Inhaled Budesonide Promotes Barrier Integrity In Vivo in a Mouse Model of Epithelial Barrier Disruption

2019 ◽  
Author(s):  
C. Rimmer ◽  
S.N. Georas ◽  
J. Veazey
Keyword(s):  
Mouse Model ◽  
Epithelial Barrier ◽  
Barrier Integrity ◽  
Barrier Disruption ◽  
Inhaled Budesonide

Vasoactive intestinal peptide prevents PKCε-induced intestinal epithelial barrier disruption during EPEC infection

2015 ◽  
Vol 308 (5) ◽  
pp. G389-G402 ◽  
Author(s):  
V. Morampudi ◽  
V. S. Conlin ◽  
U. Dalwadi ◽  
X. Wu ◽  
K. C. Marshall ◽  
...  
Keyword(s):  
Vasoactive Intestinal Peptide ◽  
Critical Role ◽  
Term Treatment ◽  
Epithelial Barrier ◽  
Protective Effects ◽  
Short Term Treatment ◽  
Barrier Integrity ◽  
Barrier Disruption ◽  
Long Term Treatment

We previously showed that vasoactive intestinal peptide (VIP) protects against bacterial pathogen-induced epithelial barrier disruption and colitis, although the mechanisms remain poorly defined. The aim of the current study was to identify cellular pathways of VIP-mediated protection with use of pharmacological inhibitors during enteropathogenic Escherichia coli (EPEC) infection of Caco-2 cell monolayers and during Citrobacter rodentium-induced colitis. EPEC-induced epithelial barrier disruption involved the PKC pathway but was independent of functional cAMP, Rho, and NF-κB pathways. VIP mediated its protective effects by inhibiting EPEC-induced PKC activity and increasing expression of the junctional protein claudin-4. Short-term treatment with TPA, which is known to activate PKC, was inhibited by VIP pretreatment, while PKC degradation via long-term treatment with TPA mimicked the protective actions of VIP. Immunostaining for specific PKC isotypes showed upregulated expression of PKCθ and PKCε during EPEC infection. Treatment with specific inhibitors revealed a critical role for PKCε in EPEC-induced barrier disruption. Furthermore, activation of PKCε and loss of barrier integrity correlated with claudin-4 degradation. In contrast, inhibition of PKCε by VIP pretreatment or the PKCε inhibitor maintained membrane-bound claudin-4 levels, along with barrier function. Finally, in vivo treatment with the PKCε inhibitor protected mice from C. rodentium-induced colitis. In conclusion, EPEC infection increases intracellular PKCε levels, leading to decreased claudin-4 levels and compromising epithelial barrier integrity. VIP inhibits PKCε activation, thereby attenuating EPEC-induced barrier disruption.

scholarly journals Budesonide promotes airway epithelial barrier integrity following double-stranded RNA challenge

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260706
Author(s):  
Clara Rimmer ◽  
Savas Hetelekides ◽  
Sophia I. Eliseeva ◽  
Steve N. Georas ◽  
Janelle M. Veazey
Keyword(s):  
Barrier Function ◽  
Large Fraction ◽  
Beta Agonist ◽  
Epithelial Barrier ◽  
Airway Epithelial ◽  
Barrier Dysfunction ◽  
Double Stranded Rna ◽  
Barrier Integrity ◽  
Barrier Disruption

Airway epithelial barrier dysfunction is increasingly recognized as a key feature of asthma and other lung diseases. Respiratory viruses are responsible for a large fraction of asthma exacerbations, and are particularly potent at disrupting epithelial barrier function through pattern recognition receptor engagement leading to tight junction dysfunction. Although different mechanisms of barrier dysfunction have been described, relatively little is known about whether barrier integrity can be promoted to limit disease. Here, we tested three classes of drugs commonly prescribed to treat asthma for their ability to promote barrier function using a cell culture model of virus-induced airway epithelial barrier disruption. Specifically, we studied the corticosteroid budesonide, the long acting beta-agonist formoterol, and the leukotriene receptor antagonist montelukast for their ability to promote barrier integrity of a monolayer of human bronchial epithelial cells (16HBE) before exposure to the viral mimetic double-stranded RNA. Of the three, only budesonide treatment limited transepithelial electrical resistance and small molecule permeability (4 kDa FITC-dextran flux). Next, we used a mouse model of acute dsRNA challenge that induces transient epithelial barrier disruption in vivo, and studied the effects budesonide when administered prophylactically or therapeutically. We found that budesonide similarly protected against dsRNA-induced airway barrier disruption in the lung, independently of its effects on airway inflammation. Taken together, these data suggest that an under-appreciated effect of inhaled budesonide is to maintain or promote airway epithelial barrier integrity during respiratory viral infections.

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 Palmitoylethanolamide Counteracts Enteric Inflammation and Bowel Motor Dysfunctions in a Mouse Model of Alzheimer’s Disease

2021 ◽  
Vol 12 ◽  
Author(s):  
Vanessa D’Antongiovanni ◽  
Carolina Pellegrini ◽  
Luca Antonioli ◽  
Laura Benvenuti ◽  
Clelia Di Salvo ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mouse Model ◽  
Epithelial Barrier ◽  
Protein Accumulation ◽  
Intestinal Epithelial ◽  
Intestinal Epithelial Barrier ◽  
Barrier Integrity ◽  
Enteric Glial Cells ◽  
Samp8 Mice

Palmitoylethanolamide (PEA), an endogenous lipid mediator, is emerging as a promising pharmacological agent in multiple neurodegenerative disorders for its anti-inflammatory and neuroprotective properties. However, its effects on enteric inflammation and colonic dysmotility associated with Alzheimer’s disease (AD) are lacking. This study was designed to investigate the beneficial effect of PEA administration in counteracting the enteric inflammation and relieving the bowel motor dysfunctions in an AD mouse model, SAMP8 mice. In addition, the ability of PEA in modulating the activation of enteric glial cells (EGCs), pivotally involved in the pathophysiology of bowel dysfunctions associated with inflammatory conditions, has also been examined. SAMP8 mice at 4 months of age were treated orally with PEA (5 mg/kg/day) for 2 months. SAMR1 animals were employed as controls. At the end of treatment, parameters dealing with colonic motility, inflammation, barrier integrity and AD protein accumulation were evaluated. The effect of PEA on EGCs was tested in cultured cells treated with lipopolysaccharide (LPS) plus β-amyloid 1–42 (Aβ). SAMP8 treated with PEA displayed: 1) an improvement of in vitro colonic motor activity, citrate synthase activity and intestinal epithelial barrier integrity and 2) a decrease in colonic Aβ and α-synuclein (α-syn) accumulation, S100-β expression as well as enteric IL-1β and circulating LPS levels, as compared with untreated SAMP8 mice. In EGCs, treatment with PEA counteracted the increment of S100-β, TLR-4, NF-κB p65 and IL-1β release induced by LPS and Aβ. These results suggest that PEA, under a condition of cognitive decline, prevents the enteric glial hyperactivation, reduces AD protein accumulation and counteracts the onset and progression of colonic inflammatory condition, as well as relieves intestinal motor dysfunctions and improves the intestinal epithelial barrier integrity. Therefore, PEA represents a viable approach for the management of the enteric inflammation and motor contractile abnormalities associated with AD.

scholarly journals LPS-induced epithelial barrier disruption via hyperactivation of CACC and ENaC

2021 ◽  
Author(s):  
Minkyoung Kim ◽  
Sang-woo Lee ◽  
Junchul Kim ◽  
Yonghwan Shin ◽  
Fengjiao Chang ◽  
...  
Keyword(s):  
Tyrosine Phosphorylation ◽  
Bacterial Infections ◽  
Apical Membrane ◽  
Short Circuit ◽  
Membrane Integrity ◽  
Paracellular Permeability ◽  
Membrane Depolarization ◽  
Epithelial Barrier ◽  
Barrier Integrity ◽  
Barrier Disruption

Gram-negative bacterial lipopolysaccharide (LPS) increases the susceptibility of cells to pathogenic diseases including inflammatory diseases and septic syndrome. In our experiments, we examined whether LPS induces epithelial barrier disruption in secretory epithelia and further investigated the underlying mechanism. The activities of Ca2+-activated Cl- channels (CACC) and epithelial Na+ channels (ENaC) were monitored with a short-circuit current using an Ussing chamber. Epithelial membrane integrity was estimated via transepithelial electrical resistance and paracellular permeability assays. We found that apical application of LPS evoked Isc through the activation of CACC and ENaC. LPS disrupted epithelial barrier integrity, but this was restored with the inhibition of CACC and ENaC. Notably, CACC or ENaC activation as well as exposure to a high K+ buffer evoked apical membrane depolarization and increased paracellular permeability, indicating the role of CACC and ENaC in the regulation of paracellular pathways. LPS induced the rapid redistribution of zonula occludens-1 (ZO-1) and reduced the expression levels of ZO-1 in tight junctions through apical membrane depolarization and tyrosine phosphorylation. However, the LPS-induced epithelial barrier disruption and degradation of ZO-1 were largely recovered by blocking CACC and ENaC. Furthermore, LPS-impaired epithelial barrier became vulnerable to secondary bacterial infections and this vulnerability was also prevented by the inhibition of CACC and ENaC. We concluded that LPS induces the disruption of epithelial barrier integrity through the activation of CACC and ENaC, resulting in apical membrane depolarization and subsequent tyrosine phosphorylation of ZO-1.

Establishment of an In Vitro Co-Culture Model of the Piglet Gut to Study Inflammatory Response and Barrier Integrity

Planta Medica ◽  
2021 ◽  
Author(s):  
Theresa Schott ◽  
Nicole Reisinger ◽  
Klaus Teichmann ◽  
Jürgen König ◽  
Andrea Ladinig ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Mononuclear Cells ◽  
Intestinal Inflammation ◽  
Epithelial Barrier ◽  
Peripheral Blood Mononuclear ◽  
Barrier Integrity ◽  
Culture Model

AbstractIn intensive farming, piglets are exposed to various challenges that activate intestinal inflammatory processes, negatively affecting animal health and leading to economic losses. To study the role of the inflammatory response on epithelial barrier integrity, co-culture systems that mimic in vivo complexity are more and more preferred over cell monocultures. In this study, an in vitro gut co-culture model consisting of intestinal porcine epithelial cells and porcine peripheral blood mononuclear cells was established. The model provides an appropriate tool to study the role of the inflammatory response on epithelial barrier integrity and to screen for feed and food components, exerting beneficial effects on gut health. In the established model, inflammation-like reactions and damage of the epithelial barrier, indicated by a decrease of transepithelial electrical resistance, were elicited by activation of peripheral blood mononuclear cells via one of 3 stimuli: lipopolysaccharide, lipoteichoic acid, or concanavalin A. Two phytogenic substances that are commonly used as feed additives, licorice extract and oregano oil, have been shown to counteract the drop in transepithelial electrical resistance values in the gut co-culture model. The established co-culture model provides a powerful in vitro tool to study the role of intestinal inflammation on epithelial barrier integrity. As it consists of porcine epithelial and porcine blood cells it perfectly mimics in vivo conditions and imitates the inter-organ communication of the piglet gut. The developed model is useful to screen for nutritional components or drugs, having the potential to balance intestinal inflammation and strengthen the epithelial barrier integrity in piglets.

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