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Kumar S, Dhiman M. Helicobacter pylori secretary Proteins-Induced oxidative stress and its role in NLRP3 inflammasome activation. Cell Immunol 2024; 399-400:104811. [PMID: 38518686 DOI: 10.1016/j.cellimm.2024.104811] [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: 07/12/2023] [Revised: 01/09/2024] [Accepted: 01/15/2024] [Indexed: 03/24/2024]
Abstract
Helicobacter pylori-associated stomach infection is a leading cause of gastric ulcer and related cancer. H. pylori modulates the functions of infiltrated immune cells to survive the killing by reactive oxygen and nitrogen species (ROS and RNS) produced by these cells. Uncontrolled immune responses further produce excess ROS and RNS which lead to mucosal damage. The persistent oxidative stress is a major cause of gastric cancer. H. pylori regulates nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOXs), nitric oxide synthase 2 (NOS2), and polyamines to control ROS and RNS release through lesser-known mechanisms. ROS and RNS produced by these pathways differentiate macrophages and T cells from protective to inflammatory phenotype. Pathogens-associated molecular patterns (PAMPs) induced ROS activates nuclear oligomerization domain (NOD), leucine rich repeats (LRR) and pyrin domain-containing protein 3 (NLRP3) inflammasome for the release of pro-inflammatory cytokines. This study evaluates the role of H. pylori secreted concentrated proteins (HPSCP) related oxidative stress role in NLRP3 inflammasome activation and macrophage differentiation. To perceive the role of ROS/RNS, THP-1 and AGS cells were treated with 10 μM diphenyleneiodonium (DPI), 50 μM salicyl hydroxamic acid (SHX), 5 μM Carbonyl cyanide-4-(trifluoromethoxy) phenylhydrazone (FCCP), which are specific inhibitors of NADPH oxidase (NOX), Myeloperoxidase (MPO), and mitochondrial oxidative phosphorylation respectively. Cells were also treated with 10 μM of NOS2 inhibitor l-NMMA and 10 μM of N-acetyl cysteine (NAC), a free radical scavenger·H2O2 (100 μM) treated and untreated cells were used as positive controls and negative control respectively. The expression of gp91phox (NOX2), NOS2, NLRP3, CD86 and CD163 was analyzed through fluorescent microscopy. THP-1 macrophages growth was unaffected whereas the gastric epithelial AGS cells proliferated in response to higher concentration of HPSCP. ROS and myeloperoxidase (MPO) level increased in THP-1 cells and nitric oxide (NO) and lipid peroxidation significantly decreased in AGS cells. gp91phox expression was unchanged, whereas NOS2 and NLRP3 downregulated in response to HPSCP, but increased after inhibition of NO, ROS and MPO in THP-1 cells. HPSCP upregulated the expression of M1 and M2 macrophage markers, CD86 and CD163 respectively, which was decreased after the inhibition of ROS. This study concludes that there are multiple pathways which are generating ROS during H. pylori infection which further regulates other cellular processes. NO is closely associated with MPO and inhibition of NLRP3 inflammasome. The low levels of NO and MPO regulates gastrointestinal tract homeostasis and overcomes the inflammatory response of NLRP3. The ROS also plays crucial role in macrophage polarization hence alter the immune responses duing H. pylori pathogenesis.
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Affiliation(s)
- Sandeep Kumar
- Department of Microbiology, School of Basic Sciences, Central University of Punjab, Bathinda, 151 401 Punjab, India
| | - Monisha Dhiman
- Department of Microbiology, School of Basic Sciences, Central University of Punjab, Bathinda, 151 401 Punjab, India.
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Fuchs S, Gong R, Gerhard M, Mejías-Luque R. Immune Biology and Persistence of Helicobacter pylori in Gastric Diseases. Curr Top Microbiol Immunol 2023; 444:83-115. [PMID: 38231216 DOI: 10.1007/978-3-031-47331-9_4] [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] [Indexed: 01/18/2024]
Abstract
Helicobacter pylori is a prevalent pathogen, which affects more than 40% of the global population. It colonizes the human stomach and persists in its host for several decades or even a lifetime, if left untreated. The persistent infection has been linked to various gastric diseases, including gastritis, peptic ulcers, and an increased risk for gastric cancer. H. pylori infection triggers a strong immune response directed against the bacterium associated with the infiltration of innate phagocytotic immune cells and the induction of a Th1/Th17 response. Even though certain immune cells seem to be capable of controlling the infection, the host is unable to eliminate the bacteria as H. pylori has developed remarkable immune evasion strategies. The bacterium avoids its killing through innate recognition mechanisms and manipulates gastric epithelial cells and immune cells to support its persistence. This chapter focuses on the innate and adaptive immune response induced by H. pylori infection, and immune evasion strategies employed by the bacterium to enable persistent infection.
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Affiliation(s)
- Sonja Fuchs
- Institute for Medical Microbiology, Immunology and Hygiene, TUM School of Medicine and Health, Department Preclinical Medicine, Technical University of Munich (TUM), Trogerstraße 30, 81675, Munich, Germany
| | - Ruolan Gong
- Institute for Medical Microbiology, Immunology and Hygiene, TUM School of Medicine and Health, Department Preclinical Medicine, Technical University of Munich (TUM), Trogerstraße 30, 81675, Munich, Germany
| | - Markus Gerhard
- Institute for Medical Microbiology, Immunology and Hygiene, TUM School of Medicine and Health, Department Preclinical Medicine, Technical University of Munich (TUM), Trogerstraße 30, 81675, Munich, Germany
| | - Raquel Mejías-Luque
- Institute for Medical Microbiology, Immunology and Hygiene, TUM School of Medicine and Health, Department Preclinical Medicine, Technical University of Munich (TUM), Trogerstraße 30, 81675, Munich, Germany.
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Qian H, Ye Z, Pi L, Ao J. Roles and current applications of S-nitrosoglutathione in anti-infective biomaterials. Mater Today Bio 2022; 16:100419. [PMID: 36105674 PMCID: PMC9465324 DOI: 10.1016/j.mtbio.2022.100419] [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: 07/12/2022] [Revised: 08/30/2022] [Accepted: 09/02/2022] [Indexed: 11/29/2022]
Abstract
Bacterial infections can compromise the physical and biological functionalities of humans and pose a huge economical and psychological burden on infected patients. Nitric oxide (NO) is a broad-spectrum antimicrobial agent, whose mechanism of action is not affected by bacterial resistance. S-nitrosoglutathione (GSNO), an endogenous donor and carrier of NO, has gained increasing attention because of its potent antibacterial activity and efficient biocompatibility. Significant breakthroughs have been made in the application of GSNO in biomaterials. This review is based on the existing evidence that comprehensively summarizes the progress of antimicrobial GSNO applications focusing on their anti-infective performance, underlying antibacterial mechanisms, and application in anti-infective biomaterials. We provide an accurate overview of the roles and applications of GSNO in antibacterial biomaterials and shed new light on the avenues for future studies.
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Key Words
- A.baumannii, Acinetobacter baumannii
- AgNPs, Silver nanoparticles
- Antibacterial property
- BMSCs, Bone marrow stem cells
- Bacterial resistance
- Biomaterials
- C.albicans, Candida albicans
- CS/GE, Chitosan/gelatin
- Cu, copper
- DMSO, Dimethyl sulfoxide
- DPA, Diethylenetriamine pentaacetic acid
- E. coli, Escherichia coli
- E.tenella, Eimeria tenella
- ECC, Extracorporeal circulation
- ECM, Experimental cerebral malaria
- GSNO, S-Nitrosoglutathione
- GSNOR, S-Nitrosoglutathione Reductase
- H.pylori, Helicobacter pylori
- HCC, Human cervical carcinoma
- HDFs, Human dermal fibroblasts
- HUVEC, Human umbilical vein endothelial cells
- ICR, Imprinted control region
- Infection
- K.Pneumonia, Klebsiella Pneumonia
- L.amazonensis, Leishmania amazonensis
- L.major, Leishmania major
- M.Tuberculosis, Mycobacterium tuberculosis
- M.smegmatis, Mycobacterium smegmatis
- MOF, Metal–organic framework
- MRPA, Multidrug-resistant Pseudomonas aeruginosa
- MRSA, Methicillin resistant Staphylococcus aureus
- N. gonorrhoeae, Neisseria gonorrhoeae
- N.meningitidis, Neisseria meningitidis
- NA, Not available
- NO-np, NO-releasing nanoparticulate platform
- NP, Nanoparticle
- P.aeruginosa, Pseudomonas aeruginosa
- P.berghei, Plasmodium berghei
- P.mirabilis, Proteus mirabilis
- PCL, Polycaprolactone
- PCVAD, Porcine circovirus-associated disease
- PDA-GSNO NPs, Polydopamine nanoparticles containing GSNO
- PDAM@Cu, polydopamine based copper coatings
- PEG, polyethylene glycol
- PHB, polyhydroxybutyrate
- PLA, polylactic acid
- PLGA, poly(lactic-co-glycolic acid)
- PTT, Photothermal therapy
- PVA, poly(vinyl alcohol)
- PVA/PEG, poly(vinyl alcohol)/poly(ethylene glycol)
- PVC, poly(vinyl chloride)
- S-nitrosoglutathione
- S. typhimurium, Salmonella typhimurium
- S.aureus, Staphylococcus aureus
- S.epidermidis, Staphylococcus epidermidis
- S.pneumoniae, Streptococcus pneumoniae
- SAKI, Septic acute kidney injury
- SCI, Spinal cord slices
- Se, Selenium
- Sp3, Specificity proteins 3
- TDC, Tunneled dialysis catheters
- TMOS, Tetramethylorthosilicate
- ZnO, Zinc oxide
- cftr, cystic fibrosis transmembrane conductance regulatory gene
- d, day
- h, hour
- min, minute
- pSiNPs, porous silicon nanoparticles
- w, week
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Affiliation(s)
- Hu Qian
- Department of Orthopaedic Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Zhimin Ye
- Department of Pathology, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Lanping Pi
- Nursing Department, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Jun Ao
- Department of Orthopaedic Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, China
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Defenses of multidrug resistant pathogens against reactive nitrogen species produced in infected hosts. Adv Microb Physiol 2022; 80:85-155. [PMID: 35489794 DOI: 10.1016/bs.ampbs.2022.02.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Bacterial pathogens have sophisticated systems that allow them to survive in hosts in which innate immunity is the frontline of defense. One of the substances produced by infected hosts is nitric oxide (NO) that together with its derived species leads to the so-called nitrosative stress, which has antimicrobial properties. In this review, we summarize the current knowledge on targets and protective systems that bacteria have to survive host-generated nitrosative stress. We focus on bacterial pathogens that pose serious health concerns due to the growing increase in resistance to currently available antimicrobials. We describe the role of nitrosative stress as a weapon for pathogen eradication, the detoxification enzymes, protein/DNA repair systems and metabolic strategies that contribute to limiting NO damage and ultimately allow survival of the pathogen in the host. Additionally, this systematization highlights the lack of available data for some of the most important human pathogens, a gap that urgently needs to be addressed.
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Marques B, Donato MM, Cardoso O, Luxo C, Martinho A, Almeida N. Study of rdxA and frxA genes mutations in metronidazole-resistant and -susceptible Helicobacter pylori clinical isolates from the central region of Portugal. J Glob Antimicrob Resist 2019; 17:300-304. [PMID: 30658199 DOI: 10.1016/j.jgar.2019.01.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 11/28/2018] [Accepted: 01/06/2019] [Indexed: 12/31/2022] Open
Abstract
OBJECTIVES Helicobacter pylori is one of the most prevalent global pathogens colonising an estimated 50% of the world's population. Although metronidazole (MTZ) is an important antibiotic playing a relevant role in various H. pylori eradication therapies, its frequent consumption results in an increased frequency of resistance with a consequent negative impact on treatment efficacy. Mutations on genes encoding NADPH nitroreductases, commonly known as rdxA gene (oxygen-insensitive) and frxA gene (flavinreductase) have been associated to H. pylori resistance to metrodinazole. The aim of this study was to evaluate the mutation profile of rdxA and frxA genes in a population of 38 H. pylori isolates with phenotypic patterns of susceptibility and resistance to this antibiotic. METHODS Touchdown PCR with the purpose of amplifying rdxA and frxA genes in one PCR was used. Sequence data were made by pair-wise sequence alignment and were examined in terms of codons, and comparison was achieved regarding amino acids. RESULTS Although repeated mutations occurred in positions 118, 131, 172 and 183 of rdxA and in positions 72, 73, 110, 126 and 193 of frxA, it must be highlighted that the mutations are widespread along these two genes in this population. Furthermore, six MTZ-resistant isolates did not present any mutation in the frxA gene. CONCLUSIONS This work appears to confirm that mutations in rdxA and frxA alone are unable to explain MTZ resistance in H. pylori isolates and therefore additional mechanisms may exist and should be investigated.
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Affiliation(s)
- Bruno Marques
- Centro do Sangue e da Transplantação de Coimbra, Instituto Português do Sangue e da Transplantação, IP, Coimbra, Portugal
| | - Maria Manuel Donato
- CIMAGO, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal.
| | - Olga Cardoso
- Laboratory of Microbiology, Faculty of Pharmacy and CIEPQPF, Department of Chemical Engineering, Faculty of Science and Technology, University of Coimbra, Coimbra, Portugal
| | - Cristina Luxo
- Laboratory of Microbiology, Faculty of Pharmacy and CIEPQPF, Department of Chemical Engineering, Faculty of Science and Technology, University of Coimbra, Coimbra, Portugal
| | - António Martinho
- Centro do Sangue e da Transplantação de Coimbra, Instituto Português do Sangue e da Transplantação, IP, Coimbra, Portugal
| | - Nuno Almeida
- Faculty of Medicine, University of Coimbra, and Gastroenterology Department, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
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Abstract
The 5-nitroimidazole drug metronidazole has remained the drug of choice in the treatment of anaerobic infections, parasitic as well as bacterial, ever since its development in 1959. In contrast to most other antimicrobials, it has a pleiotropic mode of action and reacts with a large number of molecules. Importantly, metronidazole, which is strictly speaking a prodrug, needs to be reduced at its nitro group in order to become toxic. Reduction of metronidazole, however, only takes place under very low concentrations of oxygen, explaining why metronidazole is exclusively toxic to microaerophilic and anaerobic microorganisms. In general, resistance rates amongst the pathogens treated with metronidazole have remained low until the present day. Nevertheless, metronidazole resistance does occur, and for the treatment of some pathogens, especially Helicobacter pylori, metronidazole has become almost useless in some parts of the world. This review will give an account on the current status of research on metronidazole's mode of action, metronidazole resistance in eukaryotes and prokaryotes, and on other 5-nitroimidazoles in use.
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Hanafi A, Lee WC, Loke MF, Teh X, Shaari A, Dinarvand M, Lehours P, Mégraud F, Leow AHR, Vadivelu J, Goh KL. Molecular and Proteomic Analysis of Levofloxacin and Metronidazole Resistant Helicobacter pylori. Front Microbiol 2016; 7:2015. [PMID: 28018334 PMCID: PMC5157799 DOI: 10.3389/fmicb.2016.02015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 12/01/2016] [Indexed: 12/19/2022] Open
Abstract
Antibiotic resistance in bacteria incurs fitness cost, but compensatory mechanisms may ameliorate the cost and sustain the resistance even under antibiotics-free conditions. The aim of this study was to determine compensatory mechanisms of antibiotic resistance in H. pylori. Five strains of levofloxacin-sensitive H. pylori were induced in vitro to develop resistance. In addition, four pairs of metronidazole-sensitive and -resistant H. pylori strains were isolated from patients carrying dual H. pylori populations that consist of both sensitive and resistant phenotypes. Growth rate, virulence and biofilm-forming ability of the sensitive and resistant strains were compared to determine effects of compensatory response. Proteome profiles of paired sensitive and resistant strains were analyzed by liquid chromatography/mass spectrophotometry (LC/MS). Although there were no significant differences in growth rate between sensitive and resistant pairs, bacterial virulence (in terms of abilities to induce apoptosis and form biofilm) differs from pair to pair. These findings demonstrate the complex and strain-specific phenotypic changes in compensation for antibiotics resistance. Compensation for in vitro induced levofloxacin resistance involving mutations of gyrA and gyrB was functionally random. Furthermore, higher protein translation and non-functional protein degradation capabilities in naturally-occuring dual population metronidazole sensitive-resistant strains may be a possible alternative mechanism underlying resistance to metronidazole without mutations in rdxA and frxA. This may explain the lack of mutations in target genes in ~10% of metronidazole resistant strains.
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Affiliation(s)
- Aimi Hanafi
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya Kuala Lumpur, Malaysia
| | - Woon Ching Lee
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya Kuala Lumpur, Malaysia
| | - Mun Fai Loke
- Department of Medical Microbiology, Faculty of Medicine, University of MalayaKuala Lumpur, Malaysia; Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of SingaporeSingapore, Singapore
| | - Xinsheng Teh
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya Kuala Lumpur, Malaysia
| | - Ain Shaari
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya Kuala Lumpur, Malaysia
| | - Mojdeh Dinarvand
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya Kuala Lumpur, Malaysia
| | - Philippe Lehours
- Laboratoire de Bactériologie, Université de BordeauxBordeaux, France; Institut National de la Santé et de la Recherche Médicale U853Bordeaux, France
| | - Francis Mégraud
- Laboratoire de Bactériologie, Université de BordeauxBordeaux, France; Institut National de la Santé et de la Recherche Médicale U853Bordeaux, France
| | - Alex Hwong Ruey Leow
- Department of Medicine, Faculty of Medicine, University of Malaya Kuala Lumpur, Malaysia
| | - Jamuna Vadivelu
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya Kuala Lumpur, Malaysia
| | - Khean Lee Goh
- Department of Medicine, Faculty of Medicine, University of Malaya Kuala Lumpur, Malaysia
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Flint A, Stintzi A, Saraiva LM. Oxidative and nitrosative stress defences of Helicobacter and Campylobacter species that counteract mammalian immunity. FEMS Microbiol Rev 2016; 40:938-960. [PMID: 28201757 PMCID: PMC5091033 DOI: 10.1093/femsre/fuw025] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 03/29/2016] [Accepted: 07/02/2016] [Indexed: 12/18/2022] Open
Abstract
Helicobacter and Campylobacter species are Gram-negative microaerophilic host-associated heterotrophic bacteria that invade the digestive tract of humans and animals. Campylobacter jejuni is the major worldwide cause of foodborne gastroenteritis in humans, while Helicobacter pylori is ubiquitous in over half of the world's population causing gastric and duodenal ulcers. The colonisation of the gastrointestinal system by Helicobacter and Campylobacter relies on numerous cellular defences to sense the host environment and respond to adverse conditions, including those imposed by the host immunity. An important antimicrobial tool of the mammalian innate immune system is the generation of harmful oxidative and nitrosative stresses to which pathogens are exposed during phagocytosis. This review summarises the regulators, detoxifying enzymes and subversion mechanisms of Helicobacter and Campylobacter that ultimately promote the successful infection of humans.
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Affiliation(s)
- Annika Flint
- Ottawa Institute of Systems Biology, Faculty of Medicine, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
| | - Alain Stintzi
- Ottawa Institute of Systems Biology, Faculty of Medicine, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
| | - Lígia M. Saraiva
- Instituto de Tecnologia Química e Biológica, NOVA, Av. da República, 2780-157 Oeiras, Portugal
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Parente MR, Monteiro JT, Martins GG, Saraiva LM. Helicobacter pullorum induces nitric oxide release in murine macrophages that promotes phagocytosis and killing. Microbiology (Reading) 2016; 162:503-512. [DOI: 10.1099/mic.0.000240] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Affiliation(s)
- Margarida R. Parente
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Avenida da República EAN, 2780-157, Oeiras, Portugal
| | - João T. Monteiro
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Avenida da República EAN, 2780-157, Oeiras, Portugal
| | - Gabriel G. Martins
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156, Oeiras, Portugal
| | - Lígia M. Saraiva
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Avenida da República EAN, 2780-157, Oeiras, Portugal
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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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Mirzaei N, Poursina F, Moghim S, Ghaempanah AM, Safaei HG. The Bioinformatics Report of Mutation Outcome on NADPH Flavin Oxidoreductase Protein Sequence in Clinical Isolates of H. pylori. Curr Microbiol 2016; 72:596-605. [PMID: 26821239 DOI: 10.1007/s00284-016-0992-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 12/14/2015] [Indexed: 12/23/2022]
Abstract
frxA gene has been implicated in the metronidazole nitro reduction by H. pylori. Alternatively, frxA is expected to contribute to the protection of urease and to the in vivo survival of H. pylori. The aim of present study is to report the mutation effects on the frxA protein sequence in clinical isolates of H. pylori in our community. Metronidazole resistance was proven in 27 of 48 isolates. glmM and frxA genes were used for molecular confirmation of H. pylori isolates. The primer set for detection of whole sequence of frxA gene for the effect of mutation on protein sequence was used. DNA and protein sequence evaluation and analysis were done by blast, Clustal Omega, and T COFFEE programs. Then, FrxA protein sequences from six metronidazole-resistant clinical isolates were analyzed by web-based bioinformatics tools. The result of six metronidazole-resistant clinical isolates in comparison with strain 26695 showed ten missense mutations. The result with the STRING program revealed that no change was seen after alterations in these sequences. According to consensus data involving four methods, residue substitutions at 40, 13, and 141 increase the stability of protein sequence after mutation, while other alterations decrease. Residue substitutions at 40, 43, 141, 138, 169, and 179 are deleterious, while, V7I, Q10R, V34I, and V96I alterations are neutral. As FrxA contribute to survival of bacterium and in regard to the effect of mutations on protein function, it might affect the survival and bacterium phenotype and it need to be studied more. Also, none of the stability prediction tool is perfect; iStable is the best predictor method among all methods.
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Affiliation(s)
- Nasrin Mirzaei
- Department of Microbiology, Tonekabon Branch, Islamic Azad University, Tonekabon, Iran
| | - Farkhondeh Poursina
- Department of Microbiology, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Sharareh Moghim
- Department of Microbiology, Isfahan University of Medical Sciences, Isfahan, Iran
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