351
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Kim MS, Bae JW. Spatial disturbances in altered mucosal and luminal gut viromes of diet-induced obese mice. Environ Microbiol 2016; 18:1498-510. [PMID: 26690305 DOI: 10.1111/1462-2920.13182] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 11/28/2015] [Accepted: 12/04/2015] [Indexed: 12/15/2022]
Abstract
Gut microbial biogeography is a key feature of host-microbe relationships. In gut viral ecology, biogeography and responses to dietary intervention remain poorly understood. Here, we conducted a metagenomic study to determine the composition of the mucosal and luminal viromes of the gut and to evaluate the impact of a Western diet on gut viral ecology. We found that mucosal and luminal viral assemblages comprised predominantly temperate phages. The mucosal virome significantly differed from the luminal virome in low-fat diet-fed lean mice, where spatial variation correlated with bacterial microbiota from the mucosa and lumen. The mucosal and luminal viromes of high-fat, high-sucrose 'Western' diet-fed obese mice were significantly enriched with temperate phages of the Caudovirales order. Interestingly, this community alteration occurred to a greater extent in the mucosa than lumen, leading to loss of spatial differences; however, these changes recovered after switching to a low-fat diet. Temperate phages enriched in the Western diet-induced obese mice were associated with the Bacilli, Negativicutes and Bacteroidia classes and temperate phages from the Bacteroidia class particularly encoded stress and niche-specific functions advantageous to bacterial host adaptation. This study illustrates a biogeographic view of the gut virome and phage-bacterial host connections under the diet-induced microbial dysbiosis.
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Affiliation(s)
- Min-Soo Kim
- Department of Life and Nanopharmaceutical Sciences and Department of Biology, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul, 130-701, Republic of Korea
| | - Jin-Woo Bae
- Department of Life and Nanopharmaceutical Sciences and Department of Biology, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul, 130-701, Republic of Korea
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352
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Mori K, Suzuki T, Minamishima S, Igarashi T, Inoue K, Nishimura D, Seki H, Yamada T, Kosugi S, Katori N, Hashiguchi S, Morisaki H. Neutrophil gelatinase-associated lipocalin regulates gut microbiota of mice. J Gastroenterol Hepatol 2016; 31:145-54. [PMID: 26189649 DOI: 10.1111/jgh.13042] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/25/2015] [Indexed: 12/14/2022]
Abstract
BACKGROUND AND AIM Because neutrophil gelatinase-associated lipocalin (NGAL) is known to provide significant bacteriostatic effects during infectious conditions, we tested the hypothesis that this protein is up-regulated and secreted into the intraluminal cavity of the gut under critically ill conditions and is thus responsible for the regulation of bacterial overgrowth. METHODS With our institutional approval, male C57BL/6J mouse (6-7 weeks) were enrolled and applied for lipopolysaccharide or peritonitis model compared with naïve control. We assessed NGAL protein concentrations in intestinal lumen and up-regulation of NGAL expression in intestinal tissues in in vivo as well as ex vivo settings. Simultaneously, we examined the effects of NGAL protein administration on the growth of Escherichia coli (E. coli) in in vivo and in vitro experimental settings. The localization of NGAL in intestinal tissues and lumen was also assessed by immunohistological approach using NGAL antibody. RESULTS Both lipopolysaccharide and peritonitis insults evoked the marked up-regulation of NGAL mRNA and protein levels in gut tissues such as crypt cells. In addition, the administration of NGAL protein significantly inhibited the outgrowth of enteric E. coli under both in vitro and in vivo conditions, accompanied by histological evidence. CONCLUSION Neutrophil gelatinase-associated lipocalin protein accompanied by apparent bacteriostatic action accumulated in the intestinal wall and streamed into the mucosal layer during critically ill state, thereby possibly shaping microbiota homeostasis in the gut.
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Affiliation(s)
- Katsuya Mori
- Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan.,Japan Society of the Promotion of Science, Tokyo, Japan
| | - Takeshi Suzuki
- Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan
| | - Shizuka Minamishima
- Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan
| | - Toru Igarashi
- Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan
| | - Kei Inoue
- Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan
| | - Daisuke Nishimura
- Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan
| | - Hiroyuki Seki
- Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan
| | - Takashige Yamada
- Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan
| | - Shizuko Kosugi
- Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan
| | - Nobuyuki Katori
- Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan
| | - Saori Hashiguchi
- Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan
| | - Hiroshi Morisaki
- Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan
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353
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Deschemin JC, Allouche S, Brouillard F, Vaulont S. Iron Homeostasis and Inflammatory Status in Mice Deficient for the Cystic Fibrosis Transmembrane Regulator. PLoS One 2015; 10:e0145685. [PMID: 26709821 PMCID: PMC4699203 DOI: 10.1371/journal.pone.0145685] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 12/07/2015] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Cystic Fibrosis (CF) is a frequent and lethal autosomal recessive disease caused by mutations in the gene encoding the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR). Patients with CF suffer from chronic infections and severe inflammation, which lead to progressive pulmonary and gut diseases. Recently, an expanding body of evidence has suggested that iron homeostasis was abnormal in CF with, in particular, systemic iron deficiency and iron sequestration in the epithelium airway. The molecular mechanisms responsible for iron dysregulation and the relationship with inflammation in CF are unknown. METHODS AND RESULTS We assessed the impact of CFTR deficiency on systemic and tissue iron homeostasis as well as inflammation in wildtype and CFTR knockout (KO) mice. First, in contrast to the systemic and intestinal inflammation we observed in the CFTR KO mice, we reported the absence of lung phenotype with regards to both inflammation and iron status. Second, we showed a significant decrease of plasma ferritin levels in the KO mice, as in CF patients, likely caused by a decrease in spleen ferritin levels. However, we measured unchanged plasma iron levels in the KO mice that may be explained by increased intestinal iron absorption. CONCLUSION These results indicate that in CF, the lung do not predominantly contributes to the systemic ferritin deficiency and we propose the spleen as the major organ responsible for hypoferritinemia in the KO mouse. These results should provide a better understanding of iron dysregulation in CF patients where treating or not iron deficiency remains a challenging question.
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Affiliation(s)
- Jean-Christophe Deschemin
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS, UMR8104, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
- Laboratory of Excellence GR-Ex, Paris, France
| | - Sarah Allouche
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS, UMR8104, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
- Laboratory of Excellence GR-Ex, Paris, France
| | - Franck Brouillard
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
- Institut de Chimie des Substances Naturelles, UPR2301 CNRS, Gif-sur-Yvette, France
| | - Sophie Vaulont
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS, UMR8104, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
- Laboratory of Excellence GR-Ex, Paris, France
- * E-mail:
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354
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Abella V, Scotece M, Conde J, Gómez R, Lois A, Pino J, Gómez-Reino JJ, Lago F, Mobasheri A, Gualillo O. The potential of lipocalin-2/NGAL as biomarker for inflammatory and metabolic diseases. Biomarkers 2015; 20:565-71. [PMID: 26671823 PMCID: PMC4819811 DOI: 10.3109/1354750x.2015.1123354] [Citation(s) in RCA: 176] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Lipocalin-2 (LCN2), also known as neutrophil gelatinase-associated lipocalin (NGAL), is a secreted glycoprotein that belongs to a group of transporters of small lipophilic molecules in circulation. LCN2 has been recently characterized as an adipose-derived cytokine. This adipokine is believed to bind small substances, such as steroids and lipopolysaccharides, and has been reported to have roles in the induction of apoptosis in hematopoietic cells, transport of fatty acids and iron, modulation of inflammation, and metabolic homeostasis. Recently, LCN2 has emerged as a useful biomarker and rheumatic diseases. This review provides an overview of LCN2 in inflammation, immunity, and metabolism.
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Affiliation(s)
- Vanessa Abella
- a SERGAS (Servizo Galego de Saude), Research Laboratory 9, NEIRID Lab (Neuroendocrine Interactions in Rheumatology and Inflammatory Diseases), Institute of Medical Research (IDIS), Santiago University Clinical Hospital , Santiago de Compostela , Spain .,b Departamento de Bioloxía Celular e Molecular , Facultade de Ciencias, Universidade Da Coruña (UDC) , Campus de A Coruña , Spain
| | - Morena Scotece
- a SERGAS (Servizo Galego de Saude), Research Laboratory 9, NEIRID Lab (Neuroendocrine Interactions in Rheumatology and Inflammatory Diseases), Institute of Medical Research (IDIS), Santiago University Clinical Hospital , Santiago de Compostela , Spain
| | - Javier Conde
- a SERGAS (Servizo Galego de Saude), Research Laboratory 9, NEIRID Lab (Neuroendocrine Interactions in Rheumatology and Inflammatory Diseases), Institute of Medical Research (IDIS), Santiago University Clinical Hospital , Santiago de Compostela , Spain
| | - Rodolfo Gómez
- a SERGAS (Servizo Galego de Saude), Research Laboratory 9, NEIRID Lab (Neuroendocrine Interactions in Rheumatology and Inflammatory Diseases), Institute of Medical Research (IDIS), Santiago University Clinical Hospital , Santiago de Compostela , Spain
| | - Ana Lois
- a SERGAS (Servizo Galego de Saude), Research Laboratory 9, NEIRID Lab (Neuroendocrine Interactions in Rheumatology and Inflammatory Diseases), Institute of Medical Research (IDIS), Santiago University Clinical Hospital , Santiago de Compostela , Spain
| | - Jesús Pino
- c SERGAS, Division of Orthopaedics Surgery and Traumatology, Santiago University Clinical Hospital , Santiago de Compostela , Spain
| | - Juan J Gómez-Reino
- a SERGAS (Servizo Galego de Saude), Research Laboratory 9, NEIRID Lab (Neuroendocrine Interactions in Rheumatology and Inflammatory Diseases), Institute of Medical Research (IDIS), Santiago University Clinical Hospital , Santiago de Compostela , Spain
| | - Francisca Lago
- d SERGAS (Servizo Galego de Saude), Research Laboratory 7, Molecular and Cellular Cardiology Laboratory, Institute of Medical Research (IDIS), Santiago University Clinical Hospital , Santiago de Compostela , Spain
| | - Ali Mobasheri
- e The D-BOARD European Consortium for Biomarker Discovery, Department of Veterinary Preclinical Sciences, School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey , Guildford , UK .,f Arthritis Research UK Centre for Sport, Exercise and Osteoarthritis, Arthritis Research UK Pain Centre, Medical Research Council and Arthritis Research UK Centre for Musculoskeletal Ageing Research, University of Nottingham, Queen's Medical Centre , Nottingham , UK , and.,g Center of Excellence in Genomic Medicine Research (CEGMR), King Fahd Medical Research Center (KFMRC), Faculty of Applied Medical Sciences, King AbdulAziz University , Jeddah , Kingdom of Saudi Arabia
| | - Oreste Gualillo
- a SERGAS (Servizo Galego de Saude), Research Laboratory 9, NEIRID Lab (Neuroendocrine Interactions in Rheumatology and Inflammatory Diseases), Institute of Medical Research (IDIS), Santiago University Clinical Hospital , Santiago de Compostela , Spain
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355
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Jiang C, Xie C, Lv Y, Li J, Krausz KW, Shi J, Brocker CN, Desai D, Amin SG, Bisson WH, Liu Y, Gavrilova O, Patterson AD, Gonzalez FJ. Intestine-selective farnesoid X receptor inhibition improves obesity-related metabolic dysfunction. Nat Commun 2015; 6:10166. [PMID: 26670557 PMCID: PMC4682112 DOI: 10.1038/ncomms10166] [Citation(s) in RCA: 378] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 11/10/2015] [Indexed: 12/17/2022] Open
Abstract
The farnesoid X receptor (FXR) regulates bile acid, lipid and glucose metabolism. Here we show that treatment of mice with glycine-β-muricholic acid (Gly-MCA) inhibits FXR signalling exclusively in intestine, and improves metabolic parameters in mouse models of obesity. Gly-MCA is a selective high-affinity FXR inhibitor that can be administered orally and prevents, or reverses, high-fat diet-induced and genetic obesity, insulin resistance and hepatic steatosis in mice. The high-affinity FXR agonist GW4064 blocks Gly-MCA action in the gut, and intestine-specific Fxr-null mice are unresponsive to the beneficial effects of Gly-MCA. Mechanistically, the metabolic improvements with Gly-MCA depend on reduced biosynthesis of intestinal-derived ceramides, which directly compromise beige fat thermogenic function. Consequently, ceramide treatment reverses the action of Gly-MCA in high-fat diet-induced obese mice. We further show that FXR signalling in ileum biopsies of humans positively correlates with body mass index. These data suggest that Gly-MCA may be a candidate for the treatment of metabolic disorders. The nuclear farnesoid X receptor (FXR) is activated by bile acids and influences energy metabolism. Here, the authors report a small molecule inhibitor of FXR, glycine-ß-muricholic acid, which inhibits FXR in the intestine and improves metabolic homeostasis by repressing intestinal ceramide synthesis.
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Affiliation(s)
- Changtao Jiang
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.,Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, and the Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China
| | - Cen Xie
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Ying Lv
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, and the Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China
| | - Jing Li
- Department of Gastroenterology, Peking University People's Hospital, Beijing 100044, China
| | - Kristopher W Krausz
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Jingmin Shi
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Chad N Brocker
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Dhimant Desai
- Department of Pharmacology, College of Medicine, The Pennsylvania State University, Hershey, Pennsylvania 17033, USA
| | - Shantu G Amin
- Department of Pharmacology, College of Medicine, The Pennsylvania State University, Hershey, Pennsylvania 17033, USA
| | - William H Bisson
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon 97331, USA
| | - Yulan Liu
- Department of Gastroenterology, Peking University People's Hospital, Beijing 100044, China
| | - Oksana Gavrilova
- Mouse Metabolism Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Andrew D Patterson
- Department of Veterinary and Biomedical Sciences and the Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Frank J Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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356
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Allais L, Kumar S, Debusschere K, Verschuere S, Maes T, De Smet R, Conickx G, De Vos M, Laukens D, Joos GF, Brusselle GG, Elewaut D, Cuvelier CA, Bracke KR. The Effect of Cigarette Smoke Exposure on the Development of Inflammation in Lungs, Gut and Joints of TNFΔARE Mice. PLoS One 2015; 10:e0141570. [PMID: 26523550 PMCID: PMC4629889 DOI: 10.1371/journal.pone.0141570] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 10/10/2015] [Indexed: 12/13/2022] Open
Abstract
The inflammatory cytokine TNF-α is a central mediator in many immune-mediated diseases, such as Crohn’s disease (CD), spondyloarthritis (SpA) and chronic obstructive pulmonary disease (COPD). Epidemiologic studies have shown that cigarette smoking (CS) is a prominent common risk factor in these TNF-dependent diseases. We exposed TNFΔARE mice; in which a systemic TNF-α overexpression leads to the development of inflammation; to 2 or 4 weeks of air or CS. We investigated the effect of deregulated TNF expression on CS-induced pulmonary inflammation and the effect of CS exposure on the initiation and progression of gut and joint inflammation. Upon 2 weeks of CS exposure, inflammation in lungs of TNFΔARE mice was significantly aggravated. However, upon 4 weeks of CS-exposure, this aggravation was no longer observed. TNFΔARE mice have no increases in CD4+ and CD8+ T cells and a diminished neutrophil response in the lungs after 4 weeks of CS exposure. In the gut and joints of TNFΔARE mice, 2 or 4 weeks of CS exposure did not modulate the development of inflammation. In conclusion, CS exposure does not modulate gut and joint inflammation in TNFΔARE mice. The lung responses towards CS in TNFΔARE mice however depend on the duration of CS exposure.
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Affiliation(s)
- Liesbeth Allais
- Department of Medical and Forensic Pathology, Ghent University, Ghent, Belgium
- * E-mail: ;
| | - Smitha Kumar
- Laboratory for Translational Research in Obstructive Pulmonary diseases, Department of Respiratory Medicine, Ghent University Hospital, Ghent, Belgium
| | - Karlijn Debusschere
- Laboratory for Molecular Immunology and Inflammation, Department of Rheumatology, Ghent University, Ghent, Belgium
- VIB Inflammation Research Center, Ghent University, Ghent, Belgium
| | | | - Tania Maes
- Laboratory for Translational Research in Obstructive Pulmonary diseases, Department of Respiratory Medicine, Ghent University Hospital, Ghent, Belgium
| | - Rebecca De Smet
- Department of Medical and Forensic Pathology, Ghent University, Ghent, Belgium
| | - Griet Conickx
- Laboratory for Translational Research in Obstructive Pulmonary diseases, Department of Respiratory Medicine, Ghent University Hospital, Ghent, Belgium
| | - Martine De Vos
- Department of Gastroenterology, Ghent University, Ghent, Belgium
| | - Debby Laukens
- Department of Gastroenterology, Ghent University, Ghent, Belgium
| | - Guy F. Joos
- Laboratory for Translational Research in Obstructive Pulmonary diseases, Department of Respiratory Medicine, Ghent University Hospital, Ghent, Belgium
| | - Guy G. Brusselle
- Laboratory for Translational Research in Obstructive Pulmonary diseases, Department of Respiratory Medicine, Ghent University Hospital, Ghent, Belgium
| | - Dirk Elewaut
- Laboratory for Molecular Immunology and Inflammation, Department of Rheumatology, Ghent University, Ghent, Belgium
- VIB Inflammation Research Center, Ghent University, Ghent, Belgium
| | - Claude A. Cuvelier
- Department of Medical and Forensic Pathology, Ghent University, Ghent, Belgium
| | - Ken R. Bracke
- Laboratory for Translational Research in Obstructive Pulmonary diseases, Department of Respiratory Medicine, Ghent University Hospital, Ghent, Belgium
- * E-mail: ;
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357
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Abstract
Diagnostics of inflammatory bowel diseases (IBDs) currently relies on a combination of biological and morphological tests. The current method of diagnostic remains a critical challenge for physicians in part due to their invasiveness and also for their limitations in term of diagnosis, prognosis, disease activity and severity assessment, and therapeutic outcomes. Laboratory biomarkers can be used in the diagnosis and management of IBD, but none of them has been proven to be ideal. Increasing efforts are being made to discover new biomarkers that can discriminate between the types of IBD, predict future responses to treatment, and aid in differential diagnosis, treatment planning, and prognosis prediction. This review addresses the potential for current biomarkers and the emergence of the concept of biomarker signatures in IBD diagnostic and personalized medicine.
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358
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Chassaing B, Miles-Brown J, Pellizzon M, Ulman E, Ricci M, Zhang L, Patterson AD, Vijay-Kumar M, Gewirtz AT. Lack of soluble fiber drives diet-induced adiposity in mice. Am J Physiol Gastrointest Liver Physiol 2015; 309:G528-41. [PMID: 26185332 PMCID: PMC4593822 DOI: 10.1152/ajpgi.00172.2015] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 07/08/2015] [Indexed: 01/31/2023]
Abstract
Diet-induced obesity is often modeled by comparing mice fed high-fat diet (HFD), which is made from purified ingredients, vs. normal chow diet (NCD), which is a low-fat assemblage of relatively unrefined plant and animal products. The mechanism by which HFD promotes adiposity is complex but thought to involve low-grade inflammation and altered gut microbiota. The goal of this study was to investigate the extent to which HFD-induced adiposity is driven by fat content vs. other factors that differentiate HFD vs. NCD. Mice were fed NCD, HFD, or other compositionally defined diets (CDD), designed to mimic NCD and/or explore the role of HFD components. A range of metabolic parameters reflecting low-grade inflammation and adiposity were assayed. Relative to NCD, HFD, and to a lesser, but, nonetheless, significant extent, CDD induced increased adiposity, indicating both lipid content and other aspects of HFD are obesogenic. Moreover, HFD and CDD induced a rapid and marked loss of cecal and colonic mass. Such CDD-induced effects were not affected by adjusting dietary protein levels/types but could be largely eliminated by exchanging insoluble fiber (cellulose) for soluble fiber (inulin). Replacing cellulose with inulin in HFD also protected mice against decreased intestinal mass, hyperphagia, and increased adiposity. Such beneficial effects of inulin were microbiota dependent, correlated with elevated fecal short-chain fatty acid levels analyzed via (1)H-NMR-based metabolomics and were partially recapitulated by administration of short-chain fatty acid. HFD-induced obesity is strongly promoted by its lack of soluble fiber, which supports microbiota-mediated intestinal tissue homeostasis that prevents inflammation driving obesity and metabolic syndrome.
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Affiliation(s)
- Benoit Chassaing
- 1Center for Inflammation, Immunity and Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia;
| | - Jennifer Miles-Brown
- 1Center for Inflammation, Immunity and Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia;
| | | | - Edward Ulman
- 2Research Diets, Inc., New Brunswick, New Jersey;
| | | | - Limin Zhang
- 3Departments of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, Pennsylvania; and
| | - Andrew D. Patterson
- 3Departments of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, Pennsylvania; and
| | - Matam Vijay-Kumar
- 4Departments of Nutritional Sciences & Medicine, Pennsylvania State University, University Park, Pennsylvania
| | - Andrew T. Gewirtz
- 1Center for Inflammation, Immunity and Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia;
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359
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Faecal proteomics: A tool to investigate dysbiosis and inflammation in patients with cystic fibrosis. J Cyst Fibros 2015; 15:242-50. [PMID: 26330184 DOI: 10.1016/j.jcf.2015.08.003] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 07/02/2015] [Accepted: 08/13/2015] [Indexed: 12/20/2022]
Abstract
BACKGROUND Several microbial studies reported gut microbiota dysbiosis in patients with cystic fibrosis (CF). The functional consequences of this phenomenon are poorly understood. Faecal metaproteomics allows the quantitative analysis of host and microbial proteins to address functional changes resulting from this dysbiosis. METHODS We analysed faecal protein extracts from fifteen patients with CF that have pancreatic insufficiency and from their unaffected siblings by shotgun proteomics. Novel computational and statistical tools were introduced to evaluate changes in taxonomic composition and protein abundance. RESULTS Faecal protein extracts from patients with CF were dominated by host proteins involved in inflammation and mucus formation. Taxonomic analysis of the microbial proteins confirmed the strong reduction of butyrate reducers such as Faecalibacterium prausnitzii and increase of Enterobacteriaceae, Ruminococcus gnavus and Clostridia species. CONCLUSION Faecal metaproteomics provides insights in intestinal dysbiosis, inflammation in patients with CF and can be used to monitor different disease markers in parallel.
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360
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Alternatively Spliced EDA Domain of Fibronectin Is a Target for Pharmacodelivery Applications in Inflammatory Bowel Disease. Inflamm Bowel Dis 2015; 21:1908-17. [PMID: 25993691 DOI: 10.1097/mib.0000000000000440] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The antibody-based pharmacodelivery of cytokines to sites of disease has been extensively studied for various indications but not for the treatment of inflammatory bowel diseases. Here, we report that the alternatively spliced EDA domain of fibronectin, a marker of angiogenesis and of tissue remodeling, is expressed in the dextran sodium sulfate mouse model of colitis and in patients with inflammatory bowel conditions, while being virtually undetectable in most normal adult tissues. Radiolabeled preparations of the F8 antibody, specific to the EDA domain of fibronectin, were shown to selectively localize to sites of inflammation in mice with colitis, as revealed by autoradiographic analysis. Fusion proteins of the F8 antibody with various murine payloads (interleukin-4, the p40 subunit of interleukin-12, interleukin-13) were administered to mice with colitis. IL12p40-F8 mediated an anti-inflammatory activity, which was comparable with the one of cyclosporine, whereas F8-IL4 did not inhibit colitis and F8-IL13 worsened the inflammatory conditions.
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361
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Adherent-Invasive Escherichia coli Production of Cellulose Influences Iron-Induced Bacterial Aggregation, Phagocytosis, and Induction of Colitis. Infect Immun 2015. [PMID: 26216423 DOI: 10.1128/iai.00904-15] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Adherent-invasive Escherichia coli (AIEC), a functionally distinct subset of resident intestinal E. coli associated with Crohn's disease, is characterized by enhanced epithelial adhesion and invasion, survival within macrophages, and biofilm formation. Environmental factors, such as iron, modulate E. coli production of extracellular structures, which in turn influence the formation of multicellular communities, such as biofilms, and bacterial interactions with host cells. However, the physiological and functional responses of AIEC to variable iron availability have not been thoroughly investigated. We therefore characterized the impact of iron on the physiology of AIEC strain NC101 and subsequent interactions with macrophages. Iron promoted the cellulose-dependent aggregation of NC101. Bacterial cells recovered from the aggregates were more susceptible to phagocytosis than planktonic cells, which corresponded with the decreased macrophage production of the proinflammatory cytokine interleukin-12 (IL-12) p40. Prevention of aggregate formation through the disruption of cellulose production reduced the phagocytosis of iron-exposed NC101. In contrast, under iron-limiting conditions, where NC101 aggregation is not induced, the disruption of cellulose production enhanced NC101 phagocytosis and decreased macrophage secretion of IL-12 p40. Finally, abrogation of cellulose production reduced NC101 induction of colitis when NC101 was monoassociated in inflammation-prone Il10(-/-) mice. Taken together, our results introduce cellulose as a novel physiological factor that impacts host-microbe-environment interactions and alters the proinflammatory potential of AIEC.
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362
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Zhang L, Hatzakis E, Nichols RG, Hao R, Correll J, Smith PB, Chiaro CR, Perdew GH, Patterson AD. Metabolomics Reveals that Aryl Hydrocarbon Receptor Activation by Environmental Chemicals Induces Systemic Metabolic Dysfunction in Mice. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:8067-77. [PMID: 26023891 PMCID: PMC4890155 DOI: 10.1021/acs.est.5b01389] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Environmental exposure to dioxins and dioxin-like compounds poses a significant health risk for human health. Developing a better understanding of the mechanisms of toxicity through activation of the aryl hydrocarbon receptor (AHR) is likely to improve the reliability of risk assessment. In this study, the AHR-dependent metabolic response of mice exposed to 2,3,7,8-tetrachlorodibenzofuran (TCDF) was assessed using global (1)H nuclear magnetic resonance (NMR)-based metabolomics and targeted metabolite profiling of extracts obtained from serum and liver. (1)H NMR analyses revealed that TCDF exposure suppressed gluconeogenesis and glycogenolysis, stimulated lipogenesis, and triggered inflammatory gene expression in an Ahr-dependent manner. Targeted analyses using gas chromatography coupled with mass spectrometry showed TCDF treatment altered the ratio of unsaturated/saturated fatty acids. Consistent with this observation, an increase in hepatic expression of stearoyl coenzyme A desaturase 1 was observed. In addition, TCDF exposure resulted in inhibition of de novo fatty acid biosynthesis manifested by down-regulation of acetyl-CoA, malonyl-CoA, and palmitoyl-CoA metabolites and related mRNA levels. In contrast, no significant changes in the levels of glucose and lipid were observed in serum and liver obtained from Ahr-null mice following TCDF treatment, thus strongly supporting the important role of the AHR in mediating the metabolic effects seen following TCDF exposure.
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Affiliation(s)
- Limin Zhang
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
- CAS Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Centre for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences (CAS), Wuhan 430071, China
| | - Emmanuel Hatzakis
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - Robert G. Nichols
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - Ruixin Hao
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - Jared Correll
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - Philip B. Smith
- Metabolomics Facility, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - Christopher R. Chiaro
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - Gary H. Perdew
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - Andrew D. Patterson
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
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363
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Kim JE, Park SH, Kwak MH, Go J, Koh EK, Song SH, Sung JE, Lee HS, Hong JT, Hwang DY. Characterization of Changes in Global Genes Expression in the Distal Colon of Loperamide-Induced Constipation SD Rats in Response to the Laxative Effects of Liriope platyphylla. PLoS One 2015; 10:e0129664. [PMID: 26151867 PMCID: PMC4495015 DOI: 10.1371/journal.pone.0129664] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 05/12/2015] [Indexed: 12/24/2022] Open
Abstract
To characterize the changes in global gene expression in the distal colon of constipated SD rats in response to the laxative effects of aqueous extracts of Liriope platyphylla (AEtLP), including isoflavone, saponin, oligosaccharide, succinic acid and hydroxyproline, the total RNA extracted from the distal colon of AEtLP-treated constipation rats was hybridized to oligonucleotide microarrays. The AEtLP treated rats showed an increase in the number of stools, mucosa thickness, flat luminal surface thickness, mucin secretion, and crypt number. Overall, compared to the controls, 581 genes were up-regulated and 216 genes were down-regulated by the constipation induced by loperamide in the constipated rats. After the AEtLP treatment, 67 genes were up-regulated and 421 genes were down-regulated. Among the transcripts up-regulated by constipation, 89 were significantly down-regulated and 22 were recovered to the normal levels by the AEtLP treatment. The major genes in the down-regulated categories included Slc9a5, klk10, Fgf15, and Alpi, whereas the major genes in the recovered categories were Cyp2b2, Ace, G6pc, and Setbp1. On the other hand, after the AEtLP treatment, ten of these genes down-regulated by constipation were up-regulated significantly and five were recovered to the normal levels. The major genes in the up-regulated categories included Serpina3n, Lcn2 and Slc5a8, whereas the major genes in the recovered categories were Tmem45a, Rerg and Rgc32. These results indicate that several gene functional groups and individual genes as constipation biomarkers respond to an AEtLP treatment in constipated model rats.
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Affiliation(s)
- Ji Eun Kim
- Department of Biomaterials Science, College of Natural Resources & Life Science/Life and Industry Convergence Research Institute, Pusan National University, Miryang, 627–706, Korea
| | - So Hae Park
- Department of Food Science and Nutrition, College of Human Ecology, Pusan National University, Busan, 609–735, Korea
| | - Moon Hwa Kwak
- Department of Biomaterials Science, College of Natural Resources & Life Science/Life and Industry Convergence Research Institute, Pusan National University, Miryang, 627–706, Korea
| | - Jun Go
- Department of Biomaterials Science, College of Natural Resources & Life Science/Life and Industry Convergence Research Institute, Pusan National University, Miryang, 627–706, Korea
| | - Eun Kyoung Koh
- Department of Biomaterials Science, College of Natural Resources & Life Science/Life and Industry Convergence Research Institute, Pusan National University, Miryang, 627–706, Korea
| | - Sung Hwa Song
- Department of Biomaterials Science, College of Natural Resources & Life Science/Life and Industry Convergence Research Institute, Pusan National University, Miryang, 627–706, Korea
| | - Ji Eun Sung
- Department of Biomaterials Science, College of Natural Resources & Life Science/Life and Industry Convergence Research Institute, Pusan National University, Miryang, 627–706, Korea
| | - Hee Seob Lee
- Department of Food Science and Nutrition, College of Human Ecology, Pusan National University, Busan, 609–735, Korea
| | - Jin Tae Hong
- College of Pharmacy and Medical Research Center, Chungbuk National University, Chungju, 361–763, Korea
- * E-mail: (DYH); (JTH)
| | - Dae Youn Hwang
- Department of Biomaterials Science, College of Natural Resources & Life Science/Life and Industry Convergence Research Institute, Pusan National University, Miryang, 627–706, Korea
- * E-mail: (DYH); (JTH)
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364
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Chassaing B. [Involvement of food additives in intestinal inflammation and metabolic syndrome in mice]. Med Sci (Paris) 2015; 31:586-8. [PMID: 26152155 DOI: 10.1051/medsci/20153106004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Affiliation(s)
- Benoit Chassaing
- Institute for Biomedical Sciences, Center for Inflammation, Immunity, and Infection, Georgia State University, 100 Piedmont ave SE, Petit Science Center, Atlanta, GA 30303, États-Unis
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365
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Zhang L, Nichols RG, Correll J, Murray IA, Tanaka N, Smith PB, Hubbard TD, Sebastian A, Albert I, Hatzakis E, Gonzalez FJ, Perdew GH, Patterson AD. Persistent Organic Pollutants Modify Gut Microbiota-Host Metabolic Homeostasis in Mice Through Aryl Hydrocarbon Receptor Activation. ENVIRONMENTAL HEALTH PERSPECTIVES 2015; 123:679-88. [PMID: 25768209 PMCID: PMC4492271 DOI: 10.1289/ehp.1409055] [Citation(s) in RCA: 227] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 03/09/2015] [Indexed: 05/04/2023]
Abstract
BACKGROUND Alteration of the gut microbiota through diet and environmental contaminants may disturb physiological homeostasis, leading to various diseases including obesity and type 2 diabetes. Because most exposure to environmentally persistent organic pollutants (POPs) occurs through the diet, the host gastrointestinal tract and commensal gut microbiota are likely to be exposed to POPs. OBJECTIVES We examined the effect of 2,3,7,8-tetrachlorodibenzofuran (TCDF), a persistent environmental contaminant, on gut microbiota and host metabolism, and we examined correlations between gut microbiota composition and signaling pathways. METHODS Six-week-old male wild-type and Ahr-/- mice on the C57BL/6J background were treated with 24 μg/kg TCDF in the diet for 5 days. We used 16S rRNA gene sequencing, 1H nuclear magnetic resonance (NMR) metabolomics, targeted ultra-performance liquid chromatography coupled with triplequadrupole mass spectrometry, and biochemical assays to determine the microbiota compositions and the physiological and metabolic effects of TCDF. RESULTS Dietary TCDF altered the gut microbiota by shifting the ratio of Firmicutes to Bacteroidetes. TCDF-treated mouse cecal contents were enriched with Butyrivibrio spp. but depleted in Oscillobacter spp. compared with vehicle-treated mice. These changes in the gut microbiota were associated with altered bile acid metabolism. Further, dietary TCDF inhibited the farnesoid X receptor (FXR) signaling pathway, triggered significant inflammation and host metabolic disorders as a result of activation of bacterial fermentation, and altered hepatic lipogenesis, gluconeogenesis, and glycogenolysis in an AHR-dependent manner. CONCLUSION These findings provide new insights into the biochemical consequences of TCDF exposure involving the alteration of the gut microbiota, modulation of nuclear receptor signaling, and disruption of host metabolism.
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Affiliation(s)
- Limin Zhang
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
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366
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Rausch P, Steck N, Suwandi A, Seidel JA, Künzel S, Bhullar K, Basic M, Bleich A, Johnsen JM, Vallance BA, Baines JF, Grassl GA. Expression of the Blood-Group-Related Gene B4galnt2 Alters Susceptibility to Salmonella Infection. PLoS Pathog 2015; 11:e1005008. [PMID: 26133982 PMCID: PMC4489644 DOI: 10.1371/journal.ppat.1005008] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 06/05/2015] [Indexed: 12/16/2022] Open
Abstract
Glycans play important roles in host-microbe interactions. Tissue-specific expression patterns of the blood group glycosyltransferase β-1,4-N-acetylgalactosaminyltransferase 2 (B4galnt2) are variable in wild mouse populations, and loss of B4galnt2 expression is associated with altered intestinal microbiota. We hypothesized that variation in B4galnt2 expression alters susceptibility to intestinal pathogens. To test this, we challenged mice genetically engineered to express different B4galnt2 tissue-specific patterns with a Salmonella Typhimurium infection model. We found B4galnt2 intestinal expression was strongly associated with bacterial community composition and increased Salmonella susceptibility as evidenced by increased intestinal inflammatory cytokines and infiltrating immune cells. Fecal transfer experiments demonstrated a crucial role of the B4galnt2-dependent microbiota in conferring susceptibility to intestinal inflammation, while epithelial B4galnt2 expression facilitated epithelial invasion of S. Typhimurium. These data support a critical role for B4galnt2 in gastrointestinal infections. We speculate that B4galnt2-specific differences in host susceptibility to intestinal pathogens underlie the strong signatures of balancing selection observed at the B4galnt2 locus in wild mouse populations.
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Affiliation(s)
- Philipp Rausch
- Institute for Experimental Medicine, Christian-Albrechts-University of Kiel, Kiel, Germany
- Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Natalie Steck
- Institute for Experimental Medicine, Christian-Albrechts-University of Kiel, Kiel, Germany
- Models of Inflammation, Research Center Borstel, Borstel, Germany
| | - Abdulhadi Suwandi
- Institute for Experimental Medicine, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Janice A. Seidel
- Institute for Experimental Medicine, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Sven Künzel
- Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Kirandeep Bhullar
- Department of Pediatrics, Division of Gastroenterology, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Marijana Basic
- Institute for Laboratory Animal Science, Hannover Medical School, Hannover, Germany
| | - Andre Bleich
- Institute for Laboratory Animal Science, Hannover Medical School, Hannover, Germany
| | - Jill M. Johnsen
- Research Institute, Puget Sound Blood Center, Seattle, Washington, United States of America
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Bruce A. Vallance
- Department of Pediatrics, Division of Gastroenterology, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - John F. Baines
- Institute for Experimental Medicine, Christian-Albrechts-University of Kiel, Kiel, Germany
- Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Guntram A. Grassl
- Institute for Experimental Medicine, Christian-Albrechts-University of Kiel, Kiel, Germany
- Models of Inflammation, Research Center Borstel, Borstel, Germany
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367
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Kortman GAM, Mulder MLM, Richters TJW, Shanmugam NKN, Trebicka E, Boekhorst J, Timmerman HM, Roelofs R, Wiegerinck ET, Laarakkers CM, Swinkels DW, Bolhuis A, Cherayil BJ, Tjalsma H. Low dietary iron intake restrains the intestinal inflammatory response and pathology of enteric infection by food-borne bacterial pathogens. Eur J Immunol 2015; 45:2553-67. [PMID: 26046550 DOI: 10.1002/eji.201545642] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 05/07/2015] [Accepted: 06/03/2015] [Indexed: 12/21/2022]
Abstract
Orally administrated iron is suspected to increase susceptibility to enteric infections among children in infection endemic regions. Here we investigated the effect of dietary iron on the pathology and local immune responses in intestinal infection models. Mice were held on iron-deficient, normal iron, or high iron diets and after 2 weeks they were orally challenged with the pathogen Citrobacter rodentium. Microbiome analysis by pyrosequencing revealed profound iron- and infection-induced shifts in microbiota composition. Fecal levels of the innate defensive molecules and markers of inflammation lipocalin-2 and calprotectin were not influenced by dietary iron intervention alone, but were markedly lower in mice on the iron-deficient diet after infection. Next, mice on the iron-deficient diet tended to gain more weight and to have a lower grade of colon pathology. Furthermore, survival of the nematode Caenorhabditis elegans infected with Salmonella enterica serovar Typhimurium was prolonged after iron deprivation. Together, these data show that iron limitation restricts disease pathology upon bacterial infection. However, our data also showed decreased intestinal inflammatory responses of mice fed on high iron diets. Thus additionally, our study indicates that the effects of iron on processes at the intestinal host-pathogen interface may highly depend on host iron status, immune status, and gut microbiota composition.
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Affiliation(s)
- Guus A M Kortman
- Department of Laboratory Medicine-Translational Metabolic Laboratory, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Michelle L M Mulder
- Department of Laboratory Medicine-Translational Metabolic Laboratory, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.,Mucosal Immunology and Biology Research Center, Massachusetts General Hospital, Boston, MA, USA
| | - Thijs J W Richters
- Department of Laboratory Medicine-Translational Metabolic Laboratory, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.,Mucosal Immunology and Biology Research Center, Massachusetts General Hospital, Boston, MA, USA
| | - Nanda K N Shanmugam
- Mucosal Immunology and Biology Research Center, Massachusetts General Hospital, Boston, MA, USA
| | - Estela Trebicka
- Mucosal Immunology and Biology Research Center, Massachusetts General Hospital, Boston, MA, USA
| | | | | | - Rian Roelofs
- Department of Laboratory Medicine-Translational Metabolic Laboratory, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Erwin T Wiegerinck
- Department of Laboratory Medicine-Translational Metabolic Laboratory, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Coby M Laarakkers
- Department of Laboratory Medicine-Translational Metabolic Laboratory, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Dorine W Swinkels
- Department of Laboratory Medicine-Translational Metabolic Laboratory, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Albert Bolhuis
- Department of Pharmacy and Pharmacology, University of Bath, Bath, United Kingdom
| | - Bobby J Cherayil
- Mucosal Immunology and Biology Research Center, Massachusetts General Hospital, Boston, MA, USA
| | - Harold Tjalsma
- Department of Laboratory Medicine-Translational Metabolic Laboratory, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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368
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Singh V, Yeoh BS, Carvalho F, Gewirtz AT, Vijay-Kumar M. Proneness of TLR5 deficient mice to develop colitis is microbiota dependent. Gut Microbes 2015; 6:279-83. [PMID: 26067589 PMCID: PMC4615783 DOI: 10.1080/19490976.2015.1060390] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Alterations in the gut microbiota have been implicated to play a role in potentiating inflammatory bowel diseases in both humans and mice. Mice lacking the flagellin receptor, toll-like receptor 5 (TLR5), are prone to develop spontaneous gut inflammation, but are significantly protected when treated with antibiotics or maintained in germ-free conditions. However, given that the incidence of spontaneous inflammation in TLR5KO mice is quite variable in conventional conditions (typically ∼10% show clear colitis), this result is far from definitive and does not rule out that TLR5KO mice might be prone to develop inflammation even in the absence of a microbiota. Herein, we demonstrate that neutralization of IL10 signaling induces colitis in 100% of TLR5KO mice which provide a more rigorous approach to evaluate the role of microbiota in gut inflammation. Mice treated with antibiotics or maintained in germ-free condition are substantially protected against IL-10R neutralization-induced colitis, underscoring that gut inflammation in TLR5KO mice is dependent upon the presence of a gut microbiota.
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Affiliation(s)
- Vishal Singh
- Department of Nutritional Sciences; The Pennsylvania State University; University Park, PA USA
| | - Beng San Yeoh
- Department of Nutritional Sciences; The Pennsylvania State University; University Park, PA USA
| | | | - Andrew T Gewirtz
- Institute of Biomedical Sciences; Georgia State University; Atlanta, GA USA
| | - Matam Vijay-Kumar
- Department of Nutritional Sciences; The Pennsylvania State University; University Park, PA USA,Department of Medicine; The Pennsylvania State University Medical Center; Hershey, PA USA,Correspondence to: Matam Vijay-Kumar;
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369
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Holgersen K, Kutlu B, Fox B, Serikawa K, Lord J, Hansen AK, Holm TL. High-resolution gene expression profiling using RNA sequencing in patients with inflammatory bowel disease and in mouse models of colitis. J Crohns Colitis 2015; 9:492-506. [PMID: 25795566 DOI: 10.1093/ecco-jcc/jjv050] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND AND AIMS Proper interpretation of data from preclinical animal studies requires thorough knowledge of the pathophysiology of both the human disease and animal models. In this study, the expression of inflammatory bowel disease [IBD]-associated genes was characterised in mouse models of colitis to examine the underlying molecular pathways and assess the similarity between the experimental models and human disease. METHODS RNA sequencing was performed on colon biopsies from Crohn's disease [CD] patients, ulcerative colitis [UC] patients and non-IBD controls. Genes shown to be significantly dysregulated in human IBD were used to study gene expression in colons from a piroxicam-accelerated colitis interleukin-10 knockout [PAC IL-10 k.o.], an adoptive transfer [AdTr] and a dextran sulfate sodium [DSS] colitis mouse model. RESULTS Of 115 literature-defined genes linked to IBD, 92 were significantly differentially expressed in inflamed mucosa of CD and/or UC patients compared with non-IBD controls. The most upregulated genes were shared by both diseases, including REG1A, LCN2, NOS2, CXCL1-2, and S100A9. Of those 92 IBD-associated genes, 71 [77%] were significantly dysregulated in PAC IL-10 k.o. mice, whereas 59 [64%] were significantly dysregulated in AdTr mice compared with wild-type controls. Some of the most upregulated genes, including S100a8-9, Nos2, and Lcn2, were shared by the colitis models and correlated with disease activity. CONCLUSIONS IBD and experimental murine colitis have a high degree of similarity in the colonic transcriptional profile, probably secondary to non-specific inflammatory processes. However, differences do exist between models, emphasising the need for careful selection and interpretation of qualified animal models in preclinical research.
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Affiliation(s)
- Kristine Holgersen
- Novo Nordisk-LIFE In Vivo Pharmacology Centre, Frederiksberg, Denmark Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark Department of Immunopharmacology, Novo Nordisk A/S, Maaloev, Denmark
| | - Burak Kutlu
- NNRC-Molecular Immunology, Novo Nordisk Inc., Seattle, WA, USA
| | - Brian Fox
- NNRC-Molecular Immunology, Novo Nordisk Inc., Seattle, WA, USA
| | - Kyle Serikawa
- NNRC-Molecular Immunology, Novo Nordisk Inc., Seattle, WA, USA
| | - James Lord
- Benaroya Research Institute, Virginia Mason Medical Center, Seattle, WA, USA
| | - Axel Kornerup Hansen
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
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Dietary emulsifiers impact the mouse gut microbiota promoting colitis and metabolic syndrome. Nature 2015; 519:92-6. [PMID: 25731162 PMCID: PMC4910713 DOI: 10.1038/nature14232] [Citation(s) in RCA: 1204] [Impact Index Per Article: 133.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 01/14/2015] [Indexed: 02/07/2023]
Abstract
The intestinal tract is inhabited by a large and diverse community of microbes collectively referred to as the gut microbiota. While the gut microbiota provides important benefits to its host, especially in metabolism and immune development, disturbance of the microbiota-host relationship is associated with numerous chronic inflammatory diseases, including inflammatory bowel disease and the group of obesity-associated diseases collectively referred to as metabolic syndrome. A primary means by which the intestine is protected from its microbiota is via multi-layered mucus structures that cover the intestinal surface, thereby allowing the vast majority of gut bacteria to be kept at a safe distance from epithelial cells that line the intestine. Thus, agents that disrupt mucus-bacterial interactions might have the potential to promote diseases associated with gut inflammation. Consequently, it has been hypothesized that emulsifiers, detergent-like molecules that are a ubiquitous component of processed foods and that can increase bacterial translocation across epithelia in vitro, might be promoting the increase in inflammatory bowel disease observed since the mid-twentieth century. Here we report that, in mice, relatively low concentrations of two commonly used emulsifiers, namely carboxymethylcellulose and polysorbate-80, induced low-grade inflammation and obesity/metabolic syndrome in wild-type hosts and promoted robust colitis in mice predisposed to this disorder. Emulsifier-induced metabolic syndrome was associated with microbiota encroachment, altered species composition and increased pro-inflammatory potential. Use of germ-free mice and faecal transplants indicated that such changes in microbiota were necessary and sufficient for both low-grade inflammation and metabolic syndrome. These results support the emerging concept that perturbed host-microbiota interactions resulting in low-grade inflammation can promote adiposity and its associated metabolic effects. Moreover, they suggest that the broad use of emulsifying agents might be contributing to an increased societal incidence of obesity/metabolic syndrome and other chronic inflammatory diseases.
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371
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Leoni G, Neumann PA, Kamaly N, Quiros M, Nishio H, Jones HR, Sumagin R, Hilgarth RS, Alam A, Fredman G, Argyris I, Rijcken E, Kusters D, Reutelingsperger C, Perretti M, Parkos CA, Farokhzad OC, Neish AS, Nusrat A. Annexin A1-containing extracellular vesicles and polymeric nanoparticles promote epithelial wound repair. J Clin Invest 2015; 125:1215-27. [PMID: 25664854 DOI: 10.1172/jci76693] [Citation(s) in RCA: 230] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 01/02/2015] [Indexed: 12/13/2022] Open
Abstract
Epithelial restitution is an essential process that is required to repair barrier function at mucosal surfaces following injury. Prolonged breaches in epithelial barrier function result in inflammation and further damage; therefore, a better understanding of the epithelial restitution process has potential for improving the development of therapeutics. In this work, we demonstrate that endogenous annexin A1 (ANXA1) is released as a component of extracellular vesicles (EVs) derived from intestinal epithelial cells, and these ANXA1-containing EVs activate wound repair circuits. Compared with healthy controls, patients with active inflammatory bowel disease had elevated levels of secreted ANXA1-containing EVs in sera, indicating that ANXA1-containing EVs are systemically distributed in response to the inflammatory process and could potentially serve as a biomarker of intestinal mucosal inflammation. Local intestinal delivery of an exogenous ANXA1 mimetic peptide (Ac2-26) encapsulated within targeted polymeric nanoparticles (Ac2-26 Col IV NPs) accelerated healing of murine colonic wounds after biopsy-induced injury. Moreover, one-time systemic administration of Ac2-26 Col IV NPs accelerated recovery following experimentally induced colitis. Together, our results suggest that local delivery of proresolving peptides encapsulated within nanoparticles may represent a potential therapeutic strategy for clinical situations characterized by chronic mucosal injury, such as is seen in patients with IBD.
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372
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Diverse functional roles of lipocalin-2 in the central nervous system. Neurosci Biobehav Rev 2015; 49:135-56. [DOI: 10.1016/j.neubiorev.2014.12.006] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 11/28/2014] [Accepted: 12/04/2014] [Indexed: 12/16/2022]
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373
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Chassaing B, Ley RE, Gewirtz AT. Intestinal epithelial cell toll-like receptor 5 regulates the intestinal microbiota to prevent low-grade inflammation and metabolic syndrome in mice. Gastroenterology 2014; 147:1363-77.e17. [PMID: 25172014 PMCID: PMC4253564 DOI: 10.1053/j.gastro.2014.08.033] [Citation(s) in RCA: 199] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 08/04/2014] [Accepted: 08/20/2014] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS Mice lacking the receptor Toll-like receptor 5 (TLR5-null mice), which recognizes flagellin, have an altered intestinal microbiota composition compared with wild-type mice; they develop low-grade inflammation and metabolic syndrome and are prone to colitis. The relative roles of intestinal epithelial cell (IEC) vs dendritic cell (DC) TLR5 in mediating these phenotypes are not clear; modification of intestinal microbiota composition has been reported to reflect animal husbandry practices rather than loss of TLR5. We generated mice with specific disruption of Tlr5 in IECs or DCs by using a breeding scheme that allows comparison with cohoused siblings as controls. METHODS We generated C57BL/6 mice with LoxP sites flanking Tlr5. These mice were crossed with mice expressing Cre recombinase, regulated by the villin or CD11c promoters, to generate mice that lacked expression of TLR5 by IECs (TLR5(ΔIEC)) or DCs (TLR5(ΔDC)), respectively. Tlr5(fl/fl) siblings were used as controls. On weaning, mice were housed by sex and genotype or by sex only (genotypes cohoused). Mice were examined for basal phenotypes, including microbiota composition; we also analyzed responses to pathobiont challenge, administration of dextran sodium sulfate, and high-fat diets. RESULTS Similar to previous findings from TLR5-null mice, TLR5(ΔIEC) mice had low-grade inflammation (mild splenomegaly, shortened colons, and increased fecal levels of lipocalin 2), metabolic syndrome, and an inability to clear pathobionts and were prone to developing colitis compared with their sibling controls under both housing conditions. Development of this inflammation in the TLR5(ΔIEC) mice was eliminated by administration of antibiotics and associated with alterations in localization of microbiota and levels of fecal lipopolysaccharide and flagellin. The composition of the microbiota clustered more closely according to genotype than housing. Loss of TLR5 from DCs did not associate with development of inflammation-associated phenotypes or alterations in the composition of the microbiota but resulted in complete loss of flagellin-induced production of interleukin-22. CONCLUSIONS In mice, flagellin activation of TLR5 on DCs leads to production of interleukin-22. Expression of TLR5 on IECs regulates the composition and localization of the intestinal microbiota, preventing diseases associated with intestinal inflammation.
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Affiliation(s)
- Benoit Chassaing
- Center for Inflammation, Immunity & Infection, Georgia State University, Atlanta, GA, USA
| | - Ruth E. Ley
- Department of Microbiology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY
| | - Andrew T. Gewirtz
- Center for Inflammation, Immunity & Infection, Georgia State University, Atlanta, GA, USA
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374
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Janas RM, Ochocińska A, Snitko R, Dudka D, Kierkuś J, Teisseyre M, Najberg E. Neutrophil gelatinase-associated lipocalin in blood in children with inflammatory bowel disease. J Gastroenterol Hepatol 2014; 29:1883-9. [PMID: 24720485 DOI: 10.1111/jgh.12597] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/27/2014] [Indexed: 12/09/2022]
Abstract
BACKGROUND Neutrophil gelatinase-associated lipocalin (NGAL) is a 25 kDa glycoprotein present in the bodily fluids and tissues. It is secreted by neutrophils, epithelial cells, hepatocytes and adipocytes, and its expression is highly increased in response to cellular stress. The role of NGAL in the pathophysiology of inflammatory bowel disease including Crohn's disease and ulcerative colitis in children has thus far not been studied. METHODS The following groups of children were included: (i) inflammatory bowel disease group, n = 36, aged from 1 to 18 years with Crohn's disease (n = 19) and ulcerative colitis (n = 17); (ii) control group, n = 126; and (iii) disease control group, n = 27, without inflammatory bowel disease, with a food and/or inhalant allergy. RESULTS Healthy children aged from 1 to 8 years exhibited lower NGAL level than those of 9 to 18 years old (39.0; 18.1-83.7 ng/mL vs 57.6; 28.7-107 ng/mL, P = 0.001). In the younger, but not in the older children, the serum NGAL level correlated with their age, r = 0.334, P = 0.001. In children with inflammatory bowel disease, serum NGAL level was higher (108; 37.3-245 ng/mL) than in healthy (42.0; 18.1-107 ng/mL) and allergic, noninflammatory bowel disease children (49.3; 19.3-107 ng/mL), P = 0.001. Serum NGAL levels in Crohn's disease and ulcerative colitis children did not correlate with age, gender, disease activity, and indices of the inflammation. CONCLUSION Serum NAGL levels are highly elevated in Crohn's disease and ulcerative colitis in children compared to the healthy control group. Systematic studies are needed to explain the role of this protein in the inflammatory bowel disease.
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Affiliation(s)
- Roman M Janas
- Department of Biochemistry, Radioimmunology and Experimental Medicine, The Children's Memorial Health Institute, Warsaw, Poland
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375
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Viennois E, Baker MT, Xiao B, Wang L, Laroui H, Merlin D. Longitudinal study of circulating protein biomarkers in inflammatory bowel disease. J Proteomics 2014; 112:166-79. [PMID: 25230104 DOI: 10.1016/j.jprot.2014.09.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Revised: 08/15/2014] [Accepted: 09/05/2014] [Indexed: 12/16/2022]
Abstract
UNLABELLED Inflammatory bowel diseases (IBDs) are chronic and progressive inflammatory disorders of the gastrointestinal tract. In IBD, protein serological biomarkers could be relevant tools for assessing disease activity, performing early-stage diagnosis and managing the treatment. Using the interleukin-10 knockout (IL-10(-/-)) mouse, a model that develops a time-dependent IBD-like disorder that predominates in the colon; we performed longitudinal studies of circulating protein biomarkers in IBD. Circulating protein profiles in serum samples collected from 30-, 93-, to 135-day-old IL-10(-/-) mice were investigated using two-dimensional differential gel electrophoresis and MALDI-TOF/TOF tandem mass spectrometry. A total of 15 different proteins were identified and confirmed by ELISA and Western blot to be differentially accumulated in serum samples from mid- to late-stage IL-10(-/-) mice compared to early non-inflamed IL-10(-/-) mice. The use of another model of colitis and an extra-intestinal inflammation model validated this biomarker panel and demonstrated that comprised some global inflammatory markers, some intestinal inflammation-specific markers and some chronic intestinal inflammation markers. Statistical analyses using misclassification error rate charts validated the use of these identified proteins as powerful biomarkers of colitis. Unlike standard biomarker screening studies, our analyses identified a panel of proteins that allowed the definition of protein signatures that reflect colitis status. BIOLOGICAL SIGNIFICANCE Crohn's disease (CD) and ulcerative colitis (UC) are the most common inflammatory bowel diseases (IBDs) occurring in humans. The major current diagnosis tool is colonoscopy, which is invasive and could lead to false diagnosis. The emergence of serological biomarkers enables the use of new diagnosis tools such as protein signatures for IBD diagnosis/management. Using 2D-DIGE coupled to mass spectrometry, our longitudinal study in a mouse model of colitis identified a signature of protein biomarkers for specific stages of disease.
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Affiliation(s)
- Emilie Viennois
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA; Chemistry Department, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303, USA; Veterans Affairs Medical Center, Decatur, GA, USA.
| | - Mark T Baker
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA; Chemistry Department, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303, USA
| | - Bo Xiao
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA; Chemistry Department, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303, USA
| | - Lixin Wang
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA; Chemistry Department, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303, USA; Veterans Affairs Medical Center, Decatur, GA, USA
| | - Hamed Laroui
- Chemistry Department, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303, USA
| | - Didier Merlin
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA; Chemistry Department, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303, USA; Veterans Affairs Medical Center, Decatur, GA, USA
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376
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Uchiyama R, Chassaing B, Zhang B, Gewirtz AT. MyD88-mediated TLR signaling protects against acute rotavirus infection while inflammasome cytokines direct Ab response. Innate Immun 2014; 21:416-28. [PMID: 25213347 DOI: 10.1177/1753425914547435] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 07/24/2014] [Indexed: 11/16/2022] Open
Abstract
Rotavirus (RV) infects small intestinal epithelial cells, inducing severe diarrhea in children, resulting in over 500,000 deaths annually. Relatively little is known about how innate immunity contains acute infection and drives adaptive immune responses that afford complete clearance of RV and protection against future infection. Hence, we examined the consequence of the absence of MyD88, known to be central to innate immunity, in a mouse model of RV infection. The absence of MyD88, but not combined blockade of IL-1β and IL-18 signaling, resulted in greater infectivity, as reflected by levels of RV in feces, intestinal lysates and viremia. Such increased RV levels correlated with an increase in incidence and duration of diarrhea. Loss of MyD88 also impaired humoral immunity to RV. Specifically, MyD88 knockout generated less RV-specific IgA and exhibited profoundly reduced RV-specific IgG2c/IgG1 ratios suggesting that MyD88 signaling drives RV-induced Th1 responses. A study of MyD88 bone marrow chimeras indicated that MyD88-dependent control of acute RV infection was mediated by both hemopoietic and non-hemopoietic cells, while generation of RV-specific humoral immunity was driven by MyD88 signaling in hemopoietic cells, which reflected the loss of IL-1β and IL-18 expression by these cells. Thus, TLR signaling and inflammasome cytokines drive innate and adaptive immunity to RV.
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Affiliation(s)
- Robin Uchiyama
- Center for Inflammation, Immunity, and Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA Immunology and Molecular Pathogenesis Graduate Program, Emory University, Atlanta, GA, USA
| | - Benoit Chassaing
- Center for Inflammation, Immunity, and Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA
| | - Benyue Zhang
- Center for Inflammation, Immunity, and Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA
| | - Andrew T Gewirtz
- Center for Inflammation, Immunity, and Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA Immunology and Molecular Pathogenesis Graduate Program, Emory University, Atlanta, GA, USA
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377
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Viennois E, Xiao B, Ayyadurai S, Wang L, Wang PG, Zhang Q, Chen Y, Merlin D. Micheliolide, a new sesquiterpene lactone that inhibits intestinal inflammation and colitis-associated cancer. J Transl Med 2014; 94:950-65. [PMID: 25068660 DOI: 10.1038/labinvest.2014.89] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 06/18/2014] [Indexed: 12/16/2022] Open
Abstract
Inflammatory bowel diseases (IBD) are chronic inflammatory conditions of the gastrointestinal (GI) tract associated with an increased risk of colorectal cancer (CRC). Current treatments for both IBD and colitis-associated CRC suffer from numerous side effects. Parthenolide (PTL) is a sesquiterpene lactone with anti-inflammatory activity, and previous studies have demonstrated that PTL is a potent inhibitor of the NF-κB pathway. Micheliolide (MCL), substantially more stable than PTL in vivo, was recently developed, and this study aimed to decipher its suitability as therapeutic tool for IBD and IBD-associated diseases. Similar to PTL, MCL inhibited NF-κB activation and subsequent pro-inflammatory pathways activation in vitro. Pro-drug forms of both compounds inhibited the DSS-induced colitis when administrated intraperitoneally or encapsulated in a polysaccharide gel designed to release drugs in the colon. Interestingly, MCL was found to attenuate carcinogenesis in AOM/DSS-induced CRC, thus providing new candidate for the treatment of inflammatory bowel disease and CRC.
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Affiliation(s)
- Emilie Viennois
- 1] Institute for Biomedical Sciences, Center for Inflammation, Immunity and Infection, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, USA [2] Veterans Affairs Medical Center, Decatur, GA, USA
| | - Bo Xiao
- Institute for Biomedical Sciences, Center for Inflammation, Immunity and Infection, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, USA
| | - Saravanan Ayyadurai
- Institute for Biomedical Sciences, Center for Inflammation, Immunity and Infection, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, USA
| | - Lixin Wang
- 1] Institute for Biomedical Sciences, Center for Inflammation, Immunity and Infection, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, USA [2] Veterans Affairs Medical Center, Decatur, GA, USA
| | - Peng G Wang
- 1] Department of Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, USA [2] The State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China
| | - Quan Zhang
- The State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China
| | - Yue Chen
- The State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China
| | - Didier Merlin
- 1] Institute for Biomedical Sciences, Center for Inflammation, Immunity and Infection, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, USA [2] Veterans Affairs Medical Center, Decatur, GA, USA
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378
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Lipocalin-2 test in distinguishing acute lung injury cases from septic mice without acute lung injury. ACTA ACUST UNITED AC 2014; 29:65-77. [PMID: 24998227 DOI: 10.1016/s1001-9294(14)60031-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To explore whether the amount of lipocalin-2 in the biofluid could reflect the onset of sepsis-induced acute lung injury (ALI) in mice. METHODS Lipopolysaccharide (LPS, 10 mg/kg) injection or cecal ligation and puncture (CLP) was performed to induce severe sepsis and ALI in C57 BL/6 male mice randomly divided into 5 groups (n=10 in each group): group A (intraperitoneal LPS injection), group B (intravenous LPS injection via tail vein), group C (CLP with 25% of the cecum ligated), group D (CLP with 75% of the cecum ligated), and the control group (6 sham-operation controls plus 4 saline controls). All the mice received volume resuscitation. Measurements of pulmonary morphological and functional alterations were used to identify the presence of experimental ALI. The expressions of lipocalin-2 and interleukin (IL)-6 in serum, bronchoalveolar lavage fluid (BALF), and lung tissue were quantified at both protein and mRNA levels. The overall abilities of lipocalin-2 and IL-6 tests to diagnose sepsis-induced ALI were evaluated by generating receiver operator characteristic curves (ROC) and computing area under curve (AUC). RESULTS In both group B and group D, most of the main features of experimental ALI were reproduced in mice, while group A and group C showed septic syndrome without definite evidence for the presence of ALI. Compared with septic mice without ALI (group A+group C), lipocalin-2 protein expression in septic mice with ALI (group B+group D) was significantly up-regulated in BALF (P<0.01) and in serum (P<0.01), and mRNA expression boosted in lung tissues (all P<0.05). Lipocalin-2 tests performed better than IL-6 tests in recognizing sepsis-induced ALI cases, evidenced by the larger AUC of the former (BALF tests, 0.8800 versus 0.6625; serum tests, 0.8500 versus 0.7000). Using a dual cutoff system to diagnose sepsis-induced ALI, BALF lipocalin-2 test exhibited the highest positive likelihood ratio (13.000) and the lowest negative likelihood ratio (0.077) among the tests of lipocalin-2 and IL-6 in blood and BALF. A statistically significant correlation was found between lipocalin-2 concentration in BALF and that in serum (Spearman r=0.8803, P<0.0001). CONCLUSIONS Lipocalin-2 expression is significantly up-regulated in septic ALI mice compared with those without ALI. Lipocalin-2 tests with a dual cutoff system could be an effective tool in distinguishing experimental ALI cases.
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379
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Chassaing B, Koren O, Carvalho FA, Ley RE, Gewirtz AT. AIEC pathobiont instigates chronic colitis in susceptible hosts by altering microbiota composition. Gut 2014; 63:1069-80. [PMID: 23896971 PMCID: PMC4089387 DOI: 10.1136/gutjnl-2013-304909] [Citation(s) in RCA: 157] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Inflammatory bowel disease (IBD) is driven by a seemingly aberrant immune response to the gut microbiota with disease development dictated by genetics and environmental factors. A model exemplifying this notion is our recent demonstration that colonisation of adherent-invasive Escherichia coli (AIEC) during microbiota acquisition drove chronic colitis in mice lacking the flagellin receptor TLR5 (T5KO). T5KO colitis persisted beyond AIEC clearance and requires TLR4 and the NLRC4 inflammasome. We hypothesised that AIEC instigates chronic inflammation by increasing microbial lipopolysaccharide (LPS) and flagellin levels. GOAL Examine if transient AIEC colonisation lastingly alters levels of LPS and flagellin and changes microbiota composition. METHODS Germ-free mice (wild type (WT) and T5KO) were inoculated with AIEC strain LF82 and placed in standard housing allowing a complex microbiota that eliminated AIEC in both mice strains. Faeces were assayed for the inflammatory marker, lipocalin-2, bacterial loads, and microbiota composition by pyrosequencing. Faecal LPS and flagellin bioactivity were measured via a cell-based reporter assay. RESULTS Transient AIEC colonisation, in WT mice, did not alter inflammatory markers, bacterial loads, microbiota composition, nor its pro-inflammatory potential. By contrast, transient AIEC colonisation of T5KO mice drove chronic inflammation which correlated with microbiota components having higher levels of bioactive LPS and flagellin. Such AIEC-induced elevation of LPS and flagellin persisted well beyond AIEC clearance, required AIEC be flagellated, and was associated with alteration in microbiota species composition including a loss of species diversity. CONCLUSIONS AIEC, and perhaps other pathobionts, may instigate chronic inflammation in susceptible hosts by altering the gut microbiota composition so as to give it an inherently greater ability to activate innate immunity/pro-inflammatory gene expression.
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Affiliation(s)
- Benoit Chassaing
- Center for Inflammation, Immunity, and Infection and Department of Biology, Georgia State University, Atlanta, GA 30303, USA
| | - Omry Koren
- Department of Microbiology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | | | - Ruth E. Ley
- Department of Microbiology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Andrew T. Gewirtz
- Center for Inflammation, Immunity, and Infection and Department of Biology, Georgia State University, Atlanta, GA 30303, USA
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380
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Kulkarni RM, Stuart WD, Waltz SE. Ron receptor-dependent gene regulation of Kupffer cells during endotoxemia. Hepatobiliary Pancreat Dis Int 2014; 13:281-92. [PMID: 24919612 PMCID: PMC4108450 DOI: 10.1016/s1499-3872(14)60254-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Ron receptor tyrosine kinase signaling in macrophages, including Kupffer cells and alveolar macrophages, suppresses endotoxin-induced proinflammatory cytokine/chemokine production. Further, we have also identified genes from Ron replete and Ron deplete livers that were differentially expressed during the progression of liver inflammation associated with acute liver failure in mice by microarray analyses. While important genes and signaling pathways have been identified downstream of Ron signaling during progression of inflammation by this approach, the precise role that Ron receptor plays in regulating the transcriptional landscape in macrophages, and particular in isolated Kupffer cells, has still not been investigated. METHODS Kupffer cells were isolated from wild-type (TK+/+) and Ron tyrosine kinase deficient (TK-/-) mice. Ex vivo, the cells were treated with lipopolysaccharide (LPS) in the presence or absence of the Ron ligand, hepatocyte growth factor-like protein (HGFL). Microarray and qRT-PCR analyses were utilized to identify alterations in gene expression between genotypes. RESULTS Microarray analyses identified genes expressed differentially in TK+/+ and TK-/- Kupffer cells basally as well as after HGFL and LPS treatment. Interestingly, our studies identified Mefv, a gene that codes for the anti-inflammatory protein pyrin, as an HGFL-stimulated Ron-dependent gene. Moreover, lipocalin 2, a proinflammatory gene, which is induced by LPS, was significantly suppressed by HGFL treatment. Microarray results were validated by qRT-PCR studies on Kupffer cells treated with LPS and HGFL. CONCLUSION The studies herein suggest a novel mechanism whereby HGFL-induced Ron receptor activation promotes the expression of anti-inflammatory genes while inhibiting genes involved in inflammation with a net effect of diminished inflammation in macrophages.
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381
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Soares F, Tattoli I, Rahman MA, Robertson SJ, Belcheva A, Liu D, Streutker C, Winer S, Winer DA, Martin A, Philpott DJ, Arnoult D, Girardin SE. The mitochondrial protein NLRX1 controls the balance between extrinsic and intrinsic apoptosis. J Biol Chem 2014; 289:19317-30. [PMID: 24867956 PMCID: PMC4094044 DOI: 10.1074/jbc.m114.550111] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
NLRX1 is a mitochondrial Nod-like receptor (NLR) protein whose function remains enigmatic. Here, we observed that NLRX1 expression was glucose-regulated and blunted by SV40 transformation. In transformed but not primary murine embryonic fibroblasts, NLRX1 expression mediated resistance to an extrinsic apoptotic signal, whereas conferring susceptibility to intrinsic apoptotic signals, such as glycolysis inhibition, increased cytosolic calcium and endoplasmic reticulum stress. In a murine model of colorectal cancer induced by azoxymethane, NLRX1-/- mice developed fewer tumors than wild type mice. In contrast, in a colitis-associated cancer model combining azoxymethane and dextran sulfate sodium, NLRX1-/- mice developed a more severe pathology likely due to the increased sensitivity to dextran sulfate sodium colitis. Together, these results identify NLRX1 as a critical mitochondrial protein implicated in the regulation of apoptosis in cancer cells. The unique capacity of NLRX1 to regulate the cellular sensitivity toward intrinsic versus extrinsic apoptotic signals suggests a critical role for this protein in numerous physiological processes and pathological conditions.
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Affiliation(s)
- Fraser Soares
- From the Departments of Laboratory Medicine and Pathobiology and
| | - Ivan Tattoli
- From the Departments of Laboratory Medicine and Pathobiology and Immunology
| | - Muhammed A Rahman
- From the Departments of Laboratory Medicine and Pathobiology and Immunology
| | | | | | - Daniel Liu
- From the Departments of Laboratory Medicine and Pathobiology and
| | - Catherine Streutker
- From the Departments of Laboratory Medicine and Pathobiology and Saint Michael's Hospital, and
| | - Shawn Winer
- Department of Pathology, Toronto General Hospital, University of Toronto, Toronto M6G 2T6, Canada and
| | - Daniel A Winer
- Department of Pathology, Toronto General Hospital, University of Toronto, Toronto M6G 2T6, Canada and
| | | | | | - Damien Arnoult
- INSERM U1014, Hôpital Paul Brousse, Bâtiment Lavoisier, 14 avenue Paul Vaillant Couturier, 94807 Villejuif Cedex, France
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382
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Chassaing B, Aitken JD, Malleshappa M, Vijay-Kumar M. Dextran sulfate sodium (DSS)-induced colitis in mice. ACTA ACUST UNITED AC 2014; 104:15.25.1-15.25.14. [PMID: 24510619 DOI: 10.1002/0471142735.im1525s104] [Citation(s) in RCA: 1129] [Impact Index Per Article: 112.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Inflammatory bowel diseases (IBD), mainly comprising ulcerative colitis and Crohn's Disease, are complex and multifactorial diseases with unknown etiology. For the past 20 years, to study human IBD mechanistically, a number of murine models of colitis have been developed. These models are indispensable tools to decipher underlying mechanisms of IBD pathogenesis as well as to evaluate a number of potential therapeutics. Among various chemically induced colitis models, the dextran sulfate sodium (DSS)-induced colitis model is widely used because of its simplicity and many similarities with human ulcerative colitis. This model has both advantages and disadvantages that must be considered when employed. This protocol describes the DSS-induced colitis model, focusing on details and factors that could affect DSS-induced pathology.
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Affiliation(s)
- Benoit Chassaing
- Center for Inflammation, Immunity, & Infection, Department of Biology, Georgia State University, Atlanta, Georgia
| | - Jesse D Aitken
- Center for Inflammation, Immunity, & Infection, Department of Biology, Georgia State University, Atlanta, Georgia
| | - Madhu Malleshappa
- Center for Inflammation, Immunity, & Infection, Department of Biology, Georgia State University, Atlanta, Georgia
| | - Matam Vijay-Kumar
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, Pennsylvania.,Department of Medicine, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
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383
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Uchiyama R, Chassaing B, Zhang B, Gewirtz AT. Antibiotic treatment suppresses rotavirus infection and enhances specific humoral immunity. J Infect Dis 2014; 210:171-82. [PMID: 24436449 DOI: 10.1093/infdis/jiu037] [Citation(s) in RCA: 147] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Rotavirus causes 500 000 deaths and millions of physician visits and hospitalizations per year, with worse outcomes and reduced vaccine efficacy in developing countries. We hypothesized that the gut microbiota might modulate rotavirus infection and/or antibody response and thus potentially play a role in such regional differences. METHODS The microbiota was ablated via germ-free or antibiotic approaches. Enhanced exposure to microbiota was achieved via low-dose dextran sodium sulfate (DSS) treatment. Rotavirus infection and replication was assessed by enzyme-linked immunosorbent assay (ELISA) and quantitative reverse-transcription polymerase chain reaction. Diarrhea was scored visually. Humoral responses to rotavirus were measured by ELISA and enzyme-linked immunosorbent spot assay. RESULTS Microbiota elimination delayed infection and reduced infectivity by 42%. Antibiotics did not alter ratios of positive-sense to negative-sense strands, suggesting that entry rather than replication was influenced. Antibiotics reduced the diarrhea incidence and duration, indicating that the reduction in the level of rotavirus antigen was biologically significant. Despite lowered antigen level, antibiotics resulted in a more durable rotavirus mucosal/systemic humoral response. Increased rotavirus antibody response durability correlated with increased small intestinal rotavirus-specific, immunoglobulin A-producing antibody-secreting cell concentration in antibiotic-treated mice. Conversely, DSS treatment impaired generation of rotavirus-specific antibodies. CONCLUSIONS Microbiota ablation resulted in reduced rotavirus infection/diarrhea and a more durable rotavirus antibody response, suggesting that antibiotic administration before rotavirus vaccination could raise low seroconversion rates that correlate with the vaccine's inefficacy in developing regions.
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Affiliation(s)
- Robin Uchiyama
- Center for Inflammation, Immunity, and Infection, Georgia State University Immunology and Molecular Pathogenesis Graduate Program, Emory University, Atlanta, Georgia
| | - Benoit Chassaing
- Center for Inflammation, Immunity, and Infection, Georgia State University
| | - Benyue Zhang
- Center for Inflammation, Immunity, and Infection, Georgia State University
| | - Andrew T Gewirtz
- Center for Inflammation, Immunity, and Infection, Georgia State University Immunology and Molecular Pathogenesis Graduate Program, Emory University, Atlanta, Georgia
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384
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Abstract
The intestinal tract is inhabited by a large diverse community of bacteria collectively referred to as the gut microbiota. Alterations in gut microbiota composition are associated with a variety of disease states including obesity, diabetes, and inflammatory bowel disease (IBD). Transplant of microbiota from diseased persons (or mice) to germfree mice transfers some aspects of disease phenotype, indicating that altered microbiota plays a role in disease establishment and manifestation. There are myriad potential mechanisms by which alterations in gut microbiota might promote disease, including increasing energy harvest, production of toxic metabolites, and molecular mimicry of host proteins. However, our research indicates that an overarching mechanism by which an aberrant microbiota negatively impacts health is by driving chronic inflammation. More specifically, we hypothesize that the histopathologically evident gut inflammation that defines IBD is a severe but relatively rare outcome of an altered host-microbiota relationship, while a much more common consequence of such disturbances is "low-grade" inflammation characterized by elevated proinflammatory gene expression that associates with, and may promote, metabolic syndrome. In this context, a variety of chronic inflammatory diseases may stem from inability of the mucosal immune system to properly manage a stable healthy relationship with the gut microbiota. While one's ability to manage their gut microbiota is dictated in part by genetics, it can be markedly influenced by the composition of the microbiota one inherits from their early environment. Moreover, the host-microbiota relationship can be perturbed by instigator bacteria or dietary components, which may prove to play a role in promoting chronic inflammatory disease states.
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Affiliation(s)
- Benoit Chassaing
- 1Center for Inflammation, Immunity, and Infection, Georgia State University, Atlanta, Georgia, USA
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385
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Abstract
Animal models of human disease are a critical tool in both basic research and drug development. The results of preclinical efficacy studies often inform progression of therapeutic candidates through the drug development pipeline; however, the extent to which results in inflammatory bowel disease (IBD) models predict human drug response is an ongoing concern. This review discusses how murine models are currently being used in IBD research. We focus on the considerations and caveats for commonly used models in preclinical efficacy studies and discuss the value of models that utilize specific pathogenic pathways of interest rather than model all aspects of human disease.
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Affiliation(s)
- Jason DeVoss
- Department of Immunology, Genentech, Inc., San Francisco, California, USA
| | - Lauri Diehl
- Department of Pathology, Genentech, Inc., San Francisco, California, USA
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386
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Østvik AE, Granlund AVB, Torp SH, Flatberg A, Beisvåg V, Waldum HL, Flo TH, Espevik T, Damås JK, Sandvik AK. Expression of Toll-like receptor-3 is enhanced in active inflammatory bowel disease and mediates the excessive release of lipocalin 2. Clin Exp Immunol 2013; 173:502-11. [PMID: 23668802 DOI: 10.1111/cei.12136] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/08/2013] [Indexed: 12/11/2022] Open
Abstract
Anti-microbial peptides might influence the pathogenesis and course of inflammatory bowel disease (IBD). We sought to clarify the role of the anti-microbial glycoprotein lipocalin 2 (LCN2) in the colon by determining its localization and regulation in IBD. Following a microarray gene expression study of colonic biopsies from a large IBD population (n = 133), LCN2 was localized using immunohistochemistry and in-situ hybridization. Moreover, we examined the regulation of LCN2 in HT-29 cells with a panel of pattern recognition receptors (PRRs) and sought evidence by immunohistochemistry that the most relevant PRR, the Toll-like receptor (TLR)-3, was indeed expressed in colonic epithelium in IBD. LCN2 was among the 10 most up-regulated genes in both active ulcerative colitis (UCa) and active Crohn's disease (CDa) versus healthy controls. LCN2 protein was found in both epithelial cells and infiltrating neutrophils, while mRNA synthesis was located solely to epithelial cells, indicating that de-novo synthesis and thus regulation of LCN2 as measured in the gene expression analysis takes place in the mucosal epithelial cells. LCN2 is a putative biomarker in faeces for intestinal inflammation, different from calprotectin due to its epithelial site of synthesis. LCN2 release from the colonic epithelial cell line HT-29 was enhanced by both interleukin (IL)-1β and the TLR-3 ligand poly(I:C), and TLR-3 was shown to be expressed constitutively in colonic epithelial cells and markedly increased during inflammation.
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Affiliation(s)
- A E Østvik
- Centre of Molecular Inflammation Research, Department of Cancer Research, Norwegian University of Science and Technology, Trondheim, Norway
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387
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Kim MS, Hwang SS, Park EJ, Bae JW. Strict vegetarian diet improves the risk factors associated with metabolic diseases by modulating gut microbiota and reducing intestinal inflammation. ENVIRONMENTAL MICROBIOLOGY REPORTS 2013; 5:765-75. [PMID: 24115628 DOI: 10.1111/1758-2229.12079] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2013] [Accepted: 06/19/2013] [Indexed: 05/23/2023]
Abstract
Low-grade inflammation of the intestine results in metabolic dysfunction, in which dysbiosis of the gut microbiota is intimately involved. Dietary fibre induces prebiotic effects that may restore imbalances in the gut microbiota; however, no clinical trials have been reported in patients with metabolic diseases. Here, six obese subjects with type 2 diabetes and/or hypertension were assigned to a strict vegetarian diet (SVD) for 1 month, and blood biomarkers of glucose and lipid metabolisms, faecal microbiota using 454-pyrosequencing of 16S ribosomal RNA genes, faecal lipocalin-2 and short-chain fatty acids were monitored. An SVD reduced body weight and the concentrations of triglycerides, total cholesterol, low-density lipoprotein cholesterol and haemoglobin A1c, and improved fasting glucose and postprandial glucose levels. An SVD reduced the Firmicutes-to-Bacteroidetes ratio in the gut microbiota, but did not alter enterotypes. An SVD led to a decrease in the pathobionts such as the Enterobacteriaceae and an increase in commensal microbes such as Bacteroides fragilis and Clostridium species belonging to clusters XIVa and IV, resulting in reduced intestinal lipocalin-2 and short-chain fatty acids levels. This study underscores the benefits of dietary fibre for improving the risk factors of metabolic diseases and shows that increased fibre intake reduces gut inflammation by changing the gut microbiota.
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Affiliation(s)
- Min-Soo Kim
- Department of Life and Nanopharmaceutical Sciences, Department of Biology, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul, 130-701, Republic of Korea
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388
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Viennois E, Chen F, Laroui H, Baker MT, Merlin D. Dextran sodium sulfate inhibits the activities of both polymerase and reverse transcriptase: lithium chloride purification, a rapid and efficient technique to purify RNA. BMC Res Notes 2013; 6:360. [PMID: 24010775 PMCID: PMC3847706 DOI: 10.1186/1756-0500-6-360] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 09/03/2013] [Indexed: 12/13/2022] Open
Abstract
Background Dextran sodium sulfate (DSS) is commonly used in mouse studies to induce a very reproducible colitis that effectively mimics the clinical and histological features of human inflammatory bowel disease (IBD) patients, especially ulcerative colitis. However, the mechanisms of action of DSS remain poorly understood, and observations by our laboratory and other groups indicate that DSS contamination of colonic tissues from DSS-treated mice potently inhibits the quantitative reverse-transcription polymerase chain reaction (qRT-PCR) amplification of mRNA. Results A prior study used poly-A-mediated mRNA purification to remove DSS from RNA extracts, but we herein report a second efficient and cost-effective approach to counteract this inhibition, using lithium chloride precipitation to entirely remove DSS from RNAs. We also explored how DSS interferes with qRT-PCR process, and we report for the first time that DSS can alter the binding of reverse transcriptase to previously primed RNA and specifically inhibits the enzymatic activities of reverse transcriptase and Taq polymerase in vitro. This likely explains why DSS-treated colonic RNA is not suitable to qRT-PCR amplification without a previous purification step. Conclusion In summary, we provide a simple method to remove DSS from colonic RNAs, and we demonstrate for the first time that DSS can inhibit the activities of both polymerase and reverse transcriptase. In order to reliably analyze gene expression in the colonic mucosa of DSS-treated mice, the efficiency rate of qRT-PCR must be the same between all the different experimental groups, including the water-treated control group, suggesting that whatever the duration and the percentage of the DSS treatment, RNAs must be purified.
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Affiliation(s)
- Emilie Viennois
- Department of Biology, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta GA 30303, USA.
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389
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Innate immune detection of flagellin positively and negatively regulates salmonella infection. PLoS One 2013; 8:e72047. [PMID: 23977202 PMCID: PMC3747147 DOI: 10.1371/journal.pone.0072047] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Accepted: 07/06/2013] [Indexed: 11/19/2022] Open
Abstract
Salmonella enterica serovar Typhimurium is a flagellated bacterium and one of the leading causes of gastroenteritis in humans. Bacterial flagellin is required for motility and also a prime target of the innate immune system. Innate immune recognition of flagellin is mediated by at least two independent pathways, TLR5 and Naip5-Naip6/NlrC4/Caspase-1. The functional significance of each of the two independent flagellin recognition systems for host defense against wild type Salmonella infection is complex, and innate immune detection of flagellin contributes to both protection and susceptibility. We hypothesized that efficient modulation of flagellin expression in vivo permits Salmonella to evade innate immune detection and limit the functional role of flagellin-specific host innate defenses. To test this hypothesis, we used Salmonella deficient in the anti-sigma factor flgM, which overproduce flagella and are attenuated in vivo. In this study we demonstrate that flagellin recognition by the innate immune system is responsible for the attenuation of flgM− S. Typhimurium, and dissect the contribution of each flagellin recognition pathway to bacterial clearance and inflammation. We demonstrate that caspase-1 controls mucosal and systemic infection of flgM− S. Typhimurium, and also limits intestinal inflammation and injury. In contrast, TLR5 paradoxically promotes bacterial colonization in the cecum and systemic infection, but attenuates intestinal inflammation. Our results indicate that Salmonella evasion of caspase-1 dependent flagellin recognition is critical for establishing infection and that evasion of TLR5 and caspase-1 dependent flagellin recognition helps Salmonella induce intestinal inflammation and establish a niche in the inflamed gut.
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