Search results for "Colitis"

Activation of Intestinal Epithelial Stat3 Orchestrates Tissue Defense during Gastrointestinal Infection

2015

Gastrointestinal infections with EHEC and EPEC are responsible for outbreaks of diarrheal diseases and represent a global health problem. Innate first-line-defense mechanisms such as production of mucus and antimicrobial peptides by intestinal epithelial cells are of utmost importance for host control of gastrointestinal infections. For the first time, we directly demonstrate a critical role for Stat3 activation in intestinal epithelial cells upon infection of mice with Citrobacter rodentium - a murine pathogen that mimics human infections with attaching and effacing Escherichia coli. C. rodentium induced transcription of IL-6 and IL-22 in gut samples of mice and was associated with activat…

Inhibition of Ulcerative Colitis in Mice after Oral Administration of a Polyphenol-Enriched Cocoa Extract Is Mediated by the Inhibition of STAT1 and …

2011

We studied a polyphenol-enriched cocoa extract (PCE) with epicatechin, procyanidin B2, catechin, and procyanidin B1 as the major phenolics for its anti-inflammatory properties against dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in mice. PCE reduced colon damage, with significant reductions in both the extent and the severity of the inflammation as well as in crypt damage and leukocyte infiltration in the mucosa. Analysis ex vivo showed clear decreases in the production of nitric oxide, cyclooxygenase-2, pSTAT-3, and pSTAT1α, with NF-κB p65 production being slightly reduced. Moreover, NF-κB activation was reduced in RAW 264.7 cells in vitro. In conclusion, the inhibitory eff…

Mouse models of inflammatory bowel disease.

2007

Animal models of intestinal inflammation are indispensable for our understanding of the pathogenesis of Crohn disease and Ulcerative colitis, the idiopathic forms of inflammatory bowel disease in humans. The clinical appearance of human IBD is heterogeneous, a fact that is also reflected by the steadily increasing number of mouse strains displaying IBD like intestinal alterations. The analysis of these models together with genetic studies in humans greatly enhanced our insights into immunoregulatory processes in the gut and led to the generally accepted hypothesis that a deregulated immune response against components of the intestinal microbiota is critically involved in IBD pathophysiology…

Intestinal anti-inflammatory activity of ellagic acid in the acute and chronic dextrane sulfate sodium models of mice colitis.

2013

Abstract Ethnopharmacological relevance Pomegranate (Punica granatum L.; Lythraceae) has traditionally been used for the treatment of various inflammatory diseases, including ulcerative colitis (UC). Because its fruits and extracts are rich in ellagitannins, which release ellagic acid when hydrolyzed, consumption of pomegranate products is currently being widely promoted for their potential health effects, including the prevention of inflammatory diseases and cancer. To evaluate the anti-inflammatory effects of ellagic acid on dextran sulfate sodium (DSS)-induced acute and chronic experimental colitis in two different strains of mice and to elucidate its possible mechanisms of action. Mater…

Resveratrol-induced xenophagy promotes intracellular bacteria clearance in intestinal epithelial cells and macrophages

2019

International audience; Autophagy is a lysosomal degradation process that contributes to host immunity by eliminating invasive pathogens and the modulating inflammatory response. Several infectious and immune disorders are associated with autophagy defects, suggesting that stimulation of autophagy in these diseases should be bene ficial. Here, we show that resveratrol is able to boost xenophagy, a selective form of autophagy that target invasive bacteria. We demonstrated that resveratrol promotes in vitro autophagy-dependent clearance of intracellular bacteria in intestinal epithelial cells and macrophages. These results were validated in vivo using infection in a transgenic GFP-LC3 zebra f…

A case of bowel schistosomiasis that did not adhere to the endoscopic findings.

2005

Norovirus-Host Interactions in the course of Inflammatory Bowel Disease

2021

Inflammatory bowel disease (IBD) affects around 200,000 people in France. This group of conditions includes Crohn's disease (CD), which involves the entire digestive tract, and ulcerative colitis (UC), which involves only the colon and rectum. It is known that immunological, genetic and microbiological factors are at play in IBD, but the role of viruses remains only partially explored. Among viral etiologies, human noroviruses (huNoV) are the main cause of acute viral gastroenteritis worldwide. Norovirus binds to intestinal cells through histo-blood group antigens (HBGA), including ABO and Lewis antigens. The expression of HBGA is dependent upon tissue type and the underlying physiopatholog…

Enteropathogenic e.coli sustains iodoacetamide-induced ulcerative colitis-like colitis in rats: modulation of IL-1beta, IL-6, TNF-alpha, COX-2, and a…

2012

Pathogenic or non-pathogenic bacteria from flora may play a key role in inflammatory bowel disease (IBD) pathogenesis. However, a specific infectious agent causing IBD has not been identified. This study assessed the impact of enteropathogenic E. coli (EPEC) on the modulation of IL-1beta, IL-6, TNF- alpha, COX-2, BAX and Bcl-2 expression, in sustaining inflammation of a rat colitis model. Two hundred male Sprague-Dawley rats (4 groups) were inoculated weekly or bi-weekly for 70 days, with 1 percent methylcellulose (MC), (b) 6 percent iodoacetamide (IA) in 1 percent MC, (c) 4x108 CFU of EPEC, and (d) IA+EPEC. After a month, treatment was stopped in half of the animals in each group. IL-1beta…

Nutrition in inflammatory bowel disease patients

2015

Inflammatory Bowel Diseases (IBD) is a chronic disorder characterized bya relapsing-remitting course, which alternates between active and quiescent states, ultimately impairing a patient's quality of life. The two main types of IBD are Crohn's disease (CD) and ulcerative colitis (UC). CD shows a transmural granulomatous inflammation that can involve any segment of the intestine affecting all layers of the intestinal wall while UC is limited to the mucosa and superficial sub-mucosa of the colon. In physiologial conditions the gut is costantly exposed to various antigens, commensal microflora and pathogens and the inflammatory response is finely balanced. Anyhow in some individuals with genet…

MESENCHIMAL STEM CELLS IN INFLAMMATORY BOWEL DISEASES: CLINICAL EVIDENCES AND POTENTIAL INSIGHTS FOR THE CLINICIANS

2013

Mesenchimal stem cells (MSCs) have been used experimentally and clinically in the treatment of a wide variety of pathologies MSCs can be safely transplanted in autologous and allogenic ways as they are non-immunogenic, and consequently represent a therapeutic option for refractory connective tissue diseases, fibrosing diseases like scleroderma and fistulizing colitis like in Crohn's disease (CD). The immunomodulatory properties of MSCs have already shown promise when used as therapy for otherwise medically refractory CD. Accumulating evidence suggests that the properties may also be exploited of several other conditions. The currently available experimental and clinical data indicate that, …