Multiple cell types are involved in the development and maintenance of chronic inflammation. This is also true in inflammatory bowel disease (IBD), where long-standing activation of immune and nonimmune cells results in severe structural and functional abnormalities. Studies performed during the last funding period have defined the phenotypic and functional characteristics of two types of nonimmune intestinal cells, human intestinal fibroblasts (HIF) and microvascular endothelial cells (HIMEC), and assessed their interaction with mucosal immune cells. The results demonstrated that both HIF and HIMEC play an active role in immunity and inflammation through interaction with immune cells and cytokine production. These observations strongly support the concept that immune-nonimmune cell interactions are critically involved in the pathogenesis of IBD. Investigation of genetic, microbial, and immune factors has recently shown the key role of innate immunity in IBD, and that the receptors mediating such innate immune responses are also expressed by nonimmune cells, allowing them to contribute to mucosal immunity and inflammation. This contribution is likely to be enhanced in IBD due to the increased absorption of bacterial products, which can activate HIF and HIMEC expressing Toll- like (TLR) and NOD-like (NLR) receptors, as shown in our preliminary results. Therefore, based on these premises, we propose to test the following central hypothesis: bacterial products can directly activate mesenchymal and endothelial cells and create self-sustaining stimulatory circuits that amplify and prolong gut inflammation. This hypothesis will be tested by investigating: 1) the expression, modulation and functional response of TLRs and NLRs in HIF and HIMEC;2) the response of HIF and HIMEC to combined microbial and inflammatory stimuli;3) the effect of bacterial product stimulation on HIF and HIMEC proinflammatory activity;4) the epigenetic regulation of TLR- and NLR-induced gene expression in HIF and HIMEC. The results will expand knowledge of the mechanisms of chronic gut inflammation and may identify novel pro-inflammatory pathways as potential targets of future therapeutic intervention in IBD.
This proposal aims at understanding the role of two types of intestinal cells, the fibroblasts and endothelial cells, in gut inflammation. Specifically, the proposal will investigate how these cells respond to bacteria normally present in the intestine, and how this response contributes to mechanisms of inflammation. The results may allow the development of new ways to control acute and chronic intestinal inflammation.
|Rieder, Florian; Fiocchi, Claudio; Rogler, Gerhard (2017) Mechanisms, Management, and Treatment of Fibrosis in Patients With Inflammatory Bowel Diseases. Gastroenterology 152:340-350.e6|
|Soroosh, Artin; Albeiroti, Sami; West, Gail A et al. (2016) Crohn's Disease Fibroblasts Overproduce the Novel Protein KIAA1199 to Create Proinflammatory Hyaluronan Fragments. Cell Mol Gastroenterol Hepatol 2:358-368.e4|
|Sadler, Tammy; Bhasin, Jeffrey M; Xu, Yaomin et al. (2016) Genome-wide analysis of DNA methylation and gene expression defines molecular characteristics of Crohn's disease-associated fibrosis. Clin Epigenetics 8:30|
|Schuster, Andrew T; Homer, Craig R; Kemp, Jacqueline R et al. (2015) Chromosome-associated protein D3 promotes bacterial clearance in human intestinal epithelial cells by repressing expression of amino acid transporters. Gastroenterology 148:1405-1416.e3|
|Dixon, Laura J; Kabi, Amrita; Nickerson, Kourtney P et al. (2015) Combinatorial effects of diet and genetics on inflammatory bowel disease pathogenesis. Inflamm Bowel Dis 21:912-22|
|Yoo, Jun Hwan; Ho, Samantha; Tran, Deanna Hoang-Yen et al. (2015) Anti-fibrogenic effects of the anti-microbial peptide cathelicidin in murine colitis-associated fibrosis. Cell Mol Gastroenterol Hepatol 1:55-74.e1|
|Nickerson, Kourtney P; Chanin, Rachael; McDonald, Christine (2015) Deregulation of intestinal anti-microbial defense by the dietary additive, maltodextrin. Gut Microbes 6:78-83|
|Kurada, S; Alkhouri, N; Fiocchi, C et al. (2015) Review article: breath analysis in inflammatory bowel diseases. Aliment Pharmacol Ther 41:329-41|
|Scarpa, Melania; Kessler, Sean; Sadler, Tammy et al. (2015) The epithelial danger signal IL-1? is a potent activator of fibroblasts and reactivator of intestinal inflammation. Am J Pathol 185:1624-37|
|Bakirtzi, Kyriaki; West, Gail; Fiocchi, Claudio et al. (2014) The neurotensin-HIF-1?-VEGF? axis orchestrates hypoxia, colonic inflammation, and intestinal angiogenesis. Am J Pathol 184:3405-14|
Showing the most recent 10 out of 66 publications