Biology subjects

Metwaly, A.

Publications and source records attributed to Metwaly, A..

7 recordsLinked to original sources

bioRxiv2026

Microbial Invasion and Immunosuppression Drives Adenoma Progression in Early Colorectal Cancer Development

Several inherited predispositions to colorectal cancer exist, most notably familial adenomatous polyposis (FAP), which typically involves a germline loss-of-function mutation in one APC allele. A second hit in APC or related loci leads to aberrant Wnt signalling, triggering adenoma formation with near-complete penetrance. Yet, substantial variability in disease onset and severity, even among siblings with identical APC germline mutations, implicates environmental modifiers. Emerging evidence points to the gut microbiome as a critical regulator of adenoma initiation and progression, particularly in early-onset CRC. Here, we show that bacterial invasion is associated with neutrophil immunosuppression, T-cell exclusion and adenoma progression in a porcine model of FAP. Longitudinal mapping of progressing and regressing polyps using single-cell RNA sequencing, spatial transcriptomics and integrated microbiome profiling resolved the cellular and microbial architecture underlying these divergent lesion states. Single-cell RNA-seq identified 35 cell subpopulations and showed that regressing polyps are enriched for central-memory CD4+ T cells, cytotoxic CD8+ T cells and inflammatory neutrophils, whereas progressing polyps contain immunosuppressive/PD-L1-associated neutrophils, regulatory and dysfunctional T cells. Spatial transcriptomics with a custom host panel and targeted bacterial probes linked bacterial-high adenomatous regions to immunosuppressive neutrophil niches and T cell exclusion, while regressing lesions showed predominantly lumen-adjacent bacterial localization and spatially organized immune surveillance. These results provide a spatially resolved map of cellular and microbial organisation in early colorectal polyp progression and regression and reveal a microbiome-driven, neutrophil-mediated mechanism of early tumour progression with implications for CRC interception. Grant support: This study was funded by the German Research Foundation (DFG) through SFB1371 "Microbiome signature" (Project no. 395357507; TF, DS, FE, DH) and by the German Ministry for Research and Education (BMBF) through Mi-EOCRC consortium project (Project no. 01KD2102D; KF and DH).

cancer biology↗

bioRxiv2025

Reduced intestinal GLP-1+ cell numbers are associated with an inflammation-related epithelial metabolic signature

Background & AimsEnteroendocrine cells (EECs) are known for their role in digestion and metabolism, yet their role in intestinal inflammation remains unclear. In inflammatory bowel diseases (IBD), a contribution of EECs to pathogenesis is indicated by autoantibodies affecting EEC function and general disease symptoms like insulin resistance and altered intestinal motility. Particularly, the L cell-derived hormone glucagon-like peptide 1 (GLP-1), suggested to orchestrate metabolic-inflammatory responses may influence inflammatory pathways in the intestine. MethodsWe quantified numbers of GLP-1+ cells in 4 different mouse models of intestinal inflammation and performed transcriptional analyses of colonic epithelial cells from inflamed interleukin (IL)10-deficient mice. Using a publicly available single-cell RNA sequencing dataset including mucosal biopsies from Crohns disease (CD) patients, we confirmed findings from the murine models. A model of mitochondrial dysfunction (ClpP{Delta}IEC mice) as well as murine and human intestinal organoids were used to study molecular mechanisms. ResultsNumbers of GLP-1 expressing cells are consistently reduced at the site of active disease in mouse models and CD patients. Despite this reduction, L cells from inflamed IL-10-deficient mice remained functional regarding GLP-1 secretion. Transcriptional analyses of intestinal epithelial cells indicate altered differentiation correlating with an inflammatory metabolic fingerprint. Reduced GLP-1+ cells in ClpP{Delta}IEC mice and inhibition of respiration in organoid cultures supports a causative role for metabolism in steering differentiation. ConclusionReduction of GLP-1+ cells represents a general feature of ileal and colonic inflammation in mice and human. Given the numerous properties of GLP-1, this reduction likely affects inflammatory processes in the mucosa and disease-related symptoms on multiple levels, and therefore, should be considered a therapeutic target in IBD. Data TransparencyAll data generated or analyzed during this study are included in this published article. Additional datasets, including raw data, are available from the corresponding author upon reasonable request. SynopsisThis study examines GLP-1+ cells in intestinal inflammation, showing consistent reductions in inflamed areas. Findings from mouse models and human data reveal an inflammatory metabolic profile linked to altered epithelial differentiation. GLP-1, involved in endocrine-immune crosstalk, may impact mucosal inflammation and symptoms, making it a therapeutic target. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=80 SRC="FIGDIR/small/641577v2_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@136158borg.highwire.dtl.DTLVardef@1c08461org.highwire.dtl.DTLVardef@332635org.highwire.dtl.DTLVardef@117d5f_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

bioRxiv2024

Susceptibility to inflammatory bowel diseases promotes invasive carcinomas in a murine model of ATF6-driven colon cancer

Chronic inflammation in inflammatory bowel disease (IBD) patients represents a risk factor for developing colitis-associated cancer (CAC). We previously linked the endoplasmic reticulum unfolded protein response (UPRER) signal transducer activating transcription factor 6 (ATF6) with spontaneous microbiota-dependent colonic adenoma development in mice expressing epithelial-specific activated ATF6 (nATF6IEC). To investigate IBD-related risk factors in ATF6-mediated tumorigenesis, we crossed tumor-free monoallelic (tg/wt) nATF6IEC mice with Interleukin-10 deficient mice (Il10-/-). IL10 deficiency initiated tumor susceptibility, with 77% of 12-week tg/wt;Il10-/- mice developing colonic adenomas and invasive carcinomas in this novel CAC mouse model. Tumor formation correlated with mucosal immune cell infiltration, characterized by CD11b+ granulocytes and monocytes, and mucosa-associated dysbiosis. Colonization of germ-free nATF6IEC;Il10-/- mice with minimal biosynthetic consortia and IBD stool re-established CAC, confirming microbiota-dependent ATF6-driven tumorigenesis. Increased ATF6 expression in IBD patients during active disease highlights its human relevance. Our findings show that IBD susceptibility heightens the risk for ATF6-driven tumorigenesis. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=103 SRC="FIGDIR/small/624835v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@17e280eorg.highwire.dtl.DTLVardef@177ceacorg.highwire.dtl.DTLVardef@a1916borg.highwire.dtl.DTLVardef@152374f_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2024

Microbiota metabolized Bile Acids accelerate Gastroesophageal Adenocarcinoma via FXR inhibition

BackgroundThe incidence of Barrett esophagus (BE) and Gastroesophageal Adenocarcinoma (GEAC) correlates with obesity and a diet rich in fat. Bile acids (BA) support fat digestion and undergo microbial metabolization in the gut. The farnesoid X receptor (FXR) is an important modulator of the BA homeostasis. The capacity of inhibiting cancer-related processes when activated, make FXR an appealing therapeutic target. In this work, we assess the role of diet on the microbiota-BA axis and evaluate the role of FXR in disease progression. ResultsHere we show that high fat diet (HFD) accelerated tumorigenesis in L2-IL1B mice (BE- and GEAC- mouse model) while increasing BA levels and enriching gut microbiota that convert primary to secondary BA. While upregulated in BE, expression of FXR was downregulated in GEAC in mice and humans. In L2-IL1B mice, FXR knockout enhanced the dysplastic phenotype and increased Lgr5 progenitor cell numbers. Treatment of murine organoids and L2-IL1B mice with the FXR agonist obeticholic acid (OCA) deacelerated GEAC progression. ConclusionWe provide a novel concept of GEAC carcinogenesis being accelerated via the diet-microbiome-metabolome axis and FXR inhibition on progenitor cells. Further, FXR activation protected with OCA ameliorated the phenotype in vitro and in vivo, suggesting that FXR agonists have potential as differentiation therapy in GEAC prevention. Statement of significanceIf its inhibition is linked to disease progression and its activation to cancer prevention, exploring the potential of FXR as a therapeutic target has great clinical relevance in GEAC context.

cancer biology↗

bioRxiv2023

Mitochondrial perturbation of the epithelium causes microbial dysbiosis and unresolved tissue injury in intestinal inflammation

Mitochondrial dysfunction is associated with inflammatory bowel diseases (IBD). To understand how microbial-metabolic circuits contribute to intestinal tissue injury, we disrupt mitochondrial function in the epithelium by deleting heat shock protein 60 (Hsp60{Delta}/{Delta}IEC). While metabolic perturbation causes self-resolving tissue injury, regeneration is disrupted in the absence of aryl hydrocarbon receptor (Hsp60{Delta}/{Delta}IEC;AhR-/-) or IL-10 (Hsp60{Delta}/{Delta}IEC;Il10-/-) leading to IBD-like pathology. Injury is absent in the distal colon of germ-free (GF) Hsp60{Delta}/{Delta}IEC mice, highlighting bacterial control of metabolic injury. Selective colonization of GF Hsp60{Delta}/{Delta}IEC mice with the synthetic community OMM12 confirms consistent expansion of metabolically-flexible Bacteroides spp. across all models and mono-colonization with B. caecimuris recapitulates injury. Transcriptional profiling of metabolically-impaired epithelium identifies gene signatures, including Ido1, Nos2, and Duox2, distinguishing active from inactive tissue inflammation in 343 resected samples from Crohns disease patients. In conclusion, mitochondrial perturbation of the epithelium causes microbiota-dependent tissue injury and discriminative inflammatory gene profiles relevant for IBD. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=171 SRC="FIGDIR/small/549844v6_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@240c5forg.highwire.dtl.DTLVardef@a84382org.highwire.dtl.DTLVardef@e829e3org.highwire.dtl.DTLVardef@163625_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical Abstract:C_FLOATNO Control of metabolic injury by microbial signals. C_FIG O_LIMitochondrial perturbation of the intestinal epithelium induces tissue injury C_LIO_LILoss of IL-10 and AhR-related host mechanisms accelerate injury and inflammation C_LIO_LIMitochondrial dysfunction induces dysbiosis and expansion of Bacteroides spp. C_LIO_LIMetabolic injury gene signature discriminates inflamed vs. non-inflamed IBD samples C_LI

microbiology↗

bioRxiv2022

A translational swine model for Crohn`s disease

Crohns Disease (CD) is incurable, and represents a lifelong burden for patients and its incidence is increasing worldwide. A key contributing factor is a dysregulated immune response. Here we report the generation of genome edited pigs with a deletion of the transcript-destabilizing AU-rich element (ARE) and a constitutive decay element (CDE) in the TNF gene which recapitulate major characteristics of human CD, including ulcerative transmural ileocolitis, increased abundance of proinflammatory cytokines, evidence for impaired integrity of the intestinal epithelial cell barrier, immune cell infiltration, and dysbiotic microbial communities. This physiologically relevant CD model enables human-scale and long-term studies to assess diagnostic, nutritional or microbial interventions, filling the gap for translating findings into the clinic.

bioengineering↗

bioRxiv2022

Diet prevents the expansion of segmented filamentous bacteria and ileo-colonic inflammation in a model of Crohn's disease

Crohns disease (CD) is associated with changes in the microbiota, and murine models of CD-like ileo-colonic inflammation depend on the presence of microbial triggers. Increased abundance of unknown Clostridiales and the microscopic detection of filamentous structures close to the epithelium of Tnf {Delta}ARE mice pointed towards segmented filamentous bacteria (SFB), a commensal well-known to induce the maturation of Th17 cell-derived immune responses that is highly implicated in the pathogenesis of IBD. We show that the abundance of SFB strongly correlates with the severity of CD-like ileal inflammation in Tnf {Delta}ARE and SAMP/Yit mice. SFB mono-colonization of germ-free Tnf {Delta}ARE mice confirmed the causal link and resulted in severe ileo-colonic inflammation, characterized by elevated tissue levels of Tnf and Il-17, neutrophil infiltration and loss of Paneth and goblet cell function. Co-colonization of SFB in human-microbiota associated Tnf {Delta}ARE mice confirmed that SFB presence is indispensable for disease development. Screening of 412 ileal and colonic mucosal biopsies from IBD patients using previously published and newly designed human SFB-specific primer sets showed no presence of SFB in human tissue samples. Simulating the protective effect of exclusive enteral nutrition (EEN) by feeding SFB mono-colonized Tnf {Delta}ARE mice EEN-like purified diet antagonized SFB colonization and prevented disease development in Tnf {Delta}ARE mice, clearly demonstrating the important role of diet in modulating this IBD-related but murine pathobiont.

microbiology↗