American Journal of Physiology-Gastrointestinal and Liver Physiology

BackgroundShort bowel syndrome (SBS) resulting from extensive small bowel resection is characterized by severe malabsorption and represents the leading cause of intestinal failure. Although spontaneous intestinal adaptation can partially restore nutrient absorption, the temporal coordination and hierarchy of the adaptive mechanisms involved--particularly those linking the gut microbiota, enteroendocrine function, hyperphagia, and intestinal remodeling-- remain incompletely understood. MethodsWe investigated the kinetics of spontaneous intestinal adaptation in a rat model mimicking type 2 SBS over a 28-day postoperative period. Body weight, food intake, gastrointestinal transit, fecal losses, intestinal morphology, enteroendocrine hormone secretion, hypothalamic neuropeptide expression, and gut microbiota composition were assessed longitudinally in SBS and SHAM-operated rats. ResultsExtensive small bowel resection induced marked early weight loss, accelerated intestinal transit, diarrhea, and increased fecal energy losses that persisted throughout the follow-up. Profound gut microbiota remodeling occurred as early as day 7, remained largely stable thereafter, and was characterized by reduced diversity and enrichment in Lactobacillaceae and Enterobacteriaceae. Early elongation of remaining colon and epithelial remodeling were observed, preceding the jejunal hyperplasia, which became evident from day 14 onward. Enteroendocrine adaptation was marked by an early increase in plasma peptide YY levels, whereas glucagon-like peptide-1 showed a modest response. Food intake was increased in SBS rats from day 7 onward, and hyperphagia developed gradually and reached a plateau by the end of the third postoperative week, in parallel with increased hypothalamic AgRP levels and reduced POMC levels. No significant improvement of intestinal transit and fecal energy losses was observed during the study period. ConclusionIntestinal adaptation to extensive resection follows a time-dependent sequence in which early gut microbiota remodeling and colonic adaptation precede hyperphagia and small intestinal remodeling. These findings highlight the gut microbiota and the colon as central components of the early post-resection adaptation and potential therapeutic targets in SBS.

PurposeHirschsprung-associated enterocolitis remains a major postoperative complication of Hirschsprungs disease (HD), and impaired epithelial barrier integrity has been proposed as a contributing factor. In this study, we investigated whether 12-hydroxyheptadecatrienoic acid (12-HHT), an endogenous leukotriene B4 receptor 2 (BLT-2) agonist, enhances the epithelial barrier and exerts anti-inflammatory effects in patient-derived colonic organoids. MethodsNormoganglionic specimens from rectal/rectosigmoid HD at pull-through (HD-N; n = 8) and transverse colon specimens from anorectal malformation (ARM) at colostomy closure (n = 10) were used to generate colonic organoids. Epithelia were isolated using ethylenediaminetetraacetic acid and subsequently embedded in Matrigel. Baseline expression of TJP1, TJP2, F11R (encoding junctional adhesion molecule-A), JAM2, CLDN1, CLDN3, CLDN4) and LTB4R2 (encoding BLT-2) was assessed by qPCR and immunoblotting. Organoids were then treated with 12-HHT (0.4, 2, or 10 M) for 7 days, followed by qPCR. Additional experiments assessed cytokine expression (IL1B, IL6) and TJPs after 24 h with tumor necrosis factor- (TNF-, 100 ng/mL) plus phosphate buffered saline or 12-HHT. Barrier function was evaluated using FITC-dextran influx assays. ResultsHD-N and ARM organoids exhibited similar growth efficiencies. Baseline expression for F11R, JAM2, CLDN1, CLDN3, CLDN4, and LTB4R2 was significantly lower in HD-N than in ARM. TJPs were upregulated by 12-HHT at 2 and 10 M in both groups, with stronger effects in ARM. In HD-N organoids, 10 M 12-HHT suppressed TNF--induced IL1B and IL6 elevation mitigated tight junction proteins (TJPs) downregulation more effectively than 2 M. 12-HHT attenuated TNF--induced FITC-dextran influx in HD-N organoids. Conclusion12-HHT may exert anti-inflammatory effects by integrating TJPs of HD-N.

Regeneration depends on tightly coordinated transcriptional programs governed by a dynamic epigenetic landscape to regulate cell identity, proliferation, and tissue remodelling following injury. The livers highly regenerative due to the ability to rapidly upregulate genes that drive the cell cycle and other genes important for regeneration. Trimethylation of histone 3 lysine 27 (H3K27me3) is deposited by the polycomb repressive complex 2 (PRC2) and many genes occupied by H3K27me3 in their promoters in uninjured livers become induced following PH. Here we test the hypothesis that depleting H3K27me3 by hepatocyte-specific deletion of Embryonic Ectoderm Development (EedHepKO), a key component of PRC2, changes the regenerative response in the liver. We show that Eed eliminates H3K27me3 in hepatocytes, resulting in reduced liver size, increased hepatocyte death, proliferation and fibrosis associated with upregulation of cell cycle and fibrogenic genes. Though these mice are less likely to survive two-thirds partial hepatectomy than wildtype controls, those that do survive increase liver mass faster than WTs. Importantly the genes that are occupied by H3K27me3 in control uninjured livers are upregulated in EEDHepKO and become further induced following PH. These data show that modulation of PRC2 activity disrupts epigenetic patterning, induces liver injury, and alters regenerative outcomes, suggesting that precise control of PRC2 function could be harnessed to enhance regenerative capacity.

BackgroundIn the United States over 10% of all neonates are born premature (less than 37 weeks gestational age), and many face complications related to prematurity, including necrotizing enterocolitis (NEC). NEC is the most deadly gastrointestinal disease and the leading cause of death in preterm neonates, with up to 50% mortality. Since there is no cure for NEC, prevention is the best strategy. Enhancing our understanding of intestinal epithelial cell (IEC) responses to NEC damage will provide novel therapeutic targets to prevent NEC. Published evidence suggests that the RNA-binding protein insulin-like growth factor 2 mRNA binding protein 1 (IMP1) plays roles in intestinal development, barrier function, and intestinal repair. Notably, however, roles for IMP1 in NEC are not defined. Goblet cells produce protective mucus in the intestine, and their mature function is dependent on the transcription factor Spdef. Emerging evidence suggests that goblet cell mucus complexity impacts barrier function and inflammation susceptibility. This study aimed to define the role of IMP1 in NEC pathogenesis using neonatal human enteroids and a model of NEC-like intestinal injury in mice with IEC-specific Imp1 overexpression and loss. HypothesisIMP1 expression is protective in NEC. MethodsThis study used mice with intestinal epithelial Imp1 overexpression or loss and corresponding wild-type controls. At post-natal day 3, mice of both sexes were randomly assigned to control or NEC groups. NEC was induced with the well-established experimental NEC-like intestinal injury model that includes stress, formula feeding, and hypoxia. Imp1 effects on experimental NEC were assessed using RNA sequencing, western blotting, and immunostaining. ResultsInflammatory bacteria induced IMP1 expression in neonatal human enteroids. Mice with Imp1 overexpression incur worse intestinal damage during NEC. Pathway analysis of RNA sequencing data revealed a significant enrichment of the Spdef transcriptional network in Imp1IEC-OE during NEC. This included significant upregulation of Spdef target genes such as Agr2 (in NEC WT: 617.8 {+/-} 33.56 vs Imp1IEC-OE: 812.9 {+/-} 111.3, p=0.02) and Fut2 (in NEC WT: 219.4 {+/-} 34 vs Imp1IEC-OE: 396.6 {+/-} 62.9, p=0.05). In silico analysis predicted Imp1 binding to Spdef and mucus glycosylation mediator mRNAs. Although genotype did not affect goblet cell number, Imp1IEC-OE mice with NEC exhibited significant increases (p0.05) in Spdef protein, genes responsible for goblet cell function (Spink4, Klk1, Tspg1) and mucus glycosylation (Gcnt3, B3gnt7, Qsox1). Ultimately, Imp1 overexpression led to increased mucus fucosylation during NEC. ConclusionOur data indicate that during NEC, upregulation of Imp1 promotes goblet cell function via Spdef, including enhanced goblet cell maturation and mucus fucosylation. NEW AND NOTEWORTHYExpression of the RNA-binding protein Imp1 is enhanced in neonatal human enteroids in response to inflammatory bacteria. Imp1 regulates goblet cell function in response to early intestinal inflammation in a mouse model of necrotizing enterocolitis. Specifically, Imp1 promotes a Spdef transcriptional program by upregulating Spdef, resulting in elevated gene expression of Spdef target genes. Additionally, Imp1 increases the gene expression of (1,2)fucosyltransferase, Fut2, and subsequently, production of fucosylated mucus marked by UEA1. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=178 SRC="FIGDIR/small/702645v1_ufig1.gif" ALT="Figure 1"> View larger version (63K): org.highwire.dtl.DTLVardef@189f615org.highwire.dtl.DTLVardef@7aeeedorg.highwire.dtl.DTLVardef@dc258corg.highwire.dtl.DTLVardef@1252b98_HPS_FORMAT_FIGEXP M_FIG C_FIG

Background & Aims: Per- and polyfluoroalkyl substances (PFAS) are persistent endocrine-disrupting chemicals associated with metabolic dysfunction, including metabolic dysfunction-associated steatotic liver disease (MASLD). While PFAS perturb lipid and bile acid (BA) metabolism in a sex-specific manner, the underlying mechanisms remain unclear. We tested whether steroid hormones mediate PFAS-associated metabolic alterations. Methods: In 104 patients with biopsy-characterized MASLD, we performed sex-stratified analyses applied liquid chromatography coupled to mass spectrometry (LC-MS) for chemical analysis, integrating circulating steroids, PFAS exposure, hepatic lipidomics and BA profiles. Results: Steroid hormones were associated with MASLD severity in a sexually-dimorphic manner. Dihydrotestosterone showed consistent inverse associations with steatosis, fibrosis, necroinflammation and insulin resistance, particularly in females. PFAS exposure was associated with altered steroid profiles, predominantly indicating suppressed steroidogenesis in females. These PFAS-associated hormonal changes were linked to downstream alterations in hepatic lipids and BAs. Mediation analysis supported indirect effects of PFAS on metabolic pathways via steroids, including testosterone/epi-testosterone-mediated effects on ether phospholipids and estradiol-mediated effects on lithocholic acid. Females exhibited stronger PFAS-steroid-BA associations, whereas males showed weaker, lipid-centric effects. Conclusions: PFAS exposure is associated with sex-specific disruption of steroid hormone pathways that may link environmental exposure to lipid and BA dysregulation in MASLD. These findings identify steroid hormones as potential key mediators of PFAS-associated metabolic dysfunction and highlight sex as a critical determinant in environmental liver disease.

Background & AimsIntrahepatic biliary epithelial cell (BEC) heterogeneity remains challenging to define. Here, we sought to identify BEC subpopulations and biomarkers in mouse liver. MethodsWe performed scRNA-seq on Sox9EGFP+ liver epithelium from mice subjected to bile duct ligation (BDL) and sham controls. A machine learning algorithm, NSForest, identified minimal, multi-gene signatures for BEC subpopulations. These "metagenes" were validated using hybridization chain reaction (HCR) FISH in tissue sections from wild-type mice and on primary BECs expanded in vitro. Metagenes were used to match BDL subpopulations to their corresponding sham subpopulations for differential gene expression (DGE) analysis. ResultsWe identified 4 BEC subpopulations in sham controls, each associated with 1-2 gene metagenes. Spatial localization of metagene-defined BEC subpopulations by HCR FISH revealed heterogeneous cellular composition of intrahepatic bile ducts. BECs belonging to a given subpopulation were most likely to have neighbors of the same identity, forming homogenous cellular compartments within ducts. BDL downregulated subpopulation-specific genes and upregulated a damage-associated gene set. BDL samples also included a proliferative subpopulation not found in sham controls, which contained populations enriched for three of the four metagenes. All BEC subpopulations were also found in monolayers in vitro, where they clustered spatially with BECs of the same subtype. ConclusionsNovel metagene biomarkers of BEC subpopulations facilitated spatial localization of BECs in situ, identified subpopulation specific injury responses, and confirmed that BEC heterogeneity is preserved in vitro. The presence of locally homogenous BEC "neighborhoods" in vitro suggests some degree of BEC organization may be epithelial-autonomous.

Background and AimsCholedocholithiasis (CDL) is a common condition that can lead to serious complications, requiring effective risk stratification for timely intervention. While current guidelines use clinical predictors, imaging, and laboratory markers for risk assessment, the role of glutamate dehydrogenase (GLDH) in CDL remains poorly understood. This study aims to evaluate its potential as a clinical biomarker for identifying patients with CDL. MethodsThis single-center cohort study identified 23,103 patients who presented to the emergency department of the University Medical Center Hamburg-Eppendorf and underwent routine abdominal laboratory testing between May 2021 and December 2023. Patients were classified into CDL and other diagnoses. To assess the predictive value of age, sex and laboratory markers for CDL, we developed a random forest machine learning model, conducted a backward stepwise logistic regression and performed receiver operating characteristic (ROC) analysis. Results152 patients were diagnosed with CDL and 22,951 with other diagnoses. In the random forest machine learning model, GLDH emerged as the most significant feature for predicting CDL. ROC analysis revealed that GLDH had the highest area under the curve of 0.93 among laboratory markers. At the upper limit of normal, GLDH demonstrated the best sensitivity (92%) compared to aspartate aminotransferase (AST), alanine aminotransferase (ALT) and bilirubin. High GLDH levels exceeding 150 U/L demonstrate the highest specificity (99%) for CDL, outperforming AST, ALT and bilirubin. ConclusionGLDH outperforms AST, ALT and bilirubin as a screening and predictive marker for CDL, supporting its inclusion in clinical guidelines for risk stratification.

Intestinal organoids are three-dimensional in vitro structures derived from stem cells and serve as a valuable model for studying intestinal biology and pathophysiology. This study optimized the isolation, expansion, and differentiation of canine intestinal organoids from duodenum and colon. Organoids were generated from canine intestinal crypts and cultured in Matrigel with a growth factor cocktail. The impact of prostaglandin E2 (PGE2) concentration on organoid growth was evaluated, and a two-phase differentiation protocol--comprising patterning and differentiation media--was implemented, including interleukin (IL)-22 in the duodenal differentiation phase. Organoids cultured with 100 nM PGE2 exhibited increased crypt budding and organoid-forming efficiency, indicative of enhanced stem cell proliferation. Differentiated organoids expressed key intestinal markers (VIL1, SI, CHGA, MUC2), and forskolin-induced swelling demonstrated functional Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) activity. Although the sample size (n=2) limits generalizability, this optimized protocol provides a relevant in vitro model for studying canine intestinal function. The model can be used in future research for disease modelling and translational applications, supporting downstream studies in gastrointestinal disease, drug permeability, and comparative One Health research.

BackgroundMetabolic dysfunction-associated steatotic liver disease (MASLD) is the fastest-growing etiology of hepatocellular carcinoma (HCC). A mechanistic understanding of the metabolic heterogeneity of MASLD-driven tumors is crucial to inform strategies for future treatment options. MethodsPaired tumor (n=8) and adjacent non-tumor tissue (n=8) were collected from patients with steatohepatitic HCC at the University of Kentucky Markey Cancer Center. Hematoxylin and eosin (H&E) staining was used for pathological determination of tumor and adjacent nontumor tissue by a board-certified pathologist. Lipidomic, metabolomic, and transcriptomic analyses were performed, and data were integrated across platforms to identify novel relationships across tumor and adjacent nontumor tissue. ResultsHistological analysis by H&E showed significant lipid vacuole accumulation and inflammatory foci in HCC tumors relative to nontumor tissue. Across omics platforms, we identified 1,679 genes, 1,696 metabolites, and 292 lipids that were significantly (padj<0.01) increased or decreased in tumors relative to nontumor tissue. We identified significant reductions in total ceramides and increases in fatty acyl chain saturation in tumor tissue. Furthermore, metabolites involved in amino acid and fatty acid metabolism were largely decreased in tumors relative to nontumor tissue. We also identified a total of 303 highly significant and novel transcript-metabolite associations (117 gene-metabolite; 186 gene-lipid) across tumor and nontumor tissue. ConclusionsTaken together, this integrative analysis reveals novel relationships between steady-state gene transcripts and specific metabolites in steatohepatitic tumors, thereby identifying new pharmacological targets that may be exploited for therapeutic benefit.

Mismatch repair-deficient (dMMR) endometrial tumors are often responsive to immune checkpoint inhibitors (ICI), yet recurrence and variable treatment responses remain significant clinical challenges. Characterization of the tumor microenvironment, including immune cell composition and spatial organization, may reveal predictors of recurrence and ICI responsiveness. We performed multiplex immunofluorescence imaging on 16 dMMR endometrial tumors using a 36-antibody panel. Cells were segmented, phenotyped by unsupervised clustering, and analyzed to quantify cell type proportions and spatial relationships among intratumoral, peritumoral, and whole-tissue cell populations across clinical groups. Non-recurrent tumors (n = 10) exhibited higher intratumoral CD8 T-cell proportions, tumor cell enrichment around CD8+ T cells, CD8+/CD4+ ratios, and PD-1Low CD4 T-cell proportions. In contrast, recurrent tumors (n = 6) showed higher CD4+ T cell proportions and endothelial cell enrichment surrounding CD8 and PD-1 CD8 T cells. Among the recurrent tumors, compared to non-responders (n = 2), ICI responders (n = 4) had a higher proportion of PD-1+Ki67+ CD8+ T cells. Macrophage spatial organization also differed; non-responders displayed separate clusters of CD163 macrophages and CD163- macrophages, whereas responders demonstrated more dispersed macrophages co-localized with PD-1+ CD8 T cells. Overall, these findings suggest that both immune cell composition and spatial arrangement are factors that contribute to recurrence and ICI response in dMMR endometrial cancer. Spatial profiling of the tumor microenvironment may provide biomarkers to guide patient stratification and precision immunotherapy strategies.

ObjectivesFree fatty acid receptors 2 and 3 (FFA2 and FFA3) are activated by nutrient-derived metabolites such as short-chain fatty acids (SCFAs) and ketone bodies, produced by the gut microbiota and host, respectively. This study aimed to investigate the intracellular signaling pathways recruited in glucagon-like peptide-1 (GLP-1) releasing enteroendocrine cells following activation of FFA2 and FFA3 to resolve the impact of nutrient status on enteroendocrine cell function. MethodsExperiments were performed using primary mouse colonic cultures and the mouse enteroendocrine cell line, GLUTag cells. Expression analysis by bulk RNA sequencing was used to determine expression of FFA2 and FFA3 in GLP-1 releasing cells. Measurement of GLP-1 secretion by sandwich ELISA was used to assess enteroendocrine cell function. Live-cell measurements of intracellular calcium and cAMP levels were performed to assess canonical second messenger signaling pathways. ResultsA SCFA mixture stimulated GLP-1 secretion from both primary mouse colonic cultures and GLUTag cells. In GLUTag cells, the FFA2 ligand 4-CMTB inhibited GLP-1 release independent of Gaq- and Gai-signaling as neither YM-254890 (Gaq inhibitor) nor pertussis toxin (Gai- uncoupler) altered its effect. However, 4-CMTB did elevate cAMP levels, suggesting an indirect mechanism for the increase in cAMP production. Stimulation of FFA2 with the Gai-biased ligand AZ1729 or the ketone body acetoacetate inhibited GLP-1 release and cAMP accumulation. AZ1729 was insensitive to pertussis toxin and OZITX, supporting atypical FFA2 signaling. Stimulation of FFA3 with AR420626 or the ketone body {beta}-hydroxybutyrate increased GLP-1 secretion from GLUTag cells, an effect that was not mediated by cAMP production. AR420626, but not {beta}-hydroxybutyrate increased intracellular calcium levels. ConclusionsOverall, activation of FFA2 inhibited secretory function in GLP-1-releasing enteroendocrine cells, whereas activation of FFA3 stimulated GLP-1 secretion via distinct intracellular signaling mechanisms. O_FIG O_LINKSMALLFIG WIDTH=184 HEIGHT=200 SRC="FIGDIR/small/708924v1_ufig1.gif" ALT="Figure 1"> View larger version (37K): org.highwire.dtl.DTLVardef@175dbaforg.highwire.dtl.DTLVardef@a9cc3eorg.highwire.dtl.DTLVardef@1a026e5org.highwire.dtl.DTLVardef@15997af_HPS_FORMAT_FIGEXP M_FIG Graphical Abstract C_FIG HighlightsO_LIExposure to physiological levels of SCFAs stimulates GLP-1 secretion from colonic EECs C_LIO_LIFFA2 and FFA3 regulate GLP-1 release via non-canonical signaling pathways C_LIO_LIKetone bodies activate SCFA receptors to differentially modulate GLP-1 levels C_LIO_LILigand bias enables nutrient-dependent tuning of EEC gut hormone secretion C_LI

Sepsis is defined as a dysregulated response to infection, leading to life-threatening organ dysfunction that particularly affects parenchymal organs. Clinical studies remain inconclusive regarding the impact of biological sex on sepsis, and preclinical studies are predominantly performed in male animals. We examined early (8 h) septic responses in male and female mice using a fecal-induced peritonitis (FIP) model. Blood biochemical parameters, body temperature, and murine sepsis scores provided evidence of a septic response in animals randomized to FIP compared to controls, but showed no physiological differences between male and female mice. Transcriptomic analysis of the liver, kidney, and lung showed consistent inflammatory activation in response to sepsis as compared to controls. Notably, in the kidney and lung, female mice exhibited stronger immune activation and a heightened inflammatory response compared to males. Thus, biological sex differences in the septic response can be detected in early acute sepsis without apparent physiological differences.

Background and AimsArtificial intelligence (AI) is increasingly applied to histological assessment in inflammatory bowel disease (IBD), but most approaches quantify features in isolation and ignore their anatomical location within the mucosa. We developed and validated PAIR-IBD (Perspectum AI Reading in IBD), an AI system that quantifies inflammatory cell populations, crypt injury, and epithelial damage within defined mucosal compartments to distinguish active disease, remission, and equivocal cases in ulcerative colitis (UC). MethodsA deep learning ensemble was trained on three IBD biopsy datasets to identify lymphocytes, neutrophils, eosinophils, and plasma cells, and to segment crypts, lamina propria (LP), and muscularis mucosae. Inflammatory cell densities and crypt injury metrics (mucin depletion, solidity, roughness, branching, and abscess formation) were quantified. PAIR-IBD outputs were compared between histologically active and remissive UC, evaluated in inconclusive cases, and correlated with manual pathology grading. ResultsNeutrophil density increased 3.5-fold in the LP and 15-fold within crypts in active UC (p<0.0001). Eosinophil density doubled and LP lymphocytes increased 1.4-fold. Active UC showed increased mucin depletion, crypt branching, and crypt abscesses, with reduced crypt solidity (p<0.0001 for all). PAIR-IBD metrics correlated with manual inflammatory and crypt injury scores (rs=0.23-0.72) and global indices (rs=0.27-0.65). Up to 89% of inconclusive cases aligned with remission-like profiles based on multiple independent AI metrics. ConclusionPAIR-IBD provides spatially resolved, quantitative assessment of inflammation and epithelial injury in UC, improving disease stratification and resolution of equivocal histology, with potential to support scoring consensus and improve accuracy of histological endpoints in clinical trials.

Gallbladder cancer (GBC) is a highly lethal malignancy with limited experimental models to study disease biology or evaluate therapeutic responses. Although canonical Wnt activation is commonly used for patient-derived organoid (PDO) development and expansion, gallbladder PDOs has also been generated under Wnt-inhibitory conditions. No comparative assessment has determined how Wnt pathway modulation influences gallbladder PDO development, phenotype or drug response. This study systematically compared the impact of canonical Wnt activation (WNTAct medium containing CHIR99021) versus inhibition (WNTInh medium containing DKK1) on the establishment, propagation, molecular features and therapeutic responses of PDOs generated from malignant or non-malignant gallbladder tissues derived from the same patient. Both media supported successful PDO generation with comparable efficiency, preserving biliary epithelial functions and marker expression. Transcriptomic profiling confirmed selective enrichment of canonical Wnt target genes in PDOs generated in WNTAct cultures. WNTAct conditions enabled markedly superior long-term propagation, whereas WNTInh cultures more consistently retained the dysplastic features in malignant samples. Gemcitabine response assays demonstrated significantly greater drug sensitivity in PDOs grown in WNTAct medium, a phenotype reversible upon media switching but requiring extended adaptation, indicating a dynamic and context-dependent influence of Wnt signaling on chemotherapeutic vulnerability. Collectively, the findings reveal a trade-off between long-term propagation and histological fidelity in gallbladder PDOs and show that Wnt signaling modulates gemcitabine sensitivity in a reversible manner. This comparative framework provides practical guidance for selecting culture conditions for gallbladder PDO based disease modelling and precision oncology applications.

Background and AimsHighly aggressive hepatobiliary tumours include gallbladder cancer (GBC), hepatocellular carcinoma (HCC), intrahepatic and extrahepatic cholangiocarcinoma (iCCA, eCCA) and ampulla of Vater cancer (AoV). We aimed to identify plasma biomarkers for the early diagnosis of hepatobiliary cancer by leveraging the metabolomic signatures of established clinical risk factors. MethodBased on 273,190 participants from the UK Biobank, we (1) identified metabolites associated with gallstone-related conditions (e.g. cholecystitis), primary sclerosing cholangitis (PSC) and metabolic liver diseases (e.g. cirrhosis), and (2) evaluated the relationship between the identified metabolites and the risk of GBC, HCC, iCCA, eCCA and AoV. Findings were validated in an independent group of 227,809 participants from the UK Biobank. We also derived metabolomic scores summarizing the three risk-factor signatures and evaluated their ability to stratify cancer risk. ResultsWe identified 27 metabolites associated with gallstone-related conditions, 11 with PSC, and 34 with metabolic liver diseases, some of which showed associations with inconsistent directions across risk factors, suggesting distinct pathogenic processes. Several metabolites were associated with cancer risk in both the discovery and validation datasets, independently of established risk factors, predominantly for HCC (16 signals) and for iCCA (4), with one for GBC and none for eCCA and AoV. Metabolomic scores clearly distinguished individuals at high risk for HCC and iCCA. ConclusionThe preselection of plasma metabolites associated with established risk factors facilitated the subsequent identification and validation of biomarkers for early cancer detection. The identified metabolites suggest specific pathogenic pathways for each type of hepatobiliary cancer. Wider replication is urgently needed to advance toward clinical implementation. What you need to knowO_ST_ABSBACKGROUND AND CONTEXTC_ST_ABSClinical risk factors for hepatobiliary cancers often progress silently, making early identification of high-risk individuals difficult and highlighting the need for biological markers detectable before clinical diagnosis. NEW FINDINGSRisk-factor-based serum metabolomic profiling identified circulating metabolites that predict specific hepatobiliary cancers years before diagnosis, with strongest and most consistent signals for hepatocellular and intrahepatic cholangiocarcinoma. LIMITATIONSClinical risk factors were assumed to be frequently underdiagnosed in UK Biobank, and event numbers were relatively small for some cancers, which may have reduced power and attenuated associations for less common endpoints. CLINICAL RESEARCH RELEVANCEThis study shows that serum metabolic profiles can identify individuals at increased risk for hepatobiliary cancers long before symptoms appear, particularly for hepatocellular and intrahepatic cholangiocarcinoma. These findings support the development of precision risk-stratification strategies that may ultimately enable earlier surveillance. BASIC RESEARCH RELEVANCEBy first identifying metabolites linked to specific liver and biliary clinical conditions, the study clarifies which metabolites are indirectly associated with hepatobiliary cancers through known disease pathways. Testing these metabolites again while adjusting for diagnoses of those conditions then reveals which ones also show direct, pathway-independent associations with individual hepatobiliary cancers, providing clearer insight into cancer-specific metabolic mechanisms.

BackgroundNeurogenic bowel is a major cause of morbidity in patients affected by neural tube defects (NTDs) such as spina bifida, but the underlying reasons for bowel dysfunction are unknown. An absolute requirement for gastrointestinal (GI) motility is the enteric nervous system (ENS) located within the walls of the GI tract. Enteric neurons coalesce into circumferential stripes throughout embryonic and early postnatal development, and this gradual organization of the ENS into enteric neuronal stripes correlates with the emergence of neurogenic GI motility. We hypothesized that NTDs are associated with changes in ENS organization that correlate with specific GI motility defects. MethodsWe used prenatal valproic acid (VPA) exposure as a model for NTDs in embryonic mice. We used immunohistochemistry, high resolution confocal imaging, and ex vivo motility assays to assess enteric neuronal stripes and gastrointestinal motility in embryos with a VPA-induced neural tube defect. Key resultsGI tracts from embryos with a VPA-induced NTD contain blood. Structurally, the enteric neuronal stripes are thinner with a narrower interstripe distance, leading to an increased number of stripes. Functionally, GI motility is abnormal, with increased contraction frequency and increased length of contractile segments. Conclusions and inferencesENS organization and GI motility are disrupted in mouse embryos with a VPA-induced NTD. This has important implications for our understanding of neurogenic bowel in central nervous system diseases such as spina bifida. Key Points- VPA exposure is a reliable model of neural tube defects with variable intralitter susceptibility - Embryos with a VPA-induced neural tube defect have blood in the amniotic sac and within the lumen of the gastrointestinal tract - Enteric nervous system organization is abnormal in the duodenum and jejunum of embryos with a VPA-induced neural tube defect, with thinner enteric neuronal stripes and narrower interstripe distance - Ex vivo gastrointestinal motility is abnormal in the duodenum and jejunum of embryos with a VPA-induced neural tube defect, including increased contraction frequency and increased length of the contractile segment

IntroductionPrevious studies have shown that Aquamin(R), a multi-mineral extract from red marine algae, enhances barrier integrity proteins in the human colon. These findings prompted further investigation into Aquamin(R)s effects on gastrointestinal barrier function and permeability. MethodsSubjects with mild or in remission ulcerative colitis (UC) and healthy controls were enrolled in an open-label trial and received Aquamin(R) capsules (800 mg calcium/day) for 90 days. Intestinal permeability was evaluated before and after the 90-day intervention by urinary mannitol excretion after ingestion of a 5 g mannitol solution, with collections across several time intervals (pre-drink, 0-2 h, 2-8 h, and 8-24 h). The primary outcome was the change in mannitol excretion. Serum samples were also collected to assess liver and renal function. ResultsIn this pilot study (NCT04855799), which included UC patients and healthy controls (n = 8 per group), baseline urine mannitol levels in the 0-2 h sample were 54% higher in UC patients compared to healthy subjects (p = 0.006). Following 90 days of Aquamin(R) supplementation, urinary mannitol levels in UC patients decreased by 28%, 26%, and 41% at the 0-2 h, 2-8 h, and 8-24 h timepoints, respectively; the reduction at the 0-2 h interval reached statistical significance (p = 0.015). Overall, Aquamin(R) supplementation reduced total post-intervention mannitol excretion by 29% (p = 0.024). Aquamin(R) was well tolerated, with no serious adverse events reported. The serum metabolic panel revealed a modest but statistically significant reduction in alkaline phosphatase levels after 90 days of intervention. ConclusionThese results provide preliminary evidence that Aquamin(R) supplementation beneficially modulates gut barrier function and supports epithelial integrity in UC patients. These findings support further investigation of Aquamin(R) as a safe and promising adjunct to current UC management strategies, with potential utility as a barrier therapy in UC. SummaryAquamin(R) supplementation for 90 days reduced intestinal permeability in ulcerative colitis patients, as measured by urinary mannitol excretion. The intervention was well tolerated, suggesting Aquamin(R) may be a safe, promising adjunct for enhancing gut barrier function in UC management.

Mast cells (MCs) are myeloid cells of the innate immune system. As a first line of defence they fulfill effector functions and immune modulatory properties. Upon activation they release pro-inflammatory mediators such as cytokines and proteases. It has been suggested that MCs may contribute to the development of liver fibrosis. However, investigating hepatic MC biology in mice is challenging due to low MC numbers and a lack of suitable detection techniques relying on MC proteins and their modifications. Here, we evaluated whether the expression strength of MC markers correlates with the degree of liver fibrosis in mice and aimed to determine the frequency and localization of hepatic MCs. We applied both a toxic (DEN/CCl4 treatment) and a genetic (Mdr2-/- mice) liver fibrosis model in C57BL/6 mice and found a significant correlation between fibrosis grade and the expression of several established mast cell markers. This correlation was further supported in patients with fibrosis and hepatocellular carcinoma (HCC) using publicly available transcriptomics datasets. We used FACS to purify and isolate MCs from fibrotic mouse livers and verified MC signatures by qPCR analysis of MC-specific gene expression. Hepatic MCs were predominantly negative for Mast-Cell-Protease 5 (Mcpt5) and occurred at a low frequency (approximately 1-2% of leukocytes). Using Molecular CartographyTM of fibrotic liver sections, we determined the spatial localization, expression signature, abundance (approximately 2 cells/mm2) and cellular environment of murine hepatic MCs. In summary, we demonstrated the existence of MCs in murine fibrotic livers and defined an MC expression signature that correlates with the strength of liver fibrosis. These findings will help to study MC biology in murine models of liver disease more effectively in the future.

The endometrium, the inner lining of the uterus, is a dynamic tissue that undergoes precise molecular and structural changes to achieve a receptive state capable of supporting embryo implantation. Although the uterine environment was long considered sterile, molecular studies have detected microbial signals and bioactive compounds that may influence endometrial function. Endometrial epithelial organoids (EEOs) provide a three-dimensional in vitro model that recapitulates the architecture, polarity, and hormonal responsiveness of native endometrial tissue. This study aimed to elucidate how bacterial-derived compounds, including D-lactate (D-lac), commonly associated with Lactobacillus communities, and lipopolysaccharides (LPS), a component of Gram-negative bacteria, affect the transcriptomic profile of the endometrial epithelium under a hormonally induced receptive state. EEOs were exposed to different concentrations of these compounds, and relative metabolic activity was monitored through resazurin-based assays, revealing no significant alterations across the conditions tested. Transcriptomics analysis of hormonally stimulated EEOs, mimicking the mid-secretory phase, revealed that D-lac modulated genes related to epithelial development, tissue remodelling and growth regulation, whereas LPS influenced genes associated with inflammatory signalling and immune response. While key markers of receptivity remained largely stable, small transcriptional changes suggest that microbial signals may modulate the functional balance of the receptive endometrium. These findings highlight a modulatory role of microbial signals on endometrial epithelial function and demonstrate that EEOs are a robust platform for exploring host-microbe interactions in the uterus, offering new insights into the mechanisms underlying uterine receptivity.

Equine endometrosis is a major cause of subfertility in mares characterized by fibrotic remodeling of the endometrium. Although transforming growth factor beta 1 (TGF-{beta}1) is implicated in fibrogenesis, the relationship between endometrosis severity and transcripts associated with tissue maintenance and proliferation remains incompletely defined. Present study evaluated endometrial mRNA expression of IGF1, MKI67, TGFB1, and ACTA2 in relation to endometrosis severity and defined histopathological features. Forty-seven endometrial samples were graded according to the modified Kenney and Doig (KD) categories. Relative mRNA expression was quantified by RT-qPCR and histopathology was extended using a standardized feature-based assessment. TGFB1 mRNA expression was higher in category I+ than in categories I and III (p = 0.041) and in samples with glandular basal lamina disruption (p = 0.020). MKI67 mRNA expression was lower in samples with luminal epithelial erosion (p = 0.049). IGF1 mRNA expression correlated negatively with KD category ({rho} = -0.401, p = 0.015), glandular degeneration ({rho} = -0.340, p = 0.043), overall inflammatory infiltration ({rho} = -0.387, p = 0.020), lymphocytic infiltration ({rho} = -0.426, p = 0.010), and neutrophilic infiltration ({rho} = -0.448, p = 0.006). MKI67 correlated positively with ESR1 ({rho} = 0.887, p < 0.001). These findings indicate that early endometrosis-compatible lesions are associated with increased TGFB1 transcription and that epithelial damage is accompanied by reduced MKI67 expression. The inverse associations between IGF1 expression and both lesion severity and inflammatory infiltration support a link between progressive histopathological changes and reduced expression of a growth factor involved in tissue maintenance.