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Sample records for mediates intestinal barrier

  1. Myosin Light Chain Kinase Mediates Intestinal Barrier Disruption following Burn Injury

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    Chen, Chuanli; Wang, Pei; Su, Qin; Wang, Shiliang; Wang, Fengjun

    2012-01-01

    Background Severe burn injury results in the loss of intestinal barrier function, however, the underlying mechanism remains unclear. Myosin light chain (MLC) phosphorylation mediated by MLC kinase (MLCK) is critical to the pathophysiological regulation of intestinal barrier function. We hypothesized that the MLCK-dependent MLC phosphorylation mediates the regulation of intestinal barrier function following burn injury, and that MLCK inhibition attenuates the burn-induced intestinal barrier disfunction. Methodology/Principal Findings Male balb/c mice were assigned randomly to either sham burn (control) or 30% total body surface area (TBSA) full thickness burn without or with intraperitoneal injection of ML-9 (2 mg/kg), an MLCK inhibitor. In vivo intestinal permeability to fluorescein isothiocyanate (FITC)-dextran was measured. Intestinal mucosa injury was assessed histologically. Tight junction proteins ZO-1, occludin and claudin-1 was analyzed by immunofluorescent assay. Expression of MLCK and phosphorylated MLC in ileal mucosa was assessed by Western blot. Intestinal permeability was increased significantly after burn injury, which was accompanied by mucosa injury, tight junction protein alterations, and increase of both MLCK and MLC phosphorylation. Treatment with ML-9 attenuated the burn-caused increase of intestinal permeability, mucosa injury, tight junction protein alterations, and decreased MLC phosphorylation, but not MLCK expression. Conclusions/Significance The MLCK-dependent MLC phosphorylation mediates intestinal epithelial barrier dysfunction after severe burn injury. It is suggested that MLCK-dependent MLC phosphorylation may be a critical target for the therapeutic treatment of intestinal epithelial barrier disruption after severe burn injury. PMID:22529961

  2. Myosin light chain kinase mediates intestinal barrier disruption following burn injury.

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    Chuanli Chen

    Full Text Available BACKGROUND: Severe burn injury results in the loss of intestinal barrier function, however, the underlying mechanism remains unclear. Myosin light chain (MLC phosphorylation mediated by MLC kinase (MLCK is critical to the pathophysiological regulation of intestinal barrier function. We hypothesized that the MLCK-dependent MLC phosphorylation mediates the regulation of intestinal barrier function following burn injury, and that MLCK inhibition attenuates the burn-induced intestinal barrier disfunction. METHODOLOGY/PRINCIPAL FINDINGS: Male balb/c mice were assigned randomly to either sham burn (control or 30% total body surface area (TBSA full thickness burn without or with intraperitoneal injection of ML-9 (2 mg/kg, an MLCK inhibitor. In vivo intestinal permeability to fluorescein isothiocyanate (FITC-dextran was measured. Intestinal mucosa injury was assessed histologically. Tight junction proteins ZO-1, occludin and claudin-1 was analyzed by immunofluorescent assay. Expression of MLCK and phosphorylated MLC in ileal mucosa was assessed by Western blot. Intestinal permeability was increased significantly after burn injury, which was accompanied by mucosa injury, tight junction protein alterations, and increase of both MLCK and MLC phosphorylation. Treatment with ML-9 attenuated the burn-caused increase of intestinal permeability, mucosa injury, tight junction protein alterations, and decreased MLC phosphorylation, but not MLCK expression. CONCLUSIONS/SIGNIFICANCE: The MLCK-dependent MLC phosphorylation mediates intestinal epithelial barrier dysfunction after severe burn injury. It is suggested that MLCK-dependent MLC phosphorylation may be a critical target for the therapeutic treatment of intestinal epithelial barrier disruption after severe burn injury.

  3. Physiological, Pathological, and Therapeutic Implications of Zonulin-Mediated Intestinal Barrier Modulation

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    Fasano, Alessio

    2008-01-01

    The anatomical and functional arrangement of the gastrointestinal tract suggests that this organ, beside its digestive and absorptive functions, regulates the trafficking of macromolecules between the environment and the host through a barrier mechanism. Under physiological circumstances, this trafficking is safeguarded by the competency of intercellular tight junctions, structures whose physiological modulation is mediated by, among others, the recently described protein zonulin. To prevent harm and minimize inflammation, the same paracellular pathway, in concert with the gut-associated lymphoid tissue and the neuroendocrine network, controls the equilibrium between tolerance and immunity to nonself antigens. The zonulin pathway has been exploited to deliver drugs, macromolecules, or vaccines that normally would not be absorbed through the gastrointestinal mucosal barrier. However, if the tightly regulated trafficking of macromolecules is jeopardized secondary to prolonged zonulin up-regulation, the excessive flow of nonself antigens in the intestinal submucosa can cause both intestinal and extraintestinal autoimmune disorders in genetically susceptible individuals. This new paradigm subverts traditional theories underlying the development of autoimmunity, which are based on molecular mimicry and/or the bystander effect, and suggests that the autoimmune process can be arrested if the interplay between genes and environmental triggers is prevented by re-establishing intestinal barrier competency. Understanding the role of zonulin-dependent intestinal barrier dysfunction in the pathogenesis of autoimmune diseases is an area of translational research that encompasses many fields. PMID:18832585

  4. Acrolein Disrupts Tight Junction Proteins and Causes Endoplasmic Reticulum Stress-Mediated Epithelial Cell Death Leading to Intestinal Barrier Dysfunction and Permeability.

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    Chen, Wei-Yang; Wang, Min; Zhang, Jingwen; Barve, Shirish S; McClain, Craig J; Joshi-Barve, Swati

    2017-12-01

    Increasing evidence suggests that environmental and dietary factors can affect intestinal epithelial integrity leading to gut permeability and bacterial translocation. Intestinal barrier dysfunction is a pathogenic process associated with many chronic disorders. Acrolein is an environmental and dietary pollutant and a lipid-derived endogenous metabolite. The impact of acrolein on the intestine has not been investigated before and is evaluated in this study, both in vitro and in vivo. Our data demonstrate that oral acrolein exposure in mice caused damage to the intestinal epithelial barrier, resulting in increased permeability and subsequently translocation of bacterial endotoxin-lipopolysaccharide into the blood. Similar results were seen in vitro using established Caco-2 cell monolayers wherein acrolein decreased barrier function and increased permeability. Acrolein also caused the down-regulation and/or redistribution of three representative tight junction proteins (ie, zonula occludens-1, Occludin, Claudin-1) that critically regulate epithelial paracellular permeability. In addition, acrolein induced endoplasmic reticulum stress-mediated death of epithelial cells, which is an important mechanism contributing to intestinal barrier damage/dysfunction, and gut permeability. Overall, we demonstrate that exposure to acrolein affects the intestinal epithelium by decrease/redistribution of tight junction proteins and endoplasmic reticulum stress-mediated epithelial cell death, thereby resulting in loss of barrier integrity and function. Our findings highlight the adverse consequences of environmental and dietary pollutants on intestinal barrier integrity/function with relevance to gut permeability and the development of disease. Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  5. Curcumin-mediated regulation of intestinal barrier function: The mechanism underlying its beneficial effects.

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    Ghosh, Siddhartha S; He, Hongliang; Wang, Jing; Gehr, Todd W; Ghosh, Shobha

    2018-01-02

    Curcumin has anti-inflammatory, anti-oxidant and anti-proliferative properties established largely by in vitro studies. Accordingly, oral administration of curcumin beneficially modulates many diseases including diabetes, fatty-liver disease, atherosclerosis, arthritis, cancer and neurological disorders such as depression, Alzheimer's or Parkinson's disease. However, limited bioavailability and inability to detect curcumin in circulation or target tissues has hindered the validation of a causal role. We established curcumin-mediated decrease in the release of gut bacteria-derived lipopolysaccharide (LPS) into circulation by maintaining the integrity of the intestinal barrier function as the mechanism underlying the attenuation of metabolic diseases (diabetes, atherosclerosis, kidney disease) by curcumin supplementation precluding the need for curcumin absorption. In view of the causative role of circulating LPS and resulting chronic inflammation in the development of diseases listed above, this review summarizes the mechanism by which curcumin affects the several layers of the intestinal barrier and, despite negligible absorption, can beneficially modulate these diseases.

  6. Xenobiotic Receptor-Mediated Regulation of Intestinal Barrier Function and Innate Immunity

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    Harmit S. Ranhotra

    2016-07-01

    Full Text Available The molecular basis for the regulation of the intestinal barrier is a very fertile research area. A growing body of knowledge supports the targeting of various components of intestinal barrier function as means to treat a variety of diseases, including the inflammatory bowel diseases. Herein, we will summarize the current state of knowledge of key xenobiotic receptor regulators of barrier function, highlighting recent advances, such that the field and its future are succinctly reviewed. We posit that these receptors confer an additional dimension of host-microbe interaction in the gut, by sensing and responding to metabolites released from the symbiotic microbiota, in innate immunity and also in host drug metabolism. The scientific evidence for involvement of the receptors and its molecular basis for the control of barrier function and innate immunity regulation would serve as a rationale towards development of non-toxic probes and ligands as drugs.

  7. Physiological, pathological, and therapeutic implications of zonulin-mediated intestinal barrier modulation: living life on the edge of the wall.

    Science.gov (United States)

    Fasano, Alessio

    2008-11-01

    The anatomical and functional arrangement of the gastrointestinal tract suggests that this organ, beside its digestive and absorptive functions, regulates the trafficking of macromolecules between the environment and the host through a barrier mechanism. Under physiological circumstances, this trafficking is safeguarded by the competency of intercellular tight junctions, structures whose physiological modulation is mediated by, among others, the recently described protein zonulin. To prevent harm and minimize inflammation, the same paracellular pathway, in concert with the gut-associated lymphoid tissue and the neuroendocrine network, controls the equilibrium between tolerance and immunity to nonself antigens. The zonulin pathway has been exploited to deliver drugs, macromolecules, or vaccines that normally would not be absorbed through the gastrointestinal mucosal barrier. However, if the tightly regulated trafficking of macromolecules is jeopardized secondary to prolonged zonulin up-regulation, the excessive flow of nonself antigens in the intestinal submucosa can cause both intestinal and extraintestinal autoimmune disorders in genetically susceptible individuals. This new paradigm subverts traditional theories underlying the development of autoimmunity, which are based on molecular mimicry and/or the bystander effect, and suggests that the autoimmune process can be arrested if the interplay between genes and environmental triggers is prevented by re-establishing intestinal barrier competency. Understanding the role of zonulin-dependent intestinal barrier dysfunction in the pathogenesis of autoimmune diseases is an area of translational research that encompasses many fields.

  8. Loss of guanylyl cyclase C (GCC signaling leads to dysfunctional intestinal barrier.

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    Xiaonan Han

    2011-01-01

    Full Text Available Guanylyl Cyclase C (GCC signaling via uroguanylin (UGN and guanylin activation is a critical mediator of intestinal fluid homeostasis, intestinal cell proliferation/apoptosis, and tumorigenesis. As a mechanism for some of these effects, we hypothesized that GCC signaling mediates regulation of intestinal barrier function.Paracellular permeability of intestinal segments was assessed in wild type (WT and GCC deficient (GCC-/- mice with and without lipopolysaccharide (LPS challenge, as well as in UGN deficient (UGN-/- mice. IFNγ and myosin light chain kinase (MLCK levels were determined by real time PCR. Expression of tight junction proteins (TJPs, phosphorylation of myosin II regulatory light chain (MLC, and STAT1 activation were examined in intestinal epithelial cells (IECs and intestinal mucosa. The permeability of Caco-2 and HT-29 IEC monolayers, grown on Transwell filters was determined in the absence and presence of GCC RNA interference (RNAi. We found that intestinal permeability was increased in GCC-/- and UGN-/- mice compared to WT, accompanied by increased IFNγ levels, MLCK and STAT1 activation in IECs. LPS challenge promotes greater IFNγ and STAT1 activation in IECs of GCC-/- mice compared to WT mice. Claudin-2 and JAM-A expression were reduced in GCC deficient intestine; the level of phosphorylated MLC in IECs was significantly increased in GCC-/- and UGN-/- mice compared to WT. GCC knockdown induced MLC phosphorylation, increased permeability in IEC monolayers under basal conditions, and enhanced TNFα and IFNγ-induced monolayer hyperpermeability.GCC signaling plays a protective role in the integrity of the intestinal mucosal barrier by regulating MLCK activation and TJ disassembly. GCC signaling activation may therefore represent a novel mechanism in maintaining the small bowel barrier in response to injury.

  9. Epidermal Growth Factor and Intestinal Barrier Function

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    Xiaopeng Tang

    2016-01-01

    Full Text Available Epidermal growth factor (EGF is a 53-amino acid peptide that plays an important role in regulating cell growth, survival, migration, apoptosis, proliferation, and differentiation. In addition, EGF has been established to be an effective intestinal regulator helping to protect intestinal barrier integrity, which was essential for the absorption of nutrients and health in humans and animals. Several researches have demonstrated that EGF via binding to the EGF receptor and subsequent activation of Ras/MAPK, PI3K/AKT, PLC-γ/PKC, and STATS signal pathways regulates intestinal barrier function. In this review, the relationship between epidermal growth factor and intestinal development and intestinal barrier is described, to provide a better understanding of the effects of EGF on intestine development and health.

  10. Breakdown of mucin as barrier to digestive enzymes in the ischemic rat small intestine.

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    Marisol Chang

    Full Text Available Loss of integrity of the epithelial/mucosal barrier in the small intestine has been associated with different pathologies that originate and/or develop in the gastrointestinal tract. We showed recently that mucin, the main protein in the mucus layer, is disrupted during early periods of intestinal ischemia. This event is accompanied by entry of pancreatic digestive enzymes into the intestinal wall. We hypothesize that the mucin-containing mucus layer is the main barrier preventing digestive enzymes from contacting the epithelium. Mucin breakdown may render the epithelium accessible to pancreatic enzymes, causing its disruption and increased permeability. The objective of this study was to investigate the role of mucin as a protection for epithelial integrity and function. A rat model of 30 min splanchnic arterial occlusion (SAO was used to study the degradation of two mucin isoforms (mucin 2 and 13 and two epithelial membrane proteins (E-cadherin and toll-like receptor 4, TLR4. In addition, the role of digestive enzymes in mucin breakdown was assessed in this model by luminal inhibition with acarbose, tranexamic acid, or nafamostat mesilate. Furthermore, the protective effect of the mucin layer against trypsin-mediated disruption of the intestinal epithelium was studied in vitro. Rats after SAO showed degradation of mucin 2 and fragmentation of mucin 13, which was not prevented by protease inhibition. Mucin breakdown was accompanied by increased intestinal permeability to FITC-dextran as well as degradation of E-cadherin and TLR4. Addition of mucin to intestinal epithelial cells in vitro protected against trypsin-mediated degradation of E-cadherin and TLR4 and reduced permeability of FITC-dextran across the monolayer. These results indicate that mucin plays an important role in the preservation of the mucosal barrier and that ischemia but not digestive enzymes disturbs mucin integrity, while digestive enzymes actively mediate epithelial cell

  11. TNFα/IFNγ Mediated Intestinal Epithelial Barrier Dysfunction Is Attenuated by MicroRNA-93 Downregulation of PTK6 in Mouse Colonic Epithelial Cells.

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    Ricci J Haines

    /IFNγ imposed decrease in transepithelial electrical resistance (TER, as well as excluded FoxO1 from the nucleus. Our results indicate that PTK6 may act as a novel mediator of intestinal epithelial permeability during inflammatory injury, and miR-93 may protect intestinal epithelial barrier function, at least in part, by targeting PTK6.

  12. Early effects of gliadin on enterocyte intracellular signalling involved in intestinal barrier function.

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    Clemente, M G; De Virgiliis, S; Kang, J S; Macatagney, R; Musu, M P; Di Pierro, M R; Drago, S; Congia, M; Fasano, A

    2003-02-01

    Despite the progress made in understanding the immunological aspects of the pathogenesis of coeliac disease (CD), the early steps that allow gliadin to cross the intestinal barrier are still largely unknown. The aim of this study was to establish whether gliadin activates a zonulin dependent enterocyte intracellular signalling pathway(s) leading to increased intestinal permeability. The effect of gliadin on the enterocyte actin cytoskeleton was studied on rat intestinal epithelial (IEC-6) cell cultures by fluorescence microscopy and spectrofluorimetry. Zonulin concentration was measured on cell culture supernatants by enzyme linked immunosorbent assay. Transepithelial intestinal resistance (Rt) was measured on ex vivo intestinal tissues mounted in Ussing chambers. Incubation of cells with gliadin led to a reversible protein kinase C (PKC) mediated actin polymerisation temporarily coincident with zonulin release. A significant reduction in Rt was observed after gliadin addition on rabbit intestinal mucosa mounted in Ussing chambers. Pretreatment with the zonulin inhibitor FZI/0 abolished the gliadin induced actin polymerisation and Rt reduction but not zonulin release. Gliadin induces zonulin release in intestinal epithelial cells in vitro. Activation of the zonulin pathway by PKC mediated cytoskeleton reorganisation and tight junction opening leads to a rapid increase in intestinal permeability.

  13. Mechanisms of Intestinal Barrier Dysfunction in Sepsis.

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    Yoseph, Benyam P; Klingensmith, Nathan J; Liang, Zhe; Breed, Elise R; Burd, Eileen M; Mittal, Rohit; Dominguez, Jessica A; Petrie, Benjamin; Ford, Mandy L; Coopersmith, Craig M

    2016-07-01

    Intestinal barrier dysfunction is thought to contribute to the development of multiple organ dysfunction syndrome in sepsis. Although there are similarities in clinical course following sepsis, there are significant differences in the host response depending on the initiating organism and time course of the disease, and pathways of gut injury vary widely in different preclinical models of sepsis. The purpose of this study was to determine whether the timecourse and mechanisms of intestinal barrier dysfunction are similar in disparate mouse models of sepsis with similar mortalities. FVB/N mice were randomized to receive cecal ligation and puncture (CLP) or sham laparotomy, and permeability was measured to fluoresceinisothiocyanate conjugated-dextran (FD-4) six to 48 h later. Intestinal permeability was elevated following CLP at all timepoints measured, peaking at 6 to 12 h. Tight junction proteins claudin 1, 2, 3, 4, 5, 7, 8, 13, and 15, Junctional Adhesion Molecule-A (JAM-A), occludin, and ZO-1 were than assayed by Western blot, real-time polymerase chain reaction, and immunohistochemistry 12 h after CLP to determine potential mechanisms underlying increases in intestinal permeability. Claudin 2 and JAM-A were increased by sepsis, whereas claudin-5 and occludin were decreased by sepsis. All other tight junction proteins were unchanged. A further timecourse experiment demonstrated that alterations in claudin-2 and occludin were detectable as early as 1 h after the onset of sepsis. Similar experiments were then performed in a different group of mice subjected to Pseudomonas aeruginosa pneumonia. Mice with pneumonia had an increase in intestinal permeability similar in timecourse and magnitude to that seen in CLP. Similar changes in tight junction proteins were seen in both models of sepsis although mice subjected to pneumonia also had a marked decrease in ZO-1 not seen in CLP. These results indicate that two disparate, clinically relevant models of sepsis

  14. Live Faecalibacterium prausnitzii in an apical anaerobic model of the intestinal epithelial barrier.

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    Ulluwishewa, Dulantha; Anderson, Rachel C; Young, Wayne; McNabb, Warren C; van Baarlen, Peter; Moughan, Paul J; Wells, Jerry M; Roy, Nicole C

    2015-02-01

    Faecalibacterium prausnitzii, an abundant member of the human commensal microbiota, has been proposed to have a protective role in the intestine. However, it is an obligate anaerobe, difficult to co-culture in viable form with oxygen-requiring intestinal cells. To overcome this limitation, a unique apical anaerobic model of the intestinal barrier, which enabled co-culture of live obligate anaerobes with the human intestinal cell line Caco-2, was developed. Caco-2 cells remained viable and maintained an intact barrier for at least 12 h, consistent with gene expression data, which suggested Caco-2 cells had adapted to survive in an oxygen-reduced atmosphere. Live F. prausnitzii cells, but not ultraviolet (UV)-killed F. prausnitzii, increased the permeability of mannitol across the epithelial barrier. Gene expression analysis showed inflammatory mediators to be expressed at lower amounts in Caco-2 cells exposed to live F. prausnitzii than UV-killed F. prausnitzii, This, consistent with previous reports, implies that live F. prausnitzii produces an anti-inflammatory compound in the culture supernatant, demonstrating the value of a physiologically relevant co-culture system that allows obligate anaerobic bacteria to remain viable. © 2014 John Wiley & Sons Ltd.

  15. Splenectomy attenuates severe thermal trauma-induced intestinal barrier breakdown in rats.

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    Liu, Xiang-dong; Chen, Zhen-yong; Yang, Peng; Huang, Wen-guang; Jiang, Chun-fang

    2015-12-01

    The severe local thermal trauma activates a number of systemic inflammatory mediators, such as TNF-α, NF-κB, resulting in a disruption of gut barrier. The gastrointestinal tight junction (TJ) is highly regulated by membrane-associated proteins including zonula occludens protein-1 (ZO-1) and occludin, which can be modulated by inflammatory cytokines. As splenectomy has been shown to reduce secretion of cytokines, we hypothesized that (1) severe scald injury up-regulates TNF-α and NF-κB, meanwhile down-regulates expression of ZO-1 and occludin, leading to the increased intestinal permeability, and (2) splenectomy can prevent the burn-induced decrease in ZO-1 and occludin expression, resulting in improved intestinal barrier. Wistar rats undergoing a 30% total body surface area (TBSA) thermal trauma were randomized to receive an accessorial splenectomy meanwhile or not. Intestinal injury was assessed by histological morphological analysis, and serum endotoxin levels, TNF-α, NF-κB, ZO-1 and occludin levels were detected by Western blotting in the terminal ileum mucosal tissue. 30% TBSA burn caused a significant increase in serum endotoxin levels, but NF-κB, and TNF-α, and the average intestinal villus height and mucosal thickness were decreased significantly. Burn injury could also markedly decrease the levels of ZO-1 and occludin in terminal ileum mucosal tissue (all PSplenectomy at 7th day after burn significantly reversed the burn-induced breakdown of ZO-1 and occludin (all PSplenectomy may provide a therapeutic benefit in restoring burn-induced intestinal barrier by decreasing the release of inflammatory cytokines and recovering TJ proteins.

  16. Erlotinib promotes endoplasmic reticulum stress-mediated injury in the intestinal epithelium

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    Fan, Lu; Hu, Lingna; Yang, Baofang; Fang, Xianying; Gao, Zhe; Li, Wanshuai; Sun, Yang; Shen, Yan; Wu, Xuefeng [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 22 Hankou Road, Nanjing 210093 (China); Shu, Yongqian [Department of Clinical Oncology, The First Affiliated Hospital of Nanjing Medical University, 140 Hanzhong Road, Nanjing 210029 (China); Gu, Yanhong, E-mail: guluer@163.com [Department of Clinical Oncology, The First Affiliated Hospital of Nanjing Medical University, 140 Hanzhong Road, Nanjing 210029 (China); Wu, Xudong, E-mail: xudongwu@nju.edu.cn [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 22 Hankou Road, Nanjing 210093 (China); Xu, Qiang, E-mail: molpharm@163.com [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 22 Hankou Road, Nanjing 210093 (China)

    2014-07-01

    Erlotinib, a popular drug for treating non-small cell lung cancer (NSCLC), causes diarrhea in approximately 55% of patients receiving this drug. In the present study, we found that erlotinib induced barrier dysfunction in rat small intestine epithelial cells (IEC-6) by increasing epithelial permeability and down-regulating E-cadherin. The mRNA levels of various pro-inflammatory cytokines (Il-6, Il-25 and Il-17f) were increased after erlotinib treatment in IEC-6 cells. Erlotinib concentration- and time-dependently induced apoptosis and endoplasmic reticulum (ER) stress in both IEC-6 and human colon epithelial cells (CCD 841 CoN). Intestinal epithelial injury was also observed in male C57BL/6J mice administrated with erlotinib. Knockdown of C/EBP homologous protein (CHOP) with small interference RNA partially reversed erlotinib-induced apoptosis, production of IL-6 and down-regulation of E-cadherin in cultured intestinal epithelial cells. In conclusion, erlotinib caused ER stress-mediated injury in the intestinal epithelium, contributing to its side effects of diarrhea in patients. - Highlights: • Erlotinib destroyed barrier integrity both in vitro and in vivo. • Erlotinib induced inflammation both in vitro and in vivo. • Erlotinib induced apoptosis both in vitro and in vivo. • ER stress contributed to erlotinib-induced barrier dysfunction.

  17. Erlotinib promotes endoplasmic reticulum stress-mediated injury in the intestinal epithelium

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    Fan, Lu; Hu, Lingna; Yang, Baofang; Fang, Xianying; Gao, Zhe; Li, Wanshuai; Sun, Yang; Shen, Yan; Wu, Xuefeng; Shu, Yongqian; Gu, Yanhong; Wu, Xudong; Xu, Qiang

    2014-01-01

    Erlotinib, a popular drug for treating non-small cell lung cancer (NSCLC), causes diarrhea in approximately 55% of patients receiving this drug. In the present study, we found that erlotinib induced barrier dysfunction in rat small intestine epithelial cells (IEC-6) by increasing epithelial permeability and down-regulating E-cadherin. The mRNA levels of various pro-inflammatory cytokines (Il-6, Il-25 and Il-17f) were increased after erlotinib treatment in IEC-6 cells. Erlotinib concentration- and time-dependently induced apoptosis and endoplasmic reticulum (ER) stress in both IEC-6 and human colon epithelial cells (CCD 841 CoN). Intestinal epithelial injury was also observed in male C57BL/6J mice administrated with erlotinib. Knockdown of C/EBP homologous protein (CHOP) with small interference RNA partially reversed erlotinib-induced apoptosis, production of IL-6 and down-regulation of E-cadherin in cultured intestinal epithelial cells. In conclusion, erlotinib caused ER stress-mediated injury in the intestinal epithelium, contributing to its side effects of diarrhea in patients. - Highlights: • Erlotinib destroyed barrier integrity both in vitro and in vivo. • Erlotinib induced inflammation both in vitro and in vivo. • Erlotinib induced apoptosis both in vitro and in vivo. • ER stress contributed to erlotinib-induced barrier dysfunction

  18. Ghrelin ameliorates intestinal barrier dysfunction in experimental colitis by inhibiting the activation of nuclear factor-kappa B

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    Cheng, Jian; Zhang, Lin; Dai, Weiqi; Mao, Yuqing; Li, Sainan; Wang, Jingjie; Li, Huanqing; Guo, Chuanyong; Fan, Xiaoming

    2015-01-01

    Aim: This study aimed to investigate the effect and underlying mechanism of ghrelin on intestinal barrier dysfunction in dextran sulfate sodium (DSS)-induced colitis. Methods and results: Acute colitis was induced in C57BL/6J mice by administering 2.5% DSS. Saline or 25, 125, 250 μg/kg ghrelin was administrated intraperitoneally (IP) to mice 1 day before colitis induction and on days 4, 5, and 6 after DSS administration. IP injection of a ghrelin receptor antagonist, [D-lys 3 ]-GHRP-6, was performed immediately prior to ghrelin injection. Ghrelin (125 or 250 μg/kg) could reduce the disease activity index, histological score, and myeloperoxidase activities in experimental colitis, and also prevented shortening of the colon. Ghrelin could prevent the reduction of transepithelial electrical resistance and tight junction expression, and bolstered tight junction structural integrity and regulated cytokine secretion. Ultimately, ghrelin inhibited nuclear factor kappa B (NF-κB), inhibitory κB-α, myosin light chain kinase, and phosphorylated myosin light chain 2 activation. Conclusions: Ghrelin prevented the breakdown of intestinal barrier function in DSS-induced colitis. The protective effects of ghrelin on intestinal barrier function were mediated by its receptor GHSR-1a. The inhibition of NF-κB activation might be part of the mechanism underlying the effects of ghrelin that protect against barrier dysfunction. - Highlights: • Ghrelin ameliorates intestinal barrier dysfunction in experimental colitis. • The effect of ghrelin is mediated by GHSR-1a. • Inhibition of NF-κB activation

  19. Ghrelin ameliorates intestinal barrier dysfunction in experimental colitis by inhibiting the activation of nuclear factor-kappa B

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    Cheng, Jian; Zhang, Lin [Department of Gastroenterology, Jinshan Hospital of Fudan University, Shanghai (China); Dai, Weiqi [Department of Gastroenterology, Shanghai Tenth People' s Hospital, Tongji University, Shanghai (China); Mao, Yuqing [Department of Gastroenterology, Jinshan Hospital of Fudan University, Shanghai (China); Li, Sainan [Department of Gastroenterology, Shanghai Tenth People' s Hospital, Tongji University, Shanghai (China); Wang, Jingjie; Li, Huanqing [Department of Gastroenterology, Jinshan Hospital of Fudan University, Shanghai (China); Guo, Chuanyong [Department of Gastroenterology, Shanghai Tenth People' s Hospital, Tongji University, Shanghai (China); Fan, Xiaoming, E-mail: xiaomingfan57@sina.com [Department of Gastroenterology, Jinshan Hospital of Fudan University, Shanghai (China)

    2015-02-27

    Aim: This study aimed to investigate the effect and underlying mechanism of ghrelin on intestinal barrier dysfunction in dextran sulfate sodium (DSS)-induced colitis. Methods and results: Acute colitis was induced in C57BL/6J mice by administering 2.5% DSS. Saline or 25, 125, 250 μg/kg ghrelin was administrated intraperitoneally (IP) to mice 1 day before colitis induction and on days 4, 5, and 6 after DSS administration. IP injection of a ghrelin receptor antagonist, [D-lys{sup 3}]-GHRP-6, was performed immediately prior to ghrelin injection. Ghrelin (125 or 250 μg/kg) could reduce the disease activity index, histological score, and myeloperoxidase activities in experimental colitis, and also prevented shortening of the colon. Ghrelin could prevent the reduction of transepithelial electrical resistance and tight junction expression, and bolstered tight junction structural integrity and regulated cytokine secretion. Ultimately, ghrelin inhibited nuclear factor kappa B (NF-κB), inhibitory κB-α, myosin light chain kinase, and phosphorylated myosin light chain 2 activation. Conclusions: Ghrelin prevented the breakdown of intestinal barrier function in DSS-induced colitis. The protective effects of ghrelin on intestinal barrier function were mediated by its receptor GHSR-1a. The inhibition of NF-κB activation might be part of the mechanism underlying the effects of ghrelin that protect against barrier dysfunction. - Highlights: • Ghrelin ameliorates intestinal barrier dysfunction in experimental colitis. • The effect of ghrelin is mediated by GHSR-1a. • Inhibition of NF-κB activation.

  20. Claudins, dietary milk proteins, and intestinal barrier regulation.

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    Kotler, Belinda M; Kerstetter, Jane E; Insogna, Karl L

    2013-01-01

    The family of claudin proteins plays an important role in regulating the intestinal barrier by modulating the permeability of tight junctions. The impact of dietary protein on claudin biology has not been studied extensively. Whey proteins have been reported to improve intestinal barrier function, but their mechanism of action is not clear. Recent studies, however, have demonstrated increased intestinal claudin expression in response to milk protein components. Reviewed here are new findings suggesting that whey-protein-derived transforming growth factor β transcriptionally upregulates claudin-4 expression via a Smad-4-dependent pathway. These and other data, including limited clinical studies, are summarized below and, in the aggregate, suggest a therapeutic role for whey protein in diseases of intestinal barrier dysfunction, perhaps, in part, by regulating claudin expression. © 2013 International Life Sciences Institute.

  1. TREM-1 Promotes Pancreatitis-Associated Intestinal Barrier Dysfunction

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    Shengchun Dang

    2012-01-01

    Full Text Available Severe acute pancreatitis (SAP can cause intestinal barrier dysfunction (IBD, which significantly increases the disease severity and risk of mortality. We hypothesized that the innate immunity- and inflammatory-related protein-triggering receptor expressed on myeloid cells-1 (TREM-1 contributes to this complication of SAP. Thus, we investigated the effect of TREM-1 pathway modulation on a rat model of pancreatitis-associated IBD. In this study we sought to clarify the role of TREM-1 in the pathophysiology of intestinal barrier dysfunction in SAP. Specifically, we evaluated levels of serum TREM-1 and membrane-bound TREM-1 in the intestine and pancreas from an animal model of experimentally induced SAP. TREM-1 pathway blockade by LP17 treatment may suppress pancreatitis-associated IBD and ameliorate the damage to the intestinal mucosa barrier.

  2. The intestinal barrier function and its involvement in digestive disease

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    Eloísa Salvo-Romero

    2015-11-01

    Full Text Available The gastrointestinal mucosal surface is lined with epithelial cells representing an effective barrier made up with intercellular junctions that separate the inner and the outer environments, and block the passage of potentially harmful substances. However, epithelial cells are also responsible for the absorption of nutrients and electrolytes, hence a semipermeable barrier is required that selectively allows a number of substances in while keeping others out. To this end, the intestine developed the "intestinal barrier function", a defensive system involving various elements, both intra- and extracellular, that work in a coordinated way to impede the passage of antigens, toxins, and microbial byproducts, and simultaneously preserves the correct development of the epithelial barrier, the immune system, and the acquisition of tolerance against dietary antigens and the intestinal microbiota. Disturbances in the mechanisms of the barrier function favor the development of exaggerated immune responses; while exact implications remain unknown, changes in intestinal barrier function have been associated with the development of inflammatory conditions in the gastrointestinal tract. This review details de various elements of the intestinal barrier function, and the key molecular and cellular changes described for gastrointestinal diseases associated with dysfunction in this defensive mechanism.

  3. Potential of Lactobacillus plantarum CCFM639 in Protecting against Aluminum Toxicity Mediated by Intestinal Barrier Function and Oxidative Stress.

    Science.gov (United States)

    Yu, Leilei; Zhai, Qixiao; Tian, Fengwei; Liu, Xiaoming; Wang, Gang; Zhao, Jianxin; Zhang, Hao; Narbad, Arjan; Chen, Wei

    2016-12-02

    Aluminum (Al) is a ubiquitous metal that can seriously harm the health of animals and humans. In our previous study, we demonstrated that Lactobacillus plantarum CCFM639 can decrease Al burden in the tissues of mice by inhibiting intestinal Al absorption. The main aim of the present research was to investigate whether the protection by the strain is also associated with enhancement of the intestinal barrier, alleviation of oxidative stress and modulation of the inflammatory response. In an in vitro cell model, two protection modes (intervention and therapy) were examined and the results indicated that L. plantarum CCFM639 alleviated Al-induced cytotoxicity. In a mouse model, L. plantarum CCFM639 treatment was found to significantly alleviate oxidative stress in the intestinal tract, regulate the function of the intestinal mucosal immune system, restore the integrity of tight junction proteins and maintain intestinal permeability. These results suggest that in addition to Al sequestration, L. plantarum CCFM639 can also inhibit Al absorption by protecting the intestinal barrier, alleviating Al-induced oxidative stress and inflammatory response. Therefore, L. plantarum CCFM639 has the potential to be a dietary supplement ingredient that provides protection against Al-induced gut injury.

  4. Potential of Lactobacillus plantarum CCFM639 in Protecting against Aluminum Toxicity Mediated by Intestinal Barrier Function and Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Leilei Yu

    2016-12-01

    Full Text Available Aluminum (Al is a ubiquitous metal that can seriously harm the health of animals and humans. In our previous study, we demonstrated that Lactobacillus plantarum CCFM639 can decrease Al burden in the tissues of mice by inhibiting intestinal Al absorption. The main aim of the present research was to investigate whether the protection by the strain is also associated with enhancement of the intestinal barrier, alleviation of oxidative stress and modulation of the inflammatory response. In an in vitro cell model, two protection modes (intervention and therapy were examined and the results indicated that L. plantarum CCFM639 alleviated Al-induced cytotoxicity. In a mouse model, L. plantarum CCFM639 treatment was found to significantly alleviate oxidative stress in the intestinal tract, regulate the function of the intestinal mucosal immune system, restore the integrity of tight junction proteins and maintain intestinal permeability. These results suggest that in addition to Al sequestration, L. plantarum CCFM639 can also inhibit Al absorption by protecting the intestinal barrier, alleviating Al-induced oxidative stress and inflammatory response. Therefore, L. plantarum CCFM639 has the potential to be a dietary supplement ingredient that provides protection against Al-induced gut injury.

  5. Role of intestinal mucosal barrier in the development and progression of nonalcoholic fatty liver disease

    Directory of Open Access Journals (Sweden)

    ZHANG Yuanyuan

    2016-12-01

    Full Text Available The incidence of non-alcoholic fatty liver disease (NAFLD has been increasing year by year in China. Intestinal mucosa is the largest organ for bacterial storage, and intestinal mucosal barrier includes biological barrier, mechanical barrier, immunological barrier, and chemical barrier. This article investigates the important role of intestinal mucosal barrier function in the pathogenesis of NAFLD. As for the intestinal biological barrier, abnormalities in gut microbiota occur earlier than obesity and other metabolic disorders; small intestinal bacterial overgrowth may affect energy metabolism, promote insulin resistance, and get involved in the pathogenesis of NAFLD; regulation of gut microbiota has a certain clinical effect in the treatment of NAFLD. Intestinal mechanical barrier impairment increases the mucosal permeability and is associated with intestinal dysbacteriosis. The changes in intestinal immunological barrier may be associated with obesity, metabolic disorders, and liver inflammation. The changes in intestinal chemical barrier can inhibit the synthesis and secretion of very low-density lipoprotein and low-density lipoprotein in hepatocytes and may result in triglyceride deposition in the liver. It is pointed out that the research on intestinal mucosal barrier function provides promising prospects for the prevention and treatment of NAFLD.

  6. Desmoglein 2 regulates the intestinal epithelial barrier via p38 mitogen-activated protein kinase.

    Science.gov (United States)

    Ungewiß, Hanna; Vielmuth, Franziska; Suzuki, Shintaro T; Maiser, Andreas; Harz, Hartmann; Leonhardt, Heinrich; Kugelmann, Daniela; Schlegel, Nicolas; Waschke, Jens

    2017-07-24

    Intestinal epithelial barrier properties are maintained by a junctional complex consisting of tight junctions (TJ), adherens junctions (AJ) and desmosomes. Desmoglein 2 (Dsg2), an adhesion molecule of desmosomes and the only Dsg isoform expressed in enterocytes, is required for epithelial barrier properties and may contribute to barrier defects in Crohn's disease. Here, we identified extradesmosomal Dsg2 on the surface of polarized enterocytes by Triton extraction, confocal microscopy, SIM and STED. Atomic force microscopy (AFM) revealed Dsg2-specific binding events along the cell border on the surface of enterocytes with a mean unbinding force of around 30pN. Binding events were blocked by an inhibitory antibody targeting Dsg2 which under same conditions activated p38MAPK but did not reduce cell cohesion. In enterocytes deficient for Dsg2, p38MAPK activity was reduced and both barrier integrity and reformation were impaired. Dsc2 rescue did not restore p38MAPK activity indicating that Dsg2 is required. Accordingly, direct activation of p38MAPK in Dsg2-deficient cells enhanced barrier reformation demonstrating that Dsg2-mediated activation of p38MAPK is crucial for barrier function. Collectively, our data show that Dsg2, beside its adhesion function, regulates intestinal barrier function via p38MAPK signalling. This is in contrast to keratinocytes and points towards tissue-specific signalling functions of desmosomal cadherins.

  7. Boswellia serrata Preserves Intestinal Epithelial Barrier from Oxidative and Inflammatory Damage.

    Directory of Open Access Journals (Sweden)

    Daniela Catanzaro

    elucidates the pharmacological mechanisms mediated by BSE, in protecting intestinal epithelial barrier from inflammatory damage and supports its use as safe adjuvant in patients affected by IBD.

  8. Lactobacillus frumenti Facilitates Intestinal Epithelial Barrier Function Maintenance in Early-Weaned Piglets

    Science.gov (United States)

    Hu, Jun; Chen, Lingli; Zheng, Wenyong; Shi, Min; Liu, Liu; Xie, Chunlin; Wang, Xinkai; Niu, Yaorong; Hou, Qiliang; Xu, Xiaofan; Xu, Baoyang; Tang, Yimei; Zhou, Shuyi; Yan, Yiqin; Yang, Tao; Ma, Libao; Yan, Xianghua

    2018-01-01

    Increased intestinal epithelial barrier function damages caused by early weaning stress have adverse effects on swine health and feed utilization efficiency. Probiotics have emerged as the promising antibiotic alternatives used for intestinal barrier function damage prevention. Our previous data showed that Lactobacillus frumenti was identified as a predominant Lactobacillus in the intestinal microbiota of weaned piglets. However, whether the intestinal epithelial barrier function in piglets was regulated by L. frumenti is still unclear. Here, piglets received a PBS vehicle or PBS suspension (2 ml, 108 CFU/ml) containing the L. frumenti by oral gavage once a day during the period of 6–20 days of age prior to early weaning. Our data demonstrated that oral administration of L. frumenti significantly improved the intestinal mucosal integrity and decreased the serum endotoxin and D-lactic acid levels in early-weaned piglets (26 days of age). The intestinal tight junction proteins (including ZO-1, Occludin, and Claudin-1) were significantly up-regulated by L. frumenti administration. The serum immunoglobulin G (IgG) levels, intestinal secretory immunoglobulin A (sIgA) levels, and interferon-γ (IFN-γ) levels were significantly increased by L. frumenti administration. Furthermore, our data revealed that oral administration of L. frumenti significantly increased the relative abundances of health-promoting microbes (including L. frumenti, Lactobacillus gasseri LA39, Parabacteroides distasonis, and Kazachstania telluris) and decreased the relative abundances of opportunistic pathogens (including Desulfovibrio desulfuricans and Candida humilis). Functional alteration of the intestinal bacterial community by L. frumenti administration was characterized by the significantly increased fatty acids and protein metabolism and decreased diseases-associated metabolic pathways. These findings suggest that L. frumenti facilitates intestinal epithelial barrier function maintenance

  9. Intestinal epithelial barrier function and tight junction proteins with heat and exercise

    DEFF Research Database (Denmark)

    Dokladny, Karol; Zuhl, Micah N; Moseley, Pope L

    2016-01-01

    A single layer of enterocytes and tight junctions (intercellular multiprotein complexes) form the intestinal epithelial barrier that controls transport of molecules through transcellular and paracellular pathways. A dysfunctional or "leaky" intestinal tight junction barrier allows augmented perme...

  10. Diabetes mellitus and impairment of intestinal barier function

    OpenAIRE

    Hoffmanová, Iva

    2015-01-01

    Introduction: Impairment of intestinal barrier function is involved in pathogenesis of immune mediated diseases (such as type 1 diabetes mellitus or celiac disease) and metabolic diseases (such as type 2 diabetes mellitus). Aims of study: The first aim was to analyze impairment of mucosal part of intestinal barrier in both type of diabetes and to describe differences when compared to celiac disease, which is a typical condition associated with impairment of intestinal barrier function. The se...

  11. Death following traumatic brain injury in Drosophila is associated with intestinal barrier dysfunction

    Science.gov (United States)

    Katzenberger, Rebeccah J; Chtarbanova, Stanislava; Rimkus, Stacey A; Fischer, Julie A; Kaur, Gulpreet; Seppala, Jocelyn M; Swanson, Laura C; Zajac, Jocelyn E; Ganetzky, Barry; Wassarman, David A

    2015-01-01

    Traumatic brain injury (TBI) is a major cause of death and disability worldwide. Unfavorable TBI outcomes result from primary mechanical injuries to the brain and ensuing secondary non-mechanical injuries that are not limited to the brain. Our genome-wide association study of Drosophila melanogaster revealed that the probability of death following TBI is associated with single nucleotide polymorphisms in genes involved in tissue barrier function and glucose homeostasis. We found that TBI causes intestinal and blood–brain barrier dysfunction and that intestinal barrier dysfunction is highly correlated with the probability of death. Furthermore, we found that ingestion of glucose after a primary injury increases the probability of death through a secondary injury mechanism that exacerbates intestinal barrier dysfunction. Our results indicate that natural variation in the probability of death following TBI is due in part to genetic differences that affect intestinal barrier dysfunction. DOI: http://dx.doi.org/10.7554/eLife.04790.001 PMID:25742603

  12. The intestinal complement system in inflammatory bowel disease: Shaping intestinal barrier function.

    Science.gov (United States)

    Sina, Christian; Kemper, Claudia; Derer, Stefanie

    2018-06-01

    The complement system is part of innate sensor and effector systems such as the Toll-like receptors (TLRs). It recognizes and quickly systemically and/or locally respond to microbial-associated molecular patterns (MAMPs) with a tailored defense reaction. MAMP recognition by intestinal epithelial cells (IECs) and appropriate immune responses are of major importance for the maintenance of intestinal barrier function. Enterocytes highly express various complement components that are suggested to be pivotal for proper IEC function. Appropriate activation of the intestinal complement system seems to play an important role in the resolution of chronic intestinal inflammation, while over-activation and/or dysregulation may worsen intestinal inflammation. Mice deficient for single complement components suffer from enhanced intestinal inflammation mimicking the phenotype of patients with chronic inflammatory bowel disease (IBD) such as Crohn's disease (CD) or ulcerative colitis (UC). However, the mechanisms leading to complement expression in IECs seem to differ markedly between UC and CD patients. Hence, how IECs, intestinal bacteria and epithelial cell expressed complement components interact in the course of IBD still remains to be mostly elucidated to define potential unique patterns contributing to the distinct subtypes of intestinal inflammation observed in CD and UC. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Intestinal barrier: A gentlemen's agreement between microbiota and immunity.

    Science.gov (United States)

    Caricilli, Andrea Moro; Castoldi, Angela; Câmara, Niels Olsen Saraiva

    2014-02-15

    Our body is colonized by more than a hundred trillion commensals, represented by viruses, bacteria and fungi. This complex interaction has shown that the microbiome system contributes to the host's adaptation to its environment, providing genes and functionality that give flexibility of diet and modulate the immune system in order not to reject these symbionts. In the intestine, specifically, the microbiota helps developing organ structures, participates of the metabolism of nutrients and induces immunity. Certain components of the microbiota have been shown to trigger inflammatory responses, whereas others, anti-inflammatory responses. The diversity and the composition of the microbiota, thus, play a key role in the maintenance of intestinal homeostasis and explain partially the link between intestinal microbiota changes and gut-related disorders in humans. Tight junction proteins are key molecules for determination of the paracellular permeability. In the context of intestinal inflammatory diseases, the intestinal barrier is compromised, and decreased expression and differential distribution of tight junction proteins is observed. It is still unclear what is the nature of the luminal or mucosal factors that affect the tight junction proteins function, but the modulation of the immune cells found in the intestinal lamina propria is hypothesized as having a role in this modulation. In this review, we provide an overview of the current understanding of the interaction of the gut microbiota with the immune system in the development and maintenance of the intestinal barrier.

  14. Protective Effects of Bifidobacterium on Intestinal Barrier Function in LPS-Induced Enterocyte Barrier Injury of Caco-2 Monolayers and in a Rat NEC Model.

    Science.gov (United States)

    Ling, Xiang; Linglong, Peng; Weixia, Du; Hong, Wei

    2016-01-01

    Zonulin protein is a newly discovered modulator which modulates the permeability of the intestinal epithelial barrier by disassembling intercellular tight junctions (TJ). Disruption of TJ is associated with neonatal necrotizing enterocolitis (NEC). It has been shown bifidobacterium could protect the intestinal barrier function and prophylactical administration of bifidobacterium has beneficial effects in NEC patients and animals. However, it is still unknown whether the zonulin is involved in the gut barrier dysfunction of NEC, and the protective mechanisms of bifidobacterium on intestinal barrier function are also not well understood. The present study aims to investigate the effects of bifidobacterium on intestinal barrier function, zonulin regulation, and TJ integrity both in LPS-induced enterocyte barrier injury of Caco-2 monolayers and in a rat NEC model. Our results showed bifidobacterium markedly attenuated the decrease in transepithelial electrical resistance and the increase in paracellular permeability in the Caco-2 monolayers treated with LPS (P zonulin release (P zonulin (P zonulin protein release and improvement of intestinal TJ integrity.

  15. Autophagy and tight junction proteins in the intestine and intestinal diseases

    Directory of Open Access Journals (Sweden)

    Chien-An A. Hu

    2015-09-01

    Full Text Available The intestinal epithelium (IE forms an indispensible barrier and interface between the intestinal interstitium and the luminal environment. The IE regulates water, ion and nutrient transport while providing a barrier against toxins, pathogens (bacteria, fungi and virus and antigens. The apical intercellular tight junctions (TJ are responsible for the paracellular barrier function and regulate trans-epithelial flux of ions and solutes between adjacent cells. Increased intestinal permeability caused by defects in the IE TJ barrier is considered an important pathogenic factor for the development of intestinal inflammation, diarrhea and malnutrition in humans and animals. In fact, defects in the IE TJ barrier allow increased antigenic penetration, resulting in an amplified inflammatory response in inflammatory bowel disease (IBD, necrotizing enterocolitis and ischemia-reperfusion injury. Conversely, the beneficial enhancement of the intestinal TJ barrier has been shown to resolve intestinal inflammation and apoptosis in both animal models of IBD and human IBD. Autophagy (self-eating mechanism is an intracellular lysosome-dependent degradation and recycling pathway essential for cell survival and homeostasis. Dysregulated autophagy has been shown to be directly associated with many pathological processes, including IBD. Importantly, the crosstalk between IE TJ and autophagy has been revealed recently. We showed that autophagy enhanced IE TJ barrier function by increasing transepithelial resistance and reducing the paracellular permeability of small solutes and ions, which is, in part, by targeting claudin-2, a cation-selective, pore-forming, transmembrane TJ protein, for lysosome (autophagy-mediated degradation. Interestingly, previous studies have shown that the inflamed intestinal mucosa in patients with active IBD has increased claudin-2 expression. In addition, inflammatory cytokines (for example, tumor necrosis factor-α, interleukin-6

  16. The food contaminant deoxynivalenol, decreases intestinal barrier permeability and reduces claudin expression

    International Nuclear Information System (INIS)

    Pinton, Philippe; Nougayrede, Jean-Philippe; Del Rio, Juan-Carlos; Moreno, Carolina; Marin, Daniela E.; Ferrier, Laurent; Bracarense, Ana-Paula; Kolf-Clauw, Martine; Oswald, Isabelle P.

    2009-01-01

    'The gastrointestinal tract represents the first barrier against food contaminants as well as the first target for these toxicants. Deoxynivalenol (DON) is a mycotoxin that commonly contaminates cereals and causes various toxicological effects. Through consumption of contaminated cereals and cereal products, human and pigs are exposed to this mycotoxin. Using in vitro, ex vivo and in vivo approaches, we investigated the effects of DON on the intestinal epithelium. We demonstrated that, in intestinal epithelial cell lines from porcine (IPEC-1) or human (Caco-2) origin, DON decreases trans-epithelial electrical resistance (TEER) and increases in a time and dose-dependent manner the paracellular permeability to 4 kDa dextran and to pathogenic Escherichia coli across intestinal cell monolayers. In pig explants treated with DON, we also observed an increased permeability of intestinal tissue. These alterations of barrier function were associated with a specific reduction in the expression of claudins, which was also seen in vivo in the jejunum of piglets exposed to DON-contaminated feed. In conclusion, DON alters claudin expression and decreases the barrier function of the intestinal epithelium. Considering that high levels of DON may be present in food or feed, consumption of DON-contaminated food/feed may induce intestinal damage and has consequences for human and animal health.

  17. Modulation of inflammatory mediators by Opuntia ficus-indica and Prunus avium bioproducts using an in vitro cell-based model of intestinal inflammation

    OpenAIRE

    Nunes, Sara Alexandra Luis

    2011-01-01

    Dissertation to obtain a Master Degree in Biotechnology Inflammatory Bowel Diseases, namely Ulcerative colitis and Crohn’s disease, are chronic intestinal inflammatory disorders characterized by an excessive release of pro-inflammatory mediators, intestinal barrier dysfunction and altered permeability and excessive activation of NF-κB cascade that can lead to development of colon cancer. IBD conventional therapy involves multiple medications and long-term up to life-long treatments. Furthe...

  18. The effect of fucoidan on intestinal flora and intestinal barrier function in rats with breast cancer.

    Science.gov (United States)

    Xue, Meilan; Ji, Xinqiang; Liang, Hui; Liu, Ying; Wang, Bing; Sun, Lingling; Li, Weiwei

    2018-02-21

    Recent research studies have shown that the intestinal flora are related to the occurrence and progress of breast cancer. This study investigates the effect of fucoidan on intestinal flora and intestinal barrier function in rats with 7,12-dimethylbenz[a]anthracene (DMBA)-induced breast cancers. Sixty female Sprague-Dawley rats were randomly assigned to the control group, the model group, and the F1 and F2 groups, which were fed fucoidan at concentrations of 200 and 400 mg per kg bw (body weight), respectively. Intestinal histopathological analysis was performed and 16S rDNA high-throughput sequencing was used to provide an overview of the intestinal flora composition. The contents of d-lactic acid (d-LA), diamine oxidase (DAO) and endotoxin in plasma were detected by ELISA. Expression levels of the tight junction (TJ) proteins, phosphorylated p38 MAPK and ERK1/2 were measured using western blotting. Our results suggested that the intestinal wall of the model group was damaged. However, after fucoidan intervention, the villi were gradually restored. ELISA showed that the levels of plasma endotoxin, d-LA and DAO decreased in the F1 and F2 groups compared to those in the model group. Fucoidan treatment also increased the expressions of ZO-1, occludin, claudin-1 and claudin-8. Furthermore, the expression levels of phosphorylated p38 MAPK and ERK1/2 were upregulated in fucoidan treatment groups. The results of 16S rDNA high-throughput sequencing indicated that fucoidan increased the diversity of the intestinal microbiota and induced changes in microbial composition, with the increased Bacteroidetes/Firmicutes phylum ratio. In conclusion, the supplement of fucoidan could improve the fecal microbiota composition and repair the intestinal barrier function. The study suggested the use of fucoidan as an intestinal flora modulator for potential prevention of breast cancer.

  19. Soya-saponins induce intestinal inflammation and barrier dysfunction in juvenile turbot (Scophthalmus maximus).

    Science.gov (United States)

    Gu, Min; Jia, Qian; Zhang, Zhiyu; Bai, Nan; Xu, Xiaojie; Xu, Bingying

    2018-06-01

    Soybean meal-induced enteritis (SBMIE) is a well-described condition in the distal intestine (DI) of several cultured fish species, but the exact cause is still unclear. The work on Atlantic salmon and zebrafish suggested soya-saponins, as heat-stable anti-nutritional factors in soybean meal, are the major causal agents. However, this conclusion was not supported by the research on some other fish, such as gilthead sea bream and European sea bass. Our previous work proved that soybean could induce SBMIE on turbot and the present work aimed to investigate whether soya-saponins alone could cause SBMIE and the effects of soya-saponins on the intestinal barrier function in juvenile turbot. Turbots with initial weight 11.4 ± 0.02 g were fed one of four fishmeal-based diets containing graded levels of soya-saponins (0, 2.5, 7.5, 15 g kg -1 ) for 8 weeks. At the end of the trial, all fish were weighed and plasma was obtained for diamine oxidase (DAO) activity and d-lactate level analysis and DI was sampled for histological evaluation and quantification of antioxidant parameters and inflammatory marker genes. The activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and intestinal glutathione level were selected to evaluated intestinal antioxidant system. The distal intestinal epithelial cell (IEC) proliferation and apoptosis were investigated by proliferating cell nuclear antigen (PCNA) labelling and TdT-mediated dUTP nick end labeling (TUNEL), respectively. The results showed that soya-saponins caused significantly dose-dependent decrease in the growth performance and nutrient utilization (p soya-saponins. Significantly dose-dependent increases in severity of the inflammation concomitant with up-regulated expression of il-1β, il-8, and tnf-α, increased IEC proliferation and apoptosis, and decreases in selected antioxidant parameters were detected (p soya-saponins (p soya-saponins induced enteritis and compromised

  20. Arctigenin from Fructus Arctii (Seed of Burdock) Reinforces Intestinal Barrier Function in Caco-2 Cell Monolayers

    Science.gov (United States)

    Shin, Hee Soon; Jung, Sun Young; Back, Su Yeon; Do, Jeong-Ryong; Shon, Dong-Hwa

    2015-01-01

    Fructus Arctii is used as a traditional herbal medicine to treat inflammatory diseases in oriental countries. This study aimed to investigate effect of F. Arctii extract on intestinal barrier function in human intestinal epithelial Caco-2 cells and to reveal the active component of F. Arctii. We measured transepithelial electrical resistance (TEER) value (as an index of barrier function) and ovalbumin (OVA) permeation (as an index of permeability) to observe the changes of intestinal barrier function. The treatment of F. Arctii increased TEER value and decreased OVA influx on Caco-2 cell monolayers. Furthermore, we found that arctigenin as an active component of F. Arctii increased TEER value and reduced permeability of OVA from apical to the basolateral side but not arctiin. In the present study, we revealed that F. Arctii could enhance intestinal barrier function, and its active component was an arctigenin on the functionality. We expect that the arctigenin from F. Arctii could contribute to prevention of inflammatory, allergic, and infectious diseases by reinforcing intestinal barrier function. PMID:26550018

  1. Arctigenin from Fructus Arctii (Seed of Burdock Reinforces Intestinal Barrier Function in Caco-2 Cell Monolayers

    Directory of Open Access Journals (Sweden)

    Hee Soon Shin

    2015-01-01

    Full Text Available Fructus Arctii is used as a traditional herbal medicine to treat inflammatory diseases in oriental countries. This study aimed to investigate effect of F. Arctii extract on intestinal barrier function in human intestinal epithelial Caco-2 cells and to reveal the active component of F. Arctii. We measured transepithelial electrical resistance (TEER value (as an index of barrier function and ovalbumin (OVA permeation (as an index of permeability to observe the changes of intestinal barrier function. The treatment of F. Arctii increased TEER value and decreased OVA influx on Caco-2 cell monolayers. Furthermore, we found that arctigenin as an active component of F. Arctii increased TEER value and reduced permeability of OVA from apical to the basolateral side but not arctiin. In the present study, we revealed that F. Arctii could enhance intestinal barrier function, and its active component was an arctigenin on the functionality. We expect that the arctigenin from F. Arctii could contribute to prevention of inflammatory, allergic, and infectious diseases by reinforcing intestinal barrier function.

  2. Intestinal barrier dysfunction develops at the onset of experimental autoimmune encephalomyelitis, and can be induced by adoptive transfer of auto-reactive T cells.

    Directory of Open Access Journals (Sweden)

    Mehrnaz Nouri

    Full Text Available Multiple sclerosis (MS is a chronic inflammatory demyelinating disease of the central nervous system with a pathogenesis involving a dysfunctional blood-brain barrier and myelin-specific, autoreactive T cells. Although the commensal microbiota seems to affect its pathogenesis, regulation of the interactions between luminal antigens and mucosal immune elements remains unclear. Herein, we investigated whether the intestinal mucosal barrier is also targeted in this disease. Experimental autoimmune encephalomyelitis (EAE, the prototypic animal model of MS, was induced either by active immunization or by adoptive transfer of autoreactive T cells isolated from these mice. We show increased intestinal permeability, overexpression of the tight junction protein zonulin and alterations in intestinal morphology (increased crypt depth and thickness of the submucosa and muscularis layers. These intestinal manifestations were seen at 7 days (i.e., preceding the onset of neurological symptoms and at 14 days (i.e., at the stage of paralysis after immunization. We also demonstrate an increased infiltration of proinflammatory Th1/Th17 cells and a reduced regulatory T cell number in the gut lamina propria, Peyer's patches and mesenteric lymph nodes. Adoptive transfer to healthy mice of encephalitogenic T cells, isolated from EAE-diseased animals, led to intestinal changes similar to those resulting from the immunization procedure. Our findings show that disruption of intestinal homeostasis is an early and immune-mediated event in EAE. We propose that this intestinal dysfunction may act to support disease progression, and thus represent a potential therapeutic target in MS. In particular, an increased understanding of the regulation of tight junctions at the blood-brain barrier and in the intestinal wall may be crucial for design of future innovative therapies.

  3. Intestinal Barrier Dysfunction Develops at the Onset of Experimental Autoimmune Encephalomyelitis, and Can Be Induced by Adoptive Transfer of Auto-Reactive T Cells

    Science.gov (United States)

    Nouri, Mehrnaz; Bredberg, Anders; Weström, Björn; Lavasani, Shahram

    2014-01-01

    Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system with a pathogenesis involving a dysfunctional blood-brain barrier and myelin-specific, autoreactive T cells. Although the commensal microbiota seems to affect its pathogenesis, regulation of the interactions between luminal antigens and mucosal immune elements remains unclear. Herein, we investigated whether the intestinal mucosal barrier is also targeted in this disease. Experimental autoimmune encephalomyelitis (EAE), the prototypic animal model of MS, was induced either by active immunization or by adoptive transfer of autoreactive T cells isolated from these mice. We show increased intestinal permeability, overexpression of the tight junction protein zonulin and alterations in intestinal morphology (increased crypt depth and thickness of the submucosa and muscularis layers). These intestinal manifestations were seen at 7 days (i.e., preceding the onset of neurological symptoms) and at 14 days (i.e., at the stage of paralysis) after immunization. We also demonstrate an increased infiltration of proinflammatory Th1/Th17 cells and a reduced regulatory T cell number in the gut lamina propria, Peyer's patches and mesenteric lymph nodes. Adoptive transfer to healthy mice of encephalitogenic T cells, isolated from EAE-diseased animals, led to intestinal changes similar to those resulting from the immunization procedure. Our findings show that disruption of intestinal homeostasis is an early and immune-mediated event in EAE. We propose that this intestinal dysfunction may act to support disease progression, and thus represent a potential therapeutic target in MS. In particular, an increased understanding of the regulation of tight junctions at the blood-brain barrier and in the intestinal wall may be crucial for design of future innovative therapies. PMID:25184418

  4. Low uptake of silica nanoparticles in Caco-2 intestinal epithelial barriers

    NARCIS (Netherlands)

    Ye, Dong; Bramini, Mattia; Hristov, Delyan R.; Wan, Sha; Salvati, Anna; Åberg, Christoffer; Dawson, Kenneth A.

    2017-01-01

    Cellular barriers, such as the skin, the lung epithelium or the intestinal epithelium, constitute one of the first obstacles facing nanomedicines or other nanoparticles entering organisms. It is thus important to assess the capacity of nanoparticles to enter and transport across such barriers. In

  5. The intestinal barrier in irritable bowel syndrome: subtype-specific effects of the systemic compartment in an in vitro model.

    Directory of Open Access Journals (Sweden)

    Samefko Ludidi

    Full Text Available Irritable bowel syndrome (IBS is a disorder with multifactorial pathophysiology. Intestinal barrier may be altered, especially in diarrhea-predominant IBS (IBS-D. Several mediators may contribute to increased intestinal permeability in IBS.We aimed to assess effects of tryptase and LPS on in vitro permeability using a 3-dimensional cell model after basolateral cell exposure. Furthermore, we assessed the extent to which these mediators in IBS plasma play a role in intestinal barrier function.Caco-2 cells were grown in extracellular matrix to develop into polarized spheroids and were exposed to tryptase (10 - 50 mU, LPS (1 - 50 ng/mL and two-fold diluted plasma samples of 7 patients with IBS-D, 7 with constipation-predominant IBS (IBS-C and 7 healthy controls (HC. Barrier function was assessed by the flux of FITC-dextran (FD4 using live cell imaging. Furthermore, plasma tryptase and LPS were determined.Tryptase (20 and 50 mU and LPS (6.25 - 50 ng/mL significantly increased Caco-2 permeability versus control (all P< 0.05. Plasma of IBS-D only showed significantly elevated median tryptase concentrations (7.1 [3.9 - 11.0] vs. 4.2 [2.2 - 7.0] vs. 4.2 [2.5 - 5.9] μg/mL; P<0.05 and LPS concentrations (3.65 [3.00 - 6.10] vs. 3.10 [2.60-3.80] vs. 2.65 [2.40 - 3.40] EU/ml; P< 0.05 vs. IBS-C and HC. Also, plasma of IBS-D increased Caco-2 permeability versus HC (0.14450 ± 0.00472 vs. 0.00021 ± 0.00003; P < 0.001, which was attenuated by selective inhibition of tryptase and LPS (P< 0.05.Basolateral exposure of spheroids to plasma of IBS-D patients resulted in a significantly increased FD4 permeation, which was partially abolished by selective inhibition of tryptase and LPS. These findings point to a role of systemic tryptase and LPS in the epithelial barrier alterations observed in patients with IBS-D.

  6. Intestinal barrier integrity and inflammatory bowel disease

    DEFF Research Database (Denmark)

    Holmberg, Fredrik Eric Olof; Pedersen, Jannie; Jørgensen, Peter

    2018-01-01

    Disruption of normal barrier function is a fundamental factor in the pathogenesis of inflammatory bowel disease, which includes increased epithelial cell death, modified mucus configuration, altered expression and distribution of tight junction-proteins, along with a decreased expression of antim......Disruption of normal barrier function is a fundamental factor in the pathogenesis of inflammatory bowel disease, which includes increased epithelial cell death, modified mucus configuration, altered expression and distribution of tight junction-proteins, along with a decreased expression...... of antimicrobial peptides. Inflammatory bowel disease is associated with life-long morbidity for affected patients, and both the incidence and prevalence is increasing globally, resulting in substantial economic strain for society. Mucosal healing and re-establishment of barrier integrity is associated......, novel treatment strategies to accomplish mucosal healing and to re-establish normal barrier integrity in inflammatory bowel disease are warranted, and luminal stem cell-based approaches might have an intriguing potential. Transplantation of in vitro expanded intestinal epithelial stem cells derived...

  7. Protective Effects of Bifidobacterium on Intestinal Barrier Function in LPS-Induced Enterocyte Barrier Injury of Caco-2 Monolayers and in a Rat NEC Model.

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    Xiang Ling

    Full Text Available Zonulin protein is a newly discovered modulator which modulates the permeability of the intestinal epithelial barrier by disassembling intercellular tight junctions (TJ. Disruption of TJ is associated with neonatal necrotizing enterocolitis (NEC. It has been shown bifidobacterium could protect the intestinal barrier function and prophylactical administration of bifidobacterium has beneficial effects in NEC patients and animals. However, it is still unknown whether the zonulin is involved in the gut barrier dysfunction of NEC, and the protective mechanisms of bifidobacterium on intestinal barrier function are also not well understood. The present study aims to investigate the effects of bifidobacterium on intestinal barrier function, zonulin regulation, and TJ integrity both in LPS-induced enterocyte barrier injury of Caco-2 monolayers and in a rat NEC model. Our results showed bifidobacterium markedly attenuated the decrease in transepithelial electrical resistance and the increase in paracellular permeability in the Caco-2 monolayers treated with LPS (P < 0.01. Compared with the LPS group, bifidobacterium significantly decreased the production of IL-6 and TNF-α (P < 0.01 and suppressed zonulin release (P < 0.05. In addition, bifidobacterium pretreatment up-regulated occludin, claudin-3 and ZO-1 expression (P < 0.01 and also preserved these proteins localization at TJ compared with the LPS group. In the in vivo study, bifidobacterium decreased the incidence of NEC from 88 to 47% (P < 0.05 and reduced the severity in the NEC model. Increased levels of IL-6 and TNF-α in the ileum of NEC rats were normalized in bifidobacterium treated rats (P < 0.05. Moreover, administration of bifidobacterium attenuated the increase in intestinal permeability (P < 0.01, decreased the levels of serum zonulin (P < 0.05, normalized the expression and localization of TJ proteins in the ileum compared with animals with NEC. We concluded that bifidobacterium may

  8. E. coli O124 K72 alters the intestinal barrier and the tight junctions proteins of guinea pig intestine.

    Science.gov (United States)

    Ren, Xiaomeng; Zhu, Yanyan; Gamallat, Yaser; Ma, Shenhao; Chiwala, Gift; Meyiah, Abdo; Xin, Yi

    2017-10-01

    Our research group previously isolated and identified a strain of pathogenic Escherichia coli from clinical samples called E. coli O124 K72. The present study was aimed at determining the potential effects of E. coli O124 K72 on intestinal barrier functions and structural proteins integrity in guinea pig. Guinea pigs were grouped into three groups; control (CG); E. coli O124 K72 (E. coli); and probiotics Lactobacillus rhamnosus (LGG). Initially, we create intestinal dysbiosis by giving all animals Levofloxacin for 10days, but the control group (CG) received the same volume of saline. Then, the animals received either E. coli O124 K72 (E. coli) or Lactobacillus rhamnosus (LGG) according to their assigned group. E. coli O124 K72 treatment significantly affected colon morphology and distorted intestinal barrier function by up-regulating Claudin2 and down-regulating Occludin. In addition, E. coli upregulated the mRNA expression of MUC1, MUC2, MUC13 and MUC15. Furthermore, suspected tumor was found in the E. coli treated animals. Our results suggested that E. coli O124 K72 strain has adverse effects on intestinal barrier functions and is capable of altering integrity of structural proteins in guinea pig model while at same time it may have a role in colon carcinogenesis. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  9. Escherichia coli challenge and one type of smectite alter intestinal barrier of pigs.

    Science.gov (United States)

    Almeida, Juliana Abranches Soares; Liu, Yanhong; Song, Minho; Lee, Jeong Jae; Gaskins, H Rex; Maddox, Carol Wolfgang; Osuna, Orlando; Pettigrew, James Eugene

    2013-12-20

    An experiment was conducted to determine how an E. coli challenge and dietary clays affect the intestinal barrier of pigs. Two groups of 32 pigs (initial BW: 6.9 ± 1.0 kg) were distributed in a 2 × 4 factorial arrangement of a randomized complete block design (2 challenge treatments: sham or E. coli, and 4 dietary treatments: control, 0.3% smectite A, 0.3% smectite B and 0.3% zeolite), with 8 replicates total. Diarrhea score, growth performance, goblet cell size and number, bacterial translocation from intestinal lumen to lymph nodes, intestinal morphology, and relative amounts of sulfo and sialo mucins were measured. The E. coli challenge reduced performance, increased goblet cell size and number in the ileum, increased bacterial translocation from the intestinal lumen to the lymph nodes, and increased ileal crypt depth. One of the clays (smectite A) tended to increase goblet cell size in ileum, which may indicate enhanced protection. In conclusion, E. coli infection degrades intestinal barrier integrity but smectite A may enhance it.

  10. Severe Burn-Induced Intestinal Epithelial Barrier Dysfunction Is Associated With Endoplasmic Reticulum Stress and Autophagy in Mice

    Science.gov (United States)

    Huang, Yalan; Feng, Yanhai; Wang, Yu; Wang, Pei; Wang, Fengjun; Ren, Hui

    2018-01-01

    The disruption of intestinal barrier plays a vital role in the pathophysiological changes after severe burn injury, however, the underlying mechanisms are poorly understood. Severe burn causes the disruption of intestinal tight junction (TJ) barrier. Previous studies have shown that endoplasmic reticulum (ER) stress and autophagy are closely associated with the impairment of intestinal mucosa. Thus, we hypothesize that ER stress and autophagy are likely involved in burn injury-induced intestinal epithelial barrier dysfunction. Mice received a 30% total body surface area (TBSA) full-thickness burn, and were sacrificed at 0, 1, 2, 6, 12 and 24 h postburn. The results showed that intestinal permeability was increased significantly after burn injury, accompanied by the damage of mucosa and the alteration of TJ proteins. Severe burn induced ER stress, as indicated by increased intraluminal chaperone binding protein (BIP), CCAAT/enhancer-binding protein homologous protein (CHOP) and inositol-requiring enzyme 1(IRE1)/X-box binding protein 1 splicing (XBP1). Autophagy was activated after burn injury, as evidenced by the increase of autophagy related protein 5 (ATG5), Beclin 1 and LC3II/LC3I ratio and the decrease of p62. Besides, the number of autophagosomes was also increased after burn injury. The levels of p-PI3K(Ser191), p-PI3K(Ser262), p-AKT(Ser473), and p-mTOR were decreased postburn, suggesting that autophagy-related PI3K/AKT/mTOR pathway is involved in the intestinal epithelial barrier dysfunction following severe burn. In summary, severe burn injury induces the ER stress and autophagy in intestinal epithelia, leading to the disruption of intestinal barrier. PMID:29740349

  11. Defects in small intestinal epithelial barrier function and morphology associated with peri-weaning failure to thrive syndrome (PFTS) in swine.

    Science.gov (United States)

    Moeser, Adam J; Borst, Luke B; Overman, Beth L; Pittman, Jeremy S

    2012-10-01

    The objective of this study was to investigate intestinal function and morphology associated with peri-weaning failure to thrive syndrome (PFTS) in swine. Jejunum and distal ileum from control and pigs exhibiting PFTS was harvested at weaning, 4 and 11 days post-weaning (PW) for intestinal barrier function studies and histological analyses (n=6 pigs per group). Marked disturbances in intestinal barrier function was observed in PFTS pigs, compared with controls, indicated by lower (p<0.05) TER and increased (p<0.01) permeability to FITC dextran (4 kDa). Intestines from weaned pigs, subjected to a 4-day fast, exhibited minor disturbances in intestinal barrier function. Villus atrophy and crypt hyperplasia were observed in the PFTS intestine compared with control and fasted pigs. These data demonstrate that PFTS is associated with profound disturbances in intestinal epithelial barrier function and alterations in mucosal and epithelial morphology in which anorexia is not the sole factor. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Mucosal pathobiology and molecular signature of epithelial barrier dysfunction in the small intestine in irritable bowel syndrome.

    Science.gov (United States)

    González-Castro, Ana M; Martínez, Cristina; Salvo-Romero, Eloísa; Fortea, Marina; Pardo-Camacho, Cristina; Pérez-Berezo, Teresa; Alonso-Cotoner, Carmen; Santos, Javier; Vicario, María

    2017-01-01

    Irritable bowel syndrome (IBS) is one of the most prevalent gastrointestinal disorders in developed countries. Its etiology remains unknown; however, a common finding, regardless of IBS subtype, is the presence of altered intestinal barrier. In fact, signaling and location of cell-to-cell adhesion proteins, in connection with increased immune activity, seem abnormal in the intestinal epithelium of IBS patients. Despite that most research is performed on distal segments of the intestine, altered permeability has been reported in both, the small and the large bowel of all IBS subtypes. The small intestine carries out digestion and nutrient absorption and is also the site where the majority of immune responses to luminal antigens takes place. In fact, the upper intestine is more exposed to environmental antigens than the colon and is also a site of symptom generation. Recent studies have revealed small intestinal structural alterations of the epithelial barrier and mucosal immune activation in association with intestinal dysfunction, suggesting the commitment of the intestine as a whole in the pathogenesis of IBS. This review summarizes the most recent findings on mucosal barrier alterations and its relationship to symptoms arising from the small intestine in IBS, including epithelial structural abnormalities, mucosal immune activation, and microbial dysbiosis, further supporting the hypothesis of an organic origin of IBS. © 2016 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  13. Lychee (Litchi chinensis Sonn.) Pulp Phenolic Extract Provides Protection against Alcoholic Liver Injury in Mice by Alleviating Intestinal Microbiota Dysbiosis, Intestinal Barrier Dysfunction, and Liver Inflammation.

    Science.gov (United States)

    Xiao, Juan; Zhang, Ruifen; Zhou, Qiuyun; Liu, Lei; Huang, Fei; Deng, Yuanyuan; Ma, Yongxuan; Wei, Zhencheng; Tang, Xiaojun; Zhang, Mingwei

    2017-11-08

    Liver injury is the most common consequence of alcohol abuse, which is promoted by the inflammatory response triggered by gut-derived endotoxins produced as a consequence of intestinal microbiota dysbiosis and barrier dysfunction. The aim of this study was to investigate whether modulation of intestinal microbiota and barrier function, and liver inflammation contributes to the hepatoprotective effect of lychee pulp phenolic extract (LPPE) in alcohol-fed mice. Mice were treated with an ethanol-containing liquid diet alone or in combination with LPPE for 8 weeks. LPPE supplementation alleviated ethanol-induced liver injury and downregulated key markers of inflammation. Moreover, LPPE supplementation reversed the ethanol-induced alteration of intestinal microbiota composition and increased the expression of intestinal tight junction proteins, mucus protecting proteins, and antimicrobial proteins. Furthermore, in addition to decreasing serum endotoxin level, LPPE supplementation suppressed CD14 and toll-like receptor 4 expression, and repressed the activation of nuclear factor-κB p65 in the liver. These data suggest that intestinal microbiota dysbiosis, intestinal barrier dysfunction, and liver inflammation are improved by LPPE, and therefore, the intake of LPPE or Litchi pulp may be an effective strategy to alleviate the susceptibility to alcohol-induced hepatic diseases.

  14. Mediated Intercultural Communication Barrier in No Drama Zone! Group

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    Lizal, Valentino

    2015-01-01

    This research study aimed to describe the mediated intercultural communication barriers in the No Drama Zone! group. This study is a qualitative descriptive type of research, with case study method. By doing in depth interview and observation, researcher found two barriers that generates other barriers in the group's mediated intercultural communication. The two big barriers were: language and physical barriers. Language barriers in this group generated two barriers, emotional barrier and pe...

  15. Crosstalk between Inflammation and ROCK/MLCK Signaling Pathways in Gastrointestinal Disorders with Intestinal Hyperpermeability

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    Lijun Du

    2016-01-01

    Full Text Available The barrier function of the intestine is essential for maintaining the normal homeostasis of the gut and mucosal immune system. Abnormalities in intestinal barrier function expressed by increased intestinal permeability have long been observed in various gastrointestinal disorders such as Crohn’s disease (CD, ulcerative colitis (UC, celiac disease, and irritable bowel syndrome (IBS. Imbalance of metabolizing junction proteins and mucosal inflammation contributes to intestinal hyperpermeability. Emerging studies exploring in vitro and in vivo model system demonstrate that Rho-associated coiled-coil containing protein kinase- (ROCK- and myosin light chain kinase- (MLCK- mediated pathways are involved in the regulation of intestinal permeability. With this perspective, we aim to summarize the current state of knowledge regarding the role of inflammation and ROCK-/MLCK-mediated pathways leading to intestinal hyperpermeability in gastrointestinal disorders. In the near future, it may be possible to specifically target these specific pathways to develop novel therapies for gastrointestinal disorders associated with increased gut permeability.

  16. Food Derived Bioactive Peptides and Intestinal Barrier Function

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    Olga Martínez-Augustin

    2014-12-01

    Full Text Available A wide range of food-derived bioactive peptides have been shown to exert health-promoting actions and are therefore considered functional foods or nutraceuticals. Some of these actions are related to the maintenance, reinforcement or repairment of the intestinal barrier function (IBF whose role is to selectively allow the absorption of water, nutrients and ions while preventing the influx of microorganisms from the intestinal lumen. Alterations in the IBF have been related to many disorders, such as inflammatory bowel disease or metabolic syndrome. Components of IBF are the intestinal epithelium, the mucus layer, secretory immunoglobulin A and cells of the innate and adaptive immune systems. Here we review the effects of food derived bioactive peptides on these IBF components. In vitro and in vivo effects, both in healthy and disease states, have been reviewed. Although limited, the available information indicates a potential for food-derived peptides to modify IBF and to contribute to disease treatment, but further research is needed to better isolate responsible peptides, and to help define their mode of action.

  17. Cytokine Tuning of Intestinal Epithelial Function

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    Caroline Andrews

    2018-06-01

    Full Text Available The intestine serves as both our largest single barrier to the external environment and the host of more immune cells than any other location in our bodies. Separating these potential combatants is a single layer of dynamic epithelium composed of heterogeneous epithelial subtypes, each uniquely adapted to carry out a subset of the intestine’s diverse functions. In addition to its obvious role in digestion, the intestinal epithelium is responsible for a wide array of critical tasks, including maintaining barrier integrity, preventing invasion by microbial commensals and pathogens, and modulating the intestinal immune system. Communication between these epithelial cells and resident immune cells is crucial for maintaining homeostasis and coordinating appropriate responses to disease and can occur through cell-to-cell contact or by the release or recognition of soluble mediators. The objective of this review is to highlight recent literature illuminating how cytokines and chemokines, both those made by and acting on the intestinal epithelium, orchestrate many of the diverse functions of the intestinal epithelium and its interactions with immune cells in health and disease. Areas of focus include cytokine control of intestinal epithelial proliferation, cell death, and barrier permeability. In addition, the modulation of epithelial-derived cytokines and chemokines by factors such as interactions with stromal and immune cells, pathogen and commensal exposure, and diet will be discussed.

  18. Claudin-3 expression in radiation-exposed rat models: A potential marker for radiation-induced intestinal barrier failure

    Energy Technology Data Exchange (ETDEWEB)

    Shim, Sehwan; Lee, Jong-geol; Bae, Chang-hwan; Lee, Seung Bum [National Radiation Emergency Medical Center, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Jang, Won-Suk; Lee, Sun-Joo [Laboratory of Experimental Pathology, Korea Cancer Center Hospital, Seoul (Korea, Republic of); Lee, Seung-Sook [National Radiation Emergency Medical Center, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Department of Pathology, Korea Cancer Center Hospital, Seoul (Korea, Republic of); Park, Sunhoo, E-mail: sunhoo@kcch.re.kr [National Radiation Emergency Medical Center, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Department of Pathology, Korea Cancer Center Hospital, Seoul (Korea, Republic of)

    2015-01-02

    Highlights: • Irradiation increased intestinal bacterial translocation, accompanied by claudin protein expression in rats. • Neurotensin decreased the bacterial translocation and restored claudin-3 expression. • Claudin-3 can be used as a marker in evaluating radiation induced intestinal injury. - Abstract: The molecular events leading to radiation-induced intestinal barrier failure are not well known. The influence of the expression of claudin proteins in the presence and absence of neurotensin was investigated in radiation-exposed rat intestinal epithelium. Wistar rats were randomly divided into control, irradiation, and irradiation + neurotensin groups, and bacterial translocation to the mesenteric lymph node and expression of claudins were determined. Irradiation led to intestinal barrier failure as demonstrated by significant bacterial translocation. In irradiated terminal ilea, expression of claudin-3 and claudin-4 was significantly decreased, and claudin-2 expression was increased. Administration of neurotensin significantly reduced bacterial translocation and restored the structure of the villi as seen by histologic examination. Among the three subtype of claudins, only claudin-3 expression was restored. These results suggest that the therapeutic effect of neurotensin on the disruption of the intestinal barrier is associated with claudin-3 alteration and that claudin-3 could be used as a marker in evaluating radiation-induced intestinal injury.

  19. Glycoprotein A33 deficiency: a new mouse model of impaired intestinal epithelial barrier function and inflammatory disease

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    Benjamin B. Williams

    2015-08-01

    Full Text Available The cells of the intestinal epithelium provide a selectively permeable barrier between the external environment and internal tissues. The integrity of this barrier is maintained by tight junctions, specialised cell-cell contacts that permit the absorption of water and nutrients while excluding microbes, toxins and dietary antigens. Impairment of intestinal barrier function contributes to multiple gastrointestinal disorders, including food hypersensitivity, inflammatory bowel disease (IBD and colitis-associated cancer (CAC. Glycoprotein A33 (GPA33 is an intestinal epithelium-specific cell surface marker and member of the CTX group of transmembrane proteins. Roles in cell-cell adhesion have been demonstrated for multiple CTX family members, suggesting a similar function for GPA33 within the gastrointestinal tract. To test a potential requirement for GPA33 in intestinal barrier function, we generated Gpa33−/− mice and subjected them to experimental regimens designed to produce food hypersensitivity, colitis and CAC. Gpa33−/− mice exhibited impaired intestinal barrier function. This was shown by elevated steady-state immunosurveillance in the colonic mucosa and leakiness to oral TRITC-labelled dextran after short-term exposure to dextran sodium sulphate (DSS to injure the intestinal epithelium. Gpa33−/− mice also exhibited rapid onset and reduced resolution of DSS-induced colitis, and a striking increase in the number of colitis-associated tumours produced by treatment with the colon-specific mutagen azoxymethane (AOM followed by two cycles of DSS. In contrast, Gpa33−/− mice treated with AOM alone showed no increase in sporadic tumour formation, indicating that their increased tumour susceptibility is dependent on inflammatory stimuli. Finally, Gpa33−/− mice displayed hypersensitivity to food allergens, a common co-morbidity in humans with IBD. We propose that Gpa33−/− mice provide a valuable model to study the mechanisms

  20. Breaking down the barriers: the gut microbiome, intestinal permeability and stress-related psychiatric disorders

    Science.gov (United States)

    Kelly, John R.; Kennedy, Paul J.; Cryan, John F.; Dinan, Timothy G.; Clarke, Gerard; Hyland, Niall P.

    2015-01-01

    The emerging links between our gut microbiome and the central nervous system (CNS) are regarded as a paradigm shift in neuroscience with possible implications for not only understanding the pathophysiology of stress-related psychiatric disorders, but also their treatment. Thus the gut microbiome and its influence on host barrier function is positioned to be a critical node within the brain-gut axis. Mounting preclinical evidence broadly suggests that the gut microbiota can modulate brain development, function and behavior by immune, endocrine and neural pathways of the brain-gut-microbiota axis. Detailed mechanistic insights explaining these specific interactions are currently underdeveloped. However, the concept that a “leaky gut” may facilitate communication between the microbiota and these key signaling pathways has gained traction. Deficits in intestinal permeability may underpin the chronic low-grade inflammation observed in disorders such as depression and the gut microbiome plays a critical role in regulating intestinal permeability. In this review we will discuss the possible role played by the gut microbiota in maintaining intestinal barrier function and the CNS consequences when it becomes disrupted. We will draw on both clinical and preclinical evidence to support this concept as well as the key features of the gut microbiota which are necessary for normal intestinal barrier function. PMID:26528128

  1. Lactobacillus protects the integrity of intestinal epithelial barrier damaged by pathogenic bacteria

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    Qinghua eYu

    2015-03-01

    Full Text Available Pathogens invade intestinal mucosal barrier through phagocytosis of antigen presenting cells (dendritic cell, microfold cells, or through the invasion into the intestinal epithelial directly. Some pathogens could damage the cell junction between epithelial cells and use the paracellular pathway as an entrance to invade. Moreover, some Lactobacillus could inhibit the adhesion of the pathogens and protect the integrity of the cell junction and mucosal barrier. This research focused on the potential therapeutic effect of Lactobacillus fructosus (L. fructosus C2 to attenuate ETEC K88 or S. typhimurium SL1344 induced changes to mucosal barrier. The results demonstrated that treatment of polarized Caco-2 cells with L. fructosus C2 reduced the permeation of dextran, and expression of IL-8, p-ERK and p-JNK when cells were infected with pathogenic bacteria. The findings indicated that L. fructosus C2 exerted a protective effect against the damage to the integrity of Caco-2 cells by ETEC or S. typhimurium infection.

  2. Effects of synbiotics on intestinal mucosal barrier in rat model

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    Zhigang Xue

    2017-06-01

    Conclusions: Probiotics can improve the concentration of colonic probiotics, while synbiotics can improve probiotics concentration and mucosa thickness in colon, decrease L/M ratio and bacterial translocation. Synbiotics shows more protective effects on intestinal mucosal barrier in rats after cecectomy and gastrostomy and the intervention of specific antibiotics.

  3. Anthrax lethal toxin disrupts intestinal barrier function and causes systemic infections with enteric bacteria.

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    Chen Sun

    Full Text Available A variety of intestinal pathogens have virulence factors that target mitogen activated protein kinase (MAPK signaling pathways, including Bacillus anthracis. Anthrax lethal toxin (LT has specific proteolytic activity against the upstream regulators of MAPKs, the MAPK kinases (MKKs. Using a murine model of intoxication, we show that LT causes the dose-dependent disruption of intestinal epithelial integrity, characterized by mucosal erosion, ulceration, and bleeding. This pathology correlates with an LT-dependent blockade of intestinal crypt cell proliferation, accompanied by marked apoptosis in the villus tips. C57BL/6J mice treated with intravenous LT nearly uniformly develop systemic infections with commensal enteric organisms within 72 hours of administration. LT-dependent intestinal pathology depends upon its proteolytic activity and is partially attenuated by co-administration of broad spectrum antibiotics, indicating that it is both a cause and an effect of infection. These findings indicate that targeting of MAPK signaling pathways by anthrax LT compromises the structural integrity of the mucosal layer, serving to undermine the effectiveness of the intestinal barrier. Combined with the well-described immunosuppressive effects of LT, this disruption of the intestinal barrier provides a potential mechanism for host invasion via the enteric route, a common portal of entry during the natural infection cycle of Bacillus anthracis.

  4. Probiotic-derived polyphosphate enhances the epithelial barrier function and maintains intestinal homeostasis through integrin-p38 MAPK pathway.

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    Shuichi Segawa

    Full Text Available Probiotics exhibit beneficial effects on human health, particularly in the maintenance of intestinal homeostasis in a complex manner notwithstanding the diversity of an intestinal flora between individuals. Thus, it is highly probable that some common molecules secreted by probiotic and/or commensal bacteria contribute to the maintenance of intestinal homeostasis and protect the intestinal epithelium from injurious stimuli. To address this question, we aimed to isolate the cytoprotective compound from a lactobacillus strain, Lactobacillus brevis SBC8803 which possess the ability to induce cytoprotective heat shock proteins in mouse small intestine. L. brevis was incubated in MRS broth and the supernatant was passed through with a 0.2-µm filter. Caco2/bbe cells were treated with the culture supernatant, and HSP27 expression was evaluated by Western blotting. HSP27-inducible components were separated by ammonium sulfate precipitation, DEAE anion exchange chromatography, gel filtration, and HPLC. Finally, we identified that the HSP27-inducible fraction was polyphosphate (poly P, a simple repeated structure of phosphates, which is a common product of lactobacilli and other bacteria associated with intestinal microflora without any definitive physiological functions. Then, poly P was synthesized by poly P-synthesizing enzyme polyphosphate kinase. The synthesized poly P significantly induced HSP27 from Caco2/BBE cells. In addition, Poly P suppressed the oxidant-induced intestinal permeability in the mouse small intestine and pharmacological inhibitors of p38 MAPK and integrins counteract its protective effect. Daily intrarectal administration of poly P (10 µg improved the inflammation grade and survival rate in 4% sodium dextran sulfate-administered mice. This study, for the first time, demonstrated that poly P is the molecule responsible for maintaining intestinal barrier actions which are mediated through the intestinal integrin β1-p38 MAPK.

  5. Diffused and sustained inhibitory effects of intestinal electrical stimulation on intestinal motility mediated via sympathetic pathway.

    Science.gov (United States)

    Zhao, Xiaotuan; Yin, Jieyun; Wang, Lijie; Chen, Jiande D Z

    2014-06-01

    The aims were to investigate the energy-dose response effect of intestinal electrical stimulation (IES) on small bowel motility, to compare the effect of forward and backward IES, and to explore the possibility of using intermittent IES and mechanism of IES on intestinal motility. Five dogs implanted with a duodenal cannula and one pair of intestinal serosal electrodes were studied in five sessions: 1) energy-dose response study; 2) forward IES; 3) backward IES; 4) intermittent IES vs. continuous IES; 5) administration of guanethidine. The contractile activity and tonic pressure of the small intestine were recorded. The duration of sustained effect after turning off IES was manually calculated. 1) IES with long pulse energy dose dependently inhibited contractile activity and tonic pressure of the small intestine (p intestine depended on the energy of IES delivered (p intestine. 5) Guanethidine blocked the inhibitory effect of IES on intestinal motility. IES with long pulses inhibits small intestinal motility; the effect is energy-dose dependent, diffused, and sustained. Intermittent IES has the same efficacy as the continuous IES in inhibiting small intestinal motility. Forward and backward IES have similar inhibitory effects on small bowel motility. This IES-induced inhibitory effect is mediated via the sympathetic pathway. © 2013 International Neuromodulation Society.

  6. A Lactobacillus mutant capable of accumulating long-chain polyphosphates that enhance intestinal barrier function.

    Science.gov (United States)

    Saiki, Asako; Ishida, Yasuaki; Segawa, Shuichi; Hirota, Ryuichi; Nakamura, Takeshi; Kuroda, Akio

    2016-05-01

    Inorganic polyphosphate (polyP) was previously identified as a probiotic-derived substance that enhances intestinal barrier function. PolyP-accumulating bacteria are expected to have beneficial effects on the human gastrointestinal tract. In this study, we selected Lactobacillus paracasei JCM 1163 as a strain with the potential to accumulate polyP, because among the probiotic bacteria stored in our laboratory, it had the largest amount of polyP. The chain length of polyP accumulated in L. paracasei JCM 1163 was approximately 700 phosphate (Pi) residues. L. paracasei JCM 1163 accumulated polyP when Pi was added to Pi-starved cells. We further improved the ability of L. paracasei JCM 1163 to accumulate polyP by nitrosoguanidine mutagenesis. The mutant accumulated polyP at a level of 1500 nmol/mg protein-approximately 190 times that of the wild-type strain. PolyP extracted from the L. paracasei JCM 1163 significantly suppressed the oxidant-induced intestinal permeability in mouse small intestine. In conclusion, we have succeeded in breeding the polyP-accumulating Lactobacillus mutant that is expected to enhance intestinal barrier function.

  7. Subacute stress and chronic stress interact to decrease intestinal barrier function in rats.

    Science.gov (United States)

    Lauffer, Adriana; Vanuytsel, Tim; Vanormelingen, Christophe; Vanheel, Hanne; Salim Rasoel, Shadea; Tóth, Joran; Tack, Jan; Fornari, Fernando; Farré, Ricard

    2016-01-01

    Psychological stress increases intestinal permeability, potentially leading to low-grade inflammation and symptoms in functional gastrointestinal disorders. We assessed the effect of subacute, chronic and combined stress on intestinal barrier function and mast cell density. Male Wistar rats were allocated to four experimental groups (n = 8/group): 1/sham; 2/subacute stress (isolation and limited movement for 24 h); 3/chronic crowding stress for 14 days and 4/combined subacute and chronic stress. Jejunum and colon were collected to measure: transepithelial electrical resistance (TEER; a measure of epithelial barrier function); gene expression of tight junction molecules; mast cell density. Plasma corticosterone concentration was increased in all three stress conditions versus sham, with highest concentrations in the combined stress condition. TEER in the jejunum was decreased in all stress conditions, but was significantly lower in the combined stress condition than in the other groups. TEER in the jejunum correlated negatively with corticosterone concentration. Increased expression of claudin 1, 5 and 8, occludin and zonula occludens 1 mRNAs was detected after subacute stress in the jejunum. In contrast, colonic TEER was decreased only after combined stress, and the expression of tight junction molecules was unaltered. Increased mast cell density was observed in the chronic and combined stress condition in the colon only. In conclusion, our data show that chronic stress sensitizes the gastrointestinal tract to the effects of subacute stress on intestinal barrier function; different underlying cellular and molecular alterations are indicated in the small intestine versus the colon.

  8. Regulation of intestinal health by branched-chain amino acids.

    Science.gov (United States)

    Zhou, Hua; Yu, Bing; Gao, Jun; Htoo, John Khun; Chen, Daiwen

    2018-01-01

    Besides its primary role in the digestion and absorption of nutrients, the intestine also interacts with a complex external milieu, and is the first defense line against noxious pathogens and antigens. Dysfunction of the intestinal barrier is associated with enhanced intestinal permeability and development of various gastrointestinal diseases. The branched-chain amino acids (BCAAs) are important nutrients, which are the essential substrates for protein biosynthesis. Recently, emerging evidence showed that BCAAs are involved in maintaining intestinal barrier function. It has been reported that dietary supplementation with BCAAs promotes intestinal development, enhances enterocyte proliferation, increases intestinal absorption of amino acids (AA) and glucose, and improves the immune defenses of piglets. The underlying mechanism of these effects is mediated by regulating expression of genes and proteins associate with various signaling pathways. In addition, BCAAs promote the production of beneficial bacteria in the intestine of mice. Compelling evidence supports the notion that BCAAs play important roles in both nutrition and intestinal health. Therefore, as functional amino acids with various physiological effects, BCAAs hold key roles in promoting intestinal development and health in animals and humans. © 2017 Japanese Society of Animal Science.

  9. Polyphenol-Rich Propolis Extracts Strengthen Intestinal Barrier Function by Activating AMPK and ERK Signaling

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    Kai Wang

    2016-05-01

    Full Text Available Propolis has abundant polyphenolic constituents and is used widely as a health/functional food. Here, we investigated the effects of polyphenol-rich propolis extracts (PPE on intestinal barrier function in human intestinal epithelial Caco-2 cells, as well as in rats. In Caco-2 cells, PPE increased transepithelial electrical resistance and decreased lucifer yellow flux. PPE-treated cells showed increased expression of the tight junction (TJ loci occludin and zona occludens (ZO-1. Confocal microscopy showed organized expressions in proteins related to TJ assembly, i.e., occludin and ZO-1, in response to PPE. Furthermore, PPE led to the activation of AMPK, ERK1/2, p38, and Akt. Using selective inhibitors, we found that the positive effects of PPE on barrier function were abolished in cells in which AMPK and ERK1/2 signaling were inhibited. Moreover, rats fed a diet supplemented with PPE (0.3% in the diet exhibited increased colonic epithelium ZO-1 expression. Overall, these data suggest that PPE strengthens intestinal barrier function by activating AMPK and ERK signaling and provide novel insights into the potential application of propolis for human gut health.

  10. Curcumin protects intestinal mucosal barrier function of rat enteritis via activation of MKP-1 and attenuation of p38 and NF-κB activation.

    Directory of Open Access Journals (Sweden)

    Wei-Bing Song

    Full Text Available BACKGROUND: Intestinal mucosa barrier (IMB dysfunction results in many notorious diseases for which there are currently few effective treatments. We studied curcumin's protective effect on IMB and examined its mechanism by using methotrexate (MTX induced rat enteritis model and lipopolysaccharide (LPS treated cell death model. METHODOLOGY/PRINCIPAL FINDINGS: Curcumin was intragastrically administrated from the first day, models were made for 7 days. Cells were treated with curcumin for 30 min before exposure to LPS. Rat intestinal mucosa was collected for evaluation of pathological changes. We detected the activities of D-lactate and diamine oxidase (DAO according to previous research and measured the levels of myeloperoxidase (MPO and superoxide dismutase (SOD by colorimetric method. Intercellular adhesion molecule-1 (ICAM-1, tumor necrosis factor α (TNF-α and interleukin 1β (IL-1β were determined by RT-PCR and IL-10 production was determined by ELISA. We found Curcumin decreased the levels of D-lactate, DAO, MPO, ICAM-1, IL-1β and TNF-α, but increased the levels of IL-10 and SOD in rat models. We further confirmed mitogen-activated protein kinase phosphatase-1 (MKP-1 was activated but phospho-p38 was inhibited by curcumin by western blot assay. Finally, NF-κB translocation was monitored by immunofluorescent staining. We showed that curcumin repressed I-κB and interfered with the translocation of NF-κB into nucleus. CONCLUSIONS/SIGNIFICANCE: The effect of curcumin is mediated by the MKP-1-dependent inactivation of p38 and inhibition of NF-κB-mediated transcription. Curcumin, with anti-inflammatory and anti-oxidant activities may be used as an effective reagent for protecting intestinal mucosa barrier and other related intestinal diseases.

  11. Immunomodulatory effects of Hericium erinaceus derived polysaccharides are mediated by intestinal immunology.

    Science.gov (United States)

    Sheng, Xiaotong; Yan, Jingmin; Meng, Yue; Kang, Yuying; Han, Zhen; Tai, Guihua; Zhou, Yifa; Cheng, Hairong

    2017-03-22

    This study was aimed at investigating the immunomodulating activity of Hericium erinaceus polysaccharide (HEP) in mice, by assessing splenic lymphocyte proliferation (cell-mediated immunity), serum hemolysin levels (humoral immunity), phagocytic capacity of peritoneal cavity phagocytes (macrophage phagocytosis), and NK cell activity. ELISA of immunoglobulin A (SIgA) in the lamina propria, and western blotting of small intestinal proteins were also performed to gain insight into the mechanism by which HEP affects the intestinal immune system. Here, we report that HEP improves immune function by functionally enhancing cell-mediated and humoral immunity, macrophage phagocytosis, and NK cell activity. In addition, HEP was found to upregulate the secretion of SIgA and activate the MAPK and AKT cellular signaling pathways in the intestine. In conclusion, all these results allow us to postulate that the immunomodulatory effects of HEP are most likely attributed to the effective regulation of intestinal mucosal immune activity.

  12. Identification of multi-drug resistant Pseudomonas aeruginosa clinical isolates that are highly disruptive to the intestinal epithelial barrier

    Directory of Open Access Journals (Sweden)

    Shevchenko Olga

    2006-06-01

    Full Text Available Abstract Background Multi-drug resistant Pseudomonas aeruginosa nosocomial infections are increasingly recognized worldwide. In this study, we focused on the virulence of multi-drug resistant clinical strains P. aeruginosa against the intestinal epithelial barrier, since P. aeruginosa can cause lethal sepsis from within the intestinal tract of critically ill and immuno-compromised patients via mechanisms involving disruption of epithelial barrier function. Methods We screened consecutively isolated multi-drug resistant P. aeruginosa clinical strains for their ability to disrupt the integrity of human cultured intestinal epithelial cells (Caco-2 and correlated these finding to related virulence phenotypes such as adhesiveness, motility, biofilm formation, and cytotoxicity. Results Results demonstrated that the majority of the multi-drug resistant P. aeruginosa clinical strains were attenuated in their ability to disrupt the barrier function of cultured intestinal epithelial cells. Three distinct genotypes were found that displayed an extreme epithelial barrier-disrupting phenotype. These strains were characterized and found to harbor the exoU gene and to display high swimming motility and adhesiveness. Conclusion These data suggest that detailed phenotypic analysis of the behavior of multi-drug resistant P. aeruginosa against the intestinal epithelium has the potential to identify strains most likely to place patients at risk for lethal gut-derived sepsis. Surveillance of colonizing strains of P. aeruginosa in critically ill patients beyond antibiotic sensitivity is warranted.

  13. Disruption of the epithelial barrier during intestinal inflammation: Quest for new molecules and mechanisms.

    Science.gov (United States)

    Lechuga, Susana; Ivanov, Andrei I

    2017-07-01

    The intestinal epithelium forms a key protective barrier that separates internal organs from the harmful environment of the gut lumen. Increased permeability of the gut barrier is a common manifestation of different inflammatory disorders contributing to the severity of disease. Barrier permeability is controlled by epithelial adherens junctions and tight junctions. Junctional assembly and integrity depend on fundamental homeostatic processes such as cell differentiation, rearrangements of the cytoskeleton, and vesicle trafficking. Alterations of intestinal epithelial homeostasis during mucosal inflammation may impair structure and remodeling of apical junctions, resulting in increased permeability of the gut barrier. In this review, we summarize recent advances in our understanding of how altered epithelial homeostasis affects the structure and function of adherens junctions and tight junctions in the inflamed gut. Specifically, we focus on the transcription reprogramming of the cell, alterations in the actin cytoskeleton, and junctional endocytosis and exocytosis. We pay special attention to knockout mouse model studies and discuss the relevance of these mechanisms to human gastrointestinal disorders. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Excreted/secreted Trichuris suis products reduce barrier function and suppress inflammatory cytokine production of intestinal epithelial cells

    DEFF Research Database (Denmark)

    Hiemstra, I. H.; Klaver, E. J.; Vrijland, K.

    2014-01-01

    The administration of helminths is considered a promising strategy for the treatment of autoimmune diseases due to their immunomodulatory properties. Currently, the application of the helminth Trichuris suis as a treatment for Crohn's disease is being studied in large multi-center clinical trials....... The intestinal epithelium forms an efficient barrier between the intestinal lumen containing the microbial flora and helminths, and dendritic cells (DCs) present in the lamina propria that determine the TH response. Here, we investigated how excreted/secreted (E/S) products of T. suis affect the barrier function...... of intestinal epithelial cells (IECs) in order to reach the DCs and modulate the immune response. We show that T. suis E/S products reduce the barrier function and the expression of the tight junction proteins EMP-1 and claudin-4 in IEC CMT93/69 monolayers in a glycan-dependent manner. This resulted...

  15. Vasoactive intestinal peptide is a local mediator in a gut-brain neural axis activating intestinal gluconeogenesis.

    Science.gov (United States)

    De Vadder, F; Plessier, F; Gautier-Stein, A; Mithieux, G

    2015-03-01

    Intestinal gluconeogenesis (IGN) promotes metabolic benefits through activation of a gut-brain neural axis. However, the local mediator activating gluconeogenic genes in the enterocytes remains unknown. We show that (i) vasoactive intestinal peptide (VIP) signaling through VPAC1 receptor activates the intestinal glucose-6-phosphatase gene in vivo, (ii) the activation of IGN by propionate is counteracted by VPAC1 antagonism, and (iii) VIP-positive intrinsic neurons in the submucosal plexus are increased under the action of propionate. These data support the role of VIP as a local neuromodulator released by intrinsic enteric neurons and responsible for the induction of IGN through a VPAC1 receptor-dependent mechanism in enterocytes. © 2015 John Wiley & Sons Ltd.

  16. Intestinal infection with Giardia spp. reduces epithelial barrier function in a myosin light chain kinase-dependent fashion.

    Science.gov (United States)

    Scott, Kevin G-E; Meddings, Jonathon B; Kirk, David R; Lees-Miller, Susan P; Buret, André G

    2002-10-01

    Giardiasis causes malabsorptive diarrhea, and symptoms can be present in the absence of any significant morphologic injury to the intestinal mucosa. The effects of giardiasis on epithelial permeability in vivo remain unknown, and the role of T cells and myosin light chain kinase (MLCK) in altered intestinal barrier function is unclear. This study was conducted to determine whether Giardia spp. alters intestinal permeability in vivo, to assess whether these abnormalities are dependent on T cells, and to assess the role of MLCK in altered epithelial barrier function. Immunocompetent and isogenic athymic mice were inoculated with axenic Giardia muris trophozoites or sterile vehicle (control), then assessed for trophozoite colonization and gastrointestinal permeability. Mechanistic studies using nontransformed human duodenal epithelial monolayers (SCBN) determined the effects of Giardia on myosin light chain (MLC) phosphorylation, transepithelial fluorescein isothiocyanate-dextran fluxes, cytoskeletal F-actin, tight junctional zonula occludens-1 (ZO-1), and MLCK. Giardia infection caused a significant increase in small intestinal, but not gastric or colonic, permeability that correlated with trophozoite colonization in both immunocompetent and athymic mice. In vitro, Giardia increased permeability and phosphorylation of MLC and reorganized F-actin and ZO-1. These alterations were abolished with an MLCK inhibitor. Disruption of small intestinal barrier function is T cell independent, disappears on parasite clearance, and correlates with reorganization of cytoskeletal F-actin and tight junctional ZO-1 in an MLCK-dependent fashion.

  17. Protective effect of lactobacillus acidophilus and isomaltooligosaccharide on intestinal mucosal barriers in rat models of antibiotic-associated diarrhea

    International Nuclear Information System (INIS)

    Du Dan; Fang Lichao; Chen Bingbo; Wei Hong

    2008-01-01

    Objective: To investigate the protective effect of synbiotics combined lactobacillus acidophilus and iso-malto-oligosaccharide (IMO) on intestinal mucosal barriers in rat models of antibiotic-associated diarrhea(AAD). Methods: Rat models of AAD were prepared with lincomycin gavage for 5 days. The synbiotics was orally administered to the AAD rats daily at three different strengths for 7 days. The intestinal flora and intestinal mucus SIgA levels were determined on d6, d9 and d13. The histopathological changes of ileal mucosa were studied on d13. Results: In the prepared AAD model rats (on d6) there were lower intestinal mucus SIgA levels and intestinal flora disorders were demonstrated. The intestinal floras of the rats administering synbiotics were readjusted to the similar pattern of healthy rats with bacterial translocation corrected on d13 and the levels of SIgA were not significantly different from of the control (P>0.05). The histopathological picture was basically normal in the treated models on d13. Conclusion: The synbiotics combined lactobacillus acidophilus and isomaltooligosaccharide possessed good protective effect on the intestinal mucosal barrier in lincomycin induced rat models of AAD. (authors)

  18. Deoxynivalenol affects in vitro intestinal epithelial cell barrier integrity through inhibition of protein synthesis

    International Nuclear Information System (INIS)

    Van De Walle, Jacqueline; Sergent, Therese; Piront, Neil; Toussaint, Olivier; Schneider, Yves-Jacques; Larondelle, Yvan

    2010-01-01

    Deoxynivalenol (DON), one of the most common mycotoxin contaminants of raw and processed cereal food, adversely affects the gastrointestinal tract. Since DON acts as a protein synthesis inhibitor, the constantly renewing intestinal epithelium could be particularly sensitive to DON. We analyzed the toxicological effects of DON on intestinal epithelial protein synthesis and barrier integrity. Differentiated Caco-2 cells, as a widely used model of the human intestinal barrier, were exposed to realistic intestinal concentrations of DON (50, 500 and 5000 ng/ml) during 24 h. DON caused a concentration-dependent decrease in total protein content associated with a reduction in the incorporation of [ 3 H]-leucine, demonstrating its inhibitory effect on protein synthesis. DON simultaneously increased the paracellular permeability of the monolayer as reflected through a decreased transepithelial electrical resistance associated with an increased paracellular flux of the tracer [ 3 H]-mannitol. A concentration-dependent reduction in the expression level of the tight junction constituent claudin-4 was demonstrated by Western blot, which was not due to diminished transcription, increased degradation, or NF-κB, ERK or JNK activation, and was also observed for a tight junction independent protein, i.e. intestinal alkaline phosphatase. These results demonstrate a dual toxicological effect of DON on differentiated Caco-2 cells consisting in an inhibition of protein synthesis as well as an increase in monolayer permeability, and moreover suggest a possible link between them through diminished synthesis of the tight junction constituent claudin-4.

  19. Zonulin and its regulation of intestinal barrier function: the biological door to inflammation, autoimmunity, and cancer.

    Science.gov (United States)

    Fasano, Alessio

    2011-01-01

    The primary functions of the gastrointestinal tract have traditionally been perceived to be limited to the digestion and absorption of nutrients and to electrolytes and water homeostasis. A more attentive analysis of the anatomic and functional arrangement of the gastrointestinal tract, however, suggests that another extremely important function of this organ is its ability to regulate the trafficking of macromolecules between the environment and the host through a barrier mechanism. Together with the gut-associated lymphoid tissue and the neuroendocrine network, the intestinal epithelial barrier, with its intercellular tight junctions, controls the equilibrium between tolerance and immunity to non-self antigens. Zonulin is the only physiological modulator of intercellular tight junctions described so far that is involved in trafficking of macromolecules and, therefore, in tolerance/immune response balance. When the finely tuned zonulin pathway is deregulated in genetically susceptible individuals, both intestinal and extraintestinal autoimmune, inflammatory, and neoplastic disorders can occur. This new paradigm subverts traditional theories underlying the development of these diseases and suggests that these processes can be arrested if the interplay between genes and environmental triggers is prevented by reestablishing the zonulin-dependent intestinal barrier function. This review is timely given the increased interest in the role of a "leaky gut" in the pathogenesis of several pathological conditions targeting both the intestine and extraintestinal organs.

  20. Optimization of micro-fabricated porous membranes for intestinal epithelial cell culture and in vitro modeling of the human intestinal barrier

    Science.gov (United States)

    Nair Gourikutty Sajay, Bhuvanendran; Yin, Chiam Su; Ramadan, Qasem

    2017-12-01

    In vitro modeling of organs could provide a controlled platform for studying physiological events and has great potential in the field of pharmaceutical development. Here, we describe the characterization of in vitro modeling of the human intestinal barrier mimicked using silicon porous membranes as a substrate. To mimic an intestinal in vivo setup as closely as possible, a porous substrate is required in a dynamic environment for the cells to grow rather than a static setup with an impermeable surface such as a petri dish. In this study, we focus on the detailed characterization of Caco-2 cells cultured on a silicon membrane with different pore sizes as well as the effect of dynamic fluid flow on the model. The porous silicon membrane together with continuous perfusion of liquid applying shear stress on the cells enhances the differentiation of polarized cells by providing access to the both their basal and apical surfaces. Membranes with pore sizes of 0.5-3 µm were used and a shear stress of ~0.03 dyne cm-2 was created by applying a low flow rate of 20 nl s-1. By providing these optimized conditions, cells were able to differentiate with columnar morphology, which developed microvilli structures on their apical side and tight junctions between adjacent cells like those in a healthy human intestinal barrier. In this setup, it is possible to study the important cellular functions of the intestine such as transport, absorption and secretion, and thus this model has great potential in drug screening.

  1. Imbalance of gut microbiome and intestinal epithelial barrier dysfunction in patients with high blood pressure.

    Science.gov (United States)

    Kim, Seungbum; Goel, Ruby; Kumar, Ashok; Qi, Yanfei; Lobaton, Gil; Hosaka, Koji; Mohammed, Mohammed; Handberg, Eileen M; Richards, Elaine M; Pepine, Carl J; Raizada, Mohan K

    2018-03-30

    Recent evidence indicates a link between gut pathology and microbiome with hypertension (HTN) in animal models. However, whether this association exists in humans is unknown. Thus, our objectives in the present study were to test the hypotheses that high blood pressure (BP) patients have distinct gut microbiomes and that gut-epithelial barrier function markers and microbiome composition could predict systolic BP (SBP). Fecal samples, analyzed by shotgun metagenomics, displayed taxonomic and functional changes, including altered butyrate production between patients with high BP and reference subjects. Significant increases in plasma of intestinal fatty acid binding protein (I-FABP), lipopolysaccharide (LPS), and augmented gut-targetting proinflammatory T helper 17 (Th17) cells in high BP patients demonstrated increased intestinal inflammation and permeability. Zonulin, a gut epithelial tight junction protein regulator, was markedly elevated, further supporting gut barrier dysfunction in high BP. Zonulin strongly correlated with SBP (R 2 = 0.5301, P <0.0001). Two models predicting SBP were built using stepwise linear regression analysis of microbiome data and circulating markers of gut health, and validated in a separate cohort by prediction of SBP from zonulin in plasma (R 2 = 0.4608, P <0.0001). The mouse model of HTN, chronic angiotensin II (Ang II) infusion, was used to confirm the effects of butyrate and gut barrier function on the cardiovascular system and BP. These results support our conclusion that intestinal barrier dysfunction and microbiome function are linked to HTN in humans. They suggest that manipulation of gut microbiome and its barrier functions could be the new therapeutic and diagnostic avenues for HTN. © 2018 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  2. Restoration of impaired intestinal barrier function by the hydrolysed casein diet contributes to the prevention of type 1 diabetes in the diabetes-prone BioBreeding rat

    NARCIS (Netherlands)

    Visser, J. T. J.; Lammers, K.; Hoogendijk, A.; Boer, M. W.; Brugman, S.; Beijer-Liefers, S.; Zandvoort, A.; Harmsen, H.; Welling, G.; Stellaard, F.; Bos, N. A.; Fasano, A.; Rozing, J.

    2010-01-01

    Aims/hypothesis Impaired intestinal barrier function is observed in type I diabetes patients and animal models of the disease. Exposure to diabetogenic antigens from the intestinal milieu due to a compromised intestinal barrier is considered essential for induction of the autoimmune process leading

  3. Dysfunctions at human intestinal barrier by water-borne protozoan parasites: lessons from cultured human fully differentiated colon cancer cell lines.

    Science.gov (United States)

    Liévin-Le Moal, Vanessa

    2013-06-01

    Some water-borne protozoan parasites induce diseases through their membrane-associated functional structures and virulence factors that hijack the host cellular molecules and signalling pathways leading to structural and functional lesions in the intestinal barrier. In this Microreview we analyse the insights on the mechanisms of pathogenesis of Entamoeba intestinalis, Giardia and Cryptosporidium observed in the human colon carcinoma fully differentiated colon cancer cell lines, cell subpopulations and clones expressing the structural and functional characteristics of highly specialized fully differentiated epithelial cells lining the intestinal epithelium and mimicking structurally and functionally an intestinal barrier. © 2013 John Wiley & Sons Ltd.

  4. Surmounting elusive barriers: the case for bioethics mediation.

    Science.gov (United States)

    Bergman, Edward J

    2013-01-01

    This article describes, analyzes, and advocates for management of clinical healthcare conflict by a process commonly referred to as bioethics mediation. Section I provides a brief introduction to classical mediation outside the realm of clinical healthcare. Section II highlights certain distinguishing characteristics of bioethics mediation. Section III chronicles the history of bioethics mediation and references a number of seminal writings on the subject. Finally, Section IV analyzes barriers that have, thus far, limited the widespread implementation of bioethics mediation.

  5. Permeability of the small intestine after intra-arterial injection of histamine-type mediators and irradiation

    International Nuclear Information System (INIS)

    Kingham, J.G.C.; Loehry, C.A.

    1976-01-01

    Permeability and selectivity of rabbit small intestine were estimated by a perfusion technique after intra-arterial injection of histamine-type mediators and an intestinal dose of 1.5 Mr gamma irradiation. It was shown that the histamine-type mediators caused an increase in capillary permeability which produced an overall moderate increase in transmucosal permeability with a moderate loss of selectivity. Local intestinal irradiation caused a very marked increase in permeability and a profound loss of selectivity. It was felt that this was produced partly by an increase in capillary permeability but largely by damage to the epithelial basement membrane. It is concluded that the intestinal capillary endothelium is both rate-limiting and selective, though not to a major degree in either case. The epithelial basement membrane, however, appears to be both rate-limiting and markedly selective. (author)

  6. Intestinal Barrier Dysfunction in a Randomized Trial of a Specific Probiotic Composition in Acute Pancreatitis

    NARCIS (Netherlands)

    Besselink, Marc G.; van Santvoort, Hjalmar C.; Renooij, Willem; de Smet, Martin B.; Boermeester, Marja A.; Fischer, Kathelijn; Timmerman, Harro M.; Ali, Usama Ahmed; Cirkel, Geert A.; Bollen, Thomas L.; van Ramshorst, Bert; Schaapherder, Alexander F.; Witteman, Ben J.; Ploeg, Rutger J.; van Goor, Harry; van Laarhoven, Cornelis J.; Tan, Adriaan C.; Brink, Menno A.; van der Harst, Erwin; Wahab, Peter J.; van Eijck, Casper H.; Dejong, Cornelis H.; van Erpecum, Karel J.; Akkermans, Louis M.; Gooszen, Hein G.

    2009-01-01

    Objectives: To determine the relation between intestinal barrier dysfunction, bacterial translocation, and clinical outcome in patients with predicted severe acute pancreatitis and the influence of probiotics on these processes. Summary of Background data: Randomized, placebo-controlled,

  7. Hummingbirds rely on both paracellular and carrier-mediated intestinal glucose absorption to fuel high metabolism

    Science.gov (United States)

    McWhorter, Todd J; Bakken, Bradley Hartman; Karasov, William H; del Rio, Carlos Martínez

    2005-01-01

    Twenty years ago, the highest active glucose transport rate and lowest passive glucose permeability in vertebrates were reported in Rufous and Anna's hummingbirds (Selasphorus rufus, Calypte anna). These first measurements of intestinal nutrient absorption in nectarivores provided an unprecedented physiological foundation for understanding their foraging ecology. They showed that physiological processes are determinants of feeding behaviour. The conclusion that active, mediated transport accounts for essentially all glucose absorption in hummingbirds influenced two decades of subsequent research on the digestive physiology and nutritional ecology of nectarivores. Here, we report new findings demonstrating that the passive permeability of hummingbird intestines to glucose is much higher than previously reported, suggesting that not all sugar uptake is mediated. Even while possessing the highest active glucose transport rates measured in vertebrates, hummingbirds must rely partially on passive non-mediated intestinal nutrient absorption to meet their high mass-specific metabolic demands. PMID:17148346

  8. Effect of trefoil factor 3 on intestinal mucous barrier in rats with nonalcoholic steatohepatitis

    Directory of Open Access Journals (Sweden)

    LIANG Kai

    2017-08-01

    Full Text Available ObjectiveTo investigate the change in intestinal mucous barrier in rats with nonalcoholic steatohepatitis (NASH, the effect of trefoil factor 3 (TFF3 on intestinal mucous barrier in NASH rats, and the therapeutic effect of TFF3 on NASH. MethodsA total of 60 clean male Sprague-Dawley rats were randomly divided into normal group, model group, and treatment group, with 20 rats in each group. The rats in the normal group were given normal diet, and those in the model group and the treatment group were given high-fat diet to induce NASH. The rats in the treatment group were given intraperitoneal injection of rhTFF3 at a dose of 1 ml/kg/d (a concentration of 0.1 mg/ml, and those in the normal group and the model group were given normal saline at a dose of 1 ml/kg/d; the course of treatment was 3 weeks for all groups. At the end of week 15, fluorescein isothiocyanate-labeled dextran was given by gavage to evaluate intestinal permeability, and after the rats were sacrificed, serum levels of aspartate aminotransferase (AST, alanine aminotransferase (ALT, total cholesterol (TC, triglyceride (TG, and endotoxin (ET and diamine oxidase (DAO activity were measured. HE staining was performed to observe the histopathological changes of the liver and the terminal ileum, PAS staining was performed to observe and count the goblet cells of the terminal ileum, immunohistochemistry was used to measure the expression of the tight junction protein Occludin and TFF3 in the terminal ileum, and quantitative real-time PCR was used to measure the mRNA transcription level of TFF3. A one-way analysis of variance was used for comparison between multiple groups, and the least significant difference t-test was used for further comparison between any two groups. ResultsThe model group had significant increases in serum levels of AST, ALT, TC, TG, and ET and DAO activity, and the treatment group had significant reductions compared with the model group (all P<0.01. The model

  9. Primary human polarized small intestinal epithelial barriers respond differently to a hazardous and an innocuous protein.

    Science.gov (United States)

    Eaton, A D; Zimmermann, C; Delaney, B; Hurley, B P

    2017-08-01

    An experimental platform employing human derived intestinal epithelial cell (IEC) line monolayers grown on permeable Transwell ® filters was previously investigated to differentiate between hazardous and innocuous proteins. This approach was effective at distinguishing these types of proteins and perturbation of monolayer integrity, particularly transepithelial electrical resistance (TEER), was the most sensitive indicator. In the current report, in vitro indicators of monolayer integrity, cytotoxicity, and inflammation were evaluated using primary (non-transformed) human polarized small intestinal epithelial barriers cultured on Transwell ® filters to compare effects of a hazardous protein (Clostridium difficile Toxin A [ToxA]) and an innocuous protein (bovine serum albumin [BSA]). ToxA exerted a reproducible decrease on barrier integrity at doses comparable to those producing effects observed from cell line-derived IEC monolayers, with TEER being the most sensitive indicator. In contrast, BSA, tested at concentrations substantially higher than ToxA, did not cause changes in any of the tested variables. These results demonstrate a similarity in response to certain proteins between cell line-derived polarized IEC models and a primary human polarized small intestinal epithelial barrier model, thereby reinforcing the potential usefulness of cell line-derived polarized IECs as a valid experimental platform to differentiate between hazardous and non-hazardous proteins. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Host-dependent zonulin secretion causes the impairment of the small intestine barrier function after bacterial exposure.

    Science.gov (United States)

    El Asmar, Ramzi; Panigrahi, Pinaki; Bamford, Penelope; Berti, Irene; Not, Tarcisio; Coppa, Giovanni V; Catassi, Carlo; Fasano, Alessio; El Asmar, Rahzi

    2002-11-01

    Enteric infections have been implicated in the pathogenesis of both food intolerance and autoimmune diseases secondary to the impairment of the intestinal barrier. On the basis of our recent discovery of zonulin, a modulator of small-intestinal tight junctions, we asked whether microorganisms might induce zonulin secretion and increased small-intestinal permeability. Both ex vivo mammalian small intestines and intestinal cell monolayers were exposed to either pathogenic or nonpathogenic enterobacteria. Zonulin production and changes in paracellular permeability were monitored in Ussing chambers and micro-snapwells. Zonula occludens 1 protein redistribution after bacteria colonization was evaluated on cell monolayers. Small intestines exposed to enteric bacteria secreted zonulin. This secretion was independent of either the species of the small intestines or the virulence of the microorganisms tested, occurred only on the luminal aspect of the bacteria-exposed small-intestinal mucosa, and was followed by a decrease in small-intestinal tissue resistance (transepithelial electrical resistance). The transepithelial electrical resistance decrement was secondary to the zonulin-induced tight junction disassembly, as also shown by the disengagement of the protein zonula occludens 1 protein from the tight junctional complex. This zonulin-driven opening of the paracellular pathway may represent a defensive mechanism, which flushes out microorganisms and contributes to the host response against bacterial colonization of the small intestine.

  11. Dietary Bacillus subtilis-based direct-fed microbials alleviate LPS-induced intestinal immunological stress and improve intestinal barrier gene expression in commercial broiler chickens

    Science.gov (United States)

    The present study investigated the effects of B. subtilis-based probiotics on performance, modulation of host inflammatory responses and intestinal barrier integrity of broilers subjected to LPS challenge. Birds at day 0 of age were randomly allocated to one of the 3 dietary treatments - controls, ...

  12. Food-Derived Hemorphins Cross Intestinal and Blood–Brain Barriers In Vitro

    Directory of Open Access Journals (Sweden)

    Dorothée Domenger

    2018-04-01

    Full Text Available A qualitative study is presented, where the main question was whether food-derived hemorphins, i.e., originating from digested alimentary hemoglobin, could pass the intestinal barrier and/or the blood–brain barrier (BBB. Once absorbed, hemorphins are opioid receptor (OR ligands that may interact with peripheral and central OR and have effects on food intake and energy balance regulation. LLVV-YPWT (LLVV-H4, LVV-H4, VV-H4, VV-YPWTQRF (VV-H7, and VV-H7 hemorphins that were previously identified in the 120 min digest resulting from the simulated gastrointestinal digestion of hemoglobin have been synthesized to be tested in in vitro models of passage of IB and BBB. LC-MS/MS analyses yielded that all hemorphins, except the LLVV-H4 sequence, were able to cross intact the human intestinal epithelium model with Caco-2 cells within 5–60 min when applied at 5 mM. Moreover, all hemorphins crossed intact the human BBB model with brain-like endothelial cells (BLEC within 30 min when applied at 100 µM. Fragments of these hemorphins were also detected, especially the YPWT common tetrapeptide that retains OR-binding capacity. A cAMP assay performed in Caco-2 cells indicates that tested hemorphins behave as OR agonists in these cells by reducing cAMP production. We further provide preliminary results regarding the effects of hemorphins on tight junction proteins, specifically here the claudin-4 that is involved in paracellular permeability. All hemorphins at 100 µM, except the LLVV-H4 peptide, significantly decreased claudin-4 mRNA levels in the Caco-2 intestinal model. This in vitro study is a first step toward demonstrating food-derived hemorphins bioavailability which is in line with the growing body of evidence supporting physiological functions for food-derived peptides.

  13. Effects of positive acceleration exposure on intestinal mucosal barrier and sIgA level in rats

    Directory of Open Access Journals (Sweden)

    Jie QIU

    2016-10-01

    Full Text Available Objective  To explore the effect of positive acceleration (+Gz on immune barrier of intestinal mucosa in rats. Methods  Thirty two male SD rats were randomly divided into 4 groups (8 each: Group A (control group, Group B (+5Gz group, Group C (+10Gz group and Group D (repeated exposure group. The animal centrifuge was used to simulate the exposure of acceleration. Group A was no disposed. +5Gz group and +10Gz group were subjected to centrifugal force of +5Gz and +10Gz respectively for 5min; repeated exposure group was continuously exposed to 1.5min under +5Gz value, 2min under +10Gz value and 1.5min under +5Gz. All groups were exposed to the respective acceleration once daily for 5 days. The damage of intestinal mucosa was observed by light microscopy after the experiment was finished, and the content of sIgA in intestinal mucosa was detected by ELISA. Results  Except for group A, intestinal mucosal injury was observed in the other three groups. Group D was shown as the most serious one, followed by group C and group B. Compared with group A, the level of sIgA was significantly lower in other three groups (P<0.05. The level of sIgA in group C was significantly lower than that in group B (P<0.05 and higher than that in group D (P<0.05. Conclusion  +Gz exposure can result in intestinal injury and weaken the function of immune barrier of intestinal mucosa in rats. DOI: 10.11855/j.issn.0577-7402.2016.10.14

  14. (--Epicatechin protects the intestinal barrier from high fat diet-induced permeabilization: Implications for steatosis and insulin resistance

    Directory of Open Access Journals (Sweden)

    Eleonora Cremonini

    2018-04-01

    Full Text Available Increased permeability of the intestinal barrier is proposed as an underlying factor for obesity-associated pathologies. Consumption of high fat diets (HFD is associated with increased intestinal permeabilization and increased paracellular transport of endotoxins which can promote steatosis and insulin resistance. This study investigated whether dietary (--epicatechin (EC supplementation can protect the intestinal barrier against HFD-induced permeabilization and endotoxemia, and mitigate liver damage and insulin resistance. Mechanisms leading to loss of integrity and function of the tight junction (TJ were characterized. Consumption of a HFD for 15 weeks caused obesity, steatosis, and insulin resistance in male C57BL/6J mice. This was associated with increased intestinal permeability, decreased expression of ileal TJ proteins, and endotoxemia. Supplementation with EC (2–20 mg/kg body weight mitigated all these adverse effects. EC acted modulating cell signals and the gut hormone GLP-2, which are central to the regulation of intestinal permeability. Thus, EC prevented HFD-induced ileum NOX1/NOX4 upregulation, protein oxidation, and the activation of the redox-sensitive NF-κB and ERK1/2 pathways. Supporting NADPH oxidase as a target of EC actions, in Caco-2 cells EC and apocynin inhibited tumor necrosis alpha (TNFα-induced NOX1/NOX4 overexpression, protein oxidation and monolayer permeabilization. Together, our findings demonstrate protective effects of EC against HFD-induced increased intestinal permeability and endotoxemia. This can in part underlie EC capacity to prevent steatosis and insulin resistance occurring as a consequence of HFD consumption. Keywords: Intestinal permeability, (--Epicatechin, Steatosis, Insulin resistance, Endotoxemia, NADPH oxidase

  15. The joint power of sex and stress to modulate brain-gut-microbiota axis and intestinal barrier homeostasis: implications for irritable bowel syndrome.

    Science.gov (United States)

    Pigrau, M; Rodiño-Janeiro, B K; Casado-Bedmar, M; Lobo, B; Vicario, M; Santos, J; Alonso-Cotoner, C

    2016-04-01

    Intestinal homeostasis is a dynamic process that takes place at the interface between the lumen and the mucosa of the gastrointestinal tract, where a constant scrutiny for antigens and toxins derived from food and microorganisms is carried out by the vast gut-associated immune system. Intestinal homeostasis is preserved by the ability of the mucus layer and the mucosal barrier to keep the passage of small-sized and antigenic molecules across the epithelium highly selective. When combined and preserved, immune surveillance and barrier's selective permeability, the host capacity of preventing the development of intestinal inflammation is optimized, and viceversa. In addition, the brain-gut-microbiome axis, a multidirectional communication system that integrates distant and local regulatory networks through neural, immunological, metabolic, and hormonal signaling pathways, also regulates intestinal function. Dysfunction of the brain-gut-microbiome axis may induce the loss of gut mucosal homeostasis, leading to uncontrolled permeation of toxins and immunogenic particles, increasing the risk of appearance of intestinal inflammation, mucosal damage, and gut disorders. Irritable bowel syndrome is prevalent stress-sensitive gastrointestinal disorder that shows a female predominance. Interestingly, the role of stress, sex and gonadal hormones in the regulation of intestinal mucosal and the brain-gut-microbiome axis functioning is being increasingly recognized. We aim to critically review the evidence linking sex, and stress to intestinal barrier and brain-gut-microbiome axis dysfunction and the implications for irritable bowel syndrome. © 2015 John Wiley & Sons Ltd.

  16. Influence of intestinal early enteral nutrition therapy on intestinal barrier function and immune response of patients with radiation enteritis

    International Nuclear Information System (INIS)

    Liu Guohui; Kang Xin; Chen Gong; Wang Guangyi

    2012-01-01

    Objective: To investigate the influence of early enteral nutrition therapy on the intestinal barrier function and immune response of the patients with radiation enteritis (ER) so as to find a relatively simple and effective method to treat RE. Methods: Fifty-six patients with radiation enteritis (RE) diagnosed by colonoscopy, X-rays, and pathology were randomly divided into 2 equal groups: experimental group undergoing enteral nutrition therapy, and control group undergoing conventional therapy only. Peripheral blood samples were collected 1, 11, and 21 days after admission. Plasma diamine oxidase (DAO), D-lactic acid, endotoxin, and lactulose/mannitol (L/M) ratio, and levels of IgG, IgM, and IgA, and CD4/CD8 ratio were examined. Five cases from the experimental group and 5 cases from the control group underwent second-time operation because of incomplete intestinal obstruction, intestinal stenosis, or recurrent tumor respectively. The biopsy specimens of the terminal ileum or distal descending colon taken during the first and second operations underwent pathological examination. Peripheral blood samples were collected 1, 11, and 21 days after admission. Plasma diamine oxidase (DAO), D-lactic acid, endotoxin, and lactulose/mannitol (L/M) ratio, and levels of IgG, IgM, and IgA, and CD4/CD8 ratio were examined. Results: There were no significant differences in the intestinal function and blood immunological indices between these 2 groups. The levels of DAO, D-lactic acid, and endotoxin,and the L/M ratio 11 days after admission of the experiment group were all significantly lower than those of the control group (t=2.568, 2.427, 2.143, 2.443, P<0.05), and all those indices 21 days after admission of the experiment group were all much more significantly lower in comparison with the control group (t=6.019, 12.834, 7.837, 7.997, P<0.01). The levels of IgG, IgM, and IgA, and CD4/CD8 ratio 11 days after admission of the experimental group were all significantly higher than

  17. Protective Effects of Let-7b on the Expression of Occludin by Targeting P38 MAPK in Preventing Intestinal Barrier Dysfunction

    Directory of Open Access Journals (Sweden)

    Zhihua Liu

    2018-01-01

    Full Text Available Background/Aims: Let-7b was dramatically reduced after a dicer knockout of mice with intestinal barrier function injuries. This paper aims to investigate the molecular mechanism of let-7b by targeting p38 MAPK in preventing intestinal barrier dysfunction. Methods: A total of 186 patients were enrolled, with 93 in the control group and 93 in the PRO group. Only 158 patients completed the entire study, whereas the others either did not meet the inclusion criteria or refused to participate. To further verify the role of let-7b, intestinal epithelial conditional knockout (IKO mice of mmu-let-7b model were established. Serum let-7b, zonulin, IL-6, and TNF-α concentrations were measured by ELISA or quantitative RT-PCR. Permeability assay was done by ussing chamber. The apoptotic cells were identified using an In Situ Cell Death Detection Kit. Protein was detected by western blot. Results: Probiotics can lower infection-related complications, as well as increase the serum and tissue let-7b levels. P38 MAPK was identified as the target of let-7b, as verified by NCM460 cells. P38 MAPK expression was increased, whereas tight-junction (TJ proteins were significantly decreased in let-7b IKO mice (both P<0.05. Negative regulation of p38 MAPK molecular signaling pathways was involved in the protective effects of let-7b on intestinal barrier function. Conclusion: Let-7b was identified as a novel diagnosis biomarker or a potential treatment target for preventing intestinal barrier dysfunction.

  18. Protective Effects of Let-7b on the Expression of Occludin by Targeting P38 MAPK in Preventing Intestinal Barrier Dysfunction.

    Science.gov (United States)

    Liu, Zhihua; Tian, Yinghai; Jiang, Yanqiong; Chen, Shihua; Liu, Ting; Moyer, Mary Pat; Qin, Huanlong; Zhou, Xinke

    2018-01-01

    Let-7b was dramatically reduced after a dicer knockout of mice with intestinal barrier function injuries. This paper aims to investigate the molecular mechanism of let-7b by targeting p38 MAPK in preventing intestinal barrier dysfunction. A total of 186 patients were enrolled, with 93 in the control group and 93 in the PRO group. Only 158 patients completed the entire study, whereas the others either did not meet the inclusion criteria or refused to participate. To further verify the role of let-7b, intestinal epithelial conditional knockout (IKO) mice of mmu-let-7b model were established. Serum let-7b, zonulin, IL-6, and TNF-α concentrations were measured by ELISA or quantitative RT-PCR. Permeability assay was done by ussing chamber. The apoptotic cells were identified using an In Situ Cell Death Detection Kit. Protein was detected by western blot. Probiotics can lower infection-related complications, as well as increase the serum and tissue let-7b levels. P38 MAPK was identified as the target of let-7b, as verified by NCM460 cells. P38 MAPK expression was increased, whereas tight-junction (TJ) proteins were significantly decreased in let-7b IKO mice (both P<0.05). Negative regulation of p38 MAPK molecular signaling pathways was involved in the protective effects of let-7b on intestinal barrier function. Let-7b was identified as a novel diagnosis biomarker or a potential treatment target for preventing intestinal barrier dysfunction. © 2018 The Author(s). Published by S. Karger AG, Basel.

  19. Co-treatment with grapefruit juice inhibits while chronic administration activates intestinal P-glycoprotein-mediated drug efflux.

    Science.gov (United States)

    Panchagnula, R; Bansal, T; Varma, M V S; Kaul, C L

    2005-12-01

    P-Glycoprotein (P-gp) mediated efflux is recognized as a significant biochemical barrier affecting oral absorption for a number of drugs. Various conflicting reports have been published regarding the effects of grapefruit juice (GFJ) on P-gp-mediated drug efflux, in which GFJ has been shown both to inhibit and activate it. Hence, the present study adopted a two-way approach, involving both co-treatment and chronic administration. Bi-directional transport of paclitaxel (PCL) was carried out in the absence and presence of GFJ extract, in rat everted ileum sac. Further, the effect of chronic administration of GFJ to rats was characterized by permeability studies with indinavir (INDI). Co-treatment of GFJ extract at 100% concentration reduced the asymmetric transport of PCL (efflux ratio = 20.8) by increasing absorptive (A --> B) transport by 921% and reducing secretory (B --> A) transport by 41%. Further, GFJ showed a concentration dependent effect on PCL permeability. Imipramine, a passive permeability marker with absorptive permeability of 15.33 +/- 4.26 x 10(-6) cm/s showed no asymmetric transport and also no significant (P extract inhibited P-gp-mediated efflux in co-treatment, whereas chronic administration led to increased levels of P-gp expression, thus having a profound effect on intestinal absorption and GFJ-drug interactions in vivo.

  20. Dietary l-threonine supplementation attenuates lipopolysaccharide-induced inflammatory responses and intestinal barrier damage of broiler chickens at an early age.

    Science.gov (United States)

    Chen, Yueping; Zhang, Hao; Cheng, Yefei; Li, Yue; Wen, Chao; Zhou, Yanmin

    2018-06-01

    This study was conducted to investigate the protective effects of l-threonine (l-Thr) supplementation on growth performance, inflammatory responses and intestinal barrier function of young broilers challenged with lipopolysaccharide (LPS). A total of 144 1-d-old male chicks were allocated to one of three treatments: non-challenged broilers fed a basal diet (control group), LPS-challenged broilers fed a basal diet without l-Thr supplementation and LPS-challenged broilers fed a basal diet supplemented with 3·0 g/kg l-Thr. LPS challenge was performed intraperitoneally at 17, 19 and 21 d of age, whereas the control group received physiological saline injection. Compared with the control group, LPS challenge impaired growth performance of broilers, and l-Thr administration reversed LPS-induced increase in feed/gain ratio. LPS challenge elevated blood cell counts related to inflammation, and pro-inflammatory cytokine concentrations in serum (IL-1β and TNF-α), spleen (IL-1β and TNF-α) and intestinal mucosa (jejunal interferon-γ (IFN-γ) and ileal IL-1β). The concentrations of intestinal cytokines in LPS-challenged broilers were reduced by l-Thr supplementation. LPS administration increased circulating d-lactic acid concentration, whereas it reduced villus height, the ratio between villus height and crypt depth and goblet density in both jejunum and ileum. LPS-induced decreases in jejunal villus height, intestinal villus height:crypt depth ratio and ileal goblet cell density were reversed with l-Thr supplementation. Similarly, LPS-induced alterations in the intestinal mRNA abundances of genes related to intestinal inflammation and barrier function (jejunal toll-like receptor 4, IFN- γ and claudin-3, and ileal IL-1 β and zonula occludens-1) were normalised with l-Thr administration. It can be concluded that l-Thr supplementation could attenuate LPS-induced inflammatory responses and intestinal barrier damage of young broilers.

  1. Effects of flavonoids on intestinal inflammation, barrier integrity and changes in gut microbiota during diet-induced obesity.

    Science.gov (United States)

    Gil-Cardoso, Katherine; Ginés, Iris; Pinent, Montserrat; Ardévol, Anna; Blay, Mayte; Terra, Ximena

    2016-12-01

    Diet-induced obesity is associated with low-grade inflammation, which, in most cases, leads to the development of metabolic disorders, primarily insulin resistance and type 2 diabetes. Although prior studies have implicated the adipose tissue as being primarily responsible for obesity-associated inflammation, the latest discoveries have correlated impairments in intestinal immune homeostasis and the mucosal barrier with increased activation of the inflammatory pathways and the development of insulin resistance. Therefore, it is essential to define the mechanisms underlying the obesity-associated gut alterations to develop therapies to prevent and treat obesity and its associated diseases. Flavonoids appear to be promising candidates among the natural preventive treatments that have been identified to date. They have been shown to protect against several diseases, including CVD and various cancers. Furthermore, they have clear anti-inflammatory properties, which have primarily been evaluated in non-intestinal models. At present, a growing body of evidence suggests that flavonoids could exert a protective role against obesity-associated pathologies by modulating inflammatory-related cellular events in the intestine and/or the composition of the microbiota populations. The present paper will review the literature to date that has described the protective effects of flavonoids on intestinal inflammation, barrier integrity and gut microbiota in studies conducted using in vivo and in vitro models.

  2. Comparison of the chloride channel activator lubiprostone and the oral laxative Polyethylene Glycol 3350 on mucosal barrier repair in ischemic-injured porcine intestine.

    Science.gov (United States)

    Moeser, Adam-J; Nighot, Prashant-K; Roerig, Birgit; Ueno, Ryuji; Blikslager, Anthony-T

    2008-10-21

    To investigate the effects of lubiprostone and Polyethylene Glycol 3350 (PEG) on mucosal barrier repair in ischemic-injured porcine intestine. Ileum from 6 piglets (approximately 15 kg body weight) was subjected to ischemic conditions by occluding the local mesenteric circulation for 45 min in vivo. Ileal tissues from each pig were then harvested and mounted in Ussing chambers and bathed in oxygenated Ringer's solution in vitro. Intestinal barrier function was assessed by measuring transepithelial electrical resistance (TER) and mucosal-to-serosal fluxes of (3)H-mannitol and (14)C-inulin. Statistical analyses of data collected over a 120-min time course included 2-way ANOVA for the effects of time and treatment on indices of barrier function. Application of 1 micromol/L lubiprostone to the mucosal surface of ischemic-injured ileum in vitro induced significant elevations in TER compared to non-treated tissue. Lubiprostone also reduced mucosal-to-serosal fluxes of (3)H-mannitol and (14)C-inulin. Alternatively, application of a polyethylene laxative (PEG, 20 mmol/L) to the mucosal surface of ischemic tissues significantly increased flux of (3)H-mannitol and (14)C-inulin. This experiment demonstrates that lubiprostone stimulates recovery of barrier function in ischemic intestinal tissues whereas the PEG laxative had deleterious effects on mucosal repair. These results suggest that, unlike osmotic laxatives, lubiprostone stimulates repair of the injured intestinal barrier.

  3. Saccharomyces boulardii CNCM I-745 Restores intestinal Barrier Integrity by Regulation of E-cadherin Recycling.

    Science.gov (United States)

    Terciolo, Chloé; Dobric, Aurélie; Ouaissi, Mehdi; Siret, Carole; Breuzard, Gilles; Silvy, Françoise; Marchiori, Bastien; Germain, Sébastien; Bonier, Renaté; Hama, Adel; Owens, Roisin; Lombardo, Dominique; Rigot, Véronique; André, Frédéric

    2017-08-01

    Alteration in intestinal permeability is the main factor underlying the pathogenesis of many diseases affecting the gut, such as inflammatory bowel disease [IBD]. Characterization of molecules targeting the restoration of intestinal barrier integrity is therefore vital for the development of alternative therapies. The yeast Saccharomyces boulardii CNCM I-745 [Sb], used to prevent and treat antibiotic-associated infectious and functional diarrhea, may have a beneficial effect in the treatment of IBD. We analyzed the impact of Sb supernatant on tissue integrity and components of adherens junctions using cultured explants of colon from both IBD and healthy patients. To evaluate the pathways by which Sb regulates the expression of E-cadherin at the cell surface, we developed in vitro assays using human colonic cell lines, including cell aggregation, a calcium switch assay, real-time measurement of transepithelial electrical resistance [TEER] and pulse-chase experiments. We showed that Sb supernatant treatment of colonic explants protects the epithelial morphology and maintains E-cadherin expression at the cell surface. In vitro experiments revealed that Sb supernatant enhances E-cadherin delivery to the cell surface by re-routing endocytosed E-cadherin back to the plasma membrane. This process, involving Rab11A-dependent recycling endosome, leads to restoration of enterocyte adherens junctions, in addition to the overall restoration and strengthening of intestinal barrier function. These findings open new possibilities of discovering novel options for prevention and therapy of diseases that affect intestinal permeability. Copyright © 2017 European Crohn's and Colitis Organisation (ECCO). Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com

  4. Effect of wild-type Shigella species and attenuated Shigella vaccine candidates on small intestinal barrier function, antigen trafficking, and cytokine release.

    Directory of Open Access Journals (Sweden)

    Maria Fiorentino

    Full Text Available Bacterial dysentery due to Shigella species is a major cause of morbidity and mortality worldwide. The pathogenesis of Shigella is based on the bacteria's ability to invade and replicate within the colonic epithelium, resulting in severe intestinal inflammatory response and epithelial destruction. Although the mechanisms of pathogenesis of Shigella in the colon have been extensively studied, little is known on the effect of wild-type Shigella on the small intestine and the role of the host response in the development of the disease. Moreover, to the best of our knowledge no studies have described the effects of apically administered Shigella flexneri 2a and S. dysenteriae 1 vaccine strains on human small intestinal enterocytes. The aim of this study was to assess the coordinated functional and immunological human epithelial responses evoked by strains of Shigella and candidate vaccines on small intestinal enterocytes. To model the interactions of Shigella with the intestinal mucosa, we apically exposed monolayers of human intestinal Caco2 cells to increasing bacterial inocula. We monitored changes in paracellular permeability, examined the organization of tight-junctions and the pro-inflammatory response of epithelial cells. Shigella infection of Caco2 monolayers caused severe mucosal damage, apparent as a drastic increase in paracellular permeability and disruption of tight junctions at the cell-cell boundary. Secretion of pro-inflammatory IL-8 was independent of epithelial barrier dysfunction. Shigella vaccine strains elicited a pro-inflammatory response without affecting the intestinal barrier integrity. Our data show that wild-type Shigella infection causes a severe alteration of the barrier function of a small intestinal cell monolayer (a proxy for mucosa and might contribute (along with enterotoxins to the induction of watery diarrhea. Diarrhea may be a mechanism by which the host attempts to eliminate harmful bacteria and transport them

  5. Histamine H2 Receptor-Mediated Suppression of Intestinal Inflammation by Probiotic Lactobacillus reuteri.

    Science.gov (United States)

    Gao, Chunxu; Major, Angela; Rendon, David; Lugo, Monica; Jackson, Vanessa; Shi, Zhongcheng; Mori-Akiyama, Yuko; Versalovic, James

    2015-12-15

    Probiotics and commensal intestinal microbes suppress mammalian cytokine production and intestinal inflammation in various experimental model systems. Limited information exists regarding potential mechanisms of probiotic-mediated immunomodulation in vivo. In this report, we demonstrate that specific probiotic strains of Lactobacillus reuteri suppress intestinal inflammation in a trinitrobenzene sulfonic acid (TNBS)-induced mouse colitis model. Only strains that possess the hdc gene cluster, including the histidine decarboxylase and histidine-histamine antiporter genes, can suppress colitis and mucosal cytokine (interleukin-6 [IL-6] and IL-1β in the colon) gene expression. Suppression of acute colitis in mice was documented by diminished weight loss, colonic injury, serum amyloid A (SAA) protein concentrations, and reduced uptake of [(18)F]fluorodeoxyglucose ([(18)F]FDG) in the colon by positron emission tomography (PET). The ability of probiotic L. reuteri to suppress colitis depends on the presence of a bacterial histidine decarboxylase gene(s) in the intestinal microbiome, consumption of a histidine-containing diet, and signaling via the histamine H2 receptor (H2R). Collectively, luminal conversion of l-histidine to histamine by hdc(+) L. reuteri activates H2R, and H2R signaling results in suppression of acute inflammation within the mouse colon. Probiotics are microorganisms that when administered in adequate amounts confer beneficial effects on the host. Supplementation with probiotic strains was shown to suppress intestinal inflammation in patients with inflammatory bowel disease and in rodent colitis models. However, the mechanisms of probiosis are not clear. Our current studies suggest that supplementation with hdc(+) L. reuteri, which can convert l-histidine to histamine in the gut, resulted in suppression of colonic inflammation. These findings link luminal conversion of dietary components (amino acid metabolism) by gut microbes and probiotic-mediated

  6. Effects of casein glycomacropeptide supplementation on growth performance, intestinal morphology, intestinal barrier permeability and inflammatory responses in Escherichia coli K88 challenged piglets

    Directory of Open Access Journals (Sweden)

    Yili Rong

    2015-06-01

    Full Text Available Casein glycomacropeptide (CGMP is a bioactive peptide derived from milk with multiple functions. This study was aimed at evaluating the effects of CGMP as a potential feed additive on growth performance, intestinal morphology, intestinal barrier permeability and inflammatory responses of Escherichia coli K88 (E. coli K88 challenged piglets. Eighteen weaning piglets were randomly assigned to three groups. Control group and K88 challenged group received a basal diet, and CGMP treated group received the basal diet supplemented with 1% of CGMP powder. The trail lasted for 12 days, K88 was orally administered to the piglets of K88 challenged group and CGMP treated group on days 8–10. The results showed that the diet containing 1% CGMP significantly alleviated the decrease in average daily gain (P  0.05 and barrier permeability damage (P < 0.05, and acute inflammatory response (P < 0.05 induced by E. coli K88 infection. In conclusion, CGMP supplementation in the diet protected the weaning piglets against E. coli K88 infection.

  7. Glucagon-like peptide-2 protects impaired intestinal mucosal barriers in obstructive jaundice rats.

    Science.gov (United States)

    Chen, Jun; Dong, Jia-Tian; Li, Xiao-Jing; Gu, Ye; Cheng, Zhi-Jian; Cai, Yuan-Kun

    2015-01-14

    To observe the protective effect of glucagon-like peptide-2 (GLP-2) on the intestinal barrier of rats with obstructive jaundice and determine the possible mechanisms of action involved in the protective effect. Thirty-six Sprague-Dawley rats were randomly divided into a sham operation group, an obstructive jaundice group, and a GLP-2 group; each group consisted of 12 rats. The GLP-2 group was treated with GLP-2 after the day of surgery, whereas the other two groups were treated with the same concentration of normal saline. Alanine aminotransferase (ALT), total bilirubin, and endotoxin levels were recorded at 1, 3, 7, 10 and 14 d. Furthermore, on the 14(th) day, body weight, the wet weight of the small intestine, pathological changes of the small intestine and the immunoglobulin A (IgA) expressed by plasma cells located in the small intestinal lamina propria were recorded for each group. In the rat model, jaundice was obvious, and the rats' activity decreased 4-6 d post bile duct ligation. Compared with the sham operation group, the obstructive jaundice group displayed increased yellow staining of abdominal visceral serosa, decreased small intestine wet weight, thinning of the intestinal muscle layer and villi, villous atrophy, uneven height, fusion, partial villous epithelial cell shedding, substantial inflammatory cell infiltration and significantly reduced IgA expression. However, no significant gross changes were noted between the GLP-2 and sham groups. With time, the levels of ALT, endotoxin and bilirubin in the GLP-2 group were significantly increased compared with the sham group (P jaundice group than in the GLP-2 group (P jaundice rats, which might be attributed to increased intestinal IgA and reduced bilirubin and endotoxin.

  8. Restoration of impaired intestinal barrier function by the hydrolysed casein diet contributes to the prevention of type 1 diabetes in the diabetes-prone BioBreeding rat.

    Science.gov (United States)

    Visser, J T J; Lammers, K; Hoogendijk, A; Boer, M W; Brugman, S; Beijer-Liefers, S; Zandvoort, A; Harmsen, H; Welling, G; Stellaard, F; Bos, N A; Fasano, A; Rozing, J

    2010-12-01

    Impaired intestinal barrier function is observed in type 1 diabetes patients and animal models of the disease. Exposure to diabetogenic antigens from the intestinal milieu due to a compromised intestinal barrier is considered essential for induction of the autoimmune process leading to type 1 diabetes. Since a hydrolysed casein (HC) diet prevents autoimmune diabetes onset in diabetes-prone (DP)-BioBreeding (BB) rats, we studied the role of the HC diet on intestinal barrier function and, therefore, prevention of autoimmune diabetes onset in this animal model. DP-BB rats were fed the HC diet from weaning onwards and monitored for autoimmune diabetes development. Intestinal permeability was assessed in vivo by lactulose-mannitol test and ex vivo by measuring transepithelial electrical resistance (TEER). Levels of serum zonulin, a physiological tight junction modulator, were measured by ELISA. Ileal mRNA expression of Myo9b, Cldn1, Cldn2 and Ocln (which encode the tight junction-related proteins myosin IXb, claudin-1, claudin-2 and occludin) and Il-10, Tgf-ß (also known as Il10 and Tgfb, respectively, which encode regulatory cytokines) was analysed by quantitative PCR. The HC diet reduced autoimmune diabetes by 50% in DP-BB rats. In DP-BB rats, prediabetic gut permeability negatively correlated with the moment of autoimmune diabetes onset. The improved intestinal barrier function that was induced by HC diet in DP-BB rats was visualised by decreasing lactulose:mannitol ratio, decreasing serum zonulin levels and increasing ileal TEER. The HC diet modified ileal mRNA expression of Myo9b, and Cldn1 and Cldn2, but left Ocln expression unaltered. Improved intestinal barrier function might be an important intermediate in the prevention of autoimmune diabetes by the HC diet in DP-BB rats. Effects on tight junctions, ileal cytokines and zonulin production might be important mechanisms for this effect.

  9. Live Faecalibacterium prausnitzii Does Not Enhance Epithelial Barrier Integrity in an Apical Anaerobic Co-Culture Model of the Large Intestine

    Directory of Open Access Journals (Sweden)

    Eva Maier

    2017-12-01

    Full Text Available Appropriate intestinal barrier maturation during infancy largely depends on colonization with commensal bacteria. Faecalibacterium prausnitzii is an abundant obligate anaerobe that colonizes during weaning and is thought to maintain colonic health throughout life. We previously showed that F. prausnitzii induced Toll-like receptor 2 (TLR2 activation, which is linked to enhanced tight junction formation. Therefore, we hypothesized that F. prausnitzii enhances barrier integrity, an important factor in appropriate intestinal barrier maturation. In order to test metabolically active bacteria, we used a novel apical anaerobic co-culture system that allows the survival of both obligate anaerobic bacteria and oxygen-requiring intestinal epithelial cells (Caco-2. The first aim was to optimize the culture medium to enable growth and active metabolism of F. prausnitzii while maintaining the viability and barrier integrity, as measured by trans-epithelial electrical resistance (TEER, of the Caco-2 cells. This was achieved by supplementing the apical cell culture medium with bacterial culture medium. The second aim was to test the effect of F. prausnitzii on TEER across Caco-2 cell layers. Live F. prausnitzii did not improve TEER, which indicates that its benefits are not via altering tight junction integrity. The optimization of the novel dual-environment co-culturing system performed in this research will enable the investigation of new probiotics originating from indigenous beneficial bacteria.

  10. Live Faecalibacterium prausnitzii Does Not Enhance Epithelial Barrier Integrity in an Apical Anaerobic Co-Culture Model of the Large Intestine.

    Science.gov (United States)

    Maier, Eva; Anderson, Rachel C; Roy, Nicole C

    2017-12-12

    Appropriate intestinal barrier maturation during infancy largely depends on colonization with commensal bacteria. Faecalibacterium prausnitzii is an abundant obligate anaerobe that colonizes during weaning and is thought to maintain colonic health throughout life. We previously showed that F. prausnitzii induced Toll-like receptor 2 (TLR2) activation, which is linked to enhanced tight junction formation. Therefore, we hypothesized that F. prausnitzii enhances barrier integrity, an important factor in appropriate intestinal barrier maturation. In order to test metabolically active bacteria, we used a novel apical anaerobic co-culture system that allows the survival of both obligate anaerobic bacteria and oxygen-requiring intestinal epithelial cells (Caco-2). The first aim was to optimize the culture medium to enable growth and active metabolism of F. prausnitzii while maintaining the viability and barrier integrity, as measured by trans-epithelial electrical resistance (TEER), of the Caco-2 cells. This was achieved by supplementing the apical cell culture medium with bacterial culture medium. The second aim was to test the effect of F. prausnitzii on TEER across Caco-2 cell layers. Live F. prausnitzii did not improve TEER, which indicates that its benefits are not via altering tight junction integrity. The optimization of the novel dual-environment co-culturing system performed in this research will enable the investigation of new probiotics originating from indigenous beneficial bacteria.

  11. Intestinal epithelium in inflammatory bowel disease

    DEFF Research Database (Denmark)

    Coskun, Mehmet

    2014-01-01

    The intestinal epithelium has a strategic position as a protective physical barrier to luminal microbiota and actively contributes to the mucosal immune system. This barrier is mainly formed by a monolayer of specialized intestinal epithelial cells (IECs) that are crucial in maintaining intestinal...... of inflammatory bowel disease (IBD). Understanding the role of the intestinal epithelium in IBD pathogenesis might contribute to an improved knowledge of the inflammatory processes and the identification of potential therapeutic targets....

  12. The effect of gastric inhibitory polypeptide on intestinal glucose absorption and intestinal motility in mice

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Eiichi [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); Hosokawa, Masaya [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); Faculty of Human Sciences, Tezukayama Gakuin University, Osaka (Japan); Harada, Norio; Yamane, Shunsuke; Hamasaki, Akihiro; Toyoda, Kentaro; Fujimoto, Shimpei; Fujita, Yoshihito; Fukuda, Kazuhito [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); Tsukiyama, Katsushi; Yamada, Yuichiro [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); Department of Internal Medicine, Division of Endocrinology, Diabetes and Geriatric Medicine, Akita University School of Medicine, Akita (Japan); Seino, Yutaka [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); Kansai Electric Power Hospital, Osaka (Japan); Inagaki, Nobuya, E-mail: inagaki@metab.kuhp.kyoto-u.ac.jp [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); CREST of Japan Science and Technology Cooperation (JST), Kyoto (Japan)

    2011-01-07

    Research highlights: {yields} Exogenous GIP inhibits intestinal motility through a somatostatin-mediated pathway. {yields} Exogenous GIP inhibits intestinal glucose absorption by reducing intestinal motility. {yields} The GIP-receptor-mediated action in intestine does not involve in GLP-1-mediated pathway. -- Abstract: Gastric inhibitory polypeptide (GIP) is released from the small intestine upon meal ingestion and increases insulin secretion from pancreatic {beta} cells. Although the GIP receptor is known to be expressed in small intestine, the effects of GIP in small intestine are not fully understood. This study was designed to clarify the effect of GIP on intestinal glucose absorption and intestinal motility. Intestinal glucose absorption in vivo was measured by single-pass perfusion method. Incorporation of [{sup 14}C]-glucose into everted jejunal rings in vitro was used to evaluate the effect of GIP on sodium-glucose co-transporter (SGLT). Motility of small intestine was measured by intestinal transit after oral administration of a non-absorbed marker. Intraperitoneal administration of GIP inhibited glucose absorption in wild-type mice in a concentration-dependent manner, showing maximum decrease at the dosage of 50 nmol/kg body weight. In glucagon-like-peptide-1 (GLP-1) receptor-deficient mice, GIP inhibited glucose absorption as in wild-type mice. In vitro examination of [{sup 14}C]-glucose uptake revealed that 100 nM GIP did not change SGLT-dependent glucose uptake in wild-type mice. After intraperitoneal administration of GIP (50 nmol/kg body weight), small intestinal transit was inhibited to 40% in both wild-type and GLP-1 receptor-deficient mice. Furthermore, a somatostatin receptor antagonist, cyclosomatostatin, reduced the inhibitory effect of GIP on both intestinal transit and glucose absorption in wild-type mice. These results demonstrate that exogenous GIP inhibits intestinal glucose absorption by reducing intestinal motility through a somatostatin-mediated

  13. The effect of gastric inhibitory polypeptide on intestinal glucose absorption and intestinal motility in mice

    International Nuclear Information System (INIS)

    Ogawa, Eiichi; Hosokawa, Masaya; Harada, Norio; Yamane, Shunsuke; Hamasaki, Akihiro; Toyoda, Kentaro; Fujimoto, Shimpei; Fujita, Yoshihito; Fukuda, Kazuhito; Tsukiyama, Katsushi; Yamada, Yuichiro; Seino, Yutaka; Inagaki, Nobuya

    2011-01-01

    Research highlights: → Exogenous GIP inhibits intestinal motility through a somatostatin-mediated pathway. → Exogenous GIP inhibits intestinal glucose absorption by reducing intestinal motility. → The GIP-receptor-mediated action in intestine does not involve in GLP-1-mediated pathway. -- Abstract: Gastric inhibitory polypeptide (GIP) is released from the small intestine upon meal ingestion and increases insulin secretion from pancreatic β cells. Although the GIP receptor is known to be expressed in small intestine, the effects of GIP in small intestine are not fully understood. This study was designed to clarify the effect of GIP on intestinal glucose absorption and intestinal motility. Intestinal glucose absorption in vivo was measured by single-pass perfusion method. Incorporation of [ 14 C]-glucose into everted jejunal rings in vitro was used to evaluate the effect of GIP on sodium-glucose co-transporter (SGLT). Motility of small intestine was measured by intestinal transit after oral administration of a non-absorbed marker. Intraperitoneal administration of GIP inhibited glucose absorption in wild-type mice in a concentration-dependent manner, showing maximum decrease at the dosage of 50 nmol/kg body weight. In glucagon-like-peptide-1 (GLP-1) receptor-deficient mice, GIP inhibited glucose absorption as in wild-type mice. In vitro examination of [ 14 C]-glucose uptake revealed that 100 nM GIP did not change SGLT-dependent glucose uptake in wild-type mice. After intraperitoneal administration of GIP (50 nmol/kg body weight), small intestinal transit was inhibited to 40% in both wild-type and GLP-1 receptor-deficient mice. Furthermore, a somatostatin receptor antagonist, cyclosomatostatin, reduced the inhibitory effect of GIP on both intestinal transit and glucose absorption in wild-type mice. These results demonstrate that exogenous GIP inhibits intestinal glucose absorption by reducing intestinal motility through a somatostatin-mediated pathway rather

  14. Effects of alanyl-glutamine supplementation on the small intestinal mucosa barrier in weaned piglets

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    Shen Xing

    2017-02-01

    Full Text Available Objective The study was to investigate the effects of alanyl-glutamine (Ala-Gln and glutamine (Gln supplementation on the intestinal mucosa barrier in piglets. Methods A total of 180 barrows with initial weight 10.01±0.03 kg were randomly allocated to three treatments, and each treatment consisted of three pens and twenty pigs per pen. The piglets of three groups were fed with control diet [0.62% alanine (Ala], Ala-Gln diet (0.5% Ala-Gln, Gln diet (0.34% Gln and 0.21% Ala, respectively. Results The results showed that in comparison with control diet, dietary Ala-Gln supplementation increased the height of villi in duodenum and jejunum (p<0.05, Gln supplementation increased the villi height of jejunum (p<0.05, Ala-Gln supplementation up-regulated the mRNA expressions of epidermal growth factor receptor and insulin-like growth factor 1 receptor in jejunal mucosa (p<0.05, raised the mRNA expressions of Claudin-1, Occludin, zonula occludens protein-1 (ZO-1 and the protein levels of Occludin, ZO-1 in jejunal mucosa (p<0.05, Ala-Gln supplementation enlarged the number of goblet cells in duodenal and ileal epithelium (p<0.05, Gln increased the number of goblet cells in duodenal epithelium (p<0.05 and Ala-Gln supplementation improved the concentrations of secretory immunoglobulin A and immunoglobulin G in the jejunal mucosa (p<0.05. Conclusion These results demonstrated that dietary Ala-Gln supplementation could maintain the integrity of small intestine and promote the functions of intestinal mucosa barriers in piglets.

  15. Divergent Roles of Interferon-γ and Innate Lymphoid Cells in Innate and Adaptive Immune Cell-Mediated Intestinal Inflammation.

    Science.gov (United States)

    Brasseit, Jennifer; Kwong Chung, Cheong K C; Noti, Mario; Zysset, Daniel; Hoheisel-Dickgreber, Nina; Genitsch, Vera; Corazza, Nadia; Mueller, Christoph

    2018-01-01

    Aberrant interferon gamma (IFNγ) expression is associated with the pathogenesis of numerous autoimmune- and inflammatory disorders, including inflammatory bowel diseases (IBD). However, the requirement of IFNγ for the pathogenesis of chronic intestinal inflammation remains controversial. The aim of this study was thus to investigate the role of IFNγ in experimental mouse models of innate and adaptive immune cell-mediated intestinal inflammation using genetically and microbiota-stabilized hosts. While we find that IFNγ drives acute intestinal inflammation in the anti-CD40 colitis model in an innate lymphoid cell (ILC)-dependent manner, IFNγ secreted by both transferred CD4 T cells and/or cells of the lymphopenic Rag1 -/- recipient mice was dispensable for CD4 T cell-mediated colitis. In the absence of IFNγ, intestinal inflammation in CD4 T cell recipient mice was associated with enhanced IL17 responses; consequently, targeting IL17 signaling in IFNγ-deficient mice reduced T cell-mediated colitis. Intriguingly, in contrast to the anti-CD40 model of colitis, depletion of ILC in the Rag1 -/- recipients of colitogenic CD4 T cells did not prevent induction of colonic inflammation. Together, our findings demonstrate that IFNγ represents an essential, or a redundant, pro-inflammatory cytokine for the induction of intestinal inflammation, depending on the experimental mouse model used and on the nature of the critical disease inducing immune cell populations involved.

  16. The Effector Domain Region of the Vibrio vulnificus MARTX Toxin Confers Biphasic Epithelial Barrier Disruption and Is Essential for Systemic Spread from the Intestine.

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    Hannah E Gavin

    2017-01-01

    Full Text Available Vibrio vulnificus causes highly lethal bacterial infections in which the Multifunctional Autoprocessing Repeats-in-Toxins (MARTX toxin product of the rtxA1 gene is a key virulence factor. MARTX toxins are secreted proteins up to 5208 amino acids in size. Conserved MARTX N- and C-terminal repeat regions work in concert to form pores in eukaryotic cell membranes, through which the toxin's central region of modular effector domains is translocated. Upon inositol hexakisphosphate-induced activation of the of the MARTX cysteine protease domain (CPD in the eukaryotic cytosol, effector domains are released from the holotoxin by autoproteolytic activity. We previously reported that the native MARTX toxin effector domain repertoire is dispensable for epithelial cellular necrosis in vitro, but essential for cell rounding and apoptosis prior to necrotic cell death. Here we use an intragastric mouse model to demonstrate that the effector domain region is required for bacterial virulence during intragastric infection. The MARTX effector domain region is essential for bacterial dissemination from the intestine, but dissemination occurs in the absence of overt intestinal tissue pathology. We employ an in vitro model of V. vulnificus interaction with polarized colonic epithelial cells to show that the MARTX effector domain region induces rapid intestinal barrier dysfunction and increased paracellular permeability prior to onset of cell lysis. Together, these results negate the inherent assumption that observations of necrosis in vitro directly predict bacterial virulence, and indicate a paradigm shift in our conceptual understanding of MARTX toxin function during intestinal infection. Results implicate the MARTX effector domain region in mediating early bacterial dissemination from the intestine to distal organs-a key step in V. vulnificus foodborne pathogenesis-even before onset of overt intestinal pathology.

  17. Intestinal epithelium in inflammatory bowel disease

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    Mehmet eCoskun

    2014-08-01

    Full Text Available The intestinal epithelium has a strategic position as a protective physical barrier to luminal microbiota and actively contributes to the mucosal immune system. This barrier is mainly formed by a monolayer of specialized intestinal epithelial cells (IECs that are crucial in maintaining intestinal homeostasis. Therefore, dysregulation within the epithelial layer can increase intestinal permeability, lead to abnormalities in interactions between IECs and immune cells in underlying lamina propria, and disturb the intestinal immune homeostasis, all of which are linked to the clinical disease course of inflammatory bowel disease (IBD. Understanding the role of the intestinal epithelium in IBD pathogenesis might contribute to an improved knowledge of the inflammatory processes and the identification of potential therapeutic targets.

  18. Validation of UHPLC-MS/MS methods for the determination of kaempferol and its metabolite 4-hydroxyphenyl acetic acid, and application to in vitro blood-brain barrier and intestinal drug permeability studies.

    Science.gov (United States)

    Moradi-Afrapoli, Fahimeh; Oufir, Mouhssin; Walter, Fruzsina R; Deli, Maria A; Smiesko, Martin; Zabela, Volha; Butterweck, Veronika; Hamburger, Matthias

    2016-09-05

    Sedative and anxiolytic-like properties of flavonoids such as kaempferol and quercetin, and of some of their intestinal metabolites, have been demonstrated in pharmacological studies. However, routes of administration were shown to be critical for observing in vivo activity. Therefore, the ability to cross intestinal and blood-brain barriers was assessed in cell-based models for kaempferol (KMF), and for the major intestinal metabolite of KMF, 4-hydroxyphenylacetic acid (4-HPAA). Intestinal transport studies were performed with Caco-2 cells, and blood-brain barrier transport studies with an immortalized monoculture human model and a primary triple-co-culture rat model. UHPLC-MS/MS methods for KMF and 4-HPAA in Ringer-HEPES buffer and in Hank's balanced salt solution were validated according to industry guidelines. For all methods, calibration curves were fitted by least-squares quadratic regression with 1/X(2) as weighing factor, and mean coefficients of determination (R(2)) were >0.99. Data obtained with all barrier models showed high intestinal and blood-brain barrier permeation of KMF, and no permeability of 4-HPAA, when compared to barrier integrity markers. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Development of microfluidic cell culture devices towards an in vitro human intestinal barrier model

    DEFF Research Database (Denmark)

    Tan, Hsih-Yin

    to enable real-time detection of cell responses, adjustment of cellular stimulation etc. leading to establishment of conditional experiments. In this project, microfluidic systems engineering was leveraged to develop an eight chamber multi-layer microchip for intestinal barrier studies. Sandwiched between...... the layers was a modified Teflon porous membrane for cell culture. The novelty lies in modifying the surface of the porous Teflon support membrane using thiol-ene ‘click’ chemistry, thus allowing the modified Teflon membrane to be bonded between the chip layers to form an enclosed microchip. Successful...... application of the multi-layer microchip was demonstrated by integrating the microchip to an existing cell culture fluidic system to culture the human intestinal epithelial cells, Caco-2, for long term studies. Under the continuous low flow conditions, the cells differentiated into columnar cells displaying...

  20. Mucosal innate immune cells regulate both gut homeostasis and intestinal inflammation.

    Science.gov (United States)

    Kurashima, Yosuke; Goto, Yoshiyuki; Kiyono, Hiroshi

    2013-12-01

    Continuous exposure of intestinal mucosal surfaces to diverse microorganisms and their metabolites reflects the biological necessity for a multifaceted, integrated epithelial and immune cell-mediated regulatory system. The development and function of the host cells responsible for the barrier function of the intestinal surface (e.g., M cells, Paneth cells, goblet cells, and columnar epithelial cells) are strictly regulated through both positive and negative stimulation by the luminal microbiota. Stimulation by damage-associated molecular patterns and commensal bacteria-derived microbe-associated molecular patterns provokes the assembly of inflammasomes, which are involved in maintaining the integrity of the intestinal epithelium. Mucosal immune cells located beneath the epithelium play critical roles in regulating both the mucosal barrier and the relative composition of the luminal microbiota. Innate lymphoid cells and mast cells, in particular, orchestrate the mucosal regulatory system to create a mutually beneficial environment for both the host and the microbiota. Disruption of mucosal homeostasis causes intestinal inflammation such as that seen in inflammatory bowel disease. Here, we review the recent research on the biological interplay among the luminal microbiota, epithelial cells, and mucosal innate immune cells in both healthy and pathological conditions. © 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Lentiviral-Mediated Transgene Expression Can Potentiate Intestinal Mesenchymal-Epithelial Signaling

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    Kohn Aimee

    2009-01-01

    Full Text Available Abstract Mesenchymal-epithelial signaling is essential for the development of many organs and is often disrupted in disease. In this study, we demonstrate the use of lentiviral-mediated transgene delivery as an effective approach for ectopic transgene expression and an alternative to generation of transgenic animals. One benefit to this approach is that it can be used independently or in conjunction with established transgenic or knockout animals for studying modulation of mesenchymal-epithelial interactions. To display the power of this approach, we explored ectopic expression of a Wnt ligand in the mouse intestinal mesenchyme and demonstrate its functional influence on the adjacent epithelium. Our findings highlight the efficient use of lentiviral-mediated transgene expression for modulating mesenchymal-epithelial interactions in vivo.

  2. Lentiviral-Mediated Transgene Expression Can Potentiate Intestinal Mesenchymal-Epithelial Signaling

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    Dismuke Adria D

    2009-07-01

    Full Text Available Abstract Mesenchymal-epithelial signaling is essential for the development of many organs and is often disrupted in disease. In this study, we demonstrate the use of lentiviral-mediated transgene delivery as an effective approach for ectopic transgene expression and an alternative to generation of transgenic animals. One benefit to this approach is that it can be used independently or in conjunction with established transgenic or knockout animals for studying modulation of mesenchymal-epithelial interactions. To display the power of this approach, we explored ectopic expression of a Wnt ligand in the mouse intestinal mesenchyme and demonstrate its functional influence on the adjacent epithelium. Our findings highlight the efficient use of lentiviral-mediated transgene expression for modulating mesenchymal-epithelial interactions in vivo.

  3. Aryl hydrocarbon receptor and intestinal immunity.

    Science.gov (United States)

    Lamas, Bruno; Natividad, Jane M; Sokol, Harry

    2018-04-07

    Aryl hydrocarbon receptor (AhR) is a member of the basic helix-loop-helix-(bHLH) superfamily of transcription factors, which are associated with cellular responses to environmental stimuli, such as xenobiotics and oxygen levels. Unlike other members of bHLH, AhR is the only bHLH transcription factor that is known to be ligand activated. Early AhR studies focused on understanding the role of AhR in mediating the toxicity and carcinogenesis properties of the prototypic ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In recent years, however, it has become apparent that, in addition to its toxicological involvement, AhR is highly receptive to a wide array of endogenous and exogenous ligands, and that its activation leads to a myriad of key host physiological functions. In this study, we review the current understanding of the functions of AhR in the mucosal immune system with a focus on its role in intestinal barrier function and intestinal immune cells, as well as in intestinal homeostasis.

  4. NOD-Like Receptors in Intestinal Homeostasis and Epithelial Tissue Repair

    Science.gov (United States)

    Parlato, Marianna; Yeretssian, Garabet

    2014-01-01

    The intestinal epithelium constitutes a dynamic physical barrier segregating the luminal content from the underlying mucosal tissue. Following injury, the epithelial integrity is restored by rapid migration of intestinal epithelial cells (IECs) across the denuded area in a process known as wound healing. Hence, through a sequence of events involving restitution, proliferation and differentiation of IECs the gap is resealed and homeostasis reestablished. Relapsing damage followed by healing of the inflamed mucosa is a hallmark of several intestinal disorders including inflammatory bowel diseases (IBD). While several regulatory peptides, growth factors and cytokines stimulate restitution of the epithelial layer after injury, recent evidence in the field underscores the contribution of innate immunity in controlling this process. In particular, nucleotide-binding and oligomerization domain-like receptors (NLRs) play critical roles in sensing the commensal microbiota, maintaining homeostasis, and regulating intestinal inflammation. Here, we review the process of intestinal epithelial tissue repair and we specifically focus on the impact of NLR-mediated signaling mechanisms involved in governing epithelial wound healing during disease. PMID:24886810

  5. Prediction of intestinal absorption and blood-brain barrier penetration by computational methods.

    Science.gov (United States)

    Clark, D E

    2001-09-01

    This review surveys the computational methods that have been developed with the aim of identifying drug candidates likely to fail later on the road to market. The specifications for such computational methods are outlined, including factors such as speed, interpretability, robustness and accuracy. Then, computational filters aimed at predicting "drug-likeness" in a general sense are discussed before methods for the prediction of more specific properties--intestinal absorption and blood-brain barrier penetration--are reviewed. Directions for future research are discussed and, in concluding, the impact of these methods on the drug discovery process, both now and in the future, is briefly considered.

  6. Effects of Lactobacillus johnsonii and Lactobacillus reuteri on gut barrier function and heat shock proteins in intestinal porcine epithelial cells.

    Science.gov (United States)

    Liu, Hao-Yu; Roos, Stefan; Jonsson, Hans; Ahl, David; Dicksved, Johan; Lindberg, Jan Erik; Lundh, Torbjörn

    2015-04-01

    Heat shock proteins (HSPs) are a set of highly conserved proteins that can serve as intestinal gate keepers in gut homeostasis. Here, effects of a probiotic, Lactobacillus rhamnosus GG (LGG), and two novel porcine isolates, Lactobacillus johnsonii strain P47-HY and Lactobacillus reuteri strain P43-HUV, on cytoprotective HSP expression and gut barrier function, were investigated in a porcine IPEC-J2 intestinal epithelial cell line model. The IPEC-J2 cells polarized on a permeable filter exhibited villus-like cell phenotype with development of apical microvilli. Western blot analysis detected HSP expression in IPEC-J2 and revealed that L. johnsonii and L. reuteri strains were able to significantly induce HSP27, despite high basal expression in IPEC-J2, whereas LGG did not. For HSP72, only the supernatant of L. reuteri induced the expression, which was comparable to the heat shock treatment, which indicated that HSP72 expression was more stimulus specific. The protective effect of lactobacilli was further studied in IPEC-J2 under an enterotoxigenic Escherichia coli (ETEC) challenge. ETEC caused intestinal barrier destruction, as reflected by loss of cell-cell contact, reduced IPEC-J2 cell viability and transepithelial electrical resistance, and disruption of tight junction protein zonula occludens-1. In contrast, the L. reuteri treatment substantially counteracted these detrimental effects and preserved the barrier function. L. johnsonii and LGG also achieved barrier protection, partly by directly inhibiting ETEC attachment. Together, the results indicate that specific strains of Lactobacillus can enhance gut barrier function through cytoprotective HSP induction and fortify the cell protection against ETEC challenge through tight junction protein modulation and direct interaction with pathogens. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  7. Enterocyte-specific epidermal growth factor prevents barrier dysfunction and improves mortality in murine peritonitis.

    Science.gov (United States)

    Clark, Jessica A; Gan, Heng; Samocha, Alexandr J; Fox, Amy C; Buchman, Timothy G; Coopersmith, Craig M

    2009-09-01

    Systemic administration of epidermal growth factor (EGF) decreases mortality in a murine model of septic peritonitis. Although EGF can have direct healing effects on the intestinal mucosa, it is unknown whether the benefits of systemic EGF in peritonitis are mediated through the intestine. Here, we demonstrate that enterocyte-specific overexpression of EGF is sufficient to prevent intestinal barrier dysfunction and improve survival in peritonitis. Transgenic FVB/N mice that overexpress EGF exclusively in enterocytes (IFABP-EGF) and wild-type (WT) mice were subjected to either sham laparotomy or cecal ligation and puncture (CLP). Intestinal permeability, expression of the tight junction proteins claudins-1, -2, -3, -4, -5, -7, and -8, occludin, and zonula occludens-1; villus length; intestinal epithelial proliferation; and epithelial apoptosis were evaluated. A separate cohort of mice was followed for survival. Peritonitis induced a threefold increase in intestinal permeability in WT mice. This was associated with increased claudin-2 expression and a change in subcellular localization. Permeability decreased to basal levels in IFABP-EGF septic mice, and claudin-2 expression and localization were similar to those of sham animals. Claudin-4 expression was decreased following CLP but was not different between WT septic mice and IFABP-EGF septic mice. Peritonitis-induced decreases in villus length and proliferation and increases in apoptosis seen in WT septic mice did not occur in IFABP-EGF septic mice. IFABP-EGF mice had improved 7-day mortality compared with WT septic mice (6% vs. 64%). Since enterocyte-specific overexpression of EGF is sufficient to prevent peritonitis-induced intestinal barrier dysfunction and confers a survival advantage, the protective effects of systemic EGF in septic peritonitis appear to be mediated in an intestine-specific fashion.

  8. Ginger Extract Suppresses Inflammatory Response and Maintains Barrier Function in Human Colonic Epithelial Caco-2 Cells Exposed to Inflammatory Mediators.

    Science.gov (United States)

    Kim, Yunyoung; Kim, Dong-Min; Kim, Ji Yeon

    2017-05-01

    The beneficial effects of ginger in the management of gastrointestinal disturbances have been reported. In this study, the anti-inflammatory potential of ginger extract was assessed in a cellular model of gut inflammation. In addition, the effects of ginger extract and its major active compounds on intestinal barrier function were evaluated. The response of Caco-2 cells following exposure to a mixture of inflammatory mediators [interleukin [IL]-1β, 25 ng/mL; lipopolysaccharides [LPS], 10 ng/mL; tumor necrosis factor [TNF]-α, 50 ng/mL; and interferon [INF]-γ, 50 ng/mL] were assessed by measuring the levels of secreted IL-6 and IL-8. In addition, the mRNA levels of cyclooxygenase-2 and inducible nitric oxide synthase were measured. Moreover, the degree of nuclear factor (NF)-κB inhibition was examined, and the intestinal barrier function was determined by measuring the transepithelial electrical resistance (TEER) and fluorescein isothiocyanate (FITC)-dextran transfer. It was observed that ginger extract and its constituents improved inflammatory responses by decreasing the levels of nitrite, PGE2, IL-6, and IL-8 via NF-κB inhibition. The ginger extract also increased the TEER and decreased the transfer of FITC-dextran from the apical side of the epithelium to the basolateral side. Taken together, these results show that ginger extract may be developed as a functional food for the maintenance of gastrointestinal health. © 2017 Institute of Food Technologists®.

  9. Intestinal surfactant permeation enhancers and their interaction with enterocyte cell membranes in a mucosal explant system

    DEFF Research Database (Denmark)

    Danielsen, E Michael; Hansen, Gert H

    2017-01-01

    Intestinal permeation enhancers (PEs) are agents aimed to improve oral delivery of therapeutic drugs with poor bioavailability. The main permeability barrier for oral delivery is the intestinal epithelium, and PEs act to increase the paracellular and/or transcellular passage of drugs. Transcellular...... for the fluorescent polar tracer lucifer yellow, but surprisingly, they all also blocked both constitutive -and receptor-mediated pathways of endocytosis from the brush border, indicating a complete arrest of apical membrane trafficking. At the ultrastructural level, the PEs caused longitudinal fusion of brush border...

  10. Intestinal Fork Head Regulates Nutrient Absorption and Promotes Longevity

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    Ekin Bolukbasi

    2017-10-01

    Full Text Available Reduced activity of nutrient-sensing signaling networks can extend organismal lifespan, yet the underlying biology remains unclear. We show that the anti-aging effects of rapamycin and reduced intestinal insulin/insulin growth factor (IGF signaling (IIS require the Drosophila FoxA transcription factor homolog Fork Head (FKH. Intestinal FKH induction extends lifespan, highlighting a role for the gut. FKH binds to and is phosphorylated by AKT and Target of Rapamycin. Gut-specific FKH upregulation improves gut barrier function in aged flies. Additionally, it increases the expression of nutrient transporters, as does lowered IIS. Evolutionary conservation of this effect of lowered IIS is suggested by the upregulation of related nutrient transporters in insulin receptor substrate 1 knockout mouse intestine. Our study highlights a critical role played by FKH in the gut in mediating anti-aging effects of reduced IIS. Malnutrition caused by poor intestinal absorption is a major problem in the elderly, and a better understanding of the mechanisms involved will have important therapeutic implications for human aging.

  11. Pilot study of lithium to restore intestinal barrier function in severe graft-versus-host disease.

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    Gideon Steinbach

    Full Text Available Severe intestinal graft-vs-host disease (GVHD after allogeneic hematopoietic cell transplantation (HCT causes mucosal ulceration and induces innate and adaptive immune responses that amplify and perpetuate GVHD and the associated barrier dysfunction. Pharmacological agents to target mucosal barrier dysfunction in GVHD are needed. We hypothesized that induction of Wnt signaling by lithium, an inhibitor of glycogen synthase kinase (GSK3, would potentiate intestinal crypt proliferation and mucosal repair and that inhibition of GSK3 in inflammatory cells would attenuate the deregulated inflammatory response to mucosal injury. We conducted an observational pilot study to provide data for the potential design of a randomized study of lithium. Twenty patients with steroid refractory intestinal GVHD meeting enrollment criteria were given oral lithium carbonate. GVHD was otherwise treated per current practice, including 2 mg/kg per day of prednisone equivalent. Seventeen patients had extensive mucosal denudation (extreme endoscopic grade 3 in the duodenum or colon. We observed that 8 of 12 patients (67% had a complete remission (CR of GVHD and survived more than 1 year (median 5 years when lithium administration was started promptly within 3 days of endoscopic diagnosis of denuded mucosa. When lithium was started promptly and less than 7 days from salvage therapy for refractory GVHD, 8 of 10 patients (80% had a CR and survived more than 1 year. In perspective, a review of 1447 consecutive adult HCT patients in the preceding 6 years at our cancer center showed 0% one-year survival in 27 patients with stage 3-4 intestinal GVHD and grade 3 endoscopic appearance in the duodenum or colon. Toxicities included fatigue, somnolence, confusion or blunted affect in 50% of the patients. The favorable outcomes in patients who received prompt lithium therapy appear to support the future conduct of a randomized study of lithium for management of severe GVHD with

  12. Carrier-mediated system for transport of biotin in rat intestine in vitro

    International Nuclear Information System (INIS)

    Said, H.M.; Redha, R.

    1987-01-01

    Transport of biotin was examined in rat intestine using the everted sac technique. Transport of 0.1 μM biotin was linear with time for at least 30 min of incubation and occurred at a rate 3.7 pmol g initial tissue wet wt -1 min -1 . Transport of biotin was higher in the jejunum than the ileum and was minimum in the colon (85 +/- 6, 36 +/- 6, and 2.8 +/- 0.6 pmol x g initial tissue wet wt -1 x 25 min -1 , respectively). In the jejunum, transport of biotin was saturable at low concentrations but linear at higher concentrations. The transport of low concentrations of biotin was 1) inhibited by structural analogues (desthiobiotin, biotin methyl ester, diaminobiotin, and biocytin), 2) Na + dependent, 3) energy dependent, 4) temperature dependent, and 5) proceeded against a concentration gradient in the serosal compartment. No metabolic alteration occurs to the biotin molecule during transport. This study demonstrates that biotin transport in rat intestine occurs by a carrier-mediated process at low concentrations and by simple diffusion at high concentrations. Furthermore, the carrier-mediated process is Na + , energy, and temperature dependent

  13. Role of serotonin in the intestinal mucosal epithelium barrier in weaning mice undergoing stress-induced diarrhea.

    Science.gov (United States)

    Dong, Yulan; Wang, Zixu; Qin, Zhuoming; Cao, Jing; Chen, Yaoxing

    2018-02-01

    Stress-induced diarrhea is a frequent and challenging threat to humans and domestic animals. Serotonin (5-HT) has been shown to be involved in the pathological process of stress-induced diarrhea. However, the role of 5-HT in stress-induced diarrhea remains unclear. A stress-induced diarrhea model was established in 21-day-old ICR weaning mice through an intragastric administration of 0.25 mL of 0.4 g/mL folium sennae and restraint of the hind legs with adhesive tape for 4 h to determine whether 5-HT regulates the mucosal barrier to cause diarrhea. Mice with decreased levels of 5-HT were pretreated with an intraperitoneal injection of 300 mg/kg p-chlorophenylalanine (PCPA), a 5-HT synthesis inhibitor. After 5 days of treatment, the stress level, body weight and intestinal mucosal morphology indexes were measured. Compared to the controls, the mice with stress-induced diarrhea displayed a stress reaction, with increased corticosterone levels, as well as increased 5-HT-positive cells. However, the mice with stress-induced diarrhea exhibited decreased body weights, villus height to crypt depth ratios (V/C), and Occludin and Claudin1 expression. The PCPA injection reversed these effects in mice with different degrees of stress-induced diarrhea. Based on these findings, inhibition of 5-HT synthesis relieved the stress response and improved the health of the intestinal tract, including both the intestinal absorption capacity, as determined by the villus height and crypt depth, and the mucosal barrier function, as determined by the tight junction proteins of epithelial cell.

  14. IGF-1 decreases portal vein endotoxin via regulating intestinal tight junctions and plays a role in attenuating portal hypertension of cirrhotic rats.

    Science.gov (United States)

    Zhao, Tian-Yu; Su, Li-Ping; Ma, Chun-Ye; Zhai, Xiao-Han; Duan, Zhi-Jun; Zhu, Ying; Zhao, Gang; Li, Chun-Yan; Wang, Li-Xia; Yang, Dong

    2015-07-08

    development of liver cirrhosis, and endotoxemia will develop subsequently. Correspondingly, increased endotoxin in portal system worsens tight junction dysfunction via decreasing intestinal occludin and claudin-1 expressions and increasing enterocytic apoptosis. Endotoxemia and intestinal barrier dysfunction form a vicious circle. External administration of IGF-1 breaks this vicious circle. Improvement of tight junctions might be one possible mechanism of the restoration of intestinal barrier function mediated by IGF-1.

  15. Toll-like receptor 2 mediates ischemia-reperfusion injury of the small intestine in adult mice.

    Directory of Open Access Journals (Sweden)

    Toshio Watanabe

    Full Text Available Toll-like receptor 2 (TLR2 recognizes conserved molecular patterns associated with both gram-negative and gram-positive bacteria, and detects some endogenous ligands. Previous studies demonstrated that in ischemia-reperfusion (I/R injury of the small intestine, the TLR2-dependent signaling exerted preventive effects on the damage in young mice, but did not have a significant effect in neonatal mice. We investigated the role of TLR2 in adult ischemia-reperfusion injury in the small intestine. Wild-type and TLR2 knockout mice at 16 weeks of age were subjected to intestinal I/R injury. Some wild-type mice received anti-Ly-6G antibodies to deplete circulating neutrophils. In wild-type mice, I/R induced severe small intestinal injury characterized by infiltration by inflammatory cells, disruption of the mucosal epithelium, and mucosal bleeding. Compared to wild-type mice, TLR2 knockout mice exhibited less severe mucosal injury induced by I/R, with a 35%, 33%, and 43% reduction in histological grading score and luminal concentration of hemoglobin, and the numbers of apoptotic epithelial cells, respectively. The I/R increased the activity of myeloperoxidase (MPO, a marker of neutrophil infiltration, and the levels of mRNA expression of tumor necrosis factor-α (TNF-α, intercellular adhesion molecule-1 (ICAM-1, and cyclooxygenase-2 (COX-2 in the small intestine of the wild-type mice by 3.3-, 3.2-, and 13.0-fold, respectively. TLR2 deficiency significantly inhibited the I/R-induced increase in MPO activity and the expression of mRNAs for TNF-α and ICAM-1, but did not affect the expression of COX-2 mRNA. I/R also enhanced TLR2 mRNA expression by 2.9-fold. TLR2 proteins were found to be expressed in the epithelial cells, inflammatory cells, and endothelial cells. Neutrophil depletion prevented intestinal I/R injury in wild-type mice. These findings suggest that TLR2 may mediate I/R injury of the small intestine in adult mice via induction of inflammatory

  16. Pathophysiology of increased intestinal permeability in obstructive jaundice

    Science.gov (United States)

    Assimakopoulos, Stelios F; Scopa, Chrisoula D; Vagianos, Constantine E

    2007-01-01

    Despite advances in preoperative evaluation and postoperative care, intervention, especially surgery, for relief of obstructive jaundice still carries high morbidity and mortality rates, mainly due to sepsis and renal dysfunction. The key event in the pathophysiology of obstructive jaundice-associated complications is endotoxemia of gut origin because of intestinal barrier failure. This breakage of the gut barrier in obstructive jaundice is multi-factorial, involving disruption of the immunologic, biological and mechanical barrier. Experimental and clinical studies have shown that obstructive jaundice results in increased intestinal permeability. The mechanisms implicated in this phenomenon remain unresolved, but growing research interest during the last decade has shed light in our knowledge in the field. This review summarizes the current concepts in the pathophysiology of obstructive jaundice-induced gut barrier dysfunction, analyzing pivotal factors, such as altered intestinal tight junctions expression, oxidative stress and imbalance of enterocyte proliferation and apoptosis. Clinicians handling patients with obstructive jaundice should not neglect protecting the intestinal barrier function before, during and after intervention for the relief of this condition, which may improve their patients’ outcome. PMID:18161914

  17. Myosin light chain kinase knockout improves gut barrier function and confers a survival advantage in polymicrobial sepsis.

    Science.gov (United States)

    Lorentz, C Adam; Liang, Zhe; Meng, Mei; Chen, Ching-Wen; Yoseph, Benyam P; Breed, Elise R; Mittal, Rohit; Klingensmith, Nathan J; Farris, Alton B; Burd, Eileen M; Koval, Michael; Ford, Mandy L; Coopersmith, Craig M

    2017-06-07

    Sepsis-induced intestinal hyperpermeability is mediated by disruption of the epithelial tight junction, which is closely associated with the peri-junctional actin-myosin ring. Myosin light chain kinase (MLCK) phosphorylates the myosin regulatory light chain, resulting in increased permeability. The purpose of this study was to determine whether genetic deletion of MLCK would alter gut barrier function and survival from sepsis. MLCK -/- and wild type (WT) mice were subjected to cecal ligation and puncture and assayed for both survival and mechanistic studies. Survival was significantly increased in MLCK -/- mice (95% vs. 24%, p<0.0001). Intestinal permeability increased in septic WT mice compared to unmanipulated mice. In contrast, permeability in septic MLCK -/- mice was similar to that seen in unmanipulated animals. Improved gut barrier function in MLCK -/- mice was associated with increases in the tight junction mediators ZO-1 and claudin 15 without alterations in claudin 1, 2, 3, 4, 5, 7, 8, 13, occludin or JAM-A. Other components of intestinal integrity (apoptosis, proliferation and villus length) were unaffected by MLCK deletion as were local peritoneal inflammation and distant lung injury. Systemic IL-10 was decreased greater than 10-fold in MLCK -/- mice; however, survival was similar between septic MLCK -/- mice given exogenous IL-10 or vehicle. These data demonstrate that deletion of MLCK improves survival following sepsis, associated with normalization of intestinal permeability and selected tight junction proteins.

  18. Epithelial Cell Inflammasomes in Intestinal Immunity and Inflammation

    Directory of Open Access Journals (Sweden)

    Andrea C. Lei-Leston

    2017-09-01

    Full Text Available Pattern recognition receptors (PRR, such as NOD-like receptors (NLRs, sense conserved microbial signatures, and host danger signals leading to the coordination of appropriate immune responses. Upon activation, a subset of NLR initiate the assembly of a multimeric protein complex known as the inflammasome, which processes pro-inflammatory cytokines and mediates a specialized form of cell death known as pyroptosis. The identification of inflammasome-associated genes as inflammatory bowel disease susceptibility genes implicates a role for the inflammasome in intestinal inflammation. Despite the fact that the functional importance of inflammasomes within immune cells has been well established, the contribution of inflammasome expression in non-hematopoietic cells remains comparatively understudied. Given that intestinal epithelial cells (IEC act as a barrier between the host and the intestinal microbiota, inflammasome expression by these cells is likely important for intestinal immune homeostasis. Accumulating evidence suggests that the inflammasome plays a key role in shaping epithelial responses at the host–lumen interface with many inflammasome components highly expressed by IEC. Recent studies have exposed functional roles of IEC inflammasomes in mucosal immune defense, inflammation, and tumorigenesis. In this review, we present the main features of the predominant inflammasomes and their effector mechanisms contributing to intestinal homeostasis and inflammation. We also discuss existing controversies in the field and open questions related to their implications in disease. A comprehensive understanding of the molecular basis of intestinal inflammasome signaling could hold therapeutic potential for clinical translation.

  19. Alteration of intestinal barrier function during activity-based anorexia in mice.

    Science.gov (United States)

    Jésus, Pierre; Ouelaa, Wassila; François, Marie; Riachy, Lina; Guérin, Charlène; Aziz, Moutaz; Do Rego, Jean-Claude; Déchelotte, Pierre; Fetissov, Sergueï O; Coëffier, Moïse

    2014-12-01

    Anorexia nervosa is a severe eating disorder often leading to malnutrition and cachexia, but its pathophysiology is still poorly defined. Chronic food restriction during anorexia nervosa may induce gut barrier dysfunction, which may contribute to disease development and its complications. Here we have characterized intestinal barrier function in mice with activity-based anorexia (ABA), an animal model of anorexia nervosa. Male C57Bl/6 ABA or limited food access (LFA) mice were placed respectively in cages with or without activity wheel. After 5 days of acclimatization, both ABA and LFA mice had progressively limited access to food from 6 h/d at day 6 to 3 h/d at day 9 and until the end of experiment at day 17. A group of pair-fed mice (PF) was also compared to ABA. On day 17, food intake was lower in ABA than LFA mice (2.0 ± 0.18 g vs. 3.0 ± 0.14 g, p anorexia nervosa. The role of these alterations in the pathophysiology of anorexia nervosa should be further evaluated. Copyright © 2013 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  20. A multi-chamber microfluidic intestinal barrier model using Caco-2 cells for drug transport studies

    DEFF Research Database (Denmark)

    Tan, Hsih-Yin; Trier, Sofie; Rahbek, Ulrik L

    2018-01-01

    with platinum wires, enabling parallel real-time monitoring of barrier integrity for the eight chambers. Additionally, the translucent porous Teflon membrane enabled optical monitoring of cell monolayers. The device was developed and tested with the Caco-2 intestinal model, and compared to the conventional...... through permeability studies of mannitol, dextran and insulin, alone or in combination with the absorption enhancer tetradecylmaltoside (TDM). The thiol-ene-based microchip material and electrodes were highly compatible with cell growth. In fact, Caco-2 cells cultured in the device displayed...

  1. Perceived medication adherence barriers mediating effects between gastrointestinal symptoms and health-related quality of life in pediatric inflammatory bowel disease.

    Science.gov (United States)

    Varni, James W; Shulman, Robert J; Self, Mariella M; Saeed, Shehzad A; Zacur, George M; Patel, Ashish S; Nurko, Samuel; Neigut, Deborah A; Franciosi, James P; Saps, Miguel; Denham, Jolanda M; Dark, Chelsea Vaughan; Bendo, Cristiane B; Pohl, John F

    2018-01-01

    The primary objective was to investigate the mediating effects of patient-perceived medication adherence barriers in the relationship between gastrointestinal symptoms and generic health-related quality of life (HRQOL) in adolescents with inflammatory bowel disease (IBD). The secondary objective explored patient health communication and gastrointestinal worry as additional mediators with medication adherence barriers in a serial multiple mediator model. The Pediatric Quality of Life Inventory™ Gastrointestinal Symptoms, Medicines, Communication, Gastrointestinal Worry, and Generic Core Scales were completed in a 9-site study by 172 adolescents with IBD. Gastrointestinal Symptoms Scales measuring stomach pain, constipation, or diarrhea and perceived medication adherence barriers were tested for bivariate and multivariate linear associations with HRQOL. Mediational analyses were conducted to test the hypothesized mediating effects of perceived medication adherence barriers as an intervening variable between gastrointestinal symptoms and HRQOL. The predictive effects of gastrointestinal symptoms on HRQOL were mediated in part by perceived medication adherence barriers. Patient health communication was a significant additional mediator. In predictive analytics models utilizing multiple regression analyses, demographic variables, gastrointestinal symptoms (stomach pain, constipation, or diarrhea), and perceived medication adherence barriers significantly accounted for 45, 38, and 29 percent of the variance in HRQOL (all Ps barriers explain in part the effects of gastrointestinal symptoms on HRQOL in adolescents with IBD. Patient health communication to healthcare providers and significant others further explain the mechanism in the relationship between gastrointestinal symptoms, perceived medication adherence barriers, and HRQOL.

  2. Impact of the Gut Microbiota on Intestinal Immunity Mediated by Tryptophan Metabolism

    Science.gov (United States)

    Gao, Jing; Xu, Kang; Liu, Hongnan; Liu, Gang; Bai, Miaomiao; Peng, Can; Li, Tiejun; Yin, Yulong

    2018-01-01

    The gut microbiota influences the health of the host, especially with regard to gut immune homeostasis and the intestinal immune response. In addition to serving as a nutrient enhancer, L-tryptophan (Trp) plays crucial roles in the balance between intestinal immune tolerance and gut microbiota maintenance. Recent discoveries have underscored that changes in the microbiota modulate the host immune system by modulating Trp metabolism. Moreover, Trp, endogenous Trp metabolites (kynurenines, serotonin, and melatonin), and bacterial Trp metabolites (indole, indolic acid, skatole, and tryptamine) have profound effects on gut microbial composition, microbial metabolism, the host's immune system, the host-microbiome interface, and host immune system–intestinal microbiota interactions. The aryl hydrocarbon receptor (AhR) mediates the regulation of intestinal immunity by Trp metabolites (as ligands of AhR), which is beneficial for immune homeostasis. Among Trp metabolites, AhR ligands consist of endogenous metabolites, including kynurenine, kynurenic acid, xanthurenic acid, and cinnabarinic acid, and bacterial metabolites, including indole, indole propionic acid, indole acetic acid, skatole, and tryptamine. Additional factors, such as aging, stress, probiotics, and diseases (spondyloarthritis, irritable bowel syndrome, inflammatory bowel disease, colorectal cancer), which are associated with variability in Trp metabolism, can influence Trp–microbiome–immune system interactions in the gut and also play roles in regulating gut immunity. This review clarifies how the gut microbiota regulates Trp metabolism and identifies the underlying molecular mechanisms of these interactions. Increased mechanistic insight into how the microbiota modulates the intestinal immune system through Trp metabolism may allow for the identification of innovative microbiota-based diagnostics, as well as appropriate nutritional supplementation of Trp to prevent or alleviate intestinal inflammation

  3. Enhancing the intestinal membrane permeability of zanamivir: a carrier mediated prodrug approach.

    Science.gov (United States)

    Gupta, Sheeba Varghese; Gupta, Deepak; Sun, Jing; Dahan, Arik; Tsume, Yasuhiro; Hilfinger, John; Lee, Kyung-Dall; Amidon, Gordon L

    2011-12-05

    The purpose of this study was to improve the membrane permeability and oral absorption of the poorly permeable anti-influenza agent, zanamivir. The poor oral bioavailability is attributed to the high polarity (cLogP ∼ -5) resulting from the polar and zwitterionic nature of zanamivir. In order to improve the permeability of zanamivir, prodrugs with amino acids were developed to target the intestinal membrane transporter, hPepT1. Several acyloxy ester prodrugs of zanamivir conjugated with amino acids were synthesized and characterized. The prodrugs were evaluated for their chemical stability in buffers at various pHs and for their transport and tissue activation by enzymes. The acyloxy ester prodrugs of zanamivir were shown to competitively inhibit [(3)H]Gly-Sar uptake in Caco-2 cells (IC(50): 1.19 ± 0.33 mM for L-valyl prodrug of zanamivir). The L-valyl prodrug of zanamivir exhibited ∼3-fold higher uptake in transfected HeLa/hPepT1 cells compared to wild type HeLa cells, suggesting, at least in part, carrier mediated transport by the hPepT1 transporter. Further, enhanced transcellular permeability of prodrugs across Caco-2 monolayer compared to the parent drug (P(app) = 2.24 × 10(-6) ± 1.33 × 10(-7) cm/s for L-valyl prodrug of zanamivir), with only parent zanamivir appearing in the receiver compartment, indicates that the prodrugs exhibited both enhanced transport and activation in intestinal mucosal cells. Most significantly, several of these prodrugs exhibited high intestinal jejunal membrane permeability, similar to metoprolol, in the in situ rat intestinal perfusion system, a system highly correlated with human jejunal permeability. In summary, this mechanistic targeted prodrug strategy, to enhance oral absorption via intestinal membrane carriers such as hPepT1, followed by activation to parent drug (active pharmaceutical ingredient or API) in the mucosal cell, significantly improves the intestinal epithelial cell permeability of zanamivir and has the

  4. Bioactive Milk for Intestinal Maturation in Preterm Neonates

    DEFF Research Database (Denmark)

    Li, Yanqi

    The fetal small intestine grows dramatically fast during the second and third trimester of human pregnancy. Many intestinal functions are therefore affected by preterm birth, including gastrointestinal motility, digestive and absorptive function, mucosal barrier function, and the intestinal...

  5. Distinct Shifts in Microbiota Composition during Drosophila Aging Impair Intestinal Function and Drive Mortality

    Directory of Open Access Journals (Sweden)

    Rebecca I. Clark

    2015-09-01

    Full Text Available Alterations in the composition of the intestinal microbiota have been correlated with aging and measures of frailty in the elderly. However, the relationships between microbial dynamics, age-related changes in intestinal physiology, and organismal health remain poorly understood. Here, we show that dysbiosis of the intestinal microbiota, characterized by an expansion of the Gammaproteobacteria, is tightly linked to age-onset intestinal barrier dysfunction in Drosophila. Indeed, alterations in the microbiota precede and predict the onset of intestinal barrier dysfunction in aged flies. Changes in microbial composition occurring prior to intestinal barrier dysfunction contribute to changes in excretory function and immune gene activation in the aging intestine. In addition, we show that a distinct shift in microbiota composition follows intestinal barrier dysfunction, leading to systemic immune activation and organismal death. Our results indicate that alterations in microbiota dynamics could contribute to and also predict varying rates of health decline during aging in mammals.

  6. The effects of Lactobacillus plantarum on small intestinal barrier function and mucosal gene transcription; A randomized double-blind placebo controlled trial

    NARCIS (Netherlands)

    Mujagic, Zlatan; Vos, De Paul; Boekschoten, Mark V.; Govers, Coen; Pieters, Harm J.H.M.; Wit, De Nicole J.W.; Bron, Peter A.; Masclee, Ad A.M.; Troost, Freddy J.

    2017-01-01

    The aim of this study was to investigate the effects of three Lactobacillus plantarum strains on in-vivo small intestinal barrier function and gut mucosal gene transcription in human subjects. The strains were selected for their differential effects on TLR signalling and tight junction protein

  7. The effects of Lactobacillus plantarum on small intestinal barrier function and mucosal gene transcription; a randomized double-blind placebo controlled trial

    NARCIS (Netherlands)

    Mujagic, Zlatan; Vos, de Paul; Boekschoten, Mark; Govers, Coen; Pieters, Harm J.H.M.; Wit, de Nicole; Bron, Peter A.; Masclee, Ad A.M.; Troost, Freddy J.

    2017-01-01

    The aim of this study was to investigate the effects of three Lactobacillus plantarum strains on in-vivo small intestinal barrier function and gene transcription in human subjects. The strains were selected for their differential effects on TLR signalling and tight junction protein rearrangement,

  8. The effects of Lactobacillus plantarum on small intestinal barrier function and mucosal gene transcription; a randomized double-blind placebo controlled trial

    NARCIS (Netherlands)

    Mujagic, Zlatan; de Vos, Paul; Boekschoten, Mark V.; Govers, Coen; Pieters, Harm-Jan H M; de Wit, Nicole J. W.; Bron, Peter A.; Masclee, Ad A M; Troost, Freddy J

    2017-01-01

    The aim of this study was to investigate the effects of three Lactobacillus plantarum strains on in-vivo small intestinal barrier function and gut mucosal gene transcription in human subjects. The strains were selected for their differential effects on TLR signalling and tight junction protein

  9. Krüppel-like factor 5 is essential for maintenance of barrier function in mouse colon.

    Science.gov (United States)

    Liu, Yang; Chidgey, Martyn; Yang, Vincent W; Bialkowska, Agnieszka B

    2017-11-01

    Krüppel-like factor 5 (KLF5) is a member of the zinc finger family of transcription factors that regulates homeostasis of the intestinal epithelium. Previous studies suggested an indispensable role of KLF5 in maintaining intestinal barrier function. In the current study, we investigated the mechanisms by which KLF5 regulates colonic barrier function in vivo and in vitro. We used an inducible and a constitutive intestine-specific Klf5 knockout mouse models ( Villin-CreER T2 ;Klf5 fl/fl designated as Klf5 ΔIND and Villin-Cre;Klf5 fl/fl as Klf5 ΔIS ) and studied an inducible KLF5 knockdown in Caco-2 BBe cells using a lentiviral Tet-on system (Caco-2 BBe KLF5ΔIND ). Specific knockout of Klf5 in colonic tissues, either inducible or constitutive, resulted in increased intestinal permeability. The phenotype was accompanied by a significant reduction in Dsg2 , which encodes desmoglein-2, a desmosomal cadherin, at both mRNA and protein levels. Transmission electron microscopy showed alterations of desmosomal morphology in both KLF5 knockdown Caco-2 BBe cells and Klf5 knockout mouse colonic tissues. Inducible knockdown of KLF5 in Caco-2BBe cells grown on Transwell plates led to impaired barrier function as evidenced by decreased transepithelial electrical resistance and increased paracellular permeability to fluorescein isothiocyanate-4 kDa dextran. Furthermore, DSG2 was significantly decreased in KLF5 knockdown cells, and DSG2 overexpression partially rescued the impaired barrier function caused by KLF5 knockdown. Electron microscopy studies demonstrated altered desmosomal morphology after KLF5 knockdown. In combination with chromatin immunoprecipitation analysis and promoter study, our data show that KLF5 regulates intestinal barrier function by mediating the transcription of DSG2 , a gene encoding a major component of desmosome structures. NEW & NOTEWORTHY The study is original research on the direct function of a Krüppel-like factor on intestinal barrier function

  10. Molecular Pathophysiology of Epithelial Barrier Dysfunction in Inflammatory Bowel Diseases

    Directory of Open Access Journals (Sweden)

    Jessica Y. Lee

    2018-03-01

    Full Text Available Over the years, the scientific community has explored myriads of theories in search of the etiology and a cure for inflammatory bowel disease (IBD. The cumulative evidence has pointed to the key role of the intestinal barrier and the breakdown of these mechanisms in IBD. More and more scientists and clinicians are embracing the concept of the impaired intestinal epithelial barrier and its role in the pathogenesis and natural history of IBD. However, we are missing a key tool that bridges these scientific insights to clinical practice. Our goal is to overcome the limitations in understanding the molecular physiology of intestinal barrier function and develop a clinical tool to assess and quantify it. This review article explores the proteins in the intestinal tissue that are pivotal in regulating intestinal permeability. Understanding the molecular pathophysiology of impaired intestinal barrier function in IBD may lead to the development of a biochemical method of assessing intestinal tissue integrity which will have a significant impact on the development of novel therapies targeting the intestinal mucosa.

  11. Alcohol-associated intestinal dysbiosis impairs pulmonary host defense against Klebsiella pneumoniae.

    Directory of Open Access Journals (Sweden)

    Derrick R Samuelson

    2017-06-01

    Full Text Available Chronic alcohol consumption perturbs the normal intestinal microbial communities (dysbiosis. To investigate the relationship between alcohol-mediated dysbiosis and pulmonary host defense we developed a fecal adoptive transfer model, which allows us to investigate the impact of alcohol-induced gut dysbiosis on host immune response to an infectious challenge at a distal organ, independent of prevailing alcohol use. Male C57BL/6 mice were treated with a cocktail of antibiotics (ampicillin, gentamicin, neomycin, vancomycin, and metronidazole via daily gavage for two weeks. A separate group of animals was fed a chronic alcohol (or isocaloric dextrose pair-fed controls liquid diet for 10 days. Microbiota-depleted mice were recolonized with intestinal microbiota from alcohol-fed or pair-fed (control animals. Following recolonization groups of mice were sacrificed prior to and 48 hrs. post respiratory infection with Klebsiella pneumoniae. Klebsiella lung burden, lung immunology and inflammation, as well as intestinal immunology, inflammation, and barrier damage were examined. Results showed that alcohol-associated susceptibility to K. pneumoniae is, in part, mediated by gut dysbiosis, as alcohol-naïve animals recolonized with a microbiota isolated from alcohol-fed mice had an increased respiratory burden of K. pneumoniae compared to mice recolonized with a control microbiota. The increased susceptibility in alcohol-dysbiosis recolonized animals was associated with an increase in pulmonary inflammatory cytokines, and a decrease in the number of CD4+ and CD8+ T-cells in the lung following Klebsiella infection but an increase in T-cell counts in the intestinal tract following Klebsiella infection, suggesting intestinal T-cell sequestration as a factor in impaired lung host defense. Mice recolonized with an alcohol-dysbiotic microbiota also had increased intestinal damage as measured by increased levels of serum intestinal fatty acid binding protein

  12. Functional nanoparticles exploit the bile acid pathway to overcome multiple barriers of the intestinal epithelium for oral insulin delivery

    DEFF Research Database (Denmark)

    Fan, Weiwei; Xia, Dengning; Zhu, Quanlei

    2018-01-01

    , especially to avoid lysosomal degradation, and basolateral release. Here, the functional material, deoxycholic acid-conjugated chitosan, is synthesized and loaded with the model protein drug insulin into deoxycholic acid-modified nanoparticles (DNPs). The DNPs designed in this study are demonstrated......Oral absorption of protein/peptide-loaded nanoparticles is often limited by multiple barriers of the intestinal epithelium. In addition to mucus translocation and apical endocytosis, highly efficient transepithelial absorption of nanoparticles requires successful intracellular trafficking...... to endolysosomal escape of DNPs. Additionally, DNPs can interact with a cytosolic ileal bile acid-binding protein that facilitates the intracellular trafficking and basolateral release of insulin. In rats, intravital two-photon microscopy also reveals that the transport of DNPs into the intestinal villi...

  13. Alpha-Melanocyte Stimulating Hormone Protects against Cytokine-Induced Barrier Damage in Caco-2 Intestinal Epithelial Monolayers.

    Directory of Open Access Journals (Sweden)

    Judit Váradi

    Full Text Available Alpha-melanocyte-stimulating hormone (α-MSH is a potent anti-inflammatory peptide with cytoprotective effect in various tissues. The present investigation demonstrates the ability of α-MSH to interact with intestinal epithelial cell monolayers and mitigate inflammatory processes of the epithelial barrier. The protective effect of α-MSH was studied on Caco-2 human intestinal epithelial monolayers, which were disrupted by exposure to tumor necrosis factor-α and interleukin-1β. The barrier integrity was assessed by measuring transepithelial electric resistance (TEER and permeability for marker molecules. Caco-2 monolayers were evaluated by immunohistochemistry for expression of melanocortin-1 receptor and tight junction proteins ZO-1 and claudin-4. The activation of nuclear factor kappa beta (NF-κB was detected by fluorescence microscopy and inflammatory cytokine expression was assessed by flow cytometric bead array cytokine assay. Exposure of Caco-2 monolayers to proinflammatory cytokines lowered TEER and increased permeability for fluorescein and albumin, which was accompanied by changes in ZO-1 and claudin-4 immunostaining. α-MSH was able to prevent inflammation-associated decrease of TEER in a dose-dependent manner and reduce the increased permeability for paracellular marker fluorescein. Further immunohistochemistry analysis revealed proinflammatory cytokine induced translocation of the NF-κB p65 subunit into Caco-2 cell nuclei, which was inhibited by α-MSH. As a result the IL-6 and IL-8 production of Caco-2 monolayers were also decreased with different patterns by the addition of α-MSH to the culture medium. In conclusion, Caco-2 cells showed a positive immunostaining for melanocortin-1 receptor and α-MSH protected Caco-2 cells against inflammatory barrier dysfunction and inflammatory activation induced by tumor necrosis factor-α and interleukin-1β cytokines.

  14. Does vasoactive intestinal polypeptide mediate the pathophysiology of bowel obstruction?

    Science.gov (United States)

    Basson, M D; Fielding, L P; Bilchik, A J; Zucker, K A; Ballantyne, G H; Sussman, J; Adrian, T E; Modlin, I M

    1989-01-01

    We hypothesized that bioactive peptides might be released into the portal circulation and mediate pathophysiologic alterations accompanying small bowel obstruction. We studied this question in a subacute canine small bowel obstruction model using 50 percent diameter occlusion. Control animals underwent sham laparotomy. Vasoactive intestinal peptide (VIP), peptide YY, and gastrin were measured in portal and systemic plasma by specific radioimmunoassays at 24-hour intervals as the obstruction progressed to completion over 5 days. All peptides in both groups demonstrated portal and peripheral gradients. In control dogs, peptide concentrations did not change postoperatively but VIP increased markedly in obstructed dogs, demonstrating a median portal level of 95 pmol/liter at 96 hours compared with 31.5 pmol/liter in control animals. These portal VIP levels are known to cause hypersecretion and splanchnic vasodilation in experimental models. The release of vasoactive compounds such as VIP may mediate local pathophysiology in human small bowel obstruction. A similar explanation of the systemic effects is consistent with the known cardiopulmonary bioactivity of VIP.

  15. JAK/STAT-1 Signaling Is Required for Reserve Intestinal Stem Cell Activation during Intestinal Regeneration Following Acute Inflammation

    Directory of Open Access Journals (Sweden)

    Camilla A. Richmond

    2018-01-01

    Full Text Available The intestinal epithelium serves as an essential barrier to the outside world and is maintained by functionally distinct populations of rapidly cycling intestinal stem cells (CBC ISCs and slowly cycling, reserve ISCs (r-ISCs. Because disruptions in the epithelial barrier can result from pathological activation of the immune system, we sought to investigate the impact of inflammation on ISC behavior during the regenerative response. In a murine model of αCD3 antibody-induced small-intestinal inflammation, r-ISCs proved highly resistant to injury, while CBC ISCs underwent apoptosis. Moreover, r-ISCs were induced to proliferate and functionally contribute to intestinal regeneration. Further analysis revealed that the inflammatory cytokines interferon gamma and tumor necrosis factor alpha led to r-ISC activation in enteroid culture, which could be blocked by the JAK/STAT inhibitor, tofacitinib. These results highlight an important role for r-ISCs in response to acute intestinal inflammation and show that JAK/STAT-1 signaling is required for the r-ISC regenerative response.

  16. β-1,3/1,6-Glucan alleviated intestinal mucosal barrier impairment of broiler chickens challenged with Salmonella enterica serovar Typhimurium.

    Science.gov (United States)

    Shao, Yujing; Guo, Yuming; Wang, Zhong

    2013-07-01

    This study investigated the protective effect of β-1,3/1,6-glucan on gut morphology, intestinal epithelial tight junctions, and bacterial translocation of broiler chickens challenged with Salmonella enterica serovar Typhimurium. Ninety Salmonella-free Arbor Acre male broiler chickens were randomly divided into 3 groups: negative control group (NC), Salmonella Typhimurium-infected positive group (PC), and the Salmonella Typhimurium-infected group with dietary 100 mg/kg of β-1,3/1,6-glucan supplementation (T) to determine the effect of β-1,3/1,6-glucan on intestinal barrier function. Salmonella Typhimurium challenge alone significantly decreased villus height (P chickens challenged with Salmonella Typhimurium.

  17. Valence and atomic size dependent exchange barriers in vacancy-mediated dopant diffusion

    International Nuclear Information System (INIS)

    Nelson, J.S.; Schultz, P.A.; Wright, A.F.

    1998-01-01

    First-principles pseudopotential calculations of dopant-vacancy exchange barriers indicate a strong dependency on dopant valence and atomic size, in contrast to current models of vacancy-mediated dopant diffusion. First-row elements (B, C, N) are found to have exchange barriers which are an order of magnitude larger than the assumed value of 0.3 eV (the Si vacancy migration energy). copyright 1998 American Institute of Physics

  18. Campylobacter jejuni induces transcytosis of commensal bacteria across the intestinal epithelium through M-like cells

    Science.gov (United States)

    2010-01-01

    Background Recent epidemiological analyses have implicated acute Campylobacter enteritis as a factor that may incite or exacerbate inflammatory bowel disease (IBD) in susceptible individuals. We have demonstrated previously that C. jejuni disrupts the intestinal barrier function by rapidly inducing epithelial translocation of non-invasive commensal bacteria via a transcellular lipid raft-mediated mechanism ('transcytosis'). To further characterize this mechanism, the aim of this current study was to elucidate whether C. jejuni utilizes M cells to facilitate transcytosis of commensal intestinal bacteria. Results C. jejuni induced translocation of non-invasive E. coli across confluent Caco-2 epithelial monolayers in the absence of disrupted transepithelial electrical resistance or increased permeability to a 3 kDa dextran probe. C. jejuni-infected monolayers displayed increased numbers of cells expressing the M cell-specific marker, galectin-9, reduced numbers of enterocytes that stained with the absorptive enterocyte marker, Ulex europaeus agglutinin-1, and reduced activities of enzymes typically associated with absorptive enterocytes (namely alkaline phosphatase, lactase, and sucrase). Furthermore, in Campylobacter-infected monolayers, E. coli were observed to be internalized specifically within epithelial cells displaying M-like cell characteristics. Conclusion These data indicate that C. jejuni may utilize M cells to promote transcytosis of non-invasive bacteria across the intact intestinal epithelial barrier. This mechanism may contribute to the inflammatory immune responses against commensal intestinal bacteria commonly observed in IBD patients. PMID:21040540

  19. Campylobacter jejuni induces transcytosis of commensal bacteria across the intestinal epithelium through M-like cells

    Directory of Open Access Journals (Sweden)

    Kalischuk Lisa D

    2010-11-01

    Full Text Available Abstract Background Recent epidemiological analyses have implicated acute Campylobacter enteritis as a factor that may incite or exacerbate inflammatory bowel disease (IBD in susceptible individuals. We have demonstrated previously that C. jejuni disrupts the intestinal barrier function by rapidly inducing epithelial translocation of non-invasive commensal bacteria via a transcellular lipid raft-mediated mechanism ('transcytosis'. To further characterize this mechanism, the aim of this current study was to elucidate whether C. jejuni utilizes M cells to facilitate transcytosis of commensal intestinal bacteria. Results C. jejuni induced translocation of non-invasive E. coli across confluent Caco-2 epithelial monolayers in the absence of disrupted transepithelial electrical resistance or increased permeability to a 3 kDa dextran probe. C. jejuni-infected monolayers displayed increased numbers of cells expressing the M cell-specific marker, galectin-9, reduced numbers of enterocytes that stained with the absorptive enterocyte marker, Ulex europaeus agglutinin-1, and reduced activities of enzymes typically associated with absorptive enterocytes (namely alkaline phosphatase, lactase, and sucrase. Furthermore, in Campylobacter-infected monolayers, E. coli were observed to be internalized specifically within epithelial cells displaying M-like cell characteristics. Conclusion These data indicate that C. jejuni may utilize M cells to promote transcytosis of non-invasive bacteria across the intact intestinal epithelial barrier. This mechanism may contribute to the inflammatory immune responses against commensal intestinal bacteria commonly observed in IBD patients.

  20. Mediating role of critical thinking disposition in the relationship between perceived barriers to research use and evidence-based practice.

    Science.gov (United States)

    Kim, Sun-Ae; Song, Youngshin; Sim, Hee-Sook; Ahn, Eun-Kyong; Kim, Jung-Hee

    2015-01-01

    Despite the importance of critical thinking in clinical and educational settings, little is known about its role in evidence-based practice (EBP). This study examined whether critical thinking disposition (CTD) mediates the relationship between perceived barriers to research use and EBP in clinical nurses (N=409). A path diagram using structural equation modeling was used to estimate the direct and indirect effects of perceived barriers to research use on EBP, controlling for CTD as a mediator. CTD partially mediated the relationship between perceived barriers to research use and EBP. Furthermore, the hypothesized mediation model demonstrated an appropriate fit to the data. Individual and organizational efforts are needed to help nurses further improve their critical thinking skills. CTD is important as research barriers to engage effectively in EBP. Without the skills to evaluate evidence carefully, research utilization may be compromised.

  1. INTESTINAL PERMEABILITY IN PEDIATRIC GASTROENTEROLOGY

    NARCIS (Netherlands)

    VANELBURG, RM; UIL, JJ; DEMONCHY, JGR; HEYMANS, HSA

    1992-01-01

    The role of the physiologic barrier function of the small bowel and its possible role in health and disease has attracted much attention over the past decade. The intestinal mucosal barrier for luminal macromolecules and microorganism is the result of non-immunologic and immunologic defense

  2. Celiac Disease: Role of the Epithelial BarrierSummary

    Directory of Open Access Journals (Sweden)

    Michael Schumann

    2017-03-01

    Full Text Available In celiac disease (CD a T-cell–mediated response to gluten is mounted in genetically predisposed individuals, resulting in a malabsorptive enteropathy histologically highlighted by villous atrophy and crypt hyperplasia. Recent data point to the epithelial layer as an under-rated hot spot in celiac pathophysiology to date. This overview summarizes current functional and genetic evidence on the role of the epithelial barrier in CD, consisting of the cell membranes and the apical junctional complex comprising sealing as well as ion and water channel-forming tight junction proteins and the adherens junction. Moreover, the underlying mechanisms are discussed, including apoptosis of intestinal epithelial cells, biology of intestinal stem cells, alterations in the apical junctional complex, transcytotic uptake of gluten peptides, and possible implications of a defective epithelial polarity. Current research is directed toward new treatment options for CD that are alternatives or complementary therapeutics to a gluten-free diet. Thus, strategies to target an altered epithelial barrier therapeutically also are discussed. Keywords: Celiac Sprue, Gluten-Sensitive Enteropathy, Tight Junction, Epithelial Polarity, Partitioning-Defective Proteins, α-Gliadin 33mer

  3. [Bacterial Translocation from Intestine: Microbiological, Immunological and Pathophysiological Aspects].

    Science.gov (United States)

    Podoprigora, G I; Kafarskaya, L I; Bainov, N A; Shkoporov, A N

    2015-01-01

    Bacterial translocation (BT) is both pathology and physiology phenomenon. In healthy newborns it accompanies the process of establishing the autochthonous intestinal microbiota and the host microbiome. In immunodeficiency it can be an aethio-pathogenetic link and a manifestation of infection or septic complications. The host colonization resistance to exogenous microbic colonizers is provided by gastrointestinal microbiota in concert with complex constitutional and adaptive defense mechanisms. BT may be result of barrier dysfunction and self-purification mechanisms involving the host myeloid cell phagocytic system and opsonins. Dynamic cell humoral response to microbial molecular patterns that occurs on the mucous membranes initiates receptorsignalingpathways and cascade ofreactions. Their vector and results are largely determined by cross-reactivity between microbiome and the host genome. Enterocyte barriers interacting with microbiota play leading role in providing adaptive, homeostatic and stress host reactivity. Microcirculatory ischemic tissue alterations and inflammatory reactions increase the intestinal barrier permeability and BT These processes a well as mechanisms for apoptotic cells and bacteria clearance are justified to be of prospective research interest. The inflammatory and related diseases caused by alteration and dysfunction of the intestinal barrier are reasonably considered as diseases of single origin. Maternal microbiota affects theformation of the innate immune system and the microbiota of the newborn, including intestinal commensal translocation during lactation. Deeper understanding of intestinal barrier mechanisms needs complex microbiological, immunological, pathophysiological, etc. investigations using adequate biomodels, including gnotobiotic animals.

  4. The effect of barrier layer-mediated catalytic deactivation in vertically aligned carbon nanotube growth

    International Nuclear Information System (INIS)

    Patole, S P; Yu, Seong-Man; Shin, Dong-Wook; Yoo, Ji-Beom; Kim, Ha-Jin; Han, In-Taek; Kwon, Kee-Won

    2010-01-01

    The effect of Al-barrier layer-mediated Fe-catalytic deactivation in vertically aligned carbon nanotube (CNT) growth was studied. The substrate surface morphology, catalytic diffusion and barrier layer oxidation were found to be dependent on the annealing temperature of the barrier layer, which ultimately affects CNT growth. The annealed barrier layer without complete oxidation was found to be suitable for top to bottom super aligned CNT arrays. The highest average CNT growth rate of up to 3.88 μm s -1 was observed using this simple approach. Details of the analysis are also presented.

  5. Intestinal Epithelial Cell Endoplasmic Reticulum Stress and Inflammatory Bowel Disease Pathogenesis: An Update Review

    Directory of Open Access Journals (Sweden)

    Xiaoshi Ma

    2017-10-01

    Full Text Available The intestinal epithelial cells serve essential roles in maintaining intestinal homeostasis, which relies on appropriate endoplasmic reticulum (ER function for proper protein folding, modification, and secretion. Exogenous or endogenous risk factors with an ability to disturb the ER function can impair the intestinal barrier function and activate inflammatory responses in the host. The last decade has witnessed considerable progress in the understanding of the functional role of ER stress and unfolded protein response (UPR in the gut homeostasis and its significant contribution to the pathogenesis of inflammatory bowel disease (IBD. Herein, we review recent evidence supporting the viewpoint that deregulation of ER stress and UPR signaling in the intestinal epithelium, including the absorptive cells, Paneth cells, goblet cells, and enteroendocrine cells, mediates the action of genetic or environmental factors driving colitis in experimental animals and IBD patients. In addition, we highlight pharmacologic application of chaperones or small molecules that enhance protein folding and modification capacity or improve the function of the ER. These molecules represent potential therapeutic strategies in the prevention or treatment of IBD through restoring ER homeostasis in intestinal epithelial cells.

  6. Biorelevant media resistant co-culture model mimicking permeability of human intestine.

    Science.gov (United States)

    Antoine, Delphine; Pellequer, Yann; Tempesta, Camille; Lorscheidt, Stefan; Kettel, Bernadette; Tamaddon, Lana; Jannin, Vincent; Demarne, Frédéric; Lamprecht, Alf; Béduneau, Arnaud

    2015-03-15

    Cell culture models are currently used to predict absorption pattern of new compounds and formulations in the human gastro-intestinal tract (GIT). One major drawback is the lack of relevant apical incubation fluids allowing mimicking luminal conditions in the GIT. Here, we suggest a culture model compatible with biorelevant media, namely Fasted State Simulated Intestinal Fluid (FaSSIF) and Fed State Simulated Intestinal Fluid (FeSSIF). Co-culture was set up from Caco-2 and mucus-secreting HT29-MTX cells using an original seeding procedure. Viability and cytotoxicity assays were performed following incubation of FeSSIF and FaSSIF with co-culture. Influence of biorelevant fluids on paracellular permeability or transporter proteins were also evaluated. Results were compared with Caco-2 and HT29-MTX monocultures. While Caco-2 viability was strongly affected with FeSSIF, no toxic effect was detected for the co-cultures in terms of viability and lactate dehydrogenase release. The addition of FeSSIF to the basolateral compartment of the co-culture induced cytotoxic effects which suggested the apical mucus barrier being cell protective. In contrast to FeSSIF, FaSSIF induced a slight increase of the paracellular transport and both tested media inhibited partially the P-gp-mediated efflux in the co-culture. Additionally, the absorptive transport of propranolol hydrochloride, a lipophilic β-blocker, was strongly affected by biorelevant fluids. This study demonstrated the compatibility of the Caco-2/HT29-MTX model with some of the current biorelevant media. Combining biorelevant intestinal fluids with features such as mucus secretion, adjustable paracellular and P-gp mediated transports, is a step forward to more realistic in-vitro models of the human intestine. Copyright © 2015. Published by Elsevier B.V.

  7. Oral Administration of Probiotics Increases Paneth Cells and Intestinal Antimicrobial Activity

    Directory of Open Access Journals (Sweden)

    Silvia I. Cazorla

    2018-04-01

    Full Text Available The huge amount of intestinal bacteria represents a continuing threat to the intestinal barrier. To meet this challenge, gut epithelial cells produce antimicrobial peptides (AMP that act at the forefront of innate immunity. We explore whether this antimicrobial activity and Paneth cells, the main intestinal cell responsible of AMP production, are influenced by probiotics administration, to avoid the imbalance of intestinal microbiota and preserve intestinal barrier. Administration of Lactobacillus casei CRL 431 (Lc 431 and L. paracasei CNCM I-1518 (Lp 1518 to 42 days old mice, increases the number of Paneth cells on small intestine, and the antimicrobial activity against the pathogens Staphylococcus aureus and Salmonella Typhimurium in the intestinal fluids. Specifically, strong damage of the bacterial cell with leakage of cytoplasmic content, and cellular fragmentation were observed in S. Typhimurium and S. aureus. Even more important, probiotics increase the antimicrobial activity of the intestinal fluids at the different ages, from weaning (21 days old to old age (180 days old. Intestinal antimicrobial activity stimulated by oral probiotics, do not influence significantly the composition of total anaerobic bacteria, lactobacilli and enterobacteria in the large intestine, at any age analyzed. This result, together with the antimicrobial activity observed against the same probiotic bacteria; endorse the regular consumption of probiotics without adverse effect on the intestinal homeostasis in healthy individuals. We demonstrate that oral probiotics increase intestinal antimicrobial activity and Paneth cells in order to strengthen epithelial barrier against pathogens. This effect would be another important mechanism by which probiotics protect the host mainly against infectious diseases.

  8. Type 3 innate lymphoid cells maintain intestinal epithelial stem cells after tissue damage

    NARCIS (Netherlands)

    P. Aparicio-Domingo (Patricia); M. Romera Hernández (Mónica); J.J. Karrich (Julien J.); F.H.J. Cornelissen (Ferry); N. Papazian (Natalie); D.J. Lindenbergh-Kortleve (Dicky); J.A. Butler (James A.); L. Boon (Louis); M. Coles (Mark); J.N. Samsom (Janneke); T. Cupedo (Tom)

    2015-01-01

    textabstractDisruption of the intestinal epithelial barrier allows bacterial translocation and predisposes to destructive inflammation. To ensure proper barrier composition, crypt-residing stem cells continuously proliferate and replenish all intestinal epithelial cells within days. As a consequence

  9. [Protective effect of Saccharomyces boulardii against intestinal mucosal barrier injury in rats with nonalcoholic fatty liver disease].

    Science.gov (United States)

    Liu, Y T; Li, Y Q; Wang, Y Z

    2016-12-20

    Objective: To investigate the protective effect of Saccharomyces boulardii against intestinal mucosal barrier injury in rats with nonalcoholic fatty liver disease (NAFLD). Methods: A total of 36 healthy male Sprague-Dawley rats with a mean body weight of 180±20 g were randomly divided into control group, model group, and treatment group, with 12 rats in each group, after adaptive feeding for 1 week. The rats in the control group were given basic feed, and those in the model group and treatment group were given high-fat feed. After 12 weeks of feeding, the treatment group was given Saccharomyces boulardii (75×10 8 CFU/kg/d) by gavage, and those in the control group and model group were given isotonic saline by gavage. At the 20th week, blood samples were taken from the abdominal aorta to measure the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), intestinal fatty acid binding protein (IFABP), tumor necrosis factor-α (TNF-α), and endotoxins. The liver pathological changes, intestinal histopathological changes, and expression of occludin in the intestinal mucosa were observed. Fecal samples were collected to measure the changes in Escherichia coli and Bacteroides. A one-way analysis of variance and the SNK test were used for comparison between multiple groups, and the rank sum test was used as the non-parametric test. Results: Compared with the control group, the model group had significantly higher body weight, liver mass, and liver index ( P 0.05). Compared with the control group, the model group had significant increases in the levels of endotoxin, TNF-α, and IFABP ( P Saccharomyces boulardii can reduce body weight and improve hepatocyte steatosis. Saccharomyces boulardii can reduce endotoxemia in NAFLD rats and thus alleviate inflammatory response. Saccharomyces boulardii can also adjust the proportion of Escherichia coli and Bacteroides in the intestine of NAFLD rats.

  10. Small intestinal efflux mediated by MRP2 and BCRP shifts sulfasalazine intestinal permeability from high to low, enabling its colonic targeting.

    Science.gov (United States)

    Dahan, Arik; Amidon, Gordon L

    2009-08-01

    Sulfasalazine is characterized by low intestinal absorption, which essentially enables its colonic targeting and therapeutic action. The mechanisms behind this low absorption have not yet been elucidated. The purpose of this study was to investigate the role of efflux transporters in the intestinal absorption of sulfasalazine as a potential mechanism for its low small-intestinal absorption and colonic targeting following oral administration. The effects of P-glycoprotein (P-gp), multidrug resistance-associated protein 2 (MRP2), and breast cancer resistance protein (BCRP) inhibitors on sulfasalazine bidirectional permeability were studied across Caco-2 cell monolayers, including dose-response analysis. Sulfasalazine in vivo permeability was then investigated in the rat jejunum by single-pass perfusion, in the presence vs. absence of inhibitors. Sulfasalazine exhibited 19-fold higher basolateral-to-apical (BL-AP) than apical-to-basolateral (AP-BL) Caco-2 permeability, indicative of net mucosal secretion. MRP2 inhibitors (MK-571 and indomethacin) and BCRP inhibitors [fumitremorgin C (FTC) and pantoprazole] significantly increased AP-BL and decreased BL-AP sulfasalazine Caco-2 transport in a concentration-dependent manner. No effect was observed with the P-gp inhibitors verapamil and quinidine. The IC50 values of the specific MRP2 and BCRP inhibitors MK-571 and FTC on sulfasalazine secretion were 21.5 and 2.0 microM, respectively. Simultaneous inhibition of MRP2 and BCRP completely abolished sulfasalazine Caco-2 efflux. Without inhibitors, sulfasalazine displayed low (vs. metoprolol) in vivo intestinal permeability in the rat model. MK-571 or FTC significantly increased sulfasalazine permeability, bringing it to the low-high permeability boundary. With both MK-571 and FTC present, sulfasalazine displayed high permeability. In conclusion, efflux transport mediated by MRP2 and BCRP, but not P-gp, shifts sulfasalazine permeability from high to low, thereby enabling its

  11. Effect of probiotics on gastrointestinal symptoms and small intestinal permeability in children with atopic dermatitis

    DEFF Research Database (Denmark)

    Rosenfeldt, Vibeke; Benfeldt, Eva; Valerius, Niels Henrik

    2004-01-01

    OBJECTIVE: To determine whether probiotic lactobacilli may alleviate small intestinal inflammation and strengthen the intestinal barrier function in children with atopic dermatitis. STUDY DESIGN: In a double-blinded, placebo-controlled, cross-over study, probiotic lactobacilli (Lactobacillus...... placebo and r=0.53, P=.05 after active treatment). After probiotic treatment, the lactulose to mannitol ratio was lower (0.073) than after placebo (0.110, P=.001). CONCLUSIONS: Impairment of the intestinal mucosal barrier appears to be involved in the pathogenesis of atopic dermatitis. The study suggests...... that probiotic supplementation may stabilize the intestinal barrier function and decrease gastrointestinal symptoms in children with atopic dermatitis....

  12. PVA gel as a potential adhesion barrier: a safety study in a large animal model of intestinal surgery.

    Science.gov (United States)

    Renz, Bernhard W; Leitner, Kurt; Odermatt, Erich; Worthley, Daniel L; Angele, Martin K; Jauch, Karl-Walter; Lang, Reinhold A

    2014-03-01

    Intra-abdominal adhesions following surgery are a major source of morbidity and mortality including abdominal pain and small bowel obstruction. This study evaluated the safety of PVA gel (polyvinyl alcohol and carboxymethylated cellulose gel) on intestinal anastomoses and its potential effectiveness in preventing adhesions in a clinically relevant large animal model. Experiments were performed in a pig model with median laparotomy and intestinal anastomosis following small bowel resection. The primary endpoint was the safety of PVA on small intestinal anastomoses. We also measured the incidence of postoperative adhesions in PVA vs. control groups: group A (eight pigs): stapled anastomosis with PVA gel compared to group B (eight pigs), which had no PVA gel; group C (eight pigs): hand-sewn anastomosis with PVA gel compared to group B (eight pigs), which had no anti-adhesive barrier. Animals were sacrificed 14 days after surgery and analyzed. All anastomoses had a patent lumen without any stenosis. No anastomoses leaked at an intraluminal pressure of 40 cmH2O. Thus, anastomoses healed very well in both groups, regardless of whether PVA was administered. PVA-treated animals, however, had significantly fewer adhesions in the area of stapled anastomoses. The hand-sewn PVA group also had weaker adhesions and trended towards fewer adhesions to adjacent organs. These results suggest that PVA gel does not jeopardize the integrity of intestinal anastomoses. However, larger trials are needed to investigate the potential of PVA gel to prevent adhesions in gastrointestinal surgery.

  13. Food-grade TiO2 is trapped by intestinal mucus in vitro but does not impair mucin O-glycosylation and short-chain fatty acid synthesis in vivo: implications for gut barrier protection.

    Science.gov (United States)

    Talbot, Pauline; Radziwill-Bienkowska, Joanna M; Kamphuis, Jasper B J; Steenkeste, Karine; Bettini, Sarah; Robert, Véronique; Noordine, Marie-Louise; Mayeur, Camille; Gaultier, Eric; Langella, Philippe; Robbe-Masselot, Catherine; Houdeau, Eric; Thomas, Muriel; Mercier-Bonin, Muriel

    2018-06-19

    Titanium dioxide (TiO 2 ) particles are commonly used as a food additive (E171 in the EU) for its whitening and opacifying properties. However, the risk of gut barrier disruption is an increasing concern because of the presence of a nano-sized fraction. Food-grade E171 may interact with mucus, a gut barrier protagonist still poorly explored in food nanotoxicology. To test this hypothesis, a comprehensive approach was performed to evaluate in vitro and in vivo interactions between TiO 2 and intestinal mucus, by comparing food-grade E171 with NM-105 (Aeroxyde P25) OECD reference nanomaterial. We tested E171-trapping properties of mucus in vitro using HT29-MTX intestinal epithelial cells. Time-lapse confocal laser scanning microscopy was performed without labeling to avoid modification of the particle surface. Near-UV irradiation of E171 TiO 2 particles at 364 nm resulted in fluorescence emission in the visible range, with a maximum at 510 nm. The penetration of E171 TiO 2 into the mucoid area of HT29-MTX cells was visualized in situ. One hour after exposure, TiO 2 particles accumulated inside "patchy" regions 20 µm above the substratum. The structure of mucus produced by HT29-MTX cells was characterized by MUC5AC immunofluorescence staining. The mucus layer was thin and organized into regular "islands" located approximately 20 µm above the substratum. The region-specific trapping of food-grade TiO 2 particles was attributed to this mucus patchy structure. We compared TiO 2 -mediated effects in vivo in rats after acute or sub-chronic oral daily administration of food-grade E171 and NM-105 at relevant exposure levels for humans. Cecal short-chain fatty acid profiles and gut mucin O-glycosylation patterns remained unchanged, irrespective of treatment. Food-grade TiO 2 is trapped by intestinal mucus in vitro but does not affect mucin O-glycosylation and short-chain fatty acid synthesis in vivo, suggesting the absence of a mucus barrier impairment under "healthy gut

  14. [Construction of research system for processing mechanism of traditional Chinese medicine based on chemical composition transformation combined with intestinal absorption barrier].

    Science.gov (United States)

    Sun, E; Xu, Feng-Juan; Zhang, Zhen-Hai; Wei, Ying-Jie; Tan, Xiao-Bin; Cheng, Xu-Dong; Jia, Xiao-Bin

    2014-02-01

    Based on practice of Epimedium processing mechanism for many years and integrated multidisciplinary theory and technology, this paper initially constructs the research system for processing mechanism of traditional Chinese medicine based on chemical composition transformation combined with intestinal absorption barrier, which to form an innovative research mode of the " chemical composition changes-biological transformation-metabolism in vitro and in vivo-intestinal absorption-pharmacokinetic combined pharmacodynamic-pharmacodynamic mechanism". Combined with specific examples of Epimedium and other Chinese herbal medicine processing mechanism, this paper also discusses the academic thoughts, research methods and key technologies of this research system, which will be conducive to systematically reveal the modem scientific connotation of traditional Chinese medicine processing, and enrich the theory of Chinese herbal medicine processing.

  15. Intestinal cholesterol secretion : future clinical implications

    NARCIS (Netherlands)

    Jakulj, L.; Besseling, J.; Stroes, E. S. G.; Groen, A. K.

    2013-01-01

    Together with the liver, the intestine serves as a homeostatic organ in cholesterol metabolism. Recent evidence has substantiated the pivotal role of the intestine in reverse cholesterol transport (RCT). RCT is a fundamental antiatherogenic pathway, mediating the removal of cholesterol from tissues

  16. Intestinal cholesterol secretion: future clinical implications

    NARCIS (Netherlands)

    Jakulj, L.; Besseling, J.; Stroes, E. S. G.; Groen, A. K.

    2013-01-01

    Together with the liver, the intestine serves as a homeostatic organ in cholesterol metabolism. Recent evidence has substantiated the pivotal role of the intestine in reverse cholesterol transport (RCT). RCT is a fundamental antiatherogenic pathway, mediating the removal of cholesterol from tissues

  17. Visualization of probiotic-mediated Ca2+ signaling in intestinal epithelial cells in vivo

    Directory of Open Access Journals (Sweden)

    Takahiro Adachi

    2016-12-01

    Full Text Available Probiotics, such as lactic acid bacteria (LAB and Bacillus subtilis var. natto, have been shown to modulate immune responses. It is important to understand how probiotic bacteria impact intestinal epithelial cells (IECs, because IECs are the first line of defense at the mucosal surface barrier and their activities substantially affect the gut microenvironment and immunity. However, to date, their precise mechanism remains unknown due to a lack of analytical systems available for live animal models. Recently, we generated a conditional Ca2+ biosensor Yellow Cameleon (YC3.60 transgenic mouse line and established 5D (x, y, z, time, and Ca2+ intravital imaging systems of lymphoid tissues including those in Peyer’s patches and bone marrow. In the present study, we further advance our intravital imaging system for intestinal tracts to visualize IEC responses against orally administrated food compounds in real time. Using this system, heat-killed Bacillus subtilis natto, a probiotic TTCC012 strain, is shown to directly induce Ca2+ signaling in IECs in mice housed under specific pathogen-free conditions. In contrast, this activation is not observed in the Lactococcus lactis strain C60; however, when we generate germ-free YC3.60 mice and observe the LAB stimulation of IECs in the absence of gut microbiota, C60 is capable of inducing Ca2+ signaling. This is the first study to successfully visualize the direct effect of probiotics on IECs in live animals. These data strongly suggest that probiotic strains stimulate IECs under physiological conditions, and that their activity is affected by the microenvironment of the small intestine, such as commensal bacteria.

  18. Scintigraphic visualization of bacterial translocation in experimental strangulated intestinal obstruction

    International Nuclear Information System (INIS)

    Galeev, Yu.M.; Popov, M.V.; Salato, O.V.; Lishmanov, Yu.B.; Grigorev, E.G.; Aparcin, K.A.

    2009-01-01

    The purpose of this study was to obtain scintigraphic images depicting translocation of 99m Tc-labelled Escherichia coli bacteria through the intestinal barrier and to quantify this process using methods of nuclear medicine. Thirty male Wistar rats (including 20 rats with modelled strangulated intestinal obstruction and 10 healthy rats) were used for bacterial scintigraphy. 99m Tc-labelled E. coli bacteria ( 99m Ts-E. coli) with an activity of 7.4-11.1 MBq were administered into a section of the small intestine. Scintigraphic visualization of bacterial translocation into organs and tissues of laboratory animals was recorded in dynamic (240 min) and static (15 min) modes. The number of labelled bacteria, which migrated through the intestinal barrier, was quantified by calculating the translocation index (TI). Control indicated no translocation of 99m Ts-E. coli administered into the intestine through the parietes of the small intestine's distal part in healthy animals. Animals with strangulated obstruction demonstrated different migration strength and routes of labelled bacteria from strangulated and superior to strangulation sections of the small intestine. 99m Ts-E. coli migrated from the strangulated loop into the peritoneal cavity later causing systemic bacteraemia through peritoneal resorption. The section of the small intestine, which was superior to the strangulation, demonstrated migration of labelled bacteria first into the portal and then into the systemic circulation. The strangulated section of the small intestine was the main source of bacteria dissemination since the number of labelled bacteria, which migrated from this section significantly, exceeded that of the area superior to the strangulation section of the small intestine (p = 0.0003). Bacterial scintigraphy demonstrated the possibility of visualizing migration routes of labelled bacteria and quantifying their translocation through the intestinal barrier. This approach to study bacterial

  19. Intestinal stem cells in the adult Drosophila midgut

    International Nuclear Information System (INIS)

    Jiang, Huaqi; Edgar, Bruce A.

    2011-01-01

    Drosophila has long been an excellent model organism for studying stem cell biology. Notably, studies of Drosophila's germline stem cells have been instrumental in developing the stem cell niche concept. The recent discovery of somatic stem cells in adult Drosophila, particularly the intestinal stem cells (ISCs) of the midgut, has established Drosophila as an exciting model to study stem cell-mediated adult tissue homeostasis and regeneration. Here, we review the major signaling pathways that regulate the self-renewal, proliferation and differentiation of Drosophila ISCs, discussing how this regulation maintains midgut homeostasis and mediates regeneration of the intestinal epithelium after injury. -- Highlights: ► The homeostasis and regeneration of adult fly midguts are mediated by ISCs. ► Damaged enterocytes induce the proliferation of intestinal stem cells (ISC). ► EGFR and Jak/Stat signalings mediate compensatory ISC proliferation. ► Notch signaling regulates ISC self-renewal and differentiation.

  20. CD36 mediates both cellular uptake of very long chain fatty acids and their intestinal absorption in mice.

    Science.gov (United States)

    Drover, Victor A; Nguyen, David V; Bastie, Claire C; Darlington, Yolanda F; Abumrad, Nada A; Pessin, Jeffrey E; London, Erwin; Sahoo, Daisy; Phillips, Michael C

    2008-05-09

    The intestine has an extraordinary capacity for fatty acid (FA) absorption. Numerous candidates for a protein-mediated mechanism of dietary FA absorption have been proposed, but firm evidence for this process has remained elusive. Here we show that the scavenger receptor CD36 is required both for the uptake of very long chain FAs (VLCFAs) in cultured cells and the absorption of dietary VLCFAs in mice. We found that the fraction of CD36-dependent saturated fatty acid association/absorption in these model systems is proportional to the FA chain length and specific for fatty acids and fatty alcohols containing very long saturated acyl chains. Moreover, intestinal VLCFA absorption is completely abolished in CD36-null mice fed a high fat diet, illustrating that the predominant mechanism for VLCFA absorption is CD36-dependent. Together, these findings represent the first direct evidence for protein-facilitated FA absorption in the intestine and identify a novel therapeutic target for the treatment of diseases characterized by elevated VLCFA levels.

  1. Impact of exogenous lipase supplementation on growth, intestinal function, mucosal immune and physical barrier, and related signaling molecules mRNA expression of young grass carp (Ctenopharyngodon idella).

    Science.gov (United States)

    Liu, Sen; Feng, Lin; Jiang, Wei-Dan; Liu, Yang; Jiang, Jun; Wu, Pei; Zeng, Yun-Yun; Xu, Shu-De; Kuang, Sheng-Yao; Tang, Ling; Tang, Wu-Neng; Zhang, Yong-An; Zhou, Xiao-Qiu

    2016-08-01

    This study investigated the effects of exogenous lipase supplementation on the growth performance, intestinal growth and function, immune response and physical barrier function, and related signaling molecules mRNA expression of young grass carp (Ctenopharyngodon idella). A total of 450 grass carp (255.02 ± 0.34 g) were fed five diets for 60 days. There were 5 dietary treatments that included a normal protein and lipid diet containing 30% crude protein (CP) with 5% ether extract (EE), and the low-protein and high-lipid diets (28% CP, 6% EE) supplemented with graded levels of exogenous lipase supplementation activity at 0, 1193, 2560 and 3730 U/kg diet. The results indicated that compared with a normal protein and lipid diet (30% CP, 5% EE), a low-protein and high-lipid diet (28% CP, 6% EE) (un-supplemented lipase) improved lysozyme activities and complement component 3 contents in the distal intestine (DI), interleukin 10 mRNA expression in the proximal intestine (PI), and glutathione S-transferases activity and glutathione content in the intestine of young grass carp. In addition, in low-protein and high-lipid diets, optimal exogenous lipase supplementation significantly increased acid phosphatase (ACP) activities and complement component 3 (C3) contents (P exogenous lipase supplementation significantly decreased reactive oxygen species (ROS), malondialdehyde (MDA) and protein carbonyl (PC) contents (P exogenous lipase supplementation significantly elevated the mRNA levels of tight junction proteins (Occludin, zonula occludens 1, Claudin b, Claudin c and Claudin 3) (P exogenous lipase supplementation improved growth, intestinal growth and function, intestinal immunity, physical barrier, and regulated the mRNA expression of related signal molecules of fish. The optimal level of exogenous lipase supplementation in young grass carp (255-771 g) was estimated to be 1193 U kg(-1) diet. Copyright © 2016. Published by Elsevier Ltd.

  2. Portal vein thrombosis in cirrhosis is not associated with intestinal barrier disruption or increased platelet aggregability.

    Science.gov (United States)

    Wosiewicz, Piotr; Żorniak, Michał; Hartleb, Marek; Barański, Kamil; Hartleb, Maciej; Onyszczuk, Magdalena; Pilch-Kowalczyk, Joanna; Kyrcz-Krzemień, Sławomira

    2016-12-01

    Portal vein thrombosis (PVT) is a common complication of cirrhosis, but its pathogenesis is unclear. We tested the hypotheses that PVT is the result of platelet hyperactivity or intestinal barrier disruption. This study included 49 patients with cirrhosis (15 females) of mixed etiology. Based on spiral computed-tomography, the patients were divided into two groups: with PVT (n=16) and without PVT (n=33). Serum biomarkers of intestinal barrier integrity were endotoxins and zonulin, and platelet activity was assessed with multiple electrode aggregometry. The levels of endotoxin (43.5±18.3ng/ml vs. 36.9±7.5ng/ml; P=0.19) and zonulin (56.3±31.1ng/ml vs. 69.3±63.1ng/ml; P=0.69) were not different between the patients with and without PVT. Moreover, endotoxin and zonulin did not correlate with the coagulation and platelet parameters. The platelet aggregability measured with the TRAP and the ADP tests was decreased in PVT patients. In the logistic regression analysis the PVT incidence was related to the levels of D-dimer and bilirubin as well as the TRAP test results. Patients with PVT presented with significantly higher levels of D-dimer (4.45±2.59 vs. 3.03±2.97mg/l; P<0.05) and prothrombin levels (175±98.8μg/ml vs. 115±72.9μg/ml; P<0.05) than patients without thrombosis. PVT could be excluded with a 90% negative predictive value when the D-dimer level was below 1.82mg/l. Endotoxemia and platelet activity are not determinants of PVT in patients with cirrhosis. The D-dimer measurement has diagnostic significance for PVT in patients with liver cirrhosis. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  3. Toll-Like Receptor 2 Activation by beta 2 -> 1-Fructans Protects Barrier Function of T84 Human Intestinal Epithelial Cells in a Chain Length-Dependent Manner

    NARCIS (Netherlands)

    Vogt, Leonie M.; Meyer, Diederick; Pullens, Gerdie; Faas, Marijke M.; Venema, Koen; Ramasamy, Uttara; Schols, Henk A.; de Vos, Paul

    Dietary fiber intake is associated with lower incidence and mortality from disease, but the underlying mechanisms of these protective effects are unclear. We hypothesized that beta 2 -> 1-fructan dietary fibers confer protection on intestinal epithelial cell barrier function via Toll-like receptor 2

  4. Intestinal stem cells in the adult Drosophila midgut

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Huaqi, E-mail: Huaqi.Jiang@UTSouthwestern.edu [Department of Developmental Biology, UT Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, TX, 75235 (United States); Edgar, Bruce A., E-mail: b.edgar@dkfz.de [ZMBH-DKFZ Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg (Germany); Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N., Seattle, WA 98109 (United States)

    2011-11-15

    Drosophila has long been an excellent model organism for studying stem cell biology. Notably, studies of Drosophila's germline stem cells have been instrumental in developing the stem cell niche concept. The recent discovery of somatic stem cells in adult Drosophila, particularly the intestinal stem cells (ISCs) of the midgut, has established Drosophila as an exciting model to study stem cell-mediated adult tissue homeostasis and regeneration. Here, we review the major signaling pathways that regulate the self-renewal, proliferation and differentiation of Drosophila ISCs, discussing how this regulation maintains midgut homeostasis and mediates regeneration of the intestinal epithelium after injury. -- Highlights: Black-Right-Pointing-Pointer The homeostasis and regeneration of adult fly midguts are mediated by ISCs. Black-Right-Pointing-Pointer Damaged enterocytes induce the proliferation of intestinal stem cells (ISC). Black-Right-Pointing-Pointer EGFR and Jak/Stat signalings mediate compensatory ISC proliferation. Black-Right-Pointing-Pointer Notch signaling regulates ISC self-renewal and differentiation.

  5. [Carrier-mediated Transport of Cationic Drugs across the Blood-Tissue Barrier].

    Science.gov (United States)

    Kubo, Yoshiyuki

    2015-01-01

    Studies of neurological dysfunction have revealed the neuroprotective effect of several cationic drugs, suggesting their usefulness in the treatment of neurological diseases. In the brain and retina, blood-tissue barriers such as blood-brain barrier (BBB) and blood-retinal barrier (BRB) are formed to restrict nonspecific solute transport between the circulating blood and neural tissues. Therefore study of cationic drug transport at these barriers is essential to achieve systemic delivery of neuroprotective agents into the neural tissues. In the retina, severe diseases such as diabetic retinopathy and macular degeneration can cause neurological dysfunction that dramatically affects patients' QOL. The BRB is formed by retinal capillary endothelial cells (inner BRB) and retinal pigment epithelial cells (outer BRB). Blood-to-retina transport of cationic drugs was investigated at the inner BRB, which is known to nourish two thirds of the retina. Blood-to-retinal transport of verapamil suggested that the barrier function of the BRB differs from that of the BBB. Moreover, carrier-mediated transport of verapamil and pyrilamine revealed the involvement of novel organic cation transporters at the inner BRB. The identified transport systems for cationic drugs are sensitive to several cationic neuroprotective and anti-angiogenic agents such as clonidine and propranolol, and the involvement of novel transporters was also suggested in their blood-to-retina transport across the inner BRB.

  6. Modulation of Intestinal Barrier and Bacterial Endotoxin Production Contributes to the Beneficial Effect of Nicotinic Acid on Alcohol-Induced Endotoxemia and Hepatic Inflammation in Rats

    Directory of Open Access Journals (Sweden)

    Wei Zhong

    2015-10-01

    Full Text Available Alcohol consumption causes nicotinic acid deficiency. The present study was undertaken to determine whether dietary nicotinic acid supplementation provides beneficial effects on alcohol-induced endotoxin signaling and the possible mechanisms at the gut-liver axis. Male Sprague-Dawley rats were pair-fed the Lieber-DeCarli liquid diets containing ethanol or isocaloric maltose dextrin for eight weeks, with or without dietary supplementation with 750 mg/liter nicotinic acid. Chronic alcohol feeding elevated the plasma endotoxin level and activated hepatic endotoxin signaling cascade, which were attenuated by nicotinic acid supplementation. Alcohol consumption remarkably decreased the mRNA levels of claudin-1, claudin-5, and ZO-1 in the distal intestine, whereas nicotinic acid significantly up-regulated these genes. The concentrations of endotoxin, ethanol, and acetaldehyde in the intestinal contents were increased by alcohol exposure, and niacin supplementation reduced the intestinal endotoxin and acetaldehyde levels. Nicotinic acid supplementation upregulated the intestinal genes involved in aldehyde detoxification via transcriptional regulation. These results demonstrate that modulation of the intestinal barrier function and bacterial endotoxin production accounts for the inhibitory effects of nicotinic acid on alcohol-induced endotoxemia and hepatic inflammation.

  7. Bile acids in regulation of intestinal physiology.

    LENUS (Irish Health Repository)

    Keating, Niamh

    2009-10-01

    In addition to their roles in facilitating lipid digestion and absorption, bile acids are recognized as important regulators of intestinal function. Exposure to bile acids can dramatically influence intestinal transport and barrier properties; in recent years, they have also become appreciated as important factors in regulating cell growth and survival. Indeed, few cells reside within the intestinal mucosa that are not altered to some degree by exposure to bile acids. The past decade saw great advances in the knowledge of how bile acids exert their actions at the cellular and molecular levels. In this review, we summarize the current understanding of the role of bile acids in regulation of intestinal physiology.

  8. Administration of Lactobacillus salivarius LI01 or Pediococcus pentosaceus LI05 prevents CCl4-induced liver cirrhosis by protecting the intestinal barrier in rats.

    Science.gov (United States)

    Shi, Ding; Lv, Longxian; Fang, Daiqiong; Wu, Wenrui; Hu, Chenxia; Xu, Lichen; Chen, Yanfei; Guo, Jing; Hu, Xinjun; Li, Ang; Guo, Feifei; Ye, Jianzhong; Li, Yating; Andayani, Dewi; Li, Lanjuan

    2017-07-31

    Alterations in the gut microbiome have been reported in liver cirrhosis, and probiotic interventions are considered a potential treatment strategy. This study aimed to evaluate the effects and mechanisms of Lactobacillus salivarius LI01, Pediococcus pentosaceus LI05, Lactobacillus rhamnosus GG, Clostridium butyricum MIYAIRI and Bacillus licheniformis Zhengchangsheng on CCl 4 -induced cirrhotic rats. Only administration of LI01 or LI05 prevented liver fibrosis and down-regulated the hepatic expression of profibrogenic genes. Serum endotoxins, bacterial translocations (BTs), and destruction of intestinal mucosal ultrastructure were reduced in rats treated with LI01 or LI05, indicating maintenance of the gut barrier as a mechanism; this was further confirmed by the reduction of not only hepatic inflammatory cytokines, such as TNF-α, IL-6, and IL-17A, but also hepatic TLR2, TLR4, TLR5 and TLR9. Metagenomic sequencing of 16S rRNA gene showed an increase in potential beneficial bacteria, such as Elusimicrobium and Prevotella, and a decrease in pathogenic bacteria, such as Escherichia. These alterations in gut microbiome were correlated with profibrogenic genes, gut barrier markers and inflammatory cytokines. In conclusion, L. salivarius LI01 and P. pentosaceus LI05 attenuated liver fibrosis by protecting the intestinal barrier and promoting microbiome health. These results suggest novel strategies for the prevention of liver cirrhosis.

  9. Intestinal health in carnivores

    NARCIS (Netherlands)

    Hagen-Plantinga, Esther A.; Hendriks, W.H.

    2015-01-01

    The knowledge on the influence of gastro-intestinal (GI) microbiota on the health status of humans and animals is rapidly expanding. A balanced microbiome may provide multiple benefits to the host, like triggering and stimulation of the immune system, acting as a barrier against possible pathogenic

  10. Fecal markers of intestinal inflammation and intestinal permeability are elevated in Parkinson's disease.

    Science.gov (United States)

    Schwiertz, Andreas; Spiegel, Jörg; Dillmann, Ulrich; Grundmann, David; Bürmann, Jan; Faßbender, Klaus; Schäfer, Karl-Herbert; Unger, Marcus M

    2018-02-12

    Intestinal inflammation and increased intestinal permeability (both possibly fueled by dysbiosis) have been suggested to be implicated in the multifactorial pathogenesis of Parkinson's disease (PD). The objective of the current study was to investigate whether fecal markers of inflammation and impaired intestinal barrier function corroborate this pathogenic aspect of PD. In a case-control study, we quantitatively analyzed established fecal markers of intestinal inflammation (calprotectin and lactoferrin) and fecal markers of intestinal permeability (alpha-1-antitrypsin and zonulin) in PD patients (n = 34) and controls (n = 28, group-matched for age) by enzyme-linked immunosorbent assay. The study design controlled for potential confounding factors. Calprotectin, a fecal marker of intestinal inflammation, and two fecal markers of increased intestinal permeability (alpha-1-antitrypsin and zonulin) were significantly elevated in PD patients compared to age-matched controls. Lactoferrin, as a second fecal marker of intestinal inflammation, showed a non-significant trend towards elevated concentrations in PD patients. None of the four fecal markers correlated with disease severity, PD subtype, dopaminergic therapy, or presence of constipation. Fecal markers reflecting intestinal inflammation and increased intestinal permeability have been primarily investigated in inflammatory bowel disease so far. Our data indicate that calprotectin, alpha-1-antitrypsin and zonulin could be useful non-invasive markers in PD as well. Even though these markers are not disease-specific, they corroborate the hypothesis of an intestinal inflammation as contributing factor in the pathogenesis of PD. Further investigations are needed to determine whether calprotectin, alpha-1-antitrypsin and zonulin can be used to define PD subgroups and to monitor the effect of interventions in PD. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Free Total Rhubarb Anthraquinones Protect Intestinal Injury via Regulation of the Intestinal Immune Response in a Rat Model of Severe Acute Pancreatitis

    Directory of Open Access Journals (Sweden)

    Yuxia Xiong

    2018-02-01

    Full Text Available Intestinal mucosal immune barrier dysfunction plays a key role in the pathogenesis of severe acute pancreatitis (SAP. Rhubarb is a commonly used traditional Chinese medicine as a laxative in China. It markedly protects pancreatic acinar cells from trypsin-induced injury in rats. Free total rhubarb anthraquinones (FTRAs isolated and extracted from rhubarb display the beneficial effects of antibacteria, anti-inflammation, antivirus, and anticancer. The principal aim of the present study was to investigate the effects of FTRAs on the protection of intestinal injury and modification of the intestinal barrier function through regulation of intestinal immune function in rats with SAP. We established a rat model of SAP by injecting 3.5% sodium taurocholate (STC, 350 mg/kg into the biliopancreatic duct via retrograde injection and treated the rats with FTRAs (36 or 72 mg/kg or normal saline (control immediately and 12 h after STC injection. Then, we evaluated the protective effect of FTRAs on intestinal injury by pathological analysis and determined the levels of endotoxin (ET, interleukin 1β (IL-1β, tumor necrosis factor α (TNF-α, nitric oxide (NO, myeloperoxidase (MPO, capillary permeability, nucleotide-binding oligomerization domain-like receptors 3 (NLRP3, apoptosis-associated speck-like protein containing a CARD domain (ASC, casepase-1, secretary immunoglobulin A (SIgA, regulatory T cells (Tregs, and the ratio of Th1/Th2 in the blood and/or small intestinal tissues or mesenteric lymph node (MLN cells. Moreover, the chemical profile of FTRAs was analyzed by HPLC-UV chromatogram. The results showed that FTRAs significantly protected intestinal damage and decreased the levels of ET, IL-1β, TNF-α, and NO in the blood and TNF-α, IL-1β, and protein extravasation in the intestinal tissues in SAP rats. Furthermore, FTRAs significantly decreased the expressions of NLRP3, ASC, and caspase-1, the number of Tregs and the ratio of Th1/Th2, while

  12. Intestinal permeability - a new target for disease prevention and therapy

    NARCIS (Netherlands)

    Bischoff, S.C.; Barbara, G.; Buurman, W.; Ockhuizen, T.; Schulzke, J.D.; Serino, M.; Tilg, H.; Watson, A.; Wells, J.M.

    2014-01-01

    Data are accumulating that emphasize the important role of the intestinal barrier and intestinal permeability for health and disease. However, these terms are poorly defined, their assessment is a matter of debate, and their clinical significance is not clearly established. In the present review,

  13. Lactobacillus rhamnosus GG Affects Microbiota and Suppresses Autophagy in the Intestines of Pigs Challenged with Salmonella Infantis

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2018-01-01

    Full Text Available Salmonella enterica serovar Infantis (S. Infantis is a common source of foodborne gastroenteritis worldwide. Here, Lactobacillus rhamnosus GG (LGG was administrated to weaned piglets for 1 week before S. Infantis challenge. S. Infantis caused decreased ileal mucosal microbiota diversity, a dramatic Lactobacillus amylovorus bloom, and decreased abundance of Arsenicicoccus, Janibacter, Kocuria, Nocardioides, Devosia, Paracoccus, Psychrobacter, and Weissella. The beneficial effect of LGG correlated with the moderate expansion of L. amylovorus, L. agilis, and several members of the phyla Proteobacteria, Firmicutes, and Bacteroidetes. S. Infantis translocation to the liver was decreased in the LGG-pretreated piglets. An in vitro model of LGG and S. Infantis co-incubation (involving the porcine intestinal epithelial cell line IPEC-J2 was established, and nalidixic acid was used to kill the extracellular S. Infantis. LGG suppressed the initial S. Infantis invasion in the IPEC-J2 cells and deceased the rate of cell death. LGG inhibited S. Infantis-induced autophagy and promoted epidermal growth factor receptor (EGFR and Akt phosphorylation in both the ileum and IPEC-J2 cells. Our findings suggest that LGG inhibited S. Infantis-induced autophagy by promoting EGFR-mediated activation of the negative mediator Akt, which, in turn, suppressed intestinal epithelial cell death and thus restricted systemic S. Infantis infection. LGG can restore the gut microbiota balance and preserve the autophagy-related intestinal epithelial barrier, thereby controlling infections.

  14. Role of 5-hydroxytryptamine mechanisms in mediating the effects of small intestinal glucose on blood pressure and antropyloroduodenal motility in older subjects

    NARCIS (Netherlands)

    Gentilcore, Diana; Little, Tanya J.; Feinle-Bisset, Christine; Samsom, Melvin; Smout, André J. P. M.; Horowitz, Michael; Jones, Karen L.

    2007-01-01

    Postprandial hypotension is an important clinical problem, particularly in the elderly. 5-Hydroxytryptamine3 (5-HT3) mechanisms may be important in the regulation of splanchnic blood flow and blood pressure (BP), and in mediating the effects of small intestinal nutrients on gastrointestinal

  15. Intestinal cytochromes P450 regulating the intestinal microbiota and its probiotic profile

    Directory of Open Access Journals (Sweden)

    Eugenia Elefterios Venizelos Bezirtzoglou

    2012-09-01

    Full Text Available Cytochromes P450 (CYPs enzymes metabolize a large variety of xenobiotic substances. In this vein, a plethora of studies were conducted to investigate their role, as cytochromes are located in both liver and intestinal tissues. The P450 profile of the human intestine has not been fully characterized. Human intestine serves primarily as an absorptive organ for nutrients, although it has also the ability to metabolize drugs. CYPs are responsible for the majority of phase I drug metabolism reactions. CYP3A represents the major intestinal CYP (80% followed by CYP2C9. CYP1A is expressed at high level in the duodenum, together with less abundant levels of CYP2C8-10 and CYP2D6. Cytochromes present a genetic polymorphism intra- or interindividual and intra- or interethnic. Changes in the pharmacokinetic profile of the drug are associated with increased toxicity due to reduced metabolism, altered efficacy of the drug, increased production of toxic metabolites, and adverse drug interaction. The high metabolic capacity of the intestinal flora is due to its enormous pool of enzymes, which catalyzes reactions in phase I and phase II drug metabolism. Compromised intestinal barrier conditions, when rupture of the intestinal integrity occurs, could increase passive paracellular absorption. It is clear that high microbial intestinal charge following intestinal disturbances, ageing, environment, or food-associated ailments leads to the microbial metabolism of a drug before absorption. The effect of certain bacteria having a benefic action on the intestinal ecosystem has been largely discussed during the past few years by many authors. The aim of the probiotic approach is to repair the deficiencies in the gut flora and establish a protective effect. There is a tentative multifactorial association of the CYP (P450 cytochrome role in the different diseases states, environmental toxic effects or chemical exposures and nutritional status.

  16. Inflammasome in Intestinal Inflammation and Cancer

    Directory of Open Access Journals (Sweden)

    Tiago Nunes

    2013-01-01

    Full Text Available The activation of specific cytosolic pathogen recognition receptors, the nucleotide-binding-oligomerization-domain- (NOD- like receptors (NLRs, leads to the assembly of the inflammasome, a multimeric complex platform that activates caspase-1. The caspase-1 pathway leads to the upregulation of important cytokines from the interleukin (IL-1 family, IL-1β, and IL-18, with subsequent activation of the innate immune response. In this review, we discuss the molecular structure, the mechanisms behind the inflammasome activation, and its possible role in the pathogenesis of inflammatory bowel diseases and intestinal cancer. Here, we show that the available data points towards the importance of the inflammasome in the innate intestinal immune response, being the complex involved in the maintenance of intestinal homeostasis, correct intestinal barrier function and efficient elimination of invading pathogens.

  17. Sphingosine 1-phosphate receptor 5 mediates the immune quiescence of the human brain endothelial barrier

    Directory of Open Access Journals (Sweden)

    van Doorn Ruben

    2012-06-01

    Full Text Available Abstract Background The sphingosine 1-phosphate (S1P receptor modulator FTY720P (Gilenya® potently reduces relapse rate and lesion activity in the neuroinflammatory disorder multiple sclerosis. Although most of its efficacy has been shown to be related to immunosuppression through the induction of lymphopenia, it has been suggested that a number of its beneficial effects are related to altered endothelial and blood–brain barrier (BBB functionality. However, to date it remains unknown whether brain endothelial S1P receptors are involved in the maintenance of the function of the BBB thereby mediating immune quiescence of the brain. Here we demonstrate that the brain endothelial receptor S1P5 largely contributes to the maintenance of brain endothelial barrier function. Methods We analyzed the expression of S1P5 in human post-mortem tissues using immunohistochemistry. The function of S1P5 at the BBB was assessed in cultured human brain endothelial cells (ECs using agonists and lentivirus-mediated knockdown of S1P5. Subsequent analyses of different aspects of the brain EC barrier included the formation of a tight barrier, the expression of BBB proteins and markers of inflammation and monocyte transmigration. Results We show that activation of S1P5 on cultured human brain ECs by a selective agonist elicits enhanced barrier integrity and reduced transendothelial migration of monocytes in vitro. These results were corroborated by genetically silencing S1P5 in brain ECs. Interestingly, functional studies with these cells revealed that S1P5 strongly contributes to brain EC barrier function and underlies the expression of specific BBB endothelial characteristics such as tight junctions and permeability. In addition, S1P5 maintains the immunoquiescent state of brain ECs with low expression levels of leukocyte adhesion molecules and inflammatory chemokines and cytokines through lowering the activation of the transcription factor NFκB. Conclusion Our

  18. Does sucralfate prevent apoptosis occurring in the ischemia/reperfusion-induced intestinal injury?

    Science.gov (United States)

    Sencan, A; Yilmaz, O; Ozer, E; Günşar, C; Genç, K; Ulukuş, C; Taneli, C; Mir, E

    2003-08-01

    We have shown in a previous study that sucralfate is beneficial in the prophylaxis and treatment of hypoxia/reoxygenation-induced intestinal injury. The aim of this study is to investigate whether sucralfate has any effect on the prevention of apoptosis in the ischemia/reperfusion (I/R)-induced intestinal injury. Rats were randomized into three groups. Group 1 and 2 were subjected to I/R. Group 1 (treatment group) received sucralfate while group 2 (treatment control group) did not. Group 3 served as a normal control group (sham group). The terminal ileum was harvested for histopathologic investigation by light microscopy. The presence of apoptotic enterocytes (DNA fragmentation in cell nuclei) was detected by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end-labeling (TUNEL) reaction. In treatment control group, 3 of 7 rats had severe inflammation. None of the sucralfate-treated rats showed severe inflammation, 6 of them only showed mild inflammatory changes (p < 0.05). The apoptotic percentage was found to be 37.1 +/- 9.4 in the sucralfate-treated group (group 1), whereas it was 45.4 +/- 3.9 in the untreated group (group 2) (p < 0.05). The sham group had a completely normal intestinal architecture. The present study shows that 1) the experimental model of I/R-induced intestinal injury induces enterocyte apoptosis; 2) sucralfate decreases enterocyte apoptosis in the experimental model of I/R-induced intestinal injury which may play a key role in the pathophysiological events leading to failure of the intrinsic gut barrier defense mechanisms.

  19. Effect of a Semi-Purified Oligosaccharide-Enriched Fraction from Caprine Milk on Barrier Integrity and Mucin Production of Co-Culture Models of the Small and Large Intestinal Epithelium

    Directory of Open Access Journals (Sweden)

    Alicia M. Barnett

    2016-05-01

    Full Text Available Caprine milk contains the highest amount of oligosaccharides among domestic animals, which are structurally similar to human milk oligosaccharides (HMOs. This suggests caprine milk oligosaccharides may offer similar protective and developmental effects to that of HMOs. However, to date, studies using oligosaccharides from caprine milk have been limited. Thus, this study aimed to examine the impact of a caprine milk oligosaccharide-enriched fraction (CMOF on barrier function of epithelial cell co-cultures of absorptive enterocytes (Caco-2 cells and mucus-secreting goblet cells (HT29-MTX cells, that more closely simulate the cell proportions found in the small (90:10 and large intestine (75:25. Treatment of epithelial co-cultures with 0.4, 1.0, 2.0 and 4.0 mg/mL of CMOF was shown to have no effect on metabolic activity but did enhance cell epithelial barrier integrity as measured by trans-epithelial electrical resistance (TEER, in a dose-dependent manner. The CMOF at the maximum concentration tested (4.0 mg/mL enhanced TEER, mucin gene expression and mucin protein abundance of epithelial co-cultures, all of which are essential components of intestinal barrier function.

  20. Effect of a Semi-Purified Oligosaccharide-Enriched Fraction from Caprine Milk on Barrier Integrity and Mucin Production of Co-Culture Models of the Small and Large Intestinal Epithelium.

    Science.gov (United States)

    Barnett, Alicia M; Roy, Nicole C; McNabb, Warren C; Cookson, Adrian L

    2016-05-06

    Caprine milk contains the highest amount of oligosaccharides among domestic animals, which are structurally similar to human milk oligosaccharides (HMOs). This suggests caprine milk oligosaccharides may offer similar protective and developmental effects to that of HMOs. However, to date, studies using oligosaccharides from caprine milk have been limited. Thus, this study aimed to examine the impact of a caprine milk oligosaccharide-enriched fraction (CMOF) on barrier function of epithelial cell co-cultures of absorptive enterocytes (Caco-2 cells) and mucus-secreting goblet cells (HT29-MTX cells), that more closely simulate the cell proportions found in the small (90:10) and large intestine (75:25). Treatment of epithelial co-cultures with 0.4, 1.0, 2.0 and 4.0 mg/mL of CMOF was shown to have no effect on metabolic activity but did enhance cell epithelial barrier integrity as measured by trans-epithelial electrical resistance (TEER), in a dose-dependent manner. The CMOF at the maximum concentration tested (4.0 mg/mL) enhanced TEER, mucin gene expression and mucin protein abundance of epithelial co-cultures, all of which are essential components of intestinal barrier function.

  1. Human organoids: a model system for intestinal diseases

    OpenAIRE

    Wiegerinck, C.L.

    2015-01-01

    You are what you eat. A common saying that indicates that your physical or mental state can be influenced by your choice of food. Unfortunately, not all people have the luxury to choose what to eat; this can be related to place of birth, social, economic state, or the physical inability of the diseased intestine to take up certain food. A cell layer, the epithelium, covers the intestine, and harbors the main functions of the intestine: uptake, digestion of food, and a barrier against unwanted...

  2. Rho-A prenylation and signaling link epithelial homeostasis to intestinal inflammation

    DEFF Research Database (Denmark)

    López-Posadas, Rocío; Becker, Christoph; Günther, Claudia

    2016-01-01

    Although defects in intestinal barrier function are a key pathogenic factor in patients with inflammatory bowel diseases (IBDs), the molecular pathways driving disease-specific alterations of intestinal epithelial cells (IECs) are largely unknown. Here, we addressed this issue by characterizing t...

  3. Role of 5-hydroxytryptamine mechanisms in mediating the effects of small intestinal glucose on blood pressure and antropyloroduodenal motility in older subjects

    NARCIS (Netherlands)

    Gentilcore, Diana; Little, Tanya J.; Feinle-Bisset, Christine; Samsom, Melvin; Smout, Andre J. P. M.; Horowitz, Michael; Jones, Karen L.

    2007-01-01

    5-hydroxytryptamine mechanisms in mediating the effects of small intestinal glucose on blood pressure and antropyloroduodenal motility in older subjects. Am J Physiol Gastrointest Liver Physiol 293: G692-G698, 2007. First published August 9, 2007; doi:10.1152/ajpgi.00199.2007.-Postprandial

  4. An intestinal Trojan horse for gene delivery.

    Science.gov (United States)

    Peng, Haisheng; Wang, Chao; Xu, Xiaoyang; Yu, Chenxu; Wang, Qun

    2015-03-14

    The intestinal epithelium forms an essential element of the mucosal barrier and plays a critical role in the pathophysiological response to different enteric disorders and diseases. As a major enteric dysfunction of the intestinal tract, inflammatory bowel disease is a genetic disease which results from the inappropriate and exaggerated mucosal immune response to the normal constituents in the mucosal microbiota environment. An intestine targeted drug delivery system has unique advantages in the treatment of inflammatory bowel disease. As a new concept in drug delivery, the Trojan horse system with the synergy of nanotechnology and host cells can achieve better therapeutic efficacy in specific diseases. Here, we demonstrated the feasibility of encapsulating DNA-functionalized gold nanoparticles into primary isolated intestinal stem cells to form an intestinal Trojan horse for gene regulation therapy of inflammatory bowel disease. This proof-of-concept intestinal Trojan horse will have a wide variety of applications in the diagnosis and therapy of enteric disorders and diseases.

  5. Intestinal Anti-inflammatory Effects of Outer Membrane Vesicles from Escherichia coli Nissle 1917 in DSS-Experimental Colitis in Mice

    Directory of Open Access Journals (Sweden)

    María-José Fábrega

    2017-07-01

    Full Text Available Escherichia coli Nissle 1917 (EcN is a probiotic strain with proven efficacy in inducing and maintaining remission of ulcerative colitis. However, the microbial factors that mediate these beneficial effects are not fully known. Gram-negative bacteria release outer membrane vesicles (OMVs as a direct pathway for delivering selected bacterial proteins and active compounds to the host. In fact, vesicles released by gut microbiota are emerging as key players in signaling processes in the intestinal mucosa. In the present study, the dextran sodium sulfate (DSS-induced colitis mouse model was used to investigate the potential of EcN OMVs to ameliorate mucosal injury and inflammation in the gut. The experimental protocol involved pre-treatment with OMVs for 10 days before DSS intake, and a 5-day recovery period. Oral administration of purified EcN OMVs (5 μg/day significantly reduced DSS-induced weight loss and ameliorated clinical symptoms and histological scores. OMVs treatment counteracted altered expression of cytokines and markers of intestinal barrier function. This study shows for the first time that EcN OMVs can mediate the anti-inflammatory and barrier protection effects previously reported for this probiotic in experimental colitis. Remarkably, translation of probiotics to human healthcare requires knowledge of the molecular mechanisms involved in probiotic–host interactions. Thus, OMVs, as a non-replicative bacterial form, could be explored as a new probiotic-derived therapeutic approach, with even lower risk of adverse events than probiotic administration.

  6. Wnt, RSPO and Hippo Signalling in the Intestine and Intestinal Stem Cells.

    Science.gov (United States)

    Kriz, Vitezslav; Korinek, Vladimir

    2018-01-08

    In this review, we address aspects of Wnt, R-Spondin (RSPO) and Hippo signalling, in both healthy and transformed intestinal epithelium. In intestinal stem cells (ISCs), the Wnt pathway is essential for intestinal crypt formation and renewal, whereas RSPO-mediated signalling mainly affects ISC numbers. In human colorectal cancer (CRC), aberrant Wnt signalling is the driving mechanism initiating this type of neoplasia. The signalling role of the RSPO-binding transmembrane proteins, the leucine-rich-repeat-containing G-protein-coupled receptors (LGRs), is possibly more pleiotropic and not only limited to the enhancement of Wnt signalling. There is growing evidence for multiple crosstalk between Hippo and Wnt/β-catenin signalling. In the ON state, Hippo signalling results in serine/threonine phosphorylation of Yes-associated protein (YAP1) and tafazzin (TAZ), promoting formation of the β-catenin destruction complex. In contrast, YAP1 or TAZ dephosphorylation (and YAP1 methylation) results in β-catenin destruction complex deactivation and β-catenin nuclear localization. In the Hippo OFF state, YAP1 and TAZ are engaged with the nuclear β-catenin and participate in the β-catenin-dependent transcription program. Interestingly, YAP1/TAZ are dispensable for intestinal homeostasis; however, upon Wnt pathway hyperactivation, the proteins together with TEA domain (TEAD) transcription factors drive the transcriptional program essential for intestinal cell transformation. In addition, in many CRC cells, YAP1 phosphorylation by YES proto-oncogene 1 tyrosine kinase (YES1) leads to the formation of a transcriptional complex that includes YAP1, β-catenin and T-box 5 (TBX5) DNA-binding protein. YAP1/β-catenin/T-box 5-mediated transcription is necessary for CRC cell proliferation and survival. Interestingly, dishevelled (DVL) appears to be an important mediator involved in both Wnt and Hippo (YAP1/TAZ) signalling and some of the DVL functions were assigned to the nuclear DVL

  7. Biomarkers for monitoring intestinal health in poultry: present status and future perspectives.

    Science.gov (United States)

    Ducatelle, Richard; Goossens, Evy; De Meyer, Fien; Eeckhaut, Venessa; Antonissen, Gunther; Haesebrouck, Freddy; Van Immerseel, Filip

    2018-05-08

    Intestinal health is determined by host (immunity, mucosal barrier), nutritional, microbial and environmental factors. Deficiencies in intestinal health are associated with shifts in the composition of the intestinal microbiome (dysbiosis), leakage of the mucosal barrier and/or inflammation. Since the ban on growth promoting antimicrobials in animal feed, these dysbiosis-related problems have become a major issue, especially in intensive animal farming. The economical and animal welfare consequences are considerable. Consequently, there is a need for continuous monitoring of the intestinal health status, particularly in intensively reared animals, where the intestinal function is often pushed to the limit. In the current review, the recent advances in the field of intestinal health biomarkers, both in human and veterinary medicine are discussed, trying to identify present and future markers of intestinal health in poultry. The most promising new biomarkers will be stable molecules ending up in the feces and litter that can be quantified, preferably using rapid and simple pen-side tests. It is unlikely, however, that a single biomarker will be sufficient to follow up all aspects of intestinal health. Combinations of multiple biomarkers and/or metabarcoding, metagenomic, metatranscriptomic, metaproteomic and metabolomic approaches will be the way to go in the future. Candidate biomarkers currently are being investigated by many research groups, but the validation will be a major challenge, due to the complexity of intestinal health in the field.

  8. Zinc Supplementation, via GPR39, Upregulates PKCζ to Protect Intestinal Barrier Integrity in Caco-2 Cells Challenged by Salmonella enterica Serovar Typhimurium.

    Science.gov (United States)

    Shao, Yu-Xin; Lei, Zhao; Wolf, Patricia G; Gao, Yan; Guo, Yu-Ming; Zhang, Bing-Kun

    2017-07-01

    Background: Zinc has been shown to improve intestinal barrier function against Salmonella enterica serovar Typhimurium ( S. typhimurium ) infection, but the mechanisms involved in this process remain undefined. Objective: We aimed to explore the roles of G protein-coupled receptor (GPR)39 and protein kinase Cζ (PKCζ) in the regulation by zinc of intestinal barrier function. Methods: A Transwell Caco-2 monolayer was pretreated with 0, 50, or 100 μM Zn and then incubated with S. typhimurium for 0-6 h. Afterward, cells silenced by the small interfering RNA for GPR39 or PKCζ were pretreated with 100 μM Zn and incubated with S. typhimurium for 3 h. Finally, transepithelial electrical resistance (TEER), permeability, tight junction (TJ) proteins, and signaling molecules GPR39 and PKCζ were measured. Results: Compared with controls, S. typhimurium decreased TEER by 62.3-96.2% at 4-6 h ( P 0.1). Silencing GPR39 decreased ( P zinc-activated PKCζ and blocked ( P zinc on epithelial integrity. Furthermore, silencing PKCζ counteracted the protective effect of zinc on epithelial integrity but did not inhibit GPR39 ( P = 0.138). Conclusion: We demonstrated that zinc upregulates PKCζ by activating GPR39 to enhance the abundance of ZO-1, thereby improving epithelial integrity in S. typhimurium- infected Caco-2 cells. © 2017 American Society for Nutrition.

  9. Lactobacillus rhamnosus GG treatment improves intestinal permeability and modulates inflammatory response and homeostasis of spleen and colon in experimental model of Pseudomonas aeruginosa pneumonia.

    Science.gov (United States)

    Khailova, Ludmila; Baird, Christine H; Rush, Aubri A; Barnes, Christopher; Wischmeyer, Paul E

    2017-12-01

    Recent clinical trials and in vivo models demonstrate probiotic administration can reduce occurrence and improve outcome of pneumonia and sepsis, both major clinical challenges worldwide. Potential probiotic benefits include maintenance of gut epithelial barrier homeostasis and prevention of downstream organ dysfunction due to systemic inflammation. However, mechanism(s) of probiotic-mediated protection against pneumonia remain poorly understood. This study evaluated potential mechanistic targets in the maintenance of gut barrier homeostasis following Lactobacillus rhamnosus GG (LGG) treatment in a mouse model of pneumonia. Studies were performed in 6-8 week old FVB/N mice treated (o.g.) with or without LGG (10 9  CFU/ml) and intratracheally injected with Pseudomonas aeruginosa or saline. At 4, 12, and 24 h post-bacterial treatment spleen and colonic tissue were collected for analysis. Pneumonia significantly increased intestinal permeability and gut claudin-2. LGG significantly attenuated increased gut permeability and claudin-2 following pneumonia back to sham control levels. As mucin expression is key to gut barrier homeostasis we demonstrate that LGG can enhance goblet cell expression and mucin barrier formation versus control pneumonia animals. Further as Muc2 is a key gut mucin, we show LGG corrected deficient Muc2 expression post-pneumonia. Apoptosis increased in both colon and spleen post-pneumonia, and this increase was significantly attenuated by LGG. Concomitantly, LGG corrected pneumonia-mediated loss of cell proliferation in colon and significantly enhanced cell proliferation in spleen. Finally, LGG significantly reduced pro-inflammatory cytokine gene expression in colon and spleen post-pneumonia. These data demonstrate LGG can maintain intestinal barrier homeostasis by enhancing gut mucin expression/barrier formation, reducing apoptosis, and improving cell proliferation. This was accompanied by reduced pro-inflammatory cytokine expression in the

  10. Gliadin induces an increase in intestinal permeability and zonulin release by binding to the chemokine receptor CXCR3.

    Science.gov (United States)

    Lammers, Karen M; Lu, Ruliang; Brownley, Julie; Lu, Bao; Gerard, Craig; Thomas, Karen; Rallabhandi, Prasad; Shea-Donohue, Terez; Tamiz, Amir; Alkan, Sefik; Netzel-Arnett, Sarah; Antalis, Toni; Vogel, Stefanie N; Fasano, Alessio

    2008-07-01

    Celiac disease is an immune-mediated enteropathy triggered by gliadin, a component of the grain protein gluten. Gliadin induces an MyD88-dependent zonulin release that leads to increased intestinal permeability, a postulated early element in the pathogenesis of celiac disease. We aimed to establish the molecular basis of gliadin interaction with intestinal mucosa leading to intestinal barrier impairment. Alpha-gliadin affinity column was loaded with intestinal mucosal membrane lysates to identify the putative gliadin-binding moiety. In vitro experiments with chemokine receptor CXCR3 transfectants were performed to confirm binding of gliadin and/or 26 overlapping 20mer alpha-gliadin synthetic peptides to the receptor. CXCR3 protein and gene expression were studied in intestinal epithelial cell lines and human biopsy specimens. Gliadin-CXCR3 interaction was further analyzed by immunofluorescence microscopy, laser capture microscopy, real-time reverse-transcription polymerase chain reaction, and immunoprecipitation/Western blot analysis. Ex vivo experiments were performed using C57BL/6 wild-type and CXCR3(-/-) mouse small intestines to measure intestinal permeability and zonulin release. Affinity column and colocalization experiments showed that gliadin binds to CXCR3 and that at least 2 alpha-gliadin 20mer synthetic peptides are involved in this binding. CXCR3 is expressed in mouse and human intestinal epithelia and lamina propria. Mucosal CXCR3 expression was elevated in active celiac disease but returned to baseline levels following implementation of a gluten-free diet. Gliadin induced physical association between CXCR3 and MyD88 in enterocytes. Gliadin increased zonulin release and intestinal permeability in wild-type but not CXCR3(-/-) mouse small intestine. Gliadin binds to CXCR3 and leads to MyD88-dependent zonulin release and increased intestinal permeability.

  11. Factoring the intestinal microbiome into the pathogenesis of autoimmune hepatitis.

    Science.gov (United States)

    Czaja, Albert J

    2016-11-14

    The intestinal microbiome is a reservoir of microbial antigens and activated immune cells. The aims of this review were to describe the role of the intestinal microbiome in generating innate and adaptive immune responses, indicate how these responses contribute to the development of systemic immune-mediated diseases, and encourage investigations that improve the understanding and management of autoimmune hepatitis. Alterations in the composition of the intestinal microflora (dysbiosis) can disrupt intestinal and systemic immune tolerances for commensal bacteria. Toll-like receptors within the intestine can recognize microbe-associated molecular patterns and shape subsets of T helper lymphocytes that may cross-react with host antigens (molecular mimicry). Activated gut-derived lymphocytes can migrate to lymph nodes, and gut-derived microbial antigens can translocate to extra-intestinal sites. Inflammasomes can form within hepatocytes and hepatic stellate cells, and they can drive the pro-inflammatory, immune-mediated, and fibrotic responses. Diet, designer probiotics, vitamin supplements, re-colonization methods, antibiotics, drugs that decrease intestinal permeability, and molecular interventions that block signaling pathways may emerge as adjunctive regimens that complement conventional immunosuppressive management. In conclusion, investigations of the intestinal microbiome are warranted in autoimmune hepatitis and promise to clarify pathogenic mechanisms and suggest alternative management strategies.

  12. High-throughput gene expression profiling indicates dysregulation of intestinal cell cycle mediators and growth factors during primary simian immunodeficiency virus infection

    Energy Technology Data Exchange (ETDEWEB)

    George, Michael D; Sankaran, Sumathi; Reay, Elizabeth; Gelli, Angie C; Dandekar, Satya

    2003-07-20

    During primary simian immunodeficiency virus (SIV) infection, CD4+ T cells are severely depleted in gut-associated lymphoid tissue (GALT), while CD8+ T-cell numbers dramatically increase. To gain an understanding of the molecular basis of this disruption in T-cell homeostasis, host gene expression was monitored in longitudinal jejunum tissue biopsies from SIV-infected rhesus macaques by DNA microarray analysis. Transcription of cyclin E1, CDC2, retinoblastoma, transforming growth factor (TGF), fibroblast growth factor (FGF), and interleukin-2 was repressed while cyclins B1 and D2 and transcription factor E2F were upregulated, indicating a complex dysregulation of growth and proliferation within the intestinal mucosa. Innate, cell-mediated, and humoral immune responses were markedly upregulated in animals that significantly reduced their viral loads and retained more intestinal CD4+ T cells. We conclude that the alterations in intestinal gene expression during primary SIV infection were characteristic of a broad-range immune response, and reflective of the efficacy of viral suppression.

  13. High-throughput gene expression profiling indicates dysregulation of intestinal cell cycle mediators and growth factors during primary simian immunodeficiency virus infection

    International Nuclear Information System (INIS)

    George, Michael D.; Sankaran, Sumathi; Reay, Elizabeth; Gelli, Angie C.; Dandekar, Satya

    2003-01-01

    During primary simian immunodeficiency virus (SIV) infection, CD4+ T cells are severely depleted in gut-associated lymphoid tissue (GALT), while CD8+ T-cell numbers dramatically increase. To gain an understanding of the molecular basis of this disruption in T-cell homeostasis, host gene expression was monitored in longitudinal jejunum tissue biopsies from SIV-infected rhesus macaques by DNA microarray analysis. Transcription of cyclin E1, CDC2, retinoblastoma, transforming growth factor (TGF), fibroblast growth factor (FGF), and interleukin-2 was repressed while cyclins B1 and D2 and transcription factor E2F were upregulated, indicating a complex dysregulation of growth and proliferation within the intestinal mucosa. Innate, cell-mediated, and humoral immune responses were markedly upregulated in animals that significantly reduced their viral loads and retained more intestinal CD4+ T cells. We conclude that the alterations in intestinal gene expression during primary SIV infection were characteristic of a broad-range immune response, and reflective of the efficacy of viral suppression

  14. Expression of PKA inhibitor (PKI) gene abolishes cAMP-mediated protection to endothelial barrier dysfunction.

    Science.gov (United States)

    Lum, H; Jaffe, H A; Schulz, I T; Masood, A; RayChaudhury, A; Green, R D

    1999-09-01

    We investigated the hypothesis that cAMP-dependent protein kinase (PKA) protects against endothelial barrier dysfunction in response to proinflammatory mediators. An E1-, E3-, replication-deficient adenovirus (Ad) vector was constructed containing the complete sequence of PKA inhibitor (PKI) gene (AdPKI). Infection of human microvascular endothelial cells (HMEC) with AdPKI resulted in overexpression of PKI. Treatment with 0.5 microM thrombin increased transendothelial albumin clearance rate (0.012 +/- 0.003 and 0.035 +/- 0.005 microl/min for control and thrombin, respectively); the increase was prevented with forskolin + 3-isobutyl-1-methylxanthine (F + I) treatment. Overexpression of PKI resulted in abrogation of the F + I-induced inhibition of the permeability increase. However, with HMEC infected with ultraviolet-inactivated AdPKI, the F + I-induced inhibition was present. Also, F + I treatment of HMEC transfected with reporter plasmid containing the cAMP response element-directed transcription of the luciferase gene resulted in an almost threefold increase in luciferase activity. Overexpression of PKI inhibited this induction of luciferase activity. The results show that Ad-mediated overexpression of PKI in endothelial cells abrogated the cAMP-mediated protection against increased endothelial permeability, providing direct evidence that cAMP-dependent protein kinase promotes endothelial barrier function.

  15. Pasture v. standard dairy cream in high-fat diet-fed mice: improved metabolic outcomes and stronger intestinal barrier.

    Science.gov (United States)

    Benoit, Bérengère; Plaisancié, Pascale; Géloën, Alain; Estienne, Monique; Debard, Cyrille; Meugnier, Emmanuelle; Loizon, Emmanuelle; Daira, Patricia; Bodennec, Jacques; Cousin, Olivier; Vidal, Hubert; Laugerette, Fabienne; Michalski, Marie-Caroline

    2014-08-28

    Dairy products derived from the milk of cows fed in pastures are characterised by higher amounts of conjugated linoleic acid and α-linolenic acid (ALA), and several studies have shown their ability to reduce cardiovascular risk. However, their specific metabolic effects compared with standard dairy in a high-fat diet (HFD) context remain largely unknown; this is what we determined in the present study with a focus on the metabolic and intestinal parameters. The experimental animals were fed for 12 weeks a HFD containing 20 % fat in the form of a pasture dairy cream (PDC) or a standard dairy cream (SDC). Samples of plasma, liver, white adipose tissue, duodenum, jejunum and colon were analysed. The PDC mice, despite a higher food intake, exhibited lower fat mass, plasma and hepatic TAG concentrations, and inflammation in the adipose tissue than the SDC mice. Furthermore, they exhibited a higher expression of hepatic PPARα mRNA and adipose tissue uncoupling protein 2 mRNA, suggesting an enhanced oxidative activity of the tissues. These results might be explained, in part, by the higher amounts of ALA in the PDC diet and in the liver and adipose tissue of the PDC mice. Moreover, the PDC diet was found to increase the proportions of two strategic cell populations involved in the protective function of the intestinal epithelium, namely Paneth and goblet cells in the small intestine and colon, compared with the SDC diet. In conclusion, a PDC HFD leads to improved metabolic outcomes and to a stronger gut barrier compared with a SDC HFD. This may be due, at least in part, to the protective mechanisms induced by specific lipids.

  16. Circadian rhythm disruption impairs tissue homeostasis and exacerbates chronic inflammation in the intestine.

    Science.gov (United States)

    Pagel, René; Bär, Florian; Schröder, Torsten; Sünderhauf, Annika; Künstner, Axel; Ibrahim, Saleh M; Autenrieth, Stella E; Kalies, Kathrin; König, Peter; Tsang, Anthony H; Bettenworth, Dominik; Divanovic, Senad; Lehnert, Hendrik; Fellermann, Klaus; Oster, Henrik; Derer, Stefanie; Sina, Christian

    2017-11-01

    Endogenous circadian clocks regulate 24-h rhythms of physiology and behavior. Circadian rhythm disruption (CRD) is suggested as a risk factor for inflammatory bowel disease. However, the underlying molecular mechanisms remain unknown. Intestinal biopsies from Per1/2 mutant and wild-type (WT) mice were investigated by electron microscopy, immunohistochemistry, and bromodeoxyuridine pulse-chase experiments. TNF-α was injected intraperitoneally, with or without necrostatin-1, into Per1/2 mice or rhythmic and externally desynchronized WT mice to study intestinal epithelial cell death. Experimental chronic colitis was induced by oral administration of dextran sodium sulfate. In vitro , caspase activity was assayed in Per1/2-specific small interfering RNA-transfected cells. Wee1 was overexpressed to study antiapoptosis and the cell cycle. Genetic ablation of circadian clock function or environmental CRD in mice increased susceptibility to severe intestinal inflammation and epithelial dysregulation, accompanied by excessive necroptotic cell death and a reduced number of secretory epithelial cells. Receptor-interacting serine/threonine-protein kinase (RIP)-3-mediated intestinal necroptosis was linked to increased mitotic cell cycle arrest via Per1/2-controlled Wee1, resulting in increased antiapoptosis via cellular inhibitor of apoptosis-2. Together, our data suggest that circadian rhythm stability is pivotal for the maintenance of mucosal barrier function. CRD increases intestinal necroptosis, thus rendering the gut epithelium more susceptible to inflammatory processes.-Pagel, R., Bär, F., Schröder, T., Sünderhauf, A., Künstner, A., Ibrahim, S. M., Autenrieth, S. E., Kalies, K., König, P., Tsang, A. H., Bettenworth, D., Divanovic, S., Lehnert, H., Fellermann, K., Oster, H., Derer, S., Sina, C. Circadian rhythm disruption impairs tissue homeostasis and exacerbates chronic inflammation in the intestine. © FASEB.

  17. Oral absorption of peptides and nanoparticles across the human intestine: Opportunities, limitations and studies in human tissues.

    Science.gov (United States)

    Lundquist, P; Artursson, P

    2016-11-15

    In this contribution, we review the molecular and physiological barriers to oral delivery of peptides and nanoparticles. We discuss the opportunities and predictivity of various in vitro systems with special emphasis on human intestine in Ussing chambers. First, the molecular constraints to peptide absorption are discussed. Then the physiological barriers to peptide delivery are examined. These include the gastric and intestinal environment, the mucus barrier, tight junctions between epithelial cells, the enterocytes of the intestinal epithelium, and the subepithelial tissue. Recent data from human proteome studies are used to provide information about the protein expression profiles of the different physiological barriers to peptide and nanoparticle absorption. Strategies that have been employed to increase peptide absorption across each of the barriers are discussed. Special consideration is given to attempts at utilizing endogenous transcytotic pathways. To reliably translate in vitro data on peptide or nanoparticle permeability to the in vivo situation in a human subject, the in vitro experimental system needs to realistically capture the central aspects of the mentioned barriers. Therefore, characteristics of common in vitro cell culture systems are discussed and compared to those of human intestinal tissues. Attempts to use the cell and tissue models for in vitro-in vivo extrapolation are reviewed. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  18. Recent Advances in Intestinal Stem Cells.

    Science.gov (United States)

    McCabe, Laura R; Parameswaran, Narayanan

    2017-09-01

    The intestine is a dynamic organ with rapid stem cell division generating epithelial cells that mature and apoptose in 3-5 days. Rapid turnover maintains the epithelial barrier and homeostasis. Current insights on intestinal stem cells (ISCs) and their regulation are discussed here. The Lgr5+ ISCs maintain intestinal homeostasis by dividing asymmetrically, but also divide symmetrically to extinguish or replace ISCs. Following radiation or mucosal injury, reserve BMI1+ ISCs as well as other crypt cells can de-differentiate into Lgr5+ ISCs. ISC niche cells, including Paneth, immune and myofibroblast cells secrete factors that regulate ISC proliferation. Finally, several studies indicate that the microbiome metabolites regulate ISC growth. ISC cells can be plastic and integrate a complexity of environmental/niche cues to trigger or suppress proliferation as needed.

  19. MRP2 mediated drug-drug interaction: indomethacin increases sulfasalazine absorption in the small intestine, potentially decreasing its colonic targeting.

    Science.gov (United States)

    Dahan, Arik; Amidon, Gordon L

    2010-02-15

    We have recently shown that efflux transport, mediated by multidrug resistance-associated protein 2 (MRP2) and breast cancer resistance protein (BCRP), is responsible for sulfasalazine low-permeability in the small intestine, thereby enabling its colonic targeting and therapeutic action. The purpose of the present study was to evaluate the potential pharmacokinetic interaction between indomethacin and sulfasalazine, in the mechanism of efflux transporter competition. The concentration-dependent effects of indomethacin on sulfasalazine intestinal epithelial transport were investigated across Caco-2 cell monolayers, in both apical to basolateral (AP-BL) and BL-AP directions. The interaction was then investigated in the in situ single-pass rat jejunal perfusion model. Sulfasalazine displayed 30-fold higher BL-AP than AP-BL Caco-2 permeability, indicative of net mucosal secretion. Indomethacin significantly increased AP-BL and decreased BL-AP sulfasalazine Caco-2 transport, in a concentration-dependent manner, with IC(50) values of 75 and 196 microM respectively. In the rat model, higher sulfasalazine concentrations resulted in higher intestinal permeability, consistent with saturation of efflux transporter. Without indomethacin, sulfasalazine demonstrated low rat jejunal permeability (vs. metoprolol). Indomethacin significantly increased sulfasalazine P(eff), effectively shifting it from BCS (biopharmaceutics classification system) Class IV to II. In conclusion, the data indicate that concomitant intake of indomethacin and sulfasalazine may lead to increased absorption of sulfasalazine in the small intestine, thereby reducing its colonic concentration and potentially altering its therapeutic effect. Copyright 2009 Elsevier B.V. All rights reserved.

  20. Insig proteins mediate feedback inhibition of cholesterol synthesis in the intestine.

    Science.gov (United States)

    McFarlane, Matthew R; Liang, Guosheng; Engelking, Luke J

    2014-01-24

    Enterocytes are the only cell type that must balance the de novo synthesis and absorption of cholesterol, although the coordinate regulation of these processes is not well understood. Our previous studies demonstrated that enterocytes respond to the pharmacological blockade of cholesterol absorption by ramping up de novo sterol synthesis through activation of sterol regulatory element-binding protein-2 (SREBP-2). Here, we genetically disrupt both Insig1 and Insig2 in the intestine, two closely related proteins that are required for the feedback inhibition of SREBP and HMG-CoA reductase (HMGR). This double knock-out was achieved by generating mice with an intestine-specific deletion of Insig1 using Villin-Cre in combination with a germ line deletion of Insig2. Deficiency of both Insigs in enterocytes resulted in constitutive activation of SREBP and HMGR, leading to an 11-fold increase in sterol synthesis in the small intestine and producing lipidosis of the intestinal crypts. The intestine-derived cholesterol accumulated in plasma and liver, leading to secondary feedback inhibition of hepatic SREBP2 activity. Pharmacological blockade of cholesterol absorption was unable to further induce the already elevated activities of SREBP-2 or HMGR in Insig-deficient enterocytes. These studies confirm the essential role of Insig proteins in the sterol homeostasis of enterocytes.

  1. Insig Proteins Mediate Feedback Inhibition of Cholesterol Synthesis in the Intestine*

    Science.gov (United States)

    McFarlane, Matthew R.; Liang, Guosheng; Engelking, Luke J.

    2014-01-01

    Enterocytes are the only cell type that must balance the de novo synthesis and absorption of cholesterol, although the coordinate regulation of these processes is not well understood. Our previous studies demonstrated that enterocytes respond to the pharmacological blockade of cholesterol absorption by ramping up de novo sterol synthesis through activation of sterol regulatory element-binding protein-2 (SREBP-2). Here, we genetically disrupt both Insig1 and Insig2 in the intestine, two closely related proteins that are required for the feedback inhibition of SREBP and HMG-CoA reductase (HMGR). This double knock-out was achieved by generating mice with an intestine-specific deletion of Insig1 using Villin-Cre in combination with a germ line deletion of Insig2. Deficiency of both Insigs in enterocytes resulted in constitutive activation of SREBP and HMGR, leading to an 11-fold increase in sterol synthesis in the small intestine and producing lipidosis of the intestinal crypts. The intestine-derived cholesterol accumulated in plasma and liver, leading to secondary feedback inhibition of hepatic SREBP2 activity. Pharmacological blockade of cholesterol absorption was unable to further induce the already elevated activities of SREBP-2 or HMGR in Insig-deficient enterocytes. These studies confirm the essential role of Insig proteins in the sterol homeostasis of enterocytes. PMID:24337570

  2. Use of a combination of in vitro models to investigate the impact of chlorpyrifos and inulin on the intestinal microbiota and the permeability of the intestinal mucosa.

    Science.gov (United States)

    Réquilé, Marina; Gonzàlez Alvarez, Dubàn O; Delanaud, Stéphane; Rhazi, Larbi; Bach, Véronique; Depeint, Flore; Khorsi-Cauet, Hafida

    2018-05-28

    Dietary exposure to the organophosphorothionate pesticide chlorpyrifos (CPF) has been linked to dysbiosis of the gut microbiota. We therefore sought to investigate whether (i) CPF's impact extends to the intestinal barrier and (ii) the prebiotic inulin could prevent such an effect. In vitro models mimicking the intestinal environment (the SHIME®) and the intestinal mucosa (Caco-2/TC7 cells) were exposed to CPF. After the SHIME® had been exposed to CPF and/or inulin, we assessed the system's bacterial and metabolic profiles. Extracts from the SHIME®'s colon reactors were then transferred to Caco-2/TC7 cultures, and epithelial barrier integrity and function were assessed. We found that inulin co-treatment partially reversed CPF-induced dysbiosis and increased short-chain fatty acid production in the SHIME®. Furthermore, co-treatment impacted tight junction gene expression and inhibited pro-inflammatory signaling in the Caco-2/TC7 intestinal cell line. Whereas, an isolated in vitro assessment of CPF and inulin effects provides useful information on the mechanism of dysbiosis, combining two in vitro models increases the in vivo relevance.

  3. Live Faecalibacterium prausnitzii in an apical anaerobic model of the intestinal epithelial barrier

    NARCIS (Netherlands)

    Ulluwishewa, D.; Anderson, R.C.; Young, W.; McNabb, W.C.; Baarlen, van P.; Moughan, P.J.; Wells, J.M.; Roy, N.C.

    2015-01-01

    Faecalibacterium prausnitzii, an abundant member of the human commensal microbiota, has been proposed to have a protective role in the intestine. However, it is an obligate anaerobe, difficult to co-culture in viable form with oxygen-requiring intestinal cells. To overcome this limitation, a unique

  4. Particulate matter air pollution disrupts endothelial cell barrier via calpain-mediated tight junction protein degradation

    Directory of Open Access Journals (Sweden)

    Wang Ting

    2012-08-01

    Full Text Available Abstract Background Exposure to particulate matter (PM is a significant risk factor for increased cardiopulmonary morbidity and mortality. The mechanism of PM-mediated pathophysiology remains unknown. However, PM is proinflammatory to the endothelium and increases vascular permeability in vitro and in vivo via ROS generation. Objectives We explored the role of tight junction proteins as targets for PM-induced loss of lung endothelial cell (EC barrier integrity and enhanced cardiopulmonary dysfunction. Methods Changes in human lung EC monolayer permeability were assessed by Transendothelial Electrical Resistance (TER in response to PM challenge (collected from Ft. McHenry Tunnel, Baltimore, MD, particle size >0.1 μm. Biochemical assessment of ROS generation and Ca2+ mobilization were also measured. Results PM exposure induced tight junction protein Zona occludens-1 (ZO-1 relocation from the cell periphery, which was accompanied by significant reductions in ZO-1 protein levels but not in adherens junction proteins (VE-cadherin and β-catenin. N-acetyl-cysteine (NAC, 5 mM reduced PM-induced ROS generation in ECs, which further prevented TER decreases and atteneuated ZO-1 degradation. PM also mediated intracellular calcium mobilization via the transient receptor potential cation channel M2 (TRPM2, in a ROS-dependent manner with subsequent activation of the Ca2+-dependent protease calpain. PM-activated calpain is responsible for ZO-1 degradation and EC barrier disruption. Overexpression of ZO-1 attenuated PM-induced endothelial barrier disruption and vascular hyperpermeability in vivo and in vitro. Conclusions These results demonstrate that PM induces marked increases in vascular permeability via ROS-mediated calcium leakage via activated TRPM2, and via ZO-1 degradation by activated calpain. These findings support a novel mechanism for PM-induced lung damage and adverse cardiovascular outcomes.

  5. Transepithelial Transport of PAMAM Dendrimers Across Isolated Human Intestinal Tissue.

    Science.gov (United States)

    Hubbard, Dallin; Enda, Michael; Bond, Tanner; Moghaddam, Seyyed Pouya Hadipour; Conarton, Josh; Scaife, Courtney; Volckmann, Eric; Ghandehari, Hamidreza

    2015-11-02

    Poly(amido amine) (PAMAM) dendrimers have shown transepithelial transport across intestinal epithelial barrier in rats and across Caco-2 cell monolayers. Caco-2 models innately lack mucous barriers, and rat isolated intestinal tissue has been shown to overestimate human permeability. This study is the first report of transport of PAMAM dendrimers across isolated human intestinal epithelium. It was observed that FITC labeled G4-NH2 and G3.5-COOH PAMAM dendrimers at 1 mM concentration do not have a statistically higher permeability compared to free FITC controls in isolated human jejunum and colonic tissues. Mannitol permeability was increased at 10 mM concentrations of G3.5-COOH and G4-NH2 dendrimers. Significant histological changes in human colonic and jejunal tissues were observed at G3.5-COOH and G4-NH2 concentrations of 10 mM implying that dose limiting toxicity may occur at similar concentrations in vivo. The permeability through human isolated intestinal tissue in this study was compared to previous rat and Caco-2 permeability data. This study implicates that PAMAM dendrimer oral drug delivery may be feasible, but it may be limited to highly potent drugs.

  6. High amylose resistant starch diet ameliorates oxidative stress, inflammation, and progression of chronic kidney disease

    Science.gov (United States)

    Inflammation is a major mediator of CKD progression and is partly driven by altered gut microbiome and intestinal barrier disruption, events which are caused by: urea influx in the intestine resulting in dominance of urease-possessing bacteria; disruption of epithelial barrier by urea-derived ammoni...

  7. Fish oil enhances recovery of intestinal microbiota and epithelial integrity in chronic rejection of intestinal transplant.

    Directory of Open Access Journals (Sweden)

    Qiurong Li

    Full Text Available BACKGROUND: The intestinal chronic rejection (CR is the major limitation to long-term survival of transplanted organs. This study aimed to investigate the interaction between intestinal microbiota and epithelial integrity in chronic rejection of intestinal transplantation, and to find out whether fish oil enhances recovery of intestinal microbiota and epithelial integrity. METHODS/PRINCIPAL FINDINGS: The luminal and mucosal microbiota composition of CR rats were characterized by DGGE analysis at 190 days after intestinal transplant. The specific bacterial species were determined by sequence analysis. Furthermore, changes in the localization of intestinal TJ proteins were examined by immunofluorescent staining. PCR-DGGE analysis revealed that gut microbiota in CR rats had a shift towards Escherichia coli, Bacteroides spp and Clostridium spp and a decrease in the abundance of Lactobacillales bacteria in the intestines. Fish oil supplementation could enhance the recovery of gut microbiota, showing a significant decrease of gut bacterial proportions of E. coli and Bacteroides spp and an increase of Lactobacillales spp. In addition, CR rats showed pronounced alteration of tight junction, depicted by marked changes in epithelial cell ultrastructure and redistribution of occuldin and claudins as well as disruption in TJ barrier function. Fish oil administration ameliorated disruption of epithelial integrity in CR, which was associated with an improvement of the mucosal structure leading to improved tight junctions. CONCLUSIONS/SIGNIFICANCE: Our study have presented novel evidence that fish oil is involved in the maintenance of epithelial TJ integrity and recovery of gut microbiota, which may have therapeutic potential against CR in intestinal transplantation.

  8. Neural influences on human intestinal epithelium in vitro.

    Science.gov (United States)

    Krueger, Dagmar; Michel, Klaus; Zeller, Florian; Demir, Ihsan E; Ceyhan, Güralp O; Slotta-Huspenina, Julia; Schemann, Michael

    2016-01-15

    We present the first systematic and, up to now, most comprehensive evaluation of the basic features of epithelial functions, such as basal and nerve-evoked secretion, as well as tissue resistance, in over 2200 surgical specimens of human small and large intestine. We found no evidence for impaired nerve-evoked epithelial secretion or tissue resistance with age or disease pathologies (stomach, pancreas or colon cancer, polyps, diverticulitis, stoma reversal). This indicates the validity of future studies on epithelial secretion or resistance that are based on data from a variety of surgical specimens. ACh mainly mediated nerve-evoked and basal secretion in the small intestine, whereas vasoactive intestinal peptide and nitric oxide were the primary pro-secretory transmitters in the large intestine. The results of the present study revealed novel insights into regional differences in nerve-mediated secretion in the human intestine and comprise the basis by which to more specifically target impaired epithelial functions in the diseased gut. Knowledge on basic features of epithelial functions in the human intestine is scarce. We used Ussing chamber techniques to record basal tissue resistance (R-basal) and short circuit currents (ISC; secretion) under basal conditions (ISC-basal) and after electrical field stimulation (ISC-EFS) of nerves in 2221 resectates from 435 patients. ISC-EFS was TTX-sensitive and of comparable magnitude in the small and large intestine. ISC-EFS or R-basal were not influenced by the patients' age, sex or disease pathologies (cancer, polyps, diverticulitis). Ion substitution, bumetanide or adenylate cyclase inhibition studies suggested that ISC-EFS depended on epithelial cAMP-driven chloride and bicarbonate secretion but not on amiloride-sensitive sodium absorption. Although atropine-sensitive cholinergic components prevailed for ISC-EFS of the duodenum, jejunum and ileum, PG97-269-sensitive [vasoactive intestinal peptide (VIP) receptor 1

  9. Connexin 26-mediated gap junctional intercellular communication suppresses paracellular permeability of human intestinal epithelial cell monolayers

    International Nuclear Information System (INIS)

    Morita, Hidekazu; Katsuno, Tatsuro; Hoshimoto, Aihiro; Hirano, Noriaki; Saito, Yasushi; Suzuki, Yasuo

    2004-01-01

    In some cell types, gap junctional intercellular communication (GJIC) is associated with tight junctions. The present study was performed to determine the roles of GJIC in regulation of the barrier function of tight junctions. Caco-2 human colonic cells were used as a monolayer model, and barrier function was monitored by measuring mannitol permeability and transepithelial electrical resistance (TER). The monolayers were chemically disrupted by treatment with oleic acid and taurocholic acid. Western blotting analyses were performed to evaluate the protein levels of connexins, which are components of gap junctional intercellular channels. Cx26 expression was detected in preconfluent Caco-2 cells, and its level increased gradually after the monolayer reached confluency. These results prompted us to examine whether overexpression of Cx26 affects barrier function. Monolayers of Caco-2 cells stably expressing Cx26 showed significantly lower mannitol permeability and higher TER than mock transfectants when the monolayers were chemically disrupted. The levels of claudin-4, an important component of tight junctions, were significantly increased in the stable Cx26 transfectant. These results suggest that Cx26-mediated GJIC may play a crucial role in enhancing the barrier function of Caco-2 cell monolayers

  10. Enhancement of intestinal growth in neonatal rats by epidermal growth factor in milk

    International Nuclear Information System (INIS)

    Berseth, C.L.

    1987-01-01

    Breast milk has been shown to enhance neonatal intestinal growth. Because epidermal growth factor (EGF) is present in the milk of various mammalian species, the hypothesis was tested that EGF in rodent milk mediates, in part, the breast milk-enhanced intestinal growth in neonatal rat. Fifty-eight rat pups fed artificial formal that contained 1.2, 3.0, and 6.0 μg/ml EGF for 39 h had greater incorporation of [ 3 H]thymidine into DNA and DNA content of intestine than 29 pups fed unsupplemented formula. Pups fed EGF for 5 days had significantly greater body weight, intestinal weight, length, and DNA content than control pups. Conversely, pups fed pooled rat milk containing rabbit-derived antibody to EGF for 39 h had intestines of lower weight that contained less DNA than animals fed rat milk containing normal rabbit serum. EGF appears to mediate, in part, breast milk-enhanced neonatal intestinal growth

  11. Moderated mediation to identify the knowledge stocks, learning flows and barriers at a Dutch telecom operator

    NARCIS (Netherlands)

    de Schryver, Tom; Rosendaal, Bas

    2013-01-01

    Drawing on the 4I-model of Crossan et al. (1999), we have identified the knowledge stocks, learning flows and barriers at a Dutch telecom operator by means of moderated mediation. In this company, the strategic relevant knowledge stocks move in the same direction and many processes support their

  12. Constitutively active RAS signaling reduces 1,25 dihydroxyvitamin D-mediated gene transcription in intestinal epithelial cells by reducing vitamin D receptor expression.

    Science.gov (United States)

    DeSmet, Marsha L; Fleet, James C

    2017-10-01

    High vitamin D status is associated with reduced colon cancer risk but these studies ignore the diversity in the molecular etiology of colon cancer. RAS activating mutations are common in colon cancer and they activate pro-proliferative signaling pathways. We examined the impact of RAS activating mutations on 1,25 dihydroxyvitamin D (1,25(OH) 2 D)-mediated gene expression in cultured colon and intestinal cell lines. Transient transfection of Caco-2 cells with a constitutively active mutant K-RAS (G12 V) significantly reduced 1,25(OH) 2 D-induced activity of both a human 25-hydroxyvitamin D, 24 hydroxyase (CYP24A1) promoter-luciferase and an artificial 3X vitamin D response element (VDRE) promoter-luciferase reporter gene. Young Adult Mouse Colon (YAMC) and Rat Intestinal Epithelial (RIE) cell lines with stable expression of mutant H-RAS had suppressed 1,25(OH) 2 D-mediated induction of CYP24A1 mRNA. The RAS effects were associated with lower Vitamin D receptor (VDR) mRNA and protein levels in YAMC and RIE cells and they could be partially reversed by VDR overexpression. RAS-mediated suppression of VDR levels was not due to either reduced VDR mRNA stability or increased VDR gene methylation. However, chromatin accessibility to the VDR gene at the proximal promoter (-300bp), an enhancer region at -6kb, and an enhancer region located in exon 3 was significantly reduced in RAS transformed YAMC cells (YAMC-RAS). These data show that constitutively active RAS signaling suppresses 1,25(OH) 2 D-mediated gene transcription in colon epithelial cells by reducing VDR gene transcription but the mechanism for this suppression is not yet known. These data suggest that cancers with RAS-activating mutations may be less responsive to vitamin D mediated treatment or chemoprevention. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Interplay among gut microbiota, intestinal mucosal barrier and enteric neuro-immune system: a common path to neurodegenerative diseases?

    Science.gov (United States)

    Pellegrini, Carolina; Antonioli, Luca; Colucci, Rocchina; Blandizzi, Corrado; Fornai, Matteo

    2018-05-24

    Neurological diseases, such as Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis (ALS) and multiple sclerosis, are often associated with functional gastrointestinal disorders. These gastrointestinal disturbances may occur at all stages of the neurodegenerative diseases, to such an extent that they are now considered an integral part of their clinical picture. Several lines of evidence support the contention that, in central neurodegenerative diseases, changes in gut microbiota and enteric neuro-immune system alterations could contribute to gastrointesinal dysfunctions as well as initiation and upward spreading of the neurologic disorder. The present review has been intended to provide a comprehensive overview of the available knowledge on the role played by enteric microbiota, mucosal immune system and enteric nervous system, considered as an integrated network, in the pathophysiology of the main neurological diseases known to be associated with intestinal disturbances. In addition, based on current human and pre-clinical evidence, our intent was to critically discuss whether changes in the dynamic interplay between gut microbiota, intestinal epithelial barrier and enteric neuro-immune system are a consequence of the central neurodegeneration or might represent the starting point of the neurodegenerative process. Special attention has been paid also to discuss whether alterations of the enteric bacterial-neuro-immune network could represent a common path driving the onset of the main neurodegenerative diseases, even though each disease displays its own distinct clinical features.

  14. Protective effect of salvianolic acid B against intestinal ischemia ...

    African Journals Online (AJOL)

    transplantation, strangulated hernias due to gastric barrier ... using pentabarbital sodium at the dose of 50 ..... prevents iodinated contrast media-induced acute renal injury in rats via ... mesenchymal stem cells reduce rat intestinal ischemia-.

  15. Mechanisms of methicillin-resistant Staphylococcus aureus pneumonia-induced intestinal epithelial apoptosis.

    Science.gov (United States)

    Perrone, Erin E; Jung, Enjae; Breed, Elise; Dominguez, Jessica A; Liang, Zhe; Clark, Andrew T; Dunne, W Michael; Burd, Eileen M; Coopersmith, Craig M

    2012-07-01

    Methicillin-resistant Staphylococcus aureus (MRSA) pneumonia-induced sepsis is a common cause of morbidity in the intensive care unit. Although pneumonia is initiated in the lungs, extrapulmonary manifestations occur commonly. In light of the key role the intestine plays in the pathophysiology of sepsis, we sought to determine whether MRSA pneumonia induces intestinal injury. FVB/N mice were subjected to MRSA or sham pneumonia and killed 24 h later. Septic animals had a marked increase in intestinal epithelial apoptosis by both hematoxylin-eosin and active caspase 3 staining. Methicillin-resistant S. aureus-induced intestinal apoptosis was associated with an increase in the expression of the proapoptotic proteins Bid and Bax and the antiapoptotic protein Bcl-xL in the mitochondrial pathway. In the receptor-mediated pathway, MRSA pneumonia induced an increase in Fas ligand but decreased protein levels of Fas, FADD, pFADD, TNF-R1, and TRADD. To assess the functional significance of these changes, MRSA pneumonia was induced in mice with genetic manipulations in proteins in either the mitochondrial or receptor-mediated pathways. Both Bid-/- mice and animals with intestine-specific overexpression of Bcl-2 had decreased intestinal apoptosis compared with wild-type animals. In contrast, Fas ligand-/- mice had no alterations in apoptosis. To determine if these findings were organism-specific, similar experiments were performed in mice subjected to Pseudomonas aeruginosa pneumonia. Pseudomonas aeruginosa induced gut apoptosis, but unlike MRSA, this was associated with increased Bcl-2 and TNF-R1 and decreased Fas. Methicillin-resistant S. aureus pneumonia thus induces organism-specific changes in intestinal apoptosis via changes in both the mitochondrial and receptor-mediated pathways, although the former may be more functionally significant.

  16. Artificial neural network models for prediction of intestinal permeability of oligopeptides

    Directory of Open Access Journals (Sweden)

    Kim Min-Kook

    2007-07-01

    Full Text Available Abstract Background Oral delivery is a highly desirable property for candidate drugs under development. Computational modeling could provide a quick and inexpensive way to assess the intestinal permeability of a molecule. Although there have been several studies aimed at predicting the intestinal absorption of chemical compounds, there have been no attempts to predict intestinal permeability on the basis of peptide sequence information. To develop models for predicting the intestinal permeability of peptides, we adopted an artificial neural network as a machine-learning algorithm. The positive control data consisted of intestinal barrier-permeable peptides obtained by the peroral phage display technique, and the negative control data were prepared from random sequences. Results The capacity of our models to make appropriate predictions was validated by statistical indicators including sensitivity, specificity, enrichment curve, and the area under the receiver operating characteristic (ROC curve (the ROC score. The training and test set statistics indicated that our models were of strikingly good quality and could discriminate between permeable and random sequences with a high level of confidence. Conclusion We developed artificial neural network models to predict the intestinal permeabilities of oligopeptides on the basis of peptide sequence information. Both binary and VHSE (principal components score Vectors of Hydrophobic, Steric and Electronic properties descriptors produced statistically significant training models; the models with simple neural network architectures showed slightly greater predictive power than those with complex ones. We anticipate that our models will be applicable to the selection of intestinal barrier-permeable peptides for generating peptide drugs or peptidomimetics.

  17. Probiotic Mixture Golden Bifido Prevents Neonatal Escherichia coli K1 Translocation via Enhancing Intestinal Defense

    Directory of Open Access Journals (Sweden)

    Qing Zeng

    2017-09-01

    Full Text Available Escherichia coli (E. coli K1 sepsis and meningitis is a severe infection characterized by high mortality in neonates. Successful colonization and translocation across the intestinal mucosa have been regarded as the critical steps for E. coli K1 sepsis and meningitis. We recently reported that the probiotic mixture, Golden Bifido (containing live Lactobacillus bulgaricus, Bifidobacterium, and Streptococcus thermophilus, LBS has a preventive role against neonatal E. coli K1 bacteremia and meningitis. However, the interaction between the neonatal gut barrier, probiotics and E. coli K1 is still not elucidated. The present study aims to investigate how LBS exerts its protective effects on neonatal gut barrier during E. coli K1 infection. The beneficial effects of LBS were explored in vitro and in vivo using human colon carcinoma cell lines HT-29 and rat model of neonatal E. coli K1 infection, respectively. Our results showed that stimulation with E. coli K1 was able to cause intestinal barrier dysfunction, which were reflected by E. coli K1-induced intestinal damage and apoptosis of intestinal epithelial cells, reduction of mucin, immunoglobulin A (IgA and tight junction proteins expression, as well as increase in intestinal permeability, all these changes facilitate E. coli K1 intestinal translocation. However, these changes were alleviated when HT-29 cells were treated with LBS before E. coli K1 infection. Furthermore, we found that LBS-treated neonatal rats (without E. coli K1 infection have showed higher production of mucin, ZO-1, IgA, Ki67 in intestinal mucosa as well as lower intestinal permeability than that of non-treated rats, indicating that LBS could accelerate the development of neonatal intestinal defense. Taken together, our results suggest that enhancement of the neonatal intestinal defense to fight against E. coli K1 translocation could be the potential mechanism to elucidate how LBS confers a protective effect against neonatal E

  18. Dysbiosis of Intestinal Microbiota and Decreased Antimicrobial Peptide Level in Paneth Cells during Hypertriglyceridemia-Related Acute Necrotizing Pancreatitis in Rats

    Directory of Open Access Journals (Sweden)

    Chunlan Huang

    2017-05-01

    Full Text Available Hypertriglyceridemia (HTG aggravates the course of acute pancreatitis (AP. Intestinal barrier dysfunction is implicated in the pathogenesis of AP during which dysbiosis of intestinal microbiota contributes to the dysfunction in intestinal barrier. However, few studies focus on the changes in intestine during HTG-related acute necrotizing pancreatitis (ANP. Here, we investigated the changes in intestinal microbiota and Paneth cell antimicrobial peptides (AMPs in HTG-related ANP (HANP in rats. Rats fed a high-fat diet to induce HTG and ANP was induced by retrograde injection of 3.5% sodium taurocholate into biliopancreatic duct. Rats were sacrificed at 24 and 48 h, respectively. Pancreatic and ileal injuries were evaluated by histological scores. Intestinal barrier function was assessed by plasma diamine oxidase activity and D-lactate level. Systemic and intestinal inflammation was evaluated by tumor necrosis factor alpha (TNFα, interleukin (IL-1β, and IL-17A expression. 16S rRNA high throughput sequencing was used to investigate changes in intestinal microbiota diversity and structure. AMPs (α-defensin5 and lysozyme expression was measured by real-time polymerase chain reaction (PCR and immunofluorescence. The results showed that compared with those of normal-lipid ANP (NANP groups, the HANP groups had more severe histopathological injuries in pancreas and distal ileum, aggravated intestinal barrier dysfunction and increased TNFα, IL-1β, and IL-17A expression in plasma and distal ileum. Principal component analysis showed structural segregation between the HANP and NANP group. α-Diversity estimators in the HANP group revealed decreased microbiota diversity compared with that in NANP group. Taxonomic analysis showed dysbiosis of intestinal microbiota structure. In the HANP group, at phyla level, Candidatus_Saccharibacteria and Tenericutes decreased significantly, whereas Actinobacteria increased. At genus level, Allobaculum, Bifidobacterium

  19. Gliadin, zonulin and gut permeability: Effects on celiac and non-celiac intestinal mucosa and intestinal cell lines.

    Science.gov (United States)

    Drago, Sandro; El Asmar, Ramzi; Di Pierro, Mariarosaria; Grazia Clemente, Maria; Tripathi, Amit; Sapone, Anna; Thakar, Manjusha; Iacono, Giuseppe; Carroccio, Antonio; D'Agate, Cinzia; Not, Tarcisio; Zampini, Lucia; Catassi, Carlo; Fasano, Alessio

    2006-04-01

    Little is known about the interaction of gliadin with intestinal epithelial cells and the mechanism(s) through which gliadin crosses the intestinal epithelial barrier. We investigated whether gliadin has any immediate effect on zonulin release and signaling. Both ex vivo human small intestines and intestinal cell monolayers were exposed to gliadin, and zonulin release and changes in paracellular permeability were monitored in the presence and absence of zonulin antagonism. Zonulin binding, cytoskeletal rearrangement, and zonula occludens-1 (ZO-1) redistribution were evaluated by immunofluorescence microscopy. Tight junction occludin and ZO-1 gene expression was evaluated by real-time polymerase chain reaction (PCR). When exposed to gliadin, zonulin receptor-positive IEC6 and Caco2 cells released zonulin in the cell medium with subsequent zonulin binding to the cell surface, rearrangement of the cell cytoskeleton, loss of occludin-ZO1 protein-protein interaction, and increased monolayer permeability. Pretreatment with the zonulin antagonist FZI/0 blocked these changes without affecting zonulin release. When exposed to luminal gliadin, intestinal biopsies from celiac patients in remission expressed a sustained luminal zonulin release and increase in intestinal permeability that was blocked by FZI/0 pretreatment. Conversely, biopsies from non-celiac patients demonstrated a limited, transient zonulin release which was paralleled by an increase in intestinal permeability that never reached the level of permeability seen in celiac disease (CD) tissues. Chronic gliadin exposure caused down-regulation of both ZO-1 and occludin gene expression. Based on our results, we concluded that gliadin activates zonulin signaling irrespective of the genetic expression of autoimmunity, leading to increased intestinal permeability to macromolecules.

  20. Cysteine-rich intestinal protein binds zinc during transmucosal zinc transport

    International Nuclear Information System (INIS)

    Hempe, J.M.; Cousins, R.J.

    1991-01-01

    The mechanism of zinc absorption has not been delineated, but kinetic studies show that both passive and carrier-mediated processes are involved. The authors have identified a low molecular mass zinc-binding protein in the soluble fraction of rat intestinal mucosa that could function as an intracellular zinc carrier. The protein was not detected in liver or pancreas, suggesting a role specific to the intestine. The protein binds zinc during transmucosal zinc transport and shows signs of saturation at higher luminal zinc concentrations, characteristics consistent with a role in carrier-mediated zinc absorption. Microsequence analysis of the protein purified by gel-filtration HPCL and SDS/PAGE showed complete identity within the first 41 N-terminal amino acids with the deduced protein sequence of cysteine-rich intestinal protein. These investigators showed that the gene for this protein is developmentally regulated in neonates during the suckling period, conserved in many vertebrate species, and predominantly expressed in the small intestine. Cysteine-rich intestinal protein contains a recently identified conserved sequence of histidine and cysteine residues, the LIM motif, which our results suggest confers metal-binding properties that are important for zinc transport and/or functions of this micronutrient

  1. Intestinal intraepithelial lymphocyte-enterocyte crosstalk regulates production of bactericidal angiogenin 4 by Paneth cells upon microbial challenge.

    Directory of Open Access Journals (Sweden)

    Catherine R Walker

    Full Text Available Antimicrobial proteins influence intestinal microbial ecology and limit proliferation of pathogens, yet the regulation of their expression has only been partially elucidated. Here, we have identified a putative pathway involving epithelial cells and intestinal intraepithelial lymphocytes (iIELs that leads to antimicrobial protein (AMP production by Paneth cells. Mice lacking γδ iIELs (TCRδ(-/- express significantly reduced levels of the AMP angiogenin 4 (Ang4. These mice were also unable to up-regulate Ang4 production following oral challenge by Salmonella, leading to higher levels of mucosal invasion compared to their wild type counterparts during the first 2 hours post-challenge. The transfer of γδ iIELs from wild type (WT mice to TCRδ(-/- mice restored Ang4 production and Salmonella invasion levels were reduced to those obtained in WT mice. The ability to restore Ang4 production in TCRδ(-/- mice was shown to be restricted to γδ iIELs expressing Vγ7-encoded TCRs. Using a novel intestinal crypt co-culture system we identified a putative pathway of Ang4 production initiated by exposure to Salmonella, intestinal commensals or microbial antigens that induced intestinal epithelial cells to produce cytokines including IL‑23 in a TLR-mediated manner. Exposure of TCR-Vγ7(+ γδ iIELs to IL-23 promoted IL‑22 production, which triggered Paneth cells to secrete Ang4. These findings identify a novel role for γδ iIELs in mucosal defence through sensing immediate epithelial cell cytokine responses and influencing AMP production. This in turn can contribute to the maintenance of intestinal microbial homeostasis and epithelial barrier function, and limit pathogen invasion.

  2. Both direct and indirect effects account for the pro-inflammatory activity of enteropathogenic mycotoxins on the human intestinal epithelium: Stimulation of interleukin-8 secretion, potentiation of interleukin-1β effect and increase in the transepithelial passage of commensal bacteria

    International Nuclear Information System (INIS)

    Maresca, Marc; Yahi, Nouara; Younes-Sakr, Lama; Boyron, Marilyn; Caporiccio, Bertrand; Fantini, Jacques

    2008-01-01

    Mycotoxins are fungal secondary metabolites responsible of food-mediated intoxication in animals and humans. Deoxynivalenol, ochratoxin A and patulin are the best known enteropathogenic mycotoxins able to alter intestinal functions resulting in malnutrition, diarrhea, vomiting and intestinal inflammation in vivo. Although their effects on intestinal barrier and transport activities have been extensively characterized, the mechanisms responsible for their pro-inflammatory effect are still poorly understood. Here we investigated if mycotoxin-induced intestinal inflammation results from a direct and/or indirect pro-inflammatory activity of these mycotoxins on human intestinal epithelial cells, using differentiated Caco-2 cells as model and interleukin 8 (IL-8) as an indicator of intestinal inflammation. Deoxynivalenol was the only mycotoxin able to directly increase IL-8 secretion (10- to 15-fold increase). We also investigated if these mycotoxins could indirectly stimulate IL-8 secretion through: (i) a modulation of the action of pro-inflammatory molecules such as the interleukin-1beta (IL-1β), and/or (ii) an increase in the transepithelial passage of non-invasive commensal Escherichia coli. We found that deoxynivalenol, ochratoxin A and patulin all potentiated the effect of IL-1β on IL-8 secretion (ranging from 35% to 138% increase) and increased the transepithelial passage of commensal bacteria (ranging from 12- to 1544-fold increase). In addition to potentially exacerbate established intestinal inflammation, these mycotoxins may thus participate in the induction of sepsis and intestinal inflammation in vivo. Taken together, our results suggest that the pro-inflammatory activity of enteropathogenic mycotoxins is mediated by both direct and indirect effects

  3. Enteric Virome Sensing—Its Role in Intestinal Homeostasis and Immunity

    Directory of Open Access Journals (Sweden)

    Rebecca N. Metzger

    2018-03-01

    Full Text Available Pattern recognition receptors (PRRs sensing commensal microorganisms in the intestine induce tightly controlled tonic signaling in the intestinal mucosa, which is required to maintain intestinal barrier integrity and immune homeostasis. At the same time, PRR signaling pathways rapidly trigger the innate immune defense against invasive pathogens in the intestine. Intestinal epithelial cells and mononuclear phagocytes in the intestine and the gut-associated lymphoid tissues are critically involved in sensing components of the microbiome and regulating immune responses in the intestine to sustain immune tolerance against harmless antigens and to prevent inflammation. These processes have been mostly investigated in the context of the bacterial components of the microbiome so far. The impact of viruses residing in the intestine and the virus sensors, which are activated by these enteric viruses, on intestinal homeostasis and inflammation is just beginning to be unraveled. In this review, we will summarize recent findings indicating an important role of the enteric virome for intestinal homeostasis as well as pathology when the immune system fails to control the enteric virome. We will provide an overview of the virus sensors and signaling pathways, operative in the intestine and the mononuclear phagocyte subsets, which can sense viruses and shape the intestinal immune response. We will discuss how these might interact with resident enteric viruses directly or in context with the bacterial microbiome to affect intestinal homeostasis.

  4. Enteric Virome Sensing-Its Role in Intestinal Homeostasis and Immunity.

    Science.gov (United States)

    Metzger, Rebecca N; Krug, Anne B; Eisenächer, Katharina

    2018-03-23

    Pattern recognition receptors (PRRs) sensing commensal microorganisms in the intestine induce tightly controlled tonic signaling in the intestinal mucosa, which is required to maintain intestinal barrier integrity and immune homeostasis. At the same time, PRR signaling pathways rapidly trigger the innate immune defense against invasive pathogens in the intestine. Intestinal epithelial cells and mononuclear phagocytes in the intestine and the gut-associated lymphoid tissues are critically involved in sensing components of the microbiome and regulating immune responses in the intestine to sustain immune tolerance against harmless antigens and to prevent inflammation. These processes have been mostly investigated in the context of the bacterial components of the microbiome so far. The impact of viruses residing in the intestine and the virus sensors, which are activated by these enteric viruses, on intestinal homeostasis and inflammation is just beginning to be unraveled. In this review, we will summarize recent findings indicating an important role of the enteric virome for intestinal homeostasis as well as pathology when the immune system fails to control the enteric virome. We will provide an overview of the virus sensors and signaling pathways, operative in the intestine and the mononuclear phagocyte subsets, which can sense viruses and shape the intestinal immune response. We will discuss how these might interact with resident enteric viruses directly or in context with the bacterial microbiome to affect intestinal homeostasis.

  5. Cyanidin-3-O-Glucoside Modulates the In Vitro Inflammatory Crosstalk between Intestinal Epithelial and Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Daniela Ferrari

    2017-01-01

    Full Text Available Intestinal epithelium represents a protective physical barrier and actively contributes to the mucosal immune system. Polarized basolateral intestinal secretion of inflammatory mediators, followed by activation of NF-κB signaling and inflammatory pathways in endothelial cells, efficiently triggers extravasation of neutrophils from the vasculature, therefore contributing to the development and maintenance of intestinal inflammation. Proper regulation of NF-κB activation at the epithelial interface is crucial for the maintenance of physiological tissue homeostasis. Many papers reported that anthocyanins, a group of compounds belonging to flavonoids, possess anti-inflammatory effects and modulate NF-κB activity. In this study, by using a coculture in vitro system, we aimed to evaluate the effects of TNF-α-stimulated intestinal cells on endothelial cells activation, as well as the protective effects of cyanidin-3-glucoside (C3G. In this model, TNF-α induced nuclear translocation of NF-κB and TNF-α and IL-8 gene expression in Caco-2 cells, whereas C3G pretreatment dose-dependently reduced these effects. Furthermore, TNF-α-stimulated Caco-2 cells induced endothelial cells activation with increased E-selectin and VCAM-1 mRNA, leukocyte adhesion, and NF-κB levels in HUVECs, which were inhibited by C3G. We demonstrated that selective inhibition of the NF-κB pathway in epithelial cells represents the main mechanism by which C3G exerts these protective effects. Thus, anthocyanins could contribute to the management of chronic gut inflammatory diseases.

  6. MET Signaling Mediates Intestinal Crypt-Villus Development, Regeneration, and Adenoma Formation and Is Promoted by Stem Cell CD44 Isoforms.

    Science.gov (United States)

    Joosten, Sander P J; Zeilstra, Jurrit; van Andel, Harmen; Mijnals, R Clinton; Zaunbrecher, Joost; Duivenvoorden, Annet A M; van de Wetering, Marc; Clevers, Hans; Spaargaren, Marcel; Pals, Steven T

    2017-10-01

    /Met fl/fl /LacZ mice. Lgr5 Creert2 /Met fl/fl /LacZ mice had impaired regeneration of MET-deficient ISCs. Adenoma organoids stimulated with EGF or HGF expanded to almost twice the size of nonstimulated organoids. MET-deficient adenoma organoids did not respond to HGF stimulation, but did respond to EGF. ISC-specific disruption of Met (Lgr5 Creert2 /Met fl/fl /Apc fl/fl mice) caused a twofold increase in apoptosis in microadenomas, resulting in an approximately 50% reduction of microadenoma numbers and significantly reduced average adenoma size. Total epithelial disruption of Met (Ah Cre /Met fl/fl /Apc fl/+ mice) resulted in an approximate 50% reduction in (micro)adenoma numbers. Intestinal crypts from Cd44 -/- mice did not expand to the same extent as crypts from Cd44 +/+ mice on stimulation with HGF, but had the same response to EGF. The negative effect on HGF-mediated growth was overcome by expression of CD44v4-10, but not by CD44s. Similarly, HGF-mediated expansion of adenoma organoids required CD44v4-10. In studies of intestinal organoid cultures and mice with inducible deletion of MET, we found HGF receptor signaling to regulate intestinal homeostasis and regeneration, as well as adenoma formation. These activities of MET are promoted by the stem cell CD44 isoform CD44v4-10. Our findings provide rationale for targeting signaling via MET and CD44 during anti-EGF receptor therapy of patients with colorectal cancer or in patients resistant to EGF receptor inhibitors. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

  7. Bacterial Signaling at the Intestinal Epithelial Interface in Inflammation and Cancer

    Directory of Open Access Journals (Sweden)

    Olivia I. Coleman

    2018-01-01

    Full Text Available The gastrointestinal (GI tract provides a compartmentalized interface with an enormous repertoire of immune and metabolic activities, where the multicellular structure of the mucosa has acquired mechanisms to sense luminal factors, such as nutrients, microbes, and a variety of host-derived and microbial metabolites. The GI tract is colonized by a complex ecosystem of microorganisms, which have developed a highly coevolved relationship with the host’s cellular and immune system. Intestinal epithelial pattern recognition receptors (PRRs substantially contribute to tissue homeostasis and immune surveillance. The role of bacteria-derived signals in intestinal epithelial homeostasis and repair has been addressed in mouse models deficient in PRRs and signaling adaptors. While critical for host physiology and the fortification of barrier function, the intestinal microbiota poses a considerable health challenge. Accumulating evidence indicates that dysbiosis is associated with the pathogenesis of numerous GI tract diseases, including inflammatory bowel diseases (IBD and colorectal cancer (CRC. Aberrant signal integration at the epithelial cell level contributes to such diseases. An increased understanding of bacterial-specific structure recognition and signaling mechanisms at the intestinal epithelial interface is of great importance in the translation to future treatment strategies. In this review, we summarize the growing understanding of the regulation and function of the intestinal epithelial barrier, and discuss microbial signaling in the dynamic host–microbe mutualism in both health and disease.

  8. The effects of fluorouracil, epirubicin, and cyclophosphamide (FEC60 on the intestinal barrier function and gut peptides in breast cancer patients: an observational study

    Directory of Open Access Journals (Sweden)

    Russo Francesco

    2013-02-01

    Full Text Available Abstract Background Several GI peptides linked to intestinal barrier function could be involved in the modification of intestinal permeability and the onset of diarrhea during adjuvant chemotherapy. The aim of the study was to evaluate the circulating levels of zonulin, glucagon-like peptide-2 (GLP-2, epidermal growth factor (EGF and ghrelin and their relationship with intestinal permeability and chemotherapy induced diarrhea (CTD. Methods Sixty breast cancer patients undergoing an FEC60 regimen were enrolled, 37 patients completed the study. CTD(+ patients were discriminated by appropriate questionnaire and criteria. During chemotherapy, intestinal permeability was assessed by lactulose/mannitol urinary test on day 0 and day 14. Zonulin, GLP-2, EGF and ghrelin circulating levels were evaluated by ELISA tests at five time-points (days 0, 3, 10, 14, and 21. Results During FEC60 administration, the lactulose/mannitol ratio was significantly higher on day 14 than at baseline. Zonulin levels were not affected by chemotherapy, whereas GLP-2 and EGF levels decreased significantly. GLP-2 levels on day 14 were significantly lower than those on day 0 and day 3, while EGF values were significantly lower on day 10 than at the baseline. In contrast, the total concentrations of ghrelin increased significantly at day 3 compared to days 0 and 21, respectively. Ten patients (27% suffered from diarrhea. On day 14 of chemotherapy, a significant increase of the La/Ma ratio occurred in CTD(+ patients compared to CTD(− patients. With regards to circulating gut peptides, the AUCg of GLP-2 and ghrelin were significantly lower and higher in CTD(+ patients than CTD(− ones, respectively. Finally in CTD(+ patients a significant and inverse correlation between GLP-2 and La/Ma ratio was found on day 14. Conclusions Breast cancer patients undergoing FEC60 showed alterations in the intestinal permeability, which was associated with modifications in the levels of GLP-2

  9. The effects of fluorouracil, epirubicin, and cyclophosphamide (FEC60) on the intestinal barrier function and gut peptides in breast cancer patients: an observational study.

    Science.gov (United States)

    Russo, Francesco; Linsalata, Michele; Clemente, Caterina; D'Attoma, Benedetta; Orlando, Antonella; Campanella, Giovanna; Giotta, Francesco; Riezzo, Giuseppe

    2013-02-04

    Several GI peptides linked to intestinal barrier function could be involved in the modification of intestinal permeability and the onset of diarrhea during adjuvant chemotherapy. The aim of the study was to evaluate the circulating levels of zonulin, glucagon-like peptide-2 (GLP-2), epidermal growth factor (EGF) and ghrelin and their relationship with intestinal permeability and chemotherapy induced diarrhea (CTD). Sixty breast cancer patients undergoing an FEC60 regimen were enrolled, 37 patients completed the study. CTD(+) patients were discriminated by appropriate questionnaire and criteria. During chemotherapy, intestinal permeability was assessed by lactulose/mannitol urinary test on day 0 and day 14. Zonulin, GLP-2, EGF and ghrelin circulating levels were evaluated by ELISA tests at five time-points (days 0, 3, 10, 14, and 21). During FEC60 administration, the lactulose/mannitol ratio was significantly higher on day 14 than at baseline. Zonulin levels were not affected by chemotherapy, whereas GLP-2 and EGF levels decreased significantly. GLP-2 levels on day 14 were significantly lower than those on day 0 and day 3, while EGF values were significantly lower on day 10 than at the baseline. In contrast, the total concentrations of ghrelin increased significantly at day 3 compared to days 0 and 21, respectively. Ten patients (27%) suffered from diarrhea. On day 14 of chemotherapy, a significant increase of the La/Ma ratio occurred in CTD(+) patients compared to CTD(-) patients. With regards to circulating gut peptides, the AUCg of GLP-2 and ghrelin were significantly lower and higher in CTD(+) patients than CTD(-) ones, respectively. Finally in CTD(+) patients a significant and inverse correlation between GLP-2 and La/Ma ratio was found on day 14. Breast cancer patients undergoing FEC60 showed alterations in the intestinal permeability, which was associated with modifications in the levels of GLP-2, ghrelin and EGF. In CTD(+) patients, a different GI peptide

  10. Modulation of Intestinal Paracellular Transport by Bacterial Pathogens.

    Science.gov (United States)

    Roxas, Jennifer Lising; Viswanathan, V K

    2018-03-25

    The passive and regulated movement of ions, solutes, and water via spaces between cells of the epithelial monolayer plays a critical role in the normal intestinal functioning. This paracellular pathway displays a high level of structural and functional specialization, with the membrane-spanning complexes of the tight junctions, adherens junctions, and desmosomes ensuring its integrity. Tight junction proteins, like occludin, tricellulin, and the claudin family isoforms, play prominent roles as barriers to unrestricted paracellular transport. The past decade has witnessed major advances in our understanding of the architecture and function of epithelial tight junctions. While it has been long appreciated that microbes, notably bacterial and viral pathogens, target and disrupt junctional complexes and alter paracellular permeability, the precise mechanisms remain to be defined. Notably, renewed efforts will be required to interpret the available data on pathogen-mediated barrier disruption in the context of the most recent findings on tight junction structure and function. While much of the focus has been on pathogen-induced dysregulation of junctional complexes, commensal microbiota and their products may influence paracellular permeability and contribute to the normal physiology of the gut. Finally, microbes and their products have become important tools in exploring host systems, including the junctional properties of epithelial cells. © 2018 American Physiological Society. Compr Physiol 8:823-842, 2018. Copyright © 2018 American Physiological Society. All rights reserved.

  11. Protecting intestinal epithelial integrity by galacto-oligosaccharides: Keeping it tight

    OpenAIRE

    Akbari, P.

    2016-01-01

    The intestinal barrier serves as a first line of host defense against potentially harmful stressors from the environment ingested with food, and is primarily formed by epithelial cells connected by tight junctions. Oligosaccharides have been identified as components in milk, particularly in colostrum, that support the development of intestinal microbiota in the early phase of life and contribute to the maturation of the immune system in infants. Currently, galacto-oligosaccharides (GOS) are u...

  12. The Bile Acid Receptor GPBAR-1 (TGR5) Modulates Integrity of Intestinal Barrier and Immune Response to Experimental Colitis

    Science.gov (United States)

    Cipriani, Sabrina; Mencarelli, Andrea; Chini, Maria Giovanna; Distrutti, Eleonora; Renga, Barbara; Bifulco, Giuseppe; Baldelli, Franco; Donini, Annibale; Fiorucci, Stefano

    2011-01-01

    Background GP-BAR1, a member G protein coupled receptor superfamily, is a cell surface bile acid-activated receptor highly expressed in the ileum and colon. In monocytes, ligation of GP-BAR1 by secondary bile acids results in a cAMP-dependent attenuation of cytokine generation. Aims To investigate the role GP-BAR1 in regulating intestinal homeostasis and inflammation-driven immune dysfunction in rodent models of colitis. Methods Colitis was induced in wild type and GP-BAR1−/− mice by DSS and TNBS administration. Potential GP-BAR1 agonists were identified by in silico screening and computational docking studies. Results GP-BAR1−/− mice develop an abnormal morphology of colonic mucous cells and an altered molecular architecture of epithelial tight junctions with increased expression and abnormal subcellular distribution of zonulin 1 resulting in increased intestinal permeability and susceptibility to develop severe colitis in response to DSS at early stage of life. By in silico screening and docking studies we identified ciprofloxacin as a GP-BAR1 ligand. In monocytes, ciprofloxacin increases cAMP concentrations and attenuates TNFα release induced by TLR4 ligation in a GP-BAR1 dependent manner. Treating mice rendered colitic by TNBS with ciprofloxacin and oleanolic acid, a well characterized GP-BAR1 ligand, abrogates signs and symptoms of colitis. Colonic expression of GP-BAR1 mRNA increases in rodent models of colitis and tissues from Crohn's disease patients. Flow cytometry analysis demonstrates that ≈90% of CD14+ cells isolated from the lamina propria of TNBS-treated mice stained positively for GP-BAR1. Conclusions GP-BAR1 regulates intestinal barrier structure. Its expression increases in rodent models of colitis and Crohn's disease. Ciprofloxacin is a GP-BAR1 ligand. PMID:22046243

  13. The bile acid receptor GPBAR-1 (TGR5 modulates integrity of intestinal barrier and immune response to experimental colitis.

    Directory of Open Access Journals (Sweden)

    Sabrina Cipriani

    Full Text Available BACKGROUND: GP-BAR1, a member G protein coupled receptor superfamily, is a cell surface bile acid-activated receptor highly expressed in the ileum and colon. In monocytes, ligation of GP-BAR1 by secondary bile acids results in a cAMP-dependent attenuation of cytokine generation. AIMS: To investigate the role GP-BAR1 in regulating intestinal homeostasis and inflammation-driven immune dysfunction in rodent models of colitis. METHODS: Colitis was induced in wild type and GP-BAR1(-/- mice by DSS and TNBS administration. Potential GP-BAR1 agonists were identified by in silico screening and computational docking studies. RESULTS: GP-BAR1(-/- mice develop an abnormal morphology of colonic mucous cells and an altered molecular architecture of epithelial tight junctions with increased expression and abnormal subcellular distribution of zonulin 1 resulting in increased intestinal permeability and susceptibility to develop severe colitis in response to DSS at early stage of life. By in silico screening and docking studies we identified ciprofloxacin as a GP-BAR1 ligand. In monocytes, ciprofloxacin increases cAMP concentrations and attenuates TNFα release induced by TLR4 ligation in a GP-BAR1 dependent manner. Treating mice rendered colitic by TNBS with ciprofloxacin and oleanolic acid, a well characterized GP-BAR1 ligand, abrogates signs and symptoms of colitis. Colonic expression of GP-BAR1 mRNA increases in rodent models of colitis and tissues from Crohn's disease patients. Flow cytometry analysis demonstrates that ≈90% of CD14+ cells isolated from the lamina propria of TNBS-treated mice stained positively for GP-BAR1. CONCLUSIONS: GP-BAR1 regulates intestinal barrier structure. Its expression increases in rodent models of colitis and Crohn's disease. Ciprofloxacin is a GP-BAR1 ligand.

  14. Maternal exposure to carbamazepine at environmental concentrations can cross intestinal and placental barriers

    Energy Technology Data Exchange (ETDEWEB)

    Kaushik, Gaurav, E-mail: kausgaur@isu.edu [Department of Biological Sciences, Idaho State University, Stop 8007, 921 S 8th Ave, Pocatello, ID 83209-8007 (United States); Department of Medical Pathology and Laboratory Medicine, University of California at Davis, Davis, CA 95817 (United States); Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children, Northern California, 2425 Stockton Boulevard, Sacramento, CA 95817 (United States); Huber, David P., E-mail: hubedavi@isu.edu [Department of Biological Sciences, Idaho State University, Stop 8007, 921 S 8th Ave, Pocatello, ID 83209-8007 (United States); Aho, Ken, E-mail: ahoken@isu.edu [Department of Biological Sciences, Idaho State University, Stop 8007, 921 S 8th Ave, Pocatello, ID 83209-8007 (United States); Finney, Bruce, E-mail: finney@isu.edu [Department of Biological Sciences, Idaho State University, Stop 8007, 921 S 8th Ave, Pocatello, ID 83209-8007 (United States); Bearden, Shawn, E-mail: bearshaw@isu.edu [Department of Biological Sciences, Idaho State University, Stop 8007, 921 S 8th Ave, Pocatello, ID 83209-8007 (United States); Zarbalis, Konstantinos S., E-mail: kzarbalis@ucdavis.edu [Department of Medical Pathology and Laboratory Medicine, University of California at Davis, Davis, CA 95817 (United States); Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children, Northern California, 2425 Stockton Boulevard, Sacramento, CA 95817 (United States); Thomas, Michael A., E-mail: mthomas@isu.edu [Department of Biological Sciences, Idaho State University, Stop 8007, 921 S 8th Ave, Pocatello, ID 83209-8007 (United States)

    2016-05-27

    Psychoactive pharmaceuticals have been found as teratogens at clinical dosage during pregnancy. These pharmaceuticals have also been detected in minute (ppb) concentrations in drinking water in the US, and are environmental contaminants that may be complicit in triggering neurological disorders in genetically susceptible individuals. Previous studies have determined that psychoactive pharmaceuticals (fluoxetine, venlafaxine and carbamazepine) at environmentally relevant concentrations enriched sets of genes regulating development and function of the nervous system in fathead minnows. Altered gene sets were also associated with potential neurological disorders, including autism spectrum disorders (ASD). Subsequent in vitro studies indicated that psychoactive pharmaceuticals altered ASD-associated synaptic protein expression and gene expression in human neuronal cells. However, it is unknown if environmentally relevant concentrations of these pharmaceuticals are able to cross biological barriers from mother to fetus, thus potentially posing risks to nervous system development. The main objective of this study was to test whether psychoactive pharmaceuticals (fluoxetine, venlafaxine, and carbamazepine) administered through the drinking water at environmental concentrations to pregnant mice could reach the brain of the developing embryo by crossing intestinal and placental barriers. We addressed this question by adding {sup 2}H-isotope labeled pharmaceuticals to the drinking water of female mice for 20 days (10 pre-and 10 post–conception days), and quantifying {sup 2}H-isotope enrichment signals in the dam liver and brain of developing embryos using isotope ratio mass spectrometry. Significant levels of {sup 2}H enrichment was detected in the brain of embryos and livers of carbamazepine-treated mice but not in those of control dams, or for fluoxetine or venlafaxine application. These results provide the first evidence that carbamazepine in drinking water and at

  15. Maternal exposure to carbamazepine at environmental concentrations can cross intestinal and placental barriers

    International Nuclear Information System (INIS)

    Kaushik, Gaurav; Huber, David P.; Aho, Ken; Finney, Bruce; Bearden, Shawn; Zarbalis, Konstantinos S.; Thomas, Michael A.

    2016-01-01

    Psychoactive pharmaceuticals have been found as teratogens at clinical dosage during pregnancy. These pharmaceuticals have also been detected in minute (ppb) concentrations in drinking water in the US, and are environmental contaminants that may be complicit in triggering neurological disorders in genetically susceptible individuals. Previous studies have determined that psychoactive pharmaceuticals (fluoxetine, venlafaxine and carbamazepine) at environmentally relevant concentrations enriched sets of genes regulating development and function of the nervous system in fathead minnows. Altered gene sets were also associated with potential neurological disorders, including autism spectrum disorders (ASD). Subsequent in vitro studies indicated that psychoactive pharmaceuticals altered ASD-associated synaptic protein expression and gene expression in human neuronal cells. However, it is unknown if environmentally relevant concentrations of these pharmaceuticals are able to cross biological barriers from mother to fetus, thus potentially posing risks to nervous system development. The main objective of this study was to test whether psychoactive pharmaceuticals (fluoxetine, venlafaxine, and carbamazepine) administered through the drinking water at environmental concentrations to pregnant mice could reach the brain of the developing embryo by crossing intestinal and placental barriers. We addressed this question by adding "2H-isotope labeled pharmaceuticals to the drinking water of female mice for 20 days (10 pre-and 10 post–conception days), and quantifying "2H-isotope enrichment signals in the dam liver and brain of developing embryos using isotope ratio mass spectrometry. Significant levels of "2H enrichment was detected in the brain of embryos and livers of carbamazepine-treated mice but not in those of control dams, or for fluoxetine or venlafaxine application. These results provide the first evidence that carbamazepine in drinking water and at typical

  16. Protective effect of quercetin on high-fat diet-induced non-alcoholic fatty liver disease in mice is mediated by modulating intestinal microbiota imbalance and related gut-liver axis activation.

    Science.gov (United States)

    Porras, David; Nistal, Esther; Martínez-Flórez, Susana; Pisonero-Vaquero, Sandra; Olcoz, José Luis; Jover, Ramiro; González-Gallego, Javier; García-Mediavilla, María Victoria; Sánchez-Campos, Sonia

    2017-01-01

    Gut microbiota is involved in obesity, metabolic syndrome and the progression of nonalcoholic fatty liver disease (NAFLD). It has been recently suggested that the flavonoid quercetin may have the ability to modulate the intestinal microbiota composition, suggesting a prebiotic capacity which highlights a great therapeutic potential in NAFLD. The present study aims to investigate benefits of experimental treatment with quercetin on gut microbial balance and related gut-liver axis activation in a nutritional animal model of NAFLD associated to obesity. C57BL/6J mice were challenged with high fat diet (HFD) supplemented or not with quercetin for 16 weeks. HFD induced obesity, metabolic syndrome and the development of hepatic steatosis as main hepatic histological finding. Increased accumulation of intrahepatic lipids was associated with altered gene expression related to lipid metabolism, as a result of deregulation of their major modulators. Quercetin supplementation decreased insulin resistance and NAFLD activity score, by reducing the intrahepatic lipid accumulation through its ability to modulate lipid metabolism gene expression, cytochrome P450 2E1 (CYP2E1)-dependent lipoperoxidation and related lipotoxicity. Microbiota composition was determined via 16S ribosomal RNA Illumina next-generation sequencing. Metagenomic studies revealed HFD-dependent differences at phylum, class and genus levels leading to dysbiosis, characterized by an increase in Firmicutes/Bacteroidetes ratio and in Gram-negative bacteria, and a dramatically increased detection of Helicobacter genus. Dysbiosis was accompanied by endotoxemia, intestinal barrier dysfunction and gut-liver axis alteration and subsequent inflammatory gene overexpression. Dysbiosis-mediated toll-like receptor 4 (TLR-4)-NF-κB signaling pathway activation was associated with inflammasome initiation response and reticulum stress pathway induction. Quercetin reverted gut microbiota imbalance and related endotoxemia-mediated

  17. Connexin 43 reboots meiosis and reseals blood-testis barrier following toxicant-mediated aspermatogenesis and barrier disruption.

    Science.gov (United States)

    Li, Nan; Mruk, Dolores D; Mok, Ka-Wai; Li, Michelle W M; Wong, Chris K C; Lee, Will M; Han, Daishu; Silvestrini, Bruno; Cheng, C Yan

    2016-04-01

    support round spermatids to enter spermiogenesis.-Li, N., Mruk, D. D., Mok, K.-W., Li, M. W. M., Wong, C. K. C., Lee, W. M., Han, D., Silvestrini, B., Cheng, C. Y. Connexin 43 reboots meiosis and reseals blood-testis barrier following toxicant-mediated aspermatogenesis and barrier disruption. © FASEB.

  18. Role of intestinal bacteria in gliadin-induced changes in intestinal mucosa: study in germ-free rats.

    Directory of Open Access Journals (Sweden)

    Jana Cinova

    Full Text Available BACKGROUND AND AIMS: Celiac disease (CD is a chronic inflammatory disorder of the small intestine that is induced by dietary wheat gluten proteins (gliadins in genetically predisposed individuals. The overgrowth of potentially pathogenic bacteria and infections has been suggested to contribute to CD pathogenesis. We aimed to study the effects of gliadin and various intestinal bacterial strains on mucosal barrier integrity, gliadin translocation, and cytokine production. METHODOLOGY/PRINCIPAL FINDINGS: Changes in gut mucosa were assessed in the intestinal loops of inbred Wistar-AVN rats that were reared under germ-free conditions in the presence of various intestinal bacteria (enterobacteria and bifidobacteria isolated from CD patients and healthy children, respectively and CD-triggering agents (gliadin and IFN-γ by histology, scanning electron microscopy, immunofluorescence, and a rat cytokine antibody array. Adhesion of the bacterial strains to the IEC-6 rat cell line was evaluated in vitro. Gliadin fragments alone or together with the proinflammatory cytokine interferon (IFN-γ significantly decreased the number of goblet cells in the small intestine; this effect was more pronounced in the presence of Escherichia coli CBL2 and Shigella CBD8. Shigella CBD8 and IFN-γ induced the highest mucin secretion and greatest impairment in tight junctions and, consequently, translocation of gliadin fragments into the lamina propria. Shigella CBD8 and E. coli CBL2 strongly adhered to IEC-6 epithelial cells. The number of goblet cells in small intestine increased by the simultaneous incubation of Bifidobacterium bifidum IATA-ES2 with gliadin, IFN-γ and enterobacteria. B. bifidum IATA-ES2 also enhanced the production of chemotactic factors and inhibitors of metalloproteinases, which can contribute to gut mucosal protection. CONCLUSIONS: Our results suggest that the composition of the intestinal microbiota affects the permeability of the intestinal mucosa

  19. Effects of plasma CGRP and NPY level changes on intestinal mucosal barrier injury after scald in rats

    International Nuclear Information System (INIS)

    Shao Lijian; Zhu Qingxian; He Ming; Zhang Hongyan

    2004-01-01

    Objective: To investigate the significance of plasma CGRP and NPY levels changes immediately after scald in rats. Methods: Thirty-two rat models of 30% TBSA III degree scald were prepared. Eight animals each were sacrificed at 3, 6,12 and 24 hrs; taking blood samples for determination of plasma CGRP, NPY levels and 5 cm of ileum for pathologic study. As controls, eight animals without scald were treated in the same way. Results: Plasma CGRP levels were decreased significantly after scald, reaching bottom value at 12 hr and remained lower than those in controls at 24 hr (p 0.05). Plasma levels of CGRP were negatively correlated to plasma NPY levels (p<0.01). Ileum mucosal injuries presented as edema, congestion with necrosis and slough of epithelium were most marked at 12 hr. Conclusion: Plasma CGRP and NPY levels changed significantly after scald and were mutually negatively correlated. Post-scald intestinal mucosa barrier injuries were possibly related to the changes of levels of those vasoactive peptides

  20. Translational safety biomarkers of colonic barrier integrity in the rat.

    Science.gov (United States)

    Erkens, Tim; Bueters, Ruud; van Heerden, Marjolein; Cuyckens, Filip; Vreeken, Rob; Goeminne, Nick; Lammens, Lieve

    2018-05-20

    The intestinal barrier controls intestinal permeability, and its disruption has been associated with multiple diseases. Therefore, preclinical safety biomarkers monitoring barrier integrity are essential during the development of drugs targeting the intestines, particularly if starting treatment early after onset of disease. Classical toxicology endpoints are not sensitive enough and therefore our objective was to identify non-invasive markers enabling early in vivo detection of colonic barrier perturbation. Male Sprague-Dawley rats were dosed intracolonically via the rectum, using sodium caprate or ibuprofen as tool compounds to alter barrier integrity. Several potentially translational biomarkers and probe molecules related to permeability, inflammation or tissue damage were evaluated, using various analytical platforms, including immunoassays, targeted metabolomics and highly sensitive ultra-performance liquid chromatography-tandem mass spectrometry. Several markers were identified that allow early in vivo detection of colonic barrier integrity changes, before histopathological evidence of tissue damage. The most promising permeability markers identified were plasma fluorescein isothiocyanate-dextran 4000 and a lactulose/mannitol/sucralose mixture in urine. These markers showed maximum increases over 100-fold or approximately 10-50-fold, respectively. Intracolonic administration of the above probe molecules outperformed oral administration and inflammatory or other biomarkers, such as α 2 -macroglobulin, calprotectin, cytokines, prostaglandins and a panel of metabolic molecules to identify early and subtle changes in barrier integrity. However, optimal timing of probe administration and sample collection is important for all markers evaluated. Inclusion of these probe molecules in preclinical toxicity studies might aid in risk assessment and the design of a clinical biomarker plan, as several of these markers have translational potential. Copyright © 2018 John

  1. Endocytic trafficking from the small intestinal brush border probed with FM dye

    DEFF Research Database (Denmark)

    Hansen, Gert H; Rasmussen, Karina; Niels-Christiansen, Lise-Lotte

    2009-01-01

    -linking galectins/intelectin, but little is known about the dynamic properties of this highly specialized membrane. Here, we probed the endocytic membrane trafficking from the brush border of organ cultured pig intestinal mucosal explants by use of a fixable, lipophilic FM dye. The fluorescent dye readily......, contributes to the overall permeability barrier of the gut. Key words: FM dye, small intestine, brush border, endocytosis....

  2. Pharmacologic Effects in vivo in Brain by Vector-Mediated Peptide Drug Delivery

    Science.gov (United States)

    Bickel, Ulrich; Yoshikawa, Takayoshi; Landaw, Elliot M.; Faull, Kym F.; Pardridge, William M.

    1993-04-01

    Pharmacologic effects in brain caused by systemic administration of neuropeptides are prevented by poor transport of the peptide through the brain vascular endothelium, which comprises the blood-brain barrier in vivo. In the present study, successful application of a chimeric peptide approach to enhance drug delivery through the blood-brain barrier for the purpose of achieving a central nervous system pharmacologic effect is described. The chimeric peptide was formed by linkage of a potent vasoactive intestinal peptide (VIP) analogue, which had been monobiotinylated, to a drug transport vector. The vector consisted of a covalent conjugate of avidin and the OX26 monoclonal antibody to the transferrin receptor. Owing to the high concentration of transferrin receptors on brain capillary endothelia, OX26 targets brain and undergoes receptor-mediated transcytosis through the blood-brain barrier. Systemic infusion of low doses (12 μg/kg) of the VIP chimeric peptide in rats resulted in an in vivo central nervous system pharmacologic effect: a 65% increase in cerebral blood flow. Biotinylated VIP analogue without the brain transport vector was ineffective.

  3. Inhibition of cAMP-activated intestinal chloride secretion by diclofenac: cellular mechanism and potential application in cholera.

    Science.gov (United States)

    Pongkorpsakol, Pawin; Pathomthongtaweechai, Nutthapoom; Srimanote, Potjanee; Soodvilai, Sunhapas; Chatsudthipong, Varanuj; Muanprasat, Chatchai

    2014-09-01

    Cyclic AMP-activated intestinal Cl- secretion plays an important role in pathogenesis of cholera. This study aimed to investigate the effect of diclofenac on cAMP-activated Cl- secretion, its underlying mechanisms, and possible application in the treatment of cholera. Diclofenac inhibited cAMP-activated Cl- secretion in human intestinal epithelial (T84) cells with IC50 of ∼ 20 µM. The effect required no cytochrome P450 enzyme-mediated metabolic activation. Interestingly, exposures of T84 cell monolayers to diclofenac, either in apical or basolateral solutions, produced similar degree of inhibitions. Analyses of the apical Cl- current showed that diclofenac reversibly inhibited CFTR Cl- channel activity (IC50 ∼ 10 µM) via mechanisms not involving either changes in intracellular cAMP levels or CFTR channel inactivation by AMP-activated protein kinase and protein phosphatase. Of interest, diclofenac had no effect on Na(+)-K(+) ATPases and Na(+)-K(+)-Cl- cotransporters, but inhibited cAMP-activated basolateral K(+) channels with IC50 of ∼ 3 µM. In addition, diclofenac suppressed Ca(2+)-activated Cl- channels, inwardly rectifying Cl- channels, and Ca(2+)-activated basolateral K(+) channels. Furthermore, diclofenac (up to 200 µM; 24 h of treatment) had no effect on cell viability and barrier function in T84 cells. Importantly, cholera toxin (CT)-induced Cl- secretion across T84 cell monolayers was effectively suppressed by diclofenac. Intraperitoneal administration of diclofenac (30 mg/kg) reduced both CT and Vibrio cholerae-induced intestinal fluid secretion by ∼ 70% without affecting intestinal fluid absorption in mice. Collectively, our results indicate that diclofenac inhibits both cAMP-activated and Ca(2+)-activated Cl- secretion by inhibiting both apical Cl- channels and basolateral K+ channels in intestinal epithelial cells. Diclofenac may be useful in the treatment of cholera and other types of secretory diarrheas resulting from intestinal

  4. Inhibition of cAMP-activated intestinal chloride secretion by diclofenac: cellular mechanism and potential application in cholera.

    Directory of Open Access Journals (Sweden)

    Pawin Pongkorpsakol

    2014-09-01

    Full Text Available Cyclic AMP-activated intestinal Cl- secretion plays an important role in pathogenesis of cholera. This study aimed to investigate the effect of diclofenac on cAMP-activated Cl- secretion, its underlying mechanisms, and possible application in the treatment of cholera. Diclofenac inhibited cAMP-activated Cl- secretion in human intestinal epithelial (T84 cells with IC50 of ∼ 20 µM. The effect required no cytochrome P450 enzyme-mediated metabolic activation. Interestingly, exposures of T84 cell monolayers to diclofenac, either in apical or basolateral solutions, produced similar degree of inhibitions. Analyses of the apical Cl- current showed that diclofenac reversibly inhibited CFTR Cl- channel activity (IC50 ∼ 10 µM via mechanisms not involving either changes in intracellular cAMP levels or CFTR channel inactivation by AMP-activated protein kinase and protein phosphatase. Of interest, diclofenac had no effect on Na(+-K(+ ATPases and Na(+-K(+-Cl- cotransporters, but inhibited cAMP-activated basolateral K(+ channels with IC50 of ∼ 3 µM. In addition, diclofenac suppressed Ca(2+-activated Cl- channels, inwardly rectifying Cl- channels, and Ca(2+-activated basolateral K(+ channels. Furthermore, diclofenac (up to 200 µM; 24 h of treatment had no effect on cell viability and barrier function in T84 cells. Importantly, cholera toxin (CT-induced Cl- secretion across T84 cell monolayers was effectively suppressed by diclofenac. Intraperitoneal administration of diclofenac (30 mg/kg reduced both CT and Vibrio cholerae-induced intestinal fluid secretion by ∼ 70% without affecting intestinal fluid absorption in mice. Collectively, our results indicate that diclofenac inhibits both cAMP-activated and Ca(2+-activated Cl- secretion by inhibiting both apical Cl- channels and basolateral K+ channels in intestinal epithelial cells. Diclofenac may be useful in the treatment of cholera and other types of secretory diarrheas resulting from intestinal

  5. [Changes in expression of Slingshot protein in hypoxic human intestinal epithelial cell and its relation with barrier function of the cells].

    Science.gov (United States)

    Zhang, Jian; Wang, Pei; He, Wen; Wang, Fengjun

    2016-04-01

    To study the effect of hypoxia on Slingshot protein expression in human intestinal epithelial cell and its relation with changes in barrier function of the cells. The human intestinal epithelial cell line Caco-2 was used to reproduce monolayer-cells. One portion of the monolayer-cell specimens were divided into six parts according to the random number table, and they were respectively exposed to hypoxia for 0 (without hypoxia), 1, 2, 6, 12, and 24 h. Transepithelial electrical resistance (TER) was determined with an ohmmeter. Another portion of the monolayer-cell specimens were exposed to hypoxia as above. Western blotting was used to detect the protein expressions of zonula occludens 1 (ZO-1), occludin, claudin-1, Slingshot-1, Slingshot-2, and Slingshot-3. The remaining portion of the monolayer-cell specimens were also exposed to hypoxia as above. The content of fibrous actin (F-actin) and globular actin (G-actin) was determined by fluorescence method. The sample number of above-mentioned 3 experiments was respectively 10, 10, and 18 at each time point. Data were processed with one-way analysis of variance and Dunnett test. (1) Compared with that of cells exposed to hypoxia for 0 h, TER of cells exposed to hypoxia for 1 to 24 h was significantly reduced (P values below 0.01). (2) Compared with those of cells exposed to hypoxia for 0 h (all were 1.00), the protein expressions of ZO-1, occludin, and claudin-1 of cells exposed to hypoxia for 1 to 24 h were generally lower, especially those of cells exposed to hypoxia for 12 h or 24 h (respectively 0.69 ± 0.20, 0.47 ± 0.15, and 0.47 ± 0.22, Pprotein expressions of Slingshot-1 and Slingshot-3 of cells exposed to hypoxia for 1 to 24 h were not obviously changed (P values above 0.05). The protein expression of Slingshot-2 of cells was decreased at first and then gradually increased from hypoxia hour 1 to 24. The protein expression of Slingshot-2 of cells exposed to hypoxia for 24 h (1.54 ± 0.57) was significantly

  6. Social interaction, noise and antibiotic-mediated switches in the intestinal microbiota.

    Directory of Open Access Journals (Sweden)

    Vanni Bucci

    Full Text Available The intestinal microbiota plays important roles in digestion and resistance against entero-pathogens. As with other ecosystems, its species composition is resilient against small disturbances but strong perturbations such as antibiotics can affect the consortium dramatically. Antibiotic cessation does not necessarily restore pre-treatment conditions and disturbed microbiota are often susceptible to pathogen invasion. Here we propose a mathematical model to explain how antibiotic-mediated switches in the microbiota composition can result from simple social interactions between antibiotic-tolerant and antibiotic-sensitive bacterial groups. We build a two-species (e.g. two functional-groups model and identify regions of domination by antibiotic-sensitive or antibiotic-tolerant bacteria, as well as a region of multistability where domination by either group is possible. Using a new framework that we derived from statistical physics, we calculate the duration of each microbiota composition state. This is shown to depend on the balance between random fluctuations in the bacterial densities and the strength of microbial interactions. The singular value decomposition of recent metagenomic data confirms our assumption of grouping microbes as antibiotic-tolerant or antibiotic-sensitive in response to a single antibiotic. Our methodology can be extended to multiple bacterial groups and thus it provides an ecological formalism to help interpret the present surge in microbiome data.

  7. Salmonella infection inhibits intestinal biotin transport: cellular and molecular mechanisms.

    Science.gov (United States)

    Ghosal, Abhisek; Jellbauer, Stefan; Kapadia, Rubina; Raffatellu, Manuela; Said, Hamid M

    2015-07-15

    Infection with the nontyphoidal Salmonella is a common cause of food-borne disease that leads to acute gastroenteritis/diarrhea. Severe/prolonged cases of Salmonella infection could also impact host nutritional status, but little is known about its effect on intestinal absorption of vitamins, including biotin. We examined the effect of Salmonella enterica serovar Typhimurium (S. typhimurium) infection on intestinal biotin uptake using in vivo (streptomycin-pretreated mice) and in vitro [mouse (YAMC) and human (NCM460) colonic epithelial cells, and human intestinal epithelial Caco-2 cells] models. The results showed that infecting mice with wild-type S. typhimurium, but not with its nonpathogenic isogenic invA spiB mutant, leads to a significant inhibition in jejunal/colonic biotin uptake and in level of expression of the biotin transporter, sodium-dependent multivitamin transporter. In contrast, infecting YAMC, NCM460, and Caco-2 cells with S. typhimurium did not affect biotin uptake. These findings suggest that the effect of S. typhimurium infection is indirect and is likely mediated by proinflammatory cytokines, the levels of which were markedly induced in the intestine of S. typhimurium-infected mice. Consistent with this hypothesis, exposure of NCM460 cells to the proinflammatory cytokines TNF-α and IFN-γ led to a significant inhibition of biotin uptake, sodium-dependent multivitamin transporter expression, and activity of the SLC5A6 promoter. The latter effects appear to be mediated, at least in part, via the NF-κB signaling pathway. These results demonstrate that S. typhimurium infection inhibits intestinal biotin uptake, and that the inhibition is mediated via the action of proinflammatory cytokines.

  8. Effects of Supplementation of the Synbiotic Ecologic® 825/FOS P6 on Intestinal Barrier Function in Healthy Humans: A Randomized Controlled Trial.

    Science.gov (United States)

    Wilms, E; Gerritsen, J; Smidt, H; Besseling-van der Vaart, I; Rijkers, G T; Garcia Fuentes, A R; Masclee, A A M; Troost, F J

    2016-01-01

    Probiotics, prebiotics and synbiotics have been suggested as dietary strategies to improve intestinal barrier function. This study aimed to assess the effect of two weeks synbiotic supplementation on intestinal permeability under basal and stressed conditions. Secondary aims were the assessment of two weeks synbiotic supplementation on systemic immune function and gastrointestinal symptoms including defecation pattern. Twenty healthy adults completed a double-blind, controlled, randomized, parallel design study. Groups either received synbiotic (1.5 × 1010 CFU Ecologic® 825 + 10 g fructo-oligosaccharides (FOS P6) per day) or control supplements for two weeks. Intestinal segment specific permeability was assessed non-invasively by oral administration of multiple sugar probes and, subsequently, assessing the excretion of these probes in urine. This test was conducted at baseline and at the end of intervention, in the absence and in the presence of an indomethacin challenge. Indomethacin was applied to induce a compromised gut state. Plasma zonulin, cytokines and chemokines were measured at baseline and at the end of intervention. Gastrointestinal symptoms and stool frequency were recorded at baseline and daily during intervention. Significantly more male subjects were in the synbiotic group compared to the control group (P = 0.025). Indomethacin significantly increased urinary lactulose/rhamnose ratio versus without indomethacin, both in the control group (P = 0.005) and in the synbiotic group (P = 0.017). Urinary sugar recoveries and ratios, plasma levels of zonulin, cytokines and chemokines, and gastrointestinal symptom scores were not significantly different after control or synbiotic intervention. Stool frequency within the synbiotic group was significantly increased during synbiotic intervention compared to baseline (P = 0.039) and higher compared to control intervention (P = 0.045). Two weeks Ecologic® 825/FOS P6 supplementation increased stool frequency

  9. Functions and Signaling Pathways of Amino Acids in Intestinal Inflammation

    Directory of Open Access Journals (Sweden)

    Fang He

    2018-01-01

    Full Text Available Intestine is always exposed to external environment and intestinal microorganism; thus it is more sensitive to dysfunction and dysbiosis, leading to intestinal inflammation, such as inflammatory bowel disease (IBD, irritable bowel syndrome (IBS, and diarrhea. An increasing number of studies indicate that dietary amino acids play significant roles in preventing and treating intestinal inflammation. The review aims to summarize the functions and signaling mechanisms of amino acids in intestinal inflammation. Amino acids, including essential amino acids (EAAs, conditionally essential amino acids (CEAAs, and nonessential amino acids (NEAAs, improve the functions of intestinal barrier and expressions of anti-inflammatory cytokines and tight junction proteins but decrease oxidative stress and the apoptosis of enterocytes as well as the expressions of proinflammatory cytokines in the intestinal inflammation. The functions of amino acids are associated with various signaling pathways, including mechanistic target of rapamycin (mTOR, inducible nitric oxide synthase (iNOS, calcium-sensing receptor (CaSR, nuclear factor-kappa-B (NF-κB, mitogen-activated protein kinase (MAPK, nuclear erythroid-related factor 2 (Nrf2, general controlled nonrepressed kinase 2 (GCN2, and angiotensin-converting enzyme 2 (ACE2.

  10. CD36 and Fyn kinase mediate malaria-induced lung endothelial barrier dysfunction in mice infected with Plasmodium berghei.

    Directory of Open Access Journals (Sweden)

    Ifeanyi U Anidi

    Full Text Available Severe malaria can trigger acute lung injury characterized by pulmonary edema resulting from increased endothelial permeability. However, the mechanism through which lung fluid conductance is altered during malaria remains unclear. To define the role that the scavenger receptor CD36 may play in mediating this response, C57BL/6J (WT and CD36-/- mice were infected with P. berghei ANKA and monitored for changes in pulmonary endothelial barrier function employing an isolated perfused lung system. WT lungs demonstrated a >10-fold increase in two measures of paracellular fluid conductance and a decrease in the albumin reflection coefficient (σalb compared to control lungs indicating a loss of barrier function. In contrast, malaria-infected CD36-/- mice had near normal fluid conductance but a similar reduction in σalb. In WT mice, lung sequestered iRBCs demonstrated production of reactive oxygen species (ROS. To determine whether knockout of CD36 could protect against ROS-induced endothelial barrier dysfunction, mouse lung microvascular endothelial monolayers (MLMVEC from WT and CD36-/- mice were exposed to H2O2. Unlike WT monolayers, which showed dose-dependent decreases in transendothelial electrical resistance (TER from H2O2 indicating loss of barrier function, CD36-/- MLMVEC demonstrated dose-dependent increases in TER. The differences between responses in WT and CD36-/- endothelial cells correlated with important differences in the intracellular compartmentalization of the CD36-associated Fyn kinase. Malaria infection increased total lung Fyn levels in CD36-/- lungs compared to WT, but this increase was due to elevated production of the inactive form of Fyn further suggesting a dysregulation of Fyn-mediated signaling. The importance of Fyn in CD36-dependent endothelial signaling was confirmed using in vitro Fyn knockdown as well as Fyn-/- mice, which were also protected from H2O2- and malaria-induced lung endothelial leak, respectively. Our

  11. Influence of dietary inclusion of Bacillus licheniformis on laying performance, egg quality, antioxidant enzyme activities, and intestinal barrier function of laying hens.

    Science.gov (United States)

    Lei, K; Li, Y L; Yu, D Y; Rajput, I R; Li, W F

    2013-09-01

    This experiment was conducted to evaluate the effects of dietary inclusion of Bacillus licheniformis on laying performance, egg quality, antioxidant enzyme activities, and intestinal barrier function of laying hens. Hy-Line Variety W-36 hens (n = 540; 28 wk of age) were randomized into 6 groups, each group with 6 replications (n = 15). The control group received the basal diet formulated with maize and soybean meal. The treatment groups received the same basal diets supplemented with 0.01, 0.02, 0.03, 0.06, and 0.09% Bacillus licheniformis powder (2 × 10(10) cfu/g) for an 8-wk trial. The results showed that dietary supplementation with 0.01 and 0.03% B. licheniformis significantly increased egg production and egg mass. However, no significant differences were observed in egg weight, feed consumption, and feed conversion efficiency among the 6 groups. Supplementation with different levels of B. licheniformis was found to be effective in improvement of egg quality by increasing egg shell thickness and strength. Compared with control, d-lactate content, diamine oxidase activity, and adrenocorticotropic hormone level in serum decreased significantly, and the level of estradiol and follicle-stimulating hormone increased significantly in plasma of all the experimental groups. Dietary supplementation with B. licheniformis increased the intestinal villus height and reduced the crypt depth. In conclusion, dietary inclusion of B. licheniformis could improve laying performance and egg quality significantly in a dose-dependent manner by decreasing the stress response, upregulating the growth hormone, and improving intestinal health.

  12. Transport of sennosides and sennidines from Cassia angustifolia and Cassia senna across Caco-2 monolayers--an in vitro model for intestinal absorption.

    Science.gov (United States)

    Waltenberger, B; Avula, B; Ganzera, M; Khan, I A; Stuppner, H; Khan, S I

    2008-05-01

    Laxative effects of Senna preparations are mainly mediated by rheinanthrone, a metabolite formed in the intestinal flora from dianthrones. Nevertheless, it was not clear whether dianthrones are bioavailable at all and contribute to the overall effects of this important medicinal plant. Using the Caco-2 human colonic cell line as an in vitro model of the human intestinal mucosal barrier, the bioavailability of dianthrones was studied in apical to basolateral (absorptive) and basolateral to apical (secretive) direction. Permeability coefficients (P(c)) and percent transport were calculated based on quantitations by HPLC. From the data obtained it was concluded that sennosides A and B, as well as their aglycones sennidine A and B are transported through the Caco-2 monolayers in a concentration-dependent manner and their transport was linear with time. The absorption in apical to basolateral direction was poor and P(c) values were comparable to mannitol. The transport was higher in the secretory direction, indicating a significant efflux (e.g. by efflux pumps) of the (poorly) absorbed compounds in the intestinal lumen again. Our findings support the general understanding that the laxative effects of Senna are explainable mainly by metabolites and not by the natively present dianthrones.

  13. Outer Membrane Vesicles From Probiotic and Commensal Escherichia coli Activate NOD1-Mediated Immune Responses in Intestinal Epithelial Cells

    Directory of Open Access Journals (Sweden)

    María-Alexandra Cañas

    2018-03-01

    Full Text Available Gut microbiota plays a critical role in maintaining human intestinal homeostasis and host health. Bacterial extracellular vesicles are key players in bacteria–host communication, as they allow delivery of effector molecules into the host cells. Outer membrane vesicles (OMVs released by Gram-negative bacteria carry many ligands of pattern recognition receptors that are key components of innate immunity. NOD1 and NOD2 cytosolic receptors specifically recognize peptidoglycans present within the bacterial cell wall. These intracellular immune receptors are essential in host defense against bacterial infections and in the regulation of inflammatory responses. Recent contributions show that NODs are also fundamental to maintain intestinal homeostasis and microbiota balance. Peptidoglycan from non-invasive pathogens is delivered to cytosolic NODs through OMVs, which are internalized via endocytosis. Whether this pathway could be used by microbiota to activate NOD receptors remains unexplored. Here, we report that OMVs isolated from the probiotic Escherichia coli Nissle 1917 and the commensal ECOR12 activate NOD1 signaling pathways in intestinal epithelial cells. NOD1 silencing and RIP2 inhibition significantly abolished OMV-mediated activation of NF-κB and subsequent IL-6 and IL-8 expression. Confocal fluorescence microscopy analysis confirmed that endocytosed OMVs colocalize with NOD1, trigger the formation of NOD1 aggregates, and promote NOD1 association with early endosomes. This study shows for the first time the activation of NOD1-signaling pathways by extracellular vesicles released by gut microbiota.

  14. Intestinal circulation during inhalation anesthesia

    International Nuclear Information System (INIS)

    Tverskoy, M.; Gelman, S.; Fowler, K.C.; Bradley, E.L.

    1985-01-01

    This study was designed to evaluate the influence of inhalational agents on the intestinal circulation in an isolated loop preparation. Sixty dogs were studied, using three intestinal segments from each dog. Selected intestinal segments were pumped with aortic blood at a constant pressure of 100 mmHg. A mixture of 86 Rb and 9-microns spheres labeled with 141 Ce was injected into the arterial cannula supplying the intestinal loop, while mesenteric venous blood was collected for activity counting. A very strong and significant correlation was found between rubidium clearance and microsphere entrapment (r = 0.97, P less than 0.0001). Nitrous oxide anesthesia was accompanied by a higher vascular resistance (VR), lower flow (F), rubidium clearance (Cl-Rb), and microspheres entrapment (Cl-Sph) than pentobarbital anesthesia, indicating that the vascular bed in the intestinal segment was constricted and flow (total and nutritive) decreased. Halothane, enflurane, and isoflurane anesthesia were accompanied by a much lower arteriovenous oxygen content difference (AVDO 2 ) and oxygen uptake than pentobarbital or nitrous oxide. Compared with pentobarbital, enflurane anesthesia was not accompanied by marked differences in VR, F, Cl-Rb, and Cl-Sph; halothane at 2 MAC decreased VR and increased F and Cl-Rb while isoflurane increased VR and decreased F. alpha-Adrenoceptor blockade with phentolamine (1 mg . kg-1) abolished isoflurane-induced vasoconstriction, suggesting that the increase in VR was mediated via circulating catecholamines

  15. Functional and structural alterations of epithelial barrier properties of rat ileum following X-irradiation

    International Nuclear Information System (INIS)

    Dublineau, I.; Lebrun, F.; Grison, S.; Griffiths, N.M.

    2004-01-01

    Irradiation of the digestive system leads to alterations of the small intestine. We have characterized the disruption of the barrier integrity in rat ileum from 1 to 14 days following irradiation ranging from 6 to 12 Gy. The intestinal permeability to 14 C-mannitol and 3 H-dextran 70,000 was measured in vitro in Ussing chambers. In parallel to these functional studies, immunohistochemical analyses of junctional proteins (ZO-1 and β-catenin) of ileal epithelium were performed by confocal microscopy. Irradiation with 10 Gy induced a marked decrease in epithelial tissue resistance at three days and a fivefold increase in mannitol permeability, without modifications of dextran permeability. A disorganization of the localization for ZO-1 and β-catenin was also observed. At 7 days after irradiation, we observed a recovery of the organization of junctional proteins in parallel to a return of intestinal permeability to control value. In addition to these time-dependent effects, a gradual effect on epithelial integrity of the radiation doses was observed 3 days after irradiation. This study shows a disruption of the integrity of the intestinal barrier in rat ileum following abdominal X-irradiation, depending on the time postirradiation and on the delivered dose. The loss of barrier integrity was characterized by a disorganization of proteins of tight and adherent junctions, leading to increased intestinal permeability to mannitol. (author)

  16. Bovine TLR2 and TLR4 mediate Cryptosporidium parvum recognition in bovine intestinal epithelial cells.

    Science.gov (United States)

    Yang, Zhengtao; Fu, Yunhe; Gong, Pengtao; Zheng, Jingtong; Liu, Li; Yu, Yuqiang; Li, Jianhua; Li, He; Yang, Ju; Zhang, Xichen

    2015-08-01

    Cryptosporidium parvum (C. parvum) is an intestinal parasite that causes diarrhea in neonatal calves. It results in significant morbidity of neonatal calves and economic losses for producers worldwide. Innate resistance against C. parvum is thought to depend on engagement of pattern recognition receptors. However, the role of innate responses to C. parvum has not been elucidated in bovine. The aim of this study was to evaluate the role of TLRs in host-cell responses during C. parvum infection of cultured bovine intestinal epithelial cells. The expressions of TLRs in bovine intestinal epithelial cells were detected by qRT-PCR. To determine which, if any, TLRs may play a role in the response of bovine intestinal epithelial cells to C. parvum, the cells were stimulated with C. parvum and the expression of TLRs were tested by qRT-PCR. The expression of NF-κB was detected by western blotting. Further analyses were carried out in bovine TLRs transfected HEK293 cells and by TLRs-DN transfected bovine intestinal epithelial cells. The results showed that bovine intestinal epithelial cells expressed all known TLRs. The expression of TLR2 and TLR4 were up-regulated when bovine intestinal epithelial cells were treated with C. parvum. Meanwhile, C. parvum induced IL-8 production in TLR2 or TLR4/MD-2 transfected HEK293 cells. Moreover, C. parvum induced NF-κB activation and cytokine expression in bovine intestinal epithelial cells. The induction of NF-κB activation and cytokine expression by C. parvum were reduced in TLR2-DN and TLR4-DN transfected cells. The results showed that bovine intestinal epithelial cells expressed all known TLRs, and bovine intestinal epithelial cells recognized and responded to C. parvum via TLR2 and TLR4. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. New Insight in Loss of Gut Barrier during Major Non-Abdominal Surgery.

    Directory of Open Access Journals (Sweden)

    Joep P M Derikx

    Full Text Available Gut barrier loss has been implicated as a critical event in the occurrence of postoperative complications. We aimed to study the development of gut barrier loss in patients undergoing major non-abdominal surgery.Twenty consecutive children undergoing spinal fusion surgery were included. This kind of surgery is characterized by long operation time, significant blood loss, prolonged systemic hypotension, without directly leading to compromise of the intestines by intestinal manipulation or use of extracorporeal circulation. Blood was collected preoperatively, every two hours during surgery and 2, 4, 15 and 24 hours postoperatively. Gut mucosal barrier was assessed by plasma markers for enterocyte damage (I-FABP, I-BABP and urinary presence of tight junction protein claudin-3. Intestinal mucosal perfusion was measured by gastric tonometry (P(rCO2, P(r-aCO2-gap. Plasma concentration of I-FABP, I-BABP and urinary expression of claudin-3 increased rapidly and significantly after the onset of surgery in most children. Postoperatively, all markers decreased promptly towards baseline values together with normalisation of MAP. Plasma levels of I-FABP, I-BABP were significantly negatively correlated with MAP at (1/2 hour before blood sampling (-0.726 (p<0.001, -0.483 (P<0.001, respectively. Furthermore, circulating I-FABP correlated with gastric mucosal P(rCO2, P(r-aCO2-gap measured at the same time points (0.553 (p = 0.040, 0.585 (p = 0.028, respectively.This study shows the development of gut barrier loss in children undergoing major non-abdominal surgery, which is related to preceding hypotension and mesenterial hypoperfusion. These data shed new light on the potential role of peroperative circulatory perturbation and intestinal barrier loss.

  18. New Insight in Loss of Gut Barrier during Major Non-Abdominal Surgery

    Science.gov (United States)

    Derikx, Joep P. M.; van Waardenburg, Dick A.; Thuijls, Geertje; Willigers, Henriëtte M.; Koenraads, Marianne; van Bijnen, Annemarie A.; Heineman, Erik; Poeze, Martijn; Ambergen, Ton; van Ooij, André; van Rhijn, Lodewijk W.; Buurman, Wim A.

    2008-01-01

    Background Gut barrier loss has been implicated as a critical event in the occurrence of postoperative complications. We aimed to study the development of gut barrier loss in patients undergoing major non-abdominal surgery. Methodology/Principal Findings Twenty consecutive children undergoing spinal fusion surgery were included. This kind of surgery is characterized by long operation time, significant blood loss, prolonged systemic hypotension, without directly leading to compromise of the intestines by intestinal manipulation or use of extracorporeal circulation. Blood was collected preoperatively, every two hours during surgery and 2, 4, 15 and 24 hours postoperatively. Gut mucosal barrier was assessed by plasma markers for enterocyte damage (I-FABP, I-BABP) and urinary presence of tight junction protein claudin-3. Intestinal mucosal perfusion was measured by gastric tonometry (PrCO2, Pr-aCO2-gap). Plasma concentration of I-FABP, I-BABP and urinary expression of claudin-3 increased rapidly and significantly after the onset of surgery in most children. Postoperatively, all markers decreased promptly towards baseline values together with normalisation of MAP. Plasma levels of I-FABP, I-BABP were significantly negatively correlated with MAP at ½ hour before blood sampling (−0.726 (p<0.001), −0.483 (P<0.001), respectively). Furthermore, circulating I-FABP correlated with gastric mucosal PrCO2, Pr-aCO2-gap measured at the same time points (0.553 (p = 0.040), 0.585 (p = 0.028), respectively). Conclusions/Significance This study shows the development of gut barrier loss in children undergoing major non-abdominal surgery, which is related to preceding hypotension and mesenterial hypoperfusion. These data shed new light on the potential role of peroperative circulatory perturbation and intestinal barrier loss. PMID:19088854

  19. Protective effects of ischemic postconditioning on intestinal

    Directory of Open Access Journals (Sweden)

    DING Jun-tao

    2011-04-01

    Full Text Available 【Abstract】Objective: To explore the protective effects of two types of ischemic postconditioning (IP on intestinal mucosa barrier in rabbits with crush injury of the hind limb. Methods: This study was conducted between August and December 2008 in the Department of Trauma Surgery, Daping Hospital, Third Military Medical University, Chongqing, China. The model of crush injury to the hind limb of rabbits was firstly developed by a 25 kg object with the right hind limbs fixed by wooden splints, and then two types of IP were established, including occluding/opening the common iliac artery and vein alternatively (traditional IP, IP A and binding/loosening the proximum of the injured hind limb alternatively (modified IP, IP B. Thirty-six male New Zealand white rabbits were randomly divided into three groups: IP A group, IP B group and control group, with 12 rabbits in each group. The serum levels of diamine oxidase (DAO and intestinal fatty acid-binding protein (I-FABP were detected at 2, 6, 12 and 24 hours after injury. Pathological changes of ileum were examined at 24 hours after injury. Results: The serum levels of I-FABP at 2, 6, 12 and 24 hours after injury in both IP A and IP B groups had a significant decrease, compared with control group. DAO levels also showed the same change trend at 2 and 6 hours after injury, but showed no significant difference between two IP groups. No difference in pathological changes of ileum was found among the three groups. Conclusions: IP can protect intestinal mucosa barrier function on the model of hind limb crush injury in rabbits. Meanwhile the modified IP B shows the same protection as the traditional IP A, and is worth applying in clinic. Key words: Ischemic postconditioning; Crush syndrome; Intestinal mucosa

  20. T helper type 1 memory cells disseminate postoperative ileus over the entire intestinal tract

    NARCIS (Netherlands)

    Engel, Daniel R.; Koscielny, Arne; Wehner, Sven; Maurer, Juliane; Schiwon, Marzena; Franken, Lars; Schumak, Beatrix; Limmer, Andreas; Sparwasser, Tim; Hirner, Andreas; Knolle, Percy A.; Kalff, Jörg C.; Kurts, Christian

    2010-01-01

    Localized abdominal surgery can lead to disruption of motility in the entire gastrointestinal tract (postoperative ileus). Intestinal macrophages produce mediators that paralyze myocytes, but it is unclear how the macrophages are activated, especially those in unmanipulated intestinal areas. Here we

  1. PGE2 suppresses intestinal T cell function in thermal injury: a cause of enhanced bacterial translocation.

    Science.gov (United States)

    Choudhry, M A; Fazal, N; Namak, S Y; Haque, F; Ravindranath, T; Sayeed, M M

    2001-09-01

    Increased gut bacterial translocation in burn and trauma patients has been demonstrated in a number of previous studies, however, the mechanism for such an increased gut bacterial translocation in injured patients remains poorly understood. Utilizing a rat model of burn injury, in the present study we examined the role of intestinal immune defense by analyzing the T cell functions. We investigated if intestinal T cells dysfunction contributes to bacterial translocation after burn injury. Also our study determined if burn-mediated alterations in intestinal T cell functions are related to enhanced release of PGE2. Finally, we examined whether or not burn-related alterations in intestinal T cell function are due to inappropriate activation of signaling molecule P59fyn, which is required for T cell activation and proliferation. The results presented here showed an increase in gut bacterial accumulation in mesenteric lymph nodes after thermal injury. This was accompanied by a decrease in the intestinal T cell proliferative responses. Furthermore, the treatments of burn-injured animals with PGE2 synthesis blocker (indomethacin or NS398) prevented both the decrease in intestinal T cell proliferation and enhanced bacterial translocation. Finally, our data suggested that the inhibition of intestinal T cell proliferation could result via PGE2-mediated down-regulation of the T cell activation-signaling molecule P59fyn. These findings support a role of T cell-mediated immune defense against bacterial translocation in burn injury.

  2. Tumor Necrosis Factor Induces Developmental Stage-Dependent Structural Changes in the Immature Small Intestine

    Directory of Open Access Journals (Sweden)

    Kathryn S. Brown

    2014-01-01

    Full Text Available Background. Premature infants are commonly subject to intestinal inflammation. Since the human small intestine does not reach maturity until term gestation, premature infants have a unique challenge, as either acute or chronic inflammation may alter the normal development of the intestinal tract. Tumor necrosis factor (TNF has been shown to acutely alter goblet cell numbers and villus length in adult mice. In this study we tested the effects of TNF on villus architecture and epithelial cells at different stages of development of the immature small intestine. Methods. To examine the effects of TNF-induced inflammation, we injected acute, brief, or chronic exposures of TNF in neonatal and juvenile mice. Results. TNF induced significant villus blunting through a TNF receptor-1 (TNFR1 mediated mechanism, leading to loss of villus area. This response to TNFR1 signaling was altered during intestinal development, despite constant TNFR1 protein expression. Acute TNF-mediated signaling also significantly decreased Paneth cells. Conclusions. Taken together, the morphologic changes caused by TNF provide insight as to the effects of inflammation on the developing intestinal tract. Additionally, they suggest a mechanism which, coupled with an immature immune system, may help to explain the unique susceptibility of the immature intestine to inflammatory diseases such as NEC.

  3. Endoglin negatively regulates transforming growth factor beta1-induced profibrotic responses in intestinal fibroblasts.

    LENUS (Irish Health Repository)

    Burke, J P

    2012-02-01

    BACKGROUND: Fibroblasts isolated from strictures in Crohn\\'s disease (CD) exhibit reduced responsiveness to stimulation with transforming growth factor (TGF) beta1. TGF-beta1, acting through the smad pathway, is critical to fibroblast-mediated intestinal fibrosis. The membrane glycoprotein, endoglin, is a negative regulator of TGF-beta1. METHODS: Intestinal fibroblasts were cultured from seromuscular biopsies of patients undergoing intestinal resection for CD strictures or from control patients. Endoglin expression was assessed using confocal microscopy, flow cytometry and western blot. The effect of small interfering (si) RNA-mediated knockdown and plasmid-mediated overexpression of endoglin on fibroblast responsiveness to TGF-beta1 was assessed by examining smad phosphorylation, smad binding element (SBE) promoter activity, connective tissue growth factor (CTGF) expression and ability to contract collagen. RESULTS: Crohn\\'s stricture fibroblasts expressed increased constitutive cell-surface and whole-cell endoglin relative to control cells. Endoglin co-localized with filamentous actin. Fibroblasts treated with siRNA directed against endoglin exhibited enhanced TGF-beta1-mediated smad-3 phosphorylation, and collagen contraction. Cells transfected with an endoglin plasmid did not respond to TGF-beta1 by exhibiting SBE promoter activity or producing CTGF. CONCLUSION: Fibroblasts from strictures in CD express increased constitutive endoglin. Endoglin is a negative regulator of TGF-beta1 signalling in the intestinal fibroblast, modulating smad-3 phosphorylation, SBE promoter activity, CTGF production and collagen contraction.

  4. Carrier-mediated γ-aminobutyric acid transport across the basolateral membrane of human intestinal Caco-2 cell monolayers.

    Science.gov (United States)

    Nielsen, Carsten Uhd; Carstensen, Mette; Brodin, Birger

    2012-06-01

    The aim of the present study was to investigate the transport of γ-aminobutyric acid (GABA) across the basolateral membrane of intestinal cells. The proton-coupled amino acid transporter, hPAT1, mediates the influx of GABA and GABA mimetic drug substances such as vigabatrin and gaboxadol and the anticancer prodrug δ-aminolevulinic acid across the apical membrane of small intestinal enterocytes. Little is however known about the basolateral transport of these substances. We investigated basolateral transport of GABA in mature Caco-2 cell monolayers using isotope studies. Here we report that, at least two transporters seem to be involved in the basolateral transport of GABA. The basolateral uptake consisted of a high-affinity system with a K(m) of 290 μM and V(max) of 75 pmol cm(-2) min(-1) and a low affinity system with a K(m) of approximately 64 mM and V(max) of 1.6 nmol cm(-2) min(-1). The high-affinity transporter is Na(+) and Cl(-) dependent. The substrate specificity of the high-affinity transporter was further studied and Gly-Sar, Leucine, gaboxadol, sarcosine, lysine, betaine, 5-hydroxythryptophan, proline and glycine reduced the GABA uptake to approximately 44-70% of the GABA uptake in the absence of inhibitor. Other substances such as β-alanine, GABA, 5-aminovaleric acid, taurine and δ-aminolevulinic acid reduced the basolateral GABA uptake to 6-25% of the uptake in the absence of inhibitor. Our results indicate that the distance between the charged amino- and acid-groups is particular important for inhibition of basolateral GABA uptake. Thus, there seems to be a partial substrate overlap between the basolateral GABA transporter and hPAT1, which may prove important for understanding drug interactions at the level of intestinal transport. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Defining the ATM-mediated barrier to tumorigenesis in somatic mammary cells following ErbB2 activation.

    Science.gov (United States)

    Reddy, Jay P; Peddibhotla, Sirisha; Bu, Wen; Zhao, Jing; Haricharan, Svasti; Du, Yi-Chieh Nancy; Podsypanina, Katrina; Rosen, Jeffrey M; Donehower, Larry A; Li, Yi

    2010-02-23

    p53, apoptosis, and senescence are frequently activated in preneoplastic lesions and are barriers to progression to malignancy. These barriers have been suggested to result from an ATM-mediated DNA damage response (DDR), which may follow oncogene-induced hyperproliferation and ensuing DNA replication stress. To elucidate the currently untested role of DDR in breast cancer initiation, we examined the effect of oncogene expression in several murine models of breast cancer. We did not observe a detectable DDR in early hyperplastic lesions arising in transgenic mice expressing several different oncogenes. However, DDR signaling was strongly induced in preneoplastic lesions arising from individual mammary cells transduced in vivo by retroviruses expressing either PyMT or ErbB2. Thus, activation of an oncogene after normal tissue development causes a DDR. Furthermore, in this somatic ErbB2 tumor model, ATM, and thus DDR, is required for p53 stabilization, apoptosis, and senescence. In palpable tumors in this model, p53 stabilization and apoptosis are lost, but unexpectedly senescence remains in many tumor cells. Thus, this murine model fully recapitulates early DDR signaling; the eventual suppression of its endpoints in tumorigenesis provides compelling evidence that ErbB2-induced aberrant mammary cell proliferation leads to an ATM-mediated DDR that activates apoptosis and senescence, and at least the former must be overcome to progress to malignancy. This in vivo study also uncovers an unexpected effect of ErbB2 activation previously known for its prosurvival roles, and suggests that protection of the ATM-mediated DDR-p53 signaling pathway may be important in breast cancer prevention.

  6. Protecting intestinal epithelial integrity by galacto-oligosaccharides: Keeping it tight

    NARCIS (Netherlands)

    Akbari, P.

    2016-01-01

    The intestinal barrier serves as a first line of host defense against potentially harmful stressors from the environment ingested with food, and is primarily formed by epithelial cells connected by tight junctions. Oligosaccharides have been identified as components in milk, particularly in

  7. Macleaya cordata Extract Decreased Diarrhea Score and Enhanced Intestinal Barrier Function in Growing Piglets

    Directory of Open Access Journals (Sweden)

    Gang Liu

    2016-01-01

    Full Text Available Macleaya cordata extract is of great scientific and practical interest to researchers, due to its antimicrobial and anti-inflammatory responses within experimental animals. This study was designed to determine the diarrhea score and innate immunity of growing piglets after they had received Macleaya cordata extract supplements. A total of 240 growing pigs were randomly assigned to one of three dietary treatments, with 8 replicates per treatment and 10 piglets per replicate. All pigs received a basal diet containing similar amounts of nutrients. The three treatments were a control (no additive, an antibiotic (200 mg/kg colistin, and the Macleaya cordata extract supplement group (40 mg/kg Macleaya cordata extract. The diarrhea score was calculated after D 28. The jejunal samples were obtained from five piglets selected randomly from each treatment on D 28. In comparison with the control group, the dietary Macleaya cordata extract and colistin group demonstrated a substantially decreased diarrhea score. The introduction of Macleaya cordata extract supplements to the diet significantly increased volumes of ZO-1 and claudin-1, particularly in comparison with the pigs in the control group (P<0.05. The findings indicate that Macleaya cordata extract does enhance intestinal barrier function in growing piglets and that it could be used as a viable substitute for antibiotics.

  8. Primary intestinal lymphangiectasia with generalized warts.

    Science.gov (United States)

    Lee, Soon Jae; Song, Hyun Joo; Boo, Sun-Jin; Na, Soo-Young; Kim, Heung Up; Hyun, Chang Lim

    2015-07-21

    Primary intestinal lymphangiectasia (PIL) is a rare protein-losing enteropathy with lymphatic leakage into the small intestine. Dilated lymphatics in the small intestinal wall and mesentery are observed in this disease. Laboratory tests of PIL patients revealed hypoalbuminemia, lymphocytopenia, hypogammaglobulinemia and increased stool α-1 antitrypsin clearance. Cell-mediated immunodeficiency is also present in PIL patients because of loss of lymphocytes. As a result, the patients are vulnerable to chronic viral infection and lymphoma. However, cases of PIL with chronic viral infection, such as human papilloma virus-induced warts, are rarely reported. We report a rare case of PIL with generalized warts in a 36-year-old male patient. PIL was diagnosed by capsule endoscopy and colonoscopic biopsy with histological tissue confirmation. Generalized warts were observed on the head, chest, abdomen, back, anus, and upper and lower extremities, including the hands and feet of the patient.

  9. Hes1 promotes the IL-22-mediated antimicrobial response by enhancing STAT3-dependent transcription in human intestinal epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Murano, Tatsuro [Department of Gastroenterology and Hepatology, Graduate School, Tokyo Medical and Dental University, Tokyo (Japan); Okamoto, Ryuichi, E-mail: rokamoto.gast@tmd.ac.jp [Department of Gastroenterology and Hepatology, Graduate School, Tokyo Medical and Dental University, Tokyo (Japan); Department of Advanced GI Therapeutics, Graduate School, Tokyo Medical and Dental University, Tokyo (Japan); Ito, Go; Nakata, Toru; Hibiya, Shuji; Shimizu, Hiromichi; Fujii, Satoru; Kano, Yoshihito; Mizutani, Tomohiro; Yui, Shiro; Akiyama-Morio, Junko; Nemoto, Yasuhiro [Department of Gastroenterology and Hepatology, Graduate School, Tokyo Medical and Dental University, Tokyo (Japan); Tsuchiya, Kiichiro; Nakamura, Tetsuya [Department of Gastroenterology and Hepatology, Graduate School, Tokyo Medical and Dental University, Tokyo (Japan); Department of Advanced GI Therapeutics, Graduate School, Tokyo Medical and Dental University, Tokyo (Japan); Watanabe, Mamoru [Department of Gastroenterology and Hepatology, Graduate School, Tokyo Medical and Dental University, Tokyo (Japan)

    2014-01-17

    Highlights: •Hes1 enhances IL-22-STAT3 signaling in human intestinal epithelial cells. •Hes1 enhances REG family gene induction by IL-22-STAT3 signaling. •Protein level of Hes1 restricts the response to IL-22. •Present regulation of a cytokine signal represents a new mode of Hes1 function. -- Abstract: Notch signaling plays an essential role in the proliferation and differentiation of intestinal epithelial cells (IECs). We have previously shown that Notch signaling is up-regulated in the inflamed mucosa of ulcerative colitis (UC) and thereby plays an indispensable role in tissue regeneration. Here we show that in addition to Notch signaling, STAT3 signaling is highly activated in the inflamed mucosa of UC. Forced expression of the Notch target gene Hes1 dramatically enhanced the IL-22-mediated STAT3-dependent transcription in human IECs. This enhancement of STAT3-dependent transcription was achieved by the extended phosphorylation of STAT3 by Hes1. Microarray analysis revealed that Hes1-mediated enhancement of IL-22-STAT3 signaling significantly increased the induction of genes encoding antimicrobial peptides, such as REG1A, REG3A and REG3G, in human IECs. Conversely, the reduction of Hes1 protein levels with a γ-secretase inhibitor significantly down-regulated the induction of those genes in IECs, resulting in a markedly poor response to IL-22. Our present findings identify a new role for the molecular function of Hes1 in which the protein can interact with cytokine signals and regulate the immune response of IECs.

  10. Carbachol ameliorates lipopolysaccharide-induced intestinal epithelial tight junction damage by down-regulating NF-{kappa}{beta} and myosin light-chain kinase pathways

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ying [Department of Anesthesia, Critical Care Medicine and Emergency Medicine Center, Zhongnan Hospital, Wuhan University, Wuhan 430071, Hubei Province, People' s Republic of China (China); Li, Jianguo, E-mail: 2010lijianguo@sina.cn [Department of Anesthesia, Critical Care Medicine and Emergency Medicine Center, Zhongnan Hospital, Wuhan University, Wuhan 430071, Hubei Province, People' s Republic of China (China)

    2012-11-16

    Highlights: Black-Right-Pointing-Pointer Carbachol reduced the lipopolysaccharide-induced intestinal barrier breakdown. Black-Right-Pointing-Pointer Carbachol ameliorated the lipopolysaccharide-induced ileal tight junction damage. Black-Right-Pointing-Pointer Carbachol prevented the LPS-induced NF-{kappa}{beta} and myosin light-chain kinase activation. Black-Right-Pointing-Pointer Carbachol exerted its beneficial effects in an {alpha}7 nicotinic receptor-dependent manner. -- Abstract: Carbachol is a cholinergic agonist that protects the intestines after trauma or burn injury. The present study determines the beneficial effects of carbachol and the mechanisms by which it ameliorates the lipopolysaccharide (LPS)-induced intestinal barrier breakdown. Rats were injected intraperitoneally with 10 mg/kg LPS. Results showed that the gut barrier permeability was reduced, the ultrastructural disruption of tight junctions (TJs) was prevented, the redistribution of zonula occludens-1 and claudin-2 proteins was partially reversed, and the nuclear factor-kappa beta (NF-{kappa}{beta}) and myosin light-chain kinase (MLCK) activation in the intestinal epithelium were suppressed after carbachol administration in LPS-exposed rats. Pretreatment with the {alpha}7 nicotinic acetylcholine receptor ({alpha}7nAchR) antagonist {alpha}-bungarotoxin blocked the protective action of carbachol. These results suggested that carbachol treatment can protect LPS-induced intestinal barrier dysfunction. Carbachol exerts its beneficial effect on the amelioration of the TJ damage by inhibiting the NF-{kappa}{beta} and MLCK pathways in an {alpha}7nAchR-dependent manner.

  11. Intestinal microbiota in pathophysiology and management of irritable bowel syndrome

    Science.gov (United States)

    Lee, Kang Nyeong; Lee, Oh Young

    2014-01-01

    Irritable bowel syndrome (IBS) is a functional bowel disorder without any structural or metabolic abnormalities that sufficiently explain the symptoms, which include abdominal pain and discomfort, and bowel habit changes such as diarrhea and constipation. Its pathogenesis is multifactorial: visceral hypersensitivity, dysmotility, psychosocial factors, genetic or environmental factors, dysregulation of the brain-gut axis, and altered intestinal microbiota have all been proposed as possible causes. The human intestinal microbiota are composed of more than 1000 different bacterial species and 1014 cells, and are essential for the development, function, and homeostasis of the intestine, and for individual health. The putative mechanisms that explain the role of microbiota in the development of IBS include altered composition or metabolic activity of the microbiota, mucosal immune activation and inflammation, increased intestinal permeability and impaired mucosal barrier function, sensory-motor disturbances provoked by the microbiota, and a disturbed gut-microbiota-brain axis. Therefore, modulation of the intestinal microbiota through dietary changes, and use of antibiotics, probiotics, and anti-inflammatory agents has been suggested as strategies for managing IBS symptoms. This review summarizes and discusses the accumulating evidence that intestinal microbiota play a role in the pathophysiology and management of IBS. PMID:25083061

  12. Intestinal microbiota in pathophysiology and management of irritable bowel syndrome.

    Science.gov (United States)

    Lee, Kang Nyeong; Lee, Oh Young

    2014-07-21

    Irritable bowel syndrome (IBS) is a functional bowel disorder without any structural or metabolic abnormalities that sufficiently explain the symptoms, which include abdominal pain and discomfort, and bowel habit changes such as diarrhea and constipation. Its pathogenesis is multifactorial: visceral hypersensitivity, dysmotility, psychosocial factors, genetic or environmental factors, dysregulation of the brain-gut axis, and altered intestinal microbiota have all been proposed as possible causes. The human intestinal microbiota are composed of more than 1000 different bacterial species and 10(14) cells, and are essential for the development, function, and homeostasis of the intestine, and for individual health. The putative mechanisms that explain the role of microbiota in the development of IBS include altered composition or metabolic activity of the microbiota, mucosal immune activation and inflammation, increased intestinal permeability and impaired mucosal barrier function, sensory-motor disturbances provoked by the microbiota, and a disturbed gut-microbiota-brain axis. Therefore, modulation of the intestinal microbiota through dietary changes, and use of antibiotics, probiotics, and anti-inflammatory agents has been suggested as strategies for managing IBS symptoms. This review summarizes and discusses the accumulating evidence that intestinal microbiota play a role in the pathophysiology and management of IBS.

  13. [Interaction of effective ingredients from traditional Chinese medicines with intestinal microbiota].

    Science.gov (United States)

    Zu, Xian-Peng; Lin, Zhang; Xie, Hai-Sheng; Yang, Niao; Liu, Xin-Ru; Zhang, Wei-Dong

    2016-05-01

    A large number and wide varieties of microorganisms colonize in the human gastrointestinal tract. They construct an intestinal microecological system in the intestinal environment. The intestinal symbiotic flora regulates a series of life actions, including digestion and absorption of nutrient, immune response, biological antagonism, and is closely associated with the occurrence and development of many diseases. Therefore, it is greatly essential for the host's health status to maintain the equilibrium of intestinal microecological environment. After effective compositions of traditional Chinese medicines are metabolized or biotransformed by human intestinal bacteria, their metabolites can be absorbed more easily, and can even decrease or increase toxicity and then exhibit significant different biological effects. Meanwhile, traditional Chinese medicines can also regulate the composition of the intestinal flora and protect the function of intestinal mucosal barrier to restore the homeostasis of intestinal microecology. The relevant literatures in recent 15 years about the interactive relationship between traditional Chinese medicines and gut microbiota have been collected in this review, in order to study the classification of gut microflora, the relationship between intestinal dysbacteriosis and diseases, the important roles of gut microflora in intestinal bacterial metabolism in effective ingredients of traditional Chinese medicines and bioactivities, as well as the modulation effects of Chinese medicine on intestinal dysbacteriosis. In addition, it also makes a future prospect for the research strategies to study the mechanism of action of traditional Chinese medicines based on multi-omics techniques. Copyright© by the Chinese Pharmaceutical Association.

  14. Protective effects of Astragalus-Lilygranules on intestinal mucosal barrier of mice in high altitude hypoxia

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    Ling LI

    2016-10-01

    Full Text Available Objective  To investigate the protective effect of Astragalus-Lily Granules on intestinal mucosa and intestinal flora homeostasis in mice under high altitude hypoxia condition. Methods  We put mice into high altitude hypoxia cabin to establish high altitude hypoxia model mice. Sixty Kunming mice were randomly divided into control group, model group, Astragalus-Lily particles (ALP low, medium and high dose groups [1.75, 3.5, 7g/(kg•d] respectively. After three days of routine feeding, the ALP mice received drug by intragastric administration, once a day for continuous 17 days,control group and model group were given double distilled water in same volume. From the 15th day, all the mice but control group were exposed to simulated high altitude hypoxia condition for 3 days in a high altitude hypoxia cabin after they were gavaged for half an hour daily. By the 18th day, the fresh mouse feces were collected and smeared to observe the changes of microflora. The pathological changes of intestinal tissues were observed by HE staining and the expression of HIF-1αprotein in intestines was detected by immunohistochemistry. Results  The enterococci and gram negative bacteria showed a higher proportion (65.2%±2.4% and 56.7%±3.3%, respectively in the model group compared with the control group (24.7%±1.2%, 23.2%±1.5%, respectively, P<0.05. The pathological score of intestinal mucosal necrosis and edema (3.10±0.99, 3.30±0.67 respectively and inflammatory cell count (15.93±3.30, 16.40±3.97/ HP respectively was higher compared with the model group (0.70±0.67, 0.80±0.78; 4.07±2.12, 4.28±2.16/HP respectively; P<0.05. HIF-1αexpression increased significantly compared with the model group (P<0.05. The enterococci (46.7%±2.0%, 32.0%±2.6% respectively and gram negative bacteria rate (34.2%±1.6%, 38.0%±2.8% respectively in the ALP medium and high dose groups were lower compared with the model group (24.7%±1.2%, 23.2%±1.5% respectively, P<0

  15. Lipopolysaccharide Binding Protein Enables Intestinal Epithelial Restitution Despite Lipopolysaccharide Exposure

    Science.gov (United States)

    Richter, Juli M.; Schanbacher, Brandon L.; Huang, Hong; Xue, Jianjing; Bauer, John A.; Giannone, Peter J.

    2011-01-01

    Intestinal epithelial restitution is the first part in the process of mucosal repair after injury in the intestine. Integrity of the intestinal mucosal barrier is important as a first line of defense against bacteria and endotoxin. Necrotizing enterocolitis (NEC) is a major cause of morbidity and mortality in extremely low birth weight infants, but its mechanisms are not well defined. Abnormal bacterial colonization, immature barrier function, innate immunity activation and inflammation likely play a role. Lipopolysaccharide (LPS) binding protein (LBP) is secreted by enterocytes in response to inflammatory stimuli and has concentration-dependent effects. At basal concentrations, LBP stimulates the inflammatory response by presenting LPS to its receptor. However, at high concentrations, LBP is able to neutralize LPS and prevent an exaggerated inflammatory response. We sought to determine how LBP would affect wound healing in an in vitro model of intestinal cell restitution and protect against intestinal injury in a rodent model of NEC. Immature intestinal epithelial cells (IEC-6) were seeded in poly-l-lysine coated 8 chamber slides and grown to confluence. A 500μm wound was created using a cell scraper mounted on the microscope to achieve uniform wounding. Media was replaced with media containing LPS +/− LBP. Slide wells were imaged after 0, 8, and 24 hours and then fixed. Cellular restitution was evaluated via digital images captured on an inverted microscope and wound closure was determined by automated analysis. TLR4 was determined by rtPCR after RNA isolation from wounded cells 24 hours after treatment. LPS alone attenuated wound healing in immature intestinal epithelium. This attenuation is reversed by 24 hours with increasing concentrations of LBP so that wound healing is equivalent to control (p< 0.001). TLR4 was increased with LPS alone but levels returned to that of control after addition of LBP in the higher concentrations. LBP had no effect on the

  16. Intestinal metabolism of PAH: in vitro demonstration and study of its impact on PAH transfer through the intestinal epithelium

    International Nuclear Information System (INIS)

    Cavret, Severine; Feidt, Cyril

    2005-01-01

    Food would seem to be one of the main ways of animal and human contamination with polycyclic aromatic hydrocarbons (PAHs). In vivo studies suggest a transfer in intestinal epithelium by diffusion, which appears extensively governed by the physicochemical properties of PAHs, particularly lipophilicity. However, other mechanisms, such as metabolism, are considered to intervene. Our work aimed at testing in vitro intestinal metabolism and defining its impact on transepithelial transport of PAHs. Caco-2 cells were cultivated on permeable filters and incubated with 14 C-labeled benzo[a]pyrene (BaP), pyrene (Pyr), and phenanthrene (Phe), which differ in their physicochemical properties. The results showed that the cells were able to metabolize the compounds. In basal media, Phe appeared to be the least hydroxylated molecule (45% after a 6-h exposure), followed by Pyr (65%) and finally BaP (96%). Inhibition of PAH metabolism showed a determinant effect on kinetics profiles. Transfer in the basal compartment of BaP, Pyr, and Phe radioactivities was, respectively, 26, 4, and 2 times lower with inhibitors, corroborating that intestinal metabolism of PAHs would have a positive impact on their transfer, an impact that increased with their lipophilicity. Furthermore, after a 6-h incubation, metabolites were also detected in apical medium. These findings suggested that intestinal metabolism might play a key role in intestinal barrier permeability and thus in the bioavailability of tested micropollutants

  17. Stress induces endotoxemia and low-grade inflammation by increasing barrier permeability

    Directory of Open Access Journals (Sweden)

    Karin ede Punder

    2015-05-01

    Full Text Available Chronic non-communicable diseases (NCDs are the leading causes of work absence, disability and mortality worldwide. Most of these diseases are associated with low-grade inflammation. Here we hypothesize that stresses (defined as homeostatic disturbances can induce low-grade inflammation by increasing the availability of water, sodium and energy-rich substances to meet the increased metabolic demand induced by the stressor. One way of triggering low-grade inflammation is by increasing intestinal barrier permeability through activation of various components of the stress system. Although beneficial to meet the demands necessary during stress, increased intestinal barrier permeability also raises the possibility of the translocation of bacteria and their toxins across the intestinal lumen into the blood circulation. In combination with modern life-style factors, the increase in bacteria/bacterial toxin translocation arising from a more permeable intestinal wall causes a low-grade inflammatory state. We support this hypothesis with numerous studies finding associations with NCDs and markers of endotoxemia, suggesting that this process plays a pivotal and perhaps even a causal role in the development of low-grade inflammation and its related diseases.

  18. Insulin-like growth factor 1: common mediator of multiple enterotrophic hormones and growth factors.

    Science.gov (United States)

    Bortvedt, Sarah F; Lund, P Kay

    2012-03-01

    To summarize the recent evidence that insulin-like growth factor 1 (IGF1) mediates growth effects of multiple trophic factors and discuss clinical relevance. Recent reviews and original reports indicate benefits of growth hormone (GH) and long-acting glucagon-like peptide 2 (GLP2) analogs in short bowel syndrome and Crohn's disease. This review highlights the evidence that biomarkers of sustained small intestinal growth or mucosal healing and evaluation of intestinal epithelial stem cell biomarkers may improve clinical measures of intestinal growth or response to trophic hormones. Compelling evidence that IGF1 mediates growth effects of GH and GLP2 on intestine or linear growth in preclinical models of resection or Crohn's disease is presented, along with a concept that these hormones or IGF1 may enhance sustained growth if given early after bowel resection. Evidence that suppressor of cytokine signaling protein induction by GH or GLP2 in normal or inflamed intestine may limit IGF1-induced growth, but protect against risk of dysplasia or fibrosis, is reviewed. Whether IGF1 receptor mediates IGF1 action and potential roles of insulin receptors are addressed. IGF1 has a central role in mediating trophic hormone action in small intestine. Better understanding of benefits and risks of IGF1, receptors that mediate IGF1 action, and factors that limit undesirable growth are needed.

  19. Cannabidiol restores intestinal barrier dysfunction and inhibits the apoptotic process induced by Clostridium difficile toxin A in Caco-2 cells.

    Science.gov (United States)

    Gigli, Stefano; Seguella, Luisa; Pesce, Marcella; Bruzzese, Eugenia; D'Alessandro, Alessandra; Cuomo, Rosario; Steardo, Luca; Sarnelli, Giovanni; Esposito, Giuseppe

    2017-12-01

    Clostridium difficile toxin A is responsible for colonic damage observed in infected patients. Drugs able to restore Clostridium difficile toxin A-induced toxicity have the potential to improve the recovery of infected patients. Cannabidiol is a non-psychotropic component of Cannabis sativa, which has been demonstrated to protect enterocytes against chemical and/or inflammatory damage and to restore intestinal mucosa integrity. The purpose of this study was to evaluate (a) the anti-apoptotic effect and (b) the mechanisms by which cannabidiol protects mucosal integrity in Caco-2 cells exposed to Clostridium difficile toxin A. Caco-2 cells were exposed to Clostridium difficile toxin A (30 ng/ml), with or without cannabidiol (10 -7 -10 -9  M), in the presence of the specific antagonist AM251 (10 -7  M). Cytotoxicity assay, transepithelial electrical resistence measurements, immunofluorescence analysis and immunoblot analysis were performed in the different experimental conditions. Clostridium difficile toxin A significantly decreased Caco-2 cells' viability and reduced transepithelial electrical resistence values and RhoA guanosine triphosphate (GTP), bax, zonula occludens-1 and occludin protein expression, respectively. All these effects were significantly and concentration-dependently inhibited by cannabidiol, whose effects were completely abolished in the presence of the cannabinoid receptor type 1 (CB1) antagonist, AM251. Cannabidiol improved Clostridium difficile toxin A-induced damage in Caco-2 cells, by inhibiting the apoptotic process and restoring the intestinal barrier integrity, through the involvement of the CB1 receptor.

  20. Intestinal volvulus with coagulative hepatic necrosis in a chicken.

    Science.gov (United States)

    Haridy, Mohie; Goryo, Masanobu; Sasaki, Jun; Okada, Kosuke

    2010-04-01

    A 7-week-old SPF chicken inoculated at 4 weeks of age with chicken anemia virus was puffed up depressed and had ruffled feathers and a good body condition. Intestinal volvulus involving the jejunum and part of the duodenum forming two loops with one knob was observed. Microscopically, venous infarction of the obstructed loops, periportal and sublobular multifocal coagulative hepatic necrosis and granulomatous inflammation of the cecal tonsils were observed. Gram staining revealed no bacteria in hepatic tissue; however, gram-positive bacilli were detected in the necrotic debris in the intestinal lumen. Immunosuppression might have predisposed the chicken to intestinal and cecal tonsil infection that then progressed to volvulus. Loss of the mucosal barrier in infarction might allow bacterial toxins and vasoactive factors to escape into the systemic circulation (toxemia) and be responsible for the hepatic necrosis.

  1. Characterizing microbiota-independent effects of oligosaccharides on intestinal epithelial cells

    NARCIS (Netherlands)

    Akbari, Peyman; Fink-Gremmels, Johanna; Willems, Rianne H.A.M.; Difilippo, Elisabetta; Schols, Henk A.; Schoterman, Margriet H.C.; Garssen, Johan; Braber, Saskia

    2017-01-01

    Purpose: The direct effects of galacto-oligosaccharides (GOS), including Vivinal® GOS syrup (VGOS) and purified Vivinal® GOS (PGOS), on the epithelial integrity and corresponding interleukin-8 (IL-8/CXCL8) release were examined in a Caco-2 cell model for intestinal barrier dysfunction. To

  2. Effects of Supplementation of the Synbiotic Ecologic® 825/FOS P6 on Intestinal Barrier Function in Healthy Humans: A Randomized Controlled Trial

    Science.gov (United States)

    Wilms, E.; Gerritsen, J.; Smidt, H.; Besseling-van der Vaart, I.; Rijkers, G. T.; Garcia Fuentes, A. R.; Masclee, A. A. M.; Troost, F. J.

    2016-01-01

    Background and Aims Probiotics, prebiotics and synbiotics have been suggested as dietary strategies to improve intestinal barrier function. This study aimed to assess the effect of two weeks synbiotic supplementation on intestinal permeability under basal and stressed conditions. Secondary aims were the assessment of two weeks synbiotic supplementation on systemic immune function and gastrointestinal symptoms including defecation pattern. Design Twenty healthy adults completed a double-blind, controlled, randomized, parallel design study. Intervention Groups either received synbiotic (1.5 × 1010 CFU Ecologic® 825 + 10 g fructo-oligosaccharides (FOS P6) per day) or control supplements for two weeks. Outcomes Intestinal segment specific permeability was assessed non-invasively by oral administration of multiple sugar probes and, subsequently, assessing the excretion of these probes in urine. This test was conducted at baseline and at the end of intervention, in the absence and in the presence of an indomethacin challenge. Indomethacin was applied to induce a compromised gut state. Plasma zonulin, cytokines and chemokines were measured at baseline and at the end of intervention. Gastrointestinal symptoms and stool frequency were recorded at baseline and daily during intervention. Results Significantly more male subjects were in the synbiotic group compared to the control group (P = 0.025). Indomethacin significantly increased urinary lactulose/rhamnose ratio versus without indomethacin, both in the control group (P = 0.005) and in the synbiotic group (P = 0.017). Urinary sugar recoveries and ratios, plasma levels of zonulin, cytokines and chemokines, and gastrointestinal symptom scores were not significantly different after control or synbiotic intervention. Stool frequency within the synbiotic group was significantly increased during synbiotic intervention compared to baseline (P = 0.039) and higher compared to control intervention (P = 0.045). Conclusion Two weeks

  3. Effects of Supplementation of the Synbiotic Ecologic® 825/FOS P6 on Intestinal Barrier Function in Healthy Humans: A Randomized Controlled Trial.

    Directory of Open Access Journals (Sweden)

    E Wilms

    Full Text Available Probiotics, prebiotics and synbiotics have been suggested as dietary strategies to improve intestinal barrier function. This study aimed to assess the effect of two weeks synbiotic supplementation on intestinal permeability under basal and stressed conditions. Secondary aims were the assessment of two weeks synbiotic supplementation on systemic immune function and gastrointestinal symptoms including defecation pattern.Twenty healthy adults completed a double-blind, controlled, randomized, parallel design study.Groups either received synbiotic (1.5 × 1010 CFU Ecologic® 825 + 10 g fructo-oligosaccharides (FOS P6 per day or control supplements for two weeks.Intestinal segment specific permeability was assessed non-invasively by oral administration of multiple sugar probes and, subsequently, assessing the excretion of these probes in urine. This test was conducted at baseline and at the end of intervention, in the absence and in the presence of an indomethacin challenge. Indomethacin was applied to induce a compromised gut state. Plasma zonulin, cytokines and chemokines were measured at baseline and at the end of intervention. Gastrointestinal symptoms and stool frequency were recorded at baseline and daily during intervention.Significantly more male subjects were in the synbiotic group compared to the control group (P = 0.025. Indomethacin significantly increased urinary lactulose/rhamnose ratio versus without indomethacin, both in the control group (P = 0.005 and in the synbiotic group (P = 0.017. Urinary sugar recoveries and ratios, plasma levels of zonulin, cytokines and chemokines, and gastrointestinal symptom scores were not significantly different after control or synbiotic intervention. Stool frequency within the synbiotic group was significantly increased during synbiotic intervention compared to baseline (P = 0.039 and higher compared to control intervention (P = 0.045.Two weeks Ecologic® 825/FOS P6 supplementation increased stool

  4. Mucin dynamics in intestinal bacterial infection.

    Directory of Open Access Journals (Sweden)

    Sara K Lindén

    Full Text Available Bacterial gastroenteritis causes morbidity and mortality in humans worldwide. Murine Citrobacter rodentium infection is a model for gastroenteritis caused by the human pathogens enteropathogenic Escherichia coli and enterohaemorrhagic E. coli. Mucin glycoproteins are the main component of the first barrier that bacteria encounter in the intestinal tract.Using Immunohistochemistry, we investigated intestinal expression of mucins (Alcian blue/PAS, Muc1, Muc2, Muc4, Muc5AC, Muc13 and Muc3/17 in healthy and C. rodentium infected mice. The majority of the C. rodentium infected mice developed systemic infection and colitis in the mid and distal colon by day 12. C. rodentium bound to the major secreted mucin, Muc2, in vitro, and high numbers of bacteria were found in secreted MUC2 in infected animals in vivo, indicating that mucins may limit bacterial access to the epithelial surface. In the small intestine, caecum and proximal colon, the mucin expression was similar in infected and non-infected animals. In the distal colonic epithelium, all secreted and cell surface mucins decreased with the exception of the Muc1 cell surface mucin which increased after infection (p<0.05. Similarly, during human infection Salmonella St Paul, Campylobacter jejuni and Clostridium difficile induced MUC1 in the colon.Major changes in both the cell-surface and secreted mucins occur in response to intestinal infection.

  5. Wnt target gene analysis in colorectal cancer and intestinal stem cells

    NARCIS (Netherlands)

    van der Flier, L.G.

    2009-01-01

    The intestinal epithelium is a specialized simple epithelium that lines the gut and performs primary functions of digestion, absorption and forms a barrier against luminal pathogens. It is organized in invaginations called crypts and finger-like protrusions called villi. The crypts harbor

  6. Gastric acid reduction leads to an alteration in lower intestinal microflora

    Energy Technology Data Exchange (ETDEWEB)

    Kanno, Takayuki [Department of Gastroenterology, Wakayama Medical University, 811-1 Kimiidera, Wakayama-city, Wakayama 641-0012 (Japan); Matsuki, Takahiro [Yakult Central Institute for Microbiological Research, Tokyo (Japan); Oka, Masashi; Utsunomiya, Hirotoshi [Department of Gastroenterology, Wakayama Medical University, 811-1 Kimiidera, Wakayama-city, Wakayama 641-0012 (Japan); Inada, Kenichi [First Department of Pathology, Fujita Health University School of Medicine, Aichi (Japan); Magari, Hirohito; Inoue, Izumi; Maekita, Takao; Ueda, Kazuki; Enomoto, Shotaro; Iguchi, Mikitaka; Yanaoka, Kimihiko; Tamai, Hideyuki [Department of Gastroenterology, Wakayama Medical University, 811-1 Kimiidera, Wakayama-city, Wakayama 641-0012 (Japan); Akimoto, Shigeru [Department of Microbiology, Wakayama Medical University, 811-1 Kimiidera, Wakayama-city, Wakayama 641-0012 (Japan); Nomoto, Koji; Tanaka, Ryuichiro [Yakult Central Institute for Microbiological Research, Tokyo (Japan); Ichinose, Masao, E-mail: ichinose@wakayama-med.ac.jp [Department of Gastroenterology, Wakayama Medical University, 811-1 Kimiidera, Wakayama-city, Wakayama 641-0012 (Japan)

    2009-04-17

    To clarify the alterations in lower intestinal microflora induced by gastric acid reduction, the dynamics of 12 major genera or groups of bacteria comprising the microflora in feces and colonic contents were examined by quantitative real-time PCR in proton pump inhibitor-treated rats and in asymptomatic human subjects with hypochlorhydria. In both rat and human experiments, most genera or groups of intestinal microflora (facultative and obligate anaerobes) proliferated by gastric acid reduction, and marked and significant increases in the Lactobacilli group and Veillonella, oropharyngeal bacteria, were observed. In rats, potent gastric acid inhibition led to a marked and significant increase of intestinal bacteria, including the Bacteroidesfragilis group, while Bifidobacterium, a beneficial bacterial species, remained at a constant level. These results strongly indicate that the gastric acid barrier not only controls the colonization and growth of oropharyngeal bacteria, but also regulates the population and composition of lower intestinal microflora.

  7. Gastric acid reduction leads to an alteration in lower intestinal microflora

    International Nuclear Information System (INIS)

    Kanno, Takayuki; Matsuki, Takahiro; Oka, Masashi; Utsunomiya, Hirotoshi; Inada, Kenichi; Magari, Hirohito; Inoue, Izumi; Maekita, Takao; Ueda, Kazuki; Enomoto, Shotaro; Iguchi, Mikitaka; Yanaoka, Kimihiko; Tamai, Hideyuki; Akimoto, Shigeru; Nomoto, Koji; Tanaka, Ryuichiro; Ichinose, Masao

    2009-01-01

    To clarify the alterations in lower intestinal microflora induced by gastric acid reduction, the dynamics of 12 major genera or groups of bacteria comprising the microflora in feces and colonic contents were examined by quantitative real-time PCR in proton pump inhibitor-treated rats and in asymptomatic human subjects with hypochlorhydria. In both rat and human experiments, most genera or groups of intestinal microflora (facultative and obligate anaerobes) proliferated by gastric acid reduction, and marked and significant increases in the Lactobacilli group and Veillonella, oropharyngeal bacteria, were observed. In rats, potent gastric acid inhibition led to a marked and significant increase of intestinal bacteria, including the Bacteroidesfragilis group, while Bifidobacterium, a beneficial bacterial species, remained at a constant level. These results strongly indicate that the gastric acid barrier not only controls the colonization and growth of oropharyngeal bacteria, but also regulates the population and composition of lower intestinal microflora.

  8. Zonulin, a regulator of epithelial and endothelial barrier functions, and its involvement in chronic inflammatory diseases.

    Science.gov (United States)

    Sturgeon, Craig; Fasano, Alessio

    2016-01-01

    Beside digesting nutrients and absorbing solutes and electrolytes, the intestinal epithelium with its barrier function is in charge of a tightly controlled antigen trafficking from the intestinal lumen to the submucosa. This trafficking dictates the delicate balance between tolerance and immune response causing inflammation. Loss of barrier function secondary to upregulation of zonulin, the only known physiological modulator of intercellular tight junctions, leads to uncontrolled influx of dietary and microbial antigens. Additional insights on zonulin mechanism of action and the recent appreciation of the role that altered intestinal permeability can play in the development and progression of chronic inflammatory disorders has increased interest of both basic scientists and clinicians on the potential role of zonulin in the pathogenesis of these diseases. This review focuses on the recent research implicating zonulin as a master regulator of intestinal permeability linked to the development of several chronic inflammatory disorders.

  9. Inhibition of Epithelial TNF-α Receptors by Purified Fruit Bromelain Ameliorates Intestinal Inflammation and Barrier Dysfunction in Colitis.

    Science.gov (United States)

    Zhou, Zijuan; Wang, Liang; Feng, Panpan; Yin, Lianhong; Wang, Chen; Zhi, Shengxu; Dong, Jianyi; Wang, Jingyu; Lin, Yuan; Chen, Dapeng; Xiong, Yongjian; Peng, Jinyong

    2017-01-01

    Activation of the TNF-α receptor (TNFR) leads to an inflammatory response, and anti-TNF therapy has been administered to reduce inflammation symptoms and heal mucosal ulcers in inflammatory bowel disease (IBD). Bromelain, a complex natural mixture of proteolytic enzymes, has been shown to exert anti-inflammatory effects. This study aimed to investigate the effect of purified fruit bromelain (PFB)-induced inhibition of epithelial TNFR in a rat colitis model. Colitis was established by intracolonic administration of 2, 4, 6-trinitrobenzene sulfonic acid. Expression of TNFR1 and TNFR2 was measured by quantitative RT-PCR and western blotting. The effect of PFB on colitis was evaluated by examining the inflammatory response and intestinal epithelial barrier function. Our results showed that both TNFR1 and TNFR2 expression were significantly increased in a colitis model, and the increase was significantly reversed by PFB. Colitis symptoms, including infiltration of inflammatory cells, cytokine profiles, epithelial cell apoptosis, and epithelial tight junction barrier dysfunction were significantly ameliorated by PFB. Compared with fruit bromelain and stem bromelain complex, the inhibition of TNFR2 induced by PFB was stronger than that exhibited on TNFR1. These results indicate that PFB showed a stronger selective inhibitory effect on TNFR2 than TNFR1. In other words, purification of fruit bromelain increases its selectivity on TNFR2 inhibition. High expression of epithelial TNFRs in colitis was significantly counteracted by PFB, and PFB-induced TNFR inhibition ameliorated colitis symptoms. These results supply novel insights into potential IBD treatment by PFB.

  10. Injury-induced inhibition of small intestinal protein and nucleic acid synthesis

    International Nuclear Information System (INIS)

    Carter, E.A.; Hatz, R.A.; Yarmush, M.L.; Tompkins, R.G.

    1990-01-01

    Small intestinal mucosal weight and nutrient absorption are significantly diminished early after cutaneous thermal injuries. Because these intestinal properties are highly dependent on rates of nucleic acid and protein synthesis, in vivo incorporation of thymidine, uridine, and leucine into small intestinal deoxyribonucleic acid, ribonucleic acid, and proteins were measured. Deoxyribonucleic acid synthesis was markedly decreased with the lowest thymidine incorporation in the jejunum (p less than 0.01); these findings were confirmed by autoradiographic identification of radiolabeled nuclei in the intestinal crypts. Protein synthesis was decreased by 6 h postinjury (p less than 0.01) but had returned to normal by 48 h. Consistent with a decreased rate of protein synthesis, ribonucleic acid synthesis was also decreased 18 h postinjury (p less than 0.01). These decreased deoxyribonucleic acid, ribonucleic acid, and protein synthesis rates are not likely a result of ischemia because in other studies of this injury model, intestinal blood flow was not significantly changed by the burn injury. Potentially, factors initiating the acute inflammatory reaction may directly inhibit nucleic acid and protein synthesis and lead to alterations in nutrient absorption and intestinal barrier function after injury

  11. Rebamipide suppresses diclofenac-induced intestinal permeability via mitochondrial protection in mice.

    Science.gov (United States)

    Diao, Lei; Mei, Qiao; Xu, Jian-Ming; Liu, Xiao-Chang; Hu, Jing; Jin, Juan; Yao, Qiang; Chen, Mo-Li

    2012-03-14

    To investigate the protective effect and mechanism of rebamipide on small intestinal permeability induced by diclofenac in mice. Diclofenac (2.5 mg/kg) was administered once daily for 3 d orally. A control group received the vehicle by gavage. Rebamipide (100 mg/kg, 200 mg/kg, 400 mg/kg) was administered intragastrically once a day for 3 d 4 h after diclofenac administration. Intestinal permeability was evaluated by Evans blue and the FITC-dextran method. The ultrastructure of the mucosal barrier was evaluated by transmission electron microscopy (TEM). Mitochondrial function including mitochondrial swelling, mitochondrial membrane potential, mitochondrial nicotinamide adenine dinucleotide-reduced (NADH) levels, succinate dehydrogenase (SDH) and ATPase activities were measured. Small intestinal mucosa was collected for assessment of malondialdehyde (MDA) content and myeloperoxidase (MPO) activity. Compared with the control group, intestinal permeability was significantly increased in the diclofenac group, which was accompanied by broken tight junctions, and significant increases in MDA content and MPO activity. Rebamipide significantly reduced intestinal permeability, improved inter-cellular tight junctions, and was associated with decreases in intestinal MDA content and MPO activity. At the mitochondrial level, rebamipide increased SDH and ATPase activities, NADH level and decreased mitochondrial swelling. Increased intestinal permeability induced by diclofenac can be attenuated by rebamipide, which partially contributed to the protection of mitochondrial function.

  12. The pH-sensing receptor OGR1 improves barrier function of epithelial cells and inhibits migration in an acidic environment.

    Science.gov (United States)

    de Vallière, Cheryl; Vidal, Solange; Clay, Ieuan; Jurisic, Giorgia; Tcymbarevich, Irina; Lang, Silvia; Ludwig, Marie-Gabrielle; Okoniewski, Michal; Eloranta, Jyrki J; Kullak-Ublick, Gerd A; Wagner, Carsten A; Rogler, Gerhard; Seuwen, Klaus

    2015-09-15

    The pH-sensing receptor ovarian cancer G protein-coupled receptor 1 (OGR1; GPR68) is expressed in the gut. Inflammatory bowel disease is typically associated with a decrease in local pH, which may lead to altered epithelial barrier function and subsequent gastrointestinal repair involving epithelial cell adhesion and migration. As the mechanisms underlying the response to pH changes are not well understood, we have investigated OGR1-mediated, pH-dependent signaling pathways in intestinal epithelial cells. Caco-2 cells stably overexpressing OGR1 were created and validated as tools to study OGR1 signaling. Barrier function, migration, and proliferation were measured using electric cell-substrate impedance-sensing technology. Localization of the tight junction proteins zonula occludens protein 1 and occludin and the rearrangement of cytoskeletal actin were examined by confocal microscopy. Paracellular permeability and protein and gene expression analysis using DNA microarrays were performed on filter-grown Caco-2 monolayers. We report that an acidic pH shift from pH 7.8 to 6.6 improved barrier function and stimulated reorganization of filamentous actin with prominent basal stress fiber formation. Cell migration and proliferation during in vitro wound healing were inhibited. Gene expression analysis revealed significant upregulation of genes related to cytoskeleton remodeling, cell adhesion, and growth factor signaling. We conclude that acidic extracellular pH can have a signaling function and impact the physiology of intestinal epithelial cells. The deconstruction of OGR1-dependent signaling may aid our understanding of mucosal inflammation mechanisms. Copyright © 2015 the American Physiological Society.

  13. Exogenous HIV-1 Nef upsets the IFN-γ-induced impairment of human intestinal epithelial integrity.

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    Maria Giovanna Quaranta

    Full Text Available The mucosal tissues play a central role in the transmission of HIV-1 infection as well as in the pathogenesis of AIDS. Despite several clinical studies reported intestinal dysfunction during HIV infection, the mechanisms underlying HIV-induced impairments of mucosal epithelial barrier are still unclear. It has been postulated that HIV-1 alters enterocytic function and HIV-1 proteins have been detected in several cell types of the intestinal mucosa. In the present study, we analyzed the effect of the accessory HIV-1 Nef protein on human epithelial cell line.We used unstimulated or IFN-γ-stimulated Caco-2 cells, as a model for homeostatic and inflamed gastrointestinal tracts, respectively. We investigated the effect of exogenous recombinant Nef on monolayer integrity analyzing its uptake, transepithelial electrical resistance, permeability to FITC-dextran and the expression of tight junction proteins. Moreover, we measured the induction of proinflammatory mediators. Exogenous Nef was taken up by Caco-2 cells, increased intestinal epithelial permeability and upset the IFN-γ-induced reduction of transepithelial resistance, interfering with tight junction protein expression. Moreover, Nef inhibited IFN-γ-induced apoptosis and up-regulated TNF-α, IL-6 and MIP-3α production by Caco-2 cells while down-regulated IL-10 production. The simultaneous exposure of Caco-2 cells to Nef and IFN-γ did not affect cytokine secretion respect to untreated cells. Finally, we found that Nef counteracted the IFN-γ induced arachidonic acid cascade.Our findings suggest that exogenous Nef, perturbing the IFN-γ-induced impairment of intestinal epithelial cells, could prolong cell survival, thus allowing for accumulation of viral particles. Our results may improve the understanding of AIDS pathogenesis, supporting the discovery of new therapeutic interventions.

  14. Intestinal CYP2E1: A mediator of alcohol-induced gut leakiness

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    Christopher B. Forsyth

    2014-01-01

    Full Text Available Chronic alcohol use can result in many pathological effects including alcoholic liver disease (ALD. While alcohol is necessary for the development of ALD, only 20–30% of alcoholics develop alcoholic steatohepatitis (ASH with progressive liver disease leading to cirrhosis and liver failure (ALD. This suggests that while chronic alcohol consumption is necessary it is not sufficient to induce clinically relevant liver damage in the absence of a secondary risk factor. Studies in rodent models and alcoholic patients show that increased intestinal permeability to microbial products like endotoxin play a critical role in promoting liver inflammation in ALD pathogenesis. Therefore identifying mechanisms of alcohol-induced intestinal permeability is important in identifying mechanisms of ALD and for designing new avenues for therapy. Cyp2e1 is a cytochrome P450 enzyme that metabolizes alcohol has been shown to be upregulated by chronic alcohol use and to be a major source of oxidative stress and liver injury in alcoholics and in animal and in vitro models of chronic alcohol use. Because Cyp2e1 is also expressed in the intestine and is upregulated by chronic alcohol use, we hypothesized it could play a role in alcohol-induced intestinal hyperpermeability. Our in vitro studies with intestinal Caco-2 cells and in mice fed alcohol showed that circadian clock proteins CLOCK and PER2 are required for alcohol-induced permeability. We also showed that alcohol increases Cyp2e1 protein and activity but not mRNA in Caco-2 cells and that an inhibitor of oxidative stress or siRNA knockdown of Cyp2e1 prevents the increase in CLOCK or PER2 proteins and prevents alcohol-induced hyperpermeability. With our collaborators we have also shown that Cyp2e1 knockout mice are resistant to alcohol-induced gut leakiness and liver inflammation. Taken together our data support a novel Cyp2e1-circadian clock protein mechanism for alcohol-induced gut leakiness that could provide new

  15. Protective Role of R-spondin1, an Intestinal Stem Cell Growth Factor, against Radiation-Induced Gastrointestinal Syndrome in Mice

    OpenAIRE

    Bhanja, Payel; Saha, Subhrajit; Kabarriti, Rafi; Liu, Laibin; Roy-Chowdhury, Namita; Roy-Chowdhury, Jayanta; Sellers, Rani S.; Alfieri, Alan A.; Guha, Chandan

    2009-01-01

    Background Radiation-induced gastrointestinal syndrome (RIGS) results from a combination of direct cytocidal effects on intestinal crypt and endothelial cells and subsequent loss of the mucosal barrier, resulting in electrolyte imbalance, diarrhea, weight loss, infection and mortality. Because R-spondin1 (Rspo1) acts as a mitogenic factor for intestinal stem cells, we hypothesized that systemic administration of Rspo1 would amplify the intestinal crypt cells and accelerate the regeneration of...

  16. Nanoparticle-induced neuronal toxicity across placental barriers is mediated by autophagy and dependent on astrocytes

    Science.gov (United States)

    Hawkins, Simon J.; Crompton, Lucy A.; Sood, Aman; Saunders, Margaret; Boyle, Noreen T.; Buckley, Amy; Minogue, Aedín M.; McComish, Sarah F.; Jiménez-Moreno, Natalia; Cordero-Llana, Oscar; Stathakos, Petros; Gilmore, Catherine E.; Kelly, Stephen; Lane, Jon D.; Case, C. Patrick; Caldwell, Maeve A.

    2018-05-01

    The potential for maternal nanoparticle (NP) exposures to cause developmental toxicity in the fetus without the direct passage of NPs has previously been shown, but the mechanism remained elusive. We now demonstrate that exposure of cobalt and chromium NPs to BeWo cell barriers, an in vitro model of the human placenta, triggers impairment of the autophagic flux and release of interleukin-6. This contributes to the altered differentiation of human neural progenitor cells and DNA damage in the derived neurons and astrocytes. Crucially, neuronal DNA damage is mediated by astrocytes. Inhibiting the autophagic degradation in the BeWo barrier by overexpression of the dominant-negative human ATG4BC74A significantly reduces the levels of DNA damage in astrocytes. In vivo, indirect NP toxicity in mice results in neurodevelopmental abnormalities with reactive astrogliosis and increased DNA damage in the fetal hippocampus. Our results demonstrate the potential importance of autophagy to elicit NP toxicity and the risk of indirect developmental neurotoxicity after maternal NP exposure.

  17. A low-barrier hydrogen bond mediates antibiotic resistance in a noncanonical catalytic triad

    Science.gov (United States)

    2018-01-01

    One group of enzymes that confer resistance to aminoglycoside antibiotics through covalent modification belongs to the GCN5-related N-acetyltransferase (GNAT) superfamily. We show how a unique GNAT subfamily member uses a previously unidentified noncanonical catalytic triad, consisting of a glutamic acid, a histidine, and the antibiotic substrate itself, which acts as a nucleophile and attacks the acetyl donor molecule. Neutron diffraction studies allow for unambiguous identification of a low-barrier hydrogen bond, predicted in canonical catalytic triads to increase basicity of the histidine. This work highlights the role of this unique catalytic triad in mediating antibiotic resistance while providing new insights into the design of the next generation of aminoglycosides. PMID:29632894

  18. Activation of IGF-1/IGFBP-3 signaling by berberine improves intestinal mucosal barrier of rats with acute endotoxemia.

    Science.gov (United States)

    He, Yan; Yuan, Xiaoming; Zhou, Guangrong; Feng, Aiwen

    2018-01-01

    Insulin-like growth factor I (IGF-I) and binding protein 3 (IGFBP-3) play a role in the maintenance of gut mucosal barrier function. Nevertheless, IGF-I/IGFBP-3 and tight junction protein (TJP) expression in small intestinal mucosa are often impaired during endotoxemia. In this model of acute endotoxemia, the regulatory effect of berberine on IGF-I/IGFBP-3 and TJP expression in ileal mucosa was evaluated. The findings revealed systemic injection of lipopolysaccharide (LPS) suppressed mRNA and protein expression of IGF-I and IGFBP-3, but berberine ameliorated their production. LPS injection inhibited occludin and claudin-1 protein generation, and this inhibitory effect of LPS was abolished by berberine. Inhibition of IGF-I/IGFBP-3 signaling by AG1024 or siRNAs reduced berberine-induced occludin and claudin-1 production. Additionally, GW9662 was found to repress berberine-induced IGF-I/IGFBP-3 expression, indicating of a cross-link between PPARγ and IGF-I/IGFBP-3 axis. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Circadian disorganization alters intestinal microbiota.

    Directory of Open Access Journals (Sweden)

    Robin M Voigt

    Full Text Available Intestinal dysbiosis and circadian rhythm disruption are associated with similar diseases including obesity, metabolic syndrome, and inflammatory bowel disease. Despite the overlap, the potential relationship between circadian disorganization and dysbiosis is unknown; thus, in the present study, a model of chronic circadian disruption was used to determine the impact on the intestinal microbiome. Male C57BL/6J mice underwent once weekly phase reversals of the light:dark cycle (i.e., circadian rhythm disrupted mice to determine the impact of circadian rhythm disruption on the intestinal microbiome and were fed either standard chow or a high-fat, high-sugar diet to determine how diet influences circadian disruption-induced effects on the microbiome. Weekly phase reversals of the light:dark (LD cycle did not alter the microbiome in mice fed standard chow; however, mice fed a high-fat, high-sugar diet in conjunction with phase shifts in the light:dark cycle had significantly altered microbiota. While it is yet to be established if some of the adverse effects associated with circadian disorganization in humans (e.g., shift workers, travelers moving across time zones, and in individuals with social jet lag are mediated by dysbiosis, the current study demonstrates that circadian disorganization can impact the intestinal microbiota which may have implications for inflammatory diseases.

  20. Toward improving mucosal barrier defenses: rhG-CSF plus IgG antibody.

    Science.gov (United States)

    Simmonds, Aryeh; LaGamma, Edmund F

    2006-11-01

    Epithelial cell functions ultimately define the ability of the extremely low birth weight human fetus to survive outside of the uterus. These specialized epithelial cell capacities manage all human interactions with the ex utero world including: (i) lung mechanics, surface chemistry and gas exchange, (ii) renal tubular balance of fluid and electrolytes, (iii) barrier functions of the intestine and skin for keeping bacteria out and water in, plus enabling intestinal digestion, as well as (iv) maintaining an intact neuroepithelium lining of the ventricles of the brain and retina. In Part I of this two part review, the authors describe why the gut barrier is a clinically relevant model system for studying the complex interplay between innate and adaptive immunity, dendritic &epithelial cell interactions, intraepithelial lymphocytes, M-cells, as well as the gut associated lymphoid tissues where colonization after birth, clinician feeding practices, use of antibiotics as well as exposure to prebiotics, probiotics and maternal vaginal flora all program the neonate for a life-time of immune competence distinguishing "self" from foreign antigens. These barrier defense capacities become destructive during disease processes like necrotizing enterocolitis (NEC) when an otherwise maturationally normal, yet dysregulated and immature, immune defense system is associated with high levels of certain inflammatory mediators like TNFa. In Part II the authors discuss the rationale for why rhG-CSF has theoretical advantages in managing NEC or sepsis by augmenting neonatal neutrophil number, neutrophil expression of Fcg and complement receptors, as well as phagocytic function and oxidative burst. rhG-CSF also has potent anti-TNFa functions that may serve to limit extension of tissue destruction while not impairing bacterial killing capacity. Healthy, non-infected neutropenic and septic neonates differ in their ability to respond to rhG-CSF; however, no neonatal clinical trials to date

  1. Immunology and probiotic impact of the newborn and young children intestinal microflora.

    Science.gov (United States)

    Bezirtzoglou, Eugenia; Stavropoulou, Elisabeth

    2011-12-01

    Human body has developed a holistic defence system, which mission is either to recognize and destroy the aggressive invaders or to evolve mechanisms permitting to minimize or restore the consequences of harmful actions. The host immune system keeps the capital role to preserve the microbial intestinal balance via the barrier effect. Specifically, pathogenic invaders such as, bacteria, parasites, viruses and other xenobiotic invaders are rejected out of the body via barriers formed by the skin, mucosa and intestinal flora. In case physical barriers are breached, the immune system with its many components comes into action in order to fence infection. The intestine itself is considered as an "active organ" due to its abundant bacterial flora and to its large metabolic activity. The variation among different species or even among different strains within a species reflects the complexity of the genetic polymorphism which regulates the immune system functions. Additionally factors such as, gender, particular habits, smoking, alcohol consumption, diet, religion, age, gender, precedent infections and vaccinations must be involved. Hormonal profile and stress seems to be associated to the integrity microbiota and inducing immune system alterations. Which bacterial species are needed for inducing a proper barrier effect is not known, but it is generally accepted that this barrier function can be strongly supported by providing benefic alimentary supplements called functional foods. In this vein it is stressed the fact that early intestinal colonization with organisms such as Lactobacilli and Bifidobacteria and possibly subsequent protection from many different types of diseases. Moreover, this benefic microflora dominated but Bifidobacteria and Lactobacilli support the concept of their ability to modify the gut microbiota by reducing the risk of cancer following their capacity to decrease β-glucoronidase and carcinogen levels. Because of their beneficial roles in the

  2. Proteinaceous molecules mediating Bifidobacterium-host interactions

    Directory of Open Access Journals (Sweden)

    Lorena Ruiz

    2016-08-01

    Full Text Available Bifidobacteria are commensal microoganisms found in the gastrointestinal tract.Several strains have been attributed beneficial traits at local and systemic levels, through pathogen exclusion or immune modulation, among other benefits. This has promoted a growing industrial and scientific interest in bifidobacteria as probiotic supplements. However, the molecular mechanisms mediating this cross-talk with the human host remain unknown. High-throughput technologies, from functional genomics to transcriptomics, proteomics and interactomics coupled to the development of both in vitro and in vivo models to study the dynamics of the intestinal microbiota and their effects on host cells, have eased the identification of key molecules in these interactions. Numerous secreted or surface-associated proteins or peptides have been identified as potential mediators of bifidobacteria-host interactions and molecular cross-talk, directly participating in sensing environmental factors, promoting intestinal colonization or mediating a dialogue with mucosa-associated immune cells. On the other hand, bifidobacteria induce the production of proteins in the intestine, by epithelial or immune cells, and other gut bacteria, which are key elements in orchestrating interactions among bifidobacteria, gut microbiota and host cells. This review aims to give a comprehensive overview on proteinaceous molecules described and characterized to date, as mediators of the dynamic interplay between bifidobacteria and the human host, providing a framework to identify knowledge gaps and future research needs.

  3. The Immune System Bridges the Gut Microbiota with Systemic Energy Homeostasis: Focus on TLRs, Mucosal Barrier, and SCFAs.

    Science.gov (United States)

    Spiljar, Martina; Merkler, Doron; Trajkovski, Mirko

    2017-01-01

    The gut microbiota is essential for the development and regulation of the immune system and the metabolism of the host. Germ-free animals have altered immunity with increased susceptibility to immunologic diseases and show metabolic alterations. Here, we focus on two of the major immune-mediated microbiota-influenced components that signal far beyond their local environment. First, the activation or suppression of the toll-like receptors (TLRs) by microbial signals can dictate the tone of the immune response, and they are implicated in regulation of the energy homeostasis. Second, we discuss the intestinal mucosal surface is an immunologic component that protects the host from pathogenic invasion, is tightly regulated with regard to its permeability and can influence the systemic energy balance. The short chain fatty acids are a group of molecules that can both modulate the intestinal barrier and escape the gut to influence systemic health. As modulators of the immune response, the microbiota-derived signals influence functions of distant organs and can change susceptibility to metabolic diseases.

  4. Intestinal dendritic cells in the regulation of mucosal immunity

    DEFF Research Database (Denmark)

    Bekiaris, Vasileios; Persson, Emma K.; Agace, William Winston

    2014-01-01

    immune cells within the mucosa must suitably respond to maintain intestinal integrity, while also providing the ability to mount effective immune responses to potential pathogens. Dendritic cells (DCs) are sentinel immune cells that play a central role in the initiation and differentiation of adaptive....... The recognition that dietary nutrients and microbial communities in the intestine influence both mucosal and systemic immune cell development and function as well as immune-mediated disease has led to an explosion of literature in mucosal immunology in recent years and a growing interest in the functionality...

  5. The Intestinal Microbiota Contributes to the Ability of Helminths to Modulate Allergic Inflammation

    Science.gov (United States)

    Zaiss, Mario M.; Rapin, Alexis; Lebon, Luc; Dubey, Lalit Kumar; Mosconi, Ilaria; Sarter, Kerstin; Piersigilli, Alessandra; Menin, Laure; Walker, Alan W.; Rougemont, Jacques; Paerewijck, Oonagh; Geldhof, Peter; McCoy, Kathleen D.; Macpherson, Andrew J.; Croese, John; Giacomin, Paul R.; Loukas, Alex; Junt, Tobias; Marsland, Benjamin J.; Harris, Nicola L.

    2015-01-01

    Summary Intestinal helminths are potent regulators of their host’s immune system and can ameliorate inflammatory diseases such as allergic asthma. In the present study we have assessed whether this anti-inflammatory activity was purely intrinsic to helminths, or whether it also involved crosstalk with the local microbiota. We report that chronic infection with the murine helminth Heligmosomoides polygyrus bakeri (Hpb) altered the intestinal habitat, allowing increased short chain fatty acid (SCFA) production. Transfer of the Hpb-modified microbiota alone was sufficient to mediate protection against allergic asthma. The helminth-induced anti-inflammatory cytokine secretion and regulatory T cell suppressor activity that mediated the protection required the G protein-coupled receptor (GPR)-41. A similar alteration in the metabolic potential of intestinal bacterial communities was observed with diverse parasitic and host species, suggesting that this represents an evolutionary conserved mechanism of host-microbe-helminth interactions. PMID:26522986

  6. Interferon-Lambda: A Potent Regulator of Intestinal Viral Infections.

    Science.gov (United States)

    Lee, Sanghyun; Baldridge, Megan T

    2017-01-01

    Interferon-lambda (IFN-λ) is a recently described cytokine found to be of critical importance in innate immune regulation of intestinal viruses. Endogenous IFN-λ has potent antiviral effects and has been shown to control multiple intestinal viruses and may represent a factor that contributes to human variability in response to infection. Importantly, recombinant IFN-λ has therapeutic potential against enteric viral infections, many of which lack other effective treatments. In this mini-review, we describe recent advances regarding IFN-λ-mediated regulation of enteric viruses with important clinical relevance including rotavirus, reovirus, and norovirus. We also briefly discuss IFN-λ interactions with other cytokines important in the intestine, and how IFN-λ may play a role in regulation of intestinal viruses by the commensal microbiome. Finally, we indicate currently outstanding questions regarding IFN-λ control of enteric infections that remain to be explored to enhance our understanding of this important immune molecule.

  7. Epithelial structure and function in the hen lower intestine

    DEFF Research Database (Denmark)

    Laverty, G.; Elbrønd, Vibeke Sødring; Árnason, Sigvatur S.

    2006-01-01

    In birds, transport processes in the lower intestine mediate absorption of ions, water and a variety of organic substrates, including significant amounts of glucose, amino acids derived from protein associated with urate spheres, and short-chain fatty acids derived from fermentation processes...

  8. Effects of Lactobacillus plantarum on gut barrier function in experimental obstructive jaundice

    Science.gov (United States)

    Zhou, Yu-Kun; Qin, Huan-Long; Zhang, Ming; Shen, Tong-Yi; Chen, Hong-Qi; Ma, Yan-Lei; Chu, Zhao-Xin; Zhang, Peng; Liu, Zhi-Hua

    2012-01-01

    AIM: To investigate the mechanisms of Lactobacillus plantarum (L. plantarum) action on gut barrier in preoperative and postoperative experimental obstructive jaundice in rats. METHODS: Forty rats were randomly divided into groups of sham-operation, bile duct ligation (BDL), BDL + L. plantarum, BDL + internal biliary drainage (IBD), and BDL + IBD + L. plantarum. Ten days after L. plantarum administration, blood and ileal samples were collected from the rats for morphological examination, and intestinal barrier function, liver function, intestinal oxidative stress and protein kinase C (PKC) activity measurement. The distribution and expression of the PKC and tight junction (TJ) proteins, such as occludin, zonula occludens-1, claudin-1, claudin-4, junction adhesion molecule-A and F-actin, were examined by confocal laser scanning microscopy, immunohistochemistry, Western blotting, real-time fluorescent quantitative polymerase chain reaction assay. RESULTS: L. plantarum administration substantially restored gut barrier, decreased enterocyte apoptosis, improved intestinal oxidative stress, promoted the activity and expression of protein kinase (BDL vs BDL + L. plantarum, 0.295 ± 0.007 vs 0.349 ± 0.003, P plantarum, 0.407 ± 0.046 vs 0.465 ± 0.135, P plantarum, 0.266 ± 0.118 vs 0.326 ± 0.009, P plantarum was more prominent after internal biliary drainage ( BDL + IBD vs BDL + IBD + L. plantarum, 0.415 ± 0.105 vs 0.494 ± 0.145, P plantarum can decrease intestinal epithelial cell apoptosis, reduce oxidative stress, and prevent TJ disruption in biliary obstruction by activating the PKC pathway. PMID:22912548

  9. Maintenance of the adult Drosophila intestine: all roads lead to homeostasis.

    Science.gov (United States)

    Guo, Zheng; Lucchetta, Elena; Rafel, Neus; Ohlstein, Benjamin

    2016-10-01

    Maintenance of tissue homeostasis is critical in tissues with high turnover such as the intestinal epithelium. The intestinal epithelium is under constant cellular assault due to its digestive functions and its function as a barrier to chemical and bacterial insults. The resulting high rate of cellular turnover necessitates highly controlled mechanisms of regeneration to maintain the integrity of the tissue over the lifetime of the organism. Transient increase in stem cell proliferation is a commonly used and elaborate mechanism to ensure fast and efficient repair of the gut. However, tissue repair is not limited to regulating ISC proliferation, as emerging evidence demonstrates that the Drosophila intestine uses multiple strategies to ensure proper tissue homeostasis that may also extend to other tissues. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. The surface protein HvgA mediates group B streptococcus hypervirulence and meningeal tropism in neonates.

    Science.gov (United States)

    Tazi, Asmaa; Disson, Olivier; Bellais, Samuel; Bouaboud, Abdelouhab; Dmytruk, Nicolas; Dramsi, Shaynoor; Mistou, Michel-Yves; Khun, Huot; Mechler, Charlotte; Tardieux, Isabelle; Trieu-Cuot, Patrick; Lecuit, Marc; Poyart, Claire

    2010-10-25

    Streptococcus agalactiae (group B streptococcus; GBS) is a normal constituent of the intestinal microflora and the major cause of human neonatal meningitis. A single clone, GBS ST-17, is strongly associated with a deadly form of the infection called late-onset disease (LOD), which is characterized by meningitis in infants after the first week of life. The pathophysiology of LOD remains poorly understood, but our epidemiological and histopathological results point to an oral route of infection. Here, we identify a novel ST-17-specific surface-anchored protein that we call hypervirulent GBS adhesin (HvgA), and demonstrate that its expression is required for GBS hypervirulence. GBS strains that express HvgA adhered more efficiently to intestinal epithelial cells, choroid plexus epithelial cells, and microvascular endothelial cells that constitute the blood-brain barrier (BBB), than did strains that do not express HvgA. Heterologous expression of HvgA in nonadhesive bacteria conferred the ability to adhere to intestinal barrier and BBB-constituting cells. In orally inoculated mice, HvgA was required for intestinal colonization and translocation across the intestinal barrier and the BBB, leading to meningitis. In conclusion, HvgA is a critical virulence trait of GBS in the neonatal context and stands as a promising target for the development of novel diagnostic and antibacterial strategies.

  11. Activation of intestinal epithelial Stat3 orchestrates tissue defense during gastrointestinal infection.

    Directory of Open Access Journals (Sweden)

    Nadine Wittkopf

    Full Text Available Gastrointestinal infections with EHEC and EPEC are responsible for outbreaks of diarrheal diseases and represent a global health problem. Innate first-line-defense mechanisms such as production of mucus and antimicrobial peptides by intestinal epithelial cells are of utmost importance for host control of gastrointestinal infections. For the first time, we directly demonstrate a critical role for Stat3 activation in intestinal epithelial cells upon infection of mice with Citrobacter rodentium - a murine pathogen that mimics human infections with attaching and effacing Escherichia coli. C. rodentium induced transcription of IL-6 and IL-22 in gut samples of mice and was associated with activation of the transcription factor Stat3 in intestinal epithelial cells. C. rodentium infection induced expression of several antimicrobial peptides such as RegIIIγ and Pla2g2a in the intestine which was critically dependent on Stat3 activation. Consequently, mice with specific deletion of Stat3 in intestinal epithelial cells showed increased susceptibility to C. rodentium infection as indicated by high bacterial load, severe gut inflammation, pronounced intestinal epithelial cell death and dissemination of bacteria to distant organs. Together, our data implicate an essential role for Stat3 activation in intestinal epithelial cells during C. rodentium infection. Stat3 concerts the host response to bacterial infection by controlling bacterial growth and suppression of apoptosis to maintain intestinal epithelial barrier function.

  12. Intestinal glutathione: determinant of mucosal peroxide transport, metabolism, and oxidative susceptibility

    International Nuclear Information System (INIS)

    Aw, Tak Yee

    2005-01-01

    The intestine is a primary site of nutrient absorption and a critical defense barrier against dietary-derived mutagens, carcinogens, and oxidants. Accumulation of oxidants like peroxidized lipids in the gut lumen can contribute to impairment of mucosal metabolic pathways, enterocyte dysfunction independent of cell injury, and development of gut pathologies, such as inflammation and cancer. Despite this recognition, we know little of the pathways of intestinal transport, metabolism, and luminal disposition of dietary peroxides in vivo or of the underlying mechanisms of lipid peroxide-induced genesis of intestinal disease processes. This chapter summarizes our current understanding of the determinants of intestinal absorption and metabolism of peroxidized lipids. I will review experimental evidence from our laboratory and others (Table 1) supporting the pivotal role that glutathione (GSH) and reduced nicotinamide adenine dinucleotide phosphate (NADPH) play in mucosal transport and metabolism of lipid hydroperoxides and how reductant availability can be compromised under chronic stress such as hypoxia, and the influence of GSH on oxidative susceptibility, and redox contribution to genesis of gut disorders. The discussion is pertinent to understanding dietary lipid peroxides and GSH redox balance in intestinal physiology and pathophysiology and the significance of luminal GSH in preserving the integrity of the intestinal epithelium

  13. The small intestine and irritable bowel syndrome (IBS): a batch process model.

    Science.gov (United States)

    Dobson, Brian C

    2008-11-01

    Faults in a batch process model of the small intestine create the symptoms of all types of irritable bowel syndrome. The model has three sequential processing sections corresponding to the natural divisions of the intestine. It is governed by a brain controller that is divided into four sub-controllers, each with a unique neurotransmitter. Each section has a sub-controller to manage transport. Sensors in the walls of the intestine provide input and output goes to the muscles lining the walls of the intestine. The output controls the speed of the food soup, moves it in both directions, mixes it, controls absorption, and transfers it to the next section at the correct speed (slow). The fourth sub-controller manages the addition of chemicals. It obtains input from the first section of the process via the signalling hormone Cholecystokinin and sends output to the muscles that empty the gall bladder and pancreas. The correct amounts of bile salts and enzymes are then added to the first section. The sub-controllers produce output only when input is received. When output is missing the enteric nervous system applies a default condition. This default condition normally happens when no food is in the intestine. If food is in the intestine and a transport sub-controller fails to provide output then the default condition moves the food soup to the end of that section. The movement is in one direction only (forward), at a speed dependent on the amount and type of fibre present. Cereal, bean and vegetable fibre causes high speeds. This default high speed transport causes irritable bowel syndrome. A barrier is created when a section moving fast at the default speed, precedes a section controlled by a transport sub-controller. Then the sub-controller constricts the intestine to stop the fast flow. The barrier causes constipation, cramping, and bloating. Diarrhoea results when the section terminating the process moves at the fast default speed. Two problems can occur to prevent

  14. Knockout of MIMP protein in lactobacillus plantarum lost its regulation of intestinal permeability on NCM460 epithelial cells through the zonulin pathway.

    Science.gov (United States)

    Liu, Zhihua; Kang, Liang; Li, Chao; Tong, Chao; Huang, Meijin; Zhang, Xingwei; Huang, Nanqi; Moyer, Mary Pat; Qin, Huanlong; Wang, Jianping

    2014-10-03

    Previous studies indicated that the micro integral membrane protein located within the media place of the integral membrane protein of Lactobacillus plantarum CGMCC 1258 had protective effects against the intestinal epithelial injury. In our study, we mean to establish micro integral membrane protein -knockout Lactobacillus plantarum (LPKM) to investigate the change of its protective effects and verify the role of micro integral membrane protein on protection of normal intestinal barrier function. Binding assay and intestinal permeability were performed to verify the protective effects of micro integral membrane protein on intestinal permeability in vitro and in vivo. Molecular mechanism was also determined as the zonulin pathway. Clinical data were also collected for further verification of relationship between zonulin level and postoperative septicemia. LPKM got decreased inhibition of EPEC adhesion to NCM460 cells. LPKM had lower ability to alleviate the decrease of intestinal permeability induced by enteropathogenic-e.coli, and prevent enteropathogenic-e.coli -induced increase of zonulin expression. Overexpression of zonulin lowered the intestinal permeability regulated by Lactobacillus plantarum. There was a positive correlation between zonulin level and postoperative septicemia. Therefore, micro integral membrane protein could be necessary for the protective effects of Lactobacillus plantarum on intestinal barrier. MIMP might be a positive factor for Lactobacillus plantarum to protect the intestinal epithelial cells from injury, which could be related to the zonulin pathway.

  15. Modulation of Intestinal Epithelial Permeability in Differentiated Caco-2 Cells Exposed to Aflatoxin M1 and Ochratoxin A Individually or Collectively

    Directory of Open Access Journals (Sweden)

    Yanan Gao

    2017-12-01

    Full Text Available Aflatoxin M1 (AFM1 and ochratoxin A (OTA are mycotoxins commonly found in milk; however, their effects on intestinal epithelial cells have not been reported. In the present study, we show that AFM1 (0.12 and 12 μM and OTA (0.2 and 20 μM individually or collectively increased the paracellular flux of lucifer yellow and fluorescein isothiocyanate (FITC-dextrans (4 and 40 kDa and decreased transepithelial electrical resistance values in differentiated Caco-2 cells after 48 h of exposure, indicating increased epithelial permeability. Immunoblotting and immunofluorescent analysis revealed that AFM1, OTA, and their combination decreased the expression levels of tight junction (TJ proteins and disrupted their structures, namely, claudin-3, claudin-4, occludin, and zonula occludens-1 (ZO-1, and p44/42 mitogen-activated protein kinase (MAPK partially involved in the mycotoxins-induced disruption of intestinal barrier. The effects of a combination of AFM1 and OTA on intestinal barrier function were more significant (p < 0.05 than those of AFM1 and OTA alone, yielding additive or synergistic effects. The additive or synergistic effects of AFM1 and OTA on intestinal barrier function might affect human health, especially in children, and toxin risks should be considered.

  16. Sodium butyrate attenuates soybean oil-based lipid emulsion-induced increase in intestinal permeability of lipopolysaccharide by modulation of P-glycoprotein in Caco-2 cells

    International Nuclear Information System (INIS)

    Yan, Jun-Kai; Gong, Zi-Zhen; Zhang, Tian; Cai, Wei

    2017-01-01

    Down-regulation of intestinal P-glycoprotein (P-gp) by soybean oil-based lipid emulsion (SOLE) may cause elevated intestinal permeability of lipopolysaccharide (LPS) in patients with total parenteral nutrition, but the appropriate preventative treatment is currently limited. Recently, sodium butyrate (NaBut) has been demonstrated to regulate the expression of P-gp. Therefore, this study aimed to address whether treatment with NaBut could attenuate SOLE-induced increase in intestinal permeability of LPS by modulation of P-gp in vitro. Caco-2 cells were exposed to SOLE with or without NaBut. SOLE-induced down-regulation of P-gp was significantly attenuated by co-incubation with NaBut. Nuclear recruitment of FOXO 3a in response to NaBut was involved in P-gp regulation. Transport studies revealed that SOLE-induced increase in permeability of LPS was significantly attenuated by co-incubation with NaBut. Collectively, our results suggested that NaBut may be a potentially useful medication to prevent SOLE-induced increase in intestinal permeability of LPS. - Highlights: • Caco-2 cells were used as models for studying parenteral nutrition in vitro. • NaBut restored SOLE-induced down-regulation of P-gp in Caco-2 cells. • Regulation of P-gp by NaBut was mediated via nuclear recruitment of FOXO 3a. • NaBut modulated the permeability of LPS by P-gp function, not barrier function.

  17. Intestine immune homeostasis after alcohol and burn injury.

    Science.gov (United States)

    Li, Xiaoling; Hammer, Adam M; Rendon, Juan L; Choudhry, Mashkoor A

    2015-06-01

    Traumatic injury remains one of the most prevalent reasons for patients to be hospitalized. Burn injury accounts for 40,000 hospitalizations in the United States annually, resulting in a large burden on both the health and economic system and costing millions of dollars every year. The complications associated with postburn care can quickly cause life-threatening conditions including sepsis and multiple organ dysfunction and failure. In addition, alcohol intoxication at the time of burn injury has been shown to exacerbate these problems. One of the biggest reasons for the onset of these complications is the global suppression of the host immune system and increased susceptibility to infection. It has been hypothesized that infections after burn and other traumatic injury may stem from pathogenic bacteria from within the host's gastrointestinal tract. The intestine is the major reservoir of bacteria within the host, and many studies have demonstrated perturbations of the intestinal barrier after burn injury. This article reviews the findings of these studies as they pertain to changes in the intestinal immune system after alcohol and burn injury.

  18. Lethal pneumatosis coli in a 12-month-old child caused by acute intestinal gas gangrene after prolonged artificial nutrition: a case report

    Directory of Open Access Journals (Sweden)

    Kircher Stefan

    2008-07-01

    Full Text Available Abstract Introduction Pneumatosis coli is a rare disease with heterogeneous symptoms which can be detected in the course of various acute and chronic intestinal diseases in children, such as necrotizing enterocolitis, intestinal obstruction and intestinal bacteriological infections. Case presentation We report the case of a 12-month-old boy who died of pneumatosis coli caused by an acute intestinal gas gangrene after prolonged artificial alimentation. Conclusion While intestinal gas gangrene is a highly uncommon cause of pneumatosis coli, it is important to consider it as a differential diagnosis, especially in patients receiving a prolonged artificial food supply. These patients may develop intestinal gas gangrene due to a dysfunctional intestinal barrier.

  19. A resistant starch fiber diet ameliorates oxidative stress, inflammation, and progression of chronic kidney disease (CKD)

    Science.gov (United States)

    Inflammation is a constant feature and a major mediator of CKD progression. It is, in part, driven by altered gut microbiome and disruption of intestinal epithelial barrier, events which are primarily caused by: 1- urea influx in the intestine resulting in dominance of urease-possessing bacteria; 2-...

  20. Dietary Lactobacillus rhamnosus GG Supplementation Improves the Mucosal Barrier Function in the Intestine of Weaned Piglets Challenged by Porcine Rotavirus.

    Directory of Open Access Journals (Sweden)

    Xiangbing Mao

    Full Text Available Lactobacillus rhamnosus GG (LGG has been regarded as a safe probiotic strain. The aim of this study was to investigate whether dietary LGG supplementation could alleviate diarrhea via improving jejunal mucosal barrier function in the weaned piglets challenged by RV, and further analyze the potential roles for apoptosis of jejunal mucosal cells and intestinal microbiota. A total of 24 crossbred barrows weaned at 21 d of age were assigned randomly to 1 of 2 diets: the basal diet and LGG supplementing diet. On day 11, all pigs were orally infused RV or the sterile essential medium. RV infusion increased the diarrhea rate, increased the RV-Ab, NSP4 and IL-2 concentrations and the Bax mRNA levels of jejunal mucosa (P<0.05, decreased the villus height, villus height: crypt depth, the sIgA, IL-4 and mucin 1 concentrations and the ZO-1, occludin and Bcl-2 mRNA levels of jejunal mucosa (P<0.05, and affected the microbiota of ileum and cecum (P<0.05 in the weaned pigs. Dietary LGG supplementation increased the villus height and villus height: crypt depth, the sIgA, IL-4, mucin 1 and mucin 2 concentrations, and the ZO-1, occludin and Bcl-2 mRNA levels of the jejunal mucosa (P<0.05 reduced the Bax mRNA levels of the jejunal mucosa (P<0.05 in weaned pigs. Furthermore, dietary LGG supplementation alleviated the increase of diarrhea rate in the weaned pigs challenged by RV (P<0.05, and relieve the effect of RV infection on the villus height, crypt depth and the villus height: crypt depth of the jejunal mucosa (P<0.05, the NSP4, sIgA, IL-2, IL-4, mucin 1 and mucin 2 concentrations of jejunal mucosa (P<0.05, the ZO-1, occludin, Bax and Bcl-2 mRNA levels of the jejunal mucosa (P<0.05, and the microbiota of ileum and cecum (P<0.05 in the weaned pigs challenged by RV. These results suggest that supplementing LGG in diets alleviated the diarrhea of weaned piglets challenged by RV via inhibiting the virus multiplication and improving the jejunal mucosal barrier

  1. Structural, functional and molecular analysis of the effects of aging in the small intestine and colon of C57BL/6 J mice.

    NARCIS (Netherlands)

    Steegenga, W.T.; Wit, de N.J.W.; Boekschoten, M.V.; IJssenagger, N.; Lute, C.; Keshtkar, S.; Grootte Bromhaar, M.M.; Kampman, E.; Groot, de C.P.G.M.; Muller, M.R.

    2012-01-01

    Background By regulating digestion and absorption of nutrients and providing a barrier against the external environment the intestine provides a crucial contribution to the maintenance of health. To what extent aging-related changes in the intestinal system contribute to the functional decline

  2. Stress, Nutrition, and Intestinal Immune Responses in Pigs — A Review

    Directory of Open Access Journals (Sweden)

    In Kyu Lee

    2016-08-01

    Full Text Available Modern livestock production became highly intensive and large scaled to increase production efficiency. This production environment could add stressors affecting the health and growth of animals. Major stressors can include environment (air quality and temperature, nutrition, and infection. These stressors can reduce growth performance and alter immune systems at systemic and local levels including the gastrointestinal tract. Heat stress increases the permeability, oxidative stress, and inflammatory responses in the gut. Nutritional stress from fasting, antinutritional compounds, and toxins induces the leakage and destruction of the tight junction proteins in the gut. Fasting is shown to suppress pro-inflammatory cytokines, whereas deoxynivalenol increases the recruitment of intestinal pro-inflammatory cytokines and the level of lymphocytes in the gut. Pathogenic and viral infections such as Enterotoxigenic E. coli (ETEC and porcine epidemic diarrhea virus can lead to loosening the intestinal epithelial barrier. On the other hand, supplementation of Lactobacillus or Saccharaomyces reduced infectious stress by ETEC. It was noted that major stressors altered the permeability of intestinal barriers and profiles of genes and proteins of pro-inflammatory cytokines and chemokines in mucosal system in pigs. However, it is not sufficient to fully explain the mechanism of the gut immune system in pigs under stress conditions. Correlation and interaction of gut and systemic immune system under major stressors should be better defined to overcome aforementioned obstacles.

  3. Trans-intestinal cholesterol efflux is not mediated through high density lipoprotein

    NARCIS (Netherlands)

    Vrins, Carlos L. J.; Ottenhoff, Roelof; van den Oever, Karin; de Waart, Dirk R.; Kruyt, J. Kar; Zhao, Ying; van Berkel, Theo J. C.; Havekes, Louis M.; Aerts, Johannes M.; van Eck, Miranda; Rensen, Patrick C. N.; Groen, Albert K.

    2012-01-01

    Transintestinal cholesterol efflux (TICE) provides an attractive target to increase body cholesterol excretion. At present, the cholesterol donor responsible for direct delivery of plasma cholesterol to the intestine is unknown. In this study, we investigated the role of HDL in TICE. ATP-binding

  4. [Adult intestinal malrotation associated with intestinal volvulus].

    Science.gov (United States)

    Hernando-Almudí, Ernesto; Cerdán-Pascual, Rafael; Vallejo-Bernad, Cristina; Martín-Cuartero, Joaquín; Sánchez-Rubio, María; Casamayor-Franco, Carmen

    Intestinal malrotation is a congenital anomaly of the intestinal rotation and fixation, and usually occurs in the neonatal age. Description of a clinical case associated with acute occlusive symptoms. A case of intestinal malrotation is presented in a previously asymptomatic woman of 46 years old with an intestinal obstruction, with radiology and surgical findings showing an absence of intestinal rotation. Intestinal malrotation in adults is often asymptomatic, and is diagnosed as a casual finding during a radiological examination performed for other reasons. Infrequently, it can be diagnosed in adults, associated with an acute abdomen. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

  5. A lactobacillus rhamnosus GG-derived soluble protein, p40, stimulates ligand release from intestinal epithelial cells to transactivate epidermal growth factor receptor

    Science.gov (United States)

    Protein p40, a Lactobacillus rhamnosus GG (LGG)-derived soluble protein, ameliorates intestinal injury and colitis, reduces apoptosis and preserves barrier function by activation of EGF receptor (EGFR) in intestinal epithelial cells. The aim of this study was to determine the mechanisms by which p40...

  6. Importins α and β signaling mediates endothelial cell inflammation and barrier disruption.

    Science.gov (United States)

    Leonard, Antony; Rahman, Arshad; Fazal, Fabeha

    2018-04-01

    Nucleocytoplasmic shuttling via importins is central to the function of eukaryotic cells and an integral part of the processes that lead to many human diseases. In this study, we addressed the role of α and β importins in the mechanism of endothelial cell (EC) inflammation and permeability, important pathogenic features of many inflammatory diseases such as acute lung injury and atherosclerosis. RNAi-mediated knockdown of importin α4 or α3 each inhibited NF-κB activation, proinflammatory gene (ICAM-1, VCAM-1, and IL-6) expression, and thereby endothelial adhesivity towards HL-60 cells, upon thrombin challenge. The inhibitory effect of α4 and α3 knockdown was associated with impaired nuclear import and consequently, DNA binding of RelA/p65 subunit of NF-κB and occurred independently of IκBα degradation. Intriguingly, knockdown of importins α4 and α3 also inhibited thrombin-induced RelA/p65 phosphorylation at Ser 536 , showing a novel role of α importins in regulating transcriptional activity of RelA/p65. Similarly, knockdown of importin β1, but not β2, blocked thrombin-induced activation of RelA/p65 and its target genes. In parallel studies, TNFα-mediated inflammatory responses in EC were refractory to knockdown of importins α4, α3 or β1, indicating a stimulus-specific regulation of RelA/p65 and EC inflammation by these importins. Importantly, α4, α3, or β1 knockdown also protected against thrombin-induced EC barrier disruption by inhibiting the loss of VE-cadherin at adherens junctions and by regulating actin cytoskeletal rearrangement. These results identify α4, α3 and β1 as critical mediators of EC inflammation and permeability associated with intravascular coagulation. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. Vitamin D signaling in intestinal innate immunity and homeostasis.

    Science.gov (United States)

    Dimitrov, Vassil; White, John H

    2017-09-15

    The lumen of the gut hosts a plethora of microorganisms that participate in food assimilation, inactivation of harmful particles and in vitamin synthesis. On the other hand, enteric flora, a number of food antigens, and toxins are capable of triggering immune responses causing inflammation, which, when unresolved, may lead to chronic conditions such as inflammatory bowel disease (IBD). It is important, therefore, to contain the gut bacteria within the lumen, control microbial load and composition, as well as ensure adequate innate and adaptive immune responses to pathogenic threats. There is growing evidence that vitamin D signaling has impacts on all these aspects of intestinal physiology, contributing to healthy enteric homeostasis. VD was first discovered as the curative agent for nutritional rickets, and its classical actions are associated with calcium absorption and bone health. However, vitamin D exhibits a number of extra-skeletal effects, particularly in innate immunity. Notably, it stimulates production of pattern recognition receptors, anti-microbial peptides, and cytokines, which are at the forefront of innate immune responses. They play a role in sensing the microbiota, in preventing excessive bacterial overgrowth, and complement the actions of vitamin D signaling in enhancing intestinal barrier function. Vitamin D also favours tolerogenic rather than inflammogenic T cell differentiation and function. Compromised innate immune function and overactive adaptive immunity, as well as defective intestinal barrier function, have been associated with IBD. Importantly, observational and intervention studies support a beneficial role of vitamin D supplementation in patients with Crohn's disease, a form of IBD. This review summarizes the effects of vitamin D signaling on barrier integrity and innate and adaptive immunity in the gut, as well as on microbial load and composition. Collectively, studies to date reveal that vitamin D signaling has widespread effects

  8. Arginase 1: an unexpected mediator of pulmonary capillary barrier dysfunction in models of acute lung injury

    Directory of Open Access Journals (Sweden)

    Rudolf eLucas

    2013-08-01

    Full Text Available The integrity of epithelial and endothelial barriers in the lower airspaces of the lungs has to be tightly regulated, in order to prevent leakage and to assure efficient gas exchange between the alveoli and capillaries. Both G- and G+ bacterial toxins, such as LPS and pneumolysin, respectively, can be released in high concentrations within the pulmonary compartments upon antibiotic treatment of patients suffering from acute respiratory distress syndrome (ARDS or severe pneumonia. These toxins are able to impair endothelial barrier function, either directly, or indirectly, by induction of pro-inflammatory mediators and neutrophil sequestration. Toxin-induced endothelial hyperpermeability can involve myosin light chain phosphorylation and/or microtubule rearrangement. Endothelial nitric oxide synthase (eNOS was proposed to be a guardian of basal barrier function, since eNOS knock-out mice display an impaired expression of inter-endothelial junction proteins and as such an increased vascular permeability, as compared to wild type mice. The enzyme arginase, the activity of which can be regulated by the redox status of the cell, exists in two isoforms - arginase 1 (cytosolic and arginase 2 (mitochondrial - both of which can be expressed in lung microvascular endothelial cells. Upon activation, arginase competes with eNOS for the substrate L-arginine, as such impairing eNOS-dependent NO generation and promoting ROS generation by the enzyme. This mini-review will discuss recent findings regarding the interaction between bacterial toxins and arginase during acute lung injury and will as such address the role of arginase in bacterial toxin-induced pulmonary endothelial barrier dysfunction.

  9. Receptor-mediated transcytosis of cyclophilin B through the blood-brain barrier.

    Science.gov (United States)

    Carpentier, M; Descamps, L; Allain, F; Denys, A; Durieux, S; Fenart, L; Kieda, C; Cecchelli, R; Spik, G

    1999-07-01

    Cyclophilin B (CyPB) is a cyclosporin A (CsA)-binding protein mainly located in intracellular vesicles and secreted in biological fluids. In previous works, we demonstrated that CyPB interacts with T lymphocytes and enhances in vitro cellular incorporation and activity of CsA. In addition to its immunosuppressive activity, CsA is able to promote regeneration of damaged peripheral nerves. However, the crossing of the drug from plasma to neural tissue is restricted by the relative impermeability of the blood-brain barrier. To know whether CyPB might also participate in the delivery of CsA into the brain, we have analyzed the interactions of CyPB with brain capillary endothelial cells. First, we demonstrated that CyPB binds to two types of binding sites present at the surface of capillary endothelial cells from various species of tissues. The first type of binding sites (K(D) = 300 nM; number of sites = 3 x 10(6)) is related to interactions with negatively charged compounds such as proteoglycans. The second type of binding sites, approximately 50,000 per cell, exhibits a higher affinity for CyPB (K(D) = 15 nM) and is involved in an endocytosis process, indicating it might correspond to a functional receptor. Finally, the use of an in vitro model of blood-brain barrier allowed us to demonstrate that CyPB is transcytosed by a receptor-mediated pathway (flux = 16.5 fmol/cm2/h). In these conditions, CyPB did not significantly modify the passage of CsA, indicating that it is unlikely to provide a pathway for CsA brain delivery.

  10. Farnesoid X Receptor Activation Attenuates Intestinal Ischemia Reperfusion Injury in Rats.

    Directory of Open Access Journals (Sweden)

    Laurens J Ceulemans

    Full Text Available The farnesoid X receptor (FXR is abundantly expressed in the ileum, where it exerts an enteroprotective role as a key regulator of intestinal innate immunity and homeostasis, as shown in pre-clinical models of inflammatory bowel disease. Since intestinal ischemia reperfusion injury (IRI is characterized by hyperpermeability, bacterial translocation and inflammation, we aimed to investigate, for the first time, if the FXR-agonist obeticholic acid (OCA could attenuate intestinal ischemia reperfusion injury.In a validated rat model of intestinal IRI (laparotomy + temporary mesenteric artery clamping, 3 conditions were tested (n = 16/group: laparotomy only (sham group; ischemia 60min+ reperfusion 60min + vehicle pretreatment (IR group; ischemia 60min + reperfusion 60min + OCA pretreatment (IR+OCA group. Vehicle or OCA (INT-747, 2*30mg/kg was administered by gavage 24h and 4h prior to IRI. The following end-points were analyzed: 7-day survival; biomarkers of enterocyte viability (L-lactate, I-FABP; histology (morphologic injury to villi/crypts and villus length; intestinal permeability (Ussing chamber; endotoxin translocation (Lipopolysaccharide assay; cytokines (IL-6, IL-1-β, TNFα, IFN-γ IL-10, IL-13; apoptosis (cleaved caspase-3; and autophagy (LC3, p62.It was found that intestinal IRI was associated with high mortality (90%; loss of intestinal integrity (structurally and functionally; increased endotoxin translocation and pro-inflammatory cytokine production; and inhibition of autophagy. Conversely, OCA-pretreatment improved 7-day survival up to 50% which was associated with prevention of epithelial injury, preserved intestinal architecture and permeability. Additionally, FXR-agonism led to decreased pro-inflammatory cytokine release and alleviated autophagy inhibition.Pretreatment with OCA, an FXR-agonist, improves survival in a rodent model of intestinal IRI, preserves the gut barrier function and suppresses inflammation. These results turn

  11. Cell-Penetrating Peptides as Carriers for Oral Delivery of Biopharmaceuticals

    DEFF Research Database (Denmark)

    Kristensen, Mie; Nielsen, Hanne Mørck

    2016-01-01

    Oral delivery of biopharmaceuticals, for example peptides and proteins, constitutes a great challenge in drug delivery due to their low chemical stability and poor permeation across the intestinal mucosa, to a large extent limiting the mode of administration to injections, which is not favouring...... patient compliance. Nevertheless, cell-penetrating peptides (CPPs) have shown promising potential as carriers to overcome the epithelium, and this minireview highlights recent knowledge gained within the field of CPP-mediated transepithelial delivery of therapeutic peptides and proteins from the intestine...... is to be preferred depends on the physicochemical properties of both the specific CPP and the specific cargo. In addition to the physical epithelial barrier, a metabolic barrier must be overcome in order to obtain CPP-mediated delivery of a cargo drug from the intestine, and a number of strategies have been employed...

  12. Toxic effects of maternal zearalenone exposure on intestinal oxidative stress, barrier function, immunological and morphological changes in rats.

    Directory of Open Access Journals (Sweden)

    Min Liu

    Full Text Available The present study was conducted to investigate the effects of maternal zearalenone (ZEN exposure on the intestine of pregnant Sprague-Dawley (SD rats and its offspring. Ninety-six pregnant SD rats were randomly divided into four groups and were fed with diets containing ZEN at concentrations of 0.3 mg/kg, 48.5 mg/kg, 97.6 mg/kg or 146.0 mg/kg from gestation days (GD 1 to 7. All rats were fed with mycotoxin-free diet until their offspring were weaned at three weeks of age. The small intestinal fragments from pregnant rats at GD8, weaned dams and pups were collected and studied for toxic effects of ZEN on antioxidant status, immune response, expression of junction proteins, and morphology. The results showed that ZEN induced oxidative stress, affected the villous structure and reduced the expression of junction proteins claudin-4, occludin and connexin43 (Cx43 in a dose-dependent manner in pregnant rats. Different effects on the expression of cytokines were also observed both in mRNA and protein levels in these pregnant groups. Ingestion of high levels of ZEN caused irreversible damage in weaned dams, such as oxidative stress, decreased villi hight and low expression of junction proteins and cytokines. Decreased expression of jejunal interleukin-8 (IL-8 and increased expression of gastrointestinal glutathione peroxidase (GPx2 mRNA were detected in weaned offspring, indicating long-term damage caused by maternal ZEN. We also found that the Nrf2 expression both in mRNA and protein levels were up-regulated in the ZEN-treated groups of pregnant dams and the high-dose of ZEN group of weaned dams. The data indicate that modulation of Nrf2-mediated pathway is one of mechanism via which ZEN affects gut wall antioxidant and inflammatory responses.

  13. Radioprotection of intestinal crypt cells by cox-inhibitors

    International Nuclear Information System (INIS)

    Bisnar, Paul O.; Dones, Rosa Angela S.A.; Serna, Paulene-Ver A.; Deocaris, Chester C.; Guttierez, Kalangitan V.; Deocaris, Custer C.

    2006-01-01

    The regulation of tissue homeostasis in the gastrointestinal epithelium after epithelial injury focuses on the prostaglandins(PGs) as its major mediators. The two cyclooxygenase isoforms, cox-1 and cox-2, catalyze synthesis of PGs. Cox-1 is the predominant cyclooxygenase isoform found in the normal intestine. In contrast, cox-2 is present at low levels in normal intestine but is elevated at sites of inflammation, and in adenomas and carcinomas. To study the effects of various commercially-available cox-inhibitors (Ketorolac: cox-1 selective; Celecoxib: cox-2 selective; and Indocid: cox-1/2 non-selective), we determine mouse crypt epithelial cell fate after genotoxic injury with whole-body gamma-ray exposure at 15 Gy. Intestinal tissues of mice treated with cox-2 inhibitors that showed invariable apoptotic event, however, have increased occurrence of regenerating cells. Our results suggest a potential application of cox-2 selective inhibitors as radioprotective agent for normal cells after radiotherapy. (Author)

  14. Low-methoxyl lemon pectin attenuates inflammatory responses and improves intestinal barrier integrity in caerulein-induced experimental acute pancreatitis

    NARCIS (Netherlands)

    Sun, Yajun; He, Yue; Wang, Fei; Zhang, Hao; de Vos, Paul; Sun, Jia

    Scope: Acute pancreatitis (AP) is a common clinical acute abdominal disease. The intestinal injury associated with AP will aggravate the condition retroactively. This study investigates whether the low-methoxyl pectin (LMP) isolated from lemon could attenuate AP and associated intestinal injury.

  15. Influence of fentanyl and morphine on intestinal circulation

    International Nuclear Information System (INIS)

    Tverskoy, M.; Gelman, S.; Fowler, K.C.; Bradley, E.L.

    1985-01-01

    The influence of fentanyl and morphine on the intestinal circulation was evaluated in an isolated loop preparation in 37 dogs anesthetized with pentobarbital intravenously. Selected intestinal segments were pumped with aortic blood at a constant pressure of 100 mm Hg. A mixture of 86 Rb and 9-micron spheres labeled with 141 Ce was injected into the arterial cannula supplying the intestinal loop, while mesenteric venous blood was collected for activity counting. A strong correlation was found between the clearances of rubidium and microspheres (r = 0.97, P less than 0.0001), suggesting that the shunting of 9-micron spheres through the intestines reflects the shunting of blood through nonnutritive vessels. Intravenous fentanyl decreased oxygen uptake (O 2 up), and vascular resistance (VR), and increased blood flow (BF), rubidium and microsphere clearances (Cl-Rb, Cl-Sph, respectively), and permeability--surface area product (PS) in a dose-related fashion. Intravenous morphine in a dose of 1 mg X kg-1 increased Cl-Rb (nutritive BF) without changes in total (nutritive and nonnutritive) BF. This increase in nutritive BF is probably related to morphine-induced histamine release. Morphine in a dose of 5 mg X kg-1 was accompanied by vasoconstriction that was completely abolished by alpha-adrenoceptor blockade. The data suggest that morphine-induced intestinal vasoconstriction is mediated via a release of epinephrine, apparently from the adrenal medulla. It is concluded that changes in the intestinal circulation during anesthesia with narcotics might play a certain role in the cardiovascular homeostasis during anesthesia and surgery. An increase in oxygen content in portal venous blood, resulting from a decrease in intestinal oxygen uptake, should facilitate hepatic oxygenation

  16. Influence of fentanyl and morphine on intestinal circulation

    Energy Technology Data Exchange (ETDEWEB)

    Tverskoy, M.; Gelman, S.; Fowler, K.C.; Bradley, E.L.

    1985-06-01

    The influence of fentanyl and morphine on the intestinal circulation was evaluated in an isolated loop preparation in 37 dogs anesthetized with pentobarbital intravenously. Selected intestinal segments were pumped with aortic blood at a constant pressure of 100 mm Hg. A mixture of /sup 86/Rb and 9-micron spheres labeled with /sup 141/Ce was injected into the arterial cannula supplying the intestinal loop, while mesenteric venous blood was collected for activity counting. A strong correlation was found between the clearances of rubidium and microspheres (r = 0.97, P less than 0.0001), suggesting that the shunting of 9-micron spheres through the intestines reflects the shunting of blood through nonnutritive vessels. Intravenous fentanyl decreased oxygen uptake (O/sub 2/up), and vascular resistance (VR), and increased blood flow (BF), rubidium and microsphere clearances (Cl-Rb, Cl-Sph, respectively), and permeability--surface area product (PS) in a dose-related fashion. Intravenous morphine in a dose of 1 mg X kg-1 increased Cl-Rb (nutritive BF) without changes in total (nutritive and nonnutritive) BF. This increase in nutritive BF is probably related to morphine-induced histamine release. Morphine in a dose of 5 mg X kg-1 was accompanied by vasoconstriction that was completely abolished by alpha-adrenoceptor blockade. The data suggest that morphine-induced intestinal vasoconstriction is mediated via a release of epinephrine, apparently from the adrenal medulla. It is concluded that changes in the intestinal circulation during anesthesia with narcotics might play a certain role in the cardiovascular homeostasis during anesthesia and surgery. An increase in oxygen content in portal venous blood, resulting from a decrease in intestinal oxygen uptake, should facilitate hepatic oxygenation.

  17. Dll1- and Dll4-mediated Notch signaling is required for homeostasis of intestinal stem cells

    Science.gov (United States)

    Pellegrinet, Luca; Rodilla, Veronica; Liu, Zhenyi; Chen, Shuang; Koch, Ute; Espinosa, Lluis; Kaestner, Klaus H.; Kopan, Raphael; Lewis, Julian; Radtke, Freddy

    2011-01-01

    Background & Aims Ablation of Notch signaling within the intestinal epithelium results in loss of proliferating crypt progenitors, due to their conversion into post-mitotic secretory cells. We aimed to confirm that Notch was active in stem cells (SC), investigate consequences of loss of Notch signaling within the intestinal SC compartment, and identify the physiological ligands of Notch in mouse intestine. Furthermore, we investigated whether the induction of goblet cell differentiation that results from loss of Notch requires the transcription factor Krüppel-like factor 4 (Klf4). Methods Trasgenic mice that carried a reporter of Notch1 activation were used for lineage tracing experiments. The in vivo functions of the Notch ligands Jagged1 (Jag1), Delta-like1 (Dll1), Delta-like4 (Dll4), and the transcription factor Klf4 were assessed in mice with inducible, gut-specific gene targeting (Vil-Cre-ERT2). Results Notch1 signaling was found to be activated in intestinal SC. Although deletion of Jag1 or Dll4 did not perturb the intestinal epithelium, inactivation of Dll1 resulted in a moderate increase in number of goblet cells without noticeable effects of progenitor proliferation. However, simultaneous inactivation of Dll1 and Dll4 resulted in the complete conversion of proliferating progenitors into post-mitotic goblet cells, concomitant with loss of SC (Olfm4+, Lgr5+ and Ascl2+). Klf4 inactivation did not interfere with goblet cell differentiation in adult wild-type or in Notch pathway-deficient gut. Conclusions Notch signaling in SC and progenitors is activated by Dll1 and Dll4 ligands and is required for maintenance of intestinal progenitor and SC. Klf4 is dispensable for goblet cell differentiation in intestines of adult Notch-deficient mice. PMID:21238454

  18. Dll1- and dll4-mediated notch signaling are required for homeostasis of intestinal stem cells.

    Science.gov (United States)

    Pellegrinet, Luca; Rodilla, Veronica; Liu, Zhenyi; Chen, Shuang; Koch, Ute; Espinosa, Lluis; Kaestner, Klaus H; Kopan, Raphael; Lewis, Julian; Radtke, Freddy

    2011-04-01

    Ablation of Notch signaling within the intestinal epithelium results in loss of proliferating crypt progenitors due to their conversion into postmitotic secretory cells. We aimed to confirm that Notch was active in stem cells (SCs), investigate consequences of loss of Notch signaling within the intestinal SC compartment, and identify the physiologic ligands of Notch in mouse intestine. Furthermore, we investigated whether the induction of goblet cell differentiation that results from loss of Notch requires the transcription factor Krüppel-like factor 4 (Klf4). Transgenic mice that carried a reporter of Notch1 activation were used for lineage tracing experiments. The in vivo functions of the Notch ligands Jagged1 (Jag1), Delta-like1 (Dll1), Delta-like4 (Dll4), and the transcription factor Klf4 were assessed in mice with inducible, gut-specific gene targeting (Vil-Cre-ER(T2)). Notch1 signaling was found to be activated in intestinal SCs. Although deletion of Jag1 or Dll4 did not perturb the intestinal epithelium, inactivation of Dll1 resulted in a moderate increase in number of goblet cells without noticeable effects of progenitor proliferation. However, simultaneous inactivation of Dll1 and Dll4 resulted in the complete conversion of proliferating progenitors into postmitotic goblet cells, concomitant with loss of SCs (Olfm4(+), Lgr5(+), and Ascl2(+)). Klf4 inactivation did not interfere with goblet cell differentiation in adult wild-type or in Notch pathway-deficient gut. Notch signaling in SCs and progenitors is activated by Dll1 and Dll4 ligands and is required for maintenance of intestinal progenitor and SCs. Klf4 is dispensable for goblet cell differentiation in intestines of adult Notch-deficient mice. Copyright © 2011 AGA Institute. Published by Elsevier Inc. All rights reserved.

  19. Vitamin D and intestinal calcium transport after bariatric surgery.

    Science.gov (United States)

    Schafer, Anne L

    2017-10-01

    Bariatric surgery is a highly effective treatment for obesity, but it may have detrimental effects on the skeleton. Skeletal effects are multifactorial but mediated in part by nutrient malabsorption. While there is increasing interest in non-nutritional mechanisms such as changes in fat-derived and gut-derived hormones, nutritional factors are modifiable and thus represent potential opportunities to prevent and treat skeletal complications. This review begins with a discussion of normal intestinal calcium transport, including recent advances in our understanding of its regulation by vitamin D, and areas of continued uncertainty. Human and animal studies of vitamin D and intestinal calcium transport after bariatric surgery are then summarized. In humans, even with optimized 25-hydroxyvitamin D levels and recommended calcium intake, fractional calcium absorption decreased dramatically after Roux-en-Y gastric bypass (RYGB). In rats, intestinal calcium absorption was lower after RYGB than after sham surgery, despite elevated 1,25-dihyroxyvitamin D levels and intestinal gene expression evidence of vitamin D responsiveness. Such studies have the potential to shed new light on the physiology of vitamin D and intestinal calcium transport. Moreover, understanding the effects of bariatric surgery on these processes may improve the clinical care of bariatric surgery patients. Published by Elsevier Ltd.

  20. Lactic Acid Bacteria Protects Caenorhabditis elegans from Toxicity of Graphene Oxide by Maintaining Normal Intestinal Permeability under different Genetic Backgrounds

    Science.gov (United States)

    Zhao, Yunli; Yu, Xiaoming; Jia, Ruhan; Yang, Ruilong; Rui, Qi; Wang, Dayong

    2015-11-01

    Lactic acid bacteria (LAB) is safe and useful for food and feed fermentation. We employed Caenorhabditis elegans to investigate the possible beneficial effect of LAB (Lactobacillus bulgaricus) pretreatment against toxicity of graphene oxide (GO) and the underlying mechanisms. LAB prevented GO toxicity on the functions of both primary and secondary targeted organs in wild-type nematodes. LAB blocked translocation of GO into secondary targeted organs through intestinal barrier by maintaining normal intestinal permeability in wild-type nematodes. Moreover, LAB prevented GO damage on the functions of both primary and secondary targeted organs in exposed nematodes with mutations of susceptible genes (sod-2, sod-3, gas-1, and aak-2) to GO toxicity by sustaining normal intestinal permeability. LAB also sustained the normal defecation behavior in both wild-type nematodes and nematodes with mutations of susceptible genes. Therefore, the beneficial role of LAB against GO toxicity under different genetic backgrounds may be due to the combinational effects on intestinal permeability and defecation behavior. Moreover, the beneficial effects of LAB against GO toxicity was dependent on the function of ACS-22, homologous to mammalian FATP4 to mammalian FATP4. Our study provides highlight on establishment of pharmacological strategy to protect intestinal barrier from toxicity of GO.

  1. Intestine-Specific Mttp Deletion Decreases Mortality and Prevents Sepsis-Induced Intestinal Injury in a Murine Model of Pseudomonas aeruginosa Pneumonia

    Science.gov (United States)

    Dominguez, Jessica A.; Xie, Yan; Dunne, W. Michael; Yoseph, Benyam P.; Burd, Eileen M.; Coopersmith, Craig M.; Davidson, Nicholas O.

    2012-01-01

    Background The small intestine plays a crucial role in the pathophysiology of sepsis and has been referred to as the “motor” of the systemic inflammatory response. One proposed mechanism is that toxic gut-derived lipid factors, transported in mesenteric lymph, induce systemic injury and distant organ failure. However, the pathways involved are yet to be defined and the role of intestinal chylomicron assembly and secretion in transporting these lipid factors is unknown. Here we studied the outcome of sepsis in mice with conditional, intestine-specific deletion of microsomal triglyceride transfer protein (Mttp-IKO), which exhibit a block in chylomicron assembly together with lipid malabsorption. Methodology/Principal Findings Mttp-IKO mice and controls underwent intratracheal injection with either Pseudomonas aeruginosa or sterile saline. Mttp-IKO mice exhibited decreased seven-day mortality, with 0/20 (0%) dying compared to 5/17 (29%) control mice (p<0.05). This survival advantage in Mttp-IKO mice, however, was not associated with improvements in pulmonary bacterial clearance or neutrophil infiltration. Rather, Mttp-IKO mice exhibited protection against sepsis-associated decreases in villus length and intestinal proliferation and were also protected against increased intestinal apoptosis, both central features in control septic mice. Serum IL-6 levels, a major predictor of mortality in human and mouse models of sepsis, were elevated 8-fold in septic control mice but remained unaltered in septic Mttp-IKO mice. Serum high density lipoprotein (HDL) levels were reduced in septic control mice but were increased in septic Mttp-IKO mice. The decreased levels of HDL were associated with decreased hepatic expression of apolipoprotein A1 in septic control mice. Conclusions/Significance These studies suggest that strategies directed at blocking intestinal chylomicron secretion may attenuate the progression and improve the outcome of sepsis through effects mediated by

  2. Intestine-specific Mttp deletion decreases mortality and prevents sepsis-induced intestinal injury in a murine model of Pseudomonas aeruginosa pneumonia.

    Directory of Open Access Journals (Sweden)

    Jessica A Dominguez

    Full Text Available The small intestine plays a crucial role in the pathophysiology of sepsis and has been referred to as the "motor" of the systemic inflammatory response. One proposed mechanism is that toxic gut-derived lipid factors, transported in mesenteric lymph, induce systemic injury and distant organ failure. However, the pathways involved are yet to be defined and the role of intestinal chylomicron assembly and secretion in transporting these lipid factors is unknown. Here we studied the outcome of sepsis in mice with conditional, intestine-specific deletion of microsomal triglyceride transfer protein (Mttp-IKO, which exhibit a block in chylomicron assembly together with lipid malabsorption.Mttp-IKO mice and controls underwent intratracheal injection with either Pseudomonas aeruginosa or sterile saline. Mttp-IKO mice exhibited decreased seven-day mortality, with 0/20 (0% dying compared to 5/17 (29% control mice (p<0.05. This survival advantage in Mttp-IKO mice, however, was not associated with improvements in pulmonary bacterial clearance or neutrophil infiltration. Rather, Mttp-IKO mice exhibited protection against sepsis-associated decreases in villus length and intestinal proliferation and were also protected against increased intestinal apoptosis, both central features in control septic mice. Serum IL-6 levels, a major predictor of mortality in human and mouse models of sepsis, were elevated 8-fold in septic control mice but remained unaltered in septic Mttp-IKO mice. Serum high density lipoprotein (HDL levels were reduced in septic control mice but were increased in septic Mttp-IKO mice. The decreased levels of HDL were associated with decreased hepatic expression of apolipoprotein A1 in septic control mice.These studies suggest that strategies directed at blocking intestinal chylomicron secretion may attenuate the progression and improve the outcome of sepsis through effects mediated by metabolic and physiological adaptations in both intestinal and

  3. Lactobacillus GG and tributyrin supplementation reduce antibiotic-induced intestinal injury.

    Science.gov (United States)

    Cresci, Gail; Nagy, Laura E; Ganapathy, Vadivel

    2013-11-01

    Antibiotic therapy negatively alters the gut microbiota. Lactobacillus GG (LGG) decreases antibiotic-associated diarrhea (AAD) symptoms, but the mechanisms are unknown. Butyrate has beneficial effects on gut health. Altered intestinal gene expression occurs in the absence of gut microbiota. We hypothesized that antibiotic-induced changes in gut microbiota reduce butyrate production, varying genes involved with gut barrier integrity and water and electrolyte absorption, lending to AAD, and that simultaneous supplementation with LGG and/or tributyrin would prevent these changes. C57BL/6 mice aged 6-8 weeks received a chow diet while divided into 8 treatment groups (± saline, ± LGG, ± tributyrin, or both). Mice received treatments orally for 7 days with ± broad-spectrum antibiotics. Water intake was recorded daily and body weight was measured. Intestine tissue samples were obtained and analyzed for expression of genes and proteins involved with water and electrolyte absorption, butyrate transport, and gut integrity via polymerase chain reaction and immunohistochemistry. Antibiotics decreased messenger RNA (mRNA) expression (butyrate transporter and receptor, Na(+)/H(+) exchanger, Cl(-)/HCO3 (-), and a water channel) and protein expression (butyrate transporter, Na(+)/H(+) exchanger, and tight junction proteins) in the intestinal tract. LGG and/or tributyrin supplementation maintained intestinal mRNA expression to that of the control animals, and tributyrin maintained intestinal protein intensity expression to that of control animals. Broad-spectrum antibiotics decrease expression of anion exchangers, butyrate transporter and receptor, and tight junction proteins in mouse intestine. Simultaneous oral supplementation with LGG and/or tributyrin minimizes these losses. Optimizing intestinal health with LGG and/or tributyrin may offer a preventative therapy for AAD.

  4. Effects of Clostridium perfringens iota toxin in the small intestine of mice.

    Science.gov (United States)

    Redondo, Leandro M; Redondo, Enzo A; Dailoff, Gabriela C; Leiva, Carlos L; Díaz-Carrasco, Juan M; Bruzzone, Octavio A; Cangelosi, Adriana; Geoghegan, Patricia; Fernandez-Miyakawa, Mariano E

    2017-12-01

    Iota toxin is a binary toxin solely produced by Clostridium perfringens type E strains, and is structurally related to CDT from C. difficile and CST from C. spiroforme. As type E causes hemorrhagic enteritis in cattle, it is usually assumed that associated diseases are mediated by iota toxin, although evidence in this regard has not been provided. In the present report, iota toxin intestinal effects were evaluated in vivo using a mouse model. Histological damage was observed in ileal loops treated with purified iota toxin after 4 h of incubation. Luminal iota toxin induced fluid accumulation in the small intestine in a dose dependent manner, as determined by the enteropooling and the intestinal loop assays. None of these changes were observed in the large intestine. These results suggest that C. perfringens iota toxin alters intestinal permeability, predominantly by inducing necrosis and degenerative changes in the mucosal epithelium of the small intestine, as well as changes in intestinal motility. The obtained results suggest a central role for iota toxin in the pathogenesis of C. perfringens type E hemorrhagic enteritis, and contribute to remark the importance of clostridial binary toxins in digestive diseases. Published by Elsevier Ltd.

  5. Fasting-induced intestinal damage is mediated by oxidative and inflammatory responses.

    Science.gov (United States)

    Abdeen, S; Mathew, T C; Khan, I; Dashti, H; Asfar, S

    2009-05-01

    Green tea has been shown to repair fasting-induced mucosal damage in rat intestine. The aim of this study was to elucidate the underlying mechanism. Five groups of rats were used. Group 1 had free access to chow diet and water, and those in group 2 were fasted for 3 days. Animals in group 3 were fasted for 3 days, then were allowed drinking water for a further 7 days. Groups 4 and 5 were fasted for 3 days, then given drinking water containing green tea or vitamin E respectively for 7 days. Blood was collected for estimation of total plasma antioxidants, and jejunal samples were used for immunohistochemical analysis of superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx), and for estimation of myeloperoxidase (MPO) activity. Use of green tea was associated with a significant increase in total plasma antioxidants (P fasting-induced damage to the intestinal mucosa by its antioxidant and anti-inflammatory effect. 2009 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

  6. Circulating Zonulin, a Marker of Intestinal Permeability, Is Increased in Association with Obesity-Associated Insulin Resistance

    OpenAIRE

    Moreno-Navarrete, José María; Sabater, Mònica; Ortega, Francisco; Ricart, Wifredo; Fernández-Real, José Manuel

    2012-01-01

    Zonulin is the only physiological mediator known to regulate intestinal permeability reversibly by modulating intercellular tight junctions. To investigate the relationship between intestinal permeability and obesity-associated metabolic disturbances in humans, we aimed to study circulating zonulin according to obesity and insulin resistance. Circulating zonulin (ELISA) was measured in 123 caucasian men in association with inflammatory and metabolic parameters (including minimal model-measure...

  7. Regulation of Bicarbonate Secretion in Marine Fish Intestine by the Calcium-Sensing Receptor

    Directory of Open Access Journals (Sweden)

    Sílvia F. Gregório

    2018-04-01

    Full Text Available In marine fish, high epithelial intestinal HCO3− secretion generates luminal carbonate precipitates of divalent cations that play a key role in water and ion homeostasis. The present study was designed to expose the putative role for calcium and the calcium-sensing receptor (CaSR in the regulation of HCO3− secretion in the intestine of the sea bream (Sparus aurata L.. Effects on the expression of the CaSR in the intestine were evaluated by qPCR and an increase was observed in the anterior intestine in fed fish compared with unfed fish and with different regions of intestine. CaSR expression reflected intestinal fluid calcium concentration. In addition, anterior intestine tissue was mounted in Ussing chambers to test the putative regulation of HCO3− secretion in vitro using the anterior intestine. HCO3− secretion was sensitive to varying calcium levels in luminal saline and to calcimimetic compounds known to activate/block the CaSR i.e., R 568 and NPS-2143. Subsequent experiments were performed in intestinal sacs to measure water absorption and the sensitivity of water absorption to varying luminal levels of calcium and calcimimetics were exposed as well. It appears, that CaSR mediates HCO3− secretion and water absorption in marine fish as shown by responsiveness to calcium levels and calcimimetic compounds.

  8. Distinct Roles for Intestinal Epithelial Cell-Specific Hdac1 and Hdac2 in the Regulation of Murine Intestinal Homeostasis.

    Science.gov (United States)

    Gonneaud, Alexis; Turgeon, Naomie; Boudreau, François; Perreault, Nathalie; Rivard, Nathalie; Asselin, Claude

    2016-02-01

    The intestinal epithelium responds to and transmits signals from the microbiota and the mucosal immune system to insure intestinal homeostasis. These interactions are in part conveyed by epigenetic modifications, which respond to environmental changes. Protein acetylation is an epigenetic signal regulated by histone deacetylases, including Hdac1 and Hdac2. We have previously shown that villin-Cre-inducible intestinal epithelial cell (IEC)-specific Hdac1 and Hdac2 deletions disturb intestinal homeostasis. To determine the role of Hdac1 and Hdac2 in the regulation of IEC function and the establishment of the dual knockout phenotype, we have generated villin-Cre murine models expressing one Hdac1 allele without Hdac2, or one Hdac2 allele without Hdac1. We have also investigated the effect of short-term deletion of both genes in naphtoflavone-inducible Ah-Cre and tamoxifen-inducible villin-Cre(ER) mice. Mice with one Hdac1 allele displayed normal tissue architecture, but increased sensitivity to DSS-induced colitis. In contrast, mice with one Hdac2 allele displayed intestinal architecture defects, increased proliferation, decreased goblet cell numbers as opposed to Paneth cells, increased immune cell infiltration associated with fibrosis, and increased sensitivity to DSS-induced colitis. In comparison to dual knockout mice, intermediary activation of Notch, mTOR, and Stat3 signaling pathways was observed. While villin-Cre(ER) Hdac1 and Hdac2 deletions led to an impaired epithelium and differentiation defects, Ah-Cre-mediated deletion resulted in blunted proliferation associated with the induction of a DNA damage response. Our results suggest that IEC determination and intestinal homeostasis are highly dependent on Hdac1 and Hdac2 activity levels, and that changes in the IEC acetylome may alter the mucosal environment. © 2015 Wiley Periodicals, Inc.

  9. Salmonella enterica serovar Typhimurium exploits inflammation to modify swine intestinal microbiota.

    Directory of Open Access Journals (Sweden)

    Rosanna eDrumo

    2016-01-01

    Full Text Available Salmonella enterica serovar Typhimurium is an important zoonotic gastrointestinal pathogen responsible for foodborne disease worldwide. It is a successful enteric pathogen because it has developed virulence strategies allowing it to survive in a highly inflamed intestinal environment exploiting inflammation to overcome colonization resistance provided by intestinal microbiota. In this study, we used piglets featuring an intact microbiota, which naturally develop gastroenteritis, as model for salmonellosis. We compared the effects on the intestinal microbiota induced by a wild type and an attenuated S. Typhimurium in order to evaluate whether the modifications are correlated with the virulence of the strain. This study showed that Salmonella alters microbiota in a virulence-dependent manner. We found that the wild type S. Typhimurium induced inflammation and a reduction of specific protecting microbiota species (SCFA-producing bacteria normally involved in providing a barrier against pathogens. Both these effects could contribute to impair colonization resistance, increasing the host susceptibility to wild type S. Typhimurium colonization. In contrast, the attenuated S. Typhimurium, which is characterized by a reduced ability to colonize the intestine, and by a very mild inflammatory response, was unable to successfully sustain competition with the microbiota.

  10. Actions of vasoactive intestinal peptide and secretin on chief cells prepared from guinea pig stomach

    International Nuclear Information System (INIS)

    Sutliff, V.E.; Raufman, J.P.; Jensen, R.T.; Gardner, J.D.

    1986-01-01

    Vasoactive intestinal peptide and secretin increased cellular cAMP and pepsinogen secretion in dispersed chief cells from guinea pig gastric mucosa. With each peptide there was a close correlation between the dose-response curve for changes in cellular cAMP and that for changes in pepsinogen secretion. Vasoactive intestinal peptide- (10-28) and secretin- (5-27) had no agonist activity and antagonized the actions of vasoactive intestinal peptide and secretin on cellular cAMP and pepsinogen secretion. Studies of binding of 125 I-vasoactive intestinal peptide and of 125 -secretin indicated that gastric chief cells possess four classes of binding sites for vasoactive intestinal peptide and secretin and that occupation of two of these classes of binding sites correlates with the abilities of vasoactive intestinal peptide and secretin to increase cellular cAMP and pepsinogen secretion. What function, in any, is mediated by occupation by the other two classes of binding sites remains to be determined

  11. Epidermal growth factor improves survival and prevents intestinal injury in a murine model of pseudomonas aeruginosa pneumonia.

    Science.gov (United States)

    Dominguez, Jessica A; Vithayathil, Paul J; Khailova, Ludmila; Lawrance, Christopher P; Samocha, Alexandr J; Jung, Enjae; Leathersich, Ann M; Dunne, W Michael; Coopersmith, Craig M

    2011-10-01

    Mortality from pneumonia is mediated, in part, through extrapulmonary causes. Epidermal growth factor (EGF) has broad cytoprotective effects, including potent restorative properties in the injured intestine. The purpose of this study was to determine the efficacy of EGF treatment following Pseudomonas aeruginosa pneumonia. FVB/N mice underwent intratracheal injection of either P. aeruginosa or saline and were then randomized to receive either systemic EGF or vehicle beginning immediately or 24 h after the onset of pneumonia. Systemic EGF decreased 7-day mortality from 65% to 10% when initiated immediately after the onset of pneumonia and to 27% when initiated 24 h after the onset of pneumonia. Even though injury in pneumonia is initiated in the lungs, the survival advantage conferred by EGF was not associated with improvements in pulmonary pathology. In contrast, EGF prevented intestinal injury by reversing pneumonia-induced increases in intestinal epithelial apoptosis and decreases in intestinal proliferation and villus length. Systemic cytokines and kidney and liver function were unaffected by EGF therapy, although EGF decreased pneumonia-induced splenocyte apoptosis. To determine whether the intestine was sufficient to account for extrapulmonary effects induced by EGF, a separate set of experiments was done using transgenic mice with enterocyte-specific overexpression of EGF (IFABP-EGF [intestinal fatty acid-binding protein linked to mouse EGF] mice), which were compared with wild-type mice subjected to pneumonia. IFABP-EGF mice had improved survival compared with wild-type mice following pneumonia (50% vs. 28%, respectively, P < 0.05) and were protected from pneumonia-induced intestinal injury. Thus, EGF may be a potential adjunctive therapy for pneumonia, mediated in part by its effects on the intestine.

  12. Adhesion to the host cell surface is sufficient to mediate Listeria monocytogenes entry into epithelial cells

    Science.gov (United States)

    Ortega, Fabian E.; Rengarajan, Michelle; Chavez, Natalie; Radhakrishnan, Prathima; Gloerich, Martijn; Bianchini, Julie; Siemers, Kathleen; Luckett, William S.; Lauer, Peter; Nelson, W. James; Theriot, Julie A.

    2017-01-01

    The intestinal epithelium is the first physiological barrier breached by the Gram-positive facultative pathogen Listeria monocytogenes during an in vivo infection. Listeria monocytogenes binds to the epithelial host cell receptor E-cadherin, which mediates a physical link between the bacterium and filamentous actin (F-actin). However, the importance of anchoring the bacterium to F-actin through E-cadherin for bacterial invasion has not been tested directly in epithelial cells. Here we demonstrate that depleting αE-catenin, which indirectly links E-cadherin to F-actin, did not decrease L. monocytogenes invasion of epithelial cells in tissue culture. Instead, invasion increased due to increased bacterial adhesion to epithelial monolayers with compromised cell–cell junctions. Furthermore, expression of a mutant E-cadherin lacking the intracellular domain was sufficient for efficient L. monocytogenes invasion of epithelial cells. Importantly, direct biotin-mediated binding of bacteria to surface lipids in the plasma membrane of host epithelial cells was sufficient for uptake. Our results indicate that the only requirement for L. monocytogenes invasion of epithelial cells is adhesion to the host cell surface, and that E-cadherin–mediated coupling of the bacterium to F-actin is not required. PMID:28877987

  13. Trans-intestinal cholesterol effl ux is not mediated through high density lipoprotein

    NARCIS (Netherlands)

    Vrins, C.L.; Ottenhoff, R.; Oever, K. van den; Waart, D.R. de; Kruyt, J.K.; Zhao, Y.; Berkel, T.J. van; Havekes, L.M.; Aerts, J.M.; Eck, M. van; Rensen, P.C.; Groen, A.K.

    2012-01-01

    Transintestinal cholesterol efflux (TICE) provides an attractive target to increase body cholesterol excretion. At present, the cholesterol donor responsible for direct delivery of plasma cholesterol to the intestine is unknown. In this study, we investigated the role of HDL in TICE. ATP-binding

  14. Sensing of EGTA Mediated Barrier Tissue Disruption with an Organic Transistor

    Directory of Open Access Journals (Sweden)

    Scherrine Tria

    2013-01-01

    Full Text Available Barrier tissue protects the body against external factors by restricting the passage of molecules. The gastrointestinal epithelium is an example of barrier tissue with the primary purpose of allowing the passage of ions and nutrients, while restricting the passage of pathogens and toxins. It is well known that the loss of barrier function can be instigated by a decrease in extracellular calcium levels, leading to changes in protein conformation and an increase in paracellular transport. In this study, ethylene glycol-bis(beta-aminoethyl ether-N,N,N',N'-tetra acetic acid (EGTA, a calcium chelator, was used to disrupt the gastrointestinal epithelial barrier. The effect of EGTA on barrier tissue was monitored by a novel label-free method based on an organic electrochemical transistor (OECT integrated with living cells and validated against conventional methods for measuring barrier tissue integrity. We demonstrate that the OECT can detect breaches in barrier tissue upon exposure to EGTA with the same sensitivity as existing methods but with increased temporal resolution. Due to the potential of low cost processing techniques and the flexibility in design associated with organic electronics, the OECT has great potential for high-throughput, disposable sensing and diagnostics.

  15. Attenuative effects of G-CSF in radiation induced intestinal injury

    International Nuclear Information System (INIS)

    Kim, Joong Sun; Gong, Eun Ji; Kim, Sung Dae; Heo, Kyu; Ryoo, Seung Bum; Yang, Kwang Mo

    2011-01-01

    Granulocyte colony stimulating factor (G-CSF) has been reported to protect from radiationinduced myelosuppression. Growing evidence suggests that G-CSF also has many important non-hematopoietic functions in other tissues, including the intestine (Kim et al., 2010; Kim et al., 2011). However, little is known about the influence of G-CSF on intestinal injury. Examination 12 hours after radiation (5 Gy) revealed that the G-CSF treated mice were significantly protected from apoptosis of jejunal crypt, compared with radiation controls. G-CSF treatment attenuated intestinal morphological changes such as decreased survival crypt, the number of villi, villous shortening, crypt depth and length of basal lamina of 10 enterocytes compared with the radiation control 3.5 days after radiation (10 Gy). G-CSF attenuated the change of peripheral blood from radiation-induced myelosuppression and displayed attenuation of mortality in lethally-irradiated (10 Gy) mice. The present results support the suggestion that G-CSF administrated prior to radiation plays an important role in the survival of irradiated mice, possibly due to the protection of hematopoietic cells and intestinal stem cells against radiation. The results indicate that G-CSF protects from radiation-mediated intestinal damage and from hematopoietic injury. G-CSF treatment may be useful clinically in the prevention of injury following radiation.

  16. Saccharomyces boulardii Stimulates Intestinal Immunoglobulin A Immune Response to Clostridium difficile Toxin A in Mice

    Science.gov (United States)

    Qamar, Amir; Aboudola, Samer; Warny, Michel; Michetti, Pierre; Pothoulakis, Charalabos; LaMont, J. Thomas; Kelly, Ciarán P.

    2001-01-01

    Saccharomyces boulardii is a nonpathogenic yeast that protects against antibiotic-associated diarrhea and recurrent Clostridium difficile colitis. The administration of C. difficile toxoid A by gavage to S. boulardii-fed BALB/c mice caused a 1.8-fold increase in total small intestinal immunoglobulin A levels (P = 0.003) and a 4.4-fold increase in specific intestinal anti-toxin A levels (P boulardii-mediated protection against diarrheal illnesses. PMID:11254650

  17. Intrauterine Growth Restriction Alters Mouse Intestinal Architecture during Development.

    Science.gov (United States)

    Fung, Camille M; White, Jessica R; Brown, Ashley S; Gong, Huiyu; Weitkamp, Jörn-Hendrik; Frey, Mark R; McElroy, Steven J

    2016-01-01

    Infants with intrauterine growth restriction (IUGR) are at increased risk for neonatal and lifelong morbidities affecting multiple organ systems including the intestinal tract. The underlying mechanisms for the risk to the intestine remain poorly understood. In this study, we tested the hypothesis that IUGR affects the development of goblet and Paneth cell lineages, thus compromising the innate immunity and barrier functions of the epithelium. Using a mouse model of maternal thromboxane A2-analog infusion to elicit maternal hypertension and resultant IUGR, we tested whether IUGR alters ileal maturation and specifically disrupts mucus-producing goblet and antimicrobial-secreting Paneth cell development. We measured body weights, ileal weights and ileal lengths from birth to postnatal day (P) 56. We also determined the abundance of goblet and Paneth cells and their mRNA products, localization of cellular tight junctions, cell proliferation, and apoptosis to interrogate cellular homeostasis. Comparison of the murine findings with human IUGR ileum allowed us to verify observed changes in the mouse were relevant to clinical IUGR. At P14 IUGR mice had decreased ileal lengths, fewer goblet and Paneth cells, reductions in Paneth cell specific mRNAs, and decreased cell proliferation. These findings positively correlated with severity of IUGR. Furthermore, the decrease in murine Paneth cells was also seen in human IUGR ileum. IUGR disrupts the normal trajectory of ileal development, particularly affecting the composition and secretory products of the epithelial surface of the intestine. We speculate that this abnormal intestinal development may constitute an inherent "first hit", rendering IUGR intestine susceptible to further injury, infection, or inflammation.

  18. Intestinal microbiota pathogenesis and fecal microbiota transplantation for inflammatory bowel disease

    Science.gov (United States)

    Wang, Zi-Kai; Yang, Yun-Sheng; Chen, Ye; Yuan, Jing; Sun, Gang; Peng, Li-Hua

    2014-01-01

    The intestinal microbiota plays an important role in inflammatory bowel disease (IBD). The pathogenesis of IBD involves inappropriate ongoing activation of the mucosal immune system driven by abnormal intestinal microbiota in genetically predisposed individuals. However, there are still no definitive microbial pathogens linked to the onset of IBD. The composition and function of the intestinal microbiota and their metabolites are indeed disturbed in IBD patients. The special alterations of gut microbiota associated with IBD remain to be evaluated. The microbial interactions and host-microbe immune interactions are still not clarified. Limitations of present probiotic products in IBD are mainly due to modest clinical efficacy, few available strains and no standardized administration. Fecal microbiota transplantation (FMT) may restore intestinal microbial homeostasis, and preliminary data have shown the clinical efficacy of FMT on refractory IBD or IBD combined with Clostridium difficile infection. Additionally, synthetic microbiota transplantation with the defined composition of fecal microbiota is also a promising therapeutic approach for IBD. However, FMT-related barriers, including the mechanism of restoring gut microbiota, standardized donor screening, fecal material preparation and administration, and long-term safety should be resolved. The role of intestinal microbiota and FMT in IBD should be further investigated by metagenomic and metatranscriptomic analyses combined with germ-free/human flora-associated animals and chemostat gut models. PMID:25356041

  19. Chemical form of plutonium in foodstuffs - its influence on gastro-intestinal uptake

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, J.R. (National Radiological Protection Board, Harwell (UK))

    1984-01-01

    A brief review is given of some studies of the chemical form of plutonium in food eaten by man and how this may influence gastrointestinal uptake. Phytate ligands, present in many foods, bind strongly to plutonium. High levels of enzyme phytase in rat intestines enhance the gastrointestinal uptake of plutonium phytate in rats compared to rabbits. Taking into account 1) the low levels of phytase in human intestine and 2) the possibility of competing precipitation reactions, it would seem unlikely that the phytate-mediated elevation of plutonium uptake seen in rats will apply to humans.

  20. Phenylbutyrate counteracts Shigella mediated downregulation of cathelicidin in rabbit lung and intestinal epithelia: a potential therapeutic strategy.

    Science.gov (United States)

    Sarker, Protim; Ahmed, Sultan; Tiash, Snigdha; Rekha, Rokeya Sultana; Stromberg, Roger; Andersson, Jan; Bergman, Peter; Gudmundsson, Gudmundur H; Agerberth, Birgitta; Raqib, Rubhana

    2011-01-01

    Cathelicidins and defensins are endogenous antimicrobial peptides (AMPs) that are downregulated in the mucosal epithelia of the large intestine in shigellosis. Oral treatment of Shigella infected rabbits with sodium butyrate (NaB) reduces clinical severity and counteracts the downregulation of cathelicidin (CAP-18) in the large intestinal epithelia. To develop novel regimen for treating infectious diseases by inducing innate immunity, we selected sodium 4-phenylbutyrate (PB), a registered drug for a metabolic disorder as a potential therapeutic candidate in a rabbit model of shigellosis. Since acute respiratory infections often cause secondary complications during shigellosis, the systemic effect of PB and NaB on CAP-18 expression in respiratory epithelia was also evaluated. The readouts were clinical outcomes, CAP-18 expression in mucosa of colon, rectum, lung and trachea (immunohistochemistry and real-time PCR) and release of the CAP-18 peptide/protein in stool (Western blot). Significant downregulation of CAP-18 expression in the epithelia of rectum and colon, the site of Shigella infection was confirmed. Interestingly, reduced expression of CAP-18 was also noticed in the epithelia of lung and trachea, indicating a systemic effect of the infection. This suggests a causative link to acute respiratory infections during shigellosis. Oral treatment with PB resulted in reduced clinical illness and upregulation of CAP-18 in the epithelium of rectum. Both PB and NaB counteracted the downregulation of CAP-18 in lung epithelium. The drug effect is suggested to be systemic as intravenous administration of NaB could also upregulate CAP-18 in the epithelia of lung, rectum and colon. Our results suggest that PB has treatment potential in human shigellosis. Enhancement of CAP-18 in the mucosal epithelia of the respiratory tract by PB or NaB is a novel discovery. This could mediate protection from secondary respiratory infections that frequently are the lethal causes in

  1. The intriguing role of Rifaximin in gut barrier chronic inflammation and in the treatment of Crohn's disease.

    Science.gov (United States)

    Lopetuso, Loris R; Napoli, Marco; Rizzatti, Gianenrico; Gasbarrini, Antonio

    2018-06-04

    The gastrointestinal tract acts as a functional unit organized as a semipermeable multilayer system, in which commensal gut microbiota represents the anatomical barrier. Recently,, several studies have highlighted the involvement of gut microbiota in IBD pathogenesis, in sustaining gut barrier chronic inflammation, and in conditioning disease course and therapeutical response. This evidence provides a rationale for treating patients with gut microbiota modifiers. Among these, Rifaximin represents a non-traditional antibiotic able to act as a "eubiotic" on intestinal barrier. Area covered: The purpose of this narrative review is to explore the impact of Rifaximin on gut barrier and gut microbiota in IBD, in particular in Crohn's disease, and to analyze its potential therapeutic applications. Expert opinion: The possibility of a beneficial activity of Rifaximin in chronic intestinal inflammation and Crohn's disease has been debated and evaluated with different studies having obtained promising but still preliminary data. Larger trials are therefore needed. This gut-specific antibiotic could represent an alternative to systemic antibiotics thanks to its favorable safety profile and promising efficacy data. Rifaximin could exert, when appropriate, a synergic effect with immunomodulators in IBD, acting on both the microbial and immunological sides of gut barrier impairment.

  2. WNT signaling controls expression of pro-apoptotic BOK and BAX in intestinal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zeilstra, Jurrit; Joosten, Sander P.J. [Department of Pathology, Academic Medical Center, University of Amsterdam (Netherlands); Wensveen, Felix M. [Department of Experimental Immunology, Academic Medical Center, Amsterdam (Netherlands); Dessing, Mark C.; Schuetze, Denise M. [Department of Pathology, Academic Medical Center, University of Amsterdam (Netherlands); Eldering, Eric [Department of Experimental Immunology, Academic Medical Center, Amsterdam (Netherlands); Spaargaren, Marcel [Department of Pathology, Academic Medical Center, University of Amsterdam (Netherlands); Pals, Steven T., E-mail: s.t.pals@amc.uva.nl [Department of Pathology, Academic Medical Center, University of Amsterdam (Netherlands)

    2011-03-04

    Research highlights: {yields} Intestinal adenomas initiated by aberrant activation of the WNT pathway displayed an increased sensitivity to apoptosis. {yields} Expression profiling of apoptosis-related genes in Apc{sup Min/+} mice revealed the differential expression of pro-apoptotic Bok and Bax. {yields} APC-mutant adenomatous crypts in FAP patients showed strongly increased BAX immunoreactivity. {yields} Blocking of {beta}-catenin/TCF-4-mediated signaling in colon cancer cells reduced the expression of BOK and BAX. -- Abstract: In a majority of cases, colorectal cancer is initiated by aberrant activation of the WNT signaling pathway. Mutation of the genes encoding the WNT signaling components adenomatous polyposis coli or {beta}-catenin causes constitutively active {beta}-catenin/TCF-mediated transcription, driving the transformation of intestinal crypts to cancer precursor lesions, called dysplastic aberrant crypt foci. Deregulated apoptosis is a hallmark of adenomatous colon tissue. However, the contribution of WNT signaling to this process is not fully understood. We addressed this role by analyzing the rate of epithelial apoptosis in aberrant crypts and adenomas of the Apc{sup Min/+} mouse model. In comparison with normal crypts and adenomas, aberrant crypts displayed a dramatically increased rate of apoptotic cell death. Expression profiling of apoptosis-related genes along the crypt-villus axis and in Apc mutant adenomas revealed increased expression of two pro-apoptotic Bcl-2 family members in intestinal adenomas, Bok and Bax. Analysis of the colon of familial adenomatous polyposis (FAP) patients along the crypt-to-surface axis, and of dysplastic crypts, corroborated this expression pattern. Disruption of {beta}-catenin/TCF-4-mediated signaling in the colorectal cancer cell line Ls174T significantly decreased BOK and BAX expression, confirming WNT-dependent regulation in intestinal epithelial cells. Our results suggest a feedback mechanism by which

  3. WNT signaling controls expression of pro-apoptotic BOK and BAX in intestinal cancer

    International Nuclear Information System (INIS)

    Zeilstra, Jurrit; Joosten, Sander P.J.; Wensveen, Felix M.; Dessing, Mark C.; Schuetze, Denise M.; Eldering, Eric; Spaargaren, Marcel; Pals, Steven T.

    2011-01-01

    Research highlights: → Intestinal adenomas initiated by aberrant activation of the WNT pathway displayed an increased sensitivity to apoptosis. → Expression profiling of apoptosis-related genes in Apc Min/+ mice revealed the differential expression of pro-apoptotic Bok and Bax. → APC-mutant adenomatous crypts in FAP patients showed strongly increased BAX immunoreactivity. → Blocking of β-catenin/TCF-4-mediated signaling in colon cancer cells reduced the expression of BOK and BAX. -- Abstract: In a majority of cases, colorectal cancer is initiated by aberrant activation of the WNT signaling pathway. Mutation of the genes encoding the WNT signaling components adenomatous polyposis coli or β-catenin causes constitutively active β-catenin/TCF-mediated transcription, driving the transformation of intestinal crypts to cancer precursor lesions, called dysplastic aberrant crypt foci. Deregulated apoptosis is a hallmark of adenomatous colon tissue. However, the contribution of WNT signaling to this process is not fully understood. We addressed this role by analyzing the rate of epithelial apoptosis in aberrant crypts and adenomas of the Apc Min/+ mouse model. In comparison with normal crypts and adenomas, aberrant crypts displayed a dramatically increased rate of apoptotic cell death. Expression profiling of apoptosis-related genes along the crypt-villus axis and in Apc mutant adenomas revealed increased expression of two pro-apoptotic Bcl-2 family members in intestinal adenomas, Bok and Bax. Analysis of the colon of familial adenomatous polyposis (FAP) patients along the crypt-to-surface axis, and of dysplastic crypts, corroborated this expression pattern. Disruption of β-catenin/TCF-4-mediated signaling in the colorectal cancer cell line Ls174T significantly decreased BOK and BAX expression, confirming WNT-dependent regulation in intestinal epithelial cells. Our results suggest a feedback mechanism by which uncontrolled epithelial cell proliferation in the

  4. Bifidobacterium animalis ssp. lactis CNCM-I2494 Restores Gut Barrier Permeability in Chronically Low-Grade Inflamed Mice.

    Science.gov (United States)

    Martín, Rebeca; Laval, Laure; Chain, Florian; Miquel, Sylvie; Natividad, Jane; Cherbuy, Claire; Sokol, Harry; Verdu, Elena F; van Hylckama Vlieg, Johan; Bermudez-Humaran, Luis G; Smokvina, Tamara; Langella, Philippe

    2016-01-01

    Growing evidence supports the efficacy of many probiotic strains in the management of gastrointestinal disorders associated with deregulated intestinal barrier function and/or structure. In particular, bifidobacteria have been studied for their efficacy to both prevent and treat a broad spectrum of animal and/or human gut disorders. The aim of the current work was thus to evaluate effects on intestinal barrier function of Bifidobacterium animalis ssp. lactis CNCM-I2494, a strain used in fermented dairy products. A chronic dinitrobenzene sulfonic acid (DNBS)-induced low-grade inflammation model causing gut dysfunction in mice was used in order to study markers of inflammation, intestinal permeability, and immune function in the presence of the bacterial strain. In this chronic low-grade inflammation mice model several parameters pointed out the absence of an over active inflammation process. However, gut permeability, lymphocyte populations, and colonic cytokines were found to be altered. B. animalis ssp. lactis CNCM-I2494 was able to protect barrier functions by restoring intestinal permeability, colonic goblet cell populations, and cytokine levels. Furthermore, tight junction (TJ) proteins levels were also measured by qRT-PCR showing the ability of this strain to specifically normalize the level of several TJ proteins, in particular for claudin-4. Finally, B. lactis strain counterbalanced CD4(+) lymphocyte alterations in both spleen and mesenteric lymphoid nodes. It restores the Th1/Th2 ratio altered by the DNBS challenge (which locally augments CD4(+) Th1 cells) by increasing the Th2 response as measured by the increase in the production of major representative Th2 cytokines (IL-4, IL-5, and IL-10). Altogether, these data suggest that B. animalis ssp. lactis CNCM-I2494 may efficiently prevent disorders associated with increased barrier permeability.

  5. Heat stress and reduced plane of nutrition decreases intestinal integrity and function in pigs.

    Science.gov (United States)

    Pearce, S C; Mani, V; Weber, T E; Rhoads, R P; Patience, J F; Baumgard, L H; Gabler, N K

    2013-11-01

    Heat stress can compromise intestinal integrity and induce leaky gut in a variety of species. Therefore, the objectives of this study were to determine if heat stress (HS) directly or indirectly (via reduced feed intake) increases intestinal permeability in growing pigs. We hypothesized that an increased heat-load causes physiological alterations to the intestinal epithelium, resulting in compromised barrier integrity and altered intestinal function that contributes to the overall severity of HS-related illness. Crossbred gilts (n=48, 43±4 kg BW) were housed in constant climate controlled rooms in individual pens and exposed to 1) thermal neutral (TN) conditions (20°C, 35-50% humidity) with ad libitum intake, 2) HS conditions (35°C, 20-35% humidity) with ad libitum feed intake, or 3) pair-fed in TN conditions (PFTN) to eliminate confounding effects of dissimilar feed intake. Pigs were sacrificed at 1, 3, or 7 d of environmental exposure and jejunum samples were mounted into modified Ussing chambers for assessment of transepithelial electrical resistance (TER) and intestinal fluorescein isothiocyanate (FITC)-labeled lipopolysaccharide (LPS) permeability (expressed as apparent permeability coefficient, APP). Further, gene and protein markers of intestinal integrity and stress were assessed. Irrespective of d of HS exposure, plasma endotoxin levels increased 45% (Pwarm summer months.

  6. Role of Smooth Muscle in Intestinal Inflammation

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    Stephen M Collins

    1996-01-01

    Full Text Available The notion that smooth muscle function is altered in inflammation is prompted by clinical observations of altered motility in patients with inflammatory bowel disease (IBD. While altered motility may reflect inflammation-induced changes in intrinsic or extrinsic nerves to the gut, changes in gut hormone release and changes in muscle function, recent studies have provided in vitro evidence of altered muscle contractility in muscle resected from patients with ulcerative colitis or Crohn’s disease. In addition, the observation that smooth muscle cells are more numerous and prominent in the strictured bowel of IBD patients compared with controls suggests that inflammation may alter the growth of intestinal smooth muscle. Thus, inflammation is associated with changes in smooth muscle growth and contractility that, in turn, contribute to important symptoms of IBD including diarrhea (from altered motility and pain (via either altered motility or stricture formation. The involvement of smooth muscle in this context may be as an innocent bystander, where cells and products of the inflammatory process induce alterations in muscle contractility and growth. However, it is likely that intestinal muscle cells play a more active role in the inflammatory process via the elaboration of mediators and trophic factors, including cytokines, and via the production of collagen. The concept of muscle cells as active participants in the intestinal inflammatory process is a new concept that is under intense study. This report summarizes current knowledge as it relates to these two aspects of altered muscle function (growth and contractility in the inflamed intestine, and will focus on mechanisms underlying these changes, based on data obtained from animal models of intestinal inflammation.

  7. Effects of ethanol and acetaldehyde on tight junction integrity: in vitro study in a three dimensional intestinal epithelial cell culture model.

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    Elhaseen Elamin

    Full Text Available BACKGROUND: Intestinal barrier dysfunction and translocation of endotoxins are involved in the pathogenesis of alcoholic liver disease. Exposure to ethanol and its metabolite, acetaldehyde at relatively high concentrations have been shown to disrupt intestinal epithelial tight junctions in the conventional two dimensional cell culture models. The present study investigated quantitatively and qualitatively the effects of ethanol at concentrations detected in the blood after moderate ethanol consumption, of its metabolite acetaldehyde and of the combination of both compounds on intestinal barrier function in a three-dimensional cell culture model. METHODS AND FINDINGS: Caco-2 cells were grown in a basement membrane matrix (Matrigel™ to induce spheroid formation and were then exposed to the compounds at the basolateral side. Morphological differentiation of the spheroids was assessed by immunocytochemistry and transmission electron microscopy. The barrier function was assessed by the flux of FITC-labeled dextran from the basal side into the spheroids' luminal compartment using confocal microscopy. Caco-2 cells grown on Matrigel assembled into fully differentiated and polarized spheroids with a central lumen, closely resembling enterocytes in vivo and provide an excellent model to study epithelial barrier functionality. Exposure to ethanol (10-40 mM or acetaldehyde (25-200 µM for 3 h, dose-dependently and additively increased the paracellular permeability and induced redistribution of ZO-1 and occludin without affecting cell viability or tight junction-encoding gene expression. Furthermore, ethanol and acetaldehyde induced lysine residue and microtubules hyperacetylation. CONCLUSIONS: These results indicate that ethanol at concentrations found in the blood after moderate drinking and acetaldehyde, alone and in combination, can increase the intestinal epithelial permeability. The data also point to the involvement of protein hyperacetylation in

  8. Epithelial Cell Damage Activates Bactericidal/Permeability Increasing-Protein (BPI Expression in Intestinal Epithelium

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    Arjun Balakrishnan

    2017-08-01

    Full Text Available As the first line of defense against invading pathogen, intestinal epithelium produces various antimicrobial proteins (AMP that help in clearance of pathogen. Bactericidal/permeability-increasing protein (BPI is a 55 kDa AMP that is expressed in intestinal epithelium. Dysregulation of BPI in intestinal epithelium is associated with various inflammatory diseases like Crohn’s Disease, Ulcerative colitis, and Infectious enteritis’s. In this paper, we report a direct correlation between intestinal damage and BPI expression. In Caco-2 cells, we see a significant increase in BPI levels upon membrane damage mediated by S. aureus infection and pore-forming toxins (Streptolysin and Listeriolysin. Cells detect changes in potassium level as a Danger-associated molecular pattern associated with cell damage and induce BPI expression in a p38 dependent manner. These results are further supported by in vivo findings that the BPI expression in murine intestinal epithelium is induced upon infection with bacteria which cause intestinal damage (Salmonella Typhimurium and Shigella flexneri whereas mutants that do not cause intestinal damage (STM ΔfliC and STM ΔinvC did not induce BPI expression. Our results suggest that epithelial damage associated with infection act as a signal to induce BPI expression.

  9. An Intestinal Farnesoid X Receptor–Ceramide Signaling Axis Modulates Hepatic Gluconeogenesis in Mice

    Science.gov (United States)

    Xie, Cen; Shi, Jingmin; Gao, Xiaoxia; Sun, Dongxue; Sun, Lulu; Wang, Ting; Takahashi, Shogo; Anitha, Mallappa; Krausz, Kristopher W.; Patterson, Andrew D.

    2017-01-01

    Increasing evidence supports the view that intestinal farnesoid X receptor (FXR) is involved in glucose tolerance and that FXR signaling can be profoundly impacted by the gut microbiota. Selective manipulation of the gut microbiota–FXR signaling axis was reported to significantly impact glucose intolerance, but the precise molecular mechanism remains largely unknown. Here, caffeic acid phenethyl ester (CAPE), an over-the-counter dietary supplement and an inhibitor of bacterial bile salt hydrolase, increased levels of intestinal tauro-β-muricholic acid, which selectively suppresses intestinal FXR signaling. Intestinal FXR inhibition decreased ceramide levels by suppressing expression of genes involved in ceramide synthesis specifically in the intestinal ileum epithelial cells. The lower serum ceramides mediated decreased hepatic mitochondrial acetyl-CoA levels and pyruvate carboxylase (PC) activities and attenuated hepatic gluconeogenesis, independent of body weight change and hepatic insulin signaling in vivo; this was reversed by treatment of mice with ceramides or the FXR agonist GW4064. Ceramides substantially attenuated mitochondrial citrate synthase activities primarily through the induction of endoplasmic reticulum stress, which triggers increased hepatic mitochondrial acetyl-CoA levels and PC activities. These results reveal a mechanism by which the dietary supplement CAPE and intestinal FXR regulates hepatic gluconeogenesis and suggest that inhibiting intestinal FXR is a strategy for treating hyperglycemia. PMID:28223344

  10. Intestinal microbiota: a potential diet-responsive prevention target in ApcMin mice.

    Science.gov (United States)

    Mai, Volker; Colbert, Lisa H; Perkins, Susan N; Schatzkin, Arthur; Hursting, Stephen D

    2007-01-01

    We previously reported that two dietary regimens, calorie restriction (CR) and a high olive oil-containing diet supplemented with a freeze-dried fruit and vegetable extract (OFV), reduced the development of intestinal adenomas in Apc(Min) mice by 57% and 33%, respectively, compared to control mice fed a defined diet ad libitum. The OFV diet was designed to have a strong effect on the composition of the intestinal microbiota through its high content of fiber, which represents a major source of fermentable substrate for the gut bacteria. We hypothesized that some of the observed effects of diet on intestinal carcinogenesis might be mediated by diet-related changes in the bacterial species that thrive in the gut. Therefore, we determined by fluorescent in situ hybridization (FISH) and denaturing gradient gel electrophoresis (DGGE) how the dietary interventions affected the composition of the intestinal microbiota, and we characterized specific microbiota changes that were associated with diet and reduced intestinal carcinogenesis. The OFV diet changed the overall composition of the intestinal microbiota, smaller changes were observed for the CR diet. Furthermore, we detected a 16S rDNA fragment associated with mice that did not develop polyps. Sequence analysis suggested that hitherto unidentified bacteria belonging to the family Lachnospiraceae (order Clostridiales) were its source. Thus, these bacteria may be an indicator of intestinal conditions associated with reduced intestinal carcinogenesis in Apc(Min) mice. Copyright 2006 Wiley-Liss, Inc.

  11. Intestinal Cancer

    Science.gov (United States)

    ... connects your stomach to your large intestine. Intestinal cancer is rare, but eating a high-fat diet ... increase your risk. Possible signs of small intestine cancer include Abdominal pain Weight loss for no reason ...

  12. Activation of AMPK inhibits cholera toxin stimulated chloride secretion in human and murine intestine.

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    Ailín C Rogers

    Full Text Available Increased intestinal chloride secretion through chloride channels, such as the cystic fibrosis transmembrane conductance regulator (CFTR, is one of the major molecular mechanisms underlying enterotoxigenic diarrhea. It has been demonstrated in the past that the intracellular energy sensing kinase, the AMP-activated protein kinase (AMPK, can inhibit CFTR opening. We hypothesized that pharmacological activation of AMPK can abrogate the increased chloride flux through CFTR occurring during cholera toxin (CTX mediated diarrhea. Chloride efflux was measured in isolated rat colonic crypts using real-time fluorescence imaging. AICAR and metformin were used to activate AMPK in the presence of the secretagogues CTX or forskolin (FSK. In order to substantiate our findings on the whole tissue level, short-circuit current (SCC was monitored in human and murine colonic mucosa using Ussing chambers. Furthermore, fluid accumulation was measured in excised intestinal loops. CTX and forskolin (FSK significantly increased chloride efflux in isolated colonic crypts. The increase in chloride efflux could be offset by using the AMPK activators AICAR and metformin. In human and mouse mucosal sheets, CTX and FSK increased SCC. AICAR and metformin inhibited the secretagogue induced rise in SCC, thereby confirming the findings made in isolated crypts. Moreover, AICAR decreased CTX stimulated fluid accumulation in excised intestinal segments. The present study suggests that pharmacological activation of AMPK effectively reduces CTX mediated increases in intestinal chloride secretion, which is a key factor for intestinal water accumulation. AMPK activators may therefore represent a supplemental treatment strategy for acute diarrheal illness.

  13. Bovine colostrum increases pore-forming claudin-2 protein expression but paradoxically not ion permeability possibly by a change of the intestinal cytokine milieu.

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    Peggy Bodammer

    Full Text Available An impaired intestinal barrier function is involved in the pathogenesis of inflammatory bowel disease (IBD. Several nutritional factors are supposed to be effective in IBD treatment but scientific data about the effects on the intestinal integrity remain scarce. Bovine colostrum was shown to exert beneficial effects in DSS-induced murine colitis, and the present study was undertaken to explore the underlying molecular mechanisms. Western blot revealed increased claudin-2 expression in the distal ileum of healthy mice after feeding with colostrum for 14 days, whereas other tight junction proteins (claudin-3, 4, 10, 15 remained unchanged. The colostrum-induced claudin-2 induction was confirmed in differentiated Caco-2 cells after culture with colostrum for 48 h. Paradoxically, the elevation of claudin-2, which forms a cation-selective pore, was neither accompanied by increased ion permeability nor impaired barrier function. In an in situ perfusion model, 1 h exposure of the colonic mucosa to colostrum induced significantly increased mRNA levels of barrier-strengthening cytokine transforming growth factor-β, while interleukine-2, interleukine-6, interleukine-10, interleukine-13, and tumor-necrosis factor-α remained unchanged. Thus, modulation of the intestinal transforming growth factor-β expression might have compensated the claudin-2 increase and contributed to the observed barrier strengthening effects of colostrum in vivo and in vitro.

  14. A Multi-Omic View of Host-Pathogen-Commensal Interplay in Salmonella-Mediated Intestinal Infection

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, Brooke LD; Li, Jie; Sanford, James A.; Kim, Young-Mo; Kronewitter, Scott R.; Jones, Marcus B.; Peterson, Christine; Peterson, Scott N.; Frank, Bryan C.; Purvine, Samuel O.; Brown, Joseph N.; Metz, Thomas O.; Smith, Richard D.; Heffron, Fred; Adkins, Joshua N.

    2013-06-26

    The potential for commensal microorganisms indigenous to a host (the ‘microbiome’ or ‘microbiota’) to alter infection outcome by influencing host-pathogen interplay is largely unknown. We used a multi-omics “systems” approach, incorporating proteomics, metabolomics, glycomics, and metagenomics, to explore the molecular interplay between the murine host, the pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium), and commensal gut microorganisms during intestinal infection with S. Typhimurium. We find proteomic evidence that S. Typhimurium thrives within the infected 129/SvJ mouse gut without antibiotic pre-treatment, inducing inflammation and disrupting the intestinal microbiome (e.g., suppressing Bacteroidetes and Firmicutes while promoting growth of Salmonella and Enterococcus). Alteration of the host microbiome population structure was highly correlated with gut environmental changes, including the accumulation of metabolites normally consumed by commensal microbiota. Finally, the less characterized phase of S. Typhimurium’s lifecycle was investigated, and both proteomic and glycomic evidence suggests S. Typhimurium may take advantage of increased fucose moieties to metabolize fucose while growing in the gut. The application of multiple omics measurements to Salmonella-induced intestinal inflammation provides insights into complex molecular strategies employed during pathogenesis between host, pathogen, and the microbiome.

  15. Impact of copper oxide nanomaterials on differentiated and undifferentiated Caco-2 intestinal epithelial cells; assessment of cytotoxicity, barrier integrity, cytokine production and nanomaterial penetration.

    Science.gov (United States)

    Ude, Victor C; Brown, David M; Viale, Luca; Kanase, Nilesh; Stone, Vicki; Johnston, Helinor J

    2017-08-23

    Copper oxide nanomaterials (CuO NMs) are exploited in a diverse array of products including antimicrobials, inks, cosmetics, textiles and food contact materials. There is therefore a need to assess the toxicity of CuO NMs to the gastrointestinal (GI) tract since exposure could occur via direct oral ingestion, mucocillary clearance (following inhalation) or hand to mouth contact. Undifferentiated Caco-2 intestinal cells were exposed to CuO NMs (10 nm) at concentrations ranging from 0.37 to 78.13 μg/cm 2 Cu (equivalent to 1.95 to 250 μg/ml) and cell viability assessed 24 h post exposure using the alamar blue assay. The benchmark dose (BMD 20), determined using PROAST software, was identified as 4.44 μg/cm 2 for CuO NMs, and 4.25 μg/cm 2 for copper sulphate (CuSO 4 ), which informed the selection of concentrations for further studies. The differentiation status of cells and the impact of CuO NMs and CuSO 4 on the integrity of the differentiated Caco-2 cell monolayer were assessed by measurement of trans-epithelial electrical resistance (TEER), staining for Zonula occludens-1 (ZO-1) and imaging of cell morphology using scanning electron microscopy (SEM). The impact of CuO NMs and CuSO 4 on the viability of differentiated cells was performed via assessment of cell number (DAPI staining), and visualisation of cell morphology (light microscopy). Interleukin-8 (IL-8) production by undifferentiated and differentiated Caco-2 cells following exposure to CuO NMs and CuSO 4 was determined using an ELISA. The copper concentration in the cell lysate, apical and basolateral compartments were measured with Inductive Coupled Plasma Optical Emission Spectrometry (ICP-OES) and used to calculate the apparent permeability coefficient (P app ); a measure of barrier permeability to CuO NMs. For all experiments, CuSO 4 was used as an ionic control. CuO NMs and CuSO 4 caused a concentration dependent decrease in cell viability in undifferentiated cells. CuO NMs and CuSO 4

  16. Intestinal tract diseases

    International Nuclear Information System (INIS)

    Rozenshtraukh, L.S.

    1985-01-01

    Roentgenoanatomy and physiology of the small intestine are described. Indications for radiological examinations and their possibilities in the diagnosis of the small intestine diseases are considered.Congenital anomalies and failures in the small intestine development, clinical indications and diagnosis methods for the detection of different aetiology enteritis are described. Characteristics of primary malabsorption due to congenital or acquired inferiority of the small intestine, is provided. Radiological picture of intestinal allergies is described. Clinical, morphological, radiological pictures of Crohn's disease are considered in detail. Special attention is paid to the frequency of primary and secondary tuberculosis of intestinal tract. The description of clinical indications and frequency of benign and malignant tumours of the small intestine, methods for their diagnosis are given. Radiological pictures of parasitogenic and rare diseases of the small intestine are presented. Changes in the small intestine as a result of its reaction to pathological processes, developing in other organs and systems of the organism, are described

  17. Changes in intestinal tight junction permeability associated with industrial food additives explain the rising incidence of autoimmune disease.

    Science.gov (United States)

    Lerner, Aaron; Matthias, Torsten

    2015-06-01

    The incidence of autoimmune diseases is increasing along with the expansion of industrial food processing and food additive consumption. The intestinal epithelial barrier, with its intercellular tight junction, controls the equilibrium between tolerance and immunity to non-self-antigens. As a result, particular attention is being placed on the role of tight junction dysfunction in the pathogenesis of AD. Tight junction leakage is enhanced by many luminal components, commonly used industrial food additives being some of them. Glucose, salt, emulsifiers, organic solvents, gluten, microbial transglutaminase, and nanoparticles are extensively and increasingly used by the food industry, claim the manufacturers, to improve the qualities of food. However, all of the aforementioned additives increase intestinal permeability by breaching the integrity of tight junction paracellular transfer. In fact, tight junction dysfunction is common in multiple autoimmune diseases and the central part played by the tight junction in autoimmune diseases pathogenesis is extensively described. It is hypothesized that commonly used industrial food additives abrogate human epithelial barrier function, thus, increasing intestinal permeability through the opened tight junction, resulting in entry of foreign immunogenic antigens and activation of the autoimmune cascade. Future research on food additives exposure-intestinal permeability-autoimmunity interplay will enhance our knowledge of the common mechanisms associated with autoimmune progression. Copyright © 2015. Published by Elsevier B.V.

  18. High level of fecal calprotectin at age 2 months as a marker of intestinal inflammation predicts atopic dermatitis and asthma by age 6

    NARCIS (Netherlands)

    Orivuori, L.; Mustonen, K.; de Goffau, M. C.; Hakala, S.; Paasela, M.; Roduit, C.; Dalphin, J. -C.; Genuneit, J.; Lauener, R.; Riedler, J.; Weber, J.; von Mutius, E.; Pekkanen, J.; Harmsen, H. J. M.; Vaarala, O.

    BackgroundGut microbiota and intestinal inflammation regulate the development of immune-mediated diseases, such as allergies. Fecal calprotectin is a biomarker of intestinal inflammation. ObjectiveWe evaluated the association of early-age fecal calprotectin levels to the later development of

  19. Action of cholera toxin in the intestinal epithelial cells

    International Nuclear Information System (INIS)

    Hyun, C.S.

    1982-01-01

    The primary event in the action of cholera toxin on the isolated chick intestinal epithelial cell is its interaction with the cell membrane. This involves a large number (17 million per cell) of high affinity binding sites which belong to a single class. Binding of biologically active 125 I-labeled toxin is rapid, temperature-dependent, reversible, and saturable over a wide range of concentrations and includes only a small contribution from nonspecific sites. A characteristic lag phase of 10 min occurs following the complete binding of toxin before any increase in cellular cAMP levels can be detected in the isolated cells. The response (elevation of cellular cAMP) of the enterocytes to cholera toxin is linear with time for 40-50 min and causes a six- to eight-fold increase over control levels at steady stae. cAMP and agents that increase cAMP production inhibit Cl - -independent Na + influx into the isolated enterocytes whereas chlorporomazine (CPZ) which completely abolishes toxin-induced elevation of cAMP both reverses and prevents the cAMP-mediated inhibition of Na + entry. Correlation between cellular cAMP levels and the magnitude of Na + influx into the enterocytes provides evidence for a cAMP-mediated control of intestinal Na + uptake, which may represent the mechanistic basis for the antiabsorptive effect of CT and Na + during induction of intestinal secretion. The effect of cAMP on Na + but no Cl - influx in our villus cell preparation can be partially explained in terms of a cAMP-regulated Na + /H + neutral exchange system

  20. Consequences of bisphenol a perinatal exposure on immune responses and gut barrier function in mice.

    Science.gov (United States)

    Malaisé, Yann; Ménard, Sandrine; Cartier, Christel; Lencina, Corinne; Sommer, Caroline; Gaultier, Eric; Houdeau, Eric; Guzylack-Piriou, Laurence

    2018-01-01

    The potent immunomodulatory effect of the endocrine disruptor bisphenol A during development and consequences during life span are of increasing concern. Particular interests have been raised from animal studies regarding the risk of developing food intolerance and infection. We aimed to identify immune disorders in mice triggered by perinatal exposure to bisphenol A. Gravid mice were orally exposed to bisphenol (50 μg/kg body weight/day) from day 15 of pregnancy until weaning. Gut barrier function, local and systemic immunity were assessed in adult female offspring. Mice perinatally exposed to bisphenol showed a decrease in ileal lysozyme expression and a fall of fecal antimicrobial activity. In offspring mice exposed to bisphenol, an increase in colonic permeability was observed associated with an increase in interferon-γ level and a drop of colonic IgA + cells and fecal IgA production. Interestingly, altered frequency of innate lymphoid cells type 3 occurred in the small intestine, with an increase in IgG response against commensal bacteria in sera. These effects were related to a defect in dendritic cell maturation in the lamina propria and spleen. Activated and regulatory T cells were decreased in the lamina propria. Furthermore, perinatal exposure to bisphenol promoted a sharp increase in interferon-γ and interleukin-17 production in the intestine and elicited a T helper 17 profile in the spleen. To conclude, perinatal exposure to bisphenol weakens protective and regulatory immune functions in the intestine and at systemic level in adult offspring. The increased susceptibility to inflammatory response is an interesting lead supporting bisphenol-mediated adverse consequences on food reactions and infections.

  1. Tanshinone IIA Sodium Sulfonate Attenuates LPS-Induced Intestinal Injury in Mice

    Directory of Open Access Journals (Sweden)

    Xin-Jing Yang

    2018-01-01

    Full Text Available Background. Tanshinone IIA sodium sulfonate (TSS is known to possess anti-inflammatory effects and has exhibited protective effects in various inflammatory conditions; however, its role in lipopolysaccharide- (LPS- induced intestinal injury is still unknown. Objective. The present study is designed to explore the role and possible mechanism of TSS in LPS-induced intestinal injury. Methods. Male C57BL/6J mice, challenged with intraperitoneal LPS injection, were treated with or without TSS 0.5 h prior to LPS exposure. At 1, 6, and 12 h after LPS injection, mice were sacrificed, and the small intestine was excised. The intestinal tissue injury was analyzed by HE staining. Inflammatory factors (TNF-α, IL-1β, and IL-6 in the intestinal tissue were examined by ELISA and RT-PCR. In addition, expressions of autophagy markers (microtubule-associated light chain 3 (LC3 and Beclin-1 were detected by western blot and RT-PCR. A number of autophagosomes were also observed under electron microscopy. Results. TSS treatment significantly attenuated small intestinal epithelium injury induced by LPS. LPS-induced release of inflammatory mediators, including TNF-α, IL-1β, and IL-6, were markedly inhibited by TSS. Furthermore, TSS treatment could effectively upregulate LPS-induced decrease of autophagy levels, as evidenced by the increased expression of LC3 and Beclin-1, and more autophagosomes. Conclusion. The protective effect of TSS on LPS-induced small intestinal injury may be attributed to the inhibition of inflammatory factors and promotion of autophagy levels. The present study may provide novel insight into the molecular mechanisms of TSS on the treatment of intestinal injury.

  2. Intestinal innate antiviral immunity and immunobiotics: beneficial effects against rotavirus infection

    Directory of Open Access Journals (Sweden)

    Julio Villena

    2016-12-01

    Full Text Available The mucosal tissues of the gastrointestinal tract are the main portal entry of pathogens such as rotavirus (RVs, which is a leading cause of death due to diarrhea among young children across the globe and a major cause of severe acute intestinal infection in livestock animals. The interactions between intestinal epithelial cells (IECs and immune cells with RVs have been studied for several years, and now it is known that the innate immune responses triggered by this virus can have both beneficial and detrimental effects for the host. It was demonstrated that natural RVs infection in infants and experimental challenges in mice result in the intestinal activation of pattern recognition receptors (PRRs like Toll-like receptor 3 (TLR3 and striking secretion of pro-inflammatory mediators that can lead to increased local tissue damage and immunopathology. Therefore, modulating desregulated intestinal immune responses triggered by PRRs activation are a significant promise for reducing the burden of RVs diseases. The ability of immunoregulatory probiotic microorganisms (immunobiotics to protect against intestinal infections such as those caused by RVs, are among the oldest effects studied for these important group of beneficial microbes. In this review, we provide an update of the current status on the modulation of intestinal antiviral innate immunity by immunobiotics, and their beneficial impact on RVs infection. In addition, we describe the research of our group that demonstrated the capacity of immunobiotic strains to beneficially modulated TLR3-triggered immune response in IECs, reduce the disruption of intestinal homeostasis caused by intraepithelial lymphocytes, and improve the resistance to RVs infections.

  3. Extracorporeal membrane oxygenation causes loss of intestinal epithelial barrier in the newborn piglet.

    Science.gov (United States)

    Kurundkar, Ashish R; Killingsworth, Cheryl R; McIlwain, R Britt; Timpa, Joseph G; Hartman, Yolanda E; He, Dongning; Karnatak, Rajendra K; Neel, Mary L; Clancy, John P; Anantharamaiah, G M; Maheshwari, Akhil

    2010-08-01

    Extracorporeal membrane oxygenation (ECMO) is an important life-support system used in neonates and young children with intractable cardiorespiratory failure. In this study, we used our porcine neonatal model of venoarterial ECMO to investigate whether ECMO causes gut barrier dysfunction. We subjected 3-wk-old previously healthy piglets to venoarterial ECMO for up to 8 h and evaluated gut mucosal permeability, bacterial translocation, plasma levels of bacterial products, and ultrastructural changes in gut epithelium. We also measured plasma lipopolysaccharide (LPS) levels in a small cohort of human neonates receiving ECMO. In our porcine model, ECMO caused a rapid increase in gut mucosal permeability within the first 2 h of treatment, leading to a 6- to 10-fold rise in circulating bacterial products. These changes in barrier function were associated with cytoskeletal condensation in epithelial cells, which was explained by phosphorylation of a myosin II regulatory light chain. In support of these findings, we also detected elevated plasma LPS levels in human neonates receiving ECMO, indicating a similar loss of gut barrier function in these infants. On the basis of these data, we conclude that ECMO is an independent cause of gut barrier dysfunction and bacterial translocation may be an important contributor to ECMO-related inflammation.

  4. Protein metabolism in the small intestine during cancer cachexia and chemotherapy in mice.

    Science.gov (United States)

    Samuels, S E; Knowles, A L; Tilignac, T; Debiton, E; Madelmont, J C; Attaix, D

    2000-09-01

    The impact of cancer cachexia and chemotherapy on small intestinal protein metabolism and its subsequent recovery was investigated. Cancer cachexia was induced in mice with colon 26 adenocarcinoma, which is a small and slow-growing tumor characteristic of the human condition, and can be cured with 100% efficacy using an experimental nitrosourea, cystemustine (C6H12ClN3O4S). Both healthy mice and tumor-bearing mice were given a single i.p. injection of cystemustine (20 mg/kg) 3 days after the onset of cachexia. Cancer cachexia led to a reduced in vivo rate of protein synthesis in the small intestine relative to healthy mice (-13 to -34%; P synthesis compared with healthy mice (23-34%; P < 0.05). Northern hybridizations of mRNA encoding components of the major proteolytic systems suggested that proteolysis may not have mediated intestinal wasting or recovery. A major clinical goal should be to design methods to improve small intestinal protein metabolism before the initiation of chemotherapy.

  5. The Occurrence of Antibodies Against Gluten in Children with Autism Spectrum Disorders Does Not Correlate with Serological Markers of Impaired Intestinal Permeability.

    Science.gov (United States)

    Józefczuk, Jan; Konopka, Ewa; Bierła, Joanna Beata; Trojanowska, Ilona; Sowińska, Agnieszka; Czarnecki, Rafał; Sobol, Lucjan; Józefczuk, Paweł; Surdy, Weronika; Cukrowska, Bożena

    2018-02-01

    There is evidence that children with autism spectrum disorders (ASDs) display an increased immune reactivity against gluten, which is supposed to be the effect of intestinal barrier abnormalities. The aim of study was to evaluate the relation of antibody induced by gluten to zonulin and intestinal fatty acid binding proteins (I-FABP), that is, serological markers of an impaired gut barrier. The study included 77 patients with ASDs. Zonulin, I-FABP, celiac-specific antibodies, anti-gliadin antibodies (AGA), and antibodies against neural transglutaminase 6 (TG6) of immunoglobulin (Ig) A and IgG classes were detected in sera. Celiac-specific antibodies were negative in all ASD children, four children (5.2%) had positive anti-TG6 antibodies, and increased AGA-IgG production was found in 21 patients (27.3%). Mean levels of zonulin and I-FABP in ASD patients were similar to those found in healthy controls and revealed a negative correlation with age, whereas regression analysis revealed a significant positive relationship between antibody production and the age. Serum concentrations of zonulin and I-FABP showed no statistically significant association with antibody positivity. An increased production of antibodies related to gliadin and neural TG6 in ASD children is not related to serological markers of an impaired intestinal barrier.

  6. Myoelectric activity of the small intestine during morphine dependence and withdrawal in rats

    International Nuclear Information System (INIS)

    Kuperman, D.A.; Sninsky, C.A.; Lynch, D.F.

    1987-01-01

    The authors investigated (1) the effect of morphine dependence on the migrating myoelectric complex (MMC) of the small intestine, (2) whether bacterial overgrowth developed in morphine-dependent rats, and (3) the effect of naloxone and methylbromide naltrexone, a peripheral opioid antagonist, on the MMC in morphine-naive and morphine-dependent rats. They also evaluated intestinal motility during naloxone-induced withdrawal in animals pretreated with clonidine. Intestinal myoelectric activity was monitored by four indwelling electrodes in unanesthetized, fasted rats. D-[ 14 C]xylose breath tests were performed before and after morphine-pellet implantation to evaluate the presence of bacterial overgrowth of the small intestine. Naloxone had no effect on myoelectric activity of the small intestine in morphine-naive rats. Cycling activity fronts were present in morphine-dependent animals, but there was a significant prolongation of activity front periodicity and slowing of the propagation velocity. No significant increase in 14 CO 2 excretion was noted in the morphine-dependent rats. They conclude from their studies that (1) myoelectric activity of the small intestine develops incomplete tolerance to morphine; (2) bacterial overgrowth is not a feature of morphine dependence in the rat; (3) alterations of intestinal myoelectric activity are a component of the opiate withdrawal syndrome, and they appear at least partially mediated by a peripheral mechanism that can be suppressed by an α 2 -adrenergic agonist

  7. Myoelectric activity of the small intestine during morphine dependence and withdrawal in rats

    Energy Technology Data Exchange (ETDEWEB)

    Kuperman, D.A.; Sninsky, C.A.; Lynch, D.F.

    1987-04-01

    The authors investigated (1) the effect of morphine dependence on the migrating myoelectric complex (MMC) of the small intestine, (2) whether bacterial overgrowth developed in morphine-dependent rats, and (3) the effect of naloxone and methylbromide naltrexone, a peripheral opioid antagonist, on the MMC in morphine-naive and morphine-dependent rats. They also evaluated intestinal motility during naloxone-induced withdrawal in animals pretreated with clonidine. Intestinal myoelectric activity was monitored by four indwelling electrodes in unanesthetized, fasted rats. D-(/sup 14/C)xylose breath tests were performed before and after morphine-pellet implantation to evaluate the presence of bacterial overgrowth of the small intestine. Naloxone had no effect on myoelectric activity of the small intestine in morphine-naive rats. Cycling activity fronts were present in morphine-dependent animals, but there was a significant prolongation of activity front periodicity and slowing of the propagation velocity. No significant increase in /sup 14/CO/sub 2/ excretion was noted in the morphine-dependent rats. They conclude from their studies that (1) myoelectric activity of the small intestine develops incomplete tolerance to morphine; (2) bacterial overgrowth is not a feature of morphine dependence in the rat; (3) alterations of intestinal myoelectric activity are a component of the opiate withdrawal syndrome, and they appear at least partially mediated by a peripheral mechanism that can be suppressed by an ..cap alpha../sub 2/-adrenergic agonist.

  8. Thymol and Carvacrol Affect Hybrid Tilapia through the Combination of Direct Stimulation and an Intestinal Microbiota-Mediated Effect: Insights from a Germ-Free Zebrafish Model.

    Science.gov (United States)

    Ran, Chao; Hu, Jun; Liu, Wenshu; Liu, Zhi; He, Suxu; Dan, Bui Chau Truc; Diem, Nguyen Ngoc; Ooi, Ei Lin; Zhou, Zhigang

    2016-05-01

    Essential oils (EOs) are commonly used as animal feed additives. Information is lacking on the mechanisms driving the beneficial effects of EOs in animals, especially the role played by the intestinal microbiota of the host. The purpose of this study was to clarify the relative contribution of direct effects of EOs on the physiology and immune system of tilapia and indirect effects mediated by the intestinal microbiota by using a germ-free zebrafish model. Juvenile hybrid tilapia were fed a control diet or 1 of 4 treatment diets containing 60-800 mg Next Enhance 150 (NE) (an EO product containing equal levels of thymol and carvacrol)/kg for 6 wk. The key humoral and cellular innate immune parameters were evaluated after the feeding period. In another experiment, the gut microbiota of tilapia fed a control or an NE diet (200 mg/kg) for 2 wk were transferred to 3-d postfertilization (dpf) germ-free (GF) zebrafish, and the expression of genes involved in innate immunity and tight junctions was evaluated in zebrafish at 6 dpf. Lastly, NE was directly applied to 3-dpf GF zebrafish at 3 doses ranging from 0.2 to 20 mg/L, and the direct effect of NE on zebrafish was evaluated after 1 and 3 d. NE supplementation at 200 mg/kg enhanced phagocytosis activity of head kidney macrophages (×1.36) (P tilapia compared with the control (P tilapia through a combination of factors, i.e., primarily through a direct effect on host tissue (immune-stimulating) but also an indirect effect mediated by microbial changes (immune-relieving). © 2016 American Society for Nutrition.

  9. β2-Adrenergic Receptor-Mediated HIF-1α Upregulation Mediates Blood Brain Barrier Damage in Acute Cerebral Ischemia

    Directory of Open Access Journals (Sweden)

    Yanyun Sun

    2017-08-01

    Full Text Available Disruption of the blood brain barrier (BBB within the thrombolytic time window is an antecedent event to intracerebral hemorrhage in ischemic stroke. Our recent studies showed that 2-h cerebral ischemia induced BBB damage in non-infarcted area and secreted matrix metalloproteinase-2 (MMP-2 accounted for this disruption. However, the factors that affect MMP-2 secretion and regulate BBB damage remains unknown. Since hypoxia-inducible factor-1 alpha (HIF-1α was discovered as a mater regulator in hypoxia, we sought to investigate the roles of HIF-1α in BBB damage as well as the factors regulating HIF-1α expression in the ischemic brain. in vivo rat middle cerebral artery occlusion (MCAO and in vitro oxygen glucose deprivation (OGD models were used to mimic ischemia. Pretreatment with HIF-1α inhibitor YC-1 significantly inhibited 2-h MCAO-induced BBB damage, which was accompanied by suppressed occludin degradation and vascular endothelial growth factor (VEGF mRNA upregulation. Interestingly, β2-adrenergic receptor (β2-AR antagonist ICI 118551 attenuated ischemia-induced BBB damage by regulating HIF-1α expression. Double immunostaining showed that HIF-1α was upregulated in ischemic neurons but not in astrocytes andendothelial cells. Of note, HIF-1α inhibition with inhibitor YC-1 or siRNA significantly prevented OGD-induced VEGF upregulation as well as the secretion of VEGF and MMP-2 in neurons. More importantly, blocking β2-AR with ICI 118551 suppressedHIF-1α upregulation in ischemic neurons and attenuated occludin degradation induced by the conditioned media of OGD-treatedneurons. Taken together, blockade of β2-AR-mediated HIF-1α upregulation mediates BBB damage during acute cerebral ischemia. These findings provide new mechanistic understanding of early BBB damage in ischemic stroke and may help reduce thrombolysis-related hemorrhagic complications.

  10. Non-invasive assessment of barrier integrity and function of the human gut

    NARCIS (Netherlands)

    Grootjans, J.; Thuijls, G.; Verdam, F.J.; Derikx, J.P.M.; Lenaerts, K.; Buurman, W.A.

    2010-01-01

    Over the past decades evidence has been accumulating that intestinal barrier integrity loss plays a key role in the development and perpetuation of a variety of disease states including inflammatory bowel disease and celiac disease, and is a key player in the onset of sepsis and multiple organ

  11. Effect of glutamine-enriched nutritional support on intestinal mucosal barrier function, MMP-2, MMP-9 and immune function in patients with advanced gastric cancer during perioperative chemotherapy.

    Science.gov (United States)

    Wang, Juan; Li, Yanfen; Qi, Yuanling

    2017-09-01

    We studied the effects of glutamine-enriched nutritional support on intestinal mucosal barrier, matrix metalloproteinase (MMP)-2, MMP-9 and immune function during perioperative chemotherapy in patients with advanced gastric cancer. The study was conducted on 94 patients with advanced gastric cancer admitted from April 2015 to March 2016. They were randomly divided into observation and control groups, n=47. Control group was given basic nutritional support whereas glutamine-enriched nutritional support was given to patients in observation group. High-performance liquid chromatography was used to measure lactulose and mannitol ratio in urine (L/M) and ELISA was used to measure D-lactate levels before chemotherapy and in the 1st, 2nd and 3rd cycle of chemotherapy. Immunoglobulin level was detected by immune turbidimetry assay, T lymphocyte subsets were determined by flow cytometry after 3 cycles of chemotherapy, MMP-2 and MMP-9 of patients were compared between the two groups. The serious adverse reactions incidence (grade and IV) of patients were observed. To evaluate the life quality of patients, QLQ-C30 was used after 6 months. The levels of L/M and D-lactate in both groups after the first cycle of chemotherapy were significantly higher than that before chemotherapy; they began to decline after the second or third cycle, but were still significantly higher than the levels before chemotherapy (pgroups after 1st, 2nd, 3rd cycle after chemotherapy, L/M and D-lactate levels of patients in the observation group were significantly lower than in the control group (pgroup was significantly lower than control group (pgroup were significantly higher than control group (pnutritional support can effectively protect the intestinal mucosal barrier function in patients with advanced gastric cancer in their perioperative chemotherapy, improve the level of MMP-2 and MMP-9 in patients with advanced gastric cancer, enhance their immune function, reduce the incidence of adverse

  12. Stimulation of intestinal growth and function with DPP-IV inhibition in a mouse short bowel syndrome model

    DEFF Research Database (Denmark)

    Sueyoshi, Ryo; Ignatoski, Kathleen M Woods; Okawada, Manabu

    2014-01-01

    , and 7 days followed by 23 days washout period. Adaptive response was assessed by morphology, intestinal epithelial cell (IEC) proliferation (PCNA), epithelial barrier function (transepithelial resistance), RT-PCR for intestinal transport proteins, GLP-2R, and IGF-1R, and GLP-2 plasma levels. Glucose-stimulated...... sodium transport was assessed for intestinal absorptive function. Seven days of DPP4-I treatment facilitated an increase in GLP-2R levels, intestinal growth, and IEC proliferation. Treatment led to differential effects over time with greater absorptive function early, and enhanced proliferation at later...... time points. Interestingly, 7 day treatment followed by 23 days of non-treatment showed continued adaptation. DPP-IV-I enhanced IEC proliferative action up to 90-days post-resection, but this action seemed to peak by 30 days, as did GLP-2 plasma levels. Thus, use of DPP4-I treatment may prove...

  13. Intestinal Serotonin Transporter Inhibition by Toll-Like Receptor 2 Activation. A Feedback Modulation.

    Directory of Open Access Journals (Sweden)

    Eva Latorre

    Full Text Available TLR2 is a microbiota recognition receptor that has been described to contribute to intestinal homeostasis and to ameliorate inflammatory intestinal injury. In this context, serotonin (5-HT has shown to be an essential intestinal physiological neuromodulator that is also involved in intestinal inflammatory diseases. Since the interaction between TLR2 activation and the intestinal serotoninergic system remains non-investigated, our main aim was to analyze the effect of TLR2 on intestinal serotonin transporter (SERT activity and expression and the intracellular pathways involved. Caco-2/TC7 cells were used to analyze SERT and TLR2 molecular expression and SERT activity by measuring 5-HT uptake. The results showed that apical TLR2 activation inhibits SERT activity in Caco-2/TC7 cells mainly by reducing SERT protein level either in the plasma membrane, after short-term TLR2 activation or in both the plasma membrane and cell lysate, after long-term activation. cAMP/PKA pathway appears to mediate short-term inhibitory effect of TLR2 on SERT; however, p38 MAPK pathway has been shown to be involved in both short- and long-term TLR2 effect. Reciprocally, 5-HT long-term treatment yielded TLR2 down regulation in Caco-2/TC7 cells. Finally, results from in vivo showed an augmented intestinal SERT expression in mice Tlr2-/-, thus confirming our inhibitory effect of TLR2 on intestinal SERT in vitro. The present work infers that TLR2 may act in intestinal pathophysiology, not only by its inherent innate immune role, but also by regulating the intestinal serotoninergic system.

  14. Mediating Effects of Self-Efficacy, Benefits and Barriers on the Association between Peer and Parental Factors and Physical Activity among Adolescent Girls with a Lower Educational Level.

    Directory of Open Access Journals (Sweden)

    Maite Verloigne

    Full Text Available The prevalence of physical activity among lower educated adolescent girls is low, suggesting it is important to have insights into the complex processes that may underlie their physical activity levels. Therefore, this study aimed to examine the mediating effects of self-efficacy, perceived benefits and barriers on the associations between peer and parental variables and physical activity among lower educated adolescent girls.In total, 226 girls (mean age 16.0±1.0 years; 53% technical education; 47% vocational education from a convenience sample of 6 secondary schools in Flanders, Belgium, completed a questionnaire on their total physical activity level and related peer and parental variables (i.e. modeling of physical activity, co-participation in physical activities and encouragement to be active and personal variables (i.e. self-efficacy to be active, and specific perceived benefits of physical activity and specific barriers to be active. Mediating effects were tested using MacKinnon's product-of-coefficients test based on multilevel linear regression analyses.Higher peer and parental modeling, co-participation and encouragement were significantly related to a higher physical activity level among adolescent girls (p<0.05. Self-efficacy, the perceived benefits of having fun, being around friends or meeting new people, and not being bored and the perceived barrier of not liking physical activity mediated several associations between peer and parental variables and girls' physical activity, with some of the mediated proportions exceeding 60%.This study contributed to a better understanding of the complexity of how parental and peer factors work together with personal factors to influence the physical activity levels of adolescent girls with a lower educational level. Interventions should involve both peers and parents, as they may influence girls' physical activity both directly and indirectly through the internalisation of several personal

  15. Molecular Characterization of Barrier Properties in Follicle-Associated Epithelium of Porcine Peyer's Patches Reveals Major Sealing Function of Claudin-4

    Directory of Open Access Journals (Sweden)

    Judith Radloff

    2017-08-01

    Full Text Available The pig represents a preferred model for the analysis of intestinal immunology. However, the barrier of the follicle-associated epithelium (FAE covering porcine Peyer's patches (PP has not yet been characterized in detail. This study aimed to perform this characterization in order to pave the way toward an understanding of the functional contribution of epithelial barrier properties in gut immunology. Porcine tissue specimens were taken from the distal small intestine in order to obtain electrophysiological data of PP FAE and neighboring villous epithelium (VE, employing the Ussing chamber technique. Transepithelial resistance (TER and paracellular fluorescein flux were measured, and tissues were morphometrically compared. In selfsame tissues, expression and localization of major tight junction (TJ proteins (claudin-1, -2, -3, -4, -5, and -8 were analyzed. PP FAE specimens showed a higher TER and a lower apparent permeability for sodium fluorescein than VE. Immunoblotting revealed an expression of all claudins within both epithelia, with markedly stronger expression of the sealing TJ protein claudin-4 in PP FAE compared with the neighboring VE. Immunohistochemistry confirmed the expression and localization of all claudins in both PP FAE and VE, with stronger claudin-4 abundance in PP FAE. The results are in accordance with the physiological function of the FAE, which strongly regulates and limits antigen uptake determining a mandatory transcellular route for antigen presentation, highlighting the importance of this structure for the first steps of the intestinal immune response. Thus, this study provides detailed insights into the specific barrier properties of the porcine FAE covering intestinal PP, at the interface of intestinal immunology and barriology.

  16. Intestinal Surgery.

    Science.gov (United States)

    Desrochers, André; Anderson, David E

    2016-11-01

    A wide variety of disorders affecting the intestinal tract in cattle may require surgery. Among those disorders the more common are: intestinal volvulus, jejunal hemorrhage syndrome and more recently the duodenal sigmoid flexure volvulus. Although general principles of intestinal surgery can be applied, cattle has anatomical and behavior particularities that must be known before invading the abdomen. This article focuses on surgical techniques used to optimize outcomes and discusses specific disorders of small intestine. Diagnoses and surgical techniques presented can be applied in field conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Stat6 Promotes Intestinal Tumorigenesis in a Mouse Model of Adenomatous Polyposis by Expansion of MDSCs and Inhibition of Cytotoxic CD8 Response

    Directory of Open Access Journals (Sweden)

    Asha Jayakumar

    2017-08-01

    Full Text Available Intestinal tumorigenesis in the ApcMin/+ model is initiated by aberrant activation of Wnt pathway. Increased IL-4 expression in human colorectal cancer tissue and growth of colon cancer cell lines implied that IL-4–induced Stat6-mediated tumorigenic signaling likely contributes to intestinal tumor progression in ApcMin/+ mice. Stat6 also appears to promote expansion of myeloid-derived suppressor cells (MDSCs cells. MDSCs promote polyp formation in the ApcMin/+ model. Hence, Stat6 could have a broad role in coordinating both polyp cell proliferation and MDSC expansion. We found that IL-4–induced Stat6-mediated proliferation of intestinal epithelial cells is augmented by platelet-derived growth factor–BB, a tumor-promoting growth factor. To determine whether polyp progression in ApcMin/+ mice is dependent on Stat6 signaling, we disrupted Stat6 in this model. Total polyps in the small intestine were fewer in ApcMin/+ mice lacking Stat6. Furthermore, proliferation of polyp epithelial cells was reduced, indicating that Stat6 in part controlled polyp formation. Stat6 also promoted expansion of MDSCs in the spleen and lamina propria of ApcMin/+ mice, implying regulation of antitumor T-cell response. More CD8 cells and reduced PD-1 expression on CD4 cells correlated with reduced polyps. In addition, a strong CD8-mediated cytotoxic response led to killing of tumor cells in Stat6-deficient ApcMin/+ mice. Therefore, these findings show that Stat6 has an oncogenic role in intestinal tumorigenesis by promoting polyp cell proliferation and immunosuppressive mediators, and preventing an active cytotoxic process.

  18. Stat6 Promotes Intestinal Tumorigenesis in a Mouse Model of Adenomatous Polyposis by Expansion of MDSCs and Inhibition of Cytotoxic CD8 Response.

    Science.gov (United States)

    Jayakumar, Asha; Bothwell, Alfred L M

    2017-08-01

    Intestinal tumorigenesis in the ApcMin/+ model is initiated by aberrant activation of Wnt pathway. Increased IL-4 expression in human colorectal cancer tissue and growth of colon cancer cell lines implied that IL-4-induced Stat6-mediated tumorigenic signaling likely contributes to intestinal tumor progression in ApcMin/+ mice. Stat6 also appears to promote expansion of myeloid-derived suppressor cells (MDSCs) cells. MDSCs promote polyp formation in the ApcMin/+ model. Hence, Stat6 could have a broad role in coordinating both polyp cell proliferation and MDSC expansion. We found that IL-4-induced Stat6-mediated proliferation of intestinal epithelial cells is augmented by platelet-derived growth factor-BB, a tumor-promoting growth factor. To determine whether polyp progression in ApcMin/+ mice is dependent on Stat6 signaling, we disrupted Stat6 in this model. Total polyps in the small intestine were fewer in ApcMin/+ mice lacking Stat6. Furthermore, proliferation of polyp epithelial cells was reduced, indicating that Stat6 in part controlled polyp formation. Stat6 also promoted expansion of MDSCs in the spleen and lamina propria of ApcMin/+ mice, implying regulation of antitumor T-cell response. More CD8 cells and reduced PD-1 expression on CD4 cells correlated with reduced polyps. In addition, a strong CD8-mediated cytotoxic response led to killing of tumor cells in Stat6-deficient ApcMin/+ mice. Therefore, these findings show that Stat6 has an oncogenic role in intestinal tumorigenesis by promoting polyp cell proliferation and immunosuppressive mediators, and preventing an active cytotoxic process. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  19. Possible links between intestinal permeablity and food processing: a potential therapeutic niche for glutamine

    Directory of Open Access Journals (Sweden)

    Jean Robert Rapin

    2010-01-01

    Full Text Available Increased intestinal permeability is a likely cause of various pathologies, such as allergies and metabolic or even cardiovascular disturbances. Intestinal permeability is found in many severe clinical situations and in common disorders such as irritable bowel syndrome. In these conditions, substances that are normally unable to cross the epithelial barrier gain access to the systemic circulation. To illustrate the potential harmfulness of leaky gut, we present an argument based on examples linked to protein or lipid glycation induced by modern food processing. Increased intestinal permeability should be largely improved by dietary addition of compounds, such as glutamine or curcumin, which both have the mechanistic potential to inhibit the inflammation and oxidative stress linked to tight junction opening. This brief review aims to increase physician awareness of this common, albeit largely unrecognized, pathology, which may be easily prevented or improved by means of simple nutritional changes.

  20. Possible Links between Intestinal Permeablity and Food Processing: A Potential Therapeutic Niche for Glutamine

    Science.gov (United States)

    Rapin, Jean Robert; Wiernsperger, Nicolas

    2010-01-01

    Increased intestinal permeability is a likely cause of various pathologies, such as allergies and metabolic or even cardiovascular disturbances. Intestinal permeability is found in many severe clinical situations and in common disorders such as irritable bowel syndrome. In these conditions, substances that are normally unable to cross the epithelial barrier gain access to the systemic circulation. To illustrate the potential harmfulness of leaky gut, we present an argument based on examples linked to protein or lipid glycation induced by modern food processing. Increased intestinal permeability should be largely improved by dietary addition of compounds, such as glutamine or curcumin, which both have the mechanistic potential to inhibit the inflammation and oxidative stress linked to tight junction opening. This brief review aims to increase physician awareness of this common, albeit largely unrecognized, pathology, which may be easily prevented or improved by means of simple nutritional changes. PMID:20613941

  1. L-cysteine protects intestinal integrity, attenuates intestinal inflammation and oxidant stress, and modulates NF-κB and Nrf2 pathways in weaned piglets after LPS challenge.

    Science.gov (United States)

    Song, Ze he; Tong, Guo; Xiao, Kan; Jiao, Le fei; Ke, Ya lu; Hu, Cai hong

    2016-04-01

    In this study we investigated whetherL-cysteine (L-cys) could alleviate LPS-induced intestinal disruption and its underlying mechanism. Piglets fed with anL-cys-supplemented diet had higher average daily gain.L-cys alleviated LPS-induced structural and functional disruption of intestine in weanling piglets, as demonstrated by higher villus height, villus height (VH) to crypt depth (CD) ratio, and transepithelial electrical resistance (TER) and lower FITC-dextran 4 (FD4) kDa flux in jejunum and ileum. Supplementation withL-cys up-regulated occludin and claudin-1 expression, reduced caspase-3 activity and enhanced proliferating cell nuclear antigen expression of jejunum and ileum relative to LPS group. Additionally,L-cys suppressed the LPS-induced intestinal inflammation and oxidative stress, as demonstrated by down-regulated TNF-α, IL-6 and IL-8 mRNA levels, increased catalase, superoxide dismutase, glutathione peroxidase activity, glutathione (GSH) contents and the ratio of GSH and oxidized glutathione in jejunum and ileum. Finally, a diet supplemented withL-cys inhibited NF-κB(p65) nuclear translocation and elevated NF erythroid 2-related factor 2 (Nrf2) translocation compared with the LPS group. Collectively, our results indicated the protective function ofL-cys on intestinal mucosa barrier may closely associated with its anti-inflammation, antioxidant and regulating effect on the NF-κB and Nrf2 signaling pathways. © The Author(s) 2016.

  2. Impact of Intestinal Microbiota on Intestinal Luminal Metabolome

    Science.gov (United States)

    Matsumoto, Mitsuharu; Kibe, Ryoko; Ooga, Takushi; Aiba, Yuji; Kurihara, Shin; Sawaki, Emiko; Koga, Yasuhiro; Benno, Yoshimi

    2012-01-01

    Low–molecular-weight metabolites produced by intestinal microbiota play a direct role in health and disease. In this study, we analyzed the colonic luminal metabolome using capillary electrophoresis mass spectrometry with time-of-flight (CE-TOFMS) —a novel technique for analyzing and differentially displaying metabolic profiles— in order to clarify the metabolite profiles in the intestinal lumen. CE-TOFMS identified 179 metabolites from the colonic luminal metabolome and 48 metabolites were present in significantly higher concentrations and/or incidence in the germ-free (GF) mice than in the Ex-GF mice (p metabolome and a comprehensive understanding of intestinal luminal metabolome is critical for clarifying host-intestinal bacterial interactions. PMID:22724057

  3. Small Intestine Disorders

    Science.gov (United States)

    ... disease Crohn's disease Infections Intestinal cancer Intestinal obstruction Irritable bowel syndrome Ulcers, such as peptic ulcer Treatment of disorders of the small intestine depends on the cause.

  4. Introduction for the special issue on recent advances in drug delivery across tissue barriers.

    Science.gov (United States)

    Mrsny, Randall J; Brayden, David J

    2016-01-01

    This special issue of Tissue Barriers contains a series of reviews with the common theme of how biological barriers established at epithelial tissues limit the uptake of macromolecular therapeutics. By improving our functional understanding of these barriers, the majority of the authors have highlighted potential strategies that might be applied to the non-invasive delivery of biopharmaceuticals that would otherwise require an injection format for administration. Half of the articles focus on the potential of particular technologies to assist oral delivery of peptides, proteins and other macromolecules. These include use of prodrug chemistry to improve molecule stability and permeability, and the related potential for oral delivery of poorly permeable agents by cell-penetrating peptides and dendrimers. Safety aspects of intestinal permeation enhancers are discussed, along with the more recent foray into drug-device combinations as represented by intestinal microneedles and externally-applied ultrasound. Other articles highlight the crossover between food research and oral delivery based on nanoparticle technology, while the final one provides a fascinating interpretation of the physiological problems associated with subcutaneous insulin delivery and how inefficient it is at targeting the liver.

  5. Intraepithelial lymphocytes express junctional molecules in murine small intestine

    International Nuclear Information System (INIS)

    Inagaki-Ohara, Kyoko; Sawaguchi, Akira; Suganuma, Tatsuo; Matsuzaki, Goro; Nawa, Yukifumi

    2005-01-01

    Intestinal intraepithelial lymphocytes (IEL) that reside at basolateral site regulate the proliferation and differentiation of epithelial cells (EC) for providing a first line of host defense in intestine. However, it remains unknown how IEL interact and communicate with EC. Here, we show that IEL express junctional molecules like EC. We identified mRNA expression of the junctional molecules in IEL such as zonula occludens (ZO)-1, occludin and junctional adhesion molecule (JAM) (tight junction), β-catenin and E-cadherin (adherens junction), and connexin26 (gap junction). IEL constitutively expressed occludin and E-cadherin at protein level, while other T cells in the thymus, spleen, liver, mesenteric lymph node, and Peyer's patches did not. γδ IEL showed higher level of these expressions than αβ IEL. The expression of occludin was augmented by anti-CD3 Ab stimulation. These results suggest the possibility of a novel role of IEL concerning epithelial barrier and communication between IEL and EC

  6. The role of the Hes1 crosstalk hub in Notch-Wnt interactions of the intestinal crypt

    KAUST Repository

    Kay, Sophie K.

    2017-03-01

    The Notch pathway plays a vital role in determining whether cells in the intestinal epithelium adopt a secretory or an absorptive phenotype. Cell fate specification is coordinated via Notch’s interaction with the canonical Wnt pathway. Here, we propose a new mathematical model of the Notch and Wnt pathways, in which the Hes1 promoter acts as a hub for pathway crosstalk. Computational simulations of the model can assist in understanding how healthy intestinal tissue is maintained, and predict the likely consequences of biochemical knockouts upon cell fate selection processes. Chemical reaction network theory (CRNT) is a powerful, generalised framework which assesses the capacity of our model for monostability or multistability, by analysing properties of the underlying network structure without recourse to specific parameter values or functional forms for reaction rates. CRNT highlights the role of β-catenin in stabilising the Notch pathway and damping oscillations, demonstrating that Wnt-mediated actions on the Hes1 promoter can induce dynamic transitions in the Notch system, from multistability to monostability. Time-dependent model simulations of cell pairs reveal the stabilising influence of Wnt upon the Notch pathway, in which β-catenin- and Dsh-mediated action on the Hes1 promoter are key in shaping the subcellular dynamics. Where Notch-mediated transcription of Hes1 dominates, there is Notch oscillation and maintenance of fate flexibility; Wnt-mediated transcription of Hes1 favours bistability akin to cell fate selection. Cells could therefore regulate the proportion of Wnt- and Notch-mediated control of the Hes1 promoter to coordinate the timing of cell fate selection as they migrate through the intestinal epithelium and are subject to reduced Wnt stimuli. Furthermore, mutant cells characterised by hyperstimulation of the Wnt pathway may, through coupling with Notch, invert cell fate in neighbouring healthy cells, enabling an aberrant cell to maintain

  7. The role of the Hes1 crosstalk hub in Notch-Wnt interactions of the intestinal crypt

    KAUST Repository

    Kay, Sophie K.; Harrington, Heather A.; Shepherd, Sarah; Brennan, Keith; Dale, Trevor; Osborne, James M.; Gavaghan, David J.; Byrne, Helen M.

    2017-01-01

    The Notch pathway plays a vital role in determining whether cells in the intestinal epithelium adopt a secretory or an absorptive phenotype. Cell fate specification is coordinated via Notch’s interaction with the canonical Wnt pathway. Here, we propose a new mathematical model of the Notch and Wnt pathways, in which the Hes1 promoter acts as a hub for pathway crosstalk. Computational simulations of the model can assist in understanding how healthy intestinal tissue is maintained, and predict the likely consequences of biochemical knockouts upon cell fate selection processes. Chemical reaction network theory (CRNT) is a powerful, generalised framework which assesses the capacity of our model for monostability or multistability, by analysing properties of the underlying network structure without recourse to specific parameter values or functional forms for reaction rates. CRNT highlights the role of β-catenin in stabilising the Notch pathway and damping oscillations, demonstrating that Wnt-mediated actions on the Hes1 promoter can induce dynamic transitions in the Notch system, from multistability to monostability. Time-dependent model simulations of cell pairs reveal the stabilising influence of Wnt upon the Notch pathway, in which β-catenin- and Dsh-mediated action on the Hes1 promoter are key in shaping the subcellular dynamics. Where Notch-mediated transcription of Hes1 dominates, there is Notch oscillation and maintenance of fate flexibility; Wnt-mediated transcription of Hes1 favours bistability akin to cell fate selection. Cells could therefore regulate the proportion of Wnt- and Notch-mediated control of the Hes1 promoter to coordinate the timing of cell fate selection as they migrate through the intestinal epithelium and are subject to reduced Wnt stimuli. Furthermore, mutant cells characterised by hyperstimulation of the Wnt pathway may, through coupling with Notch, invert cell fate in neighbouring healthy cells, enabling an aberrant cell to maintain

  8. The role of the Hes1 crosstalk hub in Notch-Wnt interactions of the intestinal crypt.

    Directory of Open Access Journals (Sweden)

    Sophie K Kay

    2017-02-01

    Full Text Available The Notch pathway plays a vital role in determining whether cells in the intestinal epithelium adopt a secretory or an absorptive phenotype. Cell fate specification is coordinated via Notch's interaction with the canonical Wnt pathway. Here, we propose a new mathematical model of the Notch and Wnt pathways, in which the Hes1 promoter acts as a hub for pathway crosstalk. Computational simulations of the model can assist in understanding how healthy intestinal tissue is maintained, and predict the likely consequences of biochemical knockouts upon cell fate selection processes. Chemical reaction network theory (CRNT is a powerful, generalised framework which assesses the capacity of our model for monostability or multistability, by analysing properties of the underlying network structure without recourse to specific parameter values or functional forms for reaction rates. CRNT highlights the role of β-catenin in stabilising the Notch pathway and damping oscillations, demonstrating that Wnt-mediated actions on the Hes1 promoter can induce dynamic transitions in the Notch system, from multistability to monostability. Time-dependent model simulations of cell pairs reveal the stabilising influence of Wnt upon the Notch pathway, in which β-catenin- and Dsh-mediated action on the Hes1 promoter are key in shaping the subcellular dynamics. Where Notch-mediated transcription of Hes1 dominates, there is Notch oscillation and maintenance of fate flexibility; Wnt-mediated transcription of Hes1 favours bistability akin to cell fate selection. Cells could therefore regulate the proportion of Wnt- and Notch-mediated control of the Hes1 promoter to coordinate the timing of cell fate selection as they migrate through the intestinal epithelium and are subject to reduced Wnt stimuli. Furthermore, mutant cells characterised by hyperstimulation of the Wnt pathway may, through coupling with Notch, invert cell fate in neighbouring healthy cells, enabling an aberrant

  9. BNCT of intracerebral melanoma. Enhanced survival and cure following Cereport mediated opening of the blood-brain barrier

    International Nuclear Information System (INIS)

    Barth, R.F.; Yang, W.; Bartus, R.T.; Rotaru, J.H.; Ferketich, A.K.; Moeschberger, M.L.; Nawrocky, M.M.; Coderre, J.A.

    2000-01-01

    Cereport is a bradykinin analogue that produces a transient, pharmacologically mediated opening of the blood-brain barrier (BBB). The present study was designed to determine if Cereport could enhance the delivery of BPA and the efficacy of BNCT in nude rats bearing intracerebral implants of the human MRA 27 melanoma. Animals that received intracarotid (i.c.) injection of Cereport and i.c. BPA had a mean survival time of 115 d compared to 82 d without Cereport, 42 d for i.v. BPA with Cereport and 31 d for irradiated controls. The combination of i.c. Cereport and BPA produced a 400% increase in the life span with 35% long-term survivors (>180 d). (author)

  10. The chemical form of plutonium in foodstuffs - its influence on gastro-intestinal uptake

    International Nuclear Information System (INIS)

    Cooper, J.R.

    1984-01-01

    A brief review is given of some studies of the chemical form of plutonium in food eaten by man and how this may influence gastrointestinal uptake. Phytate ligands, present in many foods, bind strongly to plutonium. High levels of enzyme phytase in rat intestines enhance the gastrointestinal uptake of plutonium phytate in rats compared to rabbits. Taking into account 1) the low levels of phytase in human intestine and 2) the possibility of competing precipitation reactions, it would seem unlikely that the phytate-mediated elevation of plutonium uptake seen in rats will apply to humans. (U.K.)

  11. Phenylbutyrate counteracts Shigella mediated downregulation of cathelicidin in rabbit lung and intestinal epithelia: a potential therapeutic strategy.

    Directory of Open Access Journals (Sweden)

    Protim Sarker

    Full Text Available BACKGROUND: Cathelicidins and defensins are endogenous antimicrobial peptides (AMPs that are downregulated in the mucosal epithelia of the large intestine in shigellosis. Oral treatment of Shigella infected rabbits with sodium butyrate (NaB reduces clinical severity and counteracts the downregulation of cathelicidin (CAP-18 in the large intestinal epithelia. AIMS: To develop novel regimen for treating infectious diseases by inducing innate immunity, we selected sodium 4-phenylbutyrate (PB, a registered drug for a metabolic disorder as a potential therapeutic candidate in a rabbit model of shigellosis. Since acute respiratory infections often cause secondary complications during shigellosis, the systemic effect of PB and NaB on CAP-18 expression in respiratory epithelia was also evaluated. METHODS: The readouts were clinical outcomes, CAP-18 expression in mucosa of colon, rectum, lung and trachea (immunohistochemistry and real-time PCR and release of the CAP-18 peptide/protein in stool (Western blot. PRINCIPAL FINDINGS: Significant downregulation of CAP-18 expression in the epithelia of rectum and colon, the site of Shigella infection was confirmed. Interestingly, reduced expression of CAP-18 was also noticed in the epithelia of lung and trachea, indicating a systemic effect of the infection. This suggests a causative link to acute respiratory infections during shigellosis. Oral treatment with PB resulted in reduced clinical illness and upregulation of CAP-18 in the epithelium of rectum. Both PB and NaB counteracted the downregulation of CAP-18 in lung epithelium. The drug effect is suggested to be systemic as intravenous administration of NaB could also upregulate CAP-18 in the epithelia of lung, rectum and colon. CONCLUSION: Our results suggest that PB has treatment potential in human shigellosis. Enhancement of CAP-18 in the mucosal epithelia of the respiratory tract by PB or NaB is a novel discovery. This could mediate protection from

  12. Compartment-specific distribution of human intestinal innate lymphoid cells is altered in HIV patients under effective therapy.

    Directory of Open Access Journals (Sweden)

    Benjamin Krämer

    2017-05-01

    Full Text Available Innate lymphocyte cells (ILCs, a novel family of innate immune cells are considered to function as key orchestrators of immune defences at mucosal surfaces and to be crucial for maintaining an intact intestinal barrier. Accordingly, first data suggest depletion of ILCs to be involved in human immunodeficiency virus (HIV-associated damage of the intestinal mucosa and subsequent microbial translocation. However, although ILCs are preferentially localized at mucosal surfaces, only little is known regarding distribution and function of ILCs in the human gastrointestinal tract. Here, we show that in HIV(- individuals composition and functional capacity of intestinal ILCs is compartment-specific with group 1 ILCs representing the major fraction in the upper gastrointestinal (GI tract, whereas ILC3 are the predominant population in ileum and colon, respectively. In addition, we present first data indicating that local cytokine concentrations, especially that of IL-7, might modulate composition of gut ILCs. Distribution of intestinal ILCs was significantly altered in HIV patients, who displayed decreased frequency of total ILCs in ileum and colon owing to reduced numbers of both CD127(+ILC1 and ILC3. Of note, frequency of colonic ILC3 was inversely correlated with serum levels of I-FABP and sCD14, surrogate markers for loss of gut barrier integrity and microbial translocation, respectively. Both expression of the IL-7 receptor CD127 on ILCs as well as mucosal IL-7 mRNA levels were decreased in HIV(+ patients, especially in those parts of the GI tract with reduced ILC frequencies, suggesting that impaired IL-7 responses of ILCs might contribute to incomplete reconstitution of ILCs under effective anti-retroviral therapy. This is the first report comparing distribution and function of ILCs along the intestinal mucosa of the entire human gastrointestinal tract in HIV(+ and HIV(- individuals.

  13. Role of non-steroidal anti-inflammatory drugs on intestinal permeability and nonalcoholic fatty liver disease.

    Science.gov (United States)

    Utzeri, Erika; Usai, Paolo

    2017-06-14

    The use of non-steroidal anti-inflammatory drugs (NSAIDs) is widespread worldwide thanks to their analgesic, anti-inflammatory and antipyretic effects. However, even more attention is placed upon the recurrence of digestive system complications in the course of their use. Recent data suggests that the complications of the lower gastro-intestinal tract may be as frequent and severe as those of the upper tract. NSAIDs enteropathy is due to enterohepatic recycling of the drugs resulting in a prolonged and repeated exposure of the intestinal mucosa to the compound and its metabolites. Thus leading to so-called topical effects, which, in turn, lead to an impairment of the intestinal barrier. This process determines bacterial translocation and toxic substances of intestinal origin in the portal circulation, leading to an endotoxaemia. This condition could determine a liver inflammatory response and might promote the development of non-alcoholic steatohepatitis, mostly in patients with risk factors such as obesity, metabolic syndrome and a high fat diet, which may induce a small intestinal bacterial overgrowth and dysbiosis. This alteration of gut microbiota may contribute to nonalcoholic fatty liver disease and its related disorders in two ways: firstly causing a malfunction of the tight junctions that play a critical role in the increase of intestinal permeability, and then secondly leading to the development of insulin resistance, body weight gain, lipogenesis, fibrogenesis and hepatic oxidative stress.

  14. Dietary zinc deficiency reduced growth performance, intestinal immune and physical barrier functions related to NF-κB, TOR, Nrf2, JNK and MLCK signaling pathway of young grass carp (Ctenopharyngodon idella).

    Science.gov (United States)

    Song, Zheng-Xing; Jiang, Wei-Dan; Liu, Yang; Wu, Pei; Jiang, Jun; Zhou, Xiao-Qiu; Kuang, Sheng-Yao; Tang, Ling; Tang, Wu-Neng; Zhang, Yong-An; Feng, Lin

    2017-07-01

    Our study investigated the effects of dietary zinc (Zn) deficiency on growth performance, intestinal immune and physical barrier functions of young grass carp (Ctenopharyngodon idella). A total of 630 grass carp (244.14 ± 0.40 g) were fed graded levels of zinc lactate (10.71, 30.21, 49.84, 72.31, 92.56, 110.78 mg Zn/kg diet) and one zinc sulfate group (56.9 mg Zn/kg diet) for 60 days. At the end of the feeding trial, fish were challenged with Aeromonas hydrophila for 14 days. These results indicated that compared with optimal dietary Zn level, dietary Zn deficiency (10.71 mg/kg diet) decreased the production of antibacterial compounds, up-regulated pro-inflammatory cytokines related to nuclear factor kappa B (NF-κB) and down-regulated anti-inflammatory cytokines related to target of rapamycin (TOR) in three intestinal segments of young grass carp (P zinc lactate as Zn source) based on percent weight gain (PWG), against enteritis morbidity, acid phosphatase (ACP) activity in the proximal intestine (PI) and malondialdehyde (MDA) content in the PI of young grass carp was estimated to be 61.2, 61.4, 69.2 and 69.5 mg/kg diet, respectively. Finally, based on specific growth rate (SGR), feed efficiency (FE) and against enteritis morbidity of young grass carp, the efficacy of zinc lactate relative to zinc sulfate were 132.59%, 135.27% and 154.04%, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Donor T cells primed on leukemia lysate-pulsed recipient APCs mediate strong graft-versus-leukemia effects across MHC barriers in full chimeras

    OpenAIRE

    Ghosh, Arnab; Koestner, Wolfgang; Hapke, Martin; Schlaphoff, Verena; Länger, Florian; Baumann, Rolf; Koenecke, Christian; Cornberg, Markus; Welte, Karl; Blazar, Bruce R.; Sauer, Martin G.

    2009-01-01

    Antigen-presenting cells (APCs) of host origin drive graft-versus-leukemia (GVL) effects but can also trigger life-threatening graft-versus-host disease (GVHD) after hematopoietic cell transplantation (HCT) across major histocompatibility complex (MHC) barriers. We show that in vitro priming of donor lymphocytes can circumvent the need of recipient-derived APCs in vivo for mediating robust GVL effects and significantly diminishes the risk of severe GVHD. In vitro, generated and expanded T cel...

  16. Emotional functioning, barriers, and medication adherence in pediatric transplant recipients.

    Science.gov (United States)

    McCormick King, Megan L; Mee, Laura L; Gutiérrez-Colina, Ana M; Eaton, Cyd K; Lee, Jennifer L; Blount, Ronald L

    2014-04-01

    This study assessed relationships among internalizing symptoms, barriers to medication adherence, and medication adherence in adolescents with solid organ transplants. The sample included 72 adolescents who had received solid organ transplants. Multiple mediator models were tested via bootstrapping methods. Bivariate correlations revealed significant relationships between barriers and internalizing symptoms of depression, anxiety, and posttraumatic stress, as well as between internalizing symptoms and medication adherence. Barriers indicative of adaptation to the medication regimen (e.g., forgetting, lack of organization) were related to medication adherence and mediated the relationship between internalizing symptoms and medication adherence. These findings indicate that barriers may serve as a more specific factor in the relationship between more general, pervasive internalizing symptoms and medication adherence. Results may help guide areas for clinical assessment, and the focus of interventions for adolescent transplant recipients who are experiencing internalizing symptoms and/or who are nonadherent to their medication regimen.

  17. Hericium erinaceus polysaccharide facilitates restoration of injured intestinal mucosal immunity in Muscovy duck reovirus-infected Muscovy ducklings.

    Science.gov (United States)

    Wu, Yijian; Jiang, Huihui; Zhu, Erpeng; Li, Jian; Wang, Quanxi; Zhou, Wuduo; Qin, Tao; Wu, Xiaoping; Wu, Baocheng; Huang, Yifan

    2018-02-01

    To elucidate the effect of Hericium erinaceus polysaccharide (HEP) on the intestinal mucosal immunity in normal and Muscovy duck reovirus (MDRV)-infected Muscovy ducklings, 1-day-old healthy Muscovy ducklings were pretreated with 0.2g/L HEP and/or following by MDRV infection in this study, duodenal samples were respectively collected at 1, 3, 6, 10, 15 and 21day post-infection, tissue sections were prepared for observation of morphological structure and determination of intestinal parameters (villus height/crypt depth ratio, villus surface area) as well as counts of intraepithelial lymphocytes (IELs), goblet cells, mast cells. Additionally, dynamics of secretory immunoglobin A (sIgA), interferon-γ (IFN-γ) and interleukin-4 (IL-4) productions in intestinal mucosa were measured with radioimmunoassay. Results showed that HEP significantly improved intestinal morphological structure and related indexes, and significantly inhibited the reduction of intestinal mucosal IELs, goblet cells and mast cells caused by MDRV infection. Furthermore, HEP significantly increased the secretion of sIgA, IFN-γ and IL-4 to enhance intestinal mucosal immune functions. Our findings indicate that HEP treatment can effectively repair MDRV-caused injures of small intestinal mucosal immune barrier, and improve mucosal immune function in sick Muscovy ducklings, which will provide valuable help for further application of HEP in prevention and treatment of MDRV infection. Copyright © 2017. Published by Elsevier B.V.

  18. The Contributions of Human Mini-Intestines to the Study of Intestinal Physiology and Pathophysiology.

    Science.gov (United States)

    Yu, Huimin; Hasan, Nesrin M; In, Julie G; Estes, Mary K; Kovbasnjuk, Olga; Zachos, Nicholas C; Donowitz, Mark

    2017-02-10

    The lack of accessibility to normal and diseased human intestine and the inability to separate the different functional compartments of the intestine even when tissue could be obtained have held back the understanding of human intestinal physiology. Clevers and his associates identified intestinal stem cells and established conditions to grow "mini-intestines" ex vivo in differentiated and undifferentiated conditions. This pioneering work has made a new model of the human intestine available and has begun making contributions to the understanding of human intestinal transport in normal physiologic conditions and the pathophysiology of intestinal diseases. However, this model is reductionist and lacks many of the complexities of normal intestine. Consequently, it is not yet possible to predict how great the advances using this model will be for understanding human physiology and pathophysiology, nor how the model will be modified to include multiple other intestinal cell types and physical forces necessary to more closely approximate normal intestine. This review describes recent studies using mini-intestines, which have readdressed previously established models of normal intestinal transport physiology and newly examined intestinal pathophysiology. The emphasis is on studies with human enteroids grown either as three-dimensional spheroids or two-dimensional monolayers. In addition, comments are provided on mouse studies in cases when human studies have not yet been described.

  19. Association of enteric parasitic infections with intestinal inflammation and permeability in asymptomatic infants of São Tomé Island.

    Science.gov (United States)

    Garzón, Marisol; Pereira-da-Silva, Luis; Seixas, Jorge; Papoila, Ana Luísa; Alves, Marta; Ferreira, Filipa; Reis, Ana

    2017-05-01

    The cumulative effect of repeated asymptomatic enteric infections on intestinal barrier is not fully understood in infants. We aimed to evaluate the association between previous enteric parasitic infections and intestinal inflammation and permeability at 24-months of age, in asymptomatic infants of São Tomé Island. A subset of infants from a birth cohort, with intestinal parasite evaluations in at least four points of assessment, was eligible. Intestinal inflammatory response and permeability were assessed using fecal S100A12 and alpha-1-antitrypsin (A1AT), respectively. The cutoff parasitic infections explained variability of fecal biomarkers, after adjusting for potential confounders. Eighty infants were included. Giardia duodenalis and soil-transmitted helminths (STH) were the most frequent parasites. The median (interquartile range) levels were 2.87 μg/g (2.41-3.92) for S100A12 and 165.1 μg/g (66.0-275.6) for A1AT. Weak evidence of association was found between S100A12 levels and G. duodenalis (p = 0.080) and STH infections (p = 0.089), and between A1AT levels and parasitic infection of any etiology (p = 0.089), at 24-months of age. Significant associations between A1AT levels and wasting (p = 0.006) and stunting (p = 0.044) were found. Previous parasitic infections were not associated with fecal biomarkers at 24 months of age. To summarize, previous asymptomatic parasitic infections showed no association with intestinal barrier dysfunction. Notwithstanding, a tendency toward increased levels of the inflammatory biomarker was observed for current G. duodenalis and STH infections, and increased levels of the permeability biomarker were significantly associated with stunting and wasting.

  20. Protein synthesis and intestinal flora in piglets

    International Nuclear Information System (INIS)

    Namioka, Shigeo

    1980-01-01

    Utilization of non-protein nitrogen (NPN) by the flora in piglet colon was studied by administration of 15 N-urea and 15 N-ammonium salt to aseptic piglets and to SPF piglets which had been acclimatized to a clean environment after settling of intestinal flora. Administration of 15 N-urea did not result in 15 N uptake by any tissue-constituting protein at any site of the aseptic piglets, almost all 15 N being excreted into the urine. In contrast, the tissue and skeletal muscle of the SPF piglets showed incorporated 15 N from urea. Urea was converted, by urease of the intestinal flora, into NH 3 , which was absorbed from the mucosa of the intestinal tract to reach the liver where it was synthesized into glutamic acid, followed by conversion into various amino acids. 15 N-ammonium administration produced a significant amount of 15 N even in the tissue protein of the aseptic piglets. After NPN administration, the liver protein-constituting amino acid fraction showed 15 N-labeling of almost all essential, as well as non-essential amino acids. Culture of colonic flora with 15 N-urea revealed 15 N-labeling of all amino acids that constituted bacterial cells, indicating the presence of urea recycling mediated by bacterial urease in single rumen animals.(Chiba, N.)

  1. Interleukin 7 from maternal milk crosses the intestinal barrier and modulates T-cell development in offspring.

    Directory of Open Access Journals (Sweden)

    Richard Aspinall

    Full Text Available Breastfeeding protects against illnesses and death in hazardous environments, an effect partly mediated by improved immune function. One hypothesis suggests that factors within milk supplement the inadequate immune response of the offspring, but this has not been able to account for a series of observations showing that factors within maternally derived milk may supplement the development of the immune system through a direct effect on the primary lymphoid organs. In a previous human study we reported evidence suggesting a link between IL-7 in breast milk and the thymic output of infants. Here we report evidence in mice of direct action of maternally-derived IL-7 on T cell development in the offspring.We have used recombinant IL-7 labelled with a fluorescent dye to trace the movement in live mice of IL-7 from the stomach across the gut and into the lymphoid tissues. To validate the functional ability of maternally derived IL-7 we cross fostered IL-7 knock-out mice onto normal wild type mothers. Subsets of thymocytes and populations of peripheral T cells were significantly higher than those found in knock-out mice receiving milk from IL-7 knock-out mothers.Our study provides direct evidence that interleukin 7, a factor which is critical in the development of T lymphocytes, when maternally derived can transfer across the intestine of the offspring, increase T cell production in the thymus and support the survival of T cells in the peripheral secondary lymphoid tissue.

  2. Inhibition of cAMP-Activated Intestinal Chloride Secretion by Diclofenac: Cellular Mechanism and Potential Application in Cholera

    OpenAIRE

    Pongkorpsakol, Pawin; Pathomthongtaweechai, Nutthapoom; Srimanote, Potjanee; Soodvilai, Sunhapas; Chatsudthipong, Varanuj; Muanprasat, Chatchai

    2014-01-01

    Cyclic AMP-activated intestinal Cl- secretion plays an important role in pathogenesis of cholera. This study aimed to investigate the effect of diclofenac on cAMP-activated Cl- secretion, its underlying mechanisms, and possible application in the treatment of cholera. Diclofenac inhibited cAMP-activated Cl- secretion in human intestinal epithelial (T84) cells with IC50 of ∼ 20 µM. The effect required no cytochrome P450 enzyme-mediated metabolic activation. Interestingly, exposures of T84 cell...

  3. Splenic dendritic cell involvement in FXR-mediated amelioration of DSS colitis

    NARCIS (Netherlands)

    Massafra, Vittoria; Ijssennagger, Noortje; Plantinga, Maud; Milona, Alexandra; Ramos Pittol, José M.; Boes, Marianne; van Mil, Saskia W C

    2016-01-01

    Inflammatory Bowel Disease (IBD) is a multifactorial disorder involving dysregulation of the immune response and bacterial translocation through the intestinal mucosal barrier. Previously, we have shown that activation of the bile acid sensor Farnesoid X Receptor (FXR), which belongs to the family

  4. Cryptoccocal menigitis as a primary manifestation in a patient with intestinal lymphangictasia

    Directory of Open Access Journals (Sweden)

    Shaik Afshan Jabeen

    2012-01-01

    Full Text Available Opportunistic infections usually occur in patients with an immunocompromised state, and can be severe. Cryptoccocal meningitis is a fatal condition if left untreated, and is usually found in such patients. We report the case of an adult patient with cryptoccocal meningitis secondary to intestinal lymphangiectasia. A 30 year old female was admitted to our hospital for meningitis. Biochemical and radiological investigations were performed. A cerebrospinal fluid latex agglutination test showed positive cryptoccocal antigen. In addition, there were features of humoral and cell mediated immunity deficiency (lymphopenia, hypoalbuminemia, hypogammaglobulinemia, with a negative human immunodeficiency virus (HIV test by enzyme linked immunosorbent assay and polymerase chain reaction. An upper gastroduodenoscopy was performed, which showed multiple lymphangiectasias, and a biopsy confirmed the diagnosis of primary intestinal lymphangiectasia (PIL. The patient was treated with intravenous amphotericin B and oral flucytosine, and the meningitis resolved. PIL should be suspected in patients with cryptoccocal meningitis, combined with humoral and cell mediated immunity with a negative HIV test. The management issues, in addition to antifungal therapy, include nutritional supplements for the protein losing enteropathy.

  5. A microfluidic cell culture device with integrated microelectrodes for barrier studies

    DEFF Research Database (Denmark)

    Tan, Hsih-Yin; Dufva, Martin; Kutter, Jörg P.

    We present an eight cell culture microfluidic device fabricated using thiol-ene ‘click’ chemistry with embedded microelectrodes for evaluating barrier properties of human intestinal epithelial cells. The capability of the microelectrodes for trans-epithelial electrical resistance (TEER) measureme......) measurements was demonstrated by using confluent human colorectal epithelial cells (Caco-2) and rat fibroblast (CT 26) cells cultured in the microfluidic device....

  6. N-cadherin is overexpressed in Crohn's stricture fibroblasts and promotes intestinal fibroblast migration.

    LENUS (Irish Health Repository)

    Burke, John P

    2012-02-01

    BACKGROUND: Intestinal fibroblasts mediate stricture formation in Crohn\\'s disease (CD). Transforming growth factor-beta (TGF-beta) is important in fibroblast activation, while cell attachment and migration is regulated by the adhesion molecule N-cadherin. The aim of this study was to investigate the expression and function of N-cadherin in intestinal fibroblasts in patients with fibrostenosing CD. METHODS: Intestinal fibroblasts were cultured from seromuscular biopsies from patients undergoing resection for terminal ileal fibrostenosing CD (n = 14) or controls patients (n = 8). N-cadherin expression was assessed using Western blot and quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Fibroblasts were stimulated with TGF-beta and selective pathway inhibitors Y27632, PD98050, and LY294002 were used to examine the Rho\\/ROCK, ERK-1\\/2, and Akt signaling pathways, respectively. Cell migration was assessed using a scratch wound assay. N-cadherin was selectively overexpressed using a plasmid. RESULTS: Fibroblasts from fibrostenosing CD express increased constitutive N-cadherin mRNA and protein and exhibit enhanced basal cell migration relative to those from directly adjacent normal bowel. Control fibroblasts treated with TGF-beta induced N-cadherin in a dose-dependent manner which was inhibited by Rho\\/ROCK and Akt pathway modulation. Control fibroblasts exhibited enhanced cell migration in response to treatment with TGF-beta or transfection with an N-cadherin plasmid. CONCLUSIONS: Fibroblasts from strictures in CD express increased constitutive N-cadherin and exhibit enhanced basal cell migration. TGF-beta is a potent inducer of N-cadherin in intestinal fibroblasts resulting in enhanced cell migration. The TGF-beta-mediated induction of N-cadherin may potentiate Crohn\\'s stricture formation.

  7. BMP signaling inhibits intestinal stem cell self-renewal through suppression of Wnt-beta-catenin signaling.

    Science.gov (United States)

    He, Xi C; Zhang, Jiwang; Tong, Wei-Gang; Tawfik, Ossama; Ross, Jason; Scoville, David H; Tian, Qiang; Zeng, Xin; He, Xi; Wiedemann, Leanne M; Mishina, Yuji; Li, Linheng

    2004-10-01

    In humans, mutations in BMPR1A, SMAD4 and PTEN are responsible for juvenile polyposis syndrome, juvenile intestinal polyposis and Cowden disease, respectively. The development of polyposis is a common feature of these diseases, suggesting that there is an association between BMP and PTEN pathways. The mechanistic link between BMP and PTEN pathways and the related etiology of juvenile polyposis is unresolved. Here we show that conditional inactivation of Bmpr1a in mice disturbs homeostasis of intestinal epithelial regeneration with an expansion of the stem and progenitor cell populations, eventually leading to intestinal polyposis resembling human juvenile polyposis syndrome. We show that BMP signaling suppresses Wnt signaling to ensure a balanced control of stem cell self-renewal. Mechanistically, PTEN, through phosphatidylinosital-3 kinase-Akt, mediates the convergence of the BMP and Wnt pathways on control of beta-catenin. Thus, BMP signaling may control the duplication of intestinal stem cells, thereby preventing crypt fission and the subsequent increase in crypt number.

  8. Contribution of intestinal barrier damage, microbial translocation and HIV-1 infection status to an inflammaging signature.

    Directory of Open Access Journals (Sweden)

    Amanda K Steele

    Full Text Available Systemic inflammation is a characteristic of both HIV-1 infection and aging ("inflammaging". Intestinal epithelial barrier damage (IEBD and microbial translocation (MT contribute to HIV-associated inflammation, but their impact on inflammaging remains unclear.Plasma biomarkers for IEBD (iFABP, MT (LPS, sCD14, T-cell activation (sCD27, and inflammation (hsCRP, IL-6 were measured in 88 HIV-1 uninfected (HIV(neg and 83 treated, HIV-1-infected (HIV(pos adults from 20-100 years old.Age positively correlated with iFABP (r = 0.284, p = 0.008, sCD14 (r = 0.646, p = <0.0001 and LPS (r = 0.421, p = 0.0002 levels in HIV(neg but not HIV(pos subjects. Age also correlated with sCD27, hsCRP, and IL-6 levels regardless of HIV status. Middle-aged HIV(pos subjects had elevated plasma biomarker levels similar to or greater than those of elderly HIV(neg subjects with the exception of sCD14. Clustering analysis described an inflammaging phenotype (IP based on iFABP, sCD14, sCD27, and hsCRP levels in HIV(neg subjects over 60 years of age. The IP in HIV(neg subjects was used to develop a classification model that was applied to HIV(pos subjects to determine whether HIV(pos subjects under 60 years of age were IP+. HIV(pos IP+ subjects were similar in age to IP- subjects but had a greater risk of cardiovascular disease (CVD based on Framingham risk score (p =  0.01.We describe a novel IP that incorporates biomarkers of IEBD, MT, immune activation as well as inflammation. Application of this novel IP in HIV-infected subjects identified a group at higher risk of CVD.

  9. Mechanistic insights of intestinal absorption and renal conservation of folate in chronic alcoholism.

    Science.gov (United States)

    Wani, Nissar Ahmad; Thakur, Shilpa; Najar, Rauf Ahmad; Nada, Ritambhara; Khanduja, Krishan Lal; Kaur, Jyotdeep

    2013-03-01

    Folate mediated one-carbon metabolism is of fundamental importance for various cellular processes, including DNA synthesis and methylation of biological molecules. Due to the exogenous requirement of folate in mammals, there exists a well developed epithelial folate transport system for regulation of normal folate homeostasis. The intestinal and renal folate uptake is tightly and diversely regulated and disturbances in folate homeostasis like in alcoholism have pathological consequences. The study was sought to delineate the regulatory mechanism of folate uptake in intestine and reabsorption in renal tubular cells that could evaluate insights of malabsorption during alcoholism. The folate transporters PCFT and RFC were found to be associated with lipid rafts of membrane surfaces in intestine and kidney. Importantly, the observed lower intestinal and renal folate uptake was associated with decreased levels of folate transporter viz. PCFT and RFC in lipid rafts of intestinal and renal membrane surfaces. The decreased association of folate transporters in lipid rafts was associated with decreased protein and mRNA levels. In addition, immunohistochemical studies showed that alcoholic conditions deranged that localization of PCFT and RFC. These findings could explain the possible mechanistic insights that may result in folate malabsorption during alcoholism. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Mobile Exercise Apps and Increased Leisure Time Exercise Activity: A Moderated Mediation Analysis of the Role of Self-Efficacy and Barriers

    Science.gov (United States)

    Rosen, Zohn; Spierer, David; Weinberger-Litman, Sarah; Goldschein, Akiva; Robinson, Jonathan

    2015-01-01

    that this association was mediated by exercise levels and self-efficacy. That relationship was also moderated by perceived barriers to exercise. Multiple serial mediation models were tested, which revealed that the association between app use and BMI is mediated by increased self-efficacy and increased exercise. Conclusions Exercise app users are more likely to exercise during their leisure time, compared to those who do not use exercise apps, essentially fulfilling the role that many of these apps were designed to accomplish. Data also suggest that one way that exercise apps may increase exercise levels and health outcomes such as BMI is by making it easier for users to overcome barriers to exercise, leading to increased self-efficacy. We discuss ways of improving the effectiveness of apps by incorporating theory-driven approaches. We conclude that exercise apps can be viewed as intervention delivery systems consisting of features that help users overcome specific barriers. PMID:26276227

  11. Mobile Exercise Apps and Increased Leisure Time Exercise Activity: A Moderated Mediation Analysis of the Role of Self-Efficacy and Barriers.

    Science.gov (United States)

    Litman, Leib; Rosen, Zohn; Spierer, David; Weinberger-Litman, Sarah; Goldschein, Akiva; Robinson, Jonathan

    2015-08-14

    There are currently over 1000 exercise apps for mobile devices on the market. These apps employ a range of features, from tracking exercise activity to providing motivational messages. However, virtually nothing is known about whether exercise apps improve exercise levels and health outcomes and, if so, the mechanisms of these effects. Our aim was to examine whether the use of exercise apps is associated with increased levels of exercise and improved health outcomes. We also develop a framework within which to understand how exercise apps may affect health and test multiple models of possible mechanisms of action and boundary conditions of these relationships. Within this framework, app use may increase physical activity by influencing variables such as self-efficacy and may help to overcome exercise barriers, leading to improved health outcomes such as lower body mass index (BMI). In this study, 726 participants with one of three backgrounds were surveyed about their use of exercise apps and health: (1) those who never used exercise apps, (2) those who used exercise apps but discontinued use, and (3) those who are currently using exercise apps. Participants were asked about their long-term levels of exercise and about their levels of exercise during the previous week with the International Physical Activity Questionnaire (IPAQ). Nearly three-quarters of current app users reported being more active compared to under half of non-users and past users. The IPAQ showed that current users had higher total leisure time metabolic equivalent of task (MET) expenditures (1169 METs), including walking and vigorous exercise, compared to those who stopped using their apps (612 METs) or who never used apps (577 METs). Importantly, physical activity levels in domains other than leisure time activity were similar across the groups. The results also showed that current users had lower BMI (25.16) than past users (26.8) and non-users (26.9) and that this association was mediated by

  12. Mechanisms involved in the intestinal digestion and absorption of dietary vitamin A.

    Science.gov (United States)

    Harrison, E H; Hussain, M M

    2001-05-01

    Dietary retinyl esters are hydrolyzed in the intestine by the pancreatic enzyme, pancreatic triglyceride lipase (PTL), and intestinal brush border enzyme, phospholipase B. Recent work on the carboxylester lipase (CEL) knockout mouse suggests that CEL may not be involved in dietary retinyl ester digestion. The possible roles of the pancreatic lipase-related proteins (PLRP) 1 and 2 and other enzymes require further investigation. Unesterified retinol is taken up by the enterocytes, perhaps involving both diffusion and protein-mediated facilitated transport. Once in the cell, retinol is complexed with cellular retinol-binding protein type 2 (CRBP2) and the complex serves as a substrate for reesterification of the retinol by the enzyme lecithin:retinol acyltransferase (LRAT). Retinol not bound to CRBP2 is esterified by acyl-CoA acyltransferase (ARAT). The retinyl esters are incorporated into chylomicrons, intestinal lipoproteins that transport other dietary lipids such as triglycerides, phospholipids, and cholesterol. Chylomicrons containing newly absorbed retinyl esters are then secreted into the lymph.

  13. alpha(4)beta(7) independent pathway for CD8(+) T cell-mediated intestinal immunity to rotavirus.

    Science.gov (United States)

    Kuklin, N A; Rott, L; Darling, J; Campbell, J J; Franco, M; Feng, N; Müller, W; Wagner, N; Altman, J; Butcher, E C; Greenberg, H B

    2000-12-01

    Rotavirus (RV), which replicates exclusively in cells of the small intestine, is the most important cause of severe diarrhea in young children worldwide. Using a mouse model, we show that expression of the intestinal homing integrin alpha(4)ss(7) is not essential for CD8(+) T cells to migrate to the intestine or provide immunity to RV. Mice deficient in ss7 expression (ss7(-/-)) and unable to express alpha(4)ss(7) integrin were found to clear RV as quickly as wild-type (wt) animals. Depletion of CD8(+) T cells in ss7(-/-) animals prolonged viral shedding, and transfer of immune ss7(-/-) CD8(+) T cells into chronically infected Rag-2-deficient mice resolved RV infection as efficiently as wt CD8(+) T cells. Paradoxically, alpha(4)ss(7)(hi) memory CD8(+) T cells purified from wt mice that had been orally immunized cleared RV more efficiently than alpha(4)ss(7)(low) CD8(+) T cells. We explained this apparent contradiction by demonstrating that expression of alpha(4)ss(7) on effector CD8(+) T cells depends upon the site of initial antigen exposure: oral immunization generates RV-specific CD8(+) T cells primarily of an alpha(4)ss(7)(hi) phenotype, but subcutaneous immunization yields both alpha(4)ss(7)(hi) and alpha(4)ss(7)(low) immune CD8(+) T cells with anti-RV effector capabilities. Thus, alpha(4)ss(7) facilitates normal intestinal immune trafficking to the gut, but it is not required for effective CD8(+) T cell immunity.

  14. Effect of heme oxygenase-1 transduced bone marrow mesenchymal stem cells on damaged intestinal epithelial cells in vitro.

    Science.gov (United States)

    Cao, Yi; Wu, Ben-Juan; Zheng, Wei-Ping; Yin, Ming-Li; Liu, Tao; Song, Hong-Li

    2017-07-01

    In this study, we explored the effects of mesenchymal stem cells (MSCs) from bone marrow overexpressing heme oxygenase-1 (HO-1) on the damaged human intestinal epithelial barrier in vitro. Rat MSCs were isolated from bone marrow and transduced with rat HO-1 recombinant adenovirus (HO-MSCs) for stable expression of HO-1. Colorectal adenocarinoma 2 (Caco2) cells were treated with tumor necrosis factor-α (TNF-α) to establish a damaged colon epithelial model. Damaged Caco2 were cocultured with MSCs, Ad-MSCs, Ad-HO + MSCs or HO-MSCs. mRNA and protein expression of Zona occludens-1 (ZO-1) and human HO-1 and the release of cytokines were measured. ZO-1 and human HO-1 in Caco2 were significantly decreased after treatment with TNF-α; and this effect was reduced when coculture with MSCs from bone marrow. Expression of ZO-1 was not significantly affected by Caco2 treatment with TNF-α, Ad-HO, and MSCs. In contrast, ZO-1 and human HO-1 increased significantly when the damaged Caco2 was treated with HO-MSCs. HO-MSCs showed the strongest effect on the expression of ZO-1 in colon epithelial cells. Coculture with HO-MSCs showed the most significant effects on reducing the expression of IL-2, IL-6, IFN-γ and increasing the expression of IL-10. HO-MSCs protected the intestinal epithelial barrier, in which endogenous HO-1 was involved. HO-MSCs play an important role in the repair process by reducing the release of inflammatory cytokines and increasing the release of anti-inflammatory factors. These results suggested that HO-MSCs from bone marrow were more effective in repairing the damaged intestinal epithelial barrier, and the effectiveness of MSCs was improved by HO-1 gene transduction, which provides favorable support for the application of stem cell therapy in the intestinal diseases. © 2017 The Authors. Cell Biology International Published by John Wiley & Sons Ltd on behalf of International Federation of Cell Biology.

  15. Dunnione ameliorates cisplatin-induced small intestinal damage by modulating NAD{sup +} metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Pandit, Arpana; Kim, Hyung-Jin; Oh, Gi-Su; Shen, AiHua; Lee, Su-Bin; Khadka, Dipendra; Lee, SeungHoon [Center for Metabolic Function Regulation & Department of Microbiology, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Shim, Hyeok; Yang, Sei-Hoon; Cho, Eun-Young [Department of Internal Medicine, School of Medicine, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Kwon, Kang-Beom [Department of Oriental Medical Physiology, School of Oriental Medicine, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Kwak, Tae Hwan [PAEAN Biotechnology, 160 Techno-2 Street, Yuseong-gu, Daejeon 305-500 (Korea, Republic of); Choe, Seong-Kyu; Park, Raekil [Center for Metabolic Function Regulation & Department of Microbiology, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); So, Hong-Seob, E-mail: jeanso@wku.ac.kr [Center for Metabolic Function Regulation & Department of Microbiology, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of)

    2015-11-27

    Although cisplatin is a widely used anticancer drug for the treatment of a variety of tumors, its use is critically limited because of adverse effects such as ototoxicity, nephrotoxicity, neuropathy, and gastrointestinal damage. Cisplatin treatment increases oxidative stress biomarkers in the small intestine, which may induce apoptosis of epithelial cells and thereby elicit damage to the small intestine. Nicotinamide adenine dinucleotide (NAD{sup +}) is a cofactor for various enzymes associated with cellular homeostasis. In the present study, we demonstrated that the hyper-activation of poly(ADP-ribose) polymerase-1 (PARP-1) is closely associated with the depletion of NAD{sup +} in the small intestine after cisplatin treatment, which results in downregulation of sirtuin1 (SIRT1) activity. Furthermore, a decrease in SIRT1 activity was found to play an important role in cisplatin-mediated small intestinal damage through nuclear factor (NF)-κB p65 activation, facilitated by its acetylation increase. However, use of dunnione as a strong substrate for the NADH:quinone oxidoreductase 1 (NQO1) enzyme led to an increase in intracellular NAD{sup +} levels and prevented the cisplatin-induced small intestinal damage correlating with the modulation of PARP-1, SIRT1, and NF-κB. These results suggest that direct modulation of cellular NAD{sup +} levels by pharmacological NQO1 substrates could be a promising therapeutic approach for protecting against cisplatin-induced small intestinal damage. - Highlights: • NAD{sup +} acts as a cofactor for numerous enzymes including Sirtuins and PARP. • Up-regulation of SIRT1 could attenuate the cisplatin-induced intestinal damage. • Modulation of the cellular NAD{sup +} could be a promising therapeutic approach.

  16. Action of cholera toxin in the intestinal epithelial cells

    International Nuclear Information System (INIS)

    Hyun, C.S.

    1982-01-01

    The primary event in the action of cholera toxin on the isolated chick intestinal epithelial cell is its interaction with a large number of high affinity binding sites in the cell membrane. Binding of 125 I-labeled toxin is rapid, temperature-dependent, reversible, and saturable over a wide range of concentrations and includes only a small contribution from nonspecific sites. A characteristic lag phase of 10 min occurs following the complete binding of toxin before any increase in cellular cAMP levels can be detected. The response (elevation of cellular cAMP) is linear with time for 40 to 50 min and causes a six- to eight-fold increase over control levels (10 to 15 picomole cAMP/mg cellular protein) at steady state. cAMP and agents that increase cAMP production inhibit Cl - -independent Na + influx into the isolated enterocytes whereas chlorpromazine (CPZ) which completely abolishes toxin-induced elevation of cAMP both reverses and prevents the cAMP-mediated inhibition of Na + entry. Correlation between cellular cAMP levels and the magnitude of Na + influx provides evidence for a cAMP-mediated control of intestinal Na + uptake, which may represent the mechanistic basis for the antiabsorptive effect of CT on Na + during induction of intestinal secretion. The effect of cAMP on Na + but not Cl - influx preparations can be partially explained in terms of a cAMP-regulated Na + /H + neutral exchange system. Data on the coupling relationship between Na + transport and the intra- and extracellular pH in the enterocytes show that an amiloride-sensitive electroneutral Na + /H + exchange process occurs. This coupling between Na + and H + is partially inhibited by CT and dbcAMP, suggesting that the Na + /H + exchange may be a cAMP-regulated process. 31 references, 32 figures, 5 tables

  17. Effects of stress on gastrointestinal function: interactions of neural and endocrine systems in mediating stress-induced intestinal dysfunction in rats

    International Nuclear Information System (INIS)

    Williams, C.L.

    1987-01-01

    The etiology of stress-induced intestinal dysfunction is completely unresolved, and the lack of an appropriate animal model has hindered studies of causality. We compared a number of stressors and their resultant effects on intestinal transit, a measure of the propulsive motor activity of the gut, in the rat. We found that the response of the intestine to stress, and the neural systems activated by stress, were dependent on the type and duration of stress, as well as the animal strain, and gender. We developed a model, acute wrapping restraint stress, to fully characterize the effects of stress on intestinal transit. Wrap restraint stress is a nonulcerogenic model in which rats are subjected to acute restraint by wrapping them in a harness of paper tape to restrict, but not prevent movement of the upper body and forelimbs. Transit was evaluated by the geometric center method, in which a radiomarker ( 51 Cr) is instilled directly into the proximal duodenum and proximal colon via a surgically placed intestinal cannula, in fasted, adult female Sprague Dawley rats

  18. Design and intestinal mucus penetration mechanism of core-shell nanocomplex.

    Science.gov (United States)

    Zhang, Xin; Cheng, Hongbo; Dong, Wei; Zhang, Meixia; Liu, Qiaoyu; Wang, Xiuhua; Guan, Jian; Wu, Haiyang; Mao, Shirui

    2018-02-28

    The objective of this study was to design intestinal mucus-penetrating core-shell nanocomplex by functionally mimicking the surface of virus, which can be used as the carrier for peroral delivery of macromolecules, and further understand the influence of nanocomplex surface properties on the mucosal permeation capacity. Taking insulin as a model drug, the core was formed by the self-assembly among positively charged chitosan, insulin and negatively charged sodium tripolyphosphate, different types of alginates were used as the shell forming material. The nanocomplex was characterized by dynamic light scattering (DLS), atomic force microscopy (AFM) and FTIR. Nanocomplex movement in mucus was recorded using multiple particle tracking (MPT) method. Permeation and uptake of different nanocomplex were studied in rat intestine. It was demonstrated that alginate coating layer was successfully formed on the core and the core-shell nanocomplex showed a good physical stability and improved enzymatic degradation protection. The mucus penetration and MPT study showed that the mucus penetration capacity of the nanocomplex was surface charge and coating polymer structure dependent, nanocomplex with negative alginate coating had 1.6-2.5 times higher mucus penetration ability than that of positively charged chitosan-insulin nanocomplex. Moreover, the mucus penetration ability of the core-shell nanocomplex was alginate structure dependent, whereas alginate with lower G content and lower molecular weight showed the best permeation enhancing ability. The improvement of intestine permeation and intestinal villi uptake of the core-shell nanocomplex were further confirmed in rat intestine and multiple uptake mechanisms were involved in the transport process. In conclusion, core-shell nanocomplex composed of oppositely charged materials could provide a strategy to overcome the mucus barrier and enhance the mucosal permeability. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Actin-interacting protein 1 controls assembly and permeability of intestinal epithelial apical junctions.

    Science.gov (United States)

    Lechuga, Susana; Baranwal, Somesh; Ivanov, Andrei I

    2015-05-01

    Adherens junctions (AJs) and tight junctions (TJs) are crucial regulators of the integrity and restitution of the intestinal epithelial barrier. The structure and function of epithelial junctions depend on their association with the cortical actin cytoskeleton that, in polarized epithelial cells, is represented by a prominent perijunctional actomyosin belt. The assembly and stability of the perijunctional cytoskeleton is controlled by constant turnover (disassembly and reassembly) of actin filaments. Actin-interacting protein (Aip) 1 is an emerging regulator of the actin cytoskeleton, playing a critical role in filament disassembly. In this study, we examined the roles of Aip1 in regulating the structure and remodeling of AJs and TJs in human intestinal epithelium. Aip1 was enriched at apical junctions in polarized human intestinal epithelial cells and normal mouse colonic mucosa. Knockdown of Aip1 by RNA interference increased the paracellular permeability of epithelial cell monolayers, decreased recruitment of AJ/TJ proteins to steady-state intercellular contacts, and attenuated junctional reassembly in a calcium-switch model. The observed defects of AJ/TJ structure and functions were accompanied by abnormal organization and dynamics of the perijunctional F-actin cytoskeleton. Moreover, loss of Aip1 impaired the apico-basal polarity of intestinal epithelial cell monolayers and inhibited formation of polarized epithelial cysts in 3-D Matrigel. Our findings demonstrate a previously unanticipated role of Aip1 in regulating the structure and remodeling of intestinal epithelial junctions and early steps of epithelial morphogenesis. Copyright © 2015 the American Physiological Society.

  20. MicroRNA-122a Regulates Zonulin by Targeting EGFR in Intestinal Epithelial Dysfunction.

    Science.gov (United States)

    Zhang, Bin; Tian, Yinghai; Jiang, Ping; Jiang, Yanqiong; Li, Chao; Liu, Ting; Zhou, Rujian; Yang, Ning; Zhou, Xinke; Liu, Zhihua

    2017-01-01

    This study aimed to investigate the role of microRNA (miR)-122a in regulating zonulin during the modulation of intestinal barrier. Zonulin proteins and their target gene expression were analyzed in miR-122a-overexpressing cell lines and in the target gene of epidermal growth factor receptor (EGFR). An mmu-miR-122a intestinal epithelial conditional transgenic (miR-122a-TG) mouse model was established to investigate EGFR and zonulin expression. MiR-122a was also detected in the clinical specimens of inflammatory bowel disease. EGFR was identified as a target gene of miR-122a. The expression level of miR-122a was positively correlated with that of zonulin. The expression level of zonulin was significantly increased, whereas the expression level of EGFR was significantly decreased in the miR-122a-TG mice and in the corresponding primary epithelial culture (P zonulin by targeting EGFR, which increased the intestinal epithelial permeability in vivo and in vitro. © 2017 The Author(s). Published by S. Karger AG, Basel.

  1. Eosinophils express muscarinic receptors and corticotropin-releasing factor to disrupt the mucosal barrier in ulcerative colitis.

    Science.gov (United States)

    Wallon, Conny; Persborn, Mats; Jönsson, Maria; Wang, Arthur; Phan, Van; Lampinen, Maria; Vicario, Maria; Santos, Javier; Sherman, Philip M; Carlson, Marie; Ericson, Ann-Charlott; McKay, Derek M; Söderholm, Johan D

    2011-05-01

    Altered intestinal barrier function has been implicated in the pathophysiology of ulcerative colitis (UC) in genetic, functional, and epidemiological studies. Mast cells and corticotropin-releasing factor (CRF) regulate the mucosal barrier in human colon. Because eosinophils are often increased in colon tissues of patients with UC, we assessed interactions among mast cells, CRF, and eosinophils in the mucosal barrier of these patients. Transmucosal fluxes of protein antigens (horseradish peroxidase) and paracellular markers ((51)Cr-EDTA, fluorescein isothiocyanate-dextran 4000) were studied in noninflamed, colonic mucosal biopsy samples collected from 26 patients with UC and 53 healthy volunteers (controls); samples were mounted in Ussing chambers. We also performed fluorescence and electron microscopy of human tissue samples, assessed isolated eosinophils, and performed mechanistic studies using in vitro cocultured eosinophils (15HL-60), mast cells (HMC-1), and a colonic epithelial cell line (T84). Colon tissues from patients with UC had significant increases in permeability to protein antigens compared with controls. Permeability was blocked by atropine (a muscarinic receptor antagonist), α-helical CRF(9-41) (a CRF receptor antagonist), and lodoxamide (a mast-cell stabilizer). Eosinophils were increased in number in UC tissues (compared with controls), expressed the most M2 and M3 muscarinic receptors of any mucosal cell type, and had immunoreactivity to CRF. In coculture studies, carbachol activation of eosinophils caused production of CRF and activation of mast cells, which increased permeability of T84 epithelial cells to macromolecules. We identified a neuroimmune intercellular circuit (from cholinergic nerves, via eosinophils to mast cells) that mediates colonic mucosal barrier dysfunction in patients with UC. This circuit might exacerbate mucosal inflammation. Copyright © 2011 AGA Institute. Published by Elsevier Inc. All rights reserved.

  2. How the intestinal peptide transporter PEPT-1 contributes to an obesity phenotype in Caenorhabditits elegans.

    Directory of Open Access Journals (Sweden)

    Britta Spanier

    Full Text Available BACKGROUND: Amino acid absorption in the form of di- and tripeptides is mediated by the intestinal proton-coupled peptide transporter PEPT-1 (formally OPT-2 in Caenorhabditits elegans. Transporter-deficient animals (pept-1(lg601 show impaired growth, slowed postembryonal development and major changes in amino acid status. PRINCIPAL FINDINGS: Here we demonstrate that abolished intestinal peptide transport also leads to major metabolic alterations that culminate in a two fold increase in total body fat content. Feeding of C. elegans with [U-(13C]-labelled E. coli revealed a decreased de novo synthesis of long-chain fatty acids in pept-1(lg601 and reduced levels of polyunsaturated fatty acids. mRNA profiling revealed increased transcript levels of enzymes/transporters needed for peroxisomal beta-oxidation and decreased levels for those required for fatty acid synthesis, elongation and desaturation. As a prime and most fundamental process that may account for the increased fat content in pept-1(lg601 we identified a highly accelerated absorption of free fatty acids from the bacterial food in the intestine. CONCLUSIONS: The influx of free fatty acids into intestinal epithelial cells is strongly dependent on alterations in intracellular pH which is regulated by the interplay of PEPT-1 and the sodium-proton exchanger NHX-2. We here provide evidence for a central mechanism by which the PEPT-1/NHX-2 system strongly influences the in vivo fat content of C. elegans. Loss of PEPT-1 decreases intestinal proton influx leading to a higher uptake of free fatty acids with fat accumulation whereas loss of NHX-2 causes intracellular acidification by the PEPT-1 mediated proton/dipeptide symport with an almost abolished uptake of fatty acids and a lean phenotype.

  3. The Drosophila MAPK p38c regulates oxidative stress and lipid homeostasis in the intestine.

    Directory of Open Access Journals (Sweden)

    Sveta Chakrabarti

    2014-09-01

    Full Text Available The p38 mitogen-activated protein (MAP kinase signaling cassette has been implicated in stress and immunity in evolutionarily diverse species. In response to a wide variety of physical, chemical and biological stresses p38 kinases phosphorylate various substrates, transcription factors of the ATF family and other protein kinases, regulating cellular adaptation to stress. The Drosophila genome encodes three p38 kinases named p38a, p38b and p38c. In this study, we have analyzed the role of p38c in the Drosophila intestine. The p38c gene is expressed in the midgut and upregulated upon intestinal infection. We showed that p38c mutant flies are more resistant to infection with the lethal pathogen Pseudomonas entomophila but are more susceptible to the non-pathogenic bacterium Erwinia carotovora 15. This phenotype was linked to a lower production of Reactive Oxygen Species (ROS in the gut of p38c mutants, whereby the transcription of the ROS-producing enzyme Duox is reduced in p38c mutant flies. Our genetic analysis shows that p38c functions in a pathway with Mekk1 and Mkk3 to induce the phosphorylation of Atf-2, a transcription factor that controls Duox expression. Interestingly, p38c deficient flies accumulate lipids in the intestine while expressing higher levels of antimicrobial peptide and metabolic genes. The role of p38c in lipid metabolism is mediated by the Atf3 transcription factor. This observation suggests that p38c and Atf3 function in a common pathway in the intestine to regulate lipid metabolism and immune homeostasis. Collectively, our study demonstrates that p38c plays a central role in the intestine of Drosophila. It also reveals that many roles initially attributed to p38a are in fact mediated by p38c.

  4. The Drosophila MAPK p38c regulates oxidative stress and lipid homeostasis in the intestine.

    Science.gov (United States)

    Chakrabarti, Sveta; Poidevin, Mickaël; Lemaitre, Bruno

    2014-09-01

    The p38 mitogen-activated protein (MAP) kinase signaling cassette has been implicated in stress and immunity in evolutionarily diverse species. In response to a wide variety of physical, chemical and biological stresses p38 kinases phosphorylate various substrates, transcription factors of the ATF family and other protein kinases, regulating cellular adaptation to stress. The Drosophila genome encodes three p38 kinases named p38a, p38b and p38c. In this study, we have analyzed the role of p38c in the Drosophila intestine. The p38c gene is expressed in the midgut and upregulated upon intestinal infection. We showed that p38c mutant flies are more resistant to infection with the lethal pathogen Pseudomonas entomophila but are more susceptible to the non-pathogenic bacterium Erwinia carotovora 15. This phenotype was linked to a lower production of Reactive Oxygen Species (ROS) in the gut of p38c mutants, whereby the transcription of the ROS-producing enzyme Duox is reduced in p38c mutant flies. Our genetic analysis shows that p38c functions in a pathway with Mekk1 and Mkk3 to induce the phosphorylation of Atf-2, a transcription factor that controls Duox expression. Interestingly, p38c deficient flies accumulate lipids in the intestine while expressing higher levels of antimicrobial peptide and metabolic genes. The role of p38c in lipid metabolism is mediated by the Atf3 transcription factor. This observation suggests that p38c and Atf3 function in a common pathway in the intestine to regulate lipid metabolism and immune homeostasis. Collectively, our study demonstrates that p38c plays a central role in the intestine of Drosophila. It also reveals that many roles initially attributed to p38a are in fact mediated by p38c.

  5. The Role of Sphingolipids on Innate Immunity to Intestinal Salmonella Infection.

    Science.gov (United States)

    Huang, Fu-Chen

    2017-08-07

    Salmonella spp. remains a major public health problem for the whole world. To reduce the use of antimicrobial agents and drug-resistant Salmonella , a better strategy is to explore alternative therapy rather than to discover another antibiotic. Sphingolipid- and cholesterol-enriched lipid microdomains attract signaling proteins and orchestrate them toward cell signaling and membrane trafficking pathways. Recent studies have highlighted the crucial role of sphingolipids in the innate immunity against infecting pathogens. It is therefore mandatory to exploit the role of the membrane sphingolipids in the innate immunity of intestinal epithelia infected by this pathogen. In the present review, we focus on the role of sphingolipids in the innate immunity of intestinal epithelia against Salmonella infection, including adhesion, autophagy, bactericidal effect, barrier function, membrane trafficking, cytokine and antimicrobial peptide expression. The intervention of sphingolipid-enhanced foods to make our life healthy or pharmacological agents regulating sphingolipids is provided at the end.

  6. Intestinal Dysbiosis and Rheumatoid Arthritis: A Link between Gut Microbiota and the Pathogenesis of Rheumatoid Arthritis

    Directory of Open Access Journals (Sweden)

    Gabriel Horta-Baas

    2017-01-01

    Full Text Available Characterization and understanding of gut microbiota has recently increased representing a wide research field, especially in autoimmune diseases. Gut microbiota is the major source of microbes which might exert beneficial as well as pathogenic effects on human health. Intestinal microbiome’s role as mediator of inflammation has only recently emerged. Microbiota has been observed to differ in subjects with early rheumatoid arthritis compared to controls, and this finding has commanded this study as a possible autoimmune process. Studies with intestinal microbiota have shown that rheumatoid arthritis is characterized by an expansion and/or decrease of bacterial groups as compared to controls. In this review, we present evidence linking intestinal dysbiosis with the autoimmune mechanisms involved in the development of rheumatoid arthritis.

  7. Intestinal Lymphangiectasia

    Science.gov (United States)

    ... Overview of Crohn Disease Additional Content Medical News Intestinal Lymphangiectasia (Idiopathic Hypoproteinemia) By Atenodoro R. Ruiz, Jr., MD, ... Overview of Malabsorption Bacterial Overgrowth Syndrome Celiac Disease Intestinal ... Intolerance Short Bowel Syndrome Tropical Sprue Whipple ...

  8. Intestinal parasites : associations with intestinal and systemic inflammation

    NARCIS (Netherlands)

    Zavala, Gerardo A; García, Olga P; Camacho, Mariela; Ronquillo, Dolores; Campos-Ponce, Maiza; Doak, Colleen; Polman, Katja; Rosado, Jorge L

    2018-01-01

    AIMS: Evaluate associations between intestinal parasitic infection with intestinal and systemic inflammatory markers in school-aged children with high rates of obesity. METHODS AND RESULTS: Plasma concentrations of CRP, leptin, TNF-α, IL-6 and IL-10 were measured as systemic inflammation markers and

  9. Rupture, Invasion and Inflammatory Destruction of the Intestinal Barrier by Shigella: The Yin and Yang of Innate Immunity

    Directory of Open Access Journals (Sweden)

    Philippe J Sansonetti

    2006-01-01

    Full Text Available Shigella is a Gram-negative bacterial species of the family Enterobacteriaceae that causes bacillary dysentery in humans. This acute colitis reflects the capacity of the microorganism to disrupt, invade and cause the inflammatory destruction of the intestinal epithelium. The pathogenesis of the Shigella infection can be seen as a disruption of the homeostatic balance that protects the gut against inflammation in the presence of its commensal flora. This provides the unified view that enteroinvasive pathogens allow for the identification of key signalling molecules and pathways involved in the regulation of intestinal inflammation, and more generally, in the regulation of the innate and adaptive immune response.

  10. Increased intestinal permeability, measured by serum zonulin, is associated with metabolic risk markers in overweight pregnant women.

    Science.gov (United States)

    Mokkala, Kati; Pellonperä, Outi; Röytiö, Henna; Pussinen, Pirkko; Rönnemaa, Tapani; Laitinen, Kirsi

    2017-04-01

    Increased intestinal permeability with subsequent metabolic endotoxemia, i.e., elevated circulating levels of bacterial lipopolysaccharide, LPS, has been introduced as a novel initiator of obesity related metabolic disturbances in non-pregnant individuals. The objective was to investigate the extent to which intestinal permeability, measured by serum zonulin concentration, is related to metabolic endotoxemia and metabolic risk markers in overweight pregnant women. This was a cross-sectional study including 100 pregnant overweight women in early pregnancy. Serum zonulin was analyzed using ELISA, and markers for metabolic endotoxemia (LPS), inflammation (high-sensitive C-reactive protein and glycoprotein acetylation GlyA), glucose metabolism (fasting glucose and insulin), and lipid metabolism were measured. Higher serum zonulin concentration associated positively with LPS (P=0.02), inflammatory markers (Pzonulin quartiles). All the observed associations were confirmed (Pzonulin concentration, i.e., increased intestinal permeability, contributes to metabolic endotoxemia, systemic inflammation, and insulin resistance in overweight pregnant women. By reinforcing intestinal barrier, it may be possible to manipulate maternal metabolism during pregnancy with subsequent health benefits. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Intestinal Obstruction

    Science.gov (United States)

    ... Colostomy ) is required to relieve an obstruction. Understanding Colostomy In a colostomy, the large intestine (colon) is cut. The part ... 1 What Causes Intestinal Strangulation? Figure 2 Understanding Colostomy Gastrointestinal Emergencies Overview of Gastrointestinal Emergencies Abdominal Abscesses ...

  12. EMMPRIN Modulates Epithelial Barrier Function through a MMP–Mediated Occludin Cleavage

    Science.gov (United States)

    Huet, Eric; Vallée, Benoit; Delbé, Jean; Mourah, Samia; Prulière-Escabasse, Virginie; Tremouilleres, Magali; Kadomatsu, Kenji; Doan, Serge; Baudouin, Christophe; Menashi, Suzanne; Gabison, Eric E.

    2011-01-01

    Dry eye is a common disease that develops as a result of alteration of tear fluid, leading to osmotic stress and a perturbed epithelial barrier. Matrix metalloproteinase-9 (MMP-9) may be important in dry eye disease, as its genetic knockout conferred resistance to the epithelial disruption. We show that extracellular matrix metalloproteinase inducer (EMMPRIN; also termed CD147), an inducer of MMP expression, participates in the pathogenesis of dry eye through MMP-mediated cleavage of occludin, an important component of tight junctions. EMMPRIN expression was increased on the ocular surface of dry eye patients and correlated with those of MMP-9. High osmolarity in cell culture, mimicking dry eye conditions, increased both EMMPRIN and MMP-9 and resulted in the disruption of epithelial junctions through the cleavage of occludin. Exogenously added recombinant EMMPRIN had similar effects that were abrogated in the presence of the MMP inhibitor marimastat. Membrane occludin immunostaining was markedly increased in the apical corneal epithelium of both EMMPRIN and MMP-9 knock-out mice. Furthermore, an inverse correlation between EMMPRIN and occludin membrane staining was consistently observed both in vitro and in vivo as a function of corneal epithelial cells differentiation. These data suggest a possible role of EMMPRIN in regulating the amount of occludin at the cell surface in homeostasis beyond pathological situations such as dry eye disease, and EMMPRIN may be essential for the formation and maintenance of organized epithelial structure. PMID:21777561

  13. Safety and Efficacy of Alginate Adhesion Barrier Gel in Compromised Intestinal Anastomosis

    NARCIS (Netherlands)

    Chaturvedi, A.; Yauw, S.T.K.; Lomme, R.M.L.M.; Hendriks, T.; Goor, H. van

    2017-01-01

    BACKGROUND: For any anti-adhesive barrier developed for abdominal surgery, the use under conditions in which anastomotic healing is compromised needs to be investigated. The current study evaluates the effect of a new ultrapure alginate gel on early healing of high-risk anastomoses in the ileum and

  14. Amebiasis intestinal Intestinal amebiasis

    Directory of Open Access Journals (Sweden)

    JULIO CÉSAR GÓMEZ

    2007-03-01

    Full Text Available Entamoeba histolytica es el patógeno intestinal más frecuente en nuestro medio -después de Giardia lamblia-, una de las principales causas de diarrea en menores de cinco años y la cuarta causa de muerte en el mundo debida a infección por protozoarios. Posee mecanismos patogénicos complejos que le permiten invadir la mucosa intestinal y causar colitis amebiana. El examen microscópico es el método más usado para su identificación pero la existencia de dos especies morfológicamente iguales, una patógena ( E. histolytica y una no patógena ( Entamoeba dispar, ha llevado al desarrollo de otros métodos de diagnóstico. El acceso al agua potable y los servicios sanitarios adecuados, un tratamiento médico oportuno y el desarrollo de una vacuna, son los ejes para disminuir la incidencia y mortalidad de esta entidad.Entamoeba histolytica is the most frequent intestinal pathogen seen in our country, after Giardia lamblia, being one of the main causes of diarrhea in children younger than five years of age, and the fourth leading cause of death due to infection for protozoa in the world. It possesses complex pathogenic mechanisms that allow it to invade the intestinal mucosa, causing amoebic colitis. Microscopy is the most used method for its identification, but the existence of two species morphologically identical, the pathogen one ( E. histolytica, and the non pathogen one ( E. dispar, have taken to the development of other methods of diagnosis. The access to drinkable water and appropriate sanitary services, an opportune medical treatment, and the development of a vaccine are the axes to diminish the incidence and mortality of this entity.

  15. Enteric Neuron Imbalance and Proximal Dysmotility in Ganglionated Intestine of the Sox10Dom/+ Hirschsprung Mouse ModelSummary

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    Melissa A. Musser

    2015-01-01

    Full Text Available Background & Aims: In Hirschsprung disease (HSCR, neural crest-derived progenitors (NCPs fail to completely colonize the intestine so that the enteric nervous system is absent from distal bowel. Despite removal of the aganglionic region, many HSCR patients suffer from residual intestinal dysmotility. To test the hypothesis that inappropriate lineage segregation of NCPs in proximal ganglionated regions of the bowel could contribute to such postoperative disease, we investigated neural crest (NC-derived lineages and motility in ganglionated, postnatal intestine of the Sox10Dom/+ HSCR mouse model. Methods: Cre-mediated fate-mapping was applied to evaluate relative proportions of NC-derived cell types. Motility assays were performed to assess gastric emptying and small intestine motility while colonic inflammation was assessed by histopathology for Sox10Dom/+ mutants relative to wild-type controls. Results: Sox10Dom/+ mice showed regional alterations in neuron and glia proportions as well as calretinin+ and neuronal nitric oxide synthase (nNOS+ neuronal subtypes. In the colon, imbalance of enteric NC derivatives correlated with the extent of aganglionosis. All Sox10Dom/+ mice exhibited reduced small intestinal transit at 4 weeks of age; at 6 weeks of age, Sox10Dom/+ males had increased gastric emptying rates. Sox10Dom/+ mice surviving to 6 weeks of age had little or no colonic inflammation when compared with wild-type littermates, suggesting that these changes in gastrointestinal motility are neurally mediated. Conclusions: The Sox10Dom mutation disrupts the balance of NC-derived lineages and affects gastrointestinal motility in the proximal, ganglionated intestine of adult animals. This is the first report identifying alterations in enteric neuronal classes in Sox10Dom/+ mutants, which suggests a previously unrecognized role for Sox10 in neuronal subtype specification. Keywords: Aganglionosis, Enteric Nervous System, Neural Crest

  16. Intestinal Leiomyositis: A Cause of Chronic Intestinal Pseudo-Obstruction in 6 Dogs.

    Science.gov (United States)

    Zacuto, A C; Pesavento, P A; Hill, S; McAlister, A; Rosenthal, K; Cherbinsky, O; Marks, S L

    2016-01-01

    Intestinal leiomyositis is a suspected autoimmune disorder affecting the muscularis propria layer of the gastrointestinal tract and is a cause of chronic intestinal pseudo-obstruction in humans and animals. To characterize the clinical presentation, histopathologic features, and outcome of dogs with intestinal leiomyositis in an effort to optimize treatment and prognosis. Six client-owned dogs. Retrospective case series. Medical records were reviewed to describe signalment, clinicopathologic and imaging findings, histopathologic diagnoses, treatment, and outcome. All biopsy specimens were reviewed by a board-certified pathologist. Median age of dogs was 5.4 years (range, 15 months-9 years). Consistent clinical signs included vomiting (6/6), regurgitation (2/6), and small bowel diarrhea (3/6). Median duration of clinical signs before presentation was 13 days (range, 5-150 days). Diagnostic imaging showed marked gastric distension with dilated small intestines in 4/6 dogs. Full-thickness intestinal biopsies were obtained in all dogs by laparotomy. Histopathology of the stomach and intestines disclosed mononuclear inflammation, myofiber degeneration and necrosis, and fibrosis centered within the region of myofiber loss in the intestinal muscularis propria. All dogs received various combinations of immunomodulatory and prokinetic treatment, antimicrobial agents, antiemetics, and IV fluids, but none of the dogs showed a clinically relevant improvement with treatment. Median survival was 19 days after diagnosis (range, 3-270 days). Intestinal leiomyositis is a cause of intestinal pseudo-obstruction and must be diagnosed by full-thickness intestinal biopsy. This disease should be considered in dogs with acute and chronic vomiting, regurgitation, and small bowel diarrhea. Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  17. Intestinal helminth co-infection and associated factors among tuberculosis patients in Arba Minch, Ethiopia.

    Science.gov (United States)

    Alemu, Getaneh; Mama, Mohammedaman

    2017-01-13

    Helminths affect the outcome of tuberculosis by shifting cell mediated immune response to humoral and by total suppression of the host immune system. On the reverse, Mycobacterium infection favors immune escape of helminths. Therefore assessing helminth co-infection rate and predisposing factors in tuberculosis patients is mandatory to set strategies for better case management. Facility based cross-sectional study was conducted in Arba Minch to assess the prevalence and associated factors of intestinal helminths among pulmonary tuberculosis patients from January to August, 2016. A structured questionnaire was used to capture data about socio-demographic characteristics, clinical history and possible risk factors for intestinal helminth infections. Height and weight were measured to calculate body-mass index. Appropriate amount of stool was collected and processed by direct saline and formol-ether concentration techniques following standard protocols. All the data were analyzed using SPSS version 20.0. A total of 213 (57.3% male and 42.7% female) pulmonary tuberculosis patients were participated in the study. The overall co-infection rate of intestinal parasites was 26.3%. The infection rate of intestinal helminths account 24.4% and that of intestinal protozoa was 6.1%. Ascaris lumbricoides accounted the highest frequency of 11.3%. Living in rural residence (AOR = 3.175, 95% CI: 1.102-9.153, p = 0.032), Eating vegetables/ fruits without washing or peeling off (AOR = 2.208, 95% CI: 1.030-4.733, p = 0.042) and having body-mass index intestinal helminth infection. The infection rate by intestinal helminths was 24.4%. Ascaris lumbricoides was the most prevalent helminth. Residence, habit of washing vegetables/fruits before use and body-mass index were associated factors with intestinal helminthiasis. Therefore health care providers should screen and treat TB patients for intestinal helminthiasis in order to ensure good prognosis.

  18. How Barriers to Collaboration Prevent Progress in Demand for Knowledge

    DEFF Research Database (Denmark)

    Goduscheit, René Chester; Knudsen, Mette Præst

    2015-01-01

    (RTOs) as potential mediators of collaboration between SMEs and universities. On the basis of a unique sample consisting of 151 SMEs, RTOs and universities from seven countries, the differences across dyads of potential collaborations are identified. In particular, the article finds that both firms...... and universities with collaboration experience with the other partner in general perceive higher barriers than inexperienced firms or universities. In terms of the mediating role of RTOs, the article illustrates that universities perceive lower barriers when collaborating with RTOs than with SMEs. A similar...... tendency to a mediating role of RTOs can be found among the SMEs' perception of university collaboration. Finally, the analysis shows that the knowledge institutions perceive the SMEs as very important collaboration partners, but the same sense of importance is not shared by the SMEs regarding...

  19. Interactions between bacteria and the gut mucosa: Do enteric neurotransmitters acting on the mucosal epithelium influence intestinal colonization or infection?

    Science.gov (United States)

    The intestinal epithelium is a critical barrier between the internal and external milieux of the mammalian host. Epithelial interactions between these two host environments have been shown to be modulated by several different, cross-communicating cell types residing in the gut mucosa. These include ...

  20. Enzyme decorated drug carriers: Targeted swords to cleave and overcome the mucus barrier.

    Science.gov (United States)

    Menzel, Claudia; Bernkop-Schnürch, Andreas

    2018-01-15

    The use of mucus permeating drug carrier systems being able to overcome the mucus barrier can lead to a remarkable enhancement in bioavailability. One promising approach is the design of mucolytic enzyme decorated carrier systems (MECS). These systems include micro- and nanoparticles as well as self-emulsifying drug delivery systems (SEDDS) decorated with mucin cleaving enzymes such as papain (PAP) or bromelain (BRO). MECS are able to cross the mucus barrier in a comparatively efficient manner by cleaving mucus substructures in front of them on their way to the epithelium. Thereby these enzymes hydrolyze peptide bonds of mucus glycoproteins forming tiny holes or passages through the mucus. In various in vitro and in vivo studies MECS proved to be superior in their mucus permeating properties over nanocarriers without enzyme decoration. PAP decorated nanoparticles, for instance, remained 3h after oral administration to an even 2.5-fold higher extend in rat small intestine than the corresponding undecorated nanoparticles permeating the intestinal mucus gel layer to a much lower degree. As MECS break up the mucus network only locally without destroying its overall protective barrier function, even long term treatments with such systems seem feasible. Within this review article we address different drug carrier systems decorated with various types of enzymes, their particular pros and cons and potential applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. [Treatment of children with intestinal failure: intestinal rehabilitation, home parenteral nutrition or small intestine transplantation?

    NARCIS (Netherlands)

    Neelis, E.G.; Oers, H.A. van; Escher, J.C.; Damen, G.M.; Rings, E.H.; Tabbers, M.M.

    2014-01-01

    Intestinal failure is characterised by inadequate absorption of food or fluids, which is caused by insufficient bowel surface area or functioning. Children with chronic intestinal failure are dependent on parenteral nutrition (PN), which can be provided at home (HPN). In the Netherlands, HPN for

  2. Colon-specific delivery of a probiotic-derived soluble protein ameliorates intestinal inflammation in mice through an EGFR-dependent mechanism

    Science.gov (United States)

    Yan, Fang; Cao, Hanwei; Cover, Timothy L.; Washington, M. Kay; Shi, Yan; Liu, LinShu; Chaturvedi, Rupesh; Peek, Richard M.; Wilson, Keith T.; Polk, D. Brent

    2011-01-01

    Probiotic bacteria can potentially have beneficial effects on the clinical course of several intestinal disorders, but our understanding of probiotic action is limited. We have identified a probiotic bacteria–derived soluble protein, p40, from Lactobacillus rhamnosus GG (LGG), which prevents cytokine-induced apoptosis in intestinal epithelial cells. In the current study, we analyzed the mechanisms by which p40 regulates cellular responses in intestinal epithelial cells and p40’s effects on experimental colitis using mouse models. We show that the recombinant p40 protein activated EGFR, leading to Akt activation. Activation of EGFR by p40 was required for inhibition of cytokine-induced apoptosis in intestinal epithelial cells in vitro and ex vivo. Furthermore, we developed a pectin/zein hydrogel bead system to specifically deliver p40 to the mouse colon, which activated EGFR in colon epithelial cells. Administration of p40-containing beads reduced intestinal epithelial apoptosis and disruption of barrier function in the colon epithelium in an EGFR-dependent manner, thereby preventing and treating DSS-induced intestinal injury and acute colitis. Furthermore, p40 activation of EGFR was required for ameliorating colon epithelial cell apoptosis and chronic inflammation in oxazolone-induced colitis. These data define what we believe to be a previously unrecognized mechanism of probiotic-derived soluble proteins in protecting the intestine from injury and inflammation. PMID:21606592

  3. Intestinal subepithelial myofibroblasts support in vitro and in vivo growth of human small intestinal epithelium.

    Directory of Open Access Journals (Sweden)

    Nicholas Lahar

    Full Text Available The intestinal crypt-niche interaction is thought to be essential to the function, maintenance, and proliferation of progenitor stem cells found at the bases of intestinal crypts. These stem cells are constantly renewing the intestinal epithelium by sending differentiated cells from the base of the crypts of Lieberkühn to the villus tips where they slough off into the intestinal lumen. The intestinal niche consists of various cell types, extracellular matrix, and growth factors and surrounds the intestinal progenitor cells. There have recently been advances in the understanding of the interactions that regulate the behavior of the intestinal epithelium and there is great interest in methods for isolating and expanding viable intestinal epithelium. However, there is no method to maintain primary human small intestinal epithelium in culture over a prolonged period of time. Similarly no method has been published that describes isolation and support of human intestinal epithelium in an in vivo model. We describe a technique to isolate and maintain human small intestinal epithelium in vitro from surgical specimens. We also describe a novel method to maintain human intestinal epithelium subcutaneously in a mouse model for a prolonged period of time. Our methods require various growth factors and the intimate interaction between intestinal sub-epithelial myofibroblasts (ISEMFs and the intestinal epithelial cells to support the epithelial in vitro and in vivo growth. Absence of these myofibroblasts precluded successful maintenance of epithelial cell formation and proliferation beyond just a few days, even in the presence of supportive growth factors. We believe that the methods described here can be used to explore the molecular basis of human intestinal stem cell support, maintenance, and growth.

  4. Saccharomyces boulardii improves intestinal epithelial cell restitution by inhibiting αvβ5 integrin activation state.

    Directory of Open Access Journals (Sweden)

    Alexandra Canonici

    Full Text Available Intestinal epithelial cell damage is frequently seen in the mucosal lesions of infectious or inflammatory bowel diseases such as ulcerative colitis or Crohn's disease. Complete remission of these diseases requires both the disappearance of inflammation and the repair of damaged epithelium. Saccharomyces boulardii (Sb, Biocodex is a non-pathogenic yeast widely used as a preventive and therapeutic probiotic for the prevention and treatment of diarrhea and other gastrointestinal disorders. We recently showed that it enhances the repair of intestinal epithelium through activation of α2β1 integrin collagen receptors. In the present study, we demonstrated that α2β1 integrin is not the sole cell-extracellular matrix receptor involved during Sb-mediated intestinal restitution. Indeed, by using cell adhesion assays, we showed that Sb supernatant contains heat sensitive molecule(s, with a molecular weight higher than 9 kDa, which decreased αvβ5 integrin-mediated adhesion to vitronectin by competing with the integrin. Moreover, Sb-mediated changes in cell adhesion to vitronectin resulted in a reduction of the αvβ5signaling pathway. We used a monolayer wounding assay that mimics in vivo cell restitution to demonstrate that down-modulation of the αvβ5 integrin-vitronectin interaction is related to Sb-induced cell migration. We therefore postulated that Sb supernatant contains motogenic factors that enhance cell restitution through multiple pathways, including the dynamic fine regulation of αvβ5 integrin binding activity. This could be of major importance in diseases characterized by severe mucosal injury, such as inflammatory and infectious bowel diseases.

  5. The Ussing Chamber Assay to Study Drug Metabolism and Transport in the Human Intestine.

    Science.gov (United States)

    Kisser, Beatrice; Mangelsen, Eva; Wingolf, Caroline; Partecke, Lars Ivo; Heidecke, Claus-Dieter; Tannergren, Christer; Oswald, Stefan; Keiser, Markus

    2017-06-22

    The Ussing chamber is an old but still powerful technique originally designed to study the vectorial transport of ions through frog skin. This technique is also used to investigate the transport of chemical agents through the intestinal barrier as well as drug metabolism in enterocytes, both of which are key determinants for the bioavailability of orally administered drugs. More contemporary model systems, such as Caco-2 cell monolayers or stably transfected cells, are more limited in their use compared to the Ussing chamber because of differences in expression rates of transporter proteins and/or metabolizing enzymes. While there are limitations to the Ussing chamber assay, the use of human intestinal tissue remains the best laboratory test for characterizing the transport and metabolism of compounds following oral administration. Detailed in this unit is a step-by-step protocol for preparing human intestinal tissue, for designing Ussing chamber experiments, and for analyzing and interpreting the findings. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  6. [Myosin B ATPase activity of the intestinal smooth muscle in intestinal obstruction].

    Science.gov (United States)

    Takamatsu, H

    1983-06-01

    Intestinal smooth myosin B was prepared from muscle layers around the lesion in dogs with experimental colonic stenosis and in patients with congenital intestinal obstruction. Mg2+-ATPase activity of the myosin B was compared between the proximal dilated segment and distal segment to obstruction. Experimental colonic stenosis: In early period after surgery, proximal colons showed higher activity of myosin B ATPase than distal colons, decreasing to less than distal colon as time passed. Congenital intestinal obstruction: In three cases, whose atresia might have occurred at earlier period of gestation, proximal bowels showed less activity of myosin B ATPase than distal bowels. However, in two cases, whose atresia might have occurred at later period of gestation, and two cases with intestinal stenosis, proximal bowels indicated higher activity of myosin B ATPase than distal bowels. These data suggested that the contractibility of the proximal intestine was depending on the duration of obstruction, and it was depressed in the former patients and was accelerated in the latter patients. These results suggested that the extensive resection of dilated proximal bowel in the congenital atresia is not always necessary to obtain good postoperative intestinal dynamics at the operation of the atresial lesions which may be induced at later period of gestation. They also suggested that surgery for intestinal obstruction should be performed before the depression of intestinal contractibility to get good bowel function.

  7. Influence of the gut microbiota on transcriptional regulation of genes involved in early life development of the intestinal mucus layer

    DEFF Research Database (Denmark)

    Bergström, Anders; Kristensen, Matilde Bylov; Metzdorff, Stine Broeng

    2010-01-01

    The interplay between the gut microbiota and the intestinal mucus layer is important both in the maintenance of the epithelial barrier as part of the innate immune defense, and in the conservation of gut homeostasis. Little is known about how the microbiota regulates mucin proteins, which protect...

  8. Influence of the gut microbiota on transcriptional regulation of genes involved in early life development of the intestinal mucus layer

    DEFF Research Database (Denmark)

    Bergström, Anders; Kristensen, Matilde Bylov; Metzdorff, Stine Broeng

    The interplay between the gut microbiota and the intestinal mucus layer is important both in the maintenance of the epithelial barrier as part of the innate immune defense, and in the conservation of gut homeostasis. Little is known about how the microbiota regulates mucin proteins, which protect...

  9. [Congenital intestinal lymphangiectasia].

    Science.gov (United States)

    Popović, Dugan D j; Spuran, Milan; Alempijević, Tamara; Krstić, Miodrag; Djuranović, Srdjan; Kovacević, Nada; Damnjanović, Svetozar; Micev, Marjan

    2011-03-01

    Congenital intestinal lymphangiectasia is a disease which leads to protein losing enteropathy. Tortuous, dilated lymphatic vessels in the intestinal wall and mesenterium are typical features of the disease. Clinical manifestations include malabsorption, diarrhea, steatorrhea, edema and effusions. Specific diet and medication are required for disease control. A 19-year old male patient was hospitalized due to diarrhea, abdominal swelling, weariness and fatigue. Physical examination revealed growth impairment, ascites, and lymphedema of the right hand and forearm. Laboratory assessment indicated iron deficiency anaemia, lymphopenia, malabsorption, inflammatory syndrome, and urinary infection. Enteroscopy and video capsule endoscopy demonstrated dilated lymphatic vessels in the small intestine. The diagnosis was confirmed by intestinal biopsy. The patient was put on high-protein diet containing medium-chain fatty acids, somatotropin and supportive therapy. Congenital intestinal lymphangiectasia is a rare disease, usually diagnosed in childhood. Early recognition of the disease and adequate treatment can prevent development of various complications.

  10. Clathrin-mediated endocytosis and transcytosis of enterotoxigenic Escherichia coli F4 fimbriae in porcine intestinal epithelial cells.

    Science.gov (United States)

    Rasschaert, Kristien; Devriendt, Bert; Favoreel, Herman; Goddeeris, Bruno M; Cox, Eric

    2010-10-15

    Enterotoxigenic Escherichia coli (ETEC) cause severe diarrhea in neonatal and recently weaned piglets. Previously, we demonstrated that oral immunization of F4 receptor positive piglets with purified F4 fimbriae induces a protective F4-specific intestinal immune response. However, in F4 receptor negative animals no F4-specific immune response can be elicited, indicating that the induction of an F4-specific mucosal immune response upon oral immunisation is receptor-dependent. Although F4 fimbriae undergo transcytosis across the intestinal epithelium in vivo, the endocytosis pathways used remain unknown. In the present study, we characterized the internalization of F4 fimbriae in the porcine intestinal epithelial cell line IPEC-J2. The results in the present study demonstrate that F4 fimbriae are internalized through a clathrin-dependent pathway. Furthermore, our results suggest that F4 fimbriae are transcytosed across differentiated IPEC-J2 cells. This receptor-dependent transcytosis of F4 fimbriae may explain the immunogenicity of these fimbriae upon oral administration in vivo. (c) 2010 Elsevier B.V. All rights reserved.

  11. Intestinal exposure to PCB 153 induces inflammation via the ATM/NEMO pathway.

    Science.gov (United States)

    Phillips, Matthew C; Dheer, Rishu; Santaolalla, Rebeca; Davies, Julie M; Burgueño, Juan; Lang, Jessica K; Toborek, Michal; Abreu, Maria T

    2018-01-15

    Polychlorinated biphenyls (PCBs) are persistent organic pollutants that adversely affect human health. PCBs bio-accumulate in organisms important for human consumption. PCBs accumulation in the body leads to activation of the transcription factor NF-κB, a major driver of inflammation. Despite dietary exposure being one of the main routes of exposure to PCBs, the gut has been widely ignored when studying the effects of PCBs. We investigated the effects of PCB 153 on the intestine and addressed whether PCB 153 affected intestinal permeability or inflammation and the mechanism by which this occurred. Mice were orally exposed to PCB 153 and gut permeability was assessed. Intestinal epithelial cells (IECs) were collected and evaluated for evidence of genotoxicity and inflammation. A human IEC line (SW480) was used to examine the direct effects of PCB 153 on epithelial function. NF-кB activation was measured using a reporter assay, DNA damage was assessed, and cytokine expression was ascertained with real-time PCR. Mice orally exposed to PCB 153 had an increase in intestinal permeability and inflammatory cytokine expression in their IECs; inhibition of NF-кB ameliorated both these effects. This inflammation was associated with genotoxic damage and NF-кB activation. Exposure of SW480 cells to PCB 153 led to similar effects as seen in vivo. We found that activation of the ATM/NEMO pathway by genotoxic stress was upstream of NF-kB activation. These results demonstrate that oral exposure to PCB 153 is genotoxic to IECs and induces downstream inflammation and barrier dysfunction in the intestinal epithelium. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. The DNA Sensor AIM2 Maintains Intestinal Homeostasis via Regulation of Epithelial Antimicrobial Host Defense

    Directory of Open Access Journals (Sweden)

    Shuiqing Hu

    2015-12-01

    Full Text Available Microbial pattern molecules in the intestine play immunoregulatory roles via diverse pattern recognition receptors. However, the role of the cytosolic DNA sensor AIM2 in the maintenance of intestinal homeostasis is unknown. Here, we show that Aim2−/− mice are highly susceptible to dextran sodium sulfate-induced colitis that is associated with microbial dysbiosis as represented by higher colonic burden of commensal Escherichia coli. Colonization of germ-free mice with Aim2−/− mouse microbiota leads to higher colitis susceptibility. In-depth investigation of AIM2-mediated host defense responses reveals that caspase-1 activation and IL-1β and IL-18 production are compromised in Aim2−/− mouse colons, consistent with defective inflammasome function. Moreover, IL-18 infusion reduces E. coli burden as well as colitis susceptibility in Aim2−/− mice. Altered microbiota in inflammasome-defective mice correlate with reduced expression of several antimicrobial peptides in intestinal epithelial cells. Together, these findings implicate DNA sensing by AIM2 as a regulatory mechanism for maintaining intestinal homeostasis.

  13. Circulating and Tissue-Resident CD4+ T Cells With Reactivity to Intestinal Microbiota Are Abundant in Healthy Individuals and Function Is Altered During Inflammation.

    Science.gov (United States)

    Hegazy, Ahmed N; West, Nathaniel R; Stubbington, Michael J T; Wendt, Emily; Suijker, Kim I M; Datsi, Angeliki; This, Sebastien; Danne, Camille; Campion, Suzanne; Duncan, Sylvia H; Owens, Benjamin M J; Uhlig, Holm H; McMichael, Andrew; Bergthaler, Andreas; Teichmann, Sarah A; Keshav, Satish; Powrie, Fiona

    2017-11-01

    cells were functionally heterogeneous, produced barrier-protective cytokines, and stimulated intestinal stromal and epithelial cells via interleukin 17A, interferon gamma, and tumor necrosis factor. In patients with inflammatory bowel diseases, microbiota-reactive CD4 + T cells were reduced in the blood compared with intestine; T-cell responses that we detected had an increased frequency of interleukin 17A production compared with responses of T cells from blood or intestinal tissues of controls. In an analysis of peripheral blood mononuclear cells and intestinal tissues from patients with inflammatory bowel diseases vs controls, we found that reactivity to intestinal bacteria is a normal property of the human CD4 + T-cell repertoire, and does not necessarily indicate disrupted interactions between immune cells and the commensal microbiota. T-cell responses to commensals might support intestinal homeostasis, by producing barrier-protective cytokines and providing a large pool of T cells that react to pathogens. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

  14. [Intestinal microbiota and cardiometabolic risk: mechanisms and diet modulation].

    Science.gov (United States)

    Moraes, Ana Carolina Franco de; Silva, Isis Tande da; Almeida-Pititto, Bianca de; Ferreira, Sandra Roberta G

    2014-06-01

    The gut microbiota obtained after birth is composed of a large range of bacteria that play different roles in the human host, such as nutrient uptake, protection against pathogens and immune modulation. The intestinal bacterial content is not completely known, but it is influenced by internal, and mainly by external factors, which modulate its composition and function. Studies indicate that the gut microbiota differs in lean and obese individuals, and in individuals with different food habits. There is evidence that the relationship between diet, inflammation, insulin resistance, and cardiometabolic risk are, in part, mediated by the composition of intestinal bacteria. Knowledge about the gut microbiota may result in different strategies to manipulate bacterial populations and promote health. This review discusses the relevance of understanding the role of dietary factors or patterns in the composition of the microbiota, as well as pathophysiological mechanisms of chronic metabolic diseases, and the potential of prebiotics and probiotics on the cardiometabolic risk profile.

  15. Growth Hormone Protects the Intestine Preserving Radiotherapy Efficacy on Tumors: A Short-Term Study.

    Directory of Open Access Journals (Sweden)

    Victor Caz

    Full Text Available The efficacy of radiotherapy on tumors is hampered by its devastating adverse effects on healthy tissue, particularly that of the gastrointestinal tract. These effects cause acute symptoms that are so disruptive to patients that they can lead to interruption of the radiotherapy program. These adverse effects could limit the intensity of radiation received by the patient, resulting in a sublethal dose to the tumor, thus increasing the risk of tumor resistance. The lack of an effective treatment to protect the bowel during radiation therapy to allow higher radiation doses that are lethal to the tumor has become a barrier to implementing effective therapy. In this study, we present a comparative analysis of both intestinal and tumor tissue in regard to the efficacy and the preventive impact of a short-term growth hormone (GH treatment in tumor-bearing rats as a protective agent during radiotherapy. Our data show that the exogenous administration of GH improved intestinal recovery after radiation treatment while preserving the therapeutic effect against the tumor. GH significantly increased proliferation in the irradiated intestine but not in the irradiated tumors, as assessed by Positron Emission Tomography and the proliferative markers Ki67, cyclin D3, and Proliferating Cell Nuclear Antigen. This proliferative effect was consistent with a significant increase in irradiated intestinal villi and crypt length. Furthermore, GH significantly decreased caspase-3 activity in the intestine, whereas GH did not produce this effect in the irradiated tumors. In conclusion, short-term GH treatment protects the bowel, inducing proliferation while reducing apoptosis in healthy intestinal tissue and preserving radiotherapy efficacy on tumors.

  16. Humoral immunity provides resident intestinal eosinophils access to luminal antigen via eosinophil-expressed low affinity Fc gamma receptors

    Science.gov (United States)

    Smith, Kalmia M.; Rahman, Raiann S.; Spencer, Lisa A.

    2016-01-01

    Eosinophils are native to the healthy gastrointestinal tract, and are associated with inflammatory diseases likely triggered by exposure to food allergens (e.g. food allergies and eosinophilic gastrointestinal disorders). In models of allergic respiratory diseases and in vitro studies, direct antigen engagement elicits eosinophil effector functions including degranulation and antigen presentation. However, it was not known whether intestinal tissue eosinophils that are separated from luminal food antigens by a columnar epithelium might similarly engage food antigens. Using an intestinal ligated loop model in mice, here we determined that resident intestinal eosinophils acquire antigen from the lumen of antigen-sensitized but not naïve mice in vivo. Antigen acquisition was immunoglobulin-dependent; intestinal eosinophils were unable to acquire antigen in sensitized immunoglobulin-deficient mice, and passive immunization with immune serum or antigen-specific IgG was sufficient to enable intestinal eosinophils in otherwise naïve mice to acquire antigen in vivo. Intestinal eosinophils expressed low affinity IgG receptors, and the activating receptor FcγRIII was necessary for immunoglobulin-mediated acquisition of antigens by isolated intestinal eosinophils in vitro. Our combined data suggest that intestinal eosinophils acquire lumen-derived food antigens in sensitized mice via FcγRIII antigen focusing, and may therefore participate in antigen-driven secondary immune responses to oral antigens. PMID:27683752

  17. Humoral Immunity Provides Resident Intestinal Eosinophils Access to Luminal Antigen via Eosinophil-Expressed Low-Affinity Fcγ Receptors.

    Science.gov (United States)

    Smith, Kalmia M; Rahman, Raiann S; Spencer, Lisa A

    2016-11-01

    Eosinophils are native to the healthy gastrointestinal tract and are associated with inflammatory diseases likely triggered by exposure to food allergens (e.g., food allergies and eosinophilic gastrointestinal disorders). In models of allergic respiratory diseases and in vitro studies, direct Ag engagement elicits eosinophil effector functions, including degranulation and Ag presentation. However, it was not known whether intestinal tissue eosinophils that are separated from luminal food Ags by a columnar epithelium might similarly engage food Ags. Using an intestinal ligated loop model in mice, in this study we determined that resident intestinal eosinophils acquire Ag from the lumen of Ag-sensitized but not naive mice in vivo. Ag acquisition was Ig-dependent; intestinal eosinophils were unable to acquire Ag in sensitized Ig-deficient mice, and passive immunization with immune serum or Ag-specific IgG was sufficient to enable intestinal eosinophils in otherwise naive mice to acquire Ag in vivo. Intestinal eosinophils expressed low-affinity IgG receptors, and the activating receptor FcγRIII was necessary for Ig-mediated acquisition of Ags by isolated intestinal eosinophils in vitro. Our combined data suggest that intestinal eosinophils acquire lumen-derived food Ags in sensitized mice via FcγRIII Ag focusing and that they may therefore participate in Ag-driven secondary immune responses to oral Ags. Copyright © 2016 by The American Association of Immunologists, Inc.

  18. Salmosan, a β-galactomannan-rich product, in combination with Lactobacillus plantarum contributes to restore intestinal epithelial barrier function by modulation of cytokine production.

    Science.gov (United States)

    Brufau, M Teresa; Campo-Sabariz, Joan; Carné, Sergi; Ferrer, Ruth; Martín-Venegas, Raquel

    2017-03-01

    Mannan-oligosaccharides (MOSs) are mannose-rich substrates with several intestinal health-promoting properties. The aim of this study was to investigate the potential capacity of Salmosan (S-βGM), a β-galactomannan-rich MOS product, to restore epithelial barrier function independently from its capacity to reduce bacterial invasion. In addition, the combination of S-βGM with the proven probiotic Lactobacillus plantarum (LP) was also tested. Paracellular permeability was assessed by transepithelial electrical resistance (TER) in co-cultures of Caco-2 cells and macrophages (differentiated from THP-1 cells) stimulated with LPS of Salmonella Enteritidis and in Caco-2 cell cultures stimulated with TNF-α in the absence or presence of 500 μg/ml S-βGM, LP (MOI 10) or a combination of both. In both culture models, TER was significantly reduced up to 25% by LPS or TNF-α stimulation, and the addition of S-βGM or LP alone did not modify TER, whereas the combination of both restored TER to values of nonstimulated cells. Under LPS stimulation, TNF-α production was significantly increased by 10-fold, whereas IL-10 and IL-6 levels were not modified. The combination of S-βGM and LP reduced TNF-α production to nonstimulated cell values and significantly increased IL-10 and IL-6 levels (5- and 7.5-fold, respectively). Moreover, S-βGM has the capacity to induce an increase of fivefold in LP growth. In conclusion, we have demonstrated that S-βGM in combination with LP protects epithelial barrier function by modulation of cytokine secretion, thus giving an additional value to this MOS as a potential symbiotic. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Autoradiographic study of the permeability characteristics of the small intestine

    Energy Technology Data Exchange (ETDEWEB)

    Kingham, J G.C.; Baker, J H; Loehry, C A [Royal Victoria Hospital, Bournemouth (UK)

    1978-02-01

    This autoradiographic study demonstrates the distribution of a range of small solutes and macromolecules in the mucosa of the guinea-pig small intestine after intracardiac injection. The substances investigated were: /sup 14/C-urea, /sup 3/H-mannose, /sup 3/H-inulin, and /sup 125/I polyvinylpyrrolidone (PVP). Small bowel biopsies were taken at intervals from one to 60 minutes after injection and the tissues processed for autoradiography. Light microscopic examination of the autoradiographs showed that the compartmental distribution depended on the molecular size of the substances being studied. Urea and mannose, as small solutes, were uniformly distributed throughout the intravascular, extravascular, and epithelial compartments. Inulin was evenly distributed in the vessel lumen and extravascular space but there was a considerable drop in concentration in the epithelium. PVP exhibited the most marked gradients, the concentration being greatest in the vascular lumina, lower in the extravascular space, least in the epithelium. Thus there appear to be two barriers to macromolecular passage which are freely permeable to small solutes: the capillary wall and the epithelium. At a light microscopical level it was not possible to observe whether the limiting membrane of each of these barriers is the cell plasmalemmal membrane or the basement membrane. The selectivity of the epithelial barrier was greater than that of the capillary barrier.

  20. Plasmacytoid dendritic cells are crucial in Bifidobacterium adolescentis-mediated inhibition of Yersinia enterocolitica infection.

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    Alexandra Wittmann

    Full Text Available In industrialized countries bacterial intestinal infections are commonly caused by enteropathogenic Enterobacteriaceae. The interaction of the microbiota with the host immune system determines the adequacy of an appropriate response against pathogens. In this study we addressed whether the probiotic Bifidobacterium adolescentis is protective during intestinal Yersinia enterocolitica infection. Female C57BL/6 mice were fed with B. adolescentis, infected with Yersinia enterocolitica, or B. adolescentis fed and subsequently infected with Yersinia enterocolitica. B. adolescentis fed and Yersinia infected mice were protected from Yersinia infection as indicated by a significantly reduced weight loss and splenic Yersinia load when compared to Yersinia infected mice. Moreover, protection from infection was associated with increased intestinal plasmacytoid dendritic cell and regulatory T-cell frequencies. Plasmacytoid dendritic cell function was investigated using depletion experiments by injecting B. adolescentis fed, Yersinia infected C57BL/6 mice with anti-mouse PDCA-1 antibody, to deplete plasmacytoid dendritic cells, or respective isotype control. The B. adolescentis-mediated protection from Yersinia dissemination to the spleen was abrogated after plasmacytoid dendritic cell depletion indicating a crucial function for pDC in control of intestinal Yersinia infection. We suggest that feeding of B. adolescentis modulates the intestinal immune system in terms of increased plasmacytoid dendritic cell and regulatory T-cell frequencies, which might account for the B. adolescentis-mediated protection from Yersinia enterocolitica infection.