scholarly journals Higher Prevalence of Bacteroides fragilis in Crohn’s Disease Exacerbations and Strain-Dependent Increase of Epithelial Resistance

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.

2020 ◽  
Author(s):  
Heike E. F. Becker ◽  
Casper Jamin ◽  
Liene Bervoets ◽  
Pan Xu ◽  
Marie J. Pierik ◽  
...  

AbstractBacteroides 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, improved when exposed to secretomes of bft-positive (increased TEER ∼160%, p<0.001) but not when exposed to bft- negative strains. Whole metagenome sequencing and metabolomics, respectively, identified 19 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 improved epithelial resistance.


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&lt;0.05, and exhibited a more pronounced effect by C48/80 and β-glucan P&lt;0.05. No difference was observed between CD and controls. In vitro studies showed increased passage, P&lt;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.


2012 ◽  
Vol 6 (4) ◽  
pp. 464-469 ◽  
Author(s):  
Rainer Noth ◽  
Eckhard Stüber ◽  
Robert Häsler ◽  
Susanna Nikolaus ◽  
Tanja Kühbacher ◽  
...  

2021 ◽  
Vol 15 (Supplement_1) ◽  
pp. S601-S601
Author(s):  
H Becker ◽  
N Kameli ◽  
A Rustichelli ◽  
H Britt ◽  
F Stassen ◽  
...  

Abstract Background Crohn’s disease (CD) is a chronic inflammatory gastro-intestinal condition with a variable disease course. Impaired intestinal integrity and microbial dysbiosis are associated with disease onset and exacerbations. We hypothesized that a perturbed microbial activity in CD patients may contribute to the impaired barrier function. Therefore, this study aimed to examine the impact of faecal bacterial products of active CD patients, CD patients in remission, and healthy controls (HC) on mucin degradation and intestinal epithelial barrier function in vitro. Methods Six HC and twelve CD patients were included. Faecal samples were obtained within one week prior to endoscopy processed within 6 hours after collection. Disease activity was determined by the short endoscopic score for CD (SES-CD). Faecal water (FW) and bacterial membrane vesicles (MVs) were applied on mucin agar to determine mucin degradation. Further, differentiated Caco-2 cell monolayers were exposed to FW and MVs to assess transepithelial electrical resistance (TEER) and paracellular junction stability using permeation of fluorescein isothiocyanate-labelled dextran of 4 kDa. Relative abundances of faecal bacterial genera were evaluated by 16S rRNA gene amplicon sequencing. Results FW-induced mucin degradation was higher in CD samples as compared to HC (p&lt;0.01), but was not linked to specific bacterial relative abundances. FW resulted in 78–87% decrease of TEER in three of the remissive (p&lt;0.001) but not the active CD or HC samples. The decrease of TEER was not linked to increased paracellular permeability. MVs did not induce mucin degradation or epithelial barrier disruption. Conclusion The higher mucin degradation capacity of CD patient-derived FW might indicate contributions of microbial products to CD pathophysiology and warrants further investigation. Moreover, the altered epithelial resistance in some individuals is not due to paracellular alterations.


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.


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.


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.


Author(s):  
Angela Effinger ◽  
Mark McAllister ◽  
Irena Tomaszewska ◽  
Caitriona M. O’Driscoll ◽  
Mark Taylor ◽  
...  

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