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Buret AG, Motta JP, Allain T, Ferraz J, Wallace JL. Pathobiont release from dysbiotic gut microbiota biofilms in intestinal inflammatory diseases: a role for iron? J Biomed Sci 2019; 26:1. [PMID: 30602371 PMCID: PMC6317250 DOI: 10.1186/s12929-018-0495-4] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 12/21/2018] [Indexed: 02/06/2023] Open
Abstract
Gut microbiota interacting with an intact mucosal surface are key to the maintenance of homeostasis and health. This review discusses the current state of knowledge of the biofilm mode of growth of these microbiota communities, and how in turn their disruptions may cause disease. Beyond alterations of relative microbial abundance and diversity, the aim of the review is to focus on the disruptions of the microbiota biofilm structure and function, the dispersion of commensal bacteria, and the mechanisms whereby these dispersed commensals may become pathobionts. Recent findings have linked iron acquisition to the expression of virulence factors in gut commensals that have become pathobionts. Causal studies are emerging, and mechanisms common to enteropathogen-induced disruptions, as well as those reported for Inflammatory Bowel Disease and colo-rectal cancer are used as examples to illustrate the great translational potential of such research. These new observations shed new light on our attempts to develop new therapies that are able to protect and restore gut microbiota homeostasis in the many disease conditions that have been linked to microbiota dysbiosis.
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Affiliation(s)
- Andre Gerald Buret
- Departments of Biological Sciences, and Pharmacology and Therapeutics, Inflammation Research Network, University of Calgary, 2500 University Dr. N.W, Calgary, T2N 1N4, Canada.
| | - Jean-Paul Motta
- Departments of Biological Sciences, and Pharmacology and Therapeutics, Inflammation Research Network, University of Calgary, 2500 University Dr. N.W, Calgary, T2N 1N4, Canada.,Institute of Digestive Health Research, INSERM UMR1220, Université Toulouse Paul Sabatier, Toulouse, France
| | - Thibault Allain
- Departments of Biological Sciences, and Pharmacology and Therapeutics, Inflammation Research Network, University of Calgary, 2500 University Dr. N.W, Calgary, T2N 1N4, Canada
| | - Jose Ferraz
- Division of Gastroenterology, Cumming School of Medicine, University of Calgary, Calgary, T2N 1N4, Canada
| | - John Lawrence Wallace
- Departments of Biological Sciences, and Pharmacology and Therapeutics, Inflammation Research Network, University of Calgary, 2500 University Dr. N.W, Calgary, T2N 1N4, Canada
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Amat CB, Motta JP, Fekete E, Moreau F, Chadee K, Buret AG. Cysteine Protease-Dependent Mucous Disruptions and Differential Mucin Gene Expression in Giardia duodenalis Infection. THE AMERICAN JOURNAL OF PATHOLOGY 2017; 187:2486-2498. [PMID: 28823873 DOI: 10.1016/j.ajpath.2017.07.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 07/04/2017] [Accepted: 07/06/2017] [Indexed: 02/08/2023]
Abstract
The intestinal mucous layer provides a critical host defense against pathogen exposure and epithelial injury, yet little is known about how enteropathogens may circumvent this physiologic barrier. Giardia duodenalis is a small intestinal parasite responsible for diarrheal disease and chronic postinfectious illness. This study reveals a complex interaction at the surface of epithelial cells, between G. duodenalis and the intestinal mucous layer. Here, we reveal mechanisms whereby G. duodenalis evades and disrupts the first line of host defense by degrading human mucin-2 (MUC2), depleting mucin stores and inducing differential gene expression in the mouse small and large intestines. Human colonic biopsy specimens exposed to G. duodenalis were depleted of mucus, and in vivo mice infected with G. duodenalis had a thinner mucous layer and demonstrated differential Muc2 and Muc5ac mucin gene expression. Infection in Muc2-/- mice elevated trophozoite colonization in the small intestine and impaired weight gain. In vitro, human LS174T goblet-like cells were depleted of mucus and had elevated levels of MUC2 mRNA expression after G. duodenalis exposure. Importantly, the cysteine protease inhibitor E64 prevented mucous degradation, mucin depletion, and the increase in MUC2 expression. This article describes a novel role for Giardia's cysteine proteases in pathogenesis and how Giardia's disruptions of the mucous barrier facilitate bacterial translocation that may contribute to the onset and propagation of disease.
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Affiliation(s)
- Christina B Amat
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Jean-Paul Motta
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Elena Fekete
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - France Moreau
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, Calgary, Alberta, Canada
| | - Kris Chadee
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, Calgary, Alberta, Canada.
| | - Andre G Buret
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada.
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Allain T, Amat CB, Motta JP, Manko A, Buret AG. Interactions of Giardia sp. with the intestinal barrier: Epithelium, mucus, and microbiota. Tissue Barriers 2017; 5:e1274354. [PMID: 28452685 DOI: 10.1080/21688370.2016.1274354] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Understanding how intestinal enteropathogens cause acute and chronic alterations has direct animal and human health perspectives. Significant advances have been made on this field by studies focusing on the dynamic crosstalk between the intestinal protozoan parasite model Giardia duodenalis and the host intestinal mucosa. The concept of intestinal barrier function is of the highest importance in the context of many gastrointestinal diseases such as infectious enteritis, inflammatory bowel disease, and post-infectious gastrointestinal disorders. This crucial function relies on 3 biotic and abiotic components, first the commensal microbiota organized as a biofilm, then an overlaying mucus layer, and finally the tightly structured intestinal epithelium. Herein we review multiple strategies used by Giardia parasite to circumvent these 3 components. We will summarize what is known and discuss preliminary observations suggesting how such enteropathogen directly and/ or indirectly impairs commensal microbiota biofilm architecture, disrupts mucus layer and damages host epithelium physiology and survival.
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Affiliation(s)
- Thibault Allain
- a Department of Biological Sciences , University of Calgary , Calgary , AB , Canada.,b Inflammation Research Network, University of Calgary , Calgary , AB , Canada.,c Host-Parasite Interactions, University of Calgary , Calgary , AB , Canada
| | - Christina B Amat
- a Department of Biological Sciences , University of Calgary , Calgary , AB , Canada.,b Inflammation Research Network, University of Calgary , Calgary , AB , Canada.,c Host-Parasite Interactions, University of Calgary , Calgary , AB , Canada
| | - Jean-Paul Motta
- a Department of Biological Sciences , University of Calgary , Calgary , AB , Canada.,b Inflammation Research Network, University of Calgary , Calgary , AB , Canada.,c Host-Parasite Interactions, University of Calgary , Calgary , AB , Canada
| | - Anna Manko
- a Department of Biological Sciences , University of Calgary , Calgary , AB , Canada.,b Inflammation Research Network, University of Calgary , Calgary , AB , Canada.,c Host-Parasite Interactions, University of Calgary , Calgary , AB , Canada
| | - André G Buret
- a Department of Biological Sciences , University of Calgary , Calgary , AB , Canada.,b Inflammation Research Network, University of Calgary , Calgary , AB , Canada.,c Host-Parasite Interactions, University of Calgary , Calgary , AB , Canada
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