Publications by authors named "Vignesh Venkatakrishnan"

Migrastatic drugs targeting cell motility and suppressing invasiveness of solid tumors, have the potential to bring about a paradigm shift in the treatment of solid cancer. Cytochalasin B (CB) is a potent migrastatic compound, but its clinical use is limited by poor selectivity. Here, a NQO1-responsive prodrug, BQTML-CB is developed, synthesized in three steps from cytochalasin B derived from Preussia similis G22.

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Glycosylation is a unique posttranslational modification that dynamically shapes the surface of cells. Glycans attached to proteins or lipids in a cell or tissue are studied as a whole and collectively designated as a glycome. UniCarb-DB is a glycomic spectral library of tandem mass spectrometry (MS/MS) fragment data.

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Candida albicans belongs to our commensal mucosal flora and in immune-competent individuals in the absence of epithelial damage, this fungus is well tolerated and controlled by our immune defense. However, C. albicans is an opportunistic microorganism that can cause different forms of infections, ranging from superficial to life-threatening systemic infections.

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Pseudomonas aeruginosa is a Gram-negative bacterium and an opportunistic pathogen ubiquitously present throughout nature. LecB, a fucose-, and mannose-binding lectin, is a prominent virulence factor of P. aeruginosa, which can be expressed on the bacterial surface but also be secreted.

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Chronic obstructive pulmonary disease (COPD) kills millions of people annually and patients suffering from exacerbations of this disorder display high morbidity and mortality. The clinical course of COPD is associated with dysbiosis and infections, but the underlying mechanisms are poorly understood. Glycosylation of proteins play roles in regulating interactions between microbes and immune cells, and knowledge on airway glycans therefore contribute to the understanding of infections.

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Neutrophils store microbicidal glycoproteins in cytosolic granules to fight intruding pathogens, but their granule distribution and formation mechanism(s) during granulopoiesis remain unmapped. Herein, we comprehensively profile the neutrophil -glycoproteome with spatiotemporal resolution by analyzing four key types of intracellular organelles isolated from blood-derived neutrophils and during their maturation from bone marrow-derived progenitors using a glycomics-guided glycoproteomics approach. Interestingly, the organelles of resting neutrophils exhibited distinctive glycophenotypes including, most strikingly, highly truncated -glycans low in α2,6-sialylation and Lewis fucosylation decorating a diverse set of microbicidal proteins (e.

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Among the responders to microbial invasion, neutrophils represent the earliest and perhaps the most important immune cells that contribute to host defense with the primary role to kill invading microbes using a plethora of stored anti-microbial molecules. One such process is the production of reactive oxygen species (ROS) by the neutrophil enzyme complex NADPH-oxidase, which can be assembled and active either extracellularly or intracellularly in phagosomes (during phagocytosis) and/or granules (in the absence of phagocytosis). One soluble factor modulating the interplay between immune cells and microbes is galectin-3 (gal-3), a carbohydrate-binding protein that regulates a wide variety of neutrophil functions.

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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.

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Brachyspira hyodysenteriae is commonly associated with swine dysentery (SD), a disease that has an economic impact on the swine industry. B. hyodysenteriae infection results in changes to the colonic mucus niche with massive mucus induction, which substantially increases the number of B.

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Fusobacterium nucleatum is a gram-negative and anaerobic oral commensal that is implicated in inflammatory conditions of the tooth-supporting structures, that is, periodontal diseases. One of the main characteristics of these conditions is an accumulation of neutrophil granulocytes in the gingival pockets where bacteria reside. Neutrophils are recruited to tissue-residing microbes by gradients of bacteria derived chemoattractants, and the cellular migration over the pocket epithelium into the gingival pocket is likely governed by chemoattractants released by the amino acid fermenting anaerobes typically colonising this site.

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Neutrophil migration from blood to tissue-residing microbes is governed by a series of chemoattractant gradients of both endogenous and microbial origin. Periodontal disease is characterized by neutrophil accumulation in the gingival pocket, recruited by the subgingival biofilm consisting mainly of gram-negative, anaerobic and proteolytic species such as . The fact that neutrophils are the dominating cell type in the gingival pocket suggests that neutrophil-specific chemoattractants are released by subgingival bacteria, but characterization of chemoattractants released by subgingival biofilm species remains incomplete.

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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 -glycosylation changes in response to acute and chronic stress.

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Myeloperoxidase (MPO) plays essential roles in neutrophil-mediated immunity via the generation of reactive oxidation products. Complex carbohydrates decorate MPO at discrete sites, but their functional relevance remains elusive. To this end, we have characterised the structure-biosynthesis-activity relationship of neutrophil MPO (nMPO).

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Protein glycosylation is essential to trafficking and immune functions of human neutrophils. During granulopoiesis in the bone marrow, distinct neutrophil granules are successively formed. Distinct receptors and effector proteins, many of which are glycosylated, are targeted to each type of granule according to their time of expression, a process called "targeting by timing.

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Evolutionary genomics has recently entered a new era in the study of host-pathogen interactions. A variety of novel genomic techniques has transformed the identification, detection and classification of both hosts and pathogens, allowing a greater resolution that helps decipher their underlying dynamics and provides novel insights into their environmental context. Nevertheless, many challenges to a general understanding of host-pathogen interactions remain, in particular in the synthesis and integration of concepts and findings across a variety of systems and different spatiotemporal and ecological scales.

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Neutrophils are capable of producing significant amounts of reactive oxygen species (ROS) by the phagocyte NADPH oxidase, which consists of membrane-bound and cytoplasmic subunits that assemble during activation. Neutrophils harbor two distinct pools of the membrane-localized oxidase components, one expressed in the plasma membrane and one in the membranes of intracellular granules. Assembly of active oxidase at either type of membrane leads to release of extracellular ROS or to the production of ROS inside intracellular compartments, respectively.

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While aberrant protein glycosylation is a recognized characteristic of human cancers, advances in glycoanalytics continue to discover new associations between glycoproteins and tumorigenesis. This glycomics-centric study investigates a possible link between protein paucimannosylation, an under-studied class of human N-glycosylation [Man GlcNAc Fuc ], and cancer. The paucimannosidic glycans (PMGs) of 34 cancer cell lines and 133 tissue samples spanning 11 cancer types and matching non-cancerous specimens are profiled from 467 published and unpublished PGC-LC-MS/MS N-glycome datasets collected over a decade.

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The mass spectrometry (MS)-based analysis of free polysaccharides and glycans released from proteins, lipids and proteoglycans increasingly relies on databases and software. Here, we review progress in the bioinformatics analysis of protein-released N- and O-linked glycans (N- and O-glycomics) and propose an e-infrastructure to overcome current deficits in data and experimental transparency. This workflow enables the standardized submission of MS-based glycomics information into the public repository UniCarb-DR.

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Infection with results in mucoid hemorrhagic diarrhea. This pathogen is associated with the colonic mucus layer, mainly composed of mucins. Infection regulates mucin -glycosylation in the colon and increases mucin secretion as well as binding sites on mucins.

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Diseases cause ethical concerns and economic losses in the Salmonid industry. The mucus layer comprised of highly -glycosylated mucins is the first contact between pathogens and fish. Mucin glycans govern pathogen adhesion, growth and virulence.

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Disease outbreaks are a limiting factor for the sustainable development of the aquaculture industry. The intestinal tract is covered by a mucus layer mainly comprised by highly glycosylated proteins called mucins. Mucins regulate pathogen adhesion, growth, and virulence, and the glycans are vital for these functions.

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colonizes the pig colon, resulting in mucoid hemorrhagic diarrhea and mucus layer changes. These changes are characterized by a disorganized mucus structure and massive mucus induction with expression of MUC5AC and increased production of MUC2. To investigate the mechanisms behind this altered mucin environment, we quantified the mRNA levels of mucin pathway genes and factors from the immune system in the colons of infected and control pigs and observed upregulation of , , , /, , β, , and expression.

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causes furunculosis in salmonids and is a threat to Atlantic salmon aquaculture. The epithelial surfaces that the pathogen colonizes are covered by a mucus layer predominantly comprised of secreted mucins. By using mass spectrometry to identify mucin glycan structures with and without enzymatic removal of glycan residues, coupled to measurements of bacterial growth, we show here that the complex Atlantic salmon intestinal mucin glycans enhance growth, whereas the more simple skin mucin glycans do not.

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The mucin -glycosylation of 10 individuals with and without gastric disease was examined in depth in order to generate a structural map of human gastric glycosylation. In the stomach, these mucins and their -glycosylation protect the epithelial surface from the acidic gastric juice and provide the first point of interaction for pathogens such as reported to cause gastritis, gastric and duodenal ulcers and gastric cancer. The rational of the present study was to map the -glycosylation that the pathogen may come in contact with.

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Brachyspira hyodysenteriae causes swine dysentery (SD), leading to global financial losses to the pig industry. Infection with this pathogen results in an increase in B. hyodysenteriae binding sites on mucins, along with increased colonic mucin secretion.

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