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Puértolas-Balint F, Schroeder BO. Does an Apple a Day Also Keep the Microbes Away? The Interplay Between Diet, Microbiota, and Host Defense Peptides at the Intestinal Mucosal Barrier. Front Immunol 2020; 11:1164. [PMID: 32655555 PMCID: PMC7325984 DOI: 10.3389/fimmu.2020.01164] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 05/12/2020] [Indexed: 12/13/2022] Open
Abstract
A crucial mechanism of intestinal defense includes the production and secretion of host defense peptides (HDPs). HDPs control pathogens and commensals at the intestinal interface by direct killing, by sequestering vital ions, or by causing bacterial cells to aggregate in the mucus layer. Accordingly, the combined activity of various HDPs neutralizes gut bacteria before reaching the mucosa and thus helps to maintain the homeostatic balance between the host and its microbes at the mucosal barrier. Defects in the mucosal barrier have been associated with various diseases that are on the rise in the Western world. These include metabolic diseases, such as obesity and type 2 diabetes, and inflammatory intestinal disorders, including ulcerative colitis and Crohn's disease, the two major entities of inflammatory bowel disease. While the etiology of these diseases is multifactorial, highly processed Western-style diet (WSD) that is rich in carbohydrates and fat and low in dietary fiber content, is considered to be a contributing lifestyle factor. As such, WSD does not only profoundly affect the resident microbes in the intestine, but can also directly alter HDP function, thereby potentially contributing to intestinal mucosal barrier dysfunction. In this review we aim to decipher the complex interaction between diet, microbiota, and HDPs. We discuss how HDP expression can be modulated by specific microbes and their metabolites as well as by dietary factors, including fibers, lipids, polyphenols and vitamins. We identify several dietary compounds that lead to reduced HDP function, but also factors that stimulate HDP production in the intestine. Furthermore, we argue that the effect of HDPs against commensal bacteria has been understudied when compared to pathogens, and that local environmental conditions also need to be considered. In addition, we discuss the known molecular mechanisms behind HDP modulation. We believe that a better understanding of the diet-microbiota-HDP interdependence will provide insights into factors underlying modern diseases and will help to identify potential dietary interventions or probiotic supplementation that can promote HDP-mediated intestinal barrier function in the Western gut.
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Affiliation(s)
- Fabiola Puértolas-Balint
- Laboratory for Molecular Infection Medicine Sweden (MIMS) -The Nordic EMBL Partnership for Molecular Medicine, Umeå University, Umeå, Sweden.,Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Bjoern O Schroeder
- Laboratory for Molecular Infection Medicine Sweden (MIMS) -The Nordic EMBL Partnership for Molecular Medicine, Umeå University, Umeå, Sweden.,Department of Molecular Biology, Umeå University, Umeå, Sweden
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Shimizu Y, Nakamura K, Yoshii A, Yokoi Y, Kikuchi M, Shinozaki R, Nakamura S, Ohira S, Sugimoto R, Ayabe T. Paneth cell α-defensin misfolding correlates with dysbiosis and ileitis in Crohn's disease model mice. Life Sci Alliance 2020; 3:3/6/e201900592. [PMID: 32345659 PMCID: PMC7190275 DOI: 10.26508/lsa.201900592] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 04/07/2020] [Accepted: 04/07/2020] [Indexed: 12/12/2022] Open
Abstract
This study provides novel insight into Crohn’s disease where α-defensin misfolding resulting from excessive ER stress in Paneth cells induces dysbiosis and disease progression. Crohn’s disease (CD) is an intractable inflammatory bowel disease, and dysbiosis, disruption of the intestinal microbiota, is associated with CD pathophysiology. ER stress, disruption of ER homeostasis in Paneth cells of the small intestine, and α-defensin misfolding have been reported in CD patients. Because α-defensins regulate the composition of the intestinal microbiota, their misfolding may cause dysbiosis. However, whether ER stress, α-defensin misfolding, and dysbiosis contribute to the pathophysiology of CD remains unknown. Here, we show that abnormal Paneth cells with markers of ER stress appear in SAMP1/YitFc, a mouse model of CD, along with disease progression. Those mice secrete reduced-form α-defensins that lack disulfide bonds into the intestinal lumen, a condition not found in normal mice, and reduced-form α-defensins correlate with dysbiosis during disease progression. Moreover, administration of reduced-form α-defensins to wild-type mice induces the dysbiosis. These data provide novel insights into CD pathogenesis induced by dysbiosis resulting from Paneth cell α-defensin misfolding and they suggest further that Paneth cells may be potential therapeutic targets.
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Affiliation(s)
- Yu Shimizu
- Innate Immunity Laboratory, Graduate School of Life Science, Hokkaido University, Hokkaido, Japan.,Department of Cell Biological Science, Faculty of Advanced Life Science, Hokkaido University, Hokkaido, Japan
| | - Kiminori Nakamura
- Innate Immunity Laboratory, Graduate School of Life Science, Hokkaido University, Hokkaido, Japan.,Department of Cell Biological Science, Faculty of Advanced Life Science, Hokkaido University, Hokkaido, Japan
| | - Aki Yoshii
- Innate Immunity Laboratory, Graduate School of Life Science, Hokkaido University, Hokkaido, Japan
| | - Yuki Yokoi
- Innate Immunity Laboratory, Graduate School of Life Science, Hokkaido University, Hokkaido, Japan.,Department of Cell Biological Science, Faculty of Advanced Life Science, Hokkaido University, Hokkaido, Japan
| | - Mani Kikuchi
- Department of Cell Biological Science, Faculty of Advanced Life Science, Hokkaido University, Hokkaido, Japan
| | - Ryuga Shinozaki
- Innate Immunity Laboratory, Graduate School of Life Science, Hokkaido University, Hokkaido, Japan
| | - Shunta Nakamura
- Innate Immunity Laboratory, Graduate School of Life Science, Hokkaido University, Hokkaido, Japan
| | - Shuya Ohira
- Innate Immunity Laboratory, Graduate School of Life Science, Hokkaido University, Hokkaido, Japan
| | - Rina Sugimoto
- Innate Immunity Laboratory, Graduate School of Life Science, Hokkaido University, Hokkaido, Japan
| | - Tokiyoshi Ayabe
- Innate Immunity Laboratory, Graduate School of Life Science, Hokkaido University, Hokkaido, Japan .,Department of Cell Biological Science, Faculty of Advanced Life Science, Hokkaido University, Hokkaido, Japan
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Wehkamp J, Stange EF. An Update Review on the Paneth Cell as Key to Ileal Crohn's Disease. Front Immunol 2020; 11:646. [PMID: 32351509 PMCID: PMC7174711 DOI: 10.3389/fimmu.2020.00646] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 03/23/2020] [Indexed: 12/12/2022] Open
Abstract
The Paneth cells reside in the small intestine at the bottom of the crypts of Lieberkühn, intermingled with stem cells, and provide a niche for their neighbors by secreting growth and Wnt-factors as well as different antimicrobial peptides including defensins, lysozyme and others. The most abundant are the human Paneth cell α-defensin 5 and 6 that keep the crypt sterile and control the local microbiome. In ileal Crohn's disease various mechanisms including established genetic risk factors contribute to defects in the production and ordered secretion of these peptides. In addition, life-style risk factors for Crohn's disease like tobacco smoking also impact on Paneth cell function. Taken together, current evidence suggest that defective Paneth cells may play the key role in initiating inflammation in ileal, and maybe ileocecal, Crohn's disease by allowing bacterial attachment and invasion.
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Affiliation(s)
- Jan Wehkamp
- University of Tübingen, Medizinische Klinik I, Tübingen, Germany
| | - Eduard F Stange
- University of Tübingen, Medizinische Klinik I, Tübingen, Germany
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