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Sample records for intestinal mucosa barrier

  1. Mechanism of acute pancreatitis complicated with injury of intestinal mucosa barrier*

    PubMed Central

    Zhang, Xi-ping; Zhang, Jie; Song, Qiao-ling; Chen, Han-qin

    2007-01-01

    Acute pancreatitis (AP) is a common acute abdomen in clinic with a rapid onset and dangerous pathogenetic condition. AP can cause an injury of intestinal mucosa barrier, leading to translocation of bacteria or endotoxin through multiple routes, bacterial translocation (BT), gutorigin endotoxaemia, and secondary infection of pancreatic tissue, and then cause systemic inflammatory response syndrome (SIRS) or multiple organ dysfunction syndrome (MODS), which are important factors influencing AP’s severity and mortality. Meanwhile, the injury of intestinal mucosa barrier plays a key role in AP’s process. Therefore, it is clinically important to study the relationship between the injury of intestinal mucosa barrier and AP. In addition, many factors such as microcirculation disturbance, ischemical reperfusion injury, excessive release of inflammatory mediators and apoptosis may also play important roles in the damage of intestinal mucosa barrier. In this review, we summarize studies on mechanisms of AP. PMID:18257123

  2. Restoration of barrier function in injured intestinal mucosa.

    PubMed

    Blikslager, Anthony T; Moeser, Adam J; Gookin, Jody L; Jones, Samuel L; Odle, Jack

    2007-04-01

    Mucosal repair is a complex event that immediately follows acute injury induced by ischemia and noxious luminal contents such as bile. In the small intestine, villous contraction is the initial phase of repair and is initiated by myofibroblasts that reside immediately beneath the epithelial basement membrane. Subsequent events include crawling of healthy epithelium adjacent to the wound, referred to as restitution. This is a highly regulated event involving signaling via basement membrane integrins by molecules such as focal adhesion kinase and growth factors. Interestingly, however, ex vivo studies of mammalian small intestine have revealed the importance of closure of the interepithelial tight junctions and the paracellular space. The critical role of tight junction closure is underscored by the prominent contribution of the paracellular space to measures of barrier function such as transepithelial electrical resistance. Additional roles are played by subepithelial cell populations, including neutrophils, related to their role in innate immunity. The net result of reparative mechanisms is remarkably rapid closure of mucosal wounds in mammalian tissues to prevent the onset of sepsis. PMID:17429041

  3. Effects of Probiotics on Intestinal Mucosa Barrier in Patients With Colorectal Cancer after Operation

    PubMed Central

    Liu, Dun; Jiang, Xiao-Ying; Zhou, Lan-Shu; Song, Ji-Hong; Zhang, Xuan

    2016-01-01

    Abstract Many studies have found that probiotics or synbiotics can be used in patients with diarrhea or inflammatory bowel disease for the prevention and treatment of some pathologies by improving gastrointestinal barrier function. However, there are few studies availing the use of probiotics in patients with colorectal cancer. To lay the foundation for the study of nutritional support in colorectal cancer patients, a meta-analysis has been carried out to assess the efficacy of probiotics on the intestinal mucosa barrier in patients with colorectal cancer after operation. To estimate the efficacy of probiotics on the intestinal mucosa barrier in patients with colorectal cancer after operation, a meta-analysis of randomized controlled trials has been conducted. Databases including PubMed, Ovid, Embase, the Cochrane Central Register of Controlled Trials, and the China National Knowledge Infrastructure have been searched to identify suitable studies. Stata 12.0 was used for statistical analysis, and sensitivity analysis was also conducted. Six indicators were chosen to evaluate probiotics in protecting the intestinal mucosa barrier in patients with colorectal cancer. Ratios of lactulose to mannitol (L/M) and Bifidobacterium to Escherichia (B/E), occludin, bacterial translocation, and levels of secretory immunoglobulin A (SIgA), interleukin-6 (IL-6), and C-reactive protein (CRP) were chosen to evaluate probiotics in protecting the intestinal mucosa barrier in patients with colorectal cancer. Seventeen studies including 1242 patients were selected for meta-analysis, including 5 English studies and 12 Chinese studies. Significant effects were found in ratios of L/M (standardized mean difference = 3.83, P = 0.001) and B/E (standardized mean difference = 3.91, P = 0.000), occludin (standardized mean difference = 4.74, P = 0.000), bacterial translocation (standardized mean difference = 3.12, P = 0.002), and levels of SIgA (standardized mean

  4. Pathways and Progress in Improving Drug Delivery through the Intestinal Mucosa and Blood-Brain Barriers

    PubMed Central

    Laksitorini, Marlyn; Prasasty, Vivitri D.; Kiptoo, Paul K.; Siahaan, Teruna J.

    2015-01-01

    One of the major hurdles in developing therapeutic agents is the difficulty in delivering drugs through the intestinal mucosa and blood-brain barriers (BBB). The goal here is to describe the general structures of the biological barriers and the strategies to enhance drug delivery across these barriers. Prodrug methods used to improve drug penetration via the transcellular pathway have been successfully developed, and some prodrugs have been used to treat patients. The use of transporters to improve absorption of some drugs (e.g., antiviral agents) has also been successful in treating patients. Other methods, including (a) blocking the efflux pumps to improve transcellular delivery and (b) modulation of cell-cell adhesion in the intercellular junctions to improve paracellular delivery across biological barriers are still in the investigational stage. PMID:25418271

  5. A coculture model mimicking the intestinal mucosa reveals a regulatory role for myofibroblasts in immune-mediated barrier disruption.

    PubMed

    Willemsen, L E M; Schreurs, C C H M; Kroes, H; Spillenaar Bilgen, E J; Van Deventer, S J H; Van Tol, E A F

    2002-10-01

    The pathogenesis of Crohn's disease involves a mucosal inflammatory response affecting the barrier function of the gut. Myofibroblasts directly underlining the intestinal epithelium may have a regulatory role in immune-mediated barrier disruption. A coculture system of T84 epithelial and CCD-18Co myofibroblasts was established in order to mimic the in situ spatial interactions between these cell types and to evaluate their role in barrier: integrity. Lamina propria mononuclear cells (LPMC) were introduced in co- and monocultures. Effects of immune cells on barrier integrity was determined by measuring resistance and permeability for macromolecules. Introduction of LPMC in both culture systems caused a time-dependent decrease in barrier integrity. This was found to be less pronounced in cocultures indicating a regulatory role for mesenchymal cells. The effects were also found to depend on the route of LPMC stimulation. Additional analyses suggested that the regulatory role of myofibroblasts in barrier integrity involves production of growth factors. PMID:12395905

  6. Intestinal barrier: Molecular pathways and modifiers.

    PubMed

    Jeon, Min Kyung; Klaus, Christina; Kaemmerer, Elke; Gassler, Nikolaus

    2013-11-15

    The gastrointestinal tract is frequently challenged by pathogens/antigens contained in food and water and the intestinal epithelium must be capable of rapid regeneration in the event of tissue damage. Disruption of the intestinal barrier leads to a number of immune-mediated diseases, including inflammatory bowel disease, food allergy, and celiac disease. The intestinal mucosa is composed of different types of epithelial cells in specific barrier functions. Epithelial cells control surface-associated bacterial populations without disrupting the intestinal microflora that is crucial for host health. They are also capable of modulating mucosal immune system, and are thus essential in maintaining homeostasis in the gut. Thus, the regulation of intestinal epithelial homeostasis is crucial for the maintenance of the structure of the mucosa and the defensive barrier functions. Recent studies have demonstrated that multiple molecular pathways are involved in the regulation of intestinal epithelial cell polarity. These include the Wnt, Notch, Hippo, transforming growth factor-β (TGF-β)/bone morphogenetic protein (BMP) and Hedgehog pathways, most of which were identified in lower organisms where they play important roles during embryogenesis. These pathways are also used in adult organisms to regulate multiple self-renewing organs. Understanding the interactions between these molecular mechanisms and intestinal barrier function will therefore provide important insight into the pathogenesis of intestinal-based immune-mediated diseases. PMID:24244877

  7. Cell volume regulation in goldfish intestinal mucosa.

    PubMed

    Groot, J A

    1981-11-01

    1. Ion and water content of goldfish intestinal mucosa, stripped free from muscular layers were measured under various incubation conditions. 2. Ouabain induces an increase in cation content that is electrically compensated for by chloride. The increase in solute content is accompanied by an increase in water content. 3. When extracellular chloride is partially replaced by sulphate, ouabain does induce cell shrinkage. 4. Anoxia induces a rapid increase in cell volume that is restored by oxygenation of the incubation solution. Ouabain prevents the restoration of volume. 5. It is concluded that the classical ouabain-sensitive Na/K pump participates in the maintenance of cellular volume. We suggest that the constancy in volume after ouabain poisoning as is reported for many tissues might be due to a low chloride conductance of its membranes. 6. Anisotonic media (range: 0.6-1.2 isotonicity), made by variation on mannitol concentration, induce changes in cell water content that deviates from the simplified van't Hoff equation by about 10%. No change in water content after the initial increase was found. 7. We conclude that goldfish enterocytes do not possess a mechanism for rapid volume readjustment. PMID:7322833

  8. The quantitative assessment of normal canine small intestinal mucosa.

    PubMed

    Hart, I R; Kidder, D E

    1978-09-01

    Quanitative methods of assessing the architecture of small intestinal mucosa have been applied to biopsy material from normal dogs. Mucosal samples taken from four predetermined sites show that there are significant quantitative differences between the various levels of the small bowel. Animals of one year of age and older show no correlation between age or weight and mucosal dimensions. The significance of these findings, in relation to examination of biopsy material from cases of clinical small intestinal disease, is discussed. PMID:364574

  9. Increased apoptosis in gastric mucosa adjacent to intestinal metaplasia

    PubMed Central

    van Grieken, N C T; Meijer, G A; zur Hausen, A; Meuwissen, S G M; Baak, J P A; Kuipers, E J

    2003-01-01

    Background: The biological processes involved in the development of gastric mucosal atrophy and intestinal metaplasia are still incompletely understood. Reports testing the hypothesis that apoptosis leads to atrophy have yielded conflicting results. The availability of new antibodies for the detection of apoptotic cells in tissue sections has facilitated the analysis of the role of apoptosis in the gastritis–atrophy–intestinal metaplasia sequence. Methods: Archival material from 40 gastric resection specimens with normal mucosa (n = 5), chronic active gastritis (n = 17), or intestinal metaplasia (n = 18) was studied. Immunohistochemistry was performed using antibodies directed against cleaved cytokeratin 18 and active caspase 3. Slides were scored on a 0–3 scale for the presence of apoptotic cells. Results: Normal gastric mucosa contained low numbers of apoptotic cells at the surface epithelium (mean score, 0.20). This number was significantly increased in cases with chronic gastritis (mean score, 1.06) and in those with intestinal metaplasia (mean score, 2.56). Within the intestinal metaplasia cases, 44 different foci of intestinal metaplasia were identified. In 39 of these 44 areas, concentrations of apoptotic cells were seen immediately adjacent to the foci of intestinal metaplasia, but not in the metaplastic epithelium itself. Conclusions: Apoptosis is uncommon in normal gastric mucosa. Chronic inflammation and intestinal metaplasia are associated with increased apoptosis, but occur mainly at the mucosal surface and not in the deeper layers. These findings do not support the concept that apoptosis underlies the loss of gastric glands and leads to atrophy, but the observed concentration of apoptotic epithelial cells adjacent to foci of intestinal metaplasia could be related to heterogeneity of epithelial damage, causing apoptosis, to which intestinal metaplasia is a response. PMID:12719456

  10. Dosimetry Model for Radioactivity Localized to Intestinal Mucosa

    SciTech Connect

    Fisher, Darrell R.; Rajon, Didier; Breitz, Hazel B.; Goris, Michael L.; Bolch, Wesley E.; Knox, Susan J.

    2004-06-30

    This paper provides a new model for calculating radiation absorbed dose to the full thickness of the small and large intestinal walls, and to the mucosal layers. The model was used to estimate the intestinal radiation doses from yttrium-90-labeled-DOTA-biotin binding to NR-LU-10-streptavidin in patients. We selected model parameters from published data and observations and used the model to calculate energy absorbed fractions using the EGS4 radiation transport code. We determined the cumulated 90Y activity in the small and large intestines of patients from gamma camera images and calculated absorbed doses to the mucosal layer and to the whole intestinal wall. The mean absorbed dose to the wall of the small intestine was 16.2 mGy/MBq (60 cGy/mCi) administered from 90Y localized in the mucosa and 70 mGy/MBq (260 cGy/mCi) to the mucosal layer within the wall. Doses to the large intestinal wall and to the mucosa of the large intestine were lower than those for small intestine by a factor of about 2.5. These doses are greater by factors of about 5 to 6 than those that would have been calculated using the standard MIRD models that assume the intestinal activity is in the bowel contents. The specific uptake of radiopharmaceuticals in mucosal tissues may lead to dose-related intestinal toxicities. Tissue dosimetry at the sub-organ level is useful for better understanding intestinal tract radiotoxicity and associated dose-response relationships.

  11. Scap is required for sterol synthesis and crypt growth in intestinal mucosa[S

    PubMed Central

    McFarlane, Matthew R.; Cantoria, Mary Jo; Linden, Albert G.; January, Brandon A.; Liang, Guosheng; Engelking, Luke J.

    2015-01-01

    SREBP cleavage-activating protein (Scap) is an endoplasmic reticulum membrane protein required for cleavage and activation of sterol regulatory element-binding proteins (SREBPs), which activate the transcription of genes in sterol and fatty acid biosynthesis. Liver-specific loss of Scap is well tolerated; hepatic synthesis of sterols and fatty acids is reduced, but mice are otherwise healthy. To determine whether Scap loss is tolerated in the intestine, we generated a mouse model (Vil-Scap−) in which tamoxifen-inducible Cre-ERT2, a fusion protein of Cre recombinase with a mutated ligand binding domain of the human estrogen receptor, ablates Scap in intestinal mucosa. After 4 days of tamoxifen, Vil-Scap− mice succumb with a severe enteropathy and near-complete collapse of intestinal mucosa. Organoids grown ex vivo from intestinal crypts of Vil-Scap− mice are readily killed when Scap is deleted by 4-hydroxytamoxifen. Death is prevented when culture medium is supplemented with cholesterol and oleate. These data show that, unlike the liver, the intestine requires Scap to sustain tissue integrity by maintaining the high levels of lipid synthesis necessary for proliferation of intestinal crypts. PMID:25896350

  12. The Effect of Peritoneal Air Exposure on Intestinal Mucosal Barrier

    PubMed Central

    Bao, Jun; Tan, Shanjun; Yu, Wenkui; Lin, Zhiliang; Dong, Yi; Chen, Qiyi; Shi, Jialiang; Duan, Kaipeng; Bai, Xiaowu; Xu, Lin; Li, Jieshou

    2014-01-01

    Background. Damage of the intestinal mucosa barrier may result in intestinal bacterial and endotoxin translocation, leading to local and systemic inflammation. The present study was designed to investigate whether peritoneal air exposure induces damage of intestinal mucosal barrier. Methods. Sprague-Dawley rats (weighing 210 to 230 g) were randomized into five groups (6/group): a control group, a sham group, and three exposure groups with peritoneal air exposure for 1, 2, and 3 h, respectively. At 24 h after surgery, blood and terminal ileum were sampled. The serum D-lactate levels were determined using an ELISA kit. The intestinal permeability was determined by measuring the intestinal clearance of FITC-dextran (FD4). The histopathological changes in terminal ileum were also assessed. Results. Compared with the controls, peritoneal air exposure caused an increase in both serum D-lactate level and intestinal FD4 clearance, which were proportional to the length of peritoneal air exposure and correlated to Chiu's scores, indices for intestinal mucosal injury. Edema and inflammatory cells were also observed in mucosa and submucosa of ileum in three exposure groups. Conclusions. Peritoneal air exposure could induce damage to the intestinal mucosal barrier, which is proportional to the time length of peritoneal air exposure. PMID:25210511

  13. Effect of dietary fat on the small intestinal mucosa.

    PubMed

    Maxton, D G; Cynk, E U; Jenkins, A P; Thompson, R P

    1989-09-01

    The presence of food within the small intestinal lumen promotes mucosal cell proliferation. To define the trophic role of triglycerides, three groups of eight female Wistar rats were isocalorically fed for four weeks with either Vivonex, or Vivonex with 50% calorie substitution with an essential fatty acid mixture, or Vivonex with 50% calorie substitution with a saturated fatty acid mixture. Although Vivonex caused greater body weight gain, both essential fatty acids and saturated fatty acids increased small intestinal weight, mucosal weight, protein and DNA overall, and in each of three intestinal segments (proximal, middle and distal), compared with Vivonex. Mucosal indices were similar for essential fatty acids and saturated fatty acids. These results show that triglycerides, regardless of essential fatty acid content, are trophic to the rat small intestinal mucosa. PMID:2806993

  14. Differences in reactive hyperemia between the intestinal mucosa and muscularis.

    PubMed

    Shepherd, A P; Riedel, G L

    1984-12-01

    In a previous study of regional intestinal blood flow by laser-Doppler velocimetry, we noted that the mucosa displayed reactive hyperemia following arterial occlusion but that the muscularis did not. Therefore, to determine whether this observation is generally valid, we compared responses of the mucosa and muscularis externa to arterial occlusion. We measured total blood flow to isolated loops of canine small bowel with an electromagnetic flow probe on the supply artery; blood flow either in the mucosa or in the muscularis was measured by laser-Doppler velocimetry. Mucosal and total blood flow consistently showed reactive hyperemia in response to a 60-s occlusion, but the muscularis did not. To determine whether metabolic rate influenced reactive hyperemia, we increased enteric oxygen uptake by placing 5% bile and transportable solutes in the lumen; these agents increased oxygen consumption by 36%. After a 60-s occlusion, the durations of both total and mucosal reactive hyperemia were significantly prolonged by increased metabolic rate. Similarly, the payback-to-debt ratios in both total and mucosal blood flows were significantly increased at elevated metabolic rate. These data support the conclusions that reactive hyperemia occurs more frequently and has a greater magnitude in the mucosa compared with the muscularis and both total and mucosal reactive hyperemia are strongly influenced by the preocclusive oxygen demand. These findings therefore constitute further evidence that metabolic factors contribute to reactive hyperemia in the intestinal circulation. PMID:6391202

  15. Acylation of lysolecithin in the intestinal mucosa of rats

    PubMed Central

    Subbaiah, P. V.; Sastry, P. S.; Ganguly, J.

    1970-01-01

    1. The presence of an active acyl-CoA–lysolecithin (1-acylglycerophosphorylcholine) acyltransferase was demonstrated in rat intestinal mucosa. 2. ATP and CoA were necessary for the incorporation of free [1-14C]oleic acid into lecithin (phosphatidylcholine). 3. The reaction was about 20 times as fast with [1-14C]oleoyl-CoA as with free oleic acid, CoA and ATP. 4. With 1-acylglycerophosphorylcholine as the acceptor, both oleic acid and palmitic acid were incorporated into the β-position of lecithin; the incorporation of palmitic acid was 60% of that of oleic acid. 5. Of the various analogues of lysolecithin tested as acyl acceptors from [1-14C]oleoyl CoA, a lysolecithin with a long-chain fatty acid at the 1-position was most efficient. 6. The enzyme was mostly present in the brush-border-free particulate fraction of the intestinal mucosa. 7. Of the various tissues of rats tested for the activity, intestinal mucosa was found to be the most active, with testes, liver, kidneys and spleen following it in decreasing order. PMID:5484668

  16. Interactions between bacteria and the gut mucosa: Do enteric neurotransmitters acting on the mucosal epithelium influence intestinal colonization or infection?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  17. Interactions between bacteria and the gut mucosa: Do enteric neurotransmitters acting on the mucosal epithelium influence intestinal colonization or infection?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 includ...

  18. Ornithine transcarbamylase and disaccharidase activities in damaged intestinal mucosa of children--diagnosis of hereditary ornithine transcarbamylase deficiency in mucosa.

    PubMed

    Cathelineau, L; Briand, P; Rabier, D; Navarro, J

    1985-12-01

    Ornithine transcarbamylase (OTC) and disaccharidase activities were measured in the intestinal mucosa from 182 children. Sixty-nine had normal mucosa, whereas the others had different degrees of mucosal damage. Brush border disaccharidases are significantly decreased in all degrees of villous atrophy. In contrast, OTC is not affected in moderate atrophy and only slightly decreased in severe atrophy. Consequently, the OTC-to-lactase ratio increases with the degree of atrophy and permits discrimination between normal and damaged mucosa. The assay of OTC activity in intestinal mucosa for the diagnosis of hereditary deficiency in male hemizygote patients generally provides nonambiguously low results, whereas in heterozygote females the amount of residual activity is in the range of the results found in damaged mucosa. PMID:4067786

  19. Do Antimicrobial Peptides and Complement Collaborate in the Intestinal Mucosa?

    PubMed Central

    Kopp, Zoë A.; Jain, Umang; Van Limbergen, Johan; Stadnyk, Andrew W.

    2015-01-01

    It is well understood that multiple antimicrobial peptides (AMPs) are constitutively deployed by the epithelium to bolster the innate defenses along the entire length of the intestines. In addition to this constitutive/homeostatic production, AMPs may be inducible and levels changed during disease. In contrast to this level of knowledge on AMP sources and roles in the intestines, our understanding of the complement cascade in the healthy and diseased intestines is rudimentary. Epithelial cells make many complement proteins and there is compelling evidence that complement becomes activated in the lumen. With the common goal of defending the host against microbes, the opportunities for cross-talk between these two processes is great, both in terms of actions on the target microbes but also on regulating the synthesis and secretion of the alternate family of molecules. This possibility is beginning to become apparent with the finding that colonic epithelial cells possess anaphylatoxin receptors. There still remains much to be learned about the possible points of collaboration between AMPs and complement, for example, whether there is reciprocal control over expression in the intestinal mucosa in homeostasis and restoring the balance following infection and inflammation. PMID:25688244

  20. The adhesiometer: a simple device to measure adherence of barium sulfate to intestinal mucosa.

    PubMed

    Salomonowitz, E; Frick, M P; Cragg, A H; Lund, G

    1984-04-01

    A simple, inexpensive device assessing barium sulfate adherence to alimentary tract mucosa was tested in an animal study using pigs and dogs. Interaction of gastric, intestinal, and colonic mucosal lining with three different barium preparations was studied. In both pigs and dogs, barium adherence to gastric mucosa was significantly stronger when compared with colonic mucosa. PMID:6608230

  1. Oxytocin evokes a pulsatile PGE2 release from ileum mucosa and is required for repair of intestinal epithelium after injury

    PubMed Central

    Chen, Dawei; Zhao, Junhan; Wang, Haoyi; An, Ning; Zhou, Yuping; Fan, Jiahui; Luo, Junwen; Su, Wenlong; Liu, Chuanyong; Li, Jingxin

    2015-01-01

    We measured the short-circuit current (Isc) in rat ileum mucosa to identify the effect of oxytocin (OT) on mucosal secretion in small intestine. We identified a COX-2-derived pulsatile PGE2 release triggered by OT in rat ileum mucosa. OT receptors (OTR) are expressed in intestine crypt epithelial cells. Notably, OT evoked a dynamic change of [Ca2+]i in ileum crypts, which was responsible for this pulsatile release of PGE2. OT ameliorated 5-FU-, radiation- or DSS- induced injury in vivo, including the improvement of weight loss, reduced villus height and impaired survival of crypt transit-amplifying cells as well as crypt. Moreover, these protective effects of OT against intestinal injury were eliminated by coadministration of a selective inhibitor of PGE2, AH6809. Our findings strongly suggest that OT, a novel and important regulator of intestine mucosa barrier, is required for repair of intestinal epithelium after injury. Considering that OT is an FDA-approved drug, this work reveals a potential novel and safe way to combat or prevent chemo-radiotherapy induced intestine injury or to treat IBD. PMID:26159321

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

    PubMed Central

    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

  3. Interactions Between Bacteria and the Gut Mucosa: Do Enteric Neurotransmitters Acting on the Mucosal Epithelium Influence Intestinal Colonization or Infection?

    PubMed

    Green, Benedict T; Brown, David R

    2016-01-01

    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 enteric neurons, whose activity is influenced by bacterial pathogens, and their secreted products. Neurotransmitters appear to influence epithelial associations with bacteria in the intestinal lumen. For example, internalization of Salmonella enterica and Escherichia coli O157:H7 into the Peyer's patch mucosa of the small intestine is altered after the inhibition of neural activity with saxitoxin, a neuronal sodium channel blocker. Catecholamine neurotransmitters, such as dopamine and norepinephrine, also alter bacterial internalization in Peyer's patches. In the large intestine, norepinephrine increases the mucosal adherence of E. coli. These neurotransmitter actions are mediated by well-defined catecholamine receptors situated on the basolateral membranes of epithelial cells rather than through direct interactions with luminal bacteria. Investigations of the involvement of neuroepithelial communication in the regulation of interactions between the intestinal mucosa and luminal bacteria will provide novel insights into the mechanisms underlying bacterial colonization and pathogenesis at mucosal surfaces. PMID:26589216

  4. Epidermal Growth Factor and Intestinal Barrier Function.

    PubMed

    Tang, Xiaopeng; Liu, Hu; Yang, Shufen; Li, Zuohua; Zhong, Jinfeng; Fang, Rejun

    2016-01-01

    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. PMID:27524860

  5. Epidermal Growth Factor and Intestinal Barrier Function

    PubMed Central

    Liu, Hu; Yang, Shufen; Li, Zuohua; Zhong, Jinfeng

    2016-01-01

    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. PMID:27524860

  6. Studies on the phospholipases of rat intestinal mucosa

    PubMed Central

    Subbaiah, P. V.; Ganguly, J.

    1970-01-01

    1. Subcellular distribution and characteristics of different phospholipases of rat intestinal mucosa were studied. 2. The presence of free fatty acid was necessary for the maximal hydrolysis of lecithin (phosphatidylcholine), but there was no accumulation of lysolecithin (1 or 2-acylglycerophosphorylcholine);lysolecithin accumulated when the reaction was carried out in the presence of sodium deoxycholate and at or above pH8.0. 3. The fatty acid-activated phospholipase B as well as lysolecithinase showed optimum activity at pH6.5, whereas for the phospholipase A it was about pH8.6. 4. The bulk of the phospholipase A was present in the microsomal fraction, whereas the phospholipase B and lysolecithinase activities were distributed between the microsomal and soluble fractions of the mucosal homogenate. 5. Phospholipase A was equally distributed between the brush border and brush-border-free particulate fraction, with the brush border having highest specific activity, whereas the other two activities were distributed between the brush-border-free particulate and soluble fractions. 6. Various treatments showed marked differences between the phospholipase A and phospholipase B activities, but not between phospholipase B and lysolecithinase activities. 7. By using (β[1-14C]-oleoyl) lecithin it was shown that the mucosal phospholipase A was specific for the β-ester linkage of the lecithin molecule. PMID:5484667

  7. The role of immunomodulators on intestinal barrier homeostasis in experimental models.

    PubMed

    Andrade, Maria Emília Rabelo; Araújo, Raquel Silva; de Barros, Patrícia Aparecida Vieira; Soares, Anne Danieli Nascimento; Abrantes, Fernanda Alves; Generoso, Simone de Vasconcelos; Fernandes, Simone Odília Antunes; Cardoso, Valbert Nascimento

    2015-12-01

    The intestinal epithelium is composed of specialized epithelial cells that form a physical and biochemical barrier to commensal and pathogenic microorganisms. However, dysregulation of the epithelial barrier function can lead to increased intestinal permeability and bacterial translocation across the intestinal mucosa, which contributes to local and systemic immune activation. The increase in these parameters is associated with inflammatory bowel disease, physical exercise under heat stress, intestinal obstruction, ischemia, and mucositis, among other conditions. Lately, there has been growing interest in immunomodulatory nutrients and probiotics that can regulate host immune and inflammatory responses and possibly restore the intestinal barrier. Immunomodulators such as amino acids (glutamine, arginine, tryptophan, and citrulline), fatty acids (short-chain and omega-3 fatty acids and conjugated linoleic acids), and probiotics (Bifidobacterium, Saccharomyces, and Lactobacillus) have been reported in the literature. Here, we review the critical roles of immunomodulatory nutrients in supporting gut barrier integrity and function. PMID:25660317

  8. Nutritional Keys for Intestinal Barrier Modulation

    PubMed Central

    De Santis, Stefania; Cavalcanti, Elisabetta; Mastronardi, Mauro; Jirillo, Emilio; Chieppa, Marcello

    2015-01-01

    The intestinal tract represents the largest interface between the external environment and the human body. Nutrient uptake mostly happens in the intestinal tract, where the epithelial surface is constantly exposed to dietary antigens. Since inflammatory response toward these antigens may be deleterious for the host, a plethora of protective mechanisms take place to avoid or attenuate local damage. For instance, the intestinal barrier is able to elicit a dynamic response that either promotes or impairs luminal antigens adhesion and crossing. Regulation of intestinal barrier is crucial to control intestinal permeability whose increase is associated with chronic inflammatory conditions. The cross talk among bacteria, immune, and dietary factors is able to modulate the mucosal barrier function, as well as the intestinal permeability. Several nutritional products have recently been proposed as regulators of the epithelial barrier, even if their effects are in part contradictory. At the same time, the metabolic function of the microbiota generates new products with different effects based on the dietary content. Besides conventional treatments, novel therapies based on complementary nutrients are now growing. Fecal therapy has been recently used for the clinical treatment of refractory Clostridium difficile infection instead of the classical antibiotic therapy. In the present review, we will outline the epithelial response to nutritional components derived from dietary intake and microbial fermentation focusing on the consequent effects on the integrity of the epithelial barrier. PMID:26697008

  9. Functional changes of intestinal mucosal barrier in surgically critical patients

    PubMed Central

    Guo, Yuan-yuan; Liu, Mu-lin; He, Xian-di; Jiang, Cong-qiao; Liu, Rui-lin

    2010-01-01

    and iFABP P<0.05). CONCLUSION: The plasma concentrations of endotoxin, DAO, D-lactate, and intestinal fatty-acid binding protein (iFABP) could reflect a better function of the intestinal mucosa barrier in surgically critical ill patients. PMID:25214969

  10. Protective effects of bifidobacterial adhesin on intestinal mucosa of stressed male rats via modulation of inflammation

    PubMed Central

    Shu, Xiao-Liang; Yu, Tin-Tin; Kang, Kai; Xu, Han; Lei, Tao

    2014-01-01

    This study aimed to assess BA impact on inflammation markers and repair of intestinal mucosa. Forty-eight rats were randomly divided into stress (n = 24) and BA (n = 24) groups. Stress was induced by fettering in all animals, fed enterally with 125.4 kJ/kg/d and 0.2 g/kg/d nitrogen. Then, rats were treated for 8 days with 5 mg/kg/d BA (BA group) or 5 mg/kg/d saline (Stress group). Levels of NF-κB, IL-10, TNF-α, and IFN-γ were measured at different time points, in plasma and intestinal mucosa samples. Changes in intestinal mucosa morphology were observed by electron microscopy. Plasma and/or mucosal levels of NF-κB, TNF-α, and IFN-γ were significantly higher in both groups after stress induction (P < 0.05). These high levels persisted in control animals throughout the experiment, and were significantly reduced in the BA group, 3 and 8 days after stress induction (P < 0.05). Interestingly, IL-10 levels were increased after BA treatment (P < 0.05). At day 8, ileal mucosal villi and crypt structure were significantly restored in the BA group. Bifidobacterial adhesin plays a role in repairing intestinal mucosa injury after stress by regulating the release of inflammatory mediators in the intestinal mucosa. PMID:25031756

  11. Intestinal REG3 Lectins Protect against Alcoholic Steatohepatitis by Reducing Mucosa-Associated Microbiota and Preventing Bacterial Translocation.

    PubMed

    Wang, Lirui; Fouts, Derrick E; Stärkel, Peter; Hartmann, Phillipp; Chen, Peng; Llorente, Cristina; DePew, Jessica; Moncera, Kelvin; Ho, Samuel B; Brenner, David A; Hooper, Lora V; Schnabl, Bernd

    2016-02-10

    Approximately half of all deaths from liver cirrhosis, the tenth leading cause of mortality in the United States, are related to alcohol use. Chronic alcohol consumption is accompanied by intestinal dysbiosis and bacterial overgrowth, yet little is known about the factors that alter the microbial composition or their contribution to liver disease. We previously associated chronic alcohol consumption with lower intestinal levels of the antimicrobial-regenerating islet-derived (REG)-3 lectins. Here, we demonstrate that intestinal deficiency in REG3B or REG3G increases numbers of mucosa-associated bacteria and enhances bacterial translocation to the mesenteric lymph nodes and liver, promoting the progression of ethanol-induced fatty liver disease toward steatohepatitis. Overexpression of Reg3g in intestinal epithelial cells restricts bacterial colonization of mucosal surfaces, reduces bacterial translocation, and protects mice from alcohol-induced steatohepatitis. Thus, alcohol appears to impair control of the mucosa-associated microbiota, and subsequent breach of the mucosal barrier facilitates progression of alcoholic liver disease. PMID:26867181

  12. Intestinal inflammation and mucosal barrier function.

    PubMed

    Sánchez de Medina, Fermín; Romero-Calvo, Isabel; Mascaraque, Cristina; Martínez-Augustin, Olga

    2014-12-01

    Intestinal mucosal barrier function is the capacity of the intestine to provide adequate containment of luminal microorganisms and molecules while preserving the ability to absorb nutrients. The central element is the epithelial layer, which physically separates the lumen and the internal milieu and is in charge of vectorial transport of ions, nutrients, and other substances. The secretion of mucus-forming mucins, sIgA, and antimicrobial peptides reinforces the mucosal barrier on the extraepithelial side, while a variety of immune cells contributes to mucosal defense in the inner side. Thus, the mucosal barrier is of physical, biochemical, and immune nature. In addition, the microbiota may be viewed as part of this system because of the mutual influence occurring between the host and the luminal microorganisms. Alteration of the mucosal barrier function with accompanying increased permeability and/or bacterial translocation has been linked with a variety of conditions, including inflammatory bowel disease. Genetic and environmental factors may converge to evoke a defective function of the barrier, which in turn may lead to overt inflammation of the intestine as a result of an exacerbated immune reaction toward the microbiota. According to this hypothesis, inflammatory bowel disease may be both precipitated and treated by either stimulation or downregulation of the different elements of the mucosal barrier, with the outcome depending on timing, the cell type affected, and other factors. In this review, we cover briefly the elements of the barrier and their involvement in functional defects and the resulting phenotype. PMID:25222662

  13. Probiotic bacteria and intestinal epithelial barrier function.

    PubMed

    Ohland, Christina L; Macnaughton, Wallace K

    2010-06-01

    The intestinal tract is a diverse microenvironment where more than 500 species of bacteria thrive. A single layer of epithelium is all that separates these commensal microorganisms and pathogens from the underlying immune cells, and thus epithelial barrier function is a key component in the arsenal of defense mechanisms required to prevent infection and inflammation. The epithelial barrier consists of a dense mucous layer containing secretory IgA and antimicrobial peptides as well as dynamic junctional complexes that regulate permeability between cells. Probiotics are live microorganisms that confer benefit to the host and that have been suggested to ameliorate or prevent diseases including antibiotic-associated diarrhea, irritable bowel syndrome, and inflammatory bowel disease. Probiotics likely function through enhancement of barrier function, immunomodulation, and competitive adherence to the mucus and epithelium. This review summarizes the evidence about effects of the many available probiotics with an emphasis on intestinal barrier function and the mechanisms affected by probiotics. PMID:20299599

  14. The intestinal epithelium as guardian of gut barrier integrity.

    PubMed

    Zhang, Kaiyi; Hornef, Mathias W; Dupont, Aline

    2015-11-01

    A single layer of epithelial cells separates the intestinal lumen from the underlying sterile tissue. It is exposed to a multitude of nutrients and a large number of commensal bacteria. Although the presence of commensal bacteria significantly contributes to nutrient digestion, vitamin synthesis and tissue maturation, their high number represents a permanent challenge to the integrity of the epithelial surface keeping the local immune system constantly on alert. In addition, the intestinal mucosa is challenged by a variety of enteropathogenic microorganisms. In both circumstances, the epithelium actively contributes to maintaining host-microbial homeostasis and antimicrobial host defence. It deploys a variety of mechanisms to restrict the presence of commensal bacteria to the intestinal lumen and to prevent translocation of commensal and pathogenic microorganisms to the underlying tissue. Enteropathogenic microorganisms in turn have learnt to evade the host's immune system and circumvent the antimicrobial host response. In the present article, we review recent advances that illustrate the intense and intimate host-microbial interaction at the epithelial level and improve our understanding of the mechanisms that maintain the integrity of the intestinal epithelial barrier. PMID:26294173

  15. Intestinal barrier in inflammatory bowel disease

    PubMed Central

    Antoni, Lena; Nuding, Sabine; Wehkamp, Jan; Stange, Eduard F

    2014-01-01

    A complex mucosal barrier protects as the first line of defense the surface of the healthy intestinal tract from adhesion and invasion by luminal microorganisms. In this review, we provide an overview about the major components of this protective system as for example an intact epithelium, the synthesis of various antimicrobial peptides (AMPs) and the formation of the mucus layer. We highlight the crucial importance of their correct functioning for the maintenance of a proper intestinal function and the prevention of dysbiosis and disease. Barrier disturbances including a defective production of AMPs, alterations in thickness or composition of the intestinal mucus layer, alterations of pattern-recognition receptors, defects in the process of autophagy as well as unresolved endoplasmic reticulum stress result in an inadequate host protection and are thought to play a crucial role in the pathogenesis of the inflammatory bowel diseases Crohn’s disease and ulcerative colitis. PMID:24574793

  16. Trophic effect of Efamol on the rat small-intestinal mucosa.

    PubMed

    Jenkins, A P; Thompson, R P

    1989-11-01

    1. The hypothesis that triacylglycerols are trophic to the small-intestinal mucosa of the rat was tested by comparing the action of the essential fatty acid-rich oil Efamol with that of glucose. 2. Two groups of nine female Wistar rats were pair-fed Vivonex HN with 50% calorie substitution by glucose or Efamol for 21 days. 3. Body weight gain was greater with glucose than with Efamol, but, despite this, whole gut weight, mucosal weight and mucosal protein were increased by Efamol in all small-intestinal segments. Total mucosal DNA was also increased with a significant change in the middle small-intestinal segment. These changes were associated with an increased crypt cell production rate. 4. Fasting plasma levels of peptidyltyrosyltyrosine ('peptide YY'), but not of enteroglucagon, were significantly elevated in the Efamol-fed group. 5. The data show a trophic effect of Efamol on the rat small-intestinal mucosa. Possible mechanisms are discussed. PMID:2582727

  17. Effects of intestinal mucosal blood flow and motility on intestinal mucosa

    PubMed Central

    Wang, Yan-Bin; Liu, Jing; Yang, Zhao-Xu

    2011-01-01

    AIM: To investigate the role of intestinal mucosal blood flow (IMBF) and motility in the damage of intestinal mucosal barrier in rats with traumatic brain injury. METHODS: Sixty-four healthy male Wistar rats were divided randomly into two groups: traumatic brain injury (TBI) group (n = 32), rats with traumatic brain injury; and control group (n = 32), rats with sham-operation. Each group was divided into four subgroups (n = 8) as 6, 12, 24 and 48 h after operation. Intestinal motility was measured by the propulsion ratio of a semi-solid colored marker (carbon-ink). IMBF was measured with the laser-Doppler technique. Endotoxin and D-xylose levels in plasma were measured to evaluate the change of intestinal mucosal barrier function following TBI. RESULTS: The level of endotoxin was significantly higher in TBI group than in the control group at each time point (0.382 ± 0.014 EU/mL vs 0.102 ± 0.007 EU/mL, 0.466 ± 0.018 EU/mL vs 0.114 ± 0.021 EU/mL, 0.478 ± 0.029 EU/mL vs 0.112 ± 0.018 EU/mL and 0.412 ± 0.036 EU/mL vs 0.108 ± 0.011 EU/mL, P < 0.05). D-xylose concentrations in plasma in TBI group were significantly higher than in the control group (6.68 ± 2.37 mmol/L vs 3.66 ± 1.07 mmol/L, 8.51 ± 2.69 mmol /L vs 3.15 ± 0.95 mmol/L, 11.68 ± 3.24 mmol/L vs 3.78 ± 1.12 mmol/L and 10.23 ± 2.83 mmol/L vs 3.34 ± 1.23 mmol/ L, P < 0.05). The IMBF in TBI group was significantly lower than that in the control group (38.5 ± 2.8 PU vs 45.6 ± 4.6 PU, 25.2 ± 3.1 PU vs 48.2 ± 5.3 PU, 21.5 ± 2.7 PU vs 44.9 ± 2.8 PU, 29. 4 ± 3.8 PU vs 46.7 ± 3.2 PU) (P < 0.05). Significant decelerations of intestinal propulsion ratio in TBI groups were found compared with the control group (0.48% ± 0.06% vs 0.62% ± 0.03%, 0.37% ± 0.05% vs 0.64% ± 0.01%, 0.39% ± 0.07% vs 0.63% ± 0.05% and 0.46% ± 0.03% vs 0.65% ± 0.02%) (P < 0.05). CONCLUSION: The intestinal mucosal permeability is increased obviously in TBI rats. Decrease of intestinal motility and IMBF occur early in TBI

  18. Interactions between the microbiota and the intestinal mucosa.

    PubMed

    Schiffrin, E J; Blum, S

    2002-08-01

    The intestinal microflora can be considered as a postnatally aquired organ composed of a large diversity of bacterial cells that can perform different functions for the host. This organ is highly exposed to environmental influences and thus modulated in its composition and functions by external factors, such as nutrition. Specific components of the intestinal microflora, including lactobacilli and bifidobacteria, have been associated with beneficial effects on the host, such as promotion of gut maturation and integrity, antagonisms against pathogens and immune modulation. In addition, the microflora seem to play a significant role in the maintenance of intestinal immune homeostasis and prevention of inflammation. At the present time, the contribution of intestinal epithlial cell in the first line of defence against pathogenic bacteria and microbial antigens has been recognized, in contrast, the interactions of intestinal epithelial cells with commensal bacteria are less understood. The present work summarizes the increasing scientific attention for mechanisms of the innate immune response of the host to different components of the autochthonous microflora and suggests a potential role for selected probiotic bacteria in the regulation of intestinal inflammation. PMID:12142966

  19. Effect of indigestible saccharides on B lymphocyte response of intestinal mucosa and cecal fermentation in rats.

    PubMed

    Kudoh, K; Shimizu, J; Wada, M; Takita, T; Kanke, Y; Innami, S

    1998-02-01

    The effects of water-soluble and -insoluble indigestible saccharides (IDS) on immune responses of the intestinal tract were studied. Male 4-week-old Sprague Dawley rats were fed for three weeks on diets containing several kinds of IDS at 5%. The results revealed that the proportion of kappa-light chain and IgA-presenting lymphocytes in small intestinal and cecal mucosa differed in increased number depending on the type of IDS. The response of colonic mucosa was not pronounced. The amounts of short-chain fatty acid (SCFA) and lactic acid in the cecal contents of the other test groups except the celfur group tended to be higher than those in the cellulose group, particularly in the lactulose group where many acids showed significant increases. The correlation between the proportion of kappa-light chain and IgA-presenting lymphocytes in the cecal mucosa and lactic acid in the cecal contents was significant, but that between the proportion of both lymphocytes and SCFA was not. Based on the above, we concluded that the oral administration of IDS induces the proliferation of kappa-light chain and IgA-producing B lymphocytes in small intestinal and cecal mucosa, but the degree of response differs depending on the type of IDS. It is thus suggested that IDS are involved in the intestinal immune system of rats. PMID:9591238

  20. Selective culturing of swine gastrointestinal bacteria on substrates simulating the intestinal mucosa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many gastrointestinal (GI) microbes are in intimate contact with the host tissues, and characterizing these tissue-associated communities is important for elucidating their role in animal and human health. The GI mucosa is an environment distinct from the intestinal lumen and is covered by a mucus l...

  1. Recombinant Human Epidermal Growth Factor Accelerates Recovery of Mouse Small Intestinal Mucosa After Radiation Damage

    SciTech Connect

    Lee, Kang Kyoo; Jo, Hyang Jeong; Hong, Joon Pio; Lee, Sang-wook Sohn, Jung Sook; Moon, Soo Young; Yang, Sei Hoon; Shim, Hyeok; Lee, Sang Ho; Ryu, Seung-Hee; Moon, Sun Rock

    2008-07-15

    Purpose: To determine whether systemically administered recombinant human epidermal growth factor (rhEGF) accelerates the recovery of mouse small intestinal mucosa after irradiation. Methods and Materials: A mouse mucosal damage model was established by administering radiation to male BALB/c mice with a single dose of 15 Gy applied to the abdomen. After irradiation, rhEGF was administered subcutaneously at various doses (0.04, 0.2, 1.0, and 5.0 mg/kg/day) eight times at 2- to 3-day intervals. The evaluation methods included histologic changes of small intestinal mucosa, change in body weight, frequency of diarrhea, and survival rate. Results: The recovery of small intestinal mucosa after irradiation was significantly improved in the mice treated with a high dose of rhEGF. In the mice that underwent irradiation without rhEGF treatment, intestinal mucosal ulceration, mucosal layer damage, and severe inflammation occurred. The regeneration of villi was noticeable in mice treated with more than 0.2 mg/kg rhEGF, and the villi recovered fully in mice given more than 1 mg/kg rhEGF. The frequency of diarrhea persisting for more than 3 days was significantly greater in the radiation control group than in the rhEGF-treated groups. Conclusions: Systemic administration of rhEGF accelerates recovery from mucosal damage induced by irradiation. We suggest that rhEGF treatment shows promise for the reduction of small intestinal damage after irradiation.

  2. Metabolism of heme and bilirubin in rat and human small intestinal mucosa.

    PubMed Central

    Hartmann, F; Bissell, D M

    1982-01-01

    Formation of heme, bilirubin, and bilirubin conjugates has been examined in mucosal cells isolated from the rat upper small intestine. Intact, viable cells were prepared by enzymatic dissociation using a combined vascular and luminal perfusion and incubated with an isotopically labeled precursor, delta-amino-[2,3-3H]levulinic acid. Labeled heme and bile pigment were formed with kinetics similar to those exhibited by hepatocytes. Moreover, the newly formed bilirubin was converted rapidly to both mono- and diglucuronide conjugates. In addition, cell-free extracts of small intestinal mucosa from rats or humans exhibited a bilirubin-UDP-glucuronyl transferase activity that was qualitatively similar to that present in liver. The data suggest that the small intestinal mucosa normally contributes to bilirubin metabolism. PMID:6806320

  3. Identification of the transcriptional response of human intestinal mucosa to Lactobacillus plantarum WCFS1 in vivo

    PubMed Central

    Troost, Freddy J; van Baarlen, Peter; Lindsey, Patrick; Kodde, Andrea; de Vos, Willem M; Kleerebezem, Michiel; Brummer, Robert-Jan M

    2008-01-01

    Background There is limited knowledge on the extent and dynamics of the mucosal response to commensal and probiotic species in the human intestinal lumen. This study aimed to identify the acute, time-dependent responses of intestinal mucosa to commensal Lactobacillus plantarum WCFS1 in vivo in two placebo-controlled human intervention studies in healthy volunteers. Transcriptional changes in duodenal mucosa upon continuous intraduodenal infusion of L. plantarum WCFS1 for one- and six h, respectively, were studied using oro- and nasogastric intubations with dedicated orogastric catheters and tissue sampling by standard flexible gastroduodenoscopy. Results One- and six-h exposure of small intestinal mucosa to L. plantarum WCFS1 induced differential expression of 669 and 424 gene reporters, respectively. While short-term exposure to L. plantarum WCFS1 inhibited fatty acid metabolism and cell cycle progression, cells switched to a more proliferative phase after prolonged exposure with an overall expression profile characterized by upregulation of genes involved in lipid metabolism, cellular growth and development. Cell death and immune responses were triggered, but cell death-executing genes or inflammatory signals were not expressed. Proteome analysis showed differential expression of several proteins. Only the microsomal protein 'microsomal triglyceride transfer protein' was regulated on both the transcriptional and the protein level in all subjects. Conclusion Overall, this study showed that intestinal exposure to L. plantarum WCFS1 induced consistent, time-dependent transcriptional responses in healthy intestinal mucosa. This extensive exploration of the human response to L. plantarum WCFS1 could eventually provide molecular support for specific or probiotic activity of this strain or species, and exemplifies the strength of the applied technology to identify the potential bio-activity of microbes in the human intestine. PMID:18681965

  4. Effects of psychological stress on small intestinal motility and bacteria and mucosa in mice

    PubMed Central

    Wang, Shao-Xuan; Wu, Wan-Chun

    2005-01-01

    AIM: To investigate the effects of psychological stress on small intestinal motility and bacteria and mucosa in mice, and to explore the relationship between small intestinal dysfunction and small intestinal motility and bacteria and mucosa under psychological stress. METHODS: Sixty mice were randomly divided into psychological stress group and control group. Each group were subdivided into small intestinal motility group (n = 10), bacteria group (n = 10), and D-xylose administered to stomach group (n = 10). An animal model with psychological stress was established housing the mice with a hungry cat in separate layers of a two-layer cage. A semi-solid colored marker (carbon-ink) was used for monitoring small intestinal transit. The proximal small intestine was harvested under sterile condition and processed for quantitation for aerobes (Escherichia coli) and anaerobes (Lactobacilli). The quantitation of bacteria was expressed as log10(colony forming units/g). D-xylose levels in plasma were measured for estimating the damage of small intestinal mucosa. RESULTS: Small intestinal transit was inhibited (39.80±9.50% vs 58.79±11.47%, P<0.01) in mice after psychological stress, compared with the controls. Psychological stress resulted in quantitative alterations in the aerobes (E. coli). There was an increase in the number of E. coli in the proximal small intestinal flora (1.78±0.30 log10(CFU/g) vs 1.37±0.21 log10(CFU/g), P<0.01), and there was decrease in relative proportion of Lactobacilli and E. coli of stressed mice (0.53±0.63 vs 1.14±1.07, P<0.05), while there was no significant difference in the anaerobes (Lactobacilli) between the two groups (2.31±0.70 log10(CFU/g) vs 2.44±0.37 log10(CFU/g), P>0.05). D-xylose concentrations in plasma in psychological stress mice were significantly higher than those in the control group (2.90±0.89 mmol/L vs 0.97±0.33 mmol/L, P<0.01). CONCLUSION: Small intestinal dysfunction under psychological stress may be related to the

  5. Urokinase and the intestinal mucosa: evidence for a role in epithelial cell turnover

    PubMed Central

    Gibson, P; Birchall, I; Rosella, O; Albert, V; Finch, C; Barkla, D; Young, G

    1998-01-01

    Background—The functions of urokinase in intestinal epithelia are unknown. 
Aims—To determine the relation of urokinase expressed by intestinal epithelial cells to their position in the crypt-villus/surface axis and of mucosal urokinase activity to epithelial proliferative kinetics in the distal colon. 
Methods—Urokinase expression was examined immunohistochemically in human intestinal mucosa. Urokinase activity was measured colorimetrically in epithelial cells isolated sequentially from the crypt-villus axis of the rat small intestine. In separate experiments, urokinase activity and epithelial kinetics (measured stathmokinetically) were measured in homogenates of distal colonic mucosa of 14 groups of eight rats fed diets known to alter epithelial turnover. 
Results—From the crypt base, an ascending gradient of expression and activity of urokinase was associated with the epithelial cells. Median mucosal urokinase activities in each of the dietary groups of rats correlated positively with autologous median number of metaphase arrests per crypt (r=0.68; p<0.005) and per 100 crypt cells (r=0.75; p<0.001), but not with crypt column height. 
Conclusions—Localisation of an enzyme capable of leading to digestion of cell substratum in the region where cells are loosely attached to their basement membrane, and the association of its activity with indexes of cell turnover, suggest a role for urokinase in facilitating epithelial cell loss in the intestine. 

 Keywords: urokinase; intestinal epithelium; colon; epithelial proliferation PMID:9824347

  6. Pleiotropic effects of bombesin and neurotensin on intestinal mucosa: not just trefoil peptides.

    PubMed

    Assimakopoulos, Stelios-F; Scopa, Chrisoula-D; Nikolopoulou, Vassiliki-N; Vagianos, Constantine-E

    2008-06-14

    Bombesin and neurotensin are neuropeptides which exert a wide spectrum of biological actions on gastrointestinal tissues influencing intestinal growth and adaptation, intestinal motility, blood flow, secretion, nutrient absorption and immune response. Based mainly on their well-established potent enterotrophic effect, numerous experimental studies investigated their potential positive effect on the atrophic or injured intestinal mucosa. These peptides proved to be effective mucosa-healing factors, but the potential molecular and cellular mechanisms for this action remained unresolved. In a recently published study (World J Gastroenterol 2008; 14(8): 1222-1230), it was shown that their protective effect on the intestine in experimentally induced inflammatory bowel disease was related to anti-inflammatory, antioxidant and antiapoptotic actions. These results are in close agreement with our previous studies on jaundiced and hepatectomized rats that showed a regulatory effect of bombesin and neurotensin on critical cellular processes such as enterocyte' proliferation and death, oxidative stress and redox equilibrium, tight junctions' formation and function, and inflammatory response. The pleiotropic effects of bombesin and neurotensin on diverse types of intestinal injury may justify their consideration for clinical trials. PMID:18567096

  7. The influence of gut function on lymphoid cell populations in the intestinal mucosa of lambs.

    PubMed Central

    Reynolds, J D; Morris, B

    1983-01-01

    The number and type of lymphoid cells in the intestinal mucosa of lambs change during the first weeks after birth. The influence of gut function on these changes was examined by comparing the evolution of lymphoid cell populations in normal ileum with that in lengths of ileum which had been isolated surgically from the functional intestinal tract of the lamb before birth. The isolated lengths of ileum had a normal blood and nerve supply and they remained healthy throughout a period of at least 2 years, although they did not have a normal histological development. In comparison with normal ileum, the villi of the isolated ileal segments were much smaller and there were many fewer intraepithelial lymphocytes; the lamina propria had significantly fewer lymphocytes than the functional ileum and only a few plasma cells. When isolated ileal segments were reconnected into the intestinal tract after having been isolated from it for 1-3 months, the histology of the mucosa reverted to that of the normal gut, with the same number and types of lymphoid cells. Radiolabelled lymphoblasts collected from intestinal lymph and injected intravenously accumulated to only a small extent in isolated segments of ileum compared with either the normal or the reconnected segments of ileum. This suggested that the paucity of lymphocytes in the mucosa of the isolated segments was due to a reduced extravasation of these cells there. The influence which the gut contents exert on the lymphoid cell population in the mucosa is probably associated with antigenic stimulation but may also be related to other factors concerned in the normal digestive functions of the gut. Images Figure 1 Figure 2 Figure 3 PMID:6862523

  8. Mechanisms of Intestinal Barrier Dysfunction in Sepsis.

    PubMed

    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

  9. Protective effect of bone marrow mesenchymal stem cells in intestinal barrier permeability after heterotopic intestinal transplantation

    PubMed Central

    Zhang, Wen; Shen, Zhong-Yang; Song, Hong-Li; Yang, Yang; Wu, Ben-Juan; Fu, Nan-Nan; Liu, Tao

    2014-01-01

    AIM: To explore the protective effect of bone marrow mesenchymal stem cells (BM MSCs) in the small intestinal mucosal barrier following heterotopic intestinal transplantation (HIT) in a rat model. METHODS: BM MSCs were isolated from male Lewis rats by density gradient centrifugation, cultured, and analyzed by flow cytometry. The HIT models were divided into a non-rejection group, saline-treated rejection group (via penile vein), and BM MSC–treated group (via penile vein). Intestinal mucosal barrier injury was estimated by diamine oxidase (DAO) and D-lactic acid (D-LA) expression levels. Tumor necrosis factor-α (TNF-α), interferon-γ (INF-γ), interleukin-10 (IL-10), and transforming growth factor-β (TGF-β) were detected by enzyme-linked immunosorbent assay. Ultrastructural change of tight junctions (TJs) was observed under transmission electron microscope. Expression levels of the TJ proteins occludin and zona occludens (ZO)-1, affected by the inflammatory factors, were measured using real-time polymerase chain reaction and Western blotting. RESULTS: The pathological score at each time point after surgery indicated significantly less serious injury in the BM MSCs-treated group than in the rejection group (P < 0.05). In the former, graft levels of DAO and D-LA were reduced, and TNF-α and INF-γ production was inhibited (at day 7: 10.6473 ± 0.0710 vs 17.2128 ± 0.4991, P < 0.05; 545.1506 ± 31.9416 vs 810.2637 ± 25.1175, P < 0.05). IL-10 and TGF-β production was increased greatly (at day 7: 125.7773 ± 4.7719 vs 80.3756 ± 2.5866, P < 0.05; 234.5273 ± 9.3980 vs 545.1506 ± 31.9416, P < 0.05). There was increased expression of occludin and ZO-1 protein (at day 7: 0.2674 ± 0.0128 vs 0.1352 ± 0.0142, P < 0.05; at day 5: 0.7189 ± 0.0289 vs 0.4556 ± 0.0242, P < 0.05) and mRNA (at day 7: 0.3860 ± 0.0254 vs 0.1673 ± 0.0369, P < 0.05; at day 5: 0.5727 ± 0.0419 vs 0.3598 ± 0.0242, P < 0.05). CONCLUSION: BM MSCs can improve intestinal barrier permeability

  10. The nature of the natural killer (NK) cell of human intestinal mucosa and mesenteric lymph node.

    PubMed Central

    Gibson, P R; Jewell, D P

    1985-01-01

    The relationship of the mononuclear cell (MNC) from human intestinal mucosa and mesenteric lymph node mediating anti-K-562 activity with that of peripheral blood has been assessed. Depletion of macrophages did not alter the measured cytotoxicity confirming that the effector cells were lymphocytes. Complement lysis of Leu 7 and Leu 11b coated cells reduced intestinal natural killer (NK) activity by a similar degree to that of peripheral blood but mesenteric lymph node NK activity was affected to a lesser extent. The response in NK activity of mucosal and nodal MNC to short incubation with lymphoblastoid interferon was similar to that for peripheral blood MNC. Twenty-four hours incubation of MNC with low concentrations of purified interleukin-2 (IL-2) consistently augmented intestinal and nodal NK activity but failed to augment that of peripheral blood MNC. No differences between the inhibitory effects of cAMP and prostaglandin E2 on NK activity from the three sites were seen. In addition, inhibition of cyclo-oxygenase activity with indomethacin had no effect on NK activity of intestinal and peripheral blood MNC while the lipoxygenase inhibitor, nordihydroguaiaretic acid, suppressed intestinal and peripheral blood NK activity similarly. In conclusion, anti-K-562 activity by intestinal MNC is mediated by NK cells with similar phenotypic and functional properties to those of peripheral blood. However, the increased sensitivity of mucosal NK cells to IL-2 suggests that higher proportions of NK cell precursors may be present in intestinal MNC populations. PMID:2412737

  11. Inflammation and specialized intestinal metaplasia of cardiac mucosa is a manifestation of gastroesophageal reflux disease.

    PubMed Central

    Oberg, S; Peters, J H; DeMeester, T R; Chandrasoma, P; Hagen, J A; Ireland, A P; Ritter, M P; Mason, R J; Crookes, P; Bremner, C G

    1997-01-01

    OBJECTIVE: The purpose of the study was to test the hypothesis that cardiac mucosa, carditis, and specialized intestinal metaplasia at an endoscopically normal-appearing cardia are manifestations of gastroesophageal reflux disease. SUMMARY BACKGROUND DATA: In the absence of esophageal mucosal injury, the diagnosis of gastroesophageal reflux disease currently rests on 24-hour pH monitoring. Histologic examination of the esophagus is not useful. The recent identification of specialized intestinal metaplasia at the cardia, along with the observation that it occurs in inflamed cardiac mucosa, led the authors to focus on the type and condition of the mucosa at the gastroesophageal junction and its relation to gastroesophageal reflux disease. METHODS: Three hundred thirty-four consecutive patients with symptoms of foregut disease, no evidence of columnar-lined esophagus, and no history of gastric or esophageal surgery were evaluated by 1) endoscopic biopsies above, at, and below the gastroesophageal junction; 2) esophageal motility; and 3) 24-hour esophageal pH monitoring. The patients were divided into groups depending on the histologic presence of cardiac epithelium with and without inflammation or associated intestinal metaplasia. Markers of gastroesophageal reflux disease were compared between groups (i.e., lower esophageal sphincter characteristics, esophageal acid exposure, the presence of endoscopic erosive esophagitis, and hiatal hernia). RESULTS: When cardiac epithelium was found, it was inflamed in 96% of the patients. The presence of cardiac epithelium and carditis was associated with deterioration of lower esophageal sphincter characteristics and increased esophageal acid exposure. Esophagitis occurred more commonly in patients with carditis whose sphincter, on manometry, was structurally defective. Specialized intestinal metaplasia at the cardia was only seen in inflamed cardiac mucosa, and its prevalence increased both with increasing acid exposure and with

  12. Reduced expression of aquaporins in human intestinal mucosa in early stage inflammatory bowel disease

    PubMed Central

    Ricanek, Petr; Lunde, Lisa K; Frye, Stephan A; Støen, Mari; Nygård, Ståle; Morth, Jens P; Rydning, Andreas; Vatn, Morten H; Amiry-Moghaddam, Mahmood; Tønjum, Tone

    2015-01-01

    Objectives The aim of this study was to investigate the relationship between aquaporin (AQP) water channel expression and the pathological features of early untreated inflammatory bowel disease (IBD) in humans. Methods Patients suspected to have IBD on the basis of predefined symptoms, including abdominal pain, diarrhea, and/or blood in stool for more than 10 days, were examined at the local hospital. Colonoscopy with biopsies was performed and blood samples were taken. Patients who did not meet the diagnostic criteria for IBD and who displayed no evidence of infection or other pathology in the gut were included as symptomatic non-IBD controls. AQP1, 3, 4, 5, 7, 8, and 9 messenger RNA (mRNA) levels were quantified in biopsies from the distal ileum and colon by quantitative real-time polymerase chain reaction. Protein expression of selected AQPs was assessed by confocal microscopy. Through multiple alignments of the deduced amino acid sequences, the putative three-dimensional structures of AQP1, 3, 7, and 8 were modeled. Results AQP1, 3, 7, and 8 mRNAs were detected in all parts of the intestinal mucosa. Notably, AQP1 and AQP3 mRNA levels were reduced in the ileum of patients with Crohn’s disease, and AQP7 and AQP8 mRNA levels were reduced in the ileum and the colon of patients with ulcerative colitis. Immunofluorescence confocal microscopy showed localization of AQP3, 7, and 8 at the mucosal epithelium, whereas the expression of AQP1 was mainly confined to the endothelial cells and erythrocytes. The reduction in the level of AQP3, 7, and 8 mRNA was confirmed by immunofluorescence, which also indicated a reduction of apical immunolabeling for AQP8 in the colonic surface epithelium and crypts of the IBD samples. This could indicate loss of epithelial polarity in IBD, leading to disrupted barrier function. Conclusion AQPs 1 and 8 and the aquaglyceroporins AQPs 3 and 7 are the AQPs predominantly expressed in the lower intestinal tract of humans. Their expression is

  13. Intestinal mucosa in diabetes: synthesis of total proteins and sucrase-isomaltase

    SciTech Connect

    Olsen, W.A.; Perchellet, E.; Malinowski, R.L.

    1986-06-01

    The effects of insulin deficiency on nitrogen metabolism in muscle and liver have been extensively studied with recent in vivo demonstration of impaired protein synthesis in rats with streptozotocin-induced diabetes. Despite the significant contribution of small intestinal mucosa to overall protein metabolism, the effect of insulin deficiency on intestinal protein synthesis have not been completely defined. The authors studied the effects of streptozotocin-induced diabetes on total protein synthesis by small intestinal mucosa and on synthesis of a single enzyme protein of the enterocyte brush-border membrane sucrase-isomaltase. They used the flood-dose technique to minimize the difficulties of measuring specific radioactivity of precursor phenylalanine and determined incorporation into mucosal proteins and sucrase-isomaltase 20 min after injection of the labeled amino acid. Diabetes did not alter mucosal mass as determined by weight and content of protein and DNA during the 5 days after injection of streptozotocin. Increased rates of sucrase-isomaltase synthesis developed beginning on day 3, and those of total protein developed on day 5. Thus intestinal mucosal protein synthesis is not an insulin-sensitive process.

  14. Hormone-sensitive lipase is a cholesterol esterase of the intestinal mucosa.

    PubMed

    Grober, Jacques; Lucas, Stéphanie; Sörhede-Winzell, Maria; Zaghini, Isabelle; Mairal, Aline; Contreras, Juan-Antonio; Besnard, Philippe; Holm, Cecilia; Langin, Dominique

    2003-02-21

    The identity of the enzymes responsible for lipase and cholesterol esterase activities in the small intestinal mucosa is not known. Because hormone-sensitive lipase (HSL) catalyzes the hydrolysis of acylglycerols and cholesteryl esters, we sought to determine whether HSL could be involved. HSL mRNA and protein were detected in all segments of the small intestine by Northern and Western blot analyses, respectively. Immunocytochemistry experiments revealed that HSL was expressed in the differentiated enterocytes of the villi and was absent in the undifferentiated cells of the crypt. Diacylglycerol lipase and cholesterol esterase activities were found in the different segments. Analysis of gut from HSL-null mice showed that diacylglycerol lipase activity was unchanged in the duodenum and reduced in jejunum. Neutral cholesterol esterase activity was totally abolished in duodenum, jejunum, and ileum of HSL-null mice. Analysis of HSL mRNA structure showed two types of transcripts expressed in equal amounts with alternative 5'-ends transcribed from two exons. This work demonstrates that HSL is expressed in the mucosa of the small intestine. The results also reveal that the enzyme participates in acylglycerol hydrolysis in jejunal enterocytes and cholesteryl ester hydrolysis throughout the small intestine. PMID:12482847

  15. Serum anti-tissue transglutaminase antibodies detected during febrile illness may not be produced by the intestinal mucosa.

    PubMed

    De Leo, Luigina; Quaglia, Sara; Ziberna, Fabiana; Vatta, Serena; Martelossi, Stefano; Maschio, Massimo; Not, Tarcisio

    2015-03-01

    Anti-transglutaminase antibodies are the diagnostic marker of celiac disease, and are considered to be synthesized only by intestinal B-lymphocytes. During an infectious disease, these antibodies are transiently detected in serum. We show that these infection-triggered antibodies may not originate in the intestinal mucosa and are not an indication of celiac disease. PMID:25722272

  16. Characterization and distribution of alpha 2-adrenergic receptors in the human intestinal mucosa.

    PubMed Central

    Valet, P; Senard, J M; Devedjian, J C; Planat, V; Salomon, R; Voisin, T; Drean, G; Couvineau, A; Daviaud, D; Denis, C

    1993-01-01

    The subtype and the expression of the alpha 2-adrenergic receptor were investigated in the normal mucosa from human intestine by means of radioligand binding, RNase mapping, and measurement of adenylate cyclase activity. The study of the binding of the alpha 2-adrenergic antagonist, [3H]RX821002, to epithelial cell membranes indicated the existence of a single class of noninteracting sites displaying a high affinity for the radioligand (Kd = 1.1 +/- 0.5 nM). The rank order of potency of antagonists to inhibit [3H]RX821002 binding (RX821002 > yohimbine = rauwolscine > phentolamine approximately idazoxan >> chlorpromazine > prazosin) suggested that the receptor is of the alpha 2A subtype. A conclusion which is confirmed by the fact that only alpha 2C10 transcripts were found in the human intestine mucosa. Competition curves with (-)-norepinephrine demonstrated that 60% of the receptor population exhibited high affinity for agonists. This high-affinity state was abolished by the addition of GTP plus Na+ or by prior treatment of the membranes with pertussis toxin indicating it corresponded to G protein-coupled receptors. [32P]ADP-ribosylation and immunoblotting experiments identified two pertussis toxin-sensitive G proteins corresponding to Gi2 and Gi3. The study of the distribution of the receptor indicated that (a) the proximal colon is the intestine segment exhibiting the highest receptor density and (b) the receptor is predominantly expressed in crypts and is preferentially located in the basolateral membrane of the polarized cell. The distribution of the receptor along the crypt-surface axis of the colon mucosa can be correlated with a higher level of alpha 2C10-specific mRNA and a higher efficiency of UK14304 to inhibit adenylate cyclase in crypt cells. Images PMID:8098045

  17. Evaluation of different pig oral mucosa sites as permeability barrier models for drug permeation studies.

    PubMed

    Franz-Montan, Michelle; Serpe, Luciano; Martinelli, Claudia Cristina Maia; da Silva, Camila Batista; Santos, Cleiton Pita Dos; Novaes, Pedro Duarte; Volpato, Maria Cristina; de Paula, Eneida; Lopez, Renata Fonseca Vianna; Groppo, Francisco Carlos

    2016-01-01

    The objective of the present study was to investigate the influence of preparation and storage conditions on the histology and permeability of different parts of porcine oral mucosa used for in vitro studies of transbuccal formulations. Fresh and frozen (-20°C and -80°C, with or without cryoprotectant) epithelia of porcine palatal, gingival, dorsum of the tongue, and buccal mucosa were submitted for histological analyses to determine the effects of storage conditions on barrier integrity. Permeation of lidocaine hydrochloride (used as a hydrophilic model drug) across fresh and previously frozen oral epithelium was measured in order to evaluate the barrier function. Histological evaluation demonstrated that the oral epithelium was successfully separated from the connective tissue, except for gingival mucosa. After storage under different conditions, all tissues presented desquamation of superficial layers and spherical spaces induced by the freezing process. The permeability of lidocaine hydrochloride varied among the fresh oral mucosa and generally increased after freezing. In conclusion, fresh epithelium from the buccal and dorsum of the tongue mucosa should be used for in vitro studies investigating hydrophilic drug transport when these are the desired clinical application sites. However, when the palate is the target site, both fresh and frozen (for up to 4weeks, without addition of cryoprotectant) samples could be used. The addition of glycerol as a cryoprotectant should be avoided due to increased lidocaine hydrochloride permeability. PMID:26435216

  18. [Decreased intraepithelial lymphocytes in the intestinal mucosa in children with malnutrition and parasitic infections].

    PubMed

    Gendrel, D; Richard-Lenoble, D; Kombila, M; Nardou, M; Gahouma, D; Barbet, J P; Walter, P

    1992-02-01

    In Gabon, 15 children aged 13 to 36 months admitted for malnutrition with chronic diarrhea underwent a small bowel biopsy for detection of parasites in the duodenal contents and histologic evaluation of the intestinal mucosa. In every case, intraepithelial lymphocyte counts (IELC) were under the lower limit of normal for children and adults, regardless of whether or not parasites were found. Partial villous atrophy was a consistent finding. Proportion of lymphocytes among intraepithelial cells was 7.4% in the 6 children with no parasitic infection, 7.9% in the children with giardiasis, and 8.1% in the children with strongyloidiasis. Appropriate treatment of the parasitic infections was quickly followed by resolution of the diarrhea in the nine patients with demonstrable intestinal parasites. These data should be compared with the well documented lymphocyte function anomalies associated with protein-calory malnutrition. The fall in IELC and lack of response to local anigenic stimulations are features of malnutrition. PMID:1580534

  19. Prophylactic Ozone Administration Reduces Intestinal Mucosa Injury Induced by Intestinal Ischemia-Reperfusion in the Rat

    PubMed Central

    Onal, Ozkan; Yetisir, Fahri; Sarer, A. Ebru Salman; Zeybek, N. Dilara; Onal, C. Oztug; Yurekli, Banu; Celik, H. Tugrul; Sirma, Ayse; Kılıc, Mehmet

    2015-01-01

    Objectives. Intestinal ischemia-reperfusion injury is associated with mucosal damage and has a high rate of mortality. Various beneficial effects of ozone have been shown. The aim of the present study was to show the effects of ozone in ischemia reperfusion model in intestine. Material and Method. Twenty eight Wistar rats were randomized into four groups with seven rats in each group. Control group was administered serum physiologic (SF) intraperitoneally (ip) for five days. Ozone group was administered 1 mg/kg ozone ip for five days. Ischemia Reperfusion (IR) group underwent superior mesenteric artery occlusion for one hour and then reperfusion for two hours. Ozone + IR group was administered 1 mg/kg ozone ip for five days and at sixth day IR model was applied. Rats were anesthetized with ketamine∖xyzlazine and their intracardiac blood was drawn completely and they were sacrificed. Intestinal tissue samples were examined under light microscope. Levels of superoxide dismutase (SOD), catalase (CAT), glutathioneperoxidase (GSH-Px), malondyaldehide (MDA), and protein carbonyl (PCO) were analyzed in tissue samples. Total oxidant status (TOS), and total antioxidant capacity (TAC) were analyzed in blood samples. Data were evaluated statistically by Kruskal Wallis test. Results. In the ozone administered group, degree of intestinal injury was not different from the control group. IR caused an increase in intestinal injury score. The intestinal epithelium maintained its integrity and decrease in intestinal injury score was detected in Ozone + IR group. SOD, GSH-Px, and CAT values were high in ozone group and low in IR. TOS parameter was highest in the IR group and the TAC parameter was highest in the ozone group and lowest in the IR group. Conclusion. In the present study, IR model caused an increase in intestinal injury.In the present study, ozone administration had an effect improving IR associated tissue injury. In the present study, ozone therapy prevented

  20. Regeneration of the intestinal mucosa in Eimeria and E. Coli challenged broilers supplemented with amino acids.

    PubMed

    Gottardo, E T; Prokoski, K; Horn, D; Viott, A D; Santos, T C; Fernandes, J I M

    2016-05-01

    The aim of this study was to evaluate the regeneration of the intestinal mucosa in Eimeria and E. coli challenged broilers supplemented with glutamine, arginine, and threonine. Six hundred male broilers at one d of age from the Cobb strain were utilized. The design was completely randomized using a 2×3 factorial design (unchallenged and challenged and 3 diets). A commercial diet was used as a control and 2 other diets were formulated with glutamine (1.5 and 3% Aminogut®), arginine (1 and 2% L-Arginine), and threonine (1 and 2% L-threonine). The animals that consumed diets supplemented with amino acids presented better (P<0.05) feed conversion in the period from one to 42 d of age. The ability of cell proliferation and the villus:crypt ratio in response to enteric challenge were greater (P<0.05) for broilers that received diets supplemented with amino acids. High levels of amino acids in the experimental feeds reflected in greater protein levels in poultry house litter, and they did not interfere with ammonia production. The supplementation of diets with trophic amino acids can positively contribute to the regeneration and proliferation of the intestinal mucosa in broilers and to the maintenance of zootechnical performance when submitted to enteric challenges. PMID:26846258

  1. Supplementation of glutamine and vitamin E on the morphometry of the intestinal mucosa in broiler chickens.

    PubMed

    Murakami, A E; Sakamoto, M I; Natali, M R M; Souza, L M G; Franco, J R G

    2007-03-01

    The objective of this experiment was to evaluate the influence of Gln and vitamin E (VE) supplementation in the diet of broiler chickens (Cobb-Vantress) on the morphometry of the intestinal mucosa. The design was completely randomized in a 2 x 3 (VE x periods of administering Gln) factorial arrangement. The levels of VE used were 10 and 500 mg/kg of diet and 3 periods of administering (1%) Gln-supplemented starter diet (for the first 7 or 14 d of life or for no added Gln), totaling 6 treatments with 5 replicates of 50 birds per experimental unit. In the growth period (d 22 to 41 posthatch), the treatments consisted only in the respective levels of VE. On d 7, 14, 21, and 41 posthatch, 2 birds per replicate were killed, and samples of the duodenum, jejunum, and ileum were subsequently removed, fixed in Bouin solution, and later embedded in paraffin and stained with hematoxylin-eosin. The parameters analyzed were villus height and crypt depth. An ANOVA was applied to the obtained data, and the means were compared using Tukey's test (5% significance level). Greater development was observed in the duodenum, followed by the jejunum and ileum. On 41 d of life, diets with 10 mg of VE/kg supplemented with Gln (for the first 7 d of life) provided better development of the intestinal mucosa in broiler chickens. PMID:17297160

  2. Influence of pH upon the activity of glycosidases and proteinases of intestinal mucosa, chyme and microbiota in fish.

    PubMed

    Kuz'mina, V V; Skvortsova, E G; Zolotareva, G V; Sheptitskiy, V A

    2011-09-01

    It is shown that amylolytic and proteolytic activity of the intestinal mucosa, the chyme and the intestinal flora in the fishes, zander Zander lucioperca (L.), perch Perca fluviatilis L., bream Abramis brama (L.) and roach Rutilus rutilus (L.), belonging according to their feeding habits to different ecological groups at the same pH values as well as in the pH range from 5.0 to 10.0 considerably varies. The glycosidase pH optimum of the mucosa and intestinal microbiota is 7.0, whereas that of the chyme varies from 6.0 (in roach) to 8.0 (in bream). pH optimum of the mucosa proteinases in all fish species is 10.0, whereas that of the chyme and the bacterial flora can be observed in all the range of pH values. PMID:21082240

  3. Pharmaceutical drugs supporting regeneration of small-intestinal mucosa severely damaged by ionizing radiation in mice

    PubMed Central

    Ishihara, Hiroshi; Tanaka, Izumi; Yakumaru, Haruko; Tanaka, Mika; Yokochi, Kazuko; Akashi, Makoto

    2013-01-01

    Accidental exposure of the abdomen to high-dose radiation leads to severe consequences initiated by disruption of the mucosa in the small intestine. Therapeutic options are limited, even though various treatments have been investigated, particularly in the field of regenerative therapy. In order to identify readily available treatment methods, we included several current pharmaceutical drugs, for which the clinical trials have already been completed, in tests on mice that had undergone severe mucosal damage by radiation. The drugs were injected into mice 24 h after exposure to 15.7 Gy X-rays. The effects of the drugs on the damaged mucosa of the small intestine were evaluated using early regeneration indices [the expression of c-myb mRNA, and proliferation of epithelial cells in the form of microcolonies (MCs) by Days 4 and 5 post-irradiation] and the survival rate of the mice. Enhancement of mucosal regeneration at Day 4 (c-myb: P < 0.01, MC: P < 0.05) and improvement of the survival rate (P < 0.05) were observed when a clinical dose of gonadotropin, a stimulator of androgen, was injected. Similarly, a clinical dose of thiamazole (which prevents secretion of thyroid hormone) stimulated mucosal growth by Day 5 (c-myb: P < 0.01, MC: P < 0.05) and also improved the survival rate (P < 0.05). The nonclinical drugs histamine and high-dose octreotide (a growth hormone antagonist) also gave significant survival-enhancing benefits (P < 0.01 and P < 0.05, respectively). These results can be used to construct therapeutic programs and applied in various experimental studies to control the regeneration of damaged mucosa. PMID:23728323

  4. TLR2 mediates gap junctional intercellular communication through connexin-43 in intestinal epithelial barrier injury.

    PubMed

    Ey, Birgit; Eyking, Annette; Gerken, Guido; Podolsky, Daniel K; Cario, Elke

    2009-08-14

    Gap junctional intercellular communication (GJIC) coordinates cellular functions essential for sustaining tissue homeostasis; yet its regulation in the intestine is not well understood. Here, we identify a novel physiological link between Toll-like receptor (TLR) 2 and GJIC through modulation of Connexin-43 (Cx43) during acute and chronic inflammatory injury of the intestinal epithelial cell (IEC) barrier. Data from in vitro studies reveal that TLR2 activation modulates Cx43 synthesis and increases GJIC via Cx43 during IEC injury. The ulcerative colitis-associated TLR2-R753Q mutant targets Cx43 for increased proteasomal degradation, impairing TLR2-mediated GJIC during intestinal epithelial wounding. In vivo studies using mucosal RNA interference show that TLR2-mediated mucosal healing depends functionally on intestinal epithelial Cx43 during acute inflammatory stress-induced damage. Mice deficient in TLR2 exhibit IEC-specific alterations in Cx43, whereas administration of a TLR2 agonist protects GJIC by blocking accumulation of Cx43 and its hyperphosphorylation at Ser368 to prevent spontaneous chronic colitis in MDR1alpha-deficient mice. Finally, adding the TLR2 agonist to three-dimensional intestinal mucosa-like cultures of human biopsies preserves intestinal epithelial Cx43 integrity and polarization ex vivo. In conclusion, Cx43 plays an important role in innate immune control of commensal-mediated intestinal epithelial wound repair. PMID:19528242

  5. IBD Candidate Genes and Intestinal Barrier Regulation

    PubMed Central

    McCole, Declan F.

    2015-01-01

    Technological advances in the large scale analysis of human genetics have generated profound insights into possible genetic contributions to chronic diseases including the inflammatory bowel diseases (IBDs), Crohn’s disease and ulcerative colitis. To date, 163 distinct genetic risk loci have been associated with either Crohn’s disease or ulcerative colitis, with a substantial degree of genetic overlap between these 2 conditions. Although many risk variants show a reproducible correlation with disease, individual gene associations only affect a subset of patients, and the functional contribution(s) of these risk variants to the onset of IBD is largely undetermined. Although studies in twins have demonstrated that the development of IBD is not mediated solely by genetic risk, it is nevertheless important to elucidate the functional consequences of risk variants for gene function in relevant cell types known to regulate key physiological processes that are compromised in IBD. This article will discuss IBD candidate genes that are known to be, or are suspected of being, involved in regulating the intestinal epithelial barrier and several of the physiological processes presided over by this dynamic and versatile layer of cells. This will include assembly and regulation of tight junctions, cell adhesion and polarity, mucus and glycoprotein regulation, bacterial sensing, membrane transport, epithelial differentiation, and restitution. PMID:25215613

  6. The effects of enteral ghrelin administration on the remodeling of the small intestinal mucosa in neonatal piglets.

    PubMed

    Słupecka, Monika; Woliński, Jarosław; Pierzynowski, Stefan G

    2012-02-10

    Ghrelin is a multifunctional peptide produced predominantly in the stomach, however substantial amounts have also been found in colostrum and milk. The aim of the study was to investigate the effect of exogenous ghrelin, administered intra-gastrically, on the processes of mitosis, apoptosis, autophagy, crypt fission and changes in histometry of the small intestine mucosa in neonatal pigs, fed with a milk formula. Three groups (n=6) of piglets were used in the study. The pigs were fed either milk formula (C7) or milk formula together with ghrelin, administered via a stomach tube (7.5 μg/kg body weight (BW), (LG)) and 15 μg/kg BW (HG), every 8h for 6 days. Compared to the control group (C7), feeding milk formula supplemented with ghrelin resulted in significant changes in the small intestinal morphometry and mucosa histometry. The observed changes were dependent on the dosage of hormone and the part of intestine investigated. Administration of ghrelin via the stomach tube (HG) significantly influenced epithelial cell renewal. Moreover, we demonstrated that autophagy is involved in the small intestine mucosa remodeling and ghrelin may be an important factor for its regulation. In conclusion, we found that enteral ghrelin influences the gut mucosa remodeling in a dose-related manner in the early postnatal period. Moreover in neonates, stomach activity does not interfere with the action of ghrelin in the small intestine. PMID:22137939

  7. Beyond the Intestinal Celiac Mucosa: Diagnostic Role of Anti-TG2 Deposits, a Systematic Review

    PubMed Central

    Gatti, Simona; Rossi, Matilde; Alfonsi, Simona; Mandolesi, Alessandra; Cobellis, Giovanni; Catassi, Carlo

    2014-01-01

    Aim: To review the existing literature on the role and significance of intestinal transglutaminase 2 immunoglobulin A deposits (TG2 deposits) in patients with overt celiac disease (CD), potential celiac disease (PCD), and other autoimmune or gluten-related conditions. Methods: We conducted a systematic review of studies published in English, evaluating presence and characteristics of TG2 deposits in subjects with overt CD, PCD, gluten-related diseases [dermatitis herpetiformis (DH), gluten-ataxia (GA)], autoimmune disorders (type-1 diabetes), and other conditions. Studies were identified through a MEDLINE search (1950–2013). Results: Twenty-three studies were included in the review. Eleven studies were performed in children. Overall TG2 deposits were present in 100% of adults with overt CD, while in children prevalence ranged from 73.2 to 100%. Six studies with an established definition of PCD were considered, prevalence of deposits ranging from 64.7 to 100%. A single study followed-up PCD patients with repeated biopsies and identified presence of intestinal deposits as the best marker to reveal progression toward villous atrophy. Two studies investigated presence of deposits in DH, reporting prevalence between 63 and 79%. A single study documented TG2 deposits in 100% of patients with GA. In children with type-1 diabetes (T1D), positivity of intestinal TG2 deposits ranged from 25 to 78%. Conclusion: Transglutaminase 2 IgA deposits seem to be a constant feature in overt CD patients and are frequently detectable in other gluten-related conditions (DH and GA). The vast majority of PCD patients express TG2 deposits at the intestinal level, but no sufficient data are available to exactly define their prognostic role as a marker of evolution toward overt CD. The frequent finding of TG2 deposits in the intestinal mucosa of patients with T1D is an interesting observation deserving further evaluation. PMID:25705622

  8. Long noncoding RNA SPRY4-IT1 regulates intestinal epithelial barrier function by modulating the expression levels of tight junction proteins

    PubMed Central

    Xiao, Lan; Rao, Jaladanki N.; Cao, Shan; Liu, Lan; Chung, Hee Kyoung; Zhang, Yun; Zhang, Jennifer; Liu, Yulan; Gorospe, Myriam; Wang, Jian-Ying

    2016-01-01

    Epithelial cells line the intestinal mucosa and form an important barrier to a wide array of noxious substances in the lumen. Disruption of the barrier integrity occurs commonly in various pathologies. Long noncoding RNAs (lncRNAs) control diverse biological processes, but little is known about the role of lncRNAs in regulation of the gut permeability. Here we show that the lncRNA SPRY4-IT1 regulates the intestinal epithelial barrier function by altering expression of tight junction (TJ) proteins. SPRY4-IT1 silencing led to dysfunction of the epithelial barrier in cultured cells by decreasing the stability of mRNAs encoding TJ proteins claudin-1, claudin-3, occludin, and JAM-1 and repressing their translation. In contrast, increasing the levels of SPRY4-IT1 in the intestinal mucosa protected the gut barrier in mice exposed to septic stress by increasing the abundance of TJ proteins. SPRY4-IT1 directly interacted with TJ mRNAs, and this process was enhanced through the association with the RNA-binding protein HuR. Of interest, the intestinal mucosa from patients with increased gut permeability exhibited a decrease in the levels of SPRY4-IT1. These findings highlight a novel role for SPRY4-IT1 in controlling the intestinal epithelial barrier and define a mechanism by which SPRY4-IT1 modulates TJ expression by altering the stability and translation of TJ mRNAs. PMID:26680741

  9. In vitro behavior of human intestinal mucosa. The influence of acetyl choline on ion transport.

    PubMed Central

    Isaacs, P E; Corbett, C L; Riley, A K; Hawker, P C; Turnberg, L A

    1976-01-01

    The possibility that the autonomic nervous system may influence the function of intestinal mucosa was investigated by assessing the effect of acetyl choline on ion transport in human intestine. Isolated pieces of stripped ileal mucosa were mounted in Perspex flux-chambers and bathed in isotonic glucose Ringer's solution. Acetyl choline caused a rise in mean potential difference (8.8-12.3 mV, P less than 0.002) and short circuit current (287.7-417.2 muA-cm-2, P less than 0.01) (n = 12), observable at a concentration of 0.01 mM and maximal at 0.1 mM. This effect was enhanced by neostigmine and blocked by atropine. Isotopic flux determinations revealed a change from a small mean net Cl absorption (58) to a net Cl secretion (-4.3mueq-cm-2-h-1P less than 0.001) due predominantly to an increase in the serosal to mucosal unidirectional flux of Cl (10.63-14.35 mueq-cm-2-h-1P less than 0.05) and a smaller reduction in the mucosal to serosal flux (11.22 to 10.02 mueq-cm-2-h-1P less than 0.05). Unidirectional and net Na transport was unaffected. A similar electrical and ion transport response was observed in a single study of two pieces of jejunal mucosa. In the absence of glucose net chloride secretion was produced and again an insignificant effect on net sodium transport was noted. Acetyl choline did not provoke a sustained effect on mucosal cyclic adenine nucleotide levels although a short-lived cyclic adenine nucleotide response was seen in some tissues 20-30 s after drug addition. These studies demonstrate that acetyl choline does influence human intestinal ion transport by stimulating chloride secretion and suggest a possible mechanism by which the parasympathetic nervous system could be concerned in the control of ion transport. Images PMID:182722

  10. Immunoregulatory function of human intestinal mucosa lymphoid cells: evidence for enhanced suppressor cell activity in inflammatory bowel disease.

    PubMed Central

    Fiocchi, C; Youngman, K R; Farmer, R G

    1983-01-01

    Abnormalities in immune regulation at the gut level may be relevant to the pathogenesis of inflammatory bowel disease, but little is known about the immunoregulatory properties of intestinal mononuclear cells. Therefore, we wished to see if lymphoid cells derived from the lamina propria of surgically resected bowel specimens have any modulatory effect upon the immune response of peripheral blood mononuclear cells from patients with ulcerative colitis or Crohn's disease. When autologous peripheral blood and intestinal lamina propria lymphoid cells were mixed at different ratios and cultured in the presence of phytohaemagglutinin, we were able to show that intestinal mononuclear cells had the capacity to modify the mitogenic response of the cultured cells. These intestinal immunoregulatory cells, when obtained from mucosa affected by inflammatory bowel disease, express a significantly enhanced suppressor cell activity as compared with those from non-inflamed control mucosa. Such suppressor cell activity varies with cell concentration and requires cell proliferation, but it is independent of anatomical origin (small vs large bowel), type of inflammatory bowel disease (ulcerative colitis vs Crohn's disease) or immunosuppressive therapy. These findings point to an important functional difference between inflammatory bowel disease and control intestinal mucosa mononuclear cells. The enhanced suppressor activity of lamina propria mononuclear cells may be associated with impairment of cell-mediated immunity at the gut level. This may be related to the pathogenesis of inflammatory bowel disease by leading to defective intestinal immune regulatory events, which may not be detectable at the peripheral level. PMID:6223862

  11. Sodium butyrate protects the intestinal barrier function in peritonitic mice

    PubMed Central

    Han, Xiaofeng; Song, Huimin; Wang, Yunlei; Sheng, Yingmo; Chen, Jie

    2015-01-01

    Objective: Peritonitis is a commonly seen disease with high morbidity and mortality. It is prevalently considered that the impaired intestinal barrier during peritonitis is the access point of gut microbes into the blood system, and acts as the engine of the following systemic infection. In our previous study, we found that Sodium Butyrate (NaB) was protective on intestinal barrier function. In this study, we aim to evaluate the effects of NaB on overwhelming infection animal models of peritonitis. Methods: Mouse cecal ligation and puncture (CLP) model was used to study the effects of NaB on the intestinal barrier. Experimental animals were fed of NaB by gavage. Post-CLP mortality, gut permeability and intestinal histological alterations were studied. Results: Gastrointestinal NaB pharmacodynamics profiles after medication were studied. Measurements of NaB concentration in chyme showed significantly higher intestinal concentration of NaB in the NaB treated group than that of the control group. CLP-induced mortality was significantly decreased by oral NaB treatments. Gut permeability was largely increased after CLP, which was partially prevented by NaB feeding. Histological study showed that intestinal, especially ileal injury following peritonitis was substantially alleviated by NaB treatments. Moreover, tissue regeneration was also prompted by NaB. Conclusion: NaB has a potential protective effect on intestinal barrier function in peritonitis. PMID:26064302

  12. Proteome analysis of the macroscopically affected colonic mucosa of Crohn’s disease and intestinal tuberculosis

    PubMed Central

    Rukmangadachar, Lokesh A.; Makharia, Govind K.; Mishra, Asha; Das, Prasenjit; Hariprasad, Gururao; Srinivasan, Alagiri; Gupta, Siddhartha Datta; Ahuja, Vineet; Acharya, Subrat K.

    2016-01-01

    Differentiation between intestinal tuberculosis (ITB) and Crohn’s disease (CD) is challenging in geographical regions where both these diseases are prevalent. There is a need of biomarkers for differentiation between these two disorders. Colonic biopsies from inflamed mucosa of treatment-naive patients with ITB, CD and controls were used for analysis. Protein extracted from biopsies was digested with trypsin and resulting peptides were labeled with iTRAQ reagents. The peptides were subsequently analyzed using LC-MS/MS for identification and quantification. Gene ontology annotation for proteins was analyzed in PANTHER. Validation experiments were done for six differentially expressed proteins using immunohistochemistry. 533 proteins were identified and 241 proteins were quantified from 5 sets of iTRAQ experiments. While 63 were differentially expressed in colonic mucosa of patients with CD and ITB in at least one set of iTRAQ experiment, 11 proteins were differentially expressed in more than one set of experiments. Six proteins used for validation using immunohistochemistry in a larger cohort of patients; none of them however was differentially expressed in patients with ITB and CD. There are differentially expressed proteins in tissue proteome of CD and ITB. Further experiments are required using a larger cohort of homogeneous tissue samples. PMID:26988818

  13. Catecholamine-Directed Epithelial Cell Interactions with Bacteria in the Intestinal Mucosa.

    PubMed

    Brown, David R

    2016-01-01

    The catecholamines epinephrine, norepinephrine and dopamine are present in or have access to mucous membranes in the digestive, respiratory and genitourinary tracts, which represent the first sites of microbial colonization and infection within the body. Epithelial cells at mucosal surfaces establish and maintain symbiotic microbial communities and serve as the initial cellular point of contact for pathogens with the animal host. These cells express receptors that are capable of detecting and responding to microbe-associated molecular patterns and in most host species express G protein-coupled receptors for catecholamines. Although it is increasingly recognized that substances produced and released from nerves and endocrine cells can exert immuno-modulatory actions at mucosal sites, there have been few investigations focused specifically on the catecholaminergic modulation of interactions between the mucosal epithelium and bacteria or other mucosa-associated microorganisms. The potential biomedical importance of this phenomenon cannot be understated. For example, psychological stress or other conditions that activate the sympathetic nervous system to release epinephrine and norepinephrine may act to produce short-term changes in luminal and mucosal microbial communities or alter the course of a bacterial infection. This chapter will briefly review this developing and important research area of mucosa-microbe interactions with a focus on intestinal host defense. PMID:26589214

  14. Increased phospholipase A2 and decreased lysophospholipase activity in the small intestinal mucosa after ischaemia and revascularisation.

    PubMed Central

    Otamiri, T; Franzén, L; Lindmark, D; Tagesson, C

    1987-01-01

    The influence of ischaemia and revascularisation on lipid peroxidation and phospholipid metabolism in the rat small intestinal mucosa was investigated. Two hours of total ischaemia followed by five minutes of revascularisation caused not only accumulation of malondialdehyde in the mucosa, but also increased activity of phospholipase A2, decreased activity of lysophospholipase, and increased ratio between lysophosphatidylcholine and phosphatidylcholine. Pretreatment with the phospholipase A2 inhibitor, quinacrine, prevented the increases in mucosal phospholipase A2 activity and lysophosphatidylcholine/phosphatidylcholine ratio after ischaemia and morphological examinations revealed that the mucosa was then also protected against ischaemic injury. These findings point to the possibility that activation of phospholipase A2 and accumulation of lysophosphoglycerides could be involved in mediating the mucosal injury caused by small intestinal ischaemia. Images Fig. 7 PMID:3428670

  15. Regulation of the Intestinal Barrier Function by Host Defense Peptides

    PubMed Central

    Robinson, Kelsy; Deng, Zhuo; Hou, Yongqing; Zhang, Guolong

    2015-01-01

    Intestinal barrier function is achieved primarily through regulating the synthesis of mucins and tight junction (TJ) proteins, which are critical for maintaining optimal gut health and animal performance. An aberrant expression of TJ proteins results in increased paracellular permeability, leading to intestinal and systemic disorders. As an essential component of innate immunity, host defense peptides (HDPs) play a critical role in mucosal defense. Besides broad-spectrum antimicrobial activities, HDPs promotes inflammation resolution, endotoxin neutralization, wound healing, and the development of adaptive immune response. Accumulating evidence has also indicated an emerging role of HDPs in barrier function and intestinal homeostasis. HDP deficiency in the intestinal tract is associated with barrier dysfunction and dysbiosis. Several HDPs were recently shown to enhance mucosal barrier function by directly inducing the expression of multiple mucins and TJ proteins. Consistently, dietary supplementation of HDPs often leads to an improvement in intestinal morphology, production performance, and feed efficiency in livestock animals. This review summarizes current advances on the regulation of epithelial integrity and homeostasis by HDPs. Major signaling pathways mediating HDP-induced mucin and TJ protein synthesis are also discussed. As an alternative strategy to antibiotics, supplementation of exogenous HDPs or modulation of endogenous HDP synthesis may have potential to improve intestinal barrier function and animal health and productivity. PMID:26664984

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

    PubMed

    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. PMID:23282252

  17. FUT1 genetic variants impact protein glycosylation of porcine intestinal mucosa.

    PubMed

    Hesselager, Marianne O; Everest-Dass, Arun V; Thaysen-Andersen, Morten; Bendixen, Emøke; Packer, Nicolle H

    2016-06-01

    A massive use of antibiotics in industrial pig production is a major cause of the rapidly rising bacterial resistance to antibiotics. An enhanced understanding of infectious diseases and of host-microbe interactions has the potential to explore alternative ways to improve pig health and reduce the need for antibiotics. Host-microbe interactions depend on host-expressed glycans and microbe-carrying lectins. In this study, a G > A (nucleotide 307) missense mutation in the porcine α1,2fucosyltransferase 1 gene (FUT1), which has been reported to prevent infections by the common porcine enteric pathogen F18 fimbriated Escherichia coli, provided a unique opportunity to study glycan structures potentially involved in intestinal infections. N- and O-Linked glycans of the intestinal mucosa proteins were characterized in detail using LC-MS/MS. Relative abundances of all glycans were determined and compared between four heterozygous pigs (FUT1-307(A/G)) and four age-matched homozygous pigs from the same 2 litters carrying the missense FUT1 gene constellation (FUT1-307(A/A)). None of the characterized 48 N-linked glycans was found to be regulated by the FUT1 missense mutation, while 11 of the O-linked glycans showed significantly altered abundances between the two genotypes. The overall abundance of H-antigen carrying structures was decreased fivefold, while H-antigen precursors and sialylated structures were relatively more abundant in pigs with the FUT1 missense mutation. These results provide insight into the role of FUT1 on intestinal glycosylation, improve our understanding of how variation in FUT1 can modulate host-microbe interactions, and suggest that the FUT1 genetic variant may help to improve pig gut health. PMID:26858341

  18. Gastrointestinal absorption and metabolism of apple polyphenols ex vivo by the pig intestinal mucosa in the Ussing chamber.

    PubMed

    Deusser, Hannah; Rogoll, Dorothee; Scheppach, Wolfgang; Volk, Antje; Melcher, Ralph; Richling, Elke

    2013-03-01

    Polyphenols contained in food have various positive effects on human health. The absorption and metabolism of polyphenols in the intestinal tract needs to be studied to estimate these effects. The Ussing chamber technique was used to investigate the transport behavior of apple polyphenols through pig small intestinal mucosa, which served as a model for human gastrointestinal mucosa. The identities and concentrations of polyphenols and their metabolites in the half-chambers (luminal and basolateral) within an incubation period of 4 h were determined by HPLC-MS/MS and HPLC-DAD (DAD = diode-array detection). Flux values were also measured. It was found that 5-caffeoylquinic acid and caffeic acid were absorbed and translocated to the basolateral side (1.9 and 3.7%, respectively), but other compounds, including glycosides of phloretin and quercetin, were observed without translocation. A Ussing chamber utilizing pig small intestinal mucosa is a suitable model for assessing the effect of apple polyphenols on mucosal integrity and nutrition absorption across porcine mucosa. PMID:23229958

  19. Myenteric neurons and intestinal mucosa of diabetic rats after ascorbic acid supplementation

    PubMed Central

    de Freitas, Priscila; Natali, Maria Raquel Marçal; Pereira, Renata Virginia Fernandes; Neto, Marcilio Hubner Miranda; Zanoni, Jacqueline Nelisis

    2008-01-01

    AIM: To investigate the effect of ascorbic acid (AA) dietary supplementation on myenteric neurons and epithelial cell proliferation of the jejunum of adult rats with chronic diabetes mellitus. METHODS: Thirty rats at 90 d of age were divided into three groups: Non-diabetic, diabetic and diabetic treated with AA (DA) (1 g/L). After 120 d of treatment with AA the animals were killed. The myenteric neurons were stained for myosin-V and analyzed quantitatively in an area of 11.2 mm2/animal. We further measured the cellular area of 500 neurons per group. We also determined the metaphasic index (MI) of the jejunum mucosa layer of about 2500 cells in the intestinal crypts, as well as the dimensions of 30 villi and 30 crypts/animal. The data area was analyzed using the Olympus BX40 microscope. RESULTS: There was an increase of 14% in the neuronal density (792.6 ± 46.52 vs 680.6 ± 30.27) and 4.4% in the cellular area (303.4 ± 5.19 vs 291.1 ± 6.0) respectively of the diabetic group treated with AA when compared to control diabetic animals. There were no significant differences in MI parameters, villi height or crypt depths among the groups. CONCLUSION: Supplementation with AA in the diabetic animal promoted moderate neuroprotection. There was no observation of alteration of the cellular proliferation of the jejunum mucosa layer of rats with chronic diabetes mellitus with or without supplementation with AA. PMID:19030205

  20. Activation of Immune and Defense Responses in the Intestinal Mucosa by Outer Membrane Vesicles of Commensal and Probiotic Escherichia coli Strains

    PubMed Central

    José Fábrega, María; Aguilera, Laura; Giménez, Rosa; Varela, Encarna; Alexandra Cañas, María; Antolín, María; Badía, Josefa

    2016-01-01

    The influence of microbiota in human health is well-known. Imbalances in microbiome structure have been linked to several diseases. Modulation of microbiota composition through probiotic therapy is an attempt to harness the beneficial effects of commensal microbiota. Although, there is wide knowledge of the responses induced by gut microbiota, the microbial factors that mediate these effects are not well-known. Gram-negative bacteria release outer membrane vesicles (OMVs) as a secretion mechanism of microbial factors, which have an important role in intercellular communication. Here, we investigated whether OMVs from the probiotic Escherichia coli strain Nissle 1917 (EcN) or the commensal E. coli strain ECOR12 trigger immune responses in various cellular models: (i) peripheral blood mononuclear cells (PBMCs) as a model of intestinal barrier disruption, (ii) apical stimulation of Caco-2/PMBCs co-culture as a model of intact intestinal mucosa, and (iii) colonic mucosa explants as an ex vivo model. Stimulations with bacterial lysates were also performed. Whereas, both OMVs and lysates activated expression and secretion of several cytokines and chemokines in PBMCs, only OMVs induced basolateral secretion and mRNA upregulation of these mediators in the co-culture model. We provide evidence that OMVs are internalized in polarized Caco-2 cells. The activated epithelial cells elicit a response in the underlying immunocompetent cells. The OMVs effects were corroborated in the ex vivo model. This experimental study shows that OMVs are an effective strategy used by beneficial gut bacteria to communicate with and modulate host responses, activating signaling events through the intestinal epithelial barrier. PMID:27242727

  1. Activation of Immune and Defense Responses in the Intestinal Mucosa by Outer Membrane Vesicles of Commensal and Probiotic Escherichia coli Strains.

    PubMed

    José Fábrega, María; Aguilera, Laura; Giménez, Rosa; Varela, Encarna; Alexandra Cañas, María; Antolín, María; Badía, Josefa; Baldomà, Laura

    2016-01-01

    The influence of microbiota in human health is well-known. Imbalances in microbiome structure have been linked to several diseases. Modulation of microbiota composition through probiotic therapy is an attempt to harness the beneficial effects of commensal microbiota. Although, there is wide knowledge of the responses induced by gut microbiota, the microbial factors that mediate these effects are not well-known. Gram-negative bacteria release outer membrane vesicles (OMVs) as a secretion mechanism of microbial factors, which have an important role in intercellular communication. Here, we investigated whether OMVs from the probiotic Escherichia coli strain Nissle 1917 (EcN) or the commensal E. coli strain ECOR12 trigger immune responses in various cellular models: (i) peripheral blood mononuclear cells (PBMCs) as a model of intestinal barrier disruption, (ii) apical stimulation of Caco-2/PMBCs co-culture as a model of intact intestinal mucosa, and (iii) colonic mucosa explants as an ex vivo model. Stimulations with bacterial lysates were also performed. Whereas, both OMVs and lysates activated expression and secretion of several cytokines and chemokines in PBMCs, only OMVs induced basolateral secretion and mRNA upregulation of these mediators in the co-culture model. We provide evidence that OMVs are internalized in polarized Caco-2 cells. The activated epithelial cells elicit a response in the underlying immunocompetent cells. The OMVs effects were corroborated in the ex vivo model. This experimental study shows that OMVs are an effective strategy used by beneficial gut bacteria to communicate with and modulate host responses, activating signaling events through the intestinal epithelial barrier. PMID:27242727

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

    PubMed

    Williams, Benjamin B; Tebbutt, Niall C; Buchert, Michael; Putoczki, Tracy L; Doggett, Karen; Bao, Shisan; Johnstone, Cameron N; Masson, Frederick; Hollande, Frederic; Burgess, Antony W; Scott, Andrew M; Ernst, Matthias; Heath, Joan K

    2015-08-01

    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 linking intestinal

  3. Nonmuscle Myosin IIA Regulates Intestinal Epithelial Barrier in vivo and Plays a Protective Role During Experimental Colitis

    PubMed Central

    Naydenov, Nayden G.; Feygin, Alex; Wang, Dongdong; Kuemmerle, John F.; Harris, Gianni; Conti, Mary Anne; Adelstein, Robert S.; Ivanov, Andrei I.

    2016-01-01

    The actin cytoskeleton is a critical regulator of intestinal mucosal barrier permeability, and the integrity of epithelial adherens junctions (AJ) and tight junctions (TJ). Non muscle myosin II (NM II) is a key cytoskeletal motor that controls actin filament architecture and dynamics. While NM II has been implicated in the regulation of epithelial junctions in vitro, little is known about its roles in the intestinal mucosa in vivo. In this study, we generated a mouse model with an intestinal epithelial-specific knockout of NM IIA heavy chain (NM IIA cKO) and examined the structure and function of normal gut barrier, and the development of experimental colitis in these animals. Unchallenged NM IIA cKO mice showed increased intestinal permeability and altered expression/localization of several AJ/TJ proteins. They did not develop spontaneous colitis, but demonstrated signs of a low-scale mucosal inflammation manifested by prolapses, lymphoid aggregates, increased cytokine expression, and neutrophil infiltration in the gut. NM IIA cKO animals were characterized by a more severe disruption of the gut barrier and exaggerated mucosal injury during experimentally-induced colitis. Our study provides the first evidence that NM IIA plays important roles in establishing normal intestinal barrier, and protection from mucosal inflammation in vivo. PMID:27063635

  4. Chronic Kidney Disease Induced Intestinal Mucosal Barrier Damage Associated with Intestinal Oxidative Stress Injury

    PubMed Central

    Yu, Chao; Wang, Qiang; Zhou, Chunyu; Kang, Xin; Zhao, Shuang; Liu, Shuai; Fu, Huijun; Yu, Zhen; Peng, Ai

    2016-01-01

    Background. To investigate whether intestinal mucosal barrier was damaged or not in chronic kidney disease progression and the status of oxidative stress. Methods. Rats were randomized into two groups: a control group and a uremia group. The uremia rat model was induced by 5/6 kidney resection. In postoperative weeks (POW) 4, 6, 8, and 10, eight rats were randomly selected from each group to prepare samples for assessing systemic inflammation, intestinal mucosal barrier changes, and the status of intestinal oxidative stress. Results. The uremia group presented an increase trend over time in the serum tumor necrosis factor-alpha, interleukin-6 (IL-6) and IL-10, serum D-lactate and diamine oxidase, and intestinal permeability, and these biomarkers were significantly higher than those in control group in POW 8 and/or 10. Chiu's scores in uremia group were also increased over time, especially in POW 8 and 10. Furthermore, the intestinal malondialdehyde, superoxide dismutase, and glutathione peroxidase levels were significantly higher in uremia group when compared with those in control group in POW 8 and/or 10. Conclusions. The advanced chronic kidney disease could induce intestinal mucosal barrier damage and further lead to systemic inflammation. The underlying mechanism may be associated with the intestinal oxidative stress injury. PMID:27493661

  5. Self assembled hyaluronic acid nanoparticles as a potential carrier for targeting the inflamed intestinal mucosa.

    PubMed

    Vafaei, Seyed Yaser; Esmaeili, Motahareh; Amini, Mohsen; Atyabi, Fatemeh; Ostad, Seyed Naser; Dinarvand, Rassoul

    2016-06-25

    To develop a nanoparticulate drug carrier for targeting of the inflamed intestinal mucosa, amphiphilic hyaluronic acid (HA) conjugates were synthesized, which could form self-assembled nanoparticles (NPs) in aqueous solution and budesonide (BDS) was loaded into the HANPs. Their particle sizes were in the range of 177 to 293nm with negative surface charge. The model of inflammatory CACO-2 cells was utilized to investigate the therapeutic potential of budesonide loaded HA nanocarriers. The highest expression of CD44 receptors was found on inflamed Caco-2 cells, as determined by flow cytometry. FITC-labeled HANPs revealed greater uptake in inflamed CACO-2 cells compared to untreated CACO-2 and CD44-negative cell lines, NIH3T3. BDS loaded HANPs displayed almost no toxicity indicating HANPs are excellent biocompatible nano-carriers. BDS loaded HANPs demonstrated higher anti-inflammatory effect on IL-8 and TNF-α secretion in inflamed cell model compared to the same dose of free drug. These results revealed the promising potential of HA nanoparticles as a targeted drug delivery system for IBD treatment. PMID:27083829

  6. Effects of simulated weightlessness on the intestinal mucosal barrier of rats

    NASA Astrophysics Data System (ADS)

    Chen, Ying; Yang, Chun-min; Mao, Gao-ping; Liu, Qing-sen; Guo, Ming-zhou

    2011-07-01

    This study employed a rat tail-suspension model to investigate the effects of simulated weightlessness on the intestinal mucosal barrier. Twenty-four Wistar rats were randomly divided into control (CON), 14-day tail-suspension (SUS-14d), and 21-day tail-suspension (SUS-21d) groups ( n = 8 per group). Expression of occludin and zonula occludins-1 (ZO-1), proteins of the tight junction (TJ), in the intestinal mucosa was measured by immunohistochemical analysis, Western blotting, and mRNA fluorescent quantitation PCR. Plasma concentrations of diamine oxidase (DAO) and D-lactate were determined using an enzymatic spectrophotometric assay. Expression of occludin and ZO-1 was reduced in the SUS-14d and SUS-21d groups as compared to the CON group, with lowest expression observed in the SUS-21d group ( P < 0.01). Examination by transmission electron microscopy (TEM) of the jejunal epithelium revealed increased intercellular space, decreased TJ and desmosome densities, and destruction of microvilli in the SUS-14d and SUS-21d groups. Plasma DAO and D-lactate concentrations in the SUS-21d group were higher than those in SUS-14d group and significantly higher than those in the CON group ( P < 0.01). In all three groups, the expression of occludin and ZO-1 was found to correlate negatively with DAO ( P < 0.01) and D-lactate ( P < 0.01) concentrations. It is concluded that simulated weightless results in down-regulation of expression of TJ proteins in the rat intestinal mucosa. Simulated weightlessness is proposed to increase intestinal permeability through damage to the TJ.

  7. Heat stress: intestinal barrier and immune disruption in pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Economic losses to the livestock industry due to heat stress (HS) are estimated to be greater than $2.0 billion annually. HS morbidity is linked to disruption of normal intestinal tract (IT) absorptive and barrier functions, is often manifested as decreased performance; however, extreme HS can have ...

  8. Moxibustion and Acupuncture Ameliorate Crohn's Disease by Regulating the Balance between Th17 and Treg Cells in the Intestinal Mucosa

    PubMed Central

    Zhao, Chen; Bao, Chunhui; Li, Jing; Zhu, Yifang; Wang, Siyao; Yang, Ling; Shi, Yin; Liu, Huirong; Dou, Chuanzi; Ding, Guanghong; Wang, Xiaomei; Wu, Huangan

    2015-01-01

    Previous studies have demonstrated that acupuncture is beneficial to patients with Crohn's disease (CD), but the mechanism underlying its therapeutic effects remains unclear. To identify the mechanism by which acupuncture treats CD, the balance between Th17 and Treg cells was assessed in CD patients. In this study, Ninety-two CD patients were randomly and equally assigned to a treatment group that were treated with herb-partitioned moxibustion and acupuncture or a control group with wheat bran-partitioned moxibustion and superficial acupuncture. The effect of these treatments on Th17 and Treg cells and their related molecular markers in the intestinal mucosa were detected before (week 0) and after (week 12) treatment. The results suggested that the ratio of Th17 and Treg cells was significantly decreased after treatment and that the levels of IL-17 and RORγt in the intestinal mucosa were obviously reduced, while the expression of FOXP3 was increased after treatment in both groups. In the treatment group, the expression of these molecules was more markedly regulated than the control group. In conclusion, moxibustion and acupuncture have been shown to regulate the ratio of Th17 and Treg cells in the intestinal mucosa of CD patients and restore the balance between these immune cell subsets. PMID:26347488

  9. Antibiotics conspicuously affect community profiles and richness, but not the density of bacterial cells associated with mucosa in the large and small intestines of mice.

    PubMed

    Puhl, Nathan J; Uwiera, Richard R E; Yanke, L Jay; Selinger, L Brent; Inglis, G Douglas

    2012-02-01

    The influence of three antibiotics (bacitracin, enrofloxacin, and neomycin sulfate) on the mucosa-associated enteric microbiota and the intestines of mice was examined. Antibiotics caused conspicuous enlargement of ceca and an increase in overall length of the intestine. However, there were no pathologic changes associated with increased cecal size or length of the intestine. Conspicuous reductions in the richness of mucosa-associated bacteria and changes to community profiles within the small (duodenum, proximal jejunum, middle jejunum, distal jejunum, and ileum) and large (cecum, ascending colon, and descending colon) intestine occurred in mice administered antibiotics. Communities in antibiotic-treated mice were dominated by a limited number of Clostridium-like (i.e. clostridial cluster XIVa) and Bacteroides species. The richness of mucosa-associated communities within the small and large intestine increased during the 14-day recovery period. However, community profiles within the large intestine did not return to baseline (i.e. relative to the control). Although antibiotic administration greatly reduced bacterial richness, densities of mucosa-associated bacteria were not reduced correspondingly. These data showed that the antibiotics, bacitracin, enrofloxacin, and neomycin sulfate, administered for 21 days to mice did not sterilize the intestine, but did impart a tremendous and prolonged impact on mucosa-associated bacterial communities throughout the small and large intestine. PMID:22185696

  10. Effects of ε-viniferin, a dehydrodimer of resveratrol, on transepithelial active ion transport and ion permeability in the rat small and large intestinal mucosa.

    PubMed

    Karaki, Shin-Ichiro; Ishikawa, Junji; Tomizawa, Yuka; Kuwahara, Atsukazu

    2016-05-01

    ε-Viniferin is a dehydrodimer of resveratrol, a polyphenol synthesized in many plants, including grapevine. The present study investigated the effects of ε-viniferin and resveratrol on epithelial secretory and barrier functions in isolated rat small and large intestinal mucosa. Mucosa-submucosa tissue preparations of various segments of the rat large and small intestines were mounted on Ussing chambers, and short-circuit current (Isc) and tissue conductance (Gt) were continuously measured. The mucosal addition of ε-viniferin (>10(-5) mol/L) and resveratrol (>10(-4) mol/L) to the cecal mucosa, which was the most sensitive region, induced an increase in Isc and a rapid phase decrease (P-1) followed by rapid (P-2) and broad (P-3) peak increases in Gt in concentration-dependent manners. Mucosal ε-viniferin (10(-4) mol/L), but not resveratrol (10(-4) mol/L), increased the permeability of FITC-conjugated dextran (4 kDa). The mucosal ε-viniferin-evoked changes in Isc (Cl(-) secretion), but not in Gt, were attenuated by a selective cyclooxygenase (COX)-1 inhibitor and a selective EP4 prostaglandin receptor. The mucosal ε-viniferin-evoked increase in Isc was partially attenuated, and P-2, but not P-1 or P-3, change in Gt was abolished by a transient receptor potential cation channel, subfamily A, member 1 (TRPA1) inhibitor. Moreover, the mucosal ε-viniferin concentration-dependently attenuated the mucosal propionate (1 mmol/L)-evoked increases in Isc and Gt Immunohistochemical studies revealed COX-1-immunoreactive epithelial cells in the cecal crypt. The present study showed that mucosal ε-viniferin modulated transepithelial ion transport and permeability, possibly by activating sensory epithelial cells expressing COX-1 and TRPA1. Moreover, mucosal ε-viniferin decreased mucosal sensitivity to other luminal molecules such as short-chain fatty acids. In conclusion, these results suggest that ε-viniferin modifies intestinal mucosal transport and barrier

  11. A 3D co-culture of three human cell lines to model the inflamed intestinal mucosa for safety testing of nanomaterials.

    PubMed

    Susewind, Julia; de Souza Carvalho-Wodarz, Cristiane; Repnik, Urska; Collnot, Eva-Maria; Schneider-Daum, Nicole; Griffiths, Gareth Wyn; Lehr, Claus-Michael

    2016-01-01

    Oral exposure to nanomaterials is a current concern, asking for innovative biological test systems to assess their safety, especially also in conditions of inflammatory disorders. Aim of this study was to develop a 3D intestinal model, consisting of Caco-2 cells and two human immune cell lines, suitable to assess nanomaterial toxicity, in either healthy or diseased conditions. Human macrophages (THP-1) and human dendritic cells (MUTZ-3) were embedded in a collagen scaffold and seeded on the apical side of transwell inserts. Caco-2 cells were seeded on top of this layer, forming a 3D model of the intestinal mucosa. Toxicity of engineered nanoparticles (NM101 TiO2, NM300 Ag, Au) was evaluated in non-inflamed and inflamed co-cultures, and also compared to non-inflamed Caco-2 monocultures. Inflammation was elicited by IL-1β, and interactions with engineered NPs were addressed by different endpoints. The 3D co-culture showed well preserved ultrastructure and significant barrier properties. Ag NPs were found to be more toxic than TiO2 or Au NPs. But once inflamed with IL-1β, the co-cultures released higher amounts of IL-8 compared to Caco-2 monocultures. However, the cytotoxicity of Ag NPs was higher in Caco-2 monocultures than in 3D co-cultures. The naturally higher IL-8 production in the co-cultures was enhanced even further by the Ag NPs. This study shows that it is possible to mimic inflamed conditions in a 3D co-culture model of the intestinal mucosa. The fact that it is based on three easily available human cell lines makes this model valuable to study the safety of nanomaterials in the context of inflammation. PMID:25738417

  12. Effects of Soybean Agglutinin on Intestinal Barrier Permeability and Tight Junction Protein Expression in Weaned Piglets

    PubMed Central

    Zhao, Yuan; Qin, Guixin; Sun, Zewei; Che, Dongsheng; Bao, Nan; Zhang, Xiaodong

    2011-01-01

    This study was developed to provide further information on the intestinal barrier permeability and the tight junction protein expression in weaned piglets fed with different levels of soybean agglutinin (SBA). Twenty-five weaned crossbred barrows (Duroc × Landrace × Yorkshire) were selected and randomly allotted to five groups, each group with five replicates. The piglets in the control group were not fed with leguminous products. 0.05, 0.1, 0.15 and 0.2% SBA was added to the control diet to form four experimental diets, respectively. After the experimental period of 7 days (for each group), all the piglets were anesthetized with excess procaine and slaughtered. The d-lactic acid in plasma and the Ileal mucosa diamine oxidase (DAO) was analyzed to observe the change in the intestinal permeability. The tight junction proteins occludin and ZO-1 in the jejunum tissue distribution and relative expression were detected by immunohistochemistry and Western Blot. The results illustrated that a high dose of SBA (0.1–0.2%) could increase the intestinal permeability and reduce piglet intestinal epithelial tight junction protein occludin or ZO-1 expression, while low dose of SBA (0.05% of total diet) had no significant affects. The contents of DAO, d-lactic acid, occludin or ZO-1, had a linear relationship with the SBA levels (0–0.2%) in diets. The high dose SBA (0.1–0.2%) could increase the intestinal permeability and reduce piglet intestinal epithelial tight junction protein occludin or ZO-1 expression, while low dose of SBA (0.05% of total diet) had no affects. PMID:22272087

  13. Herbal prescription Chang'an II repairs intestinal mucosal barrier in rats with post-inflammation irritable bowel syndrome

    PubMed Central

    Wang, Feng-yun; Su, Min; Zheng, Yong-qiu; Wang, Xiao-ge; Kang, Nan; Chen, Ting; Zhu, En-lin; Bian, Zhao-xiang; Tang, Xu-dong

    2015-01-01

    Aim: The herbal prescription Chang'an II is derived from a classical TCM formula Tong-Xie-Yao-Fang for the treatment of liver-qi stagnation and spleen deficiency syndrome of irritable bowel syndrome (IBS). In this study we investigated the effects of Chang'an II on the intestinal mucosal immune barrier in a rat post-inflammation IBS (PI-IBS) model. Methods: A rat model of PI-IBS was established using a multi-stimulation paradigm including early postnatal sibling deprivation, bondage and intrarectal administration of TNBS. Four weeks after TNBS administration, the rats were treated with Chang'an II (2.85, 5.71 and 11.42 g·kg−1·d−1, ig) for 14 d. Intestinal sensitivity was assessed based on the abdominal withdrawal reflex (AWR) scores and fecal water content. Open field test and two-bottle sucrose intake test were used to evaluate the behavioral changes. CD4+ and CD8+ cells were counted and IL-1β and IL-4 levels were measured in intestinal mucosa. Transmission electron microscopy was used to evaluate ultrastructural changes of the intestinal mucosal barrier. Results: PI-IBS model rats showed significantly increased AWR reactivity and fecal water content, and decreased locomotor activity and sucrose intake. Chang'an II treatment not only reduced AWR reactivity and fecal water content, but also suppressed the anxiety and depressive behaviors. Ultrastructural study revealed that the gut mucosal barrier function was severely damaged in PI-IBS model rats, whereas Chang'an II treatment relieved intestinal mucosal inflammation and repaired the gut mucosal barrier. Furthermore, PI-IBS model rats showed a significantly reduced CD4+/CD8+ cell ratio in lamina propria and submucosa, and increased IL-1β and reduced IL-4 expression in intestinal mucosa, whereas Chang'an II treatment reversed PI-IBS-induced changes in CD4+/CD8+ cell ratio and expression of IL-1β and IL-4. Conclusion: Chang'an II treatment protects the intestinal mucosa against PI-IBS through anti

  14. Emerging molecular insights into the interaction between probiotics and the host intestinal mucosa.

    PubMed

    Bron, Peter A; van Baarlen, Peter; Kleerebezem, Michiel

    2012-01-01

    Probiotic bacteria can modulate immune responses in the host gastrointestinal tract to promote health. The genomics era has provided novel opportunities for the discovery and characterization of bacterial probiotic effector molecules that elicit specific responses in the intestinal system. Furthermore, nutrigenomic analyses of the response to probiotics have unravelled the signalling and immune response pathways which are modulated by probiotic bacteria. Together, these genomic approaches and nutrigenomic analyses have identified several bacterial factors that are involved in modulation of the immune system and the mucosal barrier, and have revealed that a molecular 'bandwidth of human health' could represent a key determinant in an individual's physiological responsiveness to probiotics. These approaches may lead to improved stratification of consumers and to subpopulation-level probiotic supplementation to maintain or improve health, or to reduce the risk of disease. PMID:22101918

  15. Mechanism of intestinal mucosal barrier dysfunction in a rat model of chronic obstructive pulmonary disease: An observational study

    PubMed Central

    Xin, Xiaofeng; Dai, Wei; Wu, Jie; Fang, Liping; Zhao, Ming; Zhang, Pengpeng; Chen, Min

    2016-01-01

    The aim of the present study was to investigate intestinal mucosal barrier dysfunction in a rat model of chronic obstructive pulmonary disease (COPD). Male Sprague Dawley rats (n=40) were evenly randomized into control and COPD groups and the COPD model was established by regulated exposure to cigarette smoke for 6 months. Histopathological changes of the lung and intestinal tissues were detected by hematoxylin and eosin staining. Expression of the tight junction proteins occludin and zona occludens-1 (ZO-1) in the intestinal tissues were analyzed by western blotting, serum diamine oxidase (DAO) activity was detected by spectrophotometry, the urinary lactulose to mannitol ratio (L/M) was evaluated by high performance liquid chromatography, and intestinal tissue secretion of tumor necrosis factor (TNF)-α, interferon (IFN)-γ and interleukin (IL)-8 were detected by ELISA. Lung histopathology revealed thinned alveolar walls, ruptured alveolar septa, enlarged and deformed alveoli, and the formation of bullae and emphysema due to alveolar fusion in the COPD group, while intestinal histopathology indicated clearly swollen intestines with darkened and gray mucosa, neutrophil infiltration of the intestinal mucosal and regional epithelial shedding. The occludin and ZO-1 expression levels were significantly lower in the COPD group compared with those in the corresponding control group (P<0.05), while the urinary L/M ratio was significantly higher (P<0.05). Furthermore, the serum DAO activity and secretion of TNF-α, IFN-γ and IL-8 in the intestinal tissues were significantly higher in the COPD group than in the control group (each P<0.05). Dysfunctional and structural changes were observed in the intestinal mucosal barrier in COPD model rats, which may be associated with the increased intestinal inflammatory responses. PMID:27588054

  16. Protective Effect of Huoxiang Zhengqi Oral Liquid on Intestinal Mucosal Mechanical Barrier of Rats with Postinfectious Irritable Bowel Syndrome Induced by Acetic Acid

    PubMed Central

    Liu, Yao; Liu, Wei; Peng, Qiu-Xian; Peng, Jiang-Li; Yu, Lin-Zhong; Hu, Jian-Lan

    2014-01-01

    In this study, a rat model with acetic acid-induced PI-IBS was used to study the role of HXZQ oral liquid in repairing the colonic epithelial barrier and reducing intestinal permeability. Pathomorphism of colonic tissue, epithelial ultrastructure, DAO activity in serum, and the protein expression of ZO-1 and occludin were examined to investigate protective effect mechanisms of HXZQ on intestinal mucosa barrier and then present experimental support for its use for prevention and cure of PI-IBS. PMID:25254052

  17. Butyrate attenuates lipopolysaccharide-induced inflammation in intestinal cells and Crohn's mucosa through modulation of antioxidant defense machinery.

    PubMed

    Russo, Ilaria; Luciani, Alessandro; De Cicco, Paola; Troncone, Edoardo; Ciacci, Carolina

    2012-01-01

    Oxidative stress plays an important role in the pathogenesis of inflammatory bowel disease (IBD), including Crohn's disease (CrD). High levels of Reactive Oxygen Species (ROS) induce the activation of the redox-sensitive nuclear transcription factor kappa-B (NF-κB), which in turn triggers the inflammatory mediators. Butyrate decreases pro-inflammatory cytokine expression by the lamina propria mononuclear cells in CrD patients via inhibition of NF-κB activation, but how it reduces inflammation is still unclear. We suggest that butyrate controls ROS mediated NF-κB activation and thus mucosal inflammation in intestinal epithelial cells and in CrD colonic mucosa by triggering intracellular antioxidant defense systems. Intestinal epithelial Caco-2 cells and colonic mucosa from 14 patients with CrD and 12 controls were challenged with or without lipopolysaccaride from Escherichia coli (EC-LPS) in presence or absence of butyrate for 4 and 24 h. The effects of butyrate on oxidative stress, p42/44 MAP kinase phosphorylation, p65-NF-κB activation and mucosal inflammation were investigated by real time PCR, western blot and confocal microscopy. Our results suggest that EC-LPS challenge induces a decrease in Gluthation-S-Transferase-alpha (GSTA1/A2) mRNA levels, protein expression and catalytic activity; enhanced levels of ROS induced by EC-LPS challenge mediates p65-NF-κB activation and inflammatory response in Caco-2 cells and in CrD colonic mucosa. Furthermore butyrate treatment was seen to restore GSTA1/A2 mRNA levels, protein expression and catalytic activity and to control NF-κB activation, COX-2, ICAM-1 and the release of pro-inflammatory cytokine. In conclusion, butyrate rescues the redox machinery and controls the intracellular ROS balance thus switching off EC-LPS induced inflammatory response in intestinal epithelial cells and in CrD colonic mucosa. PMID:22412931

  18. Nano-hydroxyapatite–thermally denatured small intestine sub-mucosa composites for entheses applications

    PubMed Central

    Perla, Venu; Webster, Thomas J

    2006-01-01

    The objective of the present in vitro study was to estimate the adhesion strength of nanometer crystalline hydroxyapatite (HA)–small intestine sub-mucosa (SIS) composites on model implant surfaces. Techniques of thermal denaturation (60°C, 20 min) of SIS were used to enhance the adhesion strength of entheses materials to underlying implants. Specifically, results indicated that the adhesion strength of thermally denatured SIS was 2–3 times higher than that for normal unheated SIS. In addition, aqua-sonicated, hydrothermally treated nano-HA dispersions enhanced the adhesion strength of SIS on implant surfaces. Importantly, results of the present study demonstrated that human skeletal muscle cell (hSkMC) numbers were not affected by thermally denaturing SIS in nano-HA composite coatings; however, they increased on aqua-sonicated nano-HA/SIS composites compared with SIS alone. Interestingly, thermally denatured SIS that contained aqua-sonicated, hydrothermally treated nano-HA decreased human osteoblasts (hOBs) numbers compared with respective unheated composites; all other composites when thermally denatured did not influence hOB numbers. Results also showed that the number of hOBs increased on nano-HA/SIS composites compared with SIS composites alone. Human mesenchymal stem cell (hMSC) numbers were not affected by the presence of nano-HA in SIS composites. For these reasons, the collective results of this in vitro study demonstrated a technique to increase the coating strength of entheses coatings on implant surfaces (using thermally denatured SIS and aqua-sonicated, hydrothermally prepared nano-HA) while, at the same time, supporting cell functions important for entheses regeneration. PMID:17717975

  19. The hog intestinal mucosa acylase I: subcellular localization, isolation, kinetic studies and biological function.

    PubMed

    Giardina, T; Biagini, A; Dalle Ore, F; Ferre, E; Reynier, M; Puigserver, A

    1997-05-01

    The soluble acylase I (N-acylamino acid amidohydrolase, EC 3.5.1.14) from hog intestinal mucosa was 11,000-fold purified for the first time using a new four-step procedure involving an immunoaffinity chromatography. The resulting protein, which had an isoelectric point of 5.2 and a M(r) of 90,000 was composed of two apparently identical N-acylated polypeptide chains. Its amino acid composition was comparable to that of hog kidney acylase I. The enzyme had a pH optimum at 8.0 and required Zn2+ or Co2+. The optimal temperature for the acylase reaction was 40 degrees C and the activation energy of thermodenaturation was estimated at 260 kJ mol-1. The enzyme was strongly inhibited when preincubated with chelating agents, by diethyl pyrocarbonate under histidine-modifying conditions as well as by sulfhydryl compounds. The reaction of the purified enzyme with the synthetic substrate furylacryloyl-L-methionine was partly characterized as follows: Km = 0.22 +/- 0.03 mM, kcat = 128.0 +/- 17.8 s-1 and kcat/Km = 5.8 +/- 1.6 x 10(5) M-1 s-1. The L-stereoisomer of methionine competitively inhibited the enzyme reaction with a Ki of 3.4 +/- 0.2 mM. It is suggested that acylase I might not only be involved in the catabolism of intracellular N-acylated protein but also be responsible for the biological utilization of N-acylated food proteins. PMID:9258435

  20. Epigenetic control of intestinal barrier function and inflammation in zebrafish

    PubMed Central

    Marjoram, Lindsay; Alvers, Ashley; Deerhake, M. Elizabeth; Bagwell, Jennifer; Mankiewicz, Jamie; Cocchiaro, Jordan L.; Beerman, Rebecca W.; Willer, Jason; Sumigray, Kaelyn D.; Katsanis, Nicholas; Rawls, John F.; Goll, Mary G.; Bagnat, Michel

    2015-01-01

    The intestinal epithelium forms a barrier protecting the organism from microbes and other proinflammatory stimuli. The integrity of this barrier and the proper response to infection requires precise regulation of powerful immune homing signals such as tumor necrosis factor (TNF). Dysregulation of TNF leads to inflammatory bowel diseases (IBD), but the mechanism controlling the expression of this potent cytokine and the events that trigger the onset of chronic inflammation are unknown. Here, we show that loss of function of the epigenetic regulator ubiquitin-like protein containing PHD and RING finger domains 1 (uhrf1) in zebrafish leads to a reduction in tnfa promoter methylation and the induction of tnfa expression in intestinal epithelial cells (IECs). The increase in IEC tnfa levels is microbe-dependent and results in IEC shedding and apoptosis, immune cell recruitment, and barrier dysfunction, consistent with chronic inflammation. Importantly, tnfa knockdown in uhrf1 mutants restores IEC morphology, reduces cell shedding, and improves barrier function. We propose that loss of epigenetic repression and TNF induction in the intestinal epithelium can lead to IBD onset. PMID:25730872

  1. Epigenetic control of intestinal barrier function and inflammation in zebrafish.

    PubMed

    Marjoram, Lindsay; Alvers, Ashley; Deerhake, M Elizabeth; Bagwell, Jennifer; Mankiewicz, Jamie; Cocchiaro, Jordan L; Beerman, Rebecca W; Willer, Jason; Sumigray, Kaelyn D; Katsanis, Nicholas; Tobin, David M; Rawls, John F; Goll, Mary G; Bagnat, Michel

    2015-03-01

    The intestinal epithelium forms a barrier protecting the organism from microbes and other proinflammatory stimuli. The integrity of this barrier and the proper response to infection requires precise regulation of powerful immune homing signals such as tumor necrosis factor (TNF). Dysregulation of TNF leads to inflammatory bowel diseases (IBD), but the mechanism controlling the expression of this potent cytokine and the events that trigger the onset of chronic inflammation are unknown. Here, we show that loss of function of the epigenetic regulator ubiquitin-like protein containing PHD and RING finger domains 1 (uhrf1) in zebrafish leads to a reduction in tnfa promoter methylation and the induction of tnfa expression in intestinal epithelial cells (IECs). The increase in IEC tnfa levels is microbe-dependent and results in IEC shedding and apoptosis, immune cell recruitment, and barrier dysfunction, consistent with chronic inflammation. Importantly, tnfa knockdown in uhrf1 mutants restores IEC morphology, reduces cell shedding, and improves barrier function. We propose that loss of epigenetic repression and TNF induction in the intestinal epithelium can lead to IBD onset. PMID:25730872

  2. Enteral feeding and its impact on the gut immune system and intestinal mucosal barrier.

    PubMed

    Szefel, Jarosław; Kruszewski, Wiesław J; Buczek, Tomasz

    2015-01-01

    Enteral feeding is the preferred method of nutritional therapy. Mucosal lack of contact with nutrients leads do lymphoid tissue atrophy, immune system functional decline, and intensification in bacterial translocation. Currently, it is assumed that microbiome is one of the body organs that has a significant impact on health. The composition of microbiome is not affected by age, sex, or place of residence, although it changes rapidly after diet modification. The composition of the microbiome is determined by enterotype, which is specific for each organism. It has a significant impact on the risk of diabetes, cancer, atherosclerosis, and other diseases. This review gathers data on interaction between gut-associated lymphoid tissue, mucosa-associated lymphoid tissue, microbiome, and the intestinal mucosal barrier. Usually, the information on the aforementioned is scattered in specialist-subject magazines such as gastroenterology, microbiology, genetics, biochemistry, and others. PMID:26557936

  3. Enteral feeding and its impact on the gut immune system and intestinal mucosal barrier

    PubMed Central

    Kruszewski, Wiesław J.; Buczek, Tomasz

    2015-01-01

    Enteral feeding is the preferred method of nutritional therapy. Mucosal lack of contact with nutrients leads do lymphoid tissue atrophy, immune system functional decline, and intensification in bacterial translocation. Currently, it is assumed that microbiome is one of the body organs that has a significant impact on health. The composition of microbiome is not affected by age, sex, or place of residence, although it changes rapidly after diet modification. The composition of the microbiome is determined by enterotype, which is specific for each organism. It has a significant impact on the risk of diabetes, cancer, atherosclerosis, and other diseases. This review gathers data on interaction between gut-associated lymphoid tissue, mucosa-associated lymphoid tissue, microbiome, and the intestinal mucosal barrier. Usually, the information on the aforementioned is scattered in specialist-subject magazines such as gastroenterology, microbiology, genetics, biochemistry, and others. PMID:26557936

  4. Central role of the gut epithelial barrier in the pathogenesis of chronic intestinal inflammation: lessons learned from animal models and human genetics.

    PubMed

    Pastorelli, Luca; De Salvo, Carlo; Mercado, Joseph R; Vecchi, Maurizio; Pizarro, Theresa T

    2013-01-01

    The gut mucosa is constantly challenged by a bombardment of foreign antigens and environmental microorganisms. As such, the precise regulation of the intestinal barrier allows the maintenance of mucosal immune homeostasis and prevents the onset of uncontrolled inflammation. In support of this concept, emerging evidence points to defects in components of the epithelial barrier as etiologic factors in the pathogenesis of inflammatory bowel diseases (IBDs). In fact, the integrity of the intestinal barrier relies on different elements, including robust innate immune responses, epithelial paracellular permeability, epithelial cell integrity, as well as the production of mucus. The purpose of this review is to systematically evaluate how alterations in the aforementioned epithelial components can lead to the disruption of intestinal immune homeostasis, and subsequent inflammation. In this regard, the wealth of data from mouse models of intestinal inflammation and human genetics are pivotal in understanding pathogenic pathways, for example, that are initiated from the specific loss of function of a single protein leading to the onset of intestinal disease. On the other hand, several recently proposed therapeutic approaches to treat human IBD are targeted at enhancing different elements of gut barrier function, further supporting a primary role of the epithelium in the pathogenesis of chronic intestinal inflammation and emphasizing the importance of maintaining a healthy and effective intestinal barrier. PMID:24062746

  5. The epithelial barrier is maintained by in vivo tight junction expansion during pathologic intestinal epithelial shedding

    PubMed Central

    Marchiando, Amanda M.; Shen, Le; Graham, W. Vallen; Edelblum, Karen L.; Duckworth, Carrie A.; Guan, Yanfang; Montrose, Marshall H.; Turner, Jerrold R.; Watson, Alastair J.M.

    2011-01-01

    BACKGROUND & AIMS Tumor necrosis factor (TNF) increases intestinal epithelial cell shedding and apoptosis, potentially challenging the barrier between the gastrointestinal lumen and internal tissues. We investigated the mechanism of tight junction remodeling and barrier maintenance, as well as the roles of cytoskeletal regulatory molecules during TNF-induced shedding. METHODS We studied wild-type and transgenic mice that express the fluorescent-tagged proteins enhanced green fluorescent protein–occludin or monomeric red fluorescent protein1–ZO-1. After injection of high doses of TNF (7.5µg, i.p.), laparotomies were performed and segments of small intestine were opened to visualize the mucosa by video confocal microscopy. Pharmacologic inhibitors and knockout mice were used to determine the roles of caspase activation, actomyosin, and microtubule remodeling and membrane trafficking in epithelial shedding. RESULTS Changes detected included redistribution of the tight junction proteins ZO-1 and occluding to lateral membranes of shedding cells. These proteins ultimately formed a funnel around the shedding cell that defined the site of barrier preservation. Claudins, E-cadherin, F-actin, myosin II, Rho-associated kinase (ROCK), and myosin light chain kinase (MLCK) were also recruited to lateral membranes. Caspase activity, myosin motor activity, and microtubules were required to initiate shedding, whereas completion of the process required microfilament remodeling and ROCK, MLCK, and dynamin II activities. CONCLUSIONS Maintenance of the epithelial barrier during TNF-induced cell shedding is a complex process that involves integration of microtubules, microfilaments, and membrane traffic to remove apoptotic cells. This process is accompanied by redistribution of apical junctional complex proteins to form intercellular barriers between lateral membranes and maintain mucosal function. PMID:21237166

  6. The feed contaminant deoxynivalenol affects the intestinal barrier permeability through inhibition of protein synthesis.

    PubMed

    Awad, Wageha A; Zentek, Jürgen

    2015-06-01

    Deoxynivalenol (DON) has critical health effects if the contaminated grains consumed by humans or animals. DON can have negative effects on the active transport of glucose and amino acids in the small intestine of chickens. As the underlying mechanisms are not fully elucidated, the present study was performed to delineate more precisely the effects of cycloheximide (protein synthesis inhibitor, CHX) and DON on the intestinal absorption of nutrients. This was to confirm whether DON effects on nutrient absorption are due to an inhibition of protein synthesis. Changes in ion transport and barrier function were assessed by short-circuit current (Isc) and transepithelial ion conductance (Gt) in Ussing chambers. Addition of D-glucose or L-glutamine to the luminal side of the isolated mucosa of the jejunum increased (P < 0.001) the Isc compared with basal conditions in the control tissues. However, the Isc was not increased by the glucose or glutamine addition after pre-incubation of tissues with DON or CHX. Furthermore, both DON and CHX reduced Gt, indicating that the intestinal barrier is compromised and consequently induced a greater impairment of the barrier function. The remarkable similarity between the activity of CHX and DON on nutrient uptake is consistent with their common ability to inhibit protein synthesis. It can be concluded that the decreases in transport activity by CHX was evident in this study using the chicken as experimental model. Similarly, DON has negative effects on the active transport of some nutrients, and these can be explained by its influence on protein synthesis. PMID:24888376

  7. Enteropathogenic E. coli: breaking the intestinal tight junction barrier

    PubMed Central

    Singh, Anand Prakash; Aijaz, Saima

    2016-01-01

    Enteropathogenic E. coli (EPEC) causes acute intestinal infections in infants in the developing world. Infection typically spreads through contaminated food and water and leads to severe, watery diarrhea. EPEC attaches to the intestinal epithelial cells and directly injects virulence factors which modulate multiple signaling pathways leading to host cell dysfunction. However, the molecular mechanisms that regulate the onset of diarrhea are poorly defined. A major target of EPEC is the host cell tight junction complex which acts as a barrier and regulates the passage of water and solutes through the paracellular space. In this review, we focus on the EPEC effectors that target the epithelial barrier, alter its functions and contribute to leakage through the tight junctions. PMID:27239268

  8. Vasoactive Intestinal Polypeptide Promotes Intestinal Barrier Homeostasis and Protection Against Colitis in Mice

    PubMed Central

    Wu, Xiujuan; Conlin, Victoria S.; Morampudi, Vijay; Ryz, Natasha R.; Nasser, Yasmin; Bhinder, Ganive; Bergstrom, Kirk S.; Yu, Hong B.; Waterhouse, Chris C. M.; Buchan, Allison M. J.; Popescu, Oana E.; Gibson, William T.; Waschek, James A.; Vallance, Bruce A.; Jacobson, Kevan

    2015-01-01

    Inflammatory bowel disease is a chronic gastrointestinal inflammatory disorder associated with changes in neuropeptide expression and function, including vasoactive intestinal peptide (VIP). VIP regulates intestinal vasomotor and secretomotor function and motility; however, VIP’s role in development and maintenance of colonic epithelial barrier homeostasis is unclear. Using VIP deficient (VIPKO) mice, we investigated VIP’s role in epithelial barrier homeostasis, and susceptibility to colitis. Colonic crypt morphology and epithelial barrier homeostasis were assessed in wildtype (WT) and VIPKO mice, at baseline. Colitic responses were evaluated following dinitrobenzene sulfonic acid (DNBS) or dextran-sodium sulfate (DSS) exposure. Mice were also treated with exogenous VIP. At baseline, VIPKO mice exhibited distorted colonic crypts, defects in epithelial cell proliferation and migration, increased apoptosis, and altered permeability. VIPKO mice also displayed reduced goblet cell numbers, and reduced expression of secreted goblet cell factors mucin 2 and trefoil factor 3. These changes were associated with reduced expression of caudal type homeobox 2 (Cdx2), a master regulator of intestinal function and homeostasis. DNBS and DSS-induced colitis were more severe in VIPKO than WT mice. VIP treatment rescued the phenotype, protecting VIPKO mice against DSS colitis, with results comparable to WT mice. In conclusion, VIP plays a crucial role in the development and maintenance of colonic epithelial barrier integrity under physiological conditions and promotes epithelial repair and homeostasis during colitis. PMID:25932952

  9. Dietary Lactobacillus rhamnosus GG Supplementation Improves the Mucosal Barrier Function in the Intestine of Weaned Piglets Challenged by Porcine Rotavirus

    PubMed Central

    Mao, Xiangbing; Gu, Changsong; Hu, Haiyan; Tang, Jun; Chen, Daiwen; Yu, Bing; He, Jun; Yu, Jie; Luo, Junqiu; Tian, Gang

    2016-01-01

    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 function

  10. Dietary Lactobacillus rhamnosus GG Supplementation Improves the Mucosal Barrier Function in the Intestine of Weaned Piglets Challenged by Porcine Rotavirus.

    PubMed

    Mao, Xiangbing; Gu, Changsong; Hu, Haiyan; Tang, Jun; Chen, Daiwen; Yu, Bing; He, Jun; Yu, Jie; Luo, Junqiu; Tian, Gang

    2016-01-01

    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 function

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

    PubMed

    Fiorentino, Maria; Levine, Myron M; Sztein, Marcelo B; Fasano, Alessio

    2014-01-01

    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 from the small to

  12. Enteral Nutrient Deprivation in Patients Leads to a Loss of Intestinal Epithelial Barrier Function

    PubMed Central

    Ralls, Matthew W.; Demehri, Farokh R.; Feng, Yongjia; Woods Ignatoski, Kathleen M.; Teitelbaum, Daniel H.

    2014-01-01

    Objective To investigate the effect of nutrient withdrawal on human intestinal epithelial barrier function (EBF). We hypothesized that unfed mucosa results in decreased EBF. This was tested in a series of surgical small intestinal resection specimens. Design Small bowel specifically excluding inflamed tissue, was obtained from pediatric patients (aged 2 days to 19 years) undergoing intestinal resection. EBF was assessed in Ussing chambers for transepithelial resistance (TER) and passage of FITC-Dextran (4kD). Tight junction and adherence junction proteins were imaged with immunofluorescence staining. Expression of Toll like receptors (TLR) and inflammatory cytokines were measured in loop ileostomy takedowns in a second group of patients. Results Because TER increased with patient age (p<0.01), results were stratified into infant versus teenage groups. Fed bowel had significantly greater TER versus unfed bowel (p<0.05) in both age populations. Loss of EBF was also observed by an increase in FITC-Dextran permeation in nutrient-deprived segments (p<0.05). Immunofluorescence staining showed marked declines in intensity of ZO-1, occludin, Ecadherin and Claudin-4 in unfed intestinal segments, as well as a loss of structural formation of tight junctions. Analysis of cytokine and TLR expression showed significant increases in TNF-α and TLR4 in unfed segments of bowel compared to fed segments from the same individual. Conclusion EBF declined in unfed segments of human small bowel. This work represents the first direct examination of EBF from small bowel derived from nutrient-deprived humans and may explain the increased infectious complications seen in patients not receiving enteral feeds. PMID:25704423

  13. Inactivation of corticosteroids in intestinal mucosa by 11 beta-hydroxysteroid: NADP oxidoreductase (EC 1. 1. 1. 146)

    SciTech Connect

    Burton, A.F.; Anderson, F.H.

    1983-10-01

    Activity of the enzyme 11 beta-hydroxysteroid:NADP oxidoreductase (EC 1.1.1.146) in human intestinal mucosa was determined by incubating scraped mucosa with /sup 3/H-cortisone and /sup 14/C-cortisol; these steroids were then extracted, separated chromatographically, and the radioactivity assayed to determine simultaneously both reductase and dehydrogenase activities. This was the only significant metabolic alteration which the substrate underwent. Only two cases had slight (5 and 13%) reductase activity. In 35 patients, 16 male and 19 female, including seven cases of Crohn's disease, three ulcerative colitis, five diverticulitis, two undergoing surgery for repair of injuries and 18 for carcinoma of colon or rectum, cortisol was converted to cortisone in 15 min with a wide range of values distributed uniformly up to 85% dehydrogenation, with a mean of 42%. When tissue homogenates were fortified with coenzymes, excess NADPH lowered dehydrogenase activity 81%; excess NADP increased dehydrogenase activity 2-fold in three cases. It is possible that a value is characteristic of an individual but perhaps more likely enzyme activity varies with metabolic events involving changes in the coenzyme levels in mucosa, and a random sampling might be expected to yield such a distribution of values. In any event, where activity is high most of the cortisol is inactivated within minutes. It is suggested that synthetic corticoids which escape such metabolic alteration might, except during pregnancy, prove superior in the treatment of conditions such as inflammatory bowel disease.

  14. Anemonin improves intestinal barrier restoration and influences TGF-β1 and EGFR signaling pathways in LPS-challenged piglets.

    PubMed

    Xiao, Kan; Cao, Shu Ting; Jiao, Le Fei; Lin, Fang Hui; Wang, Li; Hu, Cai Hong

    2016-07-01

    The present study was aimed at investigating whether dietary anemonin could alleviate LPS-induced intestinal injury and improve intestinal barrier restoration in a piglet model. Eighteen 35-d-old pigs were randomly assigned to three treatment groups (control, LPS and LPS+anemonin). The control and LPS groups were fed a basal diet, and the LPS + anemonin group received the basal diet + 100 mg anemonin/kg diet. After 21 d of feeding, the LPS- and anemonin-treated piglets received i.p. administration of LPS; the control group received saline. At 4 h post-injection, jejunum samples were collected. The results showed that supplemental anemonin increased villus height and transepithelial electrical resistance, and decreased crypt depth and paracellular flux of dextran (4 kDa) compared with the LPS group. Moreover, anemonin increased tight junction claudin-1, occludin and ZO-1 expression in the jejunal mucosa, compared with LPS group. Anemonin also decreased TNF-α, IL-6, IL-8 and IL-1β mRNA expression. Supplementation with anemonin also increased TGF-β1 mRNA and protein expression, Smad4 and Smad7 mRNA expressions, and epidermal growth factor and epidermal growth factor receptor (EGFR) mRNA expression in the jejunal mucosa. These findings suggest that dietary anemonin attenuates LPS-induced intestinal injury by improving mucosa restoration, alleviating intestinal inflammation and influencing TGF-β1 canonical Smads and EGFR signaling pathways. PMID:27189428

  15. Intestinal barrier function in neonatal foals: options for improvement.

    PubMed

    Vendrig, Johannes C; Fink-Gremmels, Johanna

    2012-07-01

    Gastrointestinal defence in the new-born is limited in comparison to adults, due to an immature epithelial barrier function and deficits in both innate and adaptive immune responses. Consequently, neonates (including foals) are at increased risk of disturbance to mucosal homeostasis during initial intestinal colonisation that may lead to excessive inflammation and bacterial translocation into the bloodstream, resulting in septicaemia. Bacterial recognition by Pattern Recognition Receptors (PRRs) and their downstream regulation of cytokine release have been shown to be pivotal for gastrointestinal mucosal homeostasis and the development of a functional intestinal barrier. Evidence suggests that selective PRR agonists limit the inflammatory responses and improve epithelial barrier function. Milk, and in particular colostrum, contain a broad array of oligosaccharides which seem to act as PRR agonists. This class of compounds forms a source for new dietary formulas that may orchestrate gut colonisation by the commensal flora in the early phase of life and so reduce the risks of inflammation and pathogen invasion. PMID:22377327

  16. A new role for reticulon-4B/NOGO-B in the intestinal epithelial barrier function and inflammatory bowel disease.

    PubMed

    Rodríguez-Feo, Juan Antonio; Puerto, Marta; Fernández-Mena, Carolina; Verdejo, Cristina; Lara, José Manuel; Díaz-Sánchez, María; Álvarez, Emilio; Vaquero, Javier; Marín-Jiménez, Ignacio; Bañares, Rafael; Menchén, Luis

    2015-06-15

    Inflammatory bowel disease (IBD) is characterized by an impaired intestinal barrier function. We aimed to investigate the role of reticulon-4B (RTN-4B/NOGO-B), a structural protein of the endoplasmic reticulum, in intestinal barrier function and IBD. We used immunohistochemistry, confocal microscopy, real-time PCR, and Western blotting to study tissue distribution and expression levels of RTN-4B/NOGO-B in control and IBD samples from mouse and humans. We also targeted RTN-4B/NOGO-B using siRNAs in cultured human intestinal epithelial cell (IECs). Epithelial barrier permeability was assessed by transepithelial electrical resistance (TEER) measurement. RTN-4B/NOGO-B is expressed in the intestine mainly by IECs. Confocal microscopy revealed a colocalization of RTN-4B, E-cadherin, and polymerized actin fibers in tissue and cultured IECs. RTN-4B mRNA and protein expression were lower in the colon of IL-10(-/-) compared with wild-type mice. Colocalization of RTN-4B/E-cadherin/actin was reduced in the colon of IL-10(-/-) mice. Analysis of endoscopic biopsies from IBD patients showed a significant reduction of RTN-4B/NOGO-B expression in inflamed mucosa compared with control. Treatment of IECs with H2O2 reduced TEER values and triggered phosphorylation of RTN-4B in serine 107 residues as well as downregulation of RTN-4B expression. Acute RTN-4B/NOGO-B knockdown by siRNAs resulted in a decreased TEER values and reduction of E-cadherin and α-catenin expression and in the amount of F-actin-rich filaments in IECs. Epithelial RTN-4B/NOGO-B was downregulated in human and experimental IBD. RTN-4B participates in the intestinal epithelial barrier function, most likely via its involvement in E-cadherin, α-catenin expression, and actin cytoskeleton organization at sites of cell-to-cell contacts. PMID:25907690

  17. Electrophysiology of flounder intestinal mucosa. I. Conductance properties of the cellular and paracellular pathways.

    PubMed

    Halm, D R; Krasny, E J; Frizzell, R A

    1985-06-01

    We evaluated the conductances for ion flow across the cellular and paracellular pathways of flounder intestine using microelectrode techniques and ion-replacement studies. Apical membrane conductance properties are dominated by the presence of Ba-sensitive K channels. An elevated mucosal solution K concentration, [K]m, depolarized the apical membrane potential (psi a) and, at [K]m less than 40 mM, the K dependence of psi a was abolished by 1-2 mM mucosal Ba. The basolateral membrane displayed Cl conductance behavior, as evidenced by depolarization of the basolateral membrane potential (psi b) with reduced serosal Cl concentrations, [Cl]s. psi b was unaffected by changes in [K]s or [Na]s. From the effect of mucosal Ba on transepithelial K selectivity, we estimated that paracellular conductance (Gp) normally accounts for 96% of transepithelial conductance (Gt). The high Gp attenuates the contribution of the cellular pathway to psi t while permitting the apical K and basolateral Cl conductances to influence the electrical potential differences across both membranes. Thus, psi a and psi b (approximately 60 mV, inside negative) lie between the equilibrium potentials for K (76 mV) and Cl (40 mV), thereby establishing driving forces for K secretion across the apical membrane and Cl absorption across the basolateral membrane. Equivalent circuit analysis suggests that apical conductance (Ga approximately equal to 5 mS/cm2) is sufficient to account for the observed rate of K secretion, but that basolateral conductance (Gb approximately equal to 1.5 mS/cm2) would account for only 50% of net Cl absorption. This, together with our failure to detect a basolateral K conductance, suggests that Cl absorption across this barrier involves KCl co-transport. PMID:2410537

  18. The role of intestinal epithelial barrier function in the development of NEC

    PubMed Central

    Halpern, Melissa D; Denning, Patricia W

    2015-01-01

    The intestinal epithelial barrier plays an important role in maintaining host health. Breakdown of intestinal barrier function is known to play a role in many diseases such as infectious enteritis, idiopathic inflammatory bowel disease, and neonatal inflammatory bowel diseases. Recently, increasing research has demonstrated the importance of understanding how intestinal epithelial barrier function develops in the premature neonate in order to develop strategies to promote its maturation. Optimizing intestinal barrier function is thought to be key to preventing neonatal inflammatory bowel diseases such as necrotizing enterocolitis. In this review, we will first summarize the key components of the intestinal epithelial barrier, what is known about its development, and how this may explain NEC pathogenesis. Finally, we will review what therapeutic strategies may be used to promote optimal development of neonatal intestinal barrier function in order to reduce the incidence and severity of NEC. PMID:25927016

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

    PubMed Central

    Williams, Benjamin B.; Tebbutt, Niall C.; Buchert, Michael; Putoczki, Tracy L.; Doggett, Karen; Bao, Shisan; Johnstone, Cameron N.; Masson, Frederick; Hollande, Frederic; Burgess, Antony W.; Scott, Andrew M.; Ernst, Matthias; Heath, Joan K.

    2015-01-01

    ABSTRACT 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 linking

  20. Food Derived Bioactive Peptides and Intestinal Barrier Function

    PubMed Central

    Martínez-Augustin, Olga; Rivero-Gutiérrez, Belén; Mascaraque, Cristina; Sánchez de Medina, Fermín

    2014-01-01

    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. PMID:25501338

  1. No holes barred: Invasion of the intestinal mucosa by Mycobacterium avium subspecies paratuberculosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The infection biology of Mycobacterium avium subspecies paratuberculosis (MAP) has recently crystalized with added details surrounding intestinal invasion. The involvement of pathogen-derived effector proteins such as the major membrane protein, oxidoreductase and fibronectin attachment proteins hav...

  2. Laminin α5 influences the architecture of the mouse small intestinal mucosa

    PubMed Central

    Mahoney, Zhen X.; Stappenbeck, Thaddeus S.; Miner, Jeffrey H.

    2008-01-01

    Summary The mammalian intestine displays two distinct patterns of mucosal organization. The small intestine contains mucosal epithelial invaginations called crypts of Lieberkühn that are continuous with evaginations into the lumen called villi. The colon also contains crypts, but its epithelial surface is lined by flat surface cuffs. The epithelial cells of both organs communicate with the underlying mesenchyme through a basement membrane that is composed of a variety of extracellular matrix proteins, including members of the laminin family. The basement membranes of the small intestine and colon contain distinct laminin subtypes; notably, the villus basement membrane is rich in laminin α5. Here we show that diminution of laminin α5 in a mouse model led to a compensatory deposition of colonic laminins that resulted in a transformation from a small intestinal to a colonic mucosal architecture. The alteration in mucosal architecture was associated with reduced levels of nuclear p27Kip1, a cell cycle regulator, and altered intestinal epithelial cell proliferation, migration, and differentiation. Our results suggest that laminin α5 plays a crucial role in establishing and maintaining the specific mucosal pattern of the mouse small intestine. PMID:18628307

  3. Paneth cells, defensins, and the commensal microbiota: a hypothesis on intimate interplay at the intestinal mucosa.

    PubMed

    Salzman, Nita H; Underwood, Mark A; Bevins, Charles L

    2007-04-01

    Mucosal surfaces are colonized by a diverse and dynamic microbiota. Much investigation has focused on bacterial colonization of the intestine, home to the vast majority of this microbiota. Experimental evidence has highlighted that these colonizing microbes are essential to host development and homeostasis, but less is known about host factors that may regulate the composition of this ecosystem. While evidence shows that IgA has a role in shaping this microbiota, it is likely that effector molecules of the innate immune system are also involved. One hypothesis is that gene-encoded antimicrobial peptides, key elements of innate immunity throughout nature, have an essential role in this regulation. These effector molecules characteristically have activity against a broad spectrum of bacteria and other microbes. At mucosal surfaces, antimicrobial peptides may affect the numbers and/or composition of the colonizing microbiota. In humans and other mammals, defensins are a predominant class of antimicrobial peptides. In the small intestine, Paneth cells (specialized secretory epithelial cells) produce high quantities of defensins and several other antibiotic peptides and proteins. Data from murine models indicate that Paneth cell defensins play a pivotal role in defense from food and water-borne pathogens in the intestinal lumen. Recent studies in humans provide evidence that reduced Paneth cell defensin expression may be a key pathogenic factor in ileal Crohn's disease, a subgroup of inflammatory bowel disease (IBD), and changes in the colonizing microbiota may mediate this pathogenic mechanism. It is also possible that low levels of Paneth cell defensins, characteristic of normal intestinal development, may predispose premature neonates to necrotizing enterocolitis (NEC) through similar close links with the composition of the intestinal microbiota. Future studies to further define mechanisms by which defensins and other host factors regulate the composition of the

  4. Stimulation of butyrate production in the large intestine of weaning piglets by dietary fructooligosaccharides and its influence on the histological variables of the large intestinal mucosa.

    PubMed

    Tsukahara, Takamitsu; Iwasaki, Yoshie; Nakayama, Keizo; Ushida, Kazunari

    2003-12-01

    Fructooligosaccharides (FOS) reach the large intestine and are fermented into short-chain fatty acids (SCFA), lactate, and carbon dioxide. As the major energy source for the epithelial cells of the large intestine, n-butyrate stimulates the proliferation of cells as well as mineral and water absorption from the lumen. We examined the effect of dietary FOS supplementation on luminal SCFA production and its influence on the morphometrical variables of mucosa of the large intestine in commercially available pigs. Six weaning piglets were used. After 7 d of adaptation, three pigs were given a test diet containing FOS (10%) ad libitum for 10 d. The other three remained on the basal diet and were used as controls. At the end of the experiment, their large intestines were removed, and the cecum, gyri centripetales, gyri centrifugales, and rectum were separated. The contents of each portion were collected and measured for SCFA concentration, pH, and moisture. A micrometer was used to measure the crypt depth. The numbers of epithelial and mitotic cells in the crypt columns were also counted. The concentration of SCFA was significantly higher in piglets fed FOS than in the controls. The concentration of n-butyrate was markedly stimulated by FOS. The number of epithelial. mitotic, and mucin-containing cells was higher in piglets fed FOS than in the controls. Accordingly, the crypt depth was larger in the FOS-fed piglets. The luminal n-butyrate concentration showed a significantly positive correlation with the crypt depth and the number of epithelial, mitotic, and mucin-containing cells. PMID:14974732

  5. Effect of hypokinesia on invertase activity of the mucosa of the small intestine

    NASA Technical Reports Server (NTRS)

    Abdusattarov, A.

    1980-01-01

    The effect of prolonged hypokinesia on the enzyme activity of the middle portion of the small intestine was investigated. Eighty-four mongrel white male rats weighing 170-180 g were divided into two equal groups. The experimental group were maintained in single cages under 30 days of hypokinetic conditions and the control animals were maintained under ordinary laboratory conditions. It is concluded that rates of invertase formation and its inclusion in the composition if the cellular membrane, if judged by the enzyme activity studied in sections of the small intestine, are subject to phase changes in the course of prolonged hypokinesia.

  6. Elevated IL-23R Expression and Foxp3+Rorgt+ Cells in Intestinal Mucosa During Acute and Chronic Colitis.

    PubMed

    Yang, Jiayin; Xu, Lili

    2016-01-01

    BACKGROUND IL-23/IL-23R signaling plays a pivotal role during the course of inflammatory bowel diseases (IBD). However, the underlying mechanisms are poorly characterized. Foxp3+ regulatory T cells are critical in the maintenance of gut immune homeostasis and therefore are important in preventing the development of IBD. This study was performed to clarify the association between IL-23/IL-23R signaling and Foxp3+ regulatory T cells in colitis. MATERIAL AND METHODS Acute and chronic mouse colitis models were established by administering mice DSS in drinking water. IL-23R, IL-23, IL-I7, and IFN-γ expression level, as well as regulatory T cell, Th17-, and Th1-related transcription factors Foxp3, RORgt, and T-bet were assayed by real-time PCR. The frequency of Foxp3+ RORγt+ cells in a Foxp3+ cell population in colon mucosa during acute and chronic colitis was evaluated through flow cytometry. The signaling pathway mediated by IL-23R in the colon mucosa from acute colitis mice and chronic colitis mice was monitored by Western blot analysis. RESULTS We detected elevated IL-23R, IL-23, and IFN-γ expression in colon mucosa during acute and chronic colitis and found increased IL-17 in acute colitis mice. Transcription factors Foxp3 and T-bet were elevated in colon mucosa during acute and chronic colitis. Phosphorylation of Stat3 was greatly enhanced, indicating the activation of IL-23R function in colitis mice. The percentage of Foxp3+ T cells in acute and chronic colitis mice was comparable to control mice, but there was a 2-fold increase of Foxp3+ RORγt+ cells among the Foxp3+ cell population in acute and chronic colitis mice compared to control mice. CONCLUSIONS These findings indicate that the induction of Foxp3+ RORgt+ T cells could be enhanced during inflammation in the intestine where IL-23R expression is greatly induced. Our study highlights the importance of IL-23R expression level and the instability of Foxp3+ regulatory T cells in the development of

  7. Improved Gene Delivery to Intestinal Mucosa by Adenoviral Vectors Bearing Subgroup B and D Fibers

    PubMed Central

    Lecollinet, S.; Gavard, F.; Havenga, M. J. E.; Spiller, O. B.; Lemckert, A.; Goudsmit, J.; Eloit, M.; Richardson, J.

    2006-01-01

    A major obstacle to successful oral vaccination is the lack of antigen delivery systems that are both safe and highly efficient. Conventional replication-incompetent adenoviral vectors, derived from human adenoviruses of subgroup C, are poorly efficient in delivering genetic material to differentiated intestinal epithelia. To date, 51 human adenovirus serotypes have been identified and shown to recognize different cellular receptors with different tissue distributions. This natural diversity was exploited in the present study to identify suitable adenoviral vectors for efficient gene delivery to the human intestinal epithelium. In particular, we compared the capacities of a library of adenovirus type 5-based vectors pseudotyped with fibers of several human serotypes for transduction, binding, and translocation toward the basolateral pole in human and murine tissue culture models of differentiated intestinal epithelia. In addition, antibody-based inhibition was used to gain insight into the molecular interactions needed for efficient attachment. We found that vectors differing merely in their fiber proteins displayed vastly different capacities for gene transfer to differentiated human intestinal epithelium. Notably, vectors bearing fibers derived from subgroup B and subgroup D serotypes transduced the apical pole of human epithelium with considerably greater efficiency than a subgroup C vector. Such efficiency was correlated with the capacity to use CD46 or sialic acid-containing glycoconjugates as opposed to CAR as attachment receptors. These results suggest that substantial gains could be made in gene transfer to digestive epithelium by exploiting the tropism of existing serotypes of human adenoviruses. PMID:16501084

  8. In vitro permeation of mesembrine alkaloids from Sceletium tortuosum across porcine buccal, sublingual, and intestinal mucosa.

    PubMed

    Shikanga, Emmanuel A; Hamman, Josias H; Chen, Weiyang; Combrinck, Sandra; Gericke, Nigel; Viljoen, Alvaro M

    2012-02-01

    Sceletium tortuosum is an indigenous South African plant that has traditionally been used for its mood-enhancing properties. Recently, products containing S. tortuosum have become increasingly popular and are commonly administered as tablets, capsules, teas, decoctions, or tinctures, while traditionally the dried plant material has been masticated. This study evaluated the in vitro permeability of the four major S. tortuosum alkaloids (i.e., mesembrine, mesembrenone, mesembrenol, and mesembranol) across porcine intestinal, sublingual, and buccal tissues in their pure form and in the form of three different crude plant extracts, namely water, methanol, and an acid-base alkaloid-enriched extract. The permeability of mesembrine across intestinal tissue was higher than that of the highly permeable reference compound caffeine (which served as a positive control for membrane permeability) both in its pure form, as well as in the form of crude extracts. The intestinal permeability of mesembranol was similar to that of caffeine, while those of mesembrenol and mesembrenone were lower than that of caffeine, but much higher than that of the poorly permeable reference compound atenolol (which served as a negative control for membrane permeability). In general, the permeabilities of the alkaloids were lower across the sublingual and the buccal tissues than across the intestinal tissue. However, comparing the transport of the alkaloids with that of the reference compounds, there are indications that transport across the membranes of the oral cavity may contribute considerably to the overall bioavailability of the alkaloids, depending on pre-systemic metabolism, when the plant material is chewed and kept in the mouth for prolonged periods. The results from this study confirmed the ability of the alkaloids of S. tortuosum in purified or crude extract form to permeate across intestinal, buccal, and sublingual mucosal tissues. PMID:22105579

  9. Distinct adhesion of probiotic strain Lactobacillus casei ATCC 393 to rat intestinal mucosa.

    PubMed

    Saxami, Georgia; Ypsilantis, Petros; Sidira, Marianthi; Simopoulos, Constantinos; Kourkoutas, Yiannis; Galanis, Alex

    2012-08-01

    Adhesion to the intestine represents a critical parameter for probiotic action. In this study, the adhesion ability of Lactobacillus casei ATCC 393 to the gastrointestinal tract of Wistar rats was examined after single and daily administration of fermented milk containing either free or immobilized cells on apple pieces. The adhesion of the probiotic cells at the large intestine (cecum and colon) was recorded at levels ≥6 logCFU/g (suggested minimum levels for conferring a probiotic effect) following daily administration for 7 days by combining microbiological and strain-specific multiplex PCR analysis. Single dose administration resulted in slightly reduced counts (5 logCFU/g), while they were lower at the small intestine (duodenum, jejunum, ileum) (≤3 logCFU/g), indicating that adhesion was a targeted process. Of note, the levels of L. casei ATCC 393 were enhanced in the cecal and colon fluids both at single and daily administration of immobilized cells (6 and 7 logCFU/g, respectively). The adhesion of the GI tract was transient and thus daily consumption of probiotic products containing the specific strain is suggested as an important prerequisite for retaining its levels at an effective concentration. PMID:22554894

  10. Evaluation of the mRNA and Protein Expressions of Nutritional Biomarkers in the Gastrointestinal Mucosa of Patients with Small Intestinal Disorders.

    PubMed

    Nakamura, Masanao; Hirooka, Yoshiki; Watanabe, Osamu; Yamamura, Takeshi; Funasaka, Kohei; Ohno, Eizaburo; Miyahara, Ryoji; Kawashima, Hiroki; Shimoyama, Yoshie; Goto, Hidemi

    2016-01-01

    Objective The objectives of this study were to investigate the mRNA and protein expression of biomarkers related to absorption in the small intestinal mucosa of humans and determine the relationships between small intestinal diseases and nutrition. Methods The study subjects consisted of patients scheduled to undergo double-balloon endoscopy (DBE) or total colonoscopy for suspected gastrointestinal disorder in a clinical practice. Biopsies were taken from apparently normal mucosa in the visible areas of 6 parts of the intestines from the duodenum to the colon. The mRNA expression of specific biomarkers (SGLT1, SGLT5, GIP, GLP, LAT1, LAT2, and NPC1L1) in the mucosa was compared among three patient groups: Inflammation, Tumor, and Control. Results Sixty-six patients participated in this study. Both routes of DBE were performed in 20 patients, in whom biopsy samples were obtained from the mucosa for all sections. There were no remarkable differences in the mRNA expression levels among the 3 groups. However, SGLT1, GIP, GLP, and NPC1L1 exhibited specific distribution patterns. The expression levels of GIP and NPC1L1 were highest in the upper jejunum, but were extremely low in the terminal ileum and colon. A comparison of the mRNA expression profile in each intestinal section revealed that the SGLT1 mRNA expression in the Tumor group and the GIP mRNA expression in the Inflammation group were significantly higher than the corresponding levels in the Control group in the upper jejunum. Conclusion The gastrointestinal mucosa of patients with small bowel diseases can maintain proper nutrient absorption, except in the upper jejunum. PMID:27522989

  11. Secreted adhesion molecules of Strongyloides venezuelensis are produced by oesophageal glands and are components of the wall of tunnels constructed by adult worms in the host intestinal mucosa.

    PubMed

    Maruyama, H; El-Malky, M; Kumagai, T; Ohta, N

    2003-02-01

    The parasitic female of Strongyloides venezuelensis keeps invading the epithelial layer of the host intestinal mucosa. Upon invasion, it adheres to the surface of the intestinal epithelial cells with adhesion molecules secreted from the mouth. It has been demonstrated that S. venezuelensis are expelled from the intestine because mucosal mast cells inhibit the attachment of adult worms to the mucosal surface. In the present study, we generated specific antibodies against secreted adhesion molecules to investigate their function in vivo, because these molecules have been demonstrated only in vitro in spite of the importance in the infection processes. A mouse monoclonal antibody specific to S. venezuelensis adhesion molecules inhibited the attachment of adult worms to plastic dishes and the binding of adhesion molecules to rat intestinal epithelial cells. Immunohistochemical study revealed that adhesion molecules were produced by oesophageal glands and were continuously secreted in vivo to line the wall of the tunnels formed by adult worms in the intestinal mucosa. Our findings indicate that adhesion molecules play essential roles in the infection processes of S. venezuelensis in the host intestine. PMID:12636354

  12. Mechanisms and anticarcinogenic effects of diet-related apoptosis in the intestinal mucosa.

    PubMed

    Johnson, I T

    2001-12-01

    There is now ample epidemiological evidence to show that the wide international variations in the incidence of both adenomatous polyps and colo-rectal cancer are linked to diet, but the mechanisms through which particular dietary constituents influence the onset of neoplasia are poorly understood. The crypt epithelial cells of the human gastrointestinal mucosa are amongst the most rapidly proliferating tissues in the body, and those of the colorectum are particularly vulnerable to neoplasia. Within the crypt, continuous division of basally localized stem cells gives rise to daughter cells that may divide once or twice again, before differentiating and migrating to the mucosal surface. The majority of nascent crypt epithelial cells differentiate, become senescent and are shed into the gut lumen, but a small proportion die by apoptosis soon after cell division. Various lines of evidence suggest that these pathways of programmed cell death provide a protective mechanism against induction of neoplasia by removing genetically damaged stem cells before they can divide further and give rise to precancerous lesions. There is evidence that the short-chain fatty acid butyrate and several different classes of food constituents, including some polyunsaturated fatty acids, flavonoids and glucosinolate breakdown products, can regulate the processes of cell proliferation and death in vitro, and in colorectal crypts in vivo. All three classes of food components suppress the emergence of aberrant crypt foci in animal models of carcinogenesis. The cellular mechanisms underlying these phenomena, and their possible significance for human health, are discussed. PMID:19087425

  13. Regulation of intestinal epithelial cells transcriptome by enteric glial cells: impact on intestinal epithelial barrier functions

    PubMed Central

    2009-01-01

    Background Emerging evidences suggest that enteric glial cells (EGC), a major constituent of the enteric nervous system (ENS), are key regulators of intestinal epithelial barrier (IEB) functions. Indeed EGC inhibit intestinal epithelial cells (IEC) proliferation and increase IEB paracellular permeability. However, the role of EGC on other important barrier functions and the signalling pathways involved in their effects are currently unknown. To achieve this goal, we aimed at identifying the impact of EGC upon IEC transcriptome by performing microarray studies. Results EGC induced significant changes in gene expression profiling of proliferating IEC after 24 hours of co-culture. 116 genes were identified as differentially expressed (70 up-regulated and 46 down-regulated) in IEC cultured with EGC compared to IEC cultured alone. By performing functional analysis of the 116 identified genes using Ingenuity Pathway Analysis, we showed that EGC induced a significant regulation of genes favoring both cell-to-cell and cell-to-matrix adhesion as well as cell differentiation. Consistently, functional studies showed that EGC induced a significant increase in cell adhesion. EGC also regulated genes involved in cell motility towards an enhancement of cell motility. In addition, EGC profoundly modulated expression of genes involved in cell proliferation and cell survival, although no clear functional trend could be identified. Finally, important genes involved in lipid and protein metabolism of epithelial cells were shown to be differentially regulated by EGC. Conclusion This study reinforces the emerging concept that EGC have major protective effects upon the IEB. EGC have a profound impact upon IEC transcriptome and induce a shift in IEC phenotype towards increased cell adhesion and cell differentiation. This concept needs to be further validated under both physiological and pathophysiological conditions. PMID:19883504

  14. Development of a Multicellular Three-dimensional Organotypic Model of the Human Intestinal Mucosa Grown Under Microgravity.

    PubMed

    Salerno-Goncalves, Rosangela; Fasano, Alessio; Sztein, Marcelo B

    2016-01-01

    Because cells growing in a three-dimensional (3-D) environment have the potential to bridge many gaps of cell cultivation in 2-D environments (e.g., flasks or dishes). In fact, it is widely recognized that cells grown in flasks or dishes tend to de-differentiate and lose specialized features of the tissues from which they were derived. Currently, there are mainly two types of 3-D culture systems where the cells are seeded into scaffolds mimicking the native extracellular matrix (ECM): (a) static models and (b) models using bioreactors. The first breakthrough was the static 3-D models. 3-D models using bioreactors such as the rotating-wall-vessel (RWV) bioreactors are a more recent development. The original concept of the RWV bioreactors was developed at NASA's Johnson Space Center in the early 1990s and is believed to overcome the limitations of static models such as the development of hypoxic, necrotic cores. The RWV bioreactors might circumvent this problem by providing fluid dynamics that allow the efficient diffusion of nutrients and oxygen. These bioreactors consist of a rotator base that serves to support and rotate two different formats of culture vessels that differ by their aeration source type: (1) Slow Turning Lateral Vessels (STLVs) with a co-axial oxygenator in the center, or (2) High Aspect Ratio Vessels (HARVs) with oxygenation via a flat, silicone rubber gas transfer membrane. These vessels allow efficient gas transfer while avoiding bubble formation and consequent turbulence. These conditions result in laminar flow and minimal shear force that models reduced gravity (microgravity) inside the culture vessel. Here we describe the development of a multicellular 3-D organotypic model of the human intestinal mucosa composed of an intestinal epithelial cell line and primary human lymphocytes, endothelial cells and fibroblasts cultured under microgravity provided by the RWV bioreactor. PMID:27500889

  15. Ultrastructural development of the small intestinal mucosa in the embryo and turkey poult: A light and electron microscopy study.

    PubMed

    Bohórquez, D V; Bohórquez, N E; Ferket, P R

    2011-04-01

    The potential for growth and feed efficiency in turkey poults directly correlates with the early development of the intestinal epithelium. Although the metabolic aspects of enteric maturation have been studied, little is known about the ultrastructural development of the enteric epithelium in the turkey embryo and poult. Hence, the objective of this study was to document the morphological and ultrastructural development of the jejunum mucosa in turkeys, from 15 d of incubation (embryonic day; E) to 12 d posthatch. Intestinal samples from 4 embryos or poults were collected and analyzed by light and electron microscopy (transmission and scanning). In addition, amniotic fluid volume was determined in 6 eggs from E15 to E25. Longitudinal previllus ridges at E15 gradually formed zigzag patterns that led to the formation of 2 parallel lines of mature villi by E25. The volume of amniotic fluid was rapidly depleted as the embryo swallowed it between E19 and E25. During this period, a major increase occurs in villus height, the apical end of epithelial cells is gradually tightened by the junctional complex, and mature goblet cells are visible at the apical end of villi. Villus height steadily increases until reaching a plateau at 8 d. Villi morphology shifts gradually from finger-like projections before hatch to leaf-like projections by 12 d. At this age, the enteric epithelium is in intimate association with microbes such as segmented filamentous bacteria. The profound morphological adaptations of the turkey gut epithelium in response to amniotic fluid swallowing before hatch, and dietary factors and bacteria after hatch, demonstrate the plasticity of the enteric epithelium at this time. Hence, the supplementation of enteric modulators before hatch (in ovo feeding) and after hatch has the potential to shape gut maturation and enhance the growth performance of turkey poults. PMID:21406371

  16. Femtosecond laser ablation of porcine intestinal mucosa: potential autologous transplant for segmental cystectomy

    NASA Astrophysics Data System (ADS)

    Higbee, Russell G.; Irwin, Bryan S.; Nguyen, Michael N.; Zhang, Yuanyuan; Warren, William L.

    2005-04-01

    Nearly 80% of patients with newly diagnosed bladder cancer present with superficial bladder tumors (confined to the bladder lining such as transitional cell carcinoma [90%], squamous cell carcinoma [6-8%], and adenocarcinoma[2%]) in stages Ta, Tis, or T1. Segmental cystectomy is one surgical treatment for patients who have a low-grade invasive tumor. Transposition of small intestine is a viable surgical treatment option. Success of the transplantation is also dependent upon removal of the entire SI mucosal layer. A Clark Spitfire Ti:Sapphire laser operating at 775 nm and 1 kHz repetition rate, was used to investigate the damage induced to fresh cadaveric porcine small intestinal mucosal epithelium. The laser was held constant at a focal spot diameter of 100 μm using a 200 mm focal point lens, with a power output maximum of 257 mW. A high resolution motorized X-Y-Z stage translated the SI tissue through the beam at 500 μm/sec with a line spacing of 50 μm. This produced a 50% overlap in the laser etching for each pass over a 1 cm x 1.5 cm grid. To determine if the mucosal lining of the SI was adequately removed, the targeted area was covered with 1% fluorescein solution for 30 seconds and then rinsed with phosphate buffered saline. Fluorescein staining was examined under UV illumination, to determine the initial degree of mucosal removal. Tissues were fixed and processed for light and scanning electron microscopy by standard protocols. Brightfield light microscopy of hematoxylin and eosin stained 4 μm thick cross sections, scanning electron microscopy were examined to determine the degree of mucosal tissue removal. Clear delineation of the submucosal layer by fluorescein staining was also observed. The Ti:Sapphire laser demonstrated precise, efficient removal of the mucosal epithelium with minimal submucosal damage.

  17. Oxidative Stress Markers in Intestinal Mucosa of Tunisian Inflammatory Bowel Disease Patients

    PubMed Central

    Bouzid, Dorra; Gargouri, Bochra; Mansour, Riadh Ben; Amouri, Ali; Tahri, Nabil; Lassoued, Saloua; Masmoudi, Hatem

    2013-01-01

    Background/Aims: Inflammatory bowel diseases (IBDs), Crohn's disease (CrD) and ulcerative colitis (UC), are chronic gastrointestinal inflammatory disorders. The precise etiology of IBD remains unclear, and it is thought that interactions among various factors, including, genetic factors, the host immune system and environmental factors, cause disruption of intestinal homeostasis, leading to dysregulated inflammatory responses of the gut. As inflammation is intimately related to formation of reactive intermediates, including, reactive oxygen species, oxidative stress has been proposed as a mechanism underlying the pathophysiology of IBD. The purpose of this study is to examine the lipid peroxidation, protein oxidation and anti-oxidative profile in Tunisian IBD. Materials and Methods: Malondialdehyde (MDA), conjugated dienes (CD), protein thiol levels, as well as the catalase (CAT) activity were evaluated in intestinal biopsies of 17 patients affected by IBD (12 CrD and 5 UC) and 12 healthy control individuals. Results: Oxidative stress was confirmed in these two types of disease biopsies as compared to controls. MDA and CD levels were significantly increased in both UC and CrD patients’ biopsies as compared to controls’ biopsies (P < 0.001). CAT activity was similar in UC and CrD biopsies’ and was not significantly increased in IBD patients’ biopsies compared with controls’ biopsies (P > 0.05). Anon-significant decrease in thiol (SH) level was observed in both UC and CrD patients’ biopsies compared with controls’ biopsies (P > 0.05). Conclusion: Increased levels of MDA and CD in IBD patients’ biopsies underline the implication of oxidative stress in the physiopathology of IBD. PMID:23680711

  18. Propionate Ameliorates Dextran Sodium Sulfate-Induced Colitis by Improving Intestinal Barrier Function and Reducing Inflammation and Oxidative Stress

    PubMed Central

    Tong, Ling-chang; Wang, Yue; Wang, Zhi-bin; Liu, Wei-ye; Sun, Sheng; Li, Ling; Su, Ding-feng; Zhang, Li-chao

    2016-01-01

    Propionate is a short chain fatty acid that is abundant as butyrate in the gut and blood. However, propionate has not been studied as extensively as butyrate in the treatment of colitis. The present study was to investigate the effects of sodium propionate on intestinal barrier function, inflammation and oxidative stress in dextran sulfate sodium (DSS)-induced colitis mice. Animals in DSS group received drinking water from 1 to 6 days and DSS [3% (w/v) dissolved in double distilled water] instead of drinking water from 7 to 14 days. Animals in DSS+propionate (DSS+Prop) group were given 1% sodium propionate for 14 consecutive days and supplemented with 3% DSS solution on day 7–14. Intestinal barrier function, proinflammatory factors, oxidative stress, and signal transducer and activator of transcription 3 (STAT3) signaling pathway in the colon were determined. It was found that sodium propionate ameliorated body weight loss, colon-length shortening and colonic damage in colitis mice. Sodium propionate significantly inhibited the increase of FITC-dextran in serum and the decrease of zonula occludens-1 (ZO-1), occludin, and E-cadherin expression in the colonic tissue. It also inhibited the expression of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) mRNA and phosphorylation of STAT3 in colitis mice markedly, reduced the myeloperoxidase (MPO) level, and increased the superoxide dismutase and catalase level in colon and serum compared with DSS group. Sodium propionate inhibited macrophages with CD68 marker infiltration into the colonic mucosa of colitis mice. These results suggest that oral administration of sodium propionate could ameliorate DSS-induced colitis mainly by improving intestinal barrier function and reducing inflammation and oxidative stress via the STAT3 signaling pathway. PMID:27574508

  19. Propionate Ameliorates Dextran Sodium Sulfate-Induced Colitis by Improving Intestinal Barrier Function and Reducing Inflammation and Oxidative Stress.

    PubMed

    Tong, Ling-Chang; Wang, Yue; Wang, Zhi-Bin; Liu, Wei-Ye; Sun, Sheng; Li, Ling; Su, Ding-Feng; Zhang, Li-Chao

    2016-01-01

    Propionate is a short chain fatty acid that is abundant as butyrate in the gut and blood. However, propionate has not been studied as extensively as butyrate in the treatment of colitis. The present study was to investigate the effects of sodium propionate on intestinal barrier function, inflammation and oxidative stress in dextran sulfate sodium (DSS)-induced colitis mice. Animals in DSS group received drinking water from 1 to 6 days and DSS [3% (w/v) dissolved in double distilled water] instead of drinking water from 7 to 14 days. Animals in DSS+propionate (DSS+Prop) group were given 1% sodium propionate for 14 consecutive days and supplemented with 3% DSS solution on day 7-14. Intestinal barrier function, proinflammatory factors, oxidative stress, and signal transducer and activator of transcription 3 (STAT3) signaling pathway in the colon were determined. It was found that sodium propionate ameliorated body weight loss, colon-length shortening and colonic damage in colitis mice. Sodium propionate significantly inhibited the increase of FITC-dextran in serum and the decrease of zonula occludens-1 (ZO-1), occludin, and E-cadherin expression in the colonic tissue. It also inhibited the expression of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) mRNA and phosphorylation of STAT3 in colitis mice markedly, reduced the myeloperoxidase (MPO) level, and increased the superoxide dismutase and catalase level in colon and serum compared with DSS group. Sodium propionate inhibited macrophages with CD68 marker infiltration into the colonic mucosa of colitis mice. These results suggest that oral administration of sodium propionate could ameliorate DSS-induced colitis mainly by improving intestinal barrier function and reducing inflammation and oxidative stress via the STAT3 signaling pathway. PMID:27574508

  20. Intestinal Epithelial Barrier Disruption through Altered Mucosal MicroRNA Expression in Human Immunodeficiency Virus and Simian Immunodeficiency Virus Infections

    PubMed Central

    Gaulke, Christopher A.; Porter, Matthew; Han, Yan-Hong; Sankaran-Walters, Sumathi; Grishina, Irina; George, Michael D.; Dang, Angeline T.; Ding, Shou-Wei; Jiang, Guochun; Korf, Ian

    2014-01-01

    ABSTRACT Epithelial barrier dysfunction during human immunodeficiency virus (HIV) infection has largely been attributed to the rapid and severe depletion of CD4+ T cells in the gastrointestinal (GI) tract. Although it is known that changes in mucosal gene expression contribute to intestinal enteropathy, the role of small noncoding RNAs, specifically microRNA (miRNA), has not been investigated. Using the simian immunodeficiency virus (SIV)-infected nonhuman primate model of HIV pathogenesis, we investigated the effect of viral infection on miRNA expression in intestinal mucosa. SIV infection led to a striking decrease in the expression of mucosal miRNA compared to that in uninfected controls. This decrease coincided with an increase in 5′-3′-exoribonuclease 2 protein and alterations in DICER1 and Argonaute 2 expression. Targets of depleted miRNA belonged to molecular pathways involved in epithelial proliferation, differentiation, and immune response. Decreased expression of several miRNA involved in maintaining epithelial homeostasis in the gut was localized to the proliferative crypt region of the intestinal epithelium. Our findings suggest that SIV-induced decreased expression of miRNA involved in epithelial homeostasis, disrupted expression of miRNA biogenesis machinery, and increased expression of XRN2 are involved in the development of epithelial barrier dysfunction and gastroenteropathy. IMPORTANCE MicroRNA (miRNA) regulate the development and function of intestinal epithelial cells, and many viruses disrupt normal host miRNA expression. In this study, we demonstrate that SIV and HIV disrupt expression of miRNA in the small intestine during infection. The depletion of several key miRNA is localized to the proliferative crypt region of the gut epithelium. These miRNA are known to control expression of genes involved in inflammation, cell death, and epithelial maturation. Our data indicate that this disruption might be caused by altered expression of mi

  1. Induction of Sd(a)-sialomucin and sulfated H-sulfomucin in mouse small intestinal mucosa by infection with parasitic helminth.

    PubMed

    Tsubokawa, Daigo; Ishiwata, Kenji; Goso, Yukinobu; Yokoyama, Takuya; Kanuka, Hirotaka; Ishihara, Kazuhiko; Nakamura, Takeshi; Tsuji, Naotoshi

    2015-06-01

    Mucin is a major component of mucus on gastrointestinal mucosa. Mucin alteration in the host is considered to be the principal event for expulsion of intestinal helminths. However, it is unclear what mucin alterations are induced by various helminth infections. In this study, the alterations of mouse small intestinal mucin after infection with two nematodes, Nippostrongylus brasiliensis and Heligmosomoides polygyrus, which parasitize the jejunal epithelium, and a cestode, Vampirolepis nana, which parasitizes the ileal epithelium, were examined biochemically and histologically using two anti-mucin monoclonal antibodies (mAbs), HCM31 and PGM34, which recognize Sd(a) antigen, NeuAcα2-3(GalNAcβ1-4)Galβ1-4GlcNAcβ-, and sulphated H type 2 antigen, Fucα1-2Galβ1-4GlcNAc(6SO₃H)β-, respectively. The goblet cell mucins that reacted with HCM31 increased conspicuously on the jejunal mucosa concurrently with expulsion of N. brasiliensis. Increased levels of HCM31-reactive mucins were observed in the jejunal mucosa after H. polygyrus infection, despite the ongoing parasitism. Goblet cell mucins that reacted with PGM34 increased on the ileal mucosa during V. nana parasitism. Small intestinal goblet cells reacting with the two mAbs were not observed in non-infected mice, although sialomucins and sulfomucins were abundantly present. Additionally, the number of ileal goblet cells that reacted with the two mAbs was increased at the time of expulsion of heterophyid trematode. These results indicate that the type of specific acidic mucins expressed after infection varies among species of intestinal helminth, and, furthermore, that the relationship with worm expulsion is also different. PMID:25819298

  2. Biliary tract external drainage protects against intestinal barrier injury in hemorrhagic shock rats

    PubMed Central

    Wang, Lu; Zhao, Bing; Chen, Ying; Ma, Li; Chen, Er-Zhen; Mao, En-Qiang

    2015-01-01

    AIM: To investigate the effects of biliary tract external drainage (BTED) on intestinal barrier injury in rats with hemorrhagic shock (HS). METHODS: BTED was performed via cannula insertion into the bile duct of rats. HS was induced by drawing blood from the femoral artery at a rate of 1 mL/min until a mean arterial pressure (MAP) of 40 ± 5 mmHg was achieved. That MAP was maintained for 60 min. A total of 99 Sprague-Dawley rats were randomized into a sham group, an HS group and an HS + BTED group. Nine rats in the sham group were sacrificed 0.5 h after surgery. Nine rats in each of the HS and HS + BTED groups were sacrificed 0.5 h, 1 h, 2 h, 4 h and 6 h after resuscitation. Plasma tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and lipopolysaccharide (LPS) levels were analyzed using enzyme-linked immunosorbent assay. Plasma D-lactate levels were analyzed using colorimetry. The expression levels of occludin and claudin-1 in the ileum were analyzed using Western blot and immunohistochemistry. Histology of the ileum was evaluated by hematoxylin and eosin staining. RESULTS: Plasma TNF-α levels in the HS + BTED group decreased significantly compared with the HS group at 1 h and 6 h after resuscitation (P < 0.05). Plasma IL-6 levels in the HS + BTED group decreased significantly compared with the HS group at 0.5 h, 1 h and 2 h after resuscitation (P < 0.05). Plasma D-lactate and LPS levels in the HS + BTED group decreased significantly compared with the HS group at 6 h after resuscitation (P < 0.05). The expression levels of occludin in the HS + BTED group increased significantly compared with the HS group at 4 h and 6 h after resuscitation (P < 0.05). The expression levels of claudin-1 in the HS + BTED group increased significantly compared with the HS group at 6 h after resuscitation (P < 0.05). Phenomena of putrescence and desquamation of epithelial cells in the ileal mucosa were attenuated in the HS + BTED group. Ileal histopathologic scores in the HS

  3. Impact of Toxoplasma gondii on Dendritic Cell Subset Function in the Intestinal Mucosa.

    PubMed

    Cohen, Sara B; Denkers, Eric Y

    2015-09-15

    The function of mucosal dendritic cell (DC) subsets in immunity and inflammation is not well understood. In this study, we define four DC subsets present within the lamina propria and mesenteric lymph node compartments based on expression of CD103 and CD11b. Using IL-12p40 YFP (Yet40) reporter mice, we show that CD103(+)CD11b(-) mucosal DCs are primary in vivo sources of IL-12p40; we also identified CD103(-)CD11b(-) mucosal DCs as a novel population producing this cytokine. Infection was preferentially found in CD11b(+) DCs that were negative for CD103. Lamina propria DCs containing parasites were negative for IL-12p40. Instead, production of the cytokine was strictly a property of noninfected cells. We also show that vitamin A metabolism, as measured by ALDH activity, was preferentially found in CD103(+)CD11b(+) DC and was strongly downregulated in all mucosal DC subsets during infection. Finally, overall apoptosis of lamina propria DC subsets was increased during infection. Combined, these results highlight the ability of intestinal Toxoplasma infection to alter mucosal DC activity at both the whole population level and at the level of individual subsets. PMID:26283477

  4. Element concentrations in the intestinal mucosa of the mouse as measured by X-ray microanalysis.

    PubMed

    von Zglinicki, T; Roomans, G M

    1989-06-01

    Subcellular ion distribution in villus, crypt, Paneth and smooth muscle cells of the mouse small intestine under resting conditions was investigated by X-ray microanalysis of ultrathin cryosections. In addition, the mass distribution was estimated by measuring the optical transmission of the compartments in transmission electron micrographs. Each cell type is characterized by a special composition in terms of the major monovalent ions Na, K, and Cl. In particular, among crypt epithelial cells, those cells containing small secretion granula (termed crypt A cells) also display cytoplasmic ion concentrations significantly different from crypt epithelial cells lacking secretion granula (crypt B cells). Monovalent ion concentrations in the cytoplasm of Paneth cells, muscle cells, and crypt epithelial cells lacking secretion granula are higher than expected from osmotic considerations. Hence, significant binding of ions to cytoplasmic polyelectrolytes is assumed in these cells. There are gradients of dry mass and K concentration from the luminal to the basal side of the cell, both in crypt and in villus cells. The terminal web in these cells is rich in Na and Cl. The elemental composition of the large, dark secretion granula in Paneth cells is similar to that of the small dark granula in crypt cells. However, the two morphologically different types of granula within the Paneth cells have a significantly different elemental composition, which might reflect maturation of secretion granula. PMID:2814397

  5. WISP1 Is Increased in Intestinal Mucosa and Contributes to Inflammatory Cascades in Inflammatory Bowel Disease

    PubMed Central

    Zhang, Qi; Zhang, Cuiping; Li, Xiaoyu; Yu, Yanan; Liang, Kun; Shan, Xinzhi; Zhao, Kun; Niu, Qinghui; Tian, Zibin

    2016-01-01

    Inflammatory bowel disease (IBD) is mainly characterized by intestinal tissue damage, which is caused by excessive autoimmune responses poorly controlled by corresponding regulatory mechanisms. WISP1, which belongs to the CCN protein family, is a secreted matricellular protein regulating several inflammatory pathways, such as Wnt/β-catenin pathway, and has been reported in several diseases including cancer. Here we examined the expression, regulatory mechanisms, and functions of WISP1 in IBD. WISP1 mRNA and protein expression was upregulated in colonic biopsies and lamina propria mononuclear cells (LPMC) of IBD patients compared with those of healthy controls. Tumor necrosis factor- (TNF-) α induced WISP1 expression in LPMC from healthy controls. Consistently, WISP1 mRNA expression was downregulated in colonic biopsies from IBD patients who had achieved clinical remission with infliximab (IFX). Furthermore, WISP1 expression was also found to be increased in colons from 2,4,6-trinitrobenzenesulfonic acid- (TNBS-) induced mice compared with those from control mice. Further studies confirmed that administration of rWISP1 could aggravate TNBS-induced colitis in vivo. Therefore, we concluded that WISP1 is increased in IBD and contributes to the proinflammatory cascades in the gut. PMID:27403031

  6. Impeded establishment of the infective stage of Trichinella in the intestinal mucosa of mice by passive transfer of an IgA monoclonal antibody.

    PubMed

    Inaba, Takashi; Sato, Hiroshi; Kamiya, Haruo

    2003-11-01

    Our previous study showed that the IgA monoclonal antibody (mAb) HUSM-Tb1 forms immunoprecipitates on the cuticular surface of infective larvae of Trichinella britovi, and that intraperitoneal injection of this mAb to mice 5 hr before challenge infection confers a high level of protection against intestinal T. britovi. The same treatment produced a similar effect in BALB/c mice inoculated orally with Trichinella pseudospiralis larvae, indicating that the effects may be seen upon most members of the genus Trichinella. Worms recovered from the intestinal mucosa at 1 hr after challenge infection with T. pseudospiralis was few in mice passively immunized with the mAb, whereas a substantial number of worms were recovered from the mucosa of control groups. These results suggest that the IgA mAb impedes establishment of infective Trichinella worms in the intestinal mucosa. Trichinella worms inoculated orally into BALB/c mice vaccinated with ultraviolet-irradiated muscle larvae 3 weeks earlier were expelled between days 4 and 7 after challenge infection. Although the mAb HUSM-Tb1 originated from the mesenteric lymph node cells of mice vaccinated repeatedly with such irradiated larvae, IgA-mediated expulsion does not seem to play an important role in this vaccination model. PMID:14665753

  7. Diversion of intestinal flow decreases the numbers of interleukin 4 secreting and interferon γ secreting T lymphocytes in small bowel mucosa

    PubMed Central

    Schmit, A; Van Gossum, A; Carol, M; Houben, J; Mascart, F

    2000-01-01

    BACKGROUND/AIMS—The intestinal immune system faces large amounts of antigens, and its regulation is tightly balanced by cytokines. In this study, the effect of intestinal flow diversion on spontaneous secretion of interleukin (IL)-4 and interferon (IFN)- γ was analysed.
METHODS—Eight patients (two with Crohn's disease, four with ulcerative colitis, and two with previous colon cancer) carrying a double lumen small bowel stoma after a total colectomy procedure were included in the study. For each patient, eight biopsy samples were taken endoscopically from both the diverted and non-diverted part of the small bowel. Intraepithelial lymphocytes (IELs) and lamina propria lymphocytes (LPLs) were isolated separately and assayed for numbers of cells spontaneously secreting IL-4 and/or IFN-γ by an ELISPOT technique.
RESULTS—Compared with the non-diverted mucosa, a significant decrease in the number of spontaneously IFN-γ secreting CD3 lymphocytes was observed in the diverted small bowel mucosa among both IELs (p = 0.008) and LPLs (p = 0.007). The same results, although less significant, were obtained for IL-4, especially in LPLs (p = 0.01).
CONCLUSION—The intestinal content influences the spontaneous secretion of IFN-γ and IL-4 by intestinal lymphocytes. These results could help to elucidate the anti-inflammatory role of split ileostomy in patients suffering from inflammatory bowel diseases.


Keywords: intestine; T lymphocytes; mucosa; interleukin-4; interferon-γ; ELISPOT PMID:10601053

  8. Hydrolyzed porcine mucosa in broiler diets: effects on growth performance, nutrient retention, and histomorphology of the small intestine.

    PubMed

    Frikha, M; Mohiti-Asli, M; Chetrit, C; Mateos, G G

    2014-02-01

    The effect of including hydrolyzed porcine mucosa sprayed into soybean meal (HPM) in the diet was studied in broilers. In experiment 1 (pen study), 1,080 one-day-old chicks were used in a completely randomized design with 8 treatments arranged as a 4 × 2 factorial with 4 levels of HPM (0, 2.5, 5.0, and 7.5%) and 2 levels of Lys (1.23 and 1.38%). From d 1 to 22, HPM inclusion quadratically improved BW gain (BWG, P < 0.01) and feed conversion ratio (FCR, P < 0.01). From d 1 to 8, birds fed 1.38% Lys had higher BWG (P < 0.05) and better FCR (P < 0.05) than birds fed 1.23% Lys but only a trend (P < 0.08) for improved BWG was detected from d 1 to 22. From d 22 to 37, a period in which all birds received a common finisher diet, growth performance was not affected by the previous starter diet. In experiment 2 (battery study), birds were fed for 37 d the same diets used in the starter period of experiment 1. Broilers fed HPM had higher BWG (linear, P < 0.05; Quadratic, P < 0.05) than birds fed control diet, and birds fed 1.38% Lys had higher BWG (P < 0.01) than birds fed 1.23% Lys. From d 1 to 22, BWG (P < 0.05) and ADFI (P < 0.01) increased quadratically and FCR improved linearly (P < 0.05) with HPM inclusion. Also in this period, BWG was higher at the higher Lys level (P < 0.01). Diet did not affect intestinal histomorphology of broilers on d 8 or nutrient retention on d 22. We conclude that the inclusion of 2.5 to 5% HPM in the diet improved growth performance of broilers from d 1 to 22. An increase in Lys from 1.23 to 1.38% improved growth performance up to 15 d of age, but not thereafter. Diet did not affect villus histomorphology or nutrient retention of the small intestine. PMID:24570462

  9. ClC-2 regulation of intestinal barrier function: Translation of basic science to therapeutic target.

    PubMed

    Jin, Younggeon; Blikslager, Anthony T

    2015-01-01

    The ClC-2 chloride channel is a member of the voltage-gated chloride channel family. ClC-2 is involved in various physiological processes, including fluid transport and secretion, regulation of cell volume and pH, maintaining the membrane potential of the cell, cell-to-cell communication, and tissue homeostasis. Recently, our laboratory has accumulated evidence indicating a critical role of ClC-2 in the regulation of intestinal barrier function by altering inter-epithelial tight junction composition. This review will detail the role of ClC-2 in intestinal barrier function during intestinal disorders, including experimental ischemia/reperfusion injury and dextran sodium sulfate (DSS)-induced inflammatory bowel disease. Details of pharmacological manipulation of ClC-2 via prostone agonists will also be provided in an effort to show the potential therapeutic relevance of ClC-2 regulation, particularly during intestinal barrier disruption. PMID:26716076

  10. Effect of orally administered betel leaf (Piper betle Linn.) on digestive enzymes of pancreas and intestinal mucosa and on bile production in rats.

    PubMed

    Prabhu, M S; Platel, K; Saraswathi, G; Srinivasan, K

    1995-10-01

    The influence of two varieties of betel leaf (Piper betle Linn.) namely, the pungent Mysore and non-pungent Ambadi, was examined on digestive enzymes of pancreas and intestinal mucosa and on bile secretion in experimental rats. The betel leaves were administered orally at two doses which were either comparable to human consumption level or 5 times this. The results indicated that while these betel leaves do not influence bile secretion and composition, they have a significant stimulatory influence on pancreatic lipase activity. Besides, the Ambadi variety of betel leaf has a positive stimulatory influence on intestinal digestive enzymes, especially lipase, amylase and disaccharidases. A slight lowering in the activity of these intestinal enzymes was seen when Mysore variety of betel leaf was administered, and this variety also had a negative effect on pancreatic amylase. Further, both the betel leaf varieties have shown decreasing influence on pancreatic trypsin and chymotrypsin activities. PMID:8575807

  11. Adenosine A2B receptor modulates intestinal barrier function under hypoxic and ischemia/reperfusion conditions

    PubMed Central

    Yang, Yang; Qiu, Yuan; Wang, Wensheng; Xiao, Weidong; Liang, Hongyin; Zhang, Chaojun; Yang, Hanwenbo; Teitelbaum, Daniel H; Sun, Li-Hua; Yang, Hua

    2014-01-01

    Background: Intestinal barrier function failure from ischemia/reperfusion (I/R) and acute hypoxia has been implicated as a critical determinant in the predisposition to intestinal inflammation and a number of inflammatory disorders. Here, we identified the role of Adenosine A2B receptor (A2BAR) in the regulation of intestinal barrier function under I/R and acute hypoxic conditions. Methods: C57BL/6J mice were used, and were randomized into three groups: Sham, I/R, IR+PSB1115 (a specific A2BAR antagonist) groups. After surgery, the small bowel was harvested for immunohistochemical staining, RNA and protein content, and intestinal permeability analyses. Using an epithelial cell culture model, we investigated the influence of hypoxia on the epithelial function, and the role of A2BAR in the expressions of tight junction and epithelial permeability. The expressions of Claudin-1, occludin and ZO-1 were detected by RT-PCR and Western-Blot. Epithelial barrier function was assessed with transepithelial resistance (TER). Results and conclusions: The A2BAR antagonist, PSB1115, significantly increased tight junction protein expression after intestinal I/R or acute hypoxia conditions. PSB1115 also attenuated the disrupted distribution of TJ proteins. Furthermore, inhibition of A2BAR attenuated the decrease in TER induced by I/R or acute hypoxic conditions, and maintained intestinal barrier function. Antagonism of A2BAR activity improves intestinal epithelial structure and barrier function in a mouse model of intestinal I/R and a cell model of acute hypoxia. These findings support a potentially destructive role for A2BAR under intestinal I/R and acute hypoxic conditions. PMID:24966910

  12. Mice lacking myosin IXb, an inflammatory bowel disease susceptibility gene, have impaired intestinal barrier function and superficial ulceration in the ileum.

    PubMed

    Hegan, Peter S; Chandhoke, Surjit K; Barone, Christina; Egan, Marie; Bähler, Martin; Mooseker, Mark S

    2016-04-01

    Genetic studies have implicated MYO9B, which encodes myosin IXb (Myo9b), a motor protein with a Rho GTPase activating domain (RhoGAP), as a susceptibility gene for inflammatory bowel disease (IBD). Moreover, we have recently shown that knockdown of Myo9b in an intestinal epithelial cell line impairs wound healing and barrier function. Here, we investigated whether mice lacking Myo9b have impaired intestinal barrier function and features of IBD. Myo9b knock out (KO) mice exhibit impaired weight gain and fecal occult blood (indicator of gastrointestinal bleeding), and increased intestinal epithelial cell apoptosis could be detected along the entire intestinal axis. Histologic analysis revealed intestinal mucosal damage, most consistently observed in the ileum, which included superficial ulceration and neutrophil infiltration. Focal lesions contained neutrophils and ultrastructural examination confirmed epithelial discontinuity and the deposition of extracellular matrix. We also observed impaired mucosal barrier function in KO mice. Transepithelial electrical resistance of KO ileum is >3 fold less than WT ileum. The intestinal mucosa is also permeable to high molecular weight dextran, presumably due to the presence of mucosal surface ulcerations. There is loss of tight junction-associated ZO-1, decreased lateral membrane associated E-cadherin, and loss of terminal web associated cytokeratin filaments. Consistent with increased Rho activity in the KO, there is increased subapical expression of activated myosin II (Myo2) based on localization of phosphorylated Myo2 regulatory light chain. Except for a delay in disease onset in the KO, no difference in dextran sulfate sodium-induced colitis and lethality was observed between wild-type and Myo9b KO mice. © 2016 Wiley Periodicals, Inc. PMID:26972322

  13. Effects of intraepithelial lymphocyte-derived cytokines on intestinal mucosal barrier function.

    PubMed

    Qiu, Yuan; Yang, Hua

    2013-10-01

    The mucosal surface of the gastrointestinal tract directly interacts with the mucosal lumen, which is continuously exposed to foreign antigens. Specialized intraepithelial lymphocytes (IELs), located between the basolateral surfaces of the epithelial cells, are important as the first line of defense against microbes as well as for their role in the maintenance of epithelial barrier homeostasis. Although IELs are mainly composed of T cells, they are phenotypically and functionally distinct from T cells in peripheral blood or the spleen. Not only are IELs stimulated by the antigens of the intestinal lumen but are they also stimulated by regulatory immune cells. The integrity of the intestinal mucosal barrier is closely tied to the IEL function. Cytokines produced by IELs modulate the cellular functions that trigger the downstream signaling pathways and mediate the barrier homeostasis. In this review, we will address the broad spectrum of cytokines that are derived from IELs and the functional regulation of these cytokines on the intestinal barrier. PMID:23692551

  14. Nivalenol Has a Greater Impact than Deoxynivalenol on Pig Jejunum Mucosa in Vitro on Explants and in Vivo on Intestinal Loops

    PubMed Central

    Cheat, Sophal; Gerez, Juliana R.; Cognié, Juliette; Alassane-Kpembi, Imourana; Bracarense, Ana Paula F. L.; Raymond-Letron, Isabelle; Oswald, Isabelle P.; Kolf-Clauw, Martine

    2015-01-01

    The mycotoxins deoxynivalenol (DON) and nivalenol (NIV), worldwide cereal contaminants, raise concerns for animal and human gut health, following contaminated food or feed ingestion. The impact of DON and NIV on intestinal mucosa was investigated after acute exposure, in vitro and in vivo. The histological changes induced by DON and NIV were analyzed after four-hour exposure on pig jejunum explants and loops, two alternative models. On explants, dose-dependent increases in the histological changes were induced by DON and NIV, with a two-fold increase in lesion severity at 10 µM NIV. On loops, NIV had a greater impact on the mucosa than DON. The overall proliferative cells showed 30% and 13% decrease after NIV and DON exposure, respectively, and NIV increased the proliferative index of crypt enterocytes. NIV also increased apoptosis at the top of villi and reduced by almost half the proliferative/apoptotic cell ratio. Lamina propria cells (mainly immune cells) were more sensitive than enterocytes (epithelial cells) to apoptosis induced by NIV. Our results demonstrate a greater impact of NIV than DON on the intestinal mucosa, both in vitro and in vivo, and highlight the need of a specific hazard characterization for NIV risk assessment. PMID:26035490

  15. Nivalenol has a greater impact than deoxynivalenol on pig jejunum mucosa in vitro on explants and in vivo on intestinal loops.

    PubMed

    Cheat, Sophal; Gerez, Juliana R; Cognié, Juliette; Alassane-Kpembi, Imourana; Bracarense, Ana Paula F L; Raymond-Letron, Isabelle; Oswald, Isabelle P; Kolf-Clauw, Martine

    2015-06-01

    The mycotoxins deoxynivalenol (DON) and nivalenol (NIV), worldwide cereal contaminants, raise concerns for animal and human gut health, following contaminated food or feed ingestion. The impact of DON and NIV on intestinal mucosa was investigated after acute exposure, in vitro and in vivo. The histological changes induced by DON and NIV were analyzed after four-hour exposure on pig jejunum explants and loops, two alternative models. On explants, dose-dependent increases in the histological changes were induced by DON and NIV, with a two-fold increase in lesion severity at 10 µM NIV. On loops, NIV had a greater impact on the mucosa than DON. The overall proliferative cells showed 30% and 13% decrease after NIV and DON exposure, respectively, and NIV increased the proliferative index of crypt enterocytes. NIV also increased apoptosis at the top of villi and reduced by almost half the proliferative/apoptotic cell ratio. Lamina propria cells (mainly immune cells) were more sensitive than enterocytes (epithelial cells) to apoptosis induced by NIV. Our results demonstrate a greater impact of NIV than DON on the intestinal mucosa, both in vitro and in vivo, and highlight the need of a specific hazard characterization for NIV risk assessment. PMID:26035490

  16. MyD88 adaptor-like (Mal) functions in the epithelial barrier and contributes to intestinal integrity via protein kinase C.

    PubMed

    Corr, S C; Palsson-McDermott, E M; Grishina, I; Barry, S P; Aviello, G; Bernard, N J; Casey, P G; Ward, J B J; Keely, S J; Dandekar, S; Fallon, P G; O'Neill, L A J

    2014-01-01

    MyD88 adapter-like (Mal)-deficient mice displayed increased susceptibility to oral but not intraperitoneal infection with Salmonella Typhimurium. Bone marrow chimeras demonstrated that mice with Mal-deficient non-hematopoietic cells were more susceptible to infection, indicating a role for Mal in non-myeloid cells. We observed perturbed barrier function in Mal(-/-) mice, as indicated by reduced electrical resistance and increased mucosa blood permeability following infection. Altered expression of occludin, Zonula occludens-1, and claudin-3 in intestinal epithelia from Mal(-/-) mice suggest that Mal regulates tight junction formation, which may in part contribute to intestinal integrity. Mal interacted with several protein kinase C (PKC) isoforms in a Caco-2 model of intestinal epithelia and inhibition of Mal or PKC increased permeability and bacterial invasion via a paracellular route, while a pan-PKC inhibitor increased susceptibility to oral infection in mice. Mal signaling is therefore beneficial to the integrity of the intestinal barrier during infection. PMID:23612054

  17. Antimicrobial peptide Cathelicidin-BF prevents intestinal barrier dysfunction in a mouse model of endotoxemia.

    PubMed

    Song, Deguang; Zong, Xin; Zhang, Haiwen; Wang, Tenghao; Yi, Hongbo; Luan, Chao; Wang, Yizhen

    2015-03-01

    Intestinal barrier functions are altered during the development of sepsis. Cathelicidin antimicrobial peptides, such as LL-37 and mCRAMP, can protect animals against intestinal barrier dysfunction. Cathelicidin-BF (C-BF), a new cathelicidin peptide purified from the venom of the snake Bungarus fasciatus, has been shown to have both antimicrobial and anti-inflammatory properties. This study investigated whether C-BF pretreatment could protect the intestinal barrier against dysfunction in a mouse model of endotoxemia, induced by intraperitoneal injection of LPS (10mg/kg). Mice were treated with low or high dose C-BF before treatment with LPS, and samples were collected 5h after LPS treatment. C-BF reduced LPS induced intestinal histological damage and gut permeability to 4 KD Fluorescein-isothiocyanate-conjugated dextran. Pretreatment with C-BF prevented LPS induced intestinal tight junction disruption and epithelial cell apoptosis. Moreover, C-BF down regulated the expression and secretion of TNF-α, a process involving the NF-κB signaling pathway. C-BF also reduced LPS induced TNF-α expression through the NF-κB signaling pathway in mouse RAW 264.7 macrophages. These findings indicate that C-BF can prevent gut barrier dysfunction induced by LPS, suggesting that C-BF may be used to develop a prophylactic agent for intestinal injury in endotoxemia. PMID:25639228

  18. Probing the immune and healing response of murine intestinal mucosa by time-lapse 2-photon microscopy of laser-induced lesions with real-time dosimetry

    PubMed Central

    Orzekowsky-Schroeder, Regina; Klinger, Antje; Freidank, Sebastian; Linz, Norbert; Eckert, Sebastian; Hüttmann, Gereon; Gebert, Andreas; Vogel, Alfred

    2014-01-01

    Gut mucosa is an important interface between body and environment. Immune response and healing processes of murine small intestinal mucosa were investigated by intravital time-lapse two-photon excited autofluorescence microscopy of the response to localized laser-induced damage. Epithelial lesions were created by 355-nm, 500-ps pulses from a microchip laser that produced minute cavitation bubbles. Size and dynamics of these bubbles were monitored using a novel interferometric backscattering technique with 80 nm resolution. Small bubbles (< 2.5 µm maximum radius) merely resulted in autofluorescence loss of the target cell. Larger bubbles (7-25 µm) affected several cells and provoked immigration of immune cells (polymorphonuclear leucocytes). Damaged cells were expelled into the lumen, and the epithelium healed within 2 hours by stretching and migration of adjacent epithelial cells. PMID:25360369

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

    PubMed

    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

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

    PubMed Central

    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. Evaluation of intestinal absorption enhancement and local mucosal toxicity of two promoters. I. Studies in isolated rat and human colonic mucosae.

    PubMed

    Maher, Sam; Kennelly, Rory; Bzik, Victoria A; Baird, Alan W; Wang, Xuexuan; Winter, Desmond; Brayden, David J

    2009-11-01

    The effects of two absorption promoters, (sodium caprate (C(10)) and melittin), on intestinal permeability and viability were measured in intact rat and human colonic epithelia mounted in Ussing chambers. Apical-side addition of C(10) (10 mM) and melittin (10-50 microM) rapidly reduced the transepithelial electrical resistance (TEER) and increased the apparent permeability coefficient (Papp) of [(14)C]-mannitol and FITC-dextran-4 kDa (FD4) across colonic mucosae from both species. Effects of C(10) on flux were greater than those of melittin at the concentrations selected. C(10) irreversibly decreased TEER, but the effects of melittin were partially reversible. Enhanced permeability of polar sugars (0.18-70 kDa) in colonic mucosae with C(10) was accompanied by significant release of lactate dehydrogenase (LDH) from the luminal surface as well as by inhibition of electrogenic chloride secretion induced by the muscarinic agonist, carbachol (0.1-10 microM). Although melittin did not alter electrogenic chloride secretion in rat or human colonic mucosae, it caused leakage of LDH from rat tissue. Gross histology and electron microscopy of rat and human colonic mucosae demonstrated that each permeation enhancer can induce colonic epithelial damage at concentrations required to increase marker fluxes. C(10) led to more significant mucosal damage than melittin, characterised by sloughing and mucosal erosion. Overall, these results indicate that while C(10) and melittin increase transport of paracellular flux markers across isolated human and rat colonic mucosae in vitro, these effects are associated with some cytotoxicity. PMID:19737613

  2. Candida albicans infection leads to barrier breakdown and a MAPK/NF-κB mediated stress response in the intestinal epithelial cell line C2BBe1.

    PubMed

    Böhringer, Michael; Pohlers, Susann; Schulze, Sylvie; Albrecht-Eckardt, Daniela; Piegsa, Judith; Weber, Michael; Martin, Ronny; Hünniger, Kerstin; Linde, Jörg; Guthke, Reinhard; Kurzai, Oliver

    2016-07-01

    Intestinal epithelial cells (IEC) form a tight barrier to the gut lumen. Paracellular permeability of the intestinal barrier is regulated by tight junction proteins and can be modulated by microorganisms and other stimuli. The polymorphic fungus Candida albicans, a frequent commensal of the human mucosa, has the capacity of traversing this barrier and establishing systemic disease within the host. Infection of polarized C2BBe1 IEC with wild-type C. albicans led to a transient increase of transepithelial electric resistance (TEER) before subsequent barrier disruption, accompanied by a strong decline of junctional protein levels and substantial, but considerably delayed cytotoxicity. Time-resolved microarray-based transcriptome analysis of C. albicans challenged IEC revealed a prominent role of NF-κB and MAPK signalling pathways in the response to infection. Hence, we inferred a gene regulatory network based on differentially expressed NF-κB and MAPK pathway components and their predicted transcriptional targets. The network model predicted activation of GDF15 by NF-κB was experimentally validated. Furthermore, inhibition of NF-κB activation in C. albicans infected C2BBe1 cells led to enhanced cytotoxicity in the epithelial cells. Taken together our study identifies NF-κB activation as an important protective signalling pathway in the response of epithelial cells to C. albicans. PMID:26752615

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

    SciTech Connect

    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.

    2009-05-15

    '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.

  4. [Barrier- and autophagic functions of the intestinal epithelia: role of disturbances in the pathogenesis of Crohn's disease].

    PubMed

    Lapis, Károly

    2010-10-01

    Crohn's disease is a widely known debilitating chronic inflammatory disease, mostly affecting terminal ileum and/or colon. Epidemiological, familial and twin studies suggest that genetic factors play an important role in susceptibility to the disease. Clinical observations suggest that ill-defined environmental factors also play a part. Advances in molecular genotyping technology, statistical methodologies, bioinformatics and the combined use of them in genome wide scanning and association studies resulted in the identification of more than 30 susceptibility genes and loci associated with Crohn's disease and revealed and highlighted a number of new previously unsuspected pathways playing a role in the pathogenesis of Crohn's disease. Close association of the disease with polymorphisms in the genes encoding the pattern recognition receptors particularly the NOD2 protein, the Wnt pathway transcription factor Tcf4 (also known as TCFL2) and the autophagic regulator ATG16L1 have been found. The polymorphisms involved are associated with decreased defensin production (defensin deficiency) which can lead to changes in the composition of the commensal microbial flora, defects in the intestinal barrier functions and bacterial invasion of the mucosa. Other recently recognized consequences of the polymorphisms involving the genes encoding NOD2 and ATG16L1 proteins are that the truncated NOD2 protein is unable to induce autophagy and this protein, just like the ATG16L1 T300A mutant protein, leads to failure adequately to destroy phagocytosed bacteria. The consequence is persisting low level infection, chronic intestinal inflammation, tissue injury and the clinical symptoms of the disease. Thus, Crohn's disease can be seen to be caused by defects in the innate immune defense, in particular defects in bacterial processing and clearance. The accumulated evidence suggests that Crohn's disease is associated with an exaggerated adaptive immune response to the persisting intestinal

  5. Yersinia enterocolitica Affects Intestinal Barrier Function in the Colon.

    PubMed

    Hering, Nina A; Fromm, Anja; Kikhney, Judith; Lee, In-Fah M; Moter, Annette; Schulzke, Jörg D; Bücker, Roland

    2016-04-01

    Infection with Yersinia enterocolitica causes acute diarrhea in early childhood. A mouse infection model presents new findings on pathological mechanisms in the colon. Symptoms involve diarrhea with watery feces and weight loss that have their functional correlates in decreased transepithelial electrical resistance and increased fluorescein permeability. Y. enterocolitica was present within the murine mucosa of both ileum and colon. Here, the bacterial insult was of focal nature and led to changes in tight junction protein expression and architecture. These findings are in concordance with observations from former cell culture studies and suggest a leak flux mechanism of diarrhea. PMID:26621910

  6. Effects of l-carnitine and/or maize distillers dried grains with solubles in diets of gestating and lactating sows on the intestinal barrier functions of their offspring.

    PubMed

    Wei, Bingdong; Nie, Shaoping; Meng, Qingwei; Qu, Zhe; Shan, Anshan; Chen, Zhihui

    2016-08-01

    The objective of this study was to investigate the effects of l-carnitine and/or maize distillers dried grains with solubles (DDGS) in diets of gestating and lactating sows on the intestinal barrier functions of their offspring. The experiment was designed as a 2×2 factorial with two dietary treatments (soyabean meal v. DDGS) and two l-carnitine levels (0 v. 100 mg/kg in gestating diets and 0 v. 200 mg/kg in lactating diets). Sows (Landrace×Large White) with an average parity of 4·2 with similar body weight were randomly assigned to four groups of thirty each. Dietary supplementation with l-carnitine increased the total superoxide dismutase activity but decreased the concentration of malondialdehyde of the jejunal mucosa in newborn piglets and weaning piglets on day 21. Dietary supplementation with l-carnitine decreased the concentrations of IL-1β, IL-12 and TNF-α in the jejunal mucosa of newborn piglets and decreased the concentrations of IL-6 and TNF-α in the jejunal mucosa of weaning piglets on day 21. There was an interaction between dietary treatment and l-carnitine on the bacterial numbers of total eubacteria in the digesta of caecum in weaning piglets on day 21. Bacterial numbers of total eubacteria in weaning piglets on day 21 were significantly increased by l-carnitine only in soyabean meal diet, but there was no significant effect of l-carnitine in DDGS-based diet. Dietary supplementation with l-carnitine increased the bacterial numbers of Lactobacillus spp. and bifidobacteria spp. in the digesta of caecum in weaning piglets on day 21. Dietary supplementation with l-carnitine in sows affected the expression of tight junction proteins (claudin 1, zonula occludens-1 (ZO-1) and occludin) in the jejunal mucosa of their offspring by increasing the expression of ZO-1 mRNA in the jejunal mucosa of newborn piglets, and by increasing the expression of ZO-1 and occludin mRNA in the jejunal mucosa of weaning piglets on day 21. In conclusion, dietary

  7. Intestinal barrier: A gentlemen’s agreement between microbiota and immunity

    PubMed Central

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

    2014-01-01

    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. PMID:24891972

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

    PubMed Central

    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

  9. Effects of acute intra-abdominal hypertension on multiple intestinal barrier functions in rats

    PubMed Central

    Leng, Yuxin; Yi, Min; Fan, Jie; Bai, Yu; Ge, Qinggang; Yao, Gaiqi

    2016-01-01

    Intra-abdominal hypertension (IAH) is a common and serious complication in critically ill patients for which there is no well-defined treatment strategy. Here, we explored the effect of IAH on multiple intestinal barriers and discussed whether the alteration in microflora provides clues to guide the rational therapeutic treatment of intestinal barriers during IAH. Using a rat model, we analysed the expression of tight junction proteins (TJs), mucins, chemotactic factors, and Toll-like receptor 4 (TLR4) by immunohistochemistry. We also analysed the microflora populations using 16S rRNA sequencing. We found that, in addition to enhanced permeability, acute IAH (20 mmHg for 90 min) resulted in significant disturbances to mucosal barriers. Dysbiosis of the intestinal microbiota was also induced, as represented by decreased Firmicutes (relative abundance), increased Proteobacteria and migration of Bacteroidetes from the colon to the jejunum. At the genus level, Lactobacillus species and Peptostreptococcaceae incertae sedis were decreased, whereas levels of lactococci remained unchanged. Our findings outline the characteristics of IAH-induced barrier changes, indicating that intestinal barriers might be treated to alleviate IAH, and the microflora may be an especially relevant target. PMID:26980423

  10. Administration of different Lactobacillus strains in fermented oatmeal soup: in vivo colonization of human intestinal mucosa and effect on the indigenous flora.

    PubMed Central

    Johansson, M L; Molin, G; Jeppsson, B; Nobaek, S; Ahrné, S; Bengmark, S

    1993-01-01

    In vivo colonization by different Lactobacillus strains on human intestinal mucosa of healthy volunteers was studied together with the effect of Lactobacillus administration on different groups of indigenous bacteria. A total of 19 test strains were administered in fermented oatmeal soup containing 5 x 10(6) CFU of each strain per ml by using a dose of 100 ml of soup per day for 10 days. Biopsies were taken from both the upper jejunum and the rectum 1 day before administration was started and 1 and 11 days after administration was terminated. The administration significantly increased the Lactobacillus counts on the jejunum mucosa, and high levels remained 11 days after administration was terminated. The levels of streptococci increased by 10- to 100-fold in two persons, and the levels of sulfite-reducing clostridia in the jejunum decreased by 10- to 100-fold in three of the volunteers 1 day after administration was terminated. In recta, the anaerobic bacterium counts and the gram-negative anaerobic bacterium counts decreased significantly by the end of administration. Furthermore, a decrease in the number of members of the Enterobacteriaceae by 1,000-fold was observed on the rectal mucosa of two persons. Randomly picked Lactobacillus isolates were identified phenotypically by API 50CH tests and genotypically by the plasmid profiles of strains and by restriction endonuclease analysis of chromosomal DNAs.(ABSTRACT TRUNCATED AT 250 WORDS) Images PMID:8439146

  11. LIGHT signals directly to intestinal epithelia to cause barrier dysfunction via cytoskeletal and endocytic mechanisms

    PubMed Central

    Schwarz, Brad T.; Wang, Fengjun; Shen, Le; Clayburgh, Daniel R.; Su, Liping; Wang, Yingmin; Fu, Yang-Xin; Turner, Jerrold R.

    2009-01-01

    BACKGROUND & AIMS LIGHT (lymphotoxin-like inducible protein that competes with glycoprotein D for herpes virus entry on T cells) is a TNF core family member that regulates T cell activation and causes experimental inflammatory bowel disease. Additional data suggest that LIGHT may be involved in the pathogenesis of human inflammatory bowel disease. The aim of this study was to determine if LIGHT was capable of signaling directly to intestinal epithelia and to define the mechanisms and consequences of such signaling. METHODS The effects of LIGHT and interferon-γ (IFN-γ) on barrier function, cytoskeletal regulation, and tight junction structure were assessed in mice and intestinal epithelial monolayers. RESULTS LIGHT induced barrier loss in cultured epithelia via myosin II regulatory light chain (MLC) phosphorylation; both barrier loss and MLC phosphorylation were reversed by MLC kinase (MLCK) inhibition. IFN-γ pretreatment, which induced lymphotoxin β receptor (LTβR) expression, was required for these effects and neither barrier dysfunction nor intestinal epithelial MLC phosphorylation occurred in LTβR-knockout mice. In cultured monolayers, endocytosis of the tight junction protein occludin correlated with barrier loss. Internalized occludin co-localized with caveolin-1. LIGHT-induced occludin endocytosis and barrier loss were both prevented by inhibition of caveolar endocytosis. CONCLUSIONS T cell-derived LIGHT activates intestinal epithelial LTβR to disrupt barrier function. This requires MLCK activation and caveolar endocytosis. These data suggest a novel role for LIGHT in disease pathogenesis and suggest that inhibition of MLCK-dependent caveolar endocytosis may represent an approach to restoring barrier function in inflammatory bowel disease. PMID:17570213

  12. Barrier function of the nasal mucosa in health and type-2 biased airway diseases.

    PubMed

    Zhang, N; Van Crombruggen, K; Gevaert, E; Bachert, C

    2016-03-01

    The mucosal lining of the upper airways represents the outer surface of the body to the ambient air and its contents and is prepared for it as the first line of defense. Apart from the well-described physical barrier and the mucociliary clearance, a variety of systems, including the airway microbiome, antimicrobial proteins, damage-associated molecular patterns, innate lymphoid cells, epithelial-derived cytokines and chemokines, and finally the adaptive immune system, as well as eosinophils as newly appreciated defense cells form different levels of protection against and response to any possible intruder. Of interest especially for allergic airway disease, mucosal germs might not just elicit a classical Th1/Th17-biased inflammatory response, but may directly induce a type-2 mucosal inflammation. Innovative therapeutic interventions may be possible at different levels also; however, whether modulations of the innate or adaptive immune responses will finally be more successful, and how the correction of the adaptive immune response might impact on the innate side, will be determined in the near future. PMID:26606240

  13. Electroacupuncture at Bilateral Zusanli Points (ST36) Protects Intestinal Mucosal Immune Barrier in Sepsis.

    PubMed

    Zhu, Mei-Fei; Xing, Xi; Lei, Shu; Wu, Jian-Nong; Wang, Ling-Cong; Huang, Li-Quan; Jiang, Rong-Lin

    2015-01-01

    Sepsis results in high morbidity and mortality. Immunomodulation strategies could be an adjunctive therapy to treat sepsis. Acupuncture has also been used widely for many years in China to treat sepsis. However, the underlying mechanisms are not well-defined. We demonstrated here that EA preconditioning at ST36 obviously ameliorated CLP-induced intestinal injury and high permeability and reduced the mortality of CLP-induced sepsis rats. Moreover, electroacupuncture (EA) pretreatment exerted protective effects on intestinal mucosal immune barrier by increasing the concentration of sIgA and the percentage of CD3+, γ/δ, and CD4+ T cells and the ratio of CD4+/CD8+ T cells. Although EA at ST36 treatments immediately after closing the abdomen in the CLP procedure with low-frequency or high-frequency could not reduce the mortality of CLP-induced sepsis in rats, these EA treatments could also significantly improve intestinal injury index in rats with sepsis and obviously protected intestinal mucosal immune barrier. In conclusion, our findings demonstrated that EA at ST36 could improve intestinal mucosal immune barrier in sepsis induced by CLP, while the precise mechanism underlying the effects needs to be further elucidated. PMID:26346309

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

    PubMed

    Sun, Chen; Fang, Hui; Xie, Tao; Auth, Roger D; Patel, Nayana; Murray, Patrick R; Snoy, Philip J; Frucht, David M

    2012-01-01

    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. PMID:22438953

  15. Zinc’s impact on intestinal barrier function and zinc trafficking during coccidial caccine challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to evaluate the effects of Zn supplementation on intestinal barrier function and Zn trafficking, three dietary regimens were formulated: a basal corn/SBM diet formulated with a Zn-free vitamin/mineral premix (Basal), and two Zn regimens formulated to provide 90 mg/kg total dietary Zn from ...

  16. Probiotics Prevent Intestinal Barrier Dysfunction in Acute Pancreatitis in Rats via Induction of Ileal Mucosal Glutathione Biosynthesis

    PubMed Central

    Lutgendorff, Femke; Nijmeijer, Rian M.; Sandström, Per A.; Trulsson, Lena M.; Magnusson, Karl-Eric; Timmerman, Harro M.; van Minnen, L. Paul; Rijkers, Ger T.; Gooszen, Hein G.; Akkermans, Louis M. A.; Söderholm, Johan D.

    2009-01-01

    Background During acute pancreatitis (AP), oxidative stress contributes to intestinal barrier failure. We studied actions of multispecies probiotics on barrier dysfunction and oxidative stress in experimental AP. Methodology/Principal Findings Fifty-three male Spraque-Dawley rats were randomly allocated into five groups: 1) controls, non-operated, 2) sham-operated, 3) AP, 4) AP and probiotics and 5) AP and placebo. AP was induced by intraductal glycodeoxycholate infusion and intravenous cerulein (6 h). Daily probiotics or placebo were administered intragastrically, starting five days prior to AP. After cerulein infusion, ileal mucosa was collected for measurements of E. coli K12 and 51Cr-EDTA passage in Ussing chambers. Tight junction proteins were investigated by confocal immunofluorescence imaging. Ileal mucosal apoptosis, lipid peroxidation, and glutathione levels were determined and glutamate-cysteine-ligase activity and expression were quantified. AP-induced barrier dysfunction was characterized by epithelial cell apoptosis and alterations of tight junction proteins (i.e. disruption of occludin and claudin-1 and up-regulation of claudin-2) and correlated with lipid peroxidation (r>0.8). Probiotic pre-treatment diminished the AP-induced increase in E. coli passage (probiotics 57.4±33.5 vs. placebo 223.7±93.7 a.u.; P<0.001), 51Cr-EDTA flux (16.7±10.1 vs. 32.1±10.0 cm/s10−6; P<0.005), apoptosis, lipid peroxidation (0.42±0.13 vs. 1.62±0.53 pmol MDA/mg protein; P<0.001), and prevented tight junction protein disruption. AP-induced decline in glutathione was not only prevented (14.33±1.47 vs. 8.82±1.30 nmol/mg protein, P<0.001), but probiotics even increased mucosal glutathione compared with sham rats (14.33±1.47 vs. 10.70±1.74 nmol/mg protein, P<0.001). Glutamate-cysteine-ligase activity, which is rate-limiting in glutathione biosynthesis, was enhanced in probiotic pre-treated animals (probiotics 2.88±1.21 vs. placebo 1.94±0.55 nmol/min/mg protein; P<0

  17. Claudin-2 as a mediator of leaky gut barrier during intestinal inflammation.

    PubMed

    Luettig, J; Rosenthal, R; Barmeyer, C; Schulzke, J D

    2015-01-01

    The epithelial tight junction determines the paracellular water and ion movement in the intestine and also prevents uptake of larger molecules, including antigens, in an uncontrolled manner. Claudin-2, one of the 27 mammalian claudins regulating that barrier function, forms a paracellular channel for small cations and water. It is typically expressed in leaky epithelia like proximal nephron and small intestine and provides a major pathway for the paracellular transport of sodium, potassium, and fluid. In intestinal inflammation (Crohn's disease, ulcerative colitis), immune-mediated diseases (celiac disease), and infections (HIV enteropathy), claudin-2 is upregulated in small and large intestine and contributes to diarrhea via a leak flux mechanism. In parallel to that upregulation, other epithelial and tight junctional features are altered and the luminal uptake of antigenic macromolecules is enhanced, for which claudin-2 may be partially responsible through induction of tight junction strand discontinuities. PMID:25838982

  18. Effect of Polysaccharides from Acanthopanax senticosus on Intestinal Mucosal Barrier of Escherichia coli Lipopolysaccharide Challenged Mice.

    PubMed

    Han, Jie; Xu, Yunhe; Yang, Di; Yu, Ning; Bai, Zishan; Bian, Lianquan

    2016-01-01

    To investigate the role of polysaccharide from Acanthopanax senticosus (ASPS) in preventing lipopolysaccharide (LPS)-induced intestinal injury, 18 mice (at 5 wk of age) were assigned to three groups with 6 replicates of one mouse each. Mice were administrated by oral gavage with or without ASPS (300 mg/kg body weight) for 14 days and were injected with saline or LPS at 15 days. Intestinal samples were collected at 4 h post-challenge. The results showed that ASPS ameliorated LPS-induced deterioration of digestive ability of LPS-challenged mice, indicated by an increase in intestinal lactase activity (45%, p<0.05), and the intestinal morphology, as proved by improved villus height (20.84%, p<0.05) and villus height:crypt depth ratio (42%, p<0.05), and lower crypt depth in jejunum (15.55%, p<0.05), as well as enhanced intestinal tight junction proteins expression involving occludin-1 (71.43%, p<0.05). ASPS also prevented intestinal inflammation response, supported by decrease in intestinal inflammatory mediators including tumor necrosis factor α (22.28%, p<0.05) and heat shock protein (HSP70) (77.42%, p<0.05). In addition, intestinal mucus layers were also improved by ASPS, as indicated by the increase in number of goblet cells (24.89%, p<0.05) and intestinal trefoil peptide (17.75%, p<0.05). Finally, ASPS facilitated mRNA expression of epidermal growth factor (100%, p<0.05) and its receptor (200%, p<0.05) gene. These results indicate that ASPS can prevent intestinal mucosal barrier injury under inflammatory conditions, which may be associated with up-regulating gene mRNA expression of epidermal growth factor and its receptor. PMID:26732337

  19. Effect of Polysaccharides from Acanthopanax senticosus on Intestinal Mucosal Barrier of Escherichia coli Lipopolysaccharide Challenged Mice

    PubMed Central

    Han, Jie; Xu, Yunhe; Yang, Di; Yu, Ning; Bai, Zishan; Bian, Lianquan

    2016-01-01

    To investigate the role of polysaccharide from Acanthopanax senticosus (ASPS) in preventing lipopolysaccharide (LPS)-induced intestinal injury, 18 mice (at 5 wk of age) were assigned to three groups with 6 replicates of one mouse each. Mice were administrated by oral gavage with or without ASPS (300 mg/kg body weight) for 14 days and were injected with saline or LPS at 15 days. Intestinal samples were collected at 4 h post-challenge. The results showed that ASPS ameliorated LPS-induced deterioration of digestive ability of LPS-challenged mice, indicated by an increase in intestinal lactase activity (45%, p<0.05), and the intestinal morphology, as proved by improved villus height (20.84%, p<0.05) and villus height:crypt depth ratio (42%, p<0.05), and lower crypt depth in jejunum (15.55%, p<0.05), as well as enhanced intestinal tight junction proteins expression involving occludin-1 (71.43%, p<0.05). ASPS also prevented intestinal inflammation response, supported by decrease in intestinal inflammatory mediators including tumor necrosis factor α (22.28%, p<0.05) and heat shock protein (HSP70) (77.42%, p<0.05). In addition, intestinal mucus layers were also improved by ASPS, as indicated by the increase in number of goblet cells (24.89%, p<0.05) and intestinal trefoil peptide (17.75%, p<0.05). Finally, ASPS facilitated mRNA expression of epidermal growth factor (100%, p<0.05) and its receptor (200%, p<0.05) gene. These results indicate that ASPS can prevent intestinal mucosal barrier injury under inflammatory conditions, which may be associated with up-regulating gene mRNA expression of epidermal growth factor and its receptor. PMID:26732337

  20. Hydroxyethyl Starch (HES 130/0.4) Impairs Intestinal Barrier Integrity and Metabolic Function: Findings from a Mouse Model of the Isolated Perfused Small Intestine

    PubMed Central

    Dombrowsky, Heike; Zitta, Karina; Bein, Berthold; Krause, Thorsten; Goldmann, Torsten; Frerichs, Inez; Steinfath, Markus; Weiler, Norbert; Albrecht, Martin

    2015-01-01

    Background The application of hydroxyethyl starch (HES) for volume resuscitation is controversially discussed and clinical studies have suggested adverse effects of HES substitution, leading to increased patient mortality. Although, the intestine is of high clinical relevance and plays a crucial role in sepsis and inflammation, information about the effects of HES on intestinal function and barrier integrity is very scarce. We therefore evaluated the effects of clinically relevant concentrations of HES on intestinal function and barrier integrity employing an isolated perfused model of the mouse small intestine. Methods An isolated perfused model of the mouse small intestine was established and intestines were vascularly perfused with a modified Krebs-Henseleit buffer containing 3% Albumin (N=7) or 3% HES (130/0.4; N=7). Intestinal metabolic function (galactose uptake, lactate-to-pyruvate ratio), edema formation (wet-to-dry weight ratio), morphology (histological and electron microscopical analysis), fluid shifts within the vascular, lymphatic and luminal compartments, as well as endothelial and epithelial barrier permeability (FITC-dextran translocation) were evaluated in both groups. Results Compared to the Albumin group, HES perfusion did not significantly change the wet-to-dry weight ratio and lactate-to-pyruvate ratio. However, perfusing the small intestine with 3% HES resulted in a significant loss of vascular fluid (p<0.01), an increased fluid accumulation in the intestinal lumen (p<0.001), an enhanced translocation of FITC-dextran from the vascular to the luminal compartment (p<0.001) and a significantly impaired intestinal galactose uptake (p<0.001). Morphologically, these findings were associated with an aggregation of intracellular vacuoles within the intestinal epithelial cells and enlarged intercellular spaces. Conclusion A vascular perfusion with 3% HES impairs the endothelial and epithelial barrier integrity as well as metabolic function of the small

  1. GUCY2C opposes systemic genotoxic tumorigenesis by regulating AKT-dependent intestinal barrier integrity.

    PubMed

    Lin, Jieru Egeria; Snook, Adam Eugene; Li, Peng; Stoecker, Brian Arthur; Kim, Gilbert Won; Magee, Michael Sullivan; Garcia, Alex Vladimir Mejia; Valentino, Michael Anthony; Hyslop, Terry; Schulz, Stephanie; Waldman, Scott Arthur

    2012-01-01

    The barrier separating mucosal and systemic compartments comprises epithelial cells, annealed by tight junctions, limiting permeability. GUCY2C recently emerged as an intestinal tumor suppressor coordinating AKT1-dependent crypt-villus homeostasis. Here, the contribution of GUCY2C to barrier integrity opposing colitis and systemic tumorigenesis is defined. Mice deficient in GUCY2C (Gucy2c(-/-)) exhibited barrier hyperpermeability associated with reduced junctional proteins. Conversely, activation of GUCY2C in mice reduced barrier permeability associated with increased junctional proteins. Further, silencing GUCY2C exacerbated, while activation reduced, chemical barrier disruption and colitis. Moreover, eliminating GUCY2C amplified, while activation reduced, systemic oxidative DNA damage. This genotoxicity was associated with increased spontaneous and carcinogen-induced systemic tumorigenesis in Gucy2c(-/-) mice. GUCY2C regulated barrier integrity by repressing AKT1, associated with increased junction proteins occludin and claudin 4 in mice and Caco2 cells in vitro. Thus, GUCY2C defends the intestinal barrier, opposing colitis and systemic genotoxicity and tumorigenesis. The therapeutic potential of this observation is underscored by the emerging clinical development of oral GUCY2C ligands, which can be used for chemoprophylaxis in inflammatory bowel disease and cancer. PMID:22384056

  2. Binding Studies on Isolated Porcine Small Intestinal Mucosa and in vitro Toxicity Studies Reveal Lack of Effect of C. perfringens Beta-Toxin on the Porcine Intestinal Epithelium

    PubMed Central

    Roos, Simone; Wyder, Marianne; Candi, Ahmet; Regenscheit, Nadine; Nathues, Christina; van Immerseel, Filip; Posthaus, Horst

    2015-01-01

    Beta-toxin (CPB) is the essential virulence factor of C. perfringens type C causing necrotizing enteritis (NE) in different hosts. Using a pig infection model, we showed that CPB targets small intestinal endothelial cells. Its effect on the porcine intestinal epithelium, however, could not be adequately investigated by this approach. Using porcine neonatal jejunal explants and cryosections, we performed in situ binding studies with CPB. We confirmed binding of CPB to endothelial but could not detect binding to epithelial cells. In contrast, the intact epithelial layer inhibited CPB penetration into deeper intestinal layers. CPB failed to induce cytopathic effects in cultured polarized porcine intestinal epithelial cells (IPEC-J2) and primary jejunal epithelial cells. C. perfringens type C culture supernatants were toxic for cell cultures. This, however, was not inhibited by CPB neutralization. Our results show that, in the porcine small intestine, CPB primarily targets endothelial cells and does not bind to epithelial cells. An intact intestinal epithelial layer prevents CPB diffusion into underlying tissue and CPB alone does not cause direct damage to intestinal epithelial cells. Additional factors might be involved in the early epithelial damage which is needed for CPB diffusion towards its endothelial targets in the small intestine. PMID:25860161

  3. Tuning the inflammatory response to silver nanoparticles via quercetin in Caco-2 (co-)cultures as model of the human intestinal mucosa.

    PubMed

    Martirosyan, Alina; Grintzalis, Konstantinos; Polet, Madeleine; Laloux, Laurie; Schneider, Yves-Jacques

    2016-06-24

    Interaction of nanoparticles with food matrix components may cause unpredictable health complications. Using an improved Caco-2 cell-based in vitro (co-)culture model the potential of quercetin as one of the major food flavonoids to alter the effect of silver nanoparticles (Ag-NPs) <20 nm in the human intestinal mucosa at real life concentrations was investigated. Ag-NPs (15-90 μg/ml) decreased cell viability and reduced thiol groups, induced oxidative/nitrosative stress and lipid peroxidation and led to activity changes of various antioxidant enzymes after 3h exposure. The contribution of Ag(+) ions within the concentrations released from nanoparticles was shown to be less important, compared to Ag-NPs. While leading to inflammatory response in the intestines, Ag-NPs, paradoxically, also showed a potential anti-infammatory effect manifested in down-regulated IL-8 levels. Quercetin, co-administered with Ag-NPs, led to a reduction of cytotoxicity, oxidative stress, and recovered metabolic activity of Caco-2 cells, suggesting the protective effects of this flavonoid against the harmful effect of Ag-NPs. Quercetin not only alleviated the effect of Ag-NPs on the gastrointestinal cells, but also demonstrated a potential to serve as a tool for reversible modulation of intestinal permeability. PMID:27113704

  4. Impact of oral bisphenol A at reference doses on intestinal barrier function and sex differences after perinatal exposure in rats.

    PubMed

    Braniste, Viorica; Jouault, Aurore; Gaultier, Eric; Polizzi, Arnaud; Buisson-Brenac, Claire; Leveque, Mathilde; Martin, Pascal G; Theodorou, Vassilia; Fioramonti, Jean; Houdeau, Eric

    2010-01-01

    Bisphenol A (BPA), a chemical estrogen widely used in the food-packaging industry and baby bottles, is recovered in human fluids (0.1-10 nM). Recent studies have reported that BPA is hormonally active at low doses, emphasizing the debate of a risk for human health. Estrogen receptors are expressed in the colon, and although the major route of BPA exposure is food, the effects on gut have received no attention. We first examined the endocrine disrupting potency of BPA on colonic paracellular permeability (CPP), experimental colitis, and visceral sensitivity in ovariectomized rats orally exposed to 5 mg/kg/d BPA (i.e., the no observed adverse effect level), 50 microg/kg/d BPA (i.e., tolerable daily intake), or lower doses. BPA dose-dependently decreased basal CPP, with a half-maximal inhibitory dose of 5.2 microg/kg/d, 10-fold below the tolerable daily intake. This correlated with an increase in epithelial tight junction sealing, also observed in Caco-2 cells exposed to 10 nM BPA. When ovariectomized rats were fed with BPA at the no observed adverse effect level, the severity of colitis was reduced, whereas the same dose increased pain sensitivity to colorectal stimuli. We then examined the impact of perinatal exposure to BPA on intestinal permeability and inflammatory response in the offspring. In female rats, but not in male rats, perinatal BPA evoked a decrease of CPP in adulthood, whereas the proinflammatory response of colonic mucosa was strengthened. This study first demonstrates that the xenoestrogen BPA at reference doses influences intestinal barrier function and gut nociception. Moreover, perinatal exposure promotes the development of severe inflammation in adult female offspring only. PMID:20018722

  5. High therapeutic efficacy of Cathelicidin-WA against postweaning diarrhea via inhibiting inflammation and enhancing epithelial barrier in the intestine

    PubMed Central

    Yi, Hongbo; Zhang, Lin; Gan, Zhenshun; Xiong, Haitao; Yu, Caihua; Du, Huahua; Wang, Yizhen

    2016-01-01

    Diarrhea is a leading cause of death among young mammals, especially during weaning. Here, we investigated the effects of Cathelicidin-WA (CWA) on diarrhea, intestinal morphology, inflammatory responses, epithelial barrier and microbiota in the intestine of young mammals during weaning. Piglets with clinical diarrhea were selected and treated with saline (control), CWA or enrofloxacin (Enro) for 4 days. Both CWA and Enro effectively attenuated diarrhea. Compared with the control, CWA decreased IL-6, IL-8 and IL-22 levels and reduced neutrophil infiltration into the jejunum. CWA inhibited inflammation by down-regulating the TLR4-, MyD88- and NF-κB-dependent pathways. Additionally, CWA improved intestinal morphology by increasing villus and microvillus heights and enhancing intestinal barrier function by increasing tight junction (TJ) protein expression and augmenting wound-healing ability in intestinal epithelial cells. CWA also improved microbiota composition and increased short-chain fatty acid (SCFA) levels in feces. By contrast, Enro not only disrupted the intestinal barrier but also negatively affected microbiota composition and SCFA levels in the intestine. In conclusion, CWA effectively attenuated inflammation, enhanced intestinal barrier function, and improved microbiota composition in the intestines of weaned piglets. These results suggest that CWA could be an effective and safe therapy for diarrhea or other intestinal diseases in young mammals. PMID:27181680

  6. High therapeutic efficacy of Cathelicidin-WA against postweaning diarrhea via inhibiting inflammation and enhancing epithelial barrier in the intestine.

    PubMed

    Yi, Hongbo; Zhang, Lin; Gan, Zhenshun; Xiong, Haitao; Yu, Caihua; Du, Huahua; Wang, Yizhen

    2016-01-01

    Diarrhea is a leading cause of death among young mammals, especially during weaning. Here, we investigated the effects of Cathelicidin-WA (CWA) on diarrhea, intestinal morphology, inflammatory responses, epithelial barrier and microbiota in the intestine of young mammals during weaning. Piglets with clinical diarrhea were selected and treated with saline (control), CWA or enrofloxacin (Enro) for 4 days. Both CWA and Enro effectively attenuated diarrhea. Compared with the control, CWA decreased IL-6, IL-8 and IL-22 levels and reduced neutrophil infiltration into the jejunum. CWA inhibited inflammation by down-regulating the TLR4-, MyD88- and NF-κB-dependent pathways. Additionally, CWA improved intestinal morphology by increasing villus and microvillus heights and enhancing intestinal barrier function by increasing tight junction (TJ) protein expression and augmenting wound-healing ability in intestinal epithelial cells. CWA also improved microbiota composition and increased short-chain fatty acid (SCFA) levels in feces. By contrast, Enro not only disrupted the intestinal barrier but also negatively affected microbiota composition and SCFA levels in the intestine. In conclusion, CWA effectively attenuated inflammation, enhanced intestinal barrier function, and improved microbiota composition in the intestines of weaned piglets. These results suggest that CWA could be an effective and safe therapy for diarrhea or other intestinal diseases in young mammals. PMID:27181680

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

    SciTech Connect

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

    2010-06-15

    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 [{sup 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 [{sup 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-{kappa}B, 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.

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

    PubMed Central

    2013-01-01

    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. PMID:24359581

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

    PubMed Central

    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

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

    PubMed

    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. PMID:21248165

  11. Dimethyl sulfoxide inhibits zymosan-induced intestinal inflammation and barrier dysfunction

    PubMed Central

    Li, Yu-Meng; Wang, Hai-Bin; Zheng, Jin-Guang; Bai, Xiao-Dong; Zhao, Zeng-Kai; Li, Jing-Yuan; Hu, Sen

    2015-01-01

    AIM: To investigate whether dimethyl sulfoxide (DMSO) inhibits gut inflammation and barrier dysfunction following zymosan-induced systemic inflammatory response syndrome and multiple organ dysfunction syndrome. METHODS: Sprague-Dawley rats were randomly divided into four groups: sham with administration of normal saline (SS group); sham with administration of DMSO (SD group); zymosan with administration of normal saline (ZS group); and zymosan with administration of DMSO (ZD group). Each group contained three subgroups according to 4 h, 8 h, and 24 h after surgery. At 4 h, 8 h, and 24 h after intraperitoneal injection of zymosan (750 mg/kg), the levels of intestinal inflammatory cytokines [tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-10] and oxides (myeloperoxidase, malonaldehyde, and superoxide dismutase) were examined. The levels of diamine oxidase (DAO) in plasma and intestinal mucosal blood flow (IMBF) were determined. Intestinal injury was also evaluated using an intestinal histological score and apoptosis of intestinal epithelial cells was determined by deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The intestinal epithelial tight junction protein, ZO-1, was observed by immunofluorescence. RESULTS: DMSO decreased TNF-α and increased IL-10 levels in the intestine compared with the ZS group at the corresponding time points. The activity of intestinal myeloperoxidase in the ZS group was higher than that in the ZD group 24 h after zymosan administration (P < 0.05). DMSO decreased the content of malondialdehyde (MDA) and increased the activity of superoxide dehydrogenase (SOD) 24 h after zymosan administration. The IMBF was lowest at 24 h and was 49.34% and 58.26% in the ZS group and ZD group, respectively (P < 0.05). DMSO alleviated injury in intestinal villi, and the gut injury score was significantly lower than the ZS group (3.6 ± 0.2 vs 4.2 ± 0.3, P < 0.05). DMSO decreased the level of DAO in plasma compared with the ZS

  12. Partial Enteral Nutrition Mitigated Ischemia/Reperfusion-Induced Damage of Rat Small Intestinal Barrier

    PubMed Central

    Wu, Chao; Wang, Xinying; Jiang, Tingting; Li, Chaojun; Zhang, Li; Gao, Xuejin; Tian, Feng; Li, Ning; Li, Jieshou

    2016-01-01

    Background and Aims: This study was designed to investigate a relatively optimum dose of partial enteral nutrition (PEN) which effectively attenuates intestinal barrier dysfunction initiated by ischemia/reperfusion injury (IRI). Methods: In experiment 1, 60 male Sprague-Dawley (SD) rats were subjected to intestinal IRI and assigned to six groups according to the different proportion of EN administrations: namely total parenteral nutrition (TPN or 0%EN), 10%EN, 20%EN, 40%EN, 60%EN, and total enteral nutrition (TEN or 100%) groups, the deficits of intraluminal calorie were supplemented by PN. In experiment 2, 50 male SD rats were subjected to intestinal IRI and divided into five groups based on the results of experiment 1: TPN, TEN, 20%EN, TPN plus pretreatment with NF-κB antagonist 30 min before IRI (TPN+PDTC), and TPN plus pretreatment with HIF-1α antagonist 30 min before IRI (TPN+YC-1) groups. Results: In experiment 1, previous IRI combined with subsequent EN shortage disrupted the structure of intestinal epithelial cell and tight junctions (TJs). While 20% dose of EN had an obviously protective effect on these detrimental consequences. In experiment 2, compared with TPN only, 20%EN exerted a significant protection of barrier function of intestinal epithelium. Analogous results were observed when TPN combined with specific NF-κB/HIF-1α inhibitors (PDTC and YC-1). Meanwhile, the expression of NF-κB/HIF-1α had a similar trend among the groups. Conclusions: Our findings indicate that 20%EN is the minimally effective dosage of EN which promotes the recovery of intestinal barrier function after IRI in a rat model. Furthermore, we discreetly speculate that this benefit is, at least partly, related to NF-κB/HIF-1α pathway expression. PMID:27548209

  13. Impaired function of the intestinal barrier in a novel sub-health rat model

    PubMed Central

    FENG, SISI; LIU, WEIDONG; ZUO, SHENGNAN; XIE, TINGYAN; DENG, HUI; ZHANG, QIUHUAN; ZHONG, BAIYUN

    2016-01-01

    Sub-health is a state featuring a deterioration in physiological function between health and illness, and the sub-health condition has surfaced as life-threatening in humans. The aim of the present study was to establish a sub-health model in rats, and investigate the function of the intestinal barrier in the sub-health rats and rats following intervention. To establish a sub-health model, the rats were subjected to a high-fat and sugar diet, motion restriction and chronic stress. Their serum glucose and triglyceride levels, immune function and adaptability were then measured. The levels of diamine oxidase and D-lactic acid in the plasma were analyzed as markers of the intestinal permeability. The protein and mRNA expression levels of anti-apoptotic YWHAZ in the colonic tissue was detected using immunohistochemical and reverse transcription-quantitative polymerase chain reaction analyses In the present study, the sub-health rat model was successfully established, and sub-health factors increased the intestinal permeability and reduced the expression of YWHAZ. Providing sub-health rats with normal living conditions did not improve the function of the intestinal barrier. In conclusion, the results of the present study demonstrated that intestinal disorders in the sub-health rat model may result from the damage caused by reduce intestinal barrier function as well as the decreased expression levels of YWHAZ. Additionally, rats in the sub-health condition did not recover following subsequent exposure to normal living conditions, suggesting that certain exercises or medical intervention may be necessary to improve sub-health symptoms. PMID:26957295

  14. Casein glycomacropeptide in the diet may reduce Escherichia coli attachment to the intestinal mucosa and increase the intestinal lactobacilli of early weaned piglets after an enterotoxigenic E. coli K88 challenge.

    PubMed

    Gustavo Hermes, Rafael; Molist, Francesc; Francisco Pérez, José; Gómez de Segura, Arantza; Ywazaki, Mauro; Davin, Roger; Nofrarías, Miquel; Korhonen, Timo K; Virkola, Ritva; Martín-Orúe, Susana María

    2013-03-28

    Casein glycomacropeptide (CGMP), a glycoprotein originating during cheese manufacture, has shown promising effects by promoting the growth of some beneficial bacteria in vitro, although its activity has not been well explored. The present study was designed to evaluate the effects of CGMP against enterotoxigenic Escherichia coli (ETEC) K88 in vitro (Trial 1) and in vivo (Trial 2). In Trial 1, increasing concentrations of CGMP (0, 0.5, 1.5 or 2.5 mg/ml) were tested regarding its ability to block the attachment of ETEC K88 to ileal mucosa tissues obtained from piglets. Increasing the concentration of CGMP resulted in a gradual decrease in ETEC K88 attachment to the epithelial surface. In Trial 2, seventy-two piglets were distributed in a 2 × 2 factorial combination including or omitting CGMP in the diet (control diet v. CGMP) and challenged or not with ETEC K88 (yes v. no). Inclusion of CGMP increased crude protein, ammonia and isoacid concentrations in colon digesta. CGMP also increased lactobacilli numbers in ileum and colon digesta, and reduced enterobacteria counts in mucosa scrapings and the percentage of villi with E. coli adherence measured by fluorescence in situ hybridisation. The inclusion of CGMP in the diets of challenged animals also prevented the increase of enterobacteria in ileal digesta. We can conclude that CGMP may improve gut health by diminishing the adhesion of ETEC K88 to the intestinal mucosa, by increasing the lactobacilli population in the intestine and by reducing the overgrowth of enterobacteria in the digestive tract of piglets after an ETEC K88 challenge. PMID:22850079

  15. Experimental diabetes induces an early change in the level of the G-protein subunit, alpha i2, in rat intestinal mucosa.

    PubMed

    Lacombe, C R; Viallard, V P; Schaak, S A; Paris, H J

    1996-12-01

    This study was undertaken to investigate the consequences of diabetes on Gi-protein expression and alpha 2-adrenergic receptivity in rat intestinal mucosa. Experimental diabetes was induced by treatment with streptozotocin. Quantification of alpha i-subunits by immunoblotting demonstrated that the level of the G alpha i2 but not the G alpha i3 subunit was markedly decreased in jejunum and colon membranes from diabetic rats as compared to controls. Parallel assessment of sympathetic innervation was performed by determination of norepinephrine content, measurement of tyrosine hydroxylase and monoamine oxidase activities, and quantification of alpha 2-adrenergic receptors in the different segments. At this stage of diabetes (6 weeks after streptozotocin injection), none of these parameters was significantly modified. Consequently, the decrease in G alpha i2 amount appears to be independent of the neuropathy describe in later stages of diabetes. PMID:8985652

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

    PubMed Central

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

    2015-01-01

    AIM: 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. METHODS: 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 14th 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. RESULTS: 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 < 0.01). The increasing levels of the aforementioned markers were more significant in the obstructive jaundice group than in the GLP-2 group (P < 0.01). CONCLUSION: GLP-2 reduces intestinal mucosal injuries in obstructive jaundice rats, which might be attributed to increased intestinal IgA and reduced bilirubin and endotoxin. PMID:25593463

  17. Barrier protection via Toll-like receptor 2 signaling in porcine intestinal epithelial cells damaged by deoxynivalnol.

    PubMed

    Gu, Min Jeong; Song, Sun Kwang; Lee, In Kyu; Ko, Seongyeol; Han, Seung Eun; Bae, Suhan; Ji, Sang Yun; Park, Byung-Chul; Song, Ki-Duk; Lee, Hak-Kyo; Han, Seung Hyun; Yun, Cheol-Heui

    2016-01-01

    Intestinal barrier is the first line of defense inside the body and comprises intercellular tight junction (TJ) proteins that regulate paracellular permeability. Deoxynivalenol (DON), a fungal metabolite often found in the contaminated food of domestic animals, is known to impair intestinal barrier function and may be involved in intestinal inflammation. Unlike in humans and mice, the importance of Toll-like receptor (TLR) 2 expressed in porcine intestinal epithelial cells is largely unclear. Therefore, the aim of the present study was to investigate whether TLR2 stimulation enhances intestinal barrier function and protects against DON exposure. We found that the cells treated with TLR2 ligands decreased the epithelial barrier permeability and enhanced TJ protein expression in intestinal porcine epithelial cells (IPEC-J2). In addition, pretreatment with TLR2 ligand, including Pam3CSK4 (PCSK) and lipoteichoic acid from Bacillus subtilis, prevented DON-induced barrier dysfunction by increasing the expression of TJ proteins via the PI3K-Akt-dependent pathway. It is likely that the DON-disrupted intestinal barrier caused biological changes of immune cells in the lamina propria. Thus, we conducted co-culture of differentiated IPEC-J2 cells in the upper well together with peripheral blood mononuclear cells in the bottom well and found that apical TLR2 stimulation of IPEC-J2 cells could alleviate the reduction in cell survival and proliferation of immune cells. Conclusively, TLR2 signaling on intestinal epithelial cells may enhance intestinal barrier function and prevent DON-induced barrier dysfunction of epithelial cells. PMID:26857454

  18. Fucoidan enhances intestinal barrier function by upregulating the expression of claudin-1

    PubMed Central

    Iraha, Atsushi; Chinen, Hiroshi; Hokama, Akira; Yonashiro, Takumi; Kinjo, Tetsu; Kishimoto, Kazuto; Nakamoto, Manabu; Hirata, Tetsuo; Kinjo, Nagisa; Higa, Futoshi; Tateyama, Masao; Kinjo, Fukunori; Fujita, Jiro

    2013-01-01

    AIM: To evaluate the protective effects of fucoidan on oxidative stress-induced barrier disruption in human intestinal epithelial cells. METHODS: In Caco-2 cell monolayer models, the disruption of barrier function by oxidative stress is mediated by H2O2. The integrity of polarized Caco-2 cell monolayers was determined by measuring the transepithelial resistance (TER) and permeability was estimated by measuring the paracellular transport of FITC-labeled 4-kDa dextran (FD4). The protective effects of fucoidan on epithelial barrier functions on polarized Caco-2 cell monolayers were evaluated by TER and FD4 flux. The expression of tight junction (TJ) proteins was assessed using reverse-transcription polymerase chain reaction (RT-PCR) and immunofluorescence staining. RESULTS: Without H2O2 treatment, fucoidan significantly increased the TER compared to control (P < 0.05), indicating a direct enhancement of intestinal epithelial barrier function. Next, H2O2 disrupted the epithelial barrier function in a time-dependent manner. Fucoidan prevented the H2O2-induced destruction in a dose-dependent manner. Fucoidan significantly decreased H2O2-induced FD4 flux (P < 0.01), indicating the prevention of disruption in paracellular permeability. RT-PCR showed that Caco-2 cells endogenously expressed claudin-1 and -2, and occludin and that H2O2 reduced the mRNA expression of these TJ proteins. Treatment with fucoidan attenuated the reduction in the expressions of claudin-1 and claudin-2 but not occludin. Immunofluorescence staining revealed that the expression of claudin-1 was intact and high on the cell surface. H2O2 disrupted the integrity of claudin-1. Treatment with fucoidan dramatically attenuated the expression of claudin-1. CONCLUSION: Fucoidan enhanced intestinal epithelial barrier function by upregulating the expression of claudin-1. Thus, fucoidan may be an appropriate therapy for the treatment of inflammatory bowel diseases. PMID:24023493

  19. Early weaning stress impairs development of mucosal barrier function in the porcine intestine

    PubMed Central

    Smith, Feli; Clark, Jessica E.; Overman, Beth L.; Tozel, Christena C.; Huang, Jennifer H.; Rivier, Jean E. F.; Blisklager, Anthony T.

    2010-01-01

    Early life stress is a predisposing factor for the development of chronic intestinal disorders in adult life. Here, we show that stress associated with early weaning in pigs leads to impaired mucosal barrier function. Early weaning (15- to 21-day weaning age) resulted in sustained impairment in intestinal barrier function, as indicated by reductions in jejunal transepithelial electrical resistance and elevations in mucosal-to-serosal flux of paracellular probes [3H]mannitol and [14C]inulin measured at 5 and 9 wk of age, compared with that shown in late-weaned pigs (23- to 28-day weaning age). Elevated baseline short-circuit current was observed in jejunum from early-weaned pigs and was shown to be mediated via enhanced Cl− secretion. Jejunal barrier dysfunction in early-weaned pigs coincided with increased lamina propria immune cell density particularly mucosal mast cells. The mast cell stabilizer drug sodium cromoglycolate ameliorated barrier dysfunction and hypersecretion in early-weaned pigs, demonstrating an important role of mast cells. Furthermore, activation of mast cells ex vivo with c48/80 and corticotrophin-releasing factor (CRF) in pig jejunum mounted in Ussing chambers induced barrier dysfunction and elevations in short-circuit current that were inhibited with mast cell protease inhibitors. Experiments in which selective CRF receptor antagonists were administered to early-weaned pigs revealed that CRF receptor 1 (CRFr1) activation mediates barrier dysfunction and hypersecretion, whereas CRFr2 activation may be responsible for novel protective properties in the porcine intestine in response to early life stress. PMID:19926814

  20. Trophic and cytoprotective nutrition for intestinal adaptation, mucosal repair, and barrier function.

    PubMed

    Ziegler, Thomas R; Evans, Mary E; Fernández-Estívariz, Concepción; Jones, Dean P

    2003-01-01

    Intestinal epithelial cell turnover (proliferation, migration, differentiation, and apoptosis) and gut barrier functions are dynamic processes that are markedly affected by nutritional status, the route of feeding, and the adequacy of specific nutrients in the diet. Emerging studies are defining potential therapeutic roles for specific nutrients and diet-derived compounds (including arginine, glutamate, glutamine, glutathione, glycine, vitamin A, zinc, and specific lipids) in gut mucosal turnover, repair, adaptation after massive bowel resection, and barrier function. The role and regulation of endogenous bowel flora in generating short-chain fatty acids from diet-derived fiber and other diet-derived compounds and the effects of these agents on gut function are increasingly being elucidated. Results of these investigations should define new nutritional methods for trophic and cytoprotective effects on the intestine in conditions such as inflammatory bowel disease, malnutrition, and short bowel syndrome. PMID:12626687

  1. Hypoxia-Inducible Factor 1–Dependent Induction of Intestinal Trefoil Factor Protects Barrier Function during Hypoxia

    PubMed Central

    Furuta, Glenn T.; Turner, Jerrold R.; Taylor, Cormac T.; Hershberg, Robert M.; Comerford, Katrina; Narravula, Sailaja; Podolsky, Daniel K.; Colgan, Sean P.

    2001-01-01

    Mucosal organs such as the intestine are supported by a rich and complex underlying vasculature. For this reason, the intestine, and particularly barrier-protective epithelial cells, are susceptible to damage related to diminished blood flow and concomitant tissue hypoxia. We sought to identify compensatory mechanisms that protect epithelial barrier during episodes of intestinal hypoxia. Initial studies examining T84 colonic epithelial cells revealed that barrier function is uniquely resistant to changes elicited by hypoxia. A search for intestinal-specific, barrier-protective factors revealed that the human intestinal trefoil factor (ITF) gene promoter bears a previously unappreciated binding site for hypoxia-inducible factor (HIF)-1. Hypoxia resulted in parallel induction of ITF mRNA and protein. Electrophoretic mobility shift assay analysis using ITF-specific, HIF-1 consensus motifs resulted in a hypoxia-inducible DNA binding activity, and loading cells with antisense oligonucleotides directed against the α chain of HIF-1 resulted in a loss of ITF hypoxia inducibility. Moreover, addition of anti-ITF antibody resulted in a loss of barrier function in epithelial cells exposed to hypoxia, and the addition of recombinant human ITF to vascular endothelial cells partially protected endothelial cells from hypoxia-elicited barrier disruption. Extensions of these studies in vivo revealed prominent hypoxia-elicited increases in intestinal permeability in ITF null mice. HIF-1–dependent induction of ITF may provide an adaptive link for maintenance of barrier function during hypoxia. PMID:11342587

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

    PubMed

    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. PMID:26966939

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

    PubMed Central

    Wang, Kai; Jin, Xiaolu; Chen, Yifan; Song, Zehe; Jiang, Xiasen; Hu, Fuliang; Conlon, Michael A.; Topping, David L.

    2016-01-01

    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. PMID:27164138

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

    PubMed

    Wang, Kai; Jin, Xiaolu; Chen, Yifan; Song, Zehe; Jiang, Xiasen; Hu, Fuliang; Conlon, Michael A; Topping, David L

    2016-01-01

    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. PMID:27164138

  5. Chemokines and chemokine receptors in mucosal homeostasis at the intestinal epithelial barrier in inflammatory bowel disease.

    PubMed

    Zimmerman, Noah P; Vongsa, Rebecca A; Wendt, Michael K; Dwinell, Michael B

    2008-07-01

    Chemokines, a large family of small chemoattractive cytokines, and their receptors play an integral role in the regulation of the immune response and homeostasis. The ability of chemokines to attract specific populations of immune cells sets them apart from other chemoattractants. Chemokines produced within the gastrointestinal mucosa are critical players in directing the balance between physiological and pathophysiological inflammation in health, inflammatory bowel disease (IBD), and the progression to colon cancer. In addition to the well-characterized role of chemokines in directed trafficking of immune cells to the gut mucosa, the expression of chemokine receptors on the cells of the epithelium makes them active participants in the chemokine signaling network. Recent findings demonstrate an important role for chemokines and chemokine receptors in epithelial barrier repair and maintenance as well as an intricate involvement in limiting metastasis of colonic carcinoma. Increased recognition of the association between barrier defects and inflammation and the subsequent progression to cancer in IBD thus implicates chemokines as key regulators of mucosal homeostasis and disease pathogenesis. PMID:18452220

  6. SPARC (secreted protein acidic and rich in cysteine) of the intestinal nematode Strongyloides ratti is involved in mucosa-associated parasite-host interaction.

    PubMed

    Anandarajah, Emmanuela M; Ditgen, Dana; Hansmann, Jan; Erttmann, Klaus D; Liebau, Eva; Brattig, Norbert W

    2016-06-01

    The secreted protein acidic and rich in cysteine (SPARC), found in the excretory/secretory products of Strongyloides ratti, is most strongly expressed in parasitic females. Since SPARC proteins are involved in the modulation of cell-matrix interactions, a role of the secreted S. ratti SPARC (Sr-SPARC) in the manifestation of the parasite in the host's intestine is postulated. The full-length cDNA of Sr-SPARC was identified and the protein was recombinantly expressed. The purified protein was biologically active, able to bind calcium, and to attach to mucosa-associated human cells. Addition of Sr-SPARC to an in vitro mucosal three-dimensional-cell culture model led to a time-dependent release of the cytokines TNF-α, IL-22, IL-10 and TSLP. Of importance, exposure with Sr-SPARC fostered wound closure in an intestinal epithelial cell model. Here, we demonstrate for the first time that SPARC released from the nematode is a multifunctional protein affecting the mucosal immune system. PMID:27268729

  7. Detection of a fluorescent-labeled avidin-nucleic acid nanoassembly by confocal laser endomicroscopy in the microvasculature of chronically inflamed intestinal mucosa

    PubMed Central

    Buda, Andrea; Facchin, Sonia; Dassie, Elisa; Casarin, Elisabetta; Jepson, Mark A; Neumann, Helmut; Hatem, Giorgia; Realdon, Stefano; D’Incà, Renata; Sturniolo, Giacomo Carlo; Morpurgo, Margherita

    2015-01-01

    Inflammatory bowel diseases are chronic gastrointestinal pathologies causing great discomfort in both children and adults. The pathogenesis of inflammatory bowel diseases is not yet fully understood and their diagnosis and treatment are often challenging. Nanoparticle-based strategies have been tested in local drug delivery to the inflamed colon. Here, we have investigated the use of the novel avidin-nucleic acid nanoassembly (ANANAS) platform as a potential diagnostic carrier in an experimental model of inflammatory bowel diseases. Fluorescent- labeled ANANAS nanoparticles were administered to mice with chemically induced chronic inflammation of the large intestine. Localization of mucosal nanoparticles was assessed in vivo by dual-band confocal laser endomicroscopy. This technique enables characterization of the mucosal microvasculature and crypt architecture at subcellular resolution. Intravascular nanoparticle distribution was observed in the inflamed mucosa but not in healthy controls, demonstrating the utility of the combination of ANANAS and confocal laser endomicroscopy for highlighting intestinal inflammatory conditions. The specific localization of ANANAS in inflamed tissues supports the potential of this platform as a targeted carrier for bioactive moieties in the treatment of inflammatory bowel disease. PMID:25609952

  8. Mycotoxins Deoxynivalenol and Fumonisins Alter the Extrinsic Component of Intestinal Barrier in Broiler Chickens.

    PubMed

    Antonissen, Gunther; Van Immerseel, Filip; Pasmans, Frank; Ducatelle, Richard; Janssens, Geert P J; De Baere, Siegrid; Mountzouris, Konstantinos C; Su, Shengchen; Wong, Eric A; De Meulenaer, Bruno; Verlinden, Marc; Devreese, Mathias; Haesebrouck, Freddy; Novak, Barbara; Dohnal, Ilse; Martel, An; Croubels, Siska

    2015-12-23

    Deoxynivalenol (DON) and fumonisins (FBs) are secondary metabolites produced by Fusarium fungi that frequently contaminate broiler feed. The aim of this study was to investigate the impact of DON and/or FBs on the intestinal barrier in broiler chickens, more specifically on the mucus layer and antioxidative response to oxidative stress. One-day-old broiler chicks were divided into four groups, each consisting of eight pens of seven birds each, and were fed for 15 days either a control diet, a DON-contaminated diet (4.6 mg DON/kg feed), a FBs-contaminated diet (25.4 mg FB1 + FB2/kg feed), or a DON+FBs-contaminated diet (4.3 mg DON and 22.9 mg FB1 + FB2/kg feed). DON and FBs affected the duodenal mucus layer by suppressing intestinal mucin (MUC) 2 gene expression and altering the mucin monosaccharide composition. Both mycotoxins decreased gene expression of the intestinal zinc transporter (ZnT)-1 and regulated intracellular methionine homeostasis, which are both important for preserving the cell's critical antioxidant activity. Feeding a DON- and/or FBs-contaminated diet, at concentrations close to the European Union maximum guidance levels (5 mg DON and 20 mg FB1 + FB2/kg feed) changes the intestinal mucus layer and several intestinal epithelial antioxidative mechanisms. PMID:26632976

  9. Delivery of a mucin domain enriched in cysteine residues strengthens the intestinal mucous barrier.

    PubMed

    Gouyer, Valérie; Dubuquoy, Laurent; Robbe-Masselot, Catherine; Neut, Christel; Singer, Elisabeth; Plet, Ségolène; Geboes, Karel; Desreumaux, Pierre; Gottrand, Frédéric; Desseyn, Jean-Luc

    2015-01-01

    A weakening of the gut mucous barrier permits an increase in the access of intestinal luminal contents to the epithelial cells, which will trigger the inflammatory response. In inflammatory bowel diseases, there is an inappropriate and ongoing activation of the immune system, possibly because the intestinal mucus is less protective against the endogenous microflora. General strategies aimed at improving the protection of the intestinal epithelium are still missing. We generated a transgenic mouse that secreted a molecule consisting of 12 consecutive copies of a mucin domain into its intestinal mucus, which is believed to modify the mucus layer by establishing reversible interactions. We showed that the mucus gel was more robust and that mucin O-glycosylation was altered. Notably, the gut epithelium of transgenic mice housed a greater abundance of beneficial Lactobacillus spp. These modifications were associated with a reduced susceptibility of transgenic mice to chemically induced colitis. Furthermore, transgenic mice cleared faster Citrobacter rodentium bacteria which were orally given and mice were more protected against bacterial translocation induced by gavage with adherent-invasive Escherichia coli. Our data show that delivering the mucin CYS domain into the gut lumen strengthens the intestinal mucus blanket which is impaired in inflammatory bowel diseases. PMID:25974250

  10. Delivery of a mucin domain enriched in cysteine residues strengthens the intestinal mucous barrier

    PubMed Central

    Gouyer, Valérie; Dubuquoy, Laurent; Robbe-Masselot, Catherine; Neut, Christel; Singer, Elisabeth; Plet, Ségolène; Geboes, Karel; Desreumaux, Pierre; Gottrand, Frédéric; Desseyn, Jean-Luc

    2015-01-01

    A weakening of the gut mucous barrier permits an increase in the access of intestinal luminal contents to the epithelial cells, which will trigger the inflammatory response. In inflammatory bowel diseases, there is an inappropriate and ongoing activation of the immune system, possibly because the intestinal mucus is less protective against the endogenous microflora. General strategies aimed at improving the protection of the intestinal epithelium are still missing. We generated a transgenic mouse that secreted a molecule consisting of 12 consecutive copies of a mucin domain into its intestinal mucus, which is believed to modify the mucus layer by establishing reversible interactions. We showed that the mucus gel was more robust and that mucin O-glycosylation was altered. Notably, the gut epithelium of transgenic mice housed a greater abundance of beneficial Lactobacillus spp. These modifications were associated with a reduced susceptibility of transgenic mice to chemically induced colitis. Furthermore, transgenic mice cleared faster Citrobacter rodentium bacteria which were orally given and mice were more protected against bacterial translocation induced by gavage with adherent–invasive Escherichia coli. Our data show that delivering the mucin CYS domain into the gut lumen strengthens the intestinal mucus blanket which is impaired in inflammatory bowel diseases. PMID:25974250

  11. Methotrexate administration induces differential and selective protein tyrosine nitration and cysteine nitrosylation in the subcellular organelles of the small intestinal mucosa of rats.

    PubMed

    Natarajan, Kasthuri; Abraham, Premila

    2016-05-01

    Gastrointestinal toxicity is one of the most frequent dose limiting side effects of methotrexate (MTX), a commonly used chemotherapeutic drug. Peroxynitrite (PON) overproduction is reported to contribute to MTX induced gastrointestinal mucositis. However, the consequence of PON overproduction i.e. protein tyrosine nitration and protein cysteine nitrosylation, the subcellular distribution of these modified proteins and their molecular weights have not been investigated yet. Mucositis was induced in Wistar rats by the administration of 3 consecutive i.p. injections of MTX. Tyrosine nitrated proteins and cysteine nitrosylated proteins were determined in the subcellular organelles fractions of mucosa using immunoprecipitation and western blot. The proteins in the subcellular fractions were separated by 1D electrophoresis, and probed with anti -nitrotyrosine antibody and anti-nitrosocysteine antibody. After MTX treatment, a general increase in protein tyrosine nitration as well as a change in the spectrum of proteins that underwent nitration was observed. The relative densities of the 3 nitrotyrosine protein adducts were as follows: Mitochondria > cytosol > microsomes > nucleus. In the mitochondrial fraction increased nitration of 12 kDa, 25 kDa 29Kda, 47 kDa, and 62Kda proteins, in the cytosol increased nitration of 12 kDa, 19 kDa, 45 kDa, and 60 kDa proteins and in the nuclear fraction increased nitration of 17 kDa, 35 kDa, and 58 kDa proteins was observed. On the other hand, MTX treatment resulted to a general decrease in protein cysteine nitrosylation in all the subcellular fractions. These results suggest that MTX induced, PON mediated small intestinal injury is mediated by differential nitration and nitrosylation of proteins in the subcellular organelles with increased protein tyrosine nitration and decreased cysteine nitrosylation. In addition MTX treatment results in selective nitration and nitrosylation of proteins in the intestinal mucosa. This

  12. Adaptive HIV-Specific B Cell-Derived Humoral Immune Defenses of the Intestinal Mucosa in Children Exposed to HIV via Breast-Feeding

    PubMed Central

    Moussa, Sandrine; Jenabian, Mohammad-Ali; Gody, Jean Chrysostome; Léal, Josiane; Grésenguet, Gérard; Le Faou, Alain; Bélec, Laurent

    2013-01-01

    Background We evaluated whether B cell-derived immune defenses of the gastro-intestinal tract are activated to produce HIV-specific antibodies in children continuously exposed to HIV via breast-feeding. Methods Couples of HIV-1-infected mothers (n = 14) and their breastfed non HIV-infected (n = 8) and HIV-infected (n = 6) babies, and healthy HIV-negative mothers and breastfed babies (n = 10) as controls, were prospectively included at the Complexe Pédiatrique of Bangui, Central African Republic. Immunoglobulins (IgA, IgG and IgM) and anti-gp160 antibodies from mother’s milk and stools of breastfed children were quantified by ELISA. Immunoaffinity purified anti-gp160 antibodies were characterized functionally regarding their capacity to reduce attachment and/or infection of R5- and X4- tropic HIV-1 strains on human colorectal epithelial HT29 cells line or monocyte-derived-macrophages (MDM). Results The levels of total IgA and IgG were increased in milk of HIV-infected mothers and stools of HIV-exposed children, indicating the activation of B cell-derived mucosal immunity. Breast milk samples as well as stool samples from HIV-negative and HIV-infected babies exposed to HIV by breast-feeding, contained high levels of HIV-specific antibodies, mainly IgG antibodies, less frequently IgA antibodies, and rarely IgM antibodies. Relative ratios of excretion by reference to lactoferrin calculated for HIV-specific IgA, IgG and IgM in stools of HIV-exposed children were largely superior to 1, indicating active production of HIV-specific antibodies by the intestinal mucosa. Antibodies to gp160 purified from pooled stools of HIV-exposed breastfed children inhibited the attachment of HIV-1NDK on HT29 cells by 63% and on MDM by 77%, and the attachment of HIV-1JRCSF on MDM by 40%; and the infection of MDM by HIV-1JRCSF by 93%. Conclusions The intestinal mucosa of children exposed to HIV by breast-feeding produces HIV-specific antibodies harbouring in vitro major

  13. Spatial Localization and Binding of the Probiotic Lactobacillus farciminis to the Rat Intestinal Mucosa: Influence of Chronic Stress

    PubMed Central

    Raymond, Arthur; Mercade-Loubière, Myriam; Salvador-Cartier, Christel; Ringot, Bélinda; Léonard, Renaud; Fourquaux, Isabelle; Ait-Belgnaoui, Afifa; Loubière, Pascal; Théodorou, Vassilia; Mercier-Bonin, Muriel

    2015-01-01

    The present study aimed at detecting the exogenously applied probiotic Lactobacillus farciminis in rats, after exposure to IBS-like chronic stress, based on 4-day Water Avoidance Stress (WAS). The presence of L. farciminis in both ileal and colonic mucosal tissues was demonstrated by FISH and qPCR, with ileum as the preferential niche, as for the SFB population. A different spatial distribution of the probiotic was observed: in the ileum, bacteria were organized in micro-colonies more or less close to the epithelium whereas, in the colon, they were mainly visualized far away from the epithelium. When rats were submitted to WAS, the L. farciminis population substantially decreased in both intestinal regions, due to a stress-induced increase in colonic motility and defecation, rather than a modification of bacterial binding to the intestinal mucin Muc2. PMID:26367538

  14. Activation of muscarinic cholinoceptor ameliorates tumor necrosis factor-α-induced barrier dysfunction in intestinal epithelial cells.

    PubMed

    Khan, Md Rafiqul Islam; Uwada, Junsuke; Yazawa, Takashi; Islam, Md Tariqul; Krug, Susanne M; Fromm, Michael; Karaki, Shin-ichiro; Suzuki, Yuichi; Kuwahara, Atsukazu; Yoshiki, Hatsumi; Sada, Kiyonao; Muramatsu, Ikunobu; Anisuzzaman, Abu Syed Md; Taniguchi, Takanobu

    2015-11-30

    Impaired intestinal barrier function is one of the critical issues in inflammatory bowel diseases. The aim of this study is to investigate muscarinic cholinoceptor (mAChR)-mediated signaling for the amelioration of cytokine-induced barrier dysfunction in intestinal epithelium. Rat colon challenged with TNF-α and interferon γ reduced transepithelial electrical resistance (TER). This barrier injury was attenuated by muscarinic stimulation. In HT-29/B6 intestinal epithelial cells, muscarinic stimulation suppressed TNF-α-induced activation of NF-κB signaling and barrier disruption. Finally, muscarinic stimulation promoted the shedding of TNFR1, which would be a mechanism for the attenuation of TNF-α/NF-κB signaling and barrier disruption via mAChR. PMID:26519558

  15. Gliadin intake alters the small intestinal mucosa in indomethacin-treated HLA-DQ8 transgenic mice.

    PubMed

    Mazzarella, Giuseppe; Bergamo, Paolo; Maurano, Francesco; Luongo, Diomira; Rotondi Aufiero, Vera; Bozzella, Giuseppina; Palmieri, Gianna; Troncone, Riccardo; Auricchio, Salvatore; David, Chella; Rossi, Mauro

    2014-08-01

    Celiac disease (CD) is an enteropathy caused by the ingestion of wheat gluten in genetically susceptible individuals. A complete understanding of the pathogenic mechanisms in CD has been hindered because of the lack of adequate in vivo models. In the present study, we explored the events after the intragastric administration of gliadin and of the albumin/globulin fraction from wheat in human leukocyte antigen-DQ8 transgenic mice (DQ8 mice) treated with indomethacin, an inhibitor of cyclooxygenases (COXs). After 10 days of treatment, mice showed a significant reduction of villus height, increased crypt depth, increased number of lamina propria-activated macrophages, and high basal interferon-γ secretion in mesenteric lymph nodes, all of which were specifically related to gliadin intake, whereas the albumin/globulin fraction of wheat was unable to induce similar changes. Cotreatment with NS-398, a specific inhibitor of COX-2, also induced the intestinal lesion. Enteropathy onset was further characterized by high levels of oxidative stress markers, similar to CD. Biochemical assessment of the small intestine revealed the specific activation of matrix metalloproteinases 2 and 9, high caspase-3 activity, and a significant increase of tissue transglutaminase protein levels associated with the intestinal lesion. Notably, after 30 days of treatment, enteropathic mice developed serum antibodies toward gliadin (IgA) and tissue transglutaminase (IgG). We concluded that gliadin intake in combination with COX inhibition caused a basal inflammatory status and an oxidative stress condition in the small intestine of DQ8 mice, thus triggering the mucosal lesion and, subsequently, an antigen-specific immunity. PMID:24924747

  16. Effect of fermented oatmeal soup on the cholesterol level and the Lactobacillus colonization of rat intestinal mucosa.

    PubMed

    Molin, G; Andersson, R; Ahrné, S; Lönner, C; Marklinder, I; Johansson, M L; Jeppsson, B; Bengmark, S

    1992-04-01

    Rats were fed with freeze-dried oatmeal soup fermented by six different Lactobacillus strains from rat and man; the formula is intended for enteral feeding. The serum cholesterol levels after 10 d were lower for rats eating oatmeal as compared to a commercial product, Biosorb Sond. Colonizing ability of the administered strains were evaluated in vivo. Only Lactobacillus reuteri R21c were able to, effectively, colonizing the mucosa; it represented about 30% of the Lactobacillus population 24 d after termination of the administration. L. reuteri R21c was easily recognized by the ability to produce a yellow pigment on agar plates. The identity was confirmed by carbohydrate fermentations (API 50CH), plasmid pattern and endonuclease restriction analysis of the chromosomal DNA. PMID:1519914

  17. Role of regenerating gene I in claudin expression and barrier function in the small intestine.

    PubMed

    Kitayama, Yoshitaka; Fukui, Hirokazu; Hara, Ken; Eda, Hirotsugu; Kodani, Mio; Yang, Mo; Sun, Chao; Yamagishi, Hidetsugu; Tomita, Toshihiko; Oshima, Tadayuki; Watari, Jiro; Takasawa, Shin; Miwa, Hiroto

    2016-07-01

    We have recently shown that loss of the regenerating gene (Reg) I causes susceptibility to nonsteroidal anti-inflammatory drug-induced gastrointestinal damage. However, the mechanism by which Reg I plays a protective role against this pathophysiological condition is unclear. Here, we investigated whether Reg I plays roles in the induction of tight junction proteins and mucosal barrier function in the small intestine. The small-intestinal permeability was evaluated in Reg I-deficient mice by FITC-dextran and transepithelial electrical resistance (TEER) assay. The effect of REG Iα on TEER, claudins expression, and intracellular signaling was examined using Caco2 cells in vitro. Small-intestinal expression of claudins 3 and 4 was investigated in Reg I-deficient mice in vivo. REG I deficiency significantly decreased the expression of claudin 3 in the small-intestinal epithelium. When mice were treated with indomethacin, the serum level of FITC-dextran in Reg I knockout mice was significantly higher than that in wild-type (WT) mice. The level of small-intestinal TEER was significantly decreased in Reg I knockout mice compared with WT mice under normal condition. REG Iα stimulation significantly enhanced the level of TEER in Caco2 cells. Treatment with REG Iα enhanced the expression of claudins 3 and 4 and promoted Sp1, Akt, and ERK phosphorylation in Caco2 cells, whereas these effects were attenuated by treatment with anti-REG Iα antibody. Reg I may play a role in the maintenance of mucosal barrier function by inducing tight junction proteins such as claudins 3 and 4. PMID:27055226

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

    PubMed

    Catanzaro, Daniela; Rancan, Serena; Orso, Genny; Dall'Acqua, Stefano; Brun, Paola; Giron, Maria Cecilia; Carrara, Maria; Castagliuolo, Ignazio; Ragazzi, Eugenio; Caparrotta, Laura; Montopoli, Monica

    2015-01-01

    Aminosalicylates, corticosteroids and immunosuppressants are currently the therapeutic choices in inflammatory bowel diseases (IBD), however, with limited remission and often serious side effects. Meanwhile complementary and alternative medicine (CAM) use is increasing, particularly herbal medicine. Boswellia serrata is a traditional Ayurvedic remedy with anti-inflammatory properties, of interest for its usefulness in IBDs. The mechanism of this pharmacological potential of Boswellia serrata was investigated in colonic epithelial cell monolayers exposed to H2O2 or INF-γ+TNF-α, chosen as in vitro experimental model of intestinal inflammation. The barrier function was evaluated by the transepithelial electrical resistance (TEER) and paracellular permeability assay, and by the tight junction proteins (zonula occludens-1, ZO-1 and occludin) immunofluorescence. The expression of phosphorylated NF-κB and reactive oxygen species (ROS) generation were determined by immunoblot and cytofluorimetric assay, respectively. Boswellia serrata oleo-gum extract (BSE) and its pure derivative acetyl-11-keto-β-boswellic acid (AKBA), were tested at 0.1-10 μg/ml and 0.027 μg/ml, respectively. BSE and AKBA safety was demonstrated by no alteration of intestinal cell viability and barrier function and integrity biomarkers. H2O2 or INF-γ+TNF-α treatment of Caco-2 cell monolayers significantly reduced TEER, increased paracellular permeability and caused the disassembly of tight junction proteins occludin and ZO-1. BSE and AKBA pretreatment significantly prevented functional and morphological alterations and also the NF-κB phosphorylation induced by the inflammatory stimuli. At the same concentrations BSE and AKBA counteracted the increase of ROS caused by H2O2 exposure. Data showed the positive correlation of the antioxidant activity with the mechanism involved in the physiologic maintenance of the integrity and function of the intestinal epithelium. This study elucidates the

  19. THE ROLE OF MIR-212 AND INOS IN ALCOHOL-INDUCED INTESTINAL BARRIER DYSFUNCTION AND STEATOHEPATITIS

    PubMed Central

    Tang, Yueming; Zhang, Lijuan; Forsyth, Christopher B.; Shaikh, Maliha; Song, Shiwen; Keshavarzian, Ali

    2015-01-01

    Background Alcoholic liver disease (ALD) is commonly associated with intestinal barrier dysfunction. Alcohol-induced dysregulation of intestinal tight junction (TJ) proteins, such as Zonula Occludens-1 (ZO-1), plays an important role in alcohol-induced gut leakiness. However, the mechanism of alcohol-induced disruption of TJ proteins is not well established. The goal of this study was to elucidate this mechanism by studying the role of MicroRNA 212 (miR-212) and inducible nitric oxide synthase (iNOS) in alcohol-induced gut leakiness. Methods The permeability of the Caco-2 monolayer was assessed by transepithelial electrical resistance (TER) and flux of fluorescein sulfonic acid (FSA). miR-212 was measured by real time PCR. The wild type, iNOS knockout, and miR-212 knockdown mice were fed with alcohol diet (29% of total calories, 4.5% v/v) for 8 weeks. The LNA-anti-miR-212 was used to inhibit miR-212 expression in mice. The alcohol-induced intestinal permeability, miR-212 expression and liver injuries in mice were measured. Results Our in vitro monolayer and in vivo mice studies showed that: (1) alcohol-induced over-expression of the intestinal miR-212 and intestinal hyperpermeability is prevented by using miR-212 knock-down techniques; and (2). iNOS is upregulated in the intestine by alcohol and that iNOS signaling is required for alcohol-induced miR-212 over-expression, ZO-1 disruption, gut leakiness and steatohepatis. Conclusions These studies thus support a novel miR-212 mechanism for alcohol-induced gut leakiness and a potential target that could be exploited for therapeutic intervention to prevent leaky gut and liver injury in alcoholics. PMID:26207424

  20. Nickel-Related Intestinal Mucositis in IBS-Like Patients: Laser Doppler Perfusion Imaging and Oral Mucosa Patch Test in Use.

    PubMed

    Borghini, Raffaele; Puzzono, Marta; Rosato, Edoardo; Di Tola, Marco; Marino, Mariacatia; Greco, Francesca; Picarelli, Antonio

    2016-09-01

    Nickel (Ni) is often the trigger of irritable bowel syndrome (IBS)-like gastrointestinal disorders: its ingestion may cause allergic contact mucositis, identifiable by means of oral mucosa patch test (omPT). OmPT effectiveness has been proven, but it is still an operator-dependent method. Laser Doppler perfusion imaging (LDPI) was tested to support omPT in Ni allergic contact mucositis diagnosis. Group A: 22 patients with intestinal/systemic symptoms related to the ingestion of Ni-containing foods. Group B: 12 asymptomatic volunteers. Ni-related symptoms and their severity were tested by a questionnaire. All patients underwent Ni omPT with clinical evaluation at baseline (T0), after 30 min (T1), after 2 h (T2), and after 24-48 h (T3). LDPI was performed to evaluate the mean mucosal perfusion at T0, T1, and T2. Statistical analysis was performed by ANOVA test and Bonferroni multiple-comparison test. All 22 Ni-sensitive patients (group A) presented oral mucosa hyperemia and/or edema at T2. Eight out of the same 22 patients presented a local delayed vesicular reaction at T3 (group A1), unlike the remaining 14 out of 22 patients (group A2). All 12 patients belonging to control group B did not show any alteration. The mean mucosal perfusion calculated with LDPI showed an increase in both subgroups A1 and A2. In group B, no significant perfusion variations were observed. LDPI may support omPT for diagnostic purposes in Ni allergic contact mucositis. This also applies to symptomatic Ni-sensitive patients without aphthous stomatitis after 24-48 h from omPT and that could risk to miss the diagnosis. PMID:26899317

  1. Intestinal hypoperfusion contributes to gut barrier failure in severe acute pancreatitis.

    PubMed

    Rahman, Sakhawat H; Ammori, Basil J; Holmfield, John; Larvin, Michael; McMahon, Michael J

    2003-01-01

    Intestinal barrier failure and subsequent bacterial translocation have been implicated in the development of organ dysfunction and septic complications associated with severe acute pancreatitis. Splanchnic hypoperfusion and ischemia/reperfusion injury have been postulated as a cause of increased intestinal permeability. The urinary concentration of intestinal fatty acid binding protein (IFABP) has been shown to be a sensitive marker of intestinal ischemia, with increased levels being associated with ischemia/reperfusion. The aim of the current study was to assess the relationship between excretion of IFABP in urine, gut mucosal barrier failure (intestinal hyperpermeability and systemic exposure to endotoxemia), and clinical severity. Patients with a clinical and biochemical diagnosis of acute pancreatitis were studied within 72 hours of onset of pain. Polyethylene glycol probes of 3350 kDa and 400 kDa were administered enterally, and the ratio of the percentage of retrieval of each probe after renal excretion was used as a measure of intestinal macromolecular permeability. Collected urine was also used to determine the IFABP concentration (IFABP-c) and total IFABP (IFABP-t) excreted over the 24-hour period, using an enzyme-linked immunosorbent assay technique. The systemic inflammatory response was estimated from peak 0 to 72-hour plasma C-reactive protein levels, and systemic exposure to endotoxins was measured using serum IgM endotoxin cytoplasmic antibody (EndoCAb) levels. The severity of the attack was assessed on the basis of the Atlanta criteria. Sixty-one patients with acute pancreatitis (severe in 19) and 12 healthy control subjects were studied. Compared to mild attacks, severe attacks were associated with significantly higher urinary IFABP-c (median 1092 pg/ml vs. 84 pg/ml; P < 0.001) and IFABP-t (median 1.14 microg vs. 0.21 microg; P = 0.003). Furthermore, the control group had significantly lower IFABP-c (median 37 pg/ml; P = 0.029) and IFABP-t (median

  2. Ursodeoxycholic acid ameliorates experimental ileitis counteracting intestinal barrier dysfunction and oxidative stress.

    PubMed

    Bernardes-Silva, Carlos Felipe; Damião, Adérson O M C; Sipahi, Aytan M; Laurindo, Francisco R M; Iriya, Kiyoshi; Lopasso, Fabio P; Buchpiguel, Carlos A; Lordello, Maria Laura L; Agostinho, Carmem L O; Laudanna, Antonio A

    2004-10-01

    The aim of this study was to evaluate the effect of ursodeoxycholic acid (UDCA) on intestinal permeability (IP) and reactive oxygen species (ROS) generation in indomethacin-induced enteropathy, a well-known experimental model of Crohn's disease. Seventy-eight male Wistar rats were randomly assigned to receive indomethacin, indomethacin + UDCA, or vehicles. Indomethacin induced a significant increase in the fraction of urinary excretion of 51Cr-EDTA following oral administration (7.9 +/- 1.3 vs 2.3 +/- 0.2%; P < 0.05) and lucigenin-amplified chemiluminescence in intestinal fragments ex vivo (10.1 +/- 1.9 vs 2.6 +/- 0.4 cpm x 10(3)/mg; P < 0.05) compared to controls. UDCA significantly reversed these effects (P < 0.05), without being incorporated in biliary bile acid composition (HPLC analysis). These findings support a local protective effect of UDCA in experimental ileitis by the modulation of intestinal barrier dysfunction and oxidative stress. In short, they provide insights into mechanisms of action of UDCA in intestinal inflammation and a new perspective on the treatment of Crohn's disease. PMID:15573906

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

    PubMed Central

    Yu, Qinghua; Yuan, Lixia; Deng, Jun; Yang, Qian

    2015-01-01

    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. PMID:25859435

  4. Checkpoint Kinase 1 Activation Enhances Intestinal Epithelial Barrier Function via Regulation of Claudin-5 Expression

    PubMed Central

    Watari, Akihiro; Hasegawa, Maki; Yagi, Kiyohito; Kondoh, Masuo

    2016-01-01

    Several stressors are known to influence epithelial tight junction (TJ) integrity, but the association between DNA damage and TJ integrity remains unclear. Here we examined the effects of daunorubicin and rebeccamycin, two anti-tumor chemicals that induce DNA damage, on TJ integrity in human intestinal epithelial cells. Daunorubicin and rebeccamycin dose-dependently enhanced transepithelial electrical resistance (TER) and decreased flux of the 4 kDa FITC-dextran in Caco-2 cell monolayer. Daunorubicin- or rebeccamycin-induced enhancement of the TJ barrier function partly rescued attenuation of the barrier function by the inflammatory cytokines TNF-α and IFN-γ. Daunorubicin and rebeccamycin increased claudin-5 expression and the product was distributed in the actin cytoskeleton fraction, which was enriched with TJ proteins. Caffeine, which is an inhibitor of ataxia telangiectasia mutated protein (ATM) and ataxia telangiectasia mutated and Rad3-related protein (ATR), and the Chk1 inhibitor inhibited the TER increases induced by daunorubicin and rebeccamycin, whereas a Chk2 inhibitor did not. Treatment with Chk1 siRNA also significantly inhibited the TER increases. Induction of claudin-5 expression was inhibited by Chk1 inhibitor and by siRNA treatment. Our results suggest that Chk1 activation by daunorubicin and rebeccamycin induced claudin-5 expression and enhanced TJ barrier function in Caco-2 cell monolayer, which suggests a link between DNA damage and TJ integrity in the human intestine. PMID:26727128

  5. Intestinal barrier dysfunction: implications for chronic inflammatory conditions of the bowel.

    PubMed

    Miner-Williams, Warren M; Moughan, Paul J

    2016-06-01

    The intestinal epithelium of adult humans acts as a differentially permeable barrier that separates the potentially harmful contents of the lumen from the underlying tissues. Any dysfunction of this boundary layer that disturbs the homeostatic equilibrium between the internal and external environments may initiate and sustain a biochemical cascade that results in inflammation of the intestine. Key to such dysfunction are genetic, microbial and other environmental factors that, singularly or in combination, result in chronic inflammation that is symptomatic of inflammatory bowel disease (IBD). The aim of the present review is to assess the scientific evidence to support the hypothesis that defective transepithelial transport mechanisms and the heightened absorption of intact antigenic proinflammatory oligopeptides are important contributing factors in the pathogenesis of IBD. PMID:27087106

  6. Methyl donor deficiency affects small-intestinal differentiation and barrier function in rats.

    PubMed

    Bressenot, Aude; Pooya, Shabnam; Bossenmeyer-Pourie, Carine; Gauchotte, Guillaume; Germain, Adeline; Chevaux, Jean-Baptiste; Coste, Florence; Vignaud, Jean-Michel; Guéant, Jean-Louis; Peyrin-Biroulet, Laurent

    2013-02-28

    Dietary methyl donors and their genetic determinants are associated with Crohn's disease risk. We investigated whether a methyl-deficient diet (MDD) may affect development and functions of the small intestine in rat pups from dams subjected to the MDD during gestation and lactation. At 1 month before pregnancy, adult females were fed with either a standard food or a diet without vitamin B12, folate and choline. A global wall hypotrophy was observed in the distal small bowel (MDD animals 0·30 mm v. controls 0·58 mm; P< 0·001) with increased crypt apoptosis (3·37 v. 0·4%; P< 0·001), loss of enterocyte differentiation in the villus and a reduction in intestinal alkaline phosphatase production. Cleaved caspase-3 immunostaining (MDD animals 3·37% v. controls 0·4%, P< 0·001) and the Apostain labelling index showed increased crypt apoptosis (3·5 v. 1·4%; P= 0·018). Decreased proliferation was observed in crypts of the proximal small bowel with a reduced number of minichromosome maintenance 6 (MDD animals 52·83% v. controls 83·17%; P= 0·048) and proliferating cell nuclear antigen-positive cells (46·25 v. 59 %; P= 0·05). This lack of enterocyte differentiation in the distal small bowel was associated with an impaired expression of β-catenin and a decreased β-catenin-E-cadherin interaction. The MDD affected the intestinal barrier in the proximal small bowel by decreasing Paneth cell number after immunostaining for lysosyme (MDD animals 8·66% v. controls 21·66%) and by reducing goblet cell number and mucus production after immunostaining for mucin-2 (crypts 8·66 v. 15·33%; villus 7 v. 17%). The MDD has dual effects on the small intestine by producing dramatic effects on enterocyte differentiation and barrier function in rats. PMID:22794784

  7. Stress-induced breakdown of intestinal barrier function in the rat: reversal by wood creosote.

    PubMed

    Kuge, Tomoo; Greenwood-Van Meerveld, Beverley; Sokabe, Masahiro

    2006-07-24

    Our previous studies demonstrated that wood creosote (Seirogan) inhibits intestinal secretion and normalizes the transport of electrolytes and water in rats subjected to restraint stress. The goal of the present study was to examine whether wood creosote has a protective effect against stress-induced breakdown of intestinal barrier function. F-344 rats were subjected to 90-min water avoidance stress (WAS) with wood creosote (30 mg/kg) or vehicle administered intragastrically 30 min prior to WAS. Sham stressed rats received wood creosote or vehicle treatment but did not experience the WAS. All rats were euthanized at the end of the WAS or sham-stress and the jejunum and colon were isolated. Epithelial transport was studied in modified Ussing chambers. Spontaneous secretion was assessed by electrophysiological measurement of the short circuit current (I(sc)) while electrical conductance (G) was calculated from the potential difference (PD) and I(sc) using Ohm's law. Intestinal permeability was defined by the mucosal-to-serosal flux of horseradish peroxidase (HRP). WAS significantly elevated basal I(sc) and G and increased epithelial permeability to HRP in the jejunum but not in the colon. Wood creosote resulted in a significant reduction of the stress-induced increase in I(sc), G and the mucosal-to-serosal flux of HRP compared to the vehicle-treated group. Wood creosote caused no significant effects in sham-stressed rats. The results suggest that oral administration of wood creosote may prevent stress-induced diarrhea by preventing aversive effects on small intestinal secretion and barrier function. PMID:16643959

  8. Evidence for carrier-mediated uptake and efflux of sugars at the serosal side of the rat intestinal mucosa in vitro.

    PubMed Central

    Bronk, J R; Ingham, P A

    1976-01-01

    A modification of the everted sac technique is described which allows several sacs to be prepared rapidly and simultaneously from the same segment of rat intestine. 2. A method has been developed for comparing the transport of two sugars by measuring changes in the ratios of their concentrations as they pass across the intestinal wall. 3. With this method significant differences were observed between the D-[3H]galactose and L-[14C]glucose ratios in the mucosal epithelium, the serosal tissue and the serosal compartment. These results indicate that both the efflux of galactose from the serosal side of the mucosal epithelium and the uptake of the sugar into the mucosa are carrier-mediated processes. 4. The mediated efflux of galactose at the serosal side of the epithelial layer is inhibited by the presence of phlorizin on the mucosal side and to some extent by any reduction in the mucosal Na+ concentration. Both of these treatments inhibited galactose uptake at the brush border. Serosal efflux of the sugar appeared to be saturated at high concentrations of D-galactose. 5. Pre-treatment of the sacs with mercuric chloride considerably reduced D-galactose uptake from the luminal side, but did not affect its efflux relative to L-glucose at the serosal side of the mucosal epithelium. 6. Carrier-mediated sugar uptake into the mucosal epithelium from the serosal side was also examined. The role of the bidirectional, carrier-mediated sugar transport processes at the serosal pole of the mucosal epithelial cell in transintestinal transport is discussed. PMID:1255529

  9. CXCR4 Antagonist AMD3100 Modulates Claudin Expression and Intestinal Barrier Function in Experimental Colitis

    PubMed Central

    Xia, Xian-Ming; Wang, Fang-Yu; Zhou, Ju; Hu, Kai-Feng; Li, Su-Wen; Zou, Bing-Bing

    2011-01-01

    Ulcerative colitis is a gastrointestinal disorder characterized by local inflammation and impaired epithelial barrier. Previous studies demonstrated that CXC chemokine receptor 4 (CXCR4) antagonists could reduce colonic inflammation and mucosal damage in dextran sulfate sodium (DSS)-induced colitis. Whether CXCR4 antagonist has action on intestinal barrier and the possible mechanism, is largely undefined. In the present study, the experimental colitis was induced by administration of 5% DSS for 7 days, and CXCR4 antagonist AMD3100 was administered intraperitoneally once daily during the study period. For in vitro study, HT-29/B6 colonic cells were treated with cytokines or AMD3100 for 24 h until assay. DSS-induced colitis was characterized by morphologic changes in mice. In AMD3100-treated mice, epithelial destruction, inflammatory infiltration, and submucosal edema were markedly reduced, and the disease activity index was also significantly decreased. Increased intestinal permeability in DSS-induced colitis was also significantly reduced by AMD3100. The expressions of colonic claudin-1, claudin-3, claudin-5, claudin-7 and claudin-8 were markedly decreased after DSS administration, whereas colonic claudin-2 expression was significantly decreased. Treatment with AMD3100 prevented all these changes. However, AMD3100 had no influence on claudin-3, claudin-5, claudin-7 and claudin-8 expression in HT-29/B6 cells. Cytokines as TNF-α, IL-6, and IFN-γ increased apoptosis and monolayer permeability, inhibited the wound-healing and the claudin-3, claudin-7 and claudin-8 expression in HT-29/B6 cells. We suggest that AMD3100 acted on colonic claudin expression and intestinal barrier function, at least partly, in a cytokine-dependent pathway. PMID:22073304

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

    SciTech Connect

    Shim, Sehwan; Lee, Jong-geol; Bae, Chang-hwan; Lee, Seung Bum; Jang, Won-Suk; Lee, Sun-Joo; Lee, Seung-Sook; Park, Sunhoo

    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.

  11. Bifidobacteria Prevent Tunicamycin-Induced Endoplasmic Reticulum Stress and Subsequent Barrier Disruption in Human Intestinal Epithelial Caco-2 Monolayers.

    PubMed

    Akiyama, Takuya; Oishi, Kenji; Wullaert, Andy

    2016-01-01

    Endoplasmic reticulum (ER) stress is caused by accumulation of unfolded and misfolded proteins in the ER, thereby compromising its vital cellular functions in protein production and secretion. Genome wide association studies in humans as well as experimental animal models linked ER stress in intestinal epithelial cells (IECs) with intestinal disorders including inflammatory bowel diseases. However, the mechanisms linking the outcomes of ER stress in IECs to intestinal disease have not been clarified. In this study, we investigated the impact of ER stress on intestinal epithelial barrier function using human colon carcinoma-derived Caco-2 monolayers. Tunicamycin-induced ER stress decreased the trans-epithelial electrical resistance of Caco-2 monolayers, concomitant with loss of cellular plasma membrane integrity. Epithelial barrier disruption in Caco-2 cells after ER stress was not caused by caspase- or RIPK1-dependent cell death but was accompanied by lysosomal rupture and up-regulation of the ER stress markers Grp78, sXBP1 and Chop. Interestingly, several bifidobacteria species inhibited tunicamycin-induced ER stress and thereby diminished barrier disruption in Caco-2 monolayers. Together, these results showed that ER stress compromises the epithelial barrier function of Caco-2 monolayers and demonstrate beneficial impacts of bifidobacteria on ER stress in IECs. Our results identify epithelial barrier loss as a potential link between ER stress and intestinal disease development, and suggest that bifidobacteria could exert beneficial effects on this phenomenon. PMID:27611782

  12. Intestine.

    PubMed

    Smith, J M; Skeans, M A; Horslen, S P; Edwards, E B; Harper, A M; Snyder, J J; Israni, A K; Kasiske, B L

    2016-01-01

    Intestine and intestine-liver transplant plays an important role in the treatment of intestinal failure, despite decreased morbidity associated with parenteral nutrition. In 2014, 210 new patients were added to the intestine transplant waiting list. Among prevalent patients on the list at the end of 2014, 65% were waiting for an intestine transplant and 35% were waiting for an intestine-liver transplant. The pretransplant mortality rate decreased dramatically over time for all age groups. Pretransplant mortality was highest for adult candidates, at 22.1 per 100 waitlist years compared with less than 3 per 100 waitlist years for pediatric candidates, and notably higher for candidates for intestine-liver transplant than for candidates for intestine transplant without a liver. Numbers of intestine transplants without a liver increased from a low of 51 in 2013 to 67 in 2014. Intestine-liver transplants increased from a low of 44 in 2012 to 72 in 2014. Short-gut syndrome (congenital and other) was the main cause of disease leading to both intestine and intestine-liver transplant. Graft survival improved over the past decade. Patient survival was lowest for adult intestine-liver recipients and highest for pediatric intestine recipients. PMID:26755265

  13. Studies on the physiological and structural characteristics of rat intestinal mucosa. Mitochondrial structural changes during amino acid absorption.

    PubMed

    Jasper, D K; Bronk, J R

    1968-08-01

    Sections from mucosal strips and rings of rat jejunum were studied with the light microscope and the electron microscope before and after incubation in a modified Krebs bicarbonate Ringer. Various additions were made to the incubation medium, and their effects on both the structure and the respiratory activity of the mucosal tissue were noted. In those cases in which an amino acid mixture was added, there was a pronounced increase in the rate of respiration. When strips of intestine were used, the presence of the amino acid mixture more than doubled the rate of oxygen consumption. Along with the increased levels of respiration there was a sharp rise in the percentage of mitochondria assuming a condensed ultrastructural conformation. The amino acid mixture did not cause the condensation of jejunal mitochondria if glucose was included in the incubation medium or if 2,4-dinitrophenol was present. The evidence suggests that a high proportion of the jejunal mitochondria assumes a condensed conformation in response to an increased energy demand. Apparently glucose can prevent the amino acid mixture from increasing the energy drain on the oxidative processes in these cells. Although a high rate of respiration was obtained in the presence of dinitrophenol, the studies indicated that mitochondrial condensation was only associated with a high rate of coupled oxidative phosphorylation. PMID:5664204

  14. Immunohistochemical and electron microscopic study of interaction of Yersinia enterocolitica serotype O8 with intestinal mucosa during experimental enteritis.

    PubMed Central

    Hanski, C; Kutschka, U; Schmoranzer, H P; Naumann, M; Stallmach, A; Hahn, H; Menge, H; Riecken, E O

    1989-01-01

    The experimental infection of mice with Yersinia enterocolitica serotype O8 was investigated in a quantitative and histological study. The course of bacterial penetration and spreading was precisely determined by immunohistochemical staining. After oral administration, the bacteria passed the epithelial barrier of the ileum and spread into the lamina propria. By preference they entered Peyer's patches, which were about 1,000 times more heavily colonized than the surrounding epithelium of a comparable surface area. The bacteria proliferated in the follicles, from which they spread into the lamina propria of the villi. At either site most of the bacteria multiplied extracellularly, with only a small percentage observed to be present within the phagocytes. The bacteria did not appear to be able to pass the intact basement membrane; hence, the integrity of the basement membrane is likely to play a role in determining the route of entry and limit of spread of Y. enterocolitica infection. Images PMID:2917779

  15. Nitric oxide attenuates hydrogen peroxide-induced barrier disruption and protein tyrosine phosphorylation in monolayers of intestinal epithelial cell.

    PubMed

    Katsube, Takanori; Tsuji, Hideo; Onoda, Makoto

    2007-06-01

    The intestinal epithelium provides a barrier to the transport of harmful luminal molecules into the systemic circulation. A dysfunctional epithelial barrier is closely associated with the pathogenesis of a variety of intestinal and systemic disorders. We investigated here the effects of nitric oxide (NO) and hydrogen peroxide (H(2)O(2)) on the barrier function of a human intestinal epithelial cell line, Caco-2. When treated with H(2)O(2), Caco-2 cell monolayers grown on permeable supports exhibited several remarkable features of barrier dysfunction as follows: a decrease in transepithelial electrical resistance, an increase in paracellular permeability to dextran, and a disruption of the intercellular junctional localization of the scaffolding protein ZO-1. In addition, an induction of tyrosine phosphorylation of numerous cellular proteins including ZO-1, E-cadherin, and beta-catenin, components of tight and adherens junctions, was observed. On the other hand, combined treatment of Caco-2 monolayers with H(2)O(2) and an NO donor (NOC5 or NOC12) relieved the damage to the barrier function and suppressed the protein tyrosine phosphorylation induced by H(2)O(2) alone. These results suggest that NO protects the barrier function of intestinal epithelia from oxidative stress by modulating some intracellular signaling pathways of protein tyrosine phosphorylation in epithelial cells. PMID:17451824

  16. Compromised intestinal epithelial barrier induces adaptive immune compensation that protects from colitis

    PubMed Central

    Khounlotham, Manirath; Kim, Wooki; Peatman, Eric; Nava, Porfirio; Medina-Contreras, Oscar; Addis, Caroline; Koch, Stefan; Fournier, Benedicte; Nusrat, Asma; Denning, Timothy L.; Parkos, Charles A.

    2012-01-01

    SUMMARY Mice lacking Junctional Adhesion Molecule A (JAM-A, encoded by F11r) exhibit enhanced intestinal epithelial permeability, bacterial translocation, and elevated colonic lymphocyte numbers, yet do not develop colitis. To investigate the contribution of adaptive immune compensation in response to increased intestinal epithelial permeability, we examined the susceptibility of F11r-/-Rag1-/- mice to acute colitis. Although negligible contributions of adaptive immunity in F11r-/-Rag1-/- mice were observed, F11r-/-Rag1-/- mice exhibited increased microflora-dependent colitis. Elimination of T cell subsets and cytokine analyses revealed a protective role for TGF-β-producing CD4+ T cells in F11r-/- mice. Additionally, loss of JAM-A resulted in elevated mucosal and serum IgA that was dependent upon CD4+ T cells and TGF-β. Absence of IgA in F11r+/+Igha-/- mice did not affect disease whereas F11r-/-Igha-/- mice displayed markedly increased susceptibility to acute injury induced colitis. These data establish a role for adaptive immune mediated protection from acute colitis under conditions of intestinal epithelial barrier compromise. PMID:22981539

  17. Low Dosage of Chitosan Supplementation Improves Intestinal Permeability and Impairs Barrier Function in Mice.

    PubMed

    Guan, Guiping; Wang, Hongbing; Peng, Hanhui; Li, Guanya

    2016-01-01

    The purpose of this study was to explore relationships between low dose dietary supplementation with chitosan (COS) and body weight, feed intake, intestinal barrier function, and permeability in mice. Twenty mice were randomly assigned to receive an unadulterated control diet (control group) or a dietary supplementation with 30 mg/kg dose of chitosan (COS group) for two weeks. Whilst no significant differences were found between the conditions for body weight or food and water intake, mice in the COS group had an increased serum D-lactate content (P < 0.05) and a decreased jejunal diamine oxidase (DAO) activity (P < 0.05). Furthermore, mice in COS group displayed a reduced expression of occludin and ZO-1 (P < 0.05) and a reduced expression of occludin in the ileum (P < 0.05). The conclusion drawn from these findings showed that although 30 mg/kg COS-supplemented diet had no effect on body weight or feed intake in mice, this dosage may compromise intestinal barrier function and permeability. This research will contribute to the guidance on COS supplements. PMID:27610376

  18. Probiotic-derived polyphosphate improves the intestinal barrier function through the caveolin-dependent endocytic pathway.

    PubMed

    Tanaka, Kazuyuki; Fujiya, Mikihiro; Konishi, Hiroaki; Ueno, Nobuhiro; Kashima, Shin; Sasajima, Junpei; Moriichi, Kentaro; Ikuta, Katsuya; Tanabe, Hiroki; Kohgo, Yutaka

    2015-11-20

    Probiotics exhibit beneficial functions for host homeostasis maintenance. We herein investigated the mechanism by which Lactobacillus brevis-derived poly P exhibited a beneficial function. Immunostaining indicated that poly P was captured in the plasma membrane via integrin β1 in Caco2/bbe cells. The uptake of poly P was reduced by the inhibition of integrin β1 as well as caveolin-1, a major component of lipid rafts. The function of poly P, including the induction of HSP27 and enhancement of the intestinal barrier function, was suppressed by the inhibition of caveolin-1, illustrating that the function of poly P was mediated by the endocytic pathway. High-throughput sequencing revealed that poly P induced tumor necrosis factor alpha-induced protein 3, which contributes to cytoprotection, including upregulation of the intestinal barrier function. The present study demonstrates a novel host-probiotic interaction through the uptake of bacterial substance into host cells, which is distinct from pattern recognition receptor pathways. PMID:26459590

  19. Low Dosage of Chitosan Supplementation Improves Intestinal Permeability and Impairs Barrier Function in Mice

    PubMed Central

    Peng, Hanhui; Li, Guanya

    2016-01-01

    The purpose of this study was to explore relationships between low dose dietary supplementation with chitosan (COS) and body weight, feed intake, intestinal barrier function, and permeability in mice. Twenty mice were randomly assigned to receive an unadulterated control diet (control group) or a dietary supplementation with 30 mg/kg dose of chitosan (COS group) for two weeks. Whilst no significant differences were found between the conditions for body weight or food and water intake, mice in the COS group had an increased serum D-lactate content (P < 0.05) and a decreased jejunal diamine oxidase (DAO) activity (P < 0.05). Furthermore, mice in COS group displayed a reduced expression of occludin and ZO-1 (P < 0.05) and a reduced expression of occludin in the ileum (P < 0.05). The conclusion drawn from these findings showed that although 30 mg/kg COS-supplemented diet had no effect on body weight or feed intake in mice, this dosage may compromise intestinal barrier function and permeability. This research will contribute to the guidance on COS supplements. PMID:27610376

  20. Protective effect of salvianolic acid B on NASH rat liver through restoring intestinal mucosal barrier function

    PubMed Central

    Wang, Ying-Chun; Jin, Qing-Mei; Kong, Wei-Zong; Chen, Juan

    2015-01-01

    Aim: To investigate the effect of Salvianolic acid B (Sal B) on the disease progress of NASH and change of intestinal barrier function. Methods: Sixty Sprague-Dawley (SD) rats were randomly divided into control group, model group and treated group, with the former given normal diet and the latter 2 groups rats fed high-fat diet. In treated group, rats were infused through the stomach with 1 mg/ml Sal B every day at a dose of 20 mL/kg body weight. All animals were killed at the 24th week and plasma levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), total cholesterol (TC), endotoxin (ET) and diamine oxdase (DAO) were analyzed using the blood samples. The histopathology of liver was observed by H&E staining. The expression changes of tight junction protein occludin and ZO-1 were analyzed by immunocytochemistry. Ultrastructural morphology of small intestinal tissues was investigated by transmission electron microscopy. Results: Plasma levels of ALT, AST, TG, TC, ET and DAO were significantly higher in model group than those in both control group and group treated with Sal B. In model group, vacuolated swelling of the cytoplasm with aggregates of chronic inflammatory cells was observed in the liver tissue but not in Sal B-treated group. NAFLD Activity Score in the treated group was significantly lower than that in model group. Immunohistochemical staining showed that Sal B administration recovered the expression of occludin and ZO-1, which was downregulated in the model group. Transmission electron microscopy analysis demonstrated that cell surface microvilli and major intercellular junctional complex including tight junction, gap junction and adherens junction were restored in Sal B-treated group. Conclusion: Sal B exerted protective function against high-fat diet-induced liver damage by restoring healthy barrier function of intestine in NASH rat model. PMID:26191218

  1. Epithelium-intrinsic NAIP/NLRC4 inflammasome drives infected enterocyte expulsion to restrict Salmonella replication in the intestinal mucosa.

    PubMed

    Sellin, Mikael E; Müller, Anna A; Felmy, Boas; Dolowschiak, Tamas; Diard, Médéric; Tardivel, Aubry; Maslowski, Kendle M; Hardt, Wolf-Dietrich

    2014-08-13

    The gut mucosal epithelium separates the host from the microbiota, but enteropathogens such as Salmonella Typhimurium (S.Tm) can invade and breach this barrier. Defenses against such acute insults remain incompletely understood. Using a murine model of Salmonella enterocolitis, we analyzed mechanisms limiting pathogen loads in the epithelium during early infection. Although the epithelium-invading S.Tm replicate initially, this intraepithelial replicative niche is restricted by expulsion of infected enterocytes into the lumen. This mechanism is compromised if inflammasome components (NAIP1-6, NLRC4, caspase-1/-11) are deleted, or ablated specifically in the epithelium, resulting in ∼100-fold higher intraepithelial loads and accelerated lymph node colonization. Interestingly, the cytokines downstream of inflammasome activation, interleukin (IL)-1α/β and IL-18, appear dispensable for epithelial restriction of early infection. These data establish the role of an epithelium-intrinsic inflammasome, which drives expulsion of infected cells to restrict the pathogen's intraepithelial proliferation. This may represent a general defense mechanism against mucosal infections. PMID:25121751

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

    PubMed Central

    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 < 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 protect against

  3. The role of hypoxia in intestinal inflammation.

    PubMed

    Shah, Yatrik M

    2016-12-01

    Inflammatory bowel disease (IBD) is a chronic relapsing inflammatory disease of the intestine. IBD is a multifactorial disorder, and IBD-associated genes are critical in innate immune response, inflammatory response, autophagy, and epithelial barrier integrity. Moreover, epithelial oxygen tension plays a critical role in intestinal inflammation and resolution in IBD. The intestines have a dynamic and rapid fluctuation in cellular oxygen tension, which is dysregulated in IBD. Intestinal epithelial cells have a steep oxygen gradient where the tips of the villi are hypoxic and the oxygenation increases at the base of the villi. IBD results in heightened hypoxia throughout the mucosa. Hypoxia signals through a well-conserved family of transcription factors, where hypoxia-inducible factor (HIF)-1α and HIF-2α are essential in maintaining intestinal homeostasis. In inflamed mucosa, HIF-1α increases barrier protective genes, elicits protective innate immune responses, and activates an antimicrobial response through the increase in β-defensins. HIF-2α is essential in maintaining an epithelial-elicited inflammatory response and the regenerative and proliferative capacity of the intestine following an acute injury. HIF-1α activation in colitis leads to a protective response, whereas chronic activation of HIF-2α increases the pro-inflammatory response, intestinal injury, and cancer. In this mini-review, we detail the role of HIF-1α and HIF-2α in intestinal inflammation and injury and therapeutic implications of targeting HIF signaling in IBD. PMID:26812949

  4. Microbiota and pathogen 'pas de deux': setting up and breaking down barriers to intestinal infection.

    PubMed

    McKenney, Elizabeth S; Kendall, Melissa M

    2016-07-01

    The gut microbiota plays essential roles in human health and disease. In this review, we focus on the role of the intestinal microbiota in promoting resistance to infection by bacterial pathogens as well as how pathogens overcome this barrier. We discuss how the resident microbiota restricts growth and colonization of invading pathogens by limiting availability of nutrients and through generation of a hostile environment. Additionally, we examine how microbiota-derived signaling molecules interfere with bacterial virulence. In turn, we discuss how pathogens exploit non-competitive metabolites to replicate in vivo as well as to precisely control virulence and cause disease. This bacterial two step of creating and overcoming challenges important in preventing and establishing infection highlights the complexities of elucidating interactions between the commensal bacteria and pathogens. Better understanding of microbiota-pathogen interplay will have significant implications for developing novel therapeutics to treat infectious diseases. PMID:27252177

  5. The methionine precursor DL-2-hydroxy-(4-methylthio)butanoic acid protects intestinal epithelial barrier function.

    PubMed

    Martín-Venegas, Raquel; Brufau, M Teresa; Guerrero-Zamora, Ana Maria; Mercier, Yves; Geraert, Pierre-André; Ferrer, Ruth

    2013-12-01

    DL-2-hydroxy-(4-methylthio)butanoic acid (HMTBA) is a source of dietary methionine (Met) that is widely used in poultry nutrition. We have previously shown that HMTBA is preferentially diverted to the transsulfuration pathway, which gives antioxidant metabolites such as taurine and glutathione. Therefore, here we hypothesize that this Met source can protect epithelial barrier function in an in vitro model of intestinal inflammation of Caco-2 cells. The results show that HMTBA prevents the increase in paracellular permeability induced by H2O2 or tumour necrosis factor-α. This effect can be attributed to the increased production of taurine and reduced glutathione. Similar results were obtained for DL-Met, although the protective role of the amino acid was less pronounced than that of the hydroxy analogue. In conclusion, the diversion to the transsulfuration pathway means that this Met precursor is of greater value than previously thought, due to its capacity to improve intestinal homeostasis and the quality of poultry products destined for human consumption. PMID:23870881

  6. Oral Typhoid Vaccination With Live-Attenuated Salmonella Typhi Strain Ty21a Generates Ty21a-Responsive and Heterologous Influenza Virus–Responsive CD4+ and CD8+ T Cells at the Human Intestinal Mucosa

    PubMed Central

    Pennington, Shaun H.; Thompson, Ameeka L.; Wright, Adam K. A.; Ferreira, Daniela M.; Jambo, Kondwani C.; Wright, Angela D.; Faragher, Brian; Gilmour, Jill W.; Gordon, Stephen B.; Gordon, Melita A.

    2016-01-01

    Background. Oral vaccination with live-attenuated Salmonella Typhi strain Ty21a is modestly efficacious, but the mechanisms of protection are currently unknown. While humoral and cellular immune responses are well described in peripheral blood, the cellular response at the intestinal mucosa has never been directly assessed. Methods. We vaccinated healthy adults with Ty21a and assessed humoral and cellular immunity in vaccinated volunteers and controls after 18 days. Immunoglobulin levels were assessed in peripheral blood by an enzyme-linked immunosorbent assay. Cellular responses were assessed in peripheral blood and at the duodenal and colonic mucosa by flow cytometry. Results. We demonstrate the generation of Ty21a-responsive and heterologous influenza virus–responsive CD4+ and CD8+ T cells at the duodenal mucosa. All duodenal responses were consistently correlated, and no responses were observed at the colonic mucosa. Peripheral anti-lipopolysaccharide immunoglobulin G and immunoglobulin A responses were significantly correlated with duodenal responses. The assessment of integrin β7 expression intensity among peripheral and duodenal T-cell subsets revealed varied capacities for mucosal homing and residence. Conclusions. The breadth of duodenal cellular responses was not reflected peripherally. The direct evaluation of mucosal immune defense may yield functional correlates of protection and could provide insight into mechanisms that may be manipulated to enhance vaccine immunogenicity. PMID:26810369

  7. Intestinal and Blood-Brain Barrier Permeability of Ginkgolides and Bilobalide: In Vitro and In Vivo Approaches

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study intestinal and blood brain barrier (BBB) transport of ginkgolides A, B, C, J and bilobalide, isolated from Ginkgo biloba (Family-Ginkgoaceae), was evaluated in Caco-2 and MDR1-MDCK cell monolayer models. Transepithelial transport was examined for 2 hours in both absorptive and secretor...

  8. CRF Induces Intestinal Epithelial Barrier Injury via the Release of Mast Cell Proteases and TNF-α

    PubMed Central

    Overman, Elizabeth L.; Rivier, Jean E.; Moeser, Adam J.

    2012-01-01

    Background and Aims Psychological stress is a predisposing factor in the onset and exacerbation of important gastrointestinal diseases including irritable bowel syndrome (IBS) and the inflammatory bowel diseases (IBD). The pathophysiology of stress-induced intestinal disturbances is known to be mediated by corticotropin releasing factor (CRF) but the precise signaling pathways remain poorly understood. Utilizing a porcine ex vivo intestinal model, the aim of this study was to investigate the mechanisms by which CRF mediates intestinal epithelial barrier disturbances. Methodology Ileum was harvested from 6–8 week-old pigs, mounted on Ussing Chambers, and exposed to CRF in the presence or absence of various pharmacologic inhibitors of CRF-mediated signaling pathways. Mucosal-to-serosal flux of 4 kDa-FITC dextran (FD4) and transepithelial electrical resistance (TER) were recorded as indices of intestinal epithelial barrier function. Results Exposure of porcine ileum to 0.05–0.5 µM CRF increased (p<0.05) paracellular flux compared with vehicle controls. CRF treatment had no deleterious effects on ileal TER. The effects of CRF on FD4 flux were inhibited with pre-treatment of tissue with the non-selective CRF1/2 receptor antagonist Astressin B and the mast cell stabilizer sodium cromolyn (10−4 M). Furthermore, anti-TNF-α neutralizing antibody (p<0.01), protease inhibitors (p<0.01) and the neural blocker tetrodotoxin (TTX) inhibited CRF-mediated intestinal barrier dysfunction. Conclusion These data demonstrate that CRF triggers increases in intestinal paracellular permeability via mast cell dependent release of TNF-α and proteases. Furthermore, CRF-mast cell signaling pathways and increases in intestinal permeability require critical input from the enteric nervous system. Therefore, blocking the deleterious effects of CRF may address the enteric signaling of mast cell degranulation, TNFα release, and protease secretion, hallmarks of IBS and IBD. PMID:22768175

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

    PubMed

    Segawa, Shuichi; Fujiya, Mikihiro; Konishi, Hiroaki; Ueno, Nobuhiro; Kobayashi, Naoyuki; Shigyo, Tatsuro; Kohgo, Yutaka

    2011-01-01

    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. PMID:21858054

  10. Cellular uptake and transcytosis of lipid-based nanoparticles across the intestinal barrier: Relevance for oral drug delivery.

    PubMed

    Neves, Ana Rute; Queiroz, Joana Fontes; Costa Lima, Sofia A; Figueiredo, Francisco; Fernandes, Rui; Reis, Salette

    2016-02-01

    Oral administration is the preferred route for drug delivery and nanosystems represent a promising tool for protection and transport of hardly soluble, chemically unstable and poorly permeable drugs through the intestinal barrier. In the present work, we have studied lipid nanoparticles cellular uptake, internalization pathways and transcytosis routes through Caco-2 cell monolayers. Both lipid nanosystems presented similar size (∼180nm) and surface charge (-30mV). Nanostructured lipid carriers showed a higher cellular uptake and permeability across the barrier, but solid lipid nanoparticles could enter cells faster than the former. The internalization of lipid nanoparticles occurs mainly through a clathrin-mediated endocytosis mechanism, although caveolae-mediated endocytosis is also involved in the uptake. Both lipid nanoparticles were able to cross the intestinal barrier by a preferential transcellular route. This work contributed to a better knowledge of the developed nanosystems for the oral delivery of a wide spectrum of drugs. PMID:26550783

  11. In Vivo and In Vitro Antinociceptive Effect of Fagopyrum cymosum (Trev.) Meisn Extracts: A Possible Action by Recovering Intestinal Barrier Dysfunction

    PubMed Central

    Liu, Lina; Cai, Xueting; Yan, Jing; Luo, Yi; Shao, Ming; Lu, Yin; Sun, Zhiguang; Cao, Peng

    2012-01-01

    Fagopyrum cymosum (Trev.) Meisn (Fag) is a herb rhizome which has been widely used to treat diseases. To investigate the effects and mechanisms of the Fag on irritable bowel syndrome (IBS), in vivo neonatal pups maternal separation (NMS) combined with intracolonic infusion of acetic acid (AA) was employed to establish IBS rat models. Fag reduced their visceral hyperalgesia and the whole gut permeability, ameliorated colonic mucosa inflammation and injury, and upregulated the expression of decreased tight junction proteins (TJs) of claudin-1, occludin, and ZO-1 (except ZO-2) in colonic epithelium. Caco-2 monolayer cells were incubated with TNF-α and IFN-γ  in vitro to establish an epithelial barrier dysfunction model whose transepithelial electrical resistance (TER) depended more on dose of Fag than that of the controls, and whose TJs levels were lower than those of the controls. Fag upregulated the NP-40 insoluble and soluble components of the four TJs markedly in a dose-dependent manner. These data suggest that Fag alleviated the hyperalgesia of IBS rats by reducing intestinal inflammation and enhancing mucosal epithelial function after regulating the structure and function of TJs. PMID:23365604

  12. Glial cell line-derived neurotrophic factor promotes barrier maturation and wound healing in intestinal epithelial cells in vitro.

    PubMed

    Meir, Michael; Flemming, Sven; Burkard, Natalie; Bergauer, Lisa; Metzger, Marco; Germer, Christoph-Thomas; Schlegel, Nicolas

    2015-10-15

    Recent data suggest that neurotrophic factors from the enteric nervous system are involved in intestinal epithelial barrier regulation. In this context the glial cell line-derived neurotrophic factor (GDNF) was shown to affect gut barrier properties in vivo directly or indirectly by largely undefined processes in a model of inflammatory bowel disease (IBD). We further investigated the potential role and mechanisms of GDNF in the regulation of intestinal barrier functions. Immunostaining of human gut specimen showed positive GDNF staining in enteric neuronal plexus and in enterocytes. In Western blots of the intestinal epithelial cell lines Caco2 and HT29B6, significant amounts of GDNF were detected, suggesting that enterocytes represent an additional source of GDNF. Application of recombinant GDNF on Caco2 and HT29B6 cells for 24 h resulted in significant epithelial barrier stabilization in monolayers with immature barrier functions. Wound-healing assays showed a significantly faster closure of the wounded areas after GDNF application. GDNF augmented cAMP levels and led to significant inactivation of p38 MAPK in immature cells. Activation of p38 MAPK signaling by SB-202190 mimicked GDNF-induced barrier maturation, whereas the p38 MAPK activator anisomycin blocked GDNF-induced effects. Increasing cAMP levels had adverse effects on barrier maturation, as revealed by permeability measurements. However, increased cAMP augmented the proliferation rate in Caco2 cells, and GDNF-induced proliferation of epithelial cells was abrogated by the PKA inhibitor H89. Our data show that enterocytes represent an additional source of GDNF synthesis. GDNF contributes to wound healing in a cAMP/PKA-dependent manner and promotes barrier maturation in immature enterocytes cells by inactivation of p38 MAPK signaling. PMID:26294673

  13. Crosstalk between Microbiota-Derived Short-Chain Fatty Acids and Intestinal Epithelial HIF Augments Tissue Barrier Function.

    PubMed

    Kelly, Caleb J; Zheng, Leon; Campbell, Eric L; Saeedi, Bejan; Scholz, Carsten C; Bayless, Amanda J; Wilson, Kelly E; Glover, Louise E; Kominsky, Douglas J; Magnuson, Aaron; Weir, Tiffany L; Ehrentraut, Stefan F; Pickel, Christina; Kuhn, Kristine A; Lanis, Jordi M; Nguyen, Vu; Taylor, Cormac T; Colgan, Sean P

    2015-05-13

    Interactions between the microbiota and distal gut are fundamental determinants of human health. Such interactions are concentrated at the colonic mucosa and provide energy for the host epithelium through the production of the short-chain fatty acid butyrate. We sought to determine the role of epithelial butyrate metabolism in establishing the austere oxygenation profile of the distal gut. Bacteria-derived butyrate affects epithelial O2 consumption and results in stabilization of hypoxia-inducible factor (HIF), a transcription factor coordinating barrier protection. Antibiotic-mediated depletion of the microbiota reduces colonic butyrate and HIF expression, both of which are restored by butyrate supplementation. Additionally, germ-free mice exhibit diminished retention of O2-sensitive dyes and decreased stabilized HIF. Furthermore, the influences of butyrate are lost in cells lacking HIF, thus linking butyrate metabolism to stabilized HIF and barrier function. This work highlights a mechanism where host-microbe interactions augment barrier function in the distal gut. PMID:25865369

  14. Contributions of altered permeability of intestinal barrier and defecation behavior to toxicity formation from graphene oxide in nematode Caenorhabditis elegans

    NASA Astrophysics Data System (ADS)

    Wu, Qiuli; Yin, Li; Li, Xing; Tang, Meng; Zhang, Tao; Wang, Dayong

    2013-09-01

    Graphene oxide (GO) has been extensively studied for potential biomedical applications. Meanwhile, potential GO toxicity arises in both biomedical applications and non-biomedical products where environmental exposures may occur. In the present study, we examined the potential adverse effects of GO and the underlying mechanism using nematode Caenorhabditis elegans as the assay system. We compared the in vivo effects of GO between acute exposure and prolonged exposure, and found that prolonged exposure to 0.5-100 mg L-1 of GO caused damage on functions of both primary (intestine) and secondary (neuron and reproductive organ) targeted organs. In the intestine, ROS production was significantly correlated with the formation of adverse effects on functions of both primary and secondary targeted organs. GO could be translocated into intestinal cells with loss of microvilli, and distributed to be adjacent to or surrounding mitochondria. Prolonged exposure to GO resulted in a hyper-permeable state of the intestinal barrier, an increase in mean defecation cycle length, and alteration of genes required for intestinal development and defecation behavior. Thus, our data suggest that prolonged exposure to GO may cause potential risk to environmental organisms after release into the environment. GO toxicity may be due to the combinational effects of oxidative stress in the intestinal barrier, enhanced permeability of the biological barrier, and suppressed defecation behavior in C. elegans.Graphene oxide (GO) has been extensively studied for potential biomedical applications. Meanwhile, potential GO toxicity arises in both biomedical applications and non-biomedical products where environmental exposures may occur. In the present study, we examined the potential adverse effects of GO and the underlying mechanism using nematode Caenorhabditis elegans as the assay system. We compared the in vivo effects of GO between acute exposure and prolonged exposure, and found that prolonged

  15. Protective Capacity of Resveratrol, a Natural Polyphenolic Compound, against Deoxynivalenol-Induced Intestinal Barrier Dysfunction and Bacterial Translocation.

    PubMed

    Ling, Ka-Ho; Wan, Murphy Lam Yim; El-Nezami, Hani; Wang, Mingfu

    2016-05-16

    Contamination of food/feedstuffs by mycotoxins is a serious problem worldwide, causing severe economic losses and serious health problems in animals/humans. Deoxynivalenol (DON) is a major mycotoxin contaminant and is known to impair intestinal barrier function. Grapes and red wine are rich in polyphenols, such as resveratrol (RES), which has striking antioxidant and anti-inflammatory activities. RES is a food-derived component; therefore, it may be simultaneously present with DON in the gastrointestinal tract. The aim of this study was to explore in vitro protective effects of RES against DON-induced intestinal damage. The results showed that RES could protect DON-induced bacteria translocation because of enhanced of intestinal barrier function by restoring the DON-induced decrease in transepithelial electrical resistance and increase in paracellular permeability. Further mechanistic studies demonstrated that RES protects against DON-induced barrier dysfunction by promoting the assembly of claudin-4 in the tight junction complex. This is probably mediated through modulation of IL-6 and IL-8 secretion via mitogen-activated protein kinase-dependent pathways. Our results imply that RES can protect against DON-induced intestinal damage and that RES may be used as a novel dietary intervention strategy to reduce DON toxicity in animals/humans. PMID:27058607

  16. Fermented Yupingfeng polysaccharides enhance immunity by improving the foregut microflora and intestinal barrier in weaning rex rabbits.

    PubMed

    Sun, Hao; Ni, Xueqin; Song, Xu; Wen, Bin; Zhou, Yi; Zou, Fuqin; Yang, Mingyue; Peng, Zhirong; Zhu, Hui; Zeng, Yan; Wang, Hesong; Fu, Xiangchao; Shi, Yunduo; Yin, Zhongqiong; Pan, Kangcheng; Jing, Bo; Zeng, Dong; Wang, Ping

    2016-09-01

    Yupingfeng (YPF) is a kind of Astragali radix-based ancient Chinese herbal supplemented with Atractylodis Macrocephalae Rhizoma and Radix Saposhnikoviae. Increasing evidence has proven the beneficial immunomodulating activity of YPF. However, the action mechanism(s) of it is not known. Here, we explored the immunomodulatory activity of unfermented Yupingfeng polysaccharides (UYP) and fermented Yupingfeng polysaccharides (FYP) obtained using Rhizopus oligosporus SH in weaning Rex rabbits. The results showed that both UYP and FYP exhibited notable growth-promoting and immune-enhancing activities, improvement of the intestinal flora homeostasis, and maintenance of intestinal barrier integrity and functionality. Notably, compared with UYP, FYP effectively enhanced average daily gain, organ indices, interleukin-2 (IL-2), IL-4, IL-10, tumor necrosis factor-alpha (TNF-α), TLR2, and TLR4 mRNA levels in spleen, IL-1, IL-2, IL-4, IL-6, IL-10, IL-12, TNF-α, and IFN-γ protein concentrations in serum, and TLR2 and TLR4 mRNA expressions in the gastrointestinal tract (GIT). Moreover, FYP exhibited greater beneficial effects in improving the intestinal flora, including augment flora diversity and the abundance of cellulolytic bacteria, reduction the abundance of Streptococcus spp. and Enterococcus spp. in the GIT, particularly the foregut and maintaining the intestinal barrier integrity and functionality by upregulating zonula occludens 1, claudin, polymeric immunoglobulin receptor, trefoil factor, and epidermal growth factor mRNA levels in the jejunum and ileum. Our results indicated the immunoenhancement effect of FYP is superior over that of UYP, which is probably related with the amelioration of the intestinal microflora and intestinal barrier in the foregut. PMID:27260288

  17. Apical effect of diosmectite on damage to the intestinal barrier induced by basal tumour necrosis factor-alpha.

    PubMed Central

    Mahraoui, L; Heyman, M; Plique, O; Droy-Lefaix, M T; Desjeux, J F

    1997-01-01

    BACKGROUND: In many digestive diseases the intestinal barrier is weakened by the release of proinflammatory cytokines, including tumour necrosis factor-alpha (TNF alpha). AIM: To investigate the protective effect of apical diosmectite on the intestinal dysfunction induced by the proinflammatory cytokine TNF alpha. METHODS: Filter grown monolayers of the intestinal cell line HT29-19A were incubated for 48 hours in basal medium containing 10 ng/ml TNF alpha and 5 U/ml interferon-gamma (IFN gamma). Next, 1, 10, or 100 mg/ml diosmectite was placed in the apical medium for one hour. Intestinal function was then assessed in Ussing chambers by measuring ionic conductance (G) and apicobasal fluxes of 14C-mannitol (Jman), and intact horseradish peroxidase. In control intestinal monolayers, diosmectite did not significantly modify G, Jman, or intact horseradish peroxidase. RESULTS: After incubation with TNF alpha and IFN gamma, intestinal function altered, as shown by the increases compared with control values for G (22.8 (3.7) v (9.6 (0.5) mS/cm2), Jman (33.8 (7.5) v 7.56 (0.67) micrograms/h x cm2), and intact horseradish peroxidase (1.95 (1.12) v 0.14 (0.04) micrograms/h x cm2). G and Jman were closely correlated, suggesting that the increase in permeability was paracellular. Treatment with diosmectite restored al the variables to control values. CONCLUSIONS: Basal TNF alpha disrupts the intestinal barrier through the tight junctions, and apical diosmectite counteracts this disruption. PMID:9135522

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

    SciTech Connect

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

    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.

  19. Hydrolytic activity toward pyridoxine-5'-beta-D-glucoside in rat intestinal mucosa is not increased by vitamin B-6 deficiency: effect of basal diet composition and pyridoxine intake.

    PubMed

    Mackey, Amy D; Lieu, Siam O; Carman, Catherine; Gregory, Jesse F

    2003-05-01

    Pyridoxine-5'-beta-D-glucoside (PNG), a glycosylated form of dietary vitamin B-6, is partially hydrolyzed in the small intestine by the cytosolic enzyme pyridoxine-5'-beta-D-glucoside hydrolase (PNG hydrolase) and by the brush border enzyme lactase phlorizin hydrolase (LPH) to release free pyridoxine (PN). This laboratory has previously shown that PNG hydrolase activity is inversely related to dietary vitamin B-6 in rats and guinea pigs. The current investigation was done to examine the effect of dietary PN on PNG hydrolytic activity and its distribution. Nutrient compositional differences between the AIN-76A and AIN-93G purified diets that were unrelated to vitamin B-6 were also examined in relation to PNG hydrolysis in rat small intestinal mucosa. Study one included rats (n = 29) that were fed the AIN-93G diet providing a range of PN concentrations for 5 wk. Rats (n = 49) in study two were fed either AIN-76A or AIN-93G each with graded concentrations of PN. In both studies, rat growth and plasma and liver pyridoxal 5'-phosphate (PLP) concentrations increased (P < 0.05) with increasing concentrations of dietary PN. PNG hydrolytic activity localized to the brush border membrane was five times that measured in the cytosol. Cytosolic PNG hydrolytic activity increased significantly with increasing dietary PN concentration in rats fed the AIN-76A, but not AIN-93G diet. Activity in the mucosal total membrane fraction did not increase in proportion to dietary PN concentration for either diet. Regardless of dietary PN concentration, the basal nutrient composition of the diets affected growth and PNG hydrolytic activity in intestinal mucosa. In contrast to previous results from this laboratory, intestinal hydrolytic activity toward PNG did not increase in vitamin B-6-deficient rats. PMID:12730423

  20. Adhesions and Healing of Intestinal Anastomoses: The Effect of Anti-Adhesion Barriers.

    PubMed

    Ntourakis, Dimitrios; Katsimpoulas, Michail; Tanoglidi, Anna; Barbatis, Calypso; Karayannacos, Panayotis E; Sergentanis, Theodoros N; Kostomitsopoulos, Nikolaos; Machairas, Anastasios

    2016-06-01

    Background Postoperative adhesions are the result of aberrant peritoneal healing. As they are the leading cause of postoperative bowel obstruction, anti-adherence barriers are advocated for their prevention. This study looks into the effect of these biomaterials on the healing of intestinal anastomoses. Materials and Methods Thirty-three New Zealand White rabbits underwent laparotomy, transection of the terminal ileum, and creation of an end-to-end anastomosis. Animals were randomized into 3 groups: the Control group (n = 11); the Icodextrin group, receiving icodextrin 4% intraperitonealy (n = 11); and the HA/CMC group, having the anastomosis wrapped with a hyaluronic acid/carboxymethylcellulose film (n = 11). All animals were sacrificed on the seventh postoperative day. Macroscopic adhesions were graded and anastomotic strength was tested by the burst pressure. Histological healing was assessed in a semiquantitative way for the presence of ulceration, reepithelization, granulation tissue, inflammation, eosinophilic infiltration, serosal inflammation, and microscopic adhesions. Univariate and multivariate analysis was used. Results are given as medians with interquartile range. Results The median adhesion scores were the following: Control 1 (0-3), Icodextrin 0 (0-1), HA/CMC 0 (0-0), P = .017. The burst pressure did not differ between the groups; however, all except one bowel segments tested burst away from the anastomosis. The macroscopic and histological anastomotic healing was comparable in all 3 groups. A poor histological anastomotic healing score was associated with a higher adhesion grade (odds ratio = 1.92; 95% confidence interval = 1.06-3.47; P = .032). Conclusion Adhesion formation was inhibited by the materials tested without direct detrimental effects on anastomotic healing. Poor anastomotic healing provokes adhesions even in the presence of anti-adhesion barriers. PMID:26474604

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

    PubMed

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

    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 (2)H-isotope labeled pharmaceuticals to the drinking water of female mice for 20 days (10 pre-and 10 post-conception days), and quantifying (2)H-isotope enrichment signals in the dam liver and brain of developing embryos using isotope ratio mass spectrometry. Significant levels of (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 typical

  2. Serum bile acid profiling reflects enterohepatic detoxification state and intestinal barrier function in inflammatory bowel disease

    PubMed Central

    Gnewuch, Carsten; Liebisch, Gerhard; Langmann, Thomas; Dieplinger, Benjamin; Mueller, Thomas; Haltmayer, Meinhard; Dieplinger, Hans; Zahn, Alexandra; Stremmel, Wolfgang; Rogler, Gerhard; Schmitz, Gerd

    2009-01-01

    AIM: To determine free and conjugated serum bile acid (BA) levels in inflammatory bowel disease (IBD) subgroups with defined clinical manifestations. METHODS: Comprehensive serum BA profiling was performed in 358 IBD patients and 310 healthy controls by liquid chromatography coupled to electrospray ionization tandem mass spectrometry. RESULTS: Serum levels of hyodeoxycholic acid, the CYP3A4-mediated detoxification product of the secondary BA lithocholic acid (LCA), was increased significantly in Crohn’s disease (CD) and ulcerative colitis (UC), while most other serum BA species were decreased significantly. Total BA, total BA conjugate, and total BA glycoconjugate levels were decreased only in CD, whereas total unconjugated BA levels were decreased only in UC. In UC patients with hepatobiliary manifestations, the conjugated primary BAs glycocholic acid, taurocholic acid, and glycochenodeoxycholic acid were as significantly increased as the secondary BAs LCA, ursodeoxycholic acid, and tauroursodeoxycholic acid compared to UC patients without hepatobiliary manifestations. Finally, we found that in ileocecal resected CD patients, the unconjugated primary BAs, cholic acid and chenodeoxycholic acid, were increased significantly compared to controls and patients without surgical interventions. CONCLUSION: Serum BA profiling in IBD patients that indicates impaired intestinal barrier function and increased detoxification is suitable for advanced diagnostic characterization and differentiation of IBD subgroups with defined clinical manifestations. PMID:19575493

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

    PubMed Central

    Fang, Jun; Martínez, Yordan; Bin, Peng; Duraipandiyan, Veeramuthu; Yin, Yulong

    2016-01-01

    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. PMID:27525260

  4. Protective Effects of Ferulic Acid against Heat Stress-Induced Intestinal Epithelial Barrier Dysfunction In Vitro and In Vivo

    PubMed Central

    He, Shasha; Liu, Fenghua; Xu, Lei; Yin, Peng; Li, Deyin; Mei, Chen; Jiang, Linshu; Ma, Yunfei; Xu, Jianqin

    2016-01-01

    Heat stress is important in the pathogenesis of intestinal epithelial barrier dysfunction. Ferulic acid (FA), a phenolic acid widely found in fruits and vegetables, can scavenge free radicals and activate cell stress responses. This study is aimed at investigating protective effects of FA on heat stress-induced dysfunction of the intestinal epithelial barrier in vitro and in vivo. Intestinal epithelial (IEC-6) cells were pretreated with FA for 4 h and then exposed to heat stress. Heat stress caused decreased transepithelial electrical resistance (TER) and increased permeability to 4-kDa fluorescein isothiocyanate (FITC)-dextran (FD4). Both effects were inhibited by FA in a dose-dependent manner. FA significantly attenuated the decrease in occludin, ZO-1 and E-cadherin expression observed with heat stress. The distortion and redistribution of occludin, ZO-1 and E-cadherin proteins were also effectively prevented by FA pretreatment. Moreover, heat stress diminished electron-dense material detected in tight junctions (TJs), an effect also alleviated by FA in a dose-dependent manner. In an in vivo heat stress model, FA (50 mg/kg) was administered to male Sprague–Dawley rats for 7 consecutive days prior to exposure to heat stress. FA pretreatment significantly attenuated the effects of heat stress on the small intestine, including the increased FD4 permeability, disrupted tight junctions and microvilli structure, and reduced occludin, ZO-1 and E-cadherin expression. Taken together, our results demonstrate that FA pretreatment is potentially protective against heat stress-induced intestinal epithelial barrier dysfunction. PMID:26894689

  5. Protective Effects of Ferulic Acid against Heat Stress-Induced Intestinal Epithelial Barrier Dysfunction In Vitro and In Vivo.

    PubMed

    He, Shasha; Liu, Fenghua; Xu, Lei; Yin, Peng; Li, Deyin; Mei, Chen; Jiang, Linshu; Ma, Yunfei; Xu, Jianqin

    2016-01-01

    Heat stress is important in the pathogenesis of intestinal epithelial barrier dysfunction. Ferulic acid (FA), a phenolic acid widely found in fruits and vegetables, can scavenge free radicals and activate cell stress responses. This study is aimed at investigating protective effects of FA on heat stress-induced dysfunction of the intestinal epithelial barrier in vitro and in vivo. Intestinal epithelial (IEC-6) cells were pretreated with FA for 4 h and then exposed to heat stress. Heat stress caused decreased transepithelial electrical resistance (TER) and increased permeability to 4-kDa fluorescein isothiocyanate (FITC)-dextran (FD4). Both effects were inhibited by FA in a dose-dependent manner. FA significantly attenuated the decrease in occludin, ZO-1 and E-cadherin expression observed with heat stress. The distortion and redistribution of occludin, ZO-1 and E-cadherin proteins were also effectively prevented by FA pretreatment. Moreover, heat stress diminished electron-dense material detected in tight junctions (TJs), an effect also alleviated by FA in a dose-dependent manner. In an in vivo heat stress model, FA (50 mg/kg) was administered to male Sprague-Dawley rats for 7 consecutive days prior to exposure to heat stress. FA pretreatment significantly attenuated the effects of heat stress on the small intestine, including the increased FD4 permeability, disrupted tight junctions and microvilli structure, and reduced occludin, ZO-1 and E-cadherin expression. Taken together, our results demonstrate that FA pretreatment is potentially protective against heat stress-induced intestinal epithelial barrier dysfunction. PMID:26894689

  6. CKD impairs barrier function and alters microbial flora of the intestine: a major link to inflammation and uremic toxicity

    PubMed Central

    Vaziri, Nosratola D.

    2013-01-01

    Purpose of review Chronic kidney disease (CKD) is associated with oxidative stress and inflammation which contribute to progression of kidney disease and its numerous complications. Until recently, little attention had been paid to the role of the intestine and its microbial flora in the pathogenesis of CKD-associated inflammation. This article is intended to provide an over view of the impact of uremia on the structure and function of the gut and its microbial flora and their potential link to the associated systemic inflammation. Recent findings Recent studies conducted in the author’s laboratories have demonstrated marked disintegration of the colonic epithelial barrier structure and significant alteration of the colonic bacterial flora in humans and animals with advanced CKD. The observed disruption of the intestinal epithelial barrier complex can play an important part in the development of systemic inflammation by enabling influx of endotoxin and other noxious luminal contents into the systemic circulation. Similarly via disruption of the normal symbiotic relationship and production, absorption and retention of noxious products, alteration of the microbial flora can contribute to systemic inflammation and uremic toxicity. In fact recent studies have documented the role of colonic bacteria as the primary source of several well known pro-inflammatory/pro-oxidant uremic toxins as well as many as-yet unidentified retained compounds. Summary CKD results in disruption of the intestinal barrier structure and marked alteration of its microbial flora –events that play a major role in the pathogenesis of inflammation and uremic toxicity. PMID:23010760

  7. Diosmectite-zinc oxide composite improves intestinal barrier restoration and modulates TGF-β1, ERK1/2, and Akt in piglets after acetic acid challenge.

    PubMed

    Song, Z-H; Ke, Y-L; Xiao, K; Jiao, L-F; Hong, Q-H; Hu, C-H

    2015-04-01

    The present study evaluated the beneficial effect of diosmectite-zinc oxide composite (DS-ZnO) on improving intestinal barrier restoration in piglets after acetic acid challenge and explored the underlying mechanisms. Twenty-four 35-d-old piglets (Duroc × Landrace × Yorkshire), with an average weight of 8.1 kg, were allocated to 4 treatment groups. On d 1 of the trial, colitis was induced via intrarectal injection of acetic acid (10 mL of 10% acetic acid [ACA] solution for ACA, DS-ZnO, and mixture of diosmectite [DS] and ZnO [DS+ZnO] groups) and the control group was infused with saline. Twenty-four hours after challenged, piglets were fed with the following diets: 1) control group (basal diet), 2) ACA group (basal diet), 3) DS-ZnO group (basal diet supplemented with DS-ZnO), and 4) DS+ZnO group (mixture of 1.5 g diosmectite [DS]/kg and 500 mg Zn/kg from ZnO [equal amount of DS and ZnO in the DS-ZnO treatment group]). On d 8 of the trial, piglets were sacrificed. The results showed that DS-ZnO supplementation improved (P < 0.05) ADG, ADFI, and transepithelial electrical resistance and decreased (P < 0.05) fecal scores, crypt depth, and fluorescein isothiocyanate-dextran 4 kDa (FD4) influx as compared with ACA group. Moreover, DS-ZnO increased (P < 0.05) occludin, claudin-1, and zonula occluden-1 expressions; reduced (P < 0.05) caspase-9 and caspase-3 activity and Bax expression; and improved (P < 0.05) Bcl2, XIAP, and PCNA expression. Diosmectite-zinc oxide composite supplementation also increased (P < 0.05) TGF-β1 expression and ERK1/2 and Akt activation. These results suggest that DS-ZnO attenuates the acetic acid-induced colitis by improving mucosa barrier restoration, inhibiting apoptosis, and improving intestinal epithelial cells proliferation and modulation of TGF-β1 and ERK1/2 and Akt signaling pathway. PMID:26020182

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

    PubMed

    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. PMID:25847917

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

    PubMed Central

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

    2015-01-01

    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. PMID:25847917

  10. Selenium and vitamin E together improve intestinal epithelial barrier function and alleviate oxidative stress in heat-stressed pigs.

    PubMed

    Liu, Fan; Cottrell, Jeremy J; Furness, John B; Rivera, Leni R; Kelly, Fletcher W; Wijesiriwardana, Udani; Pustovit, Ruslan V; Fothergill, Linda J; Bravo, David M; Celi, Pietro; Leury, Brian J; Gabler, Nicholas K; Dunshea, Frank R

    2016-07-01

    What is the central question of this study? Oxidative stress may play a role in compromising intestinal epithelial barrier integrity in pigs subjected to heat stress, but it is unknown whether an increase of dietary antioxidants (selenium and vitamin E) could alleviate gut leakiness in heat-stressed pigs. What is the main finding and its importance? Levels of dietary selenium (1.0 p.p.m.) and vitamin E (200 IU kg(-1) ) greater than those usually recommended for pigs reduced intestinal leakiness caused by heat stress. This finding suggests that oxidative stress plays a role in compromising intestinal epithelial barrier integrity in heat-stressed pigs and also provides a nutritional strategy for mitigating these effects. Heat stress compromises the intestinal epithelial barrier integrity of mammals through mechanisms that may include oxidative stress. Our objective was to test whether dietary supplementation with antioxidants, selenium (Se) and vitamin E (VE), protects intestinal epithelial barrier integrity in heat-stressed pigs. Female growing pigs (n = 48) were randomly assigned to four diets containing from 0.2 p.p.m. Se and 17 IU kg(-1) VE (control, National Research Council recommended) to 1.0 p.p.m. Se and 200 IU kg(-1) VE for 14 days. Six pigs from each dietary treatment were then exposed to either thermoneutral (20°C) or heat-stress conditions (35°C 09.00-17.00 h and 28°C overnight) for 2 days. Transepithelial electrical resistance and fluorescein isothiocyanate-dextran (4 kDa; FD4) permeability were measured in isolated jejunum and ileum using Ussing chambers. Rectal temperature, respiratory rate and intestinal HSP70 mRNA abundance increased (all P < 0.001), and respiratory alkalosis occurred, suggesting that pigs were heat stressed. Heat stress also increased FD4 permeability and decreased transepithelial electrical resistance (both P < 0.01). These changes were associated with changes indicative of oxidative stress, a decreased

  11. Non-animal models of epithelial barriers (skin, intestine and lung) in research, industrial applications and regulatory toxicology.

    PubMed

    Gordon, Sarah; Daneshian, Mardas; Bouwstra, Joke; Caloni, Francesca; Constant, Samuel; Davies, Donna E; Dandekar, Gudrun; Guzman, Carlos A; Fabian, Eric; Haltner, Eleonore; Hartung, Thomas; Hasiwa, Nina; Hayden, Patrick; Kandarova, Helena; Khare, Sangeeta; Krug, Harald F; Kneuer, Carsten; Leist, Marcel; Lian, Guoping; Marx, Uwe; Metzger, Marco; Ott, Katharina; Prieto, Pilar; Roberts, Michael S; Roggen, Erwin L; Tralau, Tewes; van den Braak, Claudia; Walles, Heike; Lehr, Claus-Michael

    2015-01-01

    Models of the outer epithelia of the human body - namely the skin, the intestine and the lung - have found valid applications in both research and industrial settings as attractive alternatives to animal testing. A variety of approaches to model these barriers are currently employed in such fields, ranging from the utilization of ex vivo tissue to reconstructed in vitro models, and further to chip-based technologies, synthetic membrane systems and, of increasing current interest, in silico modeling approaches. An international group of experts in the field of epithelial barriers was convened from academia, industry and regulatory bodies to present both the current state of the art of non-animal models of the skin, intestinal and pulmonary barriers in their various fields of application, and to discuss research-based, industry-driven and regulatory-relevant future directions for both the development of new models and the refinement of existing test methods. Issues of model relevance and preference, validation and standardization, acceptance, and the need for simplicity versus complexity were focal themes of the discussions. The outcomes of workshop presentations and discussions, in relation to both current status and future directions in the utilization and development of epithelial barrier models, are presented by the attending experts in the current report. PMID:26536291

  12. Fish oil enhances intestinal barrier function and inhibits corticotropin-releasing hormone/corticotropin-releasing hormone receptor 1 signalling pathway in weaned pigs after lipopolysaccharide challenge.

    PubMed

    Zhu, Huiling; Liu, Yulan; Chen, Shaokui; Wang, Xiuying; Pi, Dingan; Leng, Weibo; Chen, Feng; Zhang, Jing; Kang, Ping

    2016-06-01

    Stress induces injury in intestinal barrier function in piglets. Long-chain n-3 PUFA have been shown to exhibit potential immunomodulatory and barrier protective effects in animal models and clinical trials. In addition, corticotropin-releasing hormone (CRH)/CRH receptor (CRHR) signalling pathways play an important role in stress-induced alterations of intestinal barrier function. We hypothesised that fish oil could affect intestinal barrier function and CRH/CRHR signalling pathways. In total, thirty-two weaned pigs were allocated to one of four treatments. The experiment consisted of a 2×2 factorial design, and the main factors included immunological challenge (saline or lipopolysaccharide (LPS)) and diet (5 % maize oil or 5 % fish oil). On d 19 of the trial, piglets were treated with saline or LPS. At 4 h after injection, all pigs were killed, and the mesenteric lymph nodes (MLN), liver, spleen and intestinal samples were collected. Fish oil decreased bacterial translocation incidence and the number of translocated micro-organisms in the MLN. Fish oil increased intestinal claudin-1 protein relative concentration and villus height, as well as improved the intestinal morphology. In addition, fish oil supplementation increased intestinal intraepithelial lymphocyte number and prevented elevations in intestinal mast cell and neutrophil numbers induced by LPS challenge. Moreover, fish oil tended to decrease the mRNA expression of intestinal CRHR1, CRH and glucocorticoid receptors. These results suggest that fish oil supplementation improves intestinal barrier function and inhibits CRH/CRHR1 signalling pathway and mast cell tissue density. PMID:27080003

  13. Effect of a probiotic mixture on intestinal microflora, morphology, and barrier integrity of broilers subjected to heat stress.

    PubMed

    Song, J; Xiao, K; Ke, Y L; Jiao, L F; Hu, C H; Diao, Q Y; Shi, B; Zou, X T

    2014-03-01

    The current study investigated the efficacy of a probiotic mixture on ameliorating heat stress-induced impairment of intestinal microflora, morphology, and barrier integrity in broilers. The probiotic mixture contained Bacillus licheniformis, Bacillus subtilis, and Lactobacillus plantarum. Three hundred sixty 21-d-old Ross 308 male broilers were allocated in 4 experimental treatments, each of which was replicated 6 times with 15 broilers per replicate. A 2 × 2 factorial design was used in the study, and the main factors were composed of diet (basal diet or addition of 1.5 g/kg of probiotic mixture) and temperature (thermoneutral zone or heat stress). From d 22 to 42, birds were either raised in a thermoneutral zone (22°C) or subjected to cyclic heat stress by exposing them to 33°C for 10 h (from 0800 to 1800) and 22°C from 1800 to 0800. Compared with birds kept in the thermoneutral zone, birds subjected to heat stress had reduced ADG and ADFI; lower viable counts of Lactobacillus and Bifidobacterium and increased viable counts of coliforms and Clostridium in small intestinal contents; shorter jejunal villus height, deeper crypt depth, and lower ratio of villus height to crypt depth; decreased jejunal transepithelial electrical resistance and a higher level of jejunal paracellular permeability of fluorescein isothiocyanate dextran 4 kDa; and downregulated protein levels of occludin and zonula occludens-1 (P < 0.05). Supplemental probiotics increased (P < 0.05) small intestinal Lactobacillus and Bifidobacterium, jejunal villus height, protein level of occludin, and decreased (P < 0.05) feed to gain ratio and small intestinal coliforms. These results indicate that dietary addition of probiotic mixture was effective in partially ameliorating intestinal barrier function. But no temperature × diet interaction was observed in the present study, revealing that the supplemented probiotics had the same effect at both temperatures. PMID:24604851

  14. Cellular zinc is required for intestinal epithelial barrier maintenance via the regulation of claudin-3 and occludin expression.

    PubMed

    Miyoshi, Yuka; Tanabe, Soichi; Suzuki, Takuya

    2016-07-01

    Intracellular zinc is required for a variety of cell functions, but its precise roles in the maintenance of the intestinal tight junction (TJ) barrier remain unclear. The present study investigated the essential roles of intracellular zinc in the preservation of intestinal TJ integrity and the underlying molecular mechanisms. Depletion of intracellular zinc in both intestinal Caco-2 cells and mouse colons through the application of a cell-permeable zinc chelator N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) induced a disruption of the TJ barrier, as indicated by increased FITC-labeled dextran flux and decreased transepithelial electrical resistance. The TPEN-induced TJ disruption is associated with downregulation of two TJ proteins, occludin and claudin-3. Biotinylation of cell surface proteins revealed that the zinc depletion induced the proteolysis of occludin but not claudin-3. Occludin proteolysis was sensitive to the inhibition of calpain activity, and increased calpain activity was observed in the zinc-depleted cells. Although quantitative PCR analysis and promoter reporter assay have demonstrated that the zinc depletion-induced claudin-3 downregulation occurred at transcriptional levels, a site-directed mutation in the egr1 binding site in the claudin-3 promoter sequence induced loss of both the basal promoter activity and the TPEN-induced decreases. Reduced egr1 expression by a specific siRNA also inhibited claudin-3 expression and transepithelial electrical resistance maintenance in cells. This study shows that intracellular zinc has an essential role in the maintenance of the intestinal epithelial TJ barrier through regulation of occludin proteolysis and claudin-3 transcription. PMID:27151944

  15. Intestinal mucosal barrier dysfunction participates in the progress of nonalcoholic fatty liver disease.

    PubMed

    Mao, Jing-Wei; Tang, Hai-Ying; Zhao, Ting; Tan, Xiao-Yan; Bi, Jian; Wang, Bing-Yuan; Wang, Ying-De

    2015-01-01

    Intestinal mucosal barrier dysfunction is closely related to liver diseases, which implies impaired gut-liver axis may play a role in the pathogenesis of NAFLD. In our study, rats were divided into three groups: normal chow diet (NCD) group, high-fat diet (HFD) group and TNBS-induced colitis with high-fat diet (C-HFD) group. Liver tissues were obtained for histological observation and TNF-α, IL-6 mRNA determination and blood samples were collected for liver enzymes and LPS analysis. Ultrastructural changes of jejuna epithelium, SIBO and amounts of CD103(+)MHCII(+)DCs and CD4(+)CD25(+)FoxP3(+)T-regs in terms of percentage in mesenteric lymph nodes (MLN) were observed by electron microscope, bacterial cultivation and flow cytometry, respectively. The results demonstrated the pathological characteristics accorded with nonalcoholic simple fatty liver (NAFL) and NASH in HFD group by week 8 and 12, respectively. Besides, the degree of hepatic steatosis and steatohepatitis was more severe in C-HFD group compared with HFD-group at the same time point. NAFLD activity score (NAS), liver enzymes, concentration of LPS and mRNA expressions of TNF-α, IL-6 were higher significantly in C-HFD group compared with HFD and NCD group at week 4, 8 and 12, respectively. In HFD group, epithelium microvilli atrophy, disruptive tight junctions and SIBO were present, and these changes were more severe in NASH compared with NAFL. The percentage of CD103+MHCII+DCs and CD4+CD25+FoxP3+T-regs decreased significantly in NAFL and NASH compared with NCD group. Our conclusion was that gut-liver axis was impaired in NAFLD, which played crucial role in the pathogenesis of NAFLD. PMID:26097546

  16. Intestinal mucosal barrier dysfunction participates in the progress of nonalcoholic fatty liver disease

    PubMed Central

    Mao, Jing-Wei; Tang, Hai-Ying; Zhao, Ting; Tan, Xiao-Yan; Bi, Jian; Wang, Bing-Yuan; Wang, Ying-De

    2015-01-01

    Intestinal mucosal barrier dysfunction is closely related to liver diseases, which implies impaired gut-liver axis may play a role in the pathogenesis of NAFLD. In our study, rats were divided into three groups: normal chow diet (NCD) group, high-fat diet (HFD) group and TNBS-induced colitis with high-fat diet (C-HFD) group. Liver tissues were obtained for histological observation and TNF-α, IL-6 mRNA determination and blood samples were collected for liver enzymes and LPS analysis. Ultrastructural changes of jejuna epithelium, SIBO and amounts of CD103+MHCII+DCs and CD4+CD25+FoxP3+T-regs in terms of percentage in mesenteric lymph nodes (MLN) were observed by electron microscope, bacterial cultivation and flow cytometry, respectively. The results demonstrated the pathological characteristics accorded with nonalcoholic simple fatty liver (NAFL) and NASH in HFD group by week 8 and 12, respectively. Besides, the degree of hepatic steatosis and steatohepatitis was more severe in C-HFD group compared with HFD-group at the same time point. NAFLD activity score (NAS), liver enzymes, concentration of LPS and mRNA expressions of TNF-α, IL-6 were higher significantly in C-HFD group compared with HFD and NCD group at week 4, 8 and 12, respectively. In HFD group, epithelium microvilli atrophy, disruptive tight junctions and SIBO were present, and these changes were more severe in NASH compared with NAFL. The percentage of CD103+MHCII+DCs and CD4+CD25+FoxP3+T-regs decreased significantly in NAFL and NASH compared with NCD group. Our conclusion was that gut-liver axis was impaired in NAFLD, which played crucial role in the pathogenesis of NAFLD. PMID:26097546

  17. Gut barrier structure, mucosal immunity and intestinal microbiota in the pathogenesis and treatment of HIV infection.

    PubMed

    Tincati, Camilla; Douek, Daniel C; Marchetti, Giulia

    2016-01-01

    Over the past 10 years, extensive work has been carried out in the field of microbial translocation in HIV infection, ranging from studies on its clinical significance to investigations on its pathogenic features. In the present work, we review the most recent findings on this phenomenon, focusing on the predictive role of microbial translocation in HIV-related morbidity and mortality, the mechanisms by which it arises and potential therapeutic approaches. From a clinical perspective, current work has shown that markers of microbial translocation may be useful in predicting clinical events in untreated HIV infection, while conflicting data exist on their role in cART-experienced subjects, possibly due to the inclusion of extremely varied patient populations in cohort studies. Results from studies addressing the pathogenesis of microbial translocation have improved our knowledge of the damage of the gastrointestinal epithelial barrier occurring in HIV infection. However, the extent to which mucosal impairment translates directly to increased gastrointestinal permeability remains an open issue. In this respect, novel work has established a role for IL-17 and IL-22-secreting T cell populations in limiting microbial translocation and systemic T-cell activation/inflammation, thus representing a possible target of immune-therapeutic interventions shown to be promising in the animal model. Further, recent reports have not only confirmed the presence of a dysbiotic intestinal community in the course of HIV infection but have also shown that it may be linked to mucosal damage, microbial translocation and peripheral immune activation. Importantly, technical advances have also shed light on the metabolic activity of gut microbes, highlighting the need for novel therapeutic approaches to correct the function, as well as the composition, of the gastrointestinal microbiota. PMID:27073405

  18. Cholera toxin disrupts barrier function by inhibiting exocyst-mediated trafficking of host proteins to intestinal cell junctions

    PubMed Central

    Guichard, Annabel; Moreno, Beatriz Cruz; Aguilar, Berenice; van Sorge, Nina M.; Kuang, Jennifer; Kurkciyan, Adrianne A.; Wang, Zhipeng; Hang, Saiyu; Pineton de Chambrun, Guillaume P.; McCole, Declan F.; Watnick, Paula; Nizet, Victor; Bier, Ethan

    2013-01-01

    Summary Cholera toxin (CT), a virulence factor elaborated by Vibrio cholerae, is sufficient to induce the severe diarrhea characteristic of cholera. The enzymatic moiety of CT (CtxA) increases cAMP synthesis in intestinal epithelial cells, leading to chloride ion (Cl−) efflux through the CFTR Cl− channel. To preserve electroneutrality and osmotic balance, sodium ions and water also flow into the intestinal lumen via a paracellular route. We find that CtxA-driven cAMP increase also inhibits Rab11/exocyst-mediated trafficking of host proteins including E-cadherin and Notch signaling components to cell-cell junctions in Drosophila, human intestinal epithelial cells, and ligated mouse ileal loops, thereby disrupting barrier function. Additionally, CtxA induces junctional damage, weight loss, and dye leakage in the Drosophila gut, contributing to lethality from live V. cholerae infection, all of which can be rescued by Rab11 over-expression. These barrier-disrupting effects of CtxA may act in parallel with Cl− secretion to drive the pathophysiology of cholera. PMID:24034615

  19. Baicalein induces CD4+Foxp3+ T cells and enhances intestinal barrier function in a mouse model of food allergy

    PubMed Central

    Bae, Min-Jung; Shin, Hee Soon; See, Hye-Jeong; Jung, Sun Young; Kwon, Da-Ae; Shon, Dong-Hwa

    2016-01-01

    The incidence of food allergy, which is triggered by allergen permeation of the gastrointestinal tract followed by a T-helper (Th) 2-mediated immune response, has been increasing annually worldwide. We examined the effects of baicalein (5,6,7-trihydroxyflavone), a flavonoid from Scutellaria baicalensis used in oriental herbal medicine, on regulatory T (Treg) cell induction and intestinal barrier function through the regulation of tight junctions in a mouse model of food allergy. An allergic response was induced by oral challenge with ovalbumin, and the incidence of allergic symptoms and T cell-related activity in the mesenteric lymph nodes were analyzed with and without the presence of baicalein. Our results demonstrated that the administration of baicalein ameliorated the symptoms of food allergy and attenuated serum IgE and effector T cells. However, Treg-related factors were up-regulated by baicalein. Furthermore, baicalein was shown to enhance intestinal barrier function through the regulation of tight junctions. We also found that baicalein treatment induced the differentiation of Treg cells via aryl hydrocarbon receptors (AhRs). Thus, the action of baicalein as an agonist of AhR can induce Treg differentiation and enhance barrier function, suggesting that baicalein might serve as an effective immune regulator derived from foods for the treatment of food allergy. PMID:27561877

  20. Baicalein induces CD4(+)Foxp3(+) T cells and enhances intestinal barrier function in a mouse model of food allergy.

    PubMed

    Bae, Min-Jung; Shin, Hee Soon; See, Hye-Jeong; Jung, Sun Young; Kwon, Da-Ae; Shon, Dong-Hwa

    2016-01-01

    The incidence of food allergy, which is triggered by allergen permeation of the gastrointestinal tract followed by a T-helper (Th) 2-mediated immune response, has been increasing annually worldwide. We examined the effects of baicalein (5,6,7-trihydroxyflavone), a flavonoid from Scutellaria baicalensis used in oriental herbal medicine, on regulatory T (Treg) cell induction and intestinal barrier function through the regulation of tight junctions in a mouse model of food allergy. An allergic response was induced by oral challenge with ovalbumin, and the incidence of allergic symptoms and T cell-related activity in the mesenteric lymph nodes were analyzed with and without the presence of baicalein. Our results demonstrated that the administration of baicalein ameliorated the symptoms of food allergy and attenuated serum IgE and effector T cells. However, Treg-related factors were up-regulated by baicalein. Furthermore, baicalein was shown to enhance intestinal barrier function through the regulation of tight junctions. We also found that baicalein treatment induced the differentiation of Treg cells via aryl hydrocarbon receptors (AhRs). Thus, the action of baicalein as an agonist of AhR can induce Treg differentiation and enhance barrier function, suggesting that baicalein might serve as an effective immune regulator derived from foods for the treatment of food allergy. PMID:27561877

  1. Optimal dietary protein level improved growth, disease resistance, intestinal immune and physical barrier function of young grass carp (Ctenopharyngodon idella).

    PubMed

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

    2016-08-01

    This study investigated the effects of dietary proteins on the growth, disease resistance, intestinal immune and physical barrier functions of young grass carp (Ctenopharyngodon idella). A total of 540 young grass carp (264.11 ± 0.76 g) were fed six diets containing graded levels of protein (143.1, 176.7, 217.2, 257.5, 292.2 and 322.8 g digestible protein kg(-1) diet) for 8 weeks. After the growth trial, fish were challenged with Aeromonas hydrophila and mortalities were recorded for 14 days. The results indicated that optimal dietary protein levels: increased the production of antibacterial components, up-regulated anti-inflammatory cytokines, inhibitor of κBα, target of rapamycin and ribosomal protein S6 kinases 1 mRNA levels, whereas down-regulated pro-inflammatory cytokines, nuclear factor kappa B (NF-κB) P65, NF-κB P52, c-Rel, IκB kinase β, IκB kinase γ and eIF4E-binding proteins 2 mRNA levels in three intestinal segments of young grass carp (P < 0.05), suggesting that optimal dietary protein level could enhance fish intestinal immune barrier function; up-regulated the mRNA levels of tight junction complexes, B-cell lymphoma protein-2, inhibitor of apoptosis proteins, myeloid cell leukemia-1 and NF-E2-related factor 2, and increased the activities and mRNA levels of antioxidant enzymes, whereas down-regulated myosin light chain kinase, cysteinyl aspartic acid-protease 2, 3, 7, 8, 9, fatty acid synthetase ligand, apoptotic protease activating factor-1, Bcl-2 associated X protein, p38 mitogen-activated protein kinase, c-Jun N-terminal protein kinase and Kelch-like-ECH-associated protein 1b mRNA levels, and decreased reactive oxygen species, malondialdehyde and protein carbonyl contents in three intestinal segments of young grass carp (P < 0.05), indicating that optimal dietary protein level could improve fish intestinal physical barrier function. Finally, the optimal dietary protein levels for the growth performance (PWG) and against enteritis

  2. Altered intestinal microbial flora and impaired epithelial barrier structure and function in CKD: the nature, mechanisms, consequences and potential treatment.

    PubMed

    Vaziri, Nosratola D; Zhao, Ying-Yong; Pahl, Madeleine V

    2016-05-01

    Chronic kidney disease (CKD) results in systemic inflammation and oxidative stress which play a central role in CKD progression and its adverse consequences. Although many of the causes and consequences of oxidative stress and inflammation in CKD have been extensively explored, little attention had been paid to the intestine and its microbial flora as a potential source of these problems. Our recent studies have revealed significant disruption of the colonic, ileal, jejunal and gastric epithelial tight junction in different models of CKD in rats. Moreover, the disruption of the epithelial barrier structure and function found in uremic animals was replicated in cultured human colonocytes exposed to uremic human plasma in vitro We have further found significant changes in the composition and function of colonic bacterial flora in humans and animals with advanced CKD. Together, uremia-induced impairment of the intestinal epithelial barrier structure and function and changes in composition of the gut microbiome contribute to the systemic inflammation and uremic toxicity by accommodating the translocation of endotoxin, microbial fragments and other noxious luminal products in the circulation. In addition, colonic bacteria are the main source of several well-known pro-inflammatory uremic toxins such as indoxyl sulfate, p-cresol sulfate, trimethylamine-N-oxide and many as-yet unidentified retained compounds in end-stage renal disease patients. This review is intended to provide an overview of the effects of CKD on the gut microbiome and intestinal epithelial barrier structure and their role in the pathogenesis of systemic inflammation and uremic toxicity. In addition, potential interventions aimed at mitigating these abnormalities are briefly discussed. PMID:25883197

  3. Zinc oxide influences mitogen-activated protein kinase and TGF-β1 signaling pathways, and enhances intestinal barrier integrity in weaned pigs.

    PubMed

    Song, Ze He; Xiao, Kan; Ke, Ya Lu; Jiao, Le Fei; Hu, Cai Hong

    2015-05-01

    Weaning is the most significant event in the life of pigs and is always related with intestinal disruption. Although it is well known that zinc oxide (ZnO) exerts beneficial effects on the intestinal barrier, the mechanisms underlying these effects have not yet been fully elucidated. We examined whether ZnO protects the intestinal barrier via mitogen-activated protein kinases and TGF-β1 signaling pathways. Twelve barrows weaned at 21 d of age were randomly assigned to two treatments (0 verus 2200 mg Zn/kg from ZnO) for 1 wk. The results showed that supplementation with ZnO increased daily gain and feed intake, and decreased postweaning scour scores. ZnO improved intestinal morphology, as indicated by increased villus height and villus height:crypt depth ratio, and intestinal barrier function, indicated by increased transepithelial electrical resistance and decreased mucosal-to-serosal permeability to 4-ku FITC dextran. ZnO decreased the ratios of the phosphorylated to total JNK and p38 (p-JNK/JNK and p-p38/p38), while it increased the ratio of ERK (p-ERK/ERK). Supplementation with ZnO increased intestinal TGF-β1 expression. The results indicate that supplementation with ZnO activates ERK ½, and inhibits JNK and p38 signaling pathways, and increases intestinal TGF-β1 expression in weaned pigs. PMID:24917655

  4. Fecal microbiota transplantation and bacterial consortium transplantation have comparable effects on the re-establishment of mucosal barrier function in mice with intestinal dysbiosis

    PubMed Central

    Li, Ming; Liang, Pin; Li, Zhenzhen; Wang, Ying; Zhang, Guobin; Gao, Hongwei; Wen, Shu; Tang, Li

    2015-01-01

    Fecal microbiota transplantation (FMT) is a promising therapy, despite some reports of adverse side effects. Bacterial consortia transplantation (BCT) for targeted restoration of the intestinal ecosystem is considered a relatively safe and simple procedure. However, no systematic research has assessed the effects of FMT and BCT on immune responses of intestinal mucosal barrier in patients. We conducted complementary studies in animal models on the effects of FMT and BCT, and provide recommendations for improving the clinical outcomes of these treatments. To establish the dysbiosis model, male BALB/c mice were treated with ceftriaxone intra-gastrically for 7 days. After that, FMT and BCT were performed on ceftriaxone-treated mice for 3 consecutive days to rebuild the intestinal ecosystem. Post-FMT and post-BCT changes of the intestinal microbial community and mucosal barrier functions were investigated and compared. Disruption of intestinal microbial homeostasis impacted the integrity of mucosal epithelial layer, resulting in increased intestinal permeability. These outcomes were accompanied by overexpression of Muc2, significant decrease of SIgA secretion, and overproduction of defensins and inflammatory cytokines. After FMT and BCT, the intestinal microbiota recovered quickly, this was associated with better reconstruction of mucosal barriers and re-establishment of immune networks compared with spontaneous recovery (SR). Although based on a short-term study, our results suggest that FMT and BCT promote the re-establishment of intestinal microbial communities in mice with antibiotic-induced dysbiosis, and contribute to the temporal and spatial interactions between microbiota and mucosal barriers. The effects of BCT are comparable to that of FMT, especially in normalizing the intestinal levels of Muc2, SIgA, and defensins. PMID:26217323

  5. Protective effects of Lactobacillus plantarum on epithelial barrier disruption caused by enterotoxigenic Escherichia coli in intestinal porcine epithelial cells.

    PubMed

    Wu, Yunpeng; Zhu, Cui; Chen, Zhuang; Chen, Zhongjian; Zhang, Weina; Ma, Xianyong; Wang, Li; Yang, Xuefen; Jiang, Zongyong

    2016-04-01

    Tight junctions (TJs) play an important role in maintaining the mucosal barrier function and gastrointestinal health of animals. Lactobacillus plantarum (L. plantarum) was reported to protect the intestinal barrier function of early-weaned piglets against enterotoxigenic Escherichia coli (ETEC) K88 challenge; however, the underlying cellular mechanism of this protection was unclear. Here, an established intestinal porcine epithelia cell (IPEC-J2) model was used to investigate the protective effects and related mechanisms of L. plantarum on epithelial barrier damages induced by ETEC K88. Epithelial permeability, expression of inflammatory cytokines, and abundance of TJ proteins, were determined. Pre-treatment with L. plantarum for 6h prevented the reduction in transepithelial electrical resistance (TEER) (P<0.05), inhibited the increased transcript abundances of interleukin-8 (IL-8) and tumor necrosis factor (TNF-α) (P<0.05), decreased expression of claudin-1, occludin and zonula occludens (ZO-1) (P<0.05) and protein expression of occludin (P<0.05) of IPEC-J2 cells caused by ETEC K88. Moreover, the mRNA expression of negative regulators of toll-like receptors (TLRs) [single Ig Il-1-related receptor (SIGIRR), B-cell CLL/lymphoma 3 (Bcl3), and mitogen-activated protein kinase phosphatase-1 (MKP-1)] in IPEC-J2 cells pre-treated with L. plantarum were higher (P<0.05) compared with those in cells just exposed to K88. Furthermore, L. plantarum was shown to regulate proteins of nuclear factor κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. These results indicated that L. plantarum may improve epithelial barrier function by maintenance of TEER, inhibiting the reduction of TJ proteins, and reducing the expression of proinflammatory cytokines induced by ETEC K88, possibly through modulation of TLRs, NF-κB and MAPK pathways. PMID:27032504

  6. Dietary spray-dried chicken plasma improves intestinal barrier function and modulates immune status in weaning piglets.

    PubMed

    Zhang, Y; Zheng, P; Yu, B; He, J; Yu, J; Mao, X B; Wang, J X; Luo, J Q; Huang, Z Q; Cheng, G X; Chen, D W

    2016-01-01

    The objective of this study was to evaluate the effects of dietary addition of spray-dried chicken plasma (SDCP) as a replacement for spray-dried porcine plasma (SDPP) on serum biochemistry, intestinal barrier function, immune parameters, and the expression of intestinal development-related genes in weaning pigs. One hundred and forty-four 25-d-old weaning piglets with BW of 6.43 ± 0.39 kg were randomly allotted to 1 of 4 dietary treatments: 1) CON (basal diet; control), 2) SDPP (containing 5% SDPP), 3) SDPP + SDCP (containing 2.5% SDPP and 2.5% SDCP), and 4) SDCP (containing 5% SDCP). After a 28-d trial, 6 pigs from each treatment were randomly selected to collect serum and intestinal samples. On d 14 after the initiation of the trial, pigs in the SDPP, SDPP + SDCP, and SDCP groups had an increase ( < 0.05) in serum concentrations of total protein and IgG and a decrease ( < 0.05) in activities of alanine aminotransferase and diamine oxidase compared with the CON group. In the jejunum, supplementation with SDPP and SDCP reduced ( < 0.05) the concentration of tumor necrosis factor-α (TNF-α) and upregulated ( < 0.05) the mRNA levels of zonula occludens 1 (ZO-1), zonula occludens 2 (ZO-2), occludin (OCLN), Toll-like receptor 2 (TLR2), glucagon-like peptide 2 (GLP2), and IGF-1 compared with the CON group. In the ileum, feeding SDPP, SDPP + SDCP, and SDCP decreased ( < 0.05) the concentrations of TNF-α and secretory IgA (sIgA) and upregulated ( < 0.05) the mRNA levels of claudin 1 (CLDN-1) and TLR2 compared with feeding CON. However, there were no differences among the SDPP, SDPP + SDCP, and SDCP groups. Furthermore, supplementation with SDCP reduced ( < 0.05) the concentration of IL-10 and upregulated ( < 0.05) the mRNA levels of GLP-2, mucin 2 (MUC2), and trefoil factor family 3 (TFF3) in the ileum compared with feeding CON. Collectively, the current results indicate that dietary addition of SDCP has a beneficial influence on the health condition of weaning pigs

  7. Effects of Soybean Agglutinin on Mechanical Barrier Function and Tight Junction Protein Expression in Intestinal Epithelial Cells from Piglets

    PubMed Central

    Pan, Li; Qin, Guixin; Zhao, Yuan; Wang, Jun; Liu, Feifei; Che, Dongsheng

    2013-01-01

    In this study, we sought to investigate the role of soybean agglutinin (SBA) in mediating membrane permeability and the mechanical barrier function of intestinal epithelial cells. The IPEC-J2 cells were cultured and treated with 0, 0.5, 1.0, 1.5, 2.0, 2.5, or 3.0 mg/mL SBA. Transepithelial electrical resistance (TEER) and alkaline phosphatase (AP) activity were measured to evaluate membrane permeability. The results showed a significant decrease in TEER values (p < 0.05) in a time- and dose-dependent manner, and a pronounced increase in AP activity (p < 0.05). Cell growth and cell morphology were used to evaluate the cell viability. A significant cell growth inhibition (p < 0.05) and alteration of morphology were observed when the concentration of SBA was increased. The results of western blotting showed that the expression levels of occludin and claudin-3 were decreased by 31% and 64% compared to those of the control, respectively (p < 0.05). In addition, immunofluorescence labeling indicated an obvious decrease in staining of these targets and changes in their localizations. In conclusion, SBA increased the membrane permeability, inhibited the cell viability and reduced the levels of tight junction proteins (occludin and claudin-3), leading to a decrease in mechanical barrier function in intestinal epithelial cells. PMID:24189218

  8. Effect of Lactobacillus Strains on Intestinal Microflora and Mucosa Immunity in Escherichia coli O157:H7-Induced Diarrhea in Mice.

    PubMed

    Bian, Xin; Wang, Ting-Ting; Xu, Min; Evivie, Smith Etareri; Luo, Guang-Wen; Liang, Hong-Zhang; Yu, Shang-Fu; Huo, Gui-Cheng

    2016-07-01

    This study investigated the effects of KLDS 1.8701 and AD1 administrations by gavage on intestinal microflora and mucosal immunity in diarrhea mice infected by Escherichia coli O157:H7 compared to normal mice. The levels of E. coli, Enterobacteria, and Enterococcus decreased significantly (P < 0.05), while viable counts of Lactobacilli and Bifidobacterium increased in diarrhea mice. Moreover, KLDS 1.8701 and AD1 improved secretion of secretory immunoglobulin A and enhanced the levels of interferon-γ and interleukin. Results indicate that KLDS 1.8701 and AD1 could effectively alleviate diarrhea in mice via modulation of intestinal microflora and improve the function of immune system. The study on the effect of KLDS1.8701 and AD1 supplementation in human flora-associated animal models was recommended. PMID:27025726

  9. The Somatostatin Analog SOM230 (Pasireotide) Ameliorates Injury of the Intestinal Mucosa and Increases Survival after Total-Body Irradiation by Inhibiting Exocrine Pancreatic Secretion

    PubMed Central

    Fu, Qiang; Berbée, Maaike; Boerma, Marjan; Wang, Junru; Schmid, Herbert A.; Hauer-Jensen, Martin

    2009-01-01

    Somatostatin analogs ameliorate intestinal injury after localized irradiation. This study investigated whether SOM230, a novel, metabolically stable analog with broad receptor affinity, reduces intestinal injury and lethality in mice exposed to total-body irradiation (TBI). Male CD2F1 mice were exposed to 7–15 Gy TBI. Twice-daily administration of SOM230 (1, 4 or 10 mg/kg per day) or vehicle was started either 2 days before or 4 h after TBI and continued for either 14 or 21 days. Parameters of intestinal and hematopoietic radiation injury, bacterial translocation, and circulating cytokine levels were assessed. Animal survival was monitored for up to 30 days. SOM230 increased survival (P < 0.001) and prolonged survival time (P < 0.001) whether administration was initiated before or after TBI. There was no benefit from administration for 21 compared to 14 days. The survival benefit of SOM230 was completely reversed by co-administration of pancreatic enzymes (P = 0.009). Consistent with the presumed non-cytoprotective mechanism of action, SOM230 did not influence hematopoietic injury or intestinal crypt lethality. However, SOM230 preserved mucosal surface area (P < 0.001) and reduced bacterial translocation in a dose-dependent manner (P < 0.001). Circulating IL-12 levels were reduced in SOM230-treated mice (P = 0.007). No toxicity from SOM230 was observed. SOM230 enhances animal survival whether administration begins before or after TBI; i.e., it is effective both as a protector and as a mitigator. The mechanism likely involves reduction of intraluminal pancreatic enzymes. Because of its efficacy and favorable safety profile, SOM230 is a promising countermeasure against radiation and should undergo further development. PMID:19580476

  10. Effect of Vitamin E Supplementation on Intestinal Barrier Function in Rats Exposed to High Altitude Hypoxia Environment

    PubMed Central

    Sun, Rui; Qiao, Xiangjin; Xu, Cuicui; Shang, Xiaoya; Niu, Weining; Chao, Yu

    2014-01-01

    The study was conducted to investigate the role of vitamin E in the high altitude hypoxia-induced damage to the intestinal barrier in rats. Sprague-Dawley rats were divided into control (Control), high altitude hypoxia (HH), and high altitude hypoxia+vitamin E (250 mg/kg BW*d) (HV) groups. After the third day, the HH and HV groups were placed in a hypobaric chamber at a stimulated elevation of 7000 m for 5 days. The rats in the HV group were given vitamin E by gavage daily for 8 days. The other rats were given equal volume saline. The results showed that high altitude hypoxia caused the enlargement of heart, liver, lung and kidney, and intestinal villi damage. Supplementation with vitamin E significantly alleviated hypoxia-caused damage to the main organs including intestine, increased the serum superoxide dismutase (SOD) (p< 0.05), diamino oxidase (DAO) (p< 0.01) levels, and decreased the serum levels of interleukin-2 (IL-2) (p< 0.01), interleukin-4 (IL-4) (p<0.001), interferon-gamma (IFN-γ) (p<0.01) and malondialdehyde (MDA) (p<0.001), and decreased the serum erythropoietin (EPO) activity (p<0.05). Administration of vitamin E significantly increased the S-IgA (p<0.001) in ileum and significantly improved the expression levels of occludin and IκBα, and decreased the expression levels of hypoxia-inducible factor 1 alpha and 2 alpha (HIF-1α and HIF-2α), Toll-like receptors (TLR4), P-IκBα and nuclear factor-κB p65(NF-κB P65) in ileum compared to the HH group. This study suggested that vitamin E protectis from intestinal injury caused by high altitude hypoxia environment. These effects may be related to the HIF and TLR4/NF-κB signaling pathway. PMID:25177163

  11. Randomized Clinical Trial of Pre-operative Feeding to Evaluate Intestinal Barrier Function in Neonates Requiring Cardiac Surgery

    PubMed Central

    Zyblewski, Sinai C.; Nietert, Paul J.; Graham, Eric M.; Taylor, Sarah N.; Atz, Andrew M.; Wagner, Carol L.

    2015-01-01

    Objective To evaluate intestinal barrier function in neonates undergoing cardiac surgery using lactulose/mannitol (L/M) ratio measurements and to determine correlations with early breast milk feeding. Study design This was a single-center, prospective, randomized pilot study of 27 term neonates (≥37 weeks gestation) requiring cardiac surgery who were randomized to one of two pre-operative feeding groups: 1) nil per os (NPO) vs. 2) trophic (10 cc/kg/day) breast milk feeds. At three time points (pre-op, post-op day 7, and post-op day 14), subjects were administered an oral lactulose/mannitol solution and subsequent L/M ratios were measured using gas chromatography, with higher ratios indicative of increased intestinal permeability. Trends over time in the mean urine L/M ratios for each group were estimated using a general linear mixed model. Results There were no adverse events related to pre-operative trophic feeding. In the NPO group (n=13), the mean urine L/M ratios at pre-op, post-op day 7, and post-op day 14 were 0.06, 0.12, and 0.17, respectively. In the trophic breast milk feeds group (n=14), the mean urine L/M ratios at pre-op, post-op day 7, and post-op day 14 were 0.09, 0.19, and 0.15, respectively. Both groups had significantly higher L/M ratios at post-op day 7 and 14 compared with pre-op (p<0.05). Conclusions Neonates have increased intestinal permeability after cardiac surgery extending to at least post-op day 14. This pilot study was not powered to detect differences in benefit or adverse events comparing NPO with breast milk feeds. Further studies to identify mechanisms of intestinal injury and therapeutic interventions are warranted. Trial registration Registered with ClinicalTrials.gov: NCT01475357. PMID:25962930

  12. Protective effect of 1,25-dihydroxyvitamin D3 on ethanol-induced intestinal barrier injury both in vitro and in vivo.

    PubMed

    Chen, Shan-Wen; Ma, Yuan-Yuan; Zhu, Jing; Zuo, Shuai; Zhang, Jun-Ling; Chen, Zi-Yi; Chen, Guo-Wei; Wang, Xin; Pan, Yi-Sheng; Liu, Yu-Cun; Wang, Peng-Yuan

    2015-09-01

    Studies have suggested the role of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) in protecting intestinal barrier function from injuries induced by multiple reagents. Vitamin D deficiency was reported to be associated with poor prognosis in patients with alcoholic liver disease (ALD). This study is designed to investigate the effect of 1,25(OH)2D3 on ethanol-induced intestinal barrier dysfunction and the underlying mechanisms utilizing Caco-2 cell monolayers and a mouse model with acute ethanol injury. In Caco-2 monolayers, ethanol significantly increased monolayer permeability, disrupted TJ distribution, increased phosphorylation level of MLC, and induced generation of ROS compared with controls. However, pre-treatment with 1,25(OH)2D3 greatly ameliorated the ethanol-induced barrier dysfunction, TJ disruption, phosphorylation level of MLC, and generation of ROS compared with ethanol-exposed monolayers. Mice fed with vitamin d-sufficient diet had a higher plasma level of 25(OH)D3 and were more resistant to ethanol-induced acute intestinal barrier injury compared with the vitamin d-deficient group. These results suggest that the suppression of generation of ROS and increased phosphorylation level of MLC might be one of the mechanisms underlying the protective effect of 1,25(OH)2D3 on ethanol-induced intestinal barrier injury and provide evidence for the application of vitamin D as therapeutic factors against ethanol-induced gut leakiness. PMID:26068064

  13. Infiltration of forkhead box P3-expressing cells in small intestinal mucosa in coeliac disease but not in type 1 diabetes

    PubMed Central

    Tiittanen, M; Westerholm-Ormio, M; Verkasalo, M; Savilahti, E; Vaarala, O

    2008-01-01

    Because the role of regulatory T cells in the intestinal inflammation is unknown in coeliac disease (CD) and type 1 diabetes (T1D), the expression of forkhead box P3 (FoxP3), CD25, transforming growth factor-β, interferon (IFN)-γ, interleukin (IL)-4, IL-8, IL-10, IL-15 and IL-18 was measured by quantitative reverse transcription–polymerase chain reaction in the small intestinal biopsies from paediatric patients with active or potential CD, T1D and control patients. The numbers of FoxP3- and CD25-expressing cells were studied with immunohistochemistry. Enhanced intestinal expressions of FoxP3, IL-10 and IFN-γ mRNAs were found in active CD when compared with controls (P-values < 0·001, 0·004, <0·001). In potential CD, only the expression of IFN-γ mRNA was increased. The numbers of FoxP3-expressing cells were higher in active and potential CD (P < 0·001, P = 0·05), and the ratio of FoxP3 mRNA to the number of FoxP3-positive cells was decreased in potential CD when compared with controls (P = 0·007). The ratio of IFN-γ to FoxP3-specific mRNA was increased in active and potential CD (P = 0·001 and P = 0·002). Patients with T1D had no changes in regulatory T cell markers, but showed increased expression of IL-18 mRNA. The impaired up-regulation of FoxP3 transcripts despite the infiltration of FoxP3-positive cells in potential CD may contribute to the persistence of inflammation. The increased ratio of IFN-γ to FoxP3 mRNA in active and potential CD suggests an imbalance between regulatory and effector mechanisms. The increased intestinal expression of IL-18 mRNA in patients with T1D adds evidence in favour of the hypothesis that T1D is associated with derangements in the gut immune system. PMID:18435801

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

    PubMed Central

    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

  15. Intravital autofluorescence 2-photon microscopy of murine intestinal mucosa with ultra-broadband femtosecond laser pulse excitation: image quality, photodamage, and inflammation

    NASA Astrophysics Data System (ADS)

    Klinger, Antje; Krapf, Lisa; Orzekowsky-Schroeder, Regina; Koop, Norbert; Vogel, Alfred; Hüttmann, Gereon

    2015-11-01

    Ultra-broadband excitation with ultrashort pulses may enable simultaneous excitation of multiple endogenous fluorophores in vital tissue. Imaging living gut mucosa by autofluorescence 2-photon microscopy with more than 150 nm broad excitation at an 800-nm central wavelength from a sub-10 fs titanium-sapphire (Ti:sapphire) laser with a dielectric mirror based prechirp was compared to the excitation with 220 fs pulses of a tunable Ti:sapphire laser at 730 and 800 nm wavelengths. Excitation efficiency, image quality, and photochemical damage were evaluated. At similar excitation fluxes, the same image brightness was achieved with both lasers. As expected, with ultra-broadband pulses, fluorescence from NAD(P)H, flavines, and lipoproteins was observed simultaneously. However, nonlinear photodamage apparent as hyperfluorescence with functional and structural alterations of the tissue occurred earlier when the laser power was adjusted to the same image brightness. After only a few minutes, the immigration of polymorphonuclear leucocytes into the epithelium and degranulation of these cells, a sign of inflammation, was observed. Photodamage is promoted by the higher peak irradiances and/or by nonoptimal excitation of autofluorescence at the longer wavelength. We conclude that excitation with a tunable narrow bandwidth laser is preferable to ultra-broadband excitation for autofluorescence-based 2-photon microscopy, unless the spectral phase can be controlled to optimize excitation conditions.

  16. Production of interferon-γ by activated T-cell receptor-αβ CD8αβ intestinal intraepithelial lymphocytes is required and sufficient for disruption of the intestinal barrier integrity

    PubMed Central

    Zufferey, Christel; Erhart, Dominik; Saurer, Leslie; Mueller, Christoph

    2009-01-01

    Maintenance of intestinal epithelial barrier function is of vital importance in preventing uncontrolled influx of antigens and the potentially ensuing inflammatory disorders. Intestinal intraepithelial lymphocytes (IEL) are in intimate contact with epithelial cells and may critically regulate the epithelial barrier integrity. While a preserving impact has been ascribed to the T-cell receptor (TCR)-γδ subset of IEL, IEL have also been shown to attenuate the barrier function. The present study sought to clarify the effects of IEL by specifically investigating the influence of the TCR-αβ CD8αβ and TCR-αβ CD8αα subsets of IEL on the intestinal epithelial barrier integrity. To this end, an in vitro coculture system of the murine intestinal crypt-derived cell-line mICcl2 and syngeneic ex vivo isolated IEL was employed. Epithelial integrity was assessed by analysis of transepithelial resistance (TER) and paracellular flux of fluorescein isothiocyanate-conjugated (FITC-) dextran. The TCR-αβ CD8αα IEL and resting TCR-αβ CD8αβ IEL did not affect TER of mICcl2 or flux of FITC-dextran. In contrast, activated TCR-αβ CD8αβ IEL clearly disrupted the integrity of the mICcl2 monolayer. No disrupting effect was seen with activated TCR-αβ CD8αβ IEL from interferon-γ knockout mice. These findings demonstrate that secretion of interferon-γ by activated TCR-αβ CD8αβ IEL is strictly required and also sufficient for disrupting the intestinal epithelial barrier function. PMID:20067535

  17. Diosmectite-zinc oxide composite improves intestinal barrier function, modulates expression of pro-inflammatory cytokines and tight junction protein in early weaned pigs.

    PubMed

    Hu, Caihong; Song, Juan; Li, Yali; Luan, Zhaoshuang; Zhu, Kang

    2013-08-01

    The study evaluated whether feeding diosmectite-ZnO composite (DS-ZnO) at 500 mg Zn/kg to early weaned pigs would alleviate the weaning-related intestinal disorders as a substitute for high concentration of ZnO (2250 mg Zn/kg). The pigs weaned at an age of 21 ± 1 d were allotted to four treatments groups as follows: (1) control; (2) DS-ZnO, 500 mg Zn/kg diet; (3) ZnO, 2250 mg Zn/kg diet; and (4) mixture of 2·0 g DS/kg and 500 mg Zn/kg from ZnO (equal amount of DS and ZnO in the DS-ZnO treatment group). The results showed that, compared with the control on days 7 and 14 post-weaning, addition of DS-ZnO at 500 mg Zn/kg improved (P<0·05) daily gain and feed intake, decreased (P<0·05) post-weaning scour scores, increased (P<0·05) jejunal villus height and the ratio of villus height and crypt depth, decreased (P<0·05) jejunal paracellular permeability of fluorescein isothiocyanate dextran 4 kDa and up-regulated (P<0·05) tight junction protein expression of occludin, claudin-1 and zonula occludens-1 in jejunal mucosa. The mRNA levels of TNF-α, IL-6 and interferon-γ (IFN-γ) on day 7 post-weaning were also decreased (P<0·05). The piglets fed DS-ZnO at 500 mg Zn/kg did not differ in the above parameters from those fed ZnO at 2250 mg Zn/kg, while they had better performance than those fed the mixture of DS and ZnO. Supplementation with DS-ZnO at 500 mg Zn/kg was effective in alleviating diarrhoea, barrier dysfunction and inflammatory cytokine expression and up-regulating tight junction protein expression. PMID:23308387

  18. [Assessment of the correlations of certain clinical and laboratory data with the morphological pattern of small intestine mucosa in the malabsorption syndrome in children].

    PubMed

    Czerwionka-Szaflarska, M; Balcar-Boroń, A; Staszak-Kowalska, R; Lackowska, G; Pawłowska, M; Korenkiewicz, J; Pankowski, M

    1989-03-01

    In 92 children aged 3 to 24 months with suspected malabsorption syndrome the nutritional status was assessed, the results of routine diagnostic laboratory tests were analysed, and the correlation was sought between these parameters and the degree of atrophy of intestinal villi. A correlation was demonstrated between body weight deficit and the pathological result of the d-xylose test and the degree of villous atrophy only in the group of infants, and in children in the second year of life the changes of these parameters were not useful in the diagnosis of the malabsorption syndrome. The assessment of the shape of iron and glucose absorption curve shows a low usefulness nof these tests, and they should not be used in the diagnosis of the syndrome. PMID:2815748

  19. [Correlation of the microbiota and intestinal mucosa in the pathophysiology and treatment of irritable bowel, irritable eye, and irritable mind syndrome].

    PubMed

    Fehér, János; Kovács, Illés; Pacella, Elena; Radák, Zsolt

    2014-09-14

    Accumulating clinical evidence supports co-morbidity of irritable bowel, irritable eye and irritable mind symptoms. Furthermore, perturbation of the microbiota-host symbiosis (dysbiosis) is considered a common pathogenic mechanism connecting gastrointestinal, ocular and neuropsychiatric symptoms. Consequently, maintaining or restoring microbiota-host symbiosis represents a new approach to treat these symptoms or to prevent their relapses. Current treatment approach assigned a primary role to live probiotics alone or in combination with prebiotics to enhance colonization of beneficial bacteria and to strengthen the symbiosis. However, several papers showed major benefits of heat-killed probiotics as compared to their live counterparts on both intestinal and systemic symptoms. Recently, in addition to killing probiotics, in a proof of concept study lysates (fragments) of probiotics in combination with vitamins A, B, D and omega 3 fatty acids were successfully tested. These findings suggested a conceptual change in the approach addressed to both the microbiota and host as targets for intervention. PMID:25194867

  20. Ste20-related proline/alanine-rich kinase (SPAK) regulated transcriptionally by hyperosmolarity is involved in intestinal barrier function.

    PubMed

    Yan, Yutao; Dalmasso, Guillaume; Nguyen, Hang Thi Thu; Obertone, Tracy S; Sitaraman, Shanthi V; Merlin, Didier

    2009-01-01

    The Ste20-related protein proline/alanine-rich kinase (SPAK) plays important roles in cellular functions such as cell differentiation and regulation of chloride transport, but its roles in pathogenesis of intestinal inflammation remain largely unknown. Here we report significantly increased SPAK expression levels in hyperosmotic environments, such as mucosal biopsy samples from patients with Crohn's disease, as well as colon tissues of C57BL/6 mice and Caco2-BBE cells treated with hyperosmotic medium. NF-kappaB and Sp1-binding sites in the SPAK TATA-less promoter are essential for SPAK mRNA transcription. Hyperosmolarity increases the ability of NF-kappaB and Sp1 to bind to their binding sites. Knock-down of either NF-kappaB or Sp1 by siRNA reduces the hyperosmolarity-induced SPAK expression levels. Furthermore, expression of NF-kappaB, but not Sp1, was upregulated by hyperosmolarity in vivo and in vitro. Nuclear run-on assays showed that hyperosmolarity increases SPAK expression levels at the transcriptional level, without affecting SPAK mRNA stability. Knockdown of SPAK expression by siRNA or overexpression of SPAK in cells and transgenic mice shows that SPAK is involved in intestinal permeability in vitro and in vivo. Together, our data suggest that SPAK, the transcription of which is regulated by hyperosmolarity, plays an important role in epithelial barrier function. PMID:19343169

  1. Effect of tannic acid-fish scale gelatin hydrolysate hybrid nanoparticles on intestinal barrier function and α-amylase activity.

    PubMed

    Wu, Shao-Jung; Ho, Yi-Cheng; Jiang, Shun-Zhou; Mi, Fwu-Long

    2015-07-01

    Practical application of tannic acid is limited because it readily binds proteins to form insoluble aggregates. In this study, tannic acid was self-assembled with fish scale gelatin hydrolysates (FSGH) to form stable colloidal complex nanoparticles. The nanoparticles prepared from 4 mg ml(-1) tannic acid and 4 mg ml(-1) FSGH had a mean particle size of 260.8 ± 3.6 nm, and showed a positive zeta potential (20.4 ± 0.4 mV). The nanoparticles acted as effective nano-biochelators and free radical scavengers because they provided a large number of adsorption sites for interaction with heavy metal ions and scavenging free radicals. The maximum adsorption capacity for Cu(2+) ions was 123.5 mg g(-1) and EC50 of DPPH radical scavenging activity was 21.6 ± 1.2 μg ml(-1). Hydroxyl radical scavenging effects of the nanoparticles were investigated by electron spin resonance spectroscopy. The copper-chelating capacity and free radical scavenging activity of the nanoparticles were associated with their capacity to inhibit Cu(2+) ion-induced barrier impairment and hyperpermeability of Caco-2 intestinal epithelial tight junction (TJ). However, α-amylase inhibitory activity of the nanoparticles was significantly lower than that of free tannic acid. The results suggest that the nanoparticles can ameliorate Cu(2+) ion induced intestinal epithelial TJ dysfunction without severely inhibiting the activity of the digestive enzymes. PMID:26069899

  2. Pantethine stimulates lipolysis in adipose tissue and inhibits cholesterol and fatty acid synthesis in liver and intestinal mucosa in the normolipidemic rat.

    PubMed

    Bocos, C; Herrera, E

    1998-08-01

    In vitro effects of pantethine on adipose tissue lipolysis and on both hepatic and intestinal cholesterol and fatty acid synthesis in normolipidemic rats are determined and related to their respective in vivo hypolipidemic effects after acute oral administration. At 3, 5, 7 and 24 h after a single high dose of pantethine to rats, free fatty acids (FFA), cholesterol and triglycerides levels decreased whereas plasma glycerol increased, the effect becoming significant at 7 h. The release of glycerol and FFA by epididymal fat pad pieces from rats was measured in Krebs Ringer bicarbonate-albumin buffer supplemented or not with epinephrine and several concentrations of pantethine (0, 10(-5), 10(-4), or 10(-3) M), and it turned out to be enhanced as pantethine concentration increased. Besides, when glucose was present in the medium, this drug lowered fatty acid re-esterification in a dose-dependent manner, the effect being specially evident in the presence of epinephrine. In vitro synthesis of both cholesterol and fatty acids by slices of liver or intestinal epithelial cells was depressed as the concentration of pantethine increased in the medium. Thus, an inhibition of both cholesterolgenesis and lipogenesis seems to contribute to the hypocholesterolemic and hypotriglyceridemic effects of pantethine. On the other hand, the stimulation of lipolysis and the inhibition of fatty acid re-esterification on adipose tissue caused by pantethine must be counteracted by a high fatty acid oxidation in the liver which would explain the decrease in FFA and the increase in glycerol levels detected in the plasma of the pantethine-treated animals. PMID:21781882

  3. Carrageenan Gum and Adherent Invasive Escherichia coli in a Piglet Model of Inflammatory Bowel Disease: Impact on Intestinal Mucosa-associated Microbiota.

    PubMed

    Munyaka, Peris M; Sepehri, Shadi; Ghia, Jean-Eric; Khafipour, Ehsan

    2016-01-01

    Inflammatory bowel diseases (IBD) including Crohn's disease (CD), and ulcerative colitis (UC), are chronic conditions characterized by chronic intestinal inflammation. Adherent invasive Escherichia coli (AIEC) pathotype has been increasingly implicated in the etiopathogenesis of IBD. In a 21-day study, we investigated the effects of AIEC strain UM146 inoculation on microbiota profile of the ileal, cecal, ascending and descending colon in a pig model of experimental colitis. Carrageenan gum (CG) was used to induce colitis in weaner piglets whereas AIEC strain UM146 previously isolated from a CD patient was included to investigate a cause or consequence effect in IBD. Treatments were: (1) control; (2) CG; (3) AIEC strain UM146; and (4) CG+UM146. Pigs in groups 2 and 4 received 1% CG in drinking water from day 1 of the study while pigs in groups 3 and 4 were inoculated with UM146 on day 8. Following euthanization on day 21, tissue mucosal scrapings were collected and used for DNA extraction. The V4 region of bacterial 16S rRNA gene was then subjected to Illumina sequencing. Microbial diversity, composition, and the predicted functional metagenome were determined in addition to short chain fatty acids profiles in the digesta and inflammatory cytokines in the intestinal tissue. CG-induced colitis decreased bacterial species richness and shifted community composition. At the phylum level, an increase in Proteobacteria and Deferribacteres and a decrease in Firmicutes, Actinobacteria, and Bacteroidetes were observed in CG and CGUM146 compared to control and UM146. The metabolic capacity of the microbiome was also altered in CG and CGUM146 compared to UM146 and control in the colon. We demonstrated that CG resulted in bacterial dysbiosis and shifted community composition similar to what has been previously observed in IBD patients. However, AIEC strain UM146 alone did not cause any clear changes compared to CG or control in our experimental IBD pig model. PMID:27092122

  4. Transcriptional analysis of porcine intestinal mucosa infected with Salmonella Typhimurium revealed a massive inflammatory response and disruption of bile acid absorption in ileum.

    PubMed

    Uribe, Juber Herrera; Collado-Romero, Melania; Zaldívar-López, Sara; Arce, Cristina; Bautista, Rocío; Carvajal, Ana; Cirera, Susanna; Claros, M Gonzalo; Garrido, Juan J

    2016-01-01

    Infected pork meat is an important source of non-typhoidal human salmonellosis. Understanding of molecular mechanisms involved in disease pathogenesis is important for the development of therapeutic and preventive strategies. Thus, hereby we study the transcriptional profiles along the porcine intestine during infection with Salmonella Typhimurium, as well as post-transcriptional gene modulation by microRNAs (miRNA). Sixteen piglets were orally challenged with S. Typhimurium. Samples from jejunum, ileum and colon, collected 1, 2 and 6 days post infection (dpi) were hybridized to mRNA and miRNA expression microarrays and analyzed. Jejunum showed a reduced transcriptional response indicating mild inflammation only at 2 dpi. In ileum inflammatory genes were overexpressed (e.g., IL-1B, IL-6, IL-8, IL1RAP, TNFα), indicating a strong immune response at all times of infection. Infection also down-regulated genes of the FXR pathway (e.g., NR1H4, FABP6, APOA1, SLC10A2), indicating disruption of the bile acid absorption in ileum. This result was confirmed by decreased high-density lipoprotein cholesterol in serum of infected pigs. Ileal inflammatory gene expression changes peaked at 2 dpi and tended to resolve at 6 dpi. Furthermore, miRNA analysis of ileum at 2 dpi revealed 62 miRNAs potentially regulating target genes involved in this inflammatory process (e.g., miR-374 and miR-451). In colon, genes involved in epithelial adherence, proliferation and cellular reorganization were down-regulated at 2 and 6 dpi. In summary, here we show the transcriptional changes occurring at the intestine at different time points of the infection, which are mainly related to inflammation and disruption of the bile acid metabolism. PMID:26738723

  5. Carrageenan Gum and Adherent Invasive Escherichia coli in a Piglet Model of Inflammatory Bowel Disease: Impact on Intestinal Mucosa-associated Microbiota

    PubMed Central

    Munyaka, Peris M.; Sepehri, Shadi; Ghia, Jean-Eric; Khafipour, Ehsan

    2016-01-01

    Inflammatory bowel diseases (IBD) including Crohn's disease (CD), and ulcerative colitis (UC), are chronic conditions characterized by chronic intestinal inflammation. Adherent invasive Escherichia coli (AIEC) pathotype has been increasingly implicated in the etiopathogenesis of IBD. In a 21-day study, we investigated the effects of AIEC strain UM146 inoculation on microbiota profile of the ileal, cecal, ascending and descending colon in a pig model of experimental colitis. Carrageenan gum (CG) was used to induce colitis in weaner piglets whereas AIEC strain UM146 previously isolated from a CD patient was included to investigate a cause or consequence effect in IBD. Treatments were: (1) control; (2) CG; (3) AIEC strain UM146; and (4) CG+UM146. Pigs in groups 2 and 4 received 1% CG in drinking water from day 1 of the study while pigs in groups 3 and 4 were inoculated with UM146 on day 8. Following euthanization on day 21, tissue mucosal scrapings were collected and used for DNA extraction. The V4 region of bacterial 16S rRNA gene was then subjected to Illumina sequencing. Microbial diversity, composition, and the predicted functional metagenome were determined in addition to short chain fatty acids profiles in the digesta and inflammatory cytokines in the intestinal tissue. CG-induced colitis decreased bacterial species richness and shifted community composition. At the phylum level, an increase in Proteobacteria and Deferribacteres and a decrease in Firmicutes, Actinobacteria, and Bacteroidetes were observed in CG and CGUM146 compared to control and UM146. The metabolic capacity of the microbiome was also altered in CG and CGUM146 compared to UM146 and control in the colon. We demonstrated that CG resulted in bacterial dysbiosis and shifted community composition similar to what has been previously observed in IBD patients. However, AIEC strain UM146 alone did not cause any clear changes compared to CG or control in our experimental IBD pig model. PMID:27092122

  6. Protective effect of the traditional Chinese medicine xuesaitong on intestinal ischemia-reperfusion injury in rats

    PubMed Central

    Xu, Xuan; Li, Dengxiao; Gao, Hong; Gao, Yuejin; Zhang, Long; Du, Yuling; Wu, Jian; Gao, Pengfei

    2015-01-01

    Objective: We investigated the effect of xuesaitong on intestinal barrier dysfunction and related mechanisms in a rat model for intestinal ischemia-reperfusion. Methods: Rats were divided into sham-operated, disease-model and Xuesaitong-treated groups. In the disease-model and Xuesaitong-treated rats an intestinal ischemia-reperfusion injury (IRI) model was introduced, which was created by a temporary obstruction of the superior mesenteric artery (SMA). The xuesaitong group was pre-treated with injections into the abdominal cavity prior to the generation of the IRI model. Tissue changes were evaluated using H&E staining and electron microscopy. Samples were analyzed at 0, 3 and 24 h post IRI. Ascites volumes as well as small intestinal mucosa bleeding, injury scores, wet to dry weight ratios, and propulsions were evaluated. Apoptotic rates were determined with TUNNEL assays. Blood serum tumor necrosis factor-α (TNF-α) levels were measured using ELISA, and Bcl-2 and caspase-3 expression in small intestinal mucosa measured using immunohistochemistry. Results: We determined a significant increase of pathological damage to small intestinal tissues, intestinal wet to dry ratios, ascites volume, TNF-α levels, apoptosis rates of small intestinal mucosa, and expression of Bcl-2 and caspase-3 proteins in the disease-model group compared to the sham-operated group (P < 0.001), and intestinal motility was significantly decreased (P < 0.001). However, comparisons between disease-model and xuesaitong pre-treated animals revealed, that in the treatment group these changes occurred in significant less severities. Conclusions: Xuesaitong can effectively alleviate intestinal barrier dysfunction caused by ischemia-reperfusion injury by reducing TNF-α, up-regulating Bcl-2 and down-regulating caspase-3 expression, in addition to increasing peristalsis. PMID:25932105

  7. Intestinal barrier analysis by assessment of mucins, tight junctions, and α-defensins in healthy C57BL/6J and BALB/cJ mice.

    PubMed

    Volynets, Valentina; Rings, Andreas; Bárdos, Gyöngyi; Ostaff, Maureen J; Wehkamp, Jan; Bischoff, Stephan C

    2016-01-01

    The intestinal barrier is gaining increasing attention because it is related to intestinal homeostasis and disease. Different parameters have been used in the past to assess intestinal barrier functions in experimental studies; however most of them are poorly defined in healthy mice. Here, we compared a number of barrier markers in healthy mice, established normal values and correlations. In 48 mice (24 C57BL/6J, 24 BALB/cJ background), we measured mucus thickness, and expression of mucin-2, α-defensin-1 and -4, zonula occludens-1, occludin, junctional adhesion molecule-A, claudin-1, 2 and -5. We also analyzed claudin-3 and fatty acid binding protein-2 in urine and plasma, respectively. A higher expression of mucin-2 protein was found in the colon compared to the ileum. In contrast, the α-defensins-1 and -4 were expressed almost exclusively in the ileum. The protein expression of the tight junction molecules claudin-1, occludin and zonula occludens-1 did not differ between colon and ileum, although some differences occurred at the mRNA level. No age- or gender-related differences were found. Differences between C57BL/6J and BALB/cJ mice were found for α-defensin-1 and -4 mRNA expression, and for urine and plasma marker concentrations. The α-defensin-1 mRNA correlated with claudin-5 mRNA, whereas α-defensin-4 mRNA correlated with claudin-3 concentrations in urine. In conclusion, we identified a number of murine intestinal barrier markers requiring tissue analyses or measurable in urine or plasma. We provide normal values for these markers in mice of different genetic background. Such data might be helpful for future animal studies in which the intestinal barrier is of interest. PMID:27583194

  8. Increased Immunoendocrine Cells in Intestinal Mucosa of Postinfectious Irritable Bowel Syndrome Patients 3 Years after Acute Shigella Infection - An Observation in a Small Case Control Study

    PubMed Central

    Kim, Hee Sun; Lim, Jung Hyun; Lee, Sang In

    2010-01-01

    Purpose Postinfectiously irritable bowel syndrome (PI-IBS) develops in 3-30% of individuals with bacterial gastroenteritis. Recent studies demonstrated increases in inflammatory components in gut mucosa of PI-IBS patients even after complete resolution of infection. We aimed to investigate histological changes in colon and rectum of PI-IBS subjects after long term period of infection. Materials and Methods We recruited PI-IBS subjects who had been diagnosed IBS after complete resolution of enteritis caused by shigellosis outbreak 3 years earlier. We compared unmatched four groups, PI-IBS (n = 4), non PI-IBS (n = 7), D-IBS (n = 7, diarrhea predominant type) and healthy controls (n = 10). All of them underwent colonoscopic biopsy at three areas, including descending colon (DC), sigmoid colon (SC) and rectum, which were assessed for 5-hydroxytryptamine (5-HT)/peptide YY (PYY)-containing enterochromaffin (EC) cell, intraepithelial (IEL) and lamina propria T lymphocyte (CD3), CD8 lymphocytes, mast cells and CD68/calprotectin+ macrophages. Results All subjects had no structural or gross abnormalities at colonoscopy. In PI-IBS, 5-HT containing EC cells, PYY containing EC cells, IELs, CD3 lymphocytes, CD8 lymphocytes, mast cells, and CD68 + macrophages were increased compared to control (p < 0.05). In D-IBS, PYY containing EC cells, IELs, and CD3 lymphocytes were increased compared to control (p < 0.05). In PI-IBS, 5-HT containing EC cells tended to increase and PYY containing EC cells, CD8 lymphocytes, mast cells, and CD68+ macrophages were increased compared to non PI-IBS (p < 0.05). Calprotectin + marcrophages were decreased in PI-IBS, non PI-IBS and IBS compared to control. Conclusion The immunoendocrine cells were sporadically increased in PI-IBS, non PI-IBS and D-IBS compared with control. Our findings in a very small number of patients suggest that mucosal inflammation may play a role in long-term PI-IBS, and that other sub-groups of IBS and larger scale studies are

  9. Gut barrier function in malnourished patients

    PubMed Central

    Welsh, F; Farmery, S; MacLennan, K; Sheridan, M; Barclay, G; Guillou, P; Reynolds, J

    1998-01-01

    Background—The integrity of the gastrointestinal mucosa is a key element in preventing systemic absorption of enteric toxins and bacteria. In the critically ill, breakdown of gut barrier function may fuel sepsis. Malnourished patients have an increased risk of postoperative sepsis; however, the effects of malnutrition on intestinal barrier function in man are unknown. 
Aims—To quantify intestinal barrier function, endotoxin exposure, and the acute phase cytokine response in malnourished patients. 
Patients—Malnourished and well nourished hospitalised patients. 
Methods—Gastrointestinal permeability was measured in malnourished patients and well nourished controls using the lactulose:mannitol test. Endoscopic biopsy specimens were stained and morphological and immunohistochemical features graded. The polymerase chain reaction was used to determine mucosal cytokine expression. The immunoglobulin G antibody response to endotoxin and serum interleukin 6 were measured by enzyme linked immunosorbent assay. 
Results—There was a significant increase in intestinal permeability in the malnourished patients in association with phenotypic and molecular evidence of activation of lamina propria mononuclear cells and enterocytes, and a heightened acute phase response. 
Conclusions—Intestinal barrier function is significantly compromised in malnourished patients, but the clinical significance is unclear. 

 Keywords: protein-energy malnutrition; intestinal permeability; endotoxin; cytokine PMID:9577348

  10. Effects of phenol on barrier function of a human intestinal epithelial cell line correlate with altered tight junction protein localization.

    PubMed

    McCall, Ingrid C; Betanzos, Abigail; Weber, Dominique A; Nava, Porfirio; Miller, Gary W; Parkos, Charles A

    2009-11-15

    Phenol contamination of soil and water has raised concerns among people living near phenol-producing factories and hazardous waste sites containing the chemical. Phenol, particularly in high concentrations, is an irritating and corrosive substance, making mucosal membranes targets of toxicity in humans. However, few data on the effects of phenol after oral exposure exist. We used an in vitro model employing human intestinal epithelial cells (SK-CO15) cultured on permeable supports to examine effects of phenol on epithelial barrier function. We hypothesized that phenol disrupts epithelial barrier by altering tight junction (TJ) protein expression. The dose-response effect of phenol on epithelial barrier function was determined using transepithelial electrical resistance (TER) and FITC-dextran permeability measurements. We studied phenol-induced changes in cell morphology and expression of several tight junction proteins by immunofluorescence and Western blot analysis. Effects on cell viability were assessed by MTT, Trypan blue, propidium iodide and TUNEL staining. Exposure to phenol resulted in decreased TER and increased paracellular flux of FITC-dextran in a dose-dependent manner. Delocalization of claudin-1 and ZO-1 from TJs to cytosol correlated with the observed increase in permeability after phenol treatment. Additionally, the decrease in TER correlated with changes in the distribution of a membrane raft marker, suggesting phenol-mediated effects on membrane fluidity. Such observations were independent of effects of phenol on cell viability as enhanced permeability occurred at doses of phenol that did not cause cell death. Overall, these findings suggest that phenol may affect transiently the lipid bilayer of the cell membrane, thus destabilizing TJ-containing microdomains. PMID:19679145

  11. Effects of phenol on barrier function of a human intestinal epithelial cell line correlate with altered tight junction protein localization

    PubMed Central

    McCall, Ingrid C.; Betanzos, Abigail; Weber, Dominique A.; Nava, Porfirio; Miller, Gary W.; Parkos, Charles A.

    2010-01-01

    Phenol contamination of soil and water has raised concerns among people living near phenol-producing factories and hazardous waste sites containing the chemical. Phenol, particularly in high concentrations, is an irritating and corrosive substance, making mucosal membranes targets of toxicity in humans. However, few data on the effects of phenol after oral exposure exist. We used an in vitro model employing human intestinal epithelial cells (SK-CO15) cultured on permeable supports to examine effects of phenol on epithelial barrier function. We hypothesized that phenol disrupts epithelial barrier by altering tight junction (TJ) protein expression. The dose-response effect of phenol on epithelial barrier function was determined using transepithelial electrical resistance (TER) and FITC-dextran permeability measurements. We studied phenol-induced changes in cell morphology and expression of several tight junction proteins by immunofluorescence and Western blot analysis. Effects on cell viability were assessed by MTT, Trypan blue, propidium iodide and TUNEL staining. Exposure to phenol resulted in decreased TER and increased paracellular flux of FITC-dextran in a dose-dependent manner. Delocalization of claudin-1 and ZO-1 from TJs to cytosol correlated with the observed increase in permeability after phenol treatment. Additionally, the decrease in TER correlated with changes in the distribution of a membrane raft marker, suggesting phenol-mediated effects on membrane fluidity. Such observations were independent of effects of phenol on cell viability as enhanced permeability occurred at doses of phenol that did not cause cell death. Overall, these findings suggest that phenol may affect transiently the lipid bilayer of the cell membrane, thus destabilizing TJ-containing microdomains. PMID:19679145

  12. Effects of phenol on barrier function of a human intestinal epithelial cell line correlate with altered tight junction protein localization

    SciTech Connect

    McCall, Ingrid C.; Betanzos, Abigail; Weber, Dominique A.; Nava, Porfirio; Miller, Gary W.; Parkos, Charles A.

    2009-11-15

    Phenol contamination of soil and water has raised concerns among people living near phenol-producing factories and hazardous waste sites containing the chemical. Phenol, particularly in high concentrations, is an irritating and corrosive substance, making mucosal membranes targets of toxicity in humans. However, few data on the effects of phenol after oral exposure exist. We used an in vitro model employing human intestinal epithelial cells (SK-CO15) cultured on permeable supports to examine effects of phenol on epithelial barrier function. We hypothesized that phenol disrupts epithelial barrier by altering tight junction (TJ) protein expression. The dose-response effect of phenol on epithelial barrier function was determined using transepithelial electrical resistance (TER) and FITC-dextran permeability measurements. We studied phenol-induced changes in cell morphology and expression of several tight junction proteins by immunofluorescence and Western blot analysis. Effects on cell viability were assessed by MTT, Trypan blue, propidium iodide and TUNEL staining. Exposure to phenol resulted in decreased TER and increased paracellular flux of FITC-dextran in a dose-dependent manner. Delocalization of claudin-1 and ZO-1 from TJs to cytosol correlated with the observed increase in permeability after phenol treatment. Additionally, the decrease in TER correlated with changes in the distribution of a membrane raft marker, suggesting phenol-mediated effects on membrane fluidity. Such observations were independent of effects of phenol on cell viability as enhanced permeability occurred at doses of phenol that did not cause cell death. Overall, these findings suggest that phenol may affect transiently the lipid bilayer of the cell membrane, thus destabilizing TJ-containing microdomains.

  13. Curcumin protects against the intestinal ischemia-reperfusion injury: involvement of the tight junction protein ZO-1 and TNF-α related mechanism.

    PubMed

    Tian, Shuying; Guo, Ruixue; Wei, Sichen; Kong, Yu; Wei, Xinliang; Wang, Weiwei; Shi, Xiaomeng; Jiang, Hongyu

    2016-03-01

    Present study aimed to investigate the eff ect of curcumin-pretreatment on intestinal I/R injury and on intestinal mucosa barrier. Thirty Wistar rats were randomly divided into: sham, I/R, and curcumin groups (n=10). Animals in curcumin group were pretreated with curcumin by gastric gavage (200 mg/kg) for 2 days before I/R. Small intestine tissues were prepared for Haematoxylin & Eosin (H&E) staining. Serum diamine oxidase (DAO) and tumor necrosis factor (TNF)-α levels were measured. Expression of intestinal TNF-α and tight junction protein (ZO-1) proteins was detected by Western blot and/or immunohistochemistry. Serum DAO level and serum and intestinal TNF-α leves were signifi cantly increased after I/R, and the values were markedly reduced by curcumin pretreatment although still higher than that of sham group (p<0.05 or p<0.001). H&E staining showed the significant injury to intestinal mucosa following I/R, and curcumin pretreatment signifi cantly improved the histological structure of intestinal mucosa. I/R insult also induced significantly down-regulated expression of ZO-1, and the eff ect was dramatically attenuated by curcumin-pretreatment. Curcumin may protect the intestine from I/R injury through restoration of the epithelial structure, promotion of the recovery of intestinal permeability, as well as enhancement of ZO-1 protein expression, and this eff ect may be partly attributed to the TNF-α related pathway. PMID:26937210

  14. Curcumin protects against the intestinal ischemia-reperfusion injury: involvement of the tight junction protein ZO-1 and TNF-α related mechanism

    PubMed Central

    Tian, Shuying; Guo, Ruixue; Kong, Yu; Wei, Xinliang; Wang, Weiwei; Shi, Xiaomeng; Jiang, Hongyu

    2016-01-01

    Present study aimed to investigate the eff ect of curcumin-pretreatment on intestinal I/R injury and on intestinal mucosa barrier. Thirty Wistar rats were randomly divided into: sham, I/R, and curcumin groups (n=10). Animals in curcumin group were pretreated with curcumin by gastric gavage (200 mg/kg) for 2 days before I/R. Small intestine tissues were prepared for Haematoxylin & Eosin (H&E) staining. Serum diamine oxidase (DAO) and tumor necrosis factor (TNF)-α levels were measured. Expression of intestinal TNF-α and tight junction protein (ZO-1) proteins was detected by Western blot and/or immunohistochemistry. Serum DAO level and serum and intestinal TNF-α leves were signifi cantly increased after I/R, and the values were markedly reduced by curcumin pretreatment although still higher than that of sham group (p<0.05 or p<0.001). H&E staining showed the significant injury to intestinal mucosa following I/R, and curcumin pretreatment signifi cantly improved the histological structure of intestinal mucosa. I/R insult also induced significantly down-regulated expression of ZO-1, and the eff ect was dramatically attenuated by curcumin-pretreatment. Curcumin may protect the intestine from I/R injury through restoration of the epithelial structure, promotion of the recovery of intestinal permeability, as well as enhancement of ZO-1 protein expression, and this eff ect may be partly attributed to the TNF-α related pathway. PMID:26937210

  15. Berberine Prevents Intestinal Mucosal Barrier Damage During Early Phase of Sepsis in Rat through the Toll-Like Receptors Signaling Pathway

    PubMed Central

    Li, Guo-xun; Wang, Xi-mo; Jiang, Tao; Gong, Jian-feng; Niu, Ling-ying

    2015-01-01

    Our previous study has shown berberine prevents damage to the intestinal mucosal barrier during early phase of sepsis in rat through mechanisms independent of the NOD-like receptors signaling pathway. In this study, we explored the regulatory effects of berberine on Toll-like receptors during the intestinal mucosal damaging process in rats. Male Sprague-Dawlay (SD) rats were treated with berberine for 5 d before undergoing cecal ligation and puncture (CLP) to induce polymicrobial sepsis. The expression of Toll-like receptor 2 (TLR 2), TLR 4, TLR 9, the activity of nuclear factor-kappa B (NF-κB), the levels of selected cytokines and chemokines, percentage of cell death in intestinal epithelial cells, and mucosal permeability were investigated at 0, 2, 6, 12 and 24 h after CLP. Results showed that the tumor necrosis factor-α (TNF-α ) and interleukin-6 (IL-6) level were significantly lower in berberine-treated rats compared to the control animals. Conversely, the expression level of tight junction proteins, percentage of cell death in intestinal epithelial cells and the mucosal permeability were significantly higher in berberine-treated rats. The mRNA expression of TLR 2, TLR 4, and TLR 9 were significantly affected by berberine treatment. Our results indicate that pretreatment with berberine attenuates tissue injury and protects the intestinal mucosal barrier in early phase of sepsis and this may possibly have been mediated through the TLRs pathway. PMID:25605990

  16. Human Oral Isolate Lactobacillus fermentum AGR1487 Reduces Intestinal Barrier Integrity by Increasing the Turnover of Microtubules in Caco-2 Cells

    PubMed Central

    Anderson, Rachel C.; Young, Wayne; Clerens, Stefan; Cookson, Adrian L.; McCann, Mark J.; Armstrong, Kelly M.; Roy, Nicole C.

    2013-01-01

    Lactobacillus fermentum is found in fermented foods and thought to be harmless. In vivo and clinical studies indicate that some L. fermentum strains have beneficial properties, particularly for gastrointestinal health. However, L. fermentum AGR1487 decreases trans-epithelial electrical resistance (TEER), a measure of intestinal barrier integrity. The hypothesis was that L. fermentum AGR1487 decreases the expression of intestinal cell tight junction genes and proteins, thereby reducing barrier integrity. Transcriptomic and proteomic analyses of Caco-2 cells (model of human intestinal epithelial cells) treated with L. fermentum AGR1487 were used to obtain a global view of the effect of the bacterium on intestinal epithelial cells. Specific functional characteristics by which L. fermentum AGR1487 reduces intestinal barrier integrity were examined using confocal microscopy, cell cycle progression and adherence bioassays. The effects of TEER-enhancing L. fermentum AGR1485 were investigated for comparison. L. fermentum AGR1487 did not alter the expression of Caco-2 cell tight junction genes (compared to L. fermentum AGR1485) and tight junction proteins were not able to be detected. However, L. fermentum AGR1487 increased the expression levels of seven tubulin genes and the abundance of three microtubule-associated proteins, which have been linked to tight junction disassembly. Additionally, Caco-2 cells treated with L. fermentum AGR1487 did not have defined and uniform borders of zona occludens 2 around each cell, unlike control or AGR1485 treated cells. L. fermentum AGR1487 cells were required for the negative effect on barrier integrity (bacterial supernatant did not cause a decrease in TEER), suggesting that a physical interaction may be necessary. Increased adherence of L. fermentum AGR1487 to Caco-2 cells (compared to L. fermentum AGR1485) was likely to facilitate this cell-to-cell interaction. These findings illustrate that bacterial strains of the same species can

  17. Protective effects of ψ taraxasterol 3-O-myristate and arnidiol 3-O-myristate isolated from Calendula officinalis on epithelial intestinal barrier.

    PubMed

    Dall'Acqua, Stefano; Catanzaro, Daniela; Cocetta, Veronica; Igl, Nadine; Ragazzi, Eugenio; Giron, Maria Cecilia; Cecconello, Laura; Montopoli, Monica

    2016-03-01

    The triterpene esters ᴪ taraxasterol-3-O-myristate (1) and arnidiol-3-O-myristate (2) were tested for their ability to protect epithelial intestinal barrier in an in vitro model. Their effects on ROS production and on trans-epithelial resistance were investigated on CaCo-2 cell monolayers both in basal and stress-induced conditions. Both compounds were able to modulate the stress damage induced by H2O2 and INFγ+TNFα, showing a potential use as model compounds for the study of new therapeutic agents for intestinal inflammations. PMID:26791917

  18. Intestinal barrier function of Atlantic salmon (Salmo salar L.) post smolts is reduced by common sea cage environments and suggested as a possible physiological welfare indicator

    PubMed Central

    2010-01-01

    Background Fish farmed under high intensity aquaculture conditions are subjected to unnatural environments that may cause stress. Therefore awareness of how to maintain good health and welfare of farmed fish is important. For Atlantic salmon held in sea cages, water flow, dissolved oxygen (DO) levels and temperature will fluctuate over time and the fish can at times be exposed to detrimentally low DO levels and high temperatures. This experimental study investigates primary and secondary stress responses of Atlantic salmon post smolts to long-term exposure to reduced and fluctuating DO levels and high water temperatures, mimicking situations in the sea cages. Plasma cortisol levels and cortisol release to the water were assessed as indicators of the primary stress response and intestinal barrier integrity and physiological functions as indicators of secondary responses to changes in environmental conditions. Results Plasma cortisol levels were elevated in fish exposed to low (50% and 60% saturation) DO levels and low temperature (9°C), at days 9, 29 and 48. The intestinal barrier function, measured as electrical resistance (TER) and permeability of mannitol at the end of the experiment, were reduced at 50% DO, in both proximal and distal intestine. When low DO levels were combined with high temperature (16°C), plasma cortisol levels were elevated in the cyclic 1:5 h at 85%:50% DO group and fixed 50% DO group compared to the control (85% DO) group at day 10 but not at later time points. The intestinal barrier function was clearly disturbed in the 50% DO group; TER was reduced in both intestinal regions concomitant with increased paracellular permeability in the distal region. Conclusions This study reveals that adverse environmental conditions (low water flow, low DO levels at low and high temperature), that can occur in sea cages, elicits primary and secondary stress responses in Atlantic salmon post smolts. The intestinal barrier function was significantly

  19. Physiological and pathophysiological factors affecting the expression and activity of the drug transporter MRP2 in intestine. Impact on its function as membrane barrier.

    PubMed

    Arana, Maite R; Tocchetti, Guillermo N; Rigalli, Juan P; Mottino, Aldo D; Villanueva, Silvina S M

    2016-07-01

    The gastrointestinal epithelium functions as a selective barrier to absorb nutrients, electrolytes and water, but at the same time restricts the passage into the systemic circulation of intraluminal potentially toxic compounds. This epithelium maintains its selective barrier function through the presence of very selective and complex intercellular junctions and the ability of the absorptive cells to reject those compounds. Accordingly, the enterocytes metabolize orally incorporated xenobiotics and secrete the hydrophilic metabolites back into the intestinal lumen through specific transporters localized apically. In the recent decades, there has been increasing recognition of the existence of the intestinal cellular barrier. In the present review we focus on the role of the multidrug resistance-associated protein 2 (MRP2, ABCC2) in the apical membrane of the enterocytes, as an important component of this intestinal barrier, as well as on its regulation. We provide a detailed compilation of significant contributions demonstrating that MRP2 expression and function vary under relevant physiological and pathophysiological conditions. Because MRP2 activity modulates the availability and pharmacokinetics of many therapeutic drugs administered orally, their therapeutic efficacy and safety may vary as well. PMID:27109321

  20. Lactobacillus plantarum MB452 enhances the function of the intestinal barrier by increasing the expression levels of genes involved in tight junction formation

    PubMed Central

    2010-01-01

    Background Intestinal barrier function is important for preserving health, as a compromised barrier allows antigen entry and can induce inflammatory diseases. Probiotic bacteria can play a role in enhancing intestinal barrier function; however, the mechanisms are not fully understood. Existing studies have focused on the ability of probiotics to prevent alterations to tight junctions in disease models, and have been restricted to a few tight junction bridging proteins. No studies have previously investigated the effect of probiotic bacteria on healthy intestinal epithelial cell genes involved in the whole tight junction signalling pathway, including those encoding for bridging, plaque and dual location tight junction proteins. Alteration of tight junction signalling in healthy humans is a potential mechanism that could lead to the strengthening of the intestinal barrier, resulting in limiting the ability of antigens to enter the body and potentially triggering undesirable immune responses. Results The effect of Lactobacillus plantarum MB452 on tight junction integrity was determined by measuring trans-epithelial electrical resistance (TEER) across Caco-2 cell layers. L. plantarum MB452 caused a dose-dependent TEER increase across Caco-2 cell monolayers compared to control medium. Gene expression was compared in Caco-2 cells untreated or treated with L. plantarum MB452 for 10 hours. Caco-2 cell RNA was hybridised to human oligonucleotide arrays. Data was analysed using linear models and differently expressed genes were examined using pathway analysis tools. Nineteen tight junction-related genes had altered expression levels in response to L. plantarum MB452 (modified-P < 0.05, fold-change > 1.2), including those encoding occludin and its associated plaque proteins that anchor it to the cytoskeleton. L. plantarum MB452 also caused changes in tubulin and proteasome gene expression levels which may be linked to intestinal barrier function. Caco-2 tight junctions were

  1. Carnosinase activity of human gastrointestinal mucosa.

    PubMed Central

    Sadikali, F; Darwish, R; Watson, W C

    1975-01-01

    Carnosinase, the dipeptidase which hydrolyses carnosine and other histidine-containing dipeptides, was assayed in mucosal tissues of the human and of the rat gut. Kinetic properties of the intestinal enzyme were found to be similar to carnosinase of other animal tissues. Little or no activity was detected in human gastric or colonic mucosa, and the levels were lower in duodenal than jejunal mucosa. The distribution of carnosinase is similar to that of the disaccharidases. Mean carnosinase activity was 8-8 units/g weight in 15 patients with histologically normal mucosa compared with 5-7 units in five with villous atrophy. The enzyme levels increased with histological improvement of the mucosa in patients with coeliac disease on a gluten-free diet. Tolerance curves for carnosine and its constitutent amino acids showed malabsorption of the dipeptide in a patient with carnosinase deficiency. It is concluded that the intestinal mucosa has much less hydrolase activity for carnosine than for glycylglycine and other dipeptidases, and the relatively slow hydrolysis appears to be the rate-limiting step in the total absorptive process. PMID:1237444

  2. Modulation of Cytochrome P450 Metabolism and Transport across Intestinal Epithelial Barrier by Ginger Biophenolics

    PubMed Central

    Yang, Chunhua; Donthamsetty, Shashikiran; Cantuaria, Guilherme; Jadhav, Gajanan R.; Vangala, Subrahmanyam; Reid, Michelle D.; Aneja, Ritu

    2014-01-01

    Natural and complementary therapies in conjunction with mainstream cancer care are steadily gaining popularity. Ginger extract (GE) confers significant health-promoting benefits owing to complex additive and/or synergistic interactions between its bioactive constituents. Recently, we showed that preservation of natural “milieu” confers superior anticancer activity on GE over its constituent phytochemicals, 6-gingerol (6G), 8-gingerol (8G), 10-gingerol (10G) and 6-shogaol (6S), through enterohepatic recirculation. Here we further evaluate and compare the effects of GE and its major bioactive constituents on cytochrome P450 (CYP) enzyme activity in human liver microsomes by monitoring metabolites of CYP-specific substrates using LC/MS/MS detection methods. Our data demonstrate that individual gingerols are potent inhibitors of CYP isozymes, whereas GE exhibits a much higher half-maximal inhibition value, indicating no possible herb-drug interactions. However, GE's inhibition of CYP1A2 and CYP2C8 reflects additive interactions among the constituents. In addition, studies performed to evaluate transporter-mediated intestinal efflux using Caco-2 cells revealed that GE and its phenolics are not substrates of P-glycoprotein (Pgp). Intriguingly, however, 10G and 6S were not detected in the receiver compartment, indicating possible biotransformation across the Caco-2 monolayer. These data strengthen the notion that an interplay of complex interactions among ginger phytochemicals when fed as whole extract dictates its bioactivity highlighting the importance of consuming whole foods over single agents. Our study substantiates the need for an in-depth analysis of hepatic biotransformation events and distribution profiles of GE and its active phenolics for the design of safe regimens. PMID:25251219

  3. Influence of sodium on major diffusion barriers to passive intestinal uptake.

    PubMed

    Thomson, A B

    1982-08-01

    Intestinal active transport processes have been shown to be sodium dependent, but the effect of varying the concentration of sodium in the luminal bulk phase on the passive uptake of lipids has not been established. An in vitro technique was used to measure the uptake of fatty acids and alcohols into the rabbit jejunum under conditions of stirring of the bulk phase selected to reduce the effective resistance of the unstirred water layer (UWL). Sodium withdrawal had no effect on the uptake of a homologous series of fatty alcohols, and thus the UWL was not influenced by varying bulk-phase sodium; in contrast, the uptake of a homologous series of short-, medium, and long-chain-length saturated fatty acids (FA) was progressively inhibited by reducing bulk-phase sodium from 145 to 0 meq/l. There was no difference in FA uptake between the use of magnesium chloride and mannitol for maintenance of isotonicity with sodium withdrawal. At each sodium concentration, the uptake of FA rose with increasing FA chain length. The relation between sodium concentration and incremental change in free energy (delta delta Fw leads to 1) was described by a sigmoid-shaped curve. The uptake of cholesterol was also inhibited by reducing sodium in the bulk phase. In summary, varying bulk-phase sodium has no effect on UWL, and the influence of sodium on the uptake of FA is mediated by altering delta delta Fw leads to 1 and therefore the physicochemical properties of the brush-border membrane. PMID:7114222

  4. Intestinal steroidogenesis.

    PubMed

    Bouguen, Guillaume; Dubuquoy, Laurent; Desreumaux, Pierre; Brunner, Thomas; Bertin, Benjamin

    2015-11-01

    Steroids are fundamental hormones that control a wide variety of physiological processes such as metabolism, immune functions, and sexual characteristics. Historically, steroid synthesis was considered a function restricted to the adrenals and the gonads. In the past 20 years, a significant number of studies have demonstrated that steroids could also be synthesized or metabolized by other organs. According to these studies, the intestine appears to be a major source of de novo produced glucocorticoids as well as a tissue capable of producing and metabolizing sex steroids. This finding is based on the detection of steroidogenic enzyme expression as well as the presence of bioactive steroids in both the rodent and human gut. Within the intestinal mucosa, the intestinal epithelial cell layer is one of the main cellular sources of steroids. Glucocorticoid synthesis regulation in the intestinal epithelial cells is unique in that it does not involve the classical positive regulator steroidogenic factor-1 (SF-1) but a closely related homolog, namely the liver receptor homolog-1 (LRH-1). This local production of immunoregulatory glucocorticoids contributes to intestinal homeostasis and has been linked to pathophysiology of inflammatory bowel diseases. Intestinal epithelial cells also possess the ability to metabolize sex steroids, notably estrogen; this mechanism may impact colorectal cancer development. In this review, we contextualize and discuss what is known about intestinal steroidogenesis and regulation as well as the key role these functions play both in physiological and pathological conditions. PMID:25560486

  5. Interleukin-6 induces keratin expression in intestinal epithelial cells: potential role of keratin-8 in interleukin-6-induced barrier function alterations.

    PubMed

    Wang, Lixin; Srinivasan, Shanthi; Theiss, Arianne L; Merlin, Didier; Sitaraman, Shanthi V

    2007-03-16

    Keratin 8 (K8) and keratin-18 (K18) are the major intermediate filament proteins in the intestinal epithelia. The regulation and function of keratin in the intestinal epithelia is largely unknown. In this study we addressed the role and regulation of K8 and K18 expression by interleukin 6 (IL-6). Caco2-BBE cell line and IL-6 null mice were used to study the effect of IL-6 on keratin expression. Keratin expression was studied by Northern blot, Western blot, and confocal microscopy. Paracellular permeability was assessed by apical-to-basal transport of a fluorescein isothiocyanate dextran probe (FD-4). K8 was silenced using the small interfering RNA approach. IL-6 significantly up-regulated mRNA and protein levels of K8 and K18. Confocal microscopy showed a reticular pattern of intracellular keratin localized to the subapical region after IL-6 treatment. IL-6 also induced serine phosphorylation of K8. IL-6 decreased paracellular flux of FD-4 compared with vehicle-treated monolayers. K8 silencing abolished the decrease in paracellular permeability induced by IL-6. Administration of dextran sodium sulfate (DSS) significantly increased intestinal permeability in IL-6-/- mice compared with wild type mice given DSS. Collectively, our data demonstrate that IL-6 regulates the colonic expression of K8 and K18, and K8/K18 mediates barrier protection by IL-6 under conditions where intestinal barrier is compromised. Thus, our data uncover a novel function of these abundant cytoskeletal proteins, which may have implications in intestinal disorders such as inflammatory bowel disease wherein barrier dysfunction underlies the inflammatory response. PMID:17213200

  6. Intestinal permeability and bacterial translocation following small bowel transplantation in the rat

    SciTech Connect

    Grant, D.; Hurlbut, D.; Zhong, R.; Wang, P.Z.; Chen, H.F.; Garcia, B.; Behme, R.; Stiller, C.; Duff, J. )

    1991-08-01

    In addition to its role in absorbing nutrients, the intestinal mucosa provides an important barrier against toxins and bacteria in the bowel lumen. The present study evaluated gut barrier function following orthotopic (in continuity) intestinal grafting in rats. Graft histology, intestinal permeability, and bacterial translocation to the grafted mesenteric lymph nodes, the host's liver, and the host's spleen were assessed on the 3rd, 5th, and 7th postoperative days. The study group received no immunosuppression after allotransplantation. The two control groups included rats with isografts and rats with cyclosporine-treated allografts. On the 7th POD, the study animals had moderate transmural inflammation due to rejection, with normal histology in the isografts and CsA-treated allografts; increased intestinal permeability, measured by urinary excretion of oral 51Cr-EDTA (P less than 0.01); and increased number of bacteria in the MLN and spleen (P less than 0.05). The number of bacteria in the MLN and spleen of the study group positively correlated with the changes in intestinal permeability (P less than 0.05). Rejection of the orthotopic intestinal graft leads to increased intestinal permeability and bacterial translocation from the lumen of the graft to the host's reticuloendothelial system. Measures to improve gut barrier function and antibiotic therapy during rejection episodes may help reduce the incidence of septic complications after intestinal grafting.

  7. Neutralization of IL-6 and TNF-α ameliorates intestinal permeability in DSS-induced colitis.

    PubMed

    Xiao, Yong-Tao; Yan, Wei-Hui; Cao, Yi; Yan, Jun-Kai; Cai, Wei

    2016-07-01

    The cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) have been implicated as important mediators of the inflammatory reaction in patients with intestinal inflammation. The present study was designed to investigate the roles of these cytokines on mucosal barrier function in a mouse model of acute colitis with using anti-cytokine strategies. Mice received 3% dextran sulfate sodium (DSS) in their drinking water for 7days showed morphological alteration of mucosa and increase of intestinal permeability. Administration of IL-6 monoclonal antibody (mAb) or TNF-α mAb significantly attenuated intestinal permeability. IL-6 mAb and TNF-α mAb treatment also effectively suppressed the expression of claudin-2 and myosin light chain kinase (MLCK). Taken together, we indicated that anti-IL-6 and anti-TNF-α therapy prevent intestinal permeability induced by intestinal inflammation. PMID:27155817

  8. Malaria-associated L-arginine deficiency induces mast cell-associated disruption to intestinal barrier defenses against nontyphoidal Salmonella bacteremia.

    PubMed

    Chau, Jennifer Y; Tiffany, Caitlin M; Nimishakavi, Shilpa; Lawrence, Jessica A; Pakpour, Nazzy; Mooney, Jason P; Lokken, Kristen L; Caughey, George H; Tsolis, Renee M; Luckhart, Shirley

    2013-10-01

    Coinfection with malaria and nontyphoidal Salmonella serotypes (NTS) can cause life-threatening bacteremia in humans. Coinfection with malaria is a recognized risk factor for invasive NTS, suggesting that malaria impairs intestinal barrier function. Here, we investigated mechanisms and strategies for prevention of coinfection pathology in a mouse model. Our findings reveal that malarial-parasite-infected mice, like humans, develop L-arginine deficiency, which is associated with intestinal mastocytosis, elevated levels of histamine, and enhanced intestinal permeability. Prevention or reversal of L-arginine deficiency blunts mastocytosis in ileal villi as well as bacterial translocation, measured as numbers of mesenteric lymph node CFU of noninvasive Escherichia coli Nissle and Salmonella enterica serotype Typhimurium, the latter of which is naturally invasive in mice. Dietary supplementation of malarial-parasite-infected mice with L-arginine or L-citrulline reduced levels of ileal transcripts encoding interleukin-4 (IL-4), a key mediator of intestinal mastocytosis and macromolecular permeability. Supplementation with L-citrulline also enhanced epithelial adherens and tight junctions in the ilea of coinfected mice. These data suggest that increasing L-arginine bioavailability via oral supplementation can ameliorate malaria-induced intestinal pathology, providing a basis for testing nutritional interventions to reduce malaria-associated mortality in humans. PMID:23690397

  9. Malaria-Associated l-Arginine Deficiency Induces Mast Cell-Associated Disruption to Intestinal Barrier Defenses against Nontyphoidal Salmonella Bacteremia

    PubMed Central

    Chau, Jennifer Y.; Tiffany, Caitlin M.; Nimishakavi, Shilpa; Lawrence, Jessica A.; Pakpour, Nazzy; Mooney, Jason P.; Lokken, Kristen L.; Caughey, George H.; Tsolis, Renee M.

    2013-01-01

    Coinfection with malaria and nontyphoidal Salmonella serotypes (NTS) can cause life-threatening bacteremia in humans. Coinfection with malaria is a recognized risk factor for invasive NTS, suggesting that malaria impairs intestinal barrier function. Here, we investigated mechanisms and strategies for prevention of coinfection pathology in a mouse model. Our findings reveal that malarial-parasite-infected mice, like humans, develop l-arginine deficiency, which is associated with intestinal mastocytosis, elevated levels of histamine, and enhanced intestinal permeability. Prevention or reversal of l-arginine deficiency blunts mastocytosis in ileal villi as well as bacterial translocation, measured as numbers of mesenteric lymph node CFU of noninvasive Escherichia coli Nissle and Salmonella enterica serotype Typhimurium, the latter of which is naturally invasive in mice. Dietary supplementation of malarial-parasite-infected mice with l-arginine or l-citrulline reduced levels of ileal transcripts encoding interleukin-4 (IL-4), a key mediator of intestinal mastocytosis and macromolecular permeability. Supplementation with l-citrulline also enhanced epithelial adherens and tight junctions in the ilea of coinfected mice. These data suggest that increasing l-arginine bioavailability via oral supplementation can ameliorate malaria-induced intestinal pathology, providing a basis for testing nutritional interventions to reduce malaria-associated mortality in humans. PMID:23690397

  10. Enteropathogenic Escherichia coli inhibits type I interferon- and RNase L-mediated host defense to disrupt intestinal epithelial cell barrier function.

    PubMed

    Long, Tiha M; Nisa, Shahista; Donnenberg, Michael S; Hassel, Bret A

    2014-07-01

    Enteropathogenic Escherichia coli (EPEC) primarily infects children in developing countries and causes diarrhea that can be deadly. EPEC pathogenesis occurs through type III secretion system (T3SS)-mediated injection of effectors into intestinal epithelial cells (IECs); these effectors alter actin dynamics, modulate the immune response, and disrupt tight junction (TJ) integrity. The resulting compromised barrier function and increased gastrointestinal (GI) permeability may be responsible for the clinical symptoms of infection. Type I interferon (IFN) mediates anti-inflammatory activities and serves essential functions in intestinal immunity and homeostasis; however, its role in the immune response to enteric pathogens, such as EPEC, and its impact on IEC barrier function have not been examined. Here, we report that IFN-β is induced following EPEC infection and regulates IEC TJ proteins to maintain barrier function. The EPEC T3SS effector NleD counteracts this protective activity by inhibiting IFN-β induction and enhancing tumor necrosis factor alpha to promote barrier disruption. The endoribonuclease RNase L is a key mediator of IFN induction and action that promotes TJ protein expression and IEC barrier integrity. EPEC infection inhibits RNase L in a T3SS-dependent manner, providing a mechanism by which EPEC evades IFN-induced antibacterial activities. This work identifies novel roles for IFN-β and RNase L in IEC barrier functions that are targeted by EPEC effectors to escape host defense mechanisms and promote virulence. The IFN-RNase L axis thus represents a potential therapeutic target for enteric infections and GI diseases involving compromised barrier function. PMID:24733098

  11. Changes in intestinal barrier function and gut microbiota in high-fat diet-fed rats are dynamic and region dependent.

    PubMed

    Hamilton, M Kristina; Boudry, Gaëlle; Lemay, Danielle G; Raybould, Helen E

    2015-05-15

    A causal relationship between the pathophysiological changes in the gut epithelium and altered gut microbiota with the onset of obesity have been suggested but not defined. The aim of this study was to determine the temporal relationship between impaired intestinal barrier function and microbial dysbiosis in the small and large intestine in rodent high-fat (HF) diet-induced obesity. Rats were fed HF diet (45% fat) or normal chow (C, 10% fat) for 1, 3, or 6 wk; food intake, body weight, and adiposity were measured. Barrier function ex vivo using FITC-labeled dextran (4,000 Da, FD-4) and horseradish peroxidase (HRP) probes in Ussing chambers, gene expression, and gut microbial communities was assessed. After 1 wk, there was an immediate but reversible increase in paracellular permeability, decrease in IL-10 expression, and decrease in abundance of genera within the class Clostridia in the ileum. In the large intestine, HRP flux and abundance of genera within the order Bacteroidales increased with time on the HF diet and correlated with the onset of increased body weight and adiposity. The data show immediate insults in the ileum in response to ingestion of a HF diet, which were rapidly restored and preceded increased passage of large molecules across the large intestinal epithelium. This study provides an understanding of microbiota dysbiosis and gut pathophysiology in diet-induced obesity and has identified IL-10 and Oscillospira in the ileum and transcellular flux in the large intestine as potential early impairments in the gut that might lead to obesity and metabolic disorders. PMID:25747351

  12. The intestinal microbiome, barrier function, and immune system in inflammatory bowel disease: a tripartite pathophysiological circuit with implications for new therapeutic directions

    PubMed Central

    Vindigni, Stephen M.; Zisman, Timothy L.; Suskind, David L.; Damman, Christopher J.

    2016-01-01

    We discuss the tripartite pathophysiological circuit of inflammatory bowel disease (IBD), involving the intestinal microbiota, barrier function, and immune system. Dysfunction in each of these physiological components (dysbiosis, leaky gut, and inflammation) contributes in a mutually interdependent manner to IBD onset and exacerbation. Genetic and environmental risk factors lead to disruption of gut homeostasis: genetic risks predominantly affect the immune system, environmental risks predominantly affect the microbiota, and both affect barrier function. Multiple genetic and environmental ‘hits’ are likely necessary to establish and exacerbate disease. Most conventional IBD therapies currently target only one component of the pathophysiological circuit, inflammation; however, many patients with IBD do not respond to immune-modulating therapies. Hope lies in new classes of therapies that target the microbiota and barrier function. PMID:27366227

  13. Modulation of Intestinal Epithelial Defense Responses by Probiotic Bacteria.

    PubMed

    Wan, L Y M; Chen, Z J; Shah, N P; El-Nezami, H

    2016-12-01

    Probiotics are live microorganisms, which when administered in food confer numerous health benefits. In previous studies about beneficial effects of probiotic bacteria to health, particularly in the fields of intestinal mucosa defense responses, specific probiotics, in a strain-dependent manner, show certain degree of potential to reinforce the integrity of intestinal epithelium and/or regulate some immune components. The mechanism of probiotic action is an area of interest. Among all possible routes of modulation by probiotics of intestinal epithelial cell-mediated defense responses, modulations of intestinal barrier function, innate, and adaptive mucosal immune responses, as well as signaling pathways are considered to play important role in the intestinal defense responses against pathogenic bacteria. This review summarizes the beneficial effects of probiotic bacteria to intestinal health together with the mechanisms affected by probiotic bacteria: barrier function, innate, and adaptive defense responses such as secretion of mucins, defensins, trefoil factors, immunoglobulin A (IgA), Toll-like receptors (TLRs), cytokines, gut associated lymphoid tissues, and signaling pathways. PMID:25629818

  14. A comparison of linaclotide and lubiprostone dosing regimens on ion transport responses in human colonic mucosa.

    PubMed

    Kang, Sang Bum; Marchelletta, Ronald R; Penrose, Harrison; Docherty, Michael J; McCole, Declan F

    2015-03-01

    Linaclotide, a synthetic guanylyl cyclase C (GC-C) agonist, and the prostone analog, Lubiprostone, are approved to manage chronic idiopathic constipation and constipation-predominant irritable bowel syndrome. Lubiprostone also protects intestinal mucosal barrier function in ischemia. GC-C signaling regulates local fluid balance and other components of intestinal mucosal homeostasis including epithelial barrier function. The aim of this study was to compare if select dosing regimens differentially affect linaclotide and lubiprostone modulation of ion transport and barrier properties of normal human colonic mucosa. Normal sigmoid colon biopsies from healthy subjects were mounted in Ussing chambers. Tissues were treated with linaclotide, lubiprostone, or vehicle to determine effects on short-circuit current (I sc). Subsequent I sc responses to the cAMP agonist, forskolin, and the calcium agonist, carbachol, were also measured to assess if either drug caused desensitization. Barrier properties were assessed by measuring transepithelial electrical resistance. I sc responses to linaclotide and lubiprostone were significantly higher than vehicle control when administered bilaterally or to the mucosal side only. Single versus cumulative concentrations of linaclotide showed differences in efficacy while cumulative but not single dosing caused desensitization to forskolin. Lubiprostone reduced forskolin responses under all conditions. Linaclotide and lubiprostone exerted a positive effect on TER that was dependent on the dosing regimen. Linaclotide and lubiprostone increase ion transport responses across normal human colon but linaclotide displays increased sensitivity to the dosing regimen used. These findings may have implications for dosing protocols of these agents in patients with constipation. PMID:26038704

  15. A comparison of linaclotide and lubiprostone dosing regimens on ion transport responses in human colonic mucosa

    PubMed Central

    Kang, Sang Bum; Marchelletta, Ronald R; Penrose, Harrison; Docherty, Michael J; McCole, Declan F

    2015-01-01

    Linaclotide, a synthetic guanylyl cyclase C (GC-C) agonist, and the prostone analog, Lubiprostone, are approved to manage chronic idiopathic constipation and constipation-predominant irritable bowel syndrome. Lubiprostone also protects intestinal mucosal barrier function in ischemia. GC-C signaling regulates local fluid balance and other components of intestinal mucosal homeostasis including epithelial barrier function. The aim of this study was to compare if select dosing regimens differentially affect linaclotide and lubiprostone modulation of ion transport and barrier properties of normal human colonic mucosa. Normal sigmoid colon biopsies from healthy subjects were mounted in Ussing chambers. Tissues were treated with linaclotide, lubiprostone, or vehicle to determine effects on short-circuit current (Isc). Subsequent Isc responses to the cAMP agonist, forskolin, and the calcium agonist, carbachol, were also measured to assess if either drug caused desensitization. Barrier properties were assessed by measuring transepithelial electrical resistance. Isc responses to linaclotide and lubiprostone were significantly higher than vehicle control when administered bilaterally or to the mucosal side only. Single versus cumulative concentrations of linaclotide showed differences in efficacy while cumulative but not single dosing caused desensitization to forskolin. Lubiprostone reduced forskolin responses under all conditions. Linaclotide and lubiprostone exerted a positive effect on TER that was dependent on the dosing regimen. Linaclotide and lubiprostone increase ion transport responses across normal human colon but linaclotide displays increased sensitivity to the dosing regimen used. These findings may have implications for dosing protocols of these agents in patients with constipation. PMID:26038704

  16. Supplementing formula-fed piglets with a low molecular weight fraction of bovine colostrum whey results in an improved intestinal barrier.

    PubMed

    De Vos, M; Huygelen, V; Van Raemdonck, G; Willemen, S; Fransen, E; Van Ostade, X; Casteleyn, C; Van Cruchten, S; Van Ginneken, C

    2014-08-01

    To test the hypothesis that a low molecular weight fraction of colostral whey could affect the morphology and barrier function of the small intestine, 30 3-d-old piglets (normal or low birth weight) were suckled (n = 5), artificially fed with milk formula (n = 5), or artificially fed with milk formula with a low molecular weight fraction of colostral whey (n = 5) until 10 d of age. The small intestine was sampled for histology (haematoxylin and eosin stain; anti-KI67 immunohistochemistry) and enzyme activities (aminopeptidase A, aminopeptidase N, dipeptidylpeptidase IV, lactase, maltase, and sucrase). In addition, intestinal permeability was evaluated via a dual sugar absorption test and via the measurement of occludin abundance. Artificially feeding of piglets reduced final BW (P < 0.001), villus height (P < 0.001), lactase (P < 0.001), and dipeptidylpeptidase IV activities (P < 0.07), whereas crypt depth (P < 0.001) was increased. No difference was observed with regard to the permeability measurements when comparing artificially fed with naturally suckling piglets. Supplementing piglets with the colostral whey fraction did not affect BW, enzyme activities, or the outcome of the dual sugar absorption test. On the contrary, the small intestines of supplemented piglets had even shorter villi (P = 0.001) than unsupplemented piglets and contained more occludin (P = 0.002). In conclusion, at 10 d of age, no differences regarding intestinal morphology and permeability measurements were observed between the 2 BW categories. In both weight categories, the colostral whey fraction affected the morphology of the small intestine but did not improve the growth performances or the in vivo permeability. These findings should be acknowledged when developing formulated milk for neonatal animals with the aim of improving the performance of low birth weight piglets. PMID:25012977

  17. Evaluation of In Vitro Anti-Inflammatory Activities and Protective Effect of Fermented Preparations of Rhizoma Atractylodis Macrocephalae on Intestinal Barrier Function against Lipopolysaccharide Insult

    PubMed Central

    Bose, Shambhunath; Kim, Hojun

    2013-01-01

    Lipopolysaccharide (LPS), a potent inducer of systemic inflammatory responses, is known to cause impairment of intestinal barrier function. Here, we evaluated the in vitro protective effect of an unfermented formulation of Rhizoma Atractylodis Macrocephalae (RAM), a traditional Chinese herbal medicine widely used in the treatment of many digestive and gastrointestinal disorders, and two fermented preparations of RAM, designated as FRAM-1 (prepared in Luria-Bertani broth) and FRAM-2 (prepared in glucose), on intestinal epithelial cells (IECs) against LPS insult. In general, fermented formulations, especially FRAM-2, but not unfermented RAM, exerted an appreciable protective effect on IECs against LPS-induced perturbation of membrane resistance and permeability. Both fermented formulations exhibited appreciable anti-inflammatory activities in terms of their ability to inhibit LPS-induced gene expression and induced production of a number of key inflammatory mediators and cytokines in RAW 264.7 macrophage cells. However, in most cases, FRAM-2 exhibited stronger anti-inflammatory effects than FRAM-1. Our findings also suggest that suppression of nuclear factor-κβ (NF-κβ) activity might be one of the possible mechanisms by which the fermented RAM exerts its anti-inflammatory effects. Collectively, our results highlight the benefits of using fermented products of RAM to protect against LPS-induced inflammatory insult and impairment in intestinal barrier function. PMID:23573125

  18. Rifaximin Alters Intestinal Bacteria and Prevents Stress-Induced Gut Inflammation and Visceral Hyperalgesia in Rats

    PubMed Central

    Xu, Dabo; Gao, Jun; Gillilland, Merritt; Wu, Xiaoyin; Song, Il; Kao, John Y.; Owyang, Chung

    2014-01-01

    Background & Aims Rifaximin is used to treat patients with functional gastrointestinal disorders, but little is known about its therapeutic mechanism. We propose that rifaximin modulates the ileal bacterial community, reduces subclinical inflammation of the intestinal mucosa, and improves gut barrier function to reduce visceral hypersensitivity. Methods We induced visceral hyperalgesia in rats, via chronic water avoidance or repeat restraint stressors, and investigated whether rifaximin altered the gut microbiota, prevented intestinal inflammation, and improved gut barrier function. Quantitative polymerase chain reaction and 454 pyrosequencing were used to analyze bacterial 16S rRNA in ileal contents from the rats. Reverse transcription, immunoblot, and histologic analyses were used to evaluate levels of cytokines, the tight junction protein occludin, and mucosal inflammation, respectively. Intestinal permeability and rectal sensitivity were measured. Results Water avoidance and repeat restraint stress each led to visceral hyperalgesia, accompanied by mucosal inflammation and impaired mucosal barrier function. Oral rifaximin altered the composition of bacterial communities in the ileum (Lactobacillus species became the most abundant) and prevented mucosal inflammation, impairment to intestinal barrier function, and visceral hyperalgesia in response to chronic stress. Neomycin also changed the composition of the ileal bacterial community (Proteobacteria became the most abundant species). Neomycin did not prevent intestinal inflammation or induction of visceral hyperalgesia induced by water avoidance stress. Conclusions Rifaximin alters the bacterial population in the ileum of rats, leading to a relative abundance of Lactobacillus. These changes prevent intestinal abnormalities and visceral hyperalgesia in response to chronic psychological stress. PMID:24161699

  19. Gene expression profiling of duodenal biopsies discriminates celiac disease mucosa from normal mucosa.

    PubMed

    Bragde, Hanna; Jansson, Ulf; Jarlsfelt, Ingvar; Söderman, Jan

    2011-06-01

    Celiac disease (CD) is identified by histopathologic changes in the small intestine which normalize during a gluten-free diet. The histopathologic assessment of duodenal biopsies is usually routine but can be difficult. This study investigated gene expression profiling as a diagnostic tool. A total of 109 genes were selected to reflect alterations in crypt-villi architecture, inflammatory response, and intestinal permeability and were examined for differential expression in normal mucosa compared with CD mucosa in pediatric patients. Biopsies were classified using discriminant analysis of gene expression. Fifty genes were differentially expressed, of which eight (APOC3, CYP3A4, OCLN, MAD2L1, MKI67, CXCL11, IL17A, and CTLA4) discriminated normal mucosa from CD mucosa without classification errors using leave-one-out cross-validation (n = 39) and identified the degree of mucosal damage. Validation using an independent set of biopsies (n = 27) resulted in four discrepant cases. Biopsies from two of these cases showed a patchy distribution of lesions, indicating that discriminant analysis based on single biopsies failed to identify CD mucosa. In the other two cases, serology support class according to discriminant analysis and histologic specimens were judged suboptimal but assessable. Gene expression profiling shows promise as a diagnostic tool and for follow-up of CD, but further evaluation is needed. PMID:21378598

  20. Glutamine decreases intestinal mucosal injury in a rat model of intestinal ischemia-reperfusion by downregulating HMGB1 and inflammatory cytokine expression

    PubMed Central

    Shu, Xiaoliang; Zhang, Jian; Wang, Qingxiu; Xu, Zengguang; Yu, Tingting

    2016-01-01

    Intestinal ischemia-reperfusion (IR) is a common clinical pathophysiological process that is common in severe trauma, major surgery, and in post-resuscitation. Glutamine (Gln) reduces intestinal IR injury, however, its mechanism of action remains to be determined. High mobility group box 1 (HMGB1) protein, nuclear factor-κB (NF-κB), tumor necrosis factor-α (TNF-α), and interleukin-1 (IL-1) are mediators involved in the pathophysiology of intestinal IR injury. The aim of the present study was to investigate the effects of Gln on the intestinal mucosa of HMGB1 expression following IR to determine whether Gln relieved intestinal IR injury in the intestinal mucosal barrier. Forty-eight Sprague-Dawley rats were included in the present study. A model of intestinal ischemia-reperfusion injury was established by clamping the superior mesenteric artery of the rats to cause ischemia, followed by restoring blood flow. The animals were randomly divided into the control (n=24) and the Gln (n=24) groups for the experiments. The two groups of rats were given enteral nutrition with equal heat, nitrogen (heat 125.4 kJ/kg/day, nitrogen 0.2 g/kg/day). The Gln group of rats was fed with enteral nutrition plus 3% Gln, while the control rats were fed with enteral nutrition plus 3% soybean protein. After 7 days, the HMGB1 and plasma levels of NF-κB, TNF-α, IL-1, Gln, D-lactic acid and diamine oxidase (DAO) were observed. The changes in the morphology of intestinal mucosa were observed using electron microscopy. The plasma levels of TNF-α, IL-1, D-lactic acid and DAO, and the level of HMGB1, NF-κB, TNF-α and IL-1 in intestinal mucosa were significantly higher after IR (p<0.05), while the plasma level of Gln was lower in the two groups. In the control group, the plasma level of IL-1, TNF-α, DAO and D-lactic acid, and that of HMGB1, NF-κB, TNF-α, and IL-1 in intestinal mucosa were significantly higher, while the plasma level of Gln was lower than that prior to modeling on the 3

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

    PubMed

    Haines, Ricci J; Beard, Richard S; Eitner, Rebecca A; Chen, Liwei; Wu, Mack H

    2016-01-01

    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. PMID:27119373

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

    PubMed Central

    Beard, Richard S.; Eitner, Rebecca A.; Chen, Liwei; Wu, Mack H.

    2016-01-01

    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. PMID:27119373

  3. Genomic Landscape of Colorectal Mucosa and Adenomas.

    PubMed

    Borras, Ester; San Lucas, F Anthony; Chang, Kyle; Zhou, Ruoji; Masand, Gita; Fowler, Jerry; Mork, Maureen E; You, Y Nancy; Taggart, Melissa W; McAllister, Florencia; Jones, David A; Davies, Gareth E; Edelmann, Winfried; Ehli, Erik A; Lynch, Patrick M; Hawk, Ernest T; Capella, Gabriel; Scheet, Paul; Vilar, Eduardo

    2016-06-01

    The molecular basis of the adenoma-to-carcinoma transition has been deduced using comparative analysis of genetic alterations observed through the sequential steps of intestinal carcinogenesis. However, comprehensive genomic analyses of adenomas and at-risk mucosa are still lacking. Therefore, our aim was to characterize the genomic landscape of colonic at-risk mucosa and adenomas. We analyzed the mutation profile and copy number changes of 25 adenomas and adjacent mucosa from 12 familial adenomatous polyposis patients using whole-exome sequencing and validated allelic imbalances (AI) in 37 adenomas using SNP arrays. We assessed for evidence of clonality and performed estimations on the proportions of driver and passenger mutations using a systems biology approach. Adenomas had lower mutational rates than did colorectal cancers and showed recurrent alterations in known cancer driver genes (APC, KRAS, FBXW7, TCF7L2) and AIs in chromosomes 5, 7, and 13. Moreover, 80% of adenomas had somatic alterations in WNT pathway genes. Adenomas displayed evidence of multiclonality similar to stage I carcinomas. Strong correlations between mutational rate and patient age were observed in at-risk mucosa and adenomas. Our data indicate that at least 23% of somatic mutations are present in at-risk mucosa prior to adenoma initiation. The genomic profiles of at-risk mucosa and adenomas illustrate the evolution from normal tissue to carcinoma via greater resolution of molecular changes at the inflection point of premalignant lesions. Furthermore, substantial genomic variation exists in at-risk mucosa before adenoma formation, and deregulation of the WNT pathway is required to foster carcinogenesis. Cancer Prev Res; 9(6); 417-27. ©2016 AACR. PMID:27221540

  4. The novel porcine Lactobacillus sobrius strain protects intestinal cells from enterotoxigenic Escherichia coli K88 infection and prevents membrane barrier damage.

    PubMed

    Roselli, Marianna; Finamore, Alberto; Britti, Maria Serena; Konstantinov, Sergey R; Smidt, Hauke; de Vos, Willem M; Mengheri, Elena

    2007-12-01

    Lactobacilli have a potential to overcome intestinal disorders; however, the exact mode of action is still largely unknown. In this study, we have used the intestinal porcine intestinal IPEC-1 epithelial cells as a model to investigate a possible protective activity of a new Lactobacillus species, the L. sobrius DSM 16698(T), against intestinal injury induced by enterotoxigenic Escherichia coli (ETEC) K88 infection and the underlying mechanisms. Treatment of infected cells with L. sobrius strongly reduced the pathogen adhesion. L. sobrius was also able to prevent the ETEC-induced membrane damage by inhibiting delocalization of zonula occludens (ZO)-1, reduction of occludin amount, rearrangement of F-actin, and dephosphorylation of occludin caused by ETEC. RT-PCR and ELISA experiments showed that L. sobrius counteracted the ETEC-induced increase of IL-8 and upregulated the IL-10 expression. The involvement of IL-8 in the deleterious effects of ETEC was proven by neutralization of IL-8 with a specific antibody. A crucial role of IL-10 was indicated by blockage of IL-10 production with neutralizing anti-IL-10 antibody that fully abrogated the L. sobrius protection. L. sobrius was also able to inhibit the internalization of ETEC, which was likely favored by the leaking barrier. The protective effects were not found with L. amylovorus DSM 20531(T) treatment, a strain derived from cattle waste but phylogenetically closely related to L. sobrius. Together, the data indicate that L. sobrius exerts protection against the harmful effects of ETEC by different mechanisms, including pathogen adhesion inhibition and maintenance of membrane barrier integrity through IL-10 regulation. PMID:18029488

  5. Effect of thyme essential oil and selenium on intestine integrity and antioxidant status of broilers.

    PubMed

    Placha, I; Takacova, J; Ryzner, M; Cobanova, K; Laukova, A; Strompfova, V; Venglovska, K; Faix, S

    2014-02-01

    1. This study evaluated the duodenal wall integrity, antioxidant status as well as some immunological parameters of broiler chickens supplemented with 0.5 g Thymus vulgaris essential oil (EO)/kg diet and 0.4 mg Se/kg DM (dry matter) derived from sodium selenite. 2. A total of 192 one-d-old randomly divided chickens of both sexes (Ross 308 hybrid broilers) were divided into 4 treatment groups of 48 birds each. 3. The first group was fed on a nutritionally balanced basal diet (BD). The other three groups received BD supplemented with 0.5 g/kg thyme oil, or 0.4 mg Se/kg DM, or both feed additives together. 4. The results for the evaluated feed additives were (1) thyme oil - decreased malondialdehyde (MDA) concentration in duodenal mucosa and kidney, increased immunoglobulin A (IgA) concentration in duodenal mucosa, stimulated phagocytic activity in blood, improved intestinal barrier integrity (2) selenium - increased glutathione peroxidase (GPx) activity in blood and liver as well as thioredoxin reductase (TrxR) activity in duodenal mucosa, liver and in the kidney, (3) EO with selenium - increased thioredoxin reductase (TrxR) activity in duodenal mucosa. 5. These results demonstrated that thyme oil alone showed more effective potential to improve intestinal barrier integrity and antioxidant status as well as evoking an immune response in chickens, than if diets were supplemented with both thyme oil and selenium. PMID:24397472

  6. Proteomic changes of the porcine small intestine in response to chronic heat stress.

    PubMed

    Cui, Yanjun; Gu, Xianhong

    2015-12-01

    Acute heat stress (HS) negatively affects intestinal integrity and barrier function. In contrast, chronic mild HS poses a distinct challenge to animals. Therefore, this study integrates biochemical, histological and proteomic approaches to investigate the effects of chronic HS on the intestine in finishing pigs. Castrated male crossbreeds (79.00 ± 1.50 kg BW) were subjected to either thermal neutral (TN, 21 °C; 55% ± 5% humidity; n=8) or HS conditions (30 °C; 55% ± 5% humidity; n=8) for 3 weeks. The pigs were sacrificed after 3 weeks of high environmental exposure and the plasma hormones, the intestinal morphology, integrity, and protein profiles of the jejunum mucosa were determined. Chronic HS reduced the free triiodothyronine (FT3) and GH levels. HS damaged intestinal morphology, increased plasma d-lactate concentrations and decreased alkaline phosphatase activity of intestinal mucosa. Proteome analysis of the jejunum mucosa was conducted by 2D gel electrophoresis and mass spectrometry. Fifty-three intestinal proteins were found to be differentially abundant, 18 of which were related to cell structure and motility, and their changes in abundance could comprise intestinal integrity and function. The down-regulation of proteins involved in tricarboxylic acid cycle (TCA cycle), electron transport chain (ETC), and oxidative phosphorylation suggested that chronic HS impaired energy metabolism and thus induced oxidative stress. Moreover, the changes of ten proteins in abundance related to stress response and defense indicated pigs mediated long-term heat exposure and counteracted its negative effects of heat exposure. These findings have important implications for understanding the effect of chronic HS on intestines. PMID:26416815

  7. Proteomic changes of the porcine small intestine in response to chronic heat stress

    PubMed Central

    Cui, Yanjun; Gu, Xianhong

    2015-01-01

    Acute heat stress (HS) negatively affects intestinal integrity and barrier function. In contrast, chronic mild HS poses a distinct challenge to animals. Therefore, this study integrates biochemical, histological and proteomic approaches to investigate the effects of chronic HS on the intestine in finishing pigs. Castrated male crossbreeds (79.00±1.50 kg BW) were subjected to either thermal neutral (TN, 21 °C; 55%±5% humidity; n=8) or HS conditions (30 °C; 55%±5% humidity; n=8) for 3 weeks. The pigs were sacrificed after 3 weeks of high environmental exposure and the plasma hormones, the intestinal morphology, integrity, and protein profiles of the jejunum mucosa were determined. Chronic HS reduced the free triiodothyronine (FT3) and GH levels. HS damaged intestinal morphology, increased plasma d-lactate concentrations and decreased alkaline phosphatase activity of intestinal mucosa. Proteome analysis of the jejunum mucosa was conducted by 2D gel electrophoresis and mass spectrometry. Fifty-three intestinal proteins were found to be differentially abundant, 18 of which were related to cell structure and motility, and their changes in abundance could comprise intestinal integrity and function. The down-regulation of proteins involved in tricarboxylic acid cycle (TCA cycle), electron transport chain (ETC), and oxidative phosphorylation suggested that chronic HS impaired energy metabolism and thus induced oxidative stress. Moreover, the changes of ten proteins in abundance related to stress response and defense indicated pigs mediated long-term heat exposure and counteracted its negative effects of heat exposure. These findings have important implications for understanding the effect of chronic HS on intestines. PMID:26416815

  8. Lactobacillus rhamnosus GG supernatant promotes intestinal barrier function, balances Treg and TH17 cells and ameliorates hepatic injury in a mouse model of chronic-binge alcohol feeding.

    PubMed

    Chen, Rui-Cong; Xu, Lan-Man; Du, Shan-Jie; Huang, Si-Si; Wu, He; Dong, Jia-Jia; Huang, Jian-Rong; Wang, Xiao-Dong; Feng, Wen-Ke; Chen, Yong-Ping

    2016-01-22

    Impaired intestinal barrier function plays a critical role in alcohol-induced hepatic injury, and the subsequent excessive absorbed endotoxin and bacterial translocation activate the immune response that aggravates the liver injury. Lactobacillus rhamnosus GG supernatant (LGG-s) has been suggested to improve intestinal barrier function and alleviate the liver injury induced by chronic and binge alcohol consumption, but the underlying mechanisms are still not clear. In this study, chronic-binge alcohol fed model was used to determine the effects of LGG-s on the prevention of alcoholic liver disease in C57BL/6 mice and investigate underlying mechanisms. Mice were fed Lieber-DeCarli diet containing 5% alcohol for 10 days, and one dose of alcohol was gavaged on Day 11. In one group, LGG-s was supplemented along with alcohol. Control mice were fed isocaloric diet. Nine hours later the mice were sacrificed for analysis. Chronic-binge alcohol exposure induced an elevation in liver enzymes, steatosis and morphology changes, while LGG-s supplementation attenuated these changes. Treatment with LGG-s significantly improved intestinal barrier function reflected by increased mRNA expression of tight junction (TJ) proteins and villus-crypt histology in ileum, and decreased Escherichia coli (E. coli) protein level in liver. Importantly, flow cytometry analysis showed that alcohol reduced Treg cell population while increased TH17 cell population as well as IL-17 secretion, which was reversed by LGG-s administration. In conclusion, our findings indicate that LGG-s is effective in preventing chronic-binge alcohol exposure-induced liver injury and shed a light on the importance of the balance of Treg and TH17 cells in the role of LGG-s application. PMID:26617183

  9. 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).

    PubMed

    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 < 0.05), up-regulated the relative mRNA levels of antimicrobial peptides (liver expressed antimicrobial peptide 2 and hepcidin) and anti-inflammatory cytokines (interleukin 10 and transforming growth factor β1) and signaling molecules inhibitor protein-κBα (IκBα) and target of rapamycin (TOR) (P < 0.05), down-regulated the mRNA levels of pro-inflammatory cytokines (tumor necrosis factor α, interleukin 8, interferon γ2, and interleukin 1β), and signaling molecules (nuclear factor kappa B p65, IκB kinase β, IκB kinase γ) (P < 0.05) in the intestine of young grass carp. Moreover, optimal exogenous lipase supplementation significantly decreased reactive oxygen species (ROS), malondialdehyde

  10. Biliary Mucosal Barrier and Microbiome

    PubMed Central

    Verdier, Julien; Luedde, Tom; Sellge, Gernot

    2015-01-01

    Background The biliary system is in continuous contact with the complex microbiota of the intestine. Microbial products have recently been proposed as potential triggers for biliary diseases. Methods The aim of this review is to provide a summary of the current knowledge regarding the role of the biliary and intestinal microbiome in biliary inflammatory diseases. Results Previously, it was suggested that the healthy biliary system is a sterile organ, while acute cholangitis and cholecystitis may occur from ascending infections. Although non-inflammatory biliary colonization by certain bacteria such as Salmonella spp. has been already recognized since several decades, human and animal studies indicated only very recently that the gallbladder harbors a complex microbiota also under non-pathologic conditions. Novel findings suggested that – similar to the situation in the intestine – the biliary mucosa features a chemical, mechanical, and immunological barrier, ensuring immunological tolerance against commensals. However, microbial triggers might influence acute and chronic inflammatory disease of the biliary system and the whole liver. Conclusion Although yet undefined, dysbiosis of the biliary or intestinal microbiota rather than a single microorganism may influence disease progression. PMID:26468308

  11. 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.

    PubMed

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

    2016-09-01

    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. PMID:27281582

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

    PubMed Central

    2013-01-01

    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, ghrelin and EGF. In

  13. Clostridium perfringens epsilon toxin increases the small intestinal permeability in mice and rats.

    PubMed

    Goldstein, Jorge; Morris, Winston E; Loidl, César Fabián; Tironi-Farinati, Carla; Tironi-Farinatti, Carla; McClane, Bruce A; Uzal, Francisco A; Fernandez Miyakawa, Mariano E

    2009-01-01

    Epsilon toxin is a potent neurotoxin produced by Clostridium perfringens types B and D, an anaerobic bacterium that causes enterotoxaemia in ruminants. In the affected animal, it causes oedema of the lungs and brain by damaging the endothelial cells, inducing physiological and morphological changes. Although it is believed to compromise the intestinal barrier, thus entering the gut vasculature, little is known about the mechanism underlying this process. This study characterizes the effects of epsilon toxin on fluid transport and bioelectrical parameters in the small intestine of mice and rats. The enteropooling and the intestinal loop tests, together with the single-pass perfusion assay and in vitro and ex vivo analysis in Ussing's chamber, were all used in combination with histological and ultrastructural analysis of mice and rat small intestine, challenged with or without C. perfringens epsilon toxin. Luminal epsilon toxin induced a time and concentration dependent intestinal fluid accumulation and fall of the transepithelial resistance. Although no evident histological changes were observed, opening of the mucosa tight junction in combination with apoptotic changes in the lamina propria were seen with transmission electron microscopy. These results indicate that C. perfringens epsilon toxin alters the intestinal permeability, predominantly by opening the mucosa tight junction, increasing its permeability to macromolecules, and inducing further degenerative changes in the lamina propria of the bowel. PMID:19763257

  14. Clostridium perfringens Epsilon Toxin Increases the Small Intestinal Permeability in Mice and Rats

    PubMed Central

    Goldstein, Jorge; Morris, Winston E.; Loidl, César Fabián; Tironi-Farinatti, Carla; McClane, Bruce A.; Uzal, Francisco A.; Fernandez Miyakawa, Mariano E.

    2009-01-01

    Epsilon toxin is a potent neurotoxin produced by Clostridium perfringens types B and D, an anaerobic bacterium that causes enterotoxaemia in ruminants. In the affected animal, it causes oedema of the lungs and brain by damaging the endothelial cells, inducing physiological and morphological changes. Although it is believed to compromise the intestinal barrier, thus entering the gut vasculature, little is known about the mechanism underlying this process. This study characterizes the effects of epsilon toxin on fluid transport and bioelectrical parameters in the small intestine of mice and rats. The enteropooling and the intestinal loop tests, together with the single-pass perfusion assay and in vitro and ex vivo analysis in Ussing's chamber, were all used in combination with histological and ultrastructural analysis of mice and rat small intestine, challenged with or without C. perfringens epsilon toxin. Luminal epsilon toxin induced a time and concentration dependent intestinal fluid accumulation and fall of the transepithelial resistance. Although no evident histological changes were observed, opening of the mucosa tight junction in combination with apoptotic changes in the lamina propria were seen with transmission electron microscopy. These results indicate that C. perfringens epsilon toxin alters the intestinal permeability, predominantly by opening the mucosa tight junction, increasing its permeability to macromolecules, and inducing further degenerative changes in the lamina propria of the bowel. PMID:19763257

  15. The serine protease-mediated increase in intestinal epithelial barrier function is dependent on occludin and requires an intact tight junction.

    PubMed

    Ronaghan, Natalie J; Shang, Judie; Iablokov, Vadim; Zaheer, Raza; Colarusso, Pina; Turner, Jerrold R; MacNaughton, Wallace K

    2016-09-01

    Barrier dysfunction is a characteristic of the inflammatory bowel diseases (IBD), Crohn's disease and ulcerative colitis. Understanding how the tight junction is modified to maintain barrier function may provide avenues for treatment of IBD. We have previously shown that the apical addition of serine proteases to intestinal epithelial cell lines causes a rapid and sustained increase in transepithelial electrical resistance (TER), but the mechanisms are unknown. We hypothesized that serine proteases increase barrier function through trafficking and insertion of tight junction proteins into the membrane, and this could enhance recovery of a disrupted monolayer after calcium switch or cytokine treatment. In the canine epithelial cell line, SCBN, we showed that matriptase, an endogenous serine protease, could potently increase TER. Using detergent solubility-based cell fractionation, we found that neither trypsin nor matriptase treatment changed levels of tight junction proteins at the membrane. In a fast calcium switch assay, serine proteases did not enhance the rate of recovery of the junction. In addition, serine proteases could not reverse barrier disruption induced by IFNγ and TNFα. We knocked down occludin in our cells using siRNA and found this prevented the serine protease-induced increase in TER. Using fluorescence recovery after photobleaching (FRAP), we found serine proteases induce a greater mobile fraction of occludin in the membrane. These data suggest that a functional tight junction is needed for serine proteases to have an effect on TER, and that occludin is a crucial tight junction protein in this mechanism. PMID:27492333

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

    PubMed

    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 < 0.001), villus height/crypt depth ratio (P < 0.05), and the number of goblet cells (P < 0.001) in the jejunum at 14 d postinfection (dpi), but significantly increased the number of intestinal secretory IgA (sIgA)-expressing cells at 14 dpi (P < 0.01) and total sIgA levels in the jejunum at 7 (P < 0.05) and 14 dpi (P < 0.01) compared with the unchallenged birds (NC). Dietary β-1,3/1,6-glucan supplementation not only significantly increased villus height, villus height/crypt depth ratio, and the number of goblet cells (P < 0.01), but also increased the number of sIgA-expressing cells (P < 0.05) and sIgA content in the jejunum at 14 dpi (P < 0.01) in birds challenged with Salmonella Typhimurium in comparison with Salmonella Typhimurium challenge alone. β-1,3/1,6-Glucan addition had significant inhibitory effects (P < 0.05) on cecal Salmonella colonization levels and liver Salmonella invasion of the Salmonella Typhimurium-infected birds compared with the PC group. Intestinal tight junction proteins claudin-1, claudin-4, and occludin mRNA expression in the jejunum at 14 dpi was significantly decreased by Salmonella Typhimurium challenge alone (P < 0.01) compared with that of the NC group, whereas β-1,3/1,6-glucan supplementation significantly increased claudin-1 and occludin mRNA expression (P < 0.01) at

  17. Characterization of tight junction disruption and immune response modulation in a miniaturized Caco-2/U937 coculture-based in vitro model of the human intestinal barrier.

    PubMed

    Ramadan, Qasem; Jing, Lin

    2016-02-01

    A microfluidic-based dynamic in vitro model of the human intestinal barrier has been constructed and characterized. The intestinal epithelial monolayer was mimicked by culturing caco-2 cells on a porous membrane in a double-layered microfluidic chip and interfaced with a co-culture of U937 as a model of immune responsive cells. The physiological flow was also mimicked by a continuous perfusion of culture media from the apical and basolateral side of the porous membrane. This dynamic "in vivo-like" environment maintains a continuous supply of cell nutrient and waste removal and create mechanical shear stress within the physiological ranges which promotes uniform cell growth and tight junction formation. The monolayer permeability to soluble ion changes after treating with LPS, and TNF α as indicated by the reduction of the TEER value. In addition, the immune competent caco-2/U937-based model allowed the investigating the role of the epithelial layer as a protection barrier to biological hazards as indicated by the suppressing of the pro-inflammatory cytokine expression. PMID:26809386

  18. Bioengineered vocal fold mucosa for voice restoration.

    PubMed

    Ling, Changying; Li, Qiyao; Brown, Matthew E; Kishimoto, Yo; Toya, Yutaka; Devine, Erin E; Choi, Kyeong-Ok; Nishimoto, Kohei; Norman, Ian G; Tsegyal, Tenzin; Jiang, Jack J; Burlingham, William J; Gunasekaran, Sundaram; Smith, Lloyd M; Frey, Brian L; Welham, Nathan V

    2015-11-18

    Patients with voice impairment caused by advanced vocal fold (VF) fibrosis or tissue loss have few treatment options. A transplantable, bioengineered VF mucosa would address the individual and societal costs of voice-related communication loss. Such a tissue must be biomechanically capable of aerodynamic-to-acoustic energy transfer and high-frequency vibration and physiologically capable of maintaining a barrier against the airway lumen. We isolated primary human VF fibroblasts and epithelial cells and cocultured them under organotypic conditions. The resulting engineered mucosae showed morphologic features of native tissue, proteome-level evidence of mucosal morphogenesis and emerging extracellular matrix complexity, and rudimentary barrier function in vitro. When grafted into canine larynges ex vivo, the mucosae generated vibratory behavior and acoustic output that were indistinguishable from those of native VF tissue. When grafted into humanized mice in vivo, the mucosae survived and were well tolerated by the human adaptive immune system. This tissue engineering approach has the potential to restore voice function in patients with otherwise untreatable VF mucosal disease. PMID:26582902

  19. Protection and Restitution of Gut Barrier by Probiotics: Nutritional and Clinical Implications

    PubMed Central

    Rao, R. K.; Samak, G.

    2013-01-01

    Probiotics are beneficial bacteria present in various dietary components and many of these colonize in the human and animal intestine. In the gut probiotics help the host by assisting in maintenance of normal mucosal homeostasis. Probiotics not only help maintain normal function of the gut mucosa, but also protect mucosa from injurious factors such as toxins, allergens and pathogens. The beneficial effect of probiotics is mediated by multiple mechanisms, including cytoprotection, cell proliferation, cell migration, resistance to apoptosis, synthesis of proteins and gene expression. One of the important cytoprotective effects of probiotics in the intestinal mucosa is to strengthen the epithelial tight junctions and preservation of mucosal barrier function. Probiotics not only enhance barrier function by inducing synthesis and assembly of tight junction proteins, but also preventing disruption of tight junctions by injurious factors. Bioactive factors released by probiotics trigger activation of various cell signaling pathways that lead to strengthening of tight junctions and the barrier function. This article reviews and summarizes the current understanding of various probiotics that are involved in the protection of gut barrier function, highlights the cellular and molecular mechanisms involved in the protective effect and addresses the clinical implications of probiotic supplementation. PMID:24353483

  20. Intestinal Cell Tight Junctions Limit Invasion of Candida albicans through Active Penetration and Endocytosis in the Early Stages of the Interaction of the Fungus with the Intestinal Barrier

    PubMed Central

    Bon, Fabienne; L’Ollivier, Coralie; Laue, Michael; Holland, Gudrun; Bonnin, Alain; Dalle, Frederic

    2016-01-01

    C. albicans is a commensal yeast of the mucous membranes in healthy humans that can also cause disseminated candidiasis, mainly originating from the digestive tract, in vulnerable patients. It is necessary to understand the cellular and molecular mechanisms of the interaction of C. albicans with enterocytes to better understand the basis of commensalism and pathogenicity of the yeast and to improve the management of disseminated candidiasis. In this study, we investigated the kinetics of tight junction (TJ) formation in parallel with the invasion of C. albicans into the Caco-2 intestinal cell line. Using invasiveness assays on Caco-2 cells displaying pharmacologically altered TJ (i.e. differentiated epithelial cells treated with EGTA or patulin), we were able to demonstrate that TJ protect enterocytes against invasion of C. albicans. Moreover, treatment with a pharmacological inhibitor of endocytosis decreased invasion of the fungus into Caco-2 cells displaying altered TJ, suggesting that facilitating access of the yeast to the basolateral side of intestinal cells promotes endocytosis of C. albicans in its hyphal form. These data were supported by SEM observations of differentiated Caco-2 cells displaying altered TJ, which highlighted membrane protrusions engulfing C. albicans hyphae. We furthermore demonstrated that Als3, a hypha-specific C. albicans invasin, facilitates internalization of the fungus by active penetration and induced endocytosis by differentiated Caco-2 cells displaying altered TJ. However, our observations failed to demonstrate binding of Als3 to E-cadherin as the trigger mechanism of endocytosis of C. albicans into differentiated Caco-2 cells displaying altered TJ. PMID:26933885

  1. Pregnane X Receptor Activation Attenuates Inflammation-Associated Intestinal Epithelial Barrier Dysfunction by Inhibiting Cytokine-Induced Myosin Light-Chain Kinase Expression and c-Jun N-Terminal Kinase 1/2 Activation.

    PubMed

    Garg, Aditya; Zhao, Angela; Erickson, Sarah L; Mukherjee, Subhajit; Lau, Aik Jiang; Alston, Laurie; Chang, Thomas K H; Mani, Sridhar; Hirota, Simon A

    2016-10-01

    The inflammatory bowel diseases (IBDs) are chronic inflammatory disorders with a complex etiology. IBD is thought to arise in genetically susceptible individuals in the context of aberrant interactions with the intestinal microbiota and other environmental risk factors. Recently, the pregnane X receptor (PXR) was identified as a sensor for microbial metabolites, whose activation can regulate the intestinal epithelial barrier. Mutations in NR1I2, the gene that encodes the PXR, have been linked to IBD, and in animal models, PXR deletion leads to barrier dysfunction. In the current study, we sought to assess the mechanism(s) through which the PXR regulates barrier function during inflammation. In Caco-2 intestinal epithelial cell monolayers, tumor necrosis factor-α/interferon-γ exposure disrupted the barrier and triggered zonula occludens-1 relocalization, increased expression of myosin light-chain kinase (MLCK), and activation of c-Jun N-terminal kinase 1/2 (JNK1/2). Activation of the PXR [rifaximin and [[3,5-Bis(1,1-dimethylethyl)-4-hydroxyphenyl]ethenylidene]bis-phosphonic acid tetraethyl ester (SR12813); 10 μM] protected the barrier, an effect that was associated with attenuated MLCK expression and JNK1/2 activation. In vivo, activation of the PXR [pregnenolone 16α-carbonitrile (PCN)] attenuated barrier disruption induced by toll-like receptor 4 activation in wild-type, but not Pxr-/-, mice. Furthermore, PCN treatment protected the barrier in the dextran-sulfate sodium model of experimental colitis, an effect that was associated with reduced expression of mucosal MLCK and phosphorylated JNK1/2. Together, our data suggest that the PXR regulates the intestinal epithelial barrier during inflammation by modulating cytokine-induced MLCK expression and JNK1/2 activation. Thus, targeting the PXR may prove beneficial for the treatment of inflammation-associated barrier disruption in the context of IBD. PMID:27440420

  2. Effect of low dosage of chito-oligosaccharide supplementation on intestinal morphology, immune response, antioxidant capacity, and barrier function in weaned piglets.

    PubMed

    Xiong, X; Yang, H S; Wang, X C; Hu, Q; Liu, C X; Wu, X; Deng, D; Hou, Y Q; Nyachoti, C M; Xiao, D F; Yin, Y L

    2015-03-01

    This study was conducted to determine the effect of dietary supplementation of a low dose of chito-oligosaccharide (COS) on intestinal morphology, immune response, antioxidant capacity, and barrier function in weaned piglets. A total of 120 weaned pigs (21 d of age; 7.86 ± 0.22 kg average BW) were randomly assigned (6 pens/diet; 10 pigs/pen) to 2 dietary treatments consisting of a basal diet (negative control) or the basal diet supplemented with COS (30 mg/kg) for a 14-d period. Six randomly selected piglets from each treatment were killed for blood and tissue sampling. No significant differences were observed in ADG, ADFI, and G:F between treatment and the control group. Piglets fed the COS-supplemented diet had greater ( < 0.05) stomach pH than those fed the control diet on d 14 postweaning. Dietary supplementation with COS reduced villus height ( < 0.05) and villus height:crypt depth ( < 0.05) in the ileum. Dietary COS supplementation tended to reduce villus height in the duodenum ( = 0.065) and jejunum ( = 0.058). There was no effect on crypt depth in the intestinal segments of treatment group. Piglets fed the COS-supplemented diet increased ( < 0.05) the number of intraepithelial lymphocytes in duodenum or jejunum and goblet cells of ileum. However, COS decreased ( < 0.05) the number of intraepithelial lymphocytes in ileum of weaned piglets. The concentrations of IL-10 (duodenum, jejunum, and ileum) and secretory immunoglobulin (SIgA; duodenum and ileum) were higher in piglets fed the COS-supplemented diet compared with control ( < 0.05). Dietary COS supplementation reduced ( < 0.05) the concentration of total antioxidant capacity and superoxide dismutase of the jejunum or ileum. The mRNA expression of occludin in the ileum and ZO-1 in jejunum and ileum had a significant change in piglets fed the COS-supplemented diet compared with the control group ( < 0.05). In conclusion, these results indicated that dietary COS supplementation at 30 mg/kg had no effects

  3. Transforming growth factor-β, a whey protein component, strengthens the intestinal barrier by upregulating claudin-4 in HT-29/B6 cells.

    PubMed

    Hering, Nina A; Andres, Susanne; Fromm, Anja; van Tol, Eric A; Amasheh, Maren; Mankertz, Joachim; Fromm, Michael; Schulzke, Joerg D

    2011-05-01

    TGFβ (isoforms 1-3) has barrier-protective effects in the intestine. The mechanisms involved in regulating tight junction protein expression are poorly understood. The aim of this study was to elucidate TGFβ-dependent protective effects with special attention to promoter regulation of tight junction proteins using the HT-29/B6 cell model. In addition, the effects of whey protein concentrate 1 (WPC1), a natural source of TGFβ in human nutrition, were examined. For this purpose, the claudin-4 promoter was cloned and tested for its activity. It exhibited transactivation in response to TGFβ1, which was intensified when Smad-4 was cotransfected, indicating a Smad-4-dependent regulatory component. Shortening and mutation of the promoter altered and attenuated this effect. WPC1 induced an increase in the claudin-4 protein level and resistance of HT-29/B6 cell monolayers. Anti-TGFβ(1-3) antibodies blocked these whey protein effects, suggesting that a main part of this function was mediated through TGFβ. This effect was observed on intact monolayers as well as when barrier function was impaired by preexposure to IFNγ. In conclusion, TGFβ1 affects claudin-4 gene expression via Smad-4-dependent and -independent transcriptional regulation, resulting in barrier protection, a cytokine effect that is also found in whey protein concentrates used in enteral nutrition. PMID:21430244

  4. Characterization of in vitro effects of patulin on intestinal epithelial and immune cells.

    PubMed

    Assunção, R; Alvito, P; Kleiveland, C R; Lea, T E

    2016-05-27

    The intestinal mucosa is the first biological barrier encountered by natural toxins, and could possibly be exposed to high amounts of dietary mycotoxins. Patulin (PAT), a mycotoxin produced by Penicillium spp. during fruit spoilage, is one of the best known enteropathogenic mycotoxins able to alter functions of the intestine (Maresca et al., 2008). This study evaluated the effects of PAT on barrier function of the gut mucosa utilizing the intestinal epithelial cell model Caco-2, and scrutinized immunomodulatory effects using human peripheral blood mononuclear cells (PBMC) and human blood monocyte-derived dendritic cells (moDCs) as test systems. PAT exposure reduced Caco-2 cell viability at concentrations above 12μM. As expected, the integrity of a polarized Caco-2 monolayer was affected by PAT exposure, as demonstrated by a decrease in TER values, becoming more pronounced at 50μM. No effects were detected on the expression levels of the tight junction proteins occludin, claudin-1 and claudin-3 at 50μM. However, the expression of zonula occludens-1 (ZO-1) and myosin light chain 2 (MLC2) declined. Also, levels of phospho-MLC2 (p-MLC2) increased after 24h of exposure to 50μM of PAT. T cell proliferation was highly sensitive to PAT with major effects for concentrations above 10nM of PAT. The same conditions did not affect the maturation of moDC. PAT causes a reduction in Caco-2 barrier function mainly by perturbation of ZO-1 levels and the phosphorylation of MLC. Low doses of PAT strongly inhibited T cell proliferation induced by a polyclonal activator, but had no effect on the maturation of moDC. These results provide new information that strengthens the concept that the epithelium and immune cells of the intestinal mucosa are important targets for the toxic effects of food contaminants like mycotoxins. PMID:27067107

  5. Lipopolysaccharide induces intestinal glucocorticoid synthesis in a TNFalpha-dependent manner.

    PubMed

    Noti, Mario; Corazza, Nadia; Tuffin, Gérald; Schoonjans, Kristina; Brunner, Thomas

    2010-05-01

    Stringent control of immune responses in the intestinal mucosa is critical for the maintenance of immune homeostasis and prevention of tissue damage, such as observed during inflammatory bowel disease. Intestinal epithelial cells, primarily thought to form a simple physical barrier, critically regulate intestinal immune cell functions by producing immunoregulatory glucocorticoids on T-cell activation. In this study we investigated whether stimulation of cells of the innate immune system results in the induction of intestinal glucocorticoids synthesis and what role TNF-alpha plays in this process. Stimulation of the innate immune system with lipopolysaccharide (LPS) led to an up-regulation of colonic steroidogenic enzymes and the induction of intestinal glucocorticoid synthesis. The observed induction was dependent on macrophage effector functions, as depletion of macrophages using clodronate-containing liposomes, but not absence of T and B cells, inhibited intestinal glucocorticoid synthesis. LPS-induced glucocorticoid synthesis was critically dependent on TNF-alpha as it was significantly decreased in TNF-alpha-deficient animals. Both TNF receptor-1 and -2 were found to be equally involved in LPS- and T-cell-induced intestinal GC synthesis. These results describe a novel and critical role of TNF-alpha in immune cell-induced intestinal glucocorticoid synthesis. PMID:20056718

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

    PubMed

    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. PMID:23960122

  7. Intestinal Cell Barrier Function In Vitro Is Severely Compromised by Keratin 8 and 18 Mutations Identified in Patients with Inflammatory Bowel Disease

    PubMed Central

    Zupancic, Tina; Stojan, Jure; Lane, Ellen Birgitte; Komel, Radovan; Bedina-Zavec, Apolonija; Liovic, Mirjana

    2014-01-01

    Keratin 8 and 18 (K8/K18) mutations have been implicated in the aetiology of certain pathogenic processes of the liver and pancreas. While some K8 mutations (K8 G62C, K8 K464N) are also presumed susceptibility factors for inflammatory bowel disease (IBD), the only K18 mutation (K18 S230T) discovered so far in an IBD patient is thought to be a polymorphism. The aim of our study was to demonstrate that these mutations might also directly affect intestinal cell barrier function. Cell monolayers of genetically engineered human colonocytes expressing these mutations were tested for permeability, growth rate and resistance to heat-stress. We also calculated the change in dissociation constant (Kd, measure of affinity) each of these mutations introduces into the keratin protein, and present the first model of a keratin dimer L12 region with in silico clues to how the K18 S230T mutation may affect keratin function. Physiologically, these mutations cause up to 30% increase in paracellular permeability in vitro. Heat-stress induces little keratin clumping but instead cell monolayers peel off the surface suggesting a problem with cell junctions. K18 S230T has pronounced pathological effects in vitro marked by high Kd, low growth rate and increased permeability. The latter may be due to the altered distribution of tight junction components claudin-4 and ZO-1. This is the first time intestinal cells have been suggested also functionally impaired by K8/K18 mutations. Although an in vitro colonocyte model system does not completely mimic the epithelial lining of the intestine, nevertheless the data suggest that K8/K18 mutations may be also able to produce a phenotype in vivo. PMID:24915158

  8. Bacterial translocation and in vivo assessment of intestinal barrier permeability in rainbow trout (Oncorhynchus mykiss) with and without soyabean meal-induced inflammation.

    PubMed

    Mosberian-Tanha, Peyman; Øverland, Margareth; Landsverk, Thor; Reveco, Felipe E; Schrama, Johan W; Roem, Andries J; Agger, Jane W; Mydland, Liv T

    2016-01-01

    The primary aim of this experiment was to evaluate the intestinal barrier permeability in vivo in rainbow trout (Oncorhynchus mykiss) fed increasing levels of soyabean meal (SBM). The relationship between SBM-induced enteritis (SBMIE) and the permeability markers was also investigated. Our results showed that the mean score of morphological parameters was significantly higher as a result of 37·5 % SBM inclusion in the diet, while the scores of fish fed 25 % SBM or lower were not different from those of the fish meal-fed controls (P < 0·05). SBMIE was found in the distal intestine (DI) in 18 % of the fish (eleven of sixty): ten in the 37·5 % SBM-fed group and one in the 25 % SBM-fed group. Sugar markers in plasma showed large variation among individuals probably due to variation in feed intake. We found, however, a significant linear increase in the level of plasma d-lactate with increasing SBM inclusion level (P < 0·0001). Plasma concentration of endotoxin was not significantly different in groups with or without SBMIE. Some individual fish showed high values of endotoxin in blood, but the same individuals did not show any bacterial translocation. Plasma bacterial DNA was detected in 28 % of the fish with SBMIE, and 8 % of non-SBMIE fish (P = 0·07). Plasma concentration of d-lactate was significantly higher in fish with SBMIE (P < 0·0001). To conclude, SBMIE in the DI of rainbow trout was associated with an increase in bacterial translocation and plasma d-lactate concentration, suggesting that these permeability markers can be used to evaluate intestinal permeability in vivo. PMID:27547389

  9. Early Activation of MAPK p44/42 Is Partially Involved in DON-Induced Disruption of the Intestinal Barrier Function and Tight Junction Network.

    PubMed

    Springler, Alexandra; Hessenberger, Sabine; Schatzmayr, Gerd; Mayer, Elisabeth

    2016-01-01

    Deoxynivalenol (DON), produced by the plant pathogens Fusarium graminearum and Fusarium culmorum, is one of the most common mycotoxins, contaminating cereal and cereal-derived products. Although worldwide contamination of food and feed poses health threats to humans and animals, pigs are particularly susceptible to this mycotoxin. DON derivatives, such as deepoxy-deoxynivalenol (DOM-1), are produced by bacterial transformation of certain intestinal bacteria, which are naturally occurring or applied as feed additives. Intestinal epithelial cells are the initial barrier against these food- and feed-borne toxins. The present study confirms DON-induced activation of MAPK p44/42 and inhibition of p44/42 by MAPK-inhibitor U0126 monoethanolate. Influence of DON and DOM-1 on transepithelial electrical resistance (TEER), viability and expression of seven tight junction proteins (TJ), as well as the potential of U0126 to counteract DON-induced effects, was assessed. While DOM-1 showed no effect, DON significantly reduced TEER of differentiated IPEC-J2 and decreased expression of claudin-1 and -3, while leaving claudin-4; ZO-1, -2, and -3 and occludin unaffected. Inhibition of p44/42 counteracted DON-induced TEER decrease and restored claudin-3, but not claudin-1 expression. Therefore, effects of DON on TEER and claudin-3 are at least partially p44/42 mediated, while effects on viability and claudin-1 are likely mediated via alternative pathways. PMID:27618100

  10. Effects of early enteral nutrition on the gastrointestinal motility and intestinal mucosal barrier of patients with burn-induced invasive fungal infection

    PubMed Central

    Zhang, Yu; Gu, Fang; Wang, Fengxian; Zhang, Yuanda

    2016-01-01

    Objective: To evaluate the effects of early enteral nutrition on the gastrointestinal motility and intestinal mucosal barrier of patients with burn-induced invasive fungal infection. Methods: A total of 120 patients with burn-induced invasive fungal infection were randomly divided into an early enteral nutrition (EN) group and a parenteral nutrition (PN) group (n=60). The patients were given nutritional support intervention for 14 days, and the expression levels of serum transferrin, albumin, total protein, endotoxin, D-lactic acid and inflammatory cytokines were detected on the 1st, 7th and 14th days respectively. Results: As the treatment progressed, the levels of serum transferrin, albumin and total protein of the EN group were significantly higher than those of the PN group (P<0.05), while the levels of serum endotoxin and D-lactic acid of the form group were significantly lower (P<0.05). After treatment, the expression levels of IL-6 and TNF-α were decreased in the EN group, which were significantly different from those of the PN group (P<0.05). During treatment, the incidence rates of complications such as abdominal distension, diarrhea, sepsis, nausea, vomiting and gastric retention were similar. The mean healing time of wound surface was 9.34±0.78 days in the EN group and 12.46±2.19 days in the PN group, i.e. such time of the former was significantly shorter than that of the latter (P<0.05). Conclusion: Treating patients having burn-induced invasive fungal infection by early enteral nutrition support with arginine can safely alleviate malnutrition and stress reaction, strengthen cellular immune function and promote wound healing, thereby facilitating the recovery of gastrointestinal motility and the function of intestinal mucosal barrier. PMID:27375697

  11. A Gut Microbial Metabolite of Linoleic Acid, 10-Hydroxy-cis-12-octadecenoic Acid, Ameliorates Intestinal Epithelial Barrier Impairment Partially via GPR40-MEK-ERK Pathway*

    PubMed Central

    Miyamoto, Junki; Mizukure, Taichi; Park, Si-Bum; Kishino, Shigenobu; Kimura, Ikuo; Hirano, Kanako; Bergamo, Paolo; Rossi, Mauro; Suzuki, Takuya; Arita, Makoto; Ogawa, Jun; Tanabe, Soichi

    2015-01-01

    Gut microbial metabolites of polyunsaturated fatty acids have attracted much attention because of their various physiological properties. Dysfunction of tight junction (TJ) in the intestine contributes to the pathogenesis of many disorders such as inflammatory bowel disease. We evaluated the effects of five novel gut microbial metabolites on tumor necrosis factor (TNF)-α-induced barrier impairment in Caco-2 cells and dextran sulfate sodium-induced colitis in mice. 10-Hydroxy-cis-12-octadecenoic acid (HYA), a gut microbial metabolite of linoleic acid, suppressed TNF-α and dextran sulfate sodium-induced changes in the expression of TJ-related molecules, occludin, zonula occludens-1, and myosin light chain kinase. HYA also suppressed the expression of TNF receptor 2 (TNFR2) mRNA and protein expression in Caco-2 cells and colonic tissue. In addition, HYA suppressed the protein expression of TNFR2 in murine intestinal epithelial cells. Furthermore, HYA significantly up-regulated G protein-coupled receptor (GPR) 40 expression in Caco-2 cells. It also induced [Ca2+]i responses in HEK293 cells expressing human GPR40 with higher sensitivity than linoleic acid, its metabolic precursor. The barrier-recovering effects of HYA were abrogated by a GPR40 antagonist and MEK inhibitor in Caco-2 cells. Conversely, 10-hydroxyoctadacanoic acid, which is a gut microbial metabolite of oleic acid and lacks a carbon-carbon double bond at Δ12 position, did not show these TJ-restoring activities and down-regulated GPR40 expression. Therefore, HYA modulates TNFR2 expression, at least partially, via the GPR40-MEK-ERK pathway and may be useful in the treatment of TJ-related disorders such as inflammatory bowel disease. PMID:25505251

  12. Interleukin-23-Independent IL-17 Production Regulates Intestinal Epithelial Permeability.

    PubMed

    Lee, Jacob S; Tato, Cristina M; Joyce-Shaikh, Barbara; Gulen, Muhammet F; Gulan, Fatih; Cayatte, Corinne; Chen, Yi; Blumenschein, Wendy M; Judo, Michael; Ayanoglu, Gulesi; McClanahan, Terrill K; Li, Xiaoxia; Cua, Daniel J

    2015-10-20

    Whether interleukin-17A (IL-17A) has pathogenic and/or protective roles in the gut mucosa is controversial and few studies have analyzed specific cell populations for protective functions within the inflamed colonic tissue. Here we have provided evidence for IL-17A-dependent regulation of the tight junction protein occludin during epithelial injury that limits excessive permeability and maintains barrier integrity. Analysis of epithelial cells showed that in the absence of signaling via the IL-17 receptor adaptor protein Act-1, the protective effect of IL-17A was abrogated and inflammation was enhanced. We have demonstrated that after acute intestinal injury, IL-23R(+) γδ T cells in the colonic lamina propria were the primary producers of early, gut-protective IL-17A, and this production of IL-17A was IL-23 independent, leaving protective IL-17 intact in the absence of IL-23. These results suggest that IL-17-producing γδ T cells are important for the maintenance and protection of epithelial barriers in the intestinal mucosa. PMID:26431948

  13. The Role of Mucosal Defense in Intestinal Injury of Infants With Fetal Growth Retardation

    PubMed Central

    Panakhova, Nushaba F.

    2016-01-01

    Background: Infants with fetal growth retardation (FGR) are prone to intestinal disorders. Objectives: Aim of the study was to determine the role of mucosal defense ability in formation of gut injury in infants with FGR. Materials and Methods: 44 premature infants who were admitted to the Neonatal Intensive Care Unit were divided into two groups: 20 infants with FGR (FGR group) and 24 appropriate-for-gestational age newborns (AGA group). Control group consisted of 22 premature infants who were delivered after uncomplicated pregnancy. Gut barrier function was evaluated by detecting serum intestinal trefoil factor (ITF) and intestinal fatty acid binding protein (IFABP). The level of serum IFABP and ITF was measured by using ELISA method. Results: FGR group showed significantly higher ITF concentration than AGA group on the first days of life (P ˂ 0.01). High level of ITF in the FGR group significantly declines up to 7th - 10th day of life (P ˂ 0.01). This reduction was accompanied by increase of IFABP which is a marker of ischemic intestinal mucosal injury. Correlation analyses showed that ITF had a negative correlation with IFABP. Conclusions: Infants with fetal growth retardation are characterized by a high level of ITF on the first days of life. This protects intestinal mucosa under hypoxic conditions. Its subsequent decline accompanied by an increase of IFABP reflects the depletion of Goblet cells to secret ITF causing damage to the integrity of intestinal mucosal barrier. PMID:26848381

  14. [The correlation study between the changes of intestinal mucosa predominant bacteria and Toll-like receptor 2, Toll-like receptor 4 gene expressions in diarrhea-predominant irritable bowel syndrome patients].

    PubMed

    Guo, W T; Liu, P; Dong, L N; Wang, J P

    2016-07-01

    Based on high throughput sequencing and PCR detection technology, this study has found out that intestinal microbial diversity was impaired and the quantities of two main bacteria flora (Bacteroidetes and Clostridium) were significantly reduced in patients with diarrhea-predominant irritable bowel syndrome (D-IBS). Meanwhile mucosal expression of toll-like receptor (TLR) 2 and TLR4 were significantly enhanced, which was inversely correlated with the reduction of Bacteroidetes and Clostridium. Thus, it suggests that D-IBS may be associated with TLR signal transduction triggered by the intestinal dysbacteriosis. PMID:27373290

  15. Influence of thermally-oxidized vegetable oils and animal fats on intestinal barrier function and immune variables in young pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To evaluate the effect of feeding thermally-oxidized lipids on metabolic oxidative status, gut barrier function, and immune response of young pigs, 108 barrows (6.67 ± 0.03 kg BW) were assigned to 12 dietary treatments in a 4 × 3 factorial design in addition to a corn-soybean meal control diet. Main...

  16. Remodeling of Tight Junctions and Enhancement of Barrier Integrity of the CACO-2 Intestinal Epithelial Cell Layer by Micronutrients

    PubMed Central

    Valenzano, Mary Carmen; DiGuilio, Katherine; Mercado, Joanna; Teter, Mimi; To, Julie; Ferraro, Brendan; Mixson, Brittany; Manley, Isabel; Baker, Valerissa; Moore, Beverley A.; Wertheimer, Joshua; Mullin, James M.

    2015-01-01

    The micronutrients zinc, quercetin, butyrate, indole and berberine were evaluated for their ability to induce remodeling of epithelial tight junctions (TJs) and enhance barrier integrity in the CACO-2 gastrointestinal epithelial cell culture model. All five of these chemically very diverse micronutrients increased transepithelial electrical resistance (Rt) significantly, but only berberine also improved barrier integrity to the non-electrolyte D-mannitol. Increases of Rt as much as 200% of untreated controls were observed. Each of the five micronutrients also induced unique, signature-like changes in TJ protein composition, suggesting multiple pathways (and TJ arrangements) by which TJ barrier function can be enhanced. Decreases in abundance by as much as 90% were observed for claudin-2, and increases of over 300% could be seen for claudins -5 and -7. The exact effects of the micronutrients on barrier integrity and TJ protein composition were found to be highly dependent on the degree of differentiation of the cell layer at the time it was exposed to the micronutrient. The substratum to which the epithelial layer adheres was also found to regulate the response of the cell layer to the micronutrient. The implications of these findings for therapeutically decreasing morbidity in Inflammatory Bowel Disease are discussed. PMID:26226276

  17. Biomechanics of oral mucosa

    PubMed Central

    Chen, Junning; Ahmad, Rohana; Li, Wei; Swain, Michael; Li, Qing

    2015-01-01

    The prevalence of prosthodontic treatment has been well recognized, and the need is continuously increasing with the ageing population. While the oral mucosa plays a critical role in the treatment outcome, the associated biomechanics is not yet fully understood. Using the literature available, this paper provides a critical review on four aspects of mucosal biomechanics, including static, dynamic, volumetric and interactive responses, which are interpreted by its elasticity, viscosity/permeability, apparent Poisson's ratio and friction coefficient, respectively. Both empirical studies and numerical models are analysed and compared to gain anatomical and physiological insights. Furthermore, the clinical applications of such biomechanical knowledge on the mucosa are explored to address some critical concerns, including stimuli for tissue remodelling (interstitial hydrostatic pressure), pressure–pain thresholds, tissue displaceability and residual bone resorption. Through this review, the state of the art in mucosal biomechanics and their clinical implications are discussed for future research interests, including clinical applications, computational modelling, design optimization and prosthetic fabrication. PMID:26224566

  18. Biomechanics of oral mucosa.

    PubMed

    Chen, Junning; Ahmad, Rohana; Li, Wei; Swain, Michael; Li, Qing

    2015-08-01

    The prevalence of prosthodontic treatment has been well recognized, and the need is continuously increasing with the ageing population. While the oral mucosa plays a critical role in the treatment outcome, the associated biomechanics is not yet fully understood. Using the literature available, this paper provides a critical review on four aspects of mucosal biomechanics, including static, dynamic, volumetric and interactive responses, which are interpreted by its elasticity, viscosity/permeability, apparent Poisson's ratio and friction coefficient, respectively. Both empirical studies and numerical models are analysed and compared to gain anatomical and physiological insights. Furthermore, the clinical applications of such biomechanical knowledge on the mucosa are explored to address some critical concerns, including stimuli for tissue remodelling (interstitial hydrostatic pressure), pressure-pain thresholds, tissue displaceability and residual bone resorption. Through this review, the state of the art in mucosal biomechanics and their clinical implications are discussed for future research interests, including clinical applications, computational modelling, design optimization and prosthetic fabrication. PMID:26224566

  19. Prions efficiently cross the intestinal barrier after oral administration: Study of the bioavailability, and cellular and tissue distribution in vivo

    PubMed Central

    Urayama, Akihiko; Concha-Marambio, Luis; Khan, Uffaf; Bravo-Alegria, Javiera; Kharat, Vineetkumar; Soto, Claudio

    2016-01-01

    Natural forms of prion diseases frequently originate by oral (p.o.) infection. However, quantitative information on the gastro-intestinal (GI) absorption of prions (i.e. the bioavailability and subsequent biodistribution) is mostly unknown. The main goal of this study was to evaluate the fate of prions after oral administration, using highly purified radiolabeled PrPSc. The results showed a bi-phasic reduction of PrPSc with time in the GI, except for the ileum and colon which showed sustained increases peaking at 3–6 hr, respectively. Plasma and whole blood 125I-PrPSc reached maximal levels by 30 min and 3 hr, respectively, and blood levels were constantly higher than plasma. Upon crossing the GI-tract 125I-PrPSc became associated to blood cells, suggesting that binding to cells decreased the biological clearance of the agent. Size-exclusion chromatography revealed that oligomeric 125I-PrPSc were transported from the intestinal tract, and protein misfolding cyclic amplification showed that PrPSc in organs and blood retained the typical prion self-replicating ability. Pharmacokinetic analysis found the oral bioavailability of 125I-PrPSc to be 33.6%. Interestingly, 125I-PrPSc reached the brain in a quantity equivalent to the minimum amount needed to initiate prion disease. Our findings provide a comprehensive and quantitative study of the fate of prions upon oral infection. PMID:27573341

  20. Investigation of the effect of the uneven distribution of CYP3A4 and P-glycoprotein in the intestine on the barrier function against xenobiotics: a simulation study.

    PubMed

    Watanabe, Takao; Maeda, Kazuya; Nakai, Chikako; Sugiyama, Yuichi

    2013-09-01

    CYP3A4 and P-glycoprotein (P-gp) have similar substrate specificities and work together to form an intestinal absorption barrier against xenobiotics. Previous reports have indicated that CYP3A4 expression decreases gradually, whereas P-gp expression increases, from the upper to lower small intestine. The physiological rationale for this uneven distribution of CYP3A4 and P-gp as a barrier against xenobiotics has not been determined. To clarify the effect of these distribution patterns on barrier function, we constructed a mathematical model that included passive membrane permeation, P-gp-mediated apical efflux, and CYP3A4-mediated metabolism, and we simulated the effects of these distribution patterns on the fraction absorbed of co-substrates without changing their overall activities. The simulation showed that the physiological distribution patterns of both CYP3A4 and P-gp result in the lowest fraction absorbed, but not for drugs with low CYP3A4 and high P-gp-mediated clearances. These results suggest that the distribution pattern of CYP3A4 is especially important for the barrier function. On the other hand, physiological distribution pattern of P-gp exerts the maximum barrier function for dual good substrates for P-gp and CYP3A4, but even distribution of P-gp mostly suppresses the intestinal absorption of good P-gp, but poor CYP3A4 substrates. PMID:23754337

  1. Nutritional Factors Influencing Intestinal Health of the Neonate12

    PubMed Central

    Jacobi, Sheila K.; Odle, Jack

    2012-01-01

    Dietary nutrients are essential for gastrointestinal (GI) growth and function, and nutritional support of GI growth and development is a significant component of infant care. For healthy full-term neonates, nutritional provisions of the mother’s milk and/or formula will support normal maturation of structure and function of the GI tract in most infants. The composition of breast milk affects GI barrier function and development of a competent mucosal immune system. The functional nutrients and other bioactive components of milk support a microenvironment for gut protection and maturation. However, premature infants struggle with feeding tolerance impairing normal GI function, leading to intestinal dysfunction and even death. The high prevalence worldwide of enteric diseases and dysfunction in neonates has led to much interest in understanding the role of nutrients and food components in the establishment and maintenance of a functioning GI tract. Neonates who do not receive enteral feeding as either mother’s milk or formula are supported by total parental nutrition (TPN). The lack of enteral nutrition can compound intestinal dysfunction, leading to high morbidity and mortality in intestinally compromised infants. Reciprocally, enteral stimulation of an immature GI tract can also compound intestinal dysfunction. Therefore, further understanding of nutrient interactions with the mucosa is necessary to define nutritional requirements of the developing GI tract to minimize intestinal complications and infant morbidity. Piglet models of intestinal development and function are similar to humans, and this review summarizes recent findings regarding nutrient requirements for growth and maintenance of intestinal health. In particular, this article reviews the role of specific amino acids (arginine, glutamine, glutamate, and threonine), fatty acids (long chain polyunsaturated, medium chain, and short chain), various prebiotic carbohydrates (short-chain fructo

  2. Nutritional factors influencing intestinal health of the neonate.

    PubMed

    Jacobi, Sheila K; Odle, Jack

    2012-01-01

    Dietary nutrients are essential for gastrointestinal (GI) growth and function, and nutritional support of GI growth and development is a significant component of infant care. For healthy full-term neonates, nutritional provisions of the mother's milk and/or formula will support normal maturation of structure and function of the GI tract in most infants. The composition of breast milk affects GI barrier function and development of a competent mucosal immune system. The functional nutrients and other bioactive components of milk support a microenvironment for gut protection and maturation. However, premature infants struggle with feeding tolerance impairing normal GI function, leading to intestinal dysfunction and even death. The high prevalence worldwide of enteric diseases and dysfunction in neonates has led to much interest in understanding the role of nutrients and food components in the establishment and maintenance of a functioning GI tract. Neonates who do not receive enteral feeding as either mother's milk or formula are supported by total parental nutrition (TPN). The lack of enteral nutrition can compound intestinal dysfunction, leading to high morbidity and mortality in intestinally compromised infants. Reciprocally, enteral stimulation of an immature GI tract can also compound intestinal dysfunction. Therefore, further understanding of nutrient interactions with the mucosa is necessary to define nutritional requirements of the developing GI tract to minimize intestinal complications and infant morbidity. Piglet models of intestinal development and function are similar to humans, and this review summarizes recent findings regarding nutrient requirements for growth and maintenance of intestinal health. In particular, this article reviews the role of specific amino acids (arginine, glutamine, glutamate, and threonine), fatty acids (long chain polyunsaturated, medium chain, and short chain), various prebiotic carbohydrates (short-chain fructo

  3. The Intestinal Microbiota in Inflammatory Bowel Disease.

    PubMed

    Becker, Christoph; Neurath, Markus F; Wirtz, Stefan

    2015-01-01

    The intestinal microbiota has important metabolic and host-protective functions. Conversely to these beneficial functions, the intestinal microbiota is thought to play a central role in the etiopathogenesis of inflammatory bowel disease (IBD; Crohn's disease and ulcerative colitis), a chronic inflammation of the gut mucosa. Genetic screens and studies in experimental mouse models have clearly demonstrated that IBD can develop due to excessive translocation of bacteria into the bowel wall or dysregulated handling of bacteria in genetically susceptible hosts. In healthy individuals, the microbiota is efficiently separated from the mucosal immune system of the gut by the gut barrier, a single layer of highly specialized epithelial cells, some of which are equipped with innate immune functions to prevent or control access of bacterial antigens to the mucosal immune cells. It is currently unclear whether the composition of the microbial flora or individual bacterial strains or pathogens induces or supports the pathogenesis of IBD. Further research will be necessary to carefully dissect the contribution of individual bacterial species to this disease and to ascertain whether specific modulation of the intestinal microbiome may represent a valuable further option for future therapeutic strategies. PMID:26323629

  4. Prions efficiently cross the intestinal barrier after oral administration: Study of the bioavailability, and cellular and tissue distribution in vivo.

    PubMed

    Urayama, Akihiko; Concha-Marambio, Luis; Khan, Uffaf; Bravo-Alegria, Javiera; Kharat, Vineetkumar; Soto, Claudio

    2016-01-01

    Natural forms of prion diseases frequently originate by oral (p.o.) infection. However, quantitative information on the gastro-intestinal (GI) absorption of prions (i.e. the bioavailability and subsequent biodistribution) is mostly unknown. The main goal of this study was to evaluate the fate of prions after oral administration, using highly purified radiolabeled PrP(Sc). The results showed a bi-phasic reduction of PrP(Sc) with time in the GI, except for the ileum and colon which showed sustained increases peaking at 3-6 hr, respectively. Plasma and whole blood (125)I-PrP(Sc) reached maximal levels by 30 min and 3 hr, respectively, and blood levels were constantly higher than plasma. Upon crossing the GI-tract (125)I-PrP(Sc) became associated to blood cells, suggesting that binding to cells decreased the biological clearance of the agent. Size-exclusion chromatography revealed that oligomeric (125)I-PrP(Sc) were transported from the intestinal tract, and protein misfolding cyclic amplification showed that PrP(Sc) in organs and blood retained the typical prion self-replicating ability. Pharmacokinetic analysis found the oral bioavailability of (125)I-PrP(Sc) to be 33.6%. Interestingly, (125)I-PrP(Sc) reached the brain in a quantity equivalent to the minimum amount needed to initiate prion disease. Our findings provide a comprehensive and quantitative study of the fate of prions upon oral infection. PMID:27573341

  5. Toxic Effects of Maternal Zearalenone Exposure on Intestinal Oxidative Stress, Barrier Function, Immunological and Morphological Changes in Rats

    PubMed Central

    Liu, Min; Gao, Rui; Meng, Qingwei; Zhang, Yuanyuan; Bi, Chongpeng; Shan, Anshan

    2014-01-01

    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. PMID:25180673

  6. Effect of Candida albicans on Intestinal Ischemia-reperfusion Injury in Rats

    PubMed Central

    Yan, Lei; Wu, Chun-Rong; Wang, Chen; Yang, Chun-Hui; Tong, Guang-Zhi; Tang, Jian-Guo

    2016-01-01

    Background: Inflammation is supposed to play a key role in the pathophysiological processes of intestinal ischemia-reperfusion injury (IIRI), and Candida albicans in human gut commonly elevates inflammatory cytokines in intestinal mucosa. This study aimed to explore the effect of C. albicans on IIRI. Methods: Fifty female Wistar rats were divided into five groups according to the status of C. albicans infection and IIRI operation: group blank and sham; group blank and IIRI; group cefoperazone plus IIRI; group C. albicans plus cefoperazone and IIRI (CCI); and group C. albicans plus cefoperazone and sham. The levels of inflammatory factors tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, and diamine oxidase (DAO) measured by enzyme-linked immunosorbent assay were used to evaluate the inflammation reactivity as well as the integrity of small intestine. Histological scores were used to assess the mucosal damage, and the C. albicans blood translocation was detected to judge the permeability of intestinal mucosal barrier. Results: The levels of inflammatory factors TNF-α, IL-6, and IL-1β in serum and intestine were higher in rats undergone both C. albicans infection and IIRI operation compared with rats in other groups. The levels of DAO (serum: 44.13 ± 4.30 pg/ml, intestine: 346.21 ± 37.03 pg/g) and Chiu scores (3.41 ± 1.09) which reflected intestinal mucosal disruption were highest in group CCI after the operation. The number of C. albicans translocated into blood was most in group CCI ([33.80 ± 6.60] ×102 colony forming unit (CFU)/ml). Conclusion: Intestinal C. albicans infection worsened the IIRI-induced disruption of intestinal mucosal barrier and facilitated the subsequent C. albicans translocation and dissemination. PMID:27411459

  7. Nitric oxide synthase stimulates prostaglandin synthesis and barrier function in C. parvum-infected porcine ileum.

    PubMed

    Gookin, Jody L; Duckett, Laurel L; Armstrong, Martha U; Stauffer, Stephen H; Finnegan, Colleen P; Murtaugh, Michael P; Argenzio, Robert A

    2004-09-01

    Cell culture models implicate increased nitric oxide (NO) synthesis as a cause of mucosal hyperpermeability in intestinal epithelial infection. NO may also mediate a multitude of subepithelial events, including activation of cyclooxygenases. We examined whether NO promotes barrier function via prostaglandin synthesis using Cryptosporidium parvum-infected ileal epithelium in residence with an intact submucosa. Expression of NO synthase (NOS) isoforms was examined by real-time RT-PCR of ileal mucosa from control and C. parvum-infected piglets. The isoforms mediating and mechanism of NO action on barrier function were assessed by measuring transepithelial resistance (TER) and eicosanoid synthesis by ileal mucosa mounted in Ussing chambers in the presence of selective and nonselective NOS inhibitors and after rescue with exogenous prostaglandins. C. parvum infection results in induction of mucosal inducible NOS (iNOS), increased synthesis of NO and PGE2, and increased mucosal permeability. Nonselective inhibition of NOS (NG-nitro-L-arginine methyl ester) inhibited prostaglandin synthesis, resulting in further increases in paracellular permeability. Baseline permeability was restored in the absence of NO by exogenous PGE2. Selective inhibition of iNOS [L-N6-(1-iminoethyl)-L-lysine] accounted for approximately 50% of NOS-dependent PGE2 synthesis and TER. Using an entire intestinal mucosa, we have demonstrated for the first time that NO serves as a proximal mediator of PGE2 synthesis and barrier function in C. parvum infection. Expression of iNOS by infected mucosa was without detriment to overall barrier function and may serve to promote clearance of infected enterocytes. PMID:15155179

  8. Quantitative In Vitro and In Vivo Evaluation of Intestinal and Blood-Brain Barrier Transport Kinetics of the Plant N-Alkylamide Pellitorine.

    PubMed

    Veryser, Lieselotte; Bracke, Nathalie; Wynendaele, Evelien; Joshi, Tanmayee; Tatke, Pratima; Taevernier, Lien; De Spiegeleer, Bart

    2016-01-01

    Objective. To evaluate the gut mucosa and blood-brain barrier (BBB) pharmacokinetic permeability properties of the plant N-alkylamide pellitorine. Methods. Pure pellitorine and an Anacyclus pyrethrum extract were used to investigate the permeation of pellitorine through (1) a Caco-2 cell monolayer, (2) the rat gut after oral administration, and (3) the BBB in mice after intravenous and intracerebroventricular administration. A validated bioanalytical UPLC-MS(2) method was used to quantify pellitorine. Results. Pellitorine was able to cross the Caco-2 cell monolayer from the apical-to-basolateral and from the basolateral-to-apical side with apparent permeability coefficients between 0.6 · 10(-5) and 4.8 · 10(-5) cm/h and between 0.3 · 10(-5) and 5.8 · 10(-5) cm/h, respectively. In rats, a serum elimination rate constant of 0.3 h(-1) was obtained. Intravenous injection of pellitorine in mice resulted in a rapid and high permeation of pellitorine through the BBB with a unidirectional influx rate constant of 153 μL/(g·min). In particular, 97% of pellitorine reached the brain tissue, while only 3% remained in the brain capillaries. An efflux transfer constant of 0.05 min(-1) was obtained. Conclusion. Pellitorine shows a good gut permeation and rapidly permeates the BBB once in the blood, indicating a possible role in the treatment of central nervous system diseases. PMID:27493960

  9. Quantitative In Vitro and In Vivo Evaluation of Intestinal and Blood-Brain Barrier Transport Kinetics of the Plant N-Alkylamide Pellitorine

    PubMed Central

    Veryser, Lieselotte; Bracke, Nathalie; Wynendaele, Evelien; Joshi, Tanmayee; Tatke, Pratima; Taevernier, Lien

    2016-01-01

    Objective. To evaluate the gut mucosa and blood-brain barrier (BBB) pharmacokinetic permeability properties of the plant N-alkylamide pellitorine. Methods. Pure pellitorine and an Anacyclus pyrethrum extract were used to investigate the permeation of pellitorine through (1) a Caco-2 cell monolayer, (2) the rat gut after oral administration, and (3) the BBB in mice after intravenous and intracerebroventricular administration. A validated bioanalytical UPLC-MS2 method was used to quantify pellitorine. Results. Pellitorine was able to cross the Caco-2 cell monolayer from the apical-to-basolateral and from the basolateral-to-apical side with apparent permeability coefficients between 0.6 · 10−5 and 4.8 · 10−5 cm/h and between 0.3 · 10−5 and 5.8 · 10−5 cm/h, respectively. In rats, a serum elimination rate constant of 0.3 h−1 was obtained. Intravenous injection of pellitorine in mice resulted in a rapid and high permeation of pellitorine through the BBB with a unidirectional influx rate constant of 153 μL/(g·min). In particular, 97% of pellitorine reached the brain tissue, while only 3% remained in the brain capillaries. An efflux transfer constant of 0.05 min−1 was obtained. Conclusion. Pellitorine shows a good gut permeation and rapidly permeates the BBB once in the blood, indicating a possible role in the treatment of central nervous system diseases. PMID:27493960

  10. Metformin protects against the development of fructose-induced steatosis in mice: role of the intestinal barrier function.

    PubMed

    Spruss, Astrid; Kanuri, Giridhar; Stahl, Carolin; Bischoff, Stephan C; Bergheim, Ina

    2012-07-01

    To test the hypothesis that metformin protects against fructose-induced steatosis, and if so, to elucidate underlying mechanisms, C57BL/6J mice were either fed 30% fructose solution or plain water for 8 weeks. Some of the animals were concomitantly treated with metformin (300 mg/kg body weight/day) in the drinking solution. While chronic consumption of 30% fructose solution caused a significant increase in hepatic triglyceride accumulation and plasma alanine-aminotransferase levels, this effect of fructose was markedly attenuated in fructose-fed mice concomitantly treatment with metformin. The protective effects of the metformin treatment on the onset of fructose-induced non-alcoholic fatty liver disease (NAFLD) were associated with a protection against the loss of the tight junction proteins occludin and zonula occludens 1 in the duodenum of fructose-fed mice and the increased translocation of bacterial endotoxin found in mice only fed with fructose. In line with these findings, in metformin-treated fructose-fed animals, hepatic expression of genes of the toll-like receptor-4-dependent signalling cascade as well as the plasminogen-activator inhibitor/cMet-regulated lipid export were almost at the level of controls. Taken together, these data suggest that metformin not only protects the liver from the onset of fructose-induced NAFLD through mechanisms involving its direct effects on hepatic insulin signalling but rather through altering intestinal permeability and subsequently the endotoxin-dependent activation of hepatic Kupffer cells. PMID:22525431

  11. [Intestinal-brain axis. Neuronal and immune-inflammatory mechanisms of brain and intestine pathology].

    PubMed

    Bondarenko, V M; Riabichenko, E V

    2013-01-01

    Mutually directed connections between intestine and brain are implemented by endocrine, neural and immune systems and nonspecific natural immunity. Intestine micro flora as an active participant of intestine-brain axis not only influences intestine functions but also stimulates the development of CNS in perinatal period and interacts with higher nervous centers causing depression and cognitive disorders in pathology. A special role belongs to intestine microglia. Apart from mechanic (protective) and trophic functions for intestine neurons, glia implements neurotransmitter, immunologic, barrier and motoric functions in the intestine. An interconnection between intestine barrier function and hematoencephalic barrier regulation exists. Chronic endotoxinemia as a result of intestine barrier dysfunction forms sustained inflammation state in periventricular zone of the brain with consequent destabilization of hematoencephalic barriers and spread oF inflammation to other parts of the brain resulting in neurodegradation development. PMID:23805681

  12. Dietary fat sources differentially modulate intestinal barrier and hepatic inflammation in alcohol-induced liver injury in rats

    PubMed Central

    Zhong, Wei; Li, Qiong; Xie, Guoxiang; Sun, Xiuhua; Tan, Xiaobing; Sun, Xinguo; Jia, Wei

    2013-01-01

    Endotoxemia is a causal factor in the development of alcoholic liver injury. The present study aimed at determining the interactions of ethanol with different fat sources at the gut-liver axis. Male Sprague-Dawley rats were pair fed control or ethanol liquid diet for 8 wk. The liquid diets were based on a modified Lieber-DeCarli formula, with 30% total calories derived from corn oil (rich in polyunsaturated fatty acids). To test the effects of saturated fats, corn oil in the ethanol diet was replaced by either cocoa butter (CB, rich in long-chain saturated fatty acids) or medium-chain triglycerides (MCT, exclusively medium-chain saturated fatty acids). Ethanol feeding increased hepatic lipid accumulation and inflammatory cell infiltration and perturbed hepatic and serum metabolite profiles. Ethanol feeding with CB or MCT alleviated ethanol-induced liver injury and attenuated ethanol-induced metabolic perturbation. Both CB and MCT also normalized ethanol-induced hepatic macrophage activation, cytokine expression, and neutrophil infiltration. Ethanol feeding elevated serum endotoxin level, which was normalized by MCT but not CB. In accordance, ethanol-induced downregulations of intestinal occludin and zonula occludens-1 were normalized by MCT but not CB. However, CB normalized ethanol-increased hepatic endotoxin level in association with upregulation of an endotoxin detoxifying enzyme, argininosuccinate synthase 1 (ASS1). Knockdown ASS1 in H4IIEC3 cells resulted in impaired endotoxin clearance and upregulated cytokine expression. These data demonstrate that the protection of saturated fats against alcohol-induced liver injury occur via different actions at the gut-liver axis and are chain length dependent. PMID:24113767

  13. Loss of intestinal O-glycans promotes spontaneous duodenal tumors.

    PubMed

    Gao, Nan; Bergstrom, Kirk; Fu, Jianxin; Xie, Biao; Chen, Weichang; Xia, Lijun

    2016-07-01

    Mucin-type O-glycans, primarily core 1- and core 3-derived O-glycans, are the major mucus barrier components throughout the gastrointestinal tract. Previous reports identified the biological role of O-glycans in the stomach and colon. However, the biological function of O-glycans in the small intestine remains unknown. Using mice lacking intestinal core 1- and core 3-derived O-glycans [intestinal epithelial cell C1galt1(-/-);C3GnT(-/-) or double knockout (DKO)], we found that loss of O-glycans predisposes DKO mice to spontaneous duodenal tumorigenesis by ∼1 yr of age. Tumor incidence did not increase with age; however, tumors advanced in aggressiveness by 20 mo. O-glycan deficiency was associated with reduced luminal mucus in DKO mice before tumor development. Altered intestinal epithelial homeostasis with enhanced baseline crypt proliferation characterizes these phenotypes as assayed by Ki67 staining. In addition, fluorescence in situ hybridization analysis reveals a significantly lower bacterial burden in the duodenum compared with the large intestine. This phenotype is not reduced with antibiotic treatment, implying O-glycosylation defects, rather than bacterial-induced inflammation, which causes spontaneous duodenal tumorigenesis. Moreover, inflammatory responses in DKO duodenal mucosa are mild as assayed with histology, quantitative PCR for inflammation-associated cytokines, and immunostaining for immune cells. Importantly, inducible deletion of intestinal O-glycans in adult mice leads to analogous spontaneous duodenal tumors, although with higher incidence and heightened severity compared with mice with O-glycans constitutive deletion. In conclusion, these studies reveal O-glycans within the small intestine are critical determinants of duodenal cancer risk. Future studies will provide insights into the pathogenesis in the general population and those at risk for this rare but deadly cancer. PMID:27229122

  14. Overexpression of GRß in colonic mucosal cell line partly reflects altered gene expression in colonic mucosa of patients with inflammatory bowel disease.

    PubMed

    Nagy, Zsolt; Acs, Bence; Butz, Henriett; Feldman, Karolina; Marta, Alexa; Szabo, Peter M; Baghy, Kornelia; Pazmany, Tamas; Racz, Karoly; Liko, Istvan; Patocs, Attila

    2016-01-01

    The glucocorticoid receptor (GR) plays a crucial role in inflammatory responses. GR has several isoforms, of which the most deeply studied are the GRα and GRß. Recently it has been suggested that in addition to its negative dominant effect on GRα, the GRß may have a GRα-independent transcriptional activity. The GRß isoform was found to be frequently overexpressed in various autoimmune diseases, including inflammatory bowel disease (IBD). In this study, we wished to test whether the gene expression profile found in a GRß overexpressing intestinal cell line (Caco-2GRß) might mimic the gene expression alterations found in patients with IBD. Whole genome microarray analysis was performed in both normal and GRß overexpressing Caco-2 cell lines with and without dexamethasone treatment. IBD-related genes were identified from a meta-analysis of 245 microarrays available in online microarray deposits performed on intestinal mucosa samples from patients with IBD and healthy individuals. The differentially expressed genes were further studied using in silico pathway analysis. Overexpression of GRß altered a large proportion of genes that were not regulated by dexamethasone suggesting that GRß may have a GRα-independent role in the regulation of gene expression. About 10% of genes differentially expressed in colonic mucosa samples from IBD patients compared to normal subjects were also detected in Caco-2 GRß intestinal cell line. Common genes are involved in cell adhesion and cell proliferation. Overexpression of GRß in intestinal cells may affect appropriate mucosal repair and intact barrier function. The proposed novel role of GRß in intestinal epithelium warrants further studies. PMID:26480216

  15. In vitro prediction of human intestinal absorption and blood-brain barrier partitioning: development of a lipid analog for micellar liquid chromatography.

    PubMed

    De Vrieze, Mike; Janssens, Pieter; Szucs, Roman; Van der Eycken, Johan; Lynen, Frédéric

    2015-09-01

    Over the past decades, several in vitro methods have been tested for their ability to predict either human intestinal absorption (HIA) or penetration across the blood-brain barrier (BBB) of drugs. Micellar liquid chromatography (MLC) has been a successful approach for retention time measurements of drugs to establish models together with other molecular descriptors. Thus far, MLC approaches have only made use of commercial surfactants such as sodium dodecyl sulfate (SDS) and polyoxyethylene (23) lauryl ether (Brij35), which are not representative for the phospholipids present in human membranes. Miltefosine, a phosphocholine-based lipid, is presented here as an alternative surfactant for MLC measurements. By using the obtained retention factors and several computed descriptors for a set of 48 compounds, two models were constructed: one for the prediction of HIA and another for the prediction of penetration across the BBB expressed as log BB. All data were correlated to experimental HIA and log BB values, and the performance of the models was evaluated. Log BB prediction performed better than HIA prediction, although HIA prediction was also improved a lot (from 0.5530 to 0.7175) compared to in silico predicted HIA values. PMID:26277183

  16. Vitamin A supplementation effects on intestinal barrier function, growth, total parasitic and specific Giardia spp. infections in Brazilian children: a prospective randomized, double-blind, placebo-controlled trial

    PubMed Central

    Lima, Aldo A. M.; Soares, Alberto M.; Lima, Noélia L.; Mota, Rosa M. S.; Maciel, Bruna L. L.; Kvalsund, Michelle P.; Barrett, Leah J.; Fitzgerald, Relana P.; Blaner, William S.; Guerrant, Richard L.

    2009-01-01

    Background This study evaluates the effects of retinol on intestinal barrier function, growth, total parasites and Giardia spp. infections in children in the Northeast of Brazil. Methods The study was a double-blind, randomized placebo-controlled trial (http://clinicaltrials.gov;Register#NCT00133406) involving 79children reiceved vitamin A 100,000 - 200,000 IU (n = 39) or placebo (n = 40) at enrollment, 4 and 8 months, followed for 36 months. Intestinal barrier function was evaluated using the lactulose:mannitol test. Stool lactoferrin was used as a marker for intestinal inflammation. Results The groups were similar with regard to age, sex, nutritional parameters (z-scores), serum retinol concentrations, proportion of lactoferrin positive stool samples, and intestinal barrier function. The lactulose:mannitol ratio did not change during the same time of follow-up (p>0.05). The proportion of lactoferrin positive samples evaluated at one month did not change between groups (p>0.05). Total intestinal parasitic specifically new infections were significantly lower in the vitamin A treatment compared to control group; these were accounted for entirely by significantly fewer new Giardia infections in the vitamin A treatment group. The cumulative z-scores for weight-for-length or height (WHZ), length or height-for-age z-scores (HAZ), and weight-for-age (WAZ) did not change significantly with vitamin A intervention for 36 months of follow-up. Conclusions These data showed that total parasitic infection and Giardia spp. infections were significantly lower in the vitamin A treatment group when compared to the placebo group, suggesting that vitamin A improves host defenses against Giardia infections. PMID:20038852

  17. Toll-like receptor 2 activation by β2→1-fructans protects barrier function of T84 human intestinal epithelial cells in a chain length-dependent manner.

    PubMed

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

    2014-07-01

    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 β2→1-fructan dietary fibers confer protection on intestinal epithelial cell barrier function via Toll-like receptor 2 (TLR2), and we studied whether β2→1-fructan chain-length differences affect this process. T84 human intestinal epithelial cell monolayers were incubated with 4 β2→1-fructan formulations of different chain-length compositions and were stimulated with the proinflammatory phorbol 12-myristate 13-acetate (PMA). Transepithelial electrical resistance (TEER) was analyzed by electric cell substrate impedance sensing (ECIS) as a measure for tight junction-mediated barrier function. To confirm TLR2 involvement in barrier modulation by β2→1-fructans, ECIS experiments were repeated using TLR2 blocking antibody. After preincubation of T84 cells with short-chain β2→1-fructans, the decrease in TEER as induced by PMA (62.3 ± 5.2%, P < 0.001) was strongly attenuated (15.2 ± 8.8%, P < 0.01). However, when PMA was applied first, no effect on recovery was observed during addition of the fructans. By blocking TLR2 on the T84 cells, the protective effect of short-chain β2→1-fructans was substantially inhibited. Stimulation of human embryonic kidney human TLR2 reporter cells with β2→1-fructans induced activation of nuclear factor kappa-light-chain-enhancer of activated B cells, confirming that β2→1-fructans are specific ligands for TLR2. To conclude, β2→1-fructans exert time-dependent and chain length-dependent protective effects on the T84 intestinal epithelial cell barrier mediated via TLR2. These results suggest that TLR2 located on intestinal epithelial cells could be a target of β2→1-fructan-mediated health effects. PMID:24790027

  18. [The activity of the lipid peroxidation processes in the mucosa of the rat small intestine and its morphofunctional state under acute irradiation and the administration of combined preparations created on a base of highly dispersed silica].

    PubMed

    Iakubovskiĭ, M M; Pentiuk, A A; Khmelnitskiĭ, O K; Oleĭnik, V N

    1997-01-01

    Morphofunctional and biochemical studies were carried out on bastard male rats (weight 200-240 g). The results showed that X-ray irradiation had induced structural alterations and elevation of lipid peroxidation in small intestine. Using of complex preparations defended this organ against pathological damages. The first preparation provided rat organisms with 100 ml/kg of silica, 2 mg/kg of beta-carotene, 30 mg/kg of alpha-tocopherol and 0.2 mg/kg of natrium selenite. The second preparation provided 100 mg/kg of silica, 10 mg/kg of dry Rhodiola extract, 0.1 mg/kg of tincture of Lagochilus [correction of Ladohilli] inebrians and 0.05 ml/kg of tincture of Aralia mandshurica. The third preparation provided organism with 100 mg/kg of silica and 20 mg/kg of thiobenzimidazole derivative. All these preparations had produced marked pharmacological effect. PMID:9244524

  19. Host-compound foraging by intestinal microbiota revealed by single-cell stable isotope probing

    PubMed Central

    Berry, David; Stecher, Bärbel; Schintlmeister, Arno; Reichert, Jochen; Brugiroux, Sandrine; Wild, Birgit; Wanek, Wolfgang; Richter, Andreas; Rauch, Isabella; Decker, Thomas; Loy, Alexander; Wagner, Michael

    2013-01-01

    The animal and human intestinal mucosa secretes an assortment of compounds to establish a physical barrier between the host tissue and intestinal contents, a separation that is vital for health. Some pathogenic microorganisms as well as members of the commensal intestinal microbiota have been shown to be able to break down these secreted compounds. Our understanding of host-compound degradation by the commensal microbiota has been limited to knowledge about simplified model systems because of the difficulty in studying the complex intestinal ecosystem in vivo. In this study, we introduce an approach that overcomes previous technical limitations and allows us to observe which microbial cells in the intestine use host-derived compounds. We added stable isotope-labeled threonine i.v. to mice and combined fluorescence in situ hybridization with high-resolution secondary ion mass spectrometry imaging to characterize utilization of host proteins by individual bacterial cells. We show that two bacterial species, Bacteroides acidifaciens and Akkermansia muciniphila, are important host-protein foragers in vivo. Using gnotobiotic mice we show that microbiota composition determines the magnitude and pattern of foraging by these organisms, demonstrating that a complex microbiota is necessary in order for this niche to be fully exploited. These results underscore the importance of in vivo studies of intestinal microbiota, and the approach presented in this study will be a powerful tool to address many other key questions in animal and human microbiome research. PMID:23487774

  20. 1,25-Dihydroxyvitamin D3 preserves intestinal epithelial barrier function from TNF-α induced injury via suppression of NF-kB p65 mediated MLCK-P-MLC signaling pathway.

    PubMed

    Chen, Shanwen; Zhu, Jing; Chen, Guowei; Zuo, Shuai; Zhang, Junling; Chen, Ziyi; Wang, Xin; Li, Junxia; Liu, Yucun; Wang, Pengyuan

    2015-05-01

    Substantial studies have demonstrated the protective effect of 1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) on intestinal barrier function, but the mechanisms are not fully illustrated. In this study, the effect of 1,25(OH)2D3 on TNF-α induced barrier dysfunction was further investigated in Caco-2 cell monolayers. The barrier function of Caco-2 monolayers was evaluated by measuring trans-epithelial electrical resistance (TEER) and FITC-Dextran 40,000 Da (FD-40) trans-membrane flux. ZO-1 and Occludin were chosen as markers of the localization of tight junction (TJ) proteins for immunofluorescence. The expression of MLCK and phosphorylation level of myosin light chain (MLC) were measured by immunoblotting. The activation of NF-kB p65 was analyzed by EMSA and immunofluorescence. The results suggest that 1,25(OH)2D3 preserves intestinal epithelial barrier function from TNF-α induced injury via suppression of NF-kB p65 mediated activation of MLCK-P-MLC signaling pathway. PMID:25838204

  1. Developmental Changes of TGF-β1 and Smads Signaling Pathway in Intestinal Adaption of Weaned Pigs

    PubMed Central

    Xiao, Kan; Song, Ze-He; Jiao, Le-Fei; Ke, Ya-Lu; Hu, Cai-Hong

    2014-01-01

    Weaning stress caused marked changes in intestinal structure and function. Transforming growth factor-β1 (TGF-β1) and canonical Smads signaling pathway are suspected to play an important regulatory role in post-weaning adaptation of the small intestine. In the present study, the intestinal morphology and permeability, developmental expressions of tight junction proteins and TGF-β1 in the intestine of piglets during the 2 weeks after weaning were assessed. The expressions of TGF-β receptor I/II (TβRI, TβRII), smad2/3, smad4 and smad7 were determined to investigate whether canonical smads signaling pathways were involved in early weaning adaption process. The results showed that a shorter villus and deeper crypt were observed on d 3 and d 7 postweaning and intestinal morphology recovered to preweaning values on d 14 postweaning. Early weaning increased (P<0.05) plasma level of diamine oxidase (DAO) and decreased DAO activities (P<0.05) in intestinal mucosa on d 3 and d 7 post-weaning. Compared with the pre-weaning stage (d 0), tight junction proteins level of occludin and claudin-1 were reduced (P<0.05) on d 3, 7 and 14 post-weaning, and ZO-1 protein was reduced (P<0.05) on d 3 and d 7 post-weaning. An increase (P<0.05) of TGF-β1 in intestinal mucosa was observed on d 3 and d 7 and then level down on d 14 post-weaning. Although there was an increase (P<0.05) of TβR II protein expression in the intestinal mucosa on d3 and d 7, no significant increase of mRNA of TβRI, TβRII, smad2/3, smad4 and smad7 was observed during postweaning. The results indicated that TGF-β1 was associated with the restoration of intestinal morphology and barrier function following weaning stress. The increased intestinal endogenous TGF-β1 didn't activate the canonical Smads signaling pathway. PMID:25170924

  2. Ulcerative colitis as a polymicrobial infection characterized by sustained broken mucus barrier

    PubMed Central

    Chen, Shui-Jiao; Liu, Xiao-Wei; Liu, Jian-Ping; Yang, Xi-Yan; Lu, Fang-Gen

    2014-01-01

    To reduce medication for patients with ulcerative colitis (UC), we need to establish the etiology of UC. The intestinal microbiota of patients with inflammatory bowel disease (IBD) has been shown to differ from that of healthy controls and abundant data indicate that it changes in both composition and localization. Small intestinal bacterial overgrowth is significantly higher in IBD patients compared with controls. Probiotics have been investigated for their capacity to reduce the severity of UC. The luminal surfaces of the gastrointestinal tract are covered by a mucus layer. This normally acts as a barrier that does not allow bacteria to reach the epithelial cells and thus limits the direct contact between the host and the bacteria. The mucus layer in the colon comprises an inner layer that is firmly adherent to the intestinal mucosa, and an outer layer that can be washed off with minimal rinsing. Some bacteria can dissolve the protective inner mucus layer. Defects in renewal and formation of the inner mucus layer allow bacteria to reach the epithelium and have implications for the causes of colitis. In this review, important elements of UC pathology are thought to be the intestinal bacteria, gut mucus, and the mucosa-associated immune system. PMID:25071341

  3. The Epidemiology and Pathogenesis of Neoplasia in the Small Intestine

    PubMed Central

    SCHOTTENFELD, DAVID; BEEBE-DIMMER, JENNIFER L.; VIGNEAU, FAWN D.

    2013-01-01

    PURPOSE: The mucosa of the small intestine encompasses about 90% of the luminal surface area of the digestive system, but only 2% of the total annual gastrointestinal cancer incidence in the United States. METHODS: The remarkable contrast in age-standardized cancer incidence between the small and large intestine has been reviewed with respect to the cell type patterns, demographic features, and molecular characteristics of neoplasms. RESULTS: Particularly noteworthy is the predominance of adenocarcinoma in the colon, which exceeds 98% of the total incidence by cell type, in contrast to that of 30% to 40% in the small intestine, resulting in an age-standardized ratio of rates exceeding 50-fold. The prevalence of adenomas and carcinomas is most prominent in the duodenum and proximal jejunum. The positive correlation in global incidence rates of small and large intestinal neoplasms and the reciprocal increases in risk of second primary adenocarcinomas suggest that there are common environmental risk factors. The pathophysiology of Crohn inflammatory bowel disease and the elevated risk of adenocarcinoma demonstrate the significance of the impaired integrity of the mucosal barrier and of aberrant immune responses to luminal indigenous and potentially pathogenic microorganisms. CONCLUSION: In advancing a putative mechanism for the contrasting mucosal susceptibilities of the small and large intestine, substantial differences are underscored in the diverse taxonomy, concentration and metabolic activity of anaerobic organisms, rate of intestinal transit, changing pH, and the enterohepatic recycling and metabolism of bile acids. Experimental and epidemiologic studies are cited that suggest that the changing microecology, particularly in the colon, is associated with enhanced metabolic activation of ingested and endogenously formed procarcinogenic substrates. PMID:19064190

  4. The ANXA1 released from intestinal epithelial cells alleviate DSS-induced colitis by improving NKG2A expression of Natural Killer cells.

    PubMed

    Zou, Z; Zuo, D; Yang, J; Fan, H

    2016-09-01

    Inflammatory bowel disease (IBD) arises when intestinal immune homeostasis is broken, the maintenance of such homeostasis is principally controlled by cross talk between commensal bacteria, mucosal immune cells and intestinal epithelial cells (IECs). IECs can prevent the contact between luminal bacteria with immune cells through the formation of a physical barrier and the expression of antimicrobial peptides to maintain intestinal immune homeostasis. During Colitis the IECs can express increased ANXA1, which is important for regeneration of intestinal mucosa and function as a potent anti-inflammatory protein. Natural Killer (NK) cells can also suppress the progression of colitis. It is uncertain about the effect of the cross-talk between injured IECs and recruited NK cells during colitis. In this study, the expression of ANXA1 in IECS from DSS treated mice was increased, and more NK cells were recruited to intestinal mucosa. In addition, the expression of NKG2A was upregulated when co-cultured with NK cells. The results further proved that overexpression of NKG2A in NK cells was important for inhibiting the recruitment and activity of neutrophils to alleviate DSS-induced colitis. Here, we provide a new anti-inflammation mechanism about ANXA1 secreted from injured IECs, where ANXA1 can stimulate the expression of NKG2A in NK cells that affect the recruitment and activity of neutrophils necessary for pathology of colitis. PMID:27435504

  5. Carboxypeptidase E Modulates Intestinal Immune Homeostasis and Protects against Experimental Colitis in Mice

    PubMed Central

    Pagel, René; Schröder, Torsten; Schlichting, Heidi; Hirose, Misa; Lemcke, Susanne; Klinger, Antje; König, Peter; Karsten, Christian M.; Büning, Jürgen; Lehnert, Hendrik; Fellermann, Klaus; Ibrahim, Saleh M.; Sina, Christian

    2014-01-01

    Enteroendocrine cells (EEC) produce neuropeptides, which are crucially involved in the maintenance of the intestinal barrier. Hence, EEC dysfunction is suggested to be involved in the complex pathophysiology of inflammatory bowel disease (IBD), which is characterized by decreased intestinal barrier function. However, the underlying mechanisms for EEC dysfunction are not clear and suitable models for a better understanding are lacking. Here, we demonstrate that Carboxypeptidase E (CPE) is specifically expressed in EEC of the murine colon and ileum and that its deficiency is associated with reduced intestinal levels of Neuropeptide Y (NPY) and Peptide YY (PYY), which are both produced by EEC. Moreover, cpe−/− mice exhibit an aggravated course of DSS-induced chronic colitis compared to wildtype littermates. In addition, we observed elevated mucosal IL-6 and KC transcript levels already at baseline conditions in cpe−/− mice. Moreover, supernatants obtained from isolated intestinal crypts of cpe−/− mice lead to increased IL-6 and KC expression in MODE-K cells in the presence of LPS. This effect was reversible by co-administration of recombinant NPY, suggesting a CPE mediated immunosuppressive effect in the intestines by influencing the processing of specific neuropeptides. In this context, the chemotaxis of bone marrow derived macrophages towards respective supernatants was enhanced. In conclusion, our data point to an anti-inflammatory role of CPE in the intestine by influencing local cytokine levels and thus regulating the migration of myeloid immune cells into the mucosa. These findings highlight the importance of EEC for intestinal homeostasis and propose EEC as potential therapeutic targets in IBD. PMID:25051500

  6. Carboxypeptidase E modulates intestinal immune homeostasis and protects against experimental colitis in mice.

    PubMed

    Bär, Florian; Föh, Bandik; Pagel, René; Schröder, Torsten; Schlichting, Heidi; Hirose, Misa; Lemcke, Susanne; Klinger, Antje; König, Peter; Karsten, Christian M; Büning, Jürgen; Lehnert, Hendrik; Fellermann, Klaus; Ibrahim, Saleh M; Sina, Christian

    2014-01-01

    Enteroendocrine cells (EEC) produce neuropeptides, which are crucially involved in the maintenance of the intestinal barrier. Hence, EEC dysfunction is suggested to be involved in the complex pathophysiology of inflammatory bowel disease (IBD), which is characterized by decreased intestinal barrier function. However, the underlying mechanisms for EEC dysfunction are not clear and suitable models for a better understanding are lacking. Here, we demonstrate that Carboxypeptidase E (CPE) is specifically expressed in EEC of the murine colon and ileum and that its deficiency is associated with reduced intestinal levels of Neuropeptide Y (NPY) and Peptide YY (PYY), which are both produced by EEC. Moreover, cpe-/- mice exhibit an aggravated course of DSS-induced chronic colitis compared to wildtype littermates. In addition, we observed elevated mucosal IL-6 and KC transcript levels already at baseline conditions in cpe-/- mice. Moreover, supernatants obtained from isolated intestinal crypts of cpe-/- mice lead to increased IL-6 and KC expression in MODE-K cells in the presence of LPS. This effect was reversible by co-administration of recombinant NPY, suggesting a CPE mediated immunosuppressive effect in the intestines by influencing the processing of specific neuropeptides. In this context, the chemotaxis of bone marrow derived macrophages towards respective supernatants was enhanced. In conclusion, our data point to an anti-inflammatory role of CPE in the intestine by influencing local cytokine levels and thus regulating the migration of myeloid immune cells into the mucosa. These findings highlight the importance of EEC for intestinal homeostasis and propose EEC as potential therapeutic targets in IBD. PMID:25051500

  7. Intestinal failure: Pathophysiological elements and clinical diseases

    PubMed Central

    Ding, Lian-An; Li, Jie-Shou

    2004-01-01

    There are two main functions of gastrointestinal tract, digestion and absorption, and barrier function. The latter has an important defensive effect, which keeps the body away from the invading and damaging of bacteria and endotoxin. It maintains the systemic homeostasis. Intestinal dysfunction would happen when body suffers from diseases or harmful stimulations. The lesser dysfunction of GI tract manifests only disorder of digestion and absorption, whereas the more serious intestinal disorders would harm the intestinal protective mechanism, or intestinal barrier function, and bacterial/endotoxin translocation, of intestinal failure (IF) would ensue. This review disscussed the theory of the intestinal failure, aiming at attracting recognition and valuable comments by clinicians. PMID:15052668

  8. Overexpression of heat shock protein 70 and its relationship to intestine under acute heat stress in broilers: 2. Intestinal oxidative stress.

    PubMed

    Gu, X H; Hao, Y; Wang, X L

    2012-04-01

    Oxidative stress injury is one important factor in intestinal mucosal barrier damage. Expression of heat shock protein (HSP)70 is an endogenous mechanism by which living cells adapt to stress. This study was undertaken to investigate the protective effects of HSP70 on intestinal oxidative stress. Two hundred and forty broilers were injected intraperitoneally with HSP70 inducer l-(1)-glutamine or with the inhibitor quercetin. Twenty-four hours later, they were heat stressed for 0, 2, 3, 5, and 10 h, respectively, at 36 ± 1°C. The l-(1)-glutamine significantly increased HSP70 expression (P < 0.001). At 2 h or 3 h of heat stress, the HSP70 expression obviously elevated (P < 0.001). Levels of corticosterone and the heterophil:lymphocyte ratio significantly increased when HSP70 expression was inhibited (P < 0.0001). Serum corticosterone was negatively correlated with the HSP70 expression at 3 h of heat stress (P = 0.0015; R = -0.6537). Heat shock protein 70 significantly protected the integrity of the intestinal mucosa from heat stress, with significantly decreased lactic dehydrogenase when HSP70 expression was enhanced (P < 0.001). In addition, heat-stress time significantly affected the lactic dehydrogenase release (P < 0.001). Furthermore, HSP70 significantly elevated antioxidant enzyme activities (such as superoxide dismutase, glutathione peroxidase, and total antioxidant capacity) and inhibited lipid peroxidation to relieve intestinal mucosal oxidative injury (P < 0.001). These results suggest that HSP70 is capable of protecting the intestinal mucosa from heat-stress injury by improving antioxidant capacity of broilers and inhibiting the lipid peroxidation production. PMID:22399716

  9. Absorption of thiamine and nicotinic acid in the rat intestine during fasting and immobilization stress

    NASA Technical Reports Server (NTRS)

    Kirilyuk, O. G.; Khmelevskiy, Y. V.

    1980-01-01

    By perfusion of isolated sections of intestine with a solution containing thiamine at a concentration of 3.1 micromole, it was established that thiamine absorption in animals fasted for 72 hours decreased by 28 percent, whereas absorption increased by 12 percent in rats after 24 hour immobilization. After immobilization, absorption of label in the intestinal mucosa increased. Na K ATPase activity in the intestinal mucosa decreased by 10 percent during fasting, and it increased with immobilization of the animals. Activity of Na K ATPase in the intestinal mucosa cells determined the absorption rate of thiamine and nicotinic acid at the level of vitamin transport through the plasma membranes of the enterocytes.

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

    PubMed

    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. PMID:19571236

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

    PubMed Central

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

    2009-01-01

    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. PMID:19571236

  12. Burn-induced gut barrier injury is attenuated by phosphodiesterase inhibition: effects on tight junction structural proteins.

    PubMed

    Costantini, Todd W; Loomis, William H; Putnam, James G; Drusinsky, Dana; Deree, Jessica; Choi, Sunghyuk; Wolf, Paul; Baird, Andrew; Eliceiri, Brian; Bansal, Vishal; Coimbra, Raul

    2009-04-01

    Loss of intestinal barrier function after burn injury allows movement of intraluminal contents across the mucosa, which can lead to the development of distant organ injury and multiple organ failure. Tight junction function is highly regulated by membrane-associated proteins including occludin and zonula occludens protein 1 (ZO-1), which can be modulated by systemic inflammation. We hypothesized that (1) burn injury leads to gut barrier injury, and (2) phosphodiesterase inhibition will attenuate these burn-induced changes. Male balb/c mice undergoing a 30% steam burn were randomized to resuscitation with normal saline or normal saline + pentoxifylline (PTX; 12.5 mg/kg). Intestinal injury was assessed by histological diagnosis and TNF-alpha levels using enzyme-linked immunosorbent assay. Intestinal permeability was assessed by measuring the plasma concentration of fluorescein isothiocyanate-dextran after intraluminal injection in the distal ileum. Occludin and ZO-1 levels were analyzed by immunoblotting and immunohistochemistry. Thirty percent total body surface area (TBSA) burn results in a significant increase in intestinal permeability. Treatment with PTX after burn attenuates intestinal permeability to sham levels. Burn injury resulted in a marked decrease in the levels of tight junction proteins occludin and ZO-1 at 6 and 24 h. The use of PTX after burn significantly decreases the breakdown of occludin and ZO-1. Pentoxifylline also attenuates the burn-induced increase in plasma and intestinal TNF-alpha. Confocal microscopy demonstrates that PTX attenuates the burn-induced reorganization of occludin and ZO-1 away from the tight junction. Pentoxifylline attenuates burn-induced intestinal permeability and decreases the breakdown and reorganization of intestinal occludin and ZO-1. Therefore, phosphodiesterase inhibition may be a useful adjunct strategy in the attenuation of burn-induced gut barrier injury. PMID:18791495

  13. [Protection of the mucosal barrier by nutritional strategies. What are the therapeutic options?].

    PubMed

    Lübke, H J

    2000-05-01

    The dysfunction of intestinal barrier allows the translocation of both endotoxin and whole bacterial organisms. It plays an important role in the development of multiple organ failure (MOF). The mucosa ia one component of this barrier. Trauma, atrophy and the "systemic inflammatory response syndrome" increase gastrointestinal permeability. These abnormalities may contribute to the pathophysiology of sepsis. Malnutrition per se compromises the gut's barrier function. Maintenance of gastrointestinal blood flow may be facilitated by (glutamine-enriched?) enteral diets. The most important conclusions of the majority of controlled trials support the concept of the very early enteral nutrition (within 24 hours after trauma): the outcome of seriously ill patients is improved, the rate of complications and infections is reduced. Gastrointestinal motility disorders may interfere with the initiation and tolerance of early enteral nutrition. They may be managed by prokinetic agents (cisapride, erythromycin) or by bypassing the stomach with a nasoenteric tube. PMID:10883361

  14. 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.

    PubMed

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

    2016-01-01

    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. PMID:27164134

  15. 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

    PubMed Central

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

    2016-01-01

    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. PMID:27164134

  16. The Goblet Cell Protein Clca1 (Alias mClca3 or Gob-5) Is Not Required for Intestinal Mucus Synthesis, Structure and Barrier Function in Naive or DSS-Challenged Mice

    PubMed Central

    Mundhenk, Lars; Arike, Liisa; Glauben, Rainer; Heimesaat, Markus M.; Fischer, André; Bereswill, Stefan; Birchenough, George M. H.; Gruber, Achim D.; Johansson, Malin E. V.

    2015-01-01

    The secreted, goblet cell-derived protein Clca1 (chloride channel regulator, calcium-activated-1) has been linked to diseases with mucus overproduction, including asthma and cystic fibrosis. In the intestine Clca1 is found in the mucus with an abundance and expression pattern similar to Muc2, the major structural mucus component. We hypothesized that Clca1 is required for the synthesis, structure or barrier function of intestinal mucus and therefore compared wild type and Clca1-deficient mice under naive and at various time points of DSS (dextran sodium sulfate)-challenged conditions. The mucus phenotype in Clca1-deficient compared to wild type mice was systematically characterized by assessment of the mucus protein composition using proteomics, immunofluorescence and expression analysis of selected mucin genes on mRNA level. Mucus barrier integrity was assessed in-vivo by analysis of bacterial penetration into the mucus and translocation into sentinel organs combined analysis of the fecal microbiota and ex-vivo by assessment of mucus penetrability using beads. All of these assays revealed no relevant differences between wild type and Clca1-deficient mice under steady state or DSS-challenged conditions in mouse colon. Clca1 is not required for mucus synthesis, structure and barrier function in the murine colon. PMID:26162072

  17. Actin-interacting protein 1 controls assembly and permeability of intestinal epithelial apical junctions

    PubMed Central

    Baranwal, Somesh

    2015-01-01

    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. PMID:25792565

  18. "Green" synthesized and coated nanaosilver alters the membrance permeability of barrier (intestinal, brain, endothelial) cells and stimulates oxidative stress pathways in neurons.

    EPA Science Inventory

    Nanosilver's (nanoAg) use in medical applications and consumer products is increasing. Because of this, its "green" synthesis and surface modification with beneficial coatings are desirable. Given nanoAg's potential exposure routes (e.g., dermal, intestin...

  19. Intestinal leiomyoma

    MedlinePlus

    Leiomyoma - intestine ... McLaughlin P, Maher MM. The duodenum and small intestine. In: Adam A, Dixon AK, Gillard JH, Schaefer- ... Roline CE, Reardon RF. Disorders of the small intestine. In: Marx JA, Hockberger RS, Walls RM, et ...

  20. Intestinal Cancer

    MedlinePlus

    ... 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 ...

  1. Vermilion Reconstruction with Genital Mucosa

    PubMed Central

    Weyandt, Gerhard H.; Woeckel, Achim; Kübler, Alexander C.

    2016-01-01

    Summary: Functional and aesthetical reconstruction, especially of the upper lip after ablative tumor surgery, can be very challenging. The skin of the lip might be sufficiently reconstructed by transpositional flaps from the nasolabial or facial area. Large defects of the lip mucosa, including the vestibule, are even more challenging due to the fact that flaps from the inner lining of the oral cavity often lead to functional impairments. We present a case of multiple vermilion and skin resections of the upper lip. At the last step, we had to resect even the whole vermilion mucosa, including parts of the oral mucosa of the vestibule, leaving a bare orbicularis oris muscle. To reconstruct the mucosal layer, we used a mucosal graft from the labia minora and placed it on the compromised lip and the former transpositional flaps for the reconstructed skin of the upper lip with very good functional and aesthetic results.

  2. Vermilion Reconstruction with Genital Mucosa.

    PubMed

    Müller-Richter, Urs D A; Weyandt, Gerhard H; Woeckel, Achim; Kübler, Alexander C

    2016-05-01

    Functional and aesthetical reconstruction, especially of the upper lip after ablative tumor surgery, can be very challenging. The skin of the lip might be sufficiently reconstructed by transpositional flaps from the nasolabial or facial area. Large defects of the lip mucosa, including the vestibule, are even more challenging due to the fact that flaps from the inner lining of the oral cavity often lead to functional impairments. We present a case of multiple vermilion and skin resections of the upper lip. At the last step, we had to resect even the whole vermilion mucosa, including parts of the oral mucosa of the vestibule, leaving a bare orbicularis oris muscle. To reconstruct the mucosal layer, we used a mucosal graft from the labia minora and placed it on the compromised lip and the former transpositional flaps for the reconstructed skin of the upper lip with very good functional and aesthetic results. PMID:27579226

  3. Adrenomedullin regulates intestinal physiology and pathophysiology.

    PubMed

    Martínez-Herrero, S; Martínez, A

    2016-07-01

    Adrenomedullin (AM) and proadrenomedullin N-terminal 20 peptide (PAMP) are 2 biologically active peptides produced by the same gene, ADM, with ubiquitous distribution and many physiological functions. Adrenomedullin is composed of 52 amino acids, has an internal molecular ring composed by 6 amino acids and a disulfide bond, and shares structural similarities with calcitonin gene-related peptide, amylin, and intermedin. The AM receptor consists of a 7-transmembrane domain protein called calcitonin receptor-like receptor in combination with a single transmembrane domain protein known as receptor activity-modifying protein. Using morphologic techniques, it has been shown that AM and PAMP are expressed throughout the gastrointestinal tract, being specially abundant in the neuroendocrine cells of the gastrointestinal mucosa; in the enterochromaffin-like and chief cells of the gastric fundus; and in the submucosa of the duodenum, ileum, and colon. This wide distribution in the gastrointestinal tract suggests that AM and PAMP may act as gut hormones regulating many physiological and pathologic conditions. To date, it has been proven that AM and PAMP act as autocrine/paracrine growth factors in the gastrointestinal epithelium, play key roles in the protection of gastric mucosa from various kinds of injury, and accelerate healing in diseases such as gastric ulcer and inflammatory bowel diseases. In addition, both peptides are potent inhibitors of gastric acid secretion and gastric emptying; they regulate the active transport of sugars in the intestine, regulate water and ion transport in the colon, modulate colonic bowel movements and small-intestine motility, improve endothelial barrier function, and stabilize circulatory function during gastrointestinal inflammation. Furthermore, AM and PAMP are antimicrobial peptides, and they contribute to the mucosal host defense system by regulating gut microbiota. To get a formal demonstration of the effects that endogenous AM and

  4. Megacystis-microcolon-intestinal hypoperistalsis syndrome: evidence of intestinal myopathy.

    PubMed

    Rolle, Udo; O'Briain, Sean; Pearl, Richard H; Puri, Prem

    2002-01-01

    We investigated small- and large-bowel specimens of three newborn infants presenting with the clinical and radiological symptoms of megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS). Conventional histological staining revealed marked thinning of the longitudinal muscle layer. Electron-microscopic investigations showed typical "central core" vacuolic degeneration of smooth-muscle-cells combined with proliferation of col lagen fibres. The expression of alpha-smooth-muscle actin was absent or markedly reduced in the circular and longitudinal muscle layers and muscularis mucosae compared to the normal controls. These findings suggest that the intestinal obstruction in MMIHS is due to an abnormality of the smooth-muscle cells. PMID:11793054

  5. Intestinal Epithelial Toll-Like Receptor 4 Signaling Affects Epithelial Function and Colonic Microbiota and Promotes a Risk for Transmissible Colitis

    PubMed Central

    Dheer, Rishu; Santaolalla, Rebeca; Davies, Julie M.; Lang, Jessica K.; Phillips, Matthew C.; Pastorini, Cristhine; Vazquez-Pertejo, Maria T.

    2016-01-01

    Evidence obtained from gene knockout studies supports the role of Toll-like receptor 4 (TLR4) in intestinal inflammation and microbiota recognition. Increased epithelial TLR4 expression is observed in patients with inflammatory bowel disease. However, little is known of the effect of increased TLR4 signaling on intestinal homeostasis. Here, we examined the effect of increased TLR4 signaling on epithelial function and microbiota by using transgenic villin-TLR4 mice that overexpress TLR4 in the intestinal epithelium. Our results revealed that villin-TLR4 mice are characterized by increases in the density of mucosa-associated bacteria and bacterial translocation. Furthermore, increased epithelial TLR4 signaling was associated with an impaired epithelial barrier, altered expression of antimicrobial peptide genes, and altered epithelial cell differentiation. The composition of the colonic luminal and mucosa-associated microbiota differed between villin-TLR4 and wild-type (WT) littermates. Interestingly, WT mice cohoused with villin-TLR4 mice displayed greater susceptibility to acute colitis than singly housed WT mice did. The results of this study suggest that epithelial TLR4 expression shapes the microbiota and affects the functional properties of the epithelium. The changes in the microbiota induced by increased epithelial TLR4 signaling are transmissible and exacerbate dextran sodium sulfate-induced colitis. Together, our findings imply that host innate immune signaling can modulate intestinal bacteria and ultimately the host's susceptibility to colitis. PMID:26755160

  6. Intestinal Epithelial Toll-Like Receptor 4 Signaling Affects Epithelial Function and Colonic Microbiota and Promotes a Risk for Transmissible Colitis.

    PubMed

    Dheer, Rishu; Santaolalla, Rebeca; Davies, Julie M; Lang, Jessica K; Phillips, Matthew C; Pastorini, Cristhine; Vazquez-Pertejo, Maria T; Abreu, Maria T

    2016-03-01

    Evidence obtained from gene knockout studies supports the role of Toll-like receptor 4 (TLR4) in intestinal inflammation and microbiota recognition. Increased epithelial TLR4 expression is observed in patients with inflammatory bowel disease. However, little is known of the effect of increased TLR4 signaling on intestinal homeostasis. Here, we examined the effect of increased TLR4 signaling on epithelial function and microbiota by using transgenic villin-TLR4 mice that overexpress TLR4 in the intestinal epithelium. Our results revealed that villin-TLR4 mice are characterized by increases in the density of mucosa-associated bacteria and bacterial translocation. Furthermore, increased epithelial TLR4 signaling was associated with an impaired epithelial barrier, altered expression of antimicrobial peptide genes, and altered epithelial cell differentiation. The composition of the colonic luminal and mucosa-associated microbiota differed between villin-TLR4 and wild-type (WT) littermates. Interestingly, WT mice cohoused with villin-TLR4 mice displayed greater susceptibility to acute colitis than singly housed WT mice did. The results of this study suggest that epithelial TLR4 expression shapes the microbiota and affects the functional properties of the epithelium. The changes in the microbiota induced by increased epithelial TLR4 signaling are transmissible and exacerbate dextran sodium sulfate-induced colitis. Together, our findings imply that host innate immune signaling can modulate intestinal bacteria and ultimately the host's susceptibility to colitis. PMID:26755160

  7. Claudins in intestines

    PubMed Central

    Lu, Zhe; Ding, Lei; Lu, Qun; Chen, Yan-Hua

    2013-01-01

    Intestines are organs that not only digest food and absorb nutrients, but also provide a defense barrier against pathogens and noxious agents ingested. Tight junctions (TJs) are the most apical component of the junctional complex, providing one form of cell-cell adhesion in enterocytes and playing a critical role in regulating paracellular barrier permeability. Alteration of TJs leads to a number of pathophysiological diseases causing malabsorption of nutrition and intestinal structure disruption, which may even contribute to systemic organ failure. Claudins are the major structural and functional components of TJs with at least 24 members in mammals. Claudins have distinct charge-selectivity, either by tightening the paracellular pathway or functioning as paracellular channels, regulating ions and small molecules passing through the paracellular pathway. In this review, we have discussed the functions of claudin family members, their distribution and localization in the intestinal tract of mammals, their alterations in intestine-related diseases and chemicals/agents that regulate the expression and localization of claudins as well as the intestinal permeability, which provide a therapeutic view for treating intestinal diseases. PMID:24478939

  8. The common prophylactic therapy for bowel surgery is ineffective for clearing Bacteroidetes, the primary inducers of systemic inflammation, and causes faster death in response to intestinal barrier damage in mice

    PubMed Central

    Sinsimer, Daniel; Esseghir, Amira; Tang, May; Laouar, Amale

    2014-01-01

    Introduction and objective The role of secreted gut microbial components in the initiation of systemic inflammation and consequences of antibiotic therapies on this inflammatory process are poorly elucidated. We investigate whether peripheral innate cells mount an inflammatory response to gut microbial components, the immune cells that are the primary drivers of systemic inflammation, the bacterial populations that are predominantly responsible, and whether perioperative antibiotics affect these processes. Method and experimental design Conditioned supernatants from gut microbes were used to stimulate murine innate cell types in vitro and in vivo, and proinflammatory responses were characterised. Effects of antibiotic therapies on these responses were investigated using a model of experimental intestinal barrier damage induced by dextran sodium sulfate. Results Proinflammatory responses in the periphery are generated by components of anaerobes from the Bacteroidetes phylotype and these responses are primarily produced by myeloid dendritic cells. We found that the common prophylactic therapy for sepsis (oral neomycin and metronidazole administered to patients the day prior to surgery) is ineffective for clearing Bacteroidetes from the murine intestine. A point of critical consequence of this result is the increased systemic inflammation and premature death observed in treated mice, and these outcomes appear to be independent of gut bacterial spread in the initial phase of intestinal barrier damage. Importantly, spillage of gut microbial products, rather than dissemination of gut microbes, may underlay the initiation of systemic inflammation leading to death. Conclusions Our data further affirm the importance of a balanced gut microflora biodiversity in host immune homeostasis and reinforce the notion that inadequate antibiotic therapy can have detrimental effects on overall immune system. PMID:26462264

  9. Denatured globular protein and bile salt-coated nanoparticles for poorly water-soluble drugs: Penetration across the intestinal epithelial barrier into the circulation system and enhanced oral bioavailability.

    PubMed

    He, Wei; Yang, Ke; Fan, Lifang; Lv, Yaqi; Jin, Zhu; Zhu, Shumin; Qin, Chao; Wang, Yiao; Yin, Lifang

    2015-11-10

    Oral drug delivery is the most preferred route for patients; however, the low solubility of drugs and the resultant poor absorption compromise the benefits of oral administration. On the other hand, for years, the overwhelmingly accepted mechanism for enhanced oral absorption using lipid nanocarriers was based on the process of lipid digestion and drug solubilization in the small intestine. Few reports indicated that other bypass pathways are involved in drug absorption in the gastrointestinal tract (GIT) for oral delivery of nanocarriers. Herein, we report a new nanoemulsion system with a denatured globular protein with a diameter of 30 nm, soybean protein isolates (SPI), and bile salt as emulsifiers, aiming to enhance the absorption of insoluble drugs and explore other pathways for absorption. A BCS class II drug, fenofibrate (FB), was used as the model drug. The SPI and bile salt-coated Ns with a diameter of approximately 150 nm were prepared via a high-pressure homogenizing procedure. Interestingly, the present Ns could be converted to solid dosage form using fluid-bed coating technology, maintaining a nanoscale size. Most importantly, in a model of in situ rat intestinal perfusion, Ns could penetrate across the intestinal epithelial barrier into the systemic circulation and then obtain biodistribution into other tissues. In addition, Ns significantly improved FB oral absorption, exhibited as a greater than 2- and 2.5-fold increase in Cmax and AUC0-t, respectively, compared to the suspension formulation. Overall, the present Ns are promising nanocarriers for the oral delivery of insoluble drugs, and the penetration of intact Ns across the GIT barrier into systemic circulation may be a new strategy for improved drug absorption with the use of nanocarriers. PMID:26325310

  10. Autoimmune enteropathy: not all flat mucosa mean coeliac disease

    PubMed Central

    Volta, Umberto; Mumolo, Maria Gloria; Caio, Giacomo; Boschetti, Elisa; Latorre, Rocco; Giancola, Fiorella; Paterini, Paola; Giorgio, Roberto De

    2016-01-01

    A 62-year-old woman complaining of severe malabsorption was diagnosed with celiac disease based on the findings of flat, small intestinal mucosa and HLA-DQ2 positivity, although celiac serology was negative. This diagnosis was questioned due to the lack of clinical and histological improvement after a long period of strict gluten-free diet. The detection of enterocyte autoantibodies guided to the correct diagnosis of autoimmune enteropathy, leading to a complete recovery of the patient following an appropriate immunosuppressive treatment. Autoimmune enteropathy should be considered in the differential diagnosis of malabsorption with severe villous atrophy, including those cases with negative celiac-related serology. PMID:27099674

  11. Morpho-elasticity of intestinal villi

    PubMed Central

    Balbi, V.; Ciarletta, P.

    2013-01-01

    Villi are ubiquitous structures in the intestine of all vertebrates, originating from the embryonic development of the epithelial mucosa. Their morphogenesis has similar stages in living organisms but different forming mechanisms. In this work, we model the emergence of the bi-dimensional undulated patterns in the intestinal mucosa from which villi start to elongate. The embryonic mucosa is modelled as a growing thick-walled cylinder, and its mechanical behaviour is described using an hyperelastic constitutive model, which also accounts for the anisotropic characteristics of the reinforcing fibres at the microstructural level. The occurrence of surface undulations is investigated using a linear stability analysis based on the theory of incremental deformations superimposed on a finite deformation. The Stroh formulation of the incremental boundary value problem is derived, and a numerical solution procedure is implemented for calculating the growth thresholds of instability. The numerical results are finally discussed with respect to different growth and materials properties. In conclusion, we demonstrate that the emergence of intestinal villi in embryos is triggered by a differential growth between the mucosa and the mesenchymal tissues. The proposed model quantifies how both the geometrical and the mechanical properties of the mucosa drive the formation of previllous structures in embryos. PMID:23486174

  12. Plasticity of the brush border - the yin and yang of intestinal homeostasis.

    PubMed

    Delacour, Delphine; Salomon, Julie; Robine, Sylvie; Louvard, Daniel

    2016-03-01

    The brush border on the apical surface of enterocytes is a highly specialized structure well-adapted for efficient digestion and nutrient transport, whilst at the same time providing a protective barrier for the intestinal mucosa. The brush border is constituted of a densely ordered array of microvilli, protrusions of the plasma membrane, which are supported by actin-based microfilaments and interacting proteins and anchored in an apical network of actomyosin and intermediate filaments, the so-called terminal web. The highly dynamic, specialized apical domain is both an essential partner for the gut microbiota and an efficient signalling platform that enables adaptation to physiological stimuli from the external and internal milieu. Nevertheless, genetic alterations or various pathological stresses, such as infection, inflammation, and mechanical or nutritional alterations, can jeopardize this equilibrium and compromise intestinal functions. Long-time neglected, the intestinal brush-border shall be enlightening again as the central actor of the complex but essential intestinal homeostasis. Here, we review the processes and components involved in brush border organization and discuss pathological mechanisms that can induce brush border defects and their physiological consequences. PMID:26837713

  13. Immune responses towards intestinal bacteria--current concepts and future perspectives.

    PubMed

    Duchmann, R; Neurath, M; Märker-Hermann, E; Meyer Zum Büschenfelde, K H

    1997-05-01

    The intestinal mucosa constitutes an important barrier as it separates each individual from a large array of antigens within the bowel lumen. These luminal antigens may either be derived from pathogens or may be derived from harmless constituents such as ingested food or the normal intestinal flora. The dichotomy of potentially harmful and potentially harmless antigens encountered by the mucosal immune system poses the important task that, with regard to bacteria-derived antigens, the gut associated immune system is required to mount an efficient host defense against pathogenic bacteria but to maintain at the same time the regulatory control mechanisms which protect the human organism from hyperresponsiveness, and thus chronic inflammation, towards antigens from the normal intestinal flora. In the present review, we discuss variable host and bacterial factors which are likely to determine whether the immune response to pathogenic or normal intestinal bacteria will have beneficial or detrimental consequences for the human organism. Using infections with the prototype enteropathogens V. cholerae and enteropathogenic E. coli (ETEC), Y. enterocolitica induced reactive arthritis (ReA) and in more detail, inflammatory bowel diseases (IBD) as exemplary clinical situations, we review current hypotheses of how bacteria or their products are encountered by cellular components of the specific immune system and how this may relate to disease pathogenesis and the development of new treatment strategies. PMID:9188147