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Huang Z, Zhu Y, Li X, Yao Z, Ge R. The mechanisms of metronidazole resistance of Helicobacter pylori: A transcriptomic and biochemical study. Microb Pathog 2023; 183:106303. [PMID: 37595811 DOI: 10.1016/j.micpath.2023.106303] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 07/24/2023] [Accepted: 08/09/2023] [Indexed: 08/20/2023]
Abstract
Helicobacter pylori (H. pylori) is a bacterial pathogen in the stomach, causing gastritis, gastric ulcer, duodenal ulcer and even gastric cancer. The triple therapy containing one bismuth-containing compound or a proton-pump inhibitor with two antibiotics was the cornerstone of the treatment of H. pylori infections. However the drug resistance of Helicobacter pylori is more and more common, which leads to the continued decline in the radical cure rate. The purpose of this study was to investigate the mechanism of metronidazole resistance of H. pylori through transcriptomics and biochemical characterizations. In this study, a 128-time-higher metronidazole-resistant H. pylori strain compared to the sensitive strain was domesticated, and 374 significantly differential genes were identified by transcriptomic sequencing as compared to the metronidazole-sensitive strain. Through GO and KEGG enrichment analysis, antibiotic-resistance pathways were found to be mainly involved in redox, biofilm formation and ABC transportation, and the results were verified by qRT-PCR. The subsequent biochemical analysis found that the urease activity of the drug-resistant strain decreased, and whereas the capabilities of bacterial energy production, membrane production and diffusion ability increased. The work here will drop hints for the mechanisms of antibiotic-resistance of H. pylori and provide promising biomarkers for the further development of new-kind drugs to treat metronidazole-resistant H. pylori.
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Affiliation(s)
- Zeyuan Huang
- The Laboratory of Metalloproteins, College of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Yulin Zhu
- The Laboratory of Metalloproteins, College of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Xinhang Li
- The Laboratory of Metalloproteins, College of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Zihui Yao
- The Laboratory of Metalloproteins, College of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Ruiguang Ge
- The Laboratory of Metalloproteins, College of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, China.
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Evyapan S, Oruç-Emre EE, Sıcak Y, Karaküçük-İyidoğan A, Yılmaz GT, Öztürk M. Design, in Silico Studies and Biological Evaluation of New Chiral Thiourea and 1,3-Thiazolidine-4,5-dione Derivatives. Chem Biodivers 2023; 20:e202300626. [PMID: 37477542 DOI: 10.1002/cbdv.202300626] [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: 05/02/2023] [Revised: 07/19/2023] [Accepted: 07/20/2023] [Indexed: 07/22/2023]
Abstract
In this study, new chiral thiourea and 1,3-thiazolidine-4,5-dione derivatives were synthesized, it was aimed to evaluate the various biological activities and molecular docking of these compounds. Firstly, the new thioureas (1-16) were obtained by reacting 1-naphthylisothiocyanate with different chiral amines. Then, the chiral thioureas were cyclized with oxalyl chloride to obtain 1,3-thiazolidine-4,5-dione derivatives (17-32). All compounds were evaluated with several in vitro antioxidant and enzyme inhibition activities. Compound 30 was the most active compound against AChE, with a value of IC50 =8.09±0.58 μM. On the other hand, all compounds were tested in silico absorption, distribution, metabolism, and excretion (ADME) assays to better understand their bioavailability. These physicochemical properties, pharmacokinetics, and drug-likeness of all compounds were calculated using SwissADME. Furthermore, according to molecular docking analyses compound 30 exhibited significant binding affinities for all enzymes. Based on our overall observations, compound 30 could be recommended as a potential lead for the therapuetic of Alzheimer's.
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Affiliation(s)
- Samet Evyapan
- Department of Chemistry, Faculty of Art and Sciences, Gaziantep University, Gaziantep, 27410, Türkiye
| | - Emine Elçin Oruç-Emre
- Department of Chemistry, Faculty of Art and Sciences, Gaziantep University, Gaziantep, 27410, Türkiye
| | - Yusuf Sıcak
- Department of Medicinal and Aromatic Plants, Köyceğiz Vocational School, Muğla Sıtkı Koçman University, Muğla, 48800, Türkiye
| | | | - Gizem Tatar Yılmaz
- Department of Biostatistics and Medical Informatics, Faculty of Medicine, Karadeniz Technical University, Trabzon, 61000, Türkiye
| | - Mehmet Öztürk
- Department of Chemistry, Faculty of Sciences, Muğla Sıtkı Koçman University, Muğla, 48800, Türkiye
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Iwasaki T, Maruyama A, Inui Y, Sakurai T, Kawano T. In vitro transcytosis of Helicobacter pylori histidine-rich protein through gastric epithelial-like cells and the blood-brain barrier. Biosci Biotechnol Biochem 2022; 86:321-330. [PMID: 34935901 DOI: 10.1093/bbb/zbab221] [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: 09/22/2021] [Accepted: 12/07/2021] [Indexed: 11/14/2022]
Abstract
Recent epidemiological studies have supported the correlation between Helicobacter pylori infection and the development of Alzheimer's disease. HpHpn, a histidine-rich H. pylori protein, forms amyloid-like oligomers; it may be a pathogenic factor for Alzheimer's disease progression. HpHpn may also be transported from the gastric epithelium to the brain. However, HpHpn is secreted from H. pylori on the outer surface of gastric epithelia; therefore, the hypothesized movement of HpHpn across the gastric epithelium to the blood remains controversial. Here, we found the HpHpn showed acidic pH-dependent cellular uptake and subsequent secretion in human gastric epithelial-like carcinoma cells. Furthermore, HpHpn exhibited in vitro permeability across the blood-brain barrier. Although further in vivo experiments are required, our findings suggest that in vitro transcytosis of HpHpn in gastric epithelial cells and the blood-brain barrier may provide new insights into the correlation between H. pylori infections and Alzheimer's disease progression.
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Affiliation(s)
- Takashi Iwasaki
- Department of Bioresource Science, Faculty of Agriculture, Tottori University, Tottori, Japan
- Department of Agricultural Science, Graduate School of Sustainability Science, Tottori University, Tottori, Japan
| | - Aiki Maruyama
- Department of Bioresource Science, Faculty of Agriculture, Tottori University, Tottori, Japan
| | - Yurika Inui
- Department of Bioresource Science, Faculty of Agriculture, Tottori University, Tottori, Japan
| | - Toshihiko Sakurai
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori, Japan
| | - Tsuyoshi Kawano
- Department of Bioresource Science, Faculty of Agriculture, Tottori University, Tottori, Japan
- Department of Agricultural Science, Graduate School of Sustainability Science, Tottori University, Tottori, Japan
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Benoit SL, Maier RJ. The nickel-chelator dimethylglyoxime inhibits human amyloid beta peptide in vitro aggregation. Sci Rep 2021; 11:6622. [PMID: 33758258 PMCID: PMC7988135 DOI: 10.1038/s41598-021-86060-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 03/05/2021] [Indexed: 11/19/2022] Open
Abstract
One of the hallmarks of the most common neurodegenerative disease, Alzheimer's disease (AD), is the extracellular deposition and aggregation of Amyloid Beta (Aβ)-peptides in the brain. Previous studies have shown that select metal ions, most specifically copper (Cu) and zinc (Zn) ions, have a synergistic effect on the aggregation of Aβ-peptides. In the present study, inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the metal content of a commercial recombinant human Aβ40 peptide. Cu and Zn were among the metals detected; unexpectedly, nickel (Ni) was one of the most abundant elements. Using a fluorescence-based assay, we found that Aβ40 peptide in vitro aggregation was enhanced by addition of Zn2+ and Ni2+, and Ni2+-induced aggregation was facilitated by acidic conditions. Nickel binding to Aβ40 peptide was confirmed by isothermal titration calorimetry. Addition of the Ni-specific chelator dimethylglyoxime (DMG) inhibited Aβ40 aggregation in absence of added metal, as well as in presence of Cu2+ and Ni2+, but not in presence of Zn2+. Finally, mass spectrometry analysis revealed that DMG can coordinate Cu or Ni, but not Fe, Se or Zn. Taken together, our results indicate that Ni2+ ions enhance, whereas nickel chelation inhibits, Aβ peptide in vitro aggregation. Hence, DMG-mediated Ni-chelation constitutes a promising approach towards inhibiting or slowing down Aβ40 aggregation.
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Affiliation(s)
- Stéphane L Benoit
- Department of Microbiology, The University of Georgia, 805 Biological Sciences Bldg, Athens, GA, 30602, USA
- Center for Metalloenzyme Studies, The University of Georgia, Athens, GA, 30602, USA
| | - Robert J Maier
- Department of Microbiology, The University of Georgia, 805 Biological Sciences Bldg, Athens, GA, 30602, USA.
- Center for Metalloenzyme Studies, The University of Georgia, Athens, GA, 30602, USA.
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Doulberis M, Kotronis G, Thomann R, Polyzos SA, Boziki M, Gialamprinou D, Deretzi G, Katsinelos P, Kountouras J. Review: Impact of Helicobacter pylori on Alzheimer's disease: What do we know so far? Helicobacter 2018; 23. [PMID: 29181894 DOI: 10.1111/hel.12454] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Helicobacter pylori has changed radically gastroenterologic world, offering a new concept in patients' management. Over time, more medical data gave rise to diverse distant, extragastric manifestations and interactions of the "new" discovered bacterium. Special interest appeared within the field of neurodegenerative diseases and particularly Alzheimer's disease, as the latter and Helicobacter pylori infection are associated with a large public health burden and Alzheimer's disease ranks as the leading cause of disability. However, the relationship between Helicobacter pylori infection and Alzheimer's disease remains uncertain. METHODS We performed a narrative review regarding a possible connection between Helicobacter pylori and Alzheimer's disease. All accessible relevant (pre)clinical studies written in English were included. Both affected pathologies were briefly analyzed, and relevant studies are discussed, trying to focus on the possible pathogenetic role of this bacterium in Alzheimer's disease. RESULTS Data stemming from both epidemiologic studies and animal experiments seem to be rather encouraging, tending to confirm the hypothesis that Helicobacter pylori infection might influence the course of Alzheimer's disease pleiotropically. Possible main mechanisms may include the bacterium's access to the brain via the oral-nasal-olfactory pathway or by circulating monocytes (infected with Helicobacter pylori due to defective autophagy) through disrupted blood-brain barrier, thereby possibly triggering neurodegeneration. CONCLUSIONS Current data suggest that Helicobacter pylori infection might influence the pathophysiology of Alzheimer's disease. However, further large-scale randomized controlled trials are mandatory to clarify a possible favorable effect of Helicobacter pylori eradication on Alzheimer's disease pathophysiology, before the recommendation of short-term and cost-effective therapeutic regimens against Helicobacter pylori-related Alzheimer's disease.
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Affiliation(s)
- Michael Doulberis
- Department of Internal Medicine, Bürgerspital Hospital, Solothurn, Switzerland
| | - Georgios Kotronis
- Department of Internal Medicine, Agios Pavlos General Hospital, Thessaloniki, Macedonia, Greece
| | - Robert Thomann
- Department of Internal Medicine, Bürgerspital Hospital, Solothurn, Switzerland
| | - Stergios A Polyzos
- Department of Internal Medicine, Ippokration Hospital, Second Medical Clinic, Aristotle University of Thessaloniki, Thessaloniki, Macedonia, Greece
| | - Marina Boziki
- Department of Internal Medicine, Ippokration Hospital, Second Medical Clinic, Aristotle University of Thessaloniki, Thessaloniki, Macedonia, Greece
| | - Dimitra Gialamprinou
- Department of Pediatrics, Papageorgiou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Macedonia, Greece
| | - Georgia Deretzi
- Department of Neurology, Papageorgiou General Hospital, Multiple Sclerosis Unit, Aristotle University of Thessaloniki, Thessaloniki, Macedonia, Greece
| | - Panagiotis Katsinelos
- Department of Internal Medicine, Ippokration Hospital, Second Medical Clinic, Aristotle University of Thessaloniki, Thessaloniki, Macedonia, Greece
| | - Jannis Kountouras
- Department of Internal Medicine, Ippokration Hospital, Second Medical Clinic, Aristotle University of Thessaloniki, Thessaloniki, Macedonia, Greece
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Ponomarenko P, Chadaeva I, Rasskazov DA, Sharypova E, Kashina EV, Drachkova I, Zhechev D, Ponomarenko MP, Savinkova LK, Kolchanov N. Candidate SNP Markers of Familial and Sporadic Alzheimer's Diseases Are Predicted by a Significant Change in the Affinity of TATA-Binding Protein for Human Gene Promoters. Front Aging Neurosci 2017; 9:231. [PMID: 28775688 PMCID: PMC5517495 DOI: 10.3389/fnagi.2017.00231] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 07/04/2017] [Indexed: 12/14/2022] Open
Abstract
While year after year, conditions, quality, and duration of human lives have been improving due to the progress in science, technology, education, and medicine, only eight diseases have been increasing in prevalence and shortening human lives because of premature deaths according to the retrospective official review on the state of US health, 1990-2010. These diseases are kidney cancer, chronic kidney diseases, liver cancer, diabetes, drug addiction, poisoning cases, consequences of falls, and Alzheimer's disease (AD) as one of the leading pathologies. There are familial AD of hereditary nature (~4% of cases) and sporadic AD of unclear etiology (remaining ~96% of cases; i.e., non-familial AD). Therefore, sporadic AD is no longer a purely medical problem, but rather a social challenge when someone asks oneself: “What can I do in my own adulthood to reduce the risk of sporadic AD at my old age to save the years of my lifespan from the destruction caused by it?” Here, we combine two computational approaches for regulatory SNPs: Web service SNP_TATA_Comparator for sequence analysis and a PubMed-based keyword search for articles on the biochemical markers of diseases. Our purpose was to try to find answers to the question: “What can be done in adulthood to reduce the risk of sporadic AD in old age to prevent the lifespan reduction caused by it?” As a result, we found 89 candidate SNP markers of familial and sporadic AD (e.g., rs562962093 is associated with sporadic AD in the elderly as a complication of stroke in adulthood, where natural marine diets can reduce risks of both diseases in case of the minor allele of this SNP). In addition, rs768454929, and rs761695685 correlate with sporadic AD as a comorbidity of short stature, where maximizing stature in childhood and adolescence as an integral indicator of health can minimize (or even eliminate) the risk of sporadic AD in the elderly. After validation by clinical protocols, these candidate SNP markers may become interesting to the general population [may help to choose a lifestyle (in childhood, adolescence, and adulthood) that can reduce the risks of sporadic AD, its comorbidities, and complications in the elderly].
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Affiliation(s)
- Petr Ponomarenko
- Children's Hospital Los Angeles, University of Southern CaliforniaLos Angeles, CA, United States
| | - Irina Chadaeva
- Division for System Biology, Institute of Cytology and Genetics of Siberian Branch of Russian Academy of SciencesNovosibirsk, Russia.,Faculty of Natural Sciences, Novosibirsk State UniversityNovosibirsk, Russia
| | - Dmitry A Rasskazov
- Division for System Biology, Institute of Cytology and Genetics of Siberian Branch of Russian Academy of SciencesNovosibirsk, Russia
| | - Ekaterina Sharypova
- Division for System Biology, Institute of Cytology and Genetics of Siberian Branch of Russian Academy of SciencesNovosibirsk, Russia
| | - Elena V Kashina
- Division for System Biology, Institute of Cytology and Genetics of Siberian Branch of Russian Academy of SciencesNovosibirsk, Russia
| | - Irina Drachkova
- Division for System Biology, Institute of Cytology and Genetics of Siberian Branch of Russian Academy of SciencesNovosibirsk, Russia
| | - Dmitry Zhechev
- Division for System Biology, Institute of Cytology and Genetics of Siberian Branch of Russian Academy of SciencesNovosibirsk, Russia
| | - Mikhail P Ponomarenko
- Division for System Biology, Institute of Cytology and Genetics of Siberian Branch of Russian Academy of SciencesNovosibirsk, Russia.,Faculty of Natural Sciences, Novosibirsk State UniversityNovosibirsk, Russia
| | - Ludmila K Savinkova
- Division for System Biology, Institute of Cytology and Genetics of Siberian Branch of Russian Academy of SciencesNovosibirsk, Russia
| | - Nikolay Kolchanov
- Division for System Biology, Institute of Cytology and Genetics of Siberian Branch of Russian Academy of SciencesNovosibirsk, Russia.,Faculty of Natural Sciences, Novosibirsk State UniversityNovosibirsk, Russia
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Modification of drug delivery to improve antibiotic targeting to the stomach. Ther Deliv 2016; 6:741-62. [PMID: 26149788 DOI: 10.4155/tde.15.35] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The obstacles to the successful eradication of Helicobacter pylori infections include the presence of antibiotic-resistant bacteria and therapy requiring multiple drugs with complicated dosing schedules. Other obstacles include bacterial residence in an environment where high antibiotic concentrations are difficult to achieve. Biofilm production by the bacteria is an additional challenge to the effective treatment of this infection. Conventional oral formulations used in the treatment of this infection have a short gastric residence time, thus limiting the duration of exposure of drug to the bacteria. This review summarizes the current research in the development of gastroretentive formulations and the prospective future applications of this approach in the targeted delivery of drugs such as antibiotics to the stomach.
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Zhou Q, Qi S, Sun X, Ge R. The interaction of a histidine-rich protein hpn with the membrane mimics: implications for pathologic roles of Hpn in Helicobacter pylori. Helicobacter 2014; 19:129-35. [PMID: 24494595 DOI: 10.1111/hel.12109] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND Hpn is a small histidine-rich protein in Helicobacter pylori. This protein has been shown to play roles in nickel storage and detoxification and to exhibit cytotoxicity to gastric epithelial cells. Hpn can be secreted outside of the bacterium and forms amyloid-like structures. OBJECTIVE To study the interactions between Hpn and membrane mimics, which may further our understanding of the pathologic roles of this bacterium. METHODS Various biochemical and biophysical methods, such as secondary structure determination be CD, calcein release assay with fluorescence spectrometry, and Laurdan and Prodan generalized polarization determination have been used to characterize the interaction between Hpn and membrane mimics. RESULTS Membrane mimics induced the formation of α-helix in Hpn. The interaction disrupts the integrity of the membrane mimics and leads to the release of inner calcein probe. The experiments involving the Laurdan and Prodan fluorescence indicated that increasing the total protein/lipid ratio leads to a less ordered and more hydrated lipid membrane structure close to the water/lipid interface of lipid bilayers modeling the mitochondrial inner membrane. CONCLUSION The present data indicated that Hpn may take part in the pathological roles of Helicobacter pylori through membrane interactions.
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Affiliation(s)
- Qinglu Zhou
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, College of Life Sciences, Sun Yat-Sen University, Guangzhou, China
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Pan-In P, Banlunara W, Chaichanawongsaroj N, Wanichwecharungruang S. Ethyl cellulose nanoparticles: clarithomycin encapsulation and eradication of H. pylori. Carbohydr Polym 2014; 109:22-7. [PMID: 24815396 DOI: 10.1016/j.carbpol.2014.03.025] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 03/07/2014] [Accepted: 03/11/2014] [Indexed: 11/17/2022]
Abstract
The extreme acidic environment of the stomach, its regular voidance of contents and the restricted access to the mucus covered habitat combined with the antibiotic resistance of the bacteria, all contribute to the poor success in the treatment of Helicobacter pylori gastric infections. Here, we demonstrate that by encapsulating clarithromycin into ethyl cellulose (EC) nanoparticles, the efficiency of H. pylori clearance in C57BL/6 mice infected with these bacteria was significantly improved. Clarithomycin-loaded EC nanoparticles were prepared via a simple yet effective anti-solvent particle induction method, to yield sub-micron sized particles with 22.3 ± 0.17% (w/w) clarithromycin loading at 86 ± 0.5% (w/w) encapsulation efficiency. The particles dispersed well in water and simulated gastric fluid and gave a minimum inhibitory concentration of 0.09-0.18 μg/ml against four strains of H. pylori. Encapsulation into EC particles not only enhanced the anti-adhesion activity of clarithromycin when tested with H. pylori and Hep-2 cells, but also gave significant enhancement of H. pylori clearance in the stomach of C57BL/6 mice infected with the bacteria.
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Affiliation(s)
- Porntip Pan-In
- Program in Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Wijit Banlunara
- Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Nuntaree Chaichanawongsaroj
- Innovation Center for Research and Development of Medical Diagnostic Technology Project, Department of Transfusion Medicine, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok 10330, Thailand
| | - Supason Wanichwecharungruang
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand; Nanotec-CU Center of Excellence on Food and Agriculture, Bangkok 10330, Thailand.
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Ge RG, Wang DX, Hao MC, Sun XS. Nickel trafficking system responsible for urease maturation in Helicobacter pylori. World J Gastroenterol 2013; 19:8211-8218. [PMID: 24363511 PMCID: PMC3857443 DOI: 10.3748/wjg.v19.i45.8211] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 10/17/2013] [Accepted: 11/03/2013] [Indexed: 02/06/2023] Open
Abstract
Helicobacter pylori (H. pylori) is a common human pathogen responsible for various gastric diseases. This bacterium relies on the production of urease and hydrogenase to inhabit the acidic environment of the stomach. Nickel is an essential cofactor for urease and hydrogenase. H. pylori has to uptake sufficient nickel ions for the maturation of urease, and on the other way, to prevent the toxic effects of excessive nickel ions. Therefore, H. pylori has to strike a delicate balance between the import of nickel ions, its efficient intracellular storage, and delivery to nickel-dependent metalloenzymes when required. The assembly and maturation of the urease enzyme is a complex and timely ordered process, requiring various regulatory, uptake, chaperone and accessory proteins. In this review, we focus on several nickel trafficking proteins involved in urease maturation: NikR, NixA, HypAB, UreEFGH, HspA, Hpn and Hpnl. The work will deepen our understanding of how this pathogenic bacterium adapts to severe habitant environments in the host.
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Abstract
Late-onset Alzheimer's disease (AD) is the most prevalent cause of dementia among older adults, yet more than a century of research has not determined why this disease develops. One prevailing hypothesis is that late-onset AD is caused by infectious pathogens, an idea widely studied in both humans and experimental animal models. This review examines the infectious AD etiology hypothesis and summarizes existing evidence associating infectious agents with AD in humans. The various mechanisms through which different clinical and subclinical infections could cause or promote the progression of AD are considered, as is the concordance between putative infectious agents and the epidemiology of AD. We searched the PubMed, Web of Science, and EBSCO databases for research articles pertaining to infections and AD and systematically reviewed the evidence linking specific infectious pathogens to AD. The evidence compiled from the literature linking AD to an infectious cause is inconclusive, but the amount of evidence suggestive of an association is too substantial to ignore. Epidemiologic, clinical, and basic science studies that could improve on current understanding of the associations between AD and infections and possibly uncover ways to control this highly prevalent and debilitating disease are suggested.
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Affiliation(s)
| | - Robert Wallace
- Correspondence to Dr. Robert Wallace, Department of Epidemiology, College of Public Health, The University of Iowa, 105 River St. Iowa City, IA 52242 (e-mail: )
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Roubaud Baudron C, Letenneur L, Langlais A, Buissonnière A, Mégraud F, Dartigues JF, Salles N. Does Helicobacter pylori infection increase incidence of dementia? The Personnes Agées QUID Study. J Am Geriatr Soc 2012; 61:74-8. [PMID: 23252507 DOI: 10.1111/jgs.12065] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
OBJECTIVES To determine whether Helicobacter pylori infection was associated with dementia and risk of developing dementia in a longitudinal population-based cohort of elderly adults living in the community. DESIGN Prospective community-based cohort study. SETTING The population-based Personnes Agées QUID (PAQUID) Study. PARTICIPANTS Six hundred three noninstitutionalized individuals aged 65 and older living in the southwest of France followed from 1989 to 2008. MEASUREMENTS A descriptive and comparative analysis including dementia prevalence, according to H. pylori status (serology), was made at baseline. Cox proportional hazard models were used to study the risk of developing dementia according to H. pylori status assessed on sera samples from elderly adults initially free of dementia and followed for 20 years. A neurologist diagnosed dementia according to Diagnostic and Statistical Manual of Mental Disorders Third Edition criteria. RESULTS At baseline, 391 (64.8%) subjects (348 women, mean age 73.9 ± 6.5) were seropositive for H. pylori. Dementia prevalence was higher in the infected group (5.4% vs 1.4%, P = .02). After 20 years of follow-up, 148 incident cases of dementia were diagnosed. After controlling for age, sex, educational level, apolipoprotein E4 status, cardiovascular risk factors, and Mini-Mental State Examination score, H. pylori infection was determined to be a risk factor for developing dementia (hazard ratio = 1.46, P = .04). CONCLUSION This longitudinal population-based study provides additional epidemiological support to the hypothesis of an association between dementia and H. pylori infection, which may enhance neurodegeneration.
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Zavos C, Kountouras J, Deretzi G, Tsona A, Polyzos SA, Mantzoukis K, Katsinelos P, Kiourtidis D, Gavalas E, Pilpilidis I, Tzilves D, Vardaka E. Hpn protein as a mediator between Helicobacter pylori infection and Alzheimer’s disease in sub-populations worldwide. Med Hypotheses 2012; 78:349-50. [DOI: 10.1016/j.mehy.2011.10.033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Accepted: 10/23/2011] [Indexed: 10/15/2022]
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