bluuebunny/crossref_metadata_2025_split huggingface dataset:
P029 Loss of adipose tissue protects mice from intestinal inflammation
Authors: Omar T , Letizia M , Siegmund B , Weidinger C 
Published: January 2024

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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.