bluuebunny/crossref_metadata_2025 huggingface dataset:
P003 Metabolic Reprogramming in Intestinal Fibrosis: Integrating Metabolomics, Single-Cell Transcriptomics and Isotope Tracing
Authors: Zhang Y , Zhuang H , Gu Y , Zou D
Published: January 2024

Background

This study aims to systematically elucidate the metabolic landscape of intestinal fibrosis in Crohn's disease, revealing the key reprogrammed metabolic pathways in the fibrotic microenvironment.

Methods

We collected normal and fibrosis tissues from 122 Crohn's disease patients undergoing surgery for fibrosis-induced intestinal obstruction, and established DSS/TNBS-induced murine intestinal fibrosis model. To measure metabolites level in normal and fibrotic tissues, untargeted metabolomics was performed. C13-labeled glutamine was used for metabolic tracing to delineate metabolic fluxes in vitro and in vivo. We performed integration analysis by merging metabolomics and metabolic tracing data with established single-cell transcriptomic profiles. Isolation and further validation of human intestinal stromal cells were carried out, and gene expression was assessed using qRT-PCR and immunofluorescence.

Results

Significant metabolic heterogeneity was observed between normal and fibrotic tissues, with differential metabolites enriched in glucose and amino acid metabolism. Notably, intermediates of glycolysis were significantly increased, while tricarboxylic acid (TCA) cycle intermediates were decreased in fibrotic regions (p<0.05). Amino acids were broadly downregulated in fibrosis, whereas glutamate and glutamine were highly enriched (p<0.05). Mechanistic insights into these changes were provided by isotope tracing, revealing enhanced glycolysis and weakened TCA flux attributed to transition from TCA intermediate α-KG to glutamate. Moreover, catabolism of glutamine to glutamate was enhanced. Glutamate from above pathways converted to proline, which is the ingredient of extracellular matrix (ECM).

Single-cell transcriptomic analysis indicated a high enrichment of genes related to glutamine metabolism in stromal cells, with significant upregulation of enzymes such as GLS (Glutaminase) and PYCR1 (Pyrroline-5-carboxylate Reductase 1) involved in glutamine and proline synthesis. Immunofluorescence and qRT-PCR confirmed the upregulation of GLS and PYCR1. Further experiments using primary stromal cells and murine models demonstrated that inhibiting GLS activity reduced ECM synthesis, alleviating intestinal fibrosis.

Conclusion

In intestinal fibrosis, glycolysis and glutamine catabolism enhanced. Stromal cells utilized the reprogrammed metabolic pathway to synthesize glutamate, thereby promoting pathological ECM anabolism. Targeting the key enzyme GLS represent a potential therapeutic strategy for intestinal fibrosis.
P006 Development of a Crohn's disease molecular activity score to identify region-specific chronically inflamed and non-inflamed processes
Authors: Richards D , Venkat S , Terry N A , Vetter M , Gomez M , Freeman T C , McRae B , Feagan B , Reinisch W , Branigan P
Published: January 2024

Background

Crohn’s disease (CD) is characterized by significant heterogeneity in disease location and other clinical factors, making it challenging to define the underlying molecular mechanisms associated with disease. Here, we provide a detailed molecular characterization of baseline ileal and colonic tissue from patients enrolled in the GALAXI Ph2b study of guselkumab in CD (NCT03466411) and explore the association of regional molecular profiles with endoscopic and histologic severity.

Methods

Baseline biopsies from 241 patients were obtained from rectum (R), splenic flexure (SF), and terminal ileum (TI). Paired biopsies within a region were processed for histology and RNA sequencing (RNAseq). Cell-type specific transcriptional modules were used to evaluate differential expression and to create a disease severity axis. Principal component analysis (PCA) was applied to modules with the highest correlation with paired Global Histologic Activity Scores (GHAS) per region and the resulting PC1 was used to define an objective tissue-based molecular activity score (MAS) to identify inflamed and uninflamed tissue. Inflamed tissue was used to assess regional molecular profiles which were correlated with paired regional histology scores defined by GHAS and endoscopic severity defined by Simple Endoscopic Score for CD (SES-CD).

Results

Modules specific to inflammatory myeloid and epithelial transcriptional states, and IL-23 and interferon response pathways, were highly correlated with paired GHAS. Applying this subset of modules as a MAS revealed a bimodal distribution of inflamed and non-inflamed biopsies. MAS identified 114/241 (47.3%), 85/229 (37.1%) and 114/229 (49.8%) inflamed biopsies in the R, SF, and TI, respectively. Regional molecular profiles of inflamed biopsies demonstrated increased mRNA expression of IL-23p19 (IL23A) and Fc-γ receptor 1 (CD64) (p<0.001), and enrichment of inflammatory modules across locations. Local MAS per region showed highest correlations with paired baseline GHAS, followed by SES-CD in the segment (Figure 1 and Table 1). Notably MAS provides higher resolution to identify representative biopsies for affected regions.

Conclusion

Application of the MAS to identify inflamed tissue enabled identification of key immune and inflammatory related processes across the ileum and colon that were associated with the IL-23 pathway, and baseline regional endoscopic and histologic severity. By identifying inflamed baseline samples, molecular changes associated with treatment can be more accurately defined in future analyses to better understand regional heterogeneity in CD.
P013 Magnetic Resonance Imaging-Based Average T2 Signal as A Non-Invasive Measure of Fibrosis In Enteric Crohn’s Disease
Authors: Naim I , Clarke C , Hoad C , Jinnah N , Mukherjee A , Gowland P , Mougin O , Menys A , Bard A , Moran G W
Published: January 2024

Background

In Crohn’s Disease (CD), 10% of patients present with fibrostenosis with a further 10% progressing from inflammatory to a fibrostenotic disease behaviour over 7 years. 40% of fibrostenotic CD patients need surgery at 5 years compared to ~10% with inflammatory disease. Present non-invasive fibrosis biomarkers lack the required accuracy needed to be used routinely for clinical decision making. T1, T2, diffusion weighted imaging, motility and bowel volumes have shown promise in the non-invasive measure of fibrosis.

Methods

The primary objective of this study is to undertake biological validation of MRI measures as independent imaging biomarkers of histological fibrosis with the primary outcome being the correlation between MRI measures and histological fibrosis measures. GI-Seg (Motilent, London, UK) is an image analysis tool used to segment the gastrointestinal tract on T2W MRI scans.

Patients with CD histological diagnosis and in need of surgical resection for stenosis attended a one-hour 3T MRI scanning session within 12 weeks prior to their intestinal resection surgery. Histological samples were scored by a specialized gastrointestinal pathologist for inflammation, fibrosis, and muscular hypertrophy. An expert radiologist with the help of the histopathologist located the strictures on DWI, quantitative T2&T2 scans, and T2 weighted clinical MRI scans. GI-Seg was used to generate a 3D model of the stricture on T2W scans measuring bowel wall volume and average signal intensity of each stricture. Pearson correlation coefficient was used to quantify the correlation between the variables.

Results

A total of 10 CD patients, encompassing 20 strictures, were included in the study. The analysis revealed that the average T2 signal has a significant correlation with global fibrosis scores (r(20) = .563, p = .010) (Figure) and total inflammation scores (r(20) = .451, p = .046). Additionally, stricture volume showed a fair correlation with chronic inflammation component scores (r(20) = .453, p = .045). Notably, quantitative T1 values correlated with total inflammation scores (r(17) = .493, p = .045).

Conclusion

The study reveals fair correlations between the T2 signal average and both global fibrosis and global inflammation scores, as well as between stricture volume and chronic inflammation in CD strictures. While these findings indicate that the GI-seg tool's measurements of bowel wall volume and signal intensity have potential utility as imaging biomarkers for fibrosis and inflammation, the results also underscore the necessity for additional markers that are specifically correlated with fibrosis. Such markers are essential to distinctly identify fibrotic changes, independent of inflammatory processes.
P018 Inequalities in healthcare access, experience and outcomes in adults with Inflammatory Bowel Disease: A scoping review
Authors: Hawkins R , Zia M , Hind D , Lobo A , Ezaydi N
Published: January 2024

Background

Inflammatory Bowel Diseases (IBD) are long-term conditions requiring lifelong access to, and interactions with health services. Accumulating evidence of inequalities in health care access, experience and outcomes for individuals with IBD is apparent. However there is no existing review that systematically maps these inequalities.The purpose of this review was to map and describe the inequalities in healthcare access, experiences, and outcomes of care for adults with IBD, to identify research gaps and future research priorities in this area.

Methods

A scoping review was conducted to retrieve quantitative, qualitative, and mixed methods evidence from three electronic databases (EMBASE, Medline and CINAHL). English written articles published between 2000 and 2023 were systematically searched using a search strategy. The Joanna Briggs Institute protocol for scoping reviews was followed to perform data extraction and analysis.

Results

1343 records were identified. 51 studies met the criteria for inclusion. Studies addressed ethnic disparities of healthcare (33/51), inequalities driven by socioeconomic differences (12/51), rurality (7/51), gender (3/51), age (2/51), culture (2/51), literacy (1/51) and sexuality (1/51). The interrelationship of disparities relating to outcome, access and experience is illustrated in Figure 1. Poorer health outcomes (42/51 studies) were described in those from Black, Asian, and Hispanic ethnic groups in relation to hospital admission, readmission, emergency room attendance, length of stay, IBD-related complications, post-operative complications, treatment delay and length of stay. Deprivation, insurance status in US populations, rural location and age also affected outcome. Access inequalities (24/51 studies) were described to services, therapies and surgery but also to educational opportunities. Poor experience of care (8/51 studies) included appointment issues, lack of cultural understanding and fragmented care. A lack of research was found in the LGBTQIA+ community (1/51). No research was found to investigate inequalities in IBD patients with learning disabilities or autism.

Conclusion

Inequality affecting a wide range of population characteristics affects outcomes, access and experience in IBD care. Services need to be organised and delivered in a way that addresses this. Further research, including qualitative methods, is particularly needed to understand health experiences of underserved patient populations with IBD. The lack of research amongst LGBTQIA+ individuals, and with learning disabilities, poses a risk of creating inequalities within inequalities.
P020 Effects of Anti-TNF Treatment on Browning of Mesenteric Adipose Tissue with Crohn's Disease
Authors: Montfort-Ferré D , Vaño-Segarra I , Boronat-Toscano A , Menacho M , Moliné A , Cepero C , Mañas M J , Caro A , Serena C
Published: January 2024

Background

Crohn's disease (CD) is characterized by the expansion of mesenteric fat, known as creeping fat (CrF), to the inflamed segments of the intestine. Our group observed that CrF showed a conversion to beige tissue, a phenomenon known as "Browning", characterized by an elevated gene expression of thermogenin (UCP-1), the gene characteristic of browning1. A recent study also showed that when browning was induced in mice in a TNBS colitis model, mesenteric hypertrophy improved and inflammation in adipose tissue was reduced2. The aim of this study is to assess whether the administration of anti-TNF biologic treatment (infliximab) in patients with CD is related to the increase in adipose beige tissue in the CrF.

Methods

Immunohistochemistry staining of UCP-1 was conducted on CrF samples from CD patients receiving anti-TNF treatment (≥6 months) and anti-TNF-naïve patients. Additionally, we analysed the gene expression of beige adipose markers in CrF from CD patients treated with anti-TNF drugs, comparing them to those untreated. UCP-1 gene expression was also studied in adipose-stem cells isolated from CrF. Ongoing experiments involve treating adipose stem cells with infliximab (10ug/ml) for 24 hours to assess the potential conversion of white to beige adipose tissue.

Results

The study revealed a significant increase in UCP-1 staining in CrF samples among patients receiving anti-TNF treatment compared to anti-TNF-naïve CD patients (Fig 1.A). This trend was consistently observed in mesenteric CrF tissue. Beige markers TMEM26 and CPTB1 exhibited significant increases in anti-TNF-treated CrF, and other beige tissue markers showed a notable trend (Fig 1.B). Adipose stem cells displayed a significant increase in UCP-1 gene expression in anti-TNF-treated CrF compared to untreated patients (Fig 1.C). Exciting preliminary data suggest that infliximab treatment increases UCP-1 and the anti-inflammatory cytokine IL-4 gene expression in adipose-stem cells from active CD patients (Fig 1.D). This novel data implies a direct relationship between anti-TNF treatment and heightened browning in white adipose tissue of CD patients.

Conclusion

This study reveals a notable increase in UCP-1 gene expression in adipose tissue CrF of CD patients undergoing anti-TNF treatment. The findings suggest that anti-TNF therapy may trigger the transformation of white adipose tissue into the "beige" type, potentially mitigating inflammation. Browning CrF presents a promising therapeutic avenue for CD management, warranting further investigation.

Ref:

1. D. Monfort-Ferré et al. J Crohn Colitis., 2022;16(10):1571–83,

2. Zuo L et al. J Crohn Colitis. 2023 21;17(8):1179-1192.
P029 Loss of adipose tissue protects mice from intestinal inflammation
Authors: Omar T , Letizia M , Siegmund B , Weidinger C
Published: January 2024

Background

Crohn’s disease (CD) is associated with creeping fat, characterized by hyperplasia of mesenteric adipocytes and increased secretion of various adipokines, including leptin. Leptin can promote intestinal inflammation by inducing pro-inflammatory cytokines such as TNFα in murine and human lymphocytes. Recent meta-analyses have shown that increased body mass index (BMI) increases the risk of developing CD. However, whether the surgical removal of mesenteric fat could improve the outcome of CD patients and the impact of fat-derived signals on intestinal autoimmunity remain elusive.

Methods

To decipher the role of adipose tissue in the regulation of intestinal autoimmunity, we investigated here how the absence of adipose tissue affects epithelial barrier functions and immune cell homeostasis. Therefore, we studied lipoatrophic Ppargfl/fl-Adipoq-Cre mice, that completely lack adipose tissue, under steady-state conditions and after induction of chronic dextran sodium sulfate (DSS)-mediated inflammation, as well as in allogeneic fat transplantation models. We characterized our models using flow cytometry, RNA sequencing, immunohistochemistry, western blot analyses, ELISA and calcium measurements.

Results

At steady state, lipoatrophic mice showed a decrease in CD4 IL-17+ T cells in the ileum, and lower frequencies of CD8 T cells and CD4 FoxP3+ cells in the colon, suggesting that fat-derived signals are required for proper T cell homeostasis in mice. To understand how the absence of adipose tissue affects the severity of intestinal inflammation, we challenged lipoatrophic or WT littermates with 3 cycles of 1.5% DSS, which induced weight loss in both WT and lipoatrophic mice. However, only fat-proficient WT mice developed severe colitis, whereas lipoatrophic animals had significantly reduced intestinal inflammation and displayed disturbances in the differentiation and function of pro-inflammatory T cells including Th1 and Th17 cells. Importantly, these defects in T cell function could be rescued by allogeneic transplantation of adipose tissue from lean wild-type mice but not by adipose tissue from leptin-deficient ob/ob mice, highlighting that the role of the adiopokine leptin as an important pro-inflammatory factor in IBD.

Conclusion

Taken together, our data demonstrate that adipose tissue acts as an important regulator of intestinal autoimmunity by controlling the differentiation and function of pro-inflammatory T cells through the secretion of adipokines including leptin. We believe that these observations may help explain why obese individuals with higher BMI may be at a higher risk of developing intestinal inflammation and Crohn’s disease.
P062 Characterization of UC1 and UC2 patients: towards personalized medicine in Ulcerative Colitis
Authors: Castillo F , Selin K , Fransson J , Sorini C , Hedin C , Villablanca E
Published: January 2024

Background

Ulcerative colitis (UC) is a highly heterogeneous chronic inflammatory bowel disease (IBD) that primarily affects the colon. Although there are some available classifications, mostly based on clinical parameters, the lack of a molecular stratification prevents full comprehension of the diagnostic and prognostic heterogeneity of patients, and thus from correctly predicting their response to available treatments. We have recently developed an unbiased stratification of UC patients (UC1/UC2) based on their transcriptomic profiles (Czarnewski P; et al. Nature Communications, 2019), which holds great potential for the design of personalized medicine in IBD. However, further characterization is necessary to validate it and consolidate its clinical application.

Methods

To achieve this goal, we used bulk and single-cell RNA sequencing (sc-RNAseq) datasets from a prospective cohort of Swedish IBD patients to understand whether UC1 and UC2 are different diseases or states of the same disease, and to deeply characterize the cellular composition of UC1 and UC2 patients. In addition, we took advantage of murine spatial transcriptomics datasets of colonic tissues at steady state or during mucosal healing, to get insights into the spatiotemporal dynamics of UC1/UC2 transcriptional profiles.

Results

A longitudinal analysis of UC1/UC2 transcriptomic profiles as well as gene module analysis revealed that UC1 and UC2 profiles are fluctuant during the course of disease, eventually representing different stages of the same disease. scRNAseq analysis allowed us to identify specific cell types characterizing UC2 patients.[FC1] Finally, while genes defining UC2 patients distributed homogenously within the murine mouse colon at steady state and during mucosal healing, UC1 genes primarily mapped within damage/regeneration regions.

Conclusion

This study details the differences in immune cell composition and molecular pathways in UC1 and UC2 patients, contributing to a more comprehensive understanding of the new molecular stratification system we have developed for ulcerative colitis patients.
P071 Neonatal levels of inflammatory markers in individuals who later develop early onset Inflammatory Bowel Disease
Authors: Rudbæk J , Borbye-Lorenzen N , Poulsen G J , Skogstrand K , Jess T
Published: January 2024

Background

The early life period is suggested to be important in development of Inflammatory Bowel Disease (IBD). Studies in babies from mothers with IBD observed increased faecal calprotectin and changes in the microbial compartments compared to babies from healthy mothers1,2, which suggests that changes in early life might be associated with later disease development. Prospective studies of IBD risk following early life changes at the molecular level are sparse. We aimed to investigate if individuals with early onset (EO) IBD had changes in systemic inflammatory markers shortly after birth.

Methods

We measured the concentration of 9 cytokines in a cohort of 464 neonatal dried blood spot samples stored at the Danish National Biobank from individuals who later developed EO IBD (median age of diagnosis 11 years), as well as matched controls. Individuals who developed IBD were identified through the use of the Danish National Patient Registry. Uni- and multivariate logistic regression with adjustment for birth year, sex, and gestational age was conducted to assess the association between 6 of the inflammatory markers with later disease development (INF-γ, TNF-α, IL-1β, IL-4, IL-6 and IL-17a). Further exploratory analyses were performed investigating risk of very early onset (VEO) IBD (onset from 0-5 years) in 88 cases and their matched controls.

Results

No significant association with EO IBD was observed for any of the cytokines in uni- and multivariate models when adjusting for multiple testing. In the exploratory analysis of VEO IBD, increased IL-4 was associated with significantly reduced risk of IBD (OR=0.992, p-value=0.023) and increased IL-17a was borderline-significantly associated with increased risk of IBD (OR=1.002, p-value=0.063) in a multivariate logistic model including all 6 cytokines. This association did not remain significant when adjusting for multiple testing, which may reflect limited power.

Conclusion

In our unique study of 464 dried blood spots from later IBD patients and controls, we could not find an association between measured cytokines and EO IBD. In contrast, patients with VEO IBD had decreased levels of IL-4 and increased levels of IL-17a. This sub-cohort was small, and significance disappeared after adjusting for multiple testing. Still, we find it important to report these findings, as they are novel and may inspire future studies into the aetiology of VEO IBD.

1. Kim, E. S. et al. Longitudinal Changes in Fecal Calprotectin Levels Among Pregnant Women With and Without Inflammatory Bowel Disease and Their Babies. Gastroenterology (2021)

2. Torres, J. et al. Infants born to mothers with IBD present with altered gut microbiome that transfers abnormalities of the adaptive immune system to germ-free mice. Gut (2020)
P084 Natural extracts and omega-3 derived molecule: role in resolution of intestinal inflammation
Authors: Camba Gómez M , Arosa L , Ait Eldjoudi D , Gonzalez-Rodríguez M , Gualillo O , Conde-Aranda J
Published: January 2024

Background

In the last years there is a great interest in the characterization of natural compounds extracted from plants or omega-3 derived molecules for their possible therapeutic effects. In this scenario, the seeds of Nigella sativa and Nigella orientalis (plants with great relevance in North African traditional medicine) have shown beneficial effects in reducing inflammation. Similarly, the addition of Maresin 2 (pro-resolving mediator) to experimental animals improved symptoms in various models of inflammation. However, there is no information on the role that these potential therapies may play in the cellular and molecular processes leading to the resolution of inflammation at the intestinal level.

Methods

Eight-week-old female C57Bl/6 mice (n=30) were subjected to a DSS-induced colitis model; mice received 1.8% (weight/volume) DSS in the drinking water for 6 days followed by 6 days of regular drinking water. Mice were treated from day 5 to day 12 with vehicle, Nigella Sativa, Nigella Orientalis, and Maresin-2. After that, histology studies, flow cytometry, expression analysis and migration experiments were performed.

Results

In all the treatment groups there was a significant reduction in weight loss and improved DAI scores compared to control group. Significant differences were also observed in the epithelial score and in the infiltration score. Analysis of the immune cell infiltrate revealed that only neutrophil numbers were downregulated after the administration of the indicated treatments. Further in vivo and in vitro studies demonstrated that Nigella Sativa and Nigella Orientalis were able to decrease neutrophil viability and migration. By contrast, Mar2 seemed to affect neutrophil infiltration through indirect mechanisms and by regulating the expression of chemotactic factors

Conclusion

Overall, our study reveals novel compounds able to regulate the resolution of intestinal inflammation in vivo, and this occurs, by the modulation of neutrophil presence into the colon lamina propria.
P090 Prevotella copri promotes colitis in mice by reducing expression of ATF4 and disturbing the gut microbiota
Authors: Wang X , Cao H
Published: January 2024

Background

Colitis is a disease that carries a significant global disease burden, with a growing prevalence. Studies in humans and mice have explored the role of the intestinal microbiota that contribute to inflammatory bowel disease (IBD). Prevotella copri is a common human gut microbe that has been linked to inflammatory disorders.

Methods

C57BL/6 mice were divided into four groups: normal control group, P. copri group, DSS model group, DSS model+ P. copri group. Mice were gavaged with P. copri or PBS for 14 consecutive days, starting from the first day. Experimental colitis was induced by 2% DSS treatment from day 8. Mouse colon tissues were analyzed by quantitative real-time polymerase chain reaction, immunoblots, immunohistochemistry, and transcriptome. Serum and intestinal epithelial cell (IEC) amino acids were measured by high-performance liquid chromatography-tandem mass spectrometry. The analysis of the microbiome was done through the 16S ribosomal DNA sequencing.

Results

In the present study, our experiment confirmed that P. copri was significantly associated with the exacerbation of DSS-induced colitis by reducing expression of ATF4 and altering the gut microbiota composition. Leucine concentration of serum and IEC were increased in P. copri-gavaged mice, which clearly suppresses ATF4 expression. The dysbiosis of the intestinal microbiota and impaired α-defensin production by Paneth cells are also the leading causes of why P. copri-gavaged mice are more susceptible to DSS-induced colitis.

Conclusion

Taken together, the results proposed that P. copri aggravated the severity of colitis in the mice with DSS-induced colitis. This was done by reducing the expression of ATF4 and disturbing the gut microbiota. Thus, targeting P. copri may be an effective strategy in the treatment of IBD.
P093 Innovating in IBD care: what do patients and informal caregivers value? Preliminary results of a narrative inquiry
Authors: Thomassen B J M , Hendrix E M B , Mujagic Z , Smeets F G M , de Jong M J , Gevers T J G , Veldhuijzen G , Scherpenzeel M , Dijkstra G , Ament S M C , Pierik M J
Published: January 2024

Background

Given the increasing incidence, evolving treatment goals, and the need for tight and holistic monitoring, transformation in delivery of Inflammatory Bowel Disease (IBD) care is warranted. To innovate successfully, it is crucial to consider the values of healthcare professionals (HCP) and healthcare services, as well as the patient’s and informal caregiver’s perspective. This study aims to explore what patients with IBD and their informal caregivers value in Dutch IBD care.

Methods

In total, approximately 16 patients and 8 informal caregivers from an academic and a general hospital will be included. Respondents are recruited purposefully. Data collection will take place until data saturation is reached. The interviews are focused on real-life experiences and stories of respondents with regard to IBD. Interviews are conducted face-to-face or digitally, audio recorded and transcribed verbatim. Independent coding was executed by three researchers. A deductive thematic analysis approach was used, guided by the Picker Principles of Person Centred Care.

Results

Semi-structured narrative interviews were conducted with 8 IBD patients and 4 informal caregivers, i.e. family members, between June-September 2023. All Picker principles came across in the narratives. Respondents said that it is important to receive an effective treatment, minimizing intestinal symptoms and to function as good as possible with IBD. Involving patients in their treatment plan and paying attention to non-medical aspects, e.g. impact on work and social relationships, was relevant to respondents. Patients and caregivers valued easy and accessible communication with their HCP, the feeling to be heard, and immediate action of the HCP when required. A trustful relationship, fostered through e.g. regular face-to-face contact, was highlighted as important. Some respondents appreciated the use of eHealth tools, as these facilitate remote care if desired. Moreover, providing informal caregivers with information about the disease, treatment and impact on daily life was suggested as beneficial in supporting patients with IBD.

Conclusion

IBD patients and their informal caregivers value shared decision making, fast access to reliable healthcare advice, immediate action when needed, the feeling to be heard and a trustful relationship with their HCP when receiving IBD care in the Netherlands. These values and insight in the (shared)-values of all relevant stakeholders within the Dutch context will facilitate the development of valuable innovation and successful implementation. The perspectives of other stakeholders, such as HCPs, policymakers, health insurers, pharmaceutical companies, and eHealth providers, will be explored in an extensive qualitative study.
P108 Response to vedolizumab in ulcerative colitis is associated with reduced neutrophil extracellular traps formation and IL-1β production: insights from NEUTROVED study
Authors: Gavriilidis E , Divolis G , Kafalis N , Kogias D , Natsi A M , Antoniadou C , Papadimitriou E , Tsironidou V , Giatromanolaki A , Ritis K , Kouklakis G , Skendros P
Published: January 2024

Background

Vedolizumab (VDZ) is a humanized mAb against integrin α4β7. VDZ inhibits gut inflammation by impeding intestinal T-cell homing, however, recent data suggest that effects of α4β7 blocking extend beyond T-cells to alterations in innate immunity. Neutrophils are key components of innate immune response and inflammation in ulcerative colitis (UC). Studies have provided evidence linking neutrophils with UC pathogenesis, through autophagy induction and production of IL-1β-enriched neutrophil extracellular traps (NETs). NEUTROVED aimed to investigate the effects of VDZ treatment on neutrophils that may be associated with clinical and endoscopic response.

Methods

Patients with moderate-to-severe UC who received VDZ in standard medical care were evaluated in two timepoints, 24 hours before treatment initiation (T1) and at week 14 of treatment (T2). Clinical/endoscopic scores and common laboratory indexes were evaluated. In parallel, RNA-sequencing in peripheral neutrophils was performed, and markers of NETs in plasma and intestinal biopsies were assessed.

Results

In total 5 patients completed the study until today (Table 1). In T2, 4 patients demonstrated complete remission, and one patient had mild disease. No adverse events were recorded. RNA-sequencing analysis of paired samples revealed 248 significantly downregulated and 109 upregulated genes in peripheral neutrophils after VDZ treatment. Bioinformatics analysis using the GeneCodis4 web-based tool revealed that downregulated DEGs clustered mainly in immune-related pathways, including neutrophil degranulation, Toll-like receptor cascades, signaling by interleukins, NETs formation, and HIF-1 signaling pathway, while upregulated DEGs were involved in RNA metabolism-related processes, and the ribosome biogenesis pathway. A comparative analysis between these differentially expressed genes (DEGs) and our previous RNA-sequencing data of peripheral neutrophils isolated from active UC patients (n=24) highlighted a set of 168 DEGs as restored targets after VDZ therapy. Of note, several unique genes implicated in neutrophil activation, including IL-1 signaling components, were found significantly downregulated after VDZ therapy. In line with the abovementioned transcriptome alterations, markers of NETs and IL1β-bearing NETs in plasma and colonic tissue were significantly reduced, recapitalizing clinical and endoscopic response to VDZ.

Conclusion

Response to VDZ treatment in UC is related to anti-inflammatory actions on neutrophils characterized by reduced NETosis and IL-1β production through NETs. Further mechanistic studies investigating the possible effects of VDZ on innate immunity and neutrophil-mediated responses are warranted.
P119 Single-cell RNA sequencing in Inflammatory Bowel Disease in patients with Primary Sclerosing Cholangitis: a distinct form of colitis
Authors: Bangma A , Pibiri P , Sun S , Bigaeva E , De Jong S , Bjørk J , Verstappen G M P J , Kats-Ugurlu G , Hermoso M A , Vich Vila A , van der Wijst M G P , Faber K N , Weersma R K , Uniken Venema W T C , Festen E
Published: January 2024

Background

Primary sclerosing cholangitis (PSC) is an inflammatory disorder of the bile ducts, in which Inflammatory bowel disease (IBD) concomitantly occurs (PSC-IBD). Substantial differences in clinical presentation are observed between PSC-IBD and ulcerative colitis (UC). In this study we aim to find distinct pathomechanisms for PSC-IBD using single-cell RNA sequencing.

Methods

Forty-seven colonic samples of PSC-IBD (n=24), UC (n=18) and non-IBD subjects (n=5) were collected. Whole biopsies were dissociated into single cells using collagenase digestion. Library preparation was done with 10x Genomics and sequencing was performed on an MGI2000 sequencer. Then, differential abundance, differential expression, and cell-cell interaction analyses were performed. Stainings for DUOX2 and HLA-DR were performed on paraffin embedded colon mucosal slides.

Results

In total, 71,798 high quality cells identified 54 distinct cell types, including a new type of epithelial cells: DUOX2+ enterocytes. DUOX2+ enterocytes are almost exclusively present in diseased inflamed colon and can act as antigen presenting cells through the expression of MHC2 on its surface. A general shift in cell type composition upon inflammation was observed, comparable between PSC and UC samples. However, an increased abundance was seen for stem cells in non-inflamed (NI) PSC, and not in UC-NI, compared to healthy controls. Additionally, we found distinct gene expression patterns between PSC and UC inflammation: while activation of inflammatory monocytes was observed in PSC inflammation, several types of fibroblasts were activated upon UC inflammation.

Conclusion

We describe DUOX2+ enterocytes, which may play a role in both PSC and UC colitis through antigen presentation. Furthermore, we show that intestinal inflammation in PSC-IBD, as compared to UC, is characterized by distinct mucosal cell composition and cell-specific gene expression patterns. PSC colitis, and not UC colitis, is driven by activation of inflammatory monocytes, with antigen presentation through HLA-DRB1, and activation of CD4+ T cells. Additionally, an increased abundance of stem cells in PSC-NI could be related with the increased colorectal cancer risk in PSC-IBD.
P128 Salt-Inducible Kinase 2 is a promising therapeutic target in patients with ulcerative colitis
Authors: McMillan L , Felwick R , Barbeta G , Fenton-May A , Kelly M , Strickland M , Richmond N , Bennett N , Makrecka-Kuka M , Sanchez-Elsner T , Cummings F , Madden J , Kilty I
Published: January 2024

Background

Salt-Inducible Kinases (SIKs) are a family of 3 serine/threonine kinases which represent promising therapeutic targets in a number of inflammatory diseases including ulcerative colitis (UC). Their catalytic activity is highly phosphoregulated in response to changes in cellular homeostasis. Inactivation of SIKs results in proinflammatory cytokine downregulation and the concomitant upregulation of anti-inflammatory IL-10. Of the three isozymes, SIK2 is the most active in myeloid cells and is thought to be the key driver of IL-10 production. Selective pharmacological inhibition of SIKs has thus far proved challenging: a number of SIK inhibitors have previously been developed and whilst they have demonstrated biological activity in UC, dosing has been limited due to potential side effects underlining the need for improved selectivity. We hypothesized that more selective inhibition of SIK2 represents a promising approach in ulcerative colitis.

Methods

We sought to examine the effects of inhibiting SIK2 with a potent small molecule in both in vitro cell cultures and in ex vivo biopsies from UC patients. CD14+ monocytes were isolated from donor PBMCs and differentiated into hMDMs (monocyte-derived macrophages) and moDCs (monocyte-derived DCs). Cultures were treated with compound followed by LPS stimulation for 4 hours (hMDMs) or maturation for 48 hours (moDCs). To recapitulate the disease microenvironment ex vivo, a colonic explant culture model was used: colonic biopsies were collected from patients with active (Mayo 1 /2) and inactive UC and cultured in the presence of compound or control for 24-48h. Supernatants were assayed for cytokine and chemokine release. Cells or biopsies were lysed for qPCR. Surface markers were assessed by flow cytometry

Results

Using more SIK2-selective small molecules, we show that SIK inhibition modulates inflammatory and immunometabolic pathways in human myeloid cells. Furthermore, SIK2 inhibition drives a tolerogenic phenotype in dendritic cells, as demonstrated by suppression of proinflammatory cytokines and chemokines such as TNFα and the CC/CXC chemokine family as well as downregulation of activation markers such as CD80 and 83; functionally these modulated DCs can suppress Th1 CD4 T cell IFNγ production. Modulation of cytokine and chemokine production by SIK2 inhibition was also observed in colonic explant cultures from UC patients with a reduction in levels of TNFα and the CC chemokine family.

Conclusion

In both myeloid cellular cultures and UC biopsies, SIK2 inhibition modulates an inflammatory environment into a pro-resolution state supporting the therapeutic potential of SIK2 inhibition in UC.
P140 Serum Metabolomic Biomarkers Can Identify and Characterize Associated Subtypes and Phenotypes in Inflammatory Bowel Disease
Authors: Kim J , Suh D H , Park Y J , Oh S J , Kang H , Ji Y , Jung E S , Lee C K
Published: January 2024

Background

Metabolomics is increasingly recognized for uncovering pathophysiology and identifying diagnostic and prognostic biomarkers in inflammatory bowel disease (IBD). This study focuses on exploring comprehensive serum metabolomic profiles and corresponding specific metabolic pathways, in order to differentiate IBD patients from healthy individuals and to accurately identify IBD subtypes (Crohn's disease [CD], ulcerative colitis [UC]) through serum biomarkers with high patient acceptability.

Methods

Serum samples with matched clinical metadata were comprehensively collected from patients with IBD at Kyung Hee University Hospital, Seoul, Korea. Corresponding samples from normal controls (NCs) were obtained for comparison. Untargeted profiling was performed with Gas Chromatography-Time-Of-Flight-Mass Spectrometry, and targeted profiling of bile acids and tryptophan used Liquid Chromatography-Triple Quadrupole-Mass Spectrometry. The identification of distinct metabolites and potential biomarkers was achieved through extensive univariate and multivariate statistical analyses. Receiver operating characteristic (ROC) curves and metabolic pathway analyses were also conducted.

Results

A total of 346 subjects were analyzed, comprising 258 IBD patients (134 with CD and 124 with UC) and 88 NCs, Table 1. The patients with IBD were clearly clustered from the NCs, while IBD subgroups were not clearly separated from each other in the nontargeted profiling. Tryptophan and indole-3-acetic acid were elevated in both patients with CD and UC, while kynurenine and indole-3-propionic acid increased only in CD. Conversely, patients with UC had lower levels of indole-3-acetic acid, serotonin, and acetylcholine compared to CD. The ratio of primary and secondary bile acids was also significantly decreased in both patient groups compare with NCs. The ROC curves (Figure 1A) showed good discriminatory power for NCs vs CD (AUC:0.9738), NCs vs UC (AUC:0.9887), and UC vs CD (AUC:0.7140). Pathway analysis of the identified metabolites showed a sustained change in glyoxylate and dicarboxylate metabolism/alanine, aspartate and glutamate metabolism/glycine, serine and threonine metabolism associated with all comparisons (NCs vs UC, NCs vs CD, UC vs CD). Beta-alanine, arginine, and proline metabolism were linked to IBD compared to NCs. Glycerolipid metabolism distinctly differed between UC and CD (Figure 1B-1D). Network analysis revealed associations between metabolomic markers and specific clinical phenotypes of IBD subtypes.

Conclusion

This study demonstrates that serum metabolomic biomarkers are novel and effective tools for diagnosing IBD, as well as for identifying and characterizing its subtypes and associated phenotypes.
P141 Engineered probiotics treat inflammatory bowel disease by releasing all trans retinoic acid in the intestine
Authors: Gao M , Wang L , Kang G , Zhang Y , Huang H
Published: January 2024

Background

All trans retinoic acid (ATRA) is a potential candidate drug for the treatment of inflammatory bowel disease (IBD). ATRA can affect multiple pathways involved in the pathogenesis of IBD by binding to retinoic acid receptors. However, the shortcomings of poor compliance and significant side effects in patients who directly use ATRA limit its clinical application.

Methods

Here, we have developed a live biotherapeutic products (ELBPRA) based on synthetic biology methods for controllable delivery of ATRA on the gut. We first expressed four enzyme genes required for the synthesis of β-carotene, a precursor of retinoic acid, in Escherichia coli Nissle 1917 (EcN). In addition, we introduced the exogenous synthesis pathway of isopentane pyrophosphate into EcN to increase the yield of β-carotene. Then, β-carotene oxygenase and retinal dehydrogenase, were expressed in EcN to convert β-carotene into retinoic acid. However, considering the poor solubility of retinoic acid, we knocked out some genes related to vesicle formation in the EcN genome to increase extracellular production of retinoic acid. Finally, we investigated the therapeutic effect of ELBPRA using a colitis model induced by sodium dextran sulfate (DSS).

Results

ELBPRA continuously produces retinoic acid and delivers it in the form of vesicles. ELBPRA reduced weight loss and disease activity index in DSS-induced colitis. Similarly, the spleen index also demonstrates the effectiveness of ELBPRA in treating colitis. The ELBPRA intervention group reduced the degree of colon shortening in mice. In addition, ELBPRA improved crypt loss and disorder of crypt structure. Finally, we also evaluated the inflammatory cytokines in the serum. ELBPRA significantly increased the concentration of anti-inflammatory cytokine IL-10 and decreased the concentration of pro-inflammatory cytokine IL-1β and TNF-α.

Conclusion

Engineered probiotics ELBPRA can deliver retinoic acid in the form of vesicles to alleviate DSS-induced colitis in mice, which provides a safe and effective treatment strategy for ulcerative colitis.
P184 Challenging Barriers in Inflammatory Bowel Disease: First Observational Analysis of Double Biological Therapy in Mexico
Authors: Sosa Martinez R , Garcia-Alonso D A , Lopez-Gomez J G , Cortes-Espinosa T
Published: January 2024

Background

Inflammatory bowel disease is a chronic inflammation of the GI tract, despite advances in treatment with biologic therapy, some patients may develop an inadequate response, known as refractory IBD (rIBD).Given this reality, the approach of double biological therapy (DBT) has emerged to effectively address and improve control of inflammation, providing them with an additional therapeutic option

Methods

Pilot prospective observational study evaluateing response to DBT in patients with refractory IBD

Results

A total of 7 patients with rIBD who received DBT were included, the average age was 29 ± 9, all female. The average duration of illness before starting dual therapy was 8 ± 2years. Patients had received an average of 2 previous biological treatments, 4 (57%) had a history of surgery related to IBD, 5 (71%) and 2(29%) had a history of stenosis and fistulas respectively and 100% used steroids and immunomodulators before starting DBT. Four DBT combinations were evaluated: CERTOLIZUMAB+VEDOLIZUMAB (group 1), USTEKINUMAB+VEDOLIZUMAB (group 2), INFLIXIMAB+USTEKINUMAB (group 3) and INFLIXIMAB+VEDOLIZUMAB (group 4).Group 1 included 1 patient with improvement in clinical activity, with a decrease in endoscopic activity from i4 to i2 by Rutgeerts criteria and Nancy index 1.Group 2 included 4 patients showed improvement in clinical and endoscopic activity, there was a reduction in clinical activity by CDAI from 225 to 66, and improvement in endoscopic activity from L1 B2 to L1 B1, i0 L2 B3P to i0 L1 B1 and i3 L3 B2 to i2 L3 B1 with different activity rates, Nancy's histology that varied from 0 to 3.Group 3 included 1 patient showed a reduction in clinical activity by CDAI from 210 to 166, endoscopic activity also decreased from i0 L2B3P to i0 L1 B1 with Nancy index of 2.Group 4 includes 1 with a decrease in clinical activity by Truelove-Witts from 2 to 2, endoscopic activity also decreased from 8 to 5 accordingto UCEIS with Nancy index of 1.In all groups, a reduction in the use of steroids was observed and no cases of infections associated with dual biological therapy were reported

Conclusion

This prospective observational pilot study represents the first analysis in Mexico and, to our knowledge, in Latin America, on the use of DBT in patients with rIBD who showed clinical, endoscopic and histopathological improvement in the majority of cases. It is important to recognize the limitations of this study, such as its pilot design and sample size. This pioneering study in refractory IBD presents encouraging results that suggest clinical and endoscopic benefits in the treated patients. These results justify the conduct of larger studies to strengthen the evidence and provide a solid basis for thepotential use of this therapy in clinical practice