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Sedarat Z, Taylor-Robinson AW. Helicobacter pylori Outer Membrane Proteins and Virulence Factors: Potential Targets for Novel Therapies and Vaccines. Pathogens 2024; 13:392. [PMID: 38787244 PMCID: PMC11124246 DOI: 10.3390/pathogens13050392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 04/12/2024] [Accepted: 05/07/2024] [Indexed: 05/25/2024] Open
Abstract
Helicobacter pylori is a gastric oncopathogen that infects over half of the world's human population. It is a Gram-negative, microaerophilic, helix-shaped bacterium that is equipped with flagella, which provide high motility. Colonization of the stomach is asymptomatic in up to 90% of people but is a recognized risk factor for developing various gastric disorders such as gastric ulcers, gastric cancer and gastritis. Invasion of the human stomach occurs via numerous virulence factors such as CagA and VacA. Similarly, outer membrane proteins (OMPs) play an important role in H. pylori pathogenicity as a means to adapt to the epithelial environment and thereby facilitate infection. While some OMPs are porins, others are adhesins. The epithelial cell receptors SabA, BabA, AlpA, OipA, HopQ and HopZ have been extensively researched to evaluate their epidemiology, structure, role and genes. Moreover, numerous studies have been performed to seek to understand the complex relationship between these factors and gastric diseases. Associations exist between different H. pylori virulence factors, the co-expression of which appears to boost the pathogenicity of the bacterium. Improved knowledge of OMPs is a major step towards combatting this global disease. Here, we provide a current overview of different H. pylori OMPs and discuss their pathogenicity, epidemiology and correlation with various gastric diseases.
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Affiliation(s)
- Zahra Sedarat
- Cellular & Molecular Research Centre, Shahrekord University of Medical Sciences, Shahrekord 8813833435, Iran;
| | - Andrew W. Taylor-Robinson
- College of Health Sciences, VinUniversity, Gia Lam District, Hanoi 67000, Vietnam
- Center for Global Health, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 1904, USA
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2
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Hara T, Sakanaka A, Lamont RJ, Amano A, Kuboniwa M. Interspecies metabolite transfer fuels the methionine metabolism of Fusobacterium nucleatum to stimulate volatile methyl mercaptan production. mSystems 2024; 9:e0076423. [PMID: 38289043 PMCID: PMC10878106 DOI: 10.1128/msystems.00764-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 12/19/2023] [Indexed: 02/21/2024] Open
Abstract
The major oral odor compound methyl mercaptan (CH3SH) is strongly associated with halitosis and periodontitis. CH3SH production stems from the metabolism of polymicrobial communities in periodontal pockets and on the tongue dorsum. However, understanding of CH3SH-producing oral bacteria and their interactions is limited. This study aimed to investigate CH3SH production by major oral bacteria and the impact of interspecies interactions on its generation. Using a newly constructed large-volume anaerobic noncontact coculture system, Fusobacterium nucleatum was found to be a potent producer of CH3SH, with that production stimulated by metabolic interactions with Streptococcus gordonii, an early dental plaque colonizer. Furthermore, analysis of extracellular amino acids using an S. gordonii arginine-ornithine antiporter (ArcD) mutant demonstrated that ornithine excreted from S. gordonii is a key contributor to increased CH3SH production by F. nucleatum. Further study with 13C, 15N-methionine, as well as gene expression analysis, revealed that ornithine secreted by S. gordonii increased the demand for methionine through accelerated polyamine synthesis by F. nucleatum, leading to elevated methionine pathway activity and CH3SH production. Collectively, these findings suggest that interaction between S. gordonii and F. nucleatum plays a key role in CH3SH production, providing a new insight into the mechanism of CH3SH generation in oral microbial communities. A better understanding of the underlying interactions among oral bacteria involved in CH3SH generation can lead to the development of more appropriate prophylactic approaches to treat halitosis and periodontitis. An intervention approach like selectively disrupting this interspecies network could also offer a powerful therapeutic strategy.IMPORTANCEHalitosis can have a significant impact on the social life of affected individuals. Among oral odor compounds, CH3SH has a low olfactory threshold and halitosis is a result of its production. Recently, there has been a growing interest in the collective properties of oral polymicrobial communities, regarded as important for the development of oral diseases, which are shaped by physical and metabolic interactions among community participants. However, it has yet to be investigated whether interspecies interactions have an impact on the production of volatile compounds, leading to the development of halitosis. The present findings provide mechanistic insights indicating that ornithine, a metabolite excreted by Streptococcus gordonii, promotes polyamine synthesis by Fusobacterium nucleatum, resulting in a compensatory increase in demand for methionine, which results in elevated methionine pathway activity and CH3SH production. Elucidation of the mechanisms related to CH3SH production is expected to lead to the development of new strategies for managing halitosis.
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Affiliation(s)
- Takeshi Hara
- Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan
- Advanced Technology Institute, Mandom Corporation, Osaka, Japan
| | - Akito Sakanaka
- Department of Preventive Density, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - Richard J. Lamont
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, Kentucky, USA
| | - Atsuo Amano
- Department of Preventive Density, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - Masae Kuboniwa
- Department of Preventive Density, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
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3
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Wolpaw AJ, Dang CV. Pathways Involved in the Effect of Eflornithine in Neuroblastoma. J Clin Oncol 2024; 42:116-119. [PMID: 37883720 DOI: 10.1200/jco.23.01783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 08/22/2023] [Indexed: 10/28/2023] Open
Affiliation(s)
- Adam J Wolpaw
- Children's Hospital of Philadelphia and Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA
| | - Chi V Dang
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
- Bloomberg-Kimmel Institute for Cancer Immunotherapy, Johns Hopkins University, Baltimore, MD
- Ludwig Institute for Cancer Research, New York, NY
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4
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Motamedi H, Abiri R, Salari F, Jalili C, Alvandi A. Reduction of UreB and CagA expression level by siRNA construct in Helicobacter pylori strain SS1. BMC Microbiol 2023; 23:401. [PMID: 38114907 PMCID: PMC10729366 DOI: 10.1186/s12866-023-03143-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 12/05/2023] [Indexed: 12/21/2023] Open
Abstract
BACKGROUND Two important virulence factors, urease and cagA, play an important role in Helicobacter pylori (H. pylori) gastric cancer. Aim of this study was to investigate the expression level and function of ureB and cagA using small interfering RNAs (siRNA). METHODS SS1 strain of H. pylori was considered as host for natural transformation. siRNA designed for ureB and cagA genes were inserted in pGPU6/GFP/Neo siRNA plasmid vector to evaluate using phenotypic and genotypic approaches. Then, qPCR was performed for determining inhibition rate of ureB and cagA gene expression. RESULTS The expression levels of siRNA-ureB and siRNA-cagA in the recombinant strain SS1 were reduced by about 5000 and 1000 fold, respectively, compared to the native H. pylori strain SS1. Also, preliminary evaluation of siRNA-ureB in vitro showed inhibition of urea enzyme activity. These data suggest that siRNA may be a powerful new tool for gene silencing in vitro, and for the development of RNAi-based anti-H. pylori therapies. CONCLUSION Our results show that targeting ureB and cagA genes with siRNA seems to be a new strategy to inhibit urease enzyme activity, reduce inflammation and colonization rate.
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Affiliation(s)
- Hamid Motamedi
- Department of Microbiology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
- Student Research Committee, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Ramin Abiri
- Fertility and Infertility Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Farhad Salari
- Department of Immunology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Cyrus Jalili
- Medical Biology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Amirhoushang Alvandi
- Medical Technology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran.
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Tang Q, Ma Z, Tang X, Liu Y, Wu H, Peng Y, Jiao B, Wang R, Ye X, Ma H, Li X. Coptisine inhibits Helicobacter pylori and reduces the expression of CagA to alleviate host inflammation in vitro and in vivo. JOURNAL OF ETHNOPHARMACOLOGY 2023; 314:116618. [PMID: 37164257 DOI: 10.1016/j.jep.2023.116618] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 05/06/2023] [Accepted: 05/07/2023] [Indexed: 05/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Helicobacter pylori (H. pylori) is a major pathogen colonized in the human stomach and is implicated in gastritis, peptic ulcer, and gastric carcinoma. Antibiotics are useful for eradicating H. pylori but failed for drug resistance, making it urgent to develop effective and safe drugs. Rhizoma Coptidis was reported as one of the most effective Chinese medicines to treat H. pylori-related gastrointestinal diseases, while the precise antimicrobial mechanism remains unclear. Thus, it is of great significance to study the antimicrobial ingredients and corresponding mechanisms of Rhizoma Coptidis. AIM OF THE STUDY To search for the most effective alkaloid against H. pylori in Rhizoma Coptidis and illustrate the probable mechanisms. MATERIALS AND METHODS Five main alkaloids in Rhizoma Coptidis were isolated. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were tested to determine the most effective one. Bacterial growth experiments, Annexin V-FITC/PI staining, TUNEL staining, and transmission electron microscopy (TEM) were performed to further study the anti-H. pylori activity of coptisine (Cop). The in vivo effect of Cop on H. pylori eradication rate and H. pylori-induced inflammation was investigated in mice. Transcriptomics was used to understand the underlying mechanism of eradicating H. pylori and reducing host inflammation. Western blot, RT-PCR, and ELISA experiments were utilized and confirmed that cagA was one of the targets of Cop. RESULTS According to the MIC and MBC, Cop was the most effective alkaloid against H. pylori, especially with no drug resistance developed. In vitro experiments showed that Cop inhibited H. pylori by inducing DNA fragmentation, phosphatidylserine exposure, and membrane damage. Cop (150 mg/kg/day) effectively eradicated H. pylori in mice and reduced the levels of IL-2 and IL-6 to relieve gastric inflammation. Transcriptomic analysis revealed that virulence factor cagA was one of the hub genes associated with the inflammation-improving effect of Cop. That is, Cop could decrease the expression of CagA and subsequently reduce the translocation of CagA to gastric epithelial cells, thereby improving the morphology of hummingbird-like phenotype induced by CagA and alleviating inflammation. CONCLUSIONS Cop is the most effective alkaloid in Rhizoma Coptidis and might act through multiple mechanisms for H. pylori eradication along with reducing the expression of CagA to alleviate inflammation.
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Affiliation(s)
- Qin Tang
- Engineering Research Center of Coptis Development and Utilization (Ministry of Education), College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, China.
| | - Zhengcai Ma
- School of Life Sciences, Southwest University, Chongqing, 400715, China.
| | - Xiang Tang
- School of Life Sciences, Southwest University, Chongqing, 400715, China.
| | - Yan Liu
- Engineering Research Center of Coptis Development and Utilization (Ministry of Education), College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, China.
| | - Huimin Wu
- Engineering Research Center of Coptis Development and Utilization (Ministry of Education), College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, China.
| | - Yu Peng
- Engineering Research Center of Coptis Development and Utilization (Ministry of Education), College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, China.
| | - Baihua Jiao
- Engineering Research Center of Coptis Development and Utilization (Ministry of Education), College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, China.
| | - Rui Wang
- Engineering Research Center of Coptis Development and Utilization (Ministry of Education), College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, China.
| | - Xiaoli Ye
- School of Life Sciences, Southwest University, Chongqing, 400715, China.
| | - Hang Ma
- Engineering Research Center of Coptis Development and Utilization (Ministry of Education), College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, China.
| | - Xuegang Li
- Engineering Research Center of Coptis Development and Utilization (Ministry of Education), College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, China.
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Gedde OR, Bonde A, Golbækdal PI, Skrydstrup T. Pd‐Catalyzed Difluoromethylations of Aryl Boronic Acids, Halides, and Pseudohalides with ICF
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H Generated ex Situ. Chemistry 2022; 28:e202200997. [PMID: 35388933 PMCID: PMC9321866 DOI: 10.1002/chem.202200997] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Indexed: 02/02/2023]
Abstract
An expedient ex‐situ generation of difluoroiodomethane (DFIM) and its immediate use in a Pd‐catalyzed difluoromethylation of aryl boronic acids and ester derivatives in a two‐chamber reactor is reported. Heating a solution of bromodifluoroacetic acid with sodium iodide in sulfolane proved to be effective for the generation of near stoichiometric amounts of DFIM for the ensuing catalytic coupling step. A two‐step difluoromethylation of aryl (pseudo)halides with tetrahydroxydiboron as a low‐cost reducing agent, both promoted by Pd catalysis, proved effective to install this fluorine‐containing C1 group onto several pharmaceutically relevant molecules. Finally, the method proved adaptable to deuterium incorporation by simply adding D2O to the DFIM‐generating chamber.
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Affiliation(s)
- Oliver R. Gedde
- Carbon Dioxide Activation Center (CADIAC) The Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry Aarhus University Gustav Wieds Vej 14 8000 Aarhus C Denmark
| | - Andreas Bonde
- Carbon Dioxide Activation Center (CADIAC) The Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry Aarhus University Gustav Wieds Vej 14 8000 Aarhus C Denmark
| | - Peter I. Golbækdal
- Carbon Dioxide Activation Center (CADIAC) The Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry Aarhus University Gustav Wieds Vej 14 8000 Aarhus C Denmark
| | - Troels Skrydstrup
- Carbon Dioxide Activation Center (CADIAC) The Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry Aarhus University Gustav Wieds Vej 14 8000 Aarhus C Denmark
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7
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Targeting Cytotoxin-Associated Antigen A, a Virulent Factor of Helicobacter pylori-Associated Gastric Cancer: Structure-Based In Silico Screening of Natural Compounds. Molecules 2022; 27:molecules27030732. [PMID: 35164000 PMCID: PMC8838247 DOI: 10.3390/molecules27030732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 12/10/2022] Open
Abstract
Gastric cancer is the fifth most frequent cancer and the third major cause of mortality worldwide. Helicobacter pylori, a bacterial infection linked with GC, injects the cytotoxin-associated antigen A (CagA; an oncoprotein) into host cells. When the phosphorylated CagA protein enters the cell, it attaches to other cellular components, interfering with normal cellular signaling pathways. CagA plays an important role in the progression of GC by interacting with phosphatidylserine of the host cell membrane. Therefore, disrupting the CagA-phosphatidylserine connection using small molecules appears to be a promising therapeutic approach. In this report, we screened the natural compounds from ZINC database against the CagA protein using the bioinformatics tools. Hits were initially chosen based on their physicochemical, absorption, distribution, metabolism, excretion, and toxicity (ADMET) characteristics, as well as other drug-like characteristics. To locate safe and effective hits, the PAINS filter, binding affinities estimation, and interaction analysis were used. Three compounds with high binding affinity and specificity for the CagA binding pocket were discovered. The final hits, ZINC153731, ZINC69482055, and ZINC164387, were found to bind strongly with CagA protein, with binding energies of -11.53, -10.67, and -9.21 kcal/mol, respectively, which were higher than that of the control compound (-7.25 kcal/mol). Further, based on binding affinity and interaction pattern, two leads (ZINC153731, ZINC69482055) were chosen for molecular dynamics (MD) simulation analysis. MD results showed that they displayed stability in their vicinity at 100 ns. This study suggested that these compounds could be used as possible inhibitors of CagA protein in the fight against GC. However, additional benchwork tests are required to validate them as CagA protein inhibitors.
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8
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Ray AK, Luis PB, Mishra SK, Barry DP, Asim M, Pandey A, Chaturvedi M, Gupta J, Gupta S, Mahant S, Das R, Kumar P, Shalimar, Wilson KT, Schneider C, Chaturvedi R. Curcumin Oxidation Is Required for Inhibition of Helicobacter pylori Growth, Translocation and Phosphorylation of Cag A. Front Cell Infect Microbiol 2021; 11:765842. [PMID: 35004346 PMCID: PMC8740292 DOI: 10.3389/fcimb.2021.765842] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 12/02/2021] [Indexed: 01/22/2023] Open
Abstract
Curcumin is a potential natural remedy for preventing Helicobacter pylori-associated gastric inflammation and cancer. Here, we analyzed the effect of a phospholipid formulation of curcumin on H. pylori growth, translocation and phosphorylation of the virulence factor CagA and host protein kinase Src in vitro and in an in vivo mouse model of H. pylori infection. Growth of H. pylori was inhibited dose-dependently by curcumin in vitro. H. pylori was unable to metabolically reduce curcumin, whereas two enterobacteria, E. coli and Citrobacter rodentium, which efficiently reduced curcumin to the tetra- and hexahydro metabolites, evaded growth inhibition. Oxidative metabolism of curcumin was required for the growth inhibition of H. pylori and the translocation and phosphorylation of CagA and cSrc, since acetal- and diacetal-curcumin that do not undergo oxidative transformation were ineffective. Curcumin attenuated mRNA expression of the H. pylori virulence genes cagE and cagF in a dose-dependent manner and inhibited translocation and phosphorylation of CagA in gastric epithelial cells. H. pylori strains isolated from dietary curcumin-treated mice showed attenuated ability to induce cSrc phosphorylation and the mRNA expression of the gene encoding for IL-8, suggesting long-lasting effects of curcumin on the virulence of H. pylori. Our work provides mechanistic evidence that encourages testing of curcumin as a dietary approach to inhibit the virulence of CagA.
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Affiliation(s)
- Ashwini Kumar Ray
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
- Department of Microbiology, Saheed Rajguru College of Applied Sciences for Women, University of Delhi, New Delhi, India
- Department of Environmental Studies, University of Delhi, New Delhi, India
| | - Paula B. Luis
- Department of Pharmacology and Vanderbilt Institute of Chemical Biology, Vanderbilt University School of Medicine, Nashville, TN, United States
| | | | - Daniel P. Barry
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Mohammad Asim
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Achyut Pandey
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Maya Chaturvedi
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Jyoti Gupta
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Shilpi Gupta
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Shweta Mahant
- Centre for Medical Biotechnology, Amity Institute of Biotechnology, Amity University, Noida, India
| | - Rajashree Das
- Centre for Medical Biotechnology, Amity Institute of Biotechnology, Amity University, Noida, India
| | - Pramod Kumar
- Department of Chemistry, Sri Aurobindo College, University of Delhi, New Delhi, India
| | - Shalimar
- Department of Gastroenterology and Human Nutrition Unit, All India Institute of Medical Sciences, New Delhi, India
| | - Keith T. Wilson
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
- Center for Mucosal Inflammation and Cancer, Vanderbilt University Medical Center, Nashville, TN, United States
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN, United States
| | - Claus Schneider
- Department of Pharmacology and Vanderbilt Institute of Chemical Biology, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - Rupesh Chaturvedi
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
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Zhang Y, Zhang PS, Rong ZY, Huang C. One stomach, two subtypes of carcinoma-the differences between distal and proximal gastric cancer. Gastroenterol Rep (Oxf) 2021; 9:489-504. [PMID: 34925847 PMCID: PMC8677565 DOI: 10.1093/gastro/goab050] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 07/13/2021] [Accepted: 08/13/2021] [Indexed: 12/13/2022] Open
Abstract
Gastric cancer (GC) is one of the most common malignant tumors of the digestive tract, posing a significant risk to human health. Over the past 10 years, the pathological characteristics and the prognosis of GC have been determined based on the locations of the tumors that were then classified into two types-proximal and distal GC. This review focuses on the differences in epidemiology, etiology, cell source, pathological characteristics, gene expression, molecular markers, manifestations, treatment, prognosis, and prevention between proximal and distal GC to provide guidance and a basis for clinical diagnosis and treatment.
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Affiliation(s)
- Yuan Zhang
- Department of Gastrointestinal Surgery, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, P. R. China
| | - Peng-Shan Zhang
- Department of Gastrointestinal Surgery, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, P. R. China
| | - Ze-Yin Rong
- Department of Gastrointestinal Surgery, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, P. R. China
| | - Chen Huang
- Department of Gastrointestinal Surgery, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, P. R. China
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Abstract
Gastric cancer is the fifth most common cause of cancer and the third leading cause of cancer-related deaths globally. The number of gastric cancer-related deaths is only projected to increase, attributable primarily to the expanding aging population. Prevention is a mainstay of gastric cancer control programs, particularly in the absence of accurate, noninvasive modalities for screening and early detection, and the absence of an infrastructure for this purpose in the majority of countries worldwide. Herein, we discuss the evidence for several chemopreventive agents, along with putative mechanisms. There remains a clear, unmet need for primary chemoprevention trials for gastric cancer.
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Affiliation(s)
- Shailja C. Shah
- Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, Vanderbilt University Medical Center, 1030C MRB IV, 2215 Garland Avenue, Nashville, TN 37232-0252, USA;,Veterans Affairs Tennessee Valley Health System, Nashville Campus, Nashville, TN, USA,Corresponding author:
| | - Richard M. Peek
- Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, Vanderbilt University Medical Center, 1030C MRB IV, 2215 Garland Avenue, Nashville, TN 37232-0252, USA
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11
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McNamara KM, Gobert AP, Wilson KT. The role of polyamines in gastric cancer. Oncogene 2021; 40:4399-4412. [PMID: 34108618 PMCID: PMC8262120 DOI: 10.1038/s41388-021-01862-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 05/07/2021] [Accepted: 05/24/2021] [Indexed: 02/05/2023]
Abstract
Advancements in our understanding of polyamine molecular and cellular functions have led to increased interest in targeting polyamine metabolism for anticancer therapeutic benefits. The polyamines putrescine, spermidine, and spermine are polycationic alkylamines commonly found in all living cells and are essential for cellular growth and survival. This review summarizes the existing research on polyamine metabolism and function, specifically the role of polyamines in gastric immune cell and epithelial cell function. Polyamines have been implicated in a multitude of cancers, but in this review, we focus on the role of polyamine dysregulation in the context of Helicobacter pylori-induced gastritis and subsequent progression to gastric cancer. Due to the emerging implication of polyamines in cancer development, there is an increasing number of promising clinical trials using agents to target the polyamine metabolic pathway for potential chemoprevention and anticancer therapy.
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Affiliation(s)
- Kara M. McNamara
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA,Program in Cancer Biology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Alain P. Gobert
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA,Center for Mucosal Inflammation and Cancer, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Keith T. Wilson
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA,Program in Cancer Biology, Vanderbilt University Medical Center, Nashville, TN, USA,Center for Mucosal Inflammation and Cancer, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA,Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN, USA
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12
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Krzyżek P, Grande R. Transformation of Helicobacter pylori into Coccoid Forms as a Challenge for Research Determining Activity of Antimicrobial Substances. Pathogens 2020; 9:pathogens9030184. [PMID: 32143312 PMCID: PMC7157236 DOI: 10.3390/pathogens9030184] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 03/01/2020] [Accepted: 03/03/2020] [Indexed: 12/12/2022] Open
Abstract
Morphological variability is one of the phenotypic features related to adaptation of microorganisms to stressful environmental conditions and increased tolerance to antimicrobial substances. Helicobacter pylori, a gastric mucosal pathogen, is characterized by a high heterogeneity and an ability to transform from a spiral to a coccoid form. The presence of the coccoid form is associated with the capacity to avoid immune system detection and to promote therapeutic failures. For this reason, it seems that the investigation for new, alternative methods combating H. pylori should include research of coccoid forms of this pathogen. The current review aimed at collecting information about the activity of antibacterial substances against H. pylori in the context of the morphological variability of this bacterium. The collected data was discussed in terms of the type of substances used, applied research techniques, and interpretation of results. The review was extended by a polemic on the limitations in determining the viability of coccoid H. pylori forms. Finally, recommendations which can help in future research aiming to find new compounds with a potential to eradicate H. pylori have been formulated.
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Affiliation(s)
- Paweł Krzyżek
- Department of Microbiology, Faculty of Medicine, Wroclaw Medical University, 50-368 Wroclaw, Poland
- Correspondence:
| | - Rossella Grande
- Center for Aging Science and Translational Medicine (CeSI-MeT), Via Luigi Polacchi, 11, 66100 Chieti, Italy;
- Department of Pharmacy, University “G. d’Annunzio” of Chieti-Pescara, Via dei Vestini, 31, 66100 Chieti, Italy
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El-Saber Batiha G, Magdy Beshbishy A, Stephen Adeyemi O, Nadwa E, Rashwan E, Yokoyama N, Igarashi I. Safety and efficacy of hydroxyurea and eflornithine against most blood parasites Babesia and Theileria. PLoS One 2020; 15:e0228996. [PMID: 32053698 PMCID: PMC7018007 DOI: 10.1371/journal.pone.0228996] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 01/27/2020] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND The plenteous resistance to and undesirable consequences of the existing antipiroplasmic therapies have emphasized the urgent need for new chemotherapeutics and drug targets for both prophylaxis and chemotherapy. Hydroxyurea (HYD) is an antineoplastic agent with antitrypanosomal activity. Eflornithine (α-difluoro-methyl ornithine, DFMO) is the best choice therapy for the treatment of late-stage Gambian human African trypanosomiasis. METHODS In this study, the inhibitory and combination efficacy of HYD and DFMO with existing babesicidal drugs (diminazene aceturate (DA), atovaquone (ATV), and clofazimine (CLF)) deoxyribonucleotide in vitro against the multiplication of Babesia and Theileria. As well as, their chemotherapeutic effects were assessed on B. microti strain that infects rodents. The Cell Counting Kits-8 (CCK-8) test was used to examine their cytotoxicity on human foreskin fibroblast (HFF), mouse embryonic fibroblast (NIH/3T3), and Madin-Darby bovine kidney (MDBK) cells. FINDINGS HYD and DFMO suppressed the multiplication of all tested species (B. bigemina, B. bovis, B. caballi, B. divergens, and T. equi) in a dose-related manner. HFF, NIH/3T3, or MDBK cell viability was not influenced by DFMO at 1000 μM, while HYD affected the MDBK cell viability at EC50 value of 887.5±14.4 μM. The in vitro combination treatments of DFMO and HYD with CLF, DA, and ATV exhibited synergistic and additive efficacy toward all tested species. The in vivo experiment revealed that HYD and DFMO oral administration at 100 and 50 mg/kg inhibited B. microti multiplication in mice by 60.1% and 78.2%, respectively. HYD-DA and DFMO-DA combined treatments showed higher chemotherapeutic efficacy than their monotherapies. CONCLUSION These results indicate the prospects of HYD and DFMO as drug candidates for piroplasmosis treatment, when combined mainly with DA, ATV, and CLF. Therefore, further studies are needed to combine HYD or DFMO with either ATV or CLF and examine their impact on B. microti infection in mice.
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Affiliation(s)
- Gaber El-Saber Batiha
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
- Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicine, Damanhour University, Damanhour, Al-Beheira, Egypt
| | - Amany Magdy Beshbishy
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Oluyomi Stephen Adeyemi
- Department of Biochemistry, Medicinal Biochemistry, Nanomedicine and Toxicology Laboratory, Landmark University, Omu-Aran, Kwara State, Nigeria
| | - Eman Nadwa
- Department of Pharmacology and Therapeutics, College of Medicine, Jouf University, Jouf, Egypt
- Department of Medical Pharmacology, Faculty of Medicine, Cairo University, Cario, Egypt
| | - Eman Rashwan
- Department of Physiology, College of Medicine, Al-Azhar University, Assuit, Egypt
- Department of Physiology, College of Medicine, Jouf University, Sakaka, Saudi Arabia
| | - Naoaki Yokoyama
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Ikuo Igarashi
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
- * E-mail:
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Wilson KT. Preventing Gastric Cancer Development by Inhibiting the Virulence of H. pylori Infection. ONCOLOGY (WILLISTON PARK, N.Y.) 2019; 33:227-231. [PMID: 31219607 PMCID: PMC6685684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In this interview with ONCOLOGY, Keith Wilson, MD, discusses a drug that may help prevent gastric cancer. Dr. Wilson and his colleagues recently published a study showing that a chemopreventive drug can also act directly on Helicobacter pylori (H. pylori), a bacterium that is the primary cause of gastric cancer.[1]
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α-Difluoromethylornithine reduces gastric carcinogenesis by causing mutations in Helicobacter pylori cagY. Proc Natl Acad Sci U S A 2019; 116:5077-5085. [PMID: 30804204 DOI: 10.1073/pnas.1814497116] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Infection by Helicobacter pylori is the primary cause of gastric adenocarcinoma. The most potent H. pylori virulence factor is cytotoxin-associated gene A (CagA), which is translocated by a type 4 secretion system (T4SS) into gastric epithelial cells and activates oncogenic signaling pathways. The gene cagY encodes for a key component of the T4SS and can undergo gene rearrangements. We have shown that the cancer chemopreventive agent α-difluoromethylornithine (DFMO), known to inhibit the enzyme ornithine decarboxylase, reduces H. pylori-mediated gastric cancer incidence in Mongolian gerbils. In the present study, we questioned whether DFMO might directly affect H. pylori pathogenicity. We show that H. pylori output strains isolated from gerbils treated with DFMO exhibit reduced ability to translocate CagA in gastric epithelial cells. Further, we frequently detected genomic modifications in the middle repeat region of the cagY gene of output strains from DFMO-treated animals, which were associated with alterations in the CagY protein. Gerbils did not develop carcinoma when infected with a DFMO output strain containing rearranged cagY or the parental strain in which the wild-type cagY was replaced by cagY with DFMO-induced rearrangements. Lastly, we demonstrate that in vitro treatment of H. pylori by DFMO induces oxidative DNA damage, expression of the DNA repair enzyme MutS2, and mutations in cagY, demonstrating that DFMO directly affects genomic stability. Deletion of mutS2 abrogated the ability of DFMO to induce cagY rearrangements directly. In conclusion, DFMO-induced oxidative stress in H. pylori leads to genomic alterations and attenuates virulence.
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16
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Debraekeleer A, Remaut H. Future perspective for potentialHelicobacter pylorieradication therapies. Future Microbiol 2018; 13:671-687. [DOI: 10.2217/fmb-2017-0115] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
- Ayla Debraekeleer
- Department of Structural & Molecular Microbiology, VIB Center for Structural Biology, VIB, Pleinlaan 2, 1050 Brussels, Belgium
- Department of Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Han Remaut
- Department of Structural & Molecular Microbiology, VIB Center for Structural Biology, VIB, Pleinlaan 2, 1050 Brussels, Belgium
- Department of Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
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17
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Alexiou GA, Lianos GD, Ragos V, Galani V, Kyritsis AP. Difluoromethylornithine in cancer: new advances. Future Oncol 2017; 13:809-819. [PMID: 28125906 DOI: 10.2217/fon-2016-0266] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Difluoromethylornithine (DFMO; eflornithine) is an irreversible suicide inhibitor of the enzyme ornithine decarboxylase which is involved in polyamine synthesis. Polyamines are important for cell survival, thus DFMO was studied as an anticancer agent and as a chemoprevention agent. DFMO exhibited mainly cytostatic activity and had single agent efficacy as well as activity in combination with other chemotherapeutic drugs for some cancers and leukemias. Herewith, we summarize the current knowledge of the anticancer and chemopreventive properties of DFMO and assess the status of clinical trials.
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Affiliation(s)
- George A Alexiou
- Neurosurgical Institute, Ioannina University School of Medicine, Ioannina, GR 451 10, Greece
| | - Georgios D Lianos
- Neurosurgical Institute, Ioannina University School of Medicine, Ioannina, GR 451 10, Greece
| | - Vassileios Ragos
- Neurosurgical Institute, Ioannina University School of Medicine, Ioannina, GR 451 10, Greece
| | - Vasiliki Galani
- Department of Anatomy-Histology-Embryology, Medical School, University of Ioannina, 45110 Ioannina, Greece
| | - Athanassios P Kyritsis
- Neurosurgical Institute, Ioannina University School of Medicine, Ioannina, GR 451 10, Greece
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18
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Ornithine decarboxylase regulates M1 macrophage activation and mucosal inflammation via histone modifications. Proc Natl Acad Sci U S A 2017; 114:E751-E760. [PMID: 28096401 DOI: 10.1073/pnas.1614958114] [Citation(s) in RCA: 132] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Macrophage activation is a critical step in host responses during bacterial infections. Ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine metabolism, has been well studied in epithelial cells and is known to have essential roles in many different cellular functions. However, its role in regulating macrophage function during bacterial infections is not well characterized. We demonstrate that macrophage-derived ODC is a critical regulator of M1 macrophage activation during both Helicobacter pylori and Citrobacter rodentium infection. Myeloid-specific Odc deletion significantly increased gastric and colonic inflammation, respectively, and enhanced M1 activation. Add-back of putrescine, the product of ODC, reversed the increased macrophage activation, indicating that ODC and putrescine are regulators of macrophage function. Odc-deficient macrophages had increased histone 3, lysine 4 (H3K4) monomethylation, and H3K9 acetylation, accompanied by decreased H3K9 di/trimethylation both in vivo and ex vivo in primary macrophages. These alterations in chromatin structure directly resulted in up-regulated gene transcription, especially M1 gene expression. Thus, ODC in macrophages tempers antimicrobial, M1 macrophage responses during bacterial infections through histone modifications and altered euchromatin formation, leading to the persistence and pathogenesis of these organisms.
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19
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Galectin-3 Plays an Important Role in Innate Immunity to Gastric Infection by Helicobacter pylori. Infect Immun 2016; 84:1184-1193. [PMID: 26857579 DOI: 10.1128/iai.01299-15] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 02/02/2016] [Indexed: 02/06/2023] Open
Abstract
We studied the role of galectin-3 (Gal3) in gastric infection by Helicobacter pylori We first demonstrated that Gal3 was selectively expressed by gastric surface epithelial cells and abundantly secreted into the surface mucus layer. We next inoculated H. pylori Sydney strain 1 into wild-type (WT) and Gal3-deficient mice using a stomach tube. At 2 weeks postinoculation, the bacterial cells were mostly trapped within the surface mucus layer in WT mice. In sharp contrast, they infiltrated deep into the gastric glands in Gal3-deficient mice. Bacterial loads in the gastric tissues were also much higher in Gal3-deficient mice than in WT mice. At 6 months postinoculation,H. pylori had successfully colonized within the gastric glands of both WT and Gal3-deficient mice, although the bacterial loads were still higher in the latter. Furthermore, large lymphoid clusters mostly consisting of B cells were frequently observed in the gastric submucosa of Gal3-deficient mice.In vitro, peritoneal macrophages from Gal3-deficient mice were inefficient in killing engulfed H. pylori Furthermore, recombinant Gal3 not only induced rapid aggregation of H. pylori but also exerted a potent bactericidal effect on H. pylori as revealed by propidium iodide uptake and a morphological shift from spiral to coccoid form. However, a minor fraction of bacterial cells, probably transient phase variants of Gal3-binding sugar moieties, escaped killing by Gal3. Collectively, our data demonstrate that Gal3 plays an important role in innate immunity to infection and colonization of H. pylori.
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20
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Gobert AP, Wilson KT. The Immune Battle against Helicobacter pylori Infection: NO Offense. Trends Microbiol 2016; 24:366-376. [PMID: 26916789 DOI: 10.1016/j.tim.2016.02.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 02/01/2016] [Accepted: 02/05/2016] [Indexed: 01/07/2023]
Abstract
Helicobacter pylori is a successful pathogen of the human stomach. Despite a vigorous immune response by the gastric mucosa, the bacterium survives in its ecological niche, thus favoring diseases ranging from chronic gastritis to adenocarcinoma. The current literature demonstrates that high-output of nitric oxide (NO) production by the inducible enzyme NO synthase-2 (NOS2) plays major functions in host defense against bacterial infections. However, pathogens have elaborated several strategies to counteract the deleterious effects of NO; this includes inhibition of host NO synthesis and transcriptional regulation in response to reactive nitrogen species, allowing the bacteria to face the nitrosative stress. Moreover, NO is also a critical mediator of inflammation and carcinogenesis. In this context, we review the recent findings on the expression of NOS2 in H. pylori-infected gastric tissues and epithelial cells, the role of NO in H. pylori-related diseases and H. pylori gene expression, and the mechanisms whereby H. pylori regulates NO synthesis by host cells.
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Affiliation(s)
- Alain P Gobert
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Center for Mucosal Inflammation and Cancer, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Keith T Wilson
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Center for Mucosal Inflammation and Cancer, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN 37212, USA.
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21
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Abu-Lubad M, Meyer TF, Al-Zeer MA. Chlamydia trachomatis inhibits inducible NO synthase in human mesenchymal stem cells by stimulating polyamine synthesis. THE JOURNAL OF IMMUNOLOGY 2014; 193:2941-51. [PMID: 25114102 DOI: 10.4049/jimmunol.1400377] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Chlamydia trachomatis is considered the most common agent of sexually transmitted disease worldwide. As an obligate intracellular bacterium, it relies on the host for survival. Production of NO is an effective antimicrobial defense mechanism of the innate immune system. However, whether NO is able to arrest chlamydial growth remains unclear. Similarly, little is known about the mechanisms underlying subversion of cellular innate immunity by C. trachomatis. By analyzing protein and mRNA expression in infected human mesenchymal stem cells, combined with RNA interference and biochemical assays, we observed that infection with C. trachomatis led to downregulated expression of inducible NO synthase (iNOS) in human mesenchymal stem cells in vitro. Furthermore, infection upregulated the expression of the rate-limiting enzyme in the polyamine biosynthetic pathway, ornithine decarboxylase, diverting the iNOS substrate l-arginine toward the synthesis of polyamines. Inhibition of ornithine decarboxylase activity using small interfering RNA or the competitive inhibitor difluoromethylornithine restored iNOS protein expression and activity in infected cells and inhibited chlamydial growth. This inhibition was mediated through tyrosine nitration of chlamydial protein by peroxynitrite, an NO metabolite. Thus, Chlamydia evades innate immunity by inhibiting NO production through induction of the alternative polyamine pathway.
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Affiliation(s)
- Mohammad Abu-Lubad
- Department of Molecular Biology, Max Planck Institute for Infection Biology, 10117 Berlin, Germany
| | - Thomas F Meyer
- Department of Molecular Biology, Max Planck Institute for Infection Biology, 10117 Berlin, Germany
| | - Munir A Al-Zeer
- Department of Molecular Biology, Max Planck Institute for Infection Biology, 10117 Berlin, Germany
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22
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Hardbower DM, Peek RM, Wilson KT. At the Bench: Helicobacter pylori, dysregulated host responses, DNA damage, and gastric cancer. J Leukoc Biol 2014; 96:201-12. [PMID: 24868089 DOI: 10.1189/jlb.4bt0214-099r] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Helicobacter pylori infection is the strongest known risk factor for the development of gastric cancer. Given that ∼50% of the global population is infected with this pathogen, there is great impetus to elucidate underlying causes that mediate progression from infection to cancer. Recent evidence suggests that H. pylori-induced chronic inflammation and oxidative stress create an environment conducive to DNA damage and tissue injury. DNA damage leads to genetic instability and eventually, neoplastic transformation. Pathogen-encoded virulence factors induce a robust but futile immune response and alter host pathways that lower the threshold for carcinogenesis, including DNA damage repair, polyamine synthesis and catabolism, antioxidant responses, and cytokine production. Collectively, such dysregulation creates a protumorigenic microenvironment within the stomach. This review seeks to address each of these aspects of H. pylori infection and to call attention to areas of particular interest within this field of research. This review also seeks to prioritize areas of translational research related to H. pylori-induced gastric cancer based on insights garnered from basic research in this field. See related review by Dalal and Moss, At the Bedside: H. pylori, dysregulated host responses, DNA damage, and gastric cancer.
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Affiliation(s)
- Dana M Hardbower
- Departments of Pathology, Microbiology, and Immunology and Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA; and
| | - Richard M Peek
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA; and Cancer Biology, and
| | - Keith T Wilson
- Departments of Pathology, Microbiology, and Immunology and Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA; and Cancer Biology, and Veterans Affairs, Tennessee Valley Healthcare System, Nashville, Tennessee, USA
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23
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Tersey SA, Colvin SC, Maier B, Mirmira RG. Protective effects of polyamine depletion in mouse models of type 1 diabetes: implications for therapy. Amino Acids 2014; 46:633-42. [PMID: 23846959 PMCID: PMC3888834 DOI: 10.1007/s00726-013-1560-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2013] [Accepted: 07/03/2013] [Indexed: 01/08/2023]
Abstract
The underlying pathophysiology of type 1 diabetes involves autoimmune-mediated islet inflammation, leading to dysfunction and death of insulin-secreting islet β cells. Recent studies have shown that polyamines, which are essential for mRNA translation, cellular replication, and the formation of the hypusine modification of eIF5A may play an important role in the progression of cellular inflammation. To test a role for polyamines in type 1 diabetes pathogenesis, we administered the ornithine decarboxylase inhibitor difluoromethylornithine to two mouse models--the low-dose streptozotocin model and the NOD model--to deplete intracellular polyamines, and administered streptozotocin to a third model, which was haploinsufficient for the gene encoding the hypusination enzyme deoxyhypusine synthase. Subsequent development of diabetes and/or glucose intolerance was monitored. In the low-dose streptozotocin mouse model, continuous difluoromethylornithine administration dose-dependently reduced the incidence of hyperglycemia and led to the preservation of β cell area, whereas in the NOD mouse model of autoimmune diabetes difluoromethylornithine reduced diabetes incidence by 50%, preserved β cell area and insulin secretion, led to reductions in both islet inflammation and potentially diabetogenic Th17 cells in pancreatic lymph nodes. Difluoromethylornithine treatment reduced hypusinated eIF5A levels in both immune cells and islets. Animals haploinsufficient for the gene encoding deoxyhypusine synthase were partially protected from hyperglycemia induced by streptozotocin. Collectively, these studies suggest that interventions that interfere with polyamine biosynthesis and/or eIF5A hypusination may represent viable approaches in the treatment of diabetes.
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MESH Headings
- Animals
- Diabetes Mellitus, Experimental/chemically induced
- Diabetes Mellitus, Experimental/drug therapy
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Type 1/chemically induced
- Diabetes Mellitus, Type 1/drug therapy
- Diabetes Mellitus, Type 1/metabolism
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Eflornithine/administration & dosage
- Female
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Inbred NOD
- Mice, Knockout
- Oxidoreductases Acting on CH-NH Group Donors/deficiency
- Oxidoreductases Acting on CH-NH Group Donors/metabolism
- Peptide Initiation Factors/metabolism
- Polyamines/metabolism
- RNA-Binding Proteins/metabolism
- Streptozocin/administration & dosage
- Eukaryotic Translation Initiation Factor 5A
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Affiliation(s)
- Sarah A. Tersey
- Department of Pediatrics and the Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Stephanie C. Colvin
- Department of Pediatrics and the Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Bernhard Maier
- Department of Pediatrics and the Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Raghavendra G. Mirmira
- Department of Pediatrics and the Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Departments of Medicine, Cellular and Integrative Physiology, and Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
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Abstract
An expanding body of evidence supports a role for gut microbes in the etiology of cancer. Previously, the focus was on identifying individual bacterial species that directly initiate or promote gastrointestinal malignancies; however, the capacity of gut microbes to influence systemic inflammation and other downstream pathways suggests that the gut microbial community may also affect risk of cancer in tissues outside of the gastrointestinal tract. Functional contributions of the gut microbiota that may influence cancer susceptibility in the broad sense include (1) harvesting otherwise inaccessible nutrients and/or sources of energy from the diet (i.e., fermentation of dietary fibers and resistant starch); (2) metabolism of xenobiotics, both potentially beneficial or detrimental (i.e., dietary constituents, drugs, carcinogens, etc.); (3) renewal of gut epithelial cells and maintenance of mucosal integrity; and (4) affecting immune system development and activity. Understanding the complex and dynamic interplay between the gut microbiome, host immune system, and dietary exposures may help elucidate mechanisms for carcinogenesis and guide future cancer prevention and treatment strategies.
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Affiliation(s)
- Meredith A J Hullar
- Cancer Prevention Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, M4-B402, PO Box 19024, Seattle, WA, 98109, USA
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25
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Lo CY, Cheng HL, Hsu JL, Liao MH, Yen RL, Chen YC. The antimicrobial activities of phenylbutyrates against Helicobacter pylori. Chem Pharm Bull (Tokyo) 2013; 61:604-10. [PMID: 23727774 DOI: 10.1248/cpb.c12-00857] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Three phenyl derivatives of butyrate, 2-phenylbutyrate (2-PB), 3-phenylbutyrate (3-PB) and 4-phenylbutyrate (4-PB), were evaluated in terms of their antibacterial and cytotoxic activities. Our results indicated that PBs demonstrated specific inhibitory activity against Helicobacter pylori and Escherichia coli but did not influence the growth of Bifidobacterium bifidium and Lactobacillus reuteri. PBs also exhibited synergistic effects on H. pylori ATCC 43504 especially at pH 5.5. In the protein expression profiles in H. pylori treated by phenylbutyrates, we also found that three protein spots identified as oxidative stress-related proteins were significantly up-regulated, confirming the response of H. pylori when exposed to PBs. Due to their antibacterial activities and low or slight cytotoxicities, PBs are potential candidates for the treatment of H. pylori infection. This is the first study to discover the antibiotic effects of 2-PB, 3-PB and 4-PB (Buphenyl).
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Affiliation(s)
- Chung-Yi Lo
- Graduate Institute of Bioresource, National Pingtung University of Science and Technology, Pingtung, Taiwan, ROC
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26
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Kreul SM, Havighurst T, Kim K, Mendonça EA, Wood GS, Snow S, Borich A, Verma A, Bailey HH. A phase III skin cancer chemoprevention study of DFMO: long-term follow-up of skin cancer events and toxicity. Cancer Prev Res (Phila) 2012; 5:1368-74. [PMID: 23060038 DOI: 10.1158/1940-6207.capr-12-0233] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Decreasing the incidence of nonmelanoma skin cancer (NMSC) is of great importance in regards to future healthcare services. Given the previously reported preventive effects of α-difluoromethylornithine (DFMO) in skin and colon cancer trials, we determined appropriate cause to update the clinical data on the subjects from the recently reported randomized, double-blind, placebo-controlled phase III skin cancer prevention study of DFMO. Our intention was to retrospectively assess the further incidence of skin cancer, other malignancies, and adverse events of patients accrued to our phase III skin cancer prevention study of DFMO. Clinical records of 209 University of Wisconsin (UW) Health subjects were reviewed, and 2,092.7 person years of on study (884.3 person years) and poststudy (1,208.4 person years) follow-up for these patients were assessed for new NMSC events and recurrence rates from the on study period, the poststudy period, and the two study periods combined. No evidence of increased significant diagnoses or serious adverse events was observed in the DFMO participants. The initially observed, marginally significant reduction (P = 0.069) in NMSC rates for DFMO subjects relative to placebo continued without evidence of rebound. Event rates after discontinuation from study for total NMSCs (DFMO 0.236 NMSC/person/year, placebo 0.297, P = 0.48) or the subtypes of basal cell carcinomas (BCC; DFMO 0.179 BCC/person/year, placebo 0.190, P = 0.77) and squamous cell carcinomas (SCC; DFMO 0.057 SCC/person/year, placebo 0.107, P = 0.43) are listed. Follow-up data revealed a persistent but insignificant reduction in new NMSCs occurring in DFMO subjects without evidence of latent or cumulative toxicity relative to placebo subjects.
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Affiliation(s)
- Sarah M Kreul
- University of Wisconsin Carbone Cancer Center, Madison, Wisconsin, USA
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27
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Singh K, Coburn LA, Barry DP, Boucher JL, Chaturvedi R, Wilson KT. L-arginine uptake by cationic amino acid transporter 2 is essential for colonic epithelial cell restitution. Am J Physiol Gastrointest Liver Physiol 2012; 302:G1061-73. [PMID: 22361732 PMCID: PMC3362080 DOI: 10.1152/ajpgi.00544.2011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Restoration of the colonic epithelial barrier is an important response during colitis. L-arginine (L-Arg) is a semiessential amino acid that reduces murine colitis induced by Citrobacter rodentium. Cationic amino acid transporter (CAT) proteins increase L-Arg uptake into cells. L-Arg is utilized to produce nitric oxide (NO), by inducible NO synthase (iNOS), or L-ornithine (L-Orn) by arginase (Arg) enzymes. The latter is followed by generation of polyamines by ornithine decarboxylase (ODC) and L-proline (L-Pro) by ornithine aminotransferase (OAT). We show that L-Arg enhanced epithelial restitution in conditionally immortalized young adult mouse colon (YAMC) cells in a wound repair model, and in isolated mouse colonic epithelial cells (CECs), using a cell migration assay. Restitution was impaired by C. rodentium. Wounding induced CAT2, and inhibition of L-Arg uptake by the competitive inhibitor L-lysine (L-Lys) or by CAT2 shRNA, but not CAT1 shRNA, decreased restitution. Migration was impaired in CECs treated with L-Lys or from CAT2(-/-) mice. Wounding increased Arg1 expression, and inhibition of arginase with S-(2-boronoethyl)-L-cysteine (BEC) or Arg1 shRNA inhibited restitution in YAMC cells; cell migration in CECs was also impaired by BEC. Inhibition of ODC or iNOS did not alter restitution. L-Orn or L-Pro restored restitution in cells treated with BEC or Arg1 shRNA, whereas the polyamine putrescine had no benefit. Wounding increased OAT levels, OAT shRNA inhibited restitution, and L-Pro restored restitution in cells with OAT knockdown. Uptake of L-Arg, and its metabolism by Arg1 to L-Orn and conversion to L-Pro by OAT is essential for colonic epithelial wound repair.
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Affiliation(s)
- Kshipra Singh
- Departments of 1Medicine, Division of Gastroenterology, ,4Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee, and
| | - Lori A. Coburn
- Departments of 1Medicine, Division of Gastroenterology, ,4Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee, and
| | - Daniel P. Barry
- Departments of 1Medicine, Division of Gastroenterology, ,4Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee, and
| | | | - Rupesh Chaturvedi
- Departments of 1Medicine, Division of Gastroenterology, ,4Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee, and
| | - Keith T. Wilson
- Departments of 1Medicine, Division of Gastroenterology, ,2Cancer Biology, and ,3Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center and ,4Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee, and
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Chaturvedi R, de Sablet T, Peek RM, Wilson KT. Spermine oxidase, a polyamine catabolic enzyme that links Helicobacter pylori CagA and gastric cancer risk. Gut Microbes 2012; 3:48-56. [PMID: 22555547 PMCID: PMC3337125 DOI: 10.4161/gmic.19345] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
We have recently reported that Helicobacter pylori strains expressing the virulence factor cytotoxin-associated gene A (CagA) stimulate increased levels of spermine oxidase (SMO) in gastric epithelial cells, while cagA⁻ strains did not. SMO catabolizes the polyamine spermine and produces H₂O₂ that results in both apoptosis and DNA damage. Exogenous overexpression of CagA confirmed these findings, and knockdown or inhibition of SMO blocked CagA-mediated apoptosis and DNA damage. The strong association of SMO, apoptosis, and DNA damage was also demonstrated in humans infected with cagA⁺, but not cagA⁻ strains. In infected gerbils and mice, DNA damage was CagA-dependent and only present in epithelial cells that expressed SMO. We also discovered SMO (high) gastric epithelial cells from infected animals with dysplasia that are resistant to apoptosis despite high levels of DNA damage. Inhibition of polyamine synthesis or SMO could abrogate the development of this cell population that may represent precursors for neoplastic transformation.
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Affiliation(s)
- Rupesh Chaturvedi
- Division of Gastroenterology, Hepatology, and Nutrition; Department of Medicine; Vanderbilt University Medical Center; Nashville, TN USA
- Veterans Affairs; Tennessee Valley Healthcare System; Nashville, TN USA
| | - Thibaut de Sablet
- Division of Gastroenterology, Hepatology, and Nutrition; Department of Medicine; Vanderbilt University Medical Center; Nashville, TN USA
- Veterans Affairs; Tennessee Valley Healthcare System; Nashville, TN USA
| | - Richard M. Peek
- Division of Gastroenterology, Hepatology, and Nutrition; Department of Medicine; Vanderbilt University Medical Center; Nashville, TN USA
- Veterans Affairs; Tennessee Valley Healthcare System; Nashville, TN USA
- Department of Cancer Biology; Vanderbilt University Medical Center; Nashville, TN USA
| | - Keith T. Wilson
- Division of Gastroenterology, Hepatology, and Nutrition; Department of Medicine; Vanderbilt University Medical Center; Nashville, TN USA
- Veterans Affairs; Tennessee Valley Healthcare System; Nashville, TN USA
- Department of Cancer Biology; Vanderbilt University Medical Center; Nashville, TN USA
- Department of Pathology, Microbiology, and Immunology; Vanderbilt University Medical Center; Nashville, TN USA
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Cationic amino acid transporter 2 enhances innate immunity during Helicobacter pylori infection. PLoS One 2011; 6:e29046. [PMID: 22194986 PMCID: PMC3237590 DOI: 10.1371/journal.pone.0029046] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 11/18/2011] [Indexed: 01/19/2023] Open
Abstract
Once acquired, Helicobacter pylori infection is lifelong due to an inadequate innate and adaptive immune response. Our previous studies indicate that interactions among the various pathways of arginine metabolism in the host are critical determinants of outcomes following infection. Cationic amino acid transporter 2 (CAT2) is essential for transport of L-arginine (L-Arg) into monocytic immune cells during H. pylori infection. Once within the cell, this amino acid is utilized by opposing pathways that lead to elaboration of either bactericidal nitric oxide (NO) produced from inducible NO synthase (iNOS), or hydrogen peroxide, which causes macrophage apoptosis, via arginase and the polyamine pathway. Because of its central role in controlling L-Arg availability in macrophages, we investigated the importance of CAT2 in vivo during H. pylori infection. CAT2(-/-) mice infected for 4 months exhibited decreased gastritis and increased levels of colonization compared to wild type mice. We observed suppression of gastric macrophage levels, macrophage expression of iNOS, dendritic cell activation, and expression of granulocyte-colony stimulating factor in CAT2(-/-) mice suggesting that CAT2 is involved in enhancing the innate immune response. In addition, cytokine expression in CAT2(-/-) mice was altered from an antimicrobial Th1 response to a Th2 response, indicating that the transporter has downstream effects on adaptive immunity as well. These findings demonstrate that CAT2 is an important regulator of the immune response during H. pylori infection.
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Verbeke H, Geboes K, Van Damme J, Struyf S. The role of CXC chemokines in the transition of chronic inflammation to esophageal and gastric cancer. Biochim Biophys Acta Rev Cancer 2011; 1825:117-29. [PMID: 22079531 DOI: 10.1016/j.bbcan.2011.10.008] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 10/28/2011] [Accepted: 10/29/2011] [Indexed: 12/12/2022]
Abstract
Chronic inflammation may increase the risk to develop cancer, for instance esophagitis or gastritis may lead to development of esophageal or gastric cancer, respectively. The key molecules attracting leukocytes to local inflammatory sites are chemokines. We here provide a systematic review on the impact of CXC chemokines (binding the receptors CXCR1, CXCR2, CXCR3 and CXCR4) on the transition of chronic inflammation in the upper gastrointestinal tract to neoplasia. CXCR2 ligands, including GRO-α,β,γ/CXCL1,2,3, ENA-78/CXCL5 and IL-8/CXCL8 chemoattract pro-tumoral neutrophils. In addition, angiogenic CXCR2 ligands stimulate the formation of new blood vessels, facilitating tumor progression. The CXCR4 ligand SDF-1/CXCL12 also promotes tumor development by stimulating angiogenesis and by favoring metastasis of CXCR4-positive tumor cells to distant organs producing SDF-1/CXCL12. Furthermore, these angiogenic chemokines also directly enhance tumor cell survival and proliferation. In contrast, the CXCR3 ligands Mig/CXCL9, IP-10/CXCL10 and I-TAC/CXCL11 are angiostatic and attract anti-tumoral T lymphocytes and may therefore mediate tumor growth retardation and regression. Thus, chemokines exert diverging, sometimes dual roles in tumor biology as described for esophageal and gastric cancer. Therefore extensive research is needed to completely unravel the complex chemokine code in specific cancers. Possibly, chemokine-targeted cancer therapy will have to be adapted to the individual's chemokine profile.
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Affiliation(s)
- Hannelien Verbeke
- Laboratory of Molecular Immunology, Rega Institute for Medical Research, University of Leuven (K.U.Leuven), Belgium
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31
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Chaturvedi R, Asim M, Romero-Gallo J, Barry DP, Hoge S, de Sablet T, Delgado AG, Wroblewski LE, Piazuelo MB, Yan F, Israel DA, Casero RA, Correa P, Gobert AP, Polk DB, Peek RM, Wilson KT. Spermine oxidase mediates the gastric cancer risk associated with Helicobacter pylori CagA. Gastroenterology 2011; 141:1696-708.e1-2. [PMID: 21839041 PMCID: PMC3202654 DOI: 10.1053/j.gastro.2011.07.045] [Citation(s) in RCA: 145] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 06/28/2011] [Accepted: 07/26/2011] [Indexed: 12/15/2022]
Abstract
BACKGROUND & AIMS Helicobacter pylori-induced gastric carcinogenesis has been linked to the microbial oncoprotein cytotoxin-associated gene A (CagA). Spermine oxidase (SMO) metabolizes the polyamine spermine into spermidine and generates H(2)O(2), which causes apoptosis and DNA damage. We determined if pathogenic effects of CagA are attributable to SMO. METHODS Levels of SMO, apoptosis, and DNA damage (8-oxoguanosine) were measured in gastric epithelial cell lines infected with cagA(+) or cagA(-)H pylori strains, or transfected with a CagA expression plasmid, in the absence or presence of SMO small interfering RNA, or an SMO inhibitor. The role of CagA in induction of SMO and DNA damage was assessed in H pylori-infected gastritis tissues from humans, gerbils, and both wild-type and hypergastrinemic insulin-gastrin mice, using immunohistochemistry and flow cytometry. RESULTS cagA(+) strains or ectopic expression of CagA, but not cagA(-) strains, led to increased levels of SMO, apoptosis, and DNA damage in gastric epithelial cells, and knockdown or inhibition of SMO blocked apoptosis and DNA damage. There was increased SMO expression, apoptosis, and DNA damage in gastric tissues from humans infected with cagA(+), but not cagA(-) strains. In gerbils and mice, DNA damage was CagA-dependent and present in cells that expressed SMO. Gastric epithelial cells with DNA damage that were negative for markers of apoptosis accounted for 42%-69% of cells in gerbils and insulin-gastrin mice with dysplasia and carcinoma. CONCLUSIONS By inducing SMO, H pylori CagA generates cells with oxidative DNA damage, and a subpopulation of these cells are resistant to apoptosis and thus at high risk for malignant transformation.
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Affiliation(s)
- Rupesh Chaturvedi
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN
| | - Mohammad Asim
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN
| | - Judith Romero-Gallo
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Daniel P. Barry
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN
| | - Svea Hoge
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Department of General, Abdominal and Vascular Surgery, Otto-von-Guericke University, Magdeburg, Germany
| | - Thibaut de Sablet
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN
| | - Alberto G. Delgado
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Lydia E. Wroblewski
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - M. Blanca Piazuelo
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Fang Yan
- Division of Gastroenterology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN
| | - Dawn A. Israel
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Robert A. Casero
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Pelayo Correa
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Alain P. Gobert
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN
- Institut National de la Recherche Agronomique, Unité de Microbiologie UR454, Saint-Genès-Champanelle, France
| | - D. Brent Polk
- Division of Gastroenterology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN
- Department of Pediatrics, University of Southern California Keck School of Medicine, Los Angeles, CA
| | - Richard M. Peek
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN
| | - Keith T. Wilson
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN
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Abstract
Helicobacter pylori infections and clinical outcome are dependent on sophisticated interactions between the bacteria and its host. Crucial bacterial factors associated with pathogenicity comprise a type IV secretion system encoded by the cag pathogenicity island, the effector protein CagA, the vacuolating cytotoxin (VacA), peptidoglycan, lipopolysaccharide (LPS), γ-glutamyl transpeptidase (GGT), protease HtrA, and the adhesins BabA, SabA, and others. The high number of these factors and allelic variation of the involved genes generates a highly complex scenario and reveals the difficulties in testing the contribution of each individual factor. Much effort has been put into identifying the molecular mechanisms associated with H. pylori-associated pathogenesis using human primary tissues, Mongolian gerbils, transgenic, knockout, and other mice as well as in vitro cell model systems. Interactions between bacterial factors and host signal transduction pathways seem to be critical for mediating the induction of pathogenic downstream processes and disease development. In this review article, we discuss the most recent progress in this research field.
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Affiliation(s)
- Steffen Backert
- UCD School of Biomolecular and Biomedical Sciences, University College Dublin, Science Center West, Belfield Campus, Dublin, Ireland.
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Chaturvedi R, de Sablet T, Coburn LA, Gobert AP, Wilson KT. Arginine and polyamines in Helicobacter pylori-induced immune dysregulation and gastric carcinogenesis. Amino Acids 2011; 42:627-40. [PMID: 21874531 DOI: 10.1007/s00726-011-1038-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Accepted: 06/13/2011] [Indexed: 02/07/2023]
Abstract
L-arginine (L-Arg) is metabolized by nitric oxide synthase and arginase enzymes. The gastric pathogen Helicobacter pylori causes peptic ulcer disease and gastric cancer. We have shown that alterations in L-Arg availability and metabolism into polyamines contribute significantly to the dysregulation of the host immune response to this infection. Nitric oxide (NO) derived from inducible NO synthase (iNOS) can kill H. pylori. There are multiple mechanisms leading to failure of this process, including competition for L-Arg substrate by H. pylori arginase, and induction of host macrophage arginase II (Arg2) and ornithine decarboxylase (ODC). Generation of spermine by ODC inhibits iNOS translation and NO-mediated H. pylori killing. Expression of ODC is dependent on formation of a unique AP-1 complex, leading to upregulation of c-Myc as a transcriptional enhancer. Macrophage apoptosis is mediated by oxidation of spermine via the enzyme spermine oxidase (SMO) that generates hydrogen peroxide (H(2)O(2)), and thus oxidative stress-induced mitochondrial membrane polarization. Our studies have demonstrated that apoptosis occurs through a pERK → pc-Fos/c-Jun → c-Myc → ODC → SMO pathway. In gastric epithelial cells, activation of oxidative stress by H. pylori is dependent on SMO induction and results in both apoptosis and DNA damage, such that inhibition or knockdown of SMO markedly attenuates these events. In summary, L-Arg metabolism by the arginase-ODC pathway and the activation of SMO leads to H. pylori-induced DNA damage and immune dysregulation through polyamine-mediated oxidative stress and impairment of antimicrobial NO synthesis. Our studies indicate novel targets for therapeutic intervention in H. pylori-associated diseases, including gastritis, ulcer disease, and gastric cancer.
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Affiliation(s)
- Rupesh Chaturvedi
- Division of Gastroenterology, Department of Medicine, Vanderbilt University School of Medicine, 1030C MRBIV, 2215 Garland Avenue, Nashville, TN 37232, USA
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