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Shuman JHB, Lin AS, Westland MD, Bryant KN, Piazuelo MB, Reyzer ML, Judd AM, McDonald WH, McClain MS, Schey KL, Algood HMS, Cover TL. Remodeling of the gastric environment in Helicobacter pylori-induced atrophic gastritis. mSystems 2024; 9:e0109823. [PMID: 38059647 PMCID: PMC10805037 DOI: 10.1128/msystems.01098-23] [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: 10/14/2023] [Accepted: 10/16/2023] [Indexed: 12/08/2023] Open
Abstract
Helicobacter pylori colonization of the human stomach is a strong risk factor for gastric cancer. To investigate H. pylori-induced gastric molecular alterations, we used a Mongolian gerbil model of gastric carcinogenesis. Histologic evaluation revealed varying levels of atrophic gastritis (a premalignant condition characterized by parietal and chief cell loss) in H. pylori-infected animals, and transcriptional profiling revealed a loss of markers for these cell types. We then assessed the spatial distribution and relative abundance of proteins in the gastric tissues using imaging mass spectrometry and liquid chromatography with tandem mass spectrometry. We detected striking differences in the protein content of corpus and antrum tissues. Four hundred ninety-two proteins were preferentially localized to the corpus in uninfected animals. The abundance of 91 of these proteins was reduced in H. pylori-infected corpus tissues exhibiting atrophic gastritis compared with infected corpus tissues exhibiting non-atrophic gastritis or uninfected corpus tissues; these included numerous proteins with metabolic functions. Fifty proteins localized to the corpus in uninfected animals were diffusely delocalized throughout the stomach in infected tissues with atrophic gastritis; these included numerous proteins with roles in protein processing. The corresponding alterations were not detected in animals infected with a H. pylori ∆cagT mutant (lacking Cag type IV secretion system activity). These results indicate that H. pylori can cause loss of proteins normally localized to the gastric corpus as well as diffuse delocalization of corpus-specific proteins, resulting in marked changes in the normal gastric molecular partitioning into distinct corpus and antrum regions.IMPORTANCEA normal stomach is organized into distinct regions known as the corpus and antrum, which have different functions, cell types, and gland architectures. Previous studies have primarily used histologic methods to differentiate these regions and detect H. pylori-induced alterations leading to stomach cancer. In this study, we investigated H. pylori-induced gastric molecular alterations in a Mongolian gerbil model of carcinogenesis. We report the detection of numerous proteins that are preferentially localized to the gastric corpus but not the antrum in a normal stomach. We show that stomachs with H. pylori-induced atrophic gastritis (a precancerous condition characterized by the loss of specialized cell types) exhibit marked changes in the abundance and localization of proteins normally localized to the gastric corpus. These results provide new insights into H. pylori-induced gastric molecular alterations that are associated with the development of stomach cancer.
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Affiliation(s)
- Jennifer H. B. Shuman
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Aung Soe Lin
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Mandy D. Westland
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Kaeli N. Bryant
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - M. Blanca Piazuelo
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Michelle L. Reyzer
- Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Audra M. Judd
- Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - W. Hayes McDonald
- Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Mark S. McClain
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Kevin L. Schey
- Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Holly M. S. Algood
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee, USA
| | - Timothy L. Cover
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee, USA
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2
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Tran SC, Bryant KN, Cover TL. The Helicobacter pylori cag pathogenicity island as a determinant of gastric cancer risk. Gut Microbes 2024; 16:2314201. [PMID: 38391242 PMCID: PMC10896142 DOI: 10.1080/19490976.2024.2314201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Accepted: 01/31/2024] [Indexed: 02/24/2024] Open
Abstract
Helicobacter pylori strains can be broadly classified into two groups based on whether they contain or lack a chromosomal region known as the cag pathogenicity island (cag PAI). Colonization of the human stomach with cag PAI-positive strains is associated with an increased risk of gastric cancer and peptic ulcer disease, compared to colonization with cag PAI-negative strains. The cag PAI encodes a secreted effector protein (CagA) and components of a type IV secretion system (Cag T4SS) that delivers CagA and non-protein substrates into host cells. Animal model experiments indicate that CagA and the Cag T4SS stimulate a gastric mucosal inflammatory response and contribute to the development of gastric cancer. In this review, we discuss recent studies defining structural and functional features of CagA and the Cag T4SS and mechanisms by which H. pylori strains containing the cag PAI promote the development of gastric cancer and peptic ulcer disease.
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Affiliation(s)
- Sirena C Tran
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kaeli N Bryant
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Timothy L Cover
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN, USA
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3
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Wang H, Zhao M, Shi F, Zheng S, Xiong L, Zheng L. A review of signal pathway induced by virulent protein CagA of Helicobacter pylori. Front Cell Infect Microbiol 2023; 13:1062803. [PMID: 37124036 PMCID: PMC10140366 DOI: 10.3389/fcimb.2023.1062803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 03/24/2023] [Indexed: 05/02/2023] Open
Abstract
Gastric cancer (GC), a common and high-mortality disease, still occupies an important position in current cancer research, and Helicobacter pylori (H. pylori) infection as its important risk factor has been a hot and challenging research area. Among the numerous pathogenic factors of H. pylori, the virulence protein CagA has been widely studied as the only bacterial-derived oncoprotein. It was found that CagA entering into gastric epithelial cells (GECs) can induce the dysregulation of multiple cellular pathways such as MAPK signaling pathway, PI3K/Akt signaling pathway, NF-κB signaling pathway, Wnt/β-catenin signaling pathway, JAK-STAT signaling pathway, Hippo signaling pathway through phosphorylation and non-phosphorylation. These disordered pathways cause pathological changes in morphology, adhesion, polarity, proliferation, movement, and other processes of GECs, which eventually promotes the occurrence of GC. With the deepening of H. pylori-related research, the research on CagA-induced abnormal signaling pathway has been updated and deepened to some extent, so the key signaling pathways activated by CagA are used as the main stem to sort out the pathogenesis of CagA in this paper, aiming to provide new strategies for the H. pylori infection and treatment of GC in the future.
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Affiliation(s)
- Haiqiang Wang
- Department of Internal Medicine, First Affiliated Hospital, Heilongjiang University of Chinese Medicine, Harbin, China
| | - Mei Zhao
- Graduate School of Heilongjiang University of Chinese Medicine, Harbin, China
| | - Fan Shi
- Graduate School of Heilongjiang University of Chinese Medicine, Harbin, China
| | - Shudan Zheng
- Graduate School of Heilongjiang University of Chinese Medicine, Harbin, China
| | - Li Xiong
- Graduate School of Heilongjiang University of Chinese Medicine, Harbin, China
| | - Lihong Zheng
- Department of Internal Medicine, Fourth Affiliated Hospital, Heilongjiang University of Chinese Medicine, Harbin, China
- *Correspondence: Lihong Zheng,
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Ansari S, Yamaoka Y. Helicobacter pylori Infection, Its Laboratory Diagnosis, and Antimicrobial Resistance: a Perspective of Clinical Relevance. Clin Microbiol Rev 2022; 35:e0025821. [PMID: 35404105 PMCID: PMC9491184 DOI: 10.1128/cmr.00258-21] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Despite the recent decrease in overall prevalence of Helicobacter pylori infection, morbidity and mortality rates associated with gastric cancer remain high. The antimicrobial resistance developments and treatment failure are fueling the global burden of H. pylori-associated gastric complications. Accurate diagnosis remains the opening move for treatment and eradication of infections caused by microorganisms. Although several reports have been published on diagnostic approaches for H. pylori infection, most lack the data regarding diagnosis from a clinical perspective. Therefore, we provide an intensive, comprehensive, and updated description of the currently available diagnostic methods that can help clinicians, infection diagnosis professionals, and H. pylori researchers working on infection epidemiology to broaden their understanding and to select appropriate diagnostic methods. We also emphasize appropriate diagnostic approaches based on clinical settings (either clinical diagnosis or mass screening), patient factors (either age or other predisposing factors), and clinical factors (either upper gastrointestinal bleeding or partial gastrectomy) and appropriate methods to be considered for evaluating eradication efficacy. Furthermore, to cope with the increasing trend of antimicrobial resistance, a better understanding of its emergence and current diagnostic approaches for resistance detection remain inevitable.
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Affiliation(s)
- Shamshul Ansari
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu City, Oita, Japan
| | - Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu City, Oita, Japan
- Department of Medicine, Gastroenterology and Hepatology Section, Baylor College of Medicine, Houston, Texas, USA
- Institute of Tropical Disease, Universitas Airlangga, Surabaya, Indonesia
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5
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Biomarker Characterization and Prediction of Virulence and Antibiotic Resistance from Helicobacter pylori Next Generation Sequencing Data. Biomolecules 2022; 12:biom12050691. [PMID: 35625618 PMCID: PMC9138241 DOI: 10.3390/biom12050691] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/02/2022] [Accepted: 05/07/2022] [Indexed: 02/06/2023] Open
Abstract
The Gram-negative bacterium Helicobacter pylori colonizes c.a. 50% of human stomachs worldwide and is the major risk factor for gastric adenocarcinoma. Its high genetic variability makes it difficult to identify biomarkers of early stages of infection that can reliably predict its outcome. Moreover, the increasing antibiotic resistance found in H. pylori defies therapy, constituting a major human health problem. Here, we review H. pylori virulence factors and genes involved in antibiotic resistance, as well as the technologies currently used for their detection. Furthermore, we show that next generation sequencing may lead to faster characterization of virulence factors and prediction of the antibiotic resistance profile, thus contributing to personalized treatment and management of H. pylori-associated infections. With this new approach, more and permanent data will be generated at a lower cost, opening the future to new applications for H. pylori biomarker identification and antibiotic resistance prediction.
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Ecovoiu AA, Ratiu AC, Micheu MM, Chifiriuc MC. Inter-Species Rescue of Mutant Phenotype—The Standard for Genetic Analysis of Human Genetic Disorders in Drosophila melanogaster Model. Int J Mol Sci 2022; 23:ijms23052613. [PMID: 35269756 PMCID: PMC8909942 DOI: 10.3390/ijms23052613] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 02/23/2022] [Accepted: 02/24/2022] [Indexed: 11/16/2022] Open
Abstract
Drosophila melanogaster (the fruit fly) is arguably a superstar of genetics, an astonishing versatile experimental model which fueled no less than six Nobel prizes in medicine. Nowadays, an evolving research endeavor is to simulate and investigate human genetic diseases in the powerful D. melanogaster platform. Such a translational experimental strategy is expected to allow scientists not only to understand the molecular mechanisms of the respective disorders but also to alleviate or even cure them. In this regard, functional gene orthology should be initially confirmed in vivo by transferring human or vertebrate orthologous transgenes in specific mutant backgrounds of D. melanogaster. If such a transgene rescues, at least partially, the mutant phenotype, then it qualifies as a strong candidate for modeling the respective genetic disorder in the fruit fly. Herein, we review various examples of inter-species rescue of relevant mutant phenotypes of the fruit fly and discuss how these results recommend several human genes as candidates to study and validate genetic variants associated with human diseases. We also consider that a wider implementation of this evolutionist exploratory approach as a standard for the medicine of genetic disorders would allow this particular field of human health to advance at a faster pace.
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Affiliation(s)
- Alexandru Al. Ecovoiu
- Department of Genetics, Faculty of Biology, University of Bucharest, 060101 Bucharest, Romania;
| | - Attila Cristian Ratiu
- Department of Genetics, Faculty of Biology, University of Bucharest, 060101 Bucharest, Romania;
- Correspondence: ; Tel.: +40-722250366
| | - Miruna Mihaela Micheu
- Department of Cardiology, Clinical Emergency Hospital of Bucharest, 014461 Bucharest, Romania;
| | - Mariana Carmen Chifiriuc
- The Research Institute of the University of Bucharest and Faculty of Biology, University of Bucharest, 050095 Bucharest, Romania;
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7
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Sharafutdinov I, Backert S, Tegtmeyer N. The Helicobacter pylori type IV secretion system upregulates epithelial cortactin expression by a CagA- and JNK-dependent pathway. Cell Microbiol 2021; 23:e13376. [PMID: 34197673 DOI: 10.1111/cmi.13376] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 06/18/2021] [Accepted: 06/28/2021] [Indexed: 12/11/2022]
Abstract
Cortactin represents an important actin-binding factor, which controls actin-cytoskeletal remodelling in host cells. In this way, cortactin has been shown to exhibit crucial functions both for cell movement and tumour cell invasion. In addition, the cortactin gene cttn is amplified in various cancer types of humans. Helicobacter pylori is the causative agent of multiple gastric diseases and represents a significant risk factor for the development of gastric adenocarcinoma. It has been repeatedly shown that H. pylori manipulates cancer-related signal transduction events in infected gastric epithelial cells such as the phosphorylation status of cortactin. In fact, H. pylori modifies the activity of cortactin's binding partners to stimulate changes in the actin-cytoskeleton, cell adhesion and motility. Here we show that H. pylori infection of cultured AGS and Caco-2 cells for 24-48 hr leads to the overexpression of cortactin by 2-3 fold at the protein level. We demonstrate that this activity requires the integrity of the type IV secretion system (T4SS) encoded by the cag pathogenicity island (cagPAI) as well as the translocated effector protein CagA. We further show that ectopic expression of CagA is sufficient to stimulate cortactin overexpression. Furthermore, phosphorylation of CagA at the EPIYA-repeat region is not required, suggesting that this CagA activity proceeds in a phosphorylation-independent fashion. Inhibitor studies further demonstrate that the involved signalling pathway comprises the mitogen-activated protein kinase JNK (c-Jun N-terminal kinase), but not ERK1/2 or p38. Taken together, using H. pylori as a model system, this study discovered a previously unrecognised cortactin activation cascade by a microbial pathogen. We suggest that H. pylori targets cortactin to manipulate the cellular architecture and epithelial barrier functions that can impact gastric cancer development. TAKE AWAYS: Helicobacter pylori infection induces overexpression of cortactin at the protein level Cortactin upregulation requires the T4SS and effector protein CagA Ectopic expression of CagA is sufficient to stimulate cortactin overexpression Overexpression of cortactin proceeds CagA phosphorylation-independent The involved host cell signalling pathway comprises the MAP kinase JNK.
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Affiliation(s)
- Irshad Sharafutdinov
- Department of Biology, Division of Microbiology, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, 91058, Germany
| | - Steffen Backert
- Department of Biology, Division of Microbiology, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, 91058, Germany
| | - Nicole Tegtmeyer
- Department of Biology, Division of Microbiology, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, 91058, Germany
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8
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Palrasu M, Zaika E, El-Rifai W, Que J, Zaika AI. Role of Bacterial and Viral Pathogens in Gastric Carcinogenesis. Cancers (Basel) 2021; 13:cancers13081878. [PMID: 33919876 PMCID: PMC8070847 DOI: 10.3390/cancers13081878] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/02/2021] [Accepted: 04/11/2021] [Indexed: 01/10/2023] Open
Abstract
Simple Summary Stomach cancer is one of the most common cancers in the world, with over one million new cases diagnosed in 2020. Despite recent advances in cancer treatments, gastric cancer remains a serious clinical problem. This disease is tightly linked to gastric infections with Helicobacter pylori bacterium, Epstein–Barr virus, and some other less known pathogens. Here, we discuss how gastric pathogens induce tumorigenic changes in the stomach. Abstract Gastric cancer (GC) is one of the deadliest malignancies worldwide. In contrast to many other tumor types, gastric carcinogenesis is tightly linked to infectious events. Infections with Helicobacter pylori (H. pylori) bacterium and Epstein–Barr virus (EBV) are the two most investigated risk factors for GC. These pathogens infect more than half of the world’s population. Fortunately, only a small fraction of infected individuals develops GC, suggesting high complexity of tumorigenic processes in the human stomach. Recent studies suggest that the multifaceted interplay between microbial, environmental, and host genetic factors underlies gastric tumorigenesis. Many aspects of these interactions still remain unclear. In this review, we update on recent discoveries, focusing on the roles of various gastric pathogens and gastric microbiome in tumorigenesis.
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Affiliation(s)
- Manikandan Palrasu
- Department of Surgery, University of Miami, Miami, FL 33136, USA; (M.P.); (E.Z.); (W.E.-R.)
| | - Elena Zaika
- Department of Surgery, University of Miami, Miami, FL 33136, USA; (M.P.); (E.Z.); (W.E.-R.)
| | - Wael El-Rifai
- Department of Surgery, University of Miami, Miami, FL 33136, USA; (M.P.); (E.Z.); (W.E.-R.)
- Department of Veterans Affairs, Miami VA Healthcare System, Miami, FL 33136, USA
| | - Jianwen Que
- Department of Medicine, Columbia University Medical Center, New York, NY 10032, USA;
| | - Alexander I. Zaika
- Department of Surgery, University of Miami, Miami, FL 33136, USA; (M.P.); (E.Z.); (W.E.-R.)
- Department of Veterans Affairs, Miami VA Healthcare System, Miami, FL 33136, USA
- Correspondence:
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9
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Harnish JM, Link N, Yamamoto S. Drosophila as a Model for Infectious Diseases. Int J Mol Sci 2021; 22:2724. [PMID: 33800390 PMCID: PMC7962867 DOI: 10.3390/ijms22052724] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/11/2021] [Accepted: 02/14/2021] [Indexed: 12/19/2022] Open
Abstract
The fruit fly, Drosophila melanogaster, has been used to understand fundamental principles of genetics and biology for over a century. Drosophila is now also considered an essential tool to study mechanisms underlying numerous human genetic diseases. In this review, we will discuss how flies can be used to deepen our knowledge of infectious disease mechanisms in vivo. Flies make effective and applicable models for studying host-pathogen interactions thanks to their highly conserved innate immune systems and cellular processes commonly hijacked by pathogens. Drosophila researchers also possess the most powerful, rapid, and versatile tools for genetic manipulation in multicellular organisms. This allows for robust experiments in which specific pathogenic proteins can be expressed either one at a time or in conjunction with each other to dissect the molecular functions of each virulent factor in a cell-type-specific manner. Well documented phenotypes allow large genetic and pharmacological screens to be performed with relative ease using huge collections of mutant and transgenic strains that are publicly available. These factors combine to make Drosophila a powerful tool for dissecting out host-pathogen interactions as well as a tool to better understand how we can treat infectious diseases that pose risks to public health, including COVID-19, caused by SARS-CoV-2.
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Affiliation(s)
- J. Michael Harnish
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; (J.M.H.); (N.L.)
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX 77030, USA
| | - Nichole Link
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; (J.M.H.); (N.L.)
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX 77030, USA
- Howard Hughes Medical Institute, Houston, TX 77030, USA
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; (J.M.H.); (N.L.)
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX 77030, USA
- Department of Neuroscience, BCM, Houston, TX 77030, USA
- Development, Disease Models and Therapeutics Graduate Program, BCM, Houston, TX 77030, USA
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10
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Palrasu M, Zaika E, El-Rifai W, Garcia-Buitrago M, Piazuelo MB, Wilson KT, Peek RM, Zaika AI. Bacterial CagA protein compromises tumor suppressor mechanisms in gastric epithelial cells. J Clin Invest 2021; 130:2422-2434. [PMID: 32250340 DOI: 10.1172/jci130015] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 01/22/2020] [Indexed: 01/01/2023] Open
Abstract
Approximately half of the world's population is infected with the stomach pathogen Helicobacter pylori. Infection with H. pylori is the main risk factor for distal gastric cancer. Bacterial virulence factors, such as the oncoprotein CagA, augment cancer risk. Yet despite high infection rates, only a fraction of H. pylori-infected individuals develop gastric cancer. This raises the question of defining the specific host and bacterial factors responsible for gastric tumorigenesis. To investigate the tumorigenic determinants, we analyzed gastric tissues from human subjects and animals infected with H. pylori bacteria harboring different CagA status. For laboratory studies, well-defined H. pylori strain B128 and its cancerogenic derivative strain 7.13, as well as various bacterial isogenic mutants were employed. We found that H. pylori compromises key tumor suppressor mechanisms: the host stress and apoptotic responses. Our studies showed that CagA induces phosphorylation of XIAP E3 ubiquitin ligase, which enhances ubiquitination and proteasomal degradation of the host proapoptotic factor Siva1. This process is mediated by the PI3K/Akt pathway. Inhibition of Siva1 by H. pylori increases survival of human cells with damaged DNA. It occurs in a strain-specific manner and is associated with the ability to induce gastric tumor.
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Affiliation(s)
- Manikandan Palrasu
- Department of Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Elena Zaika
- Department of Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Wael El-Rifai
- Department of Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA.,Department of Veterans Affairs, Miami VA Healthcare System, Miami, Florida, USA
| | - Monica Garcia-Buitrago
- Department of Pathology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Maria Blanca Piazuelo
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Keith T Wilson
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA.,Department of Veterans Affairs, VA Tennessee Valley Health Care System, Nashville, Tennessee, USA
| | - Richard M Peek
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Alexander I Zaika
- Department of Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA.,Department of Veterans Affairs, Miami VA Healthcare System, Miami, Florida, USA
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11
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The Helicobacter pylori Cag Type IV Secretion System. Trends Microbiol 2020; 28:682-695. [PMID: 32451226 DOI: 10.1016/j.tim.2020.02.004] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 01/30/2020] [Accepted: 02/25/2020] [Indexed: 12/24/2022]
Abstract
Colonization of the human stomach with Helicobacter pylori strains containing the cag pathogenicity island is a risk factor for development of gastric cancer. The cag pathogenicity island contains genes encoding a secreted effector protein (CagA) and components of a type IV secretion system (Cag T4SS). The molecular architecture of the H. pylori Cag T4SS is substantially more complex than that of prototype T4SSs in other bacterial species. In this review, we discuss recent discoveries pertaining to the structure and function of the Cag T4SS and its role in gastric cancer pathogenesis.
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12
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Activity and Functional Importance of Helicobacter pylori Virulence Factors. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1149:35-56. [PMID: 31016624 DOI: 10.1007/5584_2019_358] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Helicobacter pylori is a very successful Gram-negative pathogen colonizing the stomach of humans worldwide. Infections with this bacterium can generate pathologies ranging from chronic gastritis and peptic ulceration to gastric cancer. The best characterized H. pylori virulence factors that cause direct cell damage include an effector protein encoded by the cytotoxin-associated gene A (CagA), a type IV secretion system (T4SS) encoded in the cag-pathogenicity island (cag PAI), vacuolating cytotoxin A (VacA), γ-glutamyl transpeptidase (GGT), high temperature requirement A (HtrA, a serine protease) and cholesterol glycosyl-transferase (CGT). Since these H. pylori factors are either surface-exposed, secreted or translocated, they can directly interact with host cell molecules and are able to hijack cellular functions. Studies on these bacterial factors have progressed substantially in recent years. Here, we review the current status in the characterization of signaling cascades by these factors in vivo and in vitro, which comprise the disruption of cell-to-cell junctions, induction of membrane rearrangements, cytoskeletal dynamics, proliferative, pro-inflammatory, as well as, pro-apoptotic and anti-apoptotic responses or immune evasion. The impact of these signal transduction modules in the pathogenesis of H. pylori infections is discussed.
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13
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Abstract
In addition to its role in gastric conditions,
Helicobacter pylori has been found to contribute to the development of several non-gastric issues in recent years. Eradication therapy is the only effective management strategy to minimize the
H. pylori-related gastric cancer and extra-gastric complications. For an effective “test and treat” strategy, diagnosis and therapy are both important. Because the infection is usually asymptomatic, patient selection is a critical issue for timely diagnosis and many clinical and demographic factors should be considered. Clarithromycin and metronidazole resistance rates also need to be considered while eradication therapy is offered. In this report, we discuss the issues which must be taken into account for the correct and timely diagnosis and for the antibiotic therapy-based management of
H. pylori infection.
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Affiliation(s)
- Shamshul Ansari
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu-City, Oita, 879-5593, Japan
| | - Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu-City, Oita, 879-5593, Japan.,Department of Medicine-Gastroenterology, Baylor College of Medicine, 2002 Holcombe Boulevard, Houston, TX, 77030, USA
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Jones TA, Hernandez DZ, Wong ZC, Wandler AM, Guillemin K. The bacterial virulence factor CagA induces microbial dysbiosis that contributes to excessive epithelial cell proliferation in the Drosophila gut. PLoS Pathog 2017; 13:e1006631. [PMID: 29049360 PMCID: PMC5648253 DOI: 10.1371/journal.ppat.1006631] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 09/06/2017] [Indexed: 02/07/2023] Open
Abstract
Gut microbiota facilitate many aspects of human health and development, but dysbiotic microbiota can promote hyperplasia and inflammation and contribute to human diseases such as cancer. Human patients infected with the gastric cancer-causing bacterium Helicobacter pylori have altered microbiota; however, whether dysbiosis contributes to disease in this case is unknown. Many H. pylori human disease phenotypes are associated with a potent virulence protein, CagA, which is translocated into host epithelial cells where it alters cell polarity and manipulates host-signaling pathways to promote disease. We hypothesized that CagA alone could contribute to H. pylori pathogenesis by inducing microbial dysbiosis that promotes disease. Here we use a transgenic Drosophila model of CagA expression to genetically disentangle the effects of the virulence protein CagA from that of H. pylori infection. We found that expression of CagA within Drosophila intestinal stem cells promotes excess cell proliferation and is sufficient to alter host microbiota. Rearing CagA transgenic flies germ-free revealed that the dysbiotic microbiota contributes to cell proliferation phenotypes and also elicits expression of innate immune components, Diptericin and Duox. Further investigations revealed interspecies interactions are required for this dysbiotic CagA-dependent microbiota to promote proliferation in CagA transgenic and healthy control Drosophila. Our model establishes that CagA can alter gut microbiota and exacerbate cell proliferation and immune phenotypes previously attributed to H. pylori infection. This work provides valuable new insights into the mechanisms by which interactions between a specific virulence factor and the resident microbiota can contribute to the development and progression of disease. Microbial communities in the gut, termed microbiota are important for human health, and when altered can sometimes promote disease. Infections, such as with the cancer-causing bacterium Helicobacter pylori, can cause altered gut microbiota, but why these alterations occur and whether the altered communities contribute to disease remain unknown. Here, we use Drosophila expressing the H. pylori disease-causing protein CagA, to model this virulence factor’s effect on host pathology and microbiota. We found that expression of CagA in the Drosophila gut causes excessive cell proliferation and immune activation, hallmarks of H. pylori infection. Notably, these traits did not occur when flies were reared in the absence of microbes. Further examination reveals that CagA-expressing flies have an altered gut microbial community that is sufficient to promote cell proliferation even in normal flies. This proliferative activity required the presence of two interacting bacteria, illustrating a new model for disease-promoting microbiota. This work demonstrates how a bacterial protein can cause disease indirectly through altering the microbial ecology of the host, and it suggests future treatments for infections that rely on manipulating the microbiota to mitigate disease pathology.
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Affiliation(s)
- Tiffani Alvey Jones
- Institute of Molecular Biology, University of Oregon, Eugene, OR, United States of America
| | - Diane Z. Hernandez
- Institute of Molecular Biology, University of Oregon, Eugene, OR, United States of America
| | - Zoë C. Wong
- Institute of Molecular Biology, University of Oregon, Eugene, OR, United States of America
| | - Anica M. Wandler
- Institute of Molecular Biology, University of Oregon, Eugene, OR, United States of America
| | - Karen Guillemin
- Institute of Molecular Biology, University of Oregon, Eugene, OR, United States of America
- Humans and the Microbiome Program, Canadian Institute for Advanced Research, Toronto, Ontario, Canada
- * E-mail:
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Binding of the Helicobacter pylori OipA causes apoptosis of host cells via modulation of Bax/Bcl-2 levels. Sci Rep 2017; 7:8036. [PMID: 28808292 PMCID: PMC5556102 DOI: 10.1038/s41598-017-08176-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 07/10/2017] [Indexed: 12/16/2022] Open
Abstract
The H. pylori outer inflammatory protein A (OipA) is an outer membrane protein that contributes to gastric inflammation. OipA is believed to affect intra-cellular signalling and modulate the host signalling pathways. The aim of the current study was to clarify the role of OipA in H. pylori pathogenesis and its effect on host cell signalling pathways. To this end, the oipA gene was isolated and inserted into cloning and expression vectors. The recombinant plasmid was transferred into an expression host to produce OipA, which was subsequently purified by affinity chromatography and used for antibody production. A confluent monolayer of gastric cell lines was treated with various concentrations of OipA and investigated for attachment, toxicity, and apoptosis and alterations in signalling pathways. OipA bound to gastric cell lines confirming its role in the attachment of H. pylori to host cells. The ratio of Bax/Bcl-2 and caspase3, 8, FasL in the host cells were assessed and the results showed that the Bax/Bcl-2 ratio as well as the level of cleaved-caspase 3 was elevated in OipA-treated cells. These findings suggest that OipA can bind and induce toxic events as well as triggering apoptotic cascade in host gastric cells through intrinsic pathway.
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16
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Wang W, Zhao W, Li J, Luo L, Kang L, Cui F. The c-Jun N-terminal kinase pathway of a vector insect is activated by virus capsid protein and promotes viral replication. eLife 2017; 6. [PMID: 28716183 PMCID: PMC5515582 DOI: 10.7554/elife.26591] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 06/17/2017] [Indexed: 12/21/2022] Open
Abstract
No evidence has shown whether insect-borne viruses manipulate the c-Jun N-terminal kinase (JNK) signaling pathway of vector insects. Using a system comprising the plant virus Rice stripe virus (RSV) and its vector insect, the small brown planthopper, we have studied the response of the vector insect’s JNK pathway to plant virus infection. We found that RSV increased the level of Tumor Necrosis Factor-α and decreased the level of G protein Pathway Suppressor 2 (GPS2) in the insect vector. The virus capsid protein competitively bound GPS2 to release it from inhibiting the JNK activation machinery. We confirmed that JNK activation promoted RSV replication in the vector, whereas JNK inhibition caused a significant reduction in virus production and thus delayed the disease incidence of plants. These findings suggest that inhibition of insect vector JNK may be a useful strategy for controling the transmission of plant viruses. DOI:http://dx.doi.org/10.7554/eLife.26591.001 There are over a thousand different viruses that infect plants. Many plant viruses are transmitted by insects that feed on the plants, much as mosquitoes spread diseases between people when feeding on blood. Often the plant virus can replicate inside the cells of the insect. However, unlike in the plant hosts, the viruses do not seem to cause disease in the insects that carry them. Rice stripe disease is a major viral disease of rice that can reduce the crop’s yield by more than 50% in some areas. An insect called the small brown planthopper spreads the rice stripe virus between plants. Like other animals, insects have an immune system that protects them against viral infections. This means that the rice stripe virus must manipulate the planthopper’s immune system in order to replicate inside the insect’s cells. It was not clear how the virus did this, but answering this question could provide important clues to help scientists develop new ways to protect crops against plant viruses. Wang, Zhao, Li et al. now show that rice stripe virus manipulates its insect host to produce more of a protein called TNF-α and less of a protein called GPS2. Moreover, a protein that makes up part of the virus also binds to GPS2. This stops GPS2 from inhibiting a conserved signaling pathway that involves an enzyme known as JNK. When the JNK signaling pathway becomes active, replication of the rice stripe virus inside the insect is accelerated. Further experiments showed that inhibiting JNK made it harder for the virus to replicate, which meant that it took longer for the disease to develop in rice plants. These findings uncover a host of proteins that could be manipulated in insects to benefit rice agriculture. Such alterations could possibly be achieved through breeding or otherwise genetically modifying the insects to make them less able to carry viruses and then releasing them into wild populations. Alternatively, if further studies can identify chemicals that cause insect cells to alter the levels of the proteins, such chemicals could be administered to farmland to reduce the spread of viruses. DOI:http://dx.doi.org/10.7554/eLife.26591.002
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Affiliation(s)
- Wei Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Wan Zhao
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Jing Li
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Lan Luo
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Le Kang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Feng Cui
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
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Tegtmeyer N, Neddermann M, Asche CI, Backert S. Subversion of host kinases: a key network in cellular signaling hijacked byHelicobacter pyloriCagA. Mol Microbiol 2017; 105:358-372. [DOI: 10.1111/mmi.13707] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2017] [Indexed: 12/16/2022]
Affiliation(s)
- Nicole Tegtmeyer
- Department of Biology, Division of Microbiology; Friedrich Alexander University Erlangen-Nuremberg; Staudtstr. 5 Erlangen D-91058 Germany
| | - Matthias Neddermann
- Department of Biology, Division of Microbiology; Friedrich Alexander University Erlangen-Nuremberg; Staudtstr. 5 Erlangen D-91058 Germany
| | - Carmen Isabell Asche
- Department of Biology, Division of Microbiology; Friedrich Alexander University Erlangen-Nuremberg; Staudtstr. 5 Erlangen D-91058 Germany
| | - Steffen Backert
- Department of Biology, Division of Microbiology; Friedrich Alexander University Erlangen-Nuremberg; Staudtstr. 5 Erlangen D-91058 Germany
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18
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Exploiting the Gastric Epithelial Barrier: Helicobacter pylori’s Attack on Tight and Adherens Junctions. Curr Top Microbiol Immunol 2017; 400:195-226. [DOI: 10.1007/978-3-319-50520-6_9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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19
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Li N, Tang B, Jia YP, Zhu P, Zhuang Y, Fang Y, Li Q, Wang K, Zhang WJ, Guo G, Wang TJ, Feng YJ, Qiao B, Mao XH, Zou QM. Helicobacter pylori CagA Protein Negatively Regulates Autophagy and Promotes Inflammatory Response via c-Met-PI3K/Akt-mTOR Signaling Pathway. Front Cell Infect Microbiol 2017; 7:417. [PMID: 28983474 PMCID: PMC5613121 DOI: 10.3389/fcimb.2017.00417] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Accepted: 09/08/2017] [Indexed: 12/14/2022] Open
Abstract
Cytotoxin-associated-gene A (CagA) of Helicobacter pylori (H. pylori) is a virulence factor that plays critical roles in H. pylori-induced gastric inflammation. In the present study, gastric biopsies were used for genotyping cagA and vacA genes, determining the autophagic activity, and the severity of gastric inflammation response. It was revealed that autophagy in gastric mucosal tissues infected with cagA+H. pylori strains was lower than the levels produced by cagA-H. pylori strains, accompanied with accumulation of SQSTM1 and decreased LAMP1 expression. In vitro, deletion mutant of cagA gene resulted in increased autophagic activity, and decreased expression of SQSTM1 and cytokines, whereas over-expression of CagA down-regulated the starvation-induced autophagy, and induced more production of the cytokines. Moreover, the production of the cytokines was increased by inhibition of autophagy, but decreased by enhancement of autophagy. Deletion of CagA decreased the ability to activate Akt kinase at Ser-473 site and increased autophagy. c-Met siRNA significantly affected CagA-mediated autophagy, and decreased the level of p-Akt, p-mTOR, and p-S6. Both c-Met siRNA and MK-2206 could reverse inflammatory response. H. pylori CagA protein negatively regulates autophagy and promotes the inflammation in H. pylori infection, which is regulated by c-Met-PI3K/Akt-mTOR signaling pathway activation.
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Affiliation(s)
- Na Li
- Department of Clinical Microbiology and Immunology, Southwest Hospital & College of Medical Laboratory Science, Third Military Medical UniversityChongqing, China
- Department of Microbiology and Biochemical Pharmacy, National Engineering Research Center for Immunobiological Products, College of Pharmacy, Third Military Medical UniversityChongqing, China
- Institute of Cardiovascular Disease, General Hospital of Jinan Military RegionJinan, China
| | - Bin Tang
- Department of Clinical Microbiology and Immunology, Southwest Hospital & College of Medical Laboratory Science, Third Military Medical UniversityChongqing, China
- Department of Microbiology and Biochemical Pharmacy, National Engineering Research Center for Immunobiological Products, College of Pharmacy, Third Military Medical UniversityChongqing, China
- Emei Sanatorium of PLA Rocket ForceEmeishan, China
| | - Yin-ping Jia
- Department of Clinical Microbiology and Immunology, Southwest Hospital & College of Medical Laboratory Science, Third Military Medical UniversityChongqing, China
| | - Pan Zhu
- Department of Clinical Microbiology and Immunology, Southwest Hospital & College of Medical Laboratory Science, Third Military Medical UniversityChongqing, China
| | - Yuan Zhuang
- Department of Microbiology and Biochemical Pharmacy, National Engineering Research Center for Immunobiological Products, College of Pharmacy, Third Military Medical UniversityChongqing, China
| | - Yao Fang
- Department of Clinical Microbiology and Immunology, Southwest Hospital & College of Medical Laboratory Science, Third Military Medical UniversityChongqing, China
- Department of Microbiology and Biochemical Pharmacy, National Engineering Research Center for Immunobiological Products, College of Pharmacy, Third Military Medical UniversityChongqing, China
| | - Qian Li
- Department of Clinical Microbiology and Immunology, Southwest Hospital & College of Medical Laboratory Science, Third Military Medical UniversityChongqing, China
| | - Kun Wang
- Department of Clinical Microbiology and Immunology, Southwest Hospital & College of Medical Laboratory Science, Third Military Medical UniversityChongqing, China
- Department of Microbiology and Biochemical Pharmacy, National Engineering Research Center for Immunobiological Products, College of Pharmacy, Third Military Medical UniversityChongqing, China
| | - Wei-jun Zhang
- Department of Microbiology and Biochemical Pharmacy, National Engineering Research Center for Immunobiological Products, College of Pharmacy, Third Military Medical UniversityChongqing, China
| | - Gang Guo
- Department of Microbiology and Biochemical Pharmacy, National Engineering Research Center for Immunobiological Products, College of Pharmacy, Third Military Medical UniversityChongqing, China
| | - Tong-jian Wang
- Institute of Cardiovascular Disease, General Hospital of Jinan Military RegionJinan, China
| | - You-jun Feng
- Department of Medical Microbiology and Parasitology, Zhejiang University School of MedicineHangzhou, China
| | - Bin Qiao
- Institute of Cardiovascular Disease, General Hospital of Jinan Military RegionJinan, China
- *Correspondence: Bin Qiao
| | - Xu-hu Mao
- Department of Clinical Microbiology and Immunology, Southwest Hospital & College of Medical Laboratory Science, Third Military Medical UniversityChongqing, China
- Xu-hu Mao
| | - Quan-ming Zou
- Department of Microbiology and Biochemical Pharmacy, National Engineering Research Center for Immunobiological Products, College of Pharmacy, Third Military Medical UniversityChongqing, China
- Quan-ming Zou
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Chen GY, Shu YC, Chuang DY, Wang YC. Inflammatory and Apoptotic Regulatory Activity of Tanshinone IIA in Helicobacter pylori-Infected Cells. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2016; 44:1187-1206. [PMID: 27627918 DOI: 10.1142/s0192415x1650066x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Helicobacter pylori infections induce host cell inflammation and apoptosis, however, they are conflicting. Tanshinone IIA is an active compound of Salvia miltiorrhiza Bge. In this study, we investigated the regulatory effects of tanshinone IIA on H. pylori-induced inflammation and apoptosis in vitro. Tanshinone IIA treatments (13.6-54.4[Formula: see text][Formula: see text]M) significantly decreased nuclear factor kappa B (NF-kB) and mitogen-activated protein kinase (MAPK) [p-38 and C-terminal Jun-kinase 1/2 (JNK1/2)] protein expressions and inflammatory substance [cyclooxygenase-2 (COX-2), 5-lipooxygenase (5-LOX), intercellular adhesion molecule-1 (ICAM-1), reactive oxygen species (ROS), nitric oxide (NO), inducible nitric oxide synthase (iNOS), interleukin-1[Formula: see text] (IL-1[Formula: see text], IL-6, and IL-8] production in the H. pylori-infected cells. In contrast, tanshinone IIA treatments significantly increased apoptotic relevant protein [Bcl-2-associated X protein (Bax) and caspase 9] expressions and increased mitochondrial transmembrane potential ([Formula: see text] disruption, mitochondrial cytochrome [Formula: see text] (cyt [Formula: see text] release, and caspase cascades. Tanshinone IIA treatments effectively decreased H. pylori-induced inflammation and significantly promoted H. pylori-induced intrinsic apoptosis through NF-kB and MAPK (p-38 and JNK) pathways. Tanshinone IIA has great potential as a candidate to protect host cells from H. pylori-induced severe inflammation and gastric cancer.
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Affiliation(s)
- Guan-Yu Chen
- * Department of Food Science and Biotechnology, National Chung Hsing University, Taichung 402, Taiwan, R.O.C
| | - Yu-Chieh Shu
- * Department of Food Science and Biotechnology, National Chung Hsing University, Taichung 402, Taiwan, R.O.C
| | - Duen-Yau Chuang
- † Department of Chemistry, National Chung Hsing University, Taichung 402, Taiwan, R.O.C
| | - Yuan-Chuen Wang
- * Department of Food Science and Biotechnology, National Chung Hsing University, Taichung 402, Taiwan, R.O.C.,‡ Agricultural Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan, R.O.C
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21
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Valenzuela MA, Canales J, Corvalán AH, Quest AFG. Helicobacter pylori-induced inflammation and epigenetic changes during gastric carcinogenesis. World J Gastroenterol 2015; 21:12742-12756. [PMID: 26668499 PMCID: PMC4671030 DOI: 10.3748/wjg.v21.i45.12742] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 08/08/2015] [Accepted: 10/13/2015] [Indexed: 02/06/2023] Open
Abstract
The sequence of events associated with the development of gastric cancer has been described as “the gastric precancerous cascade”. This cascade is a dynamic process that includes lesions, such as atrophic gastritis, intestinal metaplasia and dysplasia. According to this model, Helicobacter pylori (H. pylori) infection targets the normal gastric mucosa causing non-atrophic gastritis, an initiating lesion that can be cured by clearing H. pylori with antibiotics or that may then linger in the case of chronic infection and progress to atrophic gastritis. The presence of virulence factors in the infecting H. pylori drives the carcinogenesis process. Independent epidemiological and animal studies have confirmed the sequential progression of these precancerous lesions. Particularly long-term follow-up studies estimated a risk of 0.1% for atrophic gastritis/intestinal metaplasia and 6% in case of dysplasia for the long-term development of gastric cancer. With this in mind, a better understanding of the genetic and epigenetic changes associated with progression of the cascade is critical in determining the risk of gastric cancer associated with H. pylori infection. In this review, we will summarize some of the most relevant mechanisms and focus predominantly but not exclusively on the discussion of gene promoter methylation and miRNAs in this context.
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22
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Rosadi F, Fiorentini C, Fabbri A. Bacterial protein toxins in human cancers. Pathog Dis 2015; 74:ftv105. [DOI: 10.1093/femspd/ftv105] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/29/2015] [Indexed: 12/16/2022] Open
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Helicobacter pylori CagA Suppresses Apoptosis through Activation of AKT in a Nontransformed Epithelial Cell Model of Glandular Acini Formation. BIOMED RESEARCH INTERNATIONAL 2015; 2015:761501. [PMID: 26557697 PMCID: PMC4628739 DOI: 10.1155/2015/761501] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 04/16/2015] [Accepted: 04/20/2015] [Indexed: 02/07/2023]
Abstract
H. pylori infection is the most important environmental risk to develop gastric cancer, mainly through its virulence factor CagA. In vitro models of CagA function have demonstrated a phosphoprotein activity targeting multiple cellular signaling pathways, while cagA transgenic mice develop carcinomas of the gastrointestinal tract, supporting oncogenic functions. However, it is still not completely clear how CagA alters cellular processes associated with carcinogenic events. In this study, we evaluated the capacity of H. pylori CagA positive and negative strains to alter nontransformed MCF-10A glandular acini formation. We found that CagA positive strains inhibited lumen formation arguing for an evasion of apoptosis activity of central acini cells. In agreement, CagA positive strains induced a cell survival activity that correlated with phosphorylation of AKT and of proapoptotic proteins BIM and BAD. Anoikis is a specific type of apoptosis characterized by AKT and BIM activation and it is the mechanism responsible for lumen formation of MCF-10A acini in vitro and mammary glands in vivo. Anoikis resistance is also a common mechanism of invading tumor cells. Our data support that CagA positive strains signaling function targets the AKT and BIM signaling pathway and this could contribute to its oncogenic activity through anoikis evasion.
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Abstract
p53 tumor suppressor has been identified as a protein interacting with the large T antigen produced by simian vacuolating virus 40 (SV40). Subsequent research on p53 inhibition by SV40 and other tumor viruses has not only helped to gain a better understanding of viral biology, but also shaped our knowledge of human tumorigenesis. Recent studies have found, however, that inhibition of p53 is not strictly in the realm of viruses. Some bacterial pathogens also actively inhibit p53 protein and induce its degradation, resulting in alteration of cellular stress responses. This phenomenon was initially characterized in gastric epithelial cells infected with Helicobacter pylori, a bacterial pathogen that commonly infects the human stomach and is strongly linked to gastric cancer. Besides H. pylori, a number of other bacterial species were recently discovered to inhibit p53. These findings provide novel insights into host–bacteria interactions and tumorigenesis associated with bacterial infections. This review focuses on a novel aspect of host–bacteria interactions: the direct interplay between bacterial pathogens and tumor suppression mechanisms that protect the host from cancer development. Recent studies revealed that various pathogenic bacteria actively inhibit the major tumor suppression pathway mediated by p53 protein that plays a key role in the regulation of multiple cellular stress responses and prevention of cancerogenesis. Bacterial degradation of p53 was first discovered in the context of Helicobacter pylori infection, which is currently the strongest known risk factor for adenocarcinoma of the stomach. This phenomenon, however, is not limited to H. pylori, and many other bacterial pathogens inhibit p53 using various mechanisms. Inhibition of p53 by bacteria is linked to bacterial modulation of the host cellular responses to DNA damage, metabolic stress, and, potentially, other stressors. This is a dynamic area of research that will continue to evolve and make important contributions to a better understanding of host–microbe interactions and tumorigenesis. These studies may offer new molecular targets and opportunities for drug development.
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Affiliation(s)
- Alexander I. Zaika
- Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, Tennessee, United States of America
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- * E-mail:
| | - Jinxiong Wei
- Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, Tennessee, United States of America
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Jennifer M. Noto
- Department of Medicine, Division of Gastroenterology, Vanderbilt University Medical Center, Tennessee, United States of America
| | - Richard M. Peek
- Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Department of Medicine, Division of Gastroenterology, Vanderbilt University Medical Center, Tennessee, United States of America
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Yong X, Tang B, Li BS, Xie R, Hu CJ, Luo G, Qin Y, Dong H, Yang SM. Helicobacter pylori virulence factor CagA promotes tumorigenesis of gastric cancer via multiple signaling pathways. Cell Commun Signal 2015; 13:30. [PMID: 26160167 PMCID: PMC4702319 DOI: 10.1186/s12964-015-0111-0] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Accepted: 07/03/2015] [Indexed: 12/12/2022] Open
Abstract
Helicobacter pylori (H. pylori) infection is strongly associated with the development of gastric diseases but also with several extragastric diseases. The clinical outcomes caused by H. pylori infection are considered to be associated with a complex combination of host susceptibility, environmental factors and bacterial isolates. Infections involving H. pylori strains that possess the virulence factor CagA have a worse clinical outcome than those involving CagA-negative strains. It is remarkable that CagA-positive H. pylori increase the risk for gastric cancer over the risk associated with H. pylori infection alone. CagA behaves as a bacterial oncoprotein playing a key role in H. pylori-induced gastric cancer. Activation of oncogenic signaling pathways and inactivation of tumor suppressor pathways are two crucial events in the development of gastric cancer. CagA shows the ability to affect the expression or function of vital protein in oncogenic or tumor suppressor signaling pathways via several molecular mechanisms, such as direct binding or interaction, phosphorylation of vital signaling proteins and methylation of tumor suppressor genes. As a result, CagA continuously dysregulates of these signaling pathways and promotes tumorigenesis. Recent research has enriched our understanding of how CagA effects on these signaling pathways. This review summarizes the results of the most relevant studies, discusses the complex molecular mechanism involved and attempts to delineate the entire signaling pathway.
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Affiliation(s)
- Xin Yong
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, P.R. China.
| | - Bo Tang
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, P.R. China.
| | - Bo-Sheng Li
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, P.R. China.
| | - Rui Xie
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, P.R. China.
| | - Chang-Jiang Hu
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, P.R. China.
| | - Gang Luo
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, P.R. China.
| | - Yong Qin
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, P.R. China.
| | - Hui Dong
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, P.R. China.
| | - Shi-Ming Yang
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, P.R. China.
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Giannouli M, Palatucci AT, Rubino V, Ruggiero G, Romano M, Triassi M, Ricci V, Zarrilli R. Use of larvae of the wax moth Galleria mellonella as an in vivo model to study the virulence of Helicobacter pylori. BMC Microbiol 2014; 14:228. [PMID: 25170542 PMCID: PMC4148543 DOI: 10.1186/s12866-014-0228-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 08/19/2014] [Indexed: 02/08/2023] Open
Abstract
Background Helicobacter pylori is the first bacterium formally recognized as a carcinogen and is one of the most successful human pathogens, as over half of the world’s population is colonized by the bacterium. H. pylori-induced gastroduodenal disease depends on the inflammatory response of the host and on the production of specific bacterial virulence factors. The study of Helicobacter pylori pathogenic action would greatly benefit by easy-to-use models of infection. Results In the present study, we examined the effectiveness of the larvae of the wax moth Galleria mellonella as a new model for H. pylori infection. G. mellonella larvae were inoculated with bacterial suspensions or broth culture filtrates from either different wild-type H. pylori strains or their mutants defective in specific virulence determinants, such as VacA, CagA, CagE, the whole pathogenicity island (PAI) cag, urease, and gamma-glutamyl transpeptidase (GGT). We also tested purified VacA cytotoxin. Survival curves were plotted using the Kaplan-Meier method and LD50 lethal doses were calculated. Viable bacteria in the hemocoel were counted at different time points post-infection, while apoptosis in larval hemocytes was evaluated by annexin V staining. We found that wild-type and mutant H. pylori strains were able to survive and replicate in G. mellonella larvae which underwent death rapidly after infection. H. pylori mutant strains defective in either VacA, or CagA, or CagE, or cag PAI, or urease, but not GGT-defective mutants, were less virulent than the respective parental strain. Broth culture filtrates from wild-type strains G27 and 60190 and their mutants replicated the effects observed using their respective bacterial suspension. Also, purified VacA cytotoxin was able to kill the larvae. The killing of larvae always correlated with the induction of apoptosis in hemocytes. Conclusions G. mellonella larvae are susceptible to H. pylori infection and may represent an easy to use in vivo model to identify virulence factors and pathogenic mechanisms of H. pylori. The experimental model described can be useful to screen a large number of clinical H. pylori strain and to correlate virulence of H. pylori strains with patients’ disease status.
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Affiliation(s)
| | | | | | | | | | | | - Vittorio Ricci
- Department of Molecular Medicine, Human Physiology Section, University of Pavia Medical School, Pavia, Italy.
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Wang XQ, Terry PD, Cheng L, Yan H, Wang JS, Wu WA, Hu SK. Interactions between pork consumption, CagA status and IL-1B-31 genotypes in gastric cancer. World J Gastroenterol 2014; 20:8151-8157. [PMID: 25009387 PMCID: PMC4081686 DOI: 10.3748/wjg.v20.i25.8151] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Revised: 02/09/2014] [Accepted: 04/03/2014] [Indexed: 02/06/2023] Open
Abstract
AIM: To explore potential interactions among Helicobacter pylori (H. pylori), CagA status, interleukin (IL)-1B-31 genotypes, and non-cardiac gastric cancer (GC) risk.
METHODS: A case-control study of non-cardia GC was performed at 3 hospitals located in Xi’an, China, between September 2008 and July 2010. We included 171 patients with histologically diagnosed primary non-cardia GC and 367 population based controls (matched by sex, age and city of residence). A standardized questionnaire was used to obtain information regarding potential risk factors, including pork consumption. H. pylori CagA status was assessed by enzyme-linked immunosorbent assay, and IL-1B-31 genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism. Multivariate unconditional logistic regression was used to explore potential interactions among the factors.
RESULTS: The CagA appeared to confer an increased risk of GC (OR = 1.81, 95%CI: 1.25-2.61). The main associations with IL-1B-31C allele here were 0.98 (95%CI: 0.59-1.63) for CC vs TT and 0.99 (95%CI: 0.64-1.51) for C Carriers vs TT. However, no associations were observed for CagA or IL-1B-31 genotype status among subjects who reported low pork consumption (P for interaction = 0.11). In contrast, high pork consumption and IL-1B-31C genotypes appeared to synergistically increase GC risk (P for interaction = 0.048) after adjusting for confounding factors, particularly among subjects with CagA (OR = 3.07, 95%CI: 1.17-10.79). We did not observe effect modification of pork consumption by H. pylori CagA status, or between H. pylori CagA status and IL-1B-31 genotypes after adjustment for pork consumption and other factors.
CONCLUSION: These interaction relationships among CagA, IL-1B-31 and pork consumption may have implications for development of the preventive strategies for the early detection of non-cardiac GC.
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Zhao Y, Li Y, Han J, Liu T, Guan Q, Zhao P, Guo L, Liu K, He D. Helicobacter pylori enhances CIP2A expression and cell proliferation via JNK2/ATF2 signaling in human gastric cancer cells. Int J Mol Med 2014; 33:703-10. [PMID: 24398514 DOI: 10.3892/ijmm.2014.1615] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 12/24/2013] [Indexed: 11/06/2022] Open
Abstract
Helicobacter pylori (H. pylori) infection plays an important role in the development of gastric carcinomas. Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a novel human oncoprotein that functions as an important regulator of cell growth and malignant transformation. In the present study, we aimed to investigate the potential mechanisms by which H. pylori upregulates the expression of CIP2A and the functional impact of H. pylori-induced CIP2A in gastric cancer cells. We demonstrated that infection of MKN-45 cells with H. pylori led to a marked increase in the expression of CIP2A at the mRNA and protein levels. H. pylori-induced CIP2A was associated with increased cell proliferation. In addition, H. pylori was found to activate the JNK2 pathway. Importantly, both H. pylori-induced CIP2A production and cell proliferation were partially reversed by inhibition of JNK2 signaling. Similarly, the blockade of H. pylori-induced CIP2A expression by siRNA against CIP2A also inhibited cell proliferation. Thus, H. pylori appears to stimulate the expression of CIP2A and proliferation of gastric cancer cells via JNK2 signaling. These findings suggest that H. pylori-induced upregulation of CIP2A contributes to the development and progression of gastric cancer. Further in vivo studies are warranted to explore the biological role of CIP2A and its interaction with JNK2 signaling in gastric cancer.
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Affiliation(s)
- Yongxun Zhao
- The Second Clinical Medical School of Lanzhou University, Lanzhou, Gansu 730030, P.R. China
| | - Yumin Li
- Department of General Surgery, The Second Hospital of Lanzhou University, Key Laboratory of Digestive System Tumors of Gansu Province, Lanzhou, Gansu 730030, P.R. China
| | - Jian Han
- Institute of Pathogenic Biology, School of Basic Medical Science, Lanzhou University, Lanzhou, Gansu 730000, P.R. China
| | - Tao Liu
- Department of General Surgery, The Second Hospital of Lanzhou University, Key Laboratory of Digestive System Tumors of Gansu Province, Lanzhou, Gansu 730030, P.R. China
| | - Quanlin Guan
- Department of Surgical Oncology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, P.R. China
| | - Peng Zhao
- Department of Surgical Oncology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, P.R. China
| | - Lingyun Guo
- Department of General Surgery, The Second Hospital of Lanzhou University, Lanzhou, Gansu 730030, P.R. China
| | - Kaikun Liu
- The Second Clinical Medical School of Lanzhou University, Lanzhou, Gansu 730030, P.R. China
| | - Dongqiang He
- Department of General Surgery, The Second Hospital of Lanzhou University, Lanzhou, Gansu 730030, P.R. China
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Panayidou S, Ioannidou E, Apidianakis Y. Human pathogenic bacteria, fungi, and viruses in Drosophila: disease modeling, lessons, and shortcomings. Virulence 2014; 5:253-69. [PMID: 24398387 DOI: 10.4161/viru.27524] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Drosophila has been the invertebrate model organism of choice for the study of innate immune responses during the past few decades. Many Drosophila-microbe interaction studies have helped to define innate immunity pathways, and significant effort has been made lately to decipher mechanisms of microbial pathogenesis. Here we catalog 68 bacterial, fungal, and viral species studied in flies, 43 of which are relevant to human health. We discuss studies of human pathogens in flies revealing not only the elicitation and avoidance of immune response but also mechanisms of tolerance, host tissue homeostasis, regeneration, and predisposition to cancer. Prominent among those is the emerging pattern of intestinal regeneration as a defense response induced by pathogenic and innocuous bacteria. Immunopathology mechanisms and many microbial virulence factors have been elucidated, but their relevance to human health conventionally necessitates validation in mammalian models of infection.
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Affiliation(s)
- Stavria Panayidou
- Department of Biological Sciences; University of Cyprus; Nicosia, Cyprus
| | - Eleni Ioannidou
- Department of Biological Sciences; University of Cyprus; Nicosia, Cyprus
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Bangi E. Drosophila at the intersection of infection, inflammation, and cancer. Front Cell Infect Microbiol 2013; 3:103. [PMID: 24392358 PMCID: PMC3867678 DOI: 10.3389/fcimb.2013.00103] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 12/06/2013] [Indexed: 12/24/2022] Open
Abstract
Recent studies show that both cellular and humoral aspects of innate immunity play important roles during tumor progression. These interactions have traditionally been explored in vertebrate model systems. In recent years, Drosophila has emerged as a genetically tractable model system for studying key aspects of tumorigenesis including proliferation, invasion, and metastasis. The absence of adaptive immunity in Drosophila provides a unique opportunity to study the interactions between innate immune system and cancer in different genetic contexts. In this review, I discuss recent advances made by using Drosophila models of cancer to study the role of innate immune pathways Toll/Imd, JNK, and JAK-STAT, microbial infection and inflammation during tumor progression.
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Affiliation(s)
- Erdem Bangi
- Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai New York, NY, USA
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Song X, Chen HX, Wang XY, Deng XY, Xi YX, He Q, Peng TL, Chen J, Chen W, Wong BCY, Chen MH. H. pylori-encoded CagA disrupts tight junctions and induces invasiveness of AGS gastric carcinoma cells via Cdx2-dependent targeting of Claudin-2. Cell Immunol 2013; 286:22-30. [PMID: 24287273 DOI: 10.1016/j.cellimm.2013.10.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 10/02/2013] [Accepted: 10/31/2013] [Indexed: 12/13/2022]
Abstract
Helicobacter pylori encoded CagA is presently the only known virulence factor that is injected into gastric epithelial cells where it destroys apical junctional complexes and induces dedifferentiation of gastric epithelial cells, leading to H. pylori-related gastric carcinogensis. However, little is known about the molecular mechanisms by which CagA mediates these changes. Caudal-related homeobox 2 (Cdx2) is an intestine-specific transcription factor highly expressed in multistage tissues of dysplasia and cancer. One specific target of Cdx2, Claudin-2, is involved in the regulation of tight junction (TJ) permeability. In this study, our findings showed that the activity of Cdx2 binding to Cdx binding sites of CdxA (GTTTATG) and CdxB (TTTTAGG) of probes corresponding to claudin-2 flanking region increased in AGS cells, infected with CagA positive wild-type strain of H. pylori, compared to CagA negative isogenic mutant-type strain. Moreover, Cdx2 upregulated claudin-2 expression at transcriptional level and translational level. In the meantime, we found that TJs of AGS cells, infected with CagA positive wild-type strain of H. pylori, compared to CagA negative isogenic mutant-type strain, were more severely destroyed, leading to wider cell gap, interference of contact, scattering and highly elevated migration of cells. Herein, this study is firstly demonstrated that H. pylori-encoded CagA disrupts TJs and induces invasiveness of AGS gastric carcinoma cells via Cdx2-dependent targeting of Claudin-2. This provides a new mechanism whereby CagA induced dedifferentiation of AGS cells, leading to malignant behavior of biology.
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Affiliation(s)
- Xin Song
- Department of Gastroenterology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, PR China
| | - Hui-Xin Chen
- Department of Gastroenterology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, PR China
| | - Xiao-Yan Wang
- Department of Gastroenterology, Third Affiliated Hospital, Xiangya School of Medicine, Central South of University, Changsha, PR China
| | - Xi-Yun Deng
- Department of Surgery, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Yin-Xue Xi
- Department of Gastroenterology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, PR China
| | - Qing He
- Department of Gastroenterology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, PR China
| | - Tie-Li Peng
- Department of Gastroenterology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, PR China
| | - Jie Chen
- Department of Gastroenterology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, PR China
| | - Wei Chen
- Department of Gastroenterology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, PR China
| | - Benjamin Chun-Yu Wong
- Department of Medicine, Queen Mary Hospital, University of Hong Kong, Hong Kong, PR China
| | - Min-Hu Chen
- Department of Gastroenterology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, PR China.
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32
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Gonzalez C. Drosophila melanogaster: a model and a tool to investigate malignancy and identify new therapeutics. Nat Rev Cancer 2013; 13:172-83. [PMID: 23388617 DOI: 10.1038/nrc3461] [Citation(s) in RCA: 206] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
For decades, lower-model organisms such as Drosophila melanogaster have often provided the first glimpse into the mechanism of action of human cancer-related proteins, thus making a substantial contribution to elucidating the molecular basis of the disease. More recently, D. melanogaster strains that are engineered to recapitulate key aspects of specific types of human cancer have been paving the way for the future role of this 'workhorse' of biomedical research, helping to further investigate the process of malignancy, and serving as platforms for therapeutic drug discovery.
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Affiliation(s)
- Cayetano Gonzalez
- IRB-Barcelona, c/Baldiri Reixac 10-12, Barcelona, Spain. gonzalez@ irbbarcelona.org
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