scholarly journals A Dietary Cholesterol-Based Intestinal Inflammation Assay for Improving Drug-Discovery on Inflammatory Bowel Diseases

Author(s):  
Nuno-Valério Silva ◽  
Diogo Carregosa ◽  
Catarina Gonçalves ◽  
Otília V. Vieira ◽  
Cláudia Nunes dos Santos ◽  
...  

Inflammatory bowel diseases (IBD) with chronic infiltration of immune cells in the gastrointestinal tract are common and largely incurable. The therapeutic targeting of IBD has been hampered by the complex causality of the disease, with environmental insults like cholesterol-enriched Western diets playing a critical role. To address this drug development challenge, we report an easy-to-handle dietary cholesterol-based in vivo assay that allows the screening of immune-modulatory therapeutics in transgenic zebrafish models. An improvement in the feeding strategy with high cholesterol diet (HCD) selectively induces a robust and consistent infiltration of myeloid cells in larvae intestines that is highly suitable for compound discovery efforts. Using transgenics with fluorescent reporter expression in neutrophils, we take advantage of the unique zebrafish larvae clarity to monitor an acute inflammatory response in a whole organism context with a fully functional innate immune system. The use of semi-automated image acquisition and processing combined with quantitative image analysis allows categorizing anti- or pro-inflammatory compounds based on a leukocytic inflammation index. Our HCD gut inflammation (HCD-GI) assay is simple, cost- and time-effective as well as highly physiological which makes it unique when compared to chemical-based zebrafish models of IBD. Besides, diet is a highly controlled, selective and targeted trigger of intestinal inflammation that avoids extra-intestinal outcomes and reduces the chances of chemical-induced toxicity during screenings. We show the validity of this assay for a screening platform by testing two dietary phenolic acids, namely gallic acid (GA; 3,4,5-trihydroxybenzoic acid) and ferulic acid (FA; 4-hydroxy-3-methoxycinnamic acid), with well described anti-inflammatory actions in animal models of IBD. Analysis of common IBD therapeutics (Prednisolone and Mesalamine) proved the fidelity of our IBD-like intestinal inflammation model. In conclusion, the HCD-GI assay can facilitate and accelerate drug discovery efforts on IBD, by identification of novel lead molecules with immune modulatory action on intestinal neutrophilic inflammation. This will serve as a jumping-off point for more profound analyses of drug mechanisms and pathways involved in early IBD immune responses.

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Tiago Nunes ◽  
Claudio Bernardazzi ◽  
Heitor S. de Souza

Cell death mechanisms have been associated with the development of inflammatory bowel diseases in humans and mice. Recent studies suggested that a complex crosstalk between autophagy/apoptosis, microbe sensing, and enhanced endoplasmic reticulum stress in the epithelium could play a critical role in these diseases. In addition, necroptosis, a relatively novel programmed necrosis-like pathway associated with TNF receptor activation, seems to be also present in the pathogenesis of Crohn’s disease and in specific animal models for intestinal inflammation. This review attempts to cover new data related to cell death mechanisms and inflammatory bowel diseases.


Author(s):  
Huimin Chen ◽  
Xiaohan Wu ◽  
Chunjin Xu ◽  
Jian Lin ◽  
Zhanju Liu

Abstract Neutrophils are considered as complex innate immune cells and play a critical role in maintaining intestinal mucosal homeostasis. They exert robust pro-inflammatory effects and recruit other immune cells in the acute phase of pathogen infection and intestinal inflammation, but paradoxically, they also limit exogenous microbial invasion and facilitate mucosal restoration. Hyperactivation or dysfunction of neutrophils results in abnormal immune responses, leading to multiple autoimmune and inflammatory diseases including systemic lupus erythematosus, rheumatoid arthritis, and inflammatory bowel diseases (IBD). As a refractory intestinal inflammatory disease, the pathogenesis and progression of IBD are associated with complicated immune response processes in which neutrophils are profoundly involved. However, the consensus on potential roles of neutrophils in modulating pathogenic and repair processes of IBD remains not fully understood. Accumulated infiltrating neutrophils cross the epithelial barrier and contribute to microbial dysbiosis, aggravated intestinal architectural damage, compromised resolution of intestinal inflammation and increased risk of thrombosis during IBD. Paradoxically, activated neutrophils are also associated with effective elimination of invaded microbiota, promoted angiogenesis and tissue restoration of gut mucosa in IBD. Here, we discuss the beneficial and detrimental roles of neutrophils in the onset and resolution of intestinal mucosal inflammation and provide a precise overview of neutrophil functions in the pathogenesis of IBD.


2021 ◽  
Vol 22 (5) ◽  
pp. 2645
Author(s):  
Dinh Nam Tran ◽  
Seon Myeong Go ◽  
Seon-Mi Park ◽  
Eui-Man Jung ◽  
Eui-Bae Jeung

Inflammatory bowel diseases (IBDs) comprises a range of chronic inflammatory conditions of the intestinal tract. The incidence and prevalence of IBDs are increasing worldwide, but the precise etiology of these diseases is not completely understood. Calcium signaling plays a regulatory role in cellular proliferation. Nckx3, a potassium-dependent Na+/Ca2+ exchanger, is not only expressed in the brain but also in the aortic, uterine, and intestinal tissues, which contain abundant smooth muscle cells. This study investigated the role of Nckx3 in intestinal inflammation. Microarray analyses revealed the upregulation of the innate immune response-associated genes in the duodenum of Nckx3 knockout (KO) mice. The Nckx3 KO mice also showed an increase in IBD- and tumorigenesis-related genes. Using dextran sodium sulfate (DSS)-induced experimental colitis mice models, the Nckx3 KO mice showed severe colitis. Furthermore, the pathways involving p53 and NF-κB signaling were significantly upregulated by the absence of Nckx3. Overall, Nckx3 plays a critical role in the innate immune and immune response and may be central to the pathogenesis of IBD.


2015 ◽  
Vol 33 (Suppl. 1) ◽  
pp. 26-31
Author(s):  
Hans Herfarth ◽  
Andreas G. Schreyer

Diagnostic imaging techniques play an important role in the diagnosis and management of patients with inflammatory bowel diseases (IBDs). The approach should be guided by considerations of diagnostic accuracy, concerns about patient exposure to ionizing radiation, local expertise and tolerance of the endoscopic and/or imaging technique. In regard to the clinical diagnostic value (sensitivity, specificity and accuracy), no significant differences exist between CT and MRI for the evaluation of the extent of inflammation, stricturing, penetrating disease or extraluminal complications such as abscesses. Due to the absence of radiation exposure, MRI of the intestine is recommended as the first-line imaging modality in patients with suspected or established IBD. The focus of this review is the latest developments in MRI techniques to detect IBDs. Specifically, the use of new indices for the grading of inflammation or assessing bowel damage as well as innovative experimental approaches such as diffusion-weighted imaging or magnetization-transfer MRI to evaluate and quantify the degree of intestinal inflammation and fibrosis in stricturing Crohn's disease are discussed.


2021 ◽  
Author(s):  
Jiří Hrdý ◽  
Aurélie Couturier-Maillard ◽  
Denise Boutillier ◽  
Carmen Lapadatescu ◽  
Philippe Blanc ◽  
...  

Abstract Live biotherapeutic products constitute an emerging therapeutic approach to prevent or treat inflammatory bowel diseases. Lactobacillus acidophilus is a constituent of the human microbiota with probiotic potential, that are illustrated by direct and indirect antimicrobial activity against several pathogens and improvement of intestinal inflammation. In this study, we evaluated the anti-inflammatory properties of the L. acidophilus strain BIO5768 and assessed the underlying mechanisms of action. BIO5768 was able to counteract the acute colitis that is induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS). When administered alone or in combination with Bifidobacterium animalis spp. lactis BIO5764 and Limosilactobacillus reuteri, BIO5768 was also able to alleviate intestinal inflammation induced by Citrobacter rodentium infection. Supplementation of naïve mice with either strain BIO5768 alone or as mixture, increased the gene expression of several target genes involved in immune signaling, including c-type lectin Reg3 gamma. Consistently, the ability of innate lymphoid cells to secrete IL-22 was enhanced in response to BIO5768. Interestingly, the aforementioned responses were shown to be independent of NOD2 and Th17 signaling in mice that were mono-colonized with BIO5768. In conclusion, we identify a new potential probiotic strain with the ability for the management of inflammatory bowel diseases, and provide some insights into its mode of action.


2020 ◽  
Vol 79 (4) ◽  
pp. 468-478 ◽  
Author(s):  
Stefania Del Fabbro ◽  
Philip C. Calder ◽  
Caroline E. Childs

The aim of the present paper is to review the effects of non-digestible oligosaccharides (NDO) on immunity, focusing on their microbiota-independent mechanisms of action, as well as to explore their potential beneficial role in inflammatory bowel diseases (IBD). IBD are chronic, inflammatory conditions of the gastrointestinal tract. Individuals with IBD have an aberrant immune response to commensal microbiota, resulting in extensive mucosal inflammation and increased intestinal permeability. NDO are prebiotic fibres well known for their role in supporting intestinal health through modulation of the gut microbiota. NDO reach the colon intact and are fermented by commensal bacteria, resulting in the production of SCFA with immunomodulatory properties. In disease states characterised by increased gut permeability, prebiotics may also bypass the gut barrier and directly interact with intestinal and systemic immune cells, as demonstrated in patients with IBD and in infants with an immature gut. In vitro models show that fructooligosaccharides, inulin and galactooligosaccharides exert microbiota-independent effects on immunity by binding to toll-like receptors on monocytes, macrophages and intestinal epithelial cells and by modulating cytokine production and immune cell maturation. Moreover, animal models and human supplementation studies demonstrate that some prebiotics, including inulin and lactulose, might reduce intestinal inflammation and IBD symptoms. Although there are convincing preliminary data to support NDO as immunomodulators in the management of IBD, their mechanisms of action are still unclear and larger standardised studies need to be performed using a wider range of prebiotics.


2011 ◽  
Vol 11 ◽  
pp. 1536-1547 ◽  
Author(s):  
Donata Lissner ◽  
Britta Siegmund

Inflammasomes are intracellular multiprotein complexes that coordinate the maturation of interleukin (IL)-1β and IL-18 in response to pathogens and metabolic danger. Both cytokines have been linked to intestinal inflammation. However, recently evolving concepts ascribe a major role to the inflammasome in maintaining intestinal homeostasis. This review recapitulates its position in the development of inflammatory bowel disease, thereby outlining a model in which hypo- as well as hyperfunctionality can lead to an imbalance of the system, depending on the specific cell population affected. In the epithelium, the inflammasome is essential for regulation of permeability and epithelial regeneration through sensing of commensal microbes, while excessive inflammasome activation within the lamina propria contributes to severe intestinal inflammation.


Sign in / Sign up

Export Citation Format

Share Document