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gut epithelium

Seav-Ly Tran, Claire Jenkins, Valérie Livrelli, Stephanie Schüller
Shiga toxin-producing Escherichia coli (STEC) are characterized by the release of potent Shiga toxins (Stx), which are associated with severe intestinal and renal disease. Although all STEC strains produce Stx, only a few serotypes cause infection in humans. To determine which virulence traits in vitro are linked to human disease in vivo, 13 Stx2a-producing STEC strains of seropathotype (SPT) A or B (associated with severe human intestinal disease and outbreaks) and 6 strains of SPT D or E (rarely or not linked to human disease) were evaluated in a microaerobic human colonic epithelial infection model...
March 13, 2018: Microbiology
Ralitza Staneva, Jorge Barbazan, Anthony Simon, Danijela Matic Vignjevic, Denis Krndija
Cell migration is a process that ensures correct cell localization and function in development and homeostasis. In disease such as cancer, cells acquire an upregulated migratory capacity that leads to their dissemination throughout the body. Live imaging of cell migration allows for better understanding of cell behaviors in development, adult tissue homeostasis and disease. We have optimized live imaging procedures to track cell migration in adult murine tissue explants derived from: (1) healthy gut; (2) primary intestinal carcinoma; and (3) the liver, a common metastatic site...
2018: Methods in Molecular Biology
Wei Ling Lau, Javad Savoj, Michael B Nakata, Nosratola D Vaziri
In chronic kidney disease (CKD), influx of urea and other retained toxins exerts a change in the gut microbiome. There is decreased number of beneficial bacteria that produce short-chain fatty acids, an essential nutrient for the colonic epithelium, concurrent with an increase in bacteria that produce uremic toxins such as indoxyl sulphate, p -cresyl sulphate, and trimethylamine-N-oxide (TMAO). Due to intestinal wall inflammation and degradation of intercellular tight junctions, gut-derived uremic toxins translocate into the bloodstream and exert systemic effects...
March 15, 2018: Clinical Science (1979-)
Hans Clevers, Fiona M Watt
Central to the classical hematopoietic stem cell (HSC) paradigm is the concept that the maintenance of blood cell numbers is exclusively executed by a discrete physical entity: the transplantable HSC. The HSC paradigm has served as a stereotypic template in stem cell biology, yet the search for rare, hardwired professional stem cells has remained futile in most other tissues. In a more open approach, the focus on the search for stem cells as a physical entity may need to be replaced by the search for stem cell function, operationally defined as the ability of an organ to replace lost cells...
March 1, 2018: Annual Review of Biochemistry
Anzhelika Butenko, Tamara da Silva Vieira, Alexander O Frolov, Fred R Opperdoes, Rodrigo P Soares, Alexei Yu Kostygov, Julius Lukeš, Vyacheslav Yurchenko
Background: Leptomonas pyrrhocoris is a parasite of the firebug Pyrrhocoris apterus. This flagellate has been recently proposed as a model species for studying different aspects of the biology of monoxenous trypanosomatids, including host - parasite interactions. During its life cycle L. pyrrhocoris never tightly attaches to the epithelium of the insect gut. In contrast, its dixenous relatives (Leishmania spp.) establish a stable infection via attachment to the intestinal walls of their insect hosts...
February 2018: Current Genomics
Robert W McKee, Naira Aleksanyan, Elizabeth M Garrett, Rita Tamayo
Cyclic diguanylate (c-di-GMP) is a second messenger that regulates the transition from motile to sessile lifestyles in numerous bacteria and controls virulence factor production in a variety of pathogens. In Clostridium difficile , c-di-GMP negatively regulates flagellum biosynthesis and swimming motility, and promotes the production of type IV pili (TFP), biofilm formation, and surface motility in vitro Flagella have been identified as colonization factors in C. difficile , but the role of TFP in adherence to host cells and in colonization of the mammalian gut is unknown...
February 26, 2018: Infection and Immunity
Chen Li, Yong-Yan Cai, Zhi-Xin Yan
The intestinal mucosal barrier (IMB) enables the intestine to provide adequate containment of luminal microorganisms and molecules while preserving the ability to absorb nutrients. In this study, we explored the effect of brain-derived neurotrophic factor (BDNF) on IMB function and gut microbiota in mice. BDNF gene knock-out mice (the BDNF+/- group) and wild-type mice (the BDNF+/+ group) were selected. The gut microbiota of these mice was analyzed by denaturing gradient gel electrophoresis (DGGE) assay. The ultrastructure of the ileum and the colonic epithelium obtained from decapitated mice were observed by transmission electron microscopy...
March 2018: Kaohsiung Journal of Medical Sciences
Meredith Dinges, Christian Lytle, Cynthia K Larive
The large intestine (cecum and colon) is a complex biochemical factory of vital importance to human health. It plays a major role in digestion and absorption by salvaging nutrients from polysaccharides via fermentation initiated by the bacteria that comprise the gut microbiome. We hypothesize that the intestinal epithelium absorbs a limited number of luminal metabolites with bioactive potential while actively excluding those with toxic effects. To explore this concept, we combined1 H NMR detection with Ussing chamber measurements of absorptive transport by rat cecum...
February 23, 2018: Analytical Chemistry
Jörn Karhausen, Joshua D Bernstock, Kory R Johnson, Huaxin Sheng, Qing Ma, Yuntian Shen, Wei Yang, John M Hallenbeck, Wulf Paschen
The intestinal epithelium constitutes a crucial defense to the potentially life-threatening effects of gut microbiota. However, due to a complex underlying vasculature, hypoperfusion and resultant tissue ischemia pose a particular risk to function and integrity of the epithelium. The small ubiquitin-like modifier (SUMO) conjugation pathway critically regulates adaptive responses to metabolic stress and is of particular significance in the gut, as inducible knockout of the SUMO-conjugating enzyme Ubc9 results in rapid intestinal epithelial disintegration...
February 22, 2018: Laboratory Investigation; a Journal of Technical Methods and Pathology
Anna M Duraj-Thatte, Pichet Praveschotinunt, Trevor R Nash, Frederick R Ward, Neel S Joshi
Extracellular appendages play a significant role in mediating communication between bacteria and their host. Curli fibers are a class of bacterial fimbria that is highly amenable to engineering. We demonstrate the use of engineered curli fibers to rationally program interactions between bacteria and components of the mucosal epithelium. Commensal E. coli strains were engineered to produce recombinant curli fibers fused to the trefoil family of human cytokines. Biofilms formed from these strains bound more mucins than those producing wild-type curli fibers, and modulated mucin rheology as well...
February 22, 2018: Scientific Reports
Karan Gautam Kaval, Danielle A Garsin
Ethanolamine (EA) is a valuable source of carbon and/or nitrogen for bacteria capable of its catabolism. Because it is derived from the membrane phospholipid phosphatidylethanolamine, it is particularly prevalent in the gastrointestinal tract, which is membrane rich due to turnover of the intestinal epithelium and the resident microbiota. Intriguingly, many gut pathogens carry the eut (ethanolamine utilization) genes. EA utilization has been studied for about 50 years, with most of the early work occurring in just a couple of species of Enterobacteriaceae Once the metabolic pathways and enzymes were characterized by biochemical approaches, genetic screens were used to map the various activities to the eut genes...
February 20, 2018: MBio
Leon J Broom
The gut barrier, comprising the microbiota and their products, mucus layers, host-derived antimicrobial compounds [e.g., host defense peptides (HDP), IgA], epithelium, and underlying immune tissues, performs the essential function of preventing the passage of harmful microorganisms and substances into the body, while enabling the acquisition of dietary nutrients. Antibiotic growth promoters (AGP) are widely accepted as the "gold standard" of performance-enhancing feed additives, which had become integral and valuable components of modern, efficient animal production, but are now being phased out in many parts of the world...
February 15, 2018: Poultry Science
Katarzyna B Miska, Raymond H Fetterer
Coccidiosis caused by Eimeria in poultry is endemic to poultry operations and results in decreased feed intake, diarrhea, and decreased weight gain. The goal was to determine the effect of Eimeria maxima infection on the expression of genes that encode peptide and amino acid transporters (AATs), and also to determine whether decreased feed intake contributes to the change in gene expression by including a pair-fed group of broilers. Three groups of male Ross broilers: 1) not infected, 2) infected, and 3) not infected pair-fed groups were used...
February 14, 2018: Poultry Science
Wenfeng Li, Yanping Chen, Steven C Cook
Nosema ceranae is an intracellular microsporidian parasite of the Asian honey bee Apis cerana and the European honey bee Apis mellifera. Until relatively recently, A. mellifera honey bees were naïve to N. ceranae infection. Symptoms of nosemosis, or Nosema disease, in the infected hosts include immunosuppression, damage to gut epithelium, nutrient and energetic stress, precocious foraging and reduced longevity of infected bees. Links remain unclear between immunosuppression, the symptoms of nutrient and energetic stress, and precocious foraging behavior of hosts...
February 13, 2018: International Journal for Parasitology
Mayara Grizotte-Lake, Shipra Vaishnava
Autophagy is genetically associated with inflammatory bowel disease (IBD); however, its role remains unclear in disease pathogenesis. Three recent studies reveal a novel cytoprotective role of autophagy during viral, bacterial, and protozoan-triggered IBD (Burger et al., 2018; Matsuzawa-Ishimoto et al., 2017; Pott et al., 2018).
February 14, 2018: Cell Host & Microbe
Christine M Dejea, Payam Fathi, John M Craig, Annemarie Boleij, Rahwa Taddese, Abby L Geis, Xinqun Wu, Christina E DeStefano Shields, Elizabeth M Hechenbleikner, David L Huso, Robert A Anders, Francis M Giardiello, Elizabeth C Wick, Hao Wang, Shaoguang Wu, Drew M Pardoll, Franck Housseau, Cynthia L Sears
Individuals with sporadic colorectal cancer (CRC) frequently harbor abnormalities in the composition of the gut microbiome; however, the microbiota associated with precancerous lesions in hereditary CRC remains largely unknown. We studied colonic mucosa of patients with familial adenomatous polyposis (FAP), who develop benign precursor lesions (polyps) early in life. We identified patchy bacterial biofilms composed predominately of Escherichia coli and Bacteroides fragilis Genes for colibactin ( clbB ) and Bacteroides fragilis toxin ( bft ), encoding secreted oncotoxins, were highly enriched in FAP patients' colonic mucosa compared to healthy individuals...
February 2, 2018: Science
Koji Takeda, Takashi Okumura, Mayu Terahata, Mio Yamaguchi, Kiichiro Taniguchi, Takashi Adachi-Yamada
Enteroendocrine cells (EEs) are evolutionarily conserved gastrointestinal secretory cells that show scattered distribution in the intestinal epithelium. These cells classified into several subtypes based on the hormones they produce in both mammals and insects. In the fruit fly Drosophila, it has been suggested that nearly equal numbers of two subtypes of EEs (Allatostatin A: AstA and Diuretic hormone 31 : Dh31) are alternately produced from the intestinal stem cells in the posterior midgut. However, we found that these two subtypes are not always present in this manner, but are rather distributed in a complementary frequency gradient along the posterior midgut...
February 2018: Zoological Science
Wiebke Heine, Michael Beckstette, Ann Kathrin Heroven, Sophie Thiemann, Ulrike Heise, Aaron Mischa Nuss, Fabio Pisano, Till Strowig, Petra Dersch
Gastrointestinal infections caused by enteric yersiniae can become persistent and complicated by relapsing enteritis and severe autoimmune disorders. To establish a persistent infection, the bacteria have to cope with hostile surroundings when they transmigrate through the intestinal epithelium and colonize underlying gut-associated lymphatic tissues. How the bacteria gain a foothold in the face of host immune responses is poorly understood. Here, we show that the CNFY toxin, which enhances translocation of the antiphagocytic Yop effectors, induces inflammatory responses...
February 2018: PLoS Pathogens
Ana Agustina Bengoa, Lucía Zavala, Paula Carasi, Sebastián Alejandro Trejo, Silvia Bronsoms, María de Los Ángeles Serradell, Graciela Liliana Garrote, Analía Graciela Abraham
Gastrointestinal conditions along the digestive tract are the main stress to which probiotics administrated orally are exposed because they must survive these adverse conditions and arrive alive to the intestine. Adhesion to epithelium has been considered one of the key criteria for the characterization of probiotics because it extends their residence time in the intestine and as a consequence, can influence the health of the host by modifying the local microbiota or modulating the immune response. Nevertheless, there are very few reports on the adhesion properties to epithelium and mucus of microorganisms after passing through the gastrointestinal tract...
January 2018: Food Research International
Isabel L Dittmann, Thomas Zauchner, Lucy M Nevard, Maximilian J Telford, Bernhard Egger
Acoel worms are simple, often microscopic animals with direct development, a multiciliated epidermis, a statocyst, and a digestive parenchyma instead of a gut epithelium. Morphological characters of acoels have been notoriously difficult to interpret due to their relative scarcity. The nervous system is one of the most accessible and widely used comparative features in acoels, which have a so-called commissural brain without capsule and several major longitudinal neurite bundles. Here, we use the selective binding properties of a neuropeptide antibody raised in echinoderms (SALMFamide2, or S2), and a commercial antibody against serotonin (5-HT) to provide additional characters of the acoel nervous system...
February 1, 2018: Journal of Morphology
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