bluuebunny/crossref_metadata_2025_split huggingface dataset:
P129 Anastomotic healing is functionally not impaired after ileocecal resection in a mouse model of Crohn's-like ileitis
Authors: Berlin P , Fischer A , Reiner J , Schafmeyer C , Lamprecht G , Witte M 
Published: January 2024

Abstract

Background
Anastomotic leakage (AL) is a serious complication after gastrointestinal surgery that seems to occur more frequently in patients with CD than in non-IBD patients. Nucleotide-binding oligomerisation domain-containing protein 2 (NOD2) is a risk gene for CD. We have recently demonstrated that Nod2-deficent mice have impaired anastomotic healing after ileocecal resection (ICR) even in the absence of a Crohn's phenotype. It is not yet understood how CD itself affects anastomotic healing. SAMP1/YitFc mice spontaneously develop Crohn's-like ileitis and show a defect in the NOD2 receptor.
With this study we aimed to investigate whether anastomotic healing is altered after ICR in experimental ileitis.

Methods
SAMP1/YitFc mice (n=17) with histologically manifest ileitis and parental controls (AKR, n=12) were subjected to ICR. Intestinal continuity was established by end-to-end ileocolic anastomosis. On day 5, the strength of the anastomosis was assessed by bursting pressure (BP) measurement. Anastomotic healing was evaluated macroscopically using the anastomotic healing score (AHS). Hydroxyproline content and collagenase activity in the anastomosis were determined. The inflammatory status was determined by mRNA expression of inflammatory cytokines in mesenteric lymph nodes (MLN) and spleen tissue.

Results
25% of the AKR mice and 29% of the SAMP1/YitFc mice developed perioperative complications. Leakage rate was not higher in mice with ileitis. Functionally, anastomoses were not impaired in SAMP1/YitFc mice (BP SAMP1 93 mmHg vs. AKR 123 mmHg) and AHS did not differ between the groups. However, mice with ileitis were more prone to microscopic abscess formation. Collagenase activity and hydroxyproline content in the anastomotic tissue did also not differ significantly. Preoperatively, mice with ileitis expressed increased IL4 and INF-γ mRNA levels in the MLN compared to AKR controls. After ICR, the local expression of IL4, TNF-α, lysozyme 1 and IL2 was significantly decreased in SAMP1/YitFc mice (p&lt;0.05 SAMP1 d0 vs. d5, MLN). Resection induced significantly increased expression of IL4, lysozyme 1 and IL2 in the spleen of AKR mice, but not in SAMP1/YitFc mice (p&lt;0.05 AKR ICR vs. SAMP1 ICR d5).

Conclusion
The SAMP1/YitFc mouse is a suitable model to study mechanisms of anastomotic healing under the influence of experimental chronic ileitis. Ileitis alone was not a risk factor for impaired healing. Ongoing studies address the local effects of therapeutic immunomodulation on the healing process of the anastomoses.
P132 Overexpression of miR-376a-3p in exosomes circulating in peripheral blood of patients with Crohn's disease
Authors: Caparrós E , García I , Madero Velázquez L , Mira C , Martínez A , Gutiérrez Casbas A , Francés R 
Published: January 2024

Abstract

Background
MicroRNAs (miRs) can modulate the development and/or progression of chronic inflammation in patients with Crohn's disease (CD), influencing the efficacy of treatments.

Aim
The objective was to assess the miRs content of circulating exosomes in the peripheral blood of patients with CD to identify new biomarkers useful in disease management.

Methods
Patients with CD diagnosed and followed up at the Hospital General Universitario de Alicante and healthy controls were included. Extracellular vesicles were isolated from serum and exosomes were quantified by "Nanoparticle Tracking Analysis" (NTA), confirmed by Transmission Electron Microscopy (TEM) and by specific markers (Tsg101, CD63, CD81) by Western blot, performing an expression analysis of a non-targeted panel of human miRs from exosomal RNA. Patient and control samples were also subjected to enzyme-linked immunosorbent assay (ELISA) measurement of different target-predicted protein substrates.

Results
Thirty patients and ten controls were included in the study. Patients were 42±9 years old, disease duration 62±9 months, 40% women and 80% showed ileal or ileocolonic involvement. Six patients (20%) had perianal disease. Ninety-three per cent were undergoing biological treatment with infliximab (IFX, n=13), adalimumab (ADA, n=8) or ustekinumab (USTE, n=7). A significant increase in exosome concentration was observed in the serum of patients vs controls. NTA and TEM confirmed the size and purity of the obtained exosomes. The distribution in the expression of miRs and its differential analysis showed a significant increase in miR-376a-3p as well as a reduction in miR-20a-5p in patients vs. healthy controls. Functional analysis of miR-376a-3p determined its interaction with gene targets involved in autophagy (ATG4C), TGF-b signaling (ACVR1C) and cell survival (PIK3R1, IGF1R). Protein levels of these substrates indicated the potential control of TGF-beta signaling pathway by the downregulation of ACVR1C, and the increase in survival pathway measured by IGFR1 presence in patient’s serum.

Conclusion
CD patients show a higher number of circulating exosomes, with an overexpression of miR-376a-3p. The involvement of this microRNA in different intracellular signaling pathways suggests its participation in the unbalance of the immune activity present in CD.
P133 In vitro pharmacological profile of GLPG3667 suggests differentiation from the TYK2 inhibitors deucravacitinib and TAK-279 at their clinical dose regimens
Authors: Hettema W , Nolain P , Parent I , Blanqué R , Furio L , Lagoutte E , Angella L , Dao J , Galien R 
Published: January 2024

Abstract

Background
Tyrosine kinase 2 (TYK2), a Janus kinase (JAK) family member, is attracting a lot of interest as a new target to treat patients with autoimmune and inflammatory diseases, including inflammatory bowel disease, and several inhibitors are currently in clinical development. In vitro pharmacological profiling of TYK2 inhibitors has been employed to evaluate potency and selectivity; however, such data are best viewed in relation to clinical exposure levels. We compared expected levels of inhibition of TYK2-dependent and -independent pathways for deucravacitinib, TAK-279 and GLPG3667 at their respective clinical dose regimens and demonstrate that relevant differences exist between these compounds.

Methods
Potency of the TYK2 inhibitors was compared for TYK2-dependent pathways (IFNα, IL-12), TYK2-independent pathways (IL-6, IL-2, GM-CSF) and the anti-inflammatory IL-10 pathway in in vitro human whole blood assays using STAT phosphorylation (flow cytometry) and cytokine release (ELISA). Sigmoidal Emax models were fitted to the concentration–inhibition data from healthy donors to estimate IC50, Emax and Hill slope for each assay and compound. The obtained relationships were subsequently coupled to the clinical pharmacokinetic (PK) profiles of the compounds (population PK model for GLPG3667, published PK metrics such as Cavg for the other compounds) to estimate the level of inhibition of the various pathways at clinically relevant dose regimens.

Results
Human whole blood assays performed for various JAK pathways demonstrated that all TYK2 inhibitors display selectivity for TYK2 over the JAK1–3 family members, with TAK-279 being the most selective. At exposure levels associated with its clinical dose of 150 mg once daily, GLPG3667 showed inhibition of the IFNα and IL-12 pathways, similar to the expected inhibition for deucravacitinib at its clinical dose regimens, without a measurable impact on TYK2-independent pathways. TAK-279 showed the most sustained inhibition of TYK2-dependent pathways. GLPG3667 showed no measurable inhibition of IL-10-mediated signalling up to the highest concentration tested (~10-fold above clinical concentrations), while inhibition was observed with deucravacitinib and TAK-279 at concentrations corresponding to the respective clinical dose regimens.

Conclusion
At concentrations corresponding to its highest anticipated clinical dose, GLPG3667 shows selective inhibition of TYK2-mediated signalling, with a level of inhibition similar to deucravacitinib clinical dose regimens. While GLPG3667 did not show any impact on IL-10-mediated signalling, inhibition of this anti-inflammatory pathway is expected for the allosteric TYK2 inhibitors at their clinical exposure levels.
P146 Latent activation of the extrinsic coagulation pathway in patients with ulcerative colitis
Authors: Drygiannakis I , Valatas V , Filidou E , Tzenaki N , Archontoulaki E , Dovrolis N , Kandilogiannakis L , Kefalogiannis G , Sidiropoulos P , Kolios G , Koutroubakis I E 
Published: January 2024

Abstract

Background
Ulcerative colitis (UC) is associated with an increased risk of venous thromboembolism. We investigated the correlation of UC severity with latent activation of the extrinsic coagulation pathway and colonic stromal tissue factor (TF) expression.

Methods
Plasma exosomes, microparticles (EM), TF protein, activities of EM-bound TF (EM-TF) and FVIIa, as well as TF mRNA (F3) in primary colonic stromal cells in culture were measured.
Disease extent by Montreal classification, medications, UC clinical activity by partial Mayo score (PMS), endoscopic severity by the MS endoscopic component (eMS; loss of response defines as ≥2), quality of life by the short IBD questionnaire- SIBDQ, complete blood count, CRP, ESR and albumin were retrieved. Statistical significance (p) was assessed with the following tests: Student’s t for 2 groups with normally distributed values, Mann-Whitney U if not, Wilcoxon test for paired data. Correlation of continuous against scale variables was assessed with Pearson’s or Spearman’s r and corresponding p values for linear or logarithmic continuous variables, respectively.

Results
Plasma was obtained from 38 UC patients (31 males, disease duration 151±25 months, 14 with extensive colitis, 5 current smokers) and 28 healthy blood donors (HBD; 20 males) who served as controls. TF mRNA (F3) was measured in primary colonic stromal cells in culture from 12 UC patients (11 males, disease duration 169±53 months, 8 with extensive colitis, 1 current smoker) and from 7 controls undergoing screening colonoscopy.
UC patients had 4- and 3.7- times more exosomes and microparticles than controls, respectively (A). TF protein correlated with PMS (r 0.443), albumin (-0.362), ESR (0.353), PLT (0.575) and endoscopic UC severity (0.468; B). EM-TF activity was 1.6-times higher (C) and correlated to disease extent (E3: 1.9 x E2), albumin (-0.624), endoscopic severity (0.422; D) and SIBDQ (-0.64). Downstream, FVIIa activity was 2.2-times higher. Refractory-to-treatment patients had 5.8-, 1.5-, 2.1- times higher TF protein (E), MP-TF, FVIIa activity, respectively. Within responders, the need for steroids or biologics correlated with 2.2-times higher MP-TF activity. Colonic stromal cells from patients with UC maintained a 2.2-times higher F3 (F), which correlated to PMS (0.56), albumin (Spearman’s r -0.543), endoscopic severity (M3: 8.3 x M2). All the aforementioned were statistically significant with a &lt; 0.05.

Conclusion
The extent of spontaneous activation of the extrinsic coagulation pathway is associated with clinical and endoscopic UC activity and response to treatment. TF in colonic stromal cells mirrors its systemic activity and indicates the possible contribution of such cells to increased TF plasma bioactivity.
P153 Artificial Intelligence to predict interleukin-23 signalling activity from H&E stained whole slide images of Inflammatory Bowel Disease
Authors: Qaiser T , Hamidinekoo A , Daniel S , Zhang I , Kekic M , Lewis A , Angermann B , Bourke L , Gehrmann U , Neisen J , Tian S , Corridoni D , Marks D , Adissu H , Burlutskiy N 
Published: January 2024

Abstract

Background
Interleukin23 (IL-23) is a cytokine that plays a crucial role in the pathogenesis of inflammatory bowel disease (IBD), making it a highly validated therapeutic target. Understanding the role of IL-23 in IBD at the histopathological level is crucial for determining effective treatment strategies, providing insights into IBD patients who fail to respond to targeted therapies, or predicting those who are likely to lose response. In this context, there is a surge in utilizing artificial intelligence (AI) for histopathological data in IBD and other disease indications. Here, we present an automated computer vision approach to predict IL-23 signalling activity directly from routinely stained Hematoxylin and Eosin (H&E) images

Methods
A total of 1502 samples with matched clinical data and H&E biopsy images were included from 991 Crohn’s disease (CD) and 511 ulcerative colitis (UC) samples. IL-23 signalling activity was calculated using gene set variation analysis on RNA-seq data collected from the same tissue biopsies. The data were obtained from the IBD Plexus program of the Crohn’s & Colitis Foundation. The proposed approach is based on vision transformers (ViTs) which is a type of deep learning model. ViTs divide the input image into fixed-size patches, transform it into linear embedding, and analyze it with the self-attention mechanism. This enables ViTs to incorporate relationships between different patches of the input image to identify regions predictive of IL-23. Our approach was trained in a weakly supervised manner to automatically identify tissue regions that correlate with IL-23 signaling activity. The model produces interpretable heatmaps to interrogate model predictions and allow clinicians to visualize and interpret the significance of different tissue regions predictive of IL-23

Results
We performed 5-fold cross-validation on the splits obtained at the patient level, retaining the data distribution of IL-23 signaling activity, biopsy location, and diagnosis. We separately validated the performance of the proposed model on both disease categories, including CD and UC. The proposed approach achieved an area under the curve (AUC) of 0.82 ± 0.04 on unseen data from CD and an AUC of 0.80 ± 0.02 for UC. The 5-fold results for both disease categories are shown below

Conclusion
The presented results highlight the significance of computational pathology algorithms to identify IL-23 signalling activity from H&E images. Pathological interpretation from the heatmaps may help understand disease pathomechanism and optimize the treatment options for IBD patients by timely identification of IL-23 status. We are further validating the clinical utility of such heatmaps and expanding the use of H&E to predict other patient-centric endpoints
P159 Inhibition of Caspase-1 signalling subtly affect the gut microbiota and reduces Adherent-invasive Escherichia coli (AIEC)-induced inflammasome activation
Authors: Barrett K , Aguilera M , Manning C , O'Sullivan O , Clarke D , Melgar S 
Published: January 2024

Abstract

Background
Inflammatory bowel disease (IBD), encompassing Crohn’s Disease and ulcerative colitis, is a chronic gastrointestinal disorder with increasing incidence worldwide. Microbial factors such as Adherent-invasive Escherichia coli (AIEC) have been suggested to play a significant role in the pathogenesis of IBD. The inflammasome, a multi-protein complex, senses environmental signals, including bacteria, resulting in the activation of caspase-1 leading to the subsequent maturation and secretion of IL-1β. In this study we examined the impact of AIEC on inflammasome activation and on the inhibition of Caspase-1 signaling in AIEC-colonised mice and on intestinal epithelial cells (IECs).

Methods
Human IECs (CaCO2Bee1 cells) were cultured for 3hr with AIEC (HM605 and its invasiveness mutant), washed with antibiotics and further cultured in full cell media for 13hrs, followed by analysis on cytokine and inflammasome gene expression and activation by qRT-PCR, ELISA, imaging and flow cytometry. To inhibit caspase-1 activation, cells were pre-treated for 1 hr with the caspase-1 inhibitor zVAD-fmk. To establish AIEC colonisation, C57BL/6 and IL-10-/- mice were treated with streptomycin for 24hrs followed by oral gavage of AIEC-HM605 (10-8 cfu/mL) and faecal and tissue samples were collected at 6 days post AIEC-infection. Caspase-1 inhibitor was orally gavaged every in mice. Faecal samples were prepared for 16S rRNA gene sequencing and colon tissue was analysed for cytokines and inflammasome markers by qRT-PCR and ELISA.

Results
IECs cultured with AIEC and AIEC-colonised C57BL/6 and IL-10-/- mice resulted in an increased expression and activation of both canonical (Caspase-1) and non-canonical inflammasome (caspase 4). The AIEC-induced inflammasome response was dependent on the invasiveness of AIEC. Treatment with a caspase-1 inhibitor reduced the AIEC-induced inflammasome markers in IECs and in C57BL/6 mice. No major changes in alpha or beta-diversity was detected in AIEC-colonised mice or upon Caspase-1 inhibition. AIEC-colonisation resulted in an increased abundance of Bacteroides and Alistipides and reduced abundance of Lachnospiraceae, alterations reversed by Caspase-1 inhibition.

Conclusion
We show that the invasion of AIEC in IECs and colonisation of murine intestine results in activation of caspase-1 inflammasome. AIEC colonisation provoke subtle microbiota alterations which are reversed by caspase-1 inhibition. In summary, our data supports a role of AIEC in IBD pathogenesis through the activation of caspase-1 inflammasome.
P163 PI(4,5)P2 alleviates colitis by inhibiting intestinal epithelial cell pyroptosis through NNMT-mediated RBP4 m6A modification
Authors: Yang Q , Na D , Xiang G , Kang C 
Published: January 2024

Abstract

Background
Lipid metabolism disorder is a critical feature of Crohn’s disease (CD). We previously reported that phosphatidylinositol (PI), and its derivative phosphatidylinositol bisphosphate (PIP2) were significantly associated with CD activity. The underlying mechanisms remained unknown. We aimed to explore the function of phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2], the major PI derivative, in modulating CD pathogenesis.

Methods
Lipidomics was used to analyse the relationship between CD activity and PI or PIP2. The mucosal expression of PI(4,5)P2 in patients with CD was measured by immunofluorescence. Dextran sodium sulfate (DSS)-induced colitis mice and lipopolysaccharide (LPS)-induced Caco-2 cell model were established to explore the function and mechanism of PI(4,5)P2. MeRIP and mRNA sequencing were applied to further reveal the mechanism of PI(4,5)P2.

Results
Lipid PIP2 was substantially negatively associated with disease activity and high-sensitivity C-reactive protein. PI(4,5)P2 expression was downregulated in the inflamed mucosa of patients with CD. PI(4,5)P2 alleviated mice colitis, with improvements in survival rate, colon length, body weight, and disease activity index. PI(4,5)P2 also alleviated DSS-induced tissue damage, tight junction loss, and intestinal epithelial cell (IEC) pyroptosis. In the in vitro LPS-induced cell model, PI(4,5)P2 inhibited pyroptosis, NLRP3, and caspase-1 expression, and reduced IL-18, IL-1β, and lactate dehydrogenase (LDH) secretion. PI(4,5)P2 mediated NNMT upregulation in mice and Caco-2 cells. NNMT knockdown restricted the inhibitory effect of PI(4,5)P2 on IEC pyroptosis. NNMT inhibited the stability of RBP4 mRNA via the m6A modification to prevent pyroptosis upon PI(4,5)P2 treatment.

Conclusion
PI(4,5)P2 inhibited IEC pyroptosis through NNMT-mediated RBP4 m6A modification, which ameliorating colitis. PI(4,5)P2 may be a therapeutic target for CD.
P166 Optimizing PD-1 agonist signaling with membrane proximal binding of rosnilimab, a clinical stage PD-1 agonist IgG1 antibody
Authors: Parmley S , Szlyk B , Frank R T , Hsu M , Brodsky P , Sibley C , Lizzul P , Dahl M 
Published: January 2024

Abstract

Background
Checkpoint agonism represents a promising class of therapies for the treatment of autoimmune and inflammatory diseases, including ulcerative colitis (UC), where unmet needs persist despite available therapies. Binding to membrane proximal regions of checkpoint receptors, together with Fc interactions with receptors on opposing cells, can contribute to tight immune synapse formation between the immune cell and antigen presenting cell. This has been proposed to improve potency of agonistic signaling by excluding phosphatases such as CD45 from the immune synapse and promoting receptor clustering. Optimization of these characteristics results in improved agonism and depletion, with the potential for restoration of immune balance and broader clinical outcomes. Rosnilimab was engineered to leverage these important characteristics. It is a PD-1 agonist IgG1 antibody designed to optimize inhibitory signaling through the PD-1 receptor and to deplete PD-1high pathogenic T cells. Rosnilimab is in Phase 2 clinical development for UC and rheumatoid arthritis.

Methods
Mutations to surface exposed regions of the PD-1 extracellular domain were made and surface plasmon resonance was used to infer the epitopes of PD-1 agonist molecules from resulting changes to binding. Membrane proximal and distal binding antibodies were studied in in vitro functional assays to assess T cell proliferation and antibody-dependent cellular toxicity.

Results
Epitopes of agonistic antibodies were mapped to locations on the PD-1 receptor. The membrane proximal binding epitope of rosnilimab was confirmed and binding epitopes for other reference antibodies (ref) were identified. Rosnilimab and a membrane distally binding antibody (ref 1) were selected for comparison in functional assays. Rosnilimab demonstrated greater reduction of T cell proliferation and depletion of PD-1+ T cells compared to ref 1, consistent with the hypothesis that membrane proximal binding improves agonistic activity and target cell depletion.

Conclusion
By targeting and leveraging inhibitory immune regulatory mechanisms to modulate the pathogenic T cells driving disease, there is an opportunity to dampen the inflammatory cycle and restore immune balance via agonism. Rosnilimab binds to a membrane proximal region of the PD-1 receptor, resulting in potent reduction of T cell proliferation and depletion of PD-1high T cells. These mechanistic data, translational in vivo and in vitro data, robust Phase 1 healthy volunteer data, and unmet needs in UC provide rationale for an ongoing global Phase 2 study of rosnilimab in UC (NCT06127043).