1
|
Nickerson KP, Llanos-Chea A, Ingano L, Serena G, Miranda-Ribera A, Perlman M, Lima R, Sztein MB, Fasano A, Senger S, Faherty CS. A Versatile Human Intestinal Organoid-Derived Epithelial Monolayer Model for the Study of Enteric Pathogens. Microbiol Spectr 2021; 9:e0000321. [PMID: 34106568 PMCID: PMC8552518 DOI: 10.1128/spectrum.00003-21] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 04/20/2021] [Indexed: 01/09/2023] Open
Abstract
Gastrointestinal infections cause significant morbidity and mortality worldwide. The complexity of human biology and limited insights into host-specific infection mechanisms are key barriers to current therapeutic development. Here, we demonstrate that two-dimensional epithelial monolayers derived from human intestinal organoids, combined with in vivo-like bacterial culturing conditions, provide significant advancements for the study of enteropathogens. Monolayers from the terminal ileum, cecum, and ascending colon recapitulated the composition of the gastrointestinal epithelium, in which several techniques were used to detect the presence of enterocytes, mucus-producing goblet cells, and other cell types following differentiation. Importantly, the addition of receptor activator of nuclear factor kappa-B ligand (RANKL) increased the presence of M cells, critical antigen-sampling cells often exploited by enteric pathogens. For infections, bacteria were grown under in vivo-like conditions known to induce virulence. Overall, interesting patterns of tissue tropism and clinical manifestations were observed. Shigella flexneri adhered efficiently to the cecum and colon; however, invasion in the colon was best following RANKL treatment. Both Salmonella enterica serovars Typhi and Typhimurium displayed different infection patterns, with S. Typhimurium causing more destruction of the terminal ileum and S. Typhi infecting the cecum more efficiently than the ileum, particularly with regard to adherence. Finally, various pathovars of Escherichia coli validated the model by confirming only adherence was observed with these strains. This work demonstrates that the combination of human-derived tissue with targeted bacterial growth conditions enables powerful analyses of human-specific infections that could lead to important insights into pathogenesis and accelerate future vaccine development. IMPORTANCE While traditional laboratory techniques and animal models have provided valuable knowledge in discerning virulence mechanisms of enteric pathogens, the complexity of the human gastrointestinal tract has hindered our understanding of physiologically relevant, human-specific interactions; and thus, has significantly delayed successful vaccine development. The human intestinal organoid-derived epithelial monolayer (HIODEM) model closely recapitulates the diverse cell populations of the intestine, allowing for the study of human-specific infections. Differentiation conditions permit the expansion of various cell populations, including M cells that are vital to immune recognition and the establishment of infection by some bacteria. We provide details of reproducible culture methods and infection conditions for the analyses of Shigella, Salmonella, and pathogenic Escherichia coli in which tissue tropism and pathogen-specific infection patterns were detected. This system will be vital for future studies that explore infection conditions, health status, or epigenetic differences and will serve as a novel screening platform for therapeutic development.
Collapse
Affiliation(s)
- Kourtney P. Nickerson
- Mucosal Immunology and Biology Research Center, Division of Pediatric Gastroenterology and Nutrition, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Alejandro Llanos-Chea
- Mucosal Immunology and Biology Research Center, Division of Pediatric Gastroenterology and Nutrition, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Laura Ingano
- Mucosal Immunology and Biology Research Center, Division of Pediatric Gastroenterology and Nutrition, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Gloria Serena
- Mucosal Immunology and Biology Research Center, Division of Pediatric Gastroenterology and Nutrition, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Alba Miranda-Ribera
- Mucosal Immunology and Biology Research Center, Division of Pediatric Gastroenterology and Nutrition, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Meryl Perlman
- Mucosal Immunology and Biology Research Center, Division of Pediatric Gastroenterology and Nutrition, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Rosiane Lima
- Mucosal Immunology and Biology Research Center, Division of Pediatric Gastroenterology and Nutrition, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Marcelo B. Sztein
- Center for Vaccine Development and Global Health, Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Alessio Fasano
- Mucosal Immunology and Biology Research Center, Division of Pediatric Gastroenterology and Nutrition, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Stefania Senger
- Mucosal Immunology and Biology Research Center, Division of Pediatric Gastroenterology and Nutrition, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Christina S. Faherty
- Mucosal Immunology and Biology Research Center, Division of Pediatric Gastroenterology and Nutrition, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
2
|
Verma S, Prescott RA, Ingano L, Nickerson KP, Hill E, Faherty CS, Fasano A, Senger S, Cherayil BJ. The YrbE phospholipid transporter of Salmonella enterica serovar Typhi regulates the expression of flagellin and influences motility, adhesion and induction of epithelial inflammatory responses. Gut Microbes 2020; 11:526-538. [PMID: 31829769 PMCID: PMC7527071 DOI: 10.1080/19490976.2019.1697593] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
serovar Typhi is the etiologic agent of typhoid fever, a major public health problem in the developing world. Moving toward and adhering to the intestinal epithelium represents key initial steps of infection by S. Typhi. We examined the role of the S. Typhi yrbE gene, which encodes an inner membrane phospholipid transporter, in these interactions with epithelial cells. Disruption of yrbE resulted in elevated expression of flagellin and a hypermotile phenotype. It also significantly reduced the ability of S. Typhi to adhere to the HeLa epithelial cell line and to polarized primary epithelial cells derived from human ileal organoids. Interestingly, the yrbE-deficient strain of S. Typhi induced higher production of interleukin-8 from the primary human ileal epithelial cell monolayers compared to the wild-type bacteria. Deletion of the flagellin gene (fliC) in the yrbE-deficient S. Typhi inhibited motility and attenuated interleukin-8 production, but it did not correct the defect in adhesion. We also disrupted yrbE in S. Typhimurium. In contrast to the results in S. Typhi, the deficiency of yrbE in S. Typhimurium had no significant effect on flagellin expression, motility or adhesion to HeLa cells. Correspondingly, the lack of yrbE also had no effect on association with the intestine or the severity of intestinal inflammation in the mouse model of S. Typhimurium infection. Thus, our results point to an important and serovar-specific role played by yrbE in the early stages of intestinal infection by S. Typhi.
Collapse
Affiliation(s)
- Smriti Verma
- Mucosal Immunology and Biology Research Center, Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts, USA,Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Rachel A. Prescott
- Mucosal Immunology and Biology Research Center, Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Laura Ingano
- Mucosal Immunology and Biology Research Center, Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Kourtney P. Nickerson
- Mucosal Immunology and Biology Research Center, Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts, USA,Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Emily Hill
- Mucosal Immunology and Biology Research Center, Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Christina S. Faherty
- Mucosal Immunology and Biology Research Center, Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts, USA,Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Alessio Fasano
- Mucosal Immunology and Biology Research Center, Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts, USA,Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Stefania Senger
- Mucosal Immunology and Biology Research Center, Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts, USA,Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Bobby J. Cherayil
- Mucosal Immunology and Biology Research Center, Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts, USA,Department of Pediatrics, Harvard Medical School, Boston, MA, USA,CONTACT Bobby J. Cherayil Mucosal Immunology and Biology Research Center, Department of Pediatrics, Massachusetts General Hospital, Boston, MA, USA
| |
Collapse
|
3
|
Leonard MM, Bai Y, Serena G, Nickerson KP, Camhi S, Sturgeon C, Yan S, Fiorentino MR, Katz A, Nath B, Richter J, Sleeman M, Gurer C, Fasano A. RNA sequencing of intestinal mucosa reveals novel pathways functionally linked to celiac disease pathogenesis. PLoS One 2019; 14:e0215132. [PMID: 30998704 PMCID: PMC6472737 DOI: 10.1371/journal.pone.0215132] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 03/27/2019] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND & AIMS The early steps in the pathophysiology of celiac disease (CD) leading to loss of tolerance to gluten are poorly described. Our aim was to use RNA sequencing of duodenal biopsies in patients with active CD, CD in remission, and non-CD controls to gain insight into CD pathophysiology, identify additional genetic signatures linked to CD, and possibly uncover targets for future therapeutic agents. METHODS We performed whole transcriptome shotgun sequencing of intestinal biopsies in subjects with active and remission CD and non-CD controls. We also performed functional pathway analysis of differentially expressed genes to identify statistically significant pathways that are up or down regulated in subjects with active CD compared to remission CD. RESULTS We identified the upregulation of novel genes including IL12R, ITGAM and IGSF4 involved in the immune response machinery and cell adhesion process in the mucosa of subjects with active CD compared to those in remission. We identified a unique signature of genes, related to innate immunity, perturbed exclusively in CD irrespective of disease status. Finally, we highlight novel pathways of interest that may contribute to the early steps of CD pathogenesis and its comorbidities such as the spliceosome, pathways related to the innate immune response, and pathways related to autoimmunity. CONCLUSIONS Our study confirmed previous findings based on GWAS and immunological studies pertinent to CD pathogenesis and describes novel genes and pathways that with further validation may be found to contribute to the early steps in the pathogenesis of CD, ongoing inflammation, and comorbidities associated with CD.
Collapse
Affiliation(s)
- Maureen M. Leonard
- Mass General Hospital for Children and Division of Pediatric Gastroenterology and Nutrition, Harvard Medical School, Boston, Massachusetts, United States of America
- Center for Celiac Research and Treatment, Mucosal Immunology and Biology Research Center, Boston, Massachusetts, United States of America
- Celiac Research Program, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Yu Bai
- Regeneron Pharmaceuticals, Tarrytown, New York, United States of America
| | - Gloria Serena
- Center for Celiac Research and Treatment, Mucosal Immunology and Biology Research Center, Boston, Massachusetts, United States of America
- Celiac Research Program, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Kourtney P. Nickerson
- Center for Celiac Research and Treatment, Mucosal Immunology and Biology Research Center, Boston, Massachusetts, United States of America
| | - Stephanie Camhi
- Center for Celiac Research and Treatment, Mucosal Immunology and Biology Research Center, Boston, Massachusetts, United States of America
| | - Craig Sturgeon
- Graduate Program in Life Sciences, University of Maryland, Baltimore, Maryland, United States of America
| | - Shu Yan
- Center for Celiac Research and Treatment, Mucosal Immunology and Biology Research Center, Boston, Massachusetts, United States of America
| | - Maria R. Fiorentino
- Center for Celiac Research and Treatment, Mucosal Immunology and Biology Research Center, Boston, Massachusetts, United States of America
| | - Aubrey Katz
- Mass General Hospital for Children and Division of Pediatric Gastroenterology and Nutrition, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Barbara Nath
- Department of Gastroenterology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - James Richter
- Department of Gastroenterology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Matthew Sleeman
- Regeneron Pharmaceuticals, Tarrytown, New York, United States of America
| | - Cagan Gurer
- Regeneron Pharmaceuticals, Tarrytown, New York, United States of America
| | - Alessio Fasano
- Mass General Hospital for Children and Division of Pediatric Gastroenterology and Nutrition, Harvard Medical School, Boston, Massachusetts, United States of America
- Center for Celiac Research and Treatment, Mucosal Immunology and Biology Research Center, Boston, Massachusetts, United States of America
- Celiac Research Program, Harvard Medical School, Boston, Massachusetts, United States of America
| |
Collapse
|
4
|
Abstract
Biofilm formation is a dynamic, multistage process that occurs in bacteria under harsh environmental conditions or times of stress. For enteric pathogens, a significant stress response is induced during gastrointestinal transit and upon bile exposure, a normal component of human digestion. To overcome the bactericidal effects of bile, many enteric pathogens form a biofilm hypothesized to permit survival when transiting through the small intestine. Here we present methodologies to define biofilm formation through solid-phase adherence assays as well as extracellular polymeric substance (EPS) matrix detection and visualization. Furthermore, biofilm dispersion assessment is presented to mimic the analysis of events triggering release of bacteria during the infection process. Crystal violet staining is used to detect adherent bacteria in a high-throughput 96-well plate adherence assay. EPS production assessment is determined by two assays, namely microscopy staining of the EPS matrix and semi-quantitative analysis with a fluorescently-conjugated polysaccharide binding lectin. Finally, biofilm dispersion is measured through colony counts and plating. Positive data from multiple assays support the characterization of biofilms and can be utilized to identify bile salt-induced biofilm formation in other bacterial strains.
Collapse
Affiliation(s)
- Kourtney P Nickerson
- Mucosal Immunology and Biology Research Center, Division of Pediatric Gastroenterology and Nutrition, Massachusetts General Hospital; Department of Pediatrics, Harvard Medical School
| | - Christina S Faherty
- Mucosal Immunology and Biology Research Center, Division of Pediatric Gastroenterology and Nutrition, Massachusetts General Hospital; Department of Pediatrics, Harvard Medical School;
| |
Collapse
|
5
|
Nickerson KP, Senger S, Zhang Y, Lima R, Patel S, Ingano L, Flavahan WA, Kumar DKV, Fraser CM, Faherty CS, Sztein MB, Fiorentino M, Fasano A. Salmonella Typhi Colonization Provokes Extensive Transcriptional Changes Aimed at Evading Host Mucosal Immune Defense During Early Infection of Human Intestinal Tissue. EBioMedicine 2018; 31:92-109. [PMID: 29735417 PMCID: PMC6013756 DOI: 10.1016/j.ebiom.2018.04.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 04/02/2018] [Accepted: 04/05/2018] [Indexed: 12/29/2022] Open
Abstract
Commensal microorganisms influence a variety of host functions in the gut, including immune response, glucose homeostasis, metabolic pathways and oxidative stress, among others. This study describes how Salmonella Typhi, the pathogen responsible for typhoid fever, uses similar strategies to escape immune defense responses and survive within its human host. To elucidate the early mechanisms of typhoid fever, we performed studies using healthy human intestinal tissue samples and "mini-guts," organoids grown from intestinal tissue taken from biopsy specimens. We analyzed gene expression changes in human intestinal specimens and bacterial cells both separately and after colonization. Our results showed mechanistic strategies that S. Typhi uses to rearrange the cellular machinery of the host cytoskeleton to successfully invade the intestinal epithelium, promote polarized cytokine release and evade immune system activation by downregulating genes involved in antigen sampling and presentation during infection. This work adds novel information regarding S. Typhi infection pathogenesis in humans, by replicating work shown in traditional cell models, and providing new data that can be applied to future vaccine development strategies.
Collapse
Affiliation(s)
- K P Nickerson
- Department of Pediatric Gastroenterology, Mucosal Immunology and Biology Research Center, Massachusetts General Hospital, Boston, MA, United States; Department of Pediatrics, Harvard Medical School, Harvard University, Boston, MA, United States.
| | - S Senger
- Department of Pediatric Gastroenterology, Mucosal Immunology and Biology Research Center, Massachusetts General Hospital, Boston, MA, United States; Department of Pediatrics, Harvard Medical School, Harvard University, Boston, MA, United States
| | - Y Zhang
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, United States
| | - R Lima
- Department of Pediatric Gastroenterology, Mucosal Immunology and Biology Research Center, Massachusetts General Hospital, Boston, MA, United States
| | - S Patel
- Department of Pediatric Gastroenterology, Mucosal Immunology and Biology Research Center, Massachusetts General Hospital, Boston, MA, United States
| | - L Ingano
- Department of Pediatric Gastroenterology, Mucosal Immunology and Biology Research Center, Massachusetts General Hospital, Boston, MA, United States
| | - W A Flavahan
- Department of Pathology, Massachusetts General Hospital, Boston, MA, United States
| | - D K V Kumar
- Department for the Neuroscience of Genetics and Aging, Massachusetts General Hospital, Boston, MA, United States
| | - C M Fraser
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, United States
| | - C S Faherty
- Department of Pediatric Gastroenterology, Mucosal Immunology and Biology Research Center, Massachusetts General Hospital, Boston, MA, United States; Department of Pediatrics, Harvard Medical School, Harvard University, Boston, MA, United States
| | - M B Sztein
- Center for Vaccine Development, Department of Pediatrics, University of Maryland, Baltimore, MD, United States
| | - M Fiorentino
- Department of Pediatric Gastroenterology, Mucosal Immunology and Biology Research Center, Massachusetts General Hospital, Boston, MA, United States; Department of Pediatrics, Harvard Medical School, Harvard University, Boston, MA, United States
| | - A Fasano
- Department of Pediatric Gastroenterology, Mucosal Immunology and Biology Research Center, Massachusetts General Hospital, Boston, MA, United States; Department of Pediatrics, Harvard Medical School, Harvard University, Boston, MA, United States.
| |
Collapse
|
6
|
Rodriguez-Palacios A, Harding A, Menghini P, Himmelman C, Retuerto M, Nickerson KP, Lam M, Croniger CM, McLean MH, Durum SK, Pizarro TT, Ghannoum MA, Ilic S, McDonald C, Cominelli F. The Artificial Sweetener Splenda Promotes Gut Proteobacteria, Dysbiosis, and Myeloperoxidase Reactivity in Crohn's Disease-Like Ileitis. Inflamm Bowel Dis 2018; 24:1005-1020. [PMID: 29554272 PMCID: PMC5950546 DOI: 10.1093/ibd/izy060] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Indexed: 12/16/2022]
Abstract
Background Epidemiological studies indicate that the use of artificial sweeteners doubles the risk for Crohn's disease (CD). Herein, we experimentally quantified the impact of 6-week supplementation with a commercial sweetener (Splenda; ingredients sucralose maltodextrin, 1:99, w/w) on both the severity of CD-like ileitis and the intestinal microbiome alterations using SAMP1/YitFc (SAMP) mice. Methods Metagenomic shotgun DNA sequencing was first used to characterize the microbiome of ileitis-prone SAMP mice. Then, 16S rRNA microbiome sequencing, quantitative polymerase chain reaction, fluorescent in situ hybridization (FISH), bacterial culture, stereomicroscopy, histology, and myeloperoxidase (MPO) activity analyses were then implemented to compare the microbiome and ileitis phenotype in SAMP with that of control ileitis-free AKR/J mice after Splenda supplementation. Results Metagenomics indicated that SAMP mice have a gut microbial phenotype rich in Bacteroidetes, and experiments showed that Helicobacteraceae did not have an exacerbating effect on ileitis. Splenda did not increase the severity of (stereomicroscopic/histological) ileitis; however, biochemically, ileal MPO activity was increased in SAMP treated with Splenda compared with nonsupplemented mice (P < 0.022) and healthy AKR mice. Splenda promoted dysbiosis with expansion of Proteobacteria in all mice, and E. coli overgrowth with increased bacterial infiltration into the ileal lamina propria of SAMP mice. FISH showed increase malX gene-carrying bacterial clusters in the ilea of supplemented SAMP (but not AKR) mice. Conclusions Splenda promoted gut Proteobacteria, dysbiosis, and biochemical MPO reactivity in a spontaneous model of (Bacteroidetes-rich) ileal CD. Our results indicate that although Splenda may promote parallel microbiome alterations in CD-prone and healthy hosts, this did not result in elevated MPO levels in healthy mice, only CD-prone mice. The consumption of sucralose/maltodextrin-containing foods might exacerbate MPO intestinal reactivity only in individuals with a pro-inflammatory predisposition, such as CD.
Collapse
Affiliation(s)
| | - Andrew Harding
- Division of Gastroenterology and Liver Disease, Department of Medicine, School of Medicine, Cleveland, Ohio
| | - Paola Menghini
- Division of Gastroenterology and Liver Disease, Department of Medicine, School of Medicine, Cleveland, Ohio
| | - Catherine Himmelman
- Division of Gastroenterology and Liver Disease, Department of Medicine, School of Medicine, Cleveland, Ohio
| | - Mauricio Retuerto
- Center for Medical Mycology, Department of Dermatology, School of Medicine, Cleveland, Ohio
| | - Kourtney P Nickerson
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Minh Lam
- Division of Gastroenterology and Liver Disease, Department of Medicine, School of Medicine, Cleveland, Ohio
| | | | - Mairi H McLean
- Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Scotland, UK
| | - Scott K Durum
- Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland
| | - Theresa T Pizarro
- Department of Pathology, Case Western Reserve University, School of Medicine, Cleveland, Ohio
| | - Mahmoud A Ghannoum
- Center for Medical Mycology, Department of Dermatology, School of Medicine, Cleveland, Ohio
| | - Sanja Ilic
- Department of Human Sciences and Human Nutrition, The Ohio State University, Columbus, Ohio
| | - Christine McDonald
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Fabio Cominelli
- Division of Gastroenterology and Liver Disease, Department of Medicine, School of Medicine, Cleveland, Ohio
- Digestive Health Institute, University Hospitals Cleveland Medical Center, Cleveland, Ohio
| |
Collapse
|
7
|
Kessler SP, Obery DR, Nickerson KP, Petrey AC, McDonald C, de la Motte CA. Multifunctional Role of 35 Kilodalton Hyaluronan in Promoting Defense of the Intestinal Epithelium. J Histochem Cytochem 2018; 66:273-287. [PMID: 29290146 DOI: 10.1369/0022155417746775] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Intestinal epithelium plays a critical role in host defense against orally acquired pathogens. Dysregulation of this protective barrier is a primary driver of inflammatory bowel diseases (Crohn's and ulcerative colitis) and also infant gastrointestinal infections. Previously, our lab reported that hyaluronan (HA) isolated from human milk induces the expression of the antimicrobial peptide β-defensin in vivo and protects against Salmonella Typhimurium infection of epithelial cells in vitro. In addition, we demonstrated that commercially available 35 kDa size HA induces the expression of β-defensin, upregulates the expression of tight junction protein zonula occludens-1 (ZO-1), and attenuates murine Citrobacter rodentium infection in vivo. In this current study, we report that HA35 remains largely intact and biologically active during transit through the digestive tract where it directly induces β-defensin expression upon epithelial cell contact. We also demonstrate HA35 abrogation of murine Salmonella Typhimurium infection as well as downregulation of leaky tight junction protein claudin-2 expression. Taken together, we propose a dual role for HA in host innate immune defense at the epithelial cell surface, acting to induce antimicrobial peptide production and also block pathogen-induced leaky gut. HA35 is therefore a promising therapeutic in the defense against bacterially induced colitis in compromised adults and vulnerable newborns.
Collapse
Affiliation(s)
- Sean P Kessler
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio.,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Dana R Obery
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Kourtney P Nickerson
- Division of Pediatric Gastroenterology and Nutrition, Mucosal Immunology and Biology Research Center, Massachusetts General Hospital, Boston, Massachusetts.,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts
| | - Aaron C Petrey
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio.,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Christine McDonald
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio.,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Carol A de la Motte
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio.,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio
| |
Collapse
|
8
|
Schuster AT, Homer CR, Kemp JR, Nickerson KP, Deutschman E, Kim Y, West G, Sadler T, Stylianou E, Krokowski D, Hatzoglou M, de la Motte C, Rubin BP, Fiocchi C, McDonald C, Longworth MS. Chromosome-associated protein D3 promotes bacterial clearance in human intestinal epithelial cells by repressing expression of amino acid transporters. Gastroenterology 2015; 148:1405-1416.e3. [PMID: 25701737 PMCID: PMC4446190 DOI: 10.1053/j.gastro.2015.02.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 01/28/2015] [Accepted: 02/13/2015] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Defects in colonic epithelial barrier defenses are associated with ulcerative colitis (UC). The proteins that regulate bacterial clearance in the colonic epithelium have not been completely identified. The Drosophila chromosome-associated protein D3 (dCAP-D3) regulates responses to bacterial infection. We examined whether CAP-D3 promotes bacterial clearance in human colonic epithelium. METHODS Clearance of Salmonella or adherent-invasive Escherichia coli LF82 was assessed by gentamycin protection assays in HT-29 and Caco-2 cells expressing small hairpin RNAs against CAP-D3. We used immunoblot assays to measure levels of CAP-D3 in colonic epithelial cells from patients with UC and healthy individuals (controls). RNA sequencing identified genes activated by CAP-D3. We analyzed the roles of CAP-D3 target genes in bacterial clearance using gentamycin protection and immunofluorescence assays and studies with pharmacologic inhibitors. RESULTS CAP-D3 expression was reduced in colonic epithelial cells from patients with active UC. Reduced CAP-D3 expression decreased autophagy and impaired intracellular bacterial clearance by HT-29 and Caco-2 colonic epithelial cells. Lower levels of CAP-D3 increased transcription of genes encoding SLC7A5 and SLC3A2, the products of which heterodimerize to form an amino acid transporter in HT-29 cells after bacterial infection; levels of SLC7A5-SLC3A2 were increased in tissues from patients with UC compared with controls. Reduced CAP-D3 in HT-29 cells resulted in earlier recruitment of SLC7A5 to Salmonella-containing vacuoles, increased activity of mTORC1, and increased survival of bacteria. Inhibition of SLC7A5-SLC3A2 or mTORC1 activity rescued the bacterial clearance defects of CAP-D3-deficient cells. CONCLUSIONS CAP-D3 down-regulates transcription of genes that encode amino acid transporters (SLC7A5 and SLC3A2) to promote bacterial autophagy by colon epithelial cells. Levels of CAP-D3 protein are reduced in patients with active UC; strategies to increase its levels might restore mucosal homeostasis to patients with active UC.
Collapse
Affiliation(s)
- Andrew T. Schuster
- Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Craig R. Homer
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Jacqueline R. Kemp
- Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Kourtney P. Nickerson
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Emily Deutschman
- Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Yeojung Kim
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Gail West
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Tammy Sadler
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Eleni Stylianou
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Dawid Krokowski
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio
| | - Maria Hatzoglou
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio
| | - Carol de la Motte
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Brian P. Rubin
- Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
,Department of Anatomic Pathology, Taussig Cancer Institute, Cleveland, Ohio
| | - Claudio Fiocchi
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Christine McDonald
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Michelle S. Longworth
- Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| |
Collapse
|
9
|
Abstract
Inflammatory bowel disease (IBD) is a complex, multi-factorial disease thought to arise from an inappropriate immune response to commensal bacteria in a genetically susceptible person that results in chronic, cyclical, intestinal inflammation. Dietary and environmental factors are implicated in the initiation and perpetuation of IBD; however, a singular causative agent has not been identified. As of now, the role of environmental priming or triggers in IBD onset and pathogenesis are not well understood, but these factors appear to synergize with other disease susceptibility factors. In previous work, we determined that the polysaccharide dietary additive, maltodextrin (MDX), impairs cellular anti-bacterial responses and suppresses intestinal anti-microbial defense mechanisms. In this addendum, we review potential mechanisms for dietary deregulation of intestinal homeostasis, postulate how dietary and genetic risk factors may combine to result in disease pathogenesis, and discuss these ideas in the context of recent findings related to dietary interventions for IBD.
Collapse
Key Words
- AIEC, adherent-invasive Escherichia coli
- CD, Crohn's disease
- CMC, carboxymethyl cellulose
- Crohn's disease
- DSS, dextran sulfate sodium
- FDA, Food and Drug Administration
- GRAS, Generally Recognized As Safe
- IBD, inflammatory bowel disease
- IBD-AID, inflammatory bowel disease-anti-inflammatory diet
- MDX, maltodextrin
- SCD, specific carbohydrate diet
- UC, ulcerative colitis
- anti-microbial defense
- diet
- dietary additive
- inflammatory bowel disease
- intestinal homeostasis
- maltodextrin
- mucosal defense
Collapse
Affiliation(s)
- Kourtney P Nickerson
- Mucosal Immunology and Biology Research Center; Division of Pediatric Gastroenterology and Nutrition; Massachusetts General Hospital; Boston, MA USA,Department of Pediatrics; Harvard Medical School; Boston, MA USA
| | - Rachael Chanin
- Mucosal Immunology and Biology Research Center; Division of Pediatric Gastroenterology and Nutrition; Massachusetts General Hospital; Boston, MA USA
| | - Christine McDonald
- Department of Pathobiology; Lerner Research Institute; Cleveland Clinic; Cleveland, OH USA,Department of Molecular Medicine; Cleveland Clinic Lerner College of Medicine at Case Western Reserve University; Cleveland, OH USA,Correspondence to: Christine McDonald;
| |
Collapse
|
10
|
Nickerson KP, Homer CR, Kessler SP, Dixon LJ, Kabi A, Gordon IO, Johnson EE, de la Motte CA, McDonald C. The dietary polysaccharide maltodextrin promotes Salmonella survival and mucosal colonization in mice. PLoS One 2014; 9:e101789. [PMID: 25000398 PMCID: PMC4084946 DOI: 10.1371/journal.pone.0101789] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 06/11/2014] [Indexed: 11/19/2022] Open
Abstract
In the latter half of the 20th century, societal and technological changes led to a shift in the composition of the American diet to include a greater proportion of processed, pre-packaged foods high in fat and carbohydrates, and low in dietary fiber (a "Western diet"). Over the same time period, there have been parallel increases in Salmonella gastroenteritis cases and a broad range of chronic inflammatory diseases associated with intestinal dysbiosis. Several polysaccharide food additives are linked to bacterially-driven intestinal inflammation and may contribute to the pathogenic effects of a Western diet. Therefore, we examined the effect of a ubiquitous polysaccharide food additive, maltodextrin (MDX), on clearance of the enteric pathogen Salmonella using both in vitro and in vivo infection models. When examined in vitro, murine bone marrow-derived macrophages exposed to MDX had altered vesicular trafficking, suppressed NAPDH oxidase expression, and reduced recruitment of NADPH oxidase to Salmonella-containing vesicles, which resulted in persistence of Salmonella in enlarged Rab7+ late endosomal vesicles. In vivo, mice consuming MDX-supplemented water had a breakdown of the anti-microbial mucous layer separating gut bacteria from the intestinal epithelium surface. Additionally, oral infection of these mice with Salmonella resulted in increased cecal bacterial loads and enrichment of lamina propria cells harboring large Rab7+ vesicles. These findings indicate that consumption of processed foods containing the polysaccharide MDX contributes to suppression of intestinal anti-microbial defense mechanisms and may be an environmental priming factor for the development of chronic inflammatory disease.
Collapse
Affiliation(s)
- Kourtney P. Nickerson
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Craig R. Homer
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Sean P. Kessler
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Laura J. Dixon
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Amrita Kabi
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Ilyssa O. Gordon
- Department of Anatomic Pathology, Robert J. Tomsich Pathology & Laboratory Medicine Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Erin E. Johnson
- Department of Biology, John Carroll University, University Heights, Ohio, United States of America
| | - Carol A. de la Motte
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Christine McDonald
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
- * E-mail:
| |
Collapse
|
11
|
Nickerson KP, McDonald C. Crohn's disease-associated adherent-invasive Escherichia coli adhesion is enhanced by exposure to the ubiquitous dietary polysaccharide maltodextrin. PLoS One 2012; 7:e52132. [PMID: 23251695 PMCID: PMC3520894 DOI: 10.1371/journal.pone.0052132] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 11/15/2012] [Indexed: 12/12/2022] Open
Abstract
Crohn's disease (CD) is associated with intestinal dysbiosis evidenced by an altered microbiome forming thick biofilms on the epithelium. Additionally, adherent-invasive E. coli (AIEC) strains are frequently isolated from ileal lesions of CD patients indicating a potential role for these strains in disease pathogenesis. The composition and characteristics of the host microbiome are influenced by environmental factors, particularly diet. Polysaccharides added to food as emulsifiers, stabilizers or bulking agents have been linked to bacteria-associated intestinal disorders. The escalating consumption of polysaccharides in Western diets parallels an increased incidence of CD during the latter 20th century. In this study, the effect of a polysaccharide panel on adhesiveness of the CD-associated AIEC strain LF82 was analyzed to determine if these food additives promote disease-associated bacterial phenotypes. Maltodextrin (MDX), a polysaccharide derived from starch hydrolysis, markedly enhanced LF82 specific biofilm formation. Biofilm formation of multiple other E. coli strains was also promoted by MDX. MDX-induced E. coli biofilm formation was independent of polysaccharide chain length indicating a requirement for MDX metabolism. MDX exposure induced type I pili expression, which was required for MDX-enhanced biofilm formation. MDX also increased bacterial adhesion to human intestinal epithelial cell monolayers in a mechanism dependent on type 1 pili and independent of the cellular receptor CEACAM6, suggesting a novel mechanism of epithelial cell adhesion. Analysis of mucosa-associated bacteria from individuals with and without CD showed increased prevalence of malX, a gene essential for MDX metabolism, uniquely in the ileum of CD patients. These findings demonstrate that the ubiquitous dietary component MDX enhances E. coli adhesion and suggests a mechanism by which Western diets rich in specific polysaccharides may promote dysbiosis of gut microbes and contribute to disease susceptibility.
Collapse
Affiliation(s)
- Kourtney P. Nickerson
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Christine McDonald
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
- * E-mail:
| |
Collapse
|
12
|
Homer CR, Kabi A, Marina-García N, Sreekumar A, Nesvizhskii AI, Nickerson KP, Chinnaiyan AM, Nuñez G, McDonald C. A dual role for receptor-interacting protein kinase 2 (RIP2) kinase activity in nucleotide-binding oligomerization domain 2 (NOD2)-dependent autophagy. J Biol Chem 2012; 287:25565-76. [PMID: 22665475 DOI: 10.1074/jbc.m111.326835] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Autophagy is triggered by the intracellular bacterial sensor NOD2 (nucleotide-binding, oligomerization domain 2) as an anti-bacterial response. Defects in autophagy have been implicated in Crohn's disease susceptibility. The molecular mechanisms of activation and regulation of this process by NOD2 are not well understood, with recent studies reporting conflicting requirements for RIP2 (receptor-interacting protein kinase 2) in autophagy induction. We examined the requirement of NOD2 signaling mediated by RIP2 for anti-bacterial autophagy induction and clearance of Salmonella typhimurium in the intestinal epithelial cell line HCT116. Our data demonstrate that NOD2 stimulates autophagy in a process dependent on RIP2 tyrosine kinase activity. Autophagy induction requires the activity of the mitogen-activated protein kinases MEKK4 and p38 but is independent of NFκB signaling. Activation of autophagy was inhibited by a PP2A phosphatase complex, which interacts with both NOD2 and RIP2. PP2A phosphatase activity inhibited NOD2-dependent autophagy but not activation of NFκB or p38. Upon stimulation of NOD2, the phosphatase activity of the PP2A complex is inhibited through tyrosine phosphorylation of the catalytic subunit in a process dependent on RIP2 activity. These findings demonstrate that RIP2 tyrosine kinase activity is not only required for NOD2-dependent autophagy but plays a dual role in this process. RIP2 both sends a positive autophagy signal through activation of p38 MAPK and relieves repression of autophagy mediated by the phosphatase PP2A.
Collapse
Affiliation(s)
- Craig R Homer
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Richmond AL, Kabi A, Homer CR, García NM, Nickerson KP, NesvizhskiI AI, Sreekumar A, Chinnaiyan AM, Nuñez G, McDonald C. The nucleotide synthesis enzyme CAD inhibits NOD2 antibacterial function in human intestinal epithelial cells. Gastroenterology 2012; 142:1483-92.e6. [PMID: 22387394 PMCID: PMC3565430 DOI: 10.1053/j.gastro.2012.02.040] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Revised: 02/15/2012] [Accepted: 02/16/2012] [Indexed: 12/19/2022]
Abstract
BACKGROUND & AIMS Polymorphisms that reduce the function of nucleotide-binding oligomerization domain (NOD)2, a bacterial sensor, have been associated with Crohn's disease (CD). No proteins that regulate NOD2 activity have been identified as selective pharmacologic targets. We sought to discover regulators of NOD2 that might be pharmacologic targets for CD therapies. METHODS Carbamoyl phosphate synthetase/aspartate transcarbamylase/dihydroorotase (CAD) is an enzyme required for de novo pyrimidine nucleotide synthesis; it was identified as a NOD2-interacting protein by immunoprecipitation-coupled mass spectrometry. CAD expression was assessed in colon tissues from individuals with and without inflammatory bowel disease by immunohistochemistry. The interaction between CAD and NOD2 was assessed in human HCT116 intestinal epithelial cells by immunoprecipitation, immunoblot, reporter gene, and gentamicin protection assays. We also analyzed human cell lines that express variants of NOD2 and the effects of RNA interference, overexpression and CAD inhibitors. RESULTS CAD was identified as a NOD2-interacting protein expressed at increased levels in the intestinal epithelium of patients with CD compared with controls. Overexpression of CAD inhibited NOD2-dependent activation of nuclear factor κB and p38 mitogen-activated protein kinase, as well as intracellular killing of Salmonella. Reduction of CAD expression or administration of CAD inhibitors increased NOD2-dependent signaling and antibacterial functions of NOD2 variants that are and are not associated with CD. CONCLUSIONS The nucleotide synthesis enzyme CAD is a negative regulator of NOD2. The antibacterial function of NOD2 variants that have been associated with CD increased in response to pharmacologic inhibition of CAD. CAD is a potential therapeutic target for CD.
Collapse
Affiliation(s)
- Amy L. Richmond
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Amrita Kabi
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Craig R. Homer
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | | | - Kourtney P. Nickerson
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio
| | | | - Arun Sreekumar
- Department of Molecular and Cell Biology, Alkek Center for Molecular Discovery, Baylor College of Medicine, Houston, Texas
| | - Arul M. Chinnaiyan
- Department of Pathology, Comprehensive Cancer Center, Ann Arbor, Michigan,Michigan Center for Translational Pathology, Howard Hughes Medical Institute, University of Michigan Medical School, Ann Arbor, Michigan
| | - Gabriel Nuñez
- Department of Pathology, Comprehensive Cancer Center, Ann Arbor, Michigan
| | - Christine McDonald
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio
| |
Collapse
|
14
|
Kabi A, Nickerson KP, Homer CR, McDonald C. Digesting the genetics of inflammatory bowel disease: insights from studies of autophagy risk genes. Inflamm Bowel Dis 2012; 18:782-92. [PMID: 21936032 PMCID: PMC3245781 DOI: 10.1002/ibd.21868] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 07/26/2011] [Indexed: 12/16/2022]
Abstract
The success of genetic analyses identifying multiple loci associated with inflammatory bowel disease (IBD) susceptibility has resulted in the identification of several risk genes linked to a common cellular process called autophagy. Autophagy is a process involving the encapsulation of cytosolic cellular components in double-membrane vesicles, their subsequent lysosomal degradation, and recycling of the degraded components for use by the cell. It plays an important part in the innate immune response to a variety of intracellular pathogens, and it is this component of autophagy that appears to be defective in IBD. This has lead to the hypothesis that Crohn's disease may result from an impaired antibacterial response, which leads to ineffective control of bacterial infection, dysbiosis of the intestinal microbiota, and chronic inflammation. Several recurrent themes have surfaced from studies examining the function of autophagy-related genes in the context of IBD, with cellular context, disease status, risk variant effect, and risk gene interplay all affecting the interpretation of these studies. The identification of autophagy as a major risk pathway in IBD is a significant step forward and may lead to pathway-focused therapy in the future; however, there is more to understand in order to unravel the complexity of this disease.
Collapse
Affiliation(s)
- Amrita Kabi
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Kourtney P. Nickerson
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Craig R. Homer
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Christine McDonald
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio,Correspondence to: Christine McDonald, Ph.D., Department of Pathobiology, NC22, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, Ohio 44195, (216) 445-7058 phone, (216) 636-0104 fax,
| |
Collapse
|