scholarly journals Palmitic Acid Affects Intestinal Epithelial Barrier Integrity and Permeability In Vitro

Antioxidants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 417
Author(s):  
Manuele Gori ◽  
Annamaria Altomare ◽  
Silvia Cocca ◽  
Eleonora Solida ◽  
Mentore Ribolsi ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Palmitic Acid ◽  
Intestinal Permeability ◽  
Adherens Junction ◽  
Epithelial Barrier ◽  
Epithelial Cell Line ◽  
Intestinal Epithelial ◽  
Barrier Integrity ◽  
And Oxidative Stress

Palmitic acid (PA), a long-chain saturated fatty acid, might activate innate immune cells. PA plays a role in chronic liver disease, diabetes and Crohn’s disease, all of which are associated with impaired intestinal permeability. We investigated the effect of PA, at physiological postprandial intestinal concentrations, on gut epithelium as compared to lipopolysaccharide (LPS) and ethanol, using an in vitro gut model, the human intestinal epithelial cell line Caco-2 grown on transwell inserts. Cytotoxicity and oxidative stress were evaluated; epithelial barrier integrity was investigated by measuring the paracellular flux of fluorescein, and through RT-qPCR and immunofluorescence of tight junction (TJ) and adherens junction (AJ) mRNAs and proteins, respectively. In PA-exposed Caco-2 monolayers, cytotoxicity and oxidative stress were not detected. A significant increase in fluorescein flux was observed in PA-treated monolayers, after 90 min and up to 360 min, whereas with LPS and ethanol, this was only observed at later time-points. Gene expression and immunofluorescence analysis showed TJ and AJ alterations only in PA-exposed monolayers. In conclusion, PA affected intestinal permeability without inducing cytotoxicity or oxidative stress. This effect seemed to be faster and stronger than those with LPS and ethanol. Thus, we hypothesized that PA, besides having an immunomodulatory effect, might play a role in inflammatory and functional intestinal disorders in which the intestinal permeability is altered.

scholarly journals Curcumin Improves Epithelial Barrier Integrity of Caco-2 Monolayers by Inhibiting Endoplasmic Reticulum Stress and Subsequent Apoptosis

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Xinxin Zhou ◽  
Mengting Ren ◽  
Jinpu Yang ◽  
Hanghai Pan ◽  
Mosang Yu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Cell Apoptosis ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Barrier Integrity ◽  
Protein Levels ◽  
Coculture Model

Curcumin is a natural polyphenol and is supposed to possess antioxidant, anti-inflammatory, anticancer, and antiapoptotic properties. Although some studies have reported the therapeutic effects of curcumin on ulcerative colitis (UC), the specific mechanism remains unclear. An in vitro coculture model of Caco-2 and differentiated THP-1 cells was established. After administration of curcumin (10 μM), Western blot analysis was performed to evaluate the protein levels of tight junction (TJ) proteins zonula occludens- (ZO-) 1 and claudin-1. Annexin V-APC/7-AAD assays and flow cytometry were conducted to assess Caco-2 cell apoptosis. The expression levels of oxidative stress and endoplasmic reticulum stress- (ERS-) related molecules were determined by Western blot analysis. Curcumin administration significantly upregulated ZO-1 and claudin-1 protein levels and reduced Caco-2 cell apoptosis. The protein levels of oxidative stress markers inducible nitric oxide synthase (iNOS) and γH2AX and ERS-induced apoptosis-related molecules C/EBP homologous protein (CHOP) and cleaved caspase-12 were significantly downregulated upon curcumin treatment. Furthermore, curcumin administration greatly blocked the protein kinase-like endoplasmic reticulum kinase- (PERK-) eukaryotic translation initiation factor 2α- (eIF2α-) activating transcription factor 4- (ATF4-) CHOP signaling pathway. Curcumin enhanced intestinal epithelial barrier integrity in the in vitro coculture model by upregulating TJ protein expressions and reducing intestinal epithelial cell apoptosis. The potential mechanisms may be suppression of ERS and subsequent apoptosis.

scholarly journals Isoquercitrin Ameliorates Cisplatin-Induced Nephrotoxicity Via the Inhibition of Apoptosis, Inflammation, and Oxidative Stress

2020 ◽  
Vol 11 ◽  
Author(s):  
Hao Wang ◽  
Weiwei Xia ◽  
Guangfeng Long ◽  
Zhiyin Pei ◽  
Yuanyuan Li ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Renal Function ◽  
Cell Injury ◽  
Kidney Diseases ◽  
Kidney Injury ◽  
Epithelial Cell Line ◽  
Therapeutic Uses ◽  
And Oxidative Stress

Cisplatin is extensively used and is highly effective in clinical oncology; nevertheless, nephrotoxicity has severely limited its widespread utility. Isoquercitrin (IQC), a natural flavonoid widely found in herbage, is well known and recognized for its antioxidant, anti-inflammatory, and anti-apoptotic properties. However, the potential effects and mechanism of IQC in cisplatin-induced acute kidney diseases remain unknown. In this study, we postulated the potential effects and mechanism of IQC upon cisplatin exposure in vivo and in vitro. For the in vivo study, C57BL/6J mice were pretreated with IQC or saline (50 mg/kg/day) by gavage for 3 days before cisplatin single injection (25 mg/kg). Renal function, apoptosis, inflammation, oxidative stress and p-ERK were measured to evaluate kidney injury. In vitro, mouse proximal tubular cells (mPTCs) and human proximal tubule epithelial cell line (HK2) were pretreated with or without IQC (80 μM for mPTCs and 120 μM for HK2) for 2 h and then co-administrated with cisplatin for another 24 h. Apoptosis, inflammation, ROS and p-ERK of cells were also measured. In vivo, IQC administration strikingly reduced cisplatin-induced nephrotoxicity as evidenced by the improvement in renal function (serum creatinine and blood urea nitrogen), kidney histology (PAS staining), apoptotic molecules (cleaved caspase-3, caspase-8, Bax and Bcl-2), inflammatory cytokines (IL-1β, IL-6, TNF-α, and COX-2), oxidative stress (MDA and total glutathione) and p-ERK. In line with in vivo findings, IQC markedly protected against cisplatin-induced cell injury in mPTCs and HK2 cells. Collectively, these findings demonstrated that IQC administration could significantly protect against cisplatin nephrotoxicity possibly through ameliorating apoptosis, inflammation and oxidative stress accompanied by cross talk with p-ERK. Furthermore, IQC may have potential therapeutic uses in the treatment of cisplatin-induced acute kidney injury.

scholarly journals Bovine dairy complex lipids improve in vitro measures of small intestinal epithelial barrier integrity

PLoS ONE ◽  
2018 ◽  
Vol 13 (1) ◽  
pp. e0190839 ◽  
Author(s):  
Rachel C. Anderson ◽  
Alastair K. H. MacGibbon ◽  
Neill Haggarty ◽  
Kelly M. Armstrong ◽  
Nicole C. Roy
Keyword(s):  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Intestinal Epithelial Barrier ◽  
Barrier Integrity ◽  
Complex Lipids ◽  
Small Intestinal

Lipid rafts are disrupted in mildly inflamed intestinal microenvironments without overt disruption of the epithelial barrier

2012 ◽  
Vol 302 (8) ◽  
pp. G781-G793 ◽  
Author(s):  
Rachel V. Bowie ◽  
Simona Donatello ◽  
Clíona Lyes ◽  
Mark B. Owens ◽  
Irina S. Babina ◽  
...  
Keyword(s):  
Lipid Rafts ◽  
Intestinal Permeability ◽  
Barrier Function ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Intestinal Epithelial Barrier ◽  
Epithelial Barrier Function ◽  
Barrier Integrity ◽  
Ifn Γ

Intestinal epithelial barrier disruption is a feature of inflammatory bowel disease (IBD), but whether barrier disruption precedes or merely accompanies inflammation remains controversial. Tight junction (TJ) adhesion complexes control epithelial barrier integrity. Since some TJ proteins reside in cholesterol-enriched regions of the cell membrane termed lipid rafts, we sought to elucidate the relationship between rafts and intestinal epithelial barrier function. Lipid rafts were isolated from Caco-2 intestinal epithelial cells primed with the proinflammatory cytokine interferon-γ (IFN-γ) or treated with methyl-β-cyclodextrin as a positive control for raft disruption. Rafts were also isolated from the ilea of mice in which colitis had been induced in conjunction with in vivo intestinal permeability measurements, and lastly from intestinal biopsies of ulcerative colitis (UC) patients with predominantly mild or quiescent disease. Raft distribution was analyzed by measuring activity of the raft-associated enzyme alkaline phosphatase and by performing Western blot analysis for flotillin-1. Epithelial barrier integrity was estimated by measuring transepithelial resistance in cytokine-treated cells or in vivo permeability to fluorescent dextran in colitic mice. Raft and nonraft fractions were analyzed by Western blotting for the TJ proteins occludin and zonula occludens-1 (ZO-1). Our results revealed that lipid rafts were disrupted in IFN-γ-treated cells, in the ilea of mice with subclinical colitis, and in UC patients with quiescent inflammation. This was not associated with a clear pattern of occludin or ZO-1 relocalization from raft to nonraft fractions. Significantly, a time-course study in colitic mice revealed that disruption of lipid rafts preceded the onset of increased intestinal permeability. Our data suggest for the first time that lipid raft disruption occurs early in the inflammatory cascade in murine and human colitis and, we speculate, may contribute to subsequent disruption of epithelial barrier function.

scholarly journals Artificial Sweeteners Disrupt Tight Junctions and Barrier Function in the Intestinal Epithelium through Activation of the Sweet Taste Receptor, T1R3

Nutrients ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1862 ◽  
Author(s):  
Aparna Shil ◽  
Oluwatobi Olusanya ◽  
Zaynub Ghufoor ◽  
Benjamin Forson ◽  
Joanne Marks ◽  
...  
Keyword(s):  
Intestinal Permeability ◽  
Intestinal Epithelium ◽  
Taste Receptor ◽  
Sweet Taste ◽  
Epithelial Barrier ◽  
Artificial Sweeteners ◽  
Epithelial Cell Line ◽  
Intestinal Epithelial ◽  
Subsequent Increase ◽  
Sweet Taste Receptor

The breakdown of the intestinal epithelial barrier and subsequent increase in intestinal permeability can lead to systemic inflammatory diseases and multiple-organ failure. Nutrition impacts the intestinal barrier, with dietary components such as gluten increasing permeability. Artificial sweeteners are increasingly consumed by the general public in a range of foods and drinks. The sweet taste receptor (T1R3) is activated by artificial sweeteners and has been identified in the intestine to play a role in incretin release and glucose transport; however, T1R3 has not been previously linked to intestinal permeability. Here, the intestinal epithelial cell line, Caco-2, was used to study the effect of commonly-consumed artificial sweeteners, sucralose, aspartame and saccharin, on permeability. At high concentrations, aspartame and saccharin were found to induce apoptosis and cell death in intestinal epithelial cells, while at low concentrations, sucralose and aspartame increased epithelial barrier permeability and down-regulated claudin 3 at the cell surface. T1R3 knockdown was found to attenuate these effects of artificial sweeteners. Aspartame induced reactive oxygen species (ROS) production to cause permeability and claudin 3 internalization, while sweetener-induced permeability and oxidative stress was rescued by the overexpression of claudin 3. Taken together, our findings demonstrate that the artificial sweeteners sucralose, aspartame, and saccharin exert a range of negative effects on the intestinal epithelium through the sweet taste receptor T1R3.

scholarly journals A Medium-Throughput System for In Vitro Oxidative Stress Assessment in IPEC-J2 Cells

2020 ◽  
Vol 21 (19) ◽  
pp. 7263
Author(s):  
Miriam Ayuso ◽  
Steven Van Cruchten ◽  
Chris Van Ginneken
Keyword(s):  
Oxidative Stress ◽  
Fluorescence Analysis ◽  
Epithelial Cell Line ◽  
Intestinal Epithelial ◽  
Ros Accumulation ◽  
Intracellular Ros ◽  
Plate Reader ◽  
Set Up ◽  
Intracellular Oxidative Stress

The feed industry continuously seeks new molecules with antioxidant capacity since oxidative stress plays a key role in intestinal health. To improve screening of new antioxidants, this study aims to set up an assay to assess oxidative stress in the porcine small intestinal epithelial cell line IPEC-J2 using plate-reader-based analysis of fluorescence. Two oxidants, H2O2 and menadione, were tested at 1, 2 and 3 mM and 100, 200 and 300 µM, respectively. Trolox (2 mM) was used as the reference antioxidant and the probe CM-H2DCFDA was used to indicate intracellular oxidative stress. Cell culture, reactive oxygen species (ROS) production and assessment conditions were optimized to detect a significant ROS accumulation that could be counteracted by pre-incubation with trolox. Menadione (200 µM) reproducibly increased ROS levels, H2O2 failed to do so. Trolox significantly decreased intracellular ROS levels in menadione (200 µM)-exposed cells in a consistent way. The system was further used to screen different concentrations of the commercially available antioxidant ELIFE®. Concentrations between 100 and 200 ppm protected best against intracellular ROS accumulation. In conclusion, the combination of CM-H2DCFDA fluorescence analysis by a plate-reader, trolox as a reference antioxidant and 200 µM of menadione as a stressor agent, provides a replicable and reliable medium-throughput setup for the evaluation of intracellular oxidative stress in IPEC-J2 cells.

scholarly journals Salmonella Effector SpvB Disrupts Intestinal Epithelial Barrier Integrity for Bacterial Translocation

2020 ◽  
Vol 10 ◽  
Author(s):  
Lanqing Sun ◽  
Sidi Yang ◽  
Qifeng Deng ◽  
Kedi Dong ◽  
Yuanyuan Li ◽  
...  
Keyword(s):  
Bacterial Translocation ◽  
Junctional Complex ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Barrier Dysfunction ◽  
Intestinal Epithelial Barrier ◽  
Barrier Integrity ◽  
Epithelial Barrier Dysfunction

Salmonella are common enteric bacterial pathogens that infect both humans and animals. Intestinal epithelial barrier, formed by a single layer of epithelial cells and apical junctional complex (AJC), plays a crucial role in host defense against enteric pathogens to prevent bacterial translocation. However, the underlying mechanisms of intestinal epithelial barrier dysfunction caused by Salmonella are poorly understood. It is found that a locus termed Salmonella plasmid virulence (spv) gene exists extensively in clinically important Salmonella serovars. SpvB is a key effector encoded within this locus, and closely related to Salmonella pathogenicity such as interfering with autophagy and iron homeostasis. To investigate the interaction between SpvB and intestinal epithelial barrier and elucidate the underlying molecular mechanism, we used the typical foodborne disease agent Salmonella enterica serovar Typhimurium (Salmonella typhimurium) carrying spvB or not to construct infection models in vivo and in vitro. C57BL/6 mice were orally challenged with S. typhimurium wild-type strain SL1344 or spvB-deficient mutant strain SL1344-ΔspvB. Caco-2 cell monolayer model, as a widely used model to mimic the human intestinal epithelium in vitro, was infected with SL1344, SL1344-ΔspvB, or spvB complementary strain SL1344-c-ΔspvB, respectively. The results showed that SpvB enhanced bacterial pathogenicity during S. typhimurium infection in vivo, and contributed to intestinal epithelial barrier dysfunction in both infection systems. This SpvB-mediated barrier dysfunction was attributed to the cellular redistribution of Claudin-1, Occludin, and E-cadherin junctional proteins. Moreover, by using pharmacological inhibitors, we found that F-actin rearrangement and suppression of protein kinase C (PKC) signaling pathway were involved in SpvB-mediated barrier dysfunction. In conclusion, the study reveals the contribution of Salmonella effector SpvB to the dysfunction of intestinal epithelial barrier integrity, which facilitates bacterial translocation via the paracellular route to promote Salmonella systemic dissemination. Our findings broaden the understanding of host–pathogen interactions in salmonellosis, and provide new strategies for the therapy in limiting bacterial dissemination during infection.

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