bluuebunny/crossref_metadata_2025_split huggingface dataset:
P0128 IL-27 signalling, but not IL-1B, is functionally relevant in the pathophysiology of immune checkpoint inhibitor induced colitis
Authors: Ibraheim H , Cozzetto D , Goldin R , Kudo H , Zhou X , Lo J W , Powell N 
Published: January 2025

Abstract

Background
Immune checkpoint inhibitors (CPI) augment T-cell responses to tumour cells and have transformed treatment paradigms in cancer. However, CPI frequently trigger autoimmune like events, including potentially life-threatening colitis. Current immunosuppressive treatments for CPI- colitis (CPI-c) incur significant side effects and may even reduce CPI efficacy. New treatments are urgently needed.

Methods
Changes at gene level, pathway level (GSEA) and predicted upstream regulators (Ingenuity Pathway Analysis-IPA), and enrichment scores (Gene Set Variation Analysis-GSVA) were investigated in colonic biopsies (RNA-sequencing) from patients with CPI-c (n=12), CPI (no colitis) (n=6), healthy controls (n=13) and ulcerative colitis (UC) (n=12). Potentially relevant pathways were functionally tested in preclinical disease models. CPI-c was induced in mice transplanted with a pro-inflammatory microbiota and administered anti-PD-1 and anti-CTLA-4 intraperitoneally (i.p). Anti-IL1R (anakinra), MCC950 (inflammasome inhibitor) and anti-IL27 were administered i.p. Colonic leukocytes were extracted to interrogate myeloid and lymphocyte compartments by flow cytometry. Whole colon segments were processed for histology.

Results
In CPI-c patients, IL-1B was the top differentially expressed cytokine at gene level with interleukin-1 signalling significantly enriched at pathway level. IPA also identified IL-1B and IL-27 as predicted upstream activators. Interestingly, in vivo blockade of IL-1B, or the inflammasome (MCC950), had no impact on colitis.
Administration of IL-27-neutralising antibodies at the onset of CPI-colitis in mice, reduced disease susceptibility and improved histological colitis scores. This was associated with decreased infiltration of colonic lamina propria neutrophils, Ly6C+ inflammatory monocytes and the number of CD8+ IFNg+ T-cells. Conversely, administering neutralising anti-IL27 during established CPI-colitis did not ameliorate disease and was linked to an enhanced CD4+ effector response characterised by heightened production of TNFa and IFNg.
Further analysis of colonic biopsies of CPI-c patients confirmed enrichment of IL27-responsive genes which we localised to CD8+ resident memory and CD8+ cytotoxic cells in single cell RNA-seq analyses. Additionally, serum IL-27 levels were significantly elevated in CPI-c patients.

Conclusion
IL-1B signalling was shown to be dispensable to disease in mice. However, IL-27 signalling has a context specific role, serving as a functionally important activator of innate immune responses, while inhibiting later phases of acquired immunity via suppressing cytotoxic lymphocyte responses. Targeting IL-27 presents an attractive therapeutic approach for CPI-c given its potential tumourogenic effects.
P0131 Characterisation of a human multi-organ-on-chip model to unravel gut-blood-brain communication
Authors: Maes L , Van Welden S , Vandenbroucke R , Laukens D ,   IBD Research Unit
Published: January 2025

Abstract

Background
Persistent fatigue is a frequently reported symptom among patients with Inflammatory Bowel Disease (IBD), significantly diminishing quality of life. Due to the lack of understanding how IBD-associated fatigue originates, currently available treatments do not efficiently tackle this symptom. Developing targeted therapies requires tools to unravel the mechanisms behind central nervous system dysfunction in response to chronic intestinal inflammation. We are therefore establishing and characterising a human multi-organ-on-chip model to recapitulate key physiological elements of gut-brain communication via the systemic circulation.

Methods
In our model, a gut-blood barrier, comprised of Caco-2 (enterocytes) and HT29-MTX cells (goblet cells), is connected to a blood-cerebrospinal fluid (CSF) barrier, composed of HIBCPP and iHCPEnC cells (choroid plexus epithelial and endothelial cells respectively), and to a brain compartment (SH-SY5Y, neurons) via recirculation of cell culture medium. Gut inflammation was mimicked by the addition of the pro-inflammatory cytokines TNFα and IFNγ to the intestinal epithelial cells. Barrier integrity was measured by transepithelial/endothelial resistance (TEER) and by paracellular permeability assays with 4 kDa FITC-dextran. In addition, we performed a bead-based immunoassay to measure secreted IL-8 levels and RT-qPCR to analyse differential gene expression.

Results
The gut-blood barrier under low perfusion (3,6*10-4 mPa) exhibited increased expression of differentiation marker genes compared to static culture, such as LYZ, SOX9 and CYP3A4, indicating an improvement of cell differentiation. Moreover, low perfusion induced the formation of 3D villi-like structures, mucus production and the reduction of barrier strength towards more physiological relevant levels (TEER: 81,6±44,8 Ω.cm2; Papp: 1.10-5±4.10-6 cm/s). The gut-blood barrier was responsive to the addition of TNFα and IFNγ and high IL-8 levels could be measured in the circulatory blood flow. The barrier properties of the blood-CSF barrier under low perfusion (endothelial: 2,52 mPa, epithelial: 4,6*10-4 mPa) were not significantly different from a static setup, but less variance was observed in TEER. Neurons differentiated with BDNF and retinoic acid in our model displayed long projections and expressed mature neuronal marker genes (SYP, SNAP25, TUBB3).

Conclusion
We have successfully established and characterised each organ compartment of the gut-blood-brain model. Moreover, we have proven that low perfusion improves the physiological relevance of our model, especially of the gut-blood barrier. We are now exploring phenotypical and transcriptional alterations across the blood-CSF barrier and the brain compartment when gut inflammation is triggered.
P0134 Human umbilical cord-derived mesenchymal stem cells promote intestinal mucosal repair by activating fibroblasts-epithelial interactions
Authors: Huang Z , Yang H , Chao K , Gao X 
Published: January 2025

Abstract

Background
Mesenchymal stem cells (MSC) have shown promising potential for treating inflammatory bowel disease (IBD). The interactions between fibroblasts and epithelial cells play a crucial role in initiating the intestinal mucosal repair process. This study explored whether MSC therapy promoted intestinal mucosal repair via regulating fibroblast-epithelial interactions.

Methods
MSCs were isolated from human umbilical cord tissue. MSCs (2x106 cells/mouse) were injected intraperitoneally into mice treated with dextran sulfate sodium (DSS). The rate of mucosal proliferation, as indicated by Ki67 expression, was analyzed using immunofluorescence techniques. The co-culture of CCD-18co with Caco-2 was used to model the epithelial-fibroblast interaction. Wound healing assays and EdU assays were used to assess proliferative response, and RNA-sequencing to explore the mechanism.

Results
The MSC treatment reduced intestinal ulcer size in colitic mice, which was accompanied by an increase in the proliferation of epithelial cells and fibroblasts. Conditioned medium (CM) from MSCs induced a pro-wound-healing transcriptional program in CCD-18co, resulting in increased EdU-positive rates and enhanced cell migration. In the co-culture model, MSC-CM-treated CCD-18co enhanced Caco-2 proliferation by increasing EdU-positive rates and promoted wound healing through improved cell migration. Transcriptional analyses revealed that several processes associated with cell proliferation and the WNT signaling pathway were activated.

Conclusion
MSC treatment enhanced fibroblast-epithelial interactions to promote the intestinal mucosal repair.
P0139 Dynamics of the species structure of the gut microbial community in patients with ulcerative colitis
Authors: Tarasova G , Zubova A 
Published: January 2025

Abstract

Background
The potential role of microbiome in the pathogenesis, progression and treatment of ulcerative colitis (UC) is becoming a subject of considerable interest and research. The study of the microbial ecosystem of the colon in patients with UC in different stages of the disease provides an opportunity to identify key taxon-biomarkers for non-invasive monitoring of the severity of UC and the effectiveness of treatment.

Methods
The study included 21 patients (ages from 20 to 41, 13 men and 8 women) in the relapse stage of UC - left-sided UC with mild to moderate activity (Truelov-Witts scale, Mayo index); and 20 patients (ages from 26 to 52, 10 men and 10 women) in the stage of clinical endoscopic remission. The study of the coprofiltrate microbiota was carried out by NGS sequencing of the structure of the bacterial 16S ribosomal RNA gene using the Illumina MiSeq platform.

Results
Non-zero values of representation were found in 273 species in patients of the studied groups, however, differences in the presence of microorganisms were statistically significant only for 10 species presented in Table 1.
A higher level of Pelomonas_aquatica, Granulicatella_adiacens / para-adiacens, Gemella_morbillorum, Escherichia/Shigella_coli, Enterococcus_azikeevi / casseliflavus / durans / faecalis / faecium / hirae / lactis / mundtii / raffinosus / ratti / rivorum / thailandicus / villorum, Solobacterium_moorei, Streptococcus_australis / parasanguinis and lower levels of Roseburia_inulinivorans, Ruminococcus_bicirculans, Ruminococcus_callidus were found in the relapse group.

Conclusion
The differences identified in the taxonomic structure at the species level among patients in the relapse and clinical-endoscopic remission stages of UC determine the potential of the colon microbiota in non-invasive assessment of the severity of the disease.
P0146 Phosphoglycerate dehydrogenase plays a vital role in ER-stress-related intestinal inflammation
Authors: Yang G , Xiang H , Welz L , Bhardwaj A , Treitz C , Sima K , Koncina E , Kim N M , Kugler J , Tran F , Nikolaus S , Sievers L K , Liu Z , He Q , Schreiber S , Rosenstiel P , Aden K 
Published: January 2025

Abstract

Background
Inflammatory Bowel Disease (IBD) is characterized by chronic inflammation and metabolic dysregulation in the intestinal epithelium. Serine, a non-essential amino acid synthesized via the rate-limiting enzyme phosphoglycerate dehydrogenase (PHGDH) maintains cellular redox balance. Serine metabolism is upregulated in cancer and immune cells, supporting survival and growth. Our previous story shows ER stress-mediated rewiring of serine metabolism is a key molecular feature in IBD. However, the mechanism of how it influences ER stress in IBD remains unclear.

Methods
To explore the molecular regulation of de novo serine synthesis via PHGDH, we used murine intestinal epithelial cells (Mode-K cells) and murine intestinal organoids. WB and IHC were performed in vivo to analyze ER stress and PHGDH on DSS colitis model. Mode-K cells were subjected to serine starvation and co-treated with LPS. Proinflammatory cytokines (Cxcl1, Tnfα, Il6) were evaluated by qPCR and ELISA. Metabolic supplement formate and hypoxanthine were tested to mitigate hyperinflammation. Total starvation was assessed by using serine deprivation medium and PHGDH inhibitor BI-4916. Tunicamycin, NAC, Y27632, and rapamycin were used to study the biofunction under ER stress effect by using qPCR, WB, and IF. Cell viability was performed by CellTiter-Glo® 2.0 Cell Viability Assay. RNA sequencing and proteomic analyses were performed to investigate molecular mechanisms. Clinical analysis of PHGDH was assessed in two cross-sectional IBD cohorts correlating PHGDH expression with endoscopic or clinical disease activity.

Results
We show elevated ER stress and de novo serine synthesis in DSS colitis model. Using total starvation to completely block serine pathway, we observed increased ER stress which subsequently leads to dramatically enhanced inflammation signature under LPS treatment. ER stress induced by total starvation also leads to mitochondria dysfunction as assessed by Seahorse and JC-1 assay. By using cell viability assay and IF, we show ER stress induces AIF-mediated anoikis. Autophagy induced by ROS under ER stress conditions can protect cells from anoikis and inflammation. Combining RNAseq and proteomic analysis, we identified CEBPB as the critical regulator in mediating cellular anoikis and inflammation during ER stress which were further confirmed by IF and qPCR. Finally, we observed unregulated PHGDH in IBD patients showing a strong association between serine metabolism and IBD severity.

Conclusion
In this study, we demonstrate the critical roles of PHGDH and Serine metabolism in regulating cellular inflammatory responses under ER stress. Notably, we reveal a protective role of ROS in ER stress and inflammation, providing new insights into ER stress and IBD severity.
P0147 Regulation of Inflammatory Pathways by miR-338-3p and miR-378a-3p: A Novel Approach for Crohn’s Disease Treatment
Authors: Choi C H , Moon J M , Kim K U , Lim E , Hwang H W , Kyuwon K , Seo J , Shin S Y , Lim H , Min H 
Published: January 2025

Abstract

Background
MicroRNAs (miRNAs), key regulators of gene expression, are promising biomarkers and therapeutic targets in inflammatory bowel disease (IBD) due to their roles in immune response and tissue integrity. This study explores miRNA roles in IBD, focusing on Crohn's disease (CD) pathogenesis and potential therapies. We analyzed epithelial cell-derived miRNA expression in CD patients versus healthy controls and investigated how these miRNAs modulate inflammation in experimental IBD models.

Methods
Terminal ileum samples were prospectively collected via ileocolonoscopy from non-IBD healthy controls (n=26), CD patients in remission (n=34), and active CD patients (n=42). Clinical remission was defined as a Crohn’s Disease Activity Index score below 150 with endoscopic mucosal healing. For active CD cases, samples were taken from inflamed and non-inflamed regions. miRNA levels were quantified by small-RNA sequencing and validated by qRT-PCR. Based on these results, specific miRNAs were selected, and single-stranded mimics were administered in a 2.5% DSS-induced colitis model to evaluate their effects. Histological grading, immunohistochemistry, flow cytometry, and microbiome analysis using mouse fecal samples were performed.

Results
Small-RNA sequencing revealed distinct miRNA expression patterns in CD patients, both in remission and in active states (including inflamed and non-inflamed tissues), compared to healthy controls. qRT-PCR validation showed significantly reduced expression of miR-141-3p, miR-338-3p, miR-378a-3p, and miR-200b-3p, along with significantly increased levels of miR-125b-5p, miR-29b-3p, and miR-155-5p in inflamed tissue of active CD patients. Receiver operating characteristic curve indicated diagnostic potential for these miRNAs in relation to disease activity and endoscopic inflammation. In a DSS-induced colitis mouse model, miR-338-3p and miR-378a-3p showed anti-inflammatory effects, reducing body weight loss, colon inflammation, and immune cell markers. Target analyses identified MACC1 and IL-33 as key mRNA targets. Immunohistochemistry indicated an IL-33 pathway-dependent anti-inflammatory response via miR-378-3p, while miR-338-3p appeared to regulate gut inflammation by targeting MACC1 gene expression. In vitro analyses revealed that IL-33 activates MACC1, a process also reduced by miR-378a-3p treatment. Fecal microbiome analysis identified several bacterial species including Akkermansia muciniphilia and certain Bacteroides, associated with beneficial effects in the groups treated with both miRNA mimics.

Conclusion
This study identifies miR-338-3p and miR-378a-3p as modulators of inflammation in an IL-33-dependent manner in CD patients, underscoring their potential as promising targets for treatment of CD.
P0148 Studying the role of adipose tissue in intestinal inflammation using acquired generalized lipodystrophy
Authors: Letizia M , Omar T , Weidner P , Siegmund B , Weidinger C 
Published: January 2025

Abstract

Background
Crohn’s disease (CD) is associated with creeping fat, characterized by hyperplasia of mesenteric adipocytes and increased secretion of adipokines, including leptin (1). However, limited models currently exist to study the effect of adipose tissue on intestinal inflammation. Therefore, acquired generalized lipodystrophy and Crohn’s disease (AGLCD), a rare metabolic disorder characterized by the complete loss of fat tissue and intestinal inflammation, could provide a unique model to further elucidate the contribution of adipose tissue to the pathogenesis of inflammatory bowel disease.

Methods
To decipher the role of adipose tissue, we characterized the immune cell compartment in a patient with AGLCD using mass cytometry, whole exome sequencing and single cell sequencing. Samples collected for the analysis include lamina propria mononuclear cells (LPMCs) isolated from ileum biopsies and peripheral blood mononuclear cells (PBMCs) from blood obtained from 6 CD patients, one AGLCD patient, and 4 non-inflamed controls.

Results
Using mass cytometry, we were able to identify 17 intestinal immune cell clusters in the LPMCs. Namely, there was a higher frequency of CD8+ CD45RO+ T cells, CD11c+ CD11b+ myeloid cells and CD19+ CCR7+ B cells in the AGLCD sample compared to the fat-proficient CD controls. In addition, single cell sequencing of CD3+ T cells isolated from the blood of the AGLCD patient showed an expansion of CD8+ and CD4+ effector memory T cells compared to a healthy donor, suggesting that adipose tissue plays a role in T cell homeostasis in CD. To confirm that leptin plays a role in the regulation of T cells, we analyzed PBMCs from the AGLCD patient pre and post treatment with recombinant leptin. An increase in the expression of IL-17 producing CD4 T cells were present after treatment with leptin. To further investigate the expansion of CD8+ T cells, analysis of whole exome sequencing of the AGLCD showed a mutation in the NRAS gene, an essential regulator of hematopoietic development. The mutation was confirmed only in CD8 and CD4 T cells in the blood and intestinal biopsies of the AGLCD patient using Sanger sequencing.

Conclusion
These observations demonstrate that AGLCD is a unique model that can be used to further study the effects of adipose tissue in intestinal inflammation.

References
(1) Coffey JC, O'Leary DP. The mesentery: structure, function, and role in disease. Lancet Gastroenterol Hepatol 2016;1:238-247.
P0153 The role of the proglucagon-derived peptide GLP-2 in resection-triggered growth and barrier response in mice
Authors: Mohebali N , Witte M , Berlin P , Lamprecht G , Reiner J 
Published: January 2025

Abstract

Background
Ulcerative colitis (UC) and Crohn’s disease (CD) of the colon may cause significant malnutrition by “inflammation-dependent”, and “inflammation-independent” mechanisms. Glucagon-like peptide 2 (GLP-2) is secreted by ileocolonic L cells in response to nutrient intake and promotes small intestinal barrier function. GLP-2 secretion is enhanced after small bowel resection. We hypothesized that loss of GLP-2 secretion by a) genetic ablation, and b) inflammatory ablation through severe DSS-colitis, impairs small intestinal barrier dysfunction in the mouse mid small bowel resection model.

Methods
The impact of GLP-2 loss on small intestinal barrier function was evaluated using two models. In the first model, gcg knockout (KO) and wild-type (WT) mice underwent 50% mid-small bowel resection (MSBR). In the second model, male C57BL/6J mice were divided into the following groups: non-operated controls +/- DSS, MSBR alone, MSBR with dextran sulfate sodium (MSBR+DSS), and MSBR with DSS plus teduglutide (GLP-2 analogue). Body weight changes, mucosal height, tight junction mRNA expression, and FITC-4kDa-dextran flux were assessed using Ussing chambers.

Results
The gcg-WT mice did not develop diarrhea during the experimental period, while gcg-KO mice showed significantly increased stool water content two days post-surgery (p &lt; 0.05). Although no other major clinical differences were observed between gcg-WT and KO mice after MSBR, gcg-KO mice exhibited reduced mucosal height and increased FITC-dextran flux, indicating impaired barrier function (p &lt; 0.05). DSS-colitis was less severe in the MSBR-model, compared to non-operated DSS-colitis. However, in the inflammatory model, MSBR+DSS mice experienced significant body weight loss, colon shortening, all of which were significantly mitigated by teduglutide treatment. Teduglutide also improved villus length (p &lt; 0.001) and reduced FITC-dextran permeability (p &lt; 0.05). Claudin-2 expression, which was markedly elevated in MSBR+DSS mice, was significantly reduced with teduglutide treatment.

Conclusion
Our findings demonstrate that DSS-induced colitis is less severe in the 50% MSBR model. Furthermore, genetic knockout of gcg, i.e. complete ablation of GLP-2 secretion capacity, diminishes resection-triggered barrier- and growth response, while DSS-colitis, i.e. incomplete ablation of GLP-2 secretion capacity, diminishes resection-triggered barrier-, but not growth response. Thus, GLP-2-deficiency with small intestinal barrier dysfunction may be an inflammation-independent mechanism ultimately contributing to malnutrition in severe colitis.