Cellular and Molecular Gastroenterology and Hepatology最新文献

Background and aims: RNA-binding proteins (RBPs) are major effectors of post-transcriptional regulation. Recently, we described the role of MEX3A in maintaining LGR5+ intestinal stem cells identity and epithelial renewal. This work aimed to study MEX3A functional impact in colorectal cancer (CRC).

Methods: We characterized MEX3A expression profile in CRC mouse models and a cohort of CRC cases (n = 172). Mouse CRC tissues were used for the establishment of tumoroids and CRISPR/Cas9-mediated MEX3A knockout was performed in patient-derived CRC tumoroids to further understand its biological and therapeutic relevance. Simultaneously, we implemented the high-throughput technique HyperTRIBE to uncover MEX3A RNA targets.

Results: Intestinal adenomas from Apc^+/fl mice have increased Mex3a expression and Apc^+/fl;Mex3a^+/- animals presented a significant reduction in tumor burden. Apc^+/fl;Kras^+/G12D;Mex3a^+/- compound mice exhibited reduced tumor area, while corresponding tumoroids had reduced growth ability and enhanced differentiation potential associated with increased peroxisome proliferator-activated receptor gamma (PPARγ) signalling. MEX3A overexpression was observed in 85% of human CRC cases, while 72% presented PPARγ downregulation, with a significant inverse correlation (P = .039). Accordingly, MEX3A-depleted patient-derived CRC tumoroids showed decreased LGR5 expression, accompanied by increased PPARγ expression and higher sensitivity to 5-Fluorouracil/Oxaliplatin (FOLFOX)-based chemotherapy. HyperTRIBE results revealed a direct interaction between MEX3A and PPARG transcripts.

Conclusion: MEX3A contributes to colorectal carcinogenesis, in association with PPARγ signalling modulation, impacting tumor development and therapeutic response.

Gastrointestinal (GI) organoids are now widely used for disease modeling, drug discovery, regenerative-, and precision medicine. As publications using GI organoids have increased exponentially, methodological reporting across GI organoid studies remains inconsistent, making results difficult to interpret, compare, and reproduce. To address this, we present community-informed guidance for reporting key experimental details in GI organoid research. Our recommendations were developed by integrating established biomedical reporting frameworks, organoid-focused resources from international organizations, and structured input from the GI organoid community through an expert panel survey. These inputs informed a core set of reporting items, including stem cell source and donor context, media and supplement composition, extracellular matrix type, culture configuration, and other parameters essential for replication. We provide an "Organoid Reporting Toolkit" containing practical checklists and templates intended to help authors, reviewers, editors, and journals. Together, these resources aim to improve transparency and reproducibility, facilitate cross-study comparison, and streamline communication in the GI organoid field while preserving flexibility for methodological innovation.

Background and aims: Neutrophil functions play a pivotal role in hepatic pathogenesis. Our previous work has established that N2-polarized neutrophils promote hepatic fibrogenesis in Wilson's disease depends on hepatic TGF-β1 production. However, the regulators governing TGF-β1 production in orchestrating disease-associated N2 neutrophils remain elusive. In this study, we investigated the immunomodulatory effects of gut microbiota-derived short-chain fatty acids (SCFAs) on neutrophil polarization.

Approach and results: We report that Akkermansia muciniphila was markedly reduced in the gut microbiota of mice with Wilson's disease, accompanied by decreased SCFA levels, especially propionate. Additionally, transplantation of fecal bacteria from wild-type mice or A. muciniphila could promote an antifibrotic effect, elevate propionate levels, reduce TGF-β1 secretion, and decrease hepatic N2 neutrophils in mice with Wilson's disease. Moreover, administration of propionate also significantly enhanced antifibrotic immunity. Mechanistically, propionate reduced the production of TGF-β1 in hepatocytes by inhibiting histone deacetylase activity, increasing the acetylation of DNAJA3 at sites K134 and K385, thus decreasing expression of DNAJA3. Consistently, gut-derived propionate inversely correlated with hepatic injury severity in Wilson's disease patients, which could be functionally mediated by TGF-β1.

Conclusions: Gut microbiota are pivotal for hepatic neutrophil polarization and liver fibrosis in Wilson's disease. Our findings suggest that therapeutic modulation of gut microbiota, SCFA profiles, and TGF-β1 production, particularly when combined with histone deacetylase inhibitors, may represent promising therapeutic approaches for Wilson's disease.

Background & aims: Tumor immune resistance is recognized as a contributor to low survivorship in pancreatic ductal adenocarcinoma (PDAC). The inflammatory cytokine interleukin-6 (IL-6) promotes polarization of CD4 T cell populations away from immune tolerance, and induces differentiation of cytotoxic CD8 T cells. This work aims to test whether IL-6 could stimulate an anti-tumor response in PDAC METHODS: We overexpressed IL-6 in multiple Kras^G12D/+, Tp53^R172H/+, Pdx1-Cre (KPC) cell lines, which were orthotopically implanted in mice (OT-PDAC^IL6). We followed mouse survival and measured tumor growth, tumor histology, and plasma IL-6 at 5 and 10 days after tumor implantation. We measured tumor immune cell infiltration via flow cytometry and histology. We used antibody-based T cell depletion and secondary tumor implantation rechallenge to test the dependency of the durable immune reaction on T cells. We use lipid nanoparticle (LNP)-based delivery of IL-6 mRNA to the pancreas as an orthogonal approach for testing the effect of elevated IL-6 in the tumor microenvironment on anti-tumor T cell invasion.

Results: Improved survival occurred in all instances of OT-PDAC^IL6, with one cell line (KxPxCx) reproducibly resulting in long-term recurrence-free survival. With KxPxCx cells, circulating IL-6 was 100-fold higher in OT-KxPxCx^IL6 than in OT-KxPxCx^parental mice. Flow cytometry revealed increased T cells and NK cells, and decreased T regulatory cells, and we observed significantly increased lymphoid aggregates in OT-KXPXCX^IL6 as compared to OT--KxPxCx^parental tumors. Antibody-based CD4⁺ and CD8⁺ T cell depletion prevented tumor clearance and completely abolished the survival advantage in OT-KxPxCx^IL6 mice. The anti-tumor immune response to OT-KxPxCx^IL6 rendered mice immune to re-challenge with OT-KxPxCx^parental tumors. LNP delivery of IL-6 to the pancreas elevated systemic IL-6 levels ∼50 fold, lowered tumor burden, and increased anti-tumor T cell phenotypes.

Conclusions: Locally high IL-6 concentrations potently enhance the T cell-mediated anti-tumor response to PDAC.

Background & aims: Patterns of immune cell infiltration (ICI) and tumor genetic variability are key factors affecting liver hepatocellular carcinoma (LIHC) outcomes and treatment response. Yet, their precise roles remain unclear. This study investigates how these immune and genetic factors shape LIHC progression and identifies regulatory genes that could enhance immunotherapy effectiveness.

Methods: We analyzed LIHC datasets from TCGA and GEO, applying CIBERSORT and ESTIMATE algorithms to evaluate the tumor immune microenvironment (TIME) and calculate tumor mutational burden (TMB). ICI scoring was performed to identify survival-associated patterns, and gene set enrichment analysis, WGCNA, and machine learning were employed to uncover immunoregulatory genes. The role of CST7 in ICI and PD-1 blockade response was validated in mouse models.

Results: ICI analysis revealed distinct survival-associated clusters, with patients in Cluster B showing significantly improved survival. Gene subtype A was linked to prolonged survival with enhanced M1 macrophage infiltration. CST7 was identified as a key regulator, promoting CD8+ T cell infiltration and demonstrating synergy with PD-1 antibody therapy. TMB was positively correlated with ICI patterns and served as an independent prognostic marker for LIHC outcomes.

Conclusion: CST7 contributes to enhanced ICI and boosts the efficacy of PD-1 immunotherapy, suggesting its potential as a therapeutic option for LIHC.