bluuebunny/crossref_metadata_2025 huggingface dataset:
P0168 Differential expression of enteric glial cell markers in inflamed and non-inflamed tissue of patients with Ulcerative Colitis during clinically active disease and remission
Authors: Beaudeau J , Katinios G , Biskou O , Lindqvist C M , Walter S A , Bednarska O , Söderholm J D , Salomon B , Halfvarson J , Schoultz I , Hjortswang H , Keita Å V
Published: January 2025

Background

Ulcerative colitis (UC), a major subtype of inflammatory bowel disease, is characterized by chronic inflammation of the colon and rectum. Enteric glial cells (EGC) play a crucial role in gut barrier maintenance and may contribute to UC pathophysiology. This study aims to investigate EGC and their associated proteins in patients during clinically active disease and in clinical remission following anti-inflammatory treatment.

Methods

Colonic or rectal biopsies were obtained at baseline from both inflamed and non-inflamed segments in 14 patients with clinically active UC initiating anti-inflammatory therapy and from the same segments when the patients were in clinical and endoscopic remission during follow-up. As control groups, colonic biopsies from 16 patients with irritable bowel syndrome (IBS)-Mixed and 16 healthy controls were included. Immunofluorescence staining assessed two EGC markers: the glial fibrillary acidic protein (GFAP+) and S100 calcium-binding protein B (S100β+). Relative estimates of inflammatory proteins in biopsies were analysed using Olink technology, In vitro, the EGC cell line CRL-2690 was exposed to interleukins (IL)-4, IL-6, and IL-18 at varying concentrations and durations, with GFAP expression analysed by western blot.

Results

In patients with UC, immunofluorescence analysis revealed significantly higher GFAP+ and S100β+ EGC counts in inflamed biopsies during active disease compared to macroscopically non-inflamed biopsies obtained during clinical and endoscopic remission. Compared to baseline biopsies from macroscopically non-inflamed mucosa, GFAP expression significantly decreased during follow-up (Figure 1), while S100β levels remained unaltered. Regardless of mucosal inflammatory status, patients with UC exhibited higher EGC counts than IBS-mixed patients and healthy controls. Our findings also showed a significant upregulation of EGC-associated pro-inflammatory proteins, such as IL-6, IL-8 and TNF in inflamed biopsies from patients with clinically active UC, compared to biopsies obtained when the patients were in remission as well as to healthy controls. Notably, these protein levels decreased during inactive UC, approaching levels observed in the healthy controls. In vitro, IL-6 upregulated GFAP expression dose- and time-dependently, while IL-4 and IL-18 induced expression in a less predictable pattern.

Conclusion

Elevated EGC counts, and pro-inflammatory proteins characterise inflamed mucosa in UC during clinical active disease highlighting their potential roles in UC related inflammation. These findings may suggest that EGC could be explored as a potential therapeutic target and may contribute to the discovery of novel biomarkers for disease monitoring.
P0169 Relapse of ulcerative colitis on dose reduction of tofacitinib is associated with markers of T-cell activation but not clinical features: a prospective, multicentre observational study
Authors: Honap S , Kim S , Whettlock E , Centritto A , Seah D , Baillie S , Luber R , Choong L M , Samaan M , Pavlidis P , Patel K , Dart R , John S , Irving P
Published: January 2025

Background

Tofacitinib (TOF) is an effective treatment for ulcerative colitis (UC). A relationship between dose and both response and side-effect profile is recognised for JAK inhibitors. Dose reduction from 10mg bd to 5mg bd is therefore associated with improved safety but also with a risk of relapse. The BRITE study aimed to identify clinical predictors and biomarkers of relapse in a cohort of patients with stable UC undergoing TOF dose reduction.

Methods

Steroid-free patients with stable UC responding to TOF 10mg bd for at least 8 weeks were followed from dose reduction to time of relapse or for one year. Relapse was defined by worsening modified Mayo score, including an increase in the rectal bleeding and endoscopic subscores of ≥ 1 point. Clinical and endoscopic assessment with biopsy was performed prior to dose reduction (baseline) and at end of trial. PBMCs were isolated at baseline and were cryopreserved. Flow cytometry analysis of phospho-STAT levels of STAT1, STAT3, STAT4 and STAT5 was performed in T cells from unstimulated and cytokine-stimulated baseline PBMC. In addition, CD4 T cells were isolated from PBMC and were stimulated with plate-bound anti-CD3 and anti-CD28 (TCR activation) for 5 days; cell supernatants were analysed for 17 CD4 T-helper (Th) cell effector cytokines using a 17-cytokine Luminex assay.

Results

50 patients were enrolled across 3 centres; baseline characteristics are displayed in table 1. 23 (46%) patients relapsed after a median duration of 23 weeks (IQR 9-45). Demographics, disease duration, prior advanced therapy exposure (including duration on TOF), and baseline clinical, biochemical (calprotectin/CRP), and histo-endoscopic disease severity were not associated with risk of relapse. In contrast, molecular differences in CD4 T-cell function were identified in relapsers and non-relapsers. pSTAT5 levels were significantly induced by IFNa in relapse patients (p<0.05), but not in remission patients (Fig 1a), while canonical pSTAT5 activation by IL2 showed no significant differences between the two cohorts of patients. Furthermore, TCR activation of baseline CD4 T cells showed significantly higher expression of IL10 (p=0.01) in remission patients compared to relapse (Fig 1b). Higher levels of resting pSTAT1High expression that was refractory to IFNa stimulation in relapse patients but inducible in remission patients was also identified (p=<0.01).

Conclusion

In this large prospective study of TOF dose reduction, in contrast to previous studies, no baseline clinical or endoscopic predictors of relapse were found. However, potentially clinically useful association with markers of T cell activation were identified and should be investigated further.
P0170 The presence of creeping fat in a TNBS-induced colitis model is associated with greater acute inflammation and bacterial translocation
Authors: Suau R , Clua L , Guasch M , Monfort-Ferré D , Boronat-Toscano A , Aquino M E , Matute K S , Cabrer M , Calafat M , Mañosa M , Domènech E , Jimeno M , Serena C , Bartolí R , Manyé J
Published: January 2025

Background

The hyperplasia of the mesenteric adipose tissue in Crohn’s disease, known as creeping fat, is associated with transmural lesions and the translocation of microbial antigens. In a rat model of TNBS-induced colitis, 50% of the animals presented adipose hyperplasia. Macroscopic evaluations showed that these animals had a more advanced progression of the disease, and colonoscopy could predict the presence of fat two days before euthanasia (L Clua et al, ECCO, 2024).

Methods

Colitis was induced using TNBS (n=10; half female), with the animals being sacrificed after five days. Tissue from the lesion along with mesenteric adipose tissue was obtained for histopathological staining and evaluation (haematoxylin-eosin, Masson’s trichrome, and Gram). Samples of intestinal mucosa and mesenteric fat were preserved in RNAlater to assess the expression of inflammatory markers by qRT-PCR. Results were statistically compared between animals with and without creeping fat, including sex.

Results

In histopathological analysis, using a validated scoring system, animals with creeping fat showed significantly greater severity of acute inflammation at the transmural level, with an increase in cryptitis and a more pronounced and extensive fibrosis pattern. Additionally, colonies of Gram-positive cocci were detected in all animals with creeping fat. In contrast, animals without fat hyperplasia exhibited appreciable adipogenesis in only two individuals, with an average of 105 adipocytes per field, compared to 185 in animals with creeping fat. qRT-PCR revealed higher expression of Il1b, Il6, Il10, Nod2, and Tlr2 in the intestinal mucosa and hyperplastic mesenteric fat of animals with creeping fat. A significant increase in Tnfa was also observed in hyperplastic adipose tissue, while the expression of Tgfbr1 was higher in the intestinal mucosa of animals without creeping fat. No differences were found between sexes.

Conclusion

The results indicated a more intense acute inflammatory and fibrotic component in animals with creeping fat, consistent with the macroscopic observations. The hyperplasia and inflammation observed in the mesenteric adipose tissue may be provoked by bacterial translocation, whereas animals without hyperplasia present a component influenced by TGF-β1 activity that could help counteract the inflammation.

References

L Clua, R Suau, M Guasch, D Monfort-Ferré, I Vañó, C Serena, E Domènech, R Bartolí, J Manyé, P022 Development of a novel experimental model for studying creeping fat in Crohn’s Disease, Journal of Crohn’s and Colitis, Volume 18, Issue Supplement_1, January 2024, Pages i275–i276, https://doi.org/10.1093/ecco-jcc/jjad212.0152
P0171 IL-36 signaling as a drug target in Crohn’s disease patients with IL36RN mutations
Authors: Hecker J , Plattner C , Löscher B S , Saurenbach J , Letizia M , Rieder D , Freise I , Koop K , Neufert C , Kunkel D , Schütz A , Becker C , Atreya R , Trajanoski Z , Franke A , Sonnenberg E , Siegmund B , Weidinger C ,   The TRR241 IBDome Consortium
Published: January 2025

Background

The IL-36 signaling pathway has recently been identified as a key regulator of intestinal homeostasis and inflammation. However, the role of mutations in the IL-36R signaling pathway in the pathogenesis of inflammatory bowel disease remains unclear.

Methods

Mutations in the IL-36 receptor antagonist (IL-36RA, IL36RN) were identified in a cohort of 86 ulcerative colitis patients, 244 Crohn’s disease patients and 45 non-inflamed controls by whole exome sequencing followed by targeted Sanger sequencing. In-depth immune cell profiling of one IL36RN-mutated patient was performed using mass cytometry and multiplexed immunoassays. Overexpression experiments and functional assays characterized identified IL36RN mutations. Clinical and molecular responses of one IL36RN-mutated patient to a combined treatment with the IL-36R-blocking antibody spesolimab and the TNF-blocker certolizumab-pegol were assessed by fecal calprotectin, endoscopy, multiplexed immunoassays and mass cytometry.

Results

We identified four Crohn’s disease patients with heterozygous missense mutations in IL36RN. Experimental overexpression and functional assays demonstrated that two identified mutations resulted in a reduced protein expression of IL-36RA. In-depth immune profiling of one IL36RN-mutated patient revealed an increased response of PBMCs to IL-36 stimulation and elevated serum levels of IL-36-regulated cytokines. Administration of the IL-36R-blocking antibody spesolimab in combination with certolizumab-pegol over a period of 22 weeks to this patient resulted in a reduction of intestinal inflammation and alterations in immune cell composition and function.

Conclusion

Our findings indicate that pathogenic IL36RN mutations may contribute to the pathogenesis of Crohn’s disease in a subset of patients and that inhibiting IL-36 signaling in combination with TNF-blockade could offer a personalized therapeutic approach for these patients.

Disclaimer

Spesolimab was made available based on an out-of-scope request. Boehringer Ingelheim was given the opportunity to review this abstract as a courtesy. Boehringer Ingelheim had no role in the design, analysis or interpretation of the results in this study.
P0173 The impact of dietary composition on metallothionein gene expression in the intestinal epithelium by exclusive enteral nutrition
Authors: Curry D , Lemons J , Friedman E , Li Y , Hao F , Li H , Liu L , Patterson A , Henao-Mejia J , Lewis J , Wu G
Published: January 2025

Background

The mechanism by which exclusive enteral nutrition (EEN) is effective in the treatment of Crohn’s disease remains elusive. Epidemiologic studies have shown that a substantial proportion of patients with Crohn’s disease are deficient in micronutrients such as zinc, which has been shown to play an important role in the integrity of intestinal epithelial barrier function. Zinc plays a critical role in the transcriptional regulation of metallothioneins (MT), cysteine rich binding proteins that regulate both epithelial and immune function where they are generally believed to play a beneficial role in reducing disease.

Methods

Transcriptomic analyses were performed by both bulk RNAseq as well as GeoMx spatial transcriptomics. Enzymatic food digests using both bile acids and pancreatic enzymes, analyzed by Proton NMR metabolomics, were used to generate cell culture media for studies in intestinal epithelial cells.

Results

RNAseq of rectal biopsies obtained from healthy human subjects consuming EEN (Modulen-IBD, Nestlé Health Science) vs. an omnivore diet revealed a very specific induction of genes involved in mineral transport, namely MTs such as MT1G and MT2A. Spatial transcriptomics revealed that the induction of MTs was specific to the colonic epithelium. To develop a cellular model to characterize the mechanism underlying this response, we investigated the impact of animal protein, vegetable, and EEN based foods on the transcriptome of intestinal epithelial cells in culture by both RNAseq and targeted quantitative RT-PCR. This model involved the development of a physiologically relevant modality to digest whole food to generate serum-free cell culture media that was characterized using NMR-based metabolomics. Animal protein and EEN diets induced the expression of specific MTs whereas vegetable diets reduced their expression. We also show that zinc induced MT gene expression in intestinal epithelial cells whereas phytic acid, a phytochemical with known anti-nutrient properties that chelates zinc, reduces the ability of protein-based foods and EEN to induce MT gene expression.

Conclusion

The consumption of EEN leads to a very specific transcriptomic signature of MT gene expression in the rectal epithelium of humans that can be reproduced in cell culture by exposure to both animal protein-based foods and EEN. By contrast, vegetable-based foods inhibit MT gene expression possibly through the chelation of zinc. These results are consistent with the notion that the exclusion of plant-based foods through the consumption of EEN may have beneficial effects in the treatment of Crohn’s disease by reducing exposure to anti-nutrient phytochemicals that reduce the absorption of beneficial micronutrients such as zinc.
P0175 A new blocker of endothelial dysfunction ameliorates colitis independently of IL-10 by regulating both barrier function and the recruitment of immune cells
Authors: Park I S , Kim J H , Kim Y W , Kim D , Shin Y , Kim K B , Kim T I , Kim Research professor S W , Kwon Y G , Cheon J H
Published: January 2025

Background

Inflammatory bowel diseases (IBDs) like Crohn’s disease (CD) and ulcerative colitis (UC) are chronic gastrointestinal disease with complex pathogenesis, leading to a lack of effective treatments. The efficacy of CU104, a new blocker of endothelial dysfunction,1 in other IBD models with a CD-like phenotype2 and its specific mechanism of action in colitis are still unknown.

Methods

To evaluate the therapeutic potential of CU104, we induced colitis using dextran sodium sulfate (DSS) in IL-10 knockout mice3 and assessed its effectiveness. Additionally, we used Caco-2, HCT-116, and HT-29 cells to investigate its impact on intestinal barrier function, inflammatory signal pathway, actin dynamics,4 and gene expression through FITC-dextran permeability, trans-epithelial electrical resistance (TEER), reporter gene, gene expression profiling, and immune assays.

Results

CU104 demonstrated therapeutic efficacy in DSS-induced colitis in IL-10 KO mice by potently suppressing innate immune activation, vascular and intestinal barrier dysfunction, and immune cell recruitment. Mechanistically, CU104 inhibited the activation of nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) and interferon regulatory factor (IRF),5 as well as the ezrin/radixin/moesin (ERM) signaling pathways6 in vitro and in vivo, which play critical roles in maintaining barrier integrity and regulating immune cell recruitment during inflammation by regulating actin dynamics.

Conclusion

Our findings suggest that CU104, a pseudo-sugar derivative of cholesterol that regulates actin dynamics and inflammatory signaling, could be a promising new treatment for CD along with UC.

References

1.Kim, Y. S. et al. CU06-1004 Alleviates Experimental Colitis by Modulating Colonic Vessel Dysfunction. Front Pharmacol 11, 571266 (2020).

2.Katsandegwaza, B., Horsnell, W. & Smith, K. Inflammatory Bowel Disease: A Review of Pre-Clinical Murine Models of Human Disease. Int J Mol Sci 23 (2022).

3.Wei, H. X., Wang, B. & Li, B. IL-10 and IL-22 in Mucosal Immunity: Driving Protection and Pathology. Front Immunol 11, 1315 (2020).

4.Kang, S. et al. TRIM40 is a pathogenic driver of inflammatory bowel disease subverting intestinal barrier integrity. Nat Commun 14, 700 (2023).

5.Li, J. Y. et al. IRF/Type I IFN signaling serves as a valuable therapeutic target in the pathogenesis of inflammatory bowel disease. Int Immunopharmacol 92, 107350 (2021).

6.Heemskerk, N. et al. F-actin-rich contractile endothelial pores prevent vascular leakage during leukocyte diapedesis through local RhoA signalling. Nat Commun 7, 10493 (2016).
P0176 Single-cell RNA sequencing reveals the immunological mechanisms underlying Anti-saccharomyces cerevisiae antibody positivity in both non-inflamed and inflamed mucosal tissues of IBD patients
Authors: Im H W , Kim K A , Choi S , Joh C S Y , Im J P , Kim B G , Kim J S , Kim H J , Koh S J
Published: January 2025

Background

Previous studies have shown anti-saccharomyces cerevisiae antibody (ASCA) positivity in inflammatory bowel disease (IBD) patients is associated with increased risk of developing IBD and poor prognosis. However, no comprehensive study has elucidated the ASCA positive-related immunological phenotype in non-inflamed and inflamed colonic mucosa and its clinical implications.

Methods

We collected endoscopic biopsies from 43 ulcerative colitis [28 non-inflamed sites and 43 inflamed sites] and 20 Crohn’s disease at Seoul National University Hospital. Single-cell RNA sequencing (scRNA-seq) was performed on these samples according to the ASCA positivity. First, we compared ASCA-positive and -negative samples obtained from non-lesion sites of UC patients. Second, we investigated immunologic phenotypes in inflamed mucosa based on the disease activity (remission vs active).

Results

We conducted scRNA-seq analysis of over 130,000 single cells from 28 biopsies obtained from non-inflamed tissues of UC patients. Substantial reduction in the frequency of type 3 innate lymphoid cells (ILC3) and expression of IL18 and IL22 in ILC3s, along with a significant decrease in tight junction-associated genes (TJP1, CLDN3, CLDN4) within epithelial cells were observed in the positive group[P <0.05]. In addition, data from positive group exhibited decreased levels of CSF2 in ILC3s, which is likely contributing to reduced M2 macrophage polarization.

We performed scRNA-seq analysis of over 123,673 single cells from 63 biopsies obtained from inflamed tissues. In active inflamed status, the expression of IL-17A - a cytokine that helps maintain tight-junction barrier in the intestinal epithelium during inflammation was decreased in tissue-resident memory T cells (Tc17 TRM) [P 0.026]. In addition, ASCA positive resulted in decreased CD4 central memory T cells (CD4 TCM) [P 0.046], suggesting impaired gut barrier function and subsequent rapid response to reencountered antigens. Cytotoxic gene expression, including granzyme and perforin 1, was increased in CD8 T effector memory cells (CD8 TEM) [P<0.05] during remission, suggesting that ongoing subclinical inflammation may develop and contribute to tissue damage.

Conclusion

These findings suggest that Saccharomyces cerevisiae infection induces immunological changes characterized by gut barrier dysfunction, rapid responses to commensal antigens, and increased cytotoxic gene expression. Based on these findings, we believe that Saccharomyces cerevisiae may serve as a potential target for preventing disease progression in patients with IBD.
P0177 Dietary prevention of undernutrition reduces intestinal inflammation in a DSS-induced model of colitis and is associated with anti-inflammatory metabolites-producing bacteria
Authors: Leboutte M , Rebollo E , Pangault C , Ribet D , Guérin C , Bôle-Feysot C , Monnoye M , Gérard P , Savoye G , Marion-Letellier R
Published: January 2025

Background

Patients with inflammatory bowel diseases (IBD) have a high-risk for undernutrition1. Undernutrition is associated with higher complications such as an increased mortality rate, a higher disease activity and an impaired quality of life in IBD patients. The aim of the present study was to assess whether dietary prevention of undernutrition may alleviate intestinal inflammation in mice with colitis.

Methods

Mice were fed with an enriched diet (ED; 4.7 kcal/g, 38% kcal from milk fat, 29% kcal from sucrose) or a standard diet (SD; 3.9 kcal/g, 8% kcal from milk fat) for 31 days. Colitis was chemically induced by 1% dextran sulfate sodium (DSS) in male C57BL/6 mice for 7 days. Colitis severity was assessed by monitoring inflammation-related biomarkers, as colon weight/length ratio and fecal calprotectin. Gut microbiota composition was determined by 16S rRNA gene sequencing performed on DNA extracted from cecal contents. Body weight and body composition were recorded.

Results

In SD-fed mice, DSS induced body weight loss (p<0.01) associated to a decrease of fat and lean mass (p<0.01). In mice with DSS-induced colitis, ED for 3 weeks prevented body weight loss (p<0.001) and body composition alteration. ED prevented DSS-induced higher colon weight/length ratio and fecal calprotectin. Compared to SD, ED significantly increased relative abundance of 8 bacterial species, including Eisenbergiella tayi (log2FC=3.8474, p_adj<0.01) and Lactococcus lactis (log2FC=1.6034, p_adj<0.05) (Figure 1A), which are producing anti-inflammatory metabolites such as butyrate, lactate or succinate. Relative abundances of Pseudoflavonifractor capillosus and Vescimonas coprocola were negatively correlated with inflammatory markers, such as fecal calprotectin levels (r=-0.7347, p:adj=0.0332; r=-0.7846, p=0.0265, respectively) (Figure 1B).

Conclusion

Prevention of undernutrition by ED reduces DSS-induced colitis severity and is associated with higher anti-inflammatory metabolites-producing bacteria. Further studies are now required to understand the underlying mechanisms involved in these ED-induced effects.

References

1. Bischoff, S. C. et al. ESPEN guideline on Clinical Nutrition in inflammatory bowel disease. Clin Nutr 42, 352–379 (2023).
P0179 Spatial immune profiling of Crohn’s Disease fistula carcinomas - Defining a distinct cancer subtype
Authors: Lehmann M , Paclik D , Huck A , Arnold A , Kurth-Stavenhagen C , Vieth M , Treese C , Kühl A A , Siegmund B ,   German IBD Study Group (GISG)
Published: January 2025

Background

Fistula formation is a common and debilitating complication of Crohn’s disease (CD). Although rare, CD-associated fistula carcinomas present significant diagnostic and prognostic challenges. This study aims to identify disease-specific immune cell subsets in CD-associated fistula carcinomas.

Methods

The study analyzed tissue samples from 10 CD patients with fistula carcinomas, 7 patients with CD-associated fistulas, and 6 patients with sporadic colorectal cancer (CRC). In the tumor samples, the main tumor, infiltration front, and non-involved areas were included. Using a 36-marker panel, the immune landscape was characterized through imaging mass cytometry. The samples were processed, stained, and analyzed for immune cell compositions, cell-cell interactions, and spatial microenvironments.

Results

The immune infiltrate observed in fistula carcinomas displayed similarities to both CD fistulas and CRC. Fistula-carcinoma samples exhibited elevated levels of neutrophils, B cells, and CD163high macrophages. CRC main tumor samples exhibited a higher presence of intraepithelial CD8+ lymphocytes and CD163low macrophages. The highest levels of Cleaved Caspase-3 were observed in CRC main tumor samples, which exhibited a positive correlation with CD163low macrophages and cytotoxic T cells. Conversely, a negative correlation was observed between cleaved Caspase-3 and cytotoxic T cells in fistula-carcinoma main tumor samples. The analysis of cellular microenvironments and dimensionality reduction clustering based on immune cell frequencies revealed that fistula carcinomas exhibit a unique combination of immune cell characteristics derived from both CD fistulas and CRC.

Conclusion

The immune landscape of CD-associated fistula carcinomas exhibits characteristics of both CD fistulas and CRC, indicating a complex pathogenesis driven by chronic inflammation. These findings suggest that fistula carcinomas constitute a distinct cancer subtype, necessitating further research to develop targeted therapeutic strategies.
P0180 Bifidobacterium longum alleviates dextran sulfate sodium-induced colitis through the differential regulation of Toll-like receptor 5 on enteric glial cells
Authors: Zeng Q S , Zou M , Gan H
Published: January 2025

Background

Inflammatory bowel disease (IBD) is a chronic immune-associated disease arising from gastrointestinal dysbiosis and subsequent immunological dysfunction. Numerous studies have reported the beneficial effects of probiotics, such as Bifidobacterium longum (BL), on IBD, while the related mechanism behind these effects have not been fully elucidated. Enteric nervous system abnormalities have increasingly been tied to the pathogenesis of IBD, with a particular focus on the role of enteric glial cells (EGC) in this context. In this study, we aim to explore the mechanism of probiotics in the treatment of IBD from the perspective of EGC.

Methods

On base of C57BL/6 mouse, TLR5 of EGC knockdown mouse model (TLR5 KD mouse) was constructed by adeno-associated virus (serum type 6) (AAV6) which carried the interference sequence of TLR5 gene (AAV6-TLR5-RNAi). Experimental colitis was induced by dextran sulfate sodium (DSS). Mice were treated with phosphate buffer solution (PBS) or BL. Disease activity index (DAI) and histological score were applied to assess the severity of colitis. The level of GDNF、IL-1β of colonic tissue were measured by ELISA. The expression of glial fibrillary acidic protein (GFAP)、toll-like receptor 5 (TLR5)、cleaved caspase-3 of colonic tissue were tested by immunofluorescence staining and quantitative PCR (qPCR).

EGC cell line, EGC CRL2690, was exposed to probiotic (Bifidobacterium longum; BL) bacteria and pathogenic (Enterohemorrhagic Escherichia coli; EHEC). Cell apoptosis rate was assessed by flow cytometry. TLRs expression in EGC CRL2690 were evaluated at both baseline and after exposure to bacteria by qPCR and western blot analysis. GDNF and IL-1β release from EGC CRL2690, following exposure to bacteria, were measured in the presence or absence of specific TLR and pathway inhibitors.

Results

The results showed that BL ameliorated DSS-induced colitis accompanied by increased expression of GDNF, while pathogenic EHEC aggravated DSS-induced colitis combined with decreased expression of GDNF. Mechanistically, BL could up-regulate the secretion of GDNF via TLR5/p38 MAPK pathway in EGC, which was different from EHEC, which could up-regulate the secretion of IL-1β through TLR2/NF-κB pathway.

Conclusion

Our results suggested a new possible mechanism whereby probiotics ameliorate DSS-induced colitis in mice by regulating EGC via TLR5, namely, BL promotes GDNF secretion in EGC through activation of p38 MAPK signaling pathway by TLR5. Meanwhile, our results suggested that probiotic, pathogenic bacteria appeared to influence the development of intestinal inflammation by differentially modulating the secretion function of EGC via different TLRs.
P0183 GSDMD regulates interactions between macrophages and intestinal epithelial cells in inflammatory bowel disease
Authors: Gao X , Zhang X
Published: January 2025

Background

Our previous studies have demonstrated the significant role of the GSDMD-mediated pyroptotic pathway in inflammatory bowel disease (IBD). However, there remains some controversy surrounding the research findings concerning GSDMD in IBD.

Methods

Employing lentiviral transduction techniques, we manipulated GSDMD expression levels in THP-1 and HT-29 cells, assessing the impact of GSDMD on macrophage M1 polarization and epithelial barrier function. Further, co-culturing transduced THP-1 and HT-29 cells enabled the examination of changes in the intestinal barrier. Moreover, we generated conditional knockout mice with Gsdmdflox/floxLyz2-Cre and Gsdmdflox/floxVillin1-Cre, inducing experimental colitis with dextran sodium sulfate (DSS) to evaluate mucosal macrophage phenotypes and intestinal barrier integrity. Additionally, primary macrophages and intestinal epithelial cells were co-cultured, and downstream inflammatory factors were screened through transcriptome sequencing.

Results

Knockdown of GSDMD in THP-1 cells significantly reduces CD86 expression, indicating a decrease in M1 polarization efficiency, whereas overexpression of GSDMD yields opposite results. In HT-29 cells, overexpression of GSDMD followed by LPS treatment leads to a significant decrease expression of Claudin-1, Occludin, and Zo-1, whereas knockdown of GSDMD shows the opposite outcome. ELISA results demonstrate a correlation between GSDMD expression levels and levels of LDH, IL-1β, IL-18, TNF-α, and IL-6. In the inflammatory co-culture model of THP-1 and HT-29 cells with double knockdown of GSDMD, the severity of intestinal barrier damage and release of inflammatory factors is minimal. Conversely, in the inflammatory co-culture model of THP-1 and HT-29 cells with double overexpression of GSDMD, the intestinal barrier damage and release of inflammatory factors are maximal. Following DSS-induced colitis, compared to the Gsdmdflox/flox group, two conditional knockout mice exhibit reduced inflammatory evaluation. Furthermore, the protein expression of Zo-1, Occludin, and Claudin-1 in two conditional knockout mice is significantly higher than that in the Gsdmdflox/flox group. Flow cytometry results show that the proportion of M1 macrophages in the mucosal lamina propria is significantly lower in two conditional knockout mice compared to the Gsdmdflox/flox group. Additionally, primary macrophage and intestinal epithelial cell co-culture experiments, coupled with transcriptomic sequencing, revealed IL-1β as a downstream mediator of GSDMD-mediated macrophage-epithelial cell interplay.

Conclusion

It was confirmed that GSDMD serves as a key target in the pathological interplay between macrophages and epithelial cells.
P0185 Prevalence of IBS-like symptoms in Ulcerative Colitis patients in clinical remission
Authors: Ayton D , Hoque S
Published: January 2025

Background

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder with a higher prevalence in patients with inflammatory bowel disease (IBD) compared to the general population. Ulcerative colitis (UC) patients frequently report symptoms such as abdominal discomfort, bloating, altered bowel habits, and worsening symptoms due to foods or stress, even during clinical remission. This study examines the prevalence of IBS-like symptoms in UC patients at an IBD clinic in a London teaching hospital.

Methods

A survey among 100 UC patients included those with active disease (flare) and in remission. Remission status was defined by: (1) faecal calprotectin levels ≤250µg/g in the last year, (2) C-reactive protein (CRP) within the normal range in the past six months, and (3) a Mayo score of 0 on a flexible sigmoidoscopy/colonoscopy within 6 months. The IBS information questionnaire was based on WHO criteria1 and included 16 questions. Data collected included disease location, year of diagnosis, gender, and current treatment.

Results

Among the 100 patients, 34% had active disease and 66% were in remission during time of survey completion and 91% on active drug management. Total symptom scores differed significantly between active and remission groups (p=0.0066), with higher scores in active disease. However, 94% of patients in remission reported 1< symptom and the mean total score was 11.32 (SD ~6.08) indicating persistent symptoms. There is a female preponderance in symptoms scores than males in both active and remission states. In active disease, females had a mean score of 16.67 (SD: 5.91) vs males at 11.53 (SD: 5.66); in remission, females scored 11.77 (SD: 5.96) vs males at 9.59 (SD: 5.56). A statistically significant gender difference was found in active disease (p=0.0144) but not in remission (p=0.129).

Table 1 shows symptoms reported in remission. Bloating correlated with constipation (r=0.32, p=0.008), potentially indicating proximal constipation in UC remission. Additionally, loose stools were strongly correlated with bowel urgency (r=0.73, p=<0.0001), suggesting a symptom cluster. Among remission patients, proctitis showed the highest scores, while pancolitis scored the lowest. Disease location was weakly negatively correlated with symptom scores (r=-0.19, p=0.76), as was time since UC diagnosis (r=-0.13, p=0.305).

Conclusion

This study shows that IBS-like symptoms persist in UC patients during remission, with 94% reporting 1< symptom despite active drug management. Symptom clusters such as loose stools and bowel urgency and gender differences, emphasise the need for tailored, symptom-focused care. Comprehensive strategies are essential to address residual symptoms and improve quality of life for UC patients, even in remission.

References

1.World Gastroenterology Organisation. Test for Diagnosing IBS. Published 2009. Available at: https://www.worldgastroenterology.org/UserFiles/file/wdhd-2009-test-for-diagnosing-ibs.pdf
P0186 The Significance of BACH2 Expression in Mesenteric Lymph Nodes of Crohn’s Disease
Authors: Hasegawa M , Ogino T , Sekido Y , Takeda M , Hata T , Hamabe A , Miyoshi N , Uemura M , Mizushima T , Doki Y , Eguchi H
Published: January 2025

Background

In Crohn’s disease (CD), the active phase is characterized by lymphatic edema, mesenteric thickening, and enlarged mesenteric lymph nodes (MLNs). Numerous lymphoid follicle-like structures are observed in inflamed areas, suggesting that lymphoid follicles and germinal centers play critical roles in CD pathogenesis. Surgical resection including thickened mesentery may reduce recurrence; however, the role of MLNs remains unclear. BACH2, a key regulator of germinal center B-cell function, was analyzed to clarify its significance in MLNs from CD patients.

Methods

MLNs were collected from 28 CD patients undergoing bowel resection with lymph node dissection. Control MLNs were obtained from macroscopically and microscopically normal ileocecal regions in patients with colorectal cancer. BACH2 expression was evaluated via immunohistochemistry. MLNs with expression levels comparable to or exceeding those of normal MLNs were categorized as strong positive (SP), while those with lower expression were classified as weak positive (WP). Lymphoid structures (LS) were defined as clusters of ≥100 mononuclear cells; primary follicles lacked germinal centers, while secondary follicles contained germinal centers. Data are presented as medians.

Results

The median MLN diameter in CD patients was 5.6 mm, significantly larger than in controls (2.9 mm, P<0.0001). BACH2 expression was classified as SP in 64.3% and WP in 35.7% of cases. The number of dissected lymph nodes did not differ between SP and WP groups. No significant differences were observed in the total LS count or the area of primary and secondary follicles per MLN between the groups. However, SP patients were younger at the time of surgery (33.9 vs. 51.9 years, P=0.0153) and diagnosis (22.9 vs. 40.0 years, P=0.0055). Preoperative CRP levels were lower in SP patients (0.51 vs. 2.63 mg/dL, P=0.0307), and serum albumin levels were higher (3.9 vs. 3.1 g/dL, P=0.0087). Although no significant differences were observed in postoperative endoscopic recurrence rates, recurrence was more frequent in the WP group (22.2%) compared to the SP group (6.25%).

Conclusion

Reduced BACH2 expression in MLNs was observed in 35.7% of CD patients. These patients exhibited later disease onset, higher preoperative inflammation, and poorer nutritional status, with a potential trend toward higher postoperative recurrence rates. These findings suggest that reduced BACH2 expression in MLNs may reflect impaired immune regulatory in CD.
P0191 The role of myeloid mineralocorticoid receptor and its target neutrophil gelatinase-associated lipocalin in mice with colitis
Authors: Rebollo E , Leboutte M , Jaisser F , Savoye G , Marion-Letellier R
Published: January 2025

Background

Intestinal fibrosis is a common complication in IBD patients with no specific treatment. In extra-intestinal conditions, mineralocorticoid receptor (MR) antagonism inhibits inflammation and fibrosis in different pathophysiological conditions. We previously showed that pharmacological antagonism of MR also inhibits experimental intestinal fibrosis through its target neutrophil gelatinase-associated lipocalin (NGAL). We now hypothesize that myeloid MR may promote the transition from inflammation to intestinal fibrosis by modulation of macrophage plasticity. We aimed to investigate whether myeloid MR or myeloid NGAL deletion prevents colitis development in mice.

Methods

Acute and chronic colitis were respectively induced by 1% dextran sodium sulfate (DSS) in myeloid MR knock-out (MyMR KO n=10, WT n= 5) and myeloid NGAL knock-out (MyNGAL KO n=6, WT n=8). Colon tissues were collected for quantitative PCR analysis of inflammatory (Il1, Il6, Arg1, Nos2, Retnla, Adgre1) and fibrotic markers (Col1a1, Tgfb1, Fn1, Mmp3, Mmp9, Igf1, Tnf, Timp1). Fecal calprotectin and lipocalin levels were analyzed by ELISA.

Results

Myeloid MR deletion significantly reduced colon TGFβ mRNA expression (P<0.05) but did not impact weight loss or intestinal permeability in mice. Myeloid NGAL deletion significantly reduced colitis-induced weight loss (P<0.05) and inhibited fibrosis markers such as collagen 1 and metalloproteinase mRNA expression in mice with chronic colitis (Figure 1). Myeloid MR or NGAL invalidation did not significantly affect fecal calprotectin and lipocalin levels in our experimental conditions.

Conclusion

In our pilot study, myeloid MR and myeloid NGAL deletion inhibits fibrosis development but further studies are required to confirm these findings.
P0192 Activities of Sorghum bicolor diet on microbial gut-brain axis during experimental Crohn’s Colitis in adult male Wistar rats
Authors: Salami PhD A T , Akpamu U , Anyakudo G C , Oluwakorede T S , Olujimi A O , Olaleye B S
Published: January 2025

Background

Crohn’s colitis (CC) is a form of inflammatory bowel disease with increasing resistance to synthetic medications hence the search for easily-accessible medicinal plants with anti-inflammatory activities. During CC, there are reports of dysbiosis, neuro-inflammation accompanied with defective brain structure, irregular neural signaling, and associated depressive-like behavior. Sorghum bicolor leaf (SBLD) and seed (SBSD) are accessible medicinal plant with anti-inflammatory bioactive compounds. However, there is limited information regarding its activities on microbial-gut-brain axis during CC which this study evaluates.

Methods

Ethical approval was obtained from the University of Ibadan (UI-ACUREC/071-1222/31) and S.bicolor plant was identified by the institutional herbarium (UIH-23294). Eighty male Wistar rats (100-150g, n=10) were divided thus: Groups 1-normal rats, 2-colitis untreated (CCU), 3-CC+Azathioprine, 4-CC+Resveratrol, 5-CC+10% SBLD, 6-CC+20% SBLD, 7-CC+10% SBSD, 8-CC+20% SBLD. Groups 2-8 were induced with CC (1ml/kg of 1.4% NaOH single intra-rectal) by day 14 of treatment which continued for 7 days. Daily body weights, neuro-behavioural studies, and stool score were monitored. Animals were euthanized, and colon was excised for ulcer score. The excised colon and brain were submitted for biochemical estimation and histological processing and evaluation by days 3 and 7 post CC induction. Fecal samples were processed for gut microflora using 16S rDNA gene sequencing. Results were subjected to one-way ANOVA, values expressed as MEAN±SEM and statistically significant at p≤0.05.

Results

Body weight, colon weight/length ratio, stool and ulcer scores in SBLD and SBSD-treated groups significantly reduced compared with CCU, and CC+Resveratrol on days 3 and 7. Colon healing zone, and neuro-behaviour traits (rearing, grooming, and line crossing time) in SBLD and SBSD-treated groups significantly increased compared with CCU. Colon and brain malondialdehyde, carbonyl, nitric oxide, significantly reduced but increased in hydrogen peroxide, mucin, sulfhydryl, glutathione-reductase, and calcium ATPase pump activities in the SBLD and SBSD-treated groups compared with CCU on both days. Reactive cortico-hippocampal cells in SBLD and SBSD-treated groups significantly reduced compared with CCU, CC+Azathioprine and CC+Resveratrol. Lactobacillus species in the SBLD and SBSD-treated groups significantly increased compared with CCU on both days.

Conclusion

Sorghum bicolor leaf and seed diet facilitated healing of Crohn’s colitis and attenuated adverse neurobehavioural traits through reduced oxidative stress, and increased gut Lactobaccillus sp. with gut-brain signaling.
P0198 Comparative Transcriptomic Analysis of Tonsil-derived and Adipose-derived Mesenchymal Stem Cells: Proliferation, Migration, and Anti-inflammatory Potential in Murine Colitis Model
Authors: Song E M , Joo Y H , Byeon J , Choe A R , Park Y , Tae C H , Kim S E , Jung H K , Shim K N , Jung S A
Published: January 2025

Background

Tonsil-derived mesenchymal stem cells (TMSCs) have emerged as a promising alternative to traditional MSCs due to their rapid proliferation and accessibility. This study explores the unique transcriptomic and cellular properties of TMSCs compared with adipose-derived MSCs (AMSCs).

Methods

TMSCs and AMSCs were cultured under identical conditions in low-glucose DMEM with 10% FBS. Proliferation was evaluated via CCK-8 assays, and migration potential was assessed using scratch assays. Transcriptomic differences were analyzed using RNA sequencing, with key findings validated by qPCR.

Results

TMSCs displayed distinct morphological features compared to AMSCs, with TMSCs showing a spindle shape, while AMSCs appeared more irregular and rounded shape. In terms of proliferation, TMSCs demonstrated a significantly higher proliferation rate by day 7 (245.3% of control vs. 134.4% of control, p < 0.001). However, there was no significant difference in migration capacity between TMSCs and AMSCs over a 24-hour period (50.8 ± 8.2 vs. 53.8 ± 9.8, p = 0.537). RNA sequencing analysis revealed notable differences in gene expression, with TMSCs showing enrichment in pathways related to extracellular matrix, cell adhesion, and immune response, particularly with upregulation of the MAPK signaling pathway compared with AMSCs. For anti-inflammatory cytokines, IL-33, FOXF1, and HGF were upregulated in TMSCs relative to AMSCs. In relation to proliferation and migration, CCL2, CXCL12, and STC1 levels were also higher in TMSCs. Additionally, TMSCs exhibited increased expression of RAB27B, suggesting a greater potential for exosome release. In a DSS-induced acute colitis model, both TMSCs and AMSCs alleviated colitis symptoms with significant improvements in colon length (p < 0.05). Real-time PCR analysis of mouse colonic tissue also demonstrated a reduction in pro-inflammatory cytokines, such as IL-1β, with TMSCs showing a more pronounced reduction.

Conclusion

This study demonstrates that TMSCs possess unique characteristics, including a higher proliferation rate and distinct gene expression profiles compared to AMSCs. While both MSC types exhibited similar anti-inflammatory effects in murine colitis model, the enhanced anti-inflammatory potential and increased exosome release capacity of TMSCs, combined with their easy availability, highlight their promise for clinical application.
P0205 Fecal host transcriptomics accurately assesses endoscopic inflammatory activity in patients with inflammatory bowel diseases
Authors: Weintraub Y , Segal A , Matar M , Nevo-Shor A , Kantor I , Shamir R , Bahar Halpern K , Itzkovitz S , Yehuda-Cohen A , Kahan-Hanum M , Harnik Y , Shouval D
Published: January 2025

Background

The intestinal mucosa regenerates every few days, and cells are continuously shed into the gut lumen. These cells, primarily epithelial and immune cells, have recently been shown to remain viable after shedding and hold critical information for assessing bowel pathology. Analysis of endoscopic washes of luminal material during colonoscopies suggests that the human transcriptome in fecal material accurately reflects degree of histologic inflammation in patients with inflammatory bowel diseases (IBD). We aimed to define whether transcriptomic analysis of stool samples can reflect degree of intestinal inflammation in patients with IBD.

Methods

Bulk RNA sequencing was performed on stool samples to obtain fecal human transcriptomes from 82 IBD patients, as well as from healthy controls. Each sample received an inflammation score derived from a group of pro-inflammatory transcripts. Inflammatory score was compared to fecal calprotectin as well as endoscopic evaluation.

Results

The quality of human RNA isolated from fecal content was high, with a median of 2,218 human genes detected per sample. The correlation between fecal calprotectin protein levels and mRNA expression was high (r=0.75). An inflammatory score was generated based on a group of differentially expressed genes. The inflammatory score provided high sensitivity and specificity (both 90%) in predicting endoscopic inflammatory activity when compared to colonoscopic findings.

Conclusion

Fecal shed cell transcriptomics provided a novel non-invasive tool to measure inflammatory activity at the endoscopic level in patients with IBD. Ongoing studies will address whether this technology can assist in defining degree and location of inflammation, as well as predict response to different therapies.