Single cell sequencing data identify distinct B cell and fibroblast populations in stricturing Crohn's disease.

Single cell RNA sequencing of human full thickness Crohn's disease (CD) small bowel resection specimens was used to identify potential therapeutic targets for stricturing (S) CD. Using an unbiased approach, 16 cell lineages were assigned within 14,539 sequenced cells from patient-matched SCD and non-stricturing (NSCD) preparations. SCD and NSCD contained identical cell types. Amongst immune cells, B cells and plasma cells were selectively increased in SCD samples. B cell subsets suggested formation of tertiary lymphoid tissue in SCD and compared with NSCD there was an increase in IgG, and a decrease in IgA plasma cells, consistent with their potential role in CD fibrosis. Two Lumican-positive fibroblast subtypes were identified and subclassified based on expression of selectively enriched genes as fibroblast clusters (C) 12 and C9. Cells within these clusters expressed the profibrotic genes Decorin (C12) and JUN (C9). C9 cells expressed ACTA2; ECM genes COL4A1, COL4A2, COL15A1, COL6A3, COL18A1 and ADAMDEC1; LAMB1 and GREM1. GO and KEGG Biological terms showed extracellular matrix and stricture organization associated with C12 and C9, and regulation of WNT pathway genes with C9. Trajectory and differential gene analysis of C12 and C9 identified four sub-clusters. Intra sub-cluster gene analysis detected 13 co-regulated gene modules that aligned along predicted pseudotime trajectories. CXCL14 and ADAMDEC1 were key markers in module 1. Our findings support further investigation of fibroblast heterogeneity and interactions with local and circulating immune cells at earlier time points in fibrosis progression. Breaking these interactions by targeting one or other population may improve therapeutic management for SCD.

UK-wide survey of gastroenterology and hepatology trainees in 2022: endoscopy, workforce planning and the Shape of things to come.

Objective: Shape of Training has shortened the gastroenterology curriculum in the UK from a 5 to 4-year programme. There are ongoing concerns that this will negatively impact training and the attainment of competencies expected at consultant level. We undertook a UK-wide survey of gastroenterology trainees to establish their views. Method: The British Society of Gastroenterology Trainees Section collected anonymised survey responses from trainees between June and September 2022 via an online platform. Results: 40.3% of trainees responded. Strikingly, only 10% of respondents felt they could achieve certificate of completion of training (CCT) within a 4-year programme. Furthermore, 31% were not confident they would attain the required expertise in their subspecialist interest during training. 70.8% reported spending a quarter or more of their training in general internal medicine (GIM) and 71.6% felt this negatively impacted on their gastroenterology training. Only 21.6% of respondents plan to pursue a consultant post with GIM commitments.Regarding endoscopy, only 36.1% of ST7s had provisional and 22.2% full accreditation in colonoscopy. Although 92.3% of respondents wanted exposure to a 'bleed rota', this was the case for only 16.2%. Teaching quality was judged to be insufficient by 45.9% of respondents. Conclusion: Respondents had struggled to achieve the necessary competencies for CCT even prior to the newly reduced 4-year curriculum. While still maintaining service provision, we must safeguard gastroenterology training from encroaching GIM commitments. This will be critical in order to provide capable consultants of the future and prevent UK standards from falling behind internationally.

Epigenetic and metabolic reprogramming of fibroblasts in Crohn's disease strictures reveals histone deacetylases as therapeutic targets.

BACKGROUND & AIMS: No effective therapeutic intervention exists for intestinal fibrosis in Crohn's disease [CD]. We characterised fibroblast subtypes, epigenetic and metabolic changes, and signalling pathways in CD fibrosis to inform future therapeutic strategies. METHODS: We undertook immunohistochemistry, metabolic, signalling pathway and Epigenetic [Transposase-Accessible Chromatin using sequencing] analyses associated with collagen production in CCD-18Co intestinal fibroblasts and primary fibroblasts isolated from stricturing [SCD] and non-stricturing [NSCD] CD small intestine. SCD/ NSCD fibroblasts were cultured with TGFß and valproic acid [VPA]. RESULTS: Stricturing CD was characterised by distinct histone deacetylase [HDAC] expression profiles, particularly HDAC1, HDAC2, and HDAC7. As a proxy for HDAC activity, reduced numbers of H3K27ac+ cells were found in SCD compared to NSCD sections. Primary fibroblasts had increased extracellular lactate [increased glycolytic activity] and intracellular hydroxyproline [increased collagen production] in SCD compared to NSCD cultures. The metabolic effect of TGFß-stimulation was reversed by the HDAC inhibitor VPA. SCD fibroblasts appear "metabolically primed" and responded more strongly to both TGFß and VPA. Treatment with VPA revealed TGFß-dependent and independent Collagen-I production in CCD-18Co cells and primary fibroblasts. VPA altered the epigenetic landscape with reduced chromatin accessibility at the COL1A1 and COL1A2 promoters. CONCLUSIONS: Increased HDAC expression profiles, H3K27ac hypoacetylation, a significant glycolytic phenotype, and metabolic priming, characterise SCD-derived as compared to NSCD fibroblasts. Our results reveal a novel epigenetic component to Collagen-I regulation and TGFß-mediated CD fibrosis. HDAC inhibitor therapy may 'reset' the epigenetic changes associated with fibrosis.

Small-molecule Wnt inhibitors are a potential novel therapy for intestinal fibrosis in Crohns disease.

Intestinal fibrosis and stricture formation is an aggressive complication of Crohns disease (CD), linked to increased morbidity and costs. The present study investigates the contribution of Wingless-Int-1 (Wnt) signalling to intestinal fibrogenesis, considers potential cross-talk between Wnt and transforming growth factor ß1 (TGFß) signalling pathways, and assesses the therapeutic potential of small-molecule Wnt inhibitors. ß-catenin expression was explored by immunohistochemistry (IHC) in formalin-fixed paraffin embedded (FFPE) tissue from patient-matched nonstrictured (NSCD) and strictured (SCD) intestine (n=6 pairs). Functional interactions between Wnt activation, TGFß signalling, and type I collagen (Collagen-I) expression were explored in CCD-18Co cells and primary CD myofibroblast cultures established from surgical resection specimens (n=16) using small-molecule Wnt inhibitors and molecular techniques, including siRNA-mediated gene knockdown, immunofluorescence (IF), Wnt gene expression arrays, and western blotting. Fibrotic SCD tissue was marked by an increase in ß-catenin-positive cells. In vitro, activation of Wnt-ß-catenin signalling increased Collagen-I expression in CCD-18Co cells. Conversely, ICG-001, an inhibitor of ß-catenin signalling, reduced Collagen-I expression in cell lines and primary CD myofibroblasts. TGFß increased ß-catenin protein levels but did not activate canonical Wnt signalling. Rather, TGFß up-regulated WNT5B, a noncanonical Wnt ligand, and the Wnt receptor FZD8, which contributed directly to the up-regulation of Collagen-I through a ß-catenin-independent mechanism. Treatment of CCD-18Co fibroblasts and patient-derived myofibroblasts with the FZD8 inhibitor 3235-0367 reduced extracellular matrix (ECM) expression. Our data highlight small-molecule Wnt inhibitors of both canonical and noncanonical Wnt signalling, as potential antifibrotic drugs to treat SCD intestinal fibrosis. They also highlight the importance of the cross-talk between Wnt and TGFß signalling pathways in CD intestinal fibrosis.

Gastrointestinal consequences of cancer treatment: evaluation of 10 years' experience at a tertiary UK centre.

OBJECTIVE: Up to 90% of patients treated for pelvic cancers experience chronic gastrointestinal (GI) symptoms. This study characterises this patient cohort at a single centre, addressing a paucity of publications reporting 'real-world' experiences. METHOD: Outpatient referrals, from oncology to the gastroenterology and nutrition services, at a tertiary London hospital from 2006 to 2016, were retrospectively identified. Patient characteristics, reported symptoms, investigations, diagnoses, response to therapeutics and follow-up were recorded. RESULTS: Of 269 patients referred, 81% were within the latter 5 years. A total of 260 patients had diagnoses of pelvic cancers (prostatic (52%), cervical (19%) and endometrial (19%)). Among 247 treated with radiotherapy, the median time from radiotherapy to symptom onset was 8 months. Common symptoms were rectal bleeding (51%), diarrhoea (32%), faecal urgency (19%) and pain (19%). Patients underwent a median of three investigations including lower GI endoscopy (86%), thyroid function tests (33%) and glucose hydrogen breath test (30%). Diagnoses included radiation proctopathy (39%), colonic polyps (16%), pelvic floor dysfunction (12%), bile acid malabsorption (BAM) (8%), small intestinal bacterial overgrowth (SIBO) (8%), vitamin D deficiency (7%) and iron deficiency (7%). Among 164 discharged patients, the time to discharge was 7 months, after a median of two appointments. CONCLUSIONS: This unique patient group reports a complex mix of symptoms and requires specialist review and consideration of often uninvestigated diagnoses (pelvic dysfunction, BAM, SIBO and nutritional deficiencies). Such patients are often overlooked, compared with those suffering many other chronic GI disorders. Further reports from non-dedicated centres treating patients with pelvic radiation disease will aid in understanding of secondary GI diagnoses and variation in practice.

UK Patients of Bangladeshi Descent with Crohn's Disease Respond Less Well to TNF Antagonists Than Caucasian Patients.

BACKGROUND: Patients with inflammatory bowel disease are currently managed with the assumption that trial data are applicable to all ethnic groups. Previous studies demonstrate differences in disease severity and phenotype of Asian patients with Crohn's disease (CD), including Bangladeshi Asians within the UK. No study has evaluated the impact of ethnicity on response to anti-TNFs. AIM: Our primary endpoint was a comparison of failure-free survival on first prescribed anti-TNF (anti-tumor necrosis factor) therapy in UK Bangladeshi and Caucasian patients with CD. Our secondary aims were to evaluate disease phenotype, indication for anti-TNF prescription, and duration from diagnosis until first anti-TNF prescribed between groups. METHODS: The records of consecutive outpatient appointments over a 12-month period were used to identify Caucasian and Bangladeshi patients prescribed an anti-TNF for CD. Information on patient demographics, ethnicity, disease phenotype, immunomodulator use, outcome from first biologic, duration of therapy, and reason for cessation was recorded. RESULTS: In total, 224 Caucasian and Bangladeshi patients were prescribed an anti-TNF for CD. Bangladeshi patients started an anti-TNF 4.3 years earlier after diagnosis than Caucasian patients (3.9 years vs. 8.2 years: p < 0.01). Bangladeshi patients experienced shorter failure-free survival than Caucasian patients (1.8 vs. 4.8 years p < 0.01). By 2 years, significantly more Bangladeshi patients had stopped anti-TNF due to loss of response (OR 6.35, p < 0.01). CONCLUSIONS: This is the first study to suggest that Bangladeshi patients resident in the UK with CD respond less well to treatment with TNF antagonists than Caucasian patients.

The destructive combination of Scediosporium apiosperum lung disease and exuberant inflammation in cystic fibrosis.

This paper describes a patient whose decline over two years was precipitous, from an active independent life with lung function (FEV1) above 50% to requiring transplantation. The main pathogen on sputum culture throughout that period was Scediosporium apiosperum. The epidemiology pathogenicity and treatment of this fungal pathogen are discussed.