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Lechuga S, Ivanov AI. Disruption of the epithelial barrier during intestinal inflammation: Quest for new molecules and mechanisms. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:1183-1194. [PMID: 28322932 DOI: 10.1016/j.bbamcr.2017.03.007] [Citation(s) in RCA: 170] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 03/13/2017] [Accepted: 03/15/2017] [Indexed: 02/06/2023]
Abstract
The intestinal epithelium forms a key protective barrier that separates internal organs from the harmful environment of the gut lumen. Increased permeability of the gut barrier is a common manifestation of different inflammatory disorders contributing to the severity of disease. Barrier permeability is controlled by epithelial adherens junctions and tight junctions. Junctional assembly and integrity depend on fundamental homeostatic processes such as cell differentiation, rearrangements of the cytoskeleton, and vesicle trafficking. Alterations of intestinal epithelial homeostasis during mucosal inflammation may impair structure and remodeling of apical junctions, resulting in increased permeability of the gut barrier. In this review, we summarize recent advances in our understanding of how altered epithelial homeostasis affects the structure and function of adherens junctions and tight junctions in the inflamed gut. Specifically, we focus on the transcription reprogramming of the cell, alterations in the actin cytoskeleton, and junctional endocytosis and exocytosis. We pay special attention to knockout mouse model studies and discuss the relevance of these mechanisms to human gastrointestinal disorders.
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Affiliation(s)
- Susana Lechuga
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Andrei I Ivanov
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA 23298, USA; Virginia Institute of Molecular Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA; Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA.
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202
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Cominelli F, Arseneau KO, Rodriguez-Palacios A, Pizarro TT. Uncovering Pathogenic Mechanisms of Inflammatory Bowel Disease Using Mouse Models of Crohn's Disease-Like Ileitis: What is the Right Model? Cell Mol Gastroenterol Hepatol 2017; 4:19-32. [PMID: 28560286 PMCID: PMC5439236 DOI: 10.1016/j.jcmgh.2017.02.010] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 02/15/2017] [Indexed: 02/06/2023]
Abstract
Crohn's disease and ulcerative colitis, together known as inflammatory bowel disease, are debilitating chronic disorders of unknown cause and cure. Our evolving understanding of these pathologies is enhanced greatly by the use of animal models of intestinal inflammation that allow in vivo mechanistic studies, preclinical evaluation of new therapies, and investigation into the causative factors that underlie disease pathogenesis. Several animal models, most commonly generated in mice, exist for the study of colitis. The appropriateness of their use often can be determined by their mode of generation (ie, chemical induction, T-cell transfer, targeted genetic manipulation, spontaneously occurring, and so forth), the type of investigation (mechanistic studies, pathogenic experiments, preclinical evaluations, and so forth), and the type of inflammation that occurs in the model (acute vs chronic colitis, tissue injury/repair, and so forth). Although most murine models of inflammatory bowel disease develop inflammation in the colon, Crohn's disease most commonly occurs in the terminal ileum, where a very limited number of mouse models manifest disease. This review discusses appropriate experimental applications for different mouse models of colitis, and highlights the particular utility of 2 highly relevant models of Crohn's-like ileitis-the spontaneous SAMP1/YitFc inbred mouse strain and the genetically engineered TnfΔAU-rich element/+ mouse model of tumor necrosis factor overexpression, both of which bear strong resemblance to the human condition. Similar to patients with Crohn's disease, SAMP1/YitFc ileitis develops spontaneously, without chemical, genetic, or immunologic manipulation, making this model particularly relevant for studies aimed at identifying the primary defect underlying the occurrence of Crohn's ileitis, as well as preclinical testing of novel treatment modalities.
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Affiliation(s)
- Fabio Cominelli
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio,Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio,Digestive Health Research Institute, Case Western Reserve University School of Medicine, Cleveland, Ohio,Correspondence Address correspondence to: Fabio Cominelli, MD, PhD, Division of Gastroenterology, Case Western Reserve University School of Medicine, 11100 Euclid Avenue, Cleveland, Ohio 44106-5066. fax: (216) 844-7371.Division of GastroenterologyCase Western Reserve University School of Medicine11100 Euclid AvenueClevelandOhio 44106-5066
| | - Kristen O. Arseneau
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio,Digestive Health Research Institute, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Alexander Rodriguez-Palacios
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio,Digestive Health Research Institute, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Theresa T. Pizarro
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio,Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio,Digestive Health Research Institute, Case Western Reserve University School of Medicine, Cleveland, Ohio
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203
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Epithelial-specific Toll-like Receptor (TLR)5 Activation Mediates Barrier Dysfunction in Experimental Ileitis. Inflamm Bowel Dis 2017; 23:392-403. [PMID: 28146004 DOI: 10.1097/mib.0000000000001035] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND A large body of evidence supports a central role of TLR5 and its natural ligand, flagellin, in Crohn's disease (CD), with the precise mechanism(s) still unresolved. METHODS We investigated the role of flagellin/TLR5 in SAMP1/YitFc (SAMP) mice, a spontaneous model of Crohn's disease-like ileitis. RESULTS Ileal Tlr5 and serum antiflagellin IgG antibodies were increased in SAMP before the onset of inflammation and during established disease; these trends were abrogated in the absence of colonizing commensal bacteria. Irradiated SAMP receiving either wild-type (AKR) or SAMP bone marrow (BM) developed severe ileitis and displayed increased ileal Tlr5 compared with AKR recipients of either SAMP or AKR bone marrow, neither of which conferred ileitis, suggesting that elevated TLR5 in native SAMP is derived primarily from a nonhematopoietic (e.g., epithelial) source. Indeed, ileal epithelial TLR5 in preinflamed SAMP was increased compared with age-matched AKR and germ-free SAMP. TLR5-specific ex vivo activation of SAMP ileal tissues decreased epithelial barrier resistance, indicative of increased permeability, and was accompanied by altered expression of the tight junction proteins, claudin-3, occludin, and zonula occludens-1. CONCLUSIONS Our results provide evidence that aberrant, elevated TLR5 expression is present in the ileal epithelium of SAMP mice, is augmented in the presence of the gut microbiome, and that TLR5 activation in response to bacterial flagellin results in a deficiency to maintain appropriate epithelial barrier integrity. Together, these findings represent a potential mechanistic pathway leading to the exacerbation and perpetuation of chronic gut inflammation in experimental ileitis and possibly, in patients with Crohn's disease.
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204
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López-Posadas R, Neurath MF, Atreya I. Molecular pathways driving disease-specific alterations of intestinal epithelial cells. Cell Mol Life Sci 2017; 74:803-826. [PMID: 27624395 PMCID: PMC11107577 DOI: 10.1007/s00018-016-2363-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 09/06/2016] [Accepted: 09/08/2016] [Indexed: 12/22/2022]
Abstract
Due to the fact that chronic inflammation as well as tumorigenesis in the gut is crucially impacted by the fate of intestinal epithelial cells, our article provides a comprehensive overview of the composition, function, regulation and homeostasis of the gut epithelium. In particular, we focus on those aspects which were found to be altered in the context of inflammatory bowel diseases or colorectal cancer and also discuss potential molecular targets for a disease-specific therapeutic intervention.
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Affiliation(s)
- Rocío López-Posadas
- Department of Medicine 1, Friedrich-Alexander-University Erlangen-Nuremberg, Ulmenweg 18, 91054, Erlangen, Germany
| | - Markus F Neurath
- Department of Medicine 1, Friedrich-Alexander-University Erlangen-Nuremberg, Ulmenweg 18, 91054, Erlangen, Germany
| | - Imke Atreya
- Department of Medicine 1, Friedrich-Alexander-University Erlangen-Nuremberg, Ulmenweg 18, 91054, Erlangen, Germany.
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205
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Akbari P, Braber S, Varasteh S, Alizadeh A, Garssen J, Fink-Gremmels J. The intestinal barrier as an emerging target in the toxicological assessment of mycotoxins. Arch Toxicol 2017; 91:1007-1029. [PMID: 27417439 PMCID: PMC5316402 DOI: 10.1007/s00204-016-1794-8] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 07/05/2016] [Indexed: 02/08/2023]
Abstract
Mycotoxins, the secondary metabolites of fungal species, are the most frequently occurring natural food contaminants in human and animal diets. Risk assessment of mycotoxins focused as yet on their mutagenic, genotoxic and potential carcinogenic effects. Recently, there is an increasing awareness of the adverse effects of various mycotoxins on vulnerable structures in the intestines. In particular, an impairment of the barrier function of the epithelial lining cells and the sealing tight junction proteins has been noted, as this could result in an increased translocation of luminal antigens and pathogens and an excessive activation of the immune system. The current review aims to provide a summary of the available evidence regarding direct effects of various mycotoxins on the intestinal epithelial barrier. Available data, based on different cellular and animal studies, show that food-associated exposure to certain mycotoxins, especially trichothecenes and patulin, affects the intestinal barrier integrity and can result in an increased translocation of harmful stressors. It is therefore hypothesized that human exposure to certain mycotoxins, particularly deoxynivalenol, as the major trichothecene, may play an important role in etiology of various chronic intestinal inflammatory diseases, such as inflammatory bowel disease, and in the prevalence of food allergies, particularly in children.
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Affiliation(s)
- Peyman Akbari
- Division of Veterinary Pharmacology, Pharmacotherapy and Toxicology, Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 104, 3584 CM, Utrecht, The Netherlands
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, 3584 CG, Utrecht, The Netherlands
| | - Saskia Braber
- Division of Veterinary Pharmacology, Pharmacotherapy and Toxicology, Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 104, 3584 CM, Utrecht, The Netherlands.
| | - Soheil Varasteh
- Division of Veterinary Pharmacology, Pharmacotherapy and Toxicology, Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 104, 3584 CM, Utrecht, The Netherlands
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, 3584 CG, Utrecht, The Netherlands
| | - Arash Alizadeh
- Division of Veterinary Pharmacology, Pharmacotherapy and Toxicology, Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 104, 3584 CM, Utrecht, The Netherlands
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, 3584 CG, Utrecht, The Netherlands
| | - Johan Garssen
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, 3584 CG, Utrecht, The Netherlands
- Nutricia Research, 3584 CT, Utrecht, The Netherlands
| | - Johanna Fink-Gremmels
- Division of Veterinary Pharmacology, Pharmacotherapy and Toxicology, Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 104, 3584 CM, Utrecht, The Netherlands
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206
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Schultz BM, Paduro CA, Salazar GA, Salazar-Echegarai FJ, Sebastián VP, Riedel CA, Kalergis AM, Alvarez-Lobos M, Bueno SM. A Potential Role of Salmonella Infection in the Onset of Inflammatory Bowel Diseases. Front Immunol 2017; 8:191. [PMID: 28293241 PMCID: PMC5329042 DOI: 10.3389/fimmu.2017.00191] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Accepted: 02/09/2017] [Indexed: 12/13/2022] Open
Abstract
Inflammatory bowel disease (IBD) includes a set of pathologies that result from a deregulated immune response that may affect any portion of the gastrointestinal tract. The most prevalent and defined forms of IBD are Crohn’s disease and ulcerative colitis. Although the etiology of IBD is not well defined, it has been suggested that environmental and genetic factors contribute to disease development and that the interaction between these two factors can trigger the pathology. Diet, medication use, vitamin D status, smoking, and bacterial infections have been proposed to influence or contribute to the onset or development of the disease in susceptible individuals. The infection with pathogenic bacteria is a key factor that can influence the development and severity of this disease. Here, we present a comprehensive review of studies performed in human and mice susceptible to IBD, which supports the notion that infection with bacterial pathogens, such as Salmonella, could promote the onset of IBD due to permanent changes in the intestinal microbiota, disruption of the epithelial barrier and alterations of the intestinal immune response after infection.
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Affiliation(s)
- Bárbara M Schultz
- Facultad de Ciencias Biológicas, Departamento de Genética Molecular y Microbiología, Millennium Institute on Immunology and Immunotherapy, Pontificia Universidad Católica de Chile , Santiago , Chile
| | - Carolina A Paduro
- Facultad de Ciencias Biológicas, Departamento de Genética Molecular y Microbiología, Millennium Institute on Immunology and Immunotherapy, Pontificia Universidad Católica de Chile , Santiago , Chile
| | - Geraldyne A Salazar
- Facultad de Ciencias Biológicas, Departamento de Genética Molecular y Microbiología, Millennium Institute on Immunology and Immunotherapy, Pontificia Universidad Católica de Chile , Santiago , Chile
| | - Francisco J Salazar-Echegarai
- Facultad de Ciencias Biológicas, Departamento de Genética Molecular y Microbiología, Millennium Institute on Immunology and Immunotherapy, Pontificia Universidad Católica de Chile , Santiago , Chile
| | - Valentina P Sebastián
- Facultad de Ciencias Biológicas, Departamento de Genética Molecular y Microbiología, Millennium Institute on Immunology and Immunotherapy, Pontificia Universidad Católica de Chile , Santiago , Chile
| | - Claudia A Riedel
- Facultad de Ciencias Biológicas y Facultad de Medicina, Departamento de Ciencias Biológicas, Millennium Institute on Immunology and Immunotherapy, Universidad Andrés Bello , Santiago , Chile
| | - Alexis M Kalergis
- Facultad de Ciencias Biológicas, Departamento de Genética Molecular y Microbiología, Millennium Institute on Immunology and Immunotherapy, Pontificia Universidad Católica de Chile, Santiago, Chile; Facultad de Medicina, Departamento de Endocrinología, Pontificia Universidad Católica de Chile, Santiago, Chile; INSERM, UMR 1064, Nantes, France
| | - Manuel Alvarez-Lobos
- Facultad de Medicina, Departamento de Gastroenterología, Pontificia Universidad Católica de Chile , Santiago , Chile
| | - Susan M Bueno
- Facultad de Ciencias Biológicas, Departamento de Genética Molecular y Microbiología, Millennium Institute on Immunology and Immunotherapy, Pontificia Universidad Católica de Chile, Santiago, Chile; INSERM, UMR 1064, Nantes, France
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207
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Calcium-mediated oxidative stress: a common mechanism in tight junction disruption by different types of cellular stress. Biochem J 2017; 474:731-749. [PMID: 28057718 DOI: 10.1042/bcj20160679] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 08/10/2016] [Accepted: 01/05/2017] [Indexed: 02/07/2023]
Abstract
The role of reactive oxygen species (ROS) in osmotic stress, dextran sulfate sodium (DSS) and cyclic stretch-induced tight junction (TJ) disruption was investigated in Caco-2 cell monolayers in vitro and restraint stress-induced barrier dysfunction in mouse colon in vivo Live cell imaging showed that osmotic stress, cyclic stretch and DSS triggered rapid production of ROS in Caco-2 cell monolayers, which was blocked by depletion of intracellular Ca2+ by 1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid. Knockdown of CaV1.3 or TRPV6 channels blocked osmotic stress and DSS-induced ROS production and attenuated TJ disruption and barrier dysfunction. N-Acetyl l-cysteine (NAC) and l-NG-Nitroarginine methyl ester (l-NAME) blocked stress-induced TJ disruption and barrier dysfunction. NAC and l-NAME also blocked stress-induced activation of c-Jun N-terminal kinase (JNK) and c-Src. ROS was colocalized with the mitochondrial marker in stressed cells. Cyclosporin A blocked osmotic stress and DSS-induced ROS production, barrier dysfunction, TJ disruption and JNK activation. Mitochondria-targeted Mito-TEMPO blocked osmotic stress and DSS-induced barrier dysfunction and TJ disruption. Chronic restraint stress in mice resulted in the elevation of intracellular Ca2+, activation of JNK and c-Src, and disruption of TJ in the colonic epithelium. Furthermore, corticosterone administration induced JNK and c-Src activation, TJ disruption and protein thiol oxidation in colonic mucosa. The present study demonstrates that oxidative stress is a common signal in the mechanism of TJ disruption in the intestinal epithelium by different types of cellular stress in vitro and bio behavioral stress in vivo.
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208
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Li R, Yang J, Saffari A, Jacobs J, Baek KI, Hough G, Larauche MH, Ma J, Jen N, Moussaoui N, Zhou B, Kang H, Reddy S, Henning SM, Campen MJ, Pisegna J, Li Z, Fogelman AM, Sioutas C, Navab M, Hsiai TK. Ambient Ultrafine Particle Ingestion Alters Gut Microbiota in Association with Increased Atherogenic Lipid Metabolites. Sci Rep 2017; 7:42906. [PMID: 28211537 PMCID: PMC5314329 DOI: 10.1038/srep42906] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 01/17/2017] [Indexed: 12/22/2022] Open
Abstract
Ambient particulate matter (PM) exposure is associated with atherosclerosis and inflammatory bowel disease. Ultrafine particles (UFP, dp < 0.1–0.2 μm) are redox active components of PM. We hypothesized that orally ingested UFP promoted atherogenic lipid metabolites in both the intestine and plasma via altered gut microbiota composition. Low density lipoprotein receptor-null (Ldlr−/−) mice on a high-fat diet were orally administered with vehicle control or UFP (40 μg/mouse/day) for 3 days a week. After 10 weeks, UFP ingested mice developed macrophage and neutrophil infiltration in the intestinal villi, accompanied by elevated cholesterol but reduced coprostanol levels in the cecum, as well as elevated atherogenic lysophosphatidylcholine (LPC 18:1) and lysophosphatidic acids (LPAs) in the intestine and plasma. At the phylum level, Principle Component Analysis revealed significant segregation of microbiota compositions which was validated by Beta diversity analysis. UFP-exposed mice developed increased abundance in Verrocomicrobia but decreased Actinobacteria, Cyanobacteria, and Firmicutes as well as a reduced diversity in microbiome. Spearman’s analysis negatively correlated Actinobacteria with cecal cholesterol, intestinal and plasma LPC18:1, and Firmicutes and Cyanobacteria with plasma LPC 18:1. Thus, ultrafine particles ingestion alters gut microbiota composition, accompanied by increased atherogenic lipid metabolites. These findings implicate the gut-vascular axis in a atherosclerosis model.
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Affiliation(s)
- Rongsong Li
- Division of Cardiology, Department of Medicine, School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Jieping Yang
- Division of Clinical Nutrition, Department of Medicine, School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Arian Saffari
- Civil and Environmental Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Jonathan Jacobs
- Division of Gastroenterology and Hepatology, Department of Medicine, School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Kyung In Baek
- Department of Bioengineering, School of Engineering &Applied Science, University of California, Los Angeles, CA 90095, USA
| | - Greg Hough
- Division of Cardiology, Department of Medicine, School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Muriel H Larauche
- Division of Gastroenterology and Hepatology, Department of Medicine, School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Jianguo Ma
- Division of Cardiology, Department of Medicine, School of Medicine, University of California, Los Angeles, CA 90095, USA.,Department of Bioengineering, School of Engineering &Applied Science, University of California, Los Angeles, CA 90095, USA
| | - Nelson Jen
- Division of Cardiology, Department of Medicine, School of Medicine, University of California, Los Angeles, CA 90095, USA.,Department of Bioengineering, School of Engineering &Applied Science, University of California, Los Angeles, CA 90095, USA
| | - Nabila Moussaoui
- Division of Gastroenterology and Hepatology, Department of Medicine, School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Bill Zhou
- Division of Cardiology, Department of Medicine, School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Hanul Kang
- Division of Cardiology, Department of Medicine, School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Srinivasa Reddy
- Division of Cardiology, Department of Medicine, School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Susanne M Henning
- Division of Clinical Nutrition, Department of Medicine, School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Matthew J Campen
- Department of Pharmaceutical Sciences, School of Pharmacy, University of New Mexico, Albuquerque, NM 87131, USA
| | - Joseph Pisegna
- Division of Gastroenterology and Hepatology, Department of Medicine, School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Zhaoping Li
- Division of Clinical Nutrition, Department of Medicine, School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Alan M Fogelman
- Division of Cardiology, Department of Medicine, School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Constantinos Sioutas
- Civil and Environmental Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Mohamad Navab
- Division of Cardiology, Department of Medicine, School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Tzung K Hsiai
- Division of Cardiology, Department of Medicine, School of Medicine, University of California, Los Angeles, CA 90095, USA.,Department of Bioengineering, School of Engineering &Applied Science, University of California, Los Angeles, CA 90095, USA
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209
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Enteric Pathogens and Their Toxin-Induced Disruption of the Intestinal Barrier through Alteration of Tight Junctions in Chickens. Toxins (Basel) 2017; 9:toxins9020060. [PMID: 28208612 PMCID: PMC5331439 DOI: 10.3390/toxins9020060] [Citation(s) in RCA: 241] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 01/31/2017] [Accepted: 02/06/2017] [Indexed: 12/11/2022] Open
Abstract
Maintaining a healthy gut environment is a prerequisite for sustainable animal production. The gut plays a key role in the digestion and absorption of nutrients and constitutes an initial organ exposed to external factors influencing bird’s health. The intestinal epithelial barrier serves as the first line of defense between the host and the luminal environment. It consists of a continuous monolayer of intestinal epithelial cells connected by intercellular junctional complexes which shrink the space between adjacent cells. Consequently, free passing of solutes and water via the paracellular pathway is prevented. Tight junctions (TJs) are multi-protein complexes which are crucial for the integrity and function of the epithelial barrier as they not only link cells but also form channels allowing permeation between cells, resulting in epithelial surfaces of different tightness. Tight junction’s molecular composition, ultrastructure, and function are regulated differently with regard to physiological and pathological stimuli. Both in vivo and in vitro studies suggest that reduced tight junction integrity greatly results in a condition commonly known as “leaky gut”. A loss of barrier integrity allows the translocation of luminal antigens (microbes, toxins) via the mucosa to access the whole body which are normally excluded and subsequently destroys the gut mucosal homeostasis, coinciding with an increased susceptibility to systemic infection, chronic inflammation and malabsorption. There is considerable evidence that the intestinal barrier dysfunction is an important factor contributing to the pathogenicity of some enteric bacteria. It has been shown that some enteric pathogens can induce permeability defects in gut epithelia by altering tight junction proteins, mediated by their toxins. Resolving the strategies that microorganisms use to hijack the functions of tight junctions is important for our understanding of microbial pathogenesis, because some pathogens can utilize tight junction proteins as receptors for attachment and subsequent internalization, while others modify or destroy the tight junction proteins by different pathways and thereby provide a gateway to the underlying tissue. This review aims to deliver an overview of the tight junction structures and function, and its role in enteric bacterial pathogenesis with a special focus on chickens. A main conclusion will be that the molecular mechanisms used by enteric pathogens to disrupt epithelial barrier function in chickens needs a much better understanding, explicitly highlighted for Campylobacter jejuni, Salmonella enterica and Clostridium perfringens. This is a requirement in order to assist in discovering new strategies to avoid damages of the intestinal barrier or to minimize consequences from infections.
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210
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Merino-Guzmán R, Latorre JD, Delgado R, Hernandez-Velasco X, Wolfenden AD, Teague KD, Graham LE, Mahaffey BD, Baxter MFA, Hargis BM, Tellez G. Comparison of total immunoglobulin A levels in different samples in Leghorn and broiler chickens. Asian Pac J Trop Biomed 2017. [DOI: 10.1016/j.apjtb.2016.11.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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211
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Seo S, Shin JS, Lee WS, Rhee YK, Cho CW, Hong HD, Lee KT. Anti-colitis effect of Lactobacillus sakei K040706 via suppression of inflammatory responses in the dextran sulfate sodium-induced colitis mice model. J Funct Foods 2017. [DOI: 10.1016/j.jff.2016.12.045] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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212
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Takahashi S, Andreoletti G, Chen R, Munehira Y, Batra A, Afzal NA, Beattie RM, Bernstein JA, Ennis S, Snyder M. De novo and rare mutations in the HSPA1L heat shock gene associated with inflammatory bowel disease. Genome Med 2017; 9:8. [PMID: 28126021 PMCID: PMC5270254 DOI: 10.1186/s13073-016-0394-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 12/23/2016] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Inflammatory bowel disease (IBD) is a chronic, relapsing inflammatory disease of the gastrointestinal tract which includes ulcerative colitis and Crohn's disease. Genetic risk factors for IBD are not well understood. METHODS We performed a family-based whole exome sequencing (WES) analysis on a core family (Family A) to identify potential causal mutations and then analyzed exome data from a Caucasian pediatric cohort (136 patients and 106 controls) to validate the presence of mutations in the candidate gene, heat shock 70 kDa protein 1-like (HSPA1L). Biochemical assays of the de novo and rare (minor allele frequency, MAF < 0.01) mutation variant proteins further validated the predicted deleterious effects of the identified alleles. RESULTS In the proband of Family A, we found a heterozygous de novo mutation (c.830C > T; p.Ser277Leu) in HSPA1L. Through analysis of WES data of 136 patients, we identified five additional rare HSPA1L mutations (p.Gly77Ser, p.Leu172del, p.Thr267Ile, p.Ala268Thr, p.Glu558Asp) in six patients. In contrast, rare HSPA1L mutations were not observed in controls, and were significantly enriched in patients (P = 0.02). Interestingly, we did not find non-synonymous rare mutations in the HSP70 isoforms HSPA1A and HSPA1B. Biochemical assays revealed that all six rare HSPA1L variant proteins showed decreased chaperone activity in vitro. Moreover, three variants demonstrated dominant negative effects on HSPA1L and HSPA1A protein activity. CONCLUSIONS Our results indicate that de novo and rare mutations in HSPA1L are associated with IBD and provide insights into the pathogenesis of IBD, and also expand our understanding of the roles of HSP70s in human disease.
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Affiliation(s)
- Shinichi Takahashi
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA.,Rare Disease & LCM Laboratories, R & D Division, Daiichi Sankyo Co., Ltd, Tokyo, Japan
| | - Gaia Andreoletti
- Human Genetics and Genomic Medicine, University of Southampton, Southampton General Hospital, Southampton, UK
| | - Rui Chen
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Yoichi Munehira
- Department of Biology, Stanford University, Stanford, CA, USA.,Oncology Laboratories, Oncology Function, Daiichi Sankyo Co., Ltd, Tokyo, Japan
| | - Akshay Batra
- Department of Paediatric Gastroenterology, University Hospital Southampton NHS Foundation Trust, Southampton General Hospital, Tremona Road, Southampton, UK
| | - Nadeem A Afzal
- Department of Paediatric Gastroenterology, University Hospital Southampton NHS Foundation Trust, Southampton General Hospital, Tremona Road, Southampton, UK
| | - R Mark Beattie
- Department of Paediatric Gastroenterology, University Hospital Southampton NHS Foundation Trust, Southampton General Hospital, Tremona Road, Southampton, UK
| | - Jonathan A Bernstein
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | - Sarah Ennis
- Human Genetics and Genomic Medicine, University of Southampton, Southampton General Hospital, Southampton, UK.
| | - Michael Snyder
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA.
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213
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Lu P, Zhang CH, Lifshitz LM, ZhuGe R. Extraoral bitter taste receptors in health and disease. J Gen Physiol 2017; 149:181-197. [PMID: 28053191 PMCID: PMC5299619 DOI: 10.1085/jgp.201611637] [Citation(s) in RCA: 136] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 10/06/2016] [Accepted: 12/19/2016] [Indexed: 12/24/2022] Open
Abstract
Bitter taste receptors (TAS2Rs or T2Rs) belong to the superfamily of seven-transmembrane G protein-coupled receptors, which are the targets of >50% of drugs currently on the market. Canonically, T2Rs are located in taste buds of the tongue, where they initiate bitter taste perception. However, accumulating evidence indicates that T2Rs are widely expressed throughout the body and mediate diverse nontasting roles through various specialized mechanisms. It has also become apparent that T2Rs and their polymorphisms are associated with human disorders. In this review, we summarize the physiological and pathophysiological roles that extraoral T2Rs play in processes as diverse as innate immunity and reproduction, and the major challenges in this emerging field.
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Affiliation(s)
- Ping Lu
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605
| | - Cheng-Hai Zhang
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605
| | - Lawrence M Lifshitz
- Biomedical Imaging Group, University of Massachusetts Medical School, Worcester, MA 01605.,Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605
| | - Ronghua ZhuGe
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605 .,Biomedical Imaging Group, University of Massachusetts Medical School, Worcester, MA 01605
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214
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Bron PA, Kleerebezem M, Brummer RJ, Cani PD, Mercenier A, MacDonald TT, Garcia-Ródenas CL, Wells JM. Can probiotics modulate human disease by impacting intestinal barrier function? Br J Nutr 2017; 117:93-107. [PMID: 28102115 PMCID: PMC5297585 DOI: 10.1017/s0007114516004037] [Citation(s) in RCA: 259] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 09/29/2016] [Accepted: 10/25/2016] [Indexed: 12/16/2022]
Abstract
Intestinal barrier integrity is a prerequisite for homeostasis of mucosal function, which is balanced to maximise absorptive capacity, while maintaining efficient defensive reactions against chemical and microbial challenges. Evidence is mounting that disruption of epithelial barrier integrity is one of the major aetiological factors associated with several gastrointestinal diseases, including infection by pathogens, obesity and diabetes, necrotising enterocolitis, irritable bowel syndrome and inflammatory bowel disease. The notion that specific probiotic bacterial strains can affect barrier integrity fuelled research in which in vitro cell lines, animal models and clinical trials are used to assess whether probiotics can revert the diseased state back to homeostasis and health. This review catalogues and categorises the lines of evidence available in literature for the role of probiotics in epithelial integrity and, consequently, their beneficial effect for the reduction of gastrointestinal disease symptoms.
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Affiliation(s)
- Peter A. Bron
- NIZO Food Research and BE-Basic Foundation, Kernhemseweg 2, 6718ZB Ede, The Netherlands
| | - Michiel Kleerebezem
- Wageningen University, Host Microbe Interactomics Group, De Elst 1, 6708WD Wageningen, The Netherlands
| | - Robert-Jan Brummer
- Faculty of Medicine and Health, Örebro University, Fakultetsgatan 1, SE-701 82 Örebro, Sweden
| | - Patrice D. Cani
- Metabolism and Nutrition Research Group, WELBIO – Walloon Excellence in Life Sciences and BIOtechnology, Louvain Drug Research Institute, Université catholique de Louvain, Avenue E. Mounier, 73 B1.73.11, 1200 Brussels, Belgium
| | - Annick Mercenier
- Nestlé Research Center, Nutrition and Health Research, route du Jorat 57, 1000 Lausanne 26, Switzerland
| | - Thomas T. MacDonald
- Barts and The London school of Medicine and Dentistry, Blizard Institute, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Clara L. Garcia-Ródenas
- Nestlé Research Center, Nutrition and Health Research, route du Jorat 57, 1000 Lausanne 26, Switzerland
| | - Jerry M. Wells
- Wageningen University, Host Microbe Interactomics Group, De Elst 1, 6708WD Wageningen, The Netherlands
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215
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Abstract
Neuroimmune communications are facilitated by the production of neurotransmitters by immune cells and the generation of immune mediators by immune cells, which form a functional entity called the "neuroimmune synapse." There are several mechanisms that further facilitate neuroimmune interactions including the anatomic proximity between immune cells and nerves, the expression of receptors for neurotransmitters on immune cells and for immune mediators on nerves, and the receptor-mediated activation of intracellular signaling pathways that modulate nerve and immune phenotype and function. The bidirectional communication between nerves and immune cells is implicated in allostasis, a process that describes the continuous adaptation to an ever-changing environment. Neuroimmune interactions are amplified during inflammation by the influx of activated immune cells that significantly alter the microenvironment. In this context, the types of neurotransmitters released by activated neurons or immune cells can exert pro- or anti-inflammatory effects. Dysregulation of the enteric nervous system control of gastrointestinal functions, such as epithelial permeability and secretion as well as smooth muscle contractility, also contribute to the chronicity of inflammation. Persistent active inflammation in the gut leads to neuroimmune plasticity, which is a structural and functional remodeling in both the neural and immune systems. The importance of neuroimmune interactions has made them an emerging target in the development of novel therapies for GI pathologies.
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Affiliation(s)
- Terez Shea-Donohue
- Department of Radiation Oncology, University of Maryland School of Medicine, DTRS, MSTF Rm 700C, 10 Pine Street, Baltimore, MD, 21201, USA.
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
| | - Joseph F Urban
- U.S. Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, Diet, Genomics, and Immunology Laboratory, Beltsville, MD, 20705, USA
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216
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Yang L, Wang WC, Lung SCC, Sun Z, Chen C, Chen JK, Zou Q, Lin YH, Lin CH. Polycyclic aromatic hydrocarbons are associated with increased risk of chronic obstructive pulmonary disease during haze events in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 574:1649-1658. [PMID: 27614859 DOI: 10.1016/j.scitotenv.2016.08.211] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Revised: 07/28/2016] [Accepted: 08/31/2016] [Indexed: 06/06/2023]
Abstract
Although exposure to particulate matter with a diameter of <2.5μm (PM2.5) is associated with chronic obstructive pulmonary disease (COPD), the major components of PM2.5 in COPD pathogenesis are controversial. Here we employed the human lung epithelial cell line BEAS-2B to elucidate the association between COPD and the organic and water-soluble components of PM2.5. We found that the PM2.5 organic extract was a potential major risk factor for pulmonary epithelial barrier dysfunction through the depletion of proteins from the zonula occludens. This extract induced severe oxidative stress that increased DNA damage and the production of proinflammatory cytokines by BEAS-2B cells as well as decreased α1-antitrypsin expression, suggesting a mechanism that increases the risk of COPD. These effects were mainly mediated by polycyclic aromatic hydrocarbons (PAHs) through the aryl hydrocarbon receptor pathway. PAHs with high benzo(a)pyrene (BaP)-equivalent concentrations, but not major PAH components, have an increased risk of causing COPD, suggesting that BaP-equivalent concentrations represent a PM2.5-induced COPD risk metric, which may contribute to provide a rationale for the remediation of air pollution.
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Affiliation(s)
- Lingyan Yang
- Key Laboratory of Nano-Bio Interface, Division of Nanobiomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China
| | - Wen-Cheng Wang
- Research Center for Environmental Changes, Academia Sinica, Taipei 11529, Taiwan
| | | | - Zhelin Sun
- Key Laboratory of Nano-Bio Interface, Division of Nanobiomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China
| | - Chongjun Chen
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Jen-Kun Chen
- Institute of Biomedical Engineering & Nanomedicine, National Health Research Institutes, Miaoli 35053, Taiwan
| | - Qiang Zou
- Suzhou Environmental Monitor Center, Suzhou 215004, China
| | - Yu-Hsin Lin
- Department of Food and Beverage Management, Taipei College of Maritime Technology, Taipei 11174, Taiwan
| | - Chia-Hua Lin
- Department of Biotechnology, National Formosa University, Yunlin 63208, Taiwan.
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217
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Dun Y, Liu M, Chen J, Peng D, Zhao H, Zhou Z, Wang T, Liu C, Guo Y, Zhang C, Yuan D. Regulatory effects of saponins from Panax japonicus on colonic epithelial tight junctions in aging rats. J Ginseng Res 2016; 42:50-56. [PMID: 29348722 PMCID: PMC5766693 DOI: 10.1016/j.jgr.2016.12.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 10/27/2016] [Accepted: 12/20/2016] [Indexed: 12/24/2022] Open
Abstract
Background Saponins from Panax japonicus (SPJ) are the most abundant and main active components of P. japonicus, which replaces ginseng roots in treatment for many kinds of diseases in the minority ethnic group in China. Our previous studies have demonstrated that SPJ has the effects of anti-inflammation through the mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signaling pathways. The present study was designed to investigate whether SPJ can modulate intestinal tight junction barrier in aging rats and further to explore the potential mechanism. Methods Aging rats had been treated with different doses (10 mg/kg, 30 mg/kg, and 60 mg/kg) of SPJ for 6 mo since they were 18 mo old. After the rats were euthanized, the colonic samples were harvested. Levels of tight junctions (claudin-1 and occludin) were determined by immunohistochemical staining. Levels of proinflammatory cytokines (interleukin-1β and tumor necrosis factor-α) were examined by Western blot. NF-κB and phosphorylation of MAPK signaling pathways were also determined by Western blot. Results We found that SPJ increased the expression of the tight junction proteins claudin-1 and occludin in the colon of aging rats. Treatment with SPJ decreased the levels of interleukin-1β and tumor necrosis factor-α, reduced the phosphorylation of three MAPK isoforms, and inhibited the expression of NF-κB in the colon of aging rats. Conclusion The studies demonstrated that SPJ modulates the damage of intestinal epithelial tight junction in aging rats, inhibits inflammation, and downregulates the phosphorylation of the MAPK and NF-κB signaling pathways.
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Affiliation(s)
- Yaoyan Dun
- Medical College of China Three Gorges University, Yichang, China
| | - Min Liu
- Medical College of China Three Gorges University, Yichang, China
| | - Jing Chen
- Medical College of China Three Gorges University, Yichang, China
| | - Danli Peng
- Medical College of China Three Gorges University, Yichang, China
| | - Haixia Zhao
- Medical College of China Three Gorges University, Yichang, China
| | - Zhiyong Zhou
- Medical College of China Three Gorges University, Yichang, China
| | - Ting Wang
- Medical College of China Three Gorges University, Yichang, China
| | - Chaoqi Liu
- Medical College of China Three Gorges University, Yichang, China
| | - Yuhui Guo
- Medical College of China Three Gorges University, Yichang, China
| | - Changcheng Zhang
- Medical College of China Three Gorges University, Yichang, China
| | - Ding Yuan
- Renhe Hospital of China Three Gorges University, Yichang, China
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218
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Esteban-Zubero E, López-Pingarrón L, Alatorre-Jiménez MA, Ochoa-Moneo P, Buisac-Ramón C, Rivas-Jiménez M, Castán-Ruiz S, Antoñanzas-Lombarte Á, Tan DX, García JJ, Reiter RJ. Melatonin's role as a co-adjuvant treatment in colonic diseases: A review. Life Sci 2016; 170:72-81. [PMID: 27919824 DOI: 10.1016/j.lfs.2016.11.031] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Revised: 11/17/2016] [Accepted: 11/30/2016] [Indexed: 02/07/2023]
Abstract
Melatonin is produced in the pineal gland as well as many other organs, including the enterochromaffin cells of the digestive mucosa. Melatonin is a powerful antioxidant that resists oxidative stress due to its capacity to directly scavenge reactive species, to modulate the antioxidant defense system by increasing the activities of antioxidant enzymes, and to stimulate the innate immune response through its direct and indirect actions. In addition, the dysregulation of the circadian system is observed to be related with alterations in colonic motility and cell disruptions due to the modifications of clock genes expression. In the gastrointestinal tract, the activities of melatonin are mediated by melatonin receptors (MT2), serotonin (5-HT), and cholecystokinin B (CCK2) receptors and via receptor-independent processes. The levels of melatonin in the gastrointestinal tract exceed by 10-100 times the blood concentrations. Also, there is an estimated 400 times more melatonin in the gut than in the pineal gland. Gut melatonin secretion is suggested to be influenced by the food intake. Low dose melatonin treatment accelerates intestinal transit time whereas high doses may decrease gut motility. Melatonin has been studied as a co-adjuvant treatment in several gastrointestinal diseases including irritable bowel syndrome (IBS), constipation-predominant IBS (IBS-C), diarrhea-predominant IBS (IBS-D), Crohn's disease, ulcerative colitis, and necrotizing enterocolitis. The purpose of this review is to provide information regarding the potential benefits of melatonin as a co-adjuvant treatment in gastrointestinal diseases, especially IBS, Crohn's disease, ulcerative colitis, and necrotizing enterocolitis.
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Affiliation(s)
- Eduardo Esteban-Zubero
- Department of Pharmacology and Physiology, University of Zaragoza. Calle Domingo Miral s/n, 50009 Zaragoza, Spain.
| | - Laura López-Pingarrón
- Department of Medicine, Psychiatry and Dermatology, University of Zaragoza. Calle Domingo Miral s/n, 50009 Zaragoza, Spain
| | - Moisés Alejandro Alatorre-Jiménez
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
| | - Purificación Ochoa-Moneo
- Department of Medicine, Psychiatry and Dermatology, University of Zaragoza. Calle Domingo Miral s/n, 50009 Zaragoza, Spain
| | - Celia Buisac-Ramón
- Primary Care Unit, Sector Zaragoza III, Avenida San Juan Bosco 5, 50009 Zaragoza, Spain
| | - Miguel Rivas-Jiménez
- Department of Medicine, Psychiatry and Dermatology, University of Zaragoza. Calle Domingo Miral s/n, 50009 Zaragoza, Spain
| | - Silvia Castán-Ruiz
- Primary Care Unit, Sector Zaragoza III, Avenida San Juan Bosco 5, 50009 Zaragoza, Spain
| | - Ángel Antoñanzas-Lombarte
- Department of Medicine, Psychiatry and Dermatology, University of Zaragoza. Calle Domingo Miral s/n, 50009 Zaragoza, Spain
| | - Dun-Xian Tan
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
| | - José Joaquín García
- Department of Pharmacology and Physiology, University of Zaragoza. Calle Domingo Miral s/n, 50009 Zaragoza, Spain
| | - Russel J Reiter
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA.
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219
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Prado-Rebolledo OF, Delgado-Machuca JDJ, Macedo-Barragan RJ, Garcia-Márquez LJ, Morales-Barrera JE, Latorre JD, Hernandez-Velasco X, Tellez G. Evaluation of a selected lactic acid bacteria-based probiotic on Salmonella enterica serovar Enteritidis colonization and intestinal permeability in broiler chickens. Avian Pathol 2016; 46:90-94. [PMID: 27545145 DOI: 10.1080/03079457.2016.1222808] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Two experiments were conducted to evaluate the effect of a lactic acid bacteria-based probiotic (FloraMax-B11®) against Salmonella enterica serovar Enteritidis intestinal colonization and intestinal permeability in broiler chickens. Experiment 1 consisted of two independent trials. In each trial, day-old broiler chicks were assigned to one of two groups: control + S. Enteritidis or probiotic + S. Enteritidis. At 72 h post-S. Enteritidis challenge, haematology and caecal content were evaluated for S. Enteritidis colonization. In Experiment 2, day-old broiler chicks were assigned to one of four groups: negative control; probiotic; control + S. Enteritidis; or probiotic + S. Enteritidis. At 72 h post-S. Enteritidis challenge, chickens in all groups were given an oral gavage dose of fluorescein isothiocyanate dextran (FITC-d). In both trials of Experiment 1, a significant reduction (P < 0.05) in colony-forming units/gram of S. Enteritidis in caecal content and a reduction in the incidence of S. Enteritidis enriched caecal samples were observed in probiotic + S. Enteritidis chickens. In addition, significant heterophilia and lymphopaenia were observed in control + S. Enteritidis chickens. In Experiment 2, a decrease in numbers of S. Enteritidis in caeca were observed in probiotic + S. Enteritidis chickens when compared to control + S. Enteritidis. Also, an increase in serum FITC-d concentration was detected in control + S. Enteritidis. These results suggest that early infection with S. Enteritidis can increase intestinal permeability, but the adverse effects can be prevented by the administration of the probiotic tested.
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Affiliation(s)
- Omar F Prado-Rebolledo
- a Facultad de Medicina Veterinaria y Zootecnia , Universidad de Colima , Colima , México
| | | | | | - Luis J Garcia-Márquez
- b Centro Universitario de Investigación y Desarrollo Agrícola , Universidad de Colima , Colima , México
| | - Jesus E Morales-Barrera
- c Departamento de Producción Agrícola y Animal , Universidad Autónoma Metropolitana , México City , México
| | - Juan D Latorre
- d Department of Poultry Science, Center of Excellence for Poultry Science , University of Arkansas , Fayetteville , AR , USA
| | - Xochitl Hernandez-Velasco
- e Departamento de Medicina y Zootecnia de Aves, Facultad de Medicina Veterinaria y Zootecnia , Universidad Nacional Autónoma de México , México City , México
| | - Guillermo Tellez
- d Department of Poultry Science, Center of Excellence for Poultry Science , University of Arkansas , Fayetteville , AR , USA
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220
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Distinct Anti-IFI16 and Anti-GP2 Antibodies in Inflammatory Bowel Disease and Their Variation with Infliximab Therapy. Inflamm Bowel Dis 2016; 22:2977-2987. [PMID: 27636380 DOI: 10.1097/mib.0000000000000926] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Inflammatory bowel disease (IBD) is characterized by a chronic inflammation of the gut, partly driven by defects in the expression and function of pattern recognition receptors, including the IFI16 protein. Because this protein is a target for autoantibodies and its aberrant expression was reported in colonic mucosa from active patients with ulcerative colitis, we studied its expression and specific seroresponse in patients with IBD before and after infliximab (IFX) therapy. METHODS Anti-IFI16 antibodies (IgG and IgA subtypes) were measured in the sera of 74 patients with IBD: 48 patients with Crohn's disease (CD) and 26 patients with ulcerative colitis, prospectively harvested before and after IFX therapy. Anti-GP2 antibodies (both IgG and IgA subtypes) were also tested for comparison. The patient antibody statuses were qualitatively and quantitatively associated with disease phenotype and response to IFX therapy. RESULTS Significantly higher titers of anti-IFI16 IgG were found in both CD and ulcerative colitis patients compared with healthy controls. Anti-IFI16 IgA titers were also present in patients with CD. Anti-GP2 IgG subtype titers were significantly increased in patients with CD, as were IgA subtype titers. Significant changes in anti-IFI16 IgG subtype titers were observed after IFX in patients with CD who correlated with clinical remission or response. CONCLUSIONS Our results highlight the importance of IFI16 in IBD pathogenesis showing that its de novo overexpression in the gut epithelial cells leads to a breakdown in immune tolerance and the subsequent development of specific autoantibodies. Anti-IFI16 IgG antibodies hold the potential to serve as a biomarker of response to IFX therapy.
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221
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Gata4 is critical to maintain gut barrier function and mucosal integrity following epithelial injury. Sci Rep 2016; 6:36776. [PMID: 27827449 PMCID: PMC5101531 DOI: 10.1038/srep36776] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 10/20/2016] [Indexed: 12/24/2022] Open
Abstract
The intestinal epithelial barrier is critical to limit potential harmful consequences from exposure to deleterious luminal contents on the organism. Although this barrier is functionally important along the entire gut, specific regional regulatory mechanisms involved in the maintenance of this barrier are poorly defined. Herein, we identified Gata4 as a crucial regulator of barrier integrity in the mouse proximal intestinal epithelium. Conditional deletion of Gata4 in the intestine led to a drastic increase in claudin-2 expression that was associated with an important increase of gut barrier permeability without causing overt spontaneous inflammation. Administration of indomethacin, a non-steroidal anti-inflammatory drug (NSAID) that causes enteritis, led to rapid and restricted proximal small intestinal injuries in Gata4 mutant mice as opposed to control mice. Comparative analysis of gene transcript profiles from indomethacin-challenged control and Gata4 mutant mice identified defects in epithelial cell survival, inflammatory cell recruitment and tissue repair mechanisms. Altogether, these observations identify Gata4 as a novel crucial regulator of the intestinal epithelial barrier and as a critical epithelial transcription factor implicated in the maintenance of proximal intestinal mucosal integrity after injury.
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222
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Lallès JP. Microbiota-host interplay at the gut epithelial level, health and nutrition. J Anim Sci Biotechnol 2016; 7:66. [PMID: 27833747 PMCID: PMC5101664 DOI: 10.1186/s40104-016-0123-7] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 10/14/2016] [Indexed: 12/20/2022] Open
Abstract
Growing evidence suggests the implication of the gut microbiota in various facets of health and disease. In this review, the focus is put on microbiota-host molecular cross-talk at the gut epithelial level with special emphasis on two defense systems: intestinal alkaline phosphatase (IAP) and inducible heat shock proteins (iHSPs). Both IAP and iHSPs are induced by various microbial structural components (e.g. lipopolysaccharide, flagellin, CpG DNA motifs), metabolites (e.g. n-butyrate) or secreted signal molecules (e.g., toxins, various peptides, polyphosphate). IAP is produced in the small intestine and secreted into the lumen and in the interior milieu. It detoxifies microbial components by dephosphorylation and, therefore, down-regulates microbe-induced inflammation mainly by inhibiting NF-κB pro-inflammatory pathway in enterocytes. IAP gene expression and enzyme activity are influenced by the gut microbiota. Conversely, IAP controls gut microbiota composition both directly, and indirectly though the detoxification of pro-inflammatory free luminal adenosine triphosphate and inflammation inhibition. Inducible HSPs are expressed by gut epithelial cells in proportion to the microbial load along the gastro-intestinal tract. They are also induced by various microbial components, metabolites and secreted molecules. Whether iHSPs contribute to shape the gut microbiota is presently unknown. Both systems display strong anti-inflammatory and anti-oxidant properties that are protective to the gut and the host. Importantly, epithelial gene expressions and protein concentrations of IAP and iHSPs can be stimulated by probiotics, prebiotics and a large variety of dietary components, including macronutrients (protein and amino acids, especially L-glutamine, fat, fiber), and specific minerals (e.g. calcium) and vitamins (e.g. vitamins K1 and K2). Some food components (e.g. lectins, soybean proteins, various polyphenols) may inhibit or disturb these systems. The general cellular and molecular mechanisms involved in the microbiota-host epithelial crosstalk and subsequent gut protection through IAP and iHSPs are reviewed along with their nutritional modulation. Special emphasis is also given to the pig, an economically important species and valuable biomedical model.
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Affiliation(s)
- Jean-Paul Lallès
- Division of Human Nutrition Division, INRA Clermont-Ferrand, France ; Human Nutrition Research Center - West, Nantes, France ; Present Address: INRA - SDAR, Domaine de la Motte, B.P. 35327, F-35653 Le Rheu Cedex, France
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Abstract
The cause of Crohn’s disease (CD) has posed a conundrum for at least a century. A large body of work coupled with recent technological advances in genome research have at last started to provide some of the answers. Initially this review seeks to explain and to differentiate between bowel inflammation in the primary immunodeficiencies that generally lead to very early onset diffuse bowel inflammation in humans and in animal models, and the real syndrome of CD. In the latter, a trigger, almost certainly enteric infection by one of a multitude of organisms, allows the faeces access to the tissues, at which stage the response of individuals predisposed to CD is abnormal. Direct investigation of patients’ inflammatory response together with genome-wide association studies (GWAS) and DNA sequencing indicate that in CD the failure of acute inflammation and the clearance of bacteria from the tissues, and from within cells, is defective. The retained faecal products result in the characteristic chronic granulomatous inflammation and adaptive immune response. In this review I will examine the contemporary evidence that has led to this understanding, and look for explanations for the recent dramatic increase in the incidence of this disease.
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224
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Abstract
The cause of Crohn's disease (CD) has posed a conundrum for at least a century. A large body of work coupled with recent technological advances in genome research have at last started to provide some of the answers. Initially this review seeks to explain and to differentiate between bowel inflammation in the primary immunodeficiencies that generally lead to very early onset diffuse bowel inflammation in humans and in animal models, and the real syndrome of CD. In the latter, a trigger, almost certainly enteric infection by one of a multitude of organisms, allows the faeces access to the tissues, at which stage the response of individuals predisposed to CD is abnormal. Direct investigation of patients' inflammatory response together with genome-wide association studies (GWAS) and DNA sequencing indicate that in CD the failure of acute inflammation and the clearance of bacteria from the tissues, and from within cells, is defective. The retained faecal products result in the characteristic chronic granulomatous inflammation and adaptive immune response. In this review I will examine the contemporary evidence that has led to this understanding, and look for explanations for the recent dramatic increase in the incidence of this disease.
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225
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Bai JA, jie H, wei S, Wang S, Guo H, Tang Q. GART mediates the renewal of intestinal epithelial barrier via p38/p53/PUMA cascade in colitis. Apoptosis 2016; 21:1386-1397. [DOI: 10.1007/s10495-016-1301-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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226
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Składanowski M, Golinska P, Rudnicka K, Dahm H, Rai M. Evaluation of cytotoxicity, immune compatibility and antibacterial activity of biogenic silver nanoparticles. Med Microbiol Immunol 2016; 205:603-613. [PMID: 27620485 PMCID: PMC5093183 DOI: 10.1007/s00430-016-0477-7] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 09/05/2016] [Indexed: 01/14/2023]
Abstract
The study was focused on assessment of antibacterial activity, cytotoxicity and immune compatibility of biogenic silver nanoparticles (AgNPs) synthesized from Streptomyces sp. NH28 strain. Nanoparticles were biosynthesized and characterized by UV-Vis spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, nanoparticle tracking analysis system and zeta potential. Antibacterial activity was tested against Gram-positive and Gram-negative bacteria; minimal inhibitory concentration was recorded. Cytotoxicity was estimated using L929 mouse fibroblasts via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test. Biocompatibility of AgNPs was performed using THP1-XBlue™ cells. Biogenic AgNPs presented high antibacterial activity against all tested bacteria. Minimum inhibitory concentration of AgNPs against bacterial cells was found to be in range of 1.25-10 μg/mL. Silver nanoparticles did not show any harmful interaction to mouse fibroblast cell line, and no activation of nuclear factor kappa-light-chain-enhancer of activated B (NF-κB) cells was observed at concentration below 10 µg/mL. The half-maximal inhibitory concentration (IC50) value was established at 64.5 μg/mL. Biological synthesis of silver can be used as an effective system for formation of metal nanoparticles. Biosynthesized AgNPs can be used as an antibacterial agent, which can be safe for eukaryotic cells.
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Affiliation(s)
- M Składanowski
- Department of Microbiology, Nicolaus Copernicus University, Lwowska 1, Toruń, Poland
| | - P Golinska
- Department of Microbiology, Nicolaus Copernicus University, Lwowska 1, Toruń, Poland.
| | - K Rudnicka
- Gastroimmunology Lab., Department of Immunology and Infectious Biology, Institute of Microbiology, Biotechnology and Immunology, Faculty of Biology and Environmental Protection, University of Lódź, Banacha 12/16, Lodz, Poland
| | - H Dahm
- Department of Microbiology, Nicolaus Copernicus University, Lwowska 1, Toruń, Poland
| | - M Rai
- Nanobiotechnology Lab., Department of Biotechnology, S.G.B. Amravati University, Amravati, Maharashtra, India
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227
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Santisteban MM, Kim S, Pepine CJ, Raizada MK. Brain-Gut-Bone Marrow Axis: Implications for Hypertension and Related Therapeutics. Circ Res 2016; 118:1327-36. [PMID: 27081113 DOI: 10.1161/circresaha.116.307709] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 03/18/2016] [Indexed: 02/06/2023]
Abstract
Hypertension is the most prevalent modifiable risk factor for cardiovascular disease and disorders directly influencing cardiovascular disease morbidity and mortality, such as diabetes mellitus, chronic kidney disease, obstructive sleep apnea, etc. Despite aggressive attempts to influence lifestyle modifications and advances in pharmacotherapeutics, a large percentage of patients still do not achieve recommended blood pressure control worldwide. Thus, we think that mechanism-based novel strategies should be considered to significantly improve control and management of hypertension. The overall objective of this review is to summarize implications of peripheral- and neuroinflammation as well as the autonomic nervous system-bone marrow communication in hematopoietic cell homeostasis and their impact on hypertension pathophysiology. In addition, we discuss the novel and emerging field of intestinal microbiota and roles of gut permeability and dysbiosis in cardiovascular disease and hypertension. Finally, we propose a brain-gut-bone marrow triangular interaction hypothesis and discuss its potential in the development of novel therapies for hypertension.
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Affiliation(s)
- Monica M Santisteban
- From the Department of Physiology and Functional Genomics (M.M.S., S.K., M.K.R.) and Division of Cardiovascular Medicine, Department of Medicine (C.J.P.), College of Medicine, University of Florida, Gainesville
| | - Seungbum Kim
- From the Department of Physiology and Functional Genomics (M.M.S., S.K., M.K.R.) and Division of Cardiovascular Medicine, Department of Medicine (C.J.P.), College of Medicine, University of Florida, Gainesville
| | - Carl J Pepine
- From the Department of Physiology and Functional Genomics (M.M.S., S.K., M.K.R.) and Division of Cardiovascular Medicine, Department of Medicine (C.J.P.), College of Medicine, University of Florida, Gainesville
| | - Mohan K Raizada
- From the Department of Physiology and Functional Genomics (M.M.S., S.K., M.K.R.) and Division of Cardiovascular Medicine, Department of Medicine (C.J.P.), College of Medicine, University of Florida, Gainesville.
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228
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Direct Optofluidic Measurement of the Lipid Permeability of Fluoroquinolones. Sci Rep 2016; 6:32824. [PMID: 27604156 PMCID: PMC5015079 DOI: 10.1038/srep32824] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 08/11/2016] [Indexed: 11/17/2022] Open
Abstract
Quantifying drug permeability across lipid membranes is crucial for drug development. In addition, reduced membrane permeability is a leading cause of antibiotic resistance in bacteria, and hence there is a need for new technologies that can quantify antibiotic transport across biological membranes. We recently developed an optofluidic assay that directly determines the permeability coefficient of autofluorescent drug molecules across lipid membranes. Using ultraviolet fluorescence microscopy, we directly track drug accumulation in giant lipid vesicles as they traverse a microfluidic device while exposed to the drug. Importantly, our measurement does not require the knowledge of the octanol partition coefficient of the drug – we directly determine the permeability coefficient for the specific drug-lipid system. In this work, we report measurements on a range of fluoroquinolone antibiotics and find that their pH dependent lipid permeability can span over two orders of magnitude. We describe various technical improvements for our assay, and provide a new graphical user interface for data analysis to make the technology easier to use for the wider community.
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229
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Tontini GE, Pastorelli L, Ishaq S, Neumann H. Advances in endoscopic imaging in ulcerative colitis. Expert Rev Gastroenterol Hepatol 2016; 9:1393-405. [PMID: 26365308 DOI: 10.1586/17474124.2015.1087848] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Modern strategies for the treatment of ulcerative colitis require more accurate tools for gastrointestinal imaging to better assess mucosal disease activity and long-term prognostic clinical outcomes. Recent advances in gastrointestinal luminal endoscopy are radically changing the role of endoscopy in every-day clinical practice and research trials. Advanced endoscopic imaging techniques including high-definition endoscopes, optical magnification endoscopy, and various chromoendoscopy techniques have remarkably improved endoscopic assessment of ulcerative colitis. More recently, optical biopsy techniques with either endocytoscopy or confocal laser endomicroscopy have shown great potential in predicting several histological changes in real time during ongoing endoscopy. Here, we review current applications of advanced endoscopic imaging techniques in ulcerative colitis and present the most promising upcoming headways in this field.
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Affiliation(s)
- Gian Eugenio Tontini
- a 1 Gastroenterology and Digestive Endoscopy Unit, IRCCS Policlinico San Donato, San Donato Milanese, Italy
| | - Luca Pastorelli
- a 1 Gastroenterology and Digestive Endoscopy Unit, IRCCS Policlinico San Donato, San Donato Milanese, Italy.,b 2 Department of Biomedical Sciences for Health, University of Milan, Milano, Italy
| | - Sauid Ishaq
- c 3 Department of Gastroenterology, Dudley Group Hospitals, Birmingham City University, Birmingham, UK.,d 4 Department of Medicine, St. George's University, Grenada, West Indies
| | - Helmut Neumann
- e 5 Department of Medicine I, University of Erlangen-Nuremberg, Erlangen, Germany
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230
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Lee J, Moraes-Vieira PM, Castoldi A, Aryal P, Yee EU, Vickers C, Parnas O, Donaldson CJ, Saghatelian A, Kahn BB. Branched Fatty Acid Esters of Hydroxy Fatty Acids (FAHFAs) Protect against Colitis by Regulating Gut Innate and Adaptive Immune Responses. J Biol Chem 2016; 291:22207-22217. [PMID: 27573241 DOI: 10.1074/jbc.m115.703835] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Indexed: 12/25/2022] Open
Abstract
We recently discovered a structurally novel class of endogenous lipids, branched palmitic acid esters of hydroxy stearic acids (PAHSAs), with beneficial metabolic and anti-inflammatory effects. We tested whether PAHSAs protect against colitis, which is a chronic inflammatory disease driven predominantly by defects in the innate mucosal barrier and adaptive immune system. There is an unmet clinical need for safe and well tolerated oral therapeutics with direct anti-inflammatory effects. Wild-type mice were pretreated orally with vehicle or 5-PAHSA (10 mg/kg) and 9-PAHSA (5 mg/kg) once daily for 3 days, followed by 10 days of either 0% or 2% dextran sulfate sodium water with continued vehicle or PAHSA treatment. The colon was collected for histopathology, gene expression, and flow cytometry. Intestinal crypt fractions were prepared for ex vivo bactericidal assays. Bone marrow-derived dendritic cells pretreated with vehicle or PAHSA and splenic CD4+ T cells from syngeneic mice were co-cultured to assess antigen presentation and T cell activation in response to LPS. PAHSA treatment prevented weight loss, improved colitis scores (stool consistency, hematochezia, and mouse appearance), and augmented intestinal crypt Paneth cell bactericidal potency via a mechanism that may involve GPR120. In vitro, PAHSAs attenuated dendritic cell activation and subsequent T cell proliferation and Th1 polarization. The anti-inflammatory effects of PAHSAs in vivo resulted in reduced colonic T cell activation and pro-inflammatory cytokine and chemokine expression. These anti-inflammatory effects appear to be partially GPR120-dependent. We conclude that PAHSA treatment regulates innate and adaptive immune responses to prevent mucosal damage and protect against colitis. Thus, PAHSAs may be a novel treatment for colitis and related inflammation-driven diseases.
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Affiliation(s)
- Jennifer Lee
- From the Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and
| | - Pedro M Moraes-Vieira
- From the Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and
| | - Angela Castoldi
- From the Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and
| | - Pratik Aryal
- From the Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and
| | - Eric U Yee
- Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215
| | - Christopher Vickers
- the Clayton Foundation Laboratories for Peptide Biology, Helmsley Center for Genomic Medicine, Salk Institute for Biological Studies, La Jolla, California 92037, and
| | - Oren Parnas
- the Broad Institute of the Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts 02142
| | - Cynthia J Donaldson
- the Clayton Foundation Laboratories for Peptide Biology, Helmsley Center for Genomic Medicine, Salk Institute for Biological Studies, La Jolla, California 92037, and
| | - Alan Saghatelian
- the Clayton Foundation Laboratories for Peptide Biology, Helmsley Center for Genomic Medicine, Salk Institute for Biological Studies, La Jolla, California 92037, and
| | - Barbara B Kahn
- From the Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and
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231
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Ugalde-Silva P, Gonzalez-Lugo O, Navarro-Garcia F. Tight Junction Disruption Induced by Type 3 Secretion System Effectors Injected by Enteropathogenic and Enterohemorrhagic Escherichia coli. Front Cell Infect Microbiol 2016; 6:87. [PMID: 27606286 PMCID: PMC4995211 DOI: 10.3389/fcimb.2016.00087] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 08/10/2016] [Indexed: 12/18/2022] Open
Abstract
The intestinal epithelium consists of a single cell layer, which is a critical selectively permeable barrier to both absorb nutrients and avoid the entry of potentially harmful entities, including microorganisms. Epithelial cells are held together by the apical junctional complexes, consisting of adherens junctions, and tight junctions (TJs), and by underlying desmosomes. TJs lay in the apical domain of epithelial cells and are mainly composed by transmembrane proteins such as occludin, claudins, JAMs, and tricellulin, that are associated with the cytoplasmic plaque formed by proteins from the MAGUK family, such as ZO-1/2/3, connecting TJ to the actin cytoskeleton, and cingulin and paracingulin connecting TJ to the microtubule network. Extracellular bacteria such as EPEC and EHEC living in the intestinal lumen inject effectors proteins directly from the bacterial cytoplasm to the host cell cytoplasm, where they play a relevant role in the manipulation of the eukaryotic cell functions by modifying or blocking cell signaling pathways. TJ integrity depends on various cell functions such as actin cytoskeleton, microtubule network for vesicular trafficking, membrane integrity, inflammation, and cell survival. EPEC and EHEC effectors target most of these functions. Effectors encoded inside or outside of locus of enterocyte effacement (LEE) disrupt the TJ strands. EPEC and EHEC exploit the TJ dynamics to open this structure, for causing diarrhea. EPEC and EHEC secrete effectors that mimic host proteins to manipulate the signaling pathways, including those related to TJ dynamics. In this review, we focus on the known mechanisms exploited by EPEC and EHEC effectors for causing TJ disruption.
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Affiliation(s)
- Paul Ugalde-Silva
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional México City, Mexico
| | - Octavio Gonzalez-Lugo
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional México City, Mexico
| | - Fernando Navarro-Garcia
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional México City, Mexico
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232
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Williams KM, Gokulan K, Cerniglia CE, Khare S. Size and dose dependent effects of silver nanoparticle exposure on intestinal permeability in an in vitro model of the human gut epithelium. J Nanobiotechnology 2016; 14:62. [PMID: 27465730 PMCID: PMC4963959 DOI: 10.1186/s12951-016-0214-9] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 07/11/2016] [Indexed: 12/12/2022] Open
Abstract
Background The antimicrobial activity of silver nanoparticles (AgNP) has led to interest in their use in consumer products such as food contact materials, utensils, and storage containers. Incorporation of these materials into items intended for food processing and storage suggests that consumer use of these products could result in gastrointestinal exposure to AgNP, should the nanoparticles migrate from the product. The health impact of AgNP exposure is unknown, especially effects related to intestinal epithelial permeability and barrier function. This study examined the effects of AgNP exposure of different sizes (10, 20, 75 and 110 nm) and doses (20 and 100 µg/mL) on the permeability of T84 human colonic epithelial cells, which serve as an in vitro model of the human gut epithelium. Results Results showed that effects of AgNP on the T84 epithelial cells were size- and dose-dependent, with the 10 nm AgNP causing the most significant changes. Changes in permeability of the epithelial cell monolayer, as measured by transepithelial electrical resistance, after exposure to 10 nm AgNP were most dramatic at the highest dose (100 µg/mL), but also observed at the lower dose (20 µg/mL). AgNP could be visualized inside cells using transmission electron microscopy and silver was detected in basal wells using inductively coupled plasma-mass spectrometry. Exposure to AgNP significantly affected the expression of genes involved in anchoring tight junctions, cellular proliferation and signaling, endocytosis, and cell–cell adhesion, with the 10 nm AgNP having the greatest effect. Conclusions The results of this study show that small-size AgNP have significant effects on intestinal permeability in an in vitro model of the human gastrointestinal epithelium. Such effects have the potential to compromise the integrity of the intestinal epithelium and this disruption of barrier function could have health consequences for the gastrointestinal tract. Electronic supplementary material The online version of this article (doi:10.1186/s12951-016-0214-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Katherine M Williams
- Division of Microbiology, National Center for Toxicological Research, US Food and Drug Administration, 3900 NCTR Rd, Jefferson, AR, 72079, USA
| | - Kuppan Gokulan
- Division of Microbiology, National Center for Toxicological Research, US Food and Drug Administration, 3900 NCTR Rd, Jefferson, AR, 72079, USA
| | - Carl E Cerniglia
- Division of Microbiology, National Center for Toxicological Research, US Food and Drug Administration, 3900 NCTR Rd, Jefferson, AR, 72079, USA
| | - Sangeeta Khare
- Division of Microbiology, National Center for Toxicological Research, US Food and Drug Administration, 3900 NCTR Rd, Jefferson, AR, 72079, USA.
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233
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Volynets V, Rings A, Bárdos G, Ostaff MJ, Wehkamp J, Bischoff SC. Intestinal barrier analysis by assessment of mucins, tight junctions, and α-defensins in healthy C57BL/6J and BALB/cJ mice. Tissue Barriers 2016; 4:e1208468. [PMID: 27583194 DOI: 10.1080/21688370.2016.1208468] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 06/21/2016] [Accepted: 06/25/2016] [Indexed: 12/23/2022] Open
Abstract
The intestinal barrier is gaining increasing attention because it is related to intestinal homeostasis and disease. Different parameters have been used in the past to assess intestinal barrier functions in experimental studies; however most of them are poorly defined in healthy mice. Here, we compared a number of barrier markers in healthy mice, established normal values and correlations. In 48 mice (24 C57BL/6J, 24 BALB/cJ background), we measured mucus thickness, and expression of mucin-2, α-defensin-1 and -4, zonula occludens-1, occludin, junctional adhesion molecule-A, claudin-1, 2 and -5. We also analyzed claudin-3 and fatty acid binding protein-2 in urine and plasma, respectively. A higher expression of mucin-2 protein was found in the colon compared to the ileum. In contrast, the α-defensins-1 and -4 were expressed almost exclusively in the ileum. The protein expression of the tight junction molecules claudin-1, occludin and zonula occludens-1 did not differ between colon and ileum, although some differences occurred at the mRNA level. No age- or gender-related differences were found. Differences between C57BL/6J and BALB/cJ mice were found for α-defensin-1 and -4 mRNA expression, and for urine and plasma marker concentrations. The α-defensin-1 mRNA correlated with claudin-5 mRNA, whereas α-defensin-4 mRNA correlated with claudin-3 concentrations in urine. In conclusion, we identified a number of murine intestinal barrier markers requiring tissue analyses or measurable in urine or plasma. We provide normal values for these markers in mice of different genetic background. Such data might be helpful for future animal studies in which the intestinal barrier is of interest.
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Affiliation(s)
- Valentina Volynets
- Department of Nutritional Medicine, University of Hohenheim , Stuttgart, Germany
| | - Andreas Rings
- Department of Nutritional Medicine, University of Hohenheim , Stuttgart, Germany
| | - Gyöngyi Bárdos
- Department of Nutritional Medicine, University of Hohenheim , Stuttgart, Germany
| | - Maureen J Ostaff
- University of Colorado, Anschutz Medical Campus , Denver, CO, USA
| | - Jan Wehkamp
- Department of Internal Medicine, University of Tübingen , Tübingen, Germany
| | - Stephan C Bischoff
- Department of Nutritional Medicine, University of Hohenheim , Stuttgart, Germany
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234
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Briskey D, Tucker PS, Johnson DW, Coombes JS. Microbiota and the nitrogen cycle: Implications in the development and progression of CVD and CKD. Nitric Oxide 2016; 57:64-70. [DOI: 10.1016/j.niox.2016.05.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 04/11/2016] [Accepted: 05/04/2016] [Indexed: 02/07/2023]
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235
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Abstract
PURPOSE OF REVIEW Inflammatory bowel diseases (IBDs) are idiopathic chronic relapsing disorders of the gastrointestinal tract of unknown origin, characterized by heterogeneity and a multifactorial nature of their pathogenesis. Despite the recent improved options for treatment, patients with IBD still have an impaired quality of life, and require hospitalization and surgery. This review examines the contribution of animal models to the understanding and treatment of IBD. RECENT FINDINGS During the last decades, a large number of experimental models of intestinal inflammation have been developed. These models have proved to be helpful tools for obtaining new insights in the pathogenesis of the disease and for the preclinical evaluation of new therapies. However, even with the development of many new animal models in recent years, there are still limitations in the study of IBD because of lack of suitable animal models to cover all the requirements of basic research and preclinical studies. SUMMARY There is a need for a better interpretation of the data we obtain from the study of IBD animal models, in order to better understand the underlying pathogenetic mechanisms and improve the quality of the preclinical studies, and to develop more appropriate models to cover the research requirements.
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236
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Blumberg JB, Basu A, Krueger CG, Lila MA, Neto CC, Novotny JA, Reed JD, Rodriguez-Mateos A, Toner CD. Impact of Cranberries on Gut Microbiota and Cardiometabolic Health: Proceedings of the Cranberry Health Research Conference 2015. Adv Nutr 2016; 7:759S-70S. [PMID: 27422512 PMCID: PMC4942875 DOI: 10.3945/an.116.012583] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Recent advances in cranberry research have expanded the evidence for the role of this Vaccinium berry fruit in modulating gut microbiota function and cardiometabolic risk factors. The A-type structure of cranberry proanthocyanidins seems to be responsible for much of this fruit's efficacy as a natural antimicrobial. Cranberry proanthocyanidins interfere with colonization of the gut by extraintestinal pathogenic Escherichia coli in vitro and attenuate gut barrier dysfunction caused by dietary insults in vivo. Furthermore, new studies indicate synergy between these proanthocyanidins, other cranberry components such as isoprenoids and xyloglucans, and gut microbiota. Together, cranberry constituents and their bioactive catabolites have been found to contribute to mechanisms affecting bacterial adhesion, coaggregation, and biofilm formation that may underlie potential clinical benefits on gastrointestinal and urinary tract infections, as well as on systemic anti-inflammatory actions mediated via the gut microbiome. A limited but growing body of evidence from randomized clinical trials reveals favorable effects of cranberry consumption on measures of cardiometabolic health, including serum lipid profiles, blood pressure, endothelial function, glucoregulation, and a variety of biomarkers of inflammation and oxidative stress. These results warrant further research, particularly studies dedicated to the elucidation of dose-response relations, pharmacokinetic/metabolomics profiles, and relevant biomarkers of action with the use of fully characterized cranberry products. Freeze-dried whole cranberry powder and a matched placebo were recently made available to investigators to facilitate such work, including interlaboratory comparability.
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Affiliation(s)
- Jeffrey B Blumberg
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA;
| | | | - Christian G Krueger
- Complete Phytochemical Solutions, LLC, Cambridge, WI; University of Wisconsin-Madison, Madison, WI
| | | | | | - Janet A Novotny
- USDA Beltsville Human Nutrition Research Center, Beltsville, MD
| | - Jess D Reed
- Complete Phytochemical Solutions, LLC, Cambridge, WI; University of Wisconsin-Madison, Madison, WI
| | | | - Cheryl D Toner
- The Cranberry Institute, Carver, MA; and CDT Consulting, LLC, Herndon, VA
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237
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Brégeon J, Coron E, Da Silva ACC, Jaulin J, Aubert P, Chevalier J, Vergnolle N, Meurette G, Neunlist M. Sacral nerve stimulation enhances early intestinal mucosal repair following mucosal injury in a pig model. J Physiol 2016; 594:4309-23. [PMID: 26939757 DOI: 10.1113/jp271783] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 02/19/2016] [Indexed: 12/12/2022] Open
Abstract
KEY POINTS Reducing intestinal epithelial barrier (IEB) dysfunctions is recognized as being of major therapeutic interest for various intestinal disorders. Sacral nerve stimulation (SNS) is known to reduce IEB permeability. Here, we report in a pig model that SNS enhances morphological and functional recovery of IEB following mucosal injury induced via 2,4,6-trinitrobenzenesulfonic acid. These effects are associated with an increased expression of tight junction proteins such as ZO-1 and FAK. These results establish that SNS enhances intestinal barrier repair in acute mucosal injury. They further set the scientific basis for future use of SNS as a complementary or alternative therapeutic option for the treatment of gut disorders with IEB dysfunctions such as inflammatory bowel diseases or irritable bowel syndrome. ABSTRACT Intestinal epithelial barrier (IEB) dysfunctions, such as increased permeability or altered healing, are central to intestinal disorders. Sacral nerve stimulation (SNS) is known to reduce IEB permeability, but its ability to modulate IEB repair remains unknown. This study aimed to characterize the impact of SNS on mucosal repair following 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced lesions. Six pigs were stimulated by SNS 3 h prior to and 3 h after TNBS enema, while sham animals (n = 8) were not stimulated. The impact of SNS on mucosal changes was evaluated by combining in vivo imaging, histological and functional methods. Biochemical and transcriptomic approaches were used to analyse the IEB and mucosal inflammatory response. We observed that SNS enhanced the recovery from TNBS-induced increase in transcellular permeability. At 24 h, TNBS-induced alterations of mucosal morphology were significantly less in SNS compared with sham animals. SNS reduced TNBS-induced changes in ZO-1 expression and its epithelial pericellular distribution, and also increased pFAK/FAK expression compared with sham. Interestingly, SNS increased the mucosal density of neutrophils, which was correlated with an increase in trypsin and TGF-β1 levels compared with sham. Finally, SNS prevented the TNBS-induced increases in IL-1β and IL-4 over time that were observed with sham treatment. In conclusion, our results show that SNS enhances mucosal repair following injury. This study highlights novel mechanisms of action of SNS and identifies SNS as a new therapy for diseases with IEB repair disorders.
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Affiliation(s)
- Jérémy Brégeon
- INSERM, U913, Nantes, F-44093, France.,Université Nantes, Nantes, F-44093, France.,CHU Nantes, Hôtel Dieu, Institut des Maladies de l'Appareil Digestif, F-44093, France
| | - Emmanuel Coron
- INSERM, U913, Nantes, F-44093, France.,Université Nantes, Nantes, F-44093, France.,CHU Nantes, Hôtel Dieu, Institut des Maladies de l'Appareil Digestif, F-44093, France
| | - Anna Christina Cordeiro Da Silva
- INSERM, U913, Nantes, F-44093, France.,Université Nantes, Nantes, F-44093, France.,CHU Nantes, Hôtel Dieu, Institut des Maladies de l'Appareil Digestif, F-44093, France
| | - Julie Jaulin
- INSERM, U913, Nantes, F-44093, France.,Université Nantes, Nantes, F-44093, France.,CHU Nantes, Hôtel Dieu, Institut des Maladies de l'Appareil Digestif, F-44093, France
| | - Philippe Aubert
- INSERM, U913, Nantes, F-44093, France.,Université Nantes, Nantes, F-44093, France.,CHU Nantes, Hôtel Dieu, Institut des Maladies de l'Appareil Digestif, F-44093, France
| | - Julien Chevalier
- INSERM, U913, Nantes, F-44093, France.,Université Nantes, Nantes, F-44093, France.,CHU Nantes, Hôtel Dieu, Institut des Maladies de l'Appareil Digestif, F-44093, France
| | | | - Guillaume Meurette
- INSERM, U913, Nantes, F-44093, France.,Université Nantes, Nantes, F-44093, France.,CHU Nantes, Hôtel Dieu, Institut des Maladies de l'Appareil Digestif, F-44093, France
| | - Michel Neunlist
- INSERM, U913, Nantes, F-44093, France.,Université Nantes, Nantes, F-44093, France.,CHU Nantes, Hôtel Dieu, Institut des Maladies de l'Appareil Digestif, F-44093, France
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238
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Chen F, Cao A, Yao S, Evans-Marin HL, Liu H, Wu W, Carlsen ED, Dann SM, Soong L, Sun J, Zhao Q, Cong Y. mTOR Mediates IL-23 Induction of Neutrophil IL-17 and IL-22 Production. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2016; 196:4390-9. [PMID: 27067005 PMCID: PMC4868807 DOI: 10.4049/jimmunol.1501541] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 03/11/2016] [Indexed: 12/31/2022]
Abstract
It has been shown recently that neutrophils are able to produce IL-22 and IL-17, which differentially regulate the pathogenesis of inflammatory bowel disease. However, it is still largely unknown how the neutrophil production of IL-22 and IL-17 is regulated, and their role in the pathogenesis of inflammatory bowel disease. In this study, we found that IL-23 promoted neutrophil production of IL-17 and IL-22. IL-23 stimulated the neutrophil expression of IL-23R as well as rorc and ahr. Retinoid acid receptor-related orphan receptor γ t and aryl-hydrocarbon receptor differentially regulated IL-23 induction of neutrophil IL-17 and IL-22. In addition, IL-23 induced the activation of mTOR in neutrophils. Blockade of the mTOR pathway inhibited IL-23-induced expression of rorc and ahr, as well as IL-17 and IL-22 production. By using a microbiota Ag-specific T cell-mediated colitis model, we demonstrated that depletion of neutrophils, as well as blockade of IL-22, resulted in a significant increase in the severity of colitis, thereby indicating a protective role of neutrophils and IL-22 in chronic colitis. Collectively, our data revealed that neutrophils negatively regulate microbiota Ag-specific T cell induction of colitis, and IL-23 induces neutrophil production of IL-22 and IL-17 through induction of rorc and ahr, which is mediated by the mTOR pathway.
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MESH Headings
- Animals
- Cecum/pathology
- Cell Differentiation
- Colitis/immunology
- Colitis/pathology
- Colon/pathology
- Interleukin-17/biosynthesis
- Interleukin-23/metabolism
- Interleukin-23/pharmacology
- Interleukins/biosynthesis
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Neutrophils/metabolism
- Nuclear Receptor Subfamily 1, Group F, Member 3/genetics
- Nuclear Receptor Subfamily 1, Group F, Member 3/metabolism
- Phosphatidylinositol 3-Kinases/metabolism
- Receptors, Aryl Hydrocarbon/genetics
- Receptors, Aryl Hydrocarbon/metabolism
- Receptors, Interleukin/genetics
- Receptors, Interleukin/metabolism
- Signal Transduction
- TOR Serine-Threonine Kinases/genetics
- Th17 Cells/immunology
- Interleukin-22
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Affiliation(s)
- Feidi Chen
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555
| | - Anthony Cao
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555
| | - Suxia Yao
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555
| | - Heather L Evans-Marin
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555
| | - Han Liu
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555; Department of Gastroenterology, The Qilu Hospital, Shandong University, Shandong 250012, China
| | - Wei Wu
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555; Department of Gastroenterology, The Shanghai Tenth People's Hospital, Tongji University, Shanghai 200072, China
| | - Eric D Carlsen
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555; Department of Medicine, University of Texas Medical Branch, Galveston, TX 77555; and
| | - Sara M Dann
- Department of Medicine, University of Texas Medical Branch, Galveston, TX 77555; and
| | - Lynn Soong
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555; Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555
| | - Jiaren Sun
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555
| | | | - Yingzi Cong
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555; Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555;
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Abstract
The present review examines the pig as a model for physiological studies in human subjects related to nutrient sensing, appetite regulation, gut barrier function, intestinal microbiota and nutritional neuroscience. The nutrient-sensing mechanisms regarding acids (sour), carbohydrates (sweet), glutamic acid (umami) and fatty acids are conserved between humans and pigs. In contrast, pigs show limited perception of high-intensity sweeteners and NaCl and sense a wider array of amino acids than humans. Differences on bitter taste may reflect the adaptation to ecosystems. In relation to appetite regulation, plasma concentrations of cholecystokinin and glucagon-like peptide-1 are similar in pigs and humans, while peptide YY in pigs is ten to twenty times higher and ghrelin two to five times lower than in humans. Pigs are an excellent model for human studies for vagal nerve function related to the hormonal regulation of food intake. Similarly, the study of gut barrier functions reveals conserved defence mechanisms between the two species particularly in functional permeability. However, human data are scant for some of the defence systems and nutritional programming. The pig model has been valuable for studying the changes in human microbiota following nutritional interventions. In particular, the use of human flora-associated pigs is a useful model for infants, but the long-term stability of the implanted human microbiota in pigs remains to be investigated. The similarity of the pig and human brain anatomy and development is paradigmatic. Brain explorations and therapies described in pig, when compared with available human data, highlight their value in nutritional neuroscience, particularly regarding functional neuroimaging techniques.
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240
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Park K. Visualization of focal permeation sites within epithelial barriers. J Control Release 2016; 229:200. [PMID: 27109066 DOI: 10.1016/j.jconrel.2016.04.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Kinam Park
- Purdue University, Departments of Biomedical Engineering and Pharmaceutics, West Lafayette, IN 47907, USA.
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241
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Tulic MK, Vivinus-Nébot M, Rekima A, Rabelo Medeiros S, Bonnart C, Shi H, Walker A, Dainese R, Boyer J, Vergnolle N, Piche T, Verhasselt V. Presence of commensal house dust mite allergen in human gastrointestinal tract: a potential contributor to intestinal barrier dysfunction. Gut 2016; 65:757-66. [PMID: 26646935 DOI: 10.1136/gutjnl-2015-310523] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 11/05/2015] [Indexed: 12/15/2022]
Abstract
BACKGROUND Abnormal gut barrier function is the basis of gut inflammatory disease. It is known that house dust mite (HDM) aero-allergens induce inflammation in respiratory mucosa. We have recently reported allergen from Dermatophagoides pteronyssinus (Der p1) to be present in rodent gut. OBJECTIVE To examine whether Der p1 is present in human gut and to assess its effect on gut barrier function and inflammation. DESIGN Colonic biopsies, gut fluid, serum and stool were collected from healthy adults during endoscopy. Der p1 was measured by ELISA. Effect of HDM was assessed on gut permeability, tight-junction and mucin expression, and cytokine production, in presence or absence of cysteine protease inhibitors or serine protease inhibitors. In vivo effect of HDM was examined in mice given oral HDM or protease-neutralised HDM. Role of HDM in low-grade inflammation was studied in patients with IBS. RESULTS HDM Der p1 was detected in the human gut. In colonic biopsies from healthy patients, HDM increased epithelial permeability (p<0.001), reduced expression of tight-junction proteins and mucus barrier. These effects were associated with increased tumour necrosis factor (TNF)-α and interleukin (IL)-10 production and were abolished by cysteine-protease inhibitor (p<0.01). HDM effects did not require Th2 immunity. Results were confirmed in vivo in mice. In patients with IBS, HDM further deteriorated gut barrier function, induced TNF-α but failed to induce IL-10 secretion (p<0.001). CONCLUSIONS HDM, a ubiquitous environmental factor, is present in the human gut where it directly affects gut function through its proteolytic activity. HDM may be an important trigger of gut dysfunction and warrants further investigation.
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Affiliation(s)
- Meri K Tulic
- Université de Nice Sophia-Antipolis, EA 6302 Immune Tolerance (TIM), Nice, France The International Inflammation 'in-FLAME' Network, Worldwide Universities Network
| | - Mylene Vivinus-Nébot
- Université de Nice Sophia-Antipolis, EA 6302 Immune Tolerance (TIM), Nice, France Department of Immunology, Hôpital Archet 1, CHU de Nice, Université de Nice Sophia-Antipolis, Nice, France
| | - Akila Rekima
- Université de Nice Sophia-Antipolis, EA 6302 Immune Tolerance (TIM), Nice, France
| | - Samara Rabelo Medeiros
- Université de Nice Sophia-Antipolis, EA 6302 Immune Tolerance (TIM), Nice, France Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Chrystelle Bonnart
- INSERM U1043, Centre de Physiopathologie de Toulouse Purpan (CPTP), Toulouse, France CNRS, U5282, Toulouse, France Université de Toulouse, Site Paul Sabatier (UPS), Toulouse, France
| | - Haining Shi
- Mucosal Immunology and Biology Research Center, Massachusetts General Hospital, Charlestown, Massachusetts, USA
| | - Allan Walker
- Mucosal Immunology and Biology Research Center, Massachusetts General Hospital, Charlestown, Massachusetts, USA
| | - Raffaella Dainese
- Université de Nice Sophia-Antipolis, EA 6302 Immune Tolerance (TIM), Nice, France Department of Gastroenterology and Nutrition, Hôpital Archet 2, CHU de Nice, Université de Nice Sophia-Antipolis, Nice, France
| | - Julien Boyer
- Université de Nice Sophia-Antipolis, EA 6302 Immune Tolerance (TIM), Nice, France Department of Gastroenterology and Nutrition, Hôpital Archet 2, CHU de Nice, Université de Nice Sophia-Antipolis, Nice, France
| | - Nathalie Vergnolle
- INSERM U1043, Centre de Physiopathologie de Toulouse Purpan (CPTP), Toulouse, France CNRS, U5282, Toulouse, France Université de Toulouse, Site Paul Sabatier (UPS), Toulouse, France
| | - Thierry Piche
- Université de Nice Sophia-Antipolis, EA 6302 Immune Tolerance (TIM), Nice, France Department of Gastroenterology and Nutrition, Hôpital Archet 2, CHU de Nice, Université de Nice Sophia-Antipolis, Nice, France
| | - Valérie Verhasselt
- Université de Nice Sophia-Antipolis, EA 6302 Immune Tolerance (TIM), Nice, France The International Inflammation 'in-FLAME' Network, Worldwide Universities Network
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242
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Priyamvada S, Anbazhagan AN, Kumar A, Soni V, Alrefai WA, Gill RK, Dudeja PK, Saksena S. Lactobacillus acidophilus stimulates intestinal P-glycoprotein expression via a c-Fos/c-Jun-dependent mechanism in intestinal epithelial cells. Am J Physiol Gastrointest Liver Physiol 2016; 310:G599-608. [PMID: 26867563 PMCID: PMC4836133 DOI: 10.1152/ajpgi.00210.2015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 02/05/2016] [Indexed: 02/08/2023]
Abstract
Our previous studies showed that Lactobacillus acidophilus (LA) culture supernatant (CS) increased P-glycoprotein [Pgp/multidrug resistance 1 (MDR1)] function, expression, and promoter activity in Caco-2 cells. The current studies were designed to elucidate the molecular mechanisms mediating the stimulatory effects of LA CS on Pgp promoter activity. Deletion analysis indicated that the LA CS response element(s) is located in the -172/+428-bp region, and sequence analysis of this region revealed three potential binding sites for c-Fos or c-Jun: proximal activating protein (AP) 1a (-119/-98 bp), distal AP1b (-99/-78 bp), and AP1c (+175/+196 bp). LA CS (24 h) showed an approximately twofold increase in the protein expression of c-Fos and c-Jun in Caco-2 cells. Electrophoretic mobility shift assay showed that LA CS markedly increased the binding of Caco-2 nuclear proteins to AP1a and AP1b, but not AP1c. The DNA-protein complex was completely eliminated by c-Fos antibody, while c-Jun antibody partially eliminated the complex. Chromatin immunoprecipitation analysis also showed that LA CS enhanced the association of c-Fos and c-Jun (by ∼4- and 1.5-fold, respectively) with endogenous Pgp promoter in Caco-2 cells (p-172/+1). Interestingly, overexpression of c-Fos or c-Jun activated Pgp promoter by nearly twofold each. This increase was further enhanced (∼14-fold) when c-Fos and c-Jun were simultaneously overexpressed, suggesting that the presence of one of these transcription factors potentiates the effect of the other. These studies, for the first time, provide evidence for the involvement of c-Fos/c-Jun in stimulation of Pgp gene expression by LA CS in the human intestine.
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Affiliation(s)
- Shubha Priyamvada
- 1Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois; and
| | - Arivarasu N. Anbazhagan
- 1Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois; and
| | - Anoop Kumar
- 1Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois; and
| | - Vikas Soni
- 1Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois; and
| | - Waddah A. Alrefai
- 1Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois; and ,2Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois
| | - Ravinder K. Gill
- 1Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois; and
| | - Pradeep K. Dudeja
- 1Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois; and ,2Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois
| | - Seema Saksena
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois; and
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243
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Volynets V, Reichold A, Bárdos G, Rings A, Bleich A, Bischoff SC. Assessment of the Intestinal Barrier with Five Different Permeability Tests in Healthy C57BL/6J and BALB/cJ Mice. Dig Dis Sci 2016; 61:737-46. [PMID: 26520109 DOI: 10.1007/s10620-015-3935-y] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 10/14/2015] [Indexed: 12/24/2022]
Abstract
BACKGROUND Intestinal permeability is thought to be of major relevance for digestive and nutrition-related diseases, and therefore has been studied in numerous mouse models of disease. However, it is unclear which tools are the preferable ones, and how normal values should be defined. AIMS To compare different in vivo permeability tests in healthy mice of commonly used genetic backgrounds. METHODS We assessed the intestinal barrier in male and female C57BL/6J and BALB/cJ mice of different ages, using four orally administered permeability markers, FITC-dextran 4000 (FITC-D4000) and ovalbumin (OVA) measured in plasma, and polyethylene glycol (PEG) and lactulose/mannitol (Lac/Man) measured in urine, and by assessing lipopolysaccharide (LPS) in portal vein plasma. RESULTS After gavage, FITC-D4000, OVA, Lac/Man, and PEG400, but not PEG4000, were detectable in plasma or urine. Female mice tended to have a higher permeability according to the FITC-D4000, OVA, and PEG400 tests, but the Lac/Man ratio was higher in males. No significant differences between the two mouse strains of young and old mice were observed except for mannitol recovery, which was higher in BALB/cJ mice compared to C57BL/6J mice (p < 0.05). Virtually no LPS was detected in healthy mice. For all markers, normal values have been defined based on 5th-95th percentile ranges of our data. CONCLUSION Selected oral permeability tests, such as FITC-D4000, OVA, PEG400, and Lac/Man, as well as LPS measurements in portal vein plasma, could be suitable for the evaluation of the intestinal barrier in mice, if used in a standardized way.
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Affiliation(s)
- Valentina Volynets
- Department of Nutritional Medicine, University of Hohenheim, Fruwirthstr. 12, 70593, Stuttgart, Germany
| | - Astrid Reichold
- Department of Nutritional Medicine, University of Hohenheim, Fruwirthstr. 12, 70593, Stuttgart, Germany
| | - Gyöngyi Bárdos
- Department of Nutritional Medicine, University of Hohenheim, Fruwirthstr. 12, 70593, Stuttgart, Germany
| | - Andreas Rings
- Department of Nutritional Medicine, University of Hohenheim, Fruwirthstr. 12, 70593, Stuttgart, Germany
| | - André Bleich
- Institute for Laboratory Animal Science and Central Animal Facility, Hannover Medical School, Hannover, Germany
| | - Stephan C Bischoff
- Department of Nutritional Medicine, University of Hohenheim, Fruwirthstr. 12, 70593, Stuttgart, Germany.
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244
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Abstract
PURPOSE OF REVIEW This article evaluates the current status of the gut barrier in gastrointestinal disorders. RECENT FINDINGS The gut barrier is a complex, multicomponent, interactive, and bidirectional entity that includes, but is not restricted to, the epithelial cell layer. Intestinal permeability, the phenomenon most readily and commonly studied, reflects just one (albeit an important one) function of the barrier that is intimately related to and interacts with luminal contents, including the microbiota. The mucosal immune response also influences barrier integrity; effects of inflammation per se must be accounted for in the interpretation of permeability studies in disease states. SUMMARY Although several aspects of barrier function can be assessed in man, one must be aware of exactly what a given test measures, as well as of its limitations. The temptation to employ results from a test of paracellular flux to imply a role for barrier dysfunction in disorders thought to be based on bacterial or macromolecular translocation must be resisted. Although changes in barrier function have been described in several gastrointestinal disorders, their primacy remains to be defined. At present, few studies support efficacy for an intervention that improves barrier function in altering the natural history of a disease process.
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245
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Quigley EMM. Overlapping irritable bowel syndrome and inflammatory bowel disease: less to this than meets the eye? Therap Adv Gastroenterol 2016; 9:199-212. [PMID: 26929782 PMCID: PMC4749858 DOI: 10.1177/1756283x15621230] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Though distinct in terms of pathology, natural history and therapeutic approach, irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) have some features in common. These include shared symptomatology and largely similar demographics. However, in most instances, clinical presentation, together with laboratory, imaging and endoscopic findings will readily permit the differentiation of active IBD from IBS. More problematic is the situation where a subject with IBD, in apparent remission, continues to complain of symptoms which, in aggregate, satisfy commonly employed criteria for the diagnosis of IBS. Access to methodologies, such the assay for levels of calprotectin in feces, now allows identification of ongoing inflammation in some such individuals and prompts appropriate therapy. More challenging is the IBD patient with persisting symptoms and no detectable evidence of inflammation; is this coincident IBS, IBS triggered by IBD or an even more subtle level of IBD activity unrecognized by available laboratory or imaging methods? Arguments can be advanced for each of these proposals; lacking definitive data, this issue remains unresolved. The occurrence of IBS-type symptoms in the IBD patient, together with some data suggesting a very subtle level of 'inflammation' or 'immune activation' in IBS, raises other questions: is IBS a prodromal form of IBD; and are IBS and IBD part of the spectrum of the same disease? All of the available evidence indicates that the answer to both these questions should be a resounding 'no'. Indeed, the whole issue of overlap between IBS and IBD should be declared moot given their differing pathophysiologies, contrasting natural histories and divergent treatment paths. The limited symptom repertoire of the gastrointestinal tract may well be fundamental to the apparent confusion that has, of late, bedeviled this area.
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246
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Ma TM, Xu N, Ma XD, Bai ZH, Tao X, Yan HC. Moxibustion regulates inflammatory mediators and colonic mucosal barrier in ulcerative colitis rats. World J Gastroenterol 2016; 22:2566-2575. [PMID: 26937144 PMCID: PMC4768202 DOI: 10.3748/wjg.v22.i8.2566] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Revised: 10/30/2015] [Accepted: 12/01/2015] [Indexed: 02/06/2023] Open
Abstract
AIM: To observe the efficacy and mechanism of grain-sized moxibustion at different acupoints in a rat model of ulcerative colitis (UC).
METHODS: Sprague-Dawley rats were randomly divided into control, UC model, grain-sized moxibustion at a single acupoint (CV 12), grain-sized moxibustion at two acupoints (CV 12 and CV 4), grain-sized moxibustion at three acupoints (CV 12, CV 4, and ST 36), and medication groups (n = 8/group). The UC model was established by enema of trinitrobenzene sulfonic acid. Direct moxibustion was used once a day for 7 d. Disease activity index (DAI) was evaluated before and after the treatment. Morphologic changes of intestinal tissue were observed under an optical microscope. The expression of tumor necrosis factor (TNF)-α and p38 mitogen-activated protein kinase (p38MAPK) in colonic tissue was detected using Western blot, and the levels of occludin and zonula occludens-1 (ZO-1) mRNAs were detected using reverse transcription PCR.
RESULTS: Compared with the control group, the intestinal mucosae were incomplete in the model group, glandular structures were irregular, and submucosae were edematous, hyperemic, and infiltrated with inflammatory cells. The DAI scores and expression of TNF-α and p38MAPK were increased significantly in the model group compared to controls (Ps < 0.01), while the mRNA levels of occludin and ZO-1 were reduced significantly (Ps < 0.01). Compared with the model group, colonic mucosa and the arrangement of glands were complete and regular in the treatment groups. DAI scores and the expression of TNF-α and p38MAPK were reduced significantly in moxibustion groups compared to controls (Ps < 0.01), while the mRNA levels of occludin and ZO-1 were increased significantly (Ps < 0.01). The improvements in the above indices in the three acupoints group and the medication group were superior to those in the single and two acupoints groups (all P < 0.05).
CONCLUSION: Reduction of TNF-α and p38MAPK and increased expression of occludin and ZO-1 in colonic tissue represent a potential mechanism for improved intestinal mucosal tissue repair with grain-sized moxibustion.
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Song ZH, Tong G, Xiao K, Jiao LF, Ke YL, Hu CH. L-cysteine protects intestinal integrity, attenuates intestinal inflammation and oxidant stress, and modulates NF-κB and Nrf2 pathways in weaned piglets after LPS challenge. Innate Immun 2016; 22:152-61. [PMID: 26921254 DOI: 10.1177/1753425916632303] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 01/18/2016] [Indexed: 12/24/2022] Open
Abstract
In this study we investigated whetherL-cysteine (L-cys) could alleviate LPS-induced intestinal disruption and its underlying mechanism. Piglets fed with anL-cys-supplemented diet had higher average daily gain.L-cys alleviated LPS-induced structural and functional disruption of intestine in weanling piglets, as demonstrated by higher villus height, villus height (VH) to crypt depth (CD) ratio, and transepithelial electrical resistance (TER) and lower FITC-dextran 4 (FD4) kDa flux in jejunum and ileum. Supplementation withL-cys up-regulated occludin and claudin-1 expression, reduced caspase-3 activity and enhanced proliferating cell nuclear antigen expression of jejunum and ileum relative to LPS group. Additionally,L-cys suppressed the LPS-induced intestinal inflammation and oxidative stress, as demonstrated by down-regulated TNF-α, IL-6 and IL-8 mRNA levels, increased catalase, superoxide dismutase, glutathione peroxidase activity, glutathione (GSH) contents and the ratio of GSH and oxidized glutathione in jejunum and ileum. Finally, a diet supplemented withL-cys inhibited NF-κB(p65) nuclear translocation and elevated NF erythroid 2-related factor 2 (Nrf2) translocation compared with the LPS group. Collectively, our results indicated the protective function ofL-cys on intestinal mucosa barrier may closely associated with its anti-inflammation, antioxidant and regulating effect on the NF-κB and Nrf2 signaling pathways.
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Affiliation(s)
- Ze he Song
- Animal Science College, Zhejiang University, The Key Laboratory of Molecular Animal Nutrition, Ministry of Education, Hangzhou 310058, China
| | - Guo Tong
- Department of Animal Husbandry and Veterinary Medicine, Beijing Vocational College of Agriculture, Beijing City, Beijing 102442, China
| | - Kan Xiao
- Animal Science College, Zhejiang University, The Key Laboratory of Molecular Animal Nutrition, Ministry of Education, Hangzhou 310058, China
| | - Le fei Jiao
- Animal Science College, Zhejiang University, The Key Laboratory of Molecular Animal Nutrition, Ministry of Education, Hangzhou 310058, China
| | - Ya lu Ke
- Animal Science College, Zhejiang University, The Key Laboratory of Molecular Animal Nutrition, Ministry of Education, Hangzhou 310058, China
| | - Cai hong Hu
- Animal Science College, Zhejiang University, The Key Laboratory of Molecular Animal Nutrition, Ministry of Education, Hangzhou 310058, China
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Arnal ME, Lallès JP. Gut epithelial inducible heat-shock proteins and their modulation by diet and the microbiota. Nutr Rev 2016; 74:181-97. [PMID: 26883882 DOI: 10.1093/nutrit/nuv104] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The epidemic of metabolic diseases has raised questions about the interplay between the human diet and the gut and its microbiota. The gut has two vital roles: nutrient absorption and intestinal barrier function. Gut barrier defects are involved in many diseases. Excess energy intake disturbs the gut microbiota and favors body entry of microbial compounds that stimulate chronic metabolic inflammation. In this context, the natural defense mechanisms of gut epithelial cells and the potential to boost them nutritionally warrant further study. One such important defense system is the activation of inducible heat-shock proteins (iHSPs) which protect the gut epithelium against oxidative stress and inflammation. Importantly, various microbial components can induce the expression of iHSPs. This review examines gut epithelial iHSPs as the main targets of microbial signals and nutrients and presents data on diseases involving disturbances of gut epithelial iHSPs. In addition, a broad literature analysis of dietary modulation of gut epithelial iHSPs is provided. Future research aims should include the identification of gut microbes that can optimize gut-protective iHSPs and the evaluation of iHSP-mediated health benefits of nutrients and food components.
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Affiliation(s)
- Marie-Edith Arnal
- M.E. Arnal and J.P. Lallès are with the Institut National de la Recherche Agronomique (INRA), Human Nutrition Division, Clermont-Ferrand, France. J.P. Lallès is with the Centre de Recherche en Nutrition Humaine Ouest, Nantes, France
| | - Jean-Paul Lallès
- M.E. Arnal and J.P. Lallès are with the Institut National de la Recherche Agronomique (INRA), Human Nutrition Division, Clermont-Ferrand, France. J.P. Lallès is with the Centre de Recherche en Nutrition Humaine Ouest, Nantes, France.
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Abstract
Microscopic colitis (MC) is a common cause of chronic diarrhea. The 2 most frequent forms of MC are collagenous colitis and lymphocytic colitis. Over the past years, the incidence and prevalence of microscopic colitis are rising and this is largely attributed to a greater awareness, and concomitantly an increasing number of diagnoses. Patients with microscopic colitis report watery, nonbloody diarrhea of chronic course, abdominal pain, weight loss, and fatigue that may impair patient's health-related quality of life. The underlying mechanisms involved in the pathogenesis of microscopic colitis remain unspecified but is probably multifactorial. Collagenous colitis and lymphocytic colitis may represent specific mucosal responses to different luminal agents in predisposed individuals, resulting in an uncontrolled immune response. Genetic predisposition, altered modulation of cytokines and miRNAs, and aberrant response to drugs seem to be involved in the development of MC. Despite the progress of knowledge, still many questions remain unsolved regarding the etiology, pathophysiology, and optimal management of MC. This review gives an update on the immunological aspects of collagenous colitis and lymphocytic colitis.
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López-Posadas R, Becker C, Günther C, Tenzer S, Amann K, Billmeier U, Atreya R, Fiorino G, Vetrano S, Danese S, Ekici AB, Wirtz S, Thonn V, Watson AJM, Brakebusch C, Bergö M, Neurath MF, Atreya I. Rho-A prenylation and signaling link epithelial homeostasis to intestinal inflammation. J Clin Invest 2016; 126:611-26. [PMID: 26752649 DOI: 10.1172/jci80997] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 11/18/2015] [Indexed: 01/08/2023] Open
Abstract
Although defects in intestinal barrier function are a key pathogenic factor in patients with inflammatory bowel diseases (IBDs), the molecular pathways driving disease-specific alterations of intestinal epithelial cells (IECs) are largely unknown. Here, we addressed this issue by characterizing the transcriptome of IECs from IBD patients using a genome-wide approach. We observed disease-specific alterations in IECs with markedly impaired Rho-A signaling in active IBD patients. Localization of epithelial Rho-A was shifted to the cytosol in IBDs, and inflammation was associated with suppressed Rho-A activation due to reduced expression of the Rho-A prenylation enzyme geranylgeranyltransferase-I (GGTase-I). Functionally, we found that mice with conditional loss of Rhoa or the gene encoding GGTase-I, Pggt1b, in IECs exhibit spontaneous chronic intestinal inflammation with accumulation of granulocytes and CD4+ T cells. This phenotype was associated with cytoskeleton rearrangement and aberrant cell shedding, ultimately leading to loss of epithelial integrity and subsequent inflammation. These findings uncover deficient prenylation of Rho-A as a key player in the pathogenesis of IBDs. As therapeutic triggering of Rho-A signaling suppressed intestinal inflammation in mice with GGTase-I-deficient IECs, our findings suggest new avenues for treatment of epithelial injury and mucosal inflammation in IBD patients.
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