598 PROTOCADHERIN 20 DEFICIENCY IMPAIRS INTESTINAL BARRIER FUNCTION BY TARGETING ATF6 RELATED PATHWAY IN CROHN'S DISEASE

2021 ◽  
Vol 160 (6) ◽  
pp. S-116-S-117
Author(s):  
Shanshan Huang ◽  
Sheng-Hong Zhang ◽  
Minhu Chen
2012 ◽  
Vol 6 (4) ◽  
pp. 464-469 ◽  
Author(s):  
Rainer Noth ◽  
Eckhard Stüber ◽  
Robert Häsler ◽  
Susanna Nikolaus ◽  
Tanja Kühbacher ◽  
...  

2020 ◽  
Vol 21 (21) ◽  
pp. 7824
Author(s):  
Jia-Chen Hu ◽  
Christian Bojarski ◽  
Federica Branchi ◽  
Michael Fromm ◽  
Susanne Krug

Crohn’s disease (CD) has an altered intestinal barrier function, yet the underlying mechanisms remain to be disclosed. The tricellular tight junction protein tricellulin is involved in the maintenance of the paracellular macromolecule barrier and features an unchanged expression level in CD but a shifted localization. As angulins are known to regulate the localization of tricellulin, we hypothesized the involvement of angulins in CD. Using human biopsies, we found angulin-1 was downregulated in active CD compared with both controls and CD in remission. In T84 and Caco-2 monolayers, leptin, a cytokine secreted by fat tissue and affected in CD, decreased angulin-1 expression. This effect was completely blocked by STAT3 inhibitors, Stattic and WP1066, but only partially by JAK2 inhibitor AG490. The effect of leptin was also seen at a functional level as we observed in Caco-2 cells an increased permeability for FITC-dextran 4 kDa indicating an impaired barrier against macromolecule uptake. In conclusion, we were able to show that in active CD angulin-1 expression is downregulated, which leads to increased macromolecule permeability and is inducible by leptin via STAT3. This suggests that angulin-1 and leptin secretion are potential targets for intervention in CD to restore the impaired intestinal barrier.


2021 ◽  
Vol 12 ◽  
Author(s):  
Heike E. F. Becker ◽  
Casper Jamin ◽  
Liene Bervoets ◽  
Annemarie Boleij ◽  
Pan Xu ◽  
...  

Bacteroides fragilis has previously been linked to Crohn’s disease (CD) exacerbations, but results are inconsistent and underlying mechanisms unknown. This study investigates the epidemiology of B. fragilis and its virulence factors bft (enterotoxin) and ubiquitin among 181 CD patients and the impact on the intestinal epithelial barrier in vitro. The prevalence of B. fragilis was significantly higher in active (n = 69/88, 78.4%) as compared to remissive (n = 58/93, 62.4%, p = 0.018) CD patients. Moreover, B. fragilis was associated with intestinal strictures. Interestingly, the intestinal barrier function, as examined by transepithelial electrical resistance (TEER) measurements of Caco-2 monolayers, increased when exposed to secretomes of bft-positive (bft-1 and bft-2 isotype; increased TEER ∼160%, p < 0.001) but not when exposed to bft-negative strains. Whole metagenome sequencing and metabolomics, respectively, identified nine coding sequences and two metabolites that discriminated TEER-increasing from non-TEER-increasing strains. This study revealed a higher B. fragilis prevalence during exacerbation. Surprisingly, bft-positive secretomes increased epithelial resistance, but we excluded Bft as the likely causative factor.


2021 ◽  
Vol 12 ◽  
Author(s):  
Namita Power ◽  
Williams Turpin ◽  
Osvaldo Espin-Garcia ◽  
Michelle I. Smith ◽  
Kenneth Croitoru ◽  
...  

Intestinal epithelial cell tight junctions (TJs) contribute to the integrity of the intestinal barrier allowing for control of the physical barrier between external antigens or bacterial products and the internal environment. Zonula occludens-1 (ZO-1) is a protein that modulates intestinal TJs, and serum levels of ZO-1 has been suggested as a biomarker of disrupted barrier function in humans. Previous studies suggested that increased intestinal permeability was associated with evidence of TJ abnormalities. However, there is limited information on the serological measurement of ZO-1 and its relation to other tests of barrier function in healthy subjects. We investigated the correlation of serum ZO-1, with physiologic measures of intestinal permeability (as the ratio of the fractional excretion of lactulose-mannitol or LMR) in a cohort of 39 healthy FDRs of Crohn's disease (CD) patients. No significant correlation was found between LMR and ZO-1 levels (r2 = 0.004, P < 0.71), or intestinal fatty acid binding proteins (I-FABP) (r2 = 0.004, P < 0.71). In conclusion, our data show that ZO-1 and I-FABP are not a marker of gut permeability as defined by LMR.


2020 ◽  
Vol 117 (46) ◽  
pp. 28930-28938
Author(s):  
Toru Nakata ◽  
Elizabeth A. Creasey ◽  
Motohiko Kadoki ◽  
Helen Lin ◽  
Martin K. Selig ◽  
...  

Common genetic variants interact with environmental factors to impact risk of heritable diseases. A notable example of this is a single-nucleotide variant in the Solute Carrier Family 39 Member 8 (SLC39A8)geneencoding the missense variant A391T, which is associated with a variety of traits ranging from Parkinson’s disease and neuropsychiatric disease to cardiovascular and metabolic diseases and Crohn’s disease. The remarkable extent of pleiotropy exhibited bySLC39A8A391T raises key questions regarding how a single coding variant can contribute to this diversity of clinical outcomes and what is the mechanistic basis for this pleiotropy. Here, we generate a murine model for theSlc39a8A391T allele and demonstrate that these mice exhibit Mn deficiency in the colon associated with impaired intestinal barrier function and epithelial glycocalyx disruption. Consequently,Slc39a8A391T mice exhibit increased sensitivity to epithelial injury and pathological inflammation in the colon. Taken together, our results link a genetic variant with a dietary trace element to shed light on a tissue-specific mechanism of disease risk based on impaired intestinal barrier integrity.


2017 ◽  
Vol 24 (1) ◽  
pp. 166-178 ◽  
Author(s):  
John-Peter Ganda Mall ◽  
Maite Casado-Bedmar ◽  
Martin E Winberg ◽  
Robert J Brummer ◽  
Ida Schoultz ◽  
...  

Abstract Background Administration of β-glucan has shown immune-enhancing effects. Our aim was to investigate whether β-glucan could attenuate mast cell (MC)-induced hyperpermeability in follicle-associated epithelium (FAE) and villus epithelium (VE) of patients with Crohn’s disease (CD) and in noninflammatory bowel disease (IBD)-controls. Further, we studied mechanisms of β-glucan uptake and effects on MCs in vitro. Methods Segments of FAE and VE from 8 CD patients and 9 controls were mounted in Ussing chambers. Effects of the MC-degranulator compound 48/80 (C48/80) and yeast-derived β-1,3/1,6 glucan on hyperpermeability were investigated. Translocation of β-glucan and colocalization with immune cells were studied by immunofluorescence. Caco-2-cl1- and FAE-cultures were used to investigate β-glucan-uptake using endocytosis inhibitors and HMC-1.1 to study effects on MCs. Results β-glucan significantly attenuated MC-induced paracellular hyperpermeability in CD and controls. Transcellular hyperpermeability was only significantly attenuated in VE. Baseline paracellular permeability was higher in FAE than VE in both groups, P<0.05, and exhibited a more pronounced effect by C48/80 and β-glucan P<0.05. No difference was observed between CD and controls. In vitro studies showed increased passage, P<0.05, of β-glucan through FAE-culture compared to Caco-2-cl1. Passage was mildly attenuated by the inhibitor methyl-β-cyclodextrin. HMC-1.1 experiments showed a trend to decreasing MC-degranulation and levels of TNF-α but not IL-6 by β-glucan. Immunofluorescence revealed more β-glucan-uptake and higher percentage of macrophages and dendritic cells close to β-glucan in VE of CD compared to controls. Conclusions We demonstrated beneficial effects of β-glucan on intestinal barrier function and increased β-glucan-passage through FAE model. Our results provide important and novel knowledge on possible applications of β-glucan in health disorders and diseases characterized by intestinal barrier dysfunction.


Gut ◽  
1999 ◽  
Vol 44 (1) ◽  
pp. 96-100 ◽  
Author(s):  
J D Söderholm ◽  
G Olaison ◽  
E Lindberg ◽  
U Hannestad ◽  
A Vindels ◽  
...  

BackgroundA familial defect in intestinal barrier function has been found in Crohn’s disease.AimTo investigate possible genetic and environmental influences on this barrier defect by studying intestinal permeability in both relatives and spouses of patients with Crohn’s disease.SubjectsThe study included 39 patients with Crohn’s disease, 34 healthy first degree relatives, and 22 spouses. Twenty nine healthy volunteers served as controls.MethodsIntestinal permeability was assessed as the lactulose:mannitol ratio in five hour urinary excretion after oral load, both before (baseline) and after ingestion of acetylsalicylic acid. The permeability response represents the difference between the two tests. A ratio above the 95th percentile for controls was classified as abnormal.ResultsBaseline permeability was higher in patients and spouses than in controls. An abnormal baseline permeability was seen in 36% of the patients, 23% of the spouses, 18% of the relatives, and 3% of the controls. After ingestion of acetylsalicylic acid, permeability increased significantly in all groups. Relatives were similar to patients with regard to permeability after exposure to acetylsalicylic acid, whereas spouses were similar to controls. The proportions with an abnormal permeability response to acetylsalicylic acid were 32% in patients, 14% in spouses, 41% in relatives, and 3% in controls.ConclusionThe findings suggest that baseline permeability is determined by environmental factors, whereas permeability provoked by acetylsalicylic acid is a function of the genetically determined state of the mucosal barrier, and support the notion that environmental and hereditary factors interact in the pathogenesis of Crohn’s disease.


2019 ◽  
Vol 25 (11) ◽  
pp. 1796-1804 ◽  
Author(s):  
Williams Turpin ◽  
Osvaldo Espin-Garcia ◽  
Larbi Bedrani ◽  
Karen Madsen ◽  
Jonathan B Meddings ◽  
...  

Abstract Excessive intestinal permeability or intestinal barrier dysfunction as measured by various assays has been observed in various diseases. However, little is known about the factors contributing to altered gut permeability in these diseases. Our objective was to determine the genetic determinants of altered gut permeability as measured by the lactulose mannitol fractional excretion ratio (LacMan ratio) in 1075 healthy first-degree relatives of patients with Crohn’s disease (CD). In a targeted analysis of single nucleotide polymorphisms (SNPs) located in genes associated with intestinal barrier function related or not to inflammatory bowel disease, we did not find a significant association with intestinal permeability. In an untargeted genome-wide association analysis, the top 100 associations were located in 22 genomic loci, although they were not statistically significant after correction for multiple testing (raw P values [1.8 × 10–7 - 1.4 × 10–5]. The lowest P value was obtained for rs9616637 (22q13.33, C22orf34), for which the minor allele A was associated with a decreased LacMan ratio. These results suggest that host genetic background has limited contribution toward intestinal permeability. Despite this, our study is currently the largest of its kind assessing gut permeability in vivo. It remains possible that smaller genetic effect sizes on LacMan ratio are not detectable in this sized cohort. Larger studies are warranted to identify the potential genetic contribution to intestinal permeability.


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