Project description:Colonic aspirates were collected at diagnostic colonoscopy from inflammatory bowel disease (IBD) and control, treatment-naive children. The colonic mucosal-luminal interface (MLI) proteomes were analyzed for 18 control and 42 IBD patients by liquid-chromatography mass spectrometry.
Project description:Dysregulated proteolysis plays a pivotal role in the pathophysiology of inflammatory bowel disease. Nonetheless, the identity of overactive proteases released by human colonic mucosa remains unknown. Herein, we employed a serine protease-targeted activity-based probe (ABP) coupled with mass spectral analysis to identify active forms of proteases secreted by the colonic mucosa of healthy volunteers and inflammatory bowel disease patients. With this approach, we identified seven active serine proteases: cathepsin G, plasma kallikrein, plasmin, tryptase, chymotrypsin-like elastase 3A, aminopeptidase B, and thrombin. Furthermore, cathepsin G and thrombin were overactive in supernatants from inflammatory bowel disease patients once compared to healthy volunteers.
Project description:Ulcerative colitis is a chronic inflammatory disorder for which a definitive cure is still missing. This is characterized by an overwhelming inflammatory milieu in the colonic tract where a composite set of immune and non-immune cells orchestrate its pathogenesis. Over the last years, a growing body of evidence has been pinpointing gut virome dysbiosis as underlying its progression. Nonetheless, its role during the early phases of chronic inflammation is far from being fully defined. Here we show the gut virome-associated Hepatitis B virus protein X, most likely acquired after an event of zoonotic spillover, to be associated with the early stages of ulcerative colitis and to induce colonic inflammation in mice. It acts as a transcriptional regulator in epithelial cells, provoking barrier leakage and altering mucosal immunity at the level of both innate and adaptive immunity. This study paves the way to the comprehension of the aetiopathogenesis of intestinal inflammation and encourages further investigations of the virome as a trigger also in other scenarios. Moreover, it provides a brand-new standpoint that looks at the virome as a target for tailored treatments, blocking the early phases of chronic inflammation and possibly leading to better disease management.
Project description:Kilian2024 - Immune cell dynamics in Cue-Induced Extended Human Colitis Model
Single-cell technologies such as scRNA-seq and flow cytometry provide critical insights into immune cell behavior in inflammatory bowel disease (IBD). However, integrating these datasets into computational models for dynamic analysis remains challenging. Here, Kilian et al., (2024) developed a deterministic ODE-based model that incorporates these technologies to study immune cell population changes in murine colitis. The model parameters were optimized to fit experimental data, ensuring an accurate representation of immune cell behavior over time. It was then validated by comparing simulations with experimental data using Pearson’s correlation and further tested on independent datasets to confirm its robustness. Additionally, the model was applied to clinical bulk RNA-seq data from human IBD patients, providing valuable insights into immune system dynamics and potential therapeutic strategies.
Figure 4c, obtained from the simulation of human colitis model is highlighted here.
This model is described in the article:
Kilian, C., Ulrich, H., Zouboulis, V.A. et al. Longitudinal single-cell data informs deterministic modelling of inflammatory bowel disease. npj Syst Biol Appl 10, 69 (2024). https://doi.org/10.1038/s41540-024-00395-9
Abstract:
Single-cell-based methods such as flow cytometry or single-cell mRNA sequencing (scRNA-seq) allow deep molecular and cellular profiling of immunological processes. Despite their high throughput, however, these measurements represent only a snapshot in time. Here, we explore how longitudinal single-cell-based datasets can be used for deterministic ordinary differential equation (ODE)-based modelling to mechanistically describe immune dynamics. We derived longitudinal changes in cell numbers of colonic cell types during inflammatory bowel disease (IBD) from flow cytometry and scRNA-seq data of murine colitis using ODE-based models. Our mathematical model generalised well across different protocols and experimental techniques, and we hypothesised that the estimated model parameters reflect biological processes. We validated this prediction of cellular turnover rates with KI-67 staining and with gene expression information from the scRNA-seq data not used for model fitting. Finally, we tested the translational relevance of the mathematical model by deconvolution of longitudinal bulk mRNA-sequencing data from a cohort of human IBD patients treated with olamkicept. We found that neutrophil depletion may contribute to IBD patients entering remission. The predictive power of IBD deterministic modelling highlights its potential to advance our understanding of immune dynamics in health and disease.
This model was curated during the Hackathon hosted by BioMed X GmbH in 2024.
Project description:Endoplasmic reticulum stress is closely associated with the onset and progression of inflammatory bowel disease. ERdj5 is an endoplasmic reticulum-resident protein disulfide reductase that mediates the cleavage and degradation of misfolded proteins. Although ERdj5 expression is significantly higher in the colonic tissues of patients with inflammatory bowel disease than in healthy controls, its role in inflammatory bowel disease has not yet been reported. Hence, in the current study, we utilized ERdj5-knockout mice to investigate the potential roles of ERdj5 in inflammatory bowel disease. ERdj5 deficiency causes severe inflammation in mouse colitis models and weakens gut barrier function by increasing NF-κB-mediated inflammation. ERdj5 may not be indispensable for goblet cell function under steady-state conditions, while its deficiency induces goblet cell apoptosis under inflammatory stimuli.