Zonulin and Its Regulation of Intestinal Barrier Function: The Biological Door to Inflammation, Autoimmunity, and Cancer

2011 ◽  
Vol 91 (1) ◽  
pp. 151-175 ◽  
Author(s):  
Alessio Fasano
Keyword(s):  
Gastrointestinal Tract ◽  
Tight Junctions ◽  
Barrier Function ◽  
Intestinal Barrier ◽  
Intestinal Barrier Function ◽  
Intestinal Epithelial ◽  
New Paradigm ◽  
Intestinal Epithelial Barrier ◽  
Neoplastic Disorders

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.

scholarly journals Probiotics, Prebiotics and Epithelial Tight Junctions: A Promising Approach to Modulate Intestinal Barrier Function

2021 ◽  
Vol 22 (13) ◽  
pp. 6729
Author(s):  
Elizabeth C. Rose ◽  
Jack Odle ◽  
Anthony T. Blikslager ◽  
Amanda L. Ziegler
Keyword(s):  
Tight Junctions ◽  
Barrier Function ◽  
Intestinal Barrier ◽  
In Vivo Studies ◽  
Intestinal Barrier Function ◽  
Preterm Neonates ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Intestinal Epithelial Barrier ◽  
Stimulation Of

Disruptions in the intestinal epithelial barrier can result in devastating consequences and a multitude of disease syndromes, particularly among preterm neonates. The association between barrier dysfunction and intestinal dysbiosis suggests that the intestinal barrier function is interactive with specific gut commensals and pathogenic microbes. In vitro and in vivo studies demonstrate that probiotic supplementation promotes significant upregulation and relocalization of interepithelial tight junction proteins, which form the microscopic scaffolds of the intestinal barrier. Probiotics facilitate some of these effects through the ligand-mediated stimulation of several toll-like receptors that are expressed by the intestinal epithelium. In particular, bacterial-mediated stimulation of toll-like receptor-2 modulates the expression and localization of specific protein constituents of intestinal tight junctions. Given that ingested prebiotics are robust modulators of the intestinal microbiota, prebiotic supplementation has been similarly investigated as a potential, indirect mechanism of barrier preservation. Emerging evidence suggests that prebiotics may additionally exert a direct effect on intestinal barrier function through mechanisms independent of the gut microbiota. In this review, we summarize current views on the effects of pro- and prebiotics on the intestinal epithelial barrier as well as on non-epithelial cell barrier constituents, such as the enteric glial cell network. Through continued investigation of these bioactive compounds, we can maximize their therapeutic potential for preventing and treating gastrointestinal diseases associated with impaired intestinal barrier function and dysbiosis.

scholarly journals STAT3 Signalling via the IL-6ST/gp130 Cytokine Receptor Promotes Epithelial Integrity and Intestinal Barrier Function during DSS-Induced Colitis

Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 187
Author(s):  
Lokman Pang ◽  
Jennifer Huynh ◽  
Mariah G. Alorro ◽  
Xia Li ◽  
Matthias Ernst ◽  
...  
Keyword(s):  
Barrier Function ◽  
Intestinal Barrier ◽  
Intestinal Barrier Function ◽  
Intestinal Epithelial ◽  
Barrier Dysfunction ◽  
Epithelial Integrity ◽  
Barrier Integrity ◽  
Gp130 Receptor ◽  
Stat3 Signalling

The intestinal epithelium provides a barrier against commensal and pathogenic microorganisms. Barrier dysfunction promotes chronic inflammation, which can drive the pathogenesis of inflammatory bowel disease (IBD) and colorectal cancer (CRC). Although the Signal Transducer and Activator of Transcription-3 (STAT3) is overexpressed in both intestinal epithelial cells and immune cells in IBD patients, the role of the interleukin (IL)-6 family of cytokines through the shared IL-6ST/gp130 receptor and its associated STAT3 signalling in intestinal barrier integrity is unclear. We therefore investigated the role of STAT3 in retaining epithelial barrier integrity using dextran sulfate sodium (DSS)-induced colitis in two genetically modified mouse models, to either reduce STAT1/3 activation in response to IL-6 family cytokines with a truncated gp130∆STAT allele (GP130∆STAT/+), or by inducing short hairpin-mediated knockdown of Stat3 (shStat3). Here, we show that mice with reduced STAT3 activity are highly susceptible to DSS-induced colitis. Mechanistically, the IL-6/gp130/STAT3 signalling cascade orchestrates intestinal barrier function by modulating cytokine secretion and promoting epithelial integrity to maintain a defence against bacteria. Our study also identifies a crucial role of STAT3 in controlling intestinal permeability through tight junction proteins. Thus, therapeutically targeting the IL-6/gp130/STAT3 signalling axis to promote barrier function may serve as a treatment strategy for IBD patients.

scholarly journals Plumericin Protects against Experimental Inflammatory Bowel Disease by Restoring Intestinal Barrier Function and Reducing Apoptosis

Biomedicines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 67 ◽  
Author(s):  
Shara Francesca Rapa ◽  
Rosanna Di Paola ◽  
Marika Cordaro ◽  
Rosalba Siracusa ◽  
Ramona D’Amico ◽  
...  
Keyword(s):  
Barrier Function ◽  
Structural Integrity ◽  
Intestinal Barrier ◽  
Intestinal Barrier Function ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Intestinal Epithelial Barrier ◽  
Bowel Diseases ◽  
Inflammatory Bowel

Intestinal epithelial barrier impairment plays a key pathogenic role in inflammatory bowel diseases (IBDs). In particular, together with oxidative stress, intestinal epithelial barrier alteration is considered as upstream event in ulcerative colitis (UC). In order to identify new products of natural origin with a potential activity for UC treatment, this study evaluated the effects of plumericin, a spirolactone iridoid, present as one of the main bioactive components in the bark of Himatanthus sucuuba (Woodson). Plumericin was evaluated for its ability to improve barrier function and to reduce apoptotic parameters during inflammation, both in intestinal epithelial cells (IEC-6), and in an animal experimental model of 2, 4, 6-dinitrobenzene sulfonic acid (DNBS)-induced colitis. Our results indicated that plumericin increased the expression of adhesion molecules, enhanced IEC-6 cells actin cytoskeleton rearrangement, and promoted their motility. Moreover, plumericin reduced apoptotic parameters in IEC-6. These results were confirmed in vivo. Plumericin reduced the activity of myeloperoxidase, inhibited the expression of ICAM-1, P-selectin, and the formation of PAR, and reduced apoptosis parameters in mice colitis induced by DNBS. These results support a pharmacological potential of plumericin in the treatment of UC, due to its ability to improve the structural integrity of the intestinal epithelium and its barrier function.

Collagen peptides ameliorate intestinal epithelial barrier dysfunction in immunostimulatory Caco-2 cell monolayers via enhancing tight junctions

2017 ◽  
Vol 8 (3) ◽  
pp. 1144-1151 ◽  
Author(s):  
Qianru Chen ◽  
Oliver Chen ◽  
Isabela M. Martins ◽  
Hu Hou ◽  
Xue Zhao ◽  
...  
Keyword(s):  
Barrier Function ◽  
Intestinal Barrier ◽  
Intestinal Barrier Function ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Barrier Dysfunction ◽  
Intestinal Epithelial Barrier ◽  
Cell Monolayers ◽  
Collagen Peptides ◽  
Epithelial Barrier Dysfunction

Alaska pollock skin derived collagen peptides could be considered as dietary supplements for intestinal barrier function promotion and associated diseases.

scholarly journals Treatment of Nonalcoholic Fatty Liver Disease through Changes in Gut Microbiome and Intestinal Epithelial Barrier

2021 ◽  
Author(s):  
Hassan M. Heshmati
Keyword(s):  
Liver Disease ◽  
Gut Microbiome ◽  
Barrier Function ◽  
Intestinal Barrier ◽  
Intestinal Barrier Function ◽  
Epithelial Barrier ◽  
Excess Body Weight ◽  
Intestinal Epithelial ◽  
Intestinal Epithelial Barrier ◽  
Nonalcoholic Fatty Liver

Nonalcoholic fatty liver disease (NAFLD) is a leading liver disease worldwide with a prevalence of approximately 25% among adult population. The highest prevalence is observed in Middle East and the lowest prevalence in Africa. NAFLD is a spectrum of liver disorders ranging from simple steatosis to nonalcoholic steatohepatitis (NASH). Pro-inflammatory diet, overweight/obesity, inflammation, insulin resistance, prediabetes, type 2 diabetes, dyslipidemia, disrupted gut microbiome, and impaired intestinal barrier function are important risk factors associated with and/or contributing to NAFLD. Gut microbiome is a complex and diverse microbial ecosystem essential for the maintenance of human health. It is influenced by several factors including diet and medications. Gut microbiome can be disrupted in NAFLD. Intestinal epithelial barrier is the largest and most important barrier against the external environment and plays an important role in health and disease. Several factors including diet and gut microbiome impact intestinal barrier function. NAFLD can be associated with impaired intestinal barrier function (increased intestinal permeability). There are no specific drugs that directly treat NAFLD. The first-line therapy of NAFLD is currently lifestyle intervention. Weight loss is an important component in the treatment of NAFLD subjects who have excess body weight. Gut microbiome and intestinal epithelial barrier are becoming promising targets for the treatment of several diseases including NAFLD. In the absence of approved pharmacotherapy for the treatment of NAFLD/NASH, in addition to lifestyle intervention and weight loss (in case of excess body weight), focus should also be on correcting gut microbiome and intestinal permeability (directly and/or through gut microbiome modulation) using diet (e.g., low-fat diet, high-fiber diet, and Mediterranean diet), prebiotics (nondigestible food ingredients), probiotics (nonpathogenic living microorganisms), synbiotics (combination of prebiotics and probiotics), and fecal microbiota transplantation (transfer of healthy stool).

Decline in intestinal mucosal IL-10 expression and decreased intestinal barrier function in a mouse model of total parenteral nutrition

2008 ◽  
Vol 294 (1) ◽  
pp. G139-G147 ◽  
Author(s):  
Xiaoyi Sun ◽  
Hua Yang ◽  
Keisuke Nose ◽  
Satoko Nose ◽  
Emir Q. Haxhija ◽  
...  
Keyword(s):  
Parenteral Nutrition ◽  
Tight Junction ◽  
Total Parenteral Nutrition ◽  
Barrier Function ◽  
Intestinal Barrier ◽  
Intestinal Barrier Function ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Intestinal Epithelial Barrier ◽  
Junction Molecules

Loss of intestinal epithelial barrier function (EBF) is a major problem associated with total parenteral nutrition (TPN) administration. We have previously identified intestinal intraepithelial lymphocyte (IEL)-derived interferon-γ (IFN-γ) as a contributing factor to this barrier loss. The objective was to determine whether other IEL-derived cytokines may also contribute to intestinal epithelial barrier breakdown. C57BL6J male mice received TPN or enteral nutrition (control) for 7 days. IEL-derived interleukin-10 (IL-10) was then measured. A significant decline in IEL-derived IL-10 expression was seen with TPN administration, a cytokine that has been shown in vitro to maintain tight junction integrity. We hypothesized that this change in IEL-derived IL-10 expression could contribute to TPN-associated barrier loss. An additional group of mice was given exogenous recombinant IL-10. Ussing chamber experiments showed that EBF markedly declined in the TPN group. TPN resulted in a significant decrease of IEL-derived IL-10 expression. The expression of several tight junction molecules also decreased with TPN administration. Exogenous IL-10 administration in TPN mice significantly attenuated the TPN-associated decline in zonula occludens (ZO)-1, E-cadherin, and occludin expression, as well as a loss of intestinal barrier function. TPN administration led to a marked decline in IEL-derived IL-10 expression. This decline was coincident with a loss of intestinal EBF. As the decline was partially attenuated with the administration of exogenous IL-10, our findings suggest that loss of IL-10 may be a contributing mechanism to TPN-associated epithelial barrier loss.

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

2015 ◽  
Vol 308 (12) ◽  
pp. G981-G993 ◽  
Author(s):  
Juan Antonio Rodríguez-Feo ◽  
Marta Puerto ◽  
Carolina Fernández-Mena ◽  
Cristina Verdejo ◽  
José Manuel Lara ◽  
...  
Keyword(s):  
Inflammatory Bowel Disease ◽  
Barrier Function ◽  
Intestinal Barrier ◽  
Intestinal Barrier Function ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Intestinal Epithelial Barrier ◽  
Epithelial Barrier Function ◽  
Inflammatory Bowel ◽  
E Cadherin

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.

scholarly journals Matrix metalloproteinase 9-induced increase in intestinal epithelial tight junction permeability contributes to the severity of experimental DSS colitis

2015 ◽  
Vol 309 (12) ◽  
pp. G988-G997 ◽  
Author(s):  
Prashant Nighot ◽  
Rana Al-Sadi ◽  
Manmeet Rawat ◽  
Shuhong Guo ◽  
D. Martin Watterson ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Protein Expression ◽  
Barrier Function ◽  
Intestinal Inflammation ◽  
Intestinal Barrier ◽  
Intestinal Barrier Function ◽  
Intestinal Epithelial ◽  
Dss Colitis

Recent studies have implicated a pathogenic role for matrix metalloproteinases 9 (MMP-9) in inflammatory bowel disease. Although loss of epithelial barrier function has been shown to be a key pathogenic factor for the development of intestinal inflammation, the role of MMP-9 in intestinal barrier function remains unclear. The aim of this study was to investigate the role of MMP-9 in intestinal barrier function and intestinal inflammation. Wild-type (WT) and MMP-9−/−mice were subjected to experimental dextran sodium sulfate (DSS) colitis by administration of 3% DSS in drinking water for 7 days. The mouse colonic permeability was measured in vivo by recycling perfusion of the entire colon using fluorescently labeled dextran. The DSS-induced increase in the colonic permeability was accompanied by an increase in intestinal epithelial cell MMP-9 expression in WT mice. The DSS-induced increase in intestinal permeability and the severity of DSS colitis was found to be attenuated in MMP-9−/−mice. The colonic protein expression of myosin light chain kinase (MLCK) and phospho-MLC was found to be significantly increased after DSS administration in WT mice but not in MMP-9−/−mice. The DSS-induced increase in colonic permeability and colonic inflammation was attenuated in MLCK−/−mice and MLCK inhibitor ML-7-treated WT mice. The DSS-induced increase in colonic surface epithelial cell MLCK mRNA was abolished in MMP-9−/−mice. Lastly, increased MMP-9 protein expression was detected within the colonic surface epithelial cells in ulcerative colitis cases. These data suggest a role of MMP-9 in modulation of colonic epithelial permeability and inflammation via MLCK.

scholarly journals Trifostigmanoside I, an Active Compound from Sweet Potato, Restores the Activity of MUC2 and Protects the Tight Junctions through PKCα/β to Maintain Intestinal Barrier Function

2020 ◽  
Vol 22 (1) ◽  
pp. 291
Author(s):  
Amna Parveen ◽  
Seungho Choi ◽  
Ju-Hee Kang ◽  
Seung Hyun Oh ◽  
Sun Yeou Kim
Keyword(s):  
Tight Junctions ◽  
Sweet Potato ◽  
Barrier Function ◽  
Intestinal Barrier ◽  
Human Colon ◽  
Underlying Mechanism ◽  
Intestinal Barrier Function ◽  
Isolation And Identification ◽  
Human Colon Cancer ◽  
Mucin Production

Sweet potato (Ipomoea batata) is considered a superfood among vegetables and has been consumed for centuries. Traditionally, sweet potato is used to treat several illnesses, including diarrhea and stomach disorders. This study aimed to explore the protective effect of sweet potato on intestinal barrier function, and to identify the active compounds of sweet potato and their underlying mechanism of action. To this purpose, bioactivity-guided isolation, Western blotting, and immunostaining assays were applied. Interestingly, our bioactivity-guided approach enabled the first isolation and identification of trifostigmanoside I (TS I) from sweet potato. TS I induced mucin production and promoted the phosphorylation of PKCα/β in LS174T human colon cancer cells. In addition, it protected the function of tight junctions in the Caco-2 cell line. These findings suggest that TS I rescued the impaired abilities of MUC2, and protected the tight junctions through PKCα/β, to maintain intestinal barrier function.

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