P013 Potential Role of Epithelial Protein Disulphide Isomerases in Crohn's Disease Fibrosis. (27th May 2021)

• Record Type: Journal Article
• Authors: Vieujean, S; Hu, S; Bequet, E; Salée, C; Massot, C; Bletard, N; Pierre, N; Quesada Calvo, F; Baiwir, D; Mazzucchelli, G; De Pauw, E; Coimbra Marques, C; Delvenne, P; Edouard, L; Meuwis, M A
• Is Part Of: Journal of Crohn's and colitis. Volume 15(2021)Supplement 1
• Page Start: S134
• Page End: S135
• Publication Date: 2021-05-27
• Subjects: Inflammatory bowel diseases -- Periodicals; 616.344005
• DOI: 10.1093/ecco-jcc/jjab076.142
• Languages: English
• ISSNs: 1873-9946

Abstract

Abstract: Background: Intestinal fibrosis is a common complication of Crohn's disease (CD) characterized by an accumulation of fibroblasts differentiating into activated myofibroblasts secreting excessive extracellular matrix. In in-vitro experiments, this myofibroblastic differentiation is elicited by a whole series of factors among which transforming growth factor-β1 (TGF-β1) seems to play a key role. The potential role of the intestinal epithelium in this fibrotic process remains poorly defined. Methods: We performed a pilot proteomic study comparing the proteome of surface epithelium isolated by laser-capture microdissection in normal and fibrotic zones of resected ileal CD strictures (13 zones collected in 5 patients). The pro-fibrotic role of selected epithelial proteins was investigated through in-vitro experiments using HT-29 epithelial cells and a CCD-18Co fibroblast to myofibroblast differentiation model. Results: Proteomic study revealed an endoplasmic reticulum (ER) stress proteins increase in the epithelium of CD ileal fibrotic strictures, including Anterior gradient protein 2 homolog (AGR2), Protein disulphide isomerase A6 (PDIA6) and Endoplasmic reticulum resident protein 44 (ERP44) which are 3 protein disulphide isomerases. In HT-29 cells, tunicamycin-induced ER stress triggered AGR2, PDIA6, ERP44 as well as TGF-β1 intracellular expression and their secretion. Supernatant of these HT-29 cells, pre-conditioned by tunicamycin (Tm), led to a myofibroblastic differentiation when applied on CCD-18Co fibroblasts. The application of blocking agents for AGR2, PDIA6, ERP44 or TGF-β1 in the supernatant of these Tm-pre-conditioned HT-29 cells, attenuated the myofibroblastic differentiation induced by this supernatant, suggesting a pro-fibrotic role of these secreted epithelial proteins. Conclusion: The development of CD fibrotic strictures may involve ER stress in epithelial cells, releasing a whole set of proteins into their environment, including AGR2, PDIA6, ERP44 as well as TGF-β1, which could exercise a pro-fibrotic role through a paracrine action.