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Stremmel W, Staffer S, Stuhrmann N, Gan-Schreier H, Gauss A, Burger N, Hornuss D. Phospholipase A 2 of Microbiota as Pathogenetic Determinant to Induce Inflammatory States in Ulcerative Colitis: Therapeutic Implications of Phospholipase A 2 Inhibitors. Inflamm Intest Dis 2018; 2:180-187. [PMID: 29922677 DOI: 10.1159/000486858] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 01/12/2018] [Indexed: 12/17/2022] Open
Abstract
Background Attack by commensal microbiota is one component of induction of inflammatory episodes in ulcerative colitis (UC). In UC, the mucus layer is intrinsically devoid of phosphatidylcholine (PC) resulting in low hydrophobicity which facilitates bacterial invasion. Colonic ectophospholipase-carrying bacterial strains are likely candidates to further thinning the PC mucus barrier and to precipitate inflammatory episodes. Objective To evaluate the effect of phospholipase A2 (PLA2) inhibitors on inflammation in a genetic UC mouse model. Methods As PLA2 inhibitor, we applied the bile acid-phospholipid conjugate ursodeoxycholate-lysophosphatidylethanolamide (UDCA-LPE) or as control 5% Tween 80 by oral gavage to intestine-specific kindlin 2 knockout mice. Results Luminal UDCA-LPE reduced the PLA2 activity in stool by 36 ± 8%. Concomitantly no inflammatory phenotype was observed when compared to kindlin 2(-/-) mice not treated with UDCA-LPE. The improvement was documented in regard to stool consistency, calprotectin levels in stool, and macroscopic/endoscopic as well as histologic features of the mucosa. The pattern of colonic microbiota distribution obtained in the UC phenotype mice was reversed by UDCA-LPE to the control mice pattern. Conclusion The inhibition of the bacterial ectophospholipase A2 activity improves mucosal inflammation in a genetic mouse model of UC. It is assumed that the remaining mucus PC shield is better preserved when luminal PLA2 is suppressed.
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Affiliation(s)
- Wolfgang Stremmel
- Department of Internal Medicine IV, University Clinics of Heidelberg, Heidelberg, Germany
| | - Simone Staffer
- Department of Internal Medicine IV, University Clinics of Heidelberg, Heidelberg, Germany
| | - Nicole Stuhrmann
- Department of Internal Medicine IV, University Clinics of Heidelberg, Heidelberg, Germany
| | - Hongying Gan-Schreier
- Department of Internal Medicine IV, University Clinics of Heidelberg, Heidelberg, Germany
| | - Annika Gauss
- Department of Internal Medicine IV, University Clinics of Heidelberg, Heidelberg, Germany
| | - Nina Burger
- Department of Internal Medicine IV, University Clinics of Heidelberg, Heidelberg, Germany
| | - Daniel Hornuss
- Department of Internal Medicine IV, University Clinics of Heidelberg, Heidelberg, Germany
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Stremmel W, Staffer S, Schneider MJ, Gan-Schreier H, Wannhoff A, Stuhrmann N, Gauss A, Wolburg H, Mahringer A, Swidsinski A, Efferth T. Genetic Mouse Models with Intestinal-Specific Tight Junction Deletion Resemble an Ulcerative Colitis Phenotype. J Crohns Colitis 2017; 11:1247-1257. [PMID: 28575164 PMCID: PMC5881657 DOI: 10.1093/ecco-jcc/jjx075] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Accepted: 05/23/2017] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND AIMS A key pathogenetic feature of ulcerative colitis [UC] is an intrinsic low mucus phosphatidylcholine[PC] content. Recently, a paracellular transport for PC across tight junctions[TJs] was described, suggesting TJ disturbance as a cause of diminished luminal PC transport. Therefore, we aimed to generate mutant mice with TJ deletion to evaluate whether a UC phenotype developed. METHODS CL57BL/6 control wild-type mice were compared to mutant mice with tamoxifen-induced villin-Cre-dependent intestinal deletion of kindlin 1 and 2. RESULTS Electron microscopy of mucosal biopsies obtained from both mutants before overt inflammation following only 2 days of tamoxifen exposure revealed a defective TJ morphology with extended paracellular space and, by light microscopy, expanded mucosal crypt lumina. PC secretion into mucus was reduced by >65% and the mucus PC content dropped by >50%, causing a >50 % decrease of mucus hydrophobicity in both mutants. Consequently, the microbiota was able to penetrate the submucosa. After 3 days of tamoxifen exposure, intestinal inflammation was present in both mutants, with loose bloody stools as well as macroscopic and histological features of colitis. Oral PC supplementation was able to suppress inflammation. By analogy, colonic biopsies obtained from patients with UC in remission also showed a defective epithelium with widened intercellular clefts, and enlarged crypt luminal diameters with functionally impaired luminal PC secretion. CONCLUSIONS Genetic mouse models with intestinal deletion of kindlin 1 and 2 resulted in TJ deletion and revealed pathophysiological features of impaired PC secretion to the mucus leading to mucosal inflammation compatible with human UC.
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Affiliation(s)
- Wolfgang Stremmel
- Department of Internal Medicine IV, University Clinics of Heidelberg, Heidelberg, Germany,Corresponding author: Wolfgang Stremmel, MD, PhD, Professor of Medicine, University Clinics of Heidelberg, Department of Internal Medicine IV, 69120 Heidelberg, Germany. Tel: +49 6221 56 8700;
| | - Simone Staffer
- Department of Internal Medicine IV, University Clinics of Heidelberg, Heidelberg, Germany
| | | | - Hongying Gan-Schreier
- Department of Internal Medicine IV, University Clinics of Heidelberg, Heidelberg, Germany
| | - Andreas Wannhoff
- Department of Internal Medicine IV, University Clinics of Heidelberg, Heidelberg, Germany
| | - Nicole Stuhrmann
- Department of Internal Medicine IV, University Clinics of Heidelberg, Heidelberg, Germany
| | - Annika Gauss
- Department of Internal Medicine IV, University Clinics of Heidelberg, Heidelberg, Germany
| | - Hartwig Wolburg
- Department of Pathology and Neuropathology, University Medical School of Tübingen, Tübingen, Germany
| | - Anne Mahringer
- Institute of Pharmacy and Molecular Biotechnology, Ruprecht-Karls-University of Heidelberg, Heidelberg, Germany
| | - Alexander Swidsinski
- Department of Gastroenterology, University Hospital Charité of Berlin, 10115 Berlin, Germany
| | - Thomas Efferth
- Department of Pharmaceutical Biology, Institute of Pharmacy and Biochemistry, Mainz, Germany
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Hoffmann W. TFF2, a MUC6-binding lectin stabilizing the gastric mucus barrier and more (Review). Int J Oncol 2015. [PMID: 26201258 DOI: 10.3892/ijo.2015.3090] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The peptide TFF2 (formerly 'spasmolytic polypeptide'), a member of the trefoil factor family (TFF) containing two TFF domains, is mainly expressed together with the mucin MUC6 in the gastric epithelium and duodenal Brunner's glands. Pathologically, TFF2 expression is observed ectopically during stone diseases, chronic inflammatory conditions and in several metaplastic and neoplastic epithelia; most prominent being the 'spasmolytic polypeptide-expressing metaplasia' (SPEM), which is an established gastric precancerous lesion. TFF2 plays a critical role in maintaining gastric mucosal integrity and appears to restrain tumorigenesis in the stomach. Recently, porcine TFF2 has been shown to interact with the gastric mucin MUC6 and thus stabilize the gastric mucus barrier. On the one hand, TFF2 binds to MUC6 via non-covalent lectin interactions with the glycotope GlcNAcα1→4Galβ1→R. On the other hand, TFF2 is probably also covalently bound to MUC6 via disulfide bridges. Thus, implications for the complex multimeric assembly, cross-linking, and packaging of MUC6 as well as the rheology of gastric mucus are discussed in detail in this review. Furthermore, TFF2 is also expressed in minor amounts in the immune and nervous systems. Thus, similar to galectins, its lectin activity would perfectly enable TFF2 to form multivalent complexes and cross-linked lattices with a plethora of transmembrane glycoproteins and thus modulate different signal transduction processes. This could explain the multiple and diverse biological effects of TFF2 [e.g., motogenic, (anti)apoptotic, and angiogenic effects]. Finally, a function during fertilization is also possible for TFF domains because they occur as shuffled modules in certain zona pellucida proteins.
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Affiliation(s)
- Werner Hoffmann
- Institute of Molecular Biology and Medicinal Chemistry, Otto-von-Guericke-University Magdeburg, D-39120 Magdeburg, Germany
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4
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Helicobacter spp. Infection Induces Changes in Epithelial Proliferation and E-cadherin Expression in the Gastric Mucosa of Pigs. J Comp Pathol 2013; 149:402-9. [DOI: 10.1016/j.jcpa.2013.06.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 04/11/2013] [Accepted: 06/13/2013] [Indexed: 12/16/2022]
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5
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de Vrese M, Kristen H, Laue C, Schrezenmeir J. Effects of goat cheese on Helicobacter pylori activity and gastrointestinal complaints. Int Dairy J 2012. [DOI: 10.1016/j.idairyj.2012.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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6
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Dietary Phosphatidylcholine Supplementation Attenuates Inflammatory Mucosal Damage in a Rat Model of Experimental Colitis. Shock 2012; 38:177-85. [DOI: 10.1097/shk.0b013e31825d1ed0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Kouznetsova I, Kalinski T, Meyer F, Hoffmann W. Self-renewal of the human gastric epithelium: new insights from expression profiling using laser microdissection. MOLECULAR BIOSYSTEMS 2011; 7:1105-12. [DOI: 10.1039/c0mb00233j] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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8
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Ehehalt R, Braun A, Karner M, Füllekrug J, Stremmel W. Phosphatidylcholine as a constituent in the colonic mucosal barrier--physiological and clinical relevance. Biochim Biophys Acta Mol Cell Biol Lipids 2010; 1801:983-93. [PMID: 20595010 DOI: 10.1016/j.bbalip.2010.05.014] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2010] [Revised: 05/21/2010] [Accepted: 05/24/2010] [Indexed: 02/09/2023]
Abstract
Phosphatidylcholine (PC) is an important constituent of the gastrointestinal tract. PC molecules are not only important in intestinal cell membranes but also receiving increasing attention as protective agents in the gastrointestinal barrier. They are largely responsible for establishing the hydrophobic surface of the colon. Decreased phospholipids in colonic mucus could be linked to the pathogenesis of ulcerative colitis, a chronic inflammatory bowel disease. Clinical studies revealed that therapeutic addition of PC to the colonic mucus of these patients alleviated the inflammatory activity. This positive role is still elusive, however, we hypothesized that luminal PC has two possible functions: first, it is essential for surface hydrophobicity, and second, it is integrated into the plasma membrane of enterocytes and it modulates the signaling state of the mucosa. The membrane structure and lipid composition of cells is a regulatory component of the inflammatory signaling pathways. In this perspective, we will shortly summarize what is known about the localization and protective properties of PC in the colonic mucosa before turning to its evident medical importance. We will discuss how PC contributes to our understanding of the pathogenesis of ulcerative colitis and how reinforcing the luminal phospholipid monolayer can be used as a therapeutic concept in humans.
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Affiliation(s)
- Robert Ehehalt
- Department of Gastroenterology, University hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany.
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9
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Abstract
Peptic ulcer disease had a tremendous effect on morbidity and mortality until the last decades of the 20th century, when epidemiological trends started to point to an impressive fall in its incidence. Two important developments are associated with the decrease in rates of peptic ulcer disease: the discovery of effective and potent acid suppressants, and of Helicobacter pylori. With the discovery of H pylori infection, the causes, pathogenesis, and treatment of peptic ulcer disease have been rewritten. We focus on this revolution of understanding and management of peptic ulcer disease over the past 25 years. Despite substantial advances, this disease remains an important clinical problem, largely because of the increasingly widespread use of non-steroidal anti-inflammatory drugs (NSAIDs) and low-dose aspirin. We discuss the role of these agents in the causes of ulcer disease and therapeutic and preventive strategies for drug-induced ulcers. The rare but increasingly problematic H pylori-negative NSAID-negative ulcer is also examined.
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Affiliation(s)
- Peter Malfertheiner
- Department of Gastroenterology, Hepatology, and Infectious Diseases, Otto-von-Guericke University, Magdeburg, Germany.
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10
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Donelli LCG. Virulence Factors of Helicobacter pylori. MICROBIAL ECOLOGY IN HEALTH AND DISEASE 2009. [DOI: 10.1080/089106000750060512] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Luigina Cellini, Gianfranco Donelli
- Laboratory of Medical Bacteriology, Department of Biomedical Sciences, Universitá 'G. D'Annunzio', Chieti
- Laboratory of Ultrastructures, Istituto Superiore di Sanitá, Rome, Italy
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Mirzaee V, Molaei M, Shalmani HM, Zali MR. Helicobacter pylori infection and expression of DNA mismatch repair proteins. World J Gastroenterol 2008; 14:6717-21. [PMID: 19034977 PMCID: PMC2773316 DOI: 10.3748/wjg.14.6717] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To determine the expression of DNA (MMR) proteins, including hMLH1 and hMSH2, in gastric epithelial cells in the patients with or without Helicobacter pylori (H pylori)-infected gastritis.
METHODS: Fifty H pylori-positive patients and 50 H pylori-negative patients were enrolled in the study. During endoscopy of patients with non-ulcer dyspepsia, two antral and two corpus biopsies were taken for histological examination (Giemsa stain) and for immunohistochemical staining of hMLH1 and hMSH2.
RESULTS: The percentage of epithelial cell nuclei that demonstrated positivity for hMLH1 staining was 84.14 ± 7.32% in H pylori-negative patients, while it was 73.34 ± 10.10% in H pylori-positive patients (P < 0.0001). No significant difference was seen between the two groups regarding the percentage of epithelial cell nuclei that demonstrated positivity for hMSH2 staining (81.16 ± 8.32% in H pylori-negative versus 78.24 ± 8.71% in H pylori-positive patients; P = 0.09).
CONCLUSION: This study indicates that H pylori might promote development of gastric carcinoma at least in part through its ability to affect the DNA MMR system.
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Tseng HJ, Chan CC, Chan EC. Sphingomyelinase of Helicobacter pylori-induced cytotoxicity in AGS gastric epithelial cells via activation of JNK kinase. Biochem Biophys Res Commun 2004; 314:513-8. [PMID: 14733936 DOI: 10.1016/j.bbrc.2003.12.125] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The aim of this study was to determine whether the Helicobacter pylori-derived sphigomyelinase (SMase) affects the sphingomyelin pathway and growth in AGS epithelial cells. We showed that the exogenous SMase increased the intracellular level of ceramide in AGS cells and led to rapid stimulation of extracellular signal-regulated kinase (ERK) and c-Jun kinase (JNK) activities. Incubation of AGS cells with H. pylori-derived SMase also resulted in suppression of cell growth and a concomitant induction of apoptosis. Data showed that PD98059 (up to 50 microM), an ERK inhibitor, did not affect the cell viability, whereas the cytotoxicity of exogenous SMase was completely blocked by SP600125, a JNK inhibitor at a concentration of 210 nM. We conclude that the activation of the mitogen-activated protein (MAP) kinases in AGS cells by exogenous H. pylori SMase is a major pathway to mediate the cytotoxicity.
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Affiliation(s)
- Hong-Jia Tseng
- School of Medical Technology, Chang Gung University, 333 Tao-yuan, Taiwan, ROC
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13
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Chang YW, Min SK, Kim KJ, Han YS, Lee JH, Dong SH, Kim HJ, Kim BH, Lee JI, Chang R. Delta (13)C-urea breath test value is a useful indicator for Helicobacter pylori eradication in patients with functional dyspepsia. J Gastroenterol Hepatol 2003; 18:726-31. [PMID: 12753157 DOI: 10.1046/j.1440-1746.2003.03049.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Eradication of Helicobacter pylori is not routinely recommended for the symptomatic relief and the prevention of gastric cancer in patients with functional dyspepsia. The present study investigated a useful indicator of H. pylori eradication in such patients by determining the optimal cutoff value of a 13C-urea breath test (UBT). METHODS One hundred dyspeptic patients participated in the study. Dyspepsia was scored, and a 13C-UBT administered. A level of delta 13C-UBT of>4 per thousand was diagnosed as H. pylori-positive. After the stomach was endoscopically sprayed with phenol red, biopsy specimens were taken from the antrum, body and cardia of the stomach for the assessment of H. pylori density, and activity (neutrophil infiltration) and degree (lymphocyte infiltration) of gastritis. RESULTS Correlation between delta 13C-UBT and dyspepsia score was not found. Delta 13C-UBT significantly correlated with H. pylori density score in the total stomach (r = 0.53, P < 0.0001), neutrophil (r = 0.34, P = 0.0005) and lymphocyte score (r = 0.69, P < 0.0001). Twenty-six of the 100 subjects had a neutrophil score of >or=4, lymphocyte score of >or=4, and H. pylori score of >or=4. Their 95% confidence interval of mean was 58.2 per thousand, which reflects moderate to marked acute and chronic gastritis, and dense H. pylori colonization. CONCLUSIONS The 13C-UBT is a reliable semiquantitative test to assess H. pylori density and the activity and degree of gastritis. It is proposed that H. pylori eradication therapy might be beneficial for patients with functional dyspepsia with a delta 13C-UBT of >58.2 per thousand.
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Affiliation(s)
- Young-Woon Chang
- Department of Gastroenterology, Kyung Hee University College of Medicine, Seoul, South Korea.
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14
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Nakaya A, Wakabayashi H, Imamura L, Fukuta K, Makimoto S, Naganuma K, Orihara T, Minemura M, Shimizu Y, Nagasawa T, Hamazaki T, Watanabe A. Helicobacter pylori alters n-6 fatty acid metabolism and prostaglandin E2 synthesis in rat gastric mucosal cells. J Gastroenterol Hepatol 2001; 16:1197-205. [PMID: 11903735 DOI: 10.1046/j.1440-1746.2001.02541.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND AIMS Little is known about whether Helicobacter pylori infection alters fatty acid metabolism in gastric mucosal cells. By using cultured rat gastric mucosal cells (RGM-1), we investigated the effect of H. pylori broth culture filtrates on this point. Furthermore, our study aimed to find out whether n-6 long chain polyunsaturated fatty acids from linoleic acid are formed in RGM-1 cells. METHODS Rat gastric mucosal cells were incubated with 10, 20 and 40 microg/mL of linoleic acid or medium alone. Phosphatidylcholine content extracted from whole RGM-1 cells was quantitated by using a densitometer, and its fatty acid composition was analyzed by using gas chromatography. Prostaglandin E2 concentration in the culture medium was measured by using radioimmunoassay. The expression of cyclooxygenase (COX)-1 and COX-2 was examined by using reverse transcription-polymerase chain reaction. In addition, after incubation with [1-14C] linoleic acid, radioactivities of both linoleic acid and arachidonic acid components of the PC fraction were counted. The effects of H. pylori broth culture filtrates on PC content, its fatty acid composition and prostaglandin (PG)E2 synthesis were also assessed. RESULTS Linoleic acid addition caused an increase in the composition of arachidonic acid, as well as linoleic acid, and also in PGE2 concentration. Cyclo-oxygenase-2 expression was induced in RGM-1 cells by the addition of linoleic acid. In addition, [1-14C] linoleic acid added to the culture medium was converted to [1-14C] arachidonic acid in RGM-1 cells. Helicobacter pylori broth culture filtrates decreased linoleic acid composition and increased arachidonic acid composition. Moreover, after incubation with H. pylori broth culture filtrates, PGE2 concentrations were higher than that of the controls. CONCLUSIONS These findings suggest the presence of fatty acid elongase and Delta5- and Delta6-desaturases synthesize arachidonic acid from linoleic acid in RGM-1 cells. Thus, H. pylori infection may enhance PGE2 synthesis and accelerate n-6 fatty acid metabolism in gastric mucosal cells, which could make the gastric mucosal barrier more fragile.
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Affiliation(s)
- A Nakaya
- Third Department of Internal Medicine, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Toyama, Japan.
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Abstract
Peptic ulcer disease is a common gastrointestinal disease whose management and treatment has changed dramatically over the last 25 years. Treatment of peptic ulcer disease has evolved from dietary modifications and antacids to gastric acid suppression with H2-receptor antagonists and proton pump inhibitors to eradication of Helicobactor pylori infection. Treatment of patients infected with H pylori using antibiotics has changed the natural history of peptic ulcer disease. As a result of H pylori treatment and other unknown factors ulcer disease is declining and complications from ulcer disease have diminished significantly.
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Affiliation(s)
- D T Smoot
- Gastroenterology Division, Department of Medicine, Howard University, Washington, DC 20060, USA
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16
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Abstract
Non-steroidal anti-inflammatory drugs (NSAIDs) and Helicobacter pylori are known to share a number of pathogenic mechanisms, but there is no evidence to show a significant synergic action between the two risk factors. Studies assessing this subject have differed in almost every aspect of their methodology, including the definition of a NSAID user as well as the types, doses, duration and their indications for NSAID use. They also differed in their end-points, the definition of dyspepsia and the regimes used for eradication of H. pylori. However, some conclusions may be drawn from the results of clinical trials. In H. pylori-positive patients without mucosal lesions, NSAIDs may aggravate dyspeptic symptoms but, with the exception of elderly patients, they do not present a definite major risk of gastric and duodenal lesions and, above all, of ulcer-correlated complications. So what recommendations can be made with regard to H. pylori eradication in patients requiring treatment with NSAIDs? The microorganism and the anti-inflammatory drugs are undoubtedly independent causes of gastric and duodenal damage. Patients taking NSAIDs who are found to have gastric or duodenal ulcers should therefore be tested for the bacterium and specifically treated, since H. pylori and NSAID-induced ulcers may be macroscopically indistinguishable. Whether asymptomatic patients taking NSAIDs should be tested and treated for H. pylori infection is still a matter of debate.
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Affiliation(s)
- M Lazzaroni
- L. Sacco University Hospital, Via G.B. Grassi 74, 20157 Milan, Italy
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Bode G, Barth R, Song Q, Adler G. Phospholipase C activity of Helicobacter pylori is not associated with the presence of the cagA gene. Eur J Clin Invest 2001; 31:344-8. [PMID: 11298782 DOI: 10.1046/j.1365-2362.2001.00814.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Knowledge about the possible role of phospholipase C (PLC) activity of microbial pathogens in the development of disease is increasing. Recently attention has focused on investigating PLC activity elaborated by Helicobacter pylori, but the role of this enzyme in H. pylori pathogenesis is still unknown. The aim of this study was to correlate PLC-activity of H. pylori on the basis of the cagA status with the clinical diagnosis of the patients. MATERIALS AND METHODS Helicobacter pylori was isolated from patients with gastritis (G; n = 38), duodenal ulcer (DU; n = 15), gastric ulcer (GU; n = 11) and gastric cancer (GC; n = 12). Polymerase chain reaction primers DZ3/R009 which amplified a 1350-bp fragment were used to detect the cagA gene. PLC activity was determined using p-nitrophenylphosphorylcholine as substrate. RESULTS Of the strains, 60% were cagA(+) and 40% were cagA(-). All strains showed PLC activity (2.20 +/- 0.91 U mg(-1) protein). PLC activity showed no association with the cagA status: cagA(+) (2.21 +/- 1.03 U mg(-1) protein), cagA(-) (2.18 +/- 0.79 U mg(-1) protein). Patients with GU had the highest PLC activity (2.77 +/- 1.26 U mg(-1) protein) and patients with GC had the lowest activity (1.8 +/- 0.57 U mg(-1) protein). CONCLUSIONS Although PLC activity was present in all strains tested, it may only have pathological importance in patients with GU. However, the extent of PLC activity was independent of the presence of the cagA gene.
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Affiliation(s)
- G Bode
- Department of Epidemiology, University of Ulm, Germany.
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Ethell MT, Hodgson DR, Hills BA. Evidence for surfactant contributing to the gastric mucosal barrier of the horse. Equine Vet J 2000; 32:470-4. [PMID: 11093619 DOI: 10.2746/042516400777584631] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This study was undertaken to determine the hydrophobicity of the luminal surface of the equine stomach and to elucidate the ultrastructure of the lining imparting that property. Gastric and duodenal mucosal samples from 5 horses were collected immediately after euthanasia and subjected to surface contact angle measurement using a goniometer. Gastric mucosal samples from 4 horses and a foal were examined by electron microscopy following a fixation procedure known to preserve phospholipids and oligolamellar structures. Contact angles for the equine gastric glandular mucosal surface (mean +/- s.e. 78.0 +/- 11.0 degrees) were greater than for the duodenum (33.4 +/- 8.7 degrees), (P = 0.003). The contact angles for gastric squamous tissue (50.4 +/- 4.5 degrees) tended to be greater than for duodenum (P = 0.15). Electron microscopy revealed the existence of surfactant as abundant osmiophilic phospholipid material within both squamous and glandular gastric mucosae. These results indicate the hydrophobic nature of the equine gastric mucosae. We propose that the water-repellent nature of the stomach contributes to the 'gastric mucosal barrier' and is imparted by surface-active phospholipid adsorbed to the surface. Phospholipids may also be utilised as a physical barrier to back-diffusion of acid by lining intracellular canaliculi and oxyntic ducts where other defence mechanisms are absent.
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Affiliation(s)
- M T Ethell
- University Veterinary Centre, University of Sydney, Camden, New South Wales, Australia
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Mahmood A, Engle MJ, Hultgren SJ, Goetz GS, Dodson K, Alpers DH. Role of intestinal surfactant-like particles as a potential reservoir of uropathogenic Escherichia coli. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1523:49-55. [PMID: 11099857 DOI: 10.1016/s0304-4165(00)00095-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The binding of uropathogenic Escherichia coli is mediated at the tips of pili by the PapG adhesin, which recognizes the Galalpha(1-4)Gal disaccharide on the uroepithelial surface. These receptors have been identified unequivocally in the human and murine urinary tracts but not in intestinal epithelium, yet uropathogenic E. coli strains are commonly found in normal colonic microflora. The gastrointestinal tract from duodenum to rectum elaborates a phospholipid-rich membrane particle with surfactant-like properties. In these studies, we report that purified murine particles contain a receptor recognized by the class I PapG adhesin because: (1) PapD-PapG complexes and class I pili bound to surfactant-like particles in a solid-phase assay, whereas binding was not detected in microvillous membranes derived from the same tissues, (2) purified PapD-PapG complex bound to a glycolipid receptor detectable in lipid extracts from the particles, and (3) soluble Galalpha(1-4)Gal inhibited the adhesin by 72% from binding to surfactant-like particles. The Galalpha(1-4)Gal receptor present in the intestinal surfactant-like particle which overlies the intestinal mucosa could provide one means to establish an intestinal habitat for uropathogenic E. coli.
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Affiliation(s)
- A Mahmood
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, USA
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Zhang H, Jiang SL, Yao XX. Study of T-lymphocyte subsets, nitric oxide, hexosamine and Helicobacter pylori infection in patients with chronic gastric diseases. World J Gastroenterol 2000; 6:601-604. [PMID: 11819657 PMCID: PMC4723567 DOI: 10.3748/wjg.v6.i4.601] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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21
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Eliakim R, Karmeli F, Cohen P, Rachmilewitz D, Shao JS, Alpers DH. Sulphydryl blocker-induced rat colitis is ameliorated by intravenous injection of antibody to colonic surfactant-like particle. Inflamm Bowel Dis 1999; 5:16-23. [PMID: 10028445 DOI: 10.1097/00054725-199902000-00003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
A rat model of experimental colitis and jejunitis induced by iodoacetamide (IA), a sulphydryl blocker is accompanied by increased leukotriene, prostaglandin E2 (PGE2) generation, and nitric oxide synthase (NOS) activity. Rat small intestinal and colonic surfactant-like particles (SLP) that accumulate on the apical surface of mucosal cells have been identified and specific antibodies to them have been produced. The aim of this study was to evaluate a possible role of SLP in IA-induced colitis and jejunitis. Inflammation was induced in Sprague-Dawley rats either by intracolonic administration of 3% IA (0.1 ml) or by intrajejunal administration of 2% IA (0.1 ml). Antisera raised against either colonic SLP, pulmonary SP-A (a major protein associated with colonic SLP), or small intestinal SLP were injected into the tail vein of rats 48 h before, simultaneous with, or 24 h after IA administration. Rats were killed 2 or 10 days after IA was given, their colon or small intestine was isolated and rinsed, and a segment of colon (10 cm) or small bowel (30 cm) was weighed and processed for microscopy, NOS and myeloperoxidase (MPO) activities, and PGE2 generation. Intracolonic or jejunal IA resulted after 48 h in extensive macroscopic and microscopic damage, accompanied by increased segmental weight, MPO and NOS activity, and PGE2 generation. Colonic SLP antibody administration, either 48 h before or at the time of damage induction, significantly decreased macroscopic as well as microscopic damage, segmental weight, MPO activity, and PGE2 generation, but had no effect on NOS activity. Neither control sera nor antisera against SP-A had any protective effect, nor did injection of anti-colonic SLP antisera given 24 h after IA. Small bowel SLP antibody offered no protection against IA jejunitis. IA-induced colitis but not jejunitis is ameliorated by intravenous injection of SLP antibody by a mechanism yet to be determined. These data provide further evidence of a physiologic role for gastrointestinal SLP.
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Affiliation(s)
- R Eliakim
- Department of Medicine, Hadassah University Hospital, Mount Scopus, Jerusalem, Israel
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Wakabayashi H, Orihara T, Nakaya A, Miyamoto A, Watanabe A. Effect of Helicobacter pylori infection on gastric mucosal phospholipid contents and their fatty acid composition. J Gastroenterol Hepatol 1998; 13:566-71. [PMID: 9715397 DOI: 10.1111/j.1440-1746.1998.tb00691.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
To investigate the effect of Helicobacter pylori infection on the 'gastric mucosal barrier', phospholipid contents and the fatty acid composition of endoscopic biopsy specimens of the gastric mucosa were analysed in healthy volunteers with and without H. pylori infection. The gastric corporeal phosphatidylcholine (PC) content of H. pylori-positive healthy volunteers was less than that of H. pylori-negative healthy volunteers (P < 0.05). Moreover, H. pylori-positive healthy volunteers had a decrease in linoleic acid composition (P < 0.0001) and an increase in arachidonic acid composition (P < 0.0001) and in the arachidonic acid/linoleic acid ratio (P < 0.0001) of antral and corporeal PC compared with H. pylori-negative healthy volunteers. These findings suggest that H. pylori infection enhances production of various eicosanoids, resulting in changes in the gastric mucosal phospholipid contents and their fatty acid composition, that may consequently cause the gastric mucosal barrier to be weakened.
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Affiliation(s)
- H Wakabayashi
- Third Department of Internal Medicine, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Japan.
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23
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Soudan B, Tetaert D, Hennebicq S, Briand G, Zerimech F, Richet C, Demeyer D, Gagnon J, Petillot Y, Degand P. Dipeptidyl aminotransferase activity and in vitro O-glycosylation of MUC5AC mucin motif peptides by human gastric microsomal preparations. THE JOURNAL OF PEPTIDE RESEARCH : OFFICIAL JOURNAL OF THE AMERICAN PEPTIDE SOCIETY 1998; 51:346-54. [PMID: 9606014 DOI: 10.1111/j.1399-3011.1998.tb01225.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The in vitro O-glycosylation reaction of the MUC5AC mucin motif peptide, TTSAPTTS (in one-letter code), was achieved with human gastric microsomal homogenates. The analyses using capillary electrophoresis online coupled with electrospray mass spectrometry and further Edman degradation of the purified products (obtained by capillary electrophoresis at preparative scale) allowed us to distinguish two components at close masses: the addition of a mass of 202 corresponded to an N-terminal elongation of the peptide TTSAPTTS with the dipeptide (TT) and the addition of a mass of 203 corresponded to an N-acetylgalactosamine O-linkage. Using different peptidase inhibitors, a dipeptidyl peptidase/transferase activity was further characterized. A thiol dependence and an inhibition by H-Gly-PheCHN2 (specific to cathepsin C activity) were found. Moreover, besides TTSAPTTS, other MUC5AC motif peptides (GTTPSPVP, TSAPTTS) were also dipeptide donors (GT and TS, respectively) and our results suggested the involvement of a single dipeptidyl peptidase/transferase activity. Finally, this latter activity modified the in vitro GalNAc incorporation rates when using our selected MUC5AC motif peptides. Our study therefore shows that caution must be taken to prevent peptidic substrate elongation while performing in vitro O-glycosylation with microsomal preparations as the enzyme source. In fact, the results of the N-acetylgalactosamine incorporation rates and thus the microsomal N-acetylgalactosamine transferase affinity can be misinterpreted if dipeptidyl peptidase/transferase activity is not inhibited by the thiol inhibitor E-64 or the cathepsin C inhibitor H-Gly-PheCHN2.
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Affiliation(s)
- B Soudan
- INSERM Unité 377, Biologie et Physiopathologie des Cellules Mucipares, Lille, France
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24
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Figura N. Helicobacter pylori factors involved in the development of gastroduodenal mucosal damage and ulceration. J Clin Gastroenterol 1998; 25 Suppl 1:S149-63. [PMID: 9479642 DOI: 10.1097/00004836-199700001-00025] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Many putative virulence determinants of Helicobacter pylori are believed to trigger and worsen the gastroduodenal mucosa damage observed in infected patients. H. pylori urease reacts with the gastric urea and generates ammonia; ammonia combines with water and yields ammonium hydroxide, which is cytotoxic. Ammonia may also inhibit cell proliferation and cause indirect mucosal injury by stimulating neutrophils. Phospholipases may damage the gastric mucosa by degrading phospholipids and generating precursors of ulcerogenic components. Other enzymes, such as protease, neuraminidase, fucosidase, and alcohol dehydrogenase, can contribute to damage of the gastric epithelium by destroying the integrity of mucus or by inducing lipid peroxidation. Infection by vacuolating cytotoxic (VacA+) H. pylori strains is considered to constitute increased risk for development of peptic ulcer and gastric cancer. Exploration of the vacA gene structure has shown the existence of strongly toxigenic strains, and has confirmed at the molecular level the increased ulcerogenic potential of VacA+ H. pylori strains. A pathogenicity island called cag has been recently described in Type 1 H. pylori strains (VacA+/CagA+).cag contains the cagA gene (whose expression is associated with toxigenicity) and many genes, some of which are highly homologous to virulence genes of other virulent bacteria, that account for the enhanced pathogenic potential of CagA+ organisms.
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Affiliation(s)
- N Figura
- Institute of Internal Medicine, University of Siena, Italy
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25
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Lin YL, Liu JS, Chen KT, Chen CT, Chan EC. Identification of neutral and acidic sphingomyelinases in Helicobacter pylori. FEBS Lett 1998; 423:249-53. [PMID: 9512367 DOI: 10.1016/s0014-5793(98)00087-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We demonstrated for the first time the presence of sphingomyelinase (SMase) in Helicobacter pylori. Activation of SMase has been implicated as the cause of elevation of cellular ceramide levels and consequently of apoptosis. The data indicate that there are two classes of SMase, defined by their optimal pHs and cellular locations, existing in H. pylori. One is an Mg(2+)-dependent membrane-bound enzyme with an optimal activity at pH 7, and the other is an Mg(2+)-independent cytosolic enzyme with an optimal activity at pH 5. Bisalumin, a bismuth salt, was found to inhibit the activities of both forms of SMase regardless of the presence of Mg2+. By Western blot analysis, the membrane-bound SMases of H. pylori and Bacillus cereus were shown to be antigenically related and to have a similar denatured molecular mass of 28 kDa.
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Affiliation(s)
- Y L Lin
- School of Medical Technology, Chang Gung University, Taoyuan, Taiwan
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26
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Abstract
Helicobacter pylori is a gram-negative bacterium which causes chronic gastritis and plays important roles in peptic ulcer disease, gastric carcinoma, and gastric lymphoma. H. pylori has been found in the stomachs of humans in all parts of the world. In developing countries, 70 to 90% of the population carries H. pylori. In developed countries, the prevalence of infection is lower. There appears to be no substantial reservoir of H. pylori aside from the human stomach. Transmission can occur by iatrogenic, fecal-oral, and oral-oral routes. H. pylori is able to colonize and persist in a unique biological niche within the gastric lumen. All fresh isolates of H. pylori express significant urease activity, which appears essential to the survival and pathogenesis of the bacterium. A variety of tests to diagnose H. pylori infection are now available. Histological examination of gastric tissue, culture, rapid urease testing, DNA probes, and PCR analysis, when used to test gastric tissue, all require endoscopy. In contrast, breath tests, serology, gastric juice PCR, and urinary excretion of [15N]ammonia are noninvasive tests that do not require endoscopy. In this review, we highlight advances in the detection of the presence of the organism and methods of differentiating among types of H. pylori, and we provide a background for appropriate chemotherapy of the infection.
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Abstract
Helicobacter pylori-associated gastritis is characterized by an abundant inflammatory response and gastric epithelial cell injury. Adherence of H. pylori to gastric epithelial cells seems to be required for bacterial colonization of the gastric mucosa. Attachment of the bacterium to polarized gastric epithelial cells causes damage to microvilli and stimulates actin polymerization, which is associated with adherence pedestal formation. Studies suggest that H. pylori directly contributes to the injury of gastric epithelial cells by the elaboration of cytotoxic factors. The first toxin identified from H. pylori strains, known as vacuolating cytotoxin, induces vacuole formation in eukaryotic cells. Elaborated enzymes by H. pylori may also contribute directly to epithelial cell injury. Ammonia produced through urease activity may be toxic to gastric epithelial cells. H. pylori protease and lipase degrade gastric mucus and disrupt the phospholipid-rich layer at the apical epithelial cell surface, allowing for cell injury from back diffusion of gastric acid. This cell injury may lead to cell death, believed to result from induction of apoptosis. There are sufficient data to suggest that H. pylori, through direct pathogenic mechanisms, contributes significantly to the gastric mucosal injury associated with this infection, and may enhance the susceptibility of gastric epithelial cells to carcinogenic conversion.
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Affiliation(s)
- D T Smoot
- Department of Medicine, Howard University, Washington, D.C., USA
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28
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Abstract
Helicobacter pylori is a gram-negative bacterium which causes chronic gastritis and plays important roles in peptic ulcer disease, gastric carcinoma, and gastric lymphoma. H. pylori has been found in the stomachs of humans in all parts of the world. In developing countries, 70 to 90% of the population carries H. pylori. In developed countries, the prevalence of infection is lower. There appears to be no substantial reservoir of H. pylori aside from the human stomach. Transmission can occur by iatrogenic, fecal-oral, and oral-oral routes. H. pylori is able to colonize and persist in a unique biological niche within the gastric lumen. All fresh isolates of H. pylori express significant urease activity, which appears essential to the survival and pathogenesis of the bacterium. A variety of tests to diagnose H. pylori infection are now available. Histological examination of gastric tissue, culture, rapid urease testing, DNA probes, and PCR analysis, when used to test gastric tissue, all require endoscopy. In contrast, breath tests, serology, gastric juice PCR, and urinary excretion of [15N]ammonia are noninvasive tests that do not require endoscopy. In this review, we highlight advances in the detection of the presence of the organism and methods of differentiating among types of H. pylori, and we provide a background for appropriate chemotherapy of the infection.
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Affiliation(s)
- B E Dunn
- Department of Pathology, Medical College of Wisconsin, Milwaukee 53226-0509, USA
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Duggan AE, Atherton JC, Cockayne A, Balsitis M, Evison S, Hale T, Hawkey CJ, Spiller RC. Clarification of the link between polyunsaturated fatty acids and Helicobacter pylori-associated duodenal ulcer disease: a dietary intervention study. Br J Nutr 1997; 78:515-22. [PMID: 9389880 DOI: 10.1079/bjn19970171] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Epidemiological evidence has suggested that the declining prevalence of duodenal ulcer disease may be attributable to rising consumption of polyunsaturated fatty acids, a hypothesis supported by in vitro evidence of toxicity of such substances to Helicobacter pylori. The objective of the present study was to establish whether this association is causal. Forty patients with proven infection with H. pylori and endoscopic evidence of past or present duodenal ulcer disease were randomized to receive either polyunsaturated fatty acids (PUFA group), in the form of capsules and margarine, or a placebo (control). Both groups received concurrent H2 antagonist therapy. Efficacy of therapy was determined endoscopically by assessment of ulcer healing while H. pylori status was determined by antral biopsy, urease (EC 3.5.1.5) culture and histological assessment of the severity of H. pylori infection. Antral levels of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) were quantified. Compliance was monitored. Before treatment, both groups were comparable for severity of H. pylori infection, smoking status and levels of LTB4 and PGE2. Despite a significant difference in consumption of linoleic acid (19.9 (SE 1.6) g for PUFA group v. 6.7 (SE 0.8) g for controls (P < 0.01) and linolenic acid (2.6 (SE 0.2) g v. 0.6 (SE 0.03) g (P < 0.01) there was no significant change in either the severity of H. pylori infection or prostaglandin levels in either group at 6 weeks. Consumption of a considerable amount of PUFA does not inhibit the colonization of the stomach by H. pylori nor does this alter the inflammatory changes characteristic of H. pylori gastritis. We conclude that the association between duodenal ulceration and a low level of dietary PUFA is likely to be spurious, probably reflecting the effect of confounding factors such as affluence, social class or smoking.
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Affiliation(s)
- A E Duggan
- Division of Gastroenterology, University Hospital, Nottingham
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Lebovitz RM, Zhang H, Vogel H, Cartwright J, Dionne L, Lu N, Huang S, Matzuk MM. Neurodegeneration, myocardial injury, and perinatal death in mitochondrial superoxide dismutase-deficient mice. Proc Natl Acad Sci U S A 1996; 93:9782-7. [PMID: 8790408 PMCID: PMC38506 DOI: 10.1073/pnas.93.18.9782] [Citation(s) in RCA: 741] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Manganese superoxide dismutase (SOD2) converts superoxide to oxygen plus hydrogen peroxide and serves as the primary defense against mitochondrial superoxide. Impaired SOD2 activity in humans has been associated with several chronic diseases, including ovarian cancer and type I diabetes, and SOD2 overexpression appears to suppress malignancy in cultured cells. We have produced a line of SOD2 knockout mice (SOD2m1BCM/SOD2m1BCM) that survive up to 3 weeks of age and exhibit several novel pathologic phenotypes including severe anemia, degeneration of neurons in the basal ganglia and brainstem, and progressive motor disturbances characterized by weakness, rapid fatigue, and circling behavior. In addition, SOD2m1BCM/SOD2m1BCM mice older than 7 days exhibit extensive mitochondrial injury within degenerating neurons and cardiac myocytes. Approximately 10% of SOD2m1BCM/SOD2m1BCM mice exhibit markedly enlarged and dilated hearts. These observations indicate that SOD2 deficiency causes increased susceptibility to oxidative mitochondrial injury in central nervous system neurons, cardiac myocytes, and other metabolically active tissues after postnatal exposure to ambient oxygen concentrations. Our SOD2-deficient mice differ from a recently described model in which homozygotes die within the first 5 days of life with severe cardiomyopathy and do not exhibit motor disturbances, central nervous system injury, or ultrastructural evidence of mitochondrial injury.
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Affiliation(s)
- R M Lebovitz
- Department of Pathology, Baylor College of Medicine, Houston, TX 77030, USA.
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Dohi T, Nakasuji M, Nakanishi K, Yasugi E, Yuyama Y, Sugiyama N, Tabuchi Y, Horiuchi T, Oshima M. Biochemical bases in differentiation of a mouse cell line GSM06 to gastric surface cells. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1289:71-8. [PMID: 8605235 DOI: 10.1016/0304-4165(95)00138-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A mouse gastric surface cell line GSM06 established from a transgenic mouse harboring temperature-sensitive simian virus 40 large T-antigen gene was subjected to the lipid and glycoprotein analysis. When GSM06 cells were cultured for a long time after formation of a confluent monolayer, they differentiated to resemble foveolar epithelial cells morphologically. Biochemical changes during culture were studied in cells harvested just when a monolayer had formed (day 0), on day 7, and on day 21. Content of total phospholipids, cholesterol, cholesterol sulfate, total sugar and sialic acid increased about 1.5-fold from day 0 to 7 and remained elevated till day 21. The fatty acid composition of phospholipids revealed increased relative levels of oleic acid in phosphatidylcholine and phosphatidylethanolamine, and an increased level of plasmenylethanolamine from day 0 to 7. The level of dolichylphosphate continued to increase in a time-dependent manner. Glycosylation of various proteins, detected with lectins, was enhanced from day 7. In addition, greater resistance to taurodeoxycholate and acetylsalicylic acid was observed on days 7 and 21 than on day 0. Thus, enhanced glycosylation of proteins and an overall increase in the area of cellular membranes were the major changes in GSM06 cells during culture, and they were accompanied by an enhancement of cytoprotective potential.
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Affiliation(s)
- T Dohi
- Division of Bichemistry and Nutrition, Research Institute, International Medical Center of Japan, Tokyo
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Osculati F, Sbarbati A, Bertini M, Deganello A, Gaburro D. Ghosts in the stomach: may dead cells protect living ones. Gastroenterology 1995; 108:304-5. [PMID: 7806059 DOI: 10.1016/0016-5085(95)90048-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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33
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Lichtenberger LM, Romero JJ. Effect of ammonium ion on the hydrophobic and barrier properties of the gastric mucus gel layer: implications on the role of ammonium in H. pylori-induced gastritis. J Gastroenterol Hepatol 1994; 9 Suppl 1:S13-9. [PMID: 7881013 DOI: 10.1111/j.1440-1746.1994.tb01295.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Infection with the bacterium Helicobacter pylori is associated with both the development of gastritis and an attenuation in the hydrophobic properties of the stomach. In order to better understand the effect of ammonium, one of the major products of H. pylori urease on these properties, a series of in vivo and in vitro experiments was performed. In the in vivo studies rats were intragastrically administered NH4Cl alone and in combination with the mucolytic agent, Muco-Mist, in various dosing strategies and concentrations. It was determined that the intragastric administration of four consecutive doses of a NH4Cl/Muco-Mist mixture (20 mmol/L/5%) was capable of converting the stomach from a hydrophobic to hydrophilic state as determined by contact angle analysis. Further, the treated rats became more susceptible to the injurious effect of luminal acid as determined by measuring the haemoglobin concentration of a collected gastric perfusate. In the in vitro studies it was determined that exposure of the hydrophobic surface of a synthetic mucus gel layer to increasing concentrations of NH4Cl (0-20 mmol/L) resulted in a rapid transition to a hydrophilic state and an associated increase in the flux of H+ across its surface. Helicobacter pylori may induce an attenuation in both mucosal hydrophobicity and barrier properties by producing high concentrations of NH4+ in the mucus gel layer. The molecular mechanism of this action may be related to the chemical similarities of NH4+ and choline-based phospholipids which contribute to the stomach's hydrophobic surface.
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Affiliation(s)
- L M Lichtenberger
- Department of Physiology and Cell Biology, University of Texas-Houston Medical School 77225
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