scholarly journals A Role of Exopolysaccharide Produced by Streptococcus thermophilus in the Intestinal Inflammation and Mucosal Barrier in Caco-2 Monolayer and Dextran Sulphate Sodium-Induced Experimental Murine Colitis

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 513 ◽  
Author(s):  
Yun Chen ◽  
Ming Zhang ◽  
Fazheng Ren

Exopolysaccharide (EPS) produced by probiotics may play an important role in gastrointestinal disease prevention, including ulcerative colitis. However, there is no literature reporting on the intervention effects of purified EPS. The aim of this study was to investigate the alleviating effect of the purified EPS produced by Streptococcus thermophilus MN-BM-A01 on murine model of colitis induced by dextran sulphate sodium (DSS). A water-soluble heteropolysaccharide (EPS-1) isolated from MN-BM-A01 was composed of rhamnose, glucose, galactose, and mannose in a molar ratio of 12.9:26.0:60.9:0.25, with molecular weight of 4.23 × 105 Da. After EPS-1 administration, the disease severity of mouse colitis was significantly alleviated, mainly manifesting as the decrease of disease activity index and mitigated colonic epithelial cell injury. Meanwhile, pro-inflammatory cytokines levels (tumor necrosis factor-α, interleukin-6, and interferon-γ) were significantly suppressed, the reduced expressions of tight junction protein (claudin-1, occludin, and E-canherin) were counteracted. In addition, the results in vitro showed that EPS-1 protected intestinal barrier integrity from the disruption by lipopolysaccharide in Caco-2 monolayer, increased expression of tight junction and alleviated pro-inflammatory response. Collectively, our study confirmed the protective effects of purified EPS produced by Streptococcus thermophilus on acute colitis via alleviating intestinal inflammation and improving mucosal barrier function.

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yingdi Zhang ◽  
Xiaojing Zhao ◽  
Yunjuan Zhu ◽  
Jingjing Ma ◽  
Haiqin Ma ◽  
...  

Bifico is a probiotic mixture containing Bifidobacterium, Lactobacillus acidophilus, and Enterococcus. Studies support that Bifico has a protective effect in experimental colitis (IL-10-deficient and TNBS) models and in patients with inflammatory bowel disease (IBD). However, the mechanism underlying the protective effects of this mixture of probiotic bacteria remains incompletely clear. Here, we investigated the effect of Bifico on intestinal inflammation. In an in vivo experiment, dextran sulfate sodium was used to induce colitis. Bifico treatment significantly attenuated the severity of colitis in this model. Bifico increased the expression of tight junction proteins (TJs). In addition, Bifico increased the number of Tregs, but reduced the number of total CD4+ T cells in the peripheral blood. Furthermore, the expression of colonic CD4 protein was decreased while the level of forkhead box P3 (Foxp3) was upregulated. These results suggested that Bifico exerts beneficial effects on experimental colitis by increasing the expressions of TJs, upregulating the number of Tregs, and reducing the total CD4+ T cell number in both colon and peripheral blood. The intestinal damage in the pretreated + treated-Bifico-colitis group was more severe than that in only the pretreated-Bifico-colitis group. This suggested that Bifico might aggravate intestinal damage when the mucosal barrier is impaired.


2019 ◽  
Vol 123 (3) ◽  
pp. 319-327 ◽  
Author(s):  
Chih-Hsuan Changchien ◽  
Yi-Chun Han ◽  
Hsiao-Ling Chen

AbstractBoth konjac glucomannan (KGM) and inulin oligosaccharide have been shown to improve bowel function, but their effects on the mucosal barrier function and immunity are not fully understood. The aim of the present study was to determine the effects of a low-level supplementation of dietary fibres on the colonic mucosal barrier function, antioxidant enzyme defence and immunity. C57BL/6J mice (6 weeks of age, eight per group) were randomly assigned to consume one of the following diets: control or control diet supplemented with 2 % (w/w) of KGM, inulin oligosaccharide (degree polymerisation = 8) or KGM+inulin (1 %, w/w each (K+I)). Fresh faeces were collected on days 19–21. Mice were killed on day 22 after fasting. Segments of colon tissues were processed for histological procedure and stained for acidic mucins and tight junction protein marker zona occludin-1 (ZO-1). The remaining tissues were processed to determine the gene expression of mucin 2, tight junction proteins, antioxidant enzymes and cytokines. The plasma cytokines were measured. Results indicated that KGM, inulin and K+I significantly increased the mucosal layer thickness, mucin density (granule number/crypt) and gene expression of Muc2 as compared with the control. All fibre treatments increased the gene expressions of ZO-1, occludin, glutathione peroxidase, glutathione S-transferase π, catalase and IL-10. In addition, all fibre treatments increased faecal butyrate and probiotics, and plasma IL-10 concentrations. In conclusion, supplementation of low-level, 2 % (w/w), of K+I was sufficient to enhance the mucosal barrier function and anti-inflammatory status.


2012 ◽  
Vol 302 (1) ◽  
pp. C178-C187 ◽  
Author(s):  
Prashant K. Nighot ◽  
Anthony T. Blikslager

Previously, we have demonstrated that the chloride channel ClC-2 modulates intestinal mucosal barrier function. In the present study, we investigated the role of ClC-2 in epithelial barrier development and maintenance in Caco-2 cells. During early monolayer formation, silencing of ClC-2 with small interfering (si)RNA led to a significant delay in the development of transepithelial resistance (TER) and disruption of occludin localization. Proteomic analysis employing liquid chromatography-mass spectrometry /mass spectrometry revealed association of ClC-2 with key proteins involved in intracellular trafficking, including caveolin-1 and Rab5. In ClC-2 siRNA-treated cells, occludin colocalization with caveolin-1 was diffuse and in the subapical region. Subapically distributed occludin in ClC-2 siRNA-treated cells showed marked colocalization with Rab5. To study the link between ClC-2 and trafficking of occludin in confluent epithelial monolayers, a Caco-2 cell clone expressing ClC-2 short hairpin (sh)RNA was established. Disruption of caveolae with methyl-β-cyclodextrin (MβCD) caused a marked drop in TER and profound redistribution of caveolin-1-occludin coimmunofluorescence in ClC-2 shRNA cells. In ClC-2 shRNA cells, focal aggregations of Rab5-occludin coimmunofluorescence were present within the cytoplasm. Wortmannin caused an acute fall in TER in ClC-2 shRNA cells and subapical, diffuse redistribution of Rab5-occludin coimmunofluorescence in ClC-2 shRNA cells. An endocytosis and recycling assay for occludin revealed higher basal rate of endocytosis of occludin in ClC-2 shRNA cells. Wortmannin significantly reduced the rate of recycling of occludin in ClC-2 shRNA cells. These data clearly indicate that ClC-2 plays an important role in the modulation of tight junctions by influencing caveolar trafficking of the tight junction protein occludin.


2021 ◽  
Vol 27 (Supplement_1) ◽  
pp. S30-S30
Author(s):  
Isabelle Hébert-Milette ◽  
Chloé Lévesque ◽  
Guy Charron ◽  
John Rioux

Abstract Introduction Intestinal permeability is increased in unaffected 1st degree relatives of patients with inflammatory bowel disease (IBD), and is considered a risk factor for the development of IBD, likely increasing the interactions between intestinal microorganisms and the immune system. We recently reported that C1orf106, a gene located within a genomic region associated with IBD, regulates epithelial permeability. We further demonstrated that a rare coding variant within C1orf106 (p.Y333F) decreases protein stability and that lower levels of C1orf106 protein leads altered stability of adherens junctions (AJ) and to an increase in epithelial permeability. Hypothesis In addition to altering AJ, we believe that C1orf106 is also involved in the regulation of tight junction (TJ) formation, which also impacts epithelial permeability. Objectives The objectives of the project are to (a) validate the impact of C1orf106 on tight junctions and (b) verify the impact of C1orf106 IBD-associated variants on intestinal barrier integrity. Results We observed that knocking down the expression of C1orf106 in Caco-2 cells leads to a number of phenotypes in human epithelial monolayer (2D) and spheroid (3D) cultures that are associated with alterations in TJs. Specifically, when studying the dynamic reformation of TJ in 2D cultures after transient withdrawal of calcium, which is required for TJ stability, we observed that lower levels of C1orf106 resulted in (1) decreased recovery of barrier function as measured by transepithelial electrical resistance (TEER); (2) an alteration of tight junction protein localization; and (3) thickening of the circumferential actin belt. Moreover, in 3D cultures, we observed an altered spheroid formation associated with impaired epithelial polarization. In addition, our preliminary studies of human induced pluripotent stem cell (hiPSC)-derived epithelial cultures support that Y333F heterozygotes also have altered structure and function of their tight junctions. Conclusion Our observations indicate an important role of C1orf106 in apical junctional complex (AJC) formation likely mediated by a regulation of the circumferential actin belt. This can affect other functions of AJC, like the establishment of cell polarity. AJC formation is important for epithelial repair after an injury and its dysregulation impairs the formation of an impermeable epithelial barrier, which likely facilitates the passage of microorganisms and the induction and maintenance of intestinal inflammation.


2018 ◽  
Vol 20 (1) ◽  
pp. 20 ◽  
Author(s):  
Haiwei Liang ◽  
Zhaolai Dai ◽  
Jiao Kou ◽  
Kaiji Sun ◽  
Jingqing Chen ◽  
...  

l-Tryptophan (Trp) is known to play an important role in the health of the large intestine. However, a role of dietary Trp in the small-intestinal mucosal barrier and microbiota remains poorly understood. The present study was conducted with weaned piglets to address this issue. Postweaning piglets were fed for 4 weeks a corn- and soybean meal-based diet supplemented with 0 (Control), 0.1, 0.2, or 0.4% Trp. The small-intestinal microbiota and serum amino acids were analyzed by bacterial 16S rRNA gene-based high-throughput sequencing methods and high-performance liquid chromatography, respectively. The mRNA levels for genes involved in host defense and the abundances of tight-junction proteins in jejunum and duodenum were measured by real time-PCR and Western blot techniques, respectively. The concentrations of Trp in the serum of Trp-supplemented piglets increased in a dose-dependent manner. Compared with the control group, dietary supplementation with 0.2–0.4% Trp reduced the abundances of Clostridium sensu stricto and Streptococcus in the jejunum, increased the abundances of Lactobacillus and Clostridium XI (two species of bacteria that can metabolize Trp) in the jejunum, and augmented the concentrations of secretory immunoglobulin A (sIgA) as well as mRNA levels for porcine β-defensins 2 and 3 in jejunal tissues. Moreover, dietary Trp supplementation activated the mammalian target of rapamycin signaling and increased the abundances of tight-junction proteins (zonula occludens (ZO)-1, ZO-3, and claudin-1) in jejunum and duodenum. We suggested that Trp-metabolizing bacteria in the small intestine of weaned pigs primarily mediated the beneficial effects of dietary Trp on its mucosal integrity, health, and function.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Mahnaz Ramezanpour ◽  
Sophia Moraitis ◽  
Jason L. P. Smith ◽  
P. J. Wormald ◽  
Sarah Vreugde

Cytokine mediated changes in paracellular permeability contribute to a multitude of pathological conditions including chronic rhinosinusitis (CRS). The purpose of this study was to investigate the effect of interferons and of Th1, Th2, and Th17 cytokines on respiratory epithelium barrier function. Cytokines and interferons were applied to the basolateral side of air-liquid interface (ALI) cultures of primary human nasal epithelial cells (HNECs) from CRS with nasal polyp patients. Transepithelial electrical resistance (TEER) and permeability of FITC-conjugated dextrans were measured over time. Additionally, the expression of the tight junction protein Zona Occludens-1 (ZO-1) was examined via immunofluorescence. Data was analysed using ANOVA, followed by Tukey HSD post hoc test. Our results showed that application of interferons and of Th1 or Th2 cytokines did not affect the mucosal barrier function. In contrast, the Th17 cytokines IL-17, IL-22, and IL-26 showed a significant disruption of the epithelial barrier, evidenced by a loss of TEER, increased paracellular permeability of FITC-dextrans, and discontinuous ZO-1 immunolocalisation. These results indicate that Th17 cytokines may contribute to the development of CRSwNP by promoting a leaky mucosal barrier.


Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 530
Author(s):  
Gina Cecilia Pistol ◽  
Cristina Valeria Bulgaru ◽  
Daniela Eliza Marin ◽  
Alexandra Gabriela Oancea ◽  
Ionelia Taranu

Inflammatory Bowel Diseases (IBD) are chronic inflammations associated with progressive degradation of intestinal epithelium and impairment of the local innate immune response. Restoring of epithelial integrity and of the mucosal barrier function, together with modulation of inflammatory and innate immune markers, represent targets for alternative strategies in IBD. The aim of our study was to evaluate the effects of a diet including 8% grape seed meal (GSM), rich in bioactive compounds (polyphenols, polyunsaturated fatty acids (PUFAs), fiber) on the markers of colonic epithelial integrity, mucosal barrier function, pro-inflammatory, and innate immunity in DSS-treated piglets used as animal models of intestinal inflammation. Our results have demonstrated the beneficial effects of bioactive compounds from dietary GSM, exerted at three complementary levels: (a) restoration of the epithelial integrity and mucosal barrier reinforcement by modulation of claudins, Occludin (OCCL) and Zonula-1 (ZO-1) tight junction genes and proteins, myosin IXB (MYO9B) and protein tyrosine phosphatase (PTPN) tight junction regulators and mucin-2 (MUC2) gene; (b) reduction of pro-inflammatory MMP-2 (matrix metalloproteinase-2) and MMP-9 (matrix metalloproteinase-9) genes and activities; and (c) suppression of the innate immune TLR-2 (Toll-like receptor-2) and TLR-4 (Toll-like receptor-4) genes and attenuation of the expression of MyD88 (Myeloid Differentiation Primary Response 88)/MD-2 (Myeloid differentiation factor-2) signaling molecules. These beneficial effects of GSM could further attenuate the transition of chronic colitis to carcinogenesis, by modulating the in-depth signaling mediators belonging to the Wnt pathway.


2021 ◽  
Vol 12 ◽  
Author(s):  
Xin-yu You ◽  
Han-yu Zhang ◽  
Xu Han ◽  
Fang Wang ◽  
Peng-wei Zhuang ◽  
...  

Inflammatory bowel disease, irritable bowel syndrome and severe central nervous system injury can lead to intestinal mucosal barrier damage, which can cause endotoxin/enterobacteria translocation to induce infection and is closely related to the progression of metabolic diseases, cardiovascular and cerebrovascular diseases, tumors and other diseases. Hence, repairing the intestinal barrier represents a potential therapeutic target for many diseases. Enteral afferent nerves, efferent nerves and the intrinsic enteric nervous system (ENS) play key roles in regulating intestinal physiological homeostasis and coping with acute stress. Furthermore, innervation actively regulates immunity and induces inherent and adaptive immune responses through complex processes, such as secreting neurotransmitters or hormones and regulating their corresponding receptors. In addition, intestinal microorganisms and their metabolites play a regulatory role in the intestinal mucosal barrier. This paper primarily discusses the interactions between norepinephrine and β-adrenergic receptors, cholinergic anti-inflammatory pathways, nociceptive receptors, complex ENS networks, gut microbes and various immune cells with their secreted cytokines to summarize the key roles in regulating intestinal inflammation and improving mucosal barrier function.


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