1
|
Friebel J, Schinnerling K, Weigt K, Heldt C, Fromm A, Bojarski C, Siegmund B, Epple HJ, Kikhney J, Moter A, Schneider T, Schulzke JD, Moos V, Schumann M. Uptake of Tropheryma whipplei by Intestinal Epithelia. Int J Mol Sci 2023; 24:ijms24076197. [PMID: 37047170 PMCID: PMC10094206 DOI: 10.3390/ijms24076197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 03/18/2023] [Accepted: 03/21/2023] [Indexed: 03/29/2023] Open
Abstract
Background: Tropheryma whipplei (TW) can cause different pathologies, e.g., Whipple’s disease and transient gastroenteritis. The mechanism by which the bacteria pass the intestinal epithelial barrier, and the mechanism of TW-induced gastroenteritis are currently unknown. Methods: Using ex vivo disease models comprising human duodenal mucosa exposed to TW in Ussing chambers, various intestinal epithelial cell (IEC) cultures exposed to TW and a macrophage/IEC coculture model served to characterize endocytic uptake mechanisms and barrier function. Results: TW exposed ex vivo to human small intestinal mucosae is capable of autonomously entering IECs, thereby invading the mucosa. Using dominant-negative mutants, TW uptake was shown to be dynamin- and caveolin-dependent but independent of clathrin-mediated endocytosis. Complementary inhibitor experiments suggested a role for the activation of the Ras/Rac1 pathway and actin polymerization. TW-invaded IECs underwent apoptosis, thereby causing an epithelial barrier defect, and were subsequently subject to phagocytosis by macrophages. Conclusions: TW enters epithelia via an actin-, dynamin-, caveolin-, and Ras-Rac1-dependent endocytosis mechanism and consecutively causes IEC apoptosis primarily in IECs invaded by multiple TW bacteria. This results in a barrier leak. Moreover, we propose that TW-packed IECs can be subject to phagocytic uptake by macrophages, thereby opening a potential entry point of TW into intestinal macrophages.
Collapse
Affiliation(s)
- Julian Friebel
- Department of Cardiology, Angiology and Intensive Care Medicine, Deutsches Herzzentrum der Charité, 12203 Berlin, Germany
- Department of Gastroenterology, Infectiology and Rheumatology, Campus Benjamin Franklin, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany
- Berlin Institute of Health at Charité—Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Katina Schinnerling
- Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago 8370146, Chile
| | - Kathleen Weigt
- Department of Gastroenterology, Infectiology and Rheumatology, Campus Benjamin Franklin, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany
| | - Claudia Heldt
- Department of Gastroenterology, Infectiology and Rheumatology, Campus Benjamin Franklin, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany
| | - Anja Fromm
- Institute of Clinical Physiology, Campus Benjamin Franklin, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany
| | - Christian Bojarski
- Department of Gastroenterology, Infectiology and Rheumatology, Campus Benjamin Franklin, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany
| | - Britta Siegmund
- Department of Gastroenterology, Infectiology and Rheumatology, Campus Benjamin Franklin, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany
| | - Hans-Jörg Epple
- Department of Gastroenterology, Infectiology and Rheumatology, Campus Benjamin Franklin, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany
| | - Judith Kikhney
- Institute for Microbiology, Infectious Diseases, and Immunology, Biofilmcenter, Campus Benjamin Franklin, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany
- MoKi Analytics GmbH, 12207 Berlin, Germany
| | - Annette Moter
- Institute for Microbiology, Infectious Diseases, and Immunology, Biofilmcenter, Campus Benjamin Franklin, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany
- German Konsiliarlabor for Tropheryma whipplei, 10117 Berlin, Germany
- Moter Diagnostics, 12207 Berlin, Germany
| | - Thomas Schneider
- Department of Gastroenterology, Infectiology and Rheumatology, Campus Benjamin Franklin, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany
| | - Jörg D. Schulzke
- Department of Gastroenterology, Infectiology and Rheumatology, Campus Benjamin Franklin, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany
- Institute of Clinical Physiology, Campus Benjamin Franklin, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany
| | - Verena Moos
- Department of Gastroenterology, Infectiology and Rheumatology, Campus Benjamin Franklin, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany
| | - Michael Schumann
- Department of Gastroenterology, Infectiology and Rheumatology, Campus Benjamin Franklin, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany
- Berlin Institute of Health at Charité—Universitätsmedizin Berlin, 10117 Berlin, Germany
- Correspondence: ; Tel.: +49-30-450-513536
| |
Collapse
|
2
|
Weiß F, Holthaus D, Kraft M, Klotz C, Schneemann M, Schulzke JD, Krug SM. Human duodenal organoid-derived monolayers serve as a suitable barrier model for duodenal tissue. Ann N Y Acad Sci 2022; 1515:155-167. [PMID: 35666953 DOI: 10.1111/nyas.14804] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [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: 12/12/2022]
Abstract
Usually, duodenal barriers are investigated using intestinal cell lines like Caco-2, which in contrast to native tissue are limited in cell-type representation. Organoids can consist of all intestinal cell types and are supposed to better reflect the in vivo situation. Growing three-dimensionally, with the apical side facing the lumen, application of typical physiological techniques to analyze the barrier is difficult. Organoid-derived monolayers (ODMs) were developed to overcome this. After optimizing culturing conditions, ODMs were characterized and compared to Caco-2 and duodenal tissue. Tight junction composition and appearance were analyzed, and electrophysiological barrier properties, like paracellular and transcellular barrier function and macromolecule permeability, were evaluated. Furthermore, transcriptomic data were analyzed. ODMs had tight junction protein expression and paracellular barrier properties much more resembling the originating tissue than Caco-2. Transcellular barrier was similar between ODMs and native tissue but was increased in Caco-2. Transcriptomic data showed that Caco-2 expressed fewer solute carriers than ODMs and native tissue. In conclusion, while Caco-2 cells differ mostly in transcellular properties, ODMs reflect trans- and paracellular properties of the originating tissue. If cultured under optimized conditions, ODMs possess reproducible functionality, and the variety of different cell types makes them a suitable model for human tissue-specific investigations.
Collapse
Affiliation(s)
- Franziska Weiß
- Clinical Physiology/Nutritional Medicine, Charité - Universitätsmedizin Berlin, CBF, Berlin, Germany
| | - David Holthaus
- Department of Infectious Diseases, Unit 16 Mycotic and Parasitic Agents and Mycobacteria, Robert Koch-Institute, Berlin, Germany
| | - Martin Kraft
- Department of Infectious Diseases, Unit 16 Mycotic and Parasitic Agents and Mycobacteria, Robert Koch-Institute, Berlin, Germany
| | - Christian Klotz
- Department of Infectious Diseases, Unit 16 Mycotic and Parasitic Agents and Mycobacteria, Robert Koch-Institute, Berlin, Germany
| | - Martina Schneemann
- Clinical Physiology/Nutritional Medicine, Charité - Universitätsmedizin Berlin, CBF, Berlin, Germany
| | - Jörg D Schulzke
- Clinical Physiology/Nutritional Medicine, Charité - Universitätsmedizin Berlin, CBF, Berlin, Germany
| | - Susanne M Krug
- Clinical Physiology/Nutritional Medicine, Charité - Universitätsmedizin Berlin, CBF, Berlin, Germany
| |
Collapse
|
3
|
Hering NA, Luettig J, Jebautzke B, Schulzke JD, Rosenthal R. The Punicalagin Metabolites Ellagic Acid and Urolithin A Exert Different Strengthening and Anti-Inflammatory Effects on Tight Junction-Mediated Intestinal Barrier Function In Vitro. Front Pharmacol 2021; 12:610164. [PMID: 33776763 PMCID: PMC7987831 DOI: 10.3389/fphar.2021.610164] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 02/04/2021] [Indexed: 12/31/2022] Open
Abstract
Scope: Ellagitannins are polyphenols found in numerous fruits, nuts and seeds. The elagitannin punicalagin and its bioactive metabolites ellagic acid and urolithins are discussed to comprise a high potential for therapeutically or preventive medical application such as in intestinal diseases. The present study characterizes effects of punicalagin, ellagic acid and urolithin A on intestinal barrier function in the absence or presence of the proinflammatory cytokine tumor necrosis factor-α (TNFα). Methods and Results: Transepithelial resistance (TER), fluorescein and ion permeability, tight junction protein expression and signalling pathways were examined in Caco-2 and HT-29/B6 intestinal epithelial cell models. Punicalagin had less or no effects on barrier function in both cell models. Ellagic acid was most effective in ileum-like Caco-2 cells, where it increased TER and reduced fluorescein and sodium permeabilities. This was paralleled by myosin light chain kinase two mediated expression down-regulation of claudin-4, -7 and -15. Urolithin A impeded the TNFα-induced barrier loss by inhibition of claudin-1 and -2 protein expression upregulation and claudin-1 delocalization in HT-29/B6. Conclusion: Ellagic acid and urolithin A affect intestinal barrier function in distinct ways. Ellagic acid acts preventive by strengthening the barrier per se, while urolithin A protects against inflammation-induced barrier dysfunction.
Collapse
Affiliation(s)
- Nina A Hering
- Department of General and Visceral Surgery, Charité - Universitätsmedizin Berlin, Berlin, Germasny
| | - Julia Luettig
- Institute of Clinical Physiology/Nutritional Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Britta Jebautzke
- Institute of Clinical Physiology/Nutritional Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Jörg D Schulzke
- Institute of Clinical Physiology/Nutritional Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Rita Rosenthal
- Institute of Clinical Physiology/Nutritional Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
4
|
Krug SM, Lee IFM, Weiß F, Hu JCE, Fromm M, Schulzke JD. Impaired Tricellular Tight Junctions Open the Barrier for Lipopolysaccharide Uptake. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.03855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
5
|
Ayala-Torres C, Krug SM, Schulzke JD, Rosenthal R, Fromm M. Tricellulin Effect on Paracellular Water Transport. Int J Mol Sci 2019; 20:ijms20225700. [PMID: 31739405 PMCID: PMC6888685 DOI: 10.3390/ijms20225700] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 11/07/2019] [Accepted: 11/12/2019] [Indexed: 12/15/2022] Open
Abstract
In epithelia, large amounts of water pass by transcellular and paracellular pathways, driven by the osmotic gradient built up by the movement of solutes. The transcellular pathway has been molecularly characterized by the discovery of aquaporin membrane channels. Unlike this, the existence of a paracellular pathway for water through the tight junctions (TJ) was discussed controversially for many years until two molecular components of paracellular water transport, claudin-2 and claudin-15, were identified. A main protein of the tricellular TJ (tTJ), tricellulin, was shown to be downregulated in ulcerative colitis leading to increased permeability to macromolecules. Whether or not tricellulin also regulates water transport is unknown yet. To this end, an epithelial cell line featuring properties of a tight epithelium, Madin-Darby canine kidney cells clone 7 (MDCK C7), was stably transfected with small hairpin RNA (shRNA) targeting tricellulin, a protein of the tTJ essential for the barrier against passage of solutes up to 10 kDa. Water flux was induced by osmotic gradients using mannitol or 4 and 40 kDa-dextran. Water flux in tricellulin knockdown (KD) cells was higher compared to that of vector controls, indicating a direct role of tricellulin in regulating water permeability in a tight epithelial cell line. We conclude that tricellulin increases water permeability at reduced expression.
Collapse
|
6
|
Harrer A, Bücker R, Boehm M, Zarzecka U, Tegtmeyer N, Sticht H, Schulzke JD, Backert S. Campylobacter jejuni enters gut epithelial cells and impairs intestinal barrier function through cleavage of occludin by serine protease HtrA. Gut Pathog 2019; 11:4. [PMID: 30805031 PMCID: PMC6373145 DOI: 10.1186/s13099-019-0283-z] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 02/01/2019] [Indexed: 01/17/2023] Open
Abstract
Campylobacter jejuni secretes HtrA (high temperature requirement protein A), a serine protease that is involved in virulence. Here, we investigated the interaction of HtrA with the host protein occludin, a tight junction strand component. Immunofluorescence studies demonstrated that infection of polarized intestinal Caco-2 cells with C. jejuni strain 81-176 resulted in a redistribution of occludin away from the tight junctions into the cytoplasm, an effect that was also observed in human biopsies during acute campylobacteriosis. Occludin knockout Caco-2 cells were generated by CRISPR/Cas9 technology. Inactivation of this gene affected the polarization of the cells in monolayers and transepithelial electrical resistance (TER) was reduced, compared to wild-type Caco-2 cells. Although tight junctions were still being formed, occludin deficiency resulted in a slight decrease of the tight junction plaque protein ZO-1, which was redistributed off the tight junction into the lateral plasma membrane. Adherence of C. jejuni to Caco-2 cell monolayers was similar between the occludin knockout compared to wild-type cells, but invasion was enhanced, indicating that deletion of occludin allowed larger numbers of bacteria to pass the tight junctions and to reach basal membranes to target the fibronectin receptor followed by cell entry. Finally, we discovered that purified C. jejuni HtrA cleaves recombinant occludin in vitro to release a 37 kDa carboxy-terminal fragment. The same cleavage fragment was observed in Western blots upon infection of polarized Caco-2 cells with wild-type C. jejuni, but not with isogenic ΔhtrA mutants. HtrA cleavage was mapped to the second extracellular loop of occludin, and a putative cleavage site was identified. In conclusion, HtrA functions as a secreted protease targeting the tight junctions, which enables the bacteria by cleaving occludin and subcellular redistribution of other tight junction proteins to transmigrate using a paracellular mechanism and subsequently invade epithelial cells.
Collapse
Affiliation(s)
- Aileen Harrer
- 1Division of Microbiology, Dept. of Biology, University of Erlangen-Nuremberg, Staudtstr. 5, 91058 Erlangen, Germany
| | - Roland Bücker
- 2Institut für Klinische Physiologie, Med. Klinik m.S. Gastroenterologie, Infektiologie und Rheumatologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Manja Boehm
- 1Division of Microbiology, Dept. of Biology, University of Erlangen-Nuremberg, Staudtstr. 5, 91058 Erlangen, Germany
| | - Urszula Zarzecka
- 1Division of Microbiology, Dept. of Biology, University of Erlangen-Nuremberg, Staudtstr. 5, 91058 Erlangen, Germany.,4Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, 80-308 Gdansk, Poland
| | - Nicole Tegtmeyer
- 1Division of Microbiology, Dept. of Biology, University of Erlangen-Nuremberg, Staudtstr. 5, 91058 Erlangen, Germany
| | - Heinrich Sticht
- 3Division of Bioinformatics, Institute of Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Jörg D Schulzke
- 2Institut für Klinische Physiologie, Med. Klinik m.S. Gastroenterologie, Infektiologie und Rheumatologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Steffen Backert
- 1Division of Microbiology, Dept. of Biology, University of Erlangen-Nuremberg, Staudtstr. 5, 91058 Erlangen, Germany
| |
Collapse
|
7
|
Neuhaus W, Piontek A, Protze J, Eichner M, Mahringer A, Subileau EA, Lee IFM, Schulzke JD, Krause G, Piontek J. Reversible opening of the blood-brain barrier by claudin-5-binding variants of Clostridium perfringens enterotoxin's claudin-binding domain. Biomaterials 2018; 161:129-143. [DOI: 10.1016/j.biomaterials.2018.01.028] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 01/15/2018] [Accepted: 01/18/2018] [Indexed: 02/06/2023]
|
8
|
Bücker R, Krug SM, Moos V, Bojarski C, Schweiger MR, Kerick M, Fromm A, Janßen S, Fromm M, Hering NA, Siegmund B, Schneider T, Barmeyer C, Schulzke JD. Campylobacter jejuni impairs sodium transport and epithelial barrier function via cytokine release in human colon. Mucosal Immunol 2018; 11:575-577. [PMID: 29091080 DOI: 10.1038/mi.2017.78] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This corrects the article DOI: 10.1038/mi.2017.66.
Collapse
|
9
|
Zakrzewski SS, Fromm M, Schulzke JD, Günzel D. Zinc strengthens the jejunal barrier by reversibly tightening the paracellular route. Am J Physiol Gastrointest Liver Physiol 2017; 313:G537-G548. [PMID: 28864501 DOI: 10.1152/ajpgi.00355.2016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [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: 09/26/2016] [Revised: 08/28/2017] [Accepted: 08/28/2017] [Indexed: 01/31/2023]
Abstract
During the postweaning period, piglets are prone to gastrointestinal infections. The resulting impairment of intestinal barrier function may cause diarrhea associated with growth retardation or even death of piglets. Orally applied Zn is commonly used to prevent and treat diarrhea, but its mode of action still needs to be elucidated. To analyze the molecular mechanism whereby Zn acts on porcine intestinal barrier function, ex vivo studies on piglet jejunum and accompanying in vitro studies on a porcine jejunal epithelial cell line, IPEC-J2/PS, were performed with electrophysiological tools. Feeding pharmacological Zn doses exerted no significant electrophysiologically ascertainable short- and long-term effects on jejunal barrier function ex vivo. However, in IPEC-J2/PS, basolateral Zn was cytotoxic since its application caused a release of lactate dehydrogenase and an irreversible breakdown of the epithelial barrier. In contrast, apical Zn application caused an immediate increase in paracellular resistance and a decrease in permeability to the paracellular marker fluorescein, reflecting overall barrier strengthening in vitro. Apical effects were fully reversible upon washout. This indicates that Zn supplemented to feed was completely washed out during ex vivo jejunum preparation. We conclude that there is no evidence for long-term barrier effects through prophylactic Zn supplementation and that extracellular Zn acts acutely and reversibly from the apical side via tightening the paracellular route, thus counteracting leak-flux diarrhea.NEW & NOTEWORTHY Therapeutically administered Zn successfully treats diarrhea in veterinary and human medicine. Here we present data that Zn strengthens the porcine jejunal epithelial barrier by reversibly tightening the paracellular route for inorganic ions and small solutes. Acute or long-lasting Zn effects on transcellular transport (Cl- secretion) were not detected. We therefore conclude that Zn is useful for acutely treating leak-flux diarrhea rather than secretory diarrhea. Suitability as prophylactic feed supplement, however, is questionable.
Collapse
Affiliation(s)
- Silke S Zakrzewski
- Institute of Clinical Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Michael Fromm
- Institute of Clinical Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Jörg D Schulzke
- Institute of Clinical Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Dorothee Günzel
- Institute of Clinical Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
10
|
Epple HJ, Friebel J, Moos V, Troeger H, Krug SM, Allers K, Schinnerling K, Fromm A, Siegmund B, Fromm M, Schulzke JD, Schneider T. Architectural and functional alterations of the small intestinal mucosa in classical Whipple's disease. Mucosal Immunol 2017; 10:1542-1552. [PMID: 28176790 DOI: 10.1038/mi.2017.6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 01/10/2017] [Indexed: 02/04/2023]
Abstract
Classical Whipple's disease (CWD) affects the gastrointestinal tract and rather elicits regulatory than inflammatory immune reactions. Mechanisms of malabsorption, diarrhea, and systemic immune activation are unknown. We here analyzed mucosal architecture, barrier function, and immune activation as potential diarrheal trigger in specimens from 52 CWD patients. Our data demonstrate villus atrophy and crypt hyperplasia associated with epithelial apoptosis and reduced alkaline phosphatase expression in the duodenum of CWD patients. Electrophysiological and flux experiments revealed increased duodenal permeability to small solutes and macromolecules. Duodenal architecture and permeability ameliorated upon antibiotic treatment. Structural correlates for these alterations were concordant changes of membranous claudin-1, claudin-2, claudin-3, and tricellulin expression. Tumor necrosis factor-α and interleukin-13 were identified as probable mediators of epithelial apoptosis, and altered tight junction expression. Increased serum markers of microbial translocation and their decline following treatment corroborated the biological significance of the mucosal barrier defect. Hence, mucosal immune responses in CWD elicit barrier dysfunction. Diarrhea is caused by loss of absorptive capacity and leak flux of ions and water. Downregulation of tricellulin causes increased permeability to macromolecules and subsequent microbial translocation contributes to systemic inflammation. Thus, therapeutic strategies to reconstitute the mucosal barrier and control inflammation could assist symptomatic control of CWD.
Collapse
Affiliation(s)
- H-J Epple
- Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - J Friebel
- Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - V Moos
- Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - H Troeger
- Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - S M Krug
- Institute of Clinical Physiology/Nutritional Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - K Allers
- Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - K Schinnerling
- Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - A Fromm
- Institute of Clinical Physiology/Nutritional Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - B Siegmund
- Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - M Fromm
- Institute of Clinical Physiology/Nutritional Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - J D Schulzke
- Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany.,Institute of Clinical Physiology/Nutritional Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - T Schneider
- Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| |
Collapse
|
11
|
Hering NA, Luettig J, Krug SM, Wiegand S, Gross G, van Tol EA, Schulzke JD, Rosenthal R. Lactoferrin protects against intestinal inflammation and bacteria-induced barrier dysfunction in vitro. Ann N Y Acad Sci 2017; 1405:177-188. [PMID: 28614589 DOI: 10.1111/nyas.13405] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 05/05/2017] [Accepted: 05/10/2017] [Indexed: 12/15/2022]
Abstract
The iron-binding glycoprotein lactoferrin (LF) is naturally present in human breast milk. Several studies suggest that LF contributes to infant health and development owing to a variety of protective effects, including antimicrobial and anti-inflammatory features. Therefore, we aimed to elucidate its protective properties on intestinal epithelial barrier dysfunction induced by infection or inflammation using the human epithelial cell culture models HT-29/B6 and T84. During barrier perturbation induced by the proinflammatory cytokine tumor necrosis factor α (TNF-α), bovine LF restored tight junction (TJ) morphometry and inhibited TNF-α-induced epithelial apoptosis. This resulted in an attenuation of the TNF-α-induced decrease in transepithelial resistance (TER) and increases in permeability of fluorescein and FITC-dextran (4 kDa) and was as effective as the apoptosis inhibitor Q-VD-Oph. The enteropathogenic bacterium Yersinia enterocolitica is a frequent cause of diarrhea in early childhood. This involves focal changes in TJ protein expression and localization. LF diminished the Y. enterocolitica-induced drop in TER in the present in vitro model, which was paralleled by an inhibition of the Yersinia-induced reduction of claudin-8 expression via c-Jun kinase signaling. In conclusion, LF exerts protective effects against inflammation- or infection-induced barrier dysfunction in human intestinal cell lines, supporting its relevance for healthy infant development.
Collapse
Affiliation(s)
- Nina A Hering
- Department of General, Visceral and Vascular Surgery, Campus Benjamin Franklin, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Julia Luettig
- Institute of Clinical Physiology, Department of Gastroenterology, Campus Benjamin Franklin, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Susanne M Krug
- Institute of Clinical Physiology, Department of Gastroenterology, Campus Benjamin Franklin, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Stephanie Wiegand
- Institute of Clinical Physiology, Department of Gastroenterology, Campus Benjamin Franklin, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Gabriele Gross
- Mead Johnson Pediatric Nutrition Institute, Nijmegen, the Netherlands
| | - Eric A van Tol
- Mead Johnson Pediatric Nutrition Institute, Nijmegen, the Netherlands
| | - Jörg D Schulzke
- Institute of Clinical Physiology, Department of Gastroenterology, Campus Benjamin Franklin, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Rita Rosenthal
- Institute of Clinical Physiology, Department of Gastroenterology, Campus Benjamin Franklin, Charité - Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
12
|
Abstract
In celiac disease (CD) a T-cell-mediated response to gluten is mounted in genetically predisposed individuals, resulting in a malabsorptive enteropathy histologically highlighted by villous atrophy and crypt hyperplasia. Recent data point to the epithelial layer as an under-rated hot spot in celiac pathophysiology to date. This overview summarizes current functional and genetic evidence on the role of the epithelial barrier in CD, consisting of the cell membranes and the apical junctional complex comprising sealing as well as ion and water channel-forming tight junction proteins and the adherens junction. Moreover, the underlying mechanisms are discussed, including apoptosis of intestinal epithelial cells, biology of intestinal stem cells, alterations in the apical junctional complex, transcytotic uptake of gluten peptides, and possible implications of a defective epithelial polarity. Current research is directed toward new treatment options for CD that are alternatives or complementary therapeutics to a gluten-free diet. Thus, strategies to target an altered epithelial barrier therapeutically also are discussed.
Collapse
Key Words
- Bmp, bone morphogenetic protein
- CBC, crypt base columnar cell
- CD, celiac disease
- Celiac Sprue
- EGF, epidermal growth factor
- Epithelial Polarity
- GFD, gluten-free diet
- GI, gastrointestinal
- GWAS, genome-wide association studies
- Gluten-Sensitive Enteropathy
- IEC, intestinal epithelial cell
- IL, interleukin
- MIC-A, major histocompatibility complex class I chain–related gene-A
- Partitioning-Defective Proteins
- SNP, single-nucleotide polymorphism
- TJ, tight junction
- Tight Junction
- ZO, zonula occludens
- aPKC, atypical protein kinase C
- α-Gliadin 33mer
Collapse
Affiliation(s)
- Michael Schumann
- Department of Gastroenterology, Infectious Diseases and Rheumatology, Campus Benjamin Franklin, Charité–Universitätsmedizin Berlin, Berlin, Germany
- Berlin Institute of Health, Berlin, Germany
- Berlin-Brandenburg School for Regenerative Therapies, Berlin, Germany
| | - Britta Siegmund
- Department of Gastroenterology, Infectious Diseases and Rheumatology, Campus Benjamin Franklin, Charité–Universitätsmedizin Berlin, Berlin, Germany
| | - Jörg D. Schulzke
- Institute of Clinical Physiology, Campus Benjamin Franklin, Charité–Universitätsmedizin Berlin, Berlin, Germany
| | - Michael Fromm
- Institute of Clinical Physiology, Campus Benjamin Franklin, Charité–Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
13
|
Luettig J, Rosenthal R, Lee IFM, Krug SM, Schulzke JD. The ginger component 6-shogaol prevents TNF-α-induced barrier loss via inhibition of PI3K/Akt and NF-κB signaling. Mol Nutr Food Res 2016; 60:2576-2586. [PMID: 27487982 DOI: 10.1002/mnfr.201600274] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 06/20/2016] [Accepted: 07/21/2016] [Indexed: 12/26/2022]
Abstract
SCOPE Anti-inflammatory properties of the ginger-derived pungent component 6-shogaol (6-SG) have been studied intensively in recent years. Purpose of this study was to characterize the influence of 6-SG on inflammation-related intestinal barrier dysfunction, especially its paracellular component. METHODS AND RESULTS The effect of 6-SG was studied in the human intestinal cell models HT-29/B6 and Caco-2 either under control conditions or challenged by the pro-inflammatory cytokine tumor necrosis factor α (TNF-α). Electrophysiological measurements, freeze-fracture electron microscopy, and protein analyses were performed. 6-SG partially prevented both, the TNF-α-induced decrease in transepithelial resistance and the rise in fluorescein permeability. By inhibiting phosphatidylinositol-3-kinase/Akt signaling 6-SG prevented the TNF-α-induced increase in protein expression of claudin-2, a channel-forming tight junction protein. In addition, the TNF-α-induced disassembly of the sealing tight junction protein claudin-1 was attenuated, the latter of which was due to TNF-α-triggered phosphorylation of nuclear factor kappa light chain enhancer of activated B cells (NF-κB). CONCLUSION 6-SG has barrier-protective effects by affecting TNF-α-induced claudin-2 upregulation and claudin-1 disassembly via inhibition of phoshatidylinositol-3-kinase/Akt and nuclear factor kappa light chain enhancer of activated B-cell signaling. Therefore, 6-SG-containing food might be beneficial for barrier preservation during intestinal inflammation.
Collapse
Affiliation(s)
- Julia Luettig
- Nutritional Medicine and Clinical Physiology, Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Rita Rosenthal
- Nutritional Medicine and Clinical Physiology, Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - In-Fah M Lee
- Nutritional Medicine and Clinical Physiology, Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Susanne M Krug
- Nutritional Medicine and Clinical Physiology, Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Jörg D Schulzke
- Nutritional Medicine and Clinical Physiology, Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| |
Collapse
|
14
|
Hering NA, Fromm A, Kikhney J, Lee IFM, Moter A, Schulzke JD, Bücker R. Yersinia enterocolitica Affects Intestinal Barrier Function in the Colon. J Infect Dis 2015; 213:1157-62. [PMID: 26621910 DOI: 10.1093/infdis/jiv571] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 11/19/2015] [Indexed: 11/13/2022] Open
Abstract
Infection with Yersinia enterocolitica causes acute diarrhea in early childhood. A mouse infection model presents new findings on pathological mechanisms in the colon. Symptoms involve diarrhea with watery feces and weight loss that have their functional correlates in decreased transepithelial electrical resistance and increased fluorescein permeability. Y. enterocolitica was present within the murine mucosa of both ileum and colon. Here, the bacterial insult was of focal nature and led to changes in tight junction protein expression and architecture. These findings are in concordance with observations from former cell culture studies and suggest a leak flux mechanism of diarrhea.
Collapse
Affiliation(s)
- Nina A Hering
- Department of General, Visceral, and Vascular Surgery, Institute of Clinical Physiology, Campus Benjamin Franklin, Charité-University Medicine Berlin
| | - Anja Fromm
- Department of Gastroenterology, Institute of Clinical Physiology, Campus Benjamin Franklin, Charité-University Medicine Berlin
| | - Judith Kikhney
- Biofilmcenter of the German Heart Institute Berlin, Germany
| | - In-Fah M Lee
- Department of Gastroenterology, Institute of Clinical Physiology, Campus Benjamin Franklin, Charité-University Medicine Berlin
| | - Annette Moter
- Biofilmcenter of the German Heart Institute Berlin, Germany
| | - Jörg D Schulzke
- Department of Gastroenterology, Institute of Clinical Physiology, Campus Benjamin Franklin, Charité-University Medicine Berlin
| | - Roland Bücker
- Department of Gastroenterology, Institute of Clinical Physiology, Campus Benjamin Franklin, Charité-University Medicine Berlin
| |
Collapse
|
15
|
Luettig J, Rosenthal R, Barmeyer C, Schulzke JD. Claudin-2 as a mediator of leaky gut barrier during intestinal inflammation. Tissue Barriers 2015; 3:e977176. [PMID: 25838982 DOI: 10.4161/21688370.2014.977176] [Citation(s) in RCA: 171] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 10/10/2014] [Indexed: 02/07/2023] Open
Abstract
The epithelial tight junction determines the paracellular water and ion movement in the intestine and also prevents uptake of larger molecules, including antigens, in an uncontrolled manner. Claudin-2, one of the 27 mammalian claudins regulating that barrier function, forms a paracellular channel for small cations and water. It is typically expressed in leaky epithelia like proximal nephron and small intestine and provides a major pathway for the paracellular transport of sodium, potassium, and fluid. In intestinal inflammation (Crohn's disease, ulcerative colitis), immune-mediated diseases (celiac disease), and infections (HIV enteropathy), claudin-2 is upregulated in small and large intestine and contributes to diarrhea via a leak flux mechanism. In parallel to that upregulation, other epithelial and tight junctional features are altered and the luminal uptake of antigenic macromolecules is enhanced, for which claudin-2 may be partially responsible through induction of tight junction strand discontinuities.
Collapse
Key Words
- AP, activator protein
- CARD15, caspase recruitment domain-containing protein 15
- Crohn's disease
- DSS, dextran sodium sulfate
- ECL, extracellular loop
- ERK, extracellular-regulated kinase
- HIV
- HIV, human immunodeficiency virus
- HNF, hepatocyte nuclear factor
- IBD, inflammatory bowel disease
- IFN, interferon
- IFNγ
- IL, interleukin
- JAM, junctional adhesion molecule
- JNK, c-jun N-terminal kinase
- LPS, lipopolysaccharides
- MAPK, mitogen-activated protein kinase
- MDCK, Madine Darby canine kidney
- MLC, myosin light chain
- NFκB, nuclear factor kappa B
- NOD2, nucleotide-binding oligomerization domain-containing protein 2
- PI3K, phosphatidyl-inositol-3-kinase
- ROCK, Rho kinase
- Rho, ras homolog
- STAT, signal transducers and activators of transcription
- TEER, transepithelial electrical resistance
- TJ, tight junction
- TNBS, 2,4,6-trinitrobenzene sulfonic acid
- TNF, tumor necrosis factor
- TNFα
- Tat, trans-activator of transcription
- Vpr, viral protein r; ZO, zonula occludens
- celiac disease
- claudin-2
- gp, glycoprotein
- inflammatory bowel disease
- tight junction
- ulcerative colitis
Collapse
Affiliation(s)
- J Luettig
- Institute of Clinical Physiology; Department of Gastroenterology; Charité ; Berlin, Germany
| | - R Rosenthal
- Institute of Clinical Physiology; Department of Gastroenterology; Charité ; Berlin, Germany
| | - C Barmeyer
- Institute of Clinical Physiology; Department of Gastroenterology; Charité ; Berlin, Germany
| | - J D Schulzke
- Institute of Clinical Physiology; Department of Gastroenterology; Charité ; Berlin, Germany
| |
Collapse
|
16
|
Krug SM, Schulzke JD, Fromm M. Tight junction, selective permeability, and related diseases. Semin Cell Dev Biol 2014; 36:166-76. [DOI: 10.1016/j.semcdb.2014.09.002] [Citation(s) in RCA: 173] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 08/29/2014] [Accepted: 09/04/2014] [Indexed: 02/09/2023]
|
17
|
Affiliation(s)
- Jörg D Schulzke
- Department of Gastroenterology, Infectious Diseases and Rheumatology, Campus Benjamin Franklin, Charité Berlin, Berlin, Germany
| | - Britta Siegmund
- Department of Gastroenterology, Infectious Diseases and Rheumatology, Campus Benjamin Franklin, Charité Berlin, Berlin, Germany
| | - Dorothee Günzel
- Institute of Clinical Physiology, Campus Benjamin Franklin, Charité Berlin, Berlin, Germany
| |
Collapse
|
18
|
Hering NA, Richter JF, Fromm A, Wieser A, Hartmann S, Günzel D, Bücker R, Fromm M, Schulzke JD, Troeger H. TcpC protein from E. coli Nissle improves epithelial barrier function involving PKCζ and ERK1/2 signaling in HT-29/B6 cells. Mucosal Immunol 2014; 7:369-78. [PMID: 23900194 DOI: 10.1038/mi.2013.55] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 07/02/2013] [Indexed: 02/04/2023]
Abstract
The probiotic Escherichia coli Nissle 1917 (EcN) is widely used to maintain remission in ulcerative colitis. This is thought to be mediated by various immunomodulatory and barrier-stabilizing effects in the intestine. In this study, the mechanisms of barrier modulation by EcN were studied in the human epithelial HT-29/B6 cell culture model.EcN supernatant increased transepithelial resistance (TER) and reduced permeability to mannitol because of sealing of the paracellular passage pathway as revealed by two-path impedance spectroscopy. This increase in TER was attributed to the TcpC protein of EcN. TcpC induced protein kinase C-ζ (PKCζ) and extracellular-signal-regulated kinase 1/2 (ERK1/2) phosphorylation, which in turn resulted in upregulation of the barrier-forming tight junction protein claudin-14. By specific silencing of protein expression by small interfering RNA (siRNA), the sealing function of claudin-14 was confirmed. In conclusion, the TcpC protein of EcN affects innate immunity by improving intestinal barrier function through upregulation of claudin-14 via PKCζ and ERK1/2 signaling.
Collapse
Affiliation(s)
- N A Hering
- Department of Gastroenterology, Division of Nutritional Medicine, Infectious Diseases and Rheumatology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - J F Richter
- 1] Institute of Clinical Physiology, Infectious Diseases and Rheumatology, Charité-Universitätsmedizin Berlin, Berlin, Germany [2] Institute of Anatomy II, University of Jena, Jena, Germany
| | - A Fromm
- Institute of Clinical Physiology, Infectious Diseases and Rheumatology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - A Wieser
- Max von Pettenkofer-Institute for Hygiene and Medical Microbiology, Ludwig-Maximilians-University Munich, Munich, Germany
| | - S Hartmann
- Institute of Immunology, Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - D Günzel
- Institute of Clinical Physiology, Infectious Diseases and Rheumatology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - R Bücker
- Department of Gastroenterology, Division of Nutritional Medicine, Infectious Diseases and Rheumatology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - M Fromm
- Institute of Clinical Physiology, Infectious Diseases and Rheumatology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - J D Schulzke
- 1] Department of Gastroenterology, Division of Nutritional Medicine, Infectious Diseases and Rheumatology, Charité-Universitätsmedizin Berlin, Berlin, Germany [2] Department of Gastroenterology, Infectious Diseases and Rheumatology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - H Troeger
- Department of Gastroenterology, Infectious Diseases and Rheumatology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
19
|
Zakrzewski SS, Richter JF, Krug SM, Jebautzke B, Lee IFM, Rieger J, Sachtleben M, Bondzio A, Schulzke JD, Fromm M, Günzel D. Improved cell line IPEC-J2, characterized as a model for porcine jejunal epithelium. PLoS One 2013; 8:e79643. [PMID: 24260272 PMCID: PMC3829867 DOI: 10.1371/journal.pone.0079643] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 10/03/2013] [Indexed: 12/22/2022] Open
Abstract
Cell lines matching the source epithelium are indispensable for investigating porcine intestinal transport and barrier properties on a subcellular or molecular level and furthermore help to reduce animal usage. The porcine jejunal cell line IPEC-J2 is established as an in vitro model for porcine infection studies but exhibits atypically high transepithelial resistances (TER) and only low active transport rates so that the effect of nutritional factors cannot be reliably investigated. This study aimed to properly remodel IPEC-J2 and then to re-characterize these cells regarding epithelial architecture, expression of barrier-relevant tight junction (TJ) proteins, adequate TER and transport function, and reaction to secretagogues. For this, IPEC-J2 monolayers were cultured on permeable supports, either under conventional (fetal bovine serum, FBS) or species-specific (porcine serum, PS) conditions. Porcine jejunal mucosa was analyzed for comparison. Main results were that under PS conditions (IPEC-J2/PS), compared to conventional FBS culture (IPEC-J2/FBS), the cell height increased 6-fold while the cell diameter was reduced by 50%. The apical cell membrane of IPEC-J2/PS exhibited typical microvilli. Most importantly, PS caused a one order of magnitude reduction of TER and of trans- and paracellular resistance, and a 2-fold increase in secretory response to forskolin when compared to FBS condition. TJ ultrastructure and appearance of TJ proteins changed dramatically in IPEC-J2/PS. Most parameters measured under PS conditions were much closer to those of typical pig jejunocytes than ever reported since the cell line’s initial establishment in 1989. In conclusion, IPEC-J2, if cultured under defined species-specific conditions, forms a suitable model for investigating porcine paracellular intestinal barrier function.
Collapse
Affiliation(s)
- Silke S. Zakrzewski
- Institute of Clinical Physiology, Charité – Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Jan F. Richter
- Institute of Clinical Physiology, Charité – Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Susanne M. Krug
- Institute of Clinical Physiology, Charité – Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Britta Jebautzke
- Department of Gastroenterology, Division of Nutritional Medicine, Charité, Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - In-Fah M. Lee
- Institute of Clinical Physiology, Charité – Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Juliane Rieger
- Institute of Veterinary Anatomy, Freie Universität Berlin, Berlin, Germany
| | - Monika Sachtleben
- Institute of Veterinary Anatomy, Freie Universität Berlin, Berlin, Germany
| | - Angelika Bondzio
- Institute of Veterinary Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Jörg D. Schulzke
- Department of Gastroenterology, Division of Nutritional Medicine, Charité, Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Michael Fromm
- Institute of Clinical Physiology, Charité – Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Dorothee Günzel
- Institute of Clinical Physiology, Charité – Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
- * E-mail: correspondence:
| |
Collapse
|
20
|
Postrach E, Aspalter R, Elbelt U, Koller M, Schulzke JD, Valentini L. Effektivität eines Internet-basierten Programms zur eigenverantwortlichen Gewichtsreduktion: Eine Proof-of-principle Studie. Aktuel Ernahrungsmed 2012. [DOI: 10.1055/s-0032-1312530] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
21
|
Krug SM, Günzel D, Conrad MP, Rosenthal R, Fromm A, Amasheh S, Schulzke JD, Fromm M. Claudin-17 forms tight junction channels with distinct anion selectivity. Cell Mol Life Sci 2012; 69:2765-78. [DOI: 10.1007/s00018-012-0949-x] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 01/31/2012] [Accepted: 02/20/2012] [Indexed: 12/11/2022]
|
22
|
Hering NA, Richter JF, Krug SM, Günzel D, Fromm A, Bohn E, Rosenthal R, Bücker R, Fromm M, Tröger H, Schulzke JD. Modulation of epithelial barrier function by pathogenic Y. enterocolitica or probiotic E. coli Nissle. FASEB J 2011. [DOI: 10.1096/fasebj.25.1_supplement.1036.6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | - Anja Fromm
- Institute of Clinical PhysiologyBerlinGermany
| | - Erwin Bohn
- Inst. Medical Microbiology and HygieneUniv. TübingenGermanyTübingenGermany
| | | | | | | | | | - Jörg D. Schulzke
- Dept. General MedicineBerlinGermany
- Dept. GastroenterologyBerlinGermany
| |
Collapse
|
23
|
Bücker R, Krug SM, Rosenthal R, Günzel D, Fromm A, Zeitz M, Chakraborty T, Fromm M, Epple H, Schulzke JD. Aerolysin disturbs tight junction integrity and epithelial restitution. FASEB J 2011. [DOI: 10.1096/fasebj.25.1_supplement.1066.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | | | - Martin Zeitz
- Dept. GastroenterologyCharitéCampus Benjamin FranklinBerlinGermany
| | | | | | - Hans‐Jörg Epple
- Dept. GastroenterologyCharitéCampus Benjamin FranklinBerlinGermany
| | - Jörg D. Schulzke
- Dept. General Medicine
- Dept. GastroenterologyCharitéCampus Benjamin FranklinBerlinGermany
| |
Collapse
|
24
|
Amasheh S, Amasheh M, Fromm A, Krug SM, Fromm M, Schulzke JD. Claudin‐1‐ and ‐2‐based cytokine‐induced paracellular barrier impairment: prevention by the plant alkaloide, berberine. FASEB J 2011. [DOI: 10.1096/fasebj.25.1_supplement.1036.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
25
|
Schulzke JD, Andres S, Amasheh M, Fromm A, Günzel D. Anti-diarrheal mechanism of the traditional remedy Uzara via reduction of active chloride secretion. PLoS One 2011; 6:e18107. [PMID: 21479205 PMCID: PMC3068135 DOI: 10.1371/journal.pone.0018107] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2010] [Accepted: 02/21/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND AND PURPOSE The root extract of the African Uzara plant is used in traditional medicine as anti-diarrheal drug. It is known to act via inhibition of intestinal motility, but malabsorptive or antisecretory mechanisms are unknown yet. EXPERIMENTAL APPROACH HT-29/B6 cells and human colonic biopsies were studied in Ussing experiments in vitro. Uzara was tested on basal as well as on forskolin- or cholera toxin-induced Cl(-) secretion by measuring short-circuit current (I(SC)) and tracer fluxes of (22)Na(+) and (36)Cl(-). Para- and transcellular resistances were determined by two-path impedance spectroscopy. Enzymatic activity of the Na(+)/K(+)-ATPase and intracellular cAMP levels (ELISA) were measured. KEY RESULTS In HT-29/B6 cells, Uzara inhibited forskolin- as well as cholera toxin-induced I(SC) within 60 minutes indicating reduced active chloride secretion. Similar results were obtained in human colonic biopsies pre-stimulated with forskolin. In HT-29/B6, the effect of Uzara on the forskolin-induced I(SC) was time- and dose-dependent. Analyses of the cellular mechanisms of this Uzara effect revealed inhibition of the Na(+)/K(+)-ATPase, a decrease in forskolin-induced cAMP production and a decrease in paracellular resistance. Tracer flux experiments indicate that the dominant effect is the inhibition of the Na(+)/K(+)-ATPase. CONCLUSION AND IMPLICATIONS Uzara exerts anti-diarrheal effects via inhibition of active chloride secretion. This inhibition is mainly due to an inhibition of the Na(+)/K(+)-ATPase and to a lesser extent to a decrease in intracellular cAMP responses and paracellular resistance. The results imply that Uzara is suitable for treating acute secretory diarrhea.
Collapse
Affiliation(s)
- Jörg D Schulzke
- Department of Gastroenterology, Section of General Medicine and Nutrition, Charité, Campus Benjamin Franklin, Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany.
| | | | | | | | | |
Collapse
|
26
|
Bergann T, Fromm A, Borden SA, Fromm M, Schulzke JD. Glucocorticoid receptor is indispensable for physiological responses to aldosterone in epithelial Na+ channel induction via the mineralocorticoid receptor in a human colonic cell line. Eur J Cell Biol 2011; 90:432-9. [PMID: 21354648 DOI: 10.1016/j.ejcb.2011.01.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 12/17/2010] [Accepted: 01/05/2011] [Indexed: 11/26/2022] Open
Abstract
The epithelial Na+ channel (ENaC) plays a crucial role in electrogenic Na(+) absorption in the distal colon. ENaC induction via the mineralocorticoid receptor (MR) and the glucocorticoid receptor (GR) is differentially regulated by modulatory components. As most existing epithelial cell lines including colonic epithelial cell lines miss the co-expression of functional GR and MR, signaling on ENaC is only poorly characterized regarding the interplay of glucocorticoids and mineralocorticoids. In the present study, we show that GR expression and activity are indispensable for MR-dependent induction of ENaC-mediated Na(+) transport. Cooperativity of the two receptors has been studied in the highly differentiated, epithelial colonic cell line HT-29/B6-GR/MR which is equipped with the complete receptor repertoire of both GR and MR due to stable transfection. In contrast to HT-29/B6 cells solely expressing the MR, this cell line displays a physiological response to aldosterone regarding ENaC induction. To achieve this, a pre-incubation step with the GR agonist dexamethasone was required to allow for the subsequent stimulation of ENaC by aldosterone. As a result of cooperative effects between the activated GR and the MR, MR protein levels were elevated and MR-dependent transcription of ENaC subunits β and γ was increased. As an additional mechanism involved, transcription of SGK-1 (serum- and glucocorticoid-induced kinase 1) and GILZ (glucocorticoid-induced leucin zipper)--both essential for the insertion of ENaC into the apical enterocyte membrane--were also augmented by the activated MR.
Collapse
Affiliation(s)
- Theresa Bergann
- Department of General Medicine, Charité, Campus Benjamin Franklin, Hindenburgdamm 30, 12203 Berlin, Germany
| | | | | | | | | |
Collapse
|
27
|
Amasheh S, Dullat S, Fromm M, Schulzke JD, Buhr HJ, Kroesen AJ. Inflamed pouch mucosa possesses altered tight junctions indicating recurrence of inflammatory bowel disease. Int J Colorectal Dis 2009; 24:1149-56. [PMID: 19488769 DOI: 10.1007/s00384-009-0737-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/13/2009] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND AIMS The etiology of pouchitis after coloproctomucosectomy with ileal pouch-anal anastomosis in patients with ulcerative colitis is still unknown. Beside changes in luminal antigens, the immunological predisposition is assumed to be responsible. In previous electrophysiological studies, we showed that mucosal barrier and transport function in pouchitis is markedly reduced. Thus, the aim of the present study was to analyze barrier function on the molecular level. MATERIAL AND METHODS Pouch biopsies of 36 ulcerative colitis patients were analyzed. Time points were (1) intraoperative immediately prior to ileal pouch-anal anastomosis (n = 13), (2) >1 year after ileostomy closure (pouch, n = 12), and (3) during pouchitis (n = 11). Control terminal ileum biopsies were obtained from eight patients undergoing hemicolectomy due to carcinoma. Expression of tight junction proteins was analyzed by Western blotting and confocal laser-scanning microscopy. To elucidate effects on epithelial barrier properties, impedance spectroscopy was performed in miniaturized Ussing chambers. RESULTS In pouchitis, epithelial resistance was markedly reduced compared to non-inflamed pouch and control ileum. Expression of tight junction proteins claudin-1, 3, 4, 5, and 7 and occludin revealed differential expression regulation with the tightening tight junction protein claudin-1 being decreased and an increase of the pore-forming claudin-2, whereas other claudins remained constant. Morphometry indicated the mucosal surface to be unchanged. CONCLUSION Pouchitis is characterized by a selective change of tight junction proteins in favor of opening the epithelial tight junction and, thus, the paracellular pathway, which contributes to the inflammatory process. This resembles changes in inflammatory bowel disease (IBD) and indicates IBD recurrence in pouchitis.
Collapse
Affiliation(s)
- Salah Amasheh
- Institute of Clinical Physiology, CBF, Charité, Freie Universität und Humboldt Universität, 12200, Berlin, Germany.
| | | | | | | | | | | |
Collapse
|
28
|
Krug SM, Amasheh S, Richter JF, Milatz S, Günzel D, Westphal JK, Huber O, Schulzke JD, Fromm M. Tricellulin forms a barrier to macromolecules in tricellular tight junctions without affecting ion permeability. Mol Biol Cell 2009; 20:3713-24. [PMID: 19535456 DOI: 10.1091/mbc.e09-01-0080] [Citation(s) in RCA: 248] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Tricellulin is a tight junction protein localized in tricellular tight junctions (tTJs), the meeting points of three cells, but also in bicellular tight junctions (bTJs). To investigate its specific barrier functions in bTJs and tTJs, TRIC-a was expressed in low-level tricellulin-expressing cells, and MDCK II, either in all TJs or only in tTJs. When expressed in all TJs, tricellulin increased paracellular electrical resistance and decreased permeability to ions and larger solutes, which are associated with enhanced ultrastructural integrity of bTJs toward enhanced strand linearity. In tTJs in contrast, ultrastructure was unchanged and tricellulin minimized permeability to macromolecules but not to ions. This paradox is explained by properties of the tTJ central tube which is wide enough for passage of macromolecules, but too rare to contribute significantly to ion permeability. In conclusion, at low tricellulin expression the tTJ central tube forms a pathway for macromolecules. At higher expression, tricellulin forms a barrier in tTJs effective only for macromolecules and in bTJs for solutes of all sizes.
Collapse
Affiliation(s)
- Susanne M Krug
- Institute of Clinical Physiology, Charité, Freie Universität, Berlin, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Richter JF, Gitter AH, Günzel D, Weiss S, Mohamed W, Chakraborty T, Fromm M, Schulzke JD. Listeriolysin O affects barrier function and induces chloride secretion in HT-29/B6 colon epithelial cells. Am J Physiol Gastrointest Liver Physiol 2009; 296:G1350-9. [PMID: 19372105 DOI: 10.1152/ajpgi.00040.2009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Listeria monocytogenes is a food-borne pathogen, which is able to induce diarrhea when residing in the intestine. We studied the effect of listeriolysin O (LLO), an extracellular virulence factor of L. monocytogenes, on intestinal transport and barrier function in monolayers of HT-29/B6 human colon cells using the Ussing technique to understand the pathomechanisms involved. Mucosal addition of LLO, but not a LLO mutant, induced a dose- and pH-dependent increase in short-circuit current (I(SC)). Sodium and chloride tracer flux and DIDS sensitivity studies revealed that I(SC) was mainly due to electrogenic chloride secretion. Barrier function was impaired by LLO, as assessed by transepithelial resistance (R(t)) and mannitol flux measurements. Intracellular signal transduction occurred through Ca(2+) release from intracellular stores and PKC activation. In conclusion, listeriolysin induces chloride secretion and perturbs epithelial barrier function, thus potentially contributing to Listeria-induced diarrhea.
Collapse
Affiliation(s)
- Jan F Richter
- Institute of Clinical Physiology, Charité Berlin, Germany
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Bergann T, Plöger S, Fromm A, Zeissig S, Borden SA, Fromm M, Schulzke JD. A colonic mineralocorticoid receptor cell model expressing epithelial Na+ channels. Biochem Biophys Res Commun 2009; 382:280-5. [DOI: 10.1016/j.bbrc.2009.03.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Accepted: 03/04/2009] [Indexed: 11/27/2022]
|
31
|
Mankertz J, Amasheh M, Krug SM, Fromm A, Amasheh S, Hillenbrand B, Tavalali S, Fromm M, Schulzke JD. TNFalpha up-regulates claudin-2 expression in epithelial HT-29/B6 cells via phosphatidylinositol-3-kinase signaling. Cell Tissue Res 2009; 336:67-77. [PMID: 19214581 DOI: 10.1007/s00441-009-0751-8] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2008] [Accepted: 01/08/2009] [Indexed: 01/12/2023]
Abstract
Our aim has been to characterize the molecular mechanisms regulating the expression of the channel-forming tight-junctional protein claudin-2 in response to the pro-inflammatory cytokine tumor necrosis factor-alpha (TNFalpha), which is elevated, for example, in active Crohn's disease. TNFalpha caused an 89% decrease of the paracellular resistance in colonic HT-29/B6 cells, whereas transcellular resistance was unaltered. The claudin-2 protein level was increased by TNFalpha without changes in subcellular tight-junctional protein localization as revealed by confocal laser scanning microscopy. Enhanced gene expression was identified as the source of this increase, since claudin-2-specific mRNA and promoter activity was elevated, whereas mRNA stability remained unaltered. Specific inhibitors and phospho-specific antibodies revealed that the increased gene expression of claudin-2 after TNFalpha treatment was mediated by the phosphatidylinositol-3-kinase pathway. Thus, the up-regulation of claudin-2 by TNFalpha is attributable to the regulation of the expression of the gene, as a result of which epithelial barrier function is disturbed, for example, during chronic intestinal inflammation.
Collapse
Affiliation(s)
- J Mankertz
- Department of Gastroenterology, Charité, Campus Benjamin Franklin, Hindenburgdamm 30, 12200, Berlin, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Schumann M, Richter JF, Wedell I, Moos V, Zimmermann-Kordmann M, Schneider T, Daum S, Zeitz M, Fromm M, Schulzke JD. Mechanisms of epithelial translocation of the alpha(2)-gliadin-33mer in coeliac sprue. Gut 2008; 57:747-54. [PMID: 18305066 DOI: 10.1136/gut.2007.136366] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND AIMS The alpha(2)-gliadin-33mer has been shown to be important in the pathogenesis of coeliac disease. We aimed to study mechanisms of its epithelial translocation and processing in respect to transcytotic and paracellular pathways. METHODS Transepithelial passage of a fluorescence-labelled alpha(2)-gliadin-33mer was studied in Caco-2 cells by using reverse-phase high-performance liquid chromatography, mass spectrometry, confocal laser scanning microscopy (LSM) and fluorescence activated cell sorting (FACS). Endocytosis mechanisms were characterised with rab-GFP constructs transiently transfected into Caco-2 cells and in human duodenal biopsy specimens. RESULTS The alpha(2)-gliadin-33mer dose-dependently crossed the epithelial barrier in the apical-to-basal direction. Degradation analysis revealed translocation of the 33mer polypeptide in the uncleaved as well as in the degraded form. Transcellular passage was identified by confocal LSM, inhibitor experiments and FACS. Rab5 but not rab4 or rab7 vesicles were shown to be part of the transcytotic pathway. After pre-incubation with interferon-gamma, translocation of the 33mer was increased by 40%. In mucosal biopsies of the duodenum, epithelial 33mer uptake was significantly higher in untreated coeliac disease patients than in healthy controls or coeliac disease patients on a gluten-free diet. CONCLUSION Epithelial translocation of the alpha(2)-gliadin-33mer occurs by transcytosis after partial degradation through a rab5 endocytosis compartment and is regulated by interferon-gamma. Uptake of the 33mer is higher in untreated coeliac disease than in controls and coeliac disease patients on a gluten-free diet.
Collapse
Affiliation(s)
- M Schumann
- Klinik für Gastroenterologie, Charité, Campus Benjamin Franklin, 12200 Berlin, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Amasheh M, Schlichter S, Amasheh S, Mankertz J, Zeitz M, Fromm M, Schulzke JD. Quercetin enhances epithelial barrier function and increases claudin-4 expression in Caco-2 cells. J Nutr 2008; 138:1067-73. [PMID: 18492835 DOI: 10.1093/jn/138.6.1067] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Quercetin is the most abundant flavonoid and is assumed to have positive effects on the gastrointestinal mucosa after dietary intake. The aim of the study was to analyze the influence of quercetin on intestinal barrier function using the human colonic epithelial cell line Caco-2. Transepithelial resistance (R(t)), tracer fluxes of [(3)H]-mannitol, 22Na+, and 36Cl- as well as electrogenic ion transport were determined in Ussing chambers. Expression of tight junction (TJ) proteins and mRNA was analyzed in Western blots and quantitative RT-PCR, respectively. Regulation of transcription was analyzed by reporter gene assay. Cellular distribution of TJ proteins was examined by confocal laser scanning microscopy (LSM). Apoptotic rate was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining. Quercetin induced a dose-dependent increase of R(t) persisting for >2 d. Daily addition of quercetin was able to perpetuate the effect, which was seen whether quercetin was added apically or to the basolateral compartment. Parallel to the R(t) increase, quercetin induced a strong increase of the TJ protein claudin-4 but not of other claudins. Confocal LSM showed a localization of claudin-4 in TJ. Apoptotic rate was not affected by quercetin. Consistent with these changes, fluxes of Na+ and Cl-, but not of mannitol, were reduced. Reporter gene assays revealed a stimulatory effect of quercetin on claudin-4 transcription. The flavonoid quercetin enhances barrier function via transcriptional expression regulation of the TJ protein claudin-4, which represents an important protective effect of this food component against barrier disturbance in intestinal inflammation.
Collapse
Affiliation(s)
- Maren Amasheh
- Department of Gastroenterology and 5Institute of Clinical Physiology, Charité Campus Benjamin Franklin, 12200 Berlin, Germany
| | | | | | | | | | | | | |
Collapse
|
34
|
Jørgensen VL, Ibsen M, Andresen L, Schulzke JD, Perner A. Effects of endotoxaemia on markers of permeability, metabolism and inflammation in the large bowel of healthy subjects. Acta Anaesthesiol Scand 2007; 51:1085-92. [PMID: 17697304 DOI: 10.1111/j.1399-6576.2007.01381.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Increased permeability and increased luminal concentrations of L-lactate have previously been shown in the large bowel in septic patients. To advance these observations, a human model of colorectal barrier failure in sepsis is desirable. Therefore, we assessed the effects of endotoxaemia on markers of permeability, metabolism and inflammation in the large bowel in healthy subjects. METHODS Twelve healthy male subjects received intravenous endotoxin (2 ng/kg body weight) or saline in a paired cross-over design. Colorectal permeability was assessed after 3, 6, 9 and 12 h by the systemic recovery of luminally instilled (99m)Tc-diethylenetriaminepentaacetate. Luminal concentrations of L-lactate were assessed by equilibrium dialysis. Mucosal biopsies from the large bowel were sampled after 6 and 12 h, and the apoptotic ratio of the epithelium was assessed by terminal deoxynucleotidyl transferase-mediated desoxyuridinetriphosphate nick end-labelling (TUNEL) assay and the expression of inducible nitric oxide synthase (iNOS) mRNA by reverse transcriptase-polymerase chain reaction. RESULTS Systemic effects of endotoxaemia were observed, including fever, tachycardia and strongly increased plasma values of tumour necrosis factor-alpha. By contrast, the colorectal permeability, luminal lactate concentrations, mucosal infiltration of inflammatory cells, epithelial apoptotic ratio and expression of iNOS were all unaffected by endotoxin. CONCLUSIONS No effect of a single intravenous dose of endotoxin was observed on markers of large bowel permeability, metabolism and inflammation in healthy subjects. This suggests that this part of the gut is relatively resistant to the systemic inflammation induced by experimental endotoxaemia in humans.
Collapse
Affiliation(s)
- V L Jørgensen
- Department of Anaesthesia and Intensive Care, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark
| | | | | | | | | |
Collapse
|
35
|
Zeissig S, Fromm A, Mankertz J, Zeitz M, Fromm M, Schulzke JD. Restoration of ENaC expression by glucocorticoid receptor transfection in human HT-29/B6 colon cells. Biochem Biophys Res Commun 2006; 344:1065-70. [PMID: 16643850 DOI: 10.1016/j.bbrc.2006.04.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2006] [Accepted: 04/03/2006] [Indexed: 11/30/2022]
Abstract
The epithelial sodium channel (ENaC) controls colonic sodium absorption. So far, investigation of ENaC was limited by an unexplained lack of steroid-dependent ENaC expression in cultured intestinal cells, which we aimed to resolve. HT-29/B6 cells constitutively expressed the alpha-ENaC subunit, while beta- and gamma-ENaC subunits could not be detected due to deficient basal as well as corticosteroid-induced transcription. This was due to a lack of expression of both activating and inhibiting isoforms of glucocorticoid receptor (GR-alpha, -beta) and mineralocorticoid receptor. Stable transfection of GR-alpha restored intestine-specific glucocorticoid upregulation of beta- and gamma-ENaC in HT-29/B6 cells, which was followed by intact targeting of ENaC channels to the apical cell membrane and dose-dependent induction of electrogenic sodium absorption. In conclusion, ENaC deficiency is due to a lack of steroid receptors and not the consequence of a crypt-like phenotype of cultured intestinal cells. By stable GR transfection we obtained a model, in which ENaC regulation can be studied.
Collapse
Affiliation(s)
- Sebastian Zeissig
- Department of Gastroenterology, Charité, Campus Benjamin Franklin, Berlin, Germany.
| | | | | | | | | | | |
Collapse
|
36
|
Günzel D, Florian P, Richter JF, Troeger H, Schulzke JD, Fromm M, Gitter AH. Restitution of single-cell defects in the mouse colon epithelium differs from that of cultured cells. Am J Physiol Regul Integr Comp Physiol 2006; 290:R1496-507. [PMID: 16397094 DOI: 10.1152/ajpregu.00470.2005] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Integrity of colon epithelium is of crucial importance and, as small defects occur constantly, rapid repair (restitution) is essential. To investigate the mechanism of restitution, single-cell lesions were induced in mouse colonic surface epithelia by iontophoretic injection of Ca2+. Closure of the resulting defects was monitored using confocal laser scanning microscopy (CLSM), and functional sealing by electrophysiological techniques. Restitution was evaluated as the time constant tau of the exponential decrease in conductance of an induced leak and amounted to 0.28 min under control conditions. After 4 min, the leak was completely sealed. Repair was thus considerably faster than in previously investigated HT-29/B6 cells (tau=5.73 min). As in cultured cells, cytochalasin D delayed restitution in native colon epithelia (tau=0.69 min), indicating the involvement of actin in the healing process; however, no accumulation of actin surrounding the lesion was detected. Long-term incubation of epithelia with IFN-gamma alone or in combination with TNF-alpha increased tau to 0.49 and 0.59 min, respectively. In contrast to cultured cells, TNF-alpha alone did not affect restitution. A brief (<10 min) exposure to the sterile filtered supernatant of hemolytic E. coli O4 cultures did not affect the morphology of the epithelium, but delayed restitution. In CLSM studies, defects were still clearly visible 4 min after the onset of lesion induction. The supernatant of a nonhemolytic E. coli O4 mutant did not exhibit this effect. In conclusion, single-cell defects in native colon cause functional leaks that seal faster than in cell cultures. Proinflammatory cytokines and pathogenic bacteria delay restitution. This suggests a key role of very small lesions at the onset of pathogenic processes in the intestine.
Collapse
Affiliation(s)
- D Günzel
- Department of Clinical Physiology, Charité, Campus Benjamin Franklin, Hindenburgdamm 30, 12200 Berlin, and Jena University of Applied Sciences, Germany.
| | | | | | | | | | | | | |
Collapse
|
37
|
Heller F, Florian P, Bojarski C, Richter J, Christ M, Hillenbrand B, Mankertz J, Gitter AH, Bürgel N, Fromm M, Zeitz M, Fuss I, Strober W, Schulzke JD. Interleukin-13 is the key effector Th2 cytokine in ulcerative colitis that affects epithelial tight junctions, apoptosis, and cell restitution. Gastroenterology 2005; 129:550-64. [PMID: 16083712 DOI: 10.1016/j.gastro.2005.05.002] [Citation(s) in RCA: 838] [Impact Index Per Article: 44.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2004] [Accepted: 04/13/2005] [Indexed: 02/06/2023]
Abstract
BACKGROUND & AIMS Ulcerative colitis (UC) is characterized by a Th2 immune response with inflammation and epithelial barrier dysfunction. So far, Th2 cytokines have not been shown to directly influence epithelial barrier function. METHODS Lamina propria mononuclear cells (LPMCs) were stimulated and interleukin (IL)-13 was measured by enzyme-linked immunosorbent assay. Functional IL-13 and IL-4 effects were studied on HT-29/B6 colonic epithelial cells in Ussing chambers and by conductance scanning. Apoptosis was detected by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling assays. IL-13/IL-4 receptors were analyzed by reverse-transcription polymerase chain reaction and immunofluorescence. Western blotting combined with immunofluorescence was used to detect tight junction proteins. Furthermore, restitution velocity was measured. Finally, mucosal biopsy specimens from patients with UC were compared with cultured cells for these features. RESULTS LPMCs from patients with UC produced large amounts of IL-13 (985 +/- 73 pg/mL), much more than from controls or patients with Crohn's disease. IL-13Ralpha1 and IL-4Ralpha receptors were present in HT-29/B6 cells and colonic epithelial cells of control patients and patients with UC. IL-13 had a dose-dependent effect on transepithelial resistance of HT-29/B6 monolayers (reduction to 60% +/- 4%), whereas IL-4 had no effect. This was due to an increased number of apoptotic cells (5.6-fold +/- 0.9-fold) and an increased expression of the pore-forming tight junction protein claudin-2 to 295% +/- 37%, both of which contributed equally. Finally, epithelial restitution velocity decreased from 15.1 +/- 0.6 to 10.6 +/- 0.5 microm/h after treatment with IL-13. Parallel changes were observed in human samples, with an increase in claudin-2 expression to 956% +/- 252%. CONCLUSIONS IL-13 was identified as an important effector cytokine in UC that impairs epithelial barrier function by affecting epithelial apoptosis, tight junctions, and restitution velocity.
Collapse
Affiliation(s)
- Frank Heller
- Department of Gastroenterology, Charité, Campus Benjamin Franklin, Berlin, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Heller F, Florian P, Bojarski C, Richter J, Christ M, Hillenbrand B, Mankertz J, Gitter AH, Bürgel N, Fromm M, Zeitz M, Fuss I, Strober W, Schulzke JD. Interleukin-13 is the key effector Th2 cytokine in ulcerative colitis that affects epithelial tight junctions, apoptosis, and cell restitution. Gastroenterology 2005. [PMID: 16083712 DOI: 10.1053/j.gastro.2005.05.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Ulcerative colitis (UC) is characterized by a Th2 immune response with inflammation and epithelial barrier dysfunction. So far, Th2 cytokines have not been shown to directly influence epithelial barrier function. METHODS Lamina propria mononuclear cells (LPMCs) were stimulated and interleukin (IL)-13 was measured by enzyme-linked immunosorbent assay. Functional IL-13 and IL-4 effects were studied on HT-29/B6 colonic epithelial cells in Ussing chambers and by conductance scanning. Apoptosis was detected by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling assays. IL-13/IL-4 receptors were analyzed by reverse-transcription polymerase chain reaction and immunofluorescence. Western blotting combined with immunofluorescence was used to detect tight junction proteins. Furthermore, restitution velocity was measured. Finally, mucosal biopsy specimens from patients with UC were compared with cultured cells for these features. RESULTS LPMCs from patients with UC produced large amounts of IL-13 (985 +/- 73 pg/mL), much more than from controls or patients with Crohn's disease. IL-13Ralpha1 and IL-4Ralpha receptors were present in HT-29/B6 cells and colonic epithelial cells of control patients and patients with UC. IL-13 had a dose-dependent effect on transepithelial resistance of HT-29/B6 monolayers (reduction to 60% +/- 4%), whereas IL-4 had no effect. This was due to an increased number of apoptotic cells (5.6-fold +/- 0.9-fold) and an increased expression of the pore-forming tight junction protein claudin-2 to 295% +/- 37%, both of which contributed equally. Finally, epithelial restitution velocity decreased from 15.1 +/- 0.6 to 10.6 +/- 0.5 microm/h after treatment with IL-13. Parallel changes were observed in human samples, with an increase in claudin-2 expression to 956% +/- 252%. CONCLUSIONS IL-13 was identified as an important effector cytokine in UC that impairs epithelial barrier function by affecting epithelial apoptosis, tight junctions, and restitution velocity.
Collapse
Affiliation(s)
- Frank Heller
- Department of Gastroenterology, Charité, Campus Benjamin Franklin, Berlin, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Schulzke JD, Gitter AH, Mankertz J, Spiegel S, Seidler U, Amasheh S, Saitou M, Tsukita S, Fromm M. Epithelial transport and barrier function in occludin-deficient mice. Biochim Biophys Acta 2005; 1669:34-42. [PMID: 15842997 DOI: 10.1016/j.bbamem.2005.01.008] [Citation(s) in RCA: 227] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 06/09/2004] [Revised: 12/14/2004] [Accepted: 01/13/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND AND AIMS This study aimed at functional characterization of the tight junction protein occludin using the occludin-deficient mouse model. METHODS Epithelial transport and barrier functions were characterized in Ussing chambers. Impedance analysis revealed the ionic permeability of the epithelium (Re, epithelial resistance). Conductance scanning differentiated transcellular (Gc) and tight junctional conductance (Gtj). The pH-stat technique quantified gastric acid secretion. RESULTS In occludin+/+ mice, Re was 23+/-5 Omega cm2 in jejunum, 66+/-5 Omega cm2 in distal colon and 33+/-6 Omega cm2 in gastric corpus and was not altered in heterozygotic occludin+/- or homozygotic occludin-/- mice. Additionally, [3H]mannitol fluxes were unaltered. In the control colon, Gc and Gtj were 7.6+/-1.0 and 0.3+/-0.1 mS/cm2 and not different in occludin deficiency. Epithelial resistance after mechanical perturbation or EGTA exposition (low calcium switch) was not more affected in occludin-/- mice than in control. Barrier function was measured in the urinary bladder, a tight epithelium, and in the stomach. Control Rt was 5.8+/-0.8 kOmega cm2 in urinary bladder and 33+/-6 Omega cm2 in stomach and not altered in occludin-/- mice. In gastric corpus mucosa, the glandular structure exhibited a complete loss of parietal cells and mucus cell hyperplasia, as a result of which acid secretion was virtually abolished in occludin-/- mice. CONCLUSION Epithelial barrier characterization in occludin-deficiency points against an essential barrier function of occludin within the tight junction strands or to a substitutional redundancy of single tight junction molecules like occludin. A dramatic change in gastric morphology and secretory function indicates that occludin is involved in gastric epithelial differentiation.
Collapse
Affiliation(s)
- J D Schulzke
- Department of Gastroenterology, Campus Benjamin Franklin, Charité-Universitary Medicine Berlin, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Zeissig S, Bojarski C, Buergel N, Mankertz J, Zeitz M, Fromm M, Schulzke JD. Downregulation of epithelial apoptosis and barrier repair in active Crohn's disease by tumour necrosis factor alpha antibody treatment. Gut 2004; 53:1295-302. [PMID: 15306588 PMCID: PMC1774168 DOI: 10.1136/gut.2003.036632] [Citation(s) in RCA: 243] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIMS Barrier dysfunction is an important feature contributing to inflammation and diarrhoea in Crohn's disease (CD). Recently, tumour necrosis factor alpha (TNF-alpha) antibodies were recognised as effective in steroid refractory CD. The aim of this study was to characterise the effects of this therapy on the epithelial barrier. PATIENTS AND METHODS Forceps biopsies were obtained from the sigmoid colon before and 14 days after TNF-alpha antibody therapy in 11 patients treated for chronic active CD (Crohn's disease activity index >150). Epithelial apoptoses were measured after terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick end labelling (TUNEL) and 4',6-diamidino-2-phenylindole staining. Epithelial resistance was determined by alternating current impedance analysis in miniaturised Ussing chambers. Occludin, claudin 1, and claudin 4 expression was quantified in immunoblots. RESULTS The epithelial apoptotic ratio was 2.1 (0.2)% in controls and increased to 5.3 (1.0)% in CD. TNF-alpha antibody therapy decreased the apoptotic ratio to 2.9 (1.0)% (normalised in 10 of 11 patients). In parallel, epithelial resistance was lower in CD than in controls (24 (3) v 42 (3) Omegaxcm(2)) and improved to 34 (3) Omegaxcm(2) after therapy. Occludin, claudin 1, and claudin 4 were not affected by TNF-alpha antibody therapy. In support of a functional role of epithelial apoptoses in CD, a similar decrease in resistance of -40% was observed when the apoptotic rate was selectively upregulated from 2.6% to 5.4% with camptothecin in HT-29/B6 cells. CONCLUSIONS Epithelial apoptoses were upregulated in the colon in CD and restored to normal in 10 of 11 patients by TNF-alpha antibody therapy. This is the structural correlate of epithelial barrier dysfunction measured as epithelial resistance while expression of tight junction proteins did not contribute to this therapeutic effect.
Collapse
Affiliation(s)
- S Zeissig
- Medizinische Klinik I, Charitè-Universitary Medicine Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, Berlin 12200, Germany.
| | | | | | | | | | | | | |
Collapse
|
41
|
Epple HJ, Mankertz J, Ignatius R, Liesenfeld O, Fromm M, Zeitz M, Chakraborty T, Schulzke JD. Aeromonas hydrophila beta-hemolysin induces active chloride secretion in colon epithelial cells (HT-29/B6). Infect Immun 2004; 72:4848-58. [PMID: 15271947 PMCID: PMC470692 DOI: 10.1128/iai.72.8.4848-4858.2004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The diarrheal mechanisms in Aeromonas enteritis are not completely understood. In this study we investigated the effect of aeromonads and of their secretory products on ion secretion and barrier function of monolayers of human intestinal cells (HT-29/B6). Ion secretion was determined as a short-circuit current (I(SC)) of HT-29/B6 monolayers mounted in Ussing-type chambers. Transepithelial resistance (R(t)) served as a measure of permeability. A diarrheal strain of Aeromonas hydrophila (strain Sb) added to the mucosal side of HT-29/B6 monolayers induced a significant I(SC) (39 +/- 3 microA/cm(2)) and decreased the R(t) to approximately 10% of the initial value. A qualitatively identical response was obtained with sterile supernatant of strain Sb, and Aeromonas supernatant also induced a significant I(SC) in totally stripped human colon. Tracer flux and ion replacement studies revealed the I(SC) to be mainly accounted for by electrogenic Cl(-) secretion. Supernatant applied serosally completely abolished basal I(SC). The supernatant-induced I(SC) was inhibited by the protein kinase C inhibitor chelerythrine, whereas a protein kinase A inhibitor (H8) and a Ca(2+) chelator (BAPTA-AM) had no effect. Physicochemical properties indicated that the supernatant's active compound was an aerolysin-related Aeromonas beta-hemolysin. Accordingly, identical I(SC) and R(t) responses were obtained with Escherichia coli lysates harboring the cloned beta-hemolysin gene from strain SB or the aerA gene encoding for aerolysin. Sequence comparison revealed a 64% homology between aerolysin and the beta-hemolysin cloned from Aeromonas sp. strain Sb. In conclusion, beta-hemolysin secreted by pathogenic aeromonads induces active Cl(-) secretion in the intestinal epithelium, possibly by channel insertion into the apical membrane and by activation of protein kinase C.
Collapse
Affiliation(s)
- H J Epple
- Medical Clinic I, Gastroenterology, Infectiology, and Rheumatology, Berlin, Germany
| | | | | | | | | | | | | | | |
Collapse
|
42
|
Lenzner L, Bode H, Krämer O, Loddenkemper C, Kroesen AJ, Schulzke JD, Zeitz M, Ullrich R. Epitheliale Apoptoseinduktion durch die HIV-Proteaseinhibitoren Saquinavir und Nelfinavir in kolorektalen Zelllinien und Tumoren. Z Gastroenterol 2004. [DOI: 10.1055/s-2004-831591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
43
|
Barmeyer C, Harren M, Schmitz H, Heinzel-Pleines U, Mankertz J, Seidler U, Horak I, Wiedenmann B, Fromm M, Schulzke JD. Mechanisms of diarrhea in the interleukin-2-deficient mouse model of colonic inflammation. Am J Physiol Gastrointest Liver Physiol 2004; 286:G244-52. [PMID: 14715519 DOI: 10.1152/ajpgi.00141.2003] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Colitis in interleukin-2-deficient (IL-2(-/-)) mice resembles ulcerative colitis in humans. We studied epithelial transport and barrier function in IL-2(-/-) mice and used this model to characterize mechanisms of diarrhea during intestinal inflammation. (22)Na(+) and (36)Cl(-) fluxes were measured in proximal colon. Net Na(+) flux was reduced from 4.0 +/- 0.5 to 0.8 +/- 0.5 micromol.h(-1).cm(-2), which was paralleled by diminished mRNA and protein expression of the Na(+)/H(+) exchanger NHE3. Net Cl(-) flux was also decreased from 2.2 +/- 1.6 to -2.7 +/- 0.6 micromol.h(-1).cm(-2), indicating impaired Na(+)-Cl(-) absorption. In distal colon, aldosterone-induced electrogenic Na(+) absorption was 6.1 +/- 0.9 micromol.h(-1).cm(-2) in controls and was abolished in IL-2(-/-) mice. Concomitantly, mRNA expression of beta- and gamma-subunits of the epithelial sodium channel (ENaC) was reduced. Epithelial barrier was studied in proximal colon by impedance technique and mannitol fluxes. In contrast to ulcerative colitis, epithelial resistance was increased and mannitol fluxes were decreased in IL-2(-/-) mice. This was in accord with the findings of reduced ion transport as well as increased expression of tight junction proteins occludin and claudin-1, -2, -3, and -5. In conclusion, the IL-2(-/-) mucosa exhibits impaired electroneutral Na(+)-Cl(-) absorption and electrogenic Na(+) transport due to reduced mRNA and protein expression of NHE3 and ENaC beta- and gamma-subunit mRNA. This represents a model of early intestinal inflammation with absorptive dysfunction due to impaired transport protein expression/function while epithelial barrier is still intact. Therefore, this model is ideal to study regulation of transporter expression independent of barrier defects.
Collapse
Affiliation(s)
- C Barmeyer
- Department of Gastroenterology, Charité-University Medicine Berlin, 12200 Berlin, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Abstract
Interleukin-2-deficient (IL-2(-/-)) mice develop colitis with striking clinical and morphological similarities to ulcerative colitis. Since transport and barrier properties are impaired in ulcerative colitis, we studied transport and barrier functions in IL-2(-/-) mice in order to gain insight for the first time into the general pathomechanisms of disturbed transport and barrier function of the intestine during inflammation. Alternating current impedance analysis was used to determine tissue conductance in the inflamed proximal colon of IL-2(-/-) mice and to discriminate between pure epithelial and subepithelial conductance. Surprisingly, epithelial conductance was not increased but diminished in IL-2(-/-) mice compared to controls (20.2 +/- 1.3 versus 28.8 +/- 2.8 mS/cm(2)). Concomitantly, conductance of the subepithelial tissue layers was decreased in IL-2(-/-) mice as a result of edema and infiltration with inflammatory cells. In the distal colon, electrogenic Na(+) transport (J(Na)) mediated by the epithelial Na(+) channel (ENaC) was measured 8 h after stimulation with 3.10(-9) M aldosterone in vitro as the drop in I(SC) (short circuit current) after addition of 10(-4) M amiloride. In controls, J(Na) was 6.9 +/- 0.9 micromol x h(-1) x cm(-2), whereas it was abolished in IL-2(-/-) mice. In conclusion, the inflamed colon of IL-2(-/-) mice exhibits a severe disturbance in Na(+) uptake via the ENaC in the absence of a barrier defect. Thus, reduced expression of active absorptive transport and not a barrier defect is responsible for the diarrhea in this model of intestinal inflammation. This makes this model suitable for studying the general pathomechanisms of the inflammatory downregulation of intestinal transport proteins.
Collapse
Affiliation(s)
- C Barmeyer
- Medical Clinic I - Gastroenterology, Infectious Diseases and Rheumatology, University Clinic Benjamin Franklin, Free University of Berlin, Berlin, Germany
| | | | | | | | | |
Collapse
|
45
|
Amasheh S, Meiri N, Gitter AH, Schöneberg T, Mankertz J, Schulzke JD, Fromm M. Claudin-2 expression induces cation-selective channels in tight junctions of epithelial cells. J Cell Sci 2002; 115:4969-76. [PMID: 12432083 DOI: 10.1242/jcs.00165] [Citation(s) in RCA: 616] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Tight junctions seal the paracellular pathway of epithelia but, in leaky tissues, also exhibit specific permeability. In order to characterize the contribution of claudin-2 to barrier and permeability properties of the tight junction in detail, we studied two strains of Madin-Darby canine kidney cells (MDCK-C7 and MDCK-C11) with different tight junctional permeabilities. Monolayers of C7 cells exhibited a high transepithelial resistance (>1 kOhms cm(2)), compared with C11 cells (<100 Ohms cm(2)). Genuine expression of claudin-1 and claudin-2, but not of occludin or claudin-3, was reciprocal to transepithelial resistance. However, confocal microscopy revealed a marked subjunctional localization of claudin-1 in C11 cells, indicating that claudin-1 is not functionally related to the low tight junctional resistance of C11 cells. Strain MDCK-C7, which endogenously does not express junctional claudin-2, was transfected with claudin-2 cDNA. In transfected cells, but not in vector controls, the protein was detected in colocalization with junctional occludin by means of immunohistochemical analyses. Overexpression of claudin-2 in the originally tight epithelium with claudin-2 cDNA resulted in a 5.6-fold higher paracellular conductivity and relative ion permeabilities of Na(+) identical with 1, K(+)=1.02, NMDG(+)=0.79, choline(+)=0.71, Cl(-)=0.12, Br(-)=0.10 (vector control, 1:1.04:0.95:0.94:0.85:0.83). By contrast, fluxes of (radioactively labeled) mannitol and lactulose and (fluorescence labeled) 4 kDa dextran were not changed. Hence, with regular Ringer's, Na(+) conductivity was 0.2 mS cm(-2) in vector controls and 1.7 mS cm(-2) in claudin-2-transfected cells, while Cl(-) conductivity was 0.2 mS cm(-2) in both cells. Thus, presence of junctional claudin-2 causes the formation of cation-selective channels sufficient to transform a 'tight' tight junction into a leaky one.
Collapse
Affiliation(s)
- Salah Amasheh
- Department of Clinical Physiology, Benjamin Franklin Medical School, Freie Universität Berlin, Hindenburgdamm 30, 12200 Berlin, Germany
| | | | | | | | | | | | | |
Collapse
|
46
|
Florian P, Schöneberg T, Schulzke JD, Fromm M, Gitter AH. Single-cell epithelial defects close rapidly by an actinomyosin purse string mechanism with functional tight junctions. J Physiol 2002; 545:485-99. [PMID: 12456828 PMCID: PMC2290693 DOI: 10.1113/jphysiol.2002.031161] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Restitution of single-cell defects, a frequent event in epithelia with high turnover, is poorly understood. Morphological and functional changes were recorded, using intravital time-lapse video microscopy, confocal fluorescence microscopy, and conductance scanning techniques. After artificial single-cell loss from an HT-29/B6 colonic cell monolayer, the basal ends of adjacent cells extended. Concurrently, the local conductive leak associated with the defect sealed with an exponential time course (from 0.48 +/- 0.05 microS 2 min post lesion to 0.17 +/- 0.02 microS 8 min post lesion, n = 17). Between 3 and 10 min post lesion, a band of actin arose around the gap, which colocalized with a ring of ZO-1 and occludin. Hence, tight junction proteins bound to the actin band facing the gap, and competent tight junctions assembled in the adjoining cell membranes. Closure and sealing were inhibited when actin polymerization was blocked by cytochalasin D, delayed following decrease of myosin-ATPase activity by butanedione monoxime, and blocked after myosin light chain kinase inhibition by ML-7. The Rho-associated protein kinase inhibitor Y-27632 did not affect restitution. After loosening of intercellular contacts in low Ca(2+) Ringer solution, the time course of restitution was not significantly altered. Albeit epithelial conductivity was 12-fold higher in low Ca(2+) Ringer solution than in controls, under both conditions the repaired epithelium assumed the same conductivity as distant intact epithelium. In conclusion, epithelial restitution of single-cell defects comprises rapid closure by an actinomyosin 'purse-string' mechanism and simultaneous formation of a functional barrier from tight junction proteins also associated with the purse string.
Collapse
Affiliation(s)
- P Florian
- Institut für Klinische Physiologie, Universitätsklinikum Benjamin Franklin, Freie Universität Berlin, 12200 Berlin, Germany
| | | | | | | | | |
Collapse
|
47
|
Abstract
The etiology and pathogenesis of ulcerative colitis are still unclear. There is, however, a growing consensus that the disease is characterized by a complex interaction between genetic and environmental influences. Many studies in the last few years have suggested that appendectomy reduces the risk of development and improves the course of ulcerative colitis. The underlying mechanism of this effect is unknown. The appendix seems to play a more important role in the development and modulation of the mucosal immune system than believed so far.
Collapse
Affiliation(s)
- N Buergel
- Medizinische Klinik I-Gastroenterologie, Infektiologie und Rheumatologie, Universitätsklinikum Benjamin Franklin, Freie Universität Berlin, Hindenburgdamm 30, 12200 Berlin
| | | | | |
Collapse
|
48
|
Kroesen AJ, Stockmann M, Ransco C, Schulzke JD, Fromm M, Buhr HJ. Impairment of epithelial transport but not of barrier function in idiopathic pouchitis after ulcerative colitis. Gut 2002; 50:821-6. [PMID: 12010884 PMCID: PMC1773227 DOI: 10.1136/gut.50.6.821] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
BACKGROUND AND AIMS Little is known of the permeability of ileoanal pouches. Hence the aim of the present study was to determine changes in permeability and mucosal function after ileo-pouchanal anastomosis (IPAA) in patients with ulcerative colitis. MATERIALS AND METHODS Biopsies were taken from 43 patients (male:female ratio 28:15; mean age 35.2 (12.5) years) prior to colectomy (ileum prior to pouch), prior to closure of ileostomy (deviation), and after closure of ileostomy (intact pouch) in the case of pouchitis, and from 14 healthy controls. Tissues were mounted in a miniaturised Ussing chamber. Epithelial and subepithelial resistance was determined by transmural impedance analysis. Active Na(+)-glucose cotransport was measured as change in short circuit current after stepwise addition of glucose, and active Cl(-) secretion was measured after stimulation with theophylline and prostaglandin E(2). RESULTS Neither epithelial resistance nor mannitol fluxes were significantly altered compared with intact controls, indicating no barrier defect in pouchitis. Subepithelial resistances of intact pouches and pouchitis were increased compared with deviation (18.2 (1.6) and 24.3 (1.5) v. 13.6 (1.0) Omegaxcm(2)) consistent with an adaptive thickening of the subepithelial layer. In contrast, active Cl(-) secretion of pouchitis tissues was reduced versus intact pouch and controls (1.4 (0.3) v. 4.3 (0.7) and 4.6 (0.7) micromol/h/cm(2)), and Na(+)-glucose cotransport of pouchitis was reduced compared with intact pouch and controls (1.8 (0.5) v. 4.2 (0.8) and 8.8 (1.3) micromol/h/cm(2)). CONCLUSIONS Ileal mucosa in pouchitis and terminal ileum prior to IPAA exhibit impaired secretory and absorptive transport functions whereas the epithelial barrier function remains unchanged. This differs from findings in ulcerative colitis. Thus the hypothesis that pouchitis represents a remanifestation of ulcerative colitis has to be questioned.
Collapse
Affiliation(s)
- A J Kroesen
- Department of Surgery, University Hospital Benjamin Franklin, Freie Universität Berlin, Germany.
| | | | | | | | | | | |
Collapse
|
49
|
Gitter AH, Wullstein F, Fromm M, Schulzke JD. Epithelial barrier defects in ulcerative colitis: characterization and quantification by electrophysiological imaging. Gastroenterology 2001; 121:1320-8. [PMID: 11729111 DOI: 10.1053/gast.2001.29694] [Citation(s) in RCA: 180] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND & AIMS In ulcerative colitis (UC), the epithelial barrier is impaired by erosion/ulcer-type lesions and epithelial apoptosis causing local leaks, and generalized tight junction alterations increasing the basal permeability. We quantified the contribution of these mechanisms to the increased colonic ion permeability. METHODS Sigmoid colon was stripped, and the spatial distribution of current clamped across the viable epithelium was recorded by a microelectrode probe, using the conductance scanning method. Local leaks (circumscribed conductive peaks) were marked, and structural changes were studied in H&E-stained series sections. RESULTS Overall conductivity increased from 8.4 +/- 0.7 mS/cm(2) (mean +/- SEM) in controls to 11.7 +/- 0.6 in specimens with mild inflammation (i.e., with intact epithelium) and 34.4 +/- 6.2 mS/cm(2) in moderate-to-severe inflammation (i.e., with visible epithelial lesions). Only in part this was caused by a generalized increase in basal conductivity (12.2 +/- 1.5 mS/cm(2) in moderate-to-severe UC vs. 8.3 +/- 0.7 in controls). More importantly, the spatial distribution of conductivity, which was even in controls, showed dramatic leaks in UC. Leaks found in mild inflammation without epithelial lesion turned out to be foci of epithelial apoptosis. In moderate-to-severe inflammation, leaks correlated with epithelial erosion/ulcer-type lesions or crypt abscesses. CONCLUSIONS In early UC, but not in controls, seemingly intact epithelium comprises leaks at apoptotic foci. With more intensive inflammation, erosion/ulcer-type lesions are highly conductive, even if covered with fibrin. Local leaks contribute 19% to the overall epithelial conductivity in mild and 65% in moderate-to-severe inflammation.
Collapse
Affiliation(s)
- A H Gitter
- Institut für Klinische Physiologie, Universitätsklinikum Benjamin Franklin, Freie Universität Berlin, 12200 Berlin, Germany.
| | | | | | | |
Collapse
|
50
|
Abstract
BACKGROUND & AIMS Abdominal symptoms in the absence of mucosal abnormalities are features of both the irritable bowel syndrome (IBS) and latent/potential celiac disease (cd). To identify a possible subgroup of IBS patients with latent/potential cd, surrogate markers of cd were investigated in IBS patients. METHODS IBS patients suffering from diarrhea (n = 102), and patients with active cd (n = 10), treated cd (n = 26), and latent cd (n = 5) were included in the study. We measured serum immunoglobulin (Ig) A against gliadin and tissue-transglutaminase, and IgA and IgM against gliadin, tissue-transglutaminase (intestinal cd-associated antibodies), and the dietary proteins beta-lactoglobulin and ovalbumin in duodenal aspirate by enzyme-linked immunosorbent assay. Intraepithelial lymphocytes (IELs) were counted in histology sections, and the expression of HLA-DQ2 (A1*0501/B1*0201) was investigated by polymerase chain reaction. In 26 IBS patients, the effect of 6 months of gluten withdrawal was examined. RESULTS Most cd patients expressed HLA-DQ2 and had increased intestinal cd-associated antibodies, whereas cd-associated serum IgA and IEL counts were increased in active cd in contrast to treated or latent cd. In IBS patients, 35% were HLA-DQ2-positive, 23% had increased IEL counts, and 0% and 30% had increased cd-associated antibodies in serum and duodenal aspirate, respectively. Furthermore, stool frequency and intestinal IgA decreased significantly under a gluten-free diet in the subgroups of HLA-DQ2-positive and intestinal antibody-positive IBS patients when compared with IBS patients without these markers. CONCLUSIONS HLA-DQ2 expression and increased intestinal cd-associated antibodies are markers that can identify latent/potential cd in a subgroup of IBS patients who consequently appear to profit from a gluten-free diet.
Collapse
Affiliation(s)
- U Wahnschaffe
- Department of Gastroenterology and Infectious Diseases, Universitätsklinikum Benjamin Franklin, Freie Universität Berlin, D-12200 Berlin, Germany.
| | | | | | | |
Collapse
|