Stress disrupts intestinal mucus barrier in rats via mucin O-glycosylation shift: prevention by a probiotic treatment

2014 ◽  
Vol 307 (4) ◽  
pp. G420-G429 ◽  
Author(s):  
Stéphanie Da Silva ◽  
Catherine Robbe-Masselot ◽  
Afifa Ait-Belgnaoui ◽  
Alessandro Mancuso ◽  
Myriam Mercade-Loubière ◽  
...  
Keyword(s):  
Physical Properties ◽  
Goblet Cells ◽  
Visceral Hypersensitivity ◽  
Ex Situ ◽  
Mucus Layer ◽  
Visceral Sensitivity ◽  
Intestinal Mucus ◽  
Mucin Expression ◽  
Muc2 Expression ◽  
Mucus Barrier

Despite well-known intestinal epithelial barrier impairment and visceral hypersensitivity in irritable bowel syndrome (IBS) patients and IBS-like models, structural and physical changes in the mucus layer remain poorly understood. Using a water avoidance stress (WAS) model, we aimed at evaluating whether 1) WAS modified gut permeability, visceral sensitivity, mucin expression, biochemical structure of O-glycans, and related mucus physical properties, and 2) whether Lactobacillus farciminis treatment prevented these alterations. Wistar rats received orally L. farciminis or vehicle for 14 days; at day 10, they were submitted to either sham or 4-day WAS. Intestinal paracellular permeability and visceral sensitivity were measured in vivo. The number of goblet cells and Muc2 expression were evaluated by histology and immunohistochemistry, respectively. Mucosal adhesion of L. farciminis was determined ex situ. The mucin O-glycosylation profile was obtained by mass spectrometry. Surface imaging of intestinal mucus was performed at nanoscale by atomic force microscopy. WAS induced gut hyperpermeability and visceral hypersensitivity but did not modify either the number of intestinal goblet cells or Muc2 expression. In contrast, O-glycosylation of mucins was strongly affected, with the appearance of elongated polylactosaminic chain containing O-glycan structures, associated with flattening and loss of the mucus layer cohesive properties. L. farciminis bound to intestinal Muc2 and prevented WAS-induced functional alterations and changes in mucin O-glycosylation and mucus physical properties. WAS-induced functional changes were associated with mucus alterations resulting from a shift in O-glycosylation rather than from changes in mucin expression. L. farciminis treatment prevented these alterations, conferring epithelial and mucus barrier strengthening.

scholarly journals The Difference in the Mucus Organization Between the Small and Large Intestine and Its Protection of Selected Natural Substances. A Review

2018 ◽  
Vol 62 (4) ◽  
pp. 48-55
Author(s):  
R. Szabóová ◽  
Z. Faixová ◽  
Z. Maková ◽  
E. Piešová
Keyword(s):  
Goblet Cells ◽  
Mucus Layer ◽  
Mucus Production ◽  
Natural Substances ◽  
Intestinal Mucus ◽  
The Difference ◽  
Mucus Barrier ◽  
Microbial Toxins ◽  
Natural Additives

Abstract The mucus layer of the intestinal tract plays an important role of forming the front line of innate host defense. Recent studies have suggested that the involvement of feeding natural additives on protection/prevention/promotion of mucus production in the intestinal environment is beneficial. The goblet cells continually produce mucins for the retention of the mucus barrier under physiological conditions, but different factors (e. g. microorganisms, microbial toxins, viruses, cytokines, and enzymes) can have profound effects on the integrity of the intestinal epithelium covered by a protective mucus. The intestinal mucus forms enterocytes covered by transmembrane mucins and goblet cells produce by the secreted gel-forming mucins (MUC2). The mucus is organized in a single unattached mucus layer in the small intestine and in two mucus layers (inner, outer) in the colon. The main part of the review evaluates the effects of natural additives/substances supplementation to stimulate increased expression of MUC2 mucin in the intestine of animals.

scholarly journals Mucins Dynamics in Physiological and Pathological Conditions

2021 ◽  
Vol 22 (24) ◽  
pp. 13642
Author(s):  
Hassan Melhem ◽  
Daniel Regan-Komito ◽  
Jan Hendrik Niess
Keyword(s):  
Inflammatory Bowel Disease ◽  
Epithelial Cells ◽  
Molecular Mechanisms ◽  
Expression Profiles ◽  
Goblet Cells ◽  
Mucus Layer ◽  
Intestinal Mucus ◽  
Pathological Conditions ◽  
Inflammatory Bowel ◽  
Mucus Barrier

Maintaining intestinal health requires clear segregation between epithelial cells and luminal microbes. The intestinal mucus layer, produced by goblet cells (GCs), is a key element in maintaining the functional protection of the epithelium. The importance of the gut mucus barrier is highlighted in mice lacking Muc2, the major form of secreted mucins. These mice show closer bacterial residence to epithelial cells, develop spontaneous colitis and became moribund when infected with the attaching and effacing pathogen, Citrobacter rodentium. Furthermore, numerous observations have associated GCs and mucus layer dysfunction to the pathogenesis of inflammatory bowel disease (IBD). However, the molecular mechanisms that regulate the physiology of GCs and the mucus layer remain obscured. In this review, we consider novel findings describing divergent functionality and expression profiles of GCs subtypes within intestinal crypts. We also discuss internal (host) and external (diets and bacteria) factors that modulate different aspects of the mucus layer as well as the contribution of an altered mucus barrier to the onset of IBD.

scholarly journals γδ T-cell-deficient mice show alterations in mucin expression, glycosylation, and goblet cells but maintain an intact mucus layer

2014 ◽  
Vol 306 (7) ◽  
pp. G582-G593 ◽  
Author(s):  
Olivia I. Kober ◽  
David Ahl ◽  
Carmen Pin ◽  
Lena Holm ◽  
Simon R. Carding ◽  
...  
Keyword(s):  
T Cells ◽  
Small Intestine ◽  
T Cell ◽  
Γδ T Cells ◽  
Goblet Cells ◽  
Mucus Layer ◽  
Γδ T Cell ◽  
Intestinal Mucus ◽  
Mucin Expression ◽  
Mucosal Homeostasis

Intestinal homeostasis is maintained by a hierarchy of immune defenses acting in concert to minimize contact between luminal microorganisms and the intestinal epithelial cell surface. The intestinal mucus layer, covering the gastrointestinal tract epithelial cells, contributes to mucosal homeostasis by limiting bacterial invasion. In this study, we used γδ T-cell-deficient (TCRδ−/−) mice to examine whether and how γδ T-cells modulate the properties of the intestinal mucus layer. Increased susceptibility of TCRδ−/− mice to dextran sodium sulfate (DSS)-induced colitis is associated with a reduced number of goblet cells. Alterations in the number of goblet cells and crypt lengths were observed in the small intestine and colon of TCRδ−/− mice compared with C57BL/6 wild-type (WT) mice. Addition of keratinocyte growth factor to small intestinal organoid cultures from TCRδ−/− mice showed a marked increase in crypt growth and in both goblet cell number and redistribution along the crypts. There was no apparent difference in the thickness or organization of the mucus layer between TCRδ−/− and WT mice, as measured in vivo. However, γδ T-cell deficiency led to reduced sialylated mucins in association with increased gene expression of gel-secreting Muc2 and membrane-bound mucins, including Muc13 and Muc17. Collectively, these data provide evidence that γδ T cells play an important role in the maintenance of mucosal homeostasis by regulating mucin expression and promoting goblet cell function in the small intestine.

scholarly journals Bifidobacterium dentiumFortifies the Intestinal Mucus Layer via Autophagy and Calcium Signaling Pathways

mBio ◽  
2019 ◽  
Vol 10 (3) ◽  
Author(s):  
Melinda A. Engevik ◽  
Berkley Luk ◽  
Alexandra L. Chang-Graham ◽  
Anne Hall ◽  
Beatrice Herrmann ◽  
...  
Keyword(s):  
Calcium Signaling ◽  
Signaling Pathways ◽  
Goblet Cell ◽  
Cell Function ◽  
Goblet Cells ◽  
Mucus Layer ◽  
Content Type ◽  
Intestinal Mucus ◽  
Intestinal Mucus Layer

ABSTRACTMuch remains unknown about how the intestinal microbiome interfaces with the protective intestinal mucus layer.Bifidobacteriumspecies colonize the intestinal mucus layer and can modulate mucus production by goblet cells. However, selectBifidobacteriumstrains can also degrade protective glycans on mucin proteins. We hypothesized that the human-derived speciesBifidobacterium dentiumwould increase intestinal mucus synthesis and expulsion, without extensive degradation of mucin glycans.In silicodata revealed thatB. dentiumlacked the enzymes necessary to extensively degrade mucin glycans. This finding was confirmed by demonstrating thatB. dentiumcould not use naive mucin glycans as primary carbon sourcesin vitro. To examineB. dentiummucus modulationin vivo, Swiss Webster germfree mice were monoassociated with live or heat-killedB. dentium. LiveB. dentium-monoassociated mice exhibited increased colonic expression of goblet cell markersKrüppel-like factor 4(Klf4),Trefoil factor 3(Tff3),Relm-β,Muc2, and several glycosyltransferases compared to both heat-killedB. dentiumand germfree counterparts. Likewise, liveB. dentium-monoassociated colon had increased acidic mucin-filled goblet cells, as denoted by Periodic Acid-Schiff-Alcian Blue (PAS-AB) staining and MUC2 immunostaining.In vitro,B. dentium-secreted products, including acetate, were able to increase MUC2 levels in T84 cells. We also identified thatB. dentium-secreted products, such as γ-aminobutyric acid (GABA), stimulated autophagy-mediated calcium signaling and MUC2 release. This work illustrates thatB. dentiumis capable of enhancing the intestinal mucus layer and goblet cell function via upregulation of gene expression and autophagy signaling pathways, with a net increase in mucin production.IMPORTANCEMicrobe-host interactions in the intestine occur along the mucus-covered epithelium. In the gastrointestinal tract, mucus is composed of glycan-covered proteins, or mucins, which are secreted by goblet cells to form a protective gel-like structure above the epithelium. Low levels of mucin or alterations in mucin glycans are associated with inflammation and colitis in mice and humans. Although current literature links microbes to the modulation of goblet cells and mucins, the molecular pathways involved are not yet fully understood. Using a combination of gnotobiotic mice and mucus-secreting cell lines, we have identified a human-derived microbe,Bifidobacterium dentium, which adheres to intestinal mucus and secretes metabolites that upregulate the major mucin MUC2 and modulate goblet cell function. Unlike otherBifidobacteriumspecies,B. dentiumdoes not extensively degrade mucin glycans and cannot grow on mucin alone. This work points to the potential of usingB. dentiumand similar mucin-friendly microbes as therapeutic agents for intestinal disorders with disruptions in the mucus barrier.

scholarly journals Effects of different dietary manganese sources on thickness of mucus layer and selected biochemical and haematological indicators in sheep

2018 ◽  
Vol 87 (4) ◽  
pp. 351-356
Author(s):  
Zuzana Maková ◽  
Zita Faixová ◽  
Lucia Tarabová ◽  
Elena Piešová ◽  
Katarína Venglovská ◽  
...  
Keyword(s):  
Basal Diet ◽  
Mucus Layer ◽  
Total Proteins ◽  
Mucus Production ◽  
Intestinal Mucus ◽  
Intestinal Segments ◽  
Group 3 ◽  
Mucus Barrier ◽  
Group 2 ◽  
Group 1

The effects of manganese from organic and inorganic sources supplemented to diets of sheep on intestinal mucus production and on selected biochemical and haematological indicators were investigated. The experiment was carried out on 18 sheep of the Improved Valachian breed aged seven months over the period of four months. The animals were divided into three groups of six animals each (group 1 – control, basal diet with 31 mg Mn/kg, group 2 – basal diet + manganese sulphate (MnSO4) with 120 mg Mn/kg, group 3 – basal diet + manganese chelate of glycine hydrate (Mn-Gly) with 120 mg Mn/kg). Intestinal segments (duodenum, jejunum, ileum, caecum) were collected and mucus production was assessed using the quantification method. Mucus production in the duodenum and jejunum was significantly lower (P < 0.05) in group 3 (Mn-Gly) compared to the control and group 2 (MnSO4). In the duodenum in group 2 (MnSO4) mucus production was similar to the control. Biochemical indicators were determined using spectrophotometry, and haematological indicators were measured using a haematology analyzer. Significant changes (P < 0.05) were found for the concentrations of total proteins and albumins. The concentration of total proteins was lower in group 3 (Mn-Gly) compared to the control and group 2 (MnSO4). In the latter group it was higher compared to the control. The concentration of albumins was higher in group 3 (Mn-Gly) compared to the control and group 2 (P < 0.05). The results indicate a decrease of intestinal mucus in the group supplemented by Mn-Gly chelate, which may mean a lower mucus barrier for manganese absorption.

P071 MODULATION OF THE MUCUS LAYER BY BIFIDOBACTERIUM DENTIUM PROVIDES PROTECTION IN A MODEL OF COLITIS

2020 ◽  
Vol 26 (Supplement_1) ◽  
pp. S38-S38
Author(s):  
Melinda Engevik ◽  
Wenly Ruan ◽  
Faith Ihekweazu ◽  
James Versalovic
Keyword(s):  
Goblet Cell ◽  
Molecular Mechanisms ◽  
Goblet Cells ◽  
Mucus Layer ◽  
Mucin Production ◽  
Germ Free ◽  
Positive Effects ◽  
Intestinal Mucus ◽  
Intestinal Mucus Layer

Abstract Background The intestinal mucus layer serves as a critical interface between the environment and the host. Patients with inflammatory bowel disease (IBD), particularly ulcerative colitis, exhibit reduced synthesis and secretion of the mucus protein MUC2 and decreased mucus thickness. This in turn promotes immune activation and inflammation. The clinical relevance of the mucus layer emphasizes the need to address strategies to modulate this barrier. Although bifidobacteria represent only 3–6% of the healthy adult fecal microbiota, their presence has been associated with numerous health benefits, including bolstering mucus production. However, the molecular mechanisms that underlie these positive effects appear to be strain-specific and are not well defined. We hypothesized that the human-derived Bifidobacterium dentium would increase intestinal mucus synthesis and expulsion via specific metabolites. We also speculated that modulation of goblet cells would be beneficial during colitis. Methods & Results In silico genome analysis revealed that B. dentium lacked the enzymatic repertoire required for degradation of mucin glycans. Consistent with these findings, we found that B. dentium could not use mucin glycans as a primary carbon source in vitro. To examine mucus modulation in vivo, germ-free mice were mono-associated with live or heat-killed B. dentium. Live B. dentium mono-associated mice exhibited increased colonic expression of goblet cell markers Krüppel-Like Factor 4 (Klf4), Relmβ, trefoil factor 3 (Tff3), Muc2, and several mucin glycosyltransferases compared to both heat-killed B. dentium and germ-free counterparts. Likewise, live B. dentium mono-associated colon had increased acidic mucin-filled goblet cells as denoted by MUC2 and PAS-AB staining. In vitro, B. dentium secreted products, including acetate, were able to increase MUC2 levels in T84 cells, mouse colonoids and human colonoids. We also identified that B. dentium secreted products, such as GABA, stimulated autophagy-mediated calcium signaling and MUC2 release. To identify whether B. dentium could enhance MUC2 production in mice harboring a complete microbiota, specific pathogen free mice were treated with live B. dentium by oral gavage. Administration of B. dentium increased the inner mucus layer compared to controls. Moreover, in a TNBS model of colitis, B. dentium treated mice had increased goblet cell numbers and MUC2 mRNA. Mirroring these findings, B. dentium treated mice lost less weight, had improved histology and had decreased levels of TNF, KC (IL-8), and IL-6. Conclusions This work illustrates that B. dentium enhances the intestinal mucus layer and goblet cell function via upregulation of gene expression and autophagy signaling pathways with a net increase in mucin production. Ultimately, these pathways may be targeted for the development of novel therapeutics.

scholarly journals Pic, an Autotransporter Protein Secreted by Different Pathogens in the Enterobacteriaceae Family, Is a Potent Mucus Secretagogue

2010 ◽  
Vol 78 (10) ◽  
pp. 4101-4109 ◽  
Author(s):  
Fernando Navarro-Garcia ◽  
Javier Gutierrez-Jimenez ◽  
Carlos Garcia-Tovar ◽  
Luis A. Castro ◽  
Hector Salazar-Gonzalez ◽  
...  
Keyword(s):  
Serine Protease ◽  
Shigella Flexneri ◽  
Goblet Cells ◽  
Site Directed Mutagenesis ◽  
Catalytic Residue ◽  
Mucus Layer ◽  
Mucus Hypersecretion ◽  
E Coli ◽  
Intestinal Mucus

ABSTRACT A hallmark of enteroaggregative Escherichia coli (EAEC) infection is a formation of biofilm, which comprises a mucus layer with immersed bacteria in the intestines of patients. While studying the mucinolytic activity of Pic in an in vivo system, rat ileal loops, we surprisingly found that EAEC induced hypersecretion of mucus, which was accompanied by an increase in the number of mucus-containing goblet cells. Interestingly, an isogenic pic mutant (EAEC Δpic) was unable to cause this mucus hypersecretion. Furthermore, purified Pic was also able to induce intestinal mucus hypersecretion, and this effect was abolished when Pic was heat denatured. Site-directed mutagenesis of the serine protease catalytic residue of Pic showed that, unlike the mucinolytic activity, secretagogue activity did not depend on this catalytic serine protease motif. Other pathogens harboring the pic gene, such as Shigella flexneri and uropathogenic E. coli (UPEC), also showed results similar to those for EAEC, and construction of isogenic pic mutants of S. flexneri and UPEC confirmed this secretagogue activity. Thus, Pic mucinase is responsible for one of the pathophysiologic features of the diarrhea mediated by EAEC and the mucoid diarrhea induced by S. flexneri.

scholarly journals Development and Functional Properties of Intestinal Mucus Layer in Poultry

2021 ◽  
Vol 12 ◽  
Author(s):  
Yada Duangnumsawang ◽  
Jürgen Zentek ◽  
Farshad Goodarzi Boroojeni
Keyword(s):  
Functional Properties ◽  
Antibacterial Properties ◽  
Goblet Cells ◽  
Dietary Factors ◽  
Poultry Feed ◽  
Protective Mechanism ◽  
Mucus Layer ◽  
Innate Defense ◽  
Intestinal Mucus ◽  
The Impact

Intestinal mucus plays important roles in protecting the epithelial surfaces against pathogens, supporting the colonization with commensal bacteria, maintaining an appropriate environment for digestion, as well as facilitating nutrient transport from the lumen to the underlying epithelium. The mucus layer in the poultry gut is produced and preserved by mucin-secreting goblet cells that rapidly develop and mature after hatch as a response to external stimuli including environmental factors, intestinal microbiota as well as dietary factors. The ontogenetic development of goblet cells affects the mucin composition and secretion, causing an alteration in the physicochemical properties of the mucus layer. The intestinal mucus prevents the invasion of pathogens to the epithelium by its antibacterial properties (e.g. β-defensin, lysozyme, avidin and IgA) and creates a physical barrier with the ability to protect the epithelium from pathogens. Mucosal barrier is the first line of innate defense in the gastrointestinal tract. This barrier has a selective permeability that allows small particles and nutrients passing through. The structural components and functional properties of mucins have been reviewed extensively in humans and rodents, but it seems to be neglected in poultry. This review discusses the impact of age on development of goblet cells and their mucus production with relevance for the functional characteristics of mucus layer and its protective mechanism in the chicken’s intestine. Dietary factors directly and indirectly (through modification of the gut bacteria and their metabolic activities) affect goblet cell proliferation and differentiation and can be used to manipulate mucosal integrity and dynamic. However, the mode of action and mechanisms behind these effects need to be studied further. As mucins resist to digestion processes, the sloughed mucins can be utilized by bacteria in the lower part of the gut and are considered as endogenous loss of protein and energy to animal. Hydrothermal processing of poultry feed may reduce this loss by reduction in mucus shedding into the lumen. Given the significance of this loss and the lack of precise data, this matter needs to be carefully investigated in the future and the nutritional strategies reducing this loss have to be defined better.

scholarly journals Zinc Deficiency Disturbs Mucin Expression, O-Glycosylation and Secretion by Intestinal Goblet Cells

2020 ◽  
Vol 21 (17) ◽  
pp. 6149 ◽  
Author(s):  
Maria Maares ◽  
Claudia Keil ◽  
Sophia Straubing ◽  
Catherine Robbe-Masselot ◽  
Hajo Haase
Keyword(s):  
Zinc Deficiency ◽  
Molecular Mechanisms ◽  
Cell Model ◽  
Well Being ◽  
Goblet Cells ◽  
Zinc Homeostasis ◽  
Intestinal Mucus ◽  
Mucin Expression ◽  
The Impact

Approximately 1 billion people worldwide suffer from zinc deficiency, with severe consequences for their well-being, such as critically impaired intestinal health. In addition to an extreme degeneration of the intestinal epithelium, the intestinal mucus is seriously disturbed in zinc-deficient (ZD) animals. The underlying cellular processes as well as the relevance of zinc for the mucin-producing goblet cells, however, remain unknown. To this end, this study examines the impact of zinc deficiency on the synthesis, production, and secretion of intestinal mucins as well as on the zinc homeostasis of goblet cells using the in vitro goblet cell model HT-29-MTX. Zinc deprivation reduced their cellular zinc content, changed expression of the intestinal zinc transporters ZIP-4, ZIP-5, and ZnT1 and increased their zinc absorption ability, outlining the regulatory mechanisms of zinc homeostasis in goblet cells. Synthesis and secretion of mucins were severely disturbed during zinc deficiency, affecting both MUC2 and MUC5AC mRNA expression with ongoing cell differentiation. A lack of zinc perturbed mucin synthesis predominantly on the post-translational level, as ZD cells produced shorter O-glycans and the main O-glycan pattern was shifted in favor of core-3-based mucins. The expression of glycosyltransferases that determine the formation of core 1-4 O-glycans was altered in zinc deficiency. In particular, B3GNT6 mRNA catalyzing core 3 formation was elevated and C2GNT1 and C2GNT3 elongating core 1 were downregulated in ZD cells. These novel insights into the molecular mechanisms impairing intestinal mucus stability during zinc deficiency demonstrate the essentiality of zinc for the formation and maintenance of this physical barrier.

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