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.

Matching-Adjusted Indirect Comparisons of Filgotinib vs Vedolizumab, Tofacitinib, and Ustekinumab for Moderately to Severely Active Ulcerative Colitis.

BACKGROUND: Where head-to-head trials are lacking, indirect comparative effectiveness can aid treatment decisions. We conducted matching-adjusted indirect comparisons of clinical outcomes with filgotinib vs recently approved comparators (vedolizumab, tofacitinib, ustekinumab) in patients with moderately to severely active ulcerative colitis (UC). METHODS: Individual patient data from the SELECTION trial (NCT02914522) for filgotinib 200 mg were weighted to match average baseline characteristics of active treatment and placebo arms in comparator trials. Efficacy outcomes were compared for biologic-naive and biologic-experienced subgroups in induction and maintenance populations, if data were available. Safety and health-related quality of life outcomes were compared in the overall maintenance population. RESULTS: Filgotinib had a similar effect on efficacy outcomes compared with tofacitinib, ustekinumab, and subcutaneous vedolizumab in both the induction and maintenance populations. Filgotinib showed improved clinical response vs intravenous (IV) vedolizumab (odds ratio, 2.4; 95% confidence interval [CI], 1.0 to 5.5; P < .05) among the biologic-experienced induction population, and improved corticosteroid-free clinical remission (odds ratio, 15.2; 95% CI, 1.6 to 139.9; P < .05) among the biologic-naive maintenance population. Improved efficacy outcomes were reported with filgotinib compared with ustekinumab among the maintenance population. Higher estimates of serious adverse events were reported for filgotinib compared with vedolizumab IV 300 mg and tofacitinib 5 mg; however, imbalances were noted in their placebo groups. Health-related quality of life outcomes were similar between filgotinib and comparators. CONCLUSIONS: Matching-adjusted indirect comparison results suggest superiority of filgotinib 200 mg over vedolizumab IV in terms of clinical response and corticosteroid-free clinical remission in certain patient populations, noting small sample sizes and wide CIs, which may aid the selection of advanced therapies for moderately to severely active UC. A potential increased risk of serious adverse events was reported for filgotinib 200 mg vs vedolizumab IV and tofacitinib 5 mg, but findings should be interpreted with caution owing to underlying imbalances observed between the placebo groups of SELECTION and comparator trials.

Matching-adjusted indirect comparisons between filgotinib and subcutaneous vedolizumab, tofacitinib, and ustekinumab demonstrated similar effects on efficacy, safety, and health-related quality of life in patients with ulcerative colitis. Clinical response and corticosteroid-free remission were improved with filgotinib compared with intravenous vedolizumab.

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.

Epithelial down-regulation of the miR-200 family in fibrostenosing Crohn's disease is associated with features of epithelial to mesenchymal transition.

Intestinal mesenchymal cells deposit extracellular matrix in fibrotic Crohn's disease (CD). The contribution of epithelial to mesenchymal transition (EMT) to the mesenchymal cell pool in CD fibrosis remains obscure. The miR-200 family regulates fibrosis-related EMT in organs other than the gut. E-cadherin, cytokeratin-18 and vimentin expression was assessed using immunohistochemistry on paired strictured (SCD) and non-strictured (NSCD) ileal CD resections and correlated with fibrosis grade. MiR-200 expression was measured in paired SCD and NSCD tissue compartments using laser capture microdissection and RT-qPCR. Serum miR-200 expression was also measured in healthy controls and CD patients with stricturing and non-stricturing phenotypes. Extra-epithelial cytokeratin-18 staining and vimentin-positive epithelial staining were significantly greater in SCD samples (P = 0.04 and P = 0.03, respectively). Cytokeratin-18 staining correlated positively with subserosal fibrosis (P < 0.001). Four miR-200 family members were down-regulated in fresh SCD samples (miR-141, P = 0.002; miR-200a, P = 0.002; miR-200c, P = 0.001; miR-429; P = 0.004); miR-200 down-regulation in SCD tissue was localised to the epithelium (P = 0.001-0.015). The miR-200 target ZEB1 was up-regulated in SCD samples (P = 0.035). No difference in serum expression between patient groups was observed. Together, these observations suggest the presence of EMT in CD strictures and implicate the miR-200 family as regulators. Functional studies to prove this relationship are now warranted.