Colonic Mucosa Research Articles

P0044 What are the similarities between primary immunodeficiency states and ulcerative colitis: damage to the microbiome, impaired mucosal secretion of proteins and short-chain fatty acids, or something else?

Abstract Background Primary immunodeficiency (PID), common variable immunodeficiency (CVID) are primary immunodeficiencies with disorder of the adaptive immune system, organ-specific pathology, as well as defects in the gut microbiome [1]. In patients with ulcerative colitis (UC) during relapse, similar changes. Methods The aim of the research is a comprehensive study of the structure of gut microbiota and mucosal protein profile (MPP) in patients with PID, CVID and UC in different phases of the disease course. The research included 19 patients with PID, 28 with CVID and 32 with UC (22 with relapse and 10 with persistent remission of the disease), control group - 20 healthy volunteers. Estimation of gut microbiota was performed by microbacteriological seeding faeces (MSF). Content of short-chain fatty acids (SCFA) in the feces as determined by gas-chromatography-mass spectrometry (GC-MS). Mucosal protein profile was based on isoelectric focusing techniques (SDS-PAGE, 2DGE). Mass spectrograms were obtained using MALDI-TOF-MS/MS (Bruker, USA). Molecular interaction and functional characteristics of proteins were studied using the STRING 10.0 databases. Results SCFA production showed a 6-, 9- and 11-fold decrease in propionic and butyric acids, mainly in patients with PID and UC: 0.2 + 0.1, 0.14 + 0.03 and 0.04 + 0.02, 0.08 + 0.02 mg/g, respectively (tab. 1). MSF showed a decrease in titers of E. coli, bifido- and lactobacilli on average 4.6 + 0.8 Lg. The conditionally pathogenic microbiota was represented by E. coli, hemolytic strains (n=34,104/g), Proteus spp. (n=48,105/g), Staphylococcus spp. (n=29,105–6/g), Candida alb. / glabrata (n=55,104–6/g) and Clostridium spp. (n = 38,104/g). Results of MPP (detection rate of 75% or more) of the colon mucosa in patients with PID and CVID were detected: 1, 2, 4 okkludin, kininogen 1, interleukin-1B, interleukin 8, B2-glycoprotein, heat shock protein 27, in patients with CVID - translational elongation factor, apolipoprotein C-III. In patients with UC - NF-kB, alipoprotein C-III, TNF-α, heat shock protein 27, interleukin-2 and 8 were presented. MPP patients with UC (stable remission phase): a-enolase, b-defensin-1, cathepsin D, prohibitin (tab. 2). Conclusion 1. In patients with PID, CVID and UC during relapse, markers of damage to the intestinal microbiome, a decrease in the production of SCFA and proteins characteristic of inflammation, apoptosis, proliferation, as well as proteins reflecting the activity of the autoimmune process, were identified. 2. During the period of drug remission in patients with UC, PID and CVID, specific components of altered MPP disappear, and a tendency towards restoration of the gut microbiota and SCFA production is recorded. References Jørgensen SF, Trøseid M, Kummen M, et al. Altered gut microbiota profile in common variable immunodeficiency associates with levels of lipopolysaccharide and markers of systemic immune activation. Mucosal Immunol. 2016; 9:1455-1465.

DOP120 Low-intensity Pulsed Ultrasound Modulates Metabolite Release Reflecting the Inflammatory Status of Colonic Mucosa

Abstract Background Recently, we investigated Low-Intensity Pulsed Ultrasound (LIPUS) as a non-invasive and safe method to identify circulating biomarkers that reflect the colonic mucosal status in experimental colitis models. Here, we evaluate the capability of LIPUS to reveal a wide spectrum of tissue-derived proteins and metabolites as potential biomarkers of colitis. Methods Acute colitis was induced in 10 female C57B6N mice by ad-libitum administration of 2,5% dextran sodium sulfate (DSS) for 7 days. Colon-focused LIPUS stimulation (38 kHz, 150 mW/cm2, 20% duty cycle, 3 minutes) was applied at day 7 of colitic and healthy mice. Blood samples were collected 2 hours post-LIPUS exposure and plasma was analyzed by Olink® proteomics and LC-MS untargeted metabolomics. STRING database and Metabolite Enrichment Analysis Set (MSEA) were used for comprehensive pathway evaluation of proteins and metabolites. Results As expected, DSS-treated murine plasma displayed altered proteomic and metabolomic profiles compared to healthy controls at baseline, with a significant exacerbation of IL-6, IL-17A and TNF-family inflammatory mediators, tryptophan intermediates and microbial metabolites. LIPUS did not alter the cytokine profile observed before stimulation. However, microbiota-associated compounds involved in tryptophan, glutamate and riboflavin pathways, as well as phospatidylcholine (PE) family members, such as Lyso-PE, were significantly enhanced in the blood of colitic mice after LIPUS stimulation, conceiving the inflammatory status of the intestinal mucosa. Conversely, LIPUS stimulation in healthy mice upregulated circulating factors (Tnni3, Dlk1, lgmn and Kitlg) which are expressed by intestinal epithelial cells and that play a role in the epithelial-immune cell crosstalk. Nucleoside precursors of the pyrimidine metabolism and galacturonate involved in the vitamin C synthesis, which are potentially involved in intestinal mucosa homeostasis, were also significantly increased after LIPUS stimulation in healthy mice plasma. Conclusion LIPUS differentially enhances the release of specific metabolites based on the inflammatory status of the colonic mucosa. Thus, uninflamed LIPUS-stimulated intestinal mucosa releases proteins indicative of mucosal health, whilst injured intestinal mucosa readily discharges metabolites associated with the inflammatory process. This suggests the potential utility of LIPUS as a non-invasive diagnostic tool for gut inflammation assessment, improving diagnostic accuracy and efficiency in patients with colonic disorders. Further research is needed to validate these findings in humans for clinical parameter correlation. References ImmUniverse project: this project has received funding from the Innovative Medicines Initiative 2 Joint Undertaking (JU) under grant agreement No. 853995. The JU receives support from the European Union’s Horizon 2020 research and innovation programme and EFPIA. The content provided in this abstract reflects only the author's view and neither the IMI JU nor the European Commission are responsible for any use that may be made of the information it contains.

DOP123 Linking microbial genes to mucosal metabolites uncovers host-microbial interactions during 5-ASA therapy for ulcerative colitis

Abstract Background The severity of ulcerative colitis (UC) depends on the state of the colon mucosa, where achieving mucosal remission markedly improves patient prognosis and quality of life. The study aimed to characterize essential mucosal metabolites and microbial gene involved in UC remission, and to elucidate the mechanisms by which specific metabolites regulate intestinal homeostasis. Methods An integrated metagenomic and metabolomic analysis was conducted to elucidate the correlation between disease-associated microbes and host mucosal metabolites. Participants included non-UC controls and individuals with UC, comprising the responding group (UCR) and ineffective group (UCA) in 5-ASA treatment. The differential metabolite was further investigated using a DSS-induced colitis mouse model, followed by in vitro experiments to explore the mechanisms. Results The levels of mucosal secondary bile acids were found to have a significant negative association with intestinal inflammation during 5-ASA treatment. Integrated analysis of metagenomics and metabolomics revealed that host mucosal bile acid metabolites were negatively associated with the bile acid synthesis-related genes cbh in microbial genomes. Administration of the secondary bile acid mitigated mucosal inflammation in a colitis model by decreasing the proportion of Th17 and pathogenic Th17 cells. This secondary bile acid functions as an immunomodulatory metabolite, suppressing glycolysis in Th17-polarizing T cells to inhibit the Th17 cell response and modulating the gut microbiota. Conclusion These findings suggest that alterations in microbiome-metabolome interactions are critical for maintaining mucosal homeostasis during UC remission. The specific bile acid acts as an immunomodulatory metabolite, and may represent a potential therapeutic strategy for UC.

Inflammation Targeting-Triggered Healing Hydrogel for In Situ Reconstruction of Colonic Mucosa.

Inflammatory bowel disease (IBD) is characterized by intestinal mucosal damage that exacerbates inflammation and promotes disease recurrence. Although hydrogel-based therapies have shown potential for mucosal repair, challenges remain due to inadequate targeting and low hydrogel density, leading to ongoing infiltration of harmful substances and delayed mucosal healing. In this study, an inflammation-targeting-triggered healing hydrogel (ITTH hydrogel) is developed, composed of polyvinyl alcohol-alginate microgels (PALMs) and a cyclodextrin polymer crosslinker (CPC). This hydrogel specifically targets inflamed colonic sites and crosslinks in situ to form a dense network. The results demonstrate that the ITTH hydrogel adheres effectively to inflamed colonic tissue in both IBD mouse models and human samples. The dense crosslinked network acts like the mucosal barrier, preventing the penetration of detrimental substances such as bacteria and small molecules, thereby protecting the underlying mucosal tissue. Furthermore, the ITTH hydrogel significantly improved therapeutic outcomes in mice with dextran sulfate sodium (DSS)-induced colitis. These findings suggest that the ITTH hydrogel is a promising candidate for in situ reconstruction of colonic mucosa and the treatment of IBD.

Disrupted mitochondrial morphology and function exacerbate inflammation in elderly-onset ulcerative colitis

BackgroundThe characteristics of ulcerative colitis (UC) in the elderly are quite different from the young population. Mitochondrial injury is a key mechanism regulating both aging and inflammation. This study aims to reveal the role of mitochondrial damage in the pathogenesis of adult- and elderly-onset UC.MethodsRNA-sequencing of colonic mucosa from adult- and elderly-onset UC patients was performed. Mitochondria-related differentially expressive genes (mDEGs) and immune cell infiltration analysis were identified and performed in colonic tissues from UC patients. Mice aged 6–8 weeks and 20–24 months were administered 2% dextran sodium sulphate (DSS) for 7 days to induce colitis. Mitochondrial morphological changes and ATP levels were evaluated in the colons of mice. Mechanistically, we explored the association of key mDEG with reactive oxygen species (ROS), oxygen consumption rates, NLRP3/IL-1β pathway in HCT116 cell line.ResultsThirty mDEGs were identified between adult- and elderly-onset UC, which were related primarily to mitochondrial respiratory function and also had significant correlation with different infiltrates of immune cells. Compared with young colitis mice, DSS-induced colitis in the aged mice exhibited more severe inflammation, damaged mitochondrial structure and lower ATP levels in colonic tissues. ALDH1L1 was identified as a hub DEG through protein–protein interaction networks of RNA-seq, which was downregulated in UC patients or colitis mice versus healthy controls. In tumor necrosis factor-alpha-stimulated HCT116 cells, mitochondrial ROS, NLRP3 and IL-1β expression increased less and mitochondrial respiration had an upregulated trend after knocking down ALDH1L1.ConclusionThere are significant differences in mitochondrial structure, ATP production and mitochondria-related gene expression between adult- and elderly-onset UC, which have a potential link with cytokine pathways and immune microenvironment. The more prominent mitochondrial injury may be a key factor for more severe inflammatory response and poorer outcome in elderly-onset UC.

The Correlation Between Fecal Amino Acids, Colonic Mucosal Taste Receptors, and Clinical Features and Indicators of Ulcerative Colitis: A Multicenter Exploratory Study.

Patients with ulcerative colitis (UC) exhibit abnormal amino acid (AA) metabolism. Taste receptors play a crucial role in the detection of intestinal AAs. Nevertheless, it remains unclear whether UC patients exhibit abnormal expression of these receptors in the colon. An observational, multicenter study was conducted involving adult patients with active UC and healthy controls (HCs), recruited from July 2023 to March 2024. Fresh feces and rectosigmoid mucosal tissues were obtained from each participant. The concentrations of fecal AAs and the expression of taste receptors, including calcium-sensing receptor (CaSR), G protein-coupled receptor family C group 6 member A (GPRC6A), taste receptor type 1 member 1 (T1R1), and metabotropic glutamate receptor 4 (mGLuR4), in the colon were measured. Additionally, the correlation between colonic mucosal taste receptors and clinical characteristics was evaluated. Except for GPRC6A, the expression levels of CaSR, mGLuR4, and T1R1 in the colonic mucosa of UC patients were significantly elevated compared to HC. The expression of CaSR was negatively correlated with C-reactive protein and erythrocyte sedimentation rate (ESR). T1R1 expression positively correlated with defecation frequency and an Improved Mayo Endoscopic Score. The total and subtype concentrations of fecal AAs were elevated in UC patients and demonstrated a negative correlation with ESR and fecal calprotectin. The increased levels of taste receptors and fecal AAs in the colon of UC patients suggest an abnormal nutrient-sensing mechanism, potentially playing a crucial role in the development of the disease.

Effects of prebiotics from diverse sources on dysbiotic gut microbiota associated to western diet: Insights from the human Mucosal ARtificial COLon (M-ARCOL).

Associated to various illnesses, Western Diet (WD) is acknowledged to have deleterious effects on human gut microbiota, decreasing bacterial diversity, lowering gut bacteria associated to health (such as Akkermansia muciniphila), while increasing those linked to diseases (e.g., Proteobacteria). In this study, we evaluated the potential of two new prebiotics to counteract the negative effect of WD on gut microbiota, namely raffinose family oligosaccharides (RFO) from chickpeas and laminarin (LAM) from algae, when compared to the well-known inulin (INU). The effects of prebiotics on gut microbiota composition and metabolic activities were investigated in the Mucosal-Artificial Colon, set-up to reproduce WD condition, as compared to healthy control (n=3). None of the prebiotics was able to efficiently offset the shift in microbiota induced by WD. Nevertheless, when compared to non-supplemented WD, all prebiotics showed significant impacts on microbiota composition, that were both prebiotic and donor-dependant. RFO was the only prebiotic to enhance α-diversity, while it led to an increase in Blautia and Butyricicoccaceae, associated with higher amounts of gas and butyrate. LAM and INU did not strongly impact microbial metabolic activities but were associated with a rise in Prevotella_9/Agathobacter and Faecalibacterium, respectively. To conclude, this study showed that all tested prebiotics had different impacts on human gut microbiota structure and activities, which was further donor-dependent. M-ARCOL appears as a suitable in vitro tool to better understand the mechanisms of action of prebiotic compounds in relation to gut microbes and define responders and non-responders to prebiotic supplementation, opening the possibility of customized nutritional strategies.

Protein abundance of drug transporters and drug-metabolizing enzymes in paired healthy and tumor tissue from colorectal cancer patients.

The widespread prevalence of colorectal cancer and its high mortality rate emphasize the urgent need for more effective therapies. When developing new drug products, a key aspect is ensuring that sufficiently high concentrations of the active drug are reached at the site of action. Drug transporters and drug-metabolizing enzymes can significantly influence the absorption and local accumulation of drugs in intestinal tissue. To understand how their presence may affect local drug disposition, the protein abundance of multiple drug transporters and drug-metabolizing enzymes was quantified in paired healthy colonic mucosa and colorectal adenocarcinoma tissue from colorectal cancer patients, utilizing mass spectrometry-based targeted proteomics. Statistically significant changes in protein expression were observed for two transporters (MRP1 and BCRP) and three of the studied enzymes (CES1, CES2 and UGT2B17). MRP1 displayed higher levels in cancerous tissue compared to healthy mucosa samples, while BCRP, CES1, CES2 and UGT2B17 showed the opposite. Other proteins of interest which could be quantified in colonic samples were the drug transporters P-gp, MRP3, MRP4, OATP2B1, MCT1 and enzymes CYP4F2, CYP2J2 and UGT1A1. The insights from this study enhance our understanding of the extent to which drug disposition in tumor tissue of colorectal cancer patients could be impacted by drug transporters and drug-metabolizing enzymes and may facilitate a more accurate prediction of local drug concentrations.

Strategies, Technologies, and Tips for Successful Cecal Intubation.

Successful cecal intubation is crucial in ensuring a complete evaluation of the colonic mucosa. Although completion of colonoscopies should be successful in close to 100% of all examinations in the hands of experienced gastroenterologists, there are some patients with colons which can be difficult to navigate. Factors such as older age, presence of diverticular disease, as well as high or low body mass index can present challenges for endoscopists. Challenges can be divided into those that are left sided and are associated with severe angulations of the colon versus those that are right sided and present as redundant colons. Both require different strategies to achieve completion. This review will cover methods, technologies as well the evolution of colonoscope insertion tubes which can help in navigating colons, especially those that are challenging. There will also be a discussion about basic principles and techniques that should be employed in all colonoscopies.

Aldehyde free - Bovine Pericardium - A New Option of Graft in Urethral Stricture Treatment.

The current management for complex urethral strictures commonly uses open reconstruction with buccal mucosa urethroplasty. However, there are multiple situations whereby buccal mucosa is inadequate (pan-urethral stricture or prior buccal harvest) or inappropriate for utilization (heavy tobacco use or oral radiation). Multiple options exist for use as alternatives or adjuncts to buccal mucosa in complex urethral strictures (injectable antifibrotic agents, augmentation urethroplasty with skin flaps, lingual mucosa, bladder mucosa, colonic mucosa, and new developments in tissue engineering for urethral graft material) (1, 2). In the present video, we present a case where we used a new option of graft to treat urethral strictures: the L-Hydro® tissue treatment technology 100% aldehyde free, VIVENDI graft. The present study was approved according to the ethical standards of the hospital's institutional committee on experimentation with human beings. A 57 year-old male patient developed a urethral stricture due to prolonged use of a urinary catheter during a previous hospitalization. A cystourethrogram was performed, which revealed a stenosis of the penile urethra measuring 2.5 cm in length. Urethroplasty was proposed for the surgical treatment in this case. We used a longitudinal penile incision with a ventral sagittal urethrotomy in the penile stricture. A free VIVENDI graft was placed into the longitudinal incision in the dorsal urethra and fixed with interrupted suture as dorsal inlay. The ventral urethrotomy was closed over a 16Fr Foley catheter and the skin incision was then closed in layers. The patient will receive post-operative follow-up for 3 months for clinical assessment through symptoms, uroflowmetry, urethroscopy and residual urine volume after urination. No intraoperative or postoperative complications occurred. The patient could achieve satisfactory voiding and no complication was seen during the three-month follow-up. Four weeks after surgery, he underwent urethroscopy, which revealed a good appearance of the urethra, with no stenosis or signs of infection. In the present case the use of bovine pericardium graft for the treatment of penile urethral stricture had a good result and can be an option to repair complex urethral strictures. However, the results presented require a larger population group in addition to multicenter studies with longer follow-up time to ensure the findings obtained. Available at: http://www.intbrazjurol.com.br/video-section/20249928_Vieiralves_et_al.

Ulcerative Colitis, LAIR1 and TOX2 Expression, and Colorectal Cancer Deep Learning Image Classification Using Convolutional Neural Networks.

Ulcerative colitis is a chronic inflammatory bowel disease of the colon mucosa associated with a higher risk of colorectal cancer. This study classified hematoxylin and eosin (H&E) histological images of ulcerative colitis, normal colon, and colorectal cancer using artificial intelligence (deep learning). A convolutional neural network (CNN) was designed and trained to classify the three types of diagnosis, including 35 cases of ulcerative colitis (n = 9281 patches), 21 colon control (n = 12,246), and 18 colorectal cancer (n = 63,725). The data were partitioned into training (70%) and validation sets (10%) for training the network, and a test set (20%) to test the performance on the new data. The CNNs included transfer learning from ResNet-18, and a comparison with other CNN models was performed. Explainable artificial intelligence for computer vision was used with the Grad-CAM technique, and additional LAIR1 and TOX2 immunohistochemistry was performed in ulcerative colitis to analyze the immune microenvironment. Conventional clinicopathological analysis showed that steroid-requiring ulcerative colitis was characterized by higher endoscopic Baron and histologic Geboes scores and LAIR1 expression in the lamina propria, but lower TOX2 expression in isolated lymphoid follicles (all p values < 0.05) compared to mesalazine-responsive ulcerative colitis. The CNN classification accuracy was 99.1% for ulcerative colitis, 99.8% for colorectal cancer, and 99.1% for colon control. The Grad-CAM heatmap confirmed which regions of the images were the most important. The CNNs also differentiated between steroid-requiring and mesalazine-responsive ulcerative colitis based on H&E, LAIR1, and TOX2 staining. Additional classification of 10 new cases of colorectal cancer (adenocarcinoma) were correctly classified. CNNs are especially suited for image classification in conditions such as ulcerative colitis and colorectal cancer; LAIR1 and TOX2 are relevant immuno-oncology markers in ulcerative colitis.

Multi-omic analysis of biological aging biomarkers in long-term calorie restriction and endurance exercise practitioners: A cross-sectional study.

Calorie restriction (CR) and physical exercise (EX) are well-established interventions known to extend health span and lifespan in animal models. However, their impact on human biological aging remains unclear. With recent advances in omics technologies and biological age (BioAge) metrics, it is now possible to assess the impact of these lifestyle interventions without the need for long-term follow-up. This study compared BioAge biomarkers in 41 middle-aged and older adult long-term CR practitioners, 41 age- and sex-matched endurance athletes (EX), and 35 sedentary controls consuming Western diets (WD), through PhenoAge: a composite score derived from nine blood-biomarkers. Additionally, a subset of participants (12 CR, 11 EX, and 12 WD) underwent multi-omic profiling, including DNA methylation and RNAseq of colon mucosa, blood metabolomics, and stool metagenomics. A group of six young WD subjects (yWD) served as a reference for BioAge calculation using Mahalanobis distance across six omic layers. The results demonstrated consistently lower BioAge biomarkers in both CR and EX groups compared to WD controls across all layers. CR participants exhibited lower BioAge in gut microbiome and blood-derived omics, while EX participants had lower BioAge in colon mucosa-derived epigenetic and transcriptomic markers, suggesting potential tissue-specific effects. Multi-omic pathway enrichment analyses suggested both shared and intervention-specific mechanisms, including oxidative stress and basal transcription as common pathways, with ether lipid metabolism uniquely enriched in CR. Despite limitations due to sample size, these findings contribute to the broader understanding of the potential anti-aging effects of CR and EX, offering promising directions for further research.

Bile acid–induced metabolic changes in the colon promote Enterobacteriaceae expansion and associate with dysbiosis in Crohn’s disease

Bile acids (BAs) affect the growth of potentially pathogenic commensals, including those from the Enterobacteriaceae family, which are frequently overrepresented in inflammatory bowel disease (IBD). BAs are normally reabsorbed in the ileum for recycling and are often increased in the colonic lumina of patients with IBD, including those with Crohn’s disease (CD). Here, we investigated the influence of BAs on gut colonization by Enterobacteriaceae. We found increased abundance of Enterobacteriaceae in the colonic mucosae of patients with CD with a concomitant decrease in the transporters that resorb BAs in the ileum. The increase in Enterobacteriaceae colonization was greater in the colons of patients who had undergone terminal ileum resection compared with those with intact ileum, leading us to hypothesize that BAs promote intestinal colonization by Enterobacteriaceae. Exposure of human colonic epithelial cell lines to BAs reduced mitochondrial respiration, increased oxygen availability, and enhanced the epithelial adherence of several Enterobacteriaceae members. In a publicly available human dataset, mucosal Enterobacteriaceae was negatively associated with the expression of genes related to mitochondrial function. In a murine model, increased intestinal BA availability enhanced colonization by Escherichia coli in a manner that depended on bacterial respiration. Together, our findings demonstrate that BAs reduce mitochondrial respiration in the colon, leading to an increase in oxygen availability that facilitates Enterobacteriaceae colonization. This identification of BAs as facilitators of host-commensal interactions may be relevant to multiple intestinal diseases.

Impact of Nursing Interventions via Telephone and Email on the Quality of Life of Patients with Inflammatory Bowel Disease: Preliminary Results of a Comparative Observational Study.

Inflammatory bowel disease (IBD), encompassing ulcerative colitis and Crohn's disease, is a heterogeneous chronic condition characterized by periods of relapse and remission. Ulcerative colitis involves inflammation of the colon and rectum mucosa, while Crohn's disease causes deeper, transmural inflammation affecting all four gut layers from the mouth to the anus and can lead to complications such as fistulation. IBD significantly impacts patients' physical and psychological well-being, thus reducing their quality of life (QoL). We aimed to evaluate the effectiveness of nursing intervention facilitated through telephone and email support in improving the quality of life (QoL) of Inflammatory Bowel Disease (IBD) patients. A pilot comparative observational design with pre-test and post-test assessments was employed, involving 50 participants assigned to either an intervention group (Group A, n = 26) or a control group (Group B, n = 24). Group A received regular telephone consultations and prompt email responses from trained nurses; Group B received standard care. Data were collected at baseline and six months post-intervention (T1) using the Patient-Reported Outcomes Measurement Information System (PROMIS®) and Pittsburgh Sleep Quality Index. Group A showed significant improvements in anxiety, depression, fatigue, and sleep quality, with p-values indicating the significance of these findings. Tailored nursing support via remote communication significantly benefits IBD patients by alleviating psychological distress and enhancing their overall well-being, underscoring the importance of integrating such interventions into standard IBD care practices.

Comparative segmental evaluation of molecular features of colonic mucosa in villous adenomas

Aim. This study aims to determine the frequency of solitary villous adenomas by colon segment and to compare the molecular genetic features of villous adenomas with the mucosa of the indexed segment and between different colon segments, as well as to consider the characteristics of unchanged mucosa of similar colon segments.Methods. A continuous cross-sectional retrospective study of 3,086 colonoscopy results was performed. In the study, 347 cellular specimens were analysed, including 109 villous adenomas, 101 index segment mucosa samples and 137 normal mucosa samples. Detection of miRNAs and mRNAs was conducted using real-time PCR. Somatic mutations were identified with allele-specific PCR and a hydrolysable probe.Results. The overall frequency of villous adenomas in the structure of all detected epithelial neoplasms was 3%. The frequency of villous adenomas was predominant in the sigmoid colon, while in other segments of the colon their frequency did not differ significantly. The frequency of severe dysplasia was associated with the adenoma diameter. Gene mutations similar to changes in villous adenomas were detected in the mucosa of index segments in the rectum, sigmoid colon and descending colon. Evaluation of the relative expression of 9 miRNAs and 9 protein-coding genes associated with the development of CRC in the mucosa of index segments and similar mucosal segments without adenomas did not reveal significant differences. The medians of relative expression levels of the most relevant markers – NOX1, LGR5, S4A12, TIMP, Ki-67, and TERT genes, as well as miRNA-135b, -20a, -21, -31, and -34a – were compared between different colon sections.Conclusion. The results suggest that inspecting and biopsying unchanged mucosa, even within the index segment, does not provide insight into the risk of developing villous adenoma.

Human colonic organoids for understanding early events of familial adenomatous polyposis pathogenesis.

Patients with familial adenomatous polyposis (FAP) harbor mutations in the APC gene and will develop adenoma and early colorectal cancer. There is no validated treatment, and animal models are not sufficient to study FAP. Our aim was to investigate the early events associated with FAP using the intestinal organoid model in a single-center study using biopsies from nonadenomatous and adenomatous colonic mucosa of FAP patients and from healthy controls (HCs). We analyzed intestinal stem cell (ISC) activity and regulation through organoid development and expression of mRNA and proteins, as well as within colonic crypts. We used several compounds to regulate the signaling pathways controlling ISCs, such as WNT, EGFR, PI3K-AKT, TGF-β, yes-associated protein (YAP), and protease-activated receptors. In addition to their high proliferative capacity, nonadenomatous and adenomatous organoids were characterized by cysts and cysts with buds, respectively, suggesting abnormal maturation. Adenomatous organoids were enriched in the stem cell marker LGR5 and dependent on EGF and TGF-β for their growth. Downstream of EGFR, AKT, β-catenin, and YAP were found to be activated in the adenomatous organoids. While the p110β isoform of PI3K was predominant in adenomatous organoids and essential for their growth, p110α was associated with the immature state of nonadenomatous organoids. We conclude that organoids offer a relevant model for studying FAP, and this work highlights abnormal behaviors of immature cells in both nonadenomatous and adenomatous mucosa of FAP patients, which could be targeted therapeutically. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

The Gut-Lung Axis During Ethanol Exposure and a Pseudomonas aeruginosa Bacterial Challenge.

Background: Susceptibility to and severity of pulmonary infections increase with ethanol consumption. We have previously shown that ethanol-induced changes in the gut microbiome disrupt gut homeostasis, allowing for the translocation of proinflammatory mediators into the circulation and eliciting an immune response in the lung. Additionally, targeting the gut with butyrate supplementation not only rescues ethanol-induced disruptions to gut health but also reverses aspects of immune dysregulation in the lungs. Here, we assessed the impact of this connection on a subsequent infectious challenge. Methods: To assess if ethanol-induced alterations to the gut microbiome could also impact the host response to a pulmonary infectious challenge, we employed a chronic-binge ethanol-feeding mouse model followed by a nasal instillation of Pseudomonas aeruginosa. Results: In addition to altering gut microbiome composition and metabolism, ethanol consumption also disrupted the local immune response as demonstrated by suppressed cecal SIgA levels, a decreased presence of CD3+CD8a+ cytotoxic T cells in the proximal colon mucosa, and depleted CD3+CD8a+ T cells and CD11c+CD8a+ dendritic cells in the mesenteric lymph nodes. Circulatory Ly6G+CD11b+ neutrophils increased, indicating a systemic change in immune-cell presence with ethanol exposure. Ethanol exposure increased CD11c+CD64+ macrophages and Ly6G+CD11b+ neutrophils in the lungs, with neutrophil populations being further exacerbated during a bacterial challenge with Pseudomonas aeruginosa. Lipocalin 2, a marker of oxidative stress, was also elevated with ethanol consumption, though not with infection. Conclusions: These data suggest that ethanol-induced changes in the gut microbiome and immune environment are linked to dysfunctional immune responses in the intestine, blood, and the lungs, compromising the pulmonary immune response during an infectious challenge in mice.

Treatment of ulcerative colitis via the in situ restoration of local immune and microbial homeostasis by oral administration of Tremella polysaccharide drug-carrying hydrogel

Ulcerative colitis (UC) is a prevalent inflammatory bowel disease, and conventional treatments, such as anti-inflammatory medications and surgery, often prove inadequate due to frequent recurrences and various complications. To alleviate patient suffering, there is an urgent need for a therapeutic system that specifically delivers drugs to the colon for wound healing, inflammation relief, and restoration of microbial homeostasis. In this paper, we developed a Tremella polysaccharide drug-carrying hydrogel that adheres to the inflamed colonic mucosa, forming an effective artificial barrier and releasing the drug in situ to restore local immune and microbial balance. The hydrogel backbone was synthesized through the chemical cross-linking of Tremella polysaccharide with 1,4-butanediol diglycidyl ether in an alkaline environment. During this process, Soluplus® and TPGS-encapsulated ginsenoside compound K adhered to the hydrogel backbone due to electrostatic attraction. The enhanced adhesion following cross-linking enables the hydrogel to stably attach to the inflamed colonic mucosa, releasing mixed micelles that improve drug penetration and absorption by inhibiting the cellular efflux protein P-glycoprotein. This mechanism promotes local immune recovery and eliminates harmful intestinal flora, providing significant relief from UC symptoms. This natural polysaccharide-based hydrogel represents a highly effective oral treatment for UC.

Estrogen Receptor β Alleviates Colitis by Inhibiting Ferroptosis in Intestinal Epithelial Cells.

Ulcerative colitis (UC), a major type of inflammatory bowel disease, is characterized by chronic inflammation of the colonic mucosa and submucosa. Estrogen receptor β (ERβ) predominates in the colon and exerts anti-inflammatory effects. Ferroptosis, a recently discovered form of iron-dependent programmed cell death, is implicated in the pathogenesis of several diseases, including UC. However, the link between ferroptosis and the anti-inflammatory actions of ERβ in UC remains to be elucidated. We analyzed colonic mucosal samples from inflammatory and non-inflammatory regions of UC patients to assess ferroptosis levels. Experimental colitis was induced in wild-type C57BL/6 mice and intestinal epithelial cell-specific ERβ knockout (ERβ-/-) mice using dextran sulfate sodium (DSS). We measured body weight, colon length, disease activity index (DAI), and histopathological scores. RNA sequencing was performed to identify differentially expressed genes and related signaling pathways, with additional ferroptosis assessment in vivo and in vitro through biochemical markers and cellular assays. In UC patients, ferroptosis was significantly elevated in inflammatory mucosal regions compared to non-inflammatory areas. Compared to the wild-type counterparts, ERβ-/- mice exacerbated DSS-induced experimental colitis, including reduced body weight, shortened colon length, and higher DAI scores. RNA sequencing showed enrichment of inflammatory and immune response pathways, with significant activation of JAK/STAT, NF-κB, and TNF signaling in ERβ-/- mice. ERβ deficiency induced ferroptosis in both in vitro and in vivo models. Ferroptosis indicators such as PTGS2 were upregulated, GPX4 expression was downregulated, and there were increases in malondialdehyde, iron content, reactive oxygen species, and mitochondrial damage. Our findings demonstrate that ERβ deficiency exacerbates colitis and enhances ferroptosis in IECs. ERβ positively regulates GPX4 transcription, thereby inhibiting ferroptosis and alleviating colitis. These insights suggest that modulation of ERβ and its regulation of ferroptosis may represent a novel therapeutic strategy for UC.

A new technique for ureteral reconstruction using colonic mucosa graft in a beagle model

A new technique for ureteral reconstruction using colonic mucosa graft in a beagle model