Gut

Objectives: The Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet has been associated with the risk of IBD, but its impact on clinical outcomes is uncertain. This study evaluated the association between MIND diet adherence and the risk of IBD-related surgery in a prospective cohort. Methods: This study included 2,288 participants with diagnosis of Crohn's disease (CD, n=777) or ulcerative colitis (UC, n=1,511) who completed valid WebQ 24-hour dietary recall from the UK Biobank. Dietary adherence was derived from a 15-component score based on 24-hour dietary recalls. Associations with IBD-related surgery were evaluated using Cox proportional hazards models, with nonlinear trends and examined via restricted cubic splines. Effect modification was explored in pre-specified subgroups, and multiple sensitivity analyses were conducted to assess robustness. Results: During 10.9 years of follow-up, 166 incident IBD-related surgery cases occurred. Higher MIND diet adherence was associated with reduced surgical risk. Compared with the lowest tertile of adherence, the highest tertile showed a 36% reduction in surgical risk in IBD (HR 0.64, 95% CI: 0.44-0.94, P = 0.024). Notably, this protective effect was pronounced in patients with CD, exhibiting a clear linear inverse association. In contrast, a reverse J-shaped association was observed in UC, with a steep initial decline in surgical risk followed by a plateau emerging at a MIND score of approximately 5, beyond which further adherence conferred minimal additional benefit. At the component level, higher vegetable consumption and lower intake of butter and fried foods were identified as independent protective factors against surgery. Stronger inverse associations were observed among patients with shorter disease duration and those with complicated disease behavior, including stricturing or penetrating phenotypes (all P interaction < 0.05). Conclusion: Greater MIND diet adherence is associated with reduced IBD-related surgery risk among patients with IBD and CD. These findings support the MIND diet as a feasible dietary strategy to improve IBD prognosis.

Background & Aims: ACLF is defined differently by APASL (acute hepatic dysfunction) and by organ failure-based frameworks including EASL-CLIF and the recently developed A-TANGO score. Whether these definitions identify competing populations or sequential stages of the same syndrome remains unresolved, with direct implications for the timing of intervention. We tested whether APASL-defined ACLF can be integrated into the A-TANGO framework to identify a clinically actionable patient population. Methods: 4,024 patients hospitalised with acute decompensation of cirrhosis in a multicentre cohort were classified simultaneously by APASL and A-TANGO criteria. Mortality, progression to A-TANGO ACLF among A-TANGO-negative patients, and reversal of ACLF were assessed using Fine-Gray competing-risk models with death as a competing event. EASL-CLIF analyses were performed as sensitivity analyses. Results: A-TANGO-negative/APASL-positive patients comprised 8.7% of the cohort and had higher 90-day mortality than A-TANGO-negative/APASL-negative patients (22.3% vs 14.4%, p=0.001), despite similar 28-day mortality. Once A-TANGO ACLF was established, 28-day mortality was high irrespective of APASL status (45.4% in APASL-positive and 56.0% in APASL-negative patients). Among A-TANGO-negative patients, 53.5% of APASL-positive vs 27.9% of APASL-negative patients progressed to A-TANGO ACLF within 28 days, with APASL positivity independently predicting progression (adjusted sHR: 2.30, 95%CI: 1.90-2.77). Within A-TANGO-negative/APASL-negative patients an A-TANGO OF score [&ge;]8 independently enriched for progression (52% vs 19%). A-TANGO reversal occurred in 17.1% and was independently reduced by APASL positivity (adjusted sHR: 0.756, 95%CI: 0.586-0.975), while APASL reversal was rare (4.0%). EASL-CLIF sensitivity analyses were directionally consistent. Conclusions: APASL-defined ACLF does not compete with A-TANGO; it occupies an upstream position on the same disease trajectory. A-TANGO-negative/APASL-positive patients and A-TANGO-negative/APASL-negative patients with A-TANGO OF [&ge;]8 represent complementary pre-ACLF populations suitable for prevention trials and enrichment strategies.

BackgroundVedolizumab, a gut-selective anti-integrin therapy, is effective in IBD, but response rates remain variable. Conventional clinical and biochemical markers, including C-reactive protein and faecal calprotectin, have limited predictive value. Although recent transcriptomic studies have implicated T-cell-related signatures in predicting vedolizumab response, these findings lack validation across independent cohorts. MethodsWe analyzed pre-treatment transcriptomic profiles from whole blood and T-cell subsets across five independent cohorts comprising 100 patients with UC and CD. The primary outcome was clinical response. Secondary outcomes included clinical and biochemical remission. ResultsAmong the 100 patients, 61 were responders and 39 non-responders, with no significant baseline clinical differences. Gene set enrichment analyses revealed downregulation of interferon alpha and gamma signalling in responders baseline blood samples, a finding validated across independent cohorts. Downregulated interferon signalling at baseline was also observed in patients who achieved clinical and biochemical remission. To build a predictive model, an adaptive elastic net logistic regression model was applied to baseline whole-blood RNA-sequencing data. The classifier achieved an AUC of 1.0 in training, 0.71-0.83 in UC validation cohorts, and 0.64-1.0 in CD cohorts. Reduced interferon signalling was observed across CD4{square} and CD8{square} T-cell subsets, including regulatory T cells, suggesting a broad immune signature rather than cell-type specificity. ConclusionsDownregulated interferon signalling in peripheral blood prior to treatment is a reproducible molecular signature predictive of vedolizumab response and biochemical remission. Whole-blood transcriptomics revealed a robust interferon-axis signal that predicted vedolizumab response across independent cohorts, with stronger performance in UC than CD. Given heterogeneous clinical endpoints and assessment windows, these data provide proof-of-concept that warrants validation with standardised, endoscopy-based outcomes.

Background: Alpha-1 antitrypsin deficiency (AATD) caused by the PI*ZZ mutation (Glu342Lys) results in hepatic accumulation of misfolded AAT-Z protein and reduced circulating AAT levels, leading to progressive liver disease and emphysema. Gene correction therapy represents a potentially curative approach by directly correcting the underlying genetic defect. We report the first case of successful hepatic gene correction with early histological and functional assessment. Methods/Case presentation: We report the case of a 66-year-old male patient with PI*ZZ AATD who underwent gene correction therapy within the YOLT-202 phase I/Ia clinical trial (clinical trial.gov ID NCT07193615). Ten weeks post treatment a liver biopsy was performed to re-evaluate pre-existing F2 liver fibrosis as measured by elastography before entering the study. Serum samples allowed functional assessment of the AAT-mediated elastase inhibition. Results: Liver biopsy did not show signs of hepatic inflammation and demonstrated 54% (Sanger) and 57% (Illumina) gene correction rate of the PI*ZZ variant on the DNA level with no bystander edits or off-target effects. Following a transient elevation of transaminases during the early post-treatment period, liver enzymes normalized. Monthly serum AAT measurements demonstrated biologically active and stable therapeutic levels throughout follow-up. Conclusions: This case demonstrates efficient and precise hepatic gene correction without concerning histological alterations and with substantial improvement of functional parameters, supporting the feasibility and safety of gene editing approaches for AATD.

Background & AimsCeliac disease (CeD) is an autoimmune disorder triggered by dietary gluten in genetically predisposed individuals, but environmental factors contributing to disease onset remain incompletely defined. Epidemiological studies implicate enterovirus infections as potential triggers. Here, we investigated the epithelial-intrinsic mechanisms by which coxsackievirus B1 (CVB1) infection may prime the intestine for CeD. MethodsHuman intestinal organoids were infected with CVB1 and analyzed using single-cell RNA sequencing to resolve lineage-specific responses. Interferon signaling and transglutaminase 2 (TG2) regulation were interrogated using type I interferon stimulation and pharmacologic JAK inhibition. ResultsCVB1 infection induced a robust epithelial antiviral program dominated by type I interferon signaling. This response was accompanied by marked upregulation of TG2 expression and enzymatic activity. Single-cell analysis localized TG2 induction to immature goblet-lineage cells, which exhibited strong interferon-stimulated gene activation and epithelial stress signatures. Mechanistically, IFN-/{beta} stimulation was sufficient to induce TG2 via JAK-STAT signaling, while JAK inhibition effectively suppressed both TG2 expression and activity. In parallel, CVB1 infection triggered coordinated mucin remodeling, including induction of MUC5AC, indicating interferon-linked epithelial reprogramming. Notably, these effects occurred independently of immune cell involvement, highlighting a cell-intrinsic pathway. ConclusionOur findings identify a direct epithelial mechanism linking enterovirus infection to TG2 activation via interferon-driven JAK-STAT signaling. This pathway provides a mechanistic bridge between viral infection and gluten peptide modification, a critical step in the onset of CeD. The reversibility of TG2 induction by JAK inhibition suggests a potential strategy to prevent virus-mediated priming of celiac disease.

Background and Aims: Diet plays a critical role in managing Crohns disease (CD) inflammation. We assessed whether dietary replacement of animal protein (AnimalP) by soy-pea protein (SoyP) decreases the pro-inflammatory potential of gut microbiota and intestinal inflammation in CD patients. Design: In an open-label, randomized controlled feeding trial at University Hospitals Cleveland Medical Center, CD participants and healthy controls were randomized (1:1) to a soy-pea or animal protein diet for 7-days. Primary outcomes were the absolute difference (d7-d0) in; Crohns Disease Activity Index (CDAI) score and fecal myeloperoxidase (MPO). Secondary outcomes included fecal calprotectin (FC) and high-sensitivity C-reactive protein (hsCRP). Murine fecal transplantation experiments were performed to determine the inflammatory potential of diet-altered gut microbiota. Results: The study randomized 66 participants and 60 were included in the final analysis (n=31 CD, n=29 HC). After 7 days, CD-SoyP participants were more likely than CD-AnimalP to show reductions in HBI (RR=4.68, 95% CI: 1.22-17.98, P=0.009) and fecal MPO (RR=2.30, 95% CI: 1.04-4.85, P=0.032), with a similar directional trend for CDAI (RR=1.52, 95% CI: 0.89-2.58, P=0.135). No participants experienced worsening of CDAI. The rank-based composite CDAI-MPO score was lower in the CD-SoyP vs CD-AnimalP group (median [IQR]: 5 [4-6] vs 8 [7-9]; P=0.012). Stratified analyses showed significant reductions in fecal MPO among CD participants with lower baseline disease activity (CDAI <150; P<0.0001), but not in those with higher activity (P=0.799) Conclusion: Short-term addition of plant-based soy-pea protein within a controlled diet exerted a beneficial, anti-inflammatory effect in CD, with evidence of greater effects among participants with lower baseline disease activity. ClinicalTrials.gov, Number NCT04065048.

Background Gastric cancer management is heterogeneous, and although the treating surgeon leads decisions across the pathway, surgeon level outcome variation remains poorly quantified. This study assessed surgeon identity as an independent predictor of survival after risk adjustment, introducing the Surgical Assessment and Healthcare (SAH) Index. Methods This single institution retrospective study (Ruijin Hospital, Shanghai Jiao Tong University; NCT07180966) included 692 patients undergoing curative-intent resection for gastric adenocarcinoma (pStage I ,II, III) in 2019 by eight consultant surgeons. Overall survival was modelled by multivariable Cox regression (primary model, 199 events, EPV 16.6; complete-case sensitivity model, N = 647). The SAH Index expressed surgeon * stage observed-to-expected ratios for five-year mortality and major morbidity (Clavien Dindo [&ge;] IIIa). Median follow up was 74.3 months. Results Independent predictors of survival were tumour stage (HR 2.979/step), age (HR 1.030/year), and non-distal gastrectomy (HR 1.498; all p [&le;] .006). After full adjustment, surgeon identity remained significant (Wald = 14.58, df = 7, p = .042): two surgeons carried roughly double the reference hazard S6 (HR 2.219, p = .003) and S8 (HR 2.034, p = .031) both with the cohort's lowest neoadjuvant chemotherapy rates (3.0% and 7.0% versus 17.6%), implicating pre-operative pathway decisions. The effect persisted in the sensitivity model (MSI also prognostic, HR 3.162, p = .007). Morbidity benchmarking flagged no surgeon for excess complications (no Tier 2 flags) and one survival-outlier cell (S6, Stage II; Tier 3). Conclusion Surgeon identity is independently associated with survival in gastric cancer beyond measurable case mix. The SAH Index offers a reproducible tool for institutional and inter-hospital benchmarking, with tier assignments stable across all four prespecified weighting scenarios confirming tier classification is independent of weight specification.

Background & AimsPrimary sclerosing cholangitis (PSC) is a progressive cholangiopathy characterized by ductular remodeling, inflammation, and periportal fibrosis, for which effective medical therapies remain limited. The Hippo pathway effector TEAD1 has been implicated in liver regeneration and fibrogenesis; however, its role in cholestatic injury remains poorly defined. We investigated whether hepatocyte TEAD1 regulates injury-associated remodeling in a PSC-mimicking model and whether this mechanism is conserved in human PSC liver. MethodsHepatocyte-specific TEAD1 knockout mice (Alb-TEAD1-/-) and littermate controls were subjected to DDC-induced cholestatic injury. Ductular reaction, fibrosis, inflammation, and bile acid-related gene programs were assessed by histology, immunostaining, and gene expression analyses. Translational relevance was evaluated using bulk and single-cell transcriptomic datasets from human PSC liver. ResultsHepatocyte TEAD1 deletion attenuated DDC-induced fibrosis, ductular expansion, and inflammatory cell accumulation, while preserving hepatocyte proliferative responses. TEAD1-deficient livers exhibited reduced expression of profibrotic mediators, including Spp1, Ctgf, and Cyr61, with decreased extracellular matrix deposition. In contrast, canonical transcriptional adaptations to cholestatic stress, including suppression of bile acid uptake, induction of efflux pathways, and repression of bile acid synthesis genes, were preserved in the absence of TEAD1. Analysis of human PSC datasets demonstrated coordinated upregulation of TEAD1 and TEAD-associated target genes. Single-cell transcriptomic analysis further revealed hepatocyte-enriched TEAD1 expression and activation of a TEAD1 target gene program across all hepatic zones in PSC, with effect sizes exceeding those observed in non-parenchymal populations. TEAD1 activation was accompanied by co-expression of profibrotic mediators and downregulation of hepatocyte differentiation markers, consistent with a maladaptive hepatocyte state. ConclusionsHepatocyte TEAD1 drives ductular, inflammatory, and fibrogenic remodeling during cholestatic injury without disrupting bile acid metabolic adaptation. These findings identify TEAD1 as a hepatocyte-intrinsic regulator of epithelial-stromal crosstalk and establish conserved activation of this pathway in human PSC, supporting TEAD-directed signaling as a therapeutic target.

Durable therapeutic efficacy remains a major barrier to improving outcomes for patients with pancreatic ductal adenocarcinoma (PDAC). An immunosuppressive tumor microenvironment (TME) is a hallmark of PDAC and has been demonstrated to be a dominant driver of therapeutic resistance. The aberrant glycan CA19-9 is prevalent in PDAC and drives tumor progression, but the paracrine mechanisms by which it contributes to TME remodeling are unknown. To address this, we mapped TME changes and performed functional analyses using a genetically engineered mouse model (GEMM) harboring KrasG12D mutation and inducible CA19-9 expression. Elevation of CA19-9 led to expansion of antigen-presenting cancer associated fibroblasts (apCAFs) and regulatory T cells (Tregs), which can drive immunosuppression. Antibody blockade of CA19 -9 resulted in significant restoration of normal histology and decreased apCAF and Treg populations. We dissected the paracrine signaling mechanisms that drive this TME remodeling in vitro using mouse and human organoid mono- and co-culture models as well as in vivo using GEMMs and syngeneic orthotopic transplantation models. CA19-9 induced IL1a and TGFb expression, reprogramming pancreatic mesothelial cells into apCAFs in vitro, which in turn directly ligated naive Cd4+ T cells resulting in Treg differentiation in co-cultures. Antibody blockade of IL1a and TGFb in mice led to reduced apCAF and Treg differentiation. We previously reported that CA19-9 modification of the secreted Fbln3 protein increased Egfr engagement and now find that the induction of IL1a and TGFb expression by CA19-9 is dependent on Fbln3 hyperactivation of EGFR signaling. Genetic depletion of Fbln3 led to reduced tumor progression and increased Cd8+ T cell infiltration in mice. Together these findings identify a previously unknown signaling axis driving immunosuppressive phenotypes in PDAC, uncovering multiple potential nodes to relieve the immunosuppressive pressures within the PDAC TME.

Patients with gastric intestinal metaplasia (GIM), a precancerous lesion, are at high risk for progressing to gastric cancer. Identifying these patients is critical to enable gastric cancer interception. Current approaches rely primarily on histologic evaluation of GIM severity and extent, which may be improved by incorporating molecular features that distinguish high-risk lesions. Our prior single-cell and spatial transcriptomics study identified differentially expressed genes associated with the highest-risk category of GIM. They included ANPEP expressed in enterocytes and CPS1 and OLFM4 expressed in intestinal stem-like or progenitor cells. We evaluated the protein expression and localization of these three markers to understand the cellular features associated with GIM risk and their spatial distribution within metaplastic tissues. Using multiplex immunofluorescence, whole slide image analysis and confocal microscopy, we examined protein expression from 100 tissue biopsies annotated for metaplasia severity using the Operative Link on Gastric Intestinal Metaplasia Assessment (OLGIM) system. Tissue samples included control gastric tissue, GIM, dysplasia and adenocarcinoma. Quantitative whole slide image analysis demonstrated that CPS1 expression had a modest association with disease severity. Although ANPEP was strongly associated with GIM severity, it was also frequently expressed in stromal regions outside epithelial glands. In contrast, OLFM4 expression was largely restricted to epithelial glands and showed a strong association with increased OLGIM severity. These OLFM4-positive epithelial cells were present in discrete glandular foci that expanded with increasing severity of metaplasia. Within individual metaplastic glands, OLFM4 expression was highest at the gland base with decreased expression toward the gland surface. Overall, these findings identified OLFM4 as a protein marker associated with high-risk GIM. The spatial organization of OLFM4-expressing cells at the base of metaplastic glands and their focal expansion within tissues suggest the presence of a stem cell-like epithelial compartment that may contribute to the progression of GIM towards gastric cancer.

BACKGROUNDPatients with inflammatory bowel disease (IBD) are at increased risk of cardiovascular disease, yet the mechanisms linking chronic intestinal inflammation to cardiac dysfunction remain poorly understood. IBD is characterized by profound gut microbiota dysbiosis, which we hypothesize drives systemic immune dysregulation and contributes to cardiac dysfunction. METHODSA chronic colitis mouse model was used to assess gut microbiota dysbiosis, systemic immune cell metabolism, and cardiac remodeling. Cardiac outcomes were evaluated by echocardiography, histology, and molecular analyses. Mechanisms were examined using fecal microbiota transplantation, immune cell depletion, exosome transfer, bone marrow chimeras, RNA-seq, co-immunoprecipitation, confocal microscopy, and siRNA-mediated gene silencing. RESULTSChronic DSS colitis induced cardiac dysfunction, hypertrophy, and fibrosis in mice. These changes were accompanied by sustained gut microbiota dysbiosis, metabolic reprogramming, and mitochondrial dysfunction in circulating immune cells. Fecal microbiota transfer experiments demonstrated that colitis-associated microbiota were sufficient to reprogram systemic immune cells and promote cardiac dysfunction. Immune cell depletion studies identified macrophages as key mediators of colitis-associated cardiac injury. Colitis increased systemic lipopolysaccharide (LPS) translocation, bone marrow chimera experiments demonstrated that hematopoietic TLR4 signaling was required for immune cell metabolic remodeling and cardiac dysfunction during chronic colitis. Transcriptomic analysis identified guanylate-binding protein 2b (GBP2b/GBP1, hereafter referred to as GBP1) as a key downstream effector of LPS-TLR4 signaling. Upon LPS stimulation, GBP1 localized to mitochondria, where it interacted with DRP1 and FIS1 to promote mitochondrial fission, oxidative stress, and enhanced immune cell migration into the heart. In addition, GBP1 was secreted via exosomes, which were taken up by cardiomyocytes and contributed to hypertrophic remodeling, and cardiac dysfunction. CONCLUSIONSThese findings establish the LPS-TLR4-GBP1 axis as a key driver of colitis-associated cardiovascular dysfunction and highlight this pathway as a promising therapeutic target for reducing cardiovascular risk in patients with IBD. Novelty and SignificanceO_ST_ABSWhat Is Known?C_ST_ABSO_LIPatients with inflammatory bowel disease have an increased risk of cardiovascular dysfunction that cannot be fully explained by traditional cardiovascular risk factors. C_LIO_LIGut microbiota dysbiosis and chronic innate immune activation are hallmarks of inflammatory bowel disease, but their direct contribution to cardiac remodeling remains unclear. C_LI What New Information Does This Article Contribute?O_LIChronic colitis-associated gut microbiota dysbiosis induces systemic immune cell metabolic and mitochondrial reprogramming that is sufficient to drive cardiomyocyte hypertrophy and cardiac dysfunction. C_LIO_LIHematopoietic Toll-like receptor 4 signaling links colitis associated gut microbiota to immune metabolic dysfunction and cardiac impairment, establishing a causal gut-immune-heart axis. C_LIO_LIGuanylate-binding protein 2b (GBP2b/GBP1) is identified as a critical downstream effector that promotes mitochondrial fission, oxidative stress, immune cell cardiac infiltration, and exosome-mediated cardiac remodeling. C_LI

Background Recent mouse model data demonstrate that chronic colonization with toxigenic Clostridioides difficile promotes colonic tumorigenesis via intraluminal toxin B (TcdB), its main virulence factor. In a prior multisite hospital cohort, we found that history of positive tcdB stool testing was associated with increased CRC risk in a dose-dependent manner, though limited by small sample size. We aimed to validate this association in a larger cohort with extended follow-up and greater geographic distribution using the Veterans Health Administration (VHA) Corporate Data Warehouse (CDW). Methods We conducted a retrospective cohort study among adults receiving care through the VA from 2000-2025 who underwent C. difficile testing. Data collected from the VHA CDW and National Death Index (NDI) included demographics, comorbidities, medications, CRC risk factors, and cancer incidence and death. The first C. difficile test date defined cohort entry; individuals with prior CRC were excluded. Ever C. difficile positivity was defined by a positive PCR or EIA results. The number of positive tests (episodes) was also determined to define recurrent positivity. Follow-up time ended at the first occurrence of CRC incidence or mortality, death from other causes, or censor date. Follow-up time was split for individuals who converted from negative to positive, with follow-up time updated accordingly. Multivariable Cox proportional hazards models were used to estimate hazard ratios (HRs) for C. difficile exposure and CRC incidence and mortality after adjustment for confounders. Tests for linear trend and tests for interaction were conducted to assess effect modification by sex and IBD status, while time-lag intervals were evaluated for 1, 3, 5, and 10 years before the outcome. Results Among 806,844 veterans with C. difficile testing, those with positive tests were more likely to be older, male, to have diabetes, to use aspirin, and to have a lower BMI than those with negative tests. Race and IBD prevalence were similar between the groups. There was no overall association between ever C. difficile positivity and CRC incidence (HR = 0.99, 95% CI 0.93-1.05). However, recurrent C. difficile positivity was associated with increased risk in a dose-response manner [2-3 episodes HR = 1.30 (95% CI 1.16-1.47), and >3 episodes HR = 1.58 (95% CI 1.17-2.14) compared to negative tests; ptrend< 0.001]. Further, ever C. difficile positivity was associated with increased CRC mortality risk (HR = 1.21, 95% CI 1.13-1.30; p < 0.001). Recurrent C. difficile positivity was associated with increased mortality risk but was particularly strong for those with >3 episodes among individuals with IBD (HR=3.84, 95% CI 1.98-7.45). In sensitivity analyses, the increased risk of CRC incidence and mortality attenuated beyond 10 years. Conclusion Prior positive C. difficile testing was associated with increased CRC incidence and mortality in a dose-dependent manner, particularly among patients with IBD. These findings extend animal model evidence, epidemiologically establishing C. difficile presence as an independent risk factor for subsequent colorectal tumorigenesis and supporting investigation into recurrent CDI, especially among patients with IBD, as a potential modifiable CRC risk factor.

Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest cancers, with limited treatment options and poor survival rates. It is characterised by strong driver mutations, epigenetic reprogramming, and a dense tumour microenvironment (TME). A defining feature of the PDAC TME is its fibrotic stroma, which is largely composed of cancer-associated fibroblasts (CAFs). Distinct CAF populations have been implicated in PDAC progression, but the mechanisms that govern their crosstalk with the cancer cells are poorly understood. We generated genetically engineered pancreatic stellate cells (PSCs) modelling interleukin-1 (IL-1)-dependent inflammatory CAFs (iCAFs) and transforming growth factor-{beta} (TGF-{beta})-dependent myofibroblastic CAFs (myCAFs) to investigate how distinct stromal populations shape the epigenetic landscape of pancreatic ductal adenocarcinoma (PDAC). We found that iCAFs, but not myCAFs, promoted gemcitabine resistance in epithelial tumour cells and identified STAT1 as a critical mediator of iCAF-tumour cell crosstalk. Mechanistically, STAT1 drove the induction of interferon (IFN)-responsive genes, while blockade of IFN-{beta} attenuated iCAF-mediated transcriptional reprogramming. Genetic ablation of STAT1 in tumour cells abolished iCAF-induced chemoresistance and associated transcriptional changes. In an orthotopic in vivo model, STAT1 knockout significantly prolonged survival following gemcitabine treatment, supporting a central role for STAT1 signalling in stromal-driven therapy resistance. We provide a comprehensive analysis on how IL-1-dependent iCAFs contribute to epigenetic reprogramming in PDAC and uncover a previously undescribed role for STAT1 in stromal-epithelial interactions. These findings reveal distinct, non-overlapping mechanisms by which CAF subtypes modulate tumour behaviour and identify STAT1 as a therapeutic vulnerability that can be exploited to sensitise PDAC to standard chemotherapy. Significance statementThis study establishes that the epigenetic landscape of PDAC is differentially shaped by iCAF- and myCAF-like PSCs and defines STAT1 as a mediator of iCAF-induced chemoresistance and transcriptional reprogramming. We demonstrate that genetic ablation of STAT1 sensitises tumours to gemcitabine in vivo, extending survival and positioning STAT1 as an actionable target to overcome stromal-mediated therapy resistance in PDAC.

ABSTRACTGATA6 and GATA4 play key roles in pancreatic development and are essential to maintain the classical transcriptional program in pancreatic ductal adenocarcinoma (PDAC). Using genetic mouse models we show that, in contrast to GATA6, GATA4 is dispensable for the maintenance of acinar homeostasis in the adult pancreas. Deletion of Gata4 in mice expressing mutant Kras in the embryonic pancreas (KG4C) leads to PDAC development in the absence of tissue remodeling, pancreatic intraepithelial neoplasia (PanIN), or other canonical precursor lesions present in Gata4-proficient (KC) mice. Similar observations were made when Gata4 was selectively inactivated in adult, Kras-mutant, acinar cells. We identify Pale Acinar Lesions (PALes) as a previously unrecognized pancreatic lesion, distinct from acino-ductal metaplasia (ADM) and PanINs, present in KC and KG4C mice but not in wild type mice. PALes display weak expression of acinar and ductal markers and lack mucins; they have lower proliferation rates than PanINs. RNA-seq and ChIP-seq reveal that GATA4 and GATA6 partially share genomic binding sites and transcriptomic effects, but they exert opposing influences on mutant Kras-induced, haematopoietic cell-dependent, transcriptional inflammatory programs. Adenoviral-mediated pancreatic expression of IL17 restored the formation of ductal lesions in KG4C mice but failed to rescue PanIN development. Our data indicate that GATA4 functions through the coordinated action of multiple inflammatory factors that are required for ADM/PanIN formation but are dispensable for PDAC development. Collectively, these findings challenge current paradigms of PDAC initiation and progression.

BackgroundCTLA-4 haploinsufficiency (CHAI) and LRBA deficiency cause severe immune dysregulation including enteropathy. Abatacept, a CTLA-4-immunoglobulin fusion protein, targets the underlying pathway defect, but its impact on the gut microbiome remains undefined. MethodsWe performed longitudinal shotgun metagenomics (MetaPhlAn4/HUMAnN3) on stool samples from patients enrolled in the ABACHAI clinical trial, collected at pre-treatment baseline and months 3, 6, and 12. Healthy individuals from the same household served as controls. Compositional and functional microbiome changes were analyzed using linear mixed-effects models and MaAsLin3, and correlated with organ-specific CHAI Morbidity Scores. ResultsAt baseline, patients showed significantly reduced alpha diversity (Shannon index, p=0.0029) and distinct community composition (PERMANOVA p=0.0001) compared to healthy controls, characterised by enrichment of oral-associated taxa (Veillonella, Streptococcus, Lacrimispora) and depletion of butyrate-producing commensals (Ruminococcus, Oscillibacter, Dysosmobacter). Functionally, the baseline metagenome exhibited broad reductions in amino acid and SCFA biosynthesis alongside enrichment of purine salvage and folate pathways. During treatment, beta diversity shifted significantly with treatment duration (Aitchison PERMANOVA R2=0.103, p=0.015), with within-patient community turnover peaking at month 6 ({Delta}=0.216, p=0.006). Longitudinal analyses demonstrated progressive decreases in disease-enriched taxa (Veillonella, Lacrimispora) and recovery of commensals (Collinsella, Adlercreutzia). FDR-significant reductions in microbial folate and purine biosynthesis pathways were observed over the treatment course. Gut CHAI domain severity correlated inversely with butyrate-producer abundance and positively with oral taxon enrichment. ConclusionIn CTLA-4 pathway insufficiency patients, abatacept therapy is associated with an improvement of enteropathy and a progressive, measurable gut microbiome restructuring, positioning microbiome dynamics as a candidate biomarker of treatment response in this monogenic immune dysregulation disorder.

Background & AimsHepatocellular carcinoma (HCC) frequently exhibits resistance to immune checkpoint inhibitors (ICIs), particularly in {beta} -catenin-driven tumors characterized by immune exclusion. While the Unfolded Protein Response (UPR) and the Integrated Stress Responses (ISR) enable tumor adaptation to metabolic stress their role in shaping tumor immunogenicity remains incompletely understood. We investigated whether ATF4, a central effector of the integrated stress response, couples metabolic reprogramming to suppression of anti-tumor immunity in HCC. MethodsWe combined transcriptomic analyses across three independent human HCC cohorts with mechanistic studies using an immunotherapy-resistant MYC/{beta}-catenin-driven murine HCC model. We integrated CRISPR/Cas9-mediated deletion of Atf4 with RNA-sequencing and targeted metabolomics. The impact of tumor-derived metabolites on macrophage differentiation and polarization was evaluated using primary bone marrow-derived cells. Therapeutic responses were evaluated in orthotopic and subcutaneous models treated with anti-PD-1 and anti-VEGFA. ResultsATF4 and XBP1 transcriptional signatures are selectively enriched in human HCC and associate with poor prognosis, vascular invasion, and an immunosuppressive myeloid-enriched tumor microenvironment. Genetic ablation of Atf4 markedly suppressed tumor growth in immunocompetent but not immunodeficient hosts, establishing a requirement for immune-mediated tumor control. Mechanistically, Atf4 loss downregulated Aldh18a1 and disrupted proline biosynthesis, resulting in extracellular proline depletion. This proline-deficient environment abrogated monocyte-to-macrophage differentiation and decreased M2 polarization, thereby reshaping the tumor microenvironment toward enhanced T cell infiltration and activation. Functionally, Atf4-deficient tumors exhibited restored sensitivity to anti-PD-1 monotherapy and showed pronounced responses to combined anti-PD-1/anti-VEGFA treatment in aggressive orthotopic models. ConclusionATF4 programs a proline-dependent metabolic axis that sustains macrophage-mediated immunosuppression and immune evasion in {beta}-catenin-driven HCC. Disruption of this pathway converts immune-excluded tumors into T cell-inflamed states and restores responsiveness to immunotherapy. By governing proline homeostasis and macrophage-mediated immunosuppression, ATF4 is a key metabolic checkpoint for immune evasion, linking stress adaptation to immune escape and a candidate therapeutic target in HCC. Impact and implicationsWe identify ATF4 as a crucial metabolic-immune orchestrator that sustains myeloid-driven immune evasion in {beta}-catenin-dependent HCC through proline-dependent circuitry. Disrupting the ATF4-proline axis converts immune-desert tumors into T cell-inflamed lesions by blocking macrophage differentiation, thereby sensitizing tumors to immune checkpoint therapy. This work positions ATF4 as a tractable therapeutic target to overcome immunotherapy resistance in HCC. Graphical abstract Highlights- ATF4 orchestrates an immunosuppressive tumor microenvironment in HCC by coupling metabolic stress adaptation to immune evasion. - Ablation of ATF4 disrupts proline biosynthesis, leading to a marked depletion of extracellular proline. - Cancer cell-derived proline availability contributes to macrophage differentiation and M2 polarization; its loss restores T cell-mediated anti-tumor surveillance and sensitizes beta-catenin-driven HCC to immune checkpoint blockade.

Pain in pancreatic ductal adenocarcinoma (PDAC) is associated with poor survival, but whether altered pain processing carries prognostic significance is unknown. We analyzed a prospective cohort of 143 patients with PDAC who underwent pancreatic quantitative sensory testing (PQST) after diagnosis. Patients were classified as having normal pain processing (n=84), segmental hyperalgesia (n=30), or widespread hyperalgesia (n=29). Survival was measured from the date of P-QST assessment. During follow-up, 70 deaths occurred. Widespread hyperalgesia was associated with increased mortality in unadjusted Cox analysis (HR 1.96, 95% CI 1.14,3.35) and after adjustment for age, sex, tumor stage, comorbidity, opioid treatment, and body mass index (adjusted HR 2.33, 95% CI 1.30,4.15). Segmental hyperalgesia was not associated with mortality. Kaplan Meier analysis demonstrated lower survival probability in the widespread hyperalgesia group (log rank p=0.025). These findings suggest that widespread hyperalgesia, reflecting altered central pain processing, identifies a subgroup of PDAC patients at increased risk of mortality independent of conventional clinical factors.

Background Unplanned hospital admissions in Inflammatory Bowel Diseases (IBD) account for nearly three-quarters of IBD inpatient stays in the United Kingdom. Although costly to services and distressing for patients, research exploring experiences and potential drivers of admissions is limited. We undertook a qualitative study to explore the healthcare experiences and access needs of people with IBD who had unplanned admissions, along with their caregivers and clinicians. Methods Semi-structured interviews with 25 participants from a single tertiary IBD service in England (17 people with IBD, 3 informal caregivers, 5 clinicians) were conducted. We applied thematic framework analysis, guided by the Candidacy Framework, and worked with 2 patient and public contributors to generate final themes. Results We identified four themes: 1) Difficulties in Identifying flares and asserting severity before admission, summarised the prevailing uncertainty in identifying a flare and access to timely IBD care. 2) Navigating a disjointed healthcare system, highlighted how lack of care plans and systemic barriers can delay access. 2) Emergency care access challenges highlighted the gaps in emergency and inpatient care during flares. Whilst 4) fighting for care and individual advocacy needs, described the persistent assertion for care that may disproportionally impact access to vulnerable groups, also highlighting the importance of positive interpersonal relationships. Conclusions Individual, interpersonal and healthcare factors across the patient pathway were perceived to shape access to care in unplanned IBD admissions. Potentially reducing admissions requires proactive strategies, including the integration of patient education, monitoring tools, establishment of specialist rapid-access pathways, and formal psychological support to address barriers to access.

Hernias affect millions of individuals worldwide and represent a significant public health burden, yet the genetic mechanisms underlying hernia development and the extent to which they are shared across anatomical subtypes remains incompletely understood. We performed a multi-population genome-wide association meta-analysis of five hernia subtypes and identified 243 genome-wide significant loci, including 173 novel associations. Gene prioritization implicated genes involved in extracellular matrix organization, elastic fiber assembly, and embryologic development as key effectors of hernia susceptibility. Further analyses demonstrated substantial overlap in the genomic architecture of hernia, including 30 causal variants that were shared across different hernia subtypes. We employed genomic structural equation modeling to formally model this relationship, which identified two distinct latent genetic factors corresponding to putative midline fusion defects (ventral, umbilical, diaphragmatic) and inguinofemoral hernias (inguinal, femoral). Mendelian randomization analyses confirmed causal roles for body mass index, visceral adipose tissue, and abdominal subcutaneous adipose tissue in hernia development while also identifying candidate therapeutic targets. Together, these findings delineate the shared and distinct genetic architecture of hernia subtypes providing a mechanistic foundation to enable precision risk stratification and inform the development of novel preventative and therapeutic strategies.

Clostridioides difficile infection (CDI) susceptibility and severity are strongly associated with preexisting colonic inflammation. However, chronic inflammatory conditions such as cystic fibrosis rarely progress to symptomatic CDI despite high rates of C. difficile colonization, suggesting that inflammation alone is insufficient to explain disease vulnerability. Notably, populations relatively protected from symptomatic CDI exhibit impaired regenerative capacity within the colon epithelium. Here, we used single cell RNA sequencing of human colonoid monolayers to map markers of CDI susceptibility and severity to cell populations associated with inflammation and epithelial repair. We identified an inducible microfold-like (M-like) population that is largely absent from the healthy colon but emerges during inflammation and regeneration. These cells were enriched for markers of severe CDI, C. difficile toxin interaction genes, and elevated CCL20 and CFTR expression. Spatial imaging localized CCL20-producing cells to wound-like gaps in mock and CDI-treated colonoids, identifying a repair-associated niche active independent of infection. Following exposure to C. difficile, wound-healing transcription within the M-like lineage declined while tuft-like populations expanded and upregulated genes associated with immune cell recruitment. These findings demonstrate that epithelial regeneration shapes host CDI vulnerability. IMPORTANCEClostridioides difficile infection can lead to severe illness and death in vulnerable populations despite available treatments. Clinical signs of inflammation during active Clostridioides difficile infection are strongly associated with disease outcome, yet these responses primarily reflect tissue damage already underway, limiting opportunities to prevent progression. In contrast, conditions linked to severe disease, including inflammatory bowel disease and antibiotic exposure, are associated with colonic inflammation before infection or at the time of diagnosis, highlighting an opportunity for earlier identification of high-risk individuals. Using human colonoid single cell transcriptomics and spatial imaging, we identified a microfold-like cell population enriched for inflammatory mediators and Clostridioides difficile toxin interaction genes linked to severe disease. This population was active even in the absence of infection, suggesting that repair-associated populations within the inflamed colon may help identify susceptibility to severe CDI before clinical progression occurs.