scholarly journals CD147 Aggravated Inflammatory Bowel Disease by Triggering NF-κB-Mediated Pyroptosis

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Zhaohui Xu ◽  
Ruitao Liu ◽  
Ling Huang ◽  
Yuxin Xu ◽  
Mingmin Su ◽  
...  

Background. Pyroptosis, a novel form of inflammatory programmed cell death, was recently found to be a cause of mucosal barrier defect. In our pervious study, CD147 expression was documented to increase in intestinal tissue of inflammatory bowel disease (IBD). Objective. The aim of this study was to determine the function of serum CD147 in pyroptosis. Methods. The study group consisted of 96 cases. The centration of CD147, IL-1β, and IL-18 levels in serum was assessed by ELISA. Real-time PCR and WB were performed to analyze the effect of CD147 on pyroptosis. Results. In this study, our results showed that CD147 induced cell pyroptosis in intestinal epithelial cells (IECs) by enhancement of IL-1β and IL-18 expression and secretion in IECs, which is attributed to activation of inflammasomes, including caspase-1 and GSDMD as well as GSDME, leading to aggregate inflammatory reaction. Mechanically, CD147 promoted phosphorylation of NF-κB p65 in IECs, while inhibition of NF-κB activity by the NF-κB inhibitor BAY11-7082 reversed the effect of CD147 on IL-1β and IL-18 secretion. Most importantly, serum CD147 level is slightly clinically correlated with IL-1β, but not IL-18 level. Conclusion. These findings revealed a critical role of CD147 in the patients with IBD, suggesting that blockade of CD147 may be a novel therapeutic strategy for the patients with IBD.

2008 ◽  
Vol 105 (46) ◽  
pp. 17931-17936 ◽  
Author(s):  
Danyvid Olivares-Villagómez ◽  
Yanice V. Mendez-Fernandez ◽  
Vrajesh V. Parekh ◽  
Saif Lalani ◽  
Tiffaney L. Vincent ◽  
...  

Intestinal intraepithelial lymphocytes (IEL) bear a partially activated phenotype that permits them to rapidly respond to antigenic insults. However, this phenotype also implies that IEL must be highly controlled to prevent misdirected immune reactions. It has been suggested that IEL are regulated through the interaction of the CD8αα homodimer with the thymus leukemia (TL) antigen expressed by intestinal epithelial cells. We have generated and characterized mice genetically-deficient in TL expression. Our findings show that TL expression has a critical role in maintaining IEL effector functions. Also, TL deficiency accelerated colitis in a genetic model of inflammatory bowel disease. These findings reveal an important regulatory role of TL in controlling IEL function and intestinal inflammation.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Zhuo Xie ◽  
Mudan Zhang ◽  
Gaoshi Zhou ◽  
Lihui Lin ◽  
Jing Han ◽  
...  

AbstractThe Hedgehog (Hh) signalling pathway plays a critical role in the growth and patterning during embryonic development and maintenance of adult tissue homeostasis. Emerging data indicate that Hh signalling is implicated in the pathogenesis of inflammatory bowel disease (IBD). Current therapeutic treatments for IBD require optimisation, and novel effective drugs are warranted. Targeting the Hh signalling pathway may pave the way for successful IBD treatment. In this review, we introduce the molecular mechanisms underlying the Hh signalling pathway and its role in maintaining intestinal homeostasis. Then, we present interactions between the Hh signalling and other pathways involved in IBD and colitis-associated colorectal cancer (CAC), such as the Wnt and nuclear factor-kappa B (NF-κB) pathways. Furthermore, we summarise the latest research on Hh signalling associated with the occurrence and progression of IBD and CAC. Finally, we discuss the future directions for research on the role of Hh signalling in IBD pathogenesis and provide viewpoints on novel treatment options for IBD by targeting Hh signalling. An in-depth understanding of the complex role of Hh signalling in IBD pathogenesis will contribute to the development of new effective therapies for IBD patients.


2021 ◽  
Vol 4 (Supplement_1) ◽  
pp. 4-5
Author(s):  
Z Taleb ◽  
K Stokes ◽  
H Wang ◽  
S M Collins ◽  
W I Khan ◽  
...  

Abstract Background The circadian clock is a highly conserved molecular pacemaker found in nearly every cell of the body. It consists of the genes BMAL1 and CLOCK that positively regulate CRY and PER, their negative regulators, resulting in a transcription/translation feedback loop that has a 24 hour cycle. This core clock mechanism drives the rhythmic expression of over 40% of the genome in a tissue-specific manner and therefore imposes 24 hour rhythms on many physiological processes. Shift work, which causes disruptions to the natural 24 hour physiological rhythms, has been shown to lead to an increased incidence of inflammatory bowel disease (IBD). Aims This study aims to characterize daily rhythms in inflammation and regeneration of the colon upon induction of acute colitis. We also aim to investigate the intestinal epithelial-specific effects of circadian clock disruption on overall disease progression. We hypothesize that the absence of a functional circadian clock eliminates proliferation rhythms of intestinal epithelial cells and disrupts the rhythms of inflammatory cytokines, thereby increasing the pathogenesis of IBD. Methods We tested the role of the clock in IBD using BMAL1+/+ (wild type) and BMAL1-/- (null mutant) mice. We also investigated the effects of the circadian clock specific to intestinal epithelial tissue using Vil+/+;BMAL1flox/flox (control) and VilCre/+;BMAL1flox/flox (conditional intestinal epithelial mutant) mice. Dextran Sulfate Sodium (DSS) was applied to induce acute colitis. Results We observed significantly decreased survival of BMAL1 circadian clock mutant mice when given colitis. A histology analysis indicates increased lesioning and overall inflammation in BMAL1-/- colon tissue. Disease activity and cytokine analyses reveal time-dependent severity in inflammatory response that is worse in BMAL1-/- mice. To test the circadian rhythms in intestinal regeneration of mice with IBD, we performed a 24 hour analysis comparing epithelial cell proliferation and cell death in colon tissue. We observed rhythmic expression of phosphor-histone H3 (a mitosis marker) in wild type mice which is eliminated in the BMAL1-/- lacking a circadian clock. Cell death which was measured by caspase 3 did not exhibit any differences between genotypes. Based on these results, we conclude that the loss of clock function leads to impaired regeneration during IBD, in part due to decreased and arrhythmic cell proliferation. Preliminary results in our VilCre/+;BMAL1flox/flox conditional intestinal epithelial mutant mice indicate that some of these effects may be epithelial-specific. Conclusions Our results support a critical role of the circadian clock in inflammatory bowel disease development. These data highlight that the circadian clock affects the regenerative abilities of intestinal epithelial cells. Funding Agencies CIHRChron’s and Colitis Canada, Ontario, University of Windsor


2020 ◽  
Vol 14 (Supplement_1) ◽  
pp. S164-S164
Author(s):  
A Treveil ◽  
P Pavlidis ◽  
A Tsakmaki ◽  
G Bewick ◽  
T Korcsmaros ◽  
...  

Abstract Background Interactions between the immune system and the intestinal epithelium play an important role in the pathogenesis of chronic immune mediated inflammatory diseases, including inflammatory bowel disease (IBD). In IBD, debilitating symptoms and complications including abscesses and cancer are associated with aberrant cytokine production and resulting intestinal epithelial damage. Despite the advent of biological therapies targeting key pathogenic cytokines, like tumour necrosis α (TNF), only 18% of IBD patients will achieve complete disease control and mucosal healing. Here, we provide new insights into the epithelial response to cytokines using network analysis of transcriptomics data from colonic organoids (colonoids). Methods We generated an atlas of the transcriptomic effects of cytokines by treating human-derived colonoids with IFNg, IL13, IL9, IL17A and TNF (independently). By integrating the observed transcriptional changes with previously published signalling and regulatory interactions, we generated causal networks to elucidate the effect of cytokine cues on epithelial cells. These networks comprised experimentally verified protein–protein and transcription factor (TF)–target gene interactions, forming signalling pathways linking cytokines to TFs and from TFs to differentially expressed genes. Results With this analysis, we identified previously unrecognised levels of shared and distinct transcriptional regulation of colonic epithelial function by different cytokines. While IL9 had a negligible impact on the transcriptome, the transcripts with differential expression induced by IFNg, IL13, IL17A or TNF were consistent with their recognised function in other tissues. IFNg and TNF exhibited similar magnitude and directional effects on key immune pathways while IL13 had the opposite effect. Using a network approach, we found that regulatory effects of cytokines are primarily transduced through unique signalling routes, some of which converge on the same key transcription factors; CEBPA, E2F1, E2F2, ETS1, FOS, IRF1 and MAZ. We observed independent regulatory mechanisms of the different cytokines as well as complementarity in the epithelial responses regulated by different canonical cytokines. Conclusion The generated cytokine transcriptional atlas provides a unique insight into the immune-epithelial interactome by allowing the identification of shared and distinct transcriptional pathways across different types of immunity at the mucosal barrier. In addition, it provides the unique opportunity to study cytokine responses in the context of human disease and generate novel hypotheses.


2019 ◽  
Vol 10 (4) ◽  
pp. 394-400 ◽  
Author(s):  
Ole Haagen Nielsen ◽  
Thomas Irgens Hansen ◽  
John Mark Gubatan ◽  
Kim Bak Jensen ◽  
Lars Rejnmark

Management of inflammatory bowel disease (IBD), including ulcerative colitis and Crohn’s disease, is generally cumbersome for patients and is a massive health-economic burden. In recent years, the immunomodulating effects of vitamin D have gained a huge interest in its possible pathogenic influence on the pathophysiology of IBD. Vitamin D deficiency is frequent among patients with IBD. Several clinical studies have pointed to a critical role for vitamin D in ameliorating disease outcomes. Although causation versus correlation unfortunately remains an overwhelming issue in the illusive chicken versus egg debate regarding vitamin D and IBD, here we summarise the latest knowledge of the immunological effects of vitamin D in IBD and recommend from available evidence that physicians regularly monitor serum 25(OH)D levels in patients with IBD. Moreover, we propose an algorithm for optimising vitamin D status in patients with IBD in clinical practice. Awaiting well-powered controlled clinical trials, we consider vitamin D supplementation to be an affordable and widely accessible therapeutic strategy to ameliorate IBD clinical outcomes.


Author(s):  
Qin Yu

Abstract Background The transport of transepithelial Cl- and HCO3- is crucial for the function of the intestinal epithelium and maintains the acid-based homeostasis. Slc26a3 (DRA), as a key chloride-bicarbonate exchanger protein in the intestinal epithelial luminal membrane, participates in the electroneutral NaCl absorption of intestine, together with Na+/H+ exchangers. Increasing recent evidence supports the essential role of decreased DRA function or expression in infectious diarrhea and inflammatory bowel disease (IBD). Method In this review, we give an overview of the current knowledge of Slc26a3, including its cloning and expression, function, roles in infectious diarrhea and IBD, and mechanisms of actions. A better understanding of the physiological and pathophysiological relevance of Slc26a3 in infectious diarrhea and IBD may reveal novel targets for future therapy. Conclusion Understanding the physiological function, regulatory interactions, and the potential mechanisms of Slc26a3 in the pathophysiology of infectious diarrhea and IBD will define novel therapeutic approaches in future.


2019 ◽  
Vol 317 (2) ◽  
pp. G98-G107 ◽  
Author(s):  
Sumeet Solanki ◽  
Samantha N. Devenport ◽  
Sadeesh K. Ramakrishnan ◽  
Yatrik M. Shah

Hypoxia is a notable feature of inflammatory bowel disease and chronic induction of hypoxia-inducible factor (HIF)-1α and HIF-2α (endothelial PAS domain protein 1, EPAS1) play important, but opposing, roles in its pathogenesis. While activation of HIF-1α decreases intestinal inflammation and is beneficial in colitis, activation of HIF-2α exacerbates colitis and increases colon carcinogenesis in animal models, primarily due to the role of epithelial HIF-2α in mounting a potent inflammatory response. Previous work from our laboratory showed that mice overexpressing intestinal epithelial HIF-2α led to massive intestinal inflammation and decreased survival. As oxygen homeostasis and HIFs are critical in embryonic development, it is not clear whether the observed intestinal inflammatory response was secondary to developmental defects. To address this question, the present study used a mouse model to temporally modulate expression of intestinal epithelial HIF-2α to assess its role in mediating inflammatory response. Remarkably, activation of HIF-2α in intestinal epithelial cells in adult mice increased expression of proinflammatory mediators; however, no decrease in survival was observed. Furthermore, in an acute model of colitis, activation of HIF-2α was sufficient to exacerbate colitis. These data confirm our previous finding that epithelial HIF-2α mediates inflammatory response and demonstrates that activation of HIF-2α is sufficient to exacerbate colitis.NEW & NOTEWORTHY Inflammatory bowel disease (IBD) is a chronic relapsing inflammatory disease of the intestinal tract. Hypoxia and activation of its downstream transcription factors hypoxia-inducible factor (HIF)-1α and HIF-2α are notable features of IBD. HIF-1α has well-characterized protective roles in IBD; however, the role of HIF-2α has been less studied. Using novel HIF-2α mouse models, we show that activation of HIF-2α in intestinal epithelial cells is sufficient to exacerbate colitis.


2018 ◽  
Vol 19 (9) ◽  
pp. 2775 ◽  
Author(s):  
Bjoern Titz ◽  
Raffaella Gadaleta ◽  
Giuseppe Lo Sasso ◽  
Ashraf Elamin ◽  
Kim Ekroos ◽  
...  

Inflammatory bowel disease (IBD) represents a group of progressive disorders characterized by recurrent chronic inflammation of the gut. Ulcerative colitis and Crohn′s disease are the major manifestations of IBD. While our understanding of IBD has progressed in recent years, its etiology is far from being fully understood, resulting in suboptimal treatment options. Complementing other biological endpoints, bioanalytical “omics” methods that quantify many biomolecules simultaneously have great potential in the dissection of the complex pathogenesis of IBD. In this review, we focus on the rapidly evolving proteomics and lipidomics technologies and their broad applicability to IBD studies; these range from investigations of immune-regulatory mechanisms and biomarker discovery to studies dissecting host–microbiome interactions and the role of intestinal epithelial cells. Future studies can leverage recent advances, including improved analytical methodologies, additional relevant sample types, and integrative multi-omics analyses. Proteomics and lipidomics could effectively accelerate the development of novel targeted treatments and the discovery of complementary biomarkers, enabling continuous monitoring of the treatment response of individual patients; this may allow further refinement of treatment and, ultimately, facilitate a personalized medicine approach to IBD.


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