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Moreau F, Atamanyuk D, Blaukopf M, Barath M, Herczeg M, Xavier NM, Monbrun J, Airiau E, Henryon V, Leroy F, Floquet S, Bonnard D, Szabla R, Brown C, Junop MS, Kosma P, Gerusz V. Potentiating Activity of GmhA Inhibitors on Gram-Negative Bacteria. J Med Chem 2024; 67:6610-6623. [PMID: 38598312 PMCID: PMC11056994 DOI: 10.1021/acs.jmedchem.4c00037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 02/28/2024] [Accepted: 03/29/2024] [Indexed: 04/12/2024]
Abstract
Inhibition of the biosynthesis of bacterial heptoses opens novel perspectives for antimicrobial therapies. The enzyme GmhA responsible for the first committed biosynthetic step catalyzes the conversion of sedoheptulose 7-phosphate into d-glycero-d-manno-heptose 7-phosphate and harbors a Zn2+ ion in the active site. A series of phosphoryl- and phosphonyl-substituted derivatives featuring a hydroxamate moiety were designed and prepared from suitably protected ribose or hexose derivatives. High-resolution crystal structures of GmhA complexed to two N-formyl hydroxamate inhibitors confirmed the binding interactions to a central Zn2+ ion coordination site. Some of these compounds were found to be nanomolar inhibitors of GmhA. While devoid of HepG2 cytotoxicity and antibacterial activity of their own, they demonstrated in vitro lipopolysaccharide heptosylation inhibition in Enterobacteriaceae as well as the potentiation of erythromycin and rifampicin in a wild-type Escherichia coli strain. These inhibitors pave the way for a novel treatment of Gram-negative infections.
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Affiliation(s)
- François Moreau
- Mutabilis, 102 Avenue Gaston Roussel, Romainville 93230, France
| | | | - Markus Blaukopf
- Department
of Chemistry, University of Natural Resources
and Life Sciences, Muthgasse
18, Vienna A-1190, Austria
| | - Marek Barath
- Department
of Chemistry, University of Natural Resources
and Life Sciences, Muthgasse
18, Vienna A-1190, Austria
- Institute
of Chemistry, Center for Glycomics, Slovak
Academy of Sciences, Dúbravská cesta 9, Bratislava SK-845 38, Slovakia
| | - Mihály Herczeg
- Department
of Chemistry, University of Natural Resources
and Life Sciences, Muthgasse
18, Vienna A-1190, Austria
- Department
of Pharmaceutical Chemistry, University
of Debrecen, Debrecen 4032, Hungary
| | - Nuno M. Xavier
- Department
of Chemistry, University of Natural Resources
and Life Sciences, Muthgasse
18, Vienna A-1190, Austria
- Centro
de Química Estrutural, Institute of Molecular Sciences, Faculdade de Ciências, Universidade de Lisboa, Ed. C8, 5° Piso, Campo Grande, Lisboa 1749-016, Portugal
| | | | | | | | - Frédéric Leroy
- Carbosynth
Limited, 8&9 Old
Station Business Park, Compton, Berkshire RG20 6NE, U.K.
| | | | - Damien Bonnard
- Mutabilis, 102 Avenue Gaston Roussel, Romainville 93230, France
| | - Robert Szabla
- Department
of Biochemistry, University of Western Ontario, London, ON N6A 3K7, Canada
| | - Chris Brown
- Department
of Biochemistry, University of Western Ontario, London, ON N6A 3K7, Canada
| | - Murray S. Junop
- Department
of Biochemistry, University of Western Ontario, London, ON N6A 3K7, Canada
| | - Paul Kosma
- Department
of Chemistry, University of Natural Resources
and Life Sciences, Muthgasse
18, Vienna A-1190, Austria
| | - Vincent Gerusz
- Mutabilis, 102 Avenue Gaston Roussel, Romainville 93230, France
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2
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Ji X, Yu R, Zhu M, Zhang C, Zhou L, Cai T, Li W. Diadenosine tetraphosphate modulated quorum sensing in bacteria treated with kanamycin. BMC Microbiol 2023; 23:353. [PMID: 37978430 PMCID: PMC10657157 DOI: 10.1186/s12866-023-03113-3] [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: 09/14/2023] [Accepted: 11/06/2023] [Indexed: 11/19/2023] Open
Abstract
BACKGROUND The dinucleotide alarmone diadenosine tetraphosphate (Ap4A), which is found in cells, has been shown to affect the survival of bacteria under stress. RESULTS Here, we labeled Ap4A with biotin and incubated the labeled Ap4A with the total proteins extracted from kanamycin-treated Escherichia coli to identify the Ap4A binding protein in bacteria treated with kanamycin. Liquid chromatography‒mass spectrometry (LCMS) and bioinformatics were used to identify novel proteins that Ap4A interacts with that are involved in biofilm formation, quorum sensing, and lipopolysaccharide biosynthesis pathways. Then, we used the apaH knockout strain of E. coli K12-MG1655, which had increased intracellular Ap4A, to demonstrate that Ap4A affected the expression of genes in these three pathways. We also found that the swarming motility of the apaH mutant strain was reduced compared with that of the wild-type strain, and under kanamycin treatment, the biofilm formation of the mutant strain decreased. CONCLUSIONS These results showed that Ap4A can reduce the survival rate of bacteria treated with kanamycin by regulating quorum sensing (QS). These effects can expand the application of kanamycin combinations in the treatment of multidrug-resistant bacteria.
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Affiliation(s)
- Xia Ji
- School of Life Science, Huizhou University, Huizhou, 516007, China.
| | - Ruojing Yu
- School of Life Science, Huizhou University, Huizhou, 516007, China
| | - Meilian Zhu
- School of Life Science, Huizhou University, Huizhou, 516007, China
| | - Cuilin Zhang
- School of Life Science, Huizhou University, Huizhou, 516007, China
| | - Libin Zhou
- School of Life Science, Huizhou University, Huizhou, 516007, China
| | - Tianshu Cai
- Huizhou Health Sciences Polytechnic, Huizhou, 516025, China
| | - Weiwei Li
- Huizhou Health Sciences Polytechnic, Huizhou, 516025, China
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3
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Xiang DF, Xu M, Ghosh MK, Raushel FM. Metabolic Pathways for the Biosynthesis of Heptoses Used in the Construction of Capsular Polysaccharides in the Human Pathogen Campylobacter jejuni. Biochemistry 2023; 62:3145-3158. [PMID: 37890137 PMCID: PMC10680097 DOI: 10.1021/acs.biochem.3c00390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 10/11/2023] [Accepted: 10/11/2023] [Indexed: 10/29/2023]
Abstract
Campylobacter jejuni is the leading cause of food poisoning in North America. The exterior surface of this bacterium is coated with a capsular polysaccharide (CPS) that consists of a repeating sequence of 2-5 different carbohydrates that is anchored to the outer membrane. Heptoses of various configurations are among the most common monosaccharides that have been identified within the CPS. It is currently thought that all heptose variations derive from the modification of GDP-d-glycero-α-d-manno-heptose (GMH). From the associated gene clusters for CPS biosynthesis, we have identified 20 unique enzymes with different substrate profiles that are used by the various strains and serotypes of C. jejuni to make six different stereoisomers of GDP-6-deoxy-heptose, four stereoisomers of GDP-d-glycero-heptoses, and two stereoisomers of GDP-3,6-dideoxy-heptoses starting from d-sedoheptulose-7-phosphate. The modification enzymes include a C4-dehydrogenase, a C4,6-dehydratase, three C3- and/or C5-epimerases, a C3-dehydratase, eight C4-reductases, two pyranose/furanose mutases, and four enzymes for the formation of GMH from d-sedoheptulose-7-phosphate. We have mixed these enzymes in different combinations to make novel GDP-heptose modifications, including GDP-6-hydroxy-heptoses, GDP-3-deoxy-heptoses, and GDP-3,6-dideoxy-heptoses.
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Affiliation(s)
- Dao Feng Xiang
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Maggie Xu
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Manas K. Ghosh
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Frank M. Raushel
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
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4
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Rajendran V, Ponnuraj K. High-throughput virtual screening and molecular dynamics simulation reveals NPC170742 a novel chalconoid compound as a potential inhibitor of D-glycero-D-manno-heptose-1,7-bisphosphate 7-phosphatase in Helicobacter pylori. J Biomol Struct Dyn 2023:1-11. [PMID: 37723879 DOI: 10.1080/07391102.2023.2259483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 08/23/2023] [Indexed: 09/20/2023]
Abstract
Helicobacter pylori is a gram negative spiral shaped bacteria that causes peptic ulcer and gastric cancer. It Is the sixth most prevalent cancer in the world and the third leading cause of cancer death. The increase in reported cases of H. pylori resistance to the drugs and antibiotics shows the need for the development of new and efficient drugs against the pathogen. In the present study, D-glycero-D-manno-heptose-1,7-bisphosphate 7-phosphatase (GmhB), an enzyme involved in the biosynthesis of lipopolysaccharides that encourages bacterial adherence, self-aggregation and identifying the host cells was modelled and the active sites were predicted through POCASA which is an automated ligand binding site prediction server. Natural product activity and species source (NPASS) is a database of 96,481 natural compounds that were subjected to virtual screening workflow that includes Qikprop, Lipinski rule, filtering out reactive functional groups followed by high throughput virtual screening and the top 10 compounds were selected for further induced fit docking along with the substrate D-glycero-β-D-manno-heptose 1,7-bisphosphate. The compound NPC170742 (Alpha, Beta, 3,4,5,2',4',6'-Octahydroxy dihydrochalcone) showed higher affinity than the substrate, and both the substrate D-glycero-β-D-manno-heptose 1,7-bisphosphate and the compound NPC170742 were subjected to molecular dynamics simulation. The results exposed the compound NPC170742 could be a potential lead compound against the enzyme D-glycero-D-manno-heptose-1,7-bisphosphate 7-phosphatase of H. pylori.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Vijayakumar Rajendran
- Centre for Advanced Studies in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai, India
| | - Karthe Ponnuraj
- Centre for Advanced Studies in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai, India
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5
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Squillario M, Bonaretti C, La Valle A, Di Marco E, Piccolo G, Minuto N, Patti G, Napoli F, Bassi M, Maghnie M, d'Annunzio G, Biassoni R. Gut-microbiota in children and adolescents with obesity: inferred functional analysis and machine-learning algorithms to classify microorganisms. Sci Rep 2023; 13:11294. [PMID: 37438382 DOI: 10.1038/s41598-023-36533-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 06/05/2023] [Indexed: 07/14/2023] Open
Abstract
The fecal microbiome of 55 obese children and adolescents (BMI-SDS 3.2 ± 0.7) and of 25 normal-weight subjects, matched both for age and sex (BMI-SDS - 0.3 ± 1.1) was analysed. Streptococcus, Acidaminococcus, Sutterella, Prevotella, Sutterella wadsworthensis, Streptococcus thermophilus, and Prevotella copri positively correlated with obesity. The inferred pathways strongly associated with obesity concern the biosynthesis pathways of tyrosine, phenylalanine, tryptophan and methionine pathways. Furthermore, polyamine biosynthesis virulence factors and pro-inflammatory lipopolysaccharide biosynthesis pathway showed higher abundances in obese samples, while the butanediol biosynthesis showed low abundance in obese subjects. Different taxa strongly linked with obesity have been related to an increased risk of multiple diseases involving metabolic pathways related to inflammation (polyamine and lipopolysaccharide biosynthesis). Cholesterol, LDL, and CRP positively correlated with specific clusters of microbial in obese patients. The Firmicutes/Bacteroidetes-ratio was lower in obese samples than in controls and differently from the literature we state that this ratio could not be a biomarker for obesity.
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Affiliation(s)
| | - Carola Bonaretti
- Molecular Diagnostics, Analysis Laboratory, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Alberto La Valle
- Pediatric Clinic, Regional Center for Pediatric Diabetes, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Eddi Di Marco
- Molecular Diagnostics, Analysis Laboratory, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Gianluca Piccolo
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, (DINOGMI), Università degli Studi di Genova, Genoa, Italy
- Neuro-Oncology Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Nicola Minuto
- Pediatric Clinic, Regional Center for Pediatric Diabetes, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Giuseppa Patti
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, (DINOGMI), Università degli Studi di Genova, Genoa, Italy
- Department of Pediatrics, Pediatric Clinic, Regional Center for Pediatric Diabetes, IRCCS Istituto Giannina Gaslini, Via Gaslini 5, 16147, Genoa, Italy
| | - Flavia Napoli
- Department of Pediatrics, Pediatric Clinic, Regional Center for Pediatric Diabetes, IRCCS Istituto Giannina Gaslini, Via Gaslini 5, 16147, Genoa, Italy
| | - Marta Bassi
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, (DINOGMI), Università degli Studi di Genova, Genoa, Italy
- Department of Pediatrics, Pediatric Clinic, Regional Center for Pediatric Diabetes, IRCCS Istituto Giannina Gaslini, Via Gaslini 5, 16147, Genoa, Italy
| | - Mohamad Maghnie
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, (DINOGMI), Università degli Studi di Genova, Genoa, Italy
- Department of Pediatrics, Pediatric Clinic, Regional Center for Pediatric Diabetes, IRCCS Istituto Giannina Gaslini, Via Gaslini 5, 16147, Genoa, Italy
| | - Giuseppe d'Annunzio
- Department of Pediatrics, Pediatric Clinic, Regional Center for Pediatric Diabetes, IRCCS Istituto Giannina Gaslini, Via Gaslini 5, 16147, Genoa, Italy.
| | - Roberto Biassoni
- Molecular Diagnostics, Analysis Laboratory, IRCCS Istituto Giannina Gaslini, Genoa, Italy
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6
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Sidor K, Skirecki T. A Bittersweet Kiss of Gram-Negative Bacteria: The Role of ADP-Heptose in the Pathogenesis of Infection. Microorganisms 2023; 11:1316. [PMID: 37317291 DOI: 10.3390/microorganisms11051316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 05/10/2023] [Accepted: 05/15/2023] [Indexed: 06/16/2023] Open
Abstract
Due to the global crisis caused by the dramatic rise of drug resistance among Gram-negative bacteria, there is an urgent need for a thorough understanding of the pathogenesis of infections of such an etiology. In light of the limited availability of new antibiotics, therapies aimed at host-pathogen interactions emerge as potential treatment modalities. Thus, understanding the mechanism of pathogen recognition by the host and immune evasion appear to be the key scientific issues. Until recently, lipopolysaccharide (LPS) was recognized as a major pathogen-associated molecular pattern (PAMP) of Gram-negative bacteria. However, recently, ADP-L-glycero-β-D-manno-heptose (ADP-heptose), an intermediate carbohydrate metabolite of the LPS biosynthesis pathway, was discovered to activate the hosts' innate immunity. Therefore, ADP-heptose is regarded as a novel PAMP of Gram-negative bacteria that is recognized by the cytosolic alpha kinase-1 (ALPK1) protein. The conservative nature of this molecule makes it an intriguing player in host-pathogen interactions, especially in the context of changes in LPS structure or even in its loss by certain resistant pathogens. Here, we present the ADP-heptose metabolism, outline the mechanisms of its recognition and the activation of its immunity, and summarize the role of ADP-heptose in the pathogenesis of infection. Finally, we hypothesize about the routes of the entry of this sugar into cytosol and point to emerging questions that require further research.
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Affiliation(s)
- Karolina Sidor
- Department of Translational Immunology and Experimental Intensive Care, Centre of Postgraduate Medical Education, Marymoncka 99/103, 01-813 Warsaw, Poland
| | - Tomasz Skirecki
- Department of Translational Immunology and Experimental Intensive Care, Centre of Postgraduate Medical Education, Marymoncka 99/103, 01-813 Warsaw, Poland
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7
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Jelenko K, Cepec E, Nascimento FX, Trček J. Comparative Genomics and Phenotypic Characterization of Gluconacetobacter entanii, a Highly Acetic Acid-Tolerant Bacterium from Vinegars. Foods 2023; 12:foods12010214. [PMID: 36613429 PMCID: PMC9818992 DOI: 10.3390/foods12010214] [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: 11/21/2022] [Revised: 12/21/2022] [Accepted: 12/23/2022] [Indexed: 01/05/2023] Open
Abstract
The bacterial species Gluconacetobacter entanii belongs to a group of acetic acid bacteria. In 2000, it was described as a primary species of submerged spirit vinegar-producing bioreactors with a strict requirement of acetic acid, ethanol, and glucose for growth. Over the years, the type-strain of G. entanii deposited in international culture collections has lost the ability for revitalization and is thus not available any more in a culturable form. Here, we have systematically characterized phenotypic features and genomes of recently isolated G. entanii strains and compared them with characteristics of the type-strain available from published data. Using the functional annotation, genes gmhB and psp were identified as unique for G. entanii genomes among species in the clade Novacetimonas. The genome stability of G. entanii was assessed after 28 and 43 months of preculturing the strain Gluconacetobacter entanii AV429 twice a week. The strain G. entanii AV429 did not accumulate giant insertions or deletions but a few gene mutations. To unify further research into acetic acid bacteria systematics and taxonomy, we propose G. entanii AV429 as the neotype strain.
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Affiliation(s)
- Karin Jelenko
- Department of Biology, Faculty of Natural Sciences and Mathematics, University of Maribor, 2000 Maribor, Slovenia
| | - Eva Cepec
- Department of Biology, Faculty of Natural Sciences and Mathematics, University of Maribor, 2000 Maribor, Slovenia
| | | | - Janja Trček
- Department of Biology, Faculty of Natural Sciences and Mathematics, University of Maribor, 2000 Maribor, Slovenia
- Faculty of Chemistry and Chemical Engineering, University of Maribor, 2000 Maribor, Slovenia
- Correspondence: ; Tel.: +386-2-229-3749
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8
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Teng KW, Hsieh KS, Hung JS, Wang CJ, Liao EC, Chen PC, Lin YH, Wu DC, Lin CH, Wang WC, Chan HL, Huang SK, Kao MC. Helicobacter pylori employs a general protein glycosylation system for the modification of outer membrane adhesins. Gut Microbes 2022; 14:2130650. [PMID: 36206406 PMCID: PMC9553153 DOI: 10.1080/19490976.2022.2130650] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Helicobacter pylori infection is associated with the development of several gastric diseases including gastric cancer. To reach a long-term colonization in the host stomach, H. pylori employs multiple outer membrane adhesins for binding to the gastric mucosa. However, due to the redundancy of adhesins that complement the adhesive function of bacteria, targeting each individual adhesin alone usually achieves nonideal outcomes for preventing bacterial adhesion. Here, we report that key adhesins AlpA/B and BabA/B in H. pylori are modified by glycans and display a two-step molecular weight upshift pattern from the cytoplasm to the inner membrane and from the inner membrane to the outer membrane. Nevertheless, this upshift pattern is missing when the expression of some enzymes related to lipopolysaccharide (LPS) biosynthesis, including the LPS O-antigen assembly and ligation enzymes WecA, Wzk, and WaaL, is disrupted, indicating that the underlying mechanisms and the involved enzymes for the adhesin glycosylation are partially shared with the LPS biosynthesis. Loss of the adhesin glycosylation not only reduces the protease resistance and the stability of the tested adhesins but also changes the adhesin-binding ability. In addition, mutations in the LPS biosynthesis cause a significant reduction in bacterial adhesion in the in vitro cell-line model. The current findings reveal that H. pylori employs a general protein glycosylation system related to LPS biosynthesis for adhesin modification and its biological significance. The enzymes required for adhesin glycosylation rather than the adhesins themselves are potentially better drug targets for preventing or treating H. pylori infection.
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Affiliation(s)
- Kai-Wen Teng
- Institute of Molecular Medicine, College of Life Science, National Tsing Hua University, Hsinchu, Taiwan
| | - Kai-Siang Hsieh
- Institute of Molecular Medicine, College of Life Science, National Tsing Hua University, Hsinchu, Taiwan
| | - Ji-Shiuan Hung
- Institute of Molecular Medicine, College of Life Science, National Tsing Hua University, Hsinchu, Taiwan
| | - Chun-Jen Wang
- Institute of Molecular Medicine, College of Life Science, National Tsing Hua University, Hsinchu, Taiwan
| | - En-Chi Liao
- Institute of Bioinformatics and Structural Biology, College of Life Science, National Tsing Hua University, Hsinchu, Taiwan,Department of Medical Science, College of Life Science, National Tsing Hua University, Hsinchu, Taiwan
| | - Pei-Chun Chen
- Institute of Molecular Medicine, College of Life Science, National Tsing Hua University, Hsinchu, Taiwan
| | - Ying-Hsuan Lin
- Institute of Molecular Medicine, College of Life Science, National Tsing Hua University, Hsinchu, Taiwan
| | - Deng-Chyang Wu
- Division of Gastroenterology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chun-Hung Lin
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Wen-Ching Wang
- Institute of Molecular and Cellular Biology, College of Life Science, National Tsing Hua University, Hsinchu, Taiwan,Department of Life Science, College of Life Science, National Tsing Hua University, Hsinchu, Taiwan
| | - Hong-Lin Chan
- Institute of Bioinformatics and Structural Biology, College of Life Science, National Tsing Hua University, Hsinchu, Taiwan,Department of Medical Science, College of Life Science, National Tsing Hua University, Hsinchu, Taiwan
| | - Shau-Ku Huang
- National Institute of Environmental Health Sciences, National Health Research Institutes, Zhunan, Taiwan
| | - Mou-Chieh Kao
- Institute of Molecular Medicine, College of Life Science, National Tsing Hua University, Hsinchu, Taiwan,Department of Life Science, College of Life Science, National Tsing Hua University, Hsinchu, Taiwan,CONTACT Mou-Chieh Kao Institute of Molecular Medicine, College of Life Science, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 300044, Taiwan
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9
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Zhao T, Yang B, Li H, Qian A, Cong W, Sun W, Kang Y. Essential role of ascO for virulence of Aeromonas veronii and inducing apoptosis. JOURNAL OF FISH DISEASES 2022; 45:1477-1489. [PMID: 35749548 DOI: 10.1111/jfd.13676] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 06/06/2022] [Accepted: 06/10/2022] [Indexed: 06/15/2023]
Abstract
Aeromonas veronii is a significant pathogen that is capable of infecting humans, animals, and aquatic animals. The type III secretion system (T3SS) is intimately associated with bacterial pathogenicity. The ascO gene is an important core component of T3SS in A. veronii, but its function is still unclear. The ascO gene of A. veronii TH0426 was deleted by using the pRE112 suicide plasmid to study its function. The study results showed that the ability of ∆ascO to adhere and invade EPC cells was significantly reduced by 1.28 times. The toxicity of the mutant strain ΔascO to EPC cells was consistently significantly lower than wild-type strain TH0426 at 1, 2, and 4 h. The LD50 values of ∆ascO against zebrafish and Carassius auratus (C. auratus) were 53 and 15 times that of the wild-type strain. In addition, the bacterial load of the mutant strain ΔascO in blood, heart, liver, and spleen was lower than wild-type strain TH0426. The Hoechst staining showed that the apoptotic degree of EPC cells induced by the mutant strain ΔascO was lower than that of the wild-type strain TH0426. Furthermore, real-time quantitative PCR (RT-qPCR) analysis revealed lower expression levels of pro-apoptotic genes (including cytC, cas3, cas9, TNF-α, and IL-1β) in C. auratus tissues infected with the mutant strain ΔascO compared to the wild-type strain TH0426. The results of in vivo and in vitro experiments have shown that ascO gene mutation can reduce the adhesion and toxicity of A. veronii to EPC and reduce the level of apoptosis induced by A. veronii. As a result, these insights will help further elucidate the function of the ascO gene and thus contribute to understanding the pathogenesis of A. veronii.
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Affiliation(s)
- Tong Zhao
- College of Veterinary Medicine/College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
- Marine College, Shandong University, Weihai, China
| | - Bintong Yang
- Marine College, Shandong University, Weihai, China
| | - Hongjin Li
- College of Veterinary Medicine/College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
- Marine College, Shandong University, Weihai, China
| | - Aidong Qian
- College of Veterinary Medicine/College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - Wei Cong
- Marine College, Shandong University, Weihai, China
| | - Wuwen Sun
- College of Veterinary Medicine/College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - Yuanhuan Kang
- College of Veterinary Medicine/College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
- Marine College, Shandong University, Weihai, China
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10
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The Inactivation of LPS Biosynthesis Genes in E. coli Cells Leads to Oxidative Stress. Cells 2022; 11:cells11172667. [PMID: 36078074 PMCID: PMC9454879 DOI: 10.3390/cells11172667] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/22/2022] [Accepted: 08/25/2022] [Indexed: 11/17/2022] Open
Abstract
Impaired lipopolysaccharide biosynthesis in Gram-negative bacteria results in the “deep rough” phenotype, which is characterized by increased sensitivity of cells to various hydrophobic compounds, including antibiotics novobiocin, actinomycin D, erythromycin, etc. The present study showed that E. coli mutants carrying deletions of the ADP-heptose biosynthesis genes became hypersensitive to a wide range of antibacterial drugs: DNA gyrase inhibitors, protein biosynthesis inhibitors (aminoglycosides, tetracycline), RNA polymerase inhibitors (rifampicin), and β-lactams (carbenicillin). In addition, it was found that inactivation of the gmhA, hldE, rfaD, and waaC genes led to dramatic changes in the redox status of cells: a decrease in the pool of reducing NADPH and ATP equivalents, the concentration of intracellular cysteine, a change in thiol homeostasis, and a deficiency in the formation of hydrogen sulfide. In “deep rough” mutants, intensive formation of reactive oxygen species was observed, which, along with a lack of reducing agents, such as reactive sulfur species or NADPH, leads to oxidative stress and an increase in the number of dead cells in the population. Within the framework of modern ideas about the role of oxidative stress as a universal mechanism of the bactericidal action of antibiotics, inhibition of the enzymes of ADP-heptose biosynthesis is a promising direction for increasing the effectiveness of existing antibiotics and solving the problem of multidrug resistance.
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The Effects of HP0044 and HP1275 Knockout Mutations on the Structure and Function of Lipopolysaccharide in Helicobacter pylori Strain 26695. Biomedicines 2022; 10:biomedicines10010145. [PMID: 35052824 PMCID: PMC8773439 DOI: 10.3390/biomedicines10010145] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 01/06/2022] [Accepted: 01/07/2022] [Indexed: 02/07/2023] Open
Abstract
Helicobacter pylori infection is associated with several gastric diseases, including gastritis, peptic ulcer, gastric adenocarcinoma and mucosa-associated lymphatic tissue (MALT) lymphoma. Due to the prevalence and severeness of H. pylori infection, a thorough understanding of this pathogen is necessary. Lipopolysaccharide, one of the major virulence factors of H. pylori, can exert immunomodulating and immunostimulating functions on the host. In this study, the HP0044 and HP1275 genes were under investigation. These two genes potentially encode GDP-D-mannose dehydratase (GMD) and phosphomannomutase (PMM)/phosphoglucomutase (PGM), respectively, and are involved in the biosynthesis of fucose. HP0044 and HP1275 knockout mutants were generated; both mutants displayed a truncated LPS, suggesting that the encoded enzymes are not only involved in fucose production but are also important for LPS construction. In addition, these two gene knockout mutants exhibited retarded growth, increased surface hydrophobicity and autoaggregation as well as being more sensitive to the detergent SDS and the antibiotic novobiocin. Furthermore, the LPS-defective mutants also had significantly reduced bacterial infection, adhesion and internalization in the in vitro cell line model. Moreover, disruptions of the HP0044 and HP1275 genes in H. pylori altered protein sorting into outer membrane vesicles. The critical roles of HP0044 and HP1275 in LPS biosynthesis, bacterial fitness and pathogenesis make them attractive candidates for drug inventions against H. pylori infection.
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