body. The mucosal surface that lines the gastrointestinal tract is covered by a continuously secreted mucus layer that protects the epithelial surface. The mucus layer is the first barrier the pathogen must overcome for successful colonization, and is mainly composed of densely glycosylated proteins called mucins. The vast array of carbohydrate structures present on the mucins provide an important setting for host-pathogen interactions. This review summarizes the current knowledge on gastrointestinal mucins and their role during infections in farmed animals. We examine the interactions between mucins and animal pathogens, with a focus on how pathogenic bacteria can modify the mucin environment in the gut, and how this in turn affects pathogen adhesion and growth. Finally, we discuss analytical challenges and complexities of the mucus-based defense, as well as its potential to control infections in farmed animals.
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| 6. |
- Benktander, John, et al.
(författare)
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Effects of Size and Geographical Origin on Atlantic salmon, Salmo salar, Mucin O-Glycan Repertoire
- 2019
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Ingår i: Molecular & Cellular Proteomics. - 1535-9476. ; 18:6, s. 1183-1196
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Tidskriftsartikel (refereegranskat)abstract
- Diseases cause ethical concerns and economic losses in the Salmonid industry. The mucus layer comprised of highly O-glycosylated mucins is the first contact between pathogens and fish. Mucin glycans govern pathogen adhesion, growth and virulence. The Atlantic salmon O-glycome from a single location has been characterized and the interindividual variation was low. Because interindividual variation is considered a population-based defense, hindering the entire population from being wiped out by a single infection, low interindividual variation among Atlantic salmon may be a concern. Here, we analyzed the O-glycome of 25 Atlantic salmon from six cohorts grown under various conditions from Sweden, Norway and Australia (Tasmania) using mass spectrometry. This expanded the known Atlantic salmon O-glycome by 60% to 169 identified structures. The mucin O-glycosylation was relatively stable over time within a geographical region, but the size of the fish affected skin mucin glycosylation. The skin mucin glycan repertoires from Swedish and Norwegian Atlantic salmon populations were closely related compared with Tasmanian ones, regardless of size and salinity, with differences in glycan size and composition. The internal mucin glycan repertoire also clustered based on geographical origin and into pyloric cecal and distal intestinal groups, regardless of cohort and fish size. Fucosylated structures were more abundant in Tasmanian pyloric caeca and distal intestine mucins compared with Swedish ones. Overall, Tasmanian Atlantic salmon mucins have more O-glycan structures in skin but less in the gastrointestinal tract compared with Swedish fish. Low interindividual variation was confirmed within each cohort. The results can serve as a library for identifying structures of importance for host-pathogen interactions, understanding population differences of salmon mucin glycosylation in resistance to diseases and during breeding and selection of strains. The results could make it possible to predict potential vulnerabilities to diseases and suggest that inter-region breeding may increase the glycan diversity.
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| 7. |
- Benktander, John, et al.
(författare)
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Gill Mucus and Gill Mucin O-glycosylation in Healthy and Amebic Gill Disease-Affected Atlantic Salmon.
- 2020
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Ingår i: Microorganisms. - : MDPI AG. - 2076-2607. ; 8:12
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Tidskriftsartikel (refereegranskat)abstract
- Amoebic gill disease (AGD) causes poor performance and death in salmonids. Mucins are mainly comprised by carbohydrates and are main components of the mucus covering the gill. Since glycans regulate pathogen binding and growth, glycosylation changes may affect susceptibility to primary and secondary infections. We investigated gill mucin O-glycosylation from Atlantic salmon with and without AGD using liquid chromatography-mass spectrometry. Gill mucin glycans were larger and more complex, diverse and fucosylated than skin mucins. Confocal microscopy revealed that fucosylated mucus coated sialylated mucus strands in ex vivo gill mucus. Terminal HexNAcs were more abundant among O-glycans from AGD-affected Atlantic salmon, whereas core 1 structures and structures with acidic moieties such as N-acetylneuraminic acid (NeuAc) and sulfate groups were less abundant compared to non-infected fish. The fucosylated and NeuAc-containing O-glycans were inversely proportional, with infected fish on the lower scale of NeuAc abundance and high on fucosylated structures. The fucosylated epitopes were of three types: Fuc-HexNAc-R, Gal-[Fuc-]HexNAc-R and HexNAc-[Fuc-]HexNAc-R. These blood group-like structures could be an avenue to diversify the glycan repertoire to limit infection in the exposed gills. Furthermore, care must be taken when using skin mucus as proxy for gill mucus, as gill mucins are distinctly different from skin mucins.
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| 8. |
- Benktander, John, et al.
(författare)
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Stress impairs skin barrier function and induces α2-3 linked n-acetylneuraminic acid and core 1 o-glycans on skin mucins in atlantic salmon, salmo salar
- 2021
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 22:3
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Tidskriftsartikel (refereegranskat)abstract
- © 2021 by the authors. Licensee MDPI, Basel, Switzerland. The skin barrier consists of mucus, primarily comprising highly glycosylated mucins, and the epithelium. Host mucin glycosylation governs interactions with pathogens and stress is associated with impaired epithelial barrier function. We characterized Atlantic salmon skin barrier function during chronic stress (high density) and mucin O-glycosylation changes in response to acute and chronic stress. Fish held at low (LD: 14–30 kg/m3) and high densities (HD: 50-80 kg/m3) were subjected to acute stress 24 h before sampling at 17 and 21 weeks after start of the experiment. Blood parameters indicated primary and secondary stress responses at both sampling points. At the second sampling, skin barrier function towards molecules was reduced in the HD compared to the LD group (Papp mannitol; p < 0.01). Liquid chromatography–mass spectrometry revealed 81 O-glycan structures from the skin. Fish subjected to both chronic and acute stress had an increased proportion of large O-glycan structures. Overall, four of the O-glycan changes have potential as indicators of stress, especially for the combined chronic and acute stress. Stress thus impairs skin barrier function and induces glycosylation changes, which have potential to both affect interactions with pathogens and serve as stress indicators.
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| 9. |
- Jin, Chunsheng, et al.
(författare)
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Atlantic Salmon Carries a Range of Novel O-Glycan Structures Differentially Localized on Skin and Intestinal Mucins
- 2015
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 14:8, s. 3239-3251
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Tidskriftsartikel (refereegranskat)abstract
- Aquaculture is a growing industry, increasing the need for understanding host-pathogen interactions in fish. The skin and mucosal surfaces, covered by a mucus layer composed of mucins, is the first point of contact between fish and pathogens. Highly O-glycosylated mucins have been shown to be an important part of the defense against pathogens, and pathogens bind to host surfaces using lectin-like adhesins. However, knowledge of piscine O-glycosylation is very limited. We characterized mucin O-glycosylation of five freshwater acclimated Atlantic salmon, using mass spectrometry. Of the 109 O-glycans found, most were sialylated and differed in distribution among skin, pyloric ceca, and proximal and distal intestine. Skin O-glycans were shorter (2-6 residues) and less diverse (33 structures) than intestinal O-glycans (2-13 residues, 93 structures). Skin mucins carried O-glycan cores 1, 2, 3, and 5 and three types of sialic acids (Neu5Ac, Neu5Gc, and Kdn) and had sialyl-Tn as the predominant structure. Intestinal mucins carried only cores 1, 2, and 5, Neu5Ac was the only sialic acid present, and sialylated core S was the most dominant structure. This structural characterization can be used for identifying structures of putative importance in host-pathogen interactions for further testing in biological assays and disease intervention therapies.
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| 10. |
- Minniti, G., et al.
(författare)
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The Farmed Atlantic Salmon (Salmo salar) Skin-Mucus Proteome and Its Nutrient Potential for the Resident Bacterial Community
- 2019
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Ingår i: Genes. - : MDPI AG. - 2073-4425. ; 10:7
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Tidskriftsartikel (refereegranskat)abstract
- Norway is the largest producer and exporter of farmed Atlantic salmon (Salmo salar) worldwide. Skin disorders correlated with bacterial infections represent an important challenge for fish farmers due to the economic losses caused. Little is known about this topic, thus studying the skin-mucus of Salmo salar and its bacterial community depict a step forward in understanding fish welfare in aquaculture. In this study, we used label free quantitative mass spectrometry to investigate the skin-mucus proteins associated with both Atlantic salmon and bacteria. In particular, the microbial temporal proteome dynamics during nine days of mucus incubation with sterilized seawater was investigated, in order to evaluate their capacity to utilize mucus components for growth in this environment. At the start of the incubation period, the largest proportion of proteins (similar to 99%) belonged to the salmon and many of these proteins were assigned to protecting functions, confirming the defensive role of mucus. On the contrary, after nine days of incubation, most of the proteins detected were assigned to bacteria, mainly to the genera Vibrio and Pseudoalteromonas. Most of the predicted secreted proteins were affiliated with transport and metabolic processes. In particular, a large abundance and variety of bacterial proteases were observed, highlighting the capacity of bacteria to degrade the skin-mucus proteins of Atlantic salmon.
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