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- Moraes Holst, Luiza, et al.
(author)
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Downregulated Mucosal Autophagy, Alpha Kinase-1 and IL-17 Signaling Pathways in Active and Quiescent Ulcerative Colitis
- 2022
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In: Clinical and Experimental Gastroenterology. - : DOVE MEDICAL PRESS LTD. - 1178-7023. ; 15, s. 129-144
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Journal article (peer-reviewed)abstract
- Background: Improved mucosal immune profiling in active and quiescent colonic inflammatory bowel disease (IBD) is needed to develop therapeutic options for treating and preventing flares. This study therefore aimed to provide a comprehensive mucosal characterization with emphasis on immunological host response of patients with active ulcerative colitis (UC active), UC during remission (UC remission) and active colonic Crohn's disease (CD active).Methods: Colonic biopsies from 47 study subjects were collected for gene expression and pathway analyses using the NanoString host-response panel, including 776 genes and 56 immune-related pathways.Results: The majority of mucosal gene expression and signaling pathway scores were increased in active IBD (n=27) compared to healthy subjects (n=10). However, both active IBD and UC remission (n=10) demonstrated decreased gene expression and signaling pathway scores related to autophagy, alpha kinase-1 and IL-17 signaling pathways compared to healthy subjects. Further, UC remission was characterized by decreased scores of several signaling pathways linked to homeostasis along with increased mononuclear cell migration pathway score as compared to healthy subjects. No major differences in the colonic mucosal gene expression between CD active (n=7) and UC (n=20) active were observed.Conclusion: This study indicates that autophagy, alpha kinase-1 and IL-17 signaling pathways are persistently downregulated in UC irrespective of disease activity. Further, UC patients in remission present a unique mucosal environment, potentially preventing patients from reaching and sustaining true homeostasis. These findings may enable better comprehension of the remitting and relapsing pattern of colonic IBD and guide future treatment and prevention of flares.
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| 2. |
- Moraes Holst, Luiza, et al.
(author)
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Fecal Luminal Factors from Patients with Gastrointestinal Diseases Alter Gene Expression Profiles in Caco-2 Cells and Colonoids
- 2022
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In: International Journal of Molecular Sciences. - : MDPI AG. - 1422-0067 .- 1661-6596. ; 23:24
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Journal article (peer-reviewed)abstract
- Previous in vitro studies have shown that the intestinal luminal content, including metabolites, possibly regulates epithelial layer responses to harmful stimuli and promotes disease. Therefore, we aimed to test the hypothesis that fecal supernatants from patients with colon cancer (CC), ulcerative colitis (UC) and irritable bowel syndrome (IBS) contain distinct metabolite profiles and establish their effects on Caco-2 cells and human-derived colon organoids (colonoids). The metabolite profiles of fecal supernatants were analyzed by liquid chromatography-mass spectrometry and distinguished patients with CC (n = 6), UC (n = 6), IBS (n = 6) and healthy subjects (n = 6). Caco-2 monolayers and human apical-out colonoids underwent stimulation with fecal supernatants from different patient groups and healthy subjects. Their addition did not impair monolayer integrity, as measured by transepithelial electrical resistance; however, fecal supernatants from different patient groups and healthy subjects altered the gene expression of Caco-2 monolayers, as well as colonoid cultures. In conclusion, the stimulation of Caco-2 cells and colonoids with fecal supernatants derived from CC, UC and IBS patients altered gene expression profiles, potentially reflecting the luminal microenvironment of the fecal sample donor. This experimental approach allows for investigating the crosstalk at the gut barrier and the effects of the gut microenvironment in the pathogenesis of intestinal diseases.
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| 3. |
- Moraes Holst, Luiza
(author)
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Molecular biosignatures and gut-barrier alterations in inflammatory bowel diseases
- 2022
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Doctoral thesis (other academic/artistic)abstract
- Inflammatory bowel diseases (IBD) are chronic immune-mediated disorders affecting the gastrointestinal tract. The multifactorial pathophysiology of IBD is commonly explained as an abnormal interplay between genetic, immune, environmental and microbial factors. However, the understanding of the mechanisms behind IBD pathogenesis is far from complete, which limits the assessment of disease phenotypes and the identification of optimal therapy choices for an effective individualized care. This thesis has advanced the understanding of disease specific immune features on systemic as well as mucosal level, allowing for improved characterization of disease activity and phenotypes. Analyses of systemic protein profiles and mucosal gene expression identified sustained alterations in Th17 axis and barrier function during active disease and in remission, which suggest that the dysregulation of these mechanisms is involved in the relapse and remitting disease pattern observed in IBD. Further, we demonstrated that the intestinal microenvironment harbors disease specific metabolite profiles and induces distinct effects on epithelial cells in vitro. Hence, fecal supernatants, here considered as a proxy for the luminal microenvironment, from patients with colon cancer, IBD and irritable bowel syndrome induced distinct gene expression patterns in intestinal epithelial cell cultures. This indicates that the experimental setup may be an approach to study the crosstalk between the gut epithelium and the luminal content. In conclusion, the results of this thesis have improved the immunological knowledge of disease activity and phenotypes, thereby guiding future studies of how to treat and prevent flares for optimal individualized therapy. Further, a promising strategy for exploring how the luminal content interacts with the epithelial barrier and contribute to the presentation of disease pathogenesis
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