UEG's educational platform for gastroenterology education bringing recordings, courses, guidelines, and more together in one place.

UEG Week Berlin 2025 Recordings Gut Guide online

Rate for better recommendations!

Your feedback helps us show you more of what you like and less of what you dislike!

More of this!

We will show you more similar content.

Not for me!

We won't suggest this again.

Bookmark!

Save this content for later!

New to myUEG? Create an account! Log In with myUEG account

UEG Poster

Standard Poster

Share via Email Share on Facebook Share on X Share on LinkedIn Share on Bluesky

Free for all myUEG account holders. Your access level is set automatically based on your occupation. Medical professionals get full access to all content. If you are a non-medical user, you can only access UEG Week content from congresses you attended.

Not sure what you can access? Learn more about account types.

Introduction

Rarely is it mentioned how the synergistic disruption of the gut vascular barrier (GVB) and intestinal epithelial barrier (IEB) contributes to the pathophysiology of ulcerative colitis (UC). Enteric glial cells (EGCs) play a vital role in intestinal homeostasis maintenance, but their possible interactions with dual intestinal barrier function are unknown.

Aims & Methods

We aimed to investigate the role of EGCs in regulating dual intestinal barrier function in the pathogenesis of UC and the underlying mechanisms. This study was performed on the mouse models of DSS-induced colitis and biopsies from UC patients. Impaired dual intestinal barrier function was examined by permeability assays and electron microscopy. The phenotype and function of EGCs were assessed by Western Blot, Immunofluorescence, and Flow Cytometry. Dihydroartemisinin (DHA) was used to reduce inflammation in vivo and in vitro.

Results

Mice with chronic colitis had impaired IEB and GVB such as increased double intestinal barrier permeability, reduced intestinal tight junction protein expression, and increased blood circulating endotoxin levels have been observed in the chronic colitis mice model. EGCs, mainly the subgroup of GFAP⁺/S100⁺-EGCs, have been activated and proliferated when the dual intestinal barrier function is compromised. And the content of GFAP⁺/S100⁺-EGCs corresponds to the damage severity of the barrier. Both proliferation and activation of GFAP⁺/S100⁺-EGCs were markedly reduced by the DHA treatment. In addition to alleviating weight loss and colonic shortening in the model mice, DHA treatment considerably ameliorates intestinal epithelial and vascular endothelial barrier function, thus significantly reducing intestinal permeability. Moreover, DHA treatment reduced the proliferative activity of GFAP⁺/S100⁺-EGCs in vitro, and restricted the recruitment of monocytes to EGCs by inhibiting the production of CCL2, thereby alleviating intestinal inflammatory response.

Conclusion

EGCs are essential for coordinated regulation of the double intestinal barrier efficient operation, and the proliferation and activation of GFAP⁺/S100⁺-EGCs speed up UC development. Those findings will contribute to identifying novel UC treatment targets and practical neurological markers.

Disclosure

The authors declare no competing interests.

ENTERIC GLIAL CELLS IN COORDINATED REGULATION OF DUAL INTESTINAL BARRIER FUNCTION DURING ULCERATIVE COLITIS DEVELOPMENT

Peishan Qiu 1, Yuhua Chen 1, Xiaoyu Chen 1, Cong Xiao 1, Qiu Zhao 1, Lan Liu 1

1 Zhongnan Hospital of Wuhan University, Wuhan, China|||Hubei Clinical Center & Key Lab of Intestinal & Colorectal Diseases, Wuhan, China

Conference

UEG Week Copenhagen 2023

Topics

IBD

Submission format

Abstract

Session

PP 05 IBD (Posters)

Citation

United European Gastroenterology Journal 2023; 11 (Supplement 8)

Published

2023

UEG Poster

Standard Poster

Share via Email Share on Facebook Share on X Share on LinkedIn Share on Bluesky

Not sure what you can access? Learn more about account types.

Introduction

Microscopic colitis (MC) is an inflammatory bowel disease (IBD) that causes chronic non-bloody watery diarrhea and abdominal pain that significantly reduces the quality of life¹. MC can be subdivided into collagenous colitis (CC) and lymphocytic colitis (LC), which are clinically indistinguishable but differ histologically². The activation of immune responses and the alteration of the intestinal epithelial barrier via water channel aquaporin downregulation and crypt hyperproliferation are characteristic features of MC³, often shared by other gastrointestinal disorders, such as “classical” IBD (Crohn’s disease and ulcerative colitis, UC), or irritable bowel syndrome (IBS). Enteric glial cells (EGC) are key regulators of gut homeostasis and epithelial permeability, that respond to inflammation by entering a reactive state, potentially driving epithelial dysfunction. Whether EGC promote resolution or perpetuate inflammation remains unclear.⁴

Aims & Methods

MC is poorly understood and EGC role in MC is still unknown. Therefore, our aim is to investigate the involvement of EGC – due to their neuroimmune functions and involvement in intestinal dysmotility – in patients with MC. In addition, mast cells will be investigated since altered interactions with EGC have been demonstrated during IBS⁵.
Paraffin-embedded colonic biopsies from patients with active CC, LC, UC, IBS-diarrhea (D) and healthy controls (HC) were collected (n=13-26 per cohort). In addition, a subset of CC patients was also sampled during successful treatment with glucocorticosteroid 9mg budesonide (n=13). The amount of EGC was quantified using glial fibrillary acidic protein (GFAP) and S100 calcium-binding protein B (S100β). Mast cells were quantified using tryptase.

Results

Immunofluorescence analysis of EGC revealed an increased amount of EGC^GFAP+ in CC compared to HC (p<0.001). Of note, CC EGC^GFAP+ levels were comparable to those shown by biopsies from patients suffering from IBS-D and UC. Among the 13 CC patients with paired samples before and under budesonide treatment, we observed a trend toward reduced EGC^GFAP+ levels during treatment (p = 0.08). In contrast, LC patients displayed similar EGC^GFAP+ levels as to HC, but lower than those observed in biopsies from patients with CC, IBS-D, and UC (p<0.001). On the other hand, EGC^S100β+ were increased only in active CC (p<0.0001). Yet, UC patients displayed the highest level of EGC^S100β+ (p<0.0001). Mast cells analysis showed an increased counts for tryptase in CC before and under treatment compared to HC (p<0.01).

Conclusion

Our findings indicate that EGC and mast cells are involved in CC pathogenesis due to an increased reactivity of EGC and mast cells in the colonic mucosa. CC patients exhibit signs of EGC^GFAP+levels comparable to those observed in UC and IBS-D. Oppositely, LC seems to be independent of neuroinflammation as EGC and mast cells presence was comparable to HC. These preliminary findings support the theory that CC and LC are distinct disease entities. Future work will include RNA sequencing of EGC-related genes, counts of eosinophils as well as in situ analysis of mast cells and eosinophils degranulation, and assessment of budesonide effects on EGC in vitro.

References

1. Nyhlin N, Wickbom A, Montgomery SM, et al. Long-term prognosis of clinical symptoms and health-related quality of life in microscopic colitis: a case-control study. Aliment Pharmacol Ther 2014; 39: 963-972. 20140311. DOI: 10.1111/apt.12685.
2. Carrasco A, Esteve M, Salas A, et al. Immunological Differences between Lymphocytic and Collagenous Colitis. J Crohns Colitis 2016; 10: 1055-1066. 20160229. DOI: 10.1093/ecco-jcc/jjw058.
3. Escudero-Hernandez C, Munch A, Ostvik AE, et al. The Water Channel Aquaporin 8 is a Critical Regulator of Intestinal Fluid Homeostasis in Collagenous Colitis. J Crohns Colitis 2020; 14: 962-973. DOI: 10.1093/ecco-jcc/jjaa020.
4. Gonzales J and Gulbransen BD. The Physiology of Enteric Glia. Annu Rev Physiol 2024 20241115. DOI: 10.1146/annurev-physiol-022724-105016.
5. Meira de-Faria F, Casado-Bedmar M, Marten Lindqvist C, et al. Altered interaction between enteric glial cells and mast cells in the colon of women with irritable bowel syndrome. Neurogastroenterol Motil 2021; 33: e14130. 20210402. DOI: 10.1111/nmo.14130.

INVOLVEMENT OF ENTERIC GLIAL CELLS AND MAST CELLS IN MICROSCOPIC COLITIS: DISTINCT RESPONSES IN COLLAGENOUS AND LYMPHOCYTIC COLITIS

Julie Beaudeau 1, Celia Escudero-Hernández 2, Georgios Katinios 3, Gustav Orell 3, Nawroz Barazanji 3, Susanna Walter 3, Henrik Hjortswang 3, Vytautas Kiudelis 4, Juozas Kupcinskas 4, Andreas Münch 3, Åsa V. Keita 1

1 Linköping University, Linköping, Sweden

2 University Hospital Schleswig-Holstein and Christian- Albrechts-University Kiel, Kiel, Germany|||University of Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), Valladolid, Spain

3 Linköping University, Linköping, Sweden|||Linköping University, Linköping, Sweden

4 Lithuanian University of Health Sciences, Kaunas, Lithuania

Conference

UEG Week Berlin 2025

Topics

IBD

Submission format

Abstract

Session

The value of histology and ancillary tests (Posters)

Citation

United European Gastroenterology Journal 2025; 13 (Supplement 8)

Published

2025

UEG Presentation

Share via Email Share on Facebook Share on X Share on LinkedIn Share on Bluesky

IMPLICATION OF COMMENSAL FAECAL BACTERIA IN REGULATING THE COLONIC EPITHELIAL BARRIER DURING ULCERATIVE COLITIS

Not sure what you can access? Learn more about account types.

Introduction

In the gut, intestinal epithelial cells form a structural barrier, delineating the intestinal lumen from the lamina propria¹. Within the lumen, microbes exert essential functions in maintaining gastrointestinal homeostasis and functionality². Regardless of commensal or pathogenic nature of the bacteria, their interaction with gut epithelium is inevitable. During ulcerative colitis (UC), both mucosal barrier and microbial composition are disturbed³. However, it is still unclear whether naturally occurring gut bacteria might influence the control or management of the protective lining of cells in the colon.

Aims & Methods

The aim of the study was to identify which faecal microbiota components remain unaltered during UC and assess the interplay of these bacteria with colonic epithelial cells.
The study was approved by the Kaunas Regional Biomedical Research Ethics Committee (protocol no. BE-2-31). Faecal microbiota was analysed by employing 16S rRNA-gene v1-v2 region sequencing on stool samples of active and quiescent UC patients (n=47) and non-IBD controls (n=25). Functional analysis was performed using colonic epithelial organoid-derived monolayers of UC patients (n=9) and non-IBD controls (n=8). Monolayers were co-cultured with Escherichia coli (ATCC 25922) and Phocaeicola vulgatus (ATCC 8482) bacteria type strains. The interplay between bacteria and colonic epithelial cells was assessed by analysing the expression of gene markers for epithelial barrier integrity (ZO1), pathogen recognition (TLR4) and stress induction (HSPA1A, HSPB1).

Results

First, 16S rRNA-gene sequencing revealed a persistent bacterial imbalance in both active and quiescent UC patients compared to non-IBD controls. Specifically, Chao1, Shannon, and Simpson α-diversity indices were significantly lower (p_Wilcoxon< 0.05) in both active and quiescent UC patient groups when compared to non-IBD controls. Microbial community clusters, assessed by Bray-Curtis dissimilarity index, also differed significantly between UC patients and non-IBD controls (p_PERMANOVA < 0.05). Subsequent co-occurrence and differential abundance analyses identified that in contrast to healthy individuals, UC patients exhibited statistical significance (p_{adj. Wilcoxon} < 0.05) in the relative abundance of 5 genera, including Alistipes, Mediterraneibacter, Paraprevotella, etc., while 35 genera were found to be present at comparable levels (p_{adj. Wilcoxon} ≥ 0.05). Of them, the most abundant ones were Phocaeicola, Collinsella, Roseburia, Holdemanella, and Bacteroides. Functional analysis, utilizing co-cultures of commensal bacteria and colonic epithelial cells of active UC patients and non-IBD controls, showed that both E. coli and P. vulgatus did not induce pathogen-pattern recognition and stress responses. Interestingly, both species demonstrated potential to provoke diverse tight junction-related cellular reactivity (however, due to high variation in patient-to-patient responses, results did not reach statistical significance (p_{adj. Wilcoxon} ≥ 0.05)). More precisely, a contact with E. coli and P. vulgatus tended to increase the expression of ZO1 in non-IBD epithelial cells (FC = 3.59 and FC = 2.27, respectively) compared to untreated cells, while an opposite trend was observed in epithelial cells of UC patients (FC = 0.67 and FC = 0.75, respectively).

Conclusion

Diverse colonic epithelial cell responses to distinct commensal bacteria species imply the contribution of stably abundant gut microbiota to the impairment of mucosal barrier integrity during UC.

References

¹Horowitz, A., Chanez-Paredes, S.D., Haest, X. et al. Paracellular permeability and tight junction regulation in gut health and disease. Nat Rev Gastroenterol Hepatol 20, 417–432 (2023)
²Fan, Y., Pedersen, O. Gut microbiota in human metabolic health and disease. Nat Rev Microbiol 19, 55–71 (2021)
³Kobayashi, T., Siegmund, B., Le Berre, C. et al. Ulcerative colitis. Nat Rev Dis Primers 6, 74 (2020)

IMPLICATION OF COMMENSAL FAECAL BACTERIA IN REGULATING THE COLONIC EPITHELIAL BARRIER DURING ULCERATIVE COLITIS

Ruta Inciuraite 1, Simonas Juzenas 2, Rolandas Gedgaudas 3, Deimantė Tilindė 1, Rokas Lukosevicius 1, Gediminas Kiudelis 3, Laimas Virginijus Jonaitis 3, Juozas Kupcinskas 3, Jurgita Skieceviciene 1

1 Lithuanian University of Health Sciences, Kaunas, Lithuania

2 Lithuanian University of Health Sciences, Kaunas, Lithuania|||Vilnius University, Vilnius, Lithuania

3 Lithuanian University of Health Sciences, Kaunas, Lithuania|||Hospital of Lithuanian University of Health Sciences Kaunas Clinics, Kaunas, Lithuania

Event

UEG Week Vienna 2024

Topics

Gut Microbiota IBD Immunology

Submission format

Abstract

Session

Understanding disease primers of IBD: Part 2

Citation

United European Gastroenterology Journal 2024; 12 (Supplement 8)

Published

2024

UEG Presentation

Share via Email Share on Facebook Share on X Share on LinkedIn Share on Bluesky

PERSONALIZED INTESTINAL ORGANOID AND IMMUNE CELL CO-CULTURE MODEL FOR EVALUATION OF BIOLOGICAL THERAPY EFFICACY IN ULCERATIVE COLITIS PATIENTS

Not sure what you can access? Learn more about account types.

Introduction

Ulcerative colitis (UC) is a chronic inflammatory bowel disease affecting 5 million people worldwide, characterized by mucosal inflammation that can extend throughout the colon [1]. Current treatments often have limited efficacy or severe side effects [2]. As, there are no established criteria for selecting the most effective treatment for IBD, innovative preclinical drug testing systems are of major importance.

Aims & Methods

The aim of this study was to evaluate the effects of biological therapy using ulcerative colitis patient-derived personalized co-culture models of colonic epithelial and immune cells under inflammatory conditions.

The effects of upadacitinib (UPA) and ozanimod (OZA) were tested in personalized co-cultures of colonic epithelial cells and macrophages derived from UC patients (n=12) and control (Con) individuals (n=11). Inflammation was induced with inflammatory cytokines TNF-α (10 ng/mL) and IFN-γ (10 ng/mL). Barrier integrity was measured by transepithelial electrical resistance (TEER). Expression of TNF-α, CCL5, and CXCL9 genes was evaluated using qRT-PCR. Secretion of cytokines in the epithelial cells and macrophages culture media was investigated using a flow cytometry-based target protein assay. Data comparison was conducted using the Shapiro-Wilk test and the Wilcoxon rank-sum test. A difference between the values was considered significant when p ≤ 0.05 or padj. ≤ 0.05.

Results

In cell cultures stimulated with inflammatory cytokines, barrier permeability increased (TEER decreased – Con: by 452.03 Ω·cm², UC: 39.3 Ω·cm²), which partially recovered after removal of inflammatory factors (TEER increased – Con: by 65.91 Ω·cm2, UC – only 47.31 Ω·cm²). Epithelial integrity was restored after incubation with UPA and OZA (TEER increased – Con: by 116.82 Ω·cm² (UPA), by 193.77 Ω·cm2 (OZA); UC: by 226.64 Ω·cm2 (UPA), by 188.5 Ω·cm² (OZA)). At the molecular level, overnight stimulation with TNF-α and IFN-γ increased expression of CXCL9 gene in epithelial cells (UC: fold change (FC) = 3064.49 p_adj.= 2.07 x 10^-5; Con: FC = 664.44, p_adj.= 2.00 x 10^-2) and macrophages (UC: FC = 140.47 p_adj.= 0.01; Con: FC = 314.43, p_adj.= 0.01) in both groups. Co-culture treatment with UPA and OZA showed important trend of patient-specific responses to each therapeutic agent, which probably was the most important factor of non-significant values for observed changes in CCL5, CXCL9, TNF-α expression analysing summarized data. The flow cytometry-based target protein assay revealed that TNF-α and IFN-γ can influence inflammatory cytokine secretion in both epithelial cells and macrophages of UC patients and Control individuals, which can be further modified by novel biological therapy agents – UPA and OZA.

Conclusion

In conclusion, treatment with TNF-α and IFN-γ reduced epithelial barrier integrity and induced increased expression of inflammatory cytokines in epithelial cells and macrophages. Biological therapy (UPA or OZA) tended to restore disrupted barrier integrity. However, the response to novel biological therapy agents (UPA and OZA) on gene expression in both cell types and inflammatory cytokine levels in the cell culture media showed varying impacts and effectiveness, thereby revealing individualized responses of subjects to different biological preparations.

References

1. Le Berre C, Honap S, Peyrin-Biroulet L. Ulcerative colitis. Lancet. 2023 Aug 12;402(10401):571-584. doi: 10.1016/S0140-6736(23)00966-2. PMID: 37573077.
2. Singh S, Allegretti JR, Siddique SM, Terdiman JP. AGA Technical Review on the Management of Moderate to Severe Ulcerative Colitis. Gastroenterology. 2020 Apr;158(5):1465-1496.e17. doi: 10.1053/j.gastro.2020.01.007. Epub 2020 Jan 13. PMID: 31945351; PMCID: PMC7117094.

Disclosure

No conflict of interest to declare.

PERSONALIZED INTESTINAL ORGANOID AND IMMUNE CELL CO-CULTURE MODEL FOR EVALUATION OF BIOLOGICAL THERAPY EFFICACY IN ULCERATIVE COLITIS PATIENTS

Deimantė Tilindė 1, Ruta Inciuraite 1, Ugne Kulokiene 1, Indre Aleknaviciene 1, Vytautas Kiudelis 2, Laimas Virginijus Jonaitis 2, Juozas Kupcinskas 2, Jurgita Skieceviciene 1

1 Lithuanian University of Health Sciences/Institute for Digestive Research, Kaunas, Lithuania

2 Lithuanian University of Health Sciences, Kaunas, Lithuania

Event

UEG Week Vienna 2024

Topics

IBD Immunology Mechanisms & Personalised Medicine

Submission format

Abstract

Session

IBD: Latest news on a personalised approach

Citation

United European Gastroenterology Journal 2024; 12 (Supplement 8)

Published

2024

UEG Poster

Standard Poster

Share via Email Share on Facebook Share on X Share on LinkedIn Share on Bluesky

Not sure what you can access? Learn more about account types.

Introduction

Ulcerative colitis (UC) is an inflammatory disorder of the colon of unknown aetiology characterised by intestinal barrier dysfunction associated with colonic epithelial goblet cell depletion and a shift in intestinal stem cell retention and function^1,2. Pancreastatin (PST), an intestinal epithelial cells-derived peptide highly expressed in colonic tissues of patients with active UC, positively correlates with UC early onset, disease severity, and inflammatory markers³. However, the effect of PST inhibition on colonic epithelial barrier function remains undetermined.

Aims & Methods

This study aimed to investigate the impact of pancreastatin inhibitor 8 (PSTI8) on colonic epithelial barrier function in a preclinical mouse model of UC. Male and female C57BL/6 mice were treated intrarectally with PSTi8 (2.5mg/mL/kg) or PBS for six days and received 5% dextran sulfate sodium (DSS) to induce colitis or water (control) for five days. The disease activity index (DAI) was assessed daily. ELISA quantified inflammatory cytokines, interleukin (IL)-6, IL-18 and IL-22. Markers to characterise differentiated goblet cells (Mucin, MUC2), transcription factors for goblets’ lineage commitment (growth factor independent, GFI1 and Kruppel-like factor, KLF1), and colonic stem cells plasticity (fast-cycling Lgr5, fetal-like Ly6a, and reserve Hopx cells) were quantified via RT-PCR and immunofluorescence.

Results

PSTi8 treatment increased stool consistency (p<0.01) and delayed the onset of bleeding in colitic male mice compared to PBS-treated mice (2-4 days). Conversely, no differences in the DAI were noted between colitic PSTi8 and PBS-treated female mice. In non-colitic conditions, PSTi8 treatment increased (p<0.03) IL-22 in males and decreased (p<0.01) its level in female mice with no effect of IL-6. In colitic conditions, although IL-22 levels were decreased (p<0.01) in female mice and IL-6 levels were increased (p<0.001) in male mice, PSTi8 treatment did not show any effect. Conversely, in colitic females, IL-18 was significantly increased (p<0.02), and PSTi8 abolished that increase. The mRNA expression level of MUC2 remains unaltered in male and female non-colitic and colitic mice treated or not with PSTi8. Yet, immunofluorescence staining in non-colitic and colitic conditions demonstrated a decrease of MUC2 in PSTi8-treated female mice. In concordance, transcription factors KLF1 and GFI1 were significantly increased (p<0.001 and p<0.02, respectively) in colitic female mice, and PSTi8 treatment abolished that increase. No differences were seen in male mice except for a significant increase of KLF1 in PSTi8-treated colitic mice. In colitic conditions, fast-cycling cells marker Lgr5 expression in both sexes was significantly decreased (p<0.0001), and treatment with PSTi8 did not show any effect. However, in colitic male mice, fetal-like stem cells makers Ly6a expression was significantly increased (p<0.007), and PSTi8 treatment significantly decreased (p<0.02) that expression. Although a significant decrease (p<0.0001) of reserve cells marker Hopx was only seen in colitic female mice, PSTi8 treatment did not regulate that marker in male and female mice.

Conclusion

PST inhibition protects male mice from DSS-mediated colitis while exacerbating susceptibility to colitis in female mice. PST inhibition regulates the expansion of goblet and intestinal stem cells in a sex-dependent manner. Further investigation is needed to delineate the signalling pathways involved in PST action on the mucosa in both sexes. Targeting PST may lead to novel therapeutic strategies in UC.

References

1. Singh V, Johnson K, Yin J, et al. Chronic Inflammation in Ulcerative Colitis Causes Long-Term Changes in Goblet Cell Function. Cmgh. 2022;13(1):219-232.
2. Yui S, Azzolin L, Maimets M, et al. YAP/TAZ-dependent reprogramming of colonic epithelium links ECM remodeling to tissue regeneration. Cell Stem Cell. 2018;22(1):35-49.e7.
3. Eissa N, Elgazzar O, Hussein H, Hendy GN, Bernstein CN, Ghia JE. Pancreastatin reduces alternatively activated macrophages, disrupts the epithelial homeostasis and aggravates colonic inflammation. A descriptive analysis. Biomedicines. 2021;9(2):1-18.

IN A PRECLINICAL MOUSE MODEL OF ULCERATIVE COLITIS, PANCREASTATIN INHIBITION REGULATES COLONIC MUCOSAL BARRIER FUNCTION IN A SEX-DEPENDENT MANNER

Diane Tshikudi 1, Fatemeh Hesampour 1, Jean-Eric Ghia 1

1 University of Manitoba, Winnipeg, Canada

Conference

UEG Week Copenhagen 2023

Topics

IBD

Submission format

Abstract

Session

PP 05 IBD (Posters)

Citation

United European Gastroenterology Journal 2023; 11 (Supplement 8)

Published

2023

UEG Poster

Audio / Video Poster

Share via Email Share on Facebook Share on X Share on LinkedIn Share on Bluesky

Not sure what you can access? Learn more about account types.

Introduction

Chronic visceral pain is a clinical challenge in >50% of Inflammatory Bowel Disease (IBD) cases (Morrison et al., 2013). A randomized controlled trial (RCT) demonstrated that transcranial direct current stimulation (tDCS) can modulate brain activity and effectively alleviate chronic abdominal pain associated with IBD (Neeb et al., 2019). To elucidate the underlying mechanism of tDCS, we implemented this technique in a mouse model of inflammatory, chronic DSS colitis.

Aims & Methods

The tDCS protocol, including a total of 10 stimulations, was designed based on established human tDCS studies. An anodal direct current (0.5 mA, 20 min) was administered to both primary motor cortices over two separate periods with each period consisting of five consecutive days of stimulation, separated by a two-day break. The study was controlled by including a sham-treatment-group (0.5-minute sham stimulation).
For histology, H&E stained FFPE-sections of colon were assessed by scoring (Koelink et al., 2018). Barrier integrity was analysed by Ussing chamber experiments. To confirm that tDCS was affecting murine activity, mice were tracked in home cages using subcutaneously injected RFID-chips. Myenteric plexus (MP) cells of the murine small intestine, primarily the terminal ileum, were isolated and cultivated for 10 days. Staining with beta3-tubulin and S100B was performed confirming neuronal cell identity. Bulk-RNA sequencing was conducted using the NovaSeq Xplus system (read length 150 bp, read depth 30 million copies/run).

Results

The distal colon of DSS-treated mice revealed significantly stronger inflammation in the H&E scores compared to control mice (mean±SEM: Ctrl: 0.14±0.08; DSS: 1.52±0.19; MWU: p=0.0005). Only a tendency towards less inflammation was observed in tDCS-treated mice compared to sham-tDCS.
The DSS caused an inflammation-driven thickening of the colon wall, resulting in an increased transmural resistance. This effect was ameliorated by the tDCS-treatment (mean±SEM: DSS+sham-tDCS: 72.2±8.2 Ω·cm²; DSS+tDCS: 48.1±2.1 Ω·cm²; MWU: p=0.007).
DSS colitis was associated with a reduced activity, which was partially recovered by tDCS (mean±SEM: DSS+sham-tDCS: 70.7±15.2 relative distance units/day; DSS+tDCS: 205.9±40.4 relative distance units/day; MWU: p=0.029).
Neuronal cell identity was confirmed in isolated murine MP cells by immunostaining (beta3-tubulin, S100B). Bulk-RNAseq revealed a clear separation of tDCS and sham-tDCS treated colitis mice by PCA. Subsequently, 739 differentially expressed genes (DEGs) were identified in tDCS-treated DSS colitis mice compared to a sham-tDCS-treatment (622 upregulated, 117 downregulated genes; log2(fold-change)≥1.5; padj<0.05), Table 1. Analysis of KEGG and GO pathways revealed involvement in several biological processes, comprising neuroactive ligand-receptor interaction (p=7.94·10^-3), gated channel activity (p=2.4·10^-7), substrate-specific channel activity (p=1.99·10^-7), and leukocyte migration (p=3.99·10^-7).

Table 1 Selection of neurologically relevant DEGs

Gene name	Differential expression	Log2(fold-change)	Adjusted p-value
Nos1, Nitric oxide synthase 1	upregulated	2.68·10¹⁴	5.32·10^-⁰⁸
Fos, FBJ osteosarcoma oncogene	upregulated	2.21·10¹³	4.04·10^-⁰⁷
Ncam2, Neural cell adhesion molecule 2	upregulated	2.29·10¹⁴	2.66·10^-⁰⁴
Chrnb4, Cholinergic receptor, nicotinic, beta polypeptide 4	upregulated	1.69·10¹⁴	3.69·10^-⁰⁴
Cend1, Cell cycle exit and neuronal differentiation 1	upregulated	1.67·10¹⁴	6.71·10^-⁰³

Conclusion

In colitis, transcranial direct current stimulation (tDCS) has the capacity to modulate activity of DSS-treated mice and alters gene expression in MP cells. This reveals another layer of evidence for the impact of central pathways on the gut / brain-gut-axis.

References

Morrison, G. et al., Inflamm. Bowel Dis., 2013. 19(6): 1210-7: Inflammatory Bowel Diseases publishes original basic science, translational, and clinical research regarding pathogenesis, epidemiology, evaluation, and treatment of IBD.
Neeb, L. et al., Brain Stimulation, 2019: BMJ 2019; 364 doi: Comparative efficacy and acceptability of non-surgical brain stimulation for the acute treatment of major depressive episodes in adults: systematic review and network meta-analysis.
Koelink, P. J. et al., JCC 2018: Journal of Crohn’s and Colitis, Volume 12, Issue 7, July 2018, Pages 794–803, Development of Reliable, Valid and Responsive Scoring Systems for Endoscopy and Histology in Animal Models for Inflammatory Bowel Disease.

TRANSCRANIAL DIRECT CURRENT STIMULATION (TDCS) MODULATES ENTERIC NERVOUS SYSTEM (ENS)-CELL EXPRESSION PATTERNS AND INTESTINAL BARRIER IN CHRONIC DSS COLITIS

Jakob Johann Wiese 1, Franziska Weiß 1, Subhakankha Manna 1, Susanne Krug 1, Marvin Bubeck 2, Claudia Günther 2, Jay Patankar 2, Britta Siegmund 1, Magdalena Prüß 1, Nina Hering 1, Michael Schumann 1

1 Charité – University Medicine Berlin, Berlin, Germany

2 University Hospital Erlangen, Erlangen, Germany

Conference

UEG Week Vienna 2024

Topics

IBD

Submission format

Abstract

Session

IBD (Posters)

Citation

United European Gastroenterology Journal 2024; 12 (Supplement 8)

Published

2024

UEG Poster

Standard Poster

Share via Email Share on Facebook Share on X Share on LinkedIn Share on Bluesky

Not sure what you can access? Learn more about account types.

Introduction

Recent evidence suggests that appendectomy is associated with a reduced risk of developing ulcerative colitis (UC) or even the risk of flare after UC is diagnosed, thus suggesting a potential involvement of the appendix in UC pathogenesis. Interestingly, several studies support the role of the appendix in the maintenance of the intestinal microbiome and gut immunity1. We hypothesize that the appendix in UC may function as a reservoir for dysbiotic microbiota capable of promoting and re-establishing dysbiosis that could fuel inflammation in the colon in patients with UC.

Aims & Methods

The current study aimed to define the tissue-associated microbiota of the UC appendix, and investigate the changes compared to non-UC appendix. Thirty-seven patients operated on for UC or acute appendicitis were recruited. Appendicular wall tissue samples were obtained, inflammatory cells were isolated and analyzed by flow cytometry, and total DNA was extracted from the whole tissue. The V3-V4 region of the 16S rRNA gene was sequenced utilizing a MiSeq Platform (Illumina, USA). Sequences were processed using the QIIME22 pipeline, the taxonomy was assigned using the Greengenes3 database, and statistical analysis was performed in R.

Results

Twenty-seven samples were analyzed from 37 patients, 19 from UC, and 8 from acute appendicitis patients. Analyses revealed Firmicutes was the most proportionally abundant bacterial phylum in the UC appendix (mean=72.6%), followed by Proteobacteria (16%). Analysis of alpha diversity revealed no significant difference in terms of species richness, Shannon, and Pielou indices between UC and non-UC appendix (p=0.9;p=0.087;p=0.26). The PERMANOVA test revealed that UC appendix communities were significantly different from non-UC appendix communities (p=0.015). We identified 5 differentially abundant species in the study's samples, all of these significantly decreased in UC appendix vs. non-UC appendix: Fusobacterium unknown species (p=4.36x10-4), Pseudoramibacter unknown species (p=4.46x10-3), Streptococcus anginosus (p=2.67x10-2), Mogibacterium unknown species (p=2.67x10-2) and Actinomyces hyovaginalis (p=3.64x10-2). Fusobacterium, Pseudoramibacter, and Mogibacterium were also differentially abundant at the genus level (p=3.10x10-4; p=3.17x10-3; p=2.53x10-2). The expression of CD86 on activated dendritic cells (CD1a+HLAdr+CD86+) was significantly higher in UC patients than in appendicitis patients (p=0.049) and in UC patients CD1a+HLAdr+CD86+ cells rate directly correlated with disease activity as expressed by Harvey Bradshaw Index (rho=-0.513, p=0.025). The abundance of Fusobacterium unknown species inversely correlated with CD1a+HLAdr+CD86+ mean fluorescence intensity (rho=-0.466, p=0.047).

Conclusion

These preliminary data showed that specific taxa are significantly less present in the UC appendix compared to the non-UC appendix, suggesting that a distinctive UC appendix microbiota exists. Taxa with altered abundance may contribute to UC pathogenesis. These data may provide microbial signatures useful for guiding both the treatment and diagnosis of UC.

References

1. Arjomand Fard N, Armstrong H, Perry T, Wine E. Appendix and Ulcerative Colitis: a Key to Explaining the Pathogenesis and Directing Novel Therapies? Inflamm Bowel Dis. 2023;29(1):151–160. doi:10.1093/ibd/izac106.
2. Bolyen E, Rideout JR, Dillon MR, Bokulich NA, Abnet CC, Al-Ghalith GA, Alexander H, Alm EJ, Arumugam M, Asnicar F, Bai Y. Reproducible, interactive, scalable and extensible microbiome data science using QIIME 2. Nature biotechnology. 2019 Aug;37(8):852-7.
3. DeSantis TZ, Hugenholtz P, Larsen N, Rojas M, Brodie EL, Keller K, Huber T, Dalevi D, Hu P, Andersen GL. Greengenes, a chimera-checked 16S rRNA gene database and workbench compatible with ARB. Applied and environmental microbiology. 2006 Jul;72(7):5069-72.

DISTINCTIVE MICROBIOTA AND DENDRITIC CELL ACTIVATION CHARACTERIZE THE APPENDIX OF ULCERATIVE COLITIS PATIENTS

Melania Scarpa 1, Ignazio CASTAGLIUOLO 2, Astghik Stepanyan 3, Ilaria Patuzzi 4, Claudia Armellin 3, Andromachi Kotsafti 5, Edoardo Vincenzo Savarino 6, Fabiana Zingone 7, Cesare Ruffolo 3, Romeo Bardini 8, Salvatore Pucciarelli 3, Gaya Spolverato 3, Marco Scarpa 3, Imerio Angriman 3

1 Veneto Institute of Oncology IOV-IRCCS, Mestre VE, Italy

2 University of Padova, Padova, Italy

3 Azienda Ospedale Università di Padova, Padova, Italy

4 EuBiome, Padova, Italy

5 Veneto Institute of Oncology (IOV-IRCCS), Padova, Italy

6 University of Padua, Division of Gastroenterology, Padua, Italy

7 University of Padua, Padua, Italy

8 Chirurgia Generale, Padova, Italy

Conference

UEG Week Copenhagen 2023

Topics

IBD

Submission format

Abstract

Session

PP 05 IBD (Posters)

Citation

United European Gastroenterology Journal 2023; 11 (Supplement 8)

Published

2023

UEG's educational platform for gastroenterology education bringing recordings, courses, guidelines, and more together in one place.

Most popular content

Rate for better recommendations!