Therapeutic Target In Ulcerative Colitis Research Articles

Modified Zhenwu Decoction improved intestinal barrier function of experimental colitis through activation of sGC-mediated cGMP/PKG signaling

BackgroundThe invasion of luminal antigens and an aberrant immune response resulting from a disrupted physical epithelial barrier are the key characteristics of ulcerative colitis (UC). The restoration of damaged epithelial function is crucial for maintaining mucosal homeostasis and disease quiescence. Current therapies for UC primarily focus on suppressing inflammation. However, most patients fail to respond to therapy or develop secondary resistance over time, emphasizing the need to develop novel therapeutic targets for UC. Our study aimed to identify the potential targets of a novel modified herbal formula from the Zhen Wu Decoction, namely CDD-2103, which has demonstrated promising efficacy in treating chronic colitis. MethodsThe effect of CDD-2103 on epithelial barrier function was examined using in vitro and ex vivo models of tissue injury, as well as a chronic colitis C57BL/6 mouse model. Transcriptomic analysis was employed to profile gene expression changes in colonic tissues following treatment with CDD-2103. ResultsOur in vivo experiments demonstrated that CDD-2103 dose-dependently reduced disease severity in mice with chronic colitis. The efficacy of CDD-2103 was mediated by a reduction in goblet cell loss and the enhancement of tight junction protein integrity. Mechanistically, CDD-2103 suppressed epithelial cell apoptosis and tight junction protein breakdown by activating the soluble guanynyl cyclase (sGC)-mediated cyclic guanosine monophosphate (cGMP)/PKG signaling cascade. Molecular docking analysis revealed strong sGC ligand recognition by the CDD-2103-derived molecules, warranting further investigation. ConclusionOur study revealed a novel formulation CDD-2103 that restores intestinal barrier function through the activation of sGC-regulated cGMP/PKG signaling. Furthermore, our findings suggest that targeting sGC can be an effective approach for promoting mucosal healing in the management of UC.

HSP90β shapes the fate of Th17 cells with the help of glycolysis-controlled methylation modification.

Ulcerative colitis (UC) is a refractory inflammatory disease associated with immune dysregulation. Elevated levels of heat shock protein (HSP) 90 in the β but not α subtype were positively associated with disease status in UC patients. This study validated the possibility that pharmacological inhibition or reduction of HSP90β would alleviate colitis, induced by dextran sulfate sodium, in mice and elucidated its mechanisms. Histopathological and biochemical analysis assessed disease severity, and bioinformatics and correlation analysis explained the association between the many immune cells and HSP90β. Flow cytometry was used to analyse the homeostasis and transdifferentiation of Th17 and Treg cells. In vitro inhibition and adoptive transfer assays were used to investigate functions of the phenotypically transformed Th17 cells. Metabolomic analysis, DNA methylation detection and chromatin immunoprecipitation were used to explore these mechanisms. The selective pharmacological inhibitor (HSP90βi) and shHSP90β significantly mitigated UC in mice and promoted transformation of Th17 to Treg cell phenotype, via Foxp3 transcription. The phenotypically-transformed Th17 cells by HSP90βi or shHSP90β were able to inhibit lymphocyte proliferation and colitis in mice. HSP90βi and shHSP90β selectively weakened glycolysis by stopping the direct association of HSP90β and GLUT1, the key glucose transporter, to accelerate ubiquitination degradation of GLUT1, and enhance the methylation of Foxp3 CNS2 region. Then, the mediator path was identified as the "lactate-STAT5-TET2" cascade. HSP90β shapes the fate of Th17 cells via glycolysis-controlled methylation modification to affect UC progression, which provides a new therapeutic target for UC.

Arginase 2 attenuates ulcerative colitis by antioxidant effects of spermidine.

Spermidine suppress oxidative stress and is involved in various disease pathogenesis including ulcerative colitis (UC). Arginase 2 (ARG2) plays a central role in the synthesis of spermidine. This study aimed to clarify the effect of endogenously produced spermidine on colitis. The physiological role of ARG2 and spermidine was investigated using Arg2-deficient mice with reduced spermidine. Immunohistochemical staining of the rectum was used to analyze ARG2 expression and spermidine levels in healthy controls and UC patients. In mice with dextran sulfate sodium-induced colitis, ARG2 and spermidine levels were increased in the rectal epithelium. Spermidine protects colonic epithelial cells from oxidative stress and Arg2 knockdown cells reduced antioxidant activity. Organoids cultured from the small intestine and colon of Arg2-deficient mice both were more susceptible to oxidative stress. Colitis was exacerbated in Arg2-deficient mice compared to wild-type mice. Supplementation with spermidine result in comparable severity of colitis in both wild-type and Arg2-deficient mice. In the active phase of UC, rectal ARG2 expression and spermidine accumulation were increased compared to remission. ARG2 and spermidine levels were similar in healthy controls and UC remission patients. ARG2 produces spermidine endogenously in the intestinal epithelium and has a palliative effect on ulcerative colitis. ARG2 and spermidine are potential novel therapeutic targets for UC.

Exploring the Relevance of Disulfidptosis to the Pathophysiology of Ulcerative Colitis by Bioinformatics Analysis.

Ulcerative colitis (UC) is a nonspecific inflammatory disease confined to the intestinal mucosa and submucosa, and its prevalence significantly increases each year. Disulfidptosis is a recently discovered new form of cell death that has been suggested to be involved in multiple diseases. The aim of this study was to explore the relevance of disulfidptosis in UC. First, the UC datasets were downloaded from the Gene Expression Omnibus (GEO) database, and UC samples were typed based on upregulated disulfidptosis-related genes (DRGs). Then, weighted gene co-expression network analysis (WGCNA) was performed on the datasets and molecular subtypes of UC, respectively, to obtain candidate signature genes. After validation of the validation set and qRT-PCR, we constructed a nomogram model by signature genes to predict the risk of UC. Finally, single-cell sequencing analysis was used to study the heterogeneity of UC and to demonstrate the expression of DRGs and signature genes at the single-cell level. A total of 7 DRGs were significantly upregulated in the expression profiles of UC, and 180 UC samples were divided into two subtypes based on these DRGs. Five candidate signature genes were obtained by intersecting two key gene modules selected by WGCNA. After evaluation, four signature genes with diagnostic relevance (COL4A1, PRRX1, NNMT, and PECAM1) were eventually identified. The nomogram model showed excellent prediction ability. Finally, in the single-cell analysis, there were eight cell types (including B cells, T cells, monocyte, smooth muscle cells, epithelial cells, neutrophil, endothelial cells and NK cells) were identified. The signature genes were significantly expressed mainly in endothelial cells and smooth muscle cells. In this study, subtypes related to disulfidptosis were identified, and single-cell analysis was performed to understand the pathogenesis of UC from a new perspective. Four signature genes were screened and a prediction model with high accuracy was established. This provides novel insights for early diagnosis and therapeutic targets in UC.

Recent steroid use and the relapse risk in ulcerative colitis patients with endoscopic healing.

Endoscopic healing (EH) is a therapeutic target in ulcerative colitis (UC). However, even patients who have achieved EH relapse frequently. To investigate the association between recent steroid use and relapse risk in UC patients with EH. This multi-centre cohort study included 1212 UC patients with confirmed EH (Mayo endoscopic subscore ≤1). We excluded patients with current systemic steroid use or history of advanced therapy. We divided patients into a recent steroid group (last systemic steroid use within 1 year; n = 59) and a non-recent or steroid-naïve group (n = 1153). We followed the patients for 2 years to evaluate relapse, defined as induction of systemic steroids or advanced therapy. We used logistic regression to estimate the odds ratio (OR) of relapse. Relapse occurred in 28.8% of the recent steroid group and 5.6% of the non-recent/steroid-naïve group (multi-variable-adjusted OR 5.53 [95% CI 2.85-10.7]). The risk of relapse decreased with time since the last steroid use: 28.8% for less than 1 year after steroid therapy, 22.9% for 1 year, 16.0% for 2 years and 7.9% beyond 3 years, approaching 4.0% in steroid-naïve patients. (ptrend <0.001). Even for patients with UC who achieved EH, the risk of relapse remains high following recent steroid therapy. Physicians need to consider the duration since last steroid use to stratify the relapse risk in UC patients with EH.

Determining the optimal treatment target in patients with ulcerative colitis: rationale, design, protocol and interim analysis for the randomised controlled VERDICT trial

IntroductionSymptoms, endoscopy and histology have been proposed as therapeutic targets in ulcerative colitis (UC). Observational studies suggest that the achievement of histologic remission may be associated with a lower risk...

P489 Systematic review and meta-analysis of the accuracy of computer-aided diagnosis in identifying endoscopic remission in Ulcerative Colitis

Abstract Background Endoscopic remission (ER), the absence of active inflammation during endoscopy, is a key therapeutic target in Ulcerative Colitis (UC). ER is assessed during colonoscopy using standardised scoring systems. However, there remains significant inter-operator variability in assessing ER, for which the application of computer-aided diagnosis (CADx) could be a potential solution. A previous systematic review and meta-analysis on this topic was limited to literature up to June 2022 and did not assess the methodological quality of studies or heterogeneity amongst results. We aimed to update this review. Methods Searches were performed on six electronic databases and relevant reference lists up to May 2023. Data was extracted and screened independently by two reviewers. Methodological assessment was performed using the QUADAS-2 tool. An ‘image selection’ domain was added to the tool given the importance of endoscopic image quality in training and testing data on CADx’s accuracy. Meta-analysis was performed using a bivariate model. Heterogeneity was assessed through visual inspection of forest plots and receiver-operating characteristic curves, subgroup analyses and meta-regression. The overall quality of evidence was assessed using GRADE methodology. Results 17 studies (16 full-text articles and one abstract) were identified. 15 studies adopted a cross-sectional design. All studies used expert endoscopists scoring of ER as the reference standard. The Mayo Endoscopic Score was the most commonly used scoring system (13/17). CADx assessed ER in real-time in one study, but was applied to images and videos obtained from previous endoscopic procedures in all other studies. Inception-v3 was the most common CADx system used (6/17). ‘Patient selection’ was the domain of greatest concern due to a considerable number of studies using images from the same public database and under-reporting participant characteristics. All studies had a low risk of bias (ROB) in the ‘image selection’ domain. One study was deemed overall high ROB, and two were deemed overall unclear ROB. Sensitivity analysis was performed by removing these studies and the abstract, and pooled estimates were obtained from the remaining 13 studies. CADx had a pooled sensitivity of 90.3% and specificity of 94.6% for diagnosing ER. The overall quality of evidence was moderate due to the failure of a significant proportion of studies to report sufficient participant characteristics. Conclusion There is moderate quality evidence that CADx has high sensitivity and specificity for diagnosing ER in pre-clinical studies. Further evaluation is required in randomised controlled trials to evaluate its efficacy in real-time and human-computer interactions.

P403 A new criterion, combining bowel wall thickness and submucosal index (SMI), is useful for estimating endoscopic improvement in Ulcerative Colitis

Abstract Background Endoscopic improvement (EI), Mayo endoscopic subscore of 0 or 1, is considered a therapeutic target in ulcerative colitis (UC) treatment. The potential to estimate EI non-invasively is an advantage of intestinal ultrasound (IUS). In a former study, we developed a new ultrasound parameter, the submucosal index (SMI), calculated as the ratio of the thickness of the submucosa to the thickness of the bowel wall (BWT), and reported that combining BWT and SMI could be a practical criterion for estimating EI without the assessment of bowel wall vascularity using color Doppler evaluation. In the present study, we validated the EI estimation ability of our B-mode-based UC criterion, Kyorin Ultrasound Criterion for UC (KUC-UC; BWT&amp;lt;3.8mm and SMI&amp;lt;50%), using an external cohort. Methods Patients who underwent IUS and CS at Kyorin University Hospital were included. The inclusion criteria were (1) both IUS and endoscopy (sigmoidoscopy or CS) for UC were performed between July 2021 and June 2022, (2) the interval between IUS and endoscopy was within 15 days, and (3) no change or addition of therapeutic agents between the two examinations. IUS findings including BWT, SMI, and modified Limberg score were evaluated. In the modified Limberg score, the threshold of normal BWT was less than 3 mm, while the original Limberg score employed less than 4 mm. Results The KUC-UC criterion defined as BWT &amp;lt; 3.8 mm and SMI &amp;lt; 50.0% is practical because it uses only B-mode findings and does not require complex calculations. We tested the ability of this criterion to estimate EI in UC. A total of 122 colon segments were evaluated by transabdominal IUS and CS. The criteria showed a sensitivity of 67.3%, specificity of 97.1%, PPV of 94.6%, and NPV of 80.0%. In the previous development cohort, the PPV and NPV of KUC-UC were 95.5% and 82.7%, respectively. Based on the above, this validation cohort is considered equivalent to the development cohort. BWT &amp;lt; 3 mm and MUC have been reported as useful criteria for EI estimation. In the present cohort, BWT &amp;lt;3mm showed a sensitivity of 67.3%, specificity of 91.4%, PPV of 85.4%, and NPV of 79.0%, and MUC demonstrated a sensitivity of 75.0%, specificity of 88.6%, PPV of 83.0%, and NPV of 82.0%. These results indicate that KUC-UC has a considerable potential to estimate EI as BWT &amp;lt; 3 mm or MUC. Conclusion External validation showed that KUC-UC, using only B-mode findings without complicated calculations, is feasible, accurate sonographic criteria to estimate the EI of UC. The KUC-UC criterion could be one of the options for estimating EI in UC.

A combination of bowel wall thickness and submucosa index is useful for estimating endoscopic improvement in ulcerative colitis: external validation of the Kyorin Ultrasound Criterion.

Endoscopic improvement (EI; a Mayo endoscopic subscore of 0 or 1) is considered a therapeutic target in ulcerative colitis (UC) treatment. The potential to estimate EI non-invasively is an advantage of intestinal ultrasound (IUS). In a previous study, we developed a new sonographic parameter, the submucosa index (SMI), calculated as the ratio of the submucosal thickness to bowel wall thickness (BWT), and reported that combining BWT and SMI results in a practical and promising criterion for estimating EI without color Doppler assessment. This study aimed to validate the EI estimation ability of our B mode-based criterion, the 'Kyorin Ultrasound Criterion for UC' (KUC-UC; BWT < 3.8mm and SMI < 50%), using an external cohort. Patients with UC who underwent IUS and colonoscopy within 15days without a treatment change between examinations were included. IUS findings, including BWT, SMI, and modified Limberg score for vascularity of the colon, were assessed. Forty-four test pairs of IUS and colonoscopy examinations in a total of 122 colonic segments were analyzed. The KUC-UC showed positive predictive value (PPV) of 94.6% and negative predictive value (NPV) of 80.0% for EI. In comparison, PPV and NPV were 85.4% and 79.0%, respectively, for the common criterion BWT of < 3mm, and 83.0% and 82.7% for the validated Milan Ultrasound Criteria (a score of ≤ 6.2). External validation showed that the KUC-UC using only B mode findings without complicated calculations is a feasible and accurate sonographic criterion for estimating the EI of UC.

N-terminal ectodomain of BTNL2 inhibits T cell activation via a non-canonical interaction with its putative receptor that results in a delayed progression of DSS-induced ulcerative colitis

Butyrophilin-like 2 (BTNL2) is a T cell inhibitory molecule that interacts with unknown binding partners to modulate the immune response in a number of inflammatory and autoimmune diseases. In this study, we found that the inhibitory effects of BTNL2 on T cell activation and effector functions can be executed by its N-terminal IgV domain (BTNL2 IgV1) alone. Structure-guided mutation of key residues on BTNL2 IgV1 based on known receptor-ligand interfaces involving immunoglobulin superfamily members revealed that BTNL2 uses a non-canonical binding interface with its putative receptor. A high avidity BTNL2 IgV1 probe revealed that in an inducible model of ulcerative colitis, severe colitis was accompanied by a selective enrichment of BTNL2-receptor expressing effector-memory CD4+ and CD8+ T cells in the Peyer’s patches. Intraperitoneal administration of BTNL2 IgV1 resulted in a significant delay in the progression of DSS-induced colitis and also showed reduced activation of the BTNL2-receptor-expressing T cells in the Peyer’s patches. Thus, this study demonstrates that the BTNL2-receptor-expressing T cells in the Peyer’s patches participate in the disease pathogenesis and can serve as a novel therapeutic target in ulcerative colitis, which can be modulated by BTNL2 IgV1.

Intestinal epithelial damage-derived mtDNA activates STING-IL12 axis in dendritic cells to promote colitis.

Rationale: The treatment of ulcerative colitis (UC) presents an ongoing clinical challenge. Emerging research has implicated that the cGAS-STING pathway promotes the progression of UC, but conflicting results have hindered the development of STING as a therapeutic target. In the current study, we aim to comprehensively elucidate the origins, downstream signaling and pathogenic roles of myeloid STING in colitis and colitis-associated carcinoma (CAC). Methods: Tmem173 fl/fl Lyz2-Cre ert2 mice were constructed for inducible myeloid-specific deletion of STING. RNA-sequencing, flow cytometry, and multiplex immunohistochemistry were employed to investigate immune responses in DSS-induced colitis or AOM/DSS-induced carcinogenesis. Colonic organoids, primary bone marrow derived macrophages and dendritic cells, and splenic T cells were used for in vitro studies. Results: We observed that myeloid STING knockout in adult mice inhibited macrophage maturation, reduced DC cell activation, and suppressed pro-inflammatory Th1 and Th17 cells, thereby protecting against both acute and chronic colitis and CAC. However, myeloid STING deletion in neonatal or tumor-present mice exhibited impaired immune tolerance and anti-tumor immunity. Furthermore, we found that TFAM-associated mtDNA released from damaged colonic organoids, rather than bacterial products, activates STING in dendritic cells in an extracellular vesicle-independent yet endocytosis-dependent manner. Both IRF3 and NF-κB are required for STING-mediated expression of IL-12 family cytokines, promoting Th1 and Th17 differentiation and contributing to excessive inflammation in colitis. Conclusions: Detection of the TFAM-mtDNA complex from damaged intestinal epithelium by myeloid STING exacerbates colitis through IL-12 cytokines, providing new evidence to support the development of STING as a therapeutic target for UC and CAC.

Identification of novel N7-methylguanine-related gene signatures associated with ulcerative colitis and the association with biological therapy.

Ulcerative colitis (UC) is an inflammatory disease characterized by recurrent episodes of chronic intestinal inflammation. It is closely associated with immune dysregulation in the intestines. However, the mechanisms underlying the role of immune-related N7-methylguanosine (m7G) internal modification in UC remain unclear. We conducted a screening of differentially expressed genes (DEGs) associated with m7G and performed immune infiltration analysis. We then investigated the correlation between m7G-related DEGs and immune cells or pathways. To further explore the functional implications, we conducted functional enrichment analysis to identify gene modules that strongly correlated with hub gene expression. In addition, we constructed a miRNA regulatory network for the hub genes in UC. Furthermore, we examined the association between hub genes and disease remission in UC patients undergoing biologic therapy. We obtained 13 m7G-related DEGs and conducted an in-depth analysis of immune infiltration. Among them, we identified five hub genes (NUDT7, NUDT12, POLR2H, QKI, and PRKCB) that showed diagnostic potential for UC. Through WGCNA and KEGG analysis, we found that gene modules strongly correlated with m7G hub gene expression were enriched in inflammation-related pathways. Furthermore, Kaplan-Meier survival analysis revealed a significant association between changes in hub gene expression levels and disease remission in UC patients undergoing biologic therapy. The findings of this study demonstrate that five m7G-related DEGs, including the m7G-modified recognition protein QKI, play a key role in the occurrence and progression of UC intestinal inflammation, which is closely related to intestinal immunity. These results provide valuable insights into the mechanisms of m7G modification in UC development and offer new perspectives for exploring novel therapeutic targets for UC.

CIRC_0085323 SILENCING INHIBITS TNF-Α-INDUCED NORMAL HUMAN COLONIC EPITHELIAL CELL INFLAMMATION AND APOPTOSIS THROUGH THE MIR-495-3P/TRAF3 AXIS.

Background: Previous data have suggested the involvement of circular RNA (circRNA) in ulcerative colitis (UC) development. However, the role and mechanism of circ_0085323 in UC occurrence have not been reported. Methods: Normal human colonic epithelial cells (NCM460) were treated with TNF-α to simulate UC-like cell inflammation and injury in vitro. The expression of circ_0085323, microRNA-495-3p (miR-495-3p), and TNF receptor-associated factor 3 (TRAF3) was detected by quantitative real-time polymerase chain reaction. Protein expression was checked by western blotting analysis. Cell viability, cell proliferation, and cell apoptosis were investigated by cell counting kit-8 assay, 5-ethynyl-29-deoxyuridine assay, and flow cytometry analysis, respectively. IL-1β, IL-6, and IL-8 production were analyzed by enzyme-linked immunosorbent assays. Lactate dehydrogenase activity was assessed by a lactate dehydrogenase activity detection assay. The interactions among circ_0085323, miR-495-3p, and TRAF3 were identified by dual-luciferase reporter assay and RNA immunoprecipitation assay. Results: Circ_0085323 was overexpressed in the colonic mucosal tissues of UC patients and TNF-α-stimulated NCM460 cells. Circ_0085323 knockdown relieved TNF-α-induced inhibitory effect on the proliferation of NCM460 cells and promoting effects on cell apoptosis and inflammation. Circ_0085323 acted as a miR-495-3p sponge, and the effects of circ_0085323 silencing on TNF-α-induced NCM460 cell injury were attenuated by decreasing miR-495-3p expression. TRAF3 was targeted by miR-495-3p, and circ_0085323 combined with miR-495-3p to regulate TRAF3. TRAF3 depletion not only alleviated TNF-α-induced NCM460 cell damage but also partially revoked the effect of circ_0085323 silencing combined with miR-495-3p depletion on TNF-α-induced NCM460 cell injury. Conclusions: Circ_0085323 knockdown ameliorated TNF-α-induced NCM460 cell injury by regulating the miR-495-3p/TRAF3 axis, which suggested that circ_0085323 might be a therapeutic target for UC.

Excessive Mitochondrial Fission Suppresses Mucosal Repair by Impairing Butyrate Metabolism in Colonocytes.

Mucosal healing is one of the principal therapeutic targets for ulcerative colitis (UC). Mitochondria are dynamic organelles that undergo constant fusion and fission; however, the process that is most conducive to mucosal healing remains unclear. This study investigated the role of mitochondrial fission in mucosal healing in UC patients. Quantitative polymerase chain reaction, Western blotting, and immunostaining were used to detect mitochondrial fission in UC patients and a dextran sulfate sodium-induced colitis model. Colonic organoids were used to investigate the role of mitochondrial fission in butyrate metabolism. Enzyme activity assays were performed to identify the key proteins involved in this mechanism. It was found that inhibition of mitochondrial fission promoted mucosal healing in mice and that there was an increase in mitochondrial fission in colonic epithelial cells of UC patients. Excessive fission inhibits stem cell proliferation by impairing butyrate metabolism in colonic organoids. The mitochondrial fission antagonist P110 failed to promote mucosal healing in antibiotic-treated mice, and the addition of exogenous butyrate reversed this effect. Increased butyrate exposure in the colonic stem cell niche has also been observed in UC patients. Mechanistically, enzyme activity assays on colonic organoids revealed that excessive fission inhibits mitochondrial acetoacetyl-CoA thiolase activity via reactive oxygen species. Collectively, these data indicate that excessive mitochondrial fission suppresses mucosal repair by inhibiting butyrate metabolism and provides a potential target for mucosal healing in patients with ulcerative colitis.

Ferroptosis in the colon epithelial cells as a therapeutic target for ulcerative colitis.

Ferroptosis, a type of programmed cell death triggered by oxidative stress, was suspected to play a role in ulcerative colitis. Indigo naturalis is highly effective against ulcerative colitis, but its mechanism is unclear. This study found that indigo naturalis treatment suppressed ferroptosis. We analyzed 770 mRNA expressions of patients with ulcerative colitis. Suppression of ferroptosis by indigo naturalis treatment was shown using a cell death assay. Malondialdehyde levels and reactive oxygen species were analyzed in CaCo-2 cells treated with indigo naturalis. Glutathione metabolism was shown by metabolomic analysis. Extraction of the ingredients indigo naturalis from the rectal mucosa was performed using liquid chromatograph-mass spectrometry. Gene expression profiling showed that indigo naturalis treatment increased antioxidant genes in the mucosa of patients with ulcerative colitis. In vitro analysis showed that nuclear factor erythroid-2-related factor 2-related antioxidant gene expression was upregulated by indigo naturalis. Indigo naturalis treatment rendered cells resistant to ferroptosis. Metabolomic analysis suggested that an increase in reduced glutathione by indigo naturalis. The protein expression of CYP1A1 and GPX4 was increased in the rectum by treatment with indigo naturalis. The main ingredients of indigo naturalis, indirubin and indigo inhibited ferroptosis. Indirubin was detected in the rectal mucosa of patients with ulcerative colitis who were treated with indigo naturalis. Suppression of ferroptosis by indigo naturalis in the intestinal epithelium could be therapeutic target for ulcerative colitis. The main active ingredient of indigo naturalis may be indirubin.

Comprehensive analysis of endoplasmic reticulum stress-associated genes signature of ulcerative colitis.

Endoplasmic reticulum stress (ERS) is a critical factor in the development of ulcerative colitis (UC); however, the underlying molecular mechanisms remain unclear. This study aims to identify pivotal molecular mechanisms related to ERS in UC pathogenesis and provide novel therapeutic targets for UC. Colon tissue gene expression profiles and clinical information of UC patients and healthy controls were obtained from the Gene Expression Omnibus (GEO) database, and the ERS-related gene set was downloaded from GeneCards for analysis. Weighted gene co-expression network analysis (WGCNA) and differential expression analysis were utilized to identify pivotal modules and genes associated with UC. A consensus clustering algorithm was used to classify UC patients. The CIBERSORT algorithm was employed to evaluate the immune cell infiltration. Gene Set Variation Analysis (GSVA), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to explore potential biological mechanisms. The external sets were used to validate and identify the relationship of ERS-related genes with biologics. Small molecule compounds were predicted using the Connectivity Map (CMap) database. Molecular docking was performed to simulate the binding conformation of small molecule compounds and key targets. The study identified 915 differentially expressed genes (DEGs) and 11 ERS-related genes (ERSRGs) from the colonic mucosa of UC patients and healthy controls, and these genes had good diagnostic value and were highly correlated. Five potential small-molecule drugs sharing tubulin inhibitors were identified, including albendazole, fenbendazole, flubendazole, griseofulvin, and noscapine, among which noscapine exhibited the highest correlation with a high binding affinity to the targets. Active UC and 10 ERSRGs were associated with a large number of immune cells, and ERS was also associated with colon mucosal invasion of active UC. Significant differences in gene expression patterns and immune cell infiltration abundance were observed among ERS-related subtypes. The results suggest that ERS plays a vital role in UC pathogenesis, and noscapine may be a promising therapeutic agent for UC by affecting ERS.

GRK2 Mediates Macrophage Polarization by Regulating EP4-cAMP-pCREB Signaling in Ulcerative Colitis and the Therapeutic Effect of Paroxetine on Mice with DSS-Induced Colitis.

G protein-coupled receptor kinase 2 (GRK2) is one of the cytosolic enzymes, and GRK2 translocation induces prostaglandin E2 receptor 4 (EP4) over-desensitization and reduces the level of cyclic adenosine monophosphate (cAMP) to regulate macrophage polarization. However, the role of GRK2 in the pathophysiology of ulcerative colitis (UC) remains unclear. In this study, we investigated the role of GRK2 in macrophage polarization in UC, using biopsies from patients, a GRK2 heterozygous mouse model with dextran sulfate sodium (DSS)-induced colitis, and THP-1 cells. The results showed that a high level of prostaglandin E2 (PGE2) stimulated the receptor EP4 and enhanced the transmembrane activity of GRK2 in colonic lamina propria mononuclear cells (LPMCs), resulting in a down-regulation of membrane EP4 expression. Then, the suppression of cAMP-cyclic AMP responsive element-binding (CREB) signal inhibited M2 polarization in UC. Paroxetine is acknowledged as one of the selective serotonin reuptake inhibitors (SSRI), which is also considered as a potent GRK2 inhibitor with a high selectivity for GRK2. We found that paroxetine could alleviate symptoms of DSS-induced colitis in mice by regulating GPCR signaling to affect macrophage polarization. Taken together, the current results show that GRK2 may act as a novel therapeutic target in UC by regulating macrophage polarization, and paroxetine as a GRK2 inhibitor may have therapeutic effect on mice with DSS-induced colitis.

A NOVEL GUT-RESTRICTED ARYL HYDROCARBON RECEPTOR AGONIST WITH ACTIVITY IN THE DEXTRAN SODIUM SULFATE COLITIS MURINE MODEL

Patients with inflammatory bowel disease (ulcerative colitis, Crohn’s disease) have decreased production of endogenous aryl hydrocarbon receptor (AhR) ligands in colon tissue. Activation of the AhR is a potential novel therapeutic target for ulcerative colitis and may play an important role in promoting immune homeostasis through increased IL-22 production, downregulation of proinflammatory mediators, and improved epithelial barrier function. Indigo naturalis, a botanical extract containing potent AhR agonists, has been effective for the treatment of moderate-to-severe and treatment-refractory ulcerative colitis in multiple clinical studies. The most potent AhR agonist in indigo naturalis is indirubin.

P772 Association of histological remission with long-term clinical outcomes in patients with ulcerative colitis: a multi-national retrospective study with centralized histological assessment

Abstract Background Histological remission (HR) is an achievable therapeutic target in ulcerative colitis (UC), however there is limited data on the association of HR with long-term clinical outcomes. We evaluated the association between HR and a composite outcome of colectomy, UC-related hospitalization, or intravenous (IV) corticosteroid use in patients with UC. Methods This was a multi-national retrospective study of adult patients with UC treated with a biologic or small molecule drug between 09/01/2005 and 06/30/2019 in Canada, Italy, Netherlands and United States. The study included biologic-naïve (bio-naïve) and biologic-experienced (bio-exp) patients. Biopsies taken during routine practice were procured and re-assessed for histological activity by blinded gastrointestinal pathologists in a central laboratory. HR was defined as the absence of neutrophilic inflammation (Nancy Histological Index ≤1 or Robarts Histological Index ≤3 plus Geboes subgrades 2B.0/3.0) at the most recent endoscopic evaluation within 3 to 9 months after treatment initiation. Cumulative risk of time-to-event outcome over 12 months from treatment initiation was evaluated using Kaplan-Meier (KM) methods and Cox proportional hazard analysis. Statistical significance was set as p-value &amp;lt;0.05. Results We included 227 patients with UC (bio-naïve and bio-exp) (Table 1); of whom, 132 (58%) were bio-naïve (Table 2). Of the bio-naïve patients, 62 (47%) achieved HR and 70 (53%) had histologic activity; 9 (6.8%) underwent colectomy, 16 (12.1%) had UC-related hospitalizations, and 8 (6.1%) received IV corticosteroid. Unadjusted time-to-event for the composite outcome was significantly greater in bio-naïve patients who achieved HR compared to those who did not (p=0.0023; Figure 1A). In multivariable analysis, the association of HR on the composite outcome in bio-naïve patients was not statistically significant (adjusted hazard ratio [aHR], 0.26; 95% CI, 0.02-4.42). In the overall patients (bio-naïve and bio-exp), unadjusted (p&amp;lt;0.001; Figure 1B) and multivariable (aHR, 0.32; 95% CI, 0.06-1.75) associations of HR and the composite outcome were similar to the bio-naïve patients. Conclusion We used central reading to evaluate the association of HR and clinical outcomes in patients with UC. While unadjusted KM curves showed that HR was associated with decreased risk of the composite outcome, the association was no longer significant after adjustment for covariates. The target sample size for this study was not achieved and the number of events was small, resulting in reduced statistical power. Future studies are warranted to explore the association further.

OP33 Results of a randomised controlled trial to evaluate Interleukin 1 blockade with anakinra in patients with acute severe ulcerative colitis (IASO)

Abstract Background Acute severe ulcerative colitis (ASUC) is a severe manifestation of ulcerative colitis (UC) that requires hospitalisation. Despite significant advances in therapeutic options for UC and in the medical management of steroid-refractory ASUC, the initial treatment paradigm for ASUC has not changed since the 1950s and is based on the use of intravenous (IV) corticosteroids. Approximately 50% of patients do not respond and require further medical or surgical therapy. Interleukin 1 (IL-1) has been identified as a key mediator of colonic inflammation and plays a pivotal role in local activation of neutrophils and a number of downstream inflammatory mediators. The IL-1 axis has been repeatedly identified as a therapeutic target in UC. The Interleukin 1 (IL-1) blockade in Acute Severe Colitis (IASO) trial investigated whether antagonism of IL-1 signalling could improve outcomes in patients with ASUC. Methods We performed a phase II, multicentre randomised (1:1), placebo-controlled, double-blinded trial of IL-1 blockade with short-duration anakinra, given alongside IV corticosteroids to adult patients hospitalised with suspected or confirmed ASUC. The primary outcome was the incidence of medical (ie infliximab/ciclosporin) or surgical rescue therapy (colectomy) within 10 days following the commencement of IV corticosteroid therapy. Secondary outcomes included disease activity, time to clinical response, time to rescue therapy, colectomy incidence by day 98 post IV corticosteroids and safety. The trial aimed to recruit 214 patients across 20 sites in the UK. Prespecified analyses were performed for feasibility and for futility. Results At the time of the prespecified interim futility analysis, 113 patients had been randomised, 55 to placebo, and 58 to anakinra (figure 1). The incidence of medical or surgical rescue therapy by day 10 was higher in the anakinra group than in the placebo group (43% vs 26%). The incidence of colectomy by day 98 was higher in the anakinra group (11% vs 4%). These differences were not statistically significant. Logistic models containing a mixture of baseline stratification factors did not suggest that the need for rescue therapy would be reduced with anakinra treatment and on the advice of the independent data monitoring committee, the trial was terminated for futility. There was a higher incidence of adverse event in the placebo group, the most common was worsening of ulcerative colitis. Conclusion This trial shows that adding anakinra to current standard care with IV corticosteroids in patients with ASUC did not reduce the need for rescue therapy or colectomy. This suggests that IL-1 blockade is not a therapeutic target in ASUC. There were no safety concerns with anakinra treatment.