Differential effects of tofacitinib on macrophage activation contribute to lack of response in ulcerative colitis patients.

Background And Aims: Tofacitinib, a Janus kinase inhibitor, is approved for the treatment of moderate-to-severe ulcerative colitis. Nonetheless, 40-60% of patients will not respond adequately. The mechanisms underlying responses to tofacitinib remain unknown.

Mitochondrial Dysfunction: Unraveling the Elusive Biology Behind Anti-TNF Response During Ulcerative Colitis.

Background: Recent studies hint at mitochondrial genes influencing UC patient response to anti-TNF treatment. We evaluated this hypothesis by following a targeted strategy to identify gene expression that captures the relationship between mitochondrial dysregulation and response to treatment. Our objective was to initially examine this relationship in colon samples and subsequently assess whether the resulting signal persists in the bloodstream.

Single-cell integration reveals metaplasia in inflammatory gut diseases.

The gastrointestinal tract is a multi-organ system crucial for efficient nutrient uptake and barrier immunity. Advances in genomics and a surge in gastrointestinal diseases has fuelled efforts to catalogue cells constituting gastrointestinal tissues in health and disease. Here we present systematic integration of 25 single-cell RNA sequencing datasets spanning the entire healthy gastrointestinal tract in development and in adulthood.

Macrophage and neutrophil heterogeneity at single-cell spatial resolution in human inflammatory bowel disease.

Ulcerative colitis and Crohn's disease are chronic inflammatory intestinal diseases with perplexing heterogeneity in disease manifestation and response to treatment. While the molecular basis for this heterogeneity remains uncharacterized, single-cell technologies allow us to explore the transcriptional states within tissues at an unprecedented resolution which could further understanding of these complex diseases. Here, we apply single-cell RNA-sequencing to human inflamed intestine and show that the largest differences among patients are present within the myeloid compartment including macrophages and neutrophils.

Expression of HMGCS2 in intestinal epithelial cells is downregulated in inflammatory bowel disease associated with endoplasmic reticulum stress.

Introduction: The Unfolded Protein Response, a mechanism triggered by the cell in response to Endoplasmic reticulum stress, is linked to inflammatory responses. Our aim was to identify novel Unfolded Protein Response-mechanisms that might be involved in triggering or perpetuating the inflammatory response carried out by the Intestinal Epithelial Cells in the context of Inflammatory Bowel Disease.

Methods: We analyzed the transcriptional profile of human Intestinal Epithelial Cell lines treated with an Endoplasmic Reticulum stress inducer (thapsigargin) and/or proinflammatory stimuli.

Multi-omic modelling of inflammatory bowel disease with regularized canonical correlation analysis.

Background: Personalized medicine requires finding relationships between variables that influence a patient's phenotype and predicting an outcome. Sparse generalized canonical correlation analysis identifies relationships between different groups of variables. This method requires establishing a model of the expected interaction between those variables.

Dissecting Common and Unique Effects of Anti-α4β7 and Anti-Tumor Necrosis Factor Treatment in Ulcerative Colitis.

Background And Aims: Vedolizumab is an anti-α4β7 antibody approved for the treatment of ulcerative colitis [UC]. Although it is assumed that vedolizumab blocks intestinal homing of lymphocytes, its effects on different intestinal cell populations are not fully stablished. In order to establish the unique mechanisms of action of vedolizumab in UC patients, we compared its effects to those induced by anti-tumour necrosis factor [TNF].

Integrated microbiota and metabolite profiles link Crohn's disease to sulfur metabolism.

Gut microbial and metabolite alterations have been linked to the pathogenesis of inflammatory bowel diseases. Here we perform a multi-omics microbiome and metabolite analysis of a longitudinal cohort of Crohn's disease patients undergoing autologous hematopoietic stem cell transplantation, and investigational therapy that induces drug free remission in a subset of patients. Via comparison of patients who responded and maintained remission, responded but experienced disease relapse and patients who did not respond to therapy, we identify shared functional signatures that correlate with disease activity despite the variability of gut microbiota profiles at taxonomic level.

Intestinal Inflammation Modulates the Epithelial Response to Butyrate in Patients With Inflammatory Bowel Disease.

Background: Butyrate-producing gut bacteria are reduced in patients with active inflammatory bowel disease (IBD), supporting the hypothesis that butyrate supplementation may be beneficial in this setting. Nonetheless, earlier studies suggest that the oxidation of butyrate in IBD patients is altered. We propose that inflammation may decrease epithelial butyrate consumption.

T cell clonal expansions in ileal Crohn's disease are associated with smoking behaviour and postoperative recurrence.

Unlabelled: T cell clonal expansions are present in the inflamed mucosa of patients with Crohn's disease (CD) and may be implicated in postoperative recurrence after ileocolonic resection.

Methods: T cell receptor (TCR) analysis was performed in 57 patients included in a prospective multicentre cohort. Endoscopic recurrence was defined by a Rutgeerts score >i0.

Differences in Peripheral and Tissue Immune Cell Populations Following Haematopoietic Stem Cell Transplantation in Crohn's Disease Patients.

Background And Aims: Recent studies have shown the efficacy of autologous haematopoietic stem cell transplantation [HSCT] in severely refractory Crohn's disease [CD] patients. HSCT is thought to eliminate auto-reactive cells; however, no specific studies of immune reconstitution in CD patients are available.

Methods: We followed a group of CD patients [n = 18] receiving autologous HSCT, with 50% of them achieving endoscopic drug-free remission.

An RORγt Oral Inhibitor Modulates IL-17 Responses in Peripheral Blood and Intestinal Mucosa of Crohn's Disease Patients.

Despite the negative results of blocking IL-17 in Crohn's disease (CD) patients, selective modulation of Th17-dependent responses warrants further study. Inhibition of retinoic acid-related orphan receptor gamma (RORγt), the master regulator of the Th17 signature, is currently being explored in inflammatory diseases. Our aim was to determine the effect of a novel oral RORγt antagonist (BI119) in human CD and on an experimental model of intestinal inflammation.