bluuebunny/crossref_metadata_2025_split huggingface dataset:
P089 Colonic explant lactate concentration and inflammatory protein secretion in ulcerative colitis
Authors: McShane C , Corcoran R , O'Connell F , McDonagh P , O'Sullivan J , Kevans D 
Published: January 2023

Abstract

Background
Lactate, previously thought of as a waste product of cellular metabolism, is now known to act as an immunoregulator with pleiotropic effects. In murine models lactate has been shown to suppress colonic inflammation & restore colonic homeostasis. We aimed to investigate if lactate concentration in tissue cultured media (TCM) from ulcerative colitis (UC) patient-derived explants is associated with TCM concentration of inflammatory proteins known to be involved in UC pathogenesis.

Methods
UC patients were prospectively recruited in 2 cohorts: discovery (2018 – 2019) and validation (2020 - 2021). Endoscopic biopsies were collected from the sigmoid colon and TCM generated as per previously described methods. Total protein content of biopsies was quantified to allow normalisation of secretions. Patients demographics, baseline characteristics and disease behaviour were characterised. TCM secreted lactate was quantified using a colorimetric L-Lactate assay (Abcam, UK). Secreted inflammatory protein profiles were analysed via 54 V-plex ELISA (Meso Scale Diagnostics, USA).

Results
52 patients were recruited (discovery cohort n=28, replication cohort n=24), baseline characteristics are described in Figure 1. Median follow up time was significantly longer in discovery compared with validation cohort p=0.02. In the discovery cohort TCM lactate concentration was inversely correlated with CRP and CRP/Albumin ratio, however, this correlation was not replicated in the validation cohort (Figure 2). Baseline explant TCM lactate concentration did not correlate with TCM CRP concentration. Baseline explant TCM lactate concentration was correlated with IL-2 and IL-31 concentration in both discovery and validation cohorts (Figures 3 & 4). Multivariate analysis, including prior biologic exposure, clinical and endoscopic Mayo scores demonstrated TCM lactate concentration to be independently associated with IL-2 concentration in discovery and validation cohorts, p&lt;0.001 respectively. A similar multivariate analysis demonstrated TCM lactate concentration to be independently associated with IL-31 concentration in the discovery (p&lt;0.001), however, not validation cohort.

Conclusion
TCM lactate concentration is directly correlated with IL-2 & IL-31 in UC explants. The proposed immunoregulatory properties of lactate are in keeping with its positive correlation with TCM IL-2 concentration given reduced IL-2 secretion has previously been associated with UC disease progression. Further studies are required to define the effects of lactate in the UC tissue microenvironment.
P091 Gender focused investigation of sexual dysfunction, sexual satisfaction and body schema disorders in male and female patients with Inflammatory Bowel Disease
Authors: Kranzeder A , Lindenthal D , Hirning C , von Wietersheim J , Klaus J 
Published: January 2023

Abstract

Background
Gender-specific differences in Inflammatory Bowel Disease (IBD) have been reported for epidemiology, pathogenesis, clinical course and disease outcomes. However, when it comes to sexual health deviations regarding both biological sexes, research studies are scarce. In this context, gender could be an important modulating factor. The aim of this study was to investigate gender-specific sexual dysfunction, sexual satisfaction and body schema disorders in male and female patients with IBD.

Methods
A cross-sectional unicentric study was performed. 123 patients with IBD were recruited for 12 months. Of these, 50 patients were male and 73 female. Inclusion criteria included a diagnosed IBD (Crohn's disease or ulcerative colitis), age between 18 - 65 years and sufficient language skills to complete the questionnaires. Data was collected using standardised questionnaries (IBDQ, IBD-F, pMS, HBI, IIEF, BISF-W, FKKS, PHQ15, PHQ9, HADS-D). Sexual dysfunction, sexual satisfaction and body schema disorders were mainly assessed by the „Frankfurter Körperkonzeptskalen“ (FKKS), „The Brief Index of Sexual Functioning for Women“ (BISF-W) and „International Index of Erectile Function“ (IIEF).

Results
Significant differences (p &lt; 0.05) were found for the pMS, FKKS, PHQ15 and PHQ9. Male patients with IBD scored higher in the FKKS, especially in the subscale „Health and physical condition scale (SGKB)“ but also on sexuality- and body-related questions, meaning that they had fewer problems with their sexuality and biological functionality. Due to the small number of only 13 male participants, the IIEF could only be assessed to a limited extent. No significant differences were found here. Female patients with IBD had higher scores in the pMS, PHQ15 and PHQ9, meaning that they suffered more from severe disease activity, somatic impairment and depression. In addition, they scored lower on the BISF-W dimension scores "Arousal" (D2) and "Pleasure/Orgasm" (D5).

Conclusion
Sexual health seems to be impaired in male and female patients with IBD. However, it appears that men are less affected by their IBD than women in terms of sexual well-being, mental health, aesthetics and biological functionality. The reasons behind these results are diverse and cannot be clearly determined. It could be that men are overall more resilient because of their phsyical body structure or because they tend to hide supposed weaknesses.
P093 Creeping fat-derived long chain free fatty acids drive intestinal muscularis propria muscle cell proliferation via carnitine palmitoyltransferase 1 (CPT-1) – a relevant mechanism for stricturing Crohn’s disease
Authors: Le T H N , Mao R , Liu W , Czarnecki D , Chandra J , Gordon I O , Plesec T , Wang J , Lin S , Zhao S , Dejanovic D , Mukherjee P , West G , Fiocchi C , Brown J M , Rieder F 
Published: January 2023

Abstract

Background
Mesenteric fat wrapping around the intestinal wall, so called ‘creeping fat’ (CF), is spatially linked with stricture formation in Crohn’s disease (CD). Intestinal muscularis propria (MP) smooth muscle cell (HIMC) hyperplasia is a major contributor to luminal narrowing in stricturing CD. We investigated CF derived factors and their effect on HIMC hyperplasia in vitro and in vivo using human tissues, primary human cells and a colitis model.

Methods
Secretion of free fatty acids (FFA) by mesenteric fat (MF) or CF organ cultures was determined via lipidomic mass spectrometry. Effects of different length and types of FFA as well as CF and MF conditioned medium on proliferation of primary HIMF was assessed. Next generation sequencing (NGS) and lipidomics on HIMF was performed and relevant pathways inhibited with small molecules or siRNA knockdown. In the dextrane sodium sulfate (DSS) induced colitis model CPT-1 blockade was achieved via the small molecule etomoxir.

Results
Histopathology analysis of intestinal resection tissues revealed CD CF being located in the subserosa and its presence was linked with dramatic thickening of the MP. CF conditioned medium markedly upregulated HIMC proliferation compared to mesenteric fat from CD, UC and normal controls. CF released higher amounts of total, saturated and poly-unsaturated FFA with elevated levels of five long-chain (LC-)FFA, including palmitate. LC, but not medium or short chain FFA selectively increased proliferation in HIMC and fibroblasts, but not other intestinal cell types. NGS revealed gene regulation suggesting LC-FFA transport as a putative mechanism. Lipidomic analysis indicated the majority of palmitate being converted into phospholipids, predominantly phosphatidylcholine. Inhibition of LC-FFA uptake into cells via CD36, metabolism through inhibition of acyl-CoA synthetase, choline-phosphate cytidylyltransferase & choline kinase or blockade of LC-FFA uptake into mitochondria through CPT-1A reduced palmitate and CF conditioned medium induced HIMC proliferation. MP thickness increased in acute DSS colitis. Prophylactic inhibition of CPT-1 with etomoxir in acute DSS colitis did not reduce histopathologic inflammation or inflammatory cytokine gene expression, but reduced MP thickness and gene expression of the smooth muscle cell genes desmin and Sm22.

Conclusion
Subserosal CF releases LC-FFA inducing a selective proliferative response by HIMC. This effect was dependent on CD36, acyl-CoA synthetase and CPT-1. LC-FFA in HIMC are converted into phospholipids. Inhibtion of CPT-1 in DSS colitis reduced the increased MP thickness. These results point to CF as a novel contributor to stricture formation in CD.
P094 Impacts of 5-aminosalicylic acid on the intestinal microbiota leading to the anti-inflammatory effect
Authors: Wada H , Miyoshi J , Kuronuma S , Hibi N , Nishinarita Y , Oguri N , Matsuura M , Takeuchi O , Kobayashi T , Akimoto Y , Hibi T , Hisamatsu T 
Published: January 2023

Abstract

Background
5-aminosalicylic acid (5-ASA) is widely used for the treatment of inflammatory bowel disease (IBD), while its anti-inflammatory mechanisms remain controversial. The intestinal microbiota plays a certain role in the pathogenesis of IBD. We hypothesised that 5-ASA exerts anti-inflammatory effects by altering the gut microbiota. Elucidating the effects of 5-ASA on gut microbiota and its contribution to anti-inflammatory effects can lead to the development of effective and economical IBD medications.

Methods
Specific-pathogen-free (SPF) mice were orally administered 5-ASA for 4 weeks. The fecal bacterial compositions were examined with 16S rRNA gene amplicon sequencing analysis in mice of the 5-ASA-treatment group (5-ASA group) and no-treatment group (NT group). The immune profiles of the colonic mucosa were assessed. The feces from female mice in both groups were gavaged into germ-free (GF) female mice in separated isolators. In each isolator, these female mice (5-ASA dams and NT dams) were mated with GF male mice. The populations of CD4+ T cells in mesenteric lymph nodes (MLN) and colonic mucosal immune profiles were analysed in their pups. The pups were used for the dextran sulfate sodium (DSS)-induced colitis model to evaluate the anti-inflammatory effects of the gut microbiota altered by 5-ASA.

Results
The fecal bacterial compositions changed with 5-ASA treatment over time in SPF mice. At the genus level, the relative abundance of Allobaculum increased significantly in the females of the 5-ASA group compared to the NT group (corrected p &lt; 0.05). The same tendency was observed in male counterparts. The mRNA expression of IL-10 and IL-22 in the colonic mucosa increased significantly in mice of the 5-ASA group compared to their counterparts (p &lt; 0.05 in both sexes). In each isolator, the fecal bacterial compositions were similar between the dams and pups, suggesting that the gut microbiota was vertically transmitted from the dams to the pups in each group. CD4+RORgt+ T cells increased in MLN in the pups of 5-ASA dams compared to those of NT dams (p &lt; 0.01). The mRNA expression of TGF-b, claudin-2 and claudin-3 in the colonic mucosa increased significantly (p &lt; 0.001). The colonic inflammation induced by DSS was milder in 5-ASA pups compared to NT pups (Figure 1).

Conclusion
Orally-administered 5-ASA altered the intestinal microbiota affecting the host immune system and leading to less susceptibility to DSS-induced colitis. Alteration of gut microbiota could be a part of the anti-inflammatory mechanisms of 5-ASA.
P096 Characterization of suppressive immune cell subsets in mouse models of colitis-associated colorectal cancer
Authors: Frigerio S , Saris J , Franco Fernandez R , Koelink P , van Roest M , Wildenberg M , D’Haens G , Grootjans J 
Published: January 2023

Abstract

Background
Chronic colonic inflammation in inflammatory bowel disease (IBD) patients increases the risk of colitis-associated cancer (CAC). Cancer development in CAC is different from that observed in sporadic colorectal cancer (CRC). Most studies have focused on the role of pro-inflammatory immune cell subsets in CAC, yet it is becoming increasingly clear that immunosuppression may also drive cancer progression. We hypothesize that emergence of immunosuppressive cell subsets as a result of chronic intestinal inflammation, dampens anti-tumor immune responses and accelerates the development of CAC.

Methods
To simulate cancer formation in the background of chronic inflammation, mice were treated with azoxymethane (AOM) followed by three cycles of dextran sodium sulphate (DSS). Apc Min/+ mice treated with AOM were used to model sporadic CRC. After 10 weeks, immune cells from the proximal and distal colonic lamina propria, mesenteric lymph nodes (MLNs) and tumors were obtained for microscopy analyses and processed to obtain single cell suspensions for flow cytometry. Immune cell populations were studied by conventional flow cytometry and immunofluorescence.

Results
We observed a significant increase in absolute numbers of PD1+CTLA4+TIM3+ ‘exhausted’ CD4+ T cells in the lamina propria from proximal colons in CAC mice as compared to sporadic CRC mice. Interestingly, these numbers showed a positive correlation with the inflammation score in AOM/DSS, demonstrating that chronic inflammation is associated with the emergence of ‘exhausted’ T cells. In addition, we observed a trend to higher numbers of M2-like (MHCII-CD206+) suppressive macrophages and CD4+FoxP3+ regulatory T cells (Tregs) in tumors from CAC mice compared to sporadic CRC. When analysing T cell immune responses in the MLNs, we found a significant decrease in the ratio IFNγ/IL10-producing CD8+ T cells in CAC mice as compared to CRC mice, suggesting a shift towards an anti-inflammatory T cell response in CAC.

Conclusion
In summary, suppressive immune cell subsets were increased in colonic mucosa and tumors from CAC mice as a result of chronic inflammation, which may be associated with the development of dysplasia. Further functional studies are necessary to prove the role of suppressive immune subsets in IBD-associated dysplasia- and carcinoma progression.
P097 Various regulatory single nucleotide polymorphisms regulate similar biological pathways in Crohn’s disease
Authors: Modos D , Poletti M , Brooks-Warburton J , Bohar B , Madgwick M , Verstockt B , Vermeire S , Carding S , Korcsmaros T 
Published: January 2023

Abstract

Background
Single nucleotide polymorphisms (SNP) associated with Crohn’s disease (CD) are in both protein-coding and non-coding regions of the genome. Interpreting the effect of non-coding regulatory SNPs is challenging. We previously developed the iSNP pipeline, which determines how SNPs in transcription factor (TF) binding sites and miRNA target sites affect cellular regulatory networks and contribute to disease pathogenesis. We successfully used this method in Ulcerative Colitis, and now we developed this method further to study CD.

Methods
We applied the iSNP pipeline to identify CD-associated SNP affected genes in 1695 genotyped CD patients. The original iSNP approach can only analyse the direct interactors of SNP affected genes. Here, we implemented a heat propagation algorithm to uncover further downstream pathways, TFs and regulatory processes involved in the pathogenesis of CD. The heat was propagated from the proteins encoded by the SNP-affected proteins through a signalling network (using OmniPath) to TFs, and from them to their target genes (using DoRothEA).

Results
From the disease causing SNPs on the immunochip data of the patients, we identified 47 regulatory SNPs out of which 39 SNPs were in TF binding sites, 5 were affecting miRNA-target sites and 3 were affecting both. The pipeline predicted these SNPs regulate the expression of 83 proteins; 47 of them were present in the OmniPath signalling network. The network propagation analysis identified 518 proteins that were affected significantly in CD by these 47 proteins. The affected proteins were involved in antigen presentation through MHC-I, WNT signalling, C-type lectin signalling and NF-kB signalling pathways based on Gene Ontology analysis. GNAI1, RIPK2, ATG16L1, CLTC, and CARD9 were affected in 63% of the patients. TF-target gene analysis identified a downstream regulatory network containing 2067 potentially affected genes. These genes were involved in T cell activation, other immune functions, DNA repair and autophagy regulation. Genes encoding MMP9, RARA and SSB2 were affected in 70% of patients.

Conclusion
The affected signalling network showed the known importance of the WNT pathway, autophagy and type I antigen presentation in CD. We extended the list of affected processes with the network propagation modelling approach, and pointed out key functions that were commonly affected in the majority of patients with CD. Thus, patient-specific, various SNP sets converge on the same, few key functions, such as fibrosis and tissue remodelling (through MMP9 or RARA), and DNA repair (through SSB2). Overall, the new network propagation model in the iSNP pipeline pointed out genes affected in the majority of CD patients, highlighting their potential role in CD pathogenesis.
P098 Novel drug candidate for the treatment of Inflammatory Bowel Disease with unique mechanisms of action
Authors: Lee J , Kim G , Kim J C , Park J H , Han C , Kim M 
Published: January 2023

Abstract

Background
Inflammatory Bowel Disease (IBD) is characterized by chronic inflammation and severe dysfunction of the gastrointestinal tract. Despite significant improvements in therapeutic agents targeting IBD, many subjects with IBD fail to achieve recovery or do not respond to current medication. Moreover, current therapy has been limited to the management of inflammation, while almost no progress has been made in the development of anti-fibrotic therapies for IBD. NEXEL’s novel protein NP-011, targeting αVβ3 and αVβ5 integrins and phosphatidylserine, has shown anti-inflammatory and anti-fibrotic effects in various in vivo models with fibrosis. This study was designed to evaluate the therapeutic potential of NP-011 for the treatment of IBD using mice models.

Methods
Acute ulcerative colitis was induced by exposure to 2% dextran sodium sulfate (DSS)-treated drinking water from Day 1 to Day 7; Normal control animals did not receive DSS. Animals were then dosed with vehicle (NP-011 storage buffer, n=10), comparative protein, MFG-E8 (n=10), or NP-011 (n=10) daily for five days (IV) from Day 7 to Day 11. All animals were sacrificed on Day 14. The chronic colitis model was induced by exposure to 2% DSS-treated drinking water (initial three consecutive days of each week) and recovered by providing normal water (four days each from Day 3 and Day 10). Animals were dosed with the vehicle, three commercial drugs (n=10, 1.03 mg/kg, on Day 3), and NP-011 (n=10, 320, and 640 ug/kg, on Day 3 and Day 10) by intravenous injection. All animals were sacrificed on Day 18. Colon length and histological changes (inflammation and crypt damage) were analyzed.

Results
The induction of colitis was characterized by weight loss. Treatment with comparative protein or NP-011 improved body weight gain during recovery. Both proteins suppressed the shortening of the colon and reduced histological score, including intestinal inflammation and crypt damage. Notably, the administration of NP-011 showed higher efficiency than the same dose of the comparative protein in improving these pathologic parameters. NP-011 was also effective in the chronic model of colitis. Colon shortening, inflammation reactions, and crypt damage were markedly attenuated in NP-011-administered mice with comparable efficacy to commercial drugs.

Conclusion
Treatment with NP-011 demonstrated substantial improvement in histological characteristics of bowel pathology and suppression of colon shortening in the IBD mice model. Taken together, this novel protein, NP-011, could be a promising drug candidate for the treatment of IBD with unique mechanisms of action, including anti-inflammation and anti-fibrosis
*JL, GK, and JCK have equally contributed to this study.
P100 Atypical Anti-Neutrophil Cytoplasmatic Antibodies Are Antibodies Against Neutrophil Extracellular Traps: A Novel Pathophysiological Mechanism In Ulcerative Colitis
Authors: Mendieta Escalante E A , Parada-Venegas D , Bourgonje A , Roozendaal C , Hermoso Ramello M , Faber K N , Dijkstra G 
Published: January 2023

Abstract

Background
The number of mucosal neutrophils, as well as the presence of neutrophil extracellular traps (NETs), correlate with disease activity in Ulcerative colitis (UC), an inflammatory bowel disease. Most (~80%) UC patients present atypical Anti-Neutrophil Cytoplasmatic Antibodies (a-ANCAs) to a yet unknown antigen, which shows a different immunofluorescence staining pattern when compared to cytoplasmatic (c-ANCA) and perinuclear (p-ANCA) that target proteinase (PR3) and myeloperoxidase (MPO), respectively. Here, we analyzed whether a-ANCAs specifically bind to NETs.

Methods
Blood neutrophils were treated to form non-lytic NETs using LPS-treated platelets with and without DNAse and Trypsin. Patient biopsies and in vitro-formed non-lytic NETs were incubated with p-ANCA, c-ANCA and a-ANCA positive patient and ANCA negative control serum and processed for immunofluorescence microscopy. Macrophage-mediated clearance of serum-pretreated NETs was analyzed in real-time using Incucyte microscopy.

Results
Ethanol-fixed neutrophils displayed c-ANCA, p-ANCA patterns, and a-ANCA web-like staining. Only c- and p-ANCA react to DNAse-treated ethanol-fixed neutrophils (Fig 1). Serum containing a-ANCA’s bound to non-lytic NETs that disappeared upon treatment with DNAse and Trypsin whereas c- and p- ANCA binding did not disappear upon DNAse treatment (Fig 2) indicating that both DNA and proteins are needed for a-ANCAs to bind to non-lytic NETs. In inflamed colonic tissue of UC patients, a-ANCA co-stained with extracellular DNA and neutrophil elastase covering the intestinal epithelium (Fig 3). In vitro, NETs were efficiently cleared by macrophages, which was strongly inhibited after pre-incubating with a-ANCAs (Fig 4). Macrophages exposed to a-ANCA-incubated NETs expressed higher CXCL-8 and IFN-B levels than the NETs exposed to control serum (both p&lt;0.05).
Figure 1

Figure 2

Figure 3

Figure 4

Conclusion
a-ANCAs specifically bind to de novo DNA-protein antigens in non-lytic NETs, which prevents efficient macrophage-mediated clearance and induces a pro-inflammatory (M1) phenotype. This inflammatory milieu may contribute to the pathophysiology of UC.