Unveiling the Microbial Impact on Intestinal Fibrosis

Condition(s) studied

Investigational drug(s) / intervention(s)

Surgical specimens of CD and no-IBD patients: Specimens of CD patients and patients without IBD-related disease (ex. diverticulitis) will be collected during the surgery, without other risks for the patients, since we will use only material left after pathologist analysis

Study summary

Crohn's disease (CD), belonging to the class of Inflammatory Bowel Diseases, is a chronic inflammatory disorder that may affect any location of the gastrointestinal tract. It is characterized by transmural inflammation and an overwhelming immune response of the gut mucosa, which leads to severe clinical symptoms. More than 50% of CD patients develop a penetrating or stricturing disease due to fibrostenosis, which most of the time requires surgical intervention since no therapies have been found as effective yet. Among the histological features of stricturing CD, the thickening of the muscularis mucosae and muscularis propria is the main hallmark, primarily due to the excessive proliferation of mesenchymal cells and the increased accumulation of a collagen-rich extracellular matrix in the submucosa, caused by multiple mechanisms, including i) the proliferation of existing local fibroblasts, the induction of both ii) epithelial-to-, and iii) endothelial-to-mesenchymal transition. Even if the alteration of these mucosal functions is mainly caused by the continuous tissue injury occurring during CD-associated chronic inflammation, recent reports suggested that CD associated fibrosis may be driven by inflammation-independent triggers, such as microbiota dysbiosis.

Shedding the light on this aspect of CD fibrosis may lead to the development of innovative therapeutic strategies eventually blocking the gut thickening.

Eligibility

Primary outcome measure(s)

• To perform flow cytometry, RNAseq, metatranscriptomics, transcriptomics and lipidomics on CD and non-IBD cells — 1-36 months
  To evaluate how bacterial factors may impact the transcriptomic state of the different host cell compartments in terms of profibrotic pathway and gene activation. Cells will undergo FACS for CD31, EpCam, and CD90 markers for isolating endothelial cells, epithelial cells, and fibroblasts, respectively, as the well-known cellular players in the fibrotic process. Single-cell populations will undergo library preparation and will be analyzed by ribo-minus RNAseq at 30M reads of depth. Metatranscriptomics for profiling the microbial composition, as well as the transcriptomics to determine both the differential gene expression (DGE) and the Gene Set Enrichment Analysis (GSEA) will be performed. The relative abundances of Brevibacteriaceae, Caulobacteraceae, and Sphingomonadaceae-derived factors will be calculated using Kraken2 to identify which cell subtype(s) among CD-derived fibroblasts, endothelial cells, and epithelial organoids harbor(s) the fibrotic-specific microbial composition.

Trial sites (1)

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