Expression Of Inflammatory Bowel Disease Research Articles

Differential analysis of sorting nexin 10 and sterol regulatory element-binding protein 2 expression in inflammatory bowel disease.

Sorting nexin 10 (SNX10) expression induces intestinal barrier dysfunction and inflammatory responses; in contrast, its inhibition promotes intestinal mucosal healing through sterol regulatory element-binding protein 2 (SREBP2)-mediated cholesterol synthesis. However, its regulatory mechanism for the pathogenesis of inflammatory bowel disease (IBD) remains unclear. In this study, we examined SNX10 and SREBP2 expression in ulcerative colitis (UC) and Crohn's disease (CD). A total of 30 and 28 patients with UC and CD, respectively, were recruited. The expression of SNX10 and SREBP2 in the colonic mucosa was measured by immunohistochemistry (IHC). We discovered that patients with CD had significantly higher expression levels of SNX10 and SREBP2 than patients with UC and healthy controls. In addition, the expression of SREBP2 in patients with UC was significantly higher than that in healthy controls. In our study, we indicated that SNX10 and SREBP2 may serve as biomarkers for identifying patients with UC and CD, thereby providing a clinical therapeutic strategy for the treatment of IBD by inhibiting SNX10.

Epithelial neutrophil localization and tight junction Claudin-2 expression are innovative outcome predictors in inflammatory bowel disease.

Patients with inflammatory bowel disease (IBD) in clinical and endoscopic remission may still experience disease relapse. Therefore, there is a need to identify outcome predictors. Recently, the role of neutrophils in predicting outcomes in ulcerative colitis (UC) has been highlighted. Furthermore, the impairment of intestinal barrier plays a key role in forecasting disease outcomes in IBD. This observational study aimed to assess the predictive role of neutrophils according to tissue localization and intestinal barrier protein expression in IBD. IBD patients in clinical remission who underwent colonoscopy between January 2020 and June 2022 at two tertiary referral centres were enrolled. Patients with Mayo Endoscopic Score ≤1 (UC) and Simple Endoscopic Score ≤6 (Crohn's disease) were included. Histological activity was assessed using validated scores. Experienced pathologists evaluated neutrophil localization in the epithelium and lamina propria and immunohistochemical expression of Claudin-2 and junctional adhesion molecule A (JAM-A). Of 60 UC and 76 CD patients, 59.7% had histological activity. 25.8% of patients developed an adverse outcome within 12months. Neutrophils in the epithelium predicted adverse outcomes for UC (hazard ratio [HR] 5.198, p=0.01) and CD (HR 4.377, p=0.03) patients in endoscopic remission. Claudin-2 expression correlated with endoscopic and histological activity and predicted outcomes in UC. Similar results were found for JAM-A in CD despite this protein showing less specificity as a barrier predictor of outcome. This study highlights the potential role of epithelial neutrophil localization and Claudin-2 'leaky gut' expression as tools for predicting IBD outcomes and guiding further patient-tailored therapy.

The effect of rs2910686 on ERAP2 expression in IBD and epithelial inflammatory response

BackgroundERAP2 is an aminopeptidase involved in antigen processing and presentation, and harbor genetic variants linked to several inflammatory diseases such as Inflammatory Bowel Disease (IBD). The lack of an ERAP2 gene homologue in mice has hampered functional studies, and most human studies have focused on cells of hematopoietic origin. Using an IBD biobank as vantage point, this study explores how genetic variation in ERAP2 affects gene expression in human-derived epithelial organoids upon proinflammatory stimulation.MethodsAn IBD patient cohort was genotyped with regards to two single nucleotide polymorphisms (SNP) (rs2910686/rs2248374) associated with ERAP2 expression levels, and we examined the correlation between colon gene expression and genotype, specifically aiming to establish a relationship with ERAP2 expression proficiency. Human-derived colon organoids (colonoids) with known ERAP2 genotype were established and used to explore differences in whole genome gene expression between ERAP2-deficient (n = 4) and -proficient (n = 4) donors upon pro-inflammatory encounter.ResultsWhen taking rs2910686 genotype into account, ERAP2 gene expression is upregulated in the inflamed colon of IBD patients. Colonoids upregulate ERAP2 upon IFNɣ stimulation, and ERAP2 expression proficiency is dependent on rs2910686 genotype. Colonoid genotyping confirms that mechanisms independent of the frequently studied SNP rs2248374 can cause ERAP2-deficiency. A total of 586 genes involved in various molecular mechanisms are differentially expressed between ERAP2 proficient- and deficient colonoids upon proinflammatory stimulation, including genes encoding proteins with the following molecular function: catalytic activity (AOC1, CPE, ANPEP and MEP1A), regulator activity (TNFSF9, MDK, GDF15, ILR6A, LGALS3 and FLNA), transmembrane transporter activity (SLC40A1 and SLC5A1), and extracellular matrix structural constituents (FGL2, HMCN2, and MUC17).ConclusionsERAP2 is upregulated in the inflamed IBD colon mucosa, and expression proficiency is highly correlated with genotype of rs2910686. While the SNP rs2248374 is commonly used to determine ERAP2 expressional proficiency, our data confirms that mechanisms independent of this SNP can lead to ERAP2 deficiency. Our data demonstrates that epithelial ERAP2 presence affects the inflammatory response in colonoids, suggesting a pleiotropic role of ERAP2 beyond MHC class I antigen processing.

Immunohistochemical Analysis of IL-19 and IL-24 Expression in Inflammatory Bowel Disease (IBD) Patients: Results From a Single Center Retrospective Study.

Background IL-19 and IL-24 induce proinflammatory cytokine production through the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway. The primary objective of this study was to investigate any changes in IL-19 and IL-24 expression between inflammatory bowel disease (IBD) patients and healthy controls, as well asbefore and after the initiation of biologics. The secondary objective was to investigate any relation betweentheir expression anddisease phenotype and activity. Methods IL-19 and IL-24 expression was measured in intestinal tissue samples from 121 patients with moderate to severe IBD versus healthy controls using immunohistochemistry. Their expression was then measured 12 months after treatmenton the patient group treated with biologics. The disease activity was measured before and after treatment using the Harvey Bradshaw Index (HBI) for Crohn's disease (CD) patients and the Mayo Score (MS) for ulcerative colitis (UC) patients. Data were analyzed using SPSS (IBM Inc., Armonk, New York). Results IL-19 expression was raisedin the IBD group versus healthy controls. In the CD group, the IL-19 expression was related with the disease activity scorepost-biologic treatment. IL-24 was also highly expressed in patients with active UC and CD and was increased post-treatment. Itsexpression in UC was statistically related with the MS. Conclusions IL-24 and IL-19 are key factors in IBD-related intestinal inflammation and this is one of the few human studies to suggest that. An immunosuppressive role of IL-24 was demonstrated in the UC group. A future use as biomarkers of disease activity and response to treatment might be feasible.

Salivary calprotectin and neutrophils in inflammatory bowel disease in relation to oral diseases

AbstractObjectiveCalprotectin is elevated in saliva from inflammatory bowel disease (IBD) patients, but it is also affected by oral disease. We assessed the salivary concentration of calprotectin in IBD patients, in relation to intestinal and oral diseases. Furthermore, we investigated the phenotype of salivary neutrophils from IBD patients, and their ability to secrete calprotectin.Materials and MethodsThirty IBD patients and 26 controls were orally examined and sampled for stimulated saliva. Twenty‐five IBD patients provided fresh fecal samples. Calprotectin concentrations in saliva and feces were determined by an enzyme‐linked immunosorbent assay. Expression of CD11b, CD15, and CD16 on oral neutrophils was assessed by flow cytometry. Secretion of calprotectin was evaluated in cultured oral neutrophils.ResultsCalprotectin was significantly elevated in saliva of IBD patients compared to controls, particularly in Crohn's disease, irrespective of caries or periodontitis. Salivary calprotectin did not correlate to fecal calprotectin. CD11b expression was significantly reduced in salivary neutrophils from IBD patients. Salivary neutrophils from IBD patients tended to secrete more calprotectin than controls.ConclusionsSalivary calprotectin is elevated in IBD regardless of oral diseases. Furthermore, salivary neutrophils secrete calprotectin, and display lower CD11b expression in IBD.

Exploring Microbial Metabolite Receptors in Inflammatory Bowel Disease: An In Silico Analysis of Their Potential Role in Inflammation and Fibrosis.

Metabolites produced by dysbiotic intestinal microbiota can influence disease pathophysiology by participating in ligand-receptor interactions. Our aim was to investigate the differential expression of metabolite receptor (MR) genes between inflammatory bowel disease (IBD), healthy individuals (HIs), and disease controls in order to identify possible interactions with inflammatory and fibrotic pathways in the intestine. RNA-sequencing datasets containing 643 Crohn's disease (CD) patients, 467 ulcerative colitis (UC) patients and 295 HIs, and 4 Campylobacter jejuni-infected individuals were retrieved from the Sequence Read Archive, and differential expression was performed using the RaNA-seq online platform. The identified differentially expressed MR genes were used for correlation analysis with up- and downregulated genes in IBD, as well as functional enrichment analysis using a R based pipeline. Overall, 15 MR genes exhibited dysregulated expression in IBD. In inflamed CD, the hydroxycarboxylic acid receptors 2 and 3 (HCAR2, HCAR3) were upregulated and were associated with the recruitment of innate immune cells, while, in the non-inflamed CD ileum, the cannabinoid receptor 1 (CNR1) and the sphingosine-1-phospate receptor 4 (S1PR4) were downregulated and were involved in the regulation of B-cell activation. In inflamed UC, the upregulated receptors HCAR2 and HCAR3 were more closely associated with the process of TH-17 cell differentiation, while the pregnane X receptor (NR1I2) and the transient receptor potential vanilloid 1 (TRPV1) were downregulated and were involved in epithelial barrier maintenance. Our results elucidate the landscape of metabolite receptor expression in IBD, highlighting associations with disease-related functions that could guide the development of new targeted therapies.

"Decoding inflammation: glycoprotein a repetition predominant, microRNA-142-3-p, and metastasis associated lung adenocarcinoma transcript 1: as novel inflammatory biomarkers of inflammatory bowel disease".

Inflammatory bowel disease (IBD) is a chronic gastrointestinal (GI) condition comprising Crohn's disease (CD) and ulcerative colitis (UC). The pathogenesis involves immune system dysregulation, with increased Th (T helper cell)17 cells and reduced regulatory T cell (Treg) differentiation. Transforming growth factor-β (TGF-β) secretion from Tregs helps control inflammation, and its production is regulated by glycoprotein-A repetition predominant (GARP) protein along with non-coding RNAs (ncRNAs) like microRNA(miR)-142-3p and metastasis associated lung adenocarcinoma transcript 1 (MALAT1) long non-coding RNAs (LncRNAs). This study analyzed their expression in IBD. Blood samples were collected from 44 IBD patients, and 22 healthy controls (HC). RNA extraction and circular DNA (cDNA) synthesis were performed. Real-time polymerase chain reaction (RT-PCR) measured gene expression of GARP, MALAT1, and miR-142-3p. Correlations and group differences were statistically analyzed. Compared to controls, GARP was downregulated while MALAT1 and miR-142-3p were upregulated significantly in IBD group. GARP and MALAT1 expressions positively correlated in controls. MALAT1 and miR-142-3p expressions positively correlated in IBD group. MALAT1 was downregulated in aged HC but upregulated with smoking history across groups. No correlations occurred between gene expression and gender, diet, infections, or disease activity scores. Dysregulation of GARP, MALAT1, and miR-142-3p likely contributes to inflammation in IBD by reducing TGF-β. MALAT1 is linked to smoking and age-related changes. These genes have potential as diagnostic markers or therapeutic targets for personalized IBD treatment.

P379 PD-1-positive cells contribute to the diagnosis of Inflammatory Bowel Disease and can aid in predicting response to vedolizumab

Abstract Background Differentiating inflammatory bowel disease (IBD) from other inflammatory diseases is often challenging. Programmed cell death protein-1 (PD-1) is expressed in T cells and is an indicator of their exhaustion. The role of PD-1 expression in diagnosing IBD and predicting the response of biologic agents remains inconclusive. Methods In this study, endoscopic biopsy samples of 19 patients diagnosed with IBD and other inflammatory diseases were analysed using multiplexed immunohistochemistry . Other inflammatory diseases comprised five patients with intestinal tuberculosis, and five with intestinal Behçet’s disease. Additionally, a separate prospectively maintained "vedolizumab (VDZ) cohort", established in 12 ulcerative colitis(UC) patients who underwent endoscopic biopsy before VDZ administration was analysed to predict response to VDZ. Results In the immunohistochemistry analysis, the cell density of T cell subsets, including helper T cell (Th), cytotoxic T cell (Tc), regulatory T cell (Treg), PD-1+ cell, PD-1+ Th, PD-1+ Tc, and PD-1+ Treg was investigated and compared between IBD and other inflammatory disease. Cell densities of PD-1+ cells (p=0.028), PD-1+ Th (p=0.008), and PD-1+ Treg (p=0.024) were higher in IBD compared with other inflammatory disease.(Figure 1) In addition, the proportion of PD-1+ cells in Th and Treg was higher in the IBD group than in the other inflammatory disease group (median 7% vs. 3%, p=0.008; median 6% vs. 2%, p=0.004, respectively). Comparing within IBD, the cell density of Treg was higher in Crohn’s disease(CD) than in UC (p=0.042), whilst the cell density of Tc was higher in CD than in UC with marginal statistical significance (p=0.066). In the VDZ cohort, patients with a 14-week steroid-free clinical response had higher levels of PD-1+ cells (p=0.026), PD-1+ Th (p=0.026), and PD-1+ Treg (p=0.041) than the no response group.(Table 1) Conclusion We explored the relationship between PD-1 expression and IBD using multiplexed immunohistochemistry. We compared IBD and other inflammatory disease in their expression of various immune cells including PD-1+ cells, and found IBD had higher PD-1 expression, as well as higher PD-1+ Th and PD-1+ Treg compared with other inflammatory diseases. In addition, VDZ-responsive patients had higher PD-1 expression. Our study confirmed the difference in PD-1 expression in IBD and other inflammatory diseases and revealed that PD-1 expression could be a predictive marker for VDZ responsiveness.

Faecalibacterium prausnitzii promotes intestinal epithelial IL-18 production through activation of the HIF1α pathway.

Intestinal epithelial cells produce interleukin-18 (IL-18), a key factor in promoting epithelial barrier integrity. Here, we analyzed the potential role of gut bacteria and the hypoxia-inducible factor 1α (HIF1α) pathway in regulating mucosal IL18 expression in inflammatory bowel disease (IBD). Mucosal samples from patients with IBD (n = 760) were analyzed for bacterial composition, IL18 levels and HIF1α pathway activation. Wild-type Caco-2 and CRISPR/Cas9-engineered Caco-2-HIF1A-null cells were cocultured with Faecalibacterium prausnitzii in a "Human oxygen-Bacteria anaerobic" in vitro system and analyzed by RNA sequencing. Mucosal IL18 mRNA levels correlated positively with the abundance of mucosal-associated butyrate-producing bacteria, in particular F. prausnitzii, and with HIF1α pathway activation in patients with IBD. HIF1α-mediated expression of IL18, either by a pharmacological agonist (dimethyloxallyl glycine) or F. prausnitzii, was abrogated in Caco-2-HIF1A-null cells. Butyrate-producing gut bacteria like F. prausnitzii regulate mucosal IL18 expression in a HIF1α-dependent manner that may aid in mucosal healing in IBD.

Upregulated Tβ4 expression in inflammatory bowel disease impairs the intestinal mucus barrier by inhibiting autophagy in mice

Disrupted intestinal barrier homeostasis is fundamental to inflammatory bowel disease. Thymosin β4 (Tβ4) improves inflammation and has beneficial effects in dry-eye diseases, but its effects on the intestinal mucus barrier remain unknown. Therefore, this study evaluated the underlying regulatory mechanisms and effects of Tβ4 by examining Tβ4 expression in a mouse model with dextran sodium sulfate (DSS)-induced colitis and colonic barrier damage. Additionally, we intraperitoneally injected C57BL/6 mice with Tβ4 to assess barrier function, microtubule-associated protein 1 light chain 3 (LC3II) protein expression, and autophagy. Finally, normal human colon tissue and colon carcinoma cells (Caco2) were cultured to verify Tβ4-induced barrier function and autophagy changes. Mucin2 levels decreased, microbial infiltration increased, and Tβ4 expression increased in the colitis mouse model versus the control mice, indicating mucus barrier damage. Moreover, Tβ4-treated C57BL/6 mice had damaged intestinal mucus barriers and decreased LC3II levels. Tβ4 also inhibited colonic mucin2 production, disrupted tight junctions, and downregulated autophagy; these results were confirmed in Caco2 cells and normal human colon tissue. In summary, Tβ4 may be implicated in colitis by compromising the integrity of the intestinal mucus barrier and inhibiting autophagy. Thus, Tβ4 could be a new diagnostic marker for intestinal barrier defects.

Loss of claudin-3 expression increases colitis risk by promoting Gut Dysbiosis

ABSTRACT Dysregulation of both the gut barrier and microbiota (dysbiosis) promotes susceptibility to and severity of Inflammatory Bowel Diseases (IBD). Leaky gut and dysbiosis often coexist; however, potential interdependence and molecular regulation are not well understood. Robust expression of claudin-3 (CLDN3) characterizes the gut epithelium, and studies have demonstrated a positive association between CLDN3 expression and gut barrier maturity and integrity, including in response to probiotics. However, the exact status and causal role of CLDN3 in IBD and regulation of gut dysbiosis remain unknown. Analysis of mouse and human IBD cohorts helped examine CLDN3 expression in IBD. The causal role was determined by modeling CLDN3 loss of expression during experimental colitis. 16S sequencing and in silico analysis helped examine gut microbiota diversity between Cldn3KO and WT mice and potential host metabolic responses. Fecal microbiota transplant (FMT) studies were performed to assess the role of gut dysbiosis in the increased susceptibility of Cldn3KO mice to colitis. A significant decrease in CLDN3 expression characterized IBD and CLDN3 loss of expression promoted colitis. 16S sequencing analysis suggested gut microbiota changes in Cldn3KO mice that were capable of modulating fatty acid metabolism and oxidative stress response. FMT from naïve Cldn3KO mice promoted colitis susceptibility in recipient germ-free mice (GFM) compared with GFM-receiving microbiota from WT mice. Our data demonstrate a critical role of CLDN3 in maintaining normal gut microbiota and inflammatory responses, which can be harnessed to develop novel therapeutic opportunities for patients with IBD.

Decoding the IBD paradox: A triadic interplay between REG3, enterococci, and NOD2

In this issue of Cell Host & Microbe, Jang etal. decode an intriguing paradox: excessive antimicrobial peptide-regenerating family member 3 (REG3) expression in inflammatory bowel disease (IBD) patients depletes protective enterococci. This depletion impairs the NOD2 anti-inflammatory pathway and perpetuates inflammation, thus providing insight into IBD pathogenesis.

Characterization of canine intestinal microRNA expression in inflammatory bowel disease and T-cell lymphoma

Differentiating between canine inflammatory bowel disease (IBD) and intestinal T-cell lymphoma by histopathological examination of endoscopically-derived intestinal biopsies can be challenging and involves an invasive procedure requiring specialized equipment and training. A rapid, non-invasive method of diagnosis, such as blood or faecal analysis for a conserved and stable biomarker, would be a useful adjunct or replacement. Studies on dogs and humans with various types of lymphoma have shown altered microRNA (miRNA) expression patterns in blood, faeces and tissues indicating their potential use as biomarkers of disease. The present study used residual archived endoscopically-derived, formalin-fixed, paraffin-embedded (FFPE) duodenal tissue taken from pet dogs undergoing routine investigation of gastrointestinal disease. The dogs had previously been diagnosed with either normal/minimal intestinal inflammation, severe IBD or intestinal T-cell lymphoma. Next generation sequencing with qPCR validation was used to elucidate differentially expressed miRNAs between groups. Our results show that miRNA can be extracted from archived endoscopically-derived FFPE tissues from the canine duodenum and used to differentiate normal/minimally inflamed canine duodenal tissue from severe lymphoplasmacytic IBD and T-cell lymphoma.

Loss of Claudin-3 Impairs Intestinal Barrier Function and Gut Microbiota to Promote Colitis

Objective: Inflammatory Bowel Disease (IBD) is multifactorial autoimmune disorder where dysregulation of the gut barrier and gut microbiota (Dysbiosis) play critical role in disease onset and progression. A leaky gut often coexists with the dysbiotic gut microbiota, however a pathobiological integration is not well understood. Intestinal claudin-3 expression is robust, and we have reported that its loss promotes gut permeability and colon cancer. Increased gut permeability and colon cancer risk characterize Inflammatory Bowel Disease (IBD). The current study was undertaken to delineate the status and role of claudin-3 expression in IBD. Methods: Multiple murine models of colitis and IBD patient biopsy were used. Claudin-3KO mice were used to determine causal role. Multiplex ELISA, RNAseq and 16S DNA sequencing helped determine inflammatory cytokines, transcriptomic changes, and gut microbiota diversity, respectively. Fecal microbiota transplantation (FMT) and antibiotic treatment studies were done to test the role of claudin-3/gut dysbiosis axis in promoting IBD. Results: A significant decrease in claudin-3 expression was observed in IBD patient samples or the colon of mice subjected to DSS- (2.5% w/v) or C. rodentium-colitis (5 x108 CFU/oral). colitis (p<0.001). To test the causal role, claudin-3KO mice were subjected to DSS-colitis (acute and chronic), and infectious colitis. A significant change in the body weight, colon thickness, and mucosal injury score (p<0.001) characterized the colitis challenged claudin-3KO versus WT mice. P-Stat3 expression was highly upregulated in colitis challenged claudin-3KO mice. Interestingly, administration of an antibiotic cocktail rescued the colitis severity in claudin-3KO mice. The 16s metagenomics further revealed that the gut microbiota of claudin-3KO mice is diverse and clustered distinctly from the WT mice. To determine if gut dysbiosis in claudin-3KO mice promotes susceptibility to colitis, we performed FMT from naïve Claudin-3KO mice to germ-free WT mice. When subjected to DSS-colitis, germ-free mice transplanted with Claudin3-KO gut microbiota showed significantly higher colitis severity versus WT (p<0.05). Conclusion: We summarize that the loss of colonic Cldn3 deregulates mucosal barrier integrity to induce gut dysbiosis and susceptibility to IBD. We propose that claudin-3 can be a novel therapeutic target in strengthening the gut barrier integrity to diminish IBD susceptibility. National Institute of Health, Veterans Administration This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Correlations between the symptoms of insomnia, depression, sleep quality, antitumor necrosis factor therapy, and disrupted circadian clock gene expression in inflammatory bowel disease.

Inflammatory bowel disease (IBD) might be accompanied by emotional disturbances. Circadian rhythm genes, such as brain and muscle ARNT‑Like 1 (BMAL1), circadian locomotor output cycles kaput (CLOCK), neuronal PAS domain protein 2 (NPAS2), or nuclear receptor subfamily 1 group D member 1 (NR1D1) are related to inflammation and psychiatric symptoms that might modulate their expression. The study aimed to compare the expression of the BMAL1, CLOCK, NPAS2, NR1D1 mRNA in IBD patients and healthy controls (HCs). We evaluated the association between the gene expression and the disease severity, antitumor necrosis factor (TNF) therapy, sleep quality, insomnia, and depression. A total of 81 IBD patients and 44 HCs were recruited and classified according to the disease activity and IBD type (ulcerative colitis [UC] or Crohn disease [CD]). The participants filled out questionnaires assessing their sleep quality, daytime sleepiness, insomnia, and depression. Venous blood samples were collected, and the IBD patients on the anti‑TNF therapy had their blood drawn before and after 14 weeks of the treatment. In comparison with HCs, the IBD group had decreased expression of all studied genes apart from the BMAL1 gene. UC individuals with exacerbation had decreased expression of the CLOCK and the NPAS2 genes, as compared with the remission group. UC severity negatively correlated with the CLOCK, NPAS2, and NR1D1 mRNA levels. The IBD participants with depression symptoms had a decreased expression of the CLOCK and the NR1D1 genes, as compared with those without mood disturbances. Poor sleep quality was associated with a decreased expression of the NR1D1 gene. Biologic treatment decreased the expression of the BMAL1 gene. Disruption of the clock gene expression might constitute a molecular background of sleep disorders and depression in IBD and might contribute to UC exacerbation.

IL-22-Activated MUC13 Impacts on Colonic Barrier Function through JAK1/STAT3, SNAI1/ZEB1 and ROCK2/MAPK Signaling.

Overexpression of the transmembrane mucin MUC13, as seen in inflammatory bowel diseases (IBD), could potentially impact barrier function. This study aimed to explore how inflammation-induced MUC13 disrupts epithelial barrier integrity by affecting junctional protein expression in IBD, thereby also considering the involvement of MUC1. RNA sequencing and permeability assays were performed using LS513 cells transfected with MUC1 and MUC13 siRNA and subsequently stimulated with IL-22. In vivo intestinal permeability and MUC13-related signaling pathways affecting barrier function were investigated in acute and chronic DSS-induced colitis wildtype and Muc13-/- mice. Finally, the expression of MUC13, its regulators and other barrier mediators were studied in IBD and control patients. Mucin knockdown in intestinal epithelial cells affected gene expression of several barrier mediators in the presence/absence of inflammation. IL-22-induced MUC13 expression impacted barrier function by modulating the JAK1/STAT3, SNAI1/ZEB1 and ROCK2/MAPK signaling pathways, with a cooperating role for MUC1. In response to DSS, MUC13 was protective during the acute phase whereas it caused more harm upon chronic colitis. The pathways accounting for the MUC13-mediated barrier dysfunction were also altered upon inflammation in IBD patients. These novel findings indicate an active role for aberrant MUC13 signaling inducing intestinal barrier dysfunction upon inflammation with MUC1 as collaborating partner.

MiRNA-21 Regulates Multiple Factors in the Pathogenesis of IBD: A Literature Review

Introduction: Inflammatory Bowel Disease (IBD) is characterized by chronic inflammation in the gastrointestinal tract (GIT) via dysbiosis of the gut microbiome and weakening of the epithelial and mucosal barriers. Although the causative nature of IBD remains unknown, several studies have demonstrated that aberrant host-microRNA (miRNA) activity contributes to its pathophysiology. For example, miRNA-21 contributes to IBD through three mechanisms. Firstly, by increasing gut permeability via the ARF4 pathway. Secondly, by decreasing gut mucosal secretions via interfering with host goblet cells. Finally, by regulating proteins that inhibit host autophagy and decreasing immune response via the Phosphatase and Tensin Homolog (PTEN) and Akt pathway. The proposed study aims to answer the following question: how does aberrant expression of miRNA-21 in IBD contribute to the disease? Methods: This review highlights and summarizes relevant studies on the miRNA-21 regulation of key pathways in the pathogenesis of IBD. Searches used electronic databases including PubMed, and Google Scholar for keywords such as “Inflammatory bowel disease” and “miRNA-21” and other additional relevant terms from years 2016 to 2022. Review papers that met our criteria and the relevant papers they referenced, regardless of their publication date, were manually searched for. Figures were made in part using KeyNote and Serveir Medical Art. Discussion: Intracellular pathways contribute to chronic inflammation in IBD such as the PTEN pathway and pro-inflammatory cytokines like TNF-α. These pathways have been shown to influence the mucosal barrier, epithelial barrier, and the immune system in the gut. These pathways are regulated by miRNA-21, demonstrating miRNA-21 as a key regulator in IBD. Both PTEN and TNF-α also contribute to levels of angiogenesis in the gut through the regulation of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor (HIF), further demonstrating the intricacies of the miRNA-21 pathway regulation in IBD. Conclusion: The research highlighted in this review provides insight into the mechanisms of aberrant miRNA expression in IBD. Furthermore, knowledge of such molecular mechanisms has clinical and research applications, including identifying diagnostic biomarkers, less invasive screening techniques, and novel drug therapies.

MiRNA-21 Regulates Multiple Factors in the Pathogenesis of IBD: A Literature Review

Introduction: Inflammatory Bowel Disease (IBD) is characterized by chronic inflammation in the gastrointestinal tract (GIT) via dysbiosis of the gut microbiome and weakening of the epithelial and mucosal barriers. Although the causative nature of IBD remains unknown, several studies have demonstrated that aberrant host-microRNA (miRNA) activity contributes to its pathophysiology. For example, miRNA-21 contributes to IBD through three mechanisms. Firstly, by increasing gut permeability via the ARF4 pathway. Secondly, by decreasing gut mucosal secretions via interfering with host goblet cells. Finally, by regulating proteins that inhibit host autophagy and decreasing immune response via the Phosphatase and Tensin Homolog (PTEN) and Akt pathway. The proposed study aims to answer the following question: how does aberrant expression of miRNA-21 in IBD contribute to the disease? Methods: This review highlights and summarizes relevant studies on the miRNA-21 regulation of key pathways in the pathogenesis of IBD. Searches used electronic databases including PubMed, and Google Scholar for keywords such as “Inflammatory bowel disease” and “miRNA-21” and other additional relevant terms from years 2016 to 2022. Review papers that met our criteria and the relevant papers they referenced, regardless of their publication date, were manually searched for. Figures were made in part using KeyNote and Serveir Medical Art. Discussion: Intracellular pathways contribute to chronic inflammation in IBD such as the PTEN pathway and pro-inflammatory cytokines like TNF-α. These pathways have been shown to influence the mucosal barrier, epithelial barrier, and the immune system in the gut. These pathways are regulated by miRNA-21, demonstrating miRNA-21 as a key regulator in IBD. Both PTEN and TNF-α also contribute to levels of angiogenesis in the gut through the regulation of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor (HIF), further demonstrating the intricacies of the miRNA-21 pathway regulation in IBD. Conclusion: The research highlighted in this review provides insight into the mechanisms of aberrant miRNA expression in IBD. Furthermore, knowledge of such molecular mechanisms has clinical and research applications, including identifying diagnostic biomarkers, less invasive screening techniques, and novel drug therapies.

A distal super-enhancer activates oncogenic ETS2 via recruiting MECOM in inflammatory bowel disease and colorectal cancer

Abnormal activities of distal cis-regulatory elements (CREs) contribute to the initiation and progression of cancer. Gain of super-enhancer (SE), a highly active distal CRE, is essential for the activation of key oncogenes in various cancers. However, the mechanism of action for most tumor-specific SEs still largely remains elusive. Here, we report that a candidate oncogene ETS2 was activated by a distal SE in inflammatory bowel disease (IBD) and colorectal cancer (CRC). The SE physically interacted with the ETS2 promoter and was required for the transcription activation of ETS2. Strikingly, the ETS2-SE activity was dramatically upregulated in both IBD and CRC tissues when compared to normal colon controls and was strongly correlated with the level of ETS2 expression. The tumor-specific activation of ETS2-SE was further validated by increased enhancer RNA transcription from this region in CRC. Intriguingly, a known IBD-risk SNP resides in the ETS2-SE and the genetic variant modulated the level of ETS2 expression through affecting the binding of an oncogenic transcription factor MECOM. Silencing of MECOM induced significant downregulation of ETS2 in CRC cells, and the level of MECOM and ETS2 correlated well with each other in CRC and IBD samples. Functionally, MECOM and ETS2 were both required for maintaining the colony-formation and sphere-formation capacities of CRC cells and MECOM was crucial for promoting migration. Taken together, we uncovered a novel disease-specific SE that distantly drives oncogenic ETS2 expression in IBD and CRC and delineated a mechanistic link between non-coding genetic variation and epigenetic regulation of gene transcription.

Increased stromal PFKFB3-mediated glycolysis in inflammatory bowel disease contributes to intestinal inflammation.

Inflammatory bowel disease (IBD) is a chronic relapsing inflammation of the intestinal tract with currently not well-understood pathogenesis. In addition to the involvement of immune cells, increasing studies show an important role for fibroblasts in the pathogenesis of IBD. Previous work showed that glycolysis is the preferred energy source for fibroblasts in fibrotic diseases. 6-phosphofructo-2-kinase/fructose-2, 6-bisphosphatase 3 (PFKFB3) is a key kinase supporting glycolysis. Increased expression of PFKFB3 in several cancers and inflammatory diseases has been previously reported, but the metabolic status of fibroblasts and the role of PFKFB3 in patients with IBD are currently unknown. Therefore, in this study, we evaluated the role of glycolysis and PFKFB3 expression in IBD. Single-sample gene set enrichment analysis (ssGSEA) revealed that glycolysis was significantly higher in IBD intestinal samples, compared to healthy controls, which was confirmed in the validation cohorts of IBD patients. Single-cell sequencing data indicated that PFKFB3 expression was higher in IBD-derived stromal cells. In vitro, PFKFB3 expression in IBD-derived fibroblasts was increased after the stimulation with pro-inflammatory cytokines. Using seahorse real-time cell metabolic analysis, inflamed fibroblasts were shown to have a higher extracellular acidification rate and a lower oxygen consumption rate, which could be reversed by inhibition of JAK/STAT pathway. Furthermore, increased expression of pro-inflammatory cytokines and chemokines in fibroblasts could be reverted by PFK15, a specific inhibitor of PFKFB3. In vivo experiments showed that PFK15 reduced the severity of dextran sulfate sodium (DSS)- and Tcell transfer induced colitis, which was accompanied by a reduction in immune cell infiltration in the intestines. These findings suggest that increased stromal PFKFB3 expression contributes to inflammation and the pathological function of fibroblasts in IBD. Inhibition of PFKFB3 suppressed their inflammatory characteristics.