Lubiprostone Induces Claudin-1 and Protects Intestinal Barrier Function

Introduction: Lubiprostone, a chloride channel activator, is said to reduce epithelial permeability. However, whether lubiprostone has a direct effect on the epithelial barrier function and how it modulates the intestinal barrier function remain unknown. Therefore, the effects of lubiprostone on intestinal barrier function were evaluated in vitro. Methods: Caco-2 cells were used to assess the intestinal barrier function. To examine the expression of claudins, immunoblotting was performed with specific antibodies. The effects of lubiprostone on cytokines (IFNγ, IL-6, and IL-1β) and aspirin-induced epithelial barrier disruption were assessed by transepithelial electrical resistance (TEER) and fluorescein isothiocyanate (FITC) labeled-dextran permeability. Results: IFNγ, IL-6, IL-1β, and aspirin significantly decreased TEER and increased epithelial permeability. Lubiprostone significantly improved the IFNγ-induced decrease in TEER in a dose-dependent manner. Lubiprostone significantly reduced the IFNγ-induced increase in FITC labeled-dextran permeability. The changes induced by IL-6, IL-1β, and aspirin were not affected by lubiprostone. The expression of claudin-1, but not claudin-3, claudin-4, occludin, and ZO-1 was significantly increased by lubiprostone. Conclusion: Lubiprostone significantly improved the IFNγ-induced decrease in TEER and increase in FITC labeled-dextran permeability. Lubiprostone increased the expression of claudin-1, and this increase may be related to the effect of lubiprostone on the epithelial barrier function.

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3343 Identification of host-microbial interaction networks that mediate intestinal epithelial barrier function in necrotizing enterocolitis

Journal of Clinical and Translational Science ◽

10.1017/cts.2019.34 ◽

2019 ◽

Vol 3 (s1) ◽

pp. 13-13

Author(s):

David R Hill ◽

Roberto Cieza ◽

Veda K. Yadagiri ◽

Phillip Tarr ◽

Jason R. Spence ◽

...

Keyword(s):

Barrier Function ◽

Bacterial Colonization ◽

Intestinal Barrier ◽

Microbial Interactions ◽

Intestinal Barrier Function ◽

Epithelial Barrier ◽

Intestinal Epithelial ◽

Epithelial Barrier Function ◽

Novel Approach ◽

Species Specific

OBJECTIVES/SPECIFIC AIMS: The central goal of this proposal is to characterize the mechanisms that mediate success or failure of immature intestinal barrier in necrotizing enterocilitis. METHODS/STUDY POPULATION: To do this, I will utilize stem cell derived human intestinal organoids (HIOs), an innovative model of the immature intestine, and a cohort of bacterial isolates collected from premature infants who developed NEC to interrogate the cause-effect relationship of these strains on maintenance of the intestinal barrier. I hypothesize that the epithelial response to bacterial colonization is strain-dependent and results in differences in inflammatory signaling that shape epithelial barrier function in the immature intestine. RESULTS/ANTICIPATED RESULTS: Preliminary data shows that colonization of HIOs with different bacteria leads to species-specific changes in barrier function, and some species selectively damage the epithelial barrier while others enhance epithelial barrier function. I have identified key inflammatory signals that serve as central drivers of intestinal barrier function. DISCUSSION/SIGNIFICANCE OF IMPACT: Characterization of this process is expected to substantially advance scientific understanding of early events in NEC pathogenesis and lead to new opportunities for targeted therapeutic intervention to accelerate barrier maturation or prevent hyperinflammatory reactivity in the neonatal intestine. The research proposed in this application represents an entirely novel approach to studying host-microbial interactions in the immature. Conceptually, this novel translational approach will help to define the pivotal role of colonizing bacteria in initiating epithelial inflammation in NEC patients.

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Betaine attenuates LPS-induced downregulation of Occludin and Claudin-1 and restores intestinal barrier function

10.21203/rs.2.18826/v2 ◽

2020 ◽

Author(s):

Jingtao Wu ◽

Caimei He ◽

Jie Bu ◽

Yue Luo ◽

Shuyuan Yang ◽

...

Keyword(s):

Barrier Function ◽

Intestinal Barrier ◽

Protective Role ◽

Vital Role ◽

Inflammatory Factors ◽

Intestinal Barrier Function ◽

Epithelial Barrier ◽

Epithelial Barriers ◽

Vitro Model

Abstract Background：The intestinal epithelial barrier, which works as the first line of defense between the luminal environment and the host, once destroyed, it will cause serious inflammation or other intestinal diseases. Tight junctions (TJs) play a vital role to maintain the integrity of the epithelial barrier. Lipopolysaccharide (LPS), one of the most important inflammatory factors will downregulate specific TJ proteins including Occludin and Claudin-1 and impair integrity of the epithelial barrier. Betaine has excellent anti-inflammatory activity but whether betaine has any effect on TJ proteins, particularly on LPS-induced dysfunction of epithelial barriers remains unknown. The purpose of this study is to explore the pharmacological effect of betaine on improving intestinal barrier function represented by TJ proteins. Intestinal porcine epithelial cells (IPEC-J2) were used as an in vitro model. Results: The results demonstrated that betaine enhanced the expression of TJ proteins while LPS (1µg/mL) downregulates the expression of these proteins. Furthermore, betaine attenuates LPS-induced decreases of TJ proteins both shown by Western blot (WB) and Reverse transcription- polymerase chain reaction (RT-PCR). The immunofluorescent images consistently revealed that LPS induced the disruption of TJ protein Claudin-1 and reduced its expression while betaine could reverse these alterations. Similar protective role of betaine on intestinal barrier function was observed by transepithelial electrical resistance (TEER) approach. Conclusion: In conclusion, our research demonstrated that betaine attenuated LPS-induced downregulation of Occludin and Claudin-1 and restored the intestinal barrier function.

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JAM-A associates with ZO-2, afadin, and PDZ-GEF1 to activate Rap2c and regulate epithelial barrier function

Molecular Biology of the Cell ◽

10.1091/mbc.e13-06-0298 ◽

2013 ◽

Vol 24 (18) ◽

pp. 2849-2860 ◽

Cited By ~ 69

Author(s):

Ana C. Monteiro ◽

Ronen Sumagin ◽

Carl R. Rankin ◽

Giovanna Leoni ◽

Michael J. Mina ◽

...

Keyword(s):

Barrier Function ◽

Intestinal Barrier ◽

Paracellular Permeability ◽

Small Gtpase ◽

Intestinal Barrier Function ◽

Epithelial Permeability ◽

Functional Link ◽

Epithelial Barrier Function ◽

And Control ◽

Interfering Rna

Intestinal barrier function is regulated by epithelial tight junctions (TJs), structures that control paracellular permeability. Junctional adhesion molecule-A (JAM-A) is a TJ-associated protein that regulates barrier; however, mechanisms linking JAM-A to epithelial permeability are poorly understood. Here we report that JAM-A associates directly with ZO-2 and indirectly with afadin, and this complex, along with PDZ-GEF1, activates the small GTPase Rap2c. Supporting a functional link, small interfering RNA–mediated down-regulation of the foregoing regulatory proteins results in enhanced permeability similar to that observed after JAM-A loss. JAM-A–deficient mice and cultured epithelial cells demonstrate enhanced paracellular permeability to large molecules, revealing a potential role of JAM-A in controlling perijunctional actin cytoskeleton in addition to its previously reported role in regulating claudin proteins and small-molecule permeability. Further experiments suggest that JAM-A does not regulate actin turnover but modulates activity of RhoA and phosphorylation of nonmuscle myosin, both implicated in actomyosin contraction. These results suggest that JAM-A regulates epithelial permeability via association with ZO-2, afadin, and PDZ-GEF1 to activate Rap2c and control contraction of the apical cytoskeleton.

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Aflatoxin B1 and Aflatoxin M1 Induce Compromised Intestinal Integrity through Clathrin-Mediated Endocytosis

Toxins ◽

10.3390/toxins13030184 ◽

2021 ◽

Vol 13 (3) ◽

pp. 184

Author(s):

Yanan Gao ◽

Xiaoyu Bao ◽

Lu Meng ◽

Huimin Liu ◽

Jiaqi Wang ◽

...

Keyword(s):

Aflatoxin B1 ◽

Intestinal Barrier ◽

Fluorescein Isothiocyanate ◽

Intestinal Barrier Function ◽

Aflatoxin M1 ◽

Dependent Manner ◽

Simultaneous Exposure ◽

Intestinal Integrity

With the growing diversity and complexity of diet, humans are at risk of simultaneous exposure to aflatoxin B1 (AFB1) and aflatoxin M1 (AFM1), which are well-known contaminants in dairy and other agricultural products worldwide. The intestine represents the first barrier against external contaminants; however, evidence about the combined effect of AFB1 and AFM1 on intestinal integrity is lacking. In vivo, the serum biochemical parameters related to intestinal barrier function, ratio of villus height/crypt depth, and distribution pattern of claudin-1 and zonula occluden-1 were significantly affected in mice exposed to 0.3 mg/kg b.w. AFB1 and 3.0 mg/kg b.w. AFM1. In vitro results on differentiated Caco-2 cells showed that individual and combined AFB1 (0.5 and 4 μg/mL) and AFM1 (0.5 and 4 μg/mL) decreased cell viability and trans-epithelial electrical resistance values as well as increased paracellular permeability of fluorescein isothiocyanate-dextran in a dose-dependent manner. Furthermore, AFM1 aggravated AFB1-induced compromised intestinal barrier, as demonstrated by the down-regulation of tight junction proteins and their redistribution, particularly internalization. Adding the inhibitor chlorpromazine illustrated that clathrin-mediated endocytosis partially contributed to the compromised intestinal integrity. Synergistic and additive effects were the predominant interactions, suggesting that these toxins are likely to have negative effects on human health.

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Strain-Dependent Induction of Enterocyte Apoptosis by Giardia lamblia Disrupts Epithelial Barrier Function in a Caspase-3-Dependent Manner

Infection and Immunity ◽

10.1128/iai.70.7.3673-3680.2002 ◽

2002 ◽

Vol 70 (7) ◽

pp. 3673-3680 ◽

Cited By ~ 145

Author(s):

Alex C. Chin ◽

Desiree A. Teoh ◽

Kevin G.-E. Scott ◽

Jonathon B. Meddings ◽

Wallace K. Macnaughton ◽

...

Keyword(s):

Barrier Function ◽

Giardia Lamblia ◽

Caspase 3 ◽

Cytoskeletal Proteins ◽

Epithelial Barrier ◽

Dependent Manner ◽

Epithelial Permeability ◽

Epithelial Barrier Function ◽

Enterocyte Apoptosis ◽

Strain Dependent

ABSTRACT We recently demonstrated that Giardia lamblia rearranges cytoskeletal proteins and reduces transepithelial electrical resistance. The effect of G. lamblia on enterocyte apoptosis is unknown, and a possible link between microbially induced enterocyte apoptosis and altered epithelial permeability has yet to be established. The aim of this study was to assess whether G. lamblia induces enterocyte apoptosis in duodenal epithelial monolayers and whether this effect increases epithelial permeability. Monolayers of nontransformed human duodenal epithelial cells were incubated with sonicated or live G. lamblia trophozoites (NF, S2, WB, or PB strains) for 8, 24, and 48 h. Cell cultures were assessed for apoptosis by Hoechst fluorescence staining, enzyme-linked immunosorbent assay for apoptotic nucleosomes, and electron microscopy. In separate experiments, monolayers were pretreated with or without 120 μM caspase-3 inhibitor (Z-DEVD-FMK) for 1 h and were assessed for production of apoptotic nucleosomes, tight junctional integrity (with fluorescent ZO-1 staining followed by confocal laser microscopy), and transepithelial permeability for fluorescein isothiocyanate-dextran. G. lamblia strains NF and S2, but not strains WB or PB, induced enterocyte apoptosis within the monolayers, and this effect was inhibited by Z-DEVD-FMK pretreatment. Using the G. lamblia NF isolate, additional experiments investigated the possible link between enterocyte apoptosis and altered epithelial permeability. G. lamblia NF disrupted tight junctional ZO-1 and increased epithelial permeability, but these effects were also prevented by pretreatment with the caspase-3 inhibitor. These findings indicate that strain-dependent induction of enterocyte apoptosis may contribute to the pathogenesis of giardiasis. This effect is responsible for a loss of epithelial barrier function by disrupting tight junctional ZO-1 and increasing permeability in a caspase-3-dependent manner.

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Zinc strengthens the jejunal barrier by reversibly tightening the paracellular route

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00355.2016 ◽

2017 ◽

Vol 313 (6) ◽

pp. G537-G548 ◽

Cited By ~ 3

Author(s):

Silke S. Zakrzewski ◽

Michael Fromm ◽

Jörg D. Schulzke ◽

Dorothee Günzel

Keyword(s):

Barrier Function ◽

Ex Vivo ◽

Intestinal Barrier ◽

Secretory Diarrhea ◽

Intestinal Barrier Function ◽

Epithelial Barrier ◽

Gastrointestinal Infections ◽

Apical Side

During the postweaning period, piglets are prone to gastrointestinal infections. The resulting impairment of intestinal barrier function may cause diarrhea associated with growth retardation or even death of piglets. Orally applied Zn is commonly used to prevent and treat diarrhea, but its mode of action still needs to be elucidated. To analyze the molecular mechanism whereby Zn acts on porcine intestinal barrier function, ex vivo studies on piglet jejunum and accompanying in vitro studies on a porcine jejunal epithelial cell line, IPEC-J2/PS, were performed with electrophysiological tools. Feeding pharmacological Zn doses exerted no significant electrophysiologically ascertainable short- and long-term effects on jejunal barrier function ex vivo. However, in IPEC-J2/PS, basolateral Zn was cytotoxic since its application caused a release of lactate dehydrogenase and an irreversible breakdown of the epithelial barrier. In contrast, apical Zn application caused an immediate increase in paracellular resistance and a decrease in permeability to the paracellular marker fluorescein, reflecting overall barrier strengthening in vitro. Apical effects were fully reversible upon washout. This indicates that Zn supplemented to feed was completely washed out during ex vivo jejunum preparation. We conclude that there is no evidence for long-term barrier effects through prophylactic Zn supplementation and that extracellular Zn acts acutely and reversibly from the apical side via tightening the paracellular route, thus counteracting leak-flux diarrhea. NEW & NOTEWORTHY Therapeutically administered Zn successfully treats diarrhea in veterinary and human medicine. Here we present data that Zn strengthens the porcine jejunal epithelial barrier by reversibly tightening the paracellular route for inorganic ions and small solutes. Acute or long-lasting Zn effects on transcellular transport (Cl− secretion) were not detected. We therefore conclude that Zn is useful for acutely treating leak-flux diarrhea rather than secretory diarrhea. Suitability as prophylactic feed supplement, however, is questionable.

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Succinate Modulates Intestinal Barrier Function and Inflammation Response in Pigs

Biomolecules ◽

10.3390/biom9090486 ◽

2019 ◽

Vol 9 (9) ◽

pp. 486 ◽

Cited By ~ 5

Author(s):

Li ◽

Mao ◽

Zhang ◽

Yu ◽

Zhu

Keyword(s):

Barrier Function ◽

Growing Pigs ◽

Intestinal Morphology ◽

Intestinal Barrier Function ◽

Epithelial Barrier ◽

Control Group ◽

Intestinal Epithelial ◽

Intestinal Epithelial Barrier ◽

Epithelial Barrier Function

Succinate is a metabolic intermediate of the tricarboxylic acid (TCA) cycle in all aerobic organisms, and is also a vital microbial metabolite in the gut. Although succinate is known to regulate intestinal metabolism and immune function, its role in the protection of the intestinal epithelial barrier function and inflammation is poorly characterized. In this study, we evaluated the effects of succinate on intestinal epithelial barrier function and inflammation in pigs. Twenty-four growing pigs were distributed into three groups (n = 8) and received either a basal diet (control group) or the same diet supplemented with 0.1% succinate or 1% succinate. The diet supplemented with 1% succinate led to alterations in the intestinal morphology. We confirmed in vitro that 5 mM succinate treatment modulated intestinal epithelial permeability by increased transepithelial electrical resistance (TEER) in intestinal porcine epithelial cell (IPEC)-J2 cells. Furthermore, succinate treatment increased the abundance of tight junction proteins claudin-1, zona occluden (ZO)-1, and ZO-2 in the jejunum in vivo and in vitro. In addition, dietary succinate supplementation promoted the expression of inflammatory cytokines interleukin (IL)-25, IL-10, IL-8, and IL-18 in the jejunum. Taken together, these data identify a novel role of succinate in the modulation of intestinal epithelial barrier function, which may be a nutritional target to improve gut health in animals.

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Different Damage to the Mechanical Barrier Function of IPEC-J2 Induced by Soybean Allergen β-conglycinin Hydrolyzed Peptides

International Journal of Food Engineering ◽

10.1515/ijfe-2016-0370 ◽

2017 ◽

Vol 13 (10) ◽

Cited By ~ 2

Author(s):

Yuan Zhao ◽

Dandan Liu ◽

Shiyao Zhang ◽

Li Pan ◽

Guixin Qin

Keyword(s):

Alkaline Phosphatase ◽

Tight Junction ◽

Barrier Function ◽

Intestinal Barrier ◽

Dose Dependence ◽

Epithelial Barrier ◽

Epithelial Barrier Function ◽

Mechanical Barrier ◽

Soybean Allergen

AbstractThree major enzyme-hydrolyzed peptides have been produced after simulative digestionin vitroof soybean β-conglycinin. The intestinal barrier of IPEC-J2 induced by β-conglycinin enzyme-hydrolyzed peptides was evaluated in this study. The increased alkaline phosphatase (AP) activity was actually linearly correlated with the incubation time by the hydrolysate, the purified 52 kD peptide, or the mixture of 25 and 30 kD peptides. The MTT and TEER values declined in dose-dependence (0–2 mg/mL,p\lt 0.05) or in time-dependence (2–24 h,p \lt0.05). After treatment with different hydrolyzed peptides, the tight junction expression of claudin-3, claudin-4, occludin, and ZO-1 were reduced (p\lt 0.05). Finally, it is found out that the maximum damage to the epithelial barrier function was induced by the mixture of 25 and 30 kD peptide, whereas the minimum damage was caused by the 52 kD peptide.

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Betaine attenuates LPS-induced downregulation of Occludin and Claudin-1 and restores intestinal barrier function

10.21203/rs.2.18826/v3 ◽

2020 ◽

Author(s):

Jingtao Wu ◽

Caimei He ◽

Jie Bu ◽

Yue Luo ◽

Shuyuan Yang ◽

...

Keyword(s):

Barrier Function ◽

Intestinal Barrier ◽

Protective Role ◽

Vital Role ◽

Inflammatory Factors ◽

Intestinal Barrier Function ◽

Epithelial Barrier ◽

Epithelial Barriers ◽

Vitro Model

Abstract Background ： The intestinal epithelial barrier, which works as the first line of defense between the luminal environment and the host, once destroyed, it will cause serious inflammation or other intestinal diseases. Tight junctions (TJs) play a vital role to maintain the integrity of the epithelial barrier. Lipopolysaccharide (LPS), one of the most important inflammatory factors will downregulate specific TJ proteins including Occludin and Claudin-1 and impair integrity of the epithelial barrier. Betaine has excellent anti-inflammatory activity but whether betaine has any effect on TJ proteins, particularly on LPS-induced dysfunction of epithelial barriers remains unknown. The purpose of this study is to explore the pharmacological effect of betaine on improving intestinal barrier function represented by TJ proteins. Intestinal porcine epithelial cells (IPEC-J2) were used as an in vitro model. Results: The results demonstrated that betaine enhanced the expression of TJ proteins while LPS (1µg/mL) downregulates the expression of these proteins. Furthermore, betaine attenuates LPS-induced decreases of TJ proteins both shown by Western blot (WB) and Reverse transcription- polymerase chain reaction (RT-PCR). The immunofluorescent images consistently revealed that LPS induced the disruption of TJ protein Claudin-1 and reduced its expression while betaine could reverse these alterations. Similar protective role of betaine on intestinal barrier function was observed by transepithelial electrical resistance (TEER) approach. Conclusion: In conclusion, our research demonstrated that betaine attenuated LPS-induced downregulation of Occludin and Claudin-1 and restored the intestinal barrier function.

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Probiotic bacteria and intestinal epithelial barrier function

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00243.2009 ◽

2010 ◽

Vol 298 (6) ◽

pp. G807-G819 ◽

Cited By ~ 334

Author(s):

Christina L. Ohland ◽

Wallace K. MacNaughton

Keyword(s):

Barrier Function ◽

Defense Mechanisms ◽

Intestinal Barrier ◽

Single Layer ◽

Secretory Iga ◽

Intestinal Barrier Function ◽

Epithelial Barrier ◽

Epithelial Barrier Function ◽

Irritable Bowel ◽

The Many

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.

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