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Project: Proteases from epithelial cells, mediators of inflammation in IBD
The gastrointestinal tract is the organ the most exposed to proteases, which originate from many sources including the pancreas, luminal bacteria, inflammatory cells and even resident cells. Recently, we demonstrated in the context of IBD, that the inflamed intestinal epithelium secretes more elastolytic activity and releases less of the elastase inhibitor, ELAFIN. In addition we established that administration of ELAFIN has a protective action in chronic inflammatory disorders of the gut. Therefore, considering the role of proteases and their inhibitors in IBD, the proteolytic homeostasis appears as an obvious new direction to investigate. In IBD, hyper-secretion of elastase could interfere with all biological functions of the gut, including immune functions of mucosal cells such as macrophages (MØ). In inflamed intestine from patients with Crohn’s disease, there is an accumulation of early monocyte-like cells, which are spontaneously activated. MØ from patients fail to fully differentiate and promote chronic inflammation, extracellular matrix destruction, and apoptosis.
The aim of the present proposal is to investigate the role of intestinal proteolytic homeostasis in the differentiation of mucosal MØ.
The gastrointestinal tract is the organ the most exposed to proteases, which originate from many sources including the pancreas, luminal bacteria, inflammatory cells and even resident cells. Recently, we demonstrated in the context of IBD, that the inflamed intestinal epithelium secretes more elastolytic activity and releases less of the elastase inhibitor, ELAFIN. In addition we established that administration of ELAFIN has a protective action in chronic inflammatory disorders of the gut. Therefore, considering the role of proteases and their inhibitors in IBD, the proteolytic homeostasis appears as an obvious new direction to investigate. In IBD, hyper-secretion of elastase could interfere with all biological functions of the gut, including immune functions of mucosal cells such as macrophages (MØ). In inflamed intestine from patients with Crohn’s disease, there is an accumulation of early monocyte-like cells, which are spontaneously activated. MØ from patients fail to fully differentiate and promote chronic inflammation, extracellular matrix destruction, and apoptosis.
The aim of the present proposal is to investigate the role of intestinal proteolytic homeostasis in the differentiation of mucosal MØ.
Animal and Cellular models:
- colitis murine models : DSS, TNBS,
- genetically modified mice : IL10 KO, PAR2 KO
Techniques and Methods:
- Molecular biology (nucleic acid extraction and analysis, cloning and directed mutagenesis, Custom and production of lentivirus).
- Biochemistry (Enzymology, quantification of enzymatic activity in vitro and on biopsy, Immunolocalisation, optical and confocal microscopy, electron microscopy, quantitative analysis of images, Western blotting, Immunoprecipitation, Heterologous expression of protein and purification).
- Cell culture: human and murine intestinal epithelial cells and macrophage (primary cell and cell lines)