bluuebunny/crossref_metadata_2025_split huggingface dataset:
P0117 Exploring the role and mechanism of leukotriene D4 in fistulizing Crohn's disease based on multi-omics research
Authors: Zhang C 
Published: January 2025

Abstract

Background
Alterations in the gut microbiota and its metabolites are involved in the pathogenesis of Crohn's disease (CD). In a study targeting patients with different phenotypes of CD, we investigated the characteristics of the gut microbiota and metabolites between Crohn's disease with fistula and Crohn's disease without fistula.

Methods
We divided the research subjects into three groups, including 11 CD patients with fistulas, 9 CD patients without fistulas, and 5 healthy individuals (control group). Stool samples from patients were collected and sequenced. The fecal microflora was analyzed by 16S ribosomal RNA gene amplification sequence, and the metabolites were quantified by liquid chromatography tandem mass spectrometry (LC-MS/MS). Bioinformatics analysis was employed to explore the microbial and metabolite characteristics of CD fistulas. Then, we further verified through mouse experiments and cell experiments.

Results
Compared with healthy controls, CD patients mainly showed a reduction in the Firmicutes phylum and an increase in the Proteobacteria phylum. The reduction of these short-chain fatty acid-producing bacteria and the increase in harmful bacteria are likely important factors leading to CD. Compared with non-fistula patients, the beneficial bacteria such as the genus Romboutsia in fistula patients were significantly reduced. In addition, we also found structural disruption and functional dysregulation of microorganisms in fistula patients. Metabolomics analysis indicated that the increase in pro-inflammatory metabolites such as leukotriene D4 is a specific change in fistula. Spearman correlation analysis showed that the reduction of beneficial bacteria was significantly negatively correlated with the increase in leukotriene D4, suggesting that the reduction of beneficial bacteria may lead to an increase in leukotriene D4 and thus promote the formation of fistulas. In vitro experiments further demonstrated that leukotriene D4 can delay the healing of fistula in mice. Cell experiments also proved that leukotriene D4 can reduce the expression of E-cadherin and upregulate the expression of EMT-related genes (snail, vimentin). Transcriptome analysis revealed that leukotriene D4 may lead to the formation of fistulas by activating the AGE-RAGE signaling pathway in diabetic complications.

Conclusion
In CD patients, the reduction of beneficial bacteria may promote the upregulation of leukotriene D4, thus promoting the formation of fistula.
P0129 Distinct involvement of plasma cells and monocytes/macrophages in ileal and colonic ulcer formation in patients with Crohn's disease
Authors: Pierre Dr. N , Jacobs N , Fernández-Verdejo R , Louis E , Vieujean S 
Published: January 2025

Abstract

Background
Despite its interest for the development of personalised medicine, the pathophysiological distinctions between ileal and colonic Crohn’s disease (CD) have been poorly characterised. This study aims to search for immunological differences between ileal and colonic CD.

Methods
We reanalysed our proteomic dataset1 to extract non-exploited immunological information. Using mass spectrometry-based proteomics, we previously compared the proteome of ulcer edges and adjacent normal mucosa (paired design) in the ileum (n=16 biopsies) and colon (n=16 biopsies) of 16 CD patients (Figure 1). A total of 4,428 and 5,204 proteins were screened in the ileum and colon, respectively. To identify proteins specific to particular immune cell populations, we searched in the Human Proteome Atlas and literature.

Results
We identified markers specific to plasma cells (IgA1, IgM, IgG1, IgG2, IgG3, IgG4, immunoglobulin J chain [IGJ], and immunoglobulin lambda-like polypeptide 5 [IGLL5]), monocytes/macrophages (cluster of differentiation 14 [CD14]), and mast cells (chymase [CMA1], mast cell carboxypeptidase A [CPA3], and tryptase alpha/beta-1 [TPSAB1]). No specific markers were identified for the other immune cells. The number of increased plasma cell markers (ulcer edges vs adjacent normal mucosa) was higher in the ileum (IgA1, IgM, IgG1, IgG2, IgG3, IGLL5, and IGJ) than in the colon (IgG3) (Figure 2). Of note, immune exclusion markers (IgM, IgA1, IGJ) were increased in the ileum, but not the colon (ulcer edges vs adjacent normal mucosa). The marker of monocytes/macrophages CD14 was increased in the colon, but not in the ileum (ulcer edges vs adjacent normal mucosa) (Figure 2). Mast cells markers (CMA1, CPA3, and TPSAB1) showed no significant change in the ileum or colon (ulcer edges vs adjacent normal mucosa) (Figure 2).

Conclusion
Plasma cells and monocytes/macrophages may play distinct roles in the formation of ileal and colonic ulcers in patients with CD, suggesting further investigations.

References
1.Pierre N, Salée C, Massot C, Blétard N, Mazzucchelli G, Smargiasso N, et al. Proteomics Highlights Common and Distinct Pathophysiological Processes Associated with Ileal and Colonic Ulcers in Crohn’s Disease. J Crohns Colitis 2020;14(2):205–15.
P0130 Assessment of macrophage types in the intestinal tissue of treatment naïve Inflammatory Bowel Disease patients in relation to their disease and activation of the CCL2/CCR2 pathway
Authors: Begum J , Fatima A , Rimmer P , Iqbal T , Stoica V , Owusu M , Lelios I , McGettrick H , Welford R , Iqbal A 
Published: January 2025

Abstract

Background
Resident intestinal macrophages play a key role in maintaining gut homeostasis and exhibit a hypoactive tolerogenic phenotype. Recently, several subsets of intestinal macrophages have been identified based on CD11c expression which differ in their inflammatory and functional profiles. Notably, pro-inflammatory CD11c+ monocyte-like macrophages are found elevated in patients with inflammatory bowel disease (IBD), specifically Ulcerative colitis (UC) and Crohn’s disease (CD). These cells are recruited from blood monocytes via the CCR2/CCL2 chemokine pathway. Our study is focused on observing the patterns of CCL2-driven blood monocyte migration and their translation into subsets of intestinal tissue macrophages that can determine the degree of gut inflammation in newly diagnosed patients.

Methods
Patients referred with suspected IBD were seen in an inception clinic. Intestinal biopsies and matched blood samples were obtained from pre-treatment UC and CD patients during their index colonoscopy. Those with inflammation excluded during this procedure formed a ‘non-IBD’ control group. Biopsy segments were cultured to generate conditioned media and also digested for flow cytometry analysis. Plasma concentrations of CCL2 and intestinal secretome were measured using ELISA or Olink proteomic analysis respectively. Efficacy of blood monocyte chemotaxis towards CCL2 was assessed in the presence or absence of CCL2/CCR2 antagonists and the profile of monocyte subsets in whole blood were determined using whole blood flow cytometry analysis.

Results
As previously described, we observed distinct CD11c+ and CD11c- macrophage populations in IBD intestinal tissue, with expansion of the CD11c+ subset within inflamed regions which expressed higher levels of the chemokine receptors CCR2 and CX3CR1. Higher concentrations of CCL2 were observed in conditioned media from inflamed IBD tissue compared to non-inflamed regions and this correlated with elevated numbers of circulating blood monocytes. Chemotaxis assays revealed a corresponding increase in CCL2-induced monocyte migration in patients with IBD compared to the ‘non-IBD’ control group.

Conclusion
Our study provides further insights into the role of the CCL2/CCR2 chemokine axis in driving monocyte recruitment and their differentiation into pro-inflammatory intestinal macrophages in IBD. We demonstrate that inflamed intestinal regions exhibit elevated levels of CCL2 correlating with an expansion of the CD11c⁺ macrophage subset and increased CCL2-driven monocyte migration in these subjects. These findings underscore the significance of targeting the CCL2/CCR2 pathway and that it might be an important driver in the development IBD.
P0136 The role of FDG PET/CT in the and identification of fibrosis related to Crohn’s disease
Authors: Élthes Z , Sándor K , Galuska L , Farkas B , Pető S , Palatka K 
Published: January 2025

Abstract

Background
There is a constant search for non-invasive evaluation methods for the identification of fibrosis in patients treated for Crohn’s disease, since this condition can severely impact patients’ quality of life in the long run. While PET/CT is mostly used in oncological evaluation, it was previously proved that it can be useful in the evaluation of inflammation associated with Crohn’s disease activity, since segmental FDG uptake is proportional with immune cell infiltration of the bowel. However, it’s role in the detection of fibrosis needs further evaluation.
Our aim was to prospectively evaluate the prognostic value of FDG/PET CT in the identification of fibrosis related to Crohn’s disease regarding global PET scores compared to other imaging techniques (i.e. MRI, CT), simple endoscopic score (SES-CD), CD Activity Index (CDAI) intraoperative findings and histological evaluation of resected bowel segment.

Methods
We prospectively evaluated our patients from in and outpatient care between October 2021 and October 2024 who underwent bowel segment resection due to stenosis that was identified at a follow-up colonoscopy.
On PET-CT, we scored the FDG uptake in the small intestine and the 4 colon segments. Regions with increased FDG uptake were segmented with metabolically active volume (MAV), uncorrected maximal standardized uptake value (SUVmax), related to the SUVmax of the liver (as a reference for normal tissue activity) and uncorrected total lesion glycolysis (TLG).

Results
A total of 17 patients were selected, 11 (65 %) males and 6 (35 %) females, with a median age of 43 years (29-44). Ten patients (59 %) had Crohn’s disease affecting the small and large bowel, while in 3 (18 %) patients it affected only the small intestines and in 4 cases (23 %) it was localized solely on the large intestines. Seven (41 %) patients were bio naive, while 10 patients (59 %) received at least one biological therapy since their diagnosis. Five patients had a history of previous resection, from which three underwent endoscopic dilatation as well before the current surgery. In active disease, PET was more informative than endoscopy to access the extent of the inflammation, and small intestine involvement.
FDG PET-CT proved to be statistically more efficient in the identification of affected bowel segments than MRI or colonoscopy. However, we could not find an association between FDG PET-CT scores and the presence of fibrosis in our patients.

Conclusion
FDG PET-CT is a non-invasive complementary method for the evaluation of the affected bowel segments in CD, however its role in the identification of fibrosis is still not evident. This needs further investigation and a larger number of patients.
P0140 Estrogen Related Receptor Alpha Contributes to Intestinal Homeostasis by Modulating the Gut Microbiota and activating autophagy
Authors: Lee J Y , Kim S , Shin S G , Kim J K , Silwal P , Kim Y J , Shin N R , Kim P S , Won M , Lee S H , Kim S Y , Sasai M , Yamamoto M , Kim J M , Jo E K , Bae J W 
Published: January 2025

Abstract

Background
The gut microbiota plays a pivotal role in maintaining intestinal homeostasis and mitigating inflammation. The orphan nuclear receptor ESRRA (estrogen-related receptor alpha) has been identified as a critical regulator of mitochondrial function and autophagy, yet its role in gut microbiota modulation and intestinal health remains unclear.

Methods
We investigated role of ESRRA in intestinal homeostasis using Esrra-deficient mice in a dextran sodium sulfate (DSS)-induced colitis model. Colitis severity is investigated through survival rate and body weight. Gut barrier function was evaluated using FITC-dextran. Autophagic flux was evaluated using qPCR and histological methods in HT-29 cell. ESRRA expression was also assessed in human ulcerative colitis (UC) tissue samples. Gut microbiota composition was analyzed through 16S rRNA sequencing using QIIME2. Differential abundant taxa were identified using LEfSe analysis.

Results
Esrra-deficient mice exhibited heightened susceptibility to DSS-induced colitis, with body weight loss, disrupted gut barrier integrity, and elevated inflammation (Figure 1A-E). Autophagy regulators and markers Tfeb, Vps11, and Uvrag were significantly decreased in Esrra-deficient mice after DSS treatment (Figure 1F). Indeed, the mCherry-EGFP-LC3B reporter system showed secretion of autophagosome was not properly activated in Esrra-deficient cells (Figure 1G). ESRRA was also decreased in UC patients from GSE9452 and GSE11223 studies (Figure 1H). Immunohistochemical staining showed ESRRA was significantly reduced in UC colon tissues and gene set enrichment analysis showed autophagy is correlated with ESRRA expression (Figure 1I, J). Esrra-deficient mice also displayed altered gut microbiota composition, characterized by increased microbial diversity (Figure 2A-D). Unweighted UniFrac distance-based PCoA showed a significant cluster of each group (Figure 2E). LEfSe analysis showed Alloprevotella was significantly decreased in Esrra-deficient mice before/after DSS treatment (Figure 2F, H). Barnesiella and Anaserofustis were significantly decreased by DSS treatment in WT and KO mice (Figure 2G, I).

Conclusion
This study, published in the journal Autophagy 1, reveals that ESRRA is a vital regulator of intestinal homeostasis, coordinating autophagic activity and gut microbiota to protect against colitis. Targeting ESRRA or its downstream pathways could offer novel therapeutic strategies for inflammatory bowel diseases.

References
1.Kim S, Lee JY, Shin SG, Kim JK, Silwal P, Kim YJ, et al. ESRRA (estrogen related receptor alpha) is a critical regulator of intestinal homeostasis through activation of autophagic flux via gut microbiota. Autophagy 2021; 17:2856-75.
P0141 Estrogen receptor β alleviates colitis in intestinal epithelial cells by activating HIF-1α and ATG-9a mediated autophagy
Authors: Li J , Chen Y , Zhu L 
Published: January 2025

Abstract

Background
Ulcerative colitis (UC) manifests as excessive inflammation and compromised integrity of the intestinal epithelial barrier. Estrogen receptor β (ERβ) exerts anti-inflammatory effects in the colon. However, the mechanism remains unclear. This study aims to explore the role and mechanism of ERβ in alleviating colitis, and provide a novel therapeutic target for UC.

Methods
The level of ERβ and autophagy in the inflammatory and non-inflammatory colons of patients with UC were assessed. Mice with dextran sulfate sodium (DSS)-induced colitis were used to establish an in vivo model. The body weight change, colon length, disease activity index (DAI) and histological score of mice in each group were compared. In vitro, HT-29 cell inflammation was induced by lipopolysaccharide (LPS). ERB041, an ERβ specific agonist, was administered to DSS-induced mice and LPS-induced HT-29 cells. Autophagy in vivo and in vitro was evaluated by western blot, transmission electron microscope, and immunofluorescence. Co-immunoprecipitation, chromatin immunoprecipitation, and dual-luciferase reporter assay were conducted to further delineate the mechanism between ERβ and autophagy.

Results
Compared with non-inflammatory mucosa, the expression of ERβ in the inflammatory mucosa in patients with UC was down-regulated, with autophagy inhibited significantly. ERβ activation attenuated the intestinal epithelial barrier disruption, decreased the level of pro-inflammatory cytokines, and significantly attenuated DSS-induced experimental colitis. Mechanically, ERB041 intervention activated autophagy, which was manifested as up-regulation of LC3BII expression, decreased p62 level and increased number of autolysosomes. ERβ interacted with hypoxia-inducible factor 1α (HIF-1α) and activated autophagy. Furthermore, HIF-1α bound to the promoter region of ATG- 9a, and positively regulates its transcription.

Conclusion
ERβ exerts anti-inflammatory effect by up-regulating HIF-1α and activating ATG-9a mediated autophagy in intestinal epithelial cells, and may be a promising therapeutic target for UC.
P0142 CD47-SIRPα Contributes to the Microenvironment of Stricturing Crohn's Disease by Mediating the Crosstalk between Macrophages and Stromal cells: “Eat Me” or “Don't Eat Me”
Authors: Zhao X , Wang D , Sun S , Zhang Y , Zou D 
Published: January 2025

Abstract

Background
Intestinal fibrosis is a common complication of Crohn’s disease (CD), but no anti-fibrotic therapy is currently available. Collagen deposition, the pathological characteristics of intestinal fibrosis, is driven by an imbalance between extracellular matrix (ECM) production and degradation, which is controlled by the crosstalk between stromal cells and macrophage phagocytosis. The underlying mechanism of macrophage phagocytosis is the interplay between “eat me” signals and “don’t eat me”, among which CD47-SIRPa is the dominant pair. This study aims to investigate the role and therapeutic potential of CD47-SIRPa in intestinal fibrosis.

Methods
Thirty CD patients who underwent surgery due to fibrosis-induced intestinal obstruction were included in this study and the intestinal tissues were collected from both fibrotic and normal sites. Col1a2-CreERT2; Cd47 flox mice and Lyz2-Cre; SIRPα flox mice were used to conditionally ablate CD47/SIRPα. Mice intestinal fibrosis was induced by chronic dextrane sodium sulfate (DSS) and anti-CD47/anti-SIRPα antibody was treated intraperitoneally. Human and mice tissues were applied for single-cell RNA sequencing, flow cytometry, pathological evaluation, immunofluorescence staining, qPCR and in vitro experiment. Smart-seq were performed to detect the functional change of mice macrophage.

Results
Single-cell RNA sequencing and flow cytometry showed the proportion of CD47+ stromal cells and SIRPα+ macrophages significantly increased in intestinal fibrosis (Figure 1A). CD47+ stromal cells were in senescence-associated secretory phenotype (SASP), while macrophages also acquired a pro-fibrotic immature phenotype (all p&lt;0.05). Moreover, we found the elevation of macrophage SIRPα expression was caused by CD47+ stromal cells and they extensively co-located in fibrotic lesions to form a pathogenic niche(Figure 1B). Conditionally ablation of CD47 in stromal cell or SIRPα in macrophage could significantly reduce collagen deposition(Figure 1C). Meanwhile, both anti-CD47 and anti-SIRPα treatment significantly attenuated mice intestinal fibrosis compared to the control.(Figure 1D) Mice intestinal macrophages acquired an anti-fibrotic phenotype and regained the capacity of phagocytosis by upregulating Clec7a and MMP10 after antibody treatment (all p&lt;0.05) (Figure 1E). Furthermore, under the same total treatment dose, initiating antibody intervention at the earliest stage could achieve the best prognostic efficacy, highlighting its potential to be a therapeutic and preventive strategy against intestinal fibrosis (Figure 1F).

Conclusion
CD47-SIRPa mediated macrophage-stromal cell crosstalk significantly contributed to structuring CD and may be a novel therapeutic target for intestinal fibrosis.
P0145 Role of PPARg on anti-inflammatory effects mediated by AhR ligands in a Caco-2/THP-1 in vitro “inflamed gut” model
Authors: Oliveira Da Rocha G H , Müller C , Przybylski-Wartner S , Schaller H , Riemschneider S , Lehmann J 
Published: January 2025

Abstract

Background
Inflammatory Bowel Diseases (IBD) lack therapeutic options capable of inducing long-term remission in a cost-efficient manner. Repurposing strategies have allowed already established receptors and ligands to be tested as alternative pharmacotherapy for treatment of IBD. Agonists of the aryl hydrocarbon receptor (AhR), a ligand-dependent transcription factor traditionally associated with xenobiotic toxicity, have been explored as potential anti-inflammatory drugs to treat IBD, but specific mechanisms have yet to be elucidated. Like AhR, the peroxisome proliferator-activated receptor gamma (PPARg), responsible for control of lipid metabolism, has been evidenced as a key player in control of inflammation. In this study, we have explored a hypothetical crosstalk between PPARg and AhR in attenuating intestinal inflammation.

Methods
Bioinformatics analyses of a GEO RNAseq dataset of gut macrophages from IBD patients were used to assess correlations between PPARg and AhR. In vitro, macrophage-differentiated THP-1 cells and Caco-2 gut epithelial cells were seeded in Transwell® inserts to generate a gut-like co-culture model. Cells were treated with 100 ng/mL lipopolysaccharide (LPS) for 24 h in order to mimic a phenotype of intestinal inflammation, and also with combinations of AhR/PPARg agonists and antagonists at concentrations of 10 µM each. Proprietary AhR agonists were also tested. AhR translocation and cytokine secretion in macrophages as well as monolayer integrity and expression of tight junction proteins (e.g., claudin-2) in epithelial cells were assessed.

Results
Principal component analysis and Pearson correlation tests of the RNAseq dataset revealed that PPARg and AhR correlate with each other during intestinal homeostasis, but their expression patterns diverge during gut inflammation. In our co-culture model, blocking PPARg in THP-1 macrophages with a specific antagonist (GW9662) prevented AhR agonist 6-formylindolo[3,2-b]carbazole (FICZ) from inducing AhR nuclear translocation and secreting interleukin (IL)-6. In Caco-2 gut epithelial cells, GW9662 blocked the anti-inflammatory effects of FICZ on monolayer disruption and claudin-2 expression. These effects of FICZ were confirmed to be AhR-dependent, as they were prevented under treatment with the AhR antagonist CH223191. Proprietary AhR ligands also inhibited IL-6 secretion, which was shown to be the most dominant parameter in terms of converging anti-inflammatory effects of both PPARg and AhR.

Conclusion
Our data points to a pivotal cross-talk between AhR and PPARg, where PPARg is likely recruited downstream of AhR activation and contributes to the anti-inflammatory effects of FICZ, especially inhibition of IL-6 secretion.