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Zhang Q, Soulère L, Queneau Y. Amide bioisosteric replacement in the design and synthesis of quorum sensing modulators. Eur J Med Chem 2024; 273:116525. [PMID: 38801798 DOI: 10.1016/j.ejmech.2024.116525] [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: 03/13/2024] [Revised: 05/08/2024] [Accepted: 05/20/2024] [Indexed: 05/29/2024]
Abstract
The prevention or control of bacterial infections requires continuous search for novel approaches among which bacterial quorum sensing inhibition is considered as a complementary antibacterial strategy. Quorum sensing, used by many different bacteria, functions through a cell-to-cell communication mechanism relying on chemical signals, referred to as autoinducers, such as N-acyl homoserine lactones (AHLs) which are the most common chemical signals in this system. Designing analogs of these autoinducers is one of the possible ways to interfere with quorum sensing. Since bioisosteres are powerful tools in medicinal chemistry, targeting analogs of AHLs or other signal molecules and mimics of known QS modulators built on amide bond bioisosteres is a relevant strategy in molecular design and synthetic routes. This review highlights the application of amide bond bioisosteric replacement in the design and synthesis of novel quorum sensing inhibitors.
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Affiliation(s)
- Qiang Zhang
- Hubei Key Laboratory of Purification and Application of Plant Anti-cancer Active Ingredients, Hubei University of Education, 129 Second Gaoxin Road, Wuhan 430205, China
| | - Laurent Soulère
- INSA Lyon, CNRS, Universite Claude Bernard Lyon 1, UMR 5246, ICBMS, Bât. E. Lederer, 1 rue Victor Grignard, F-69622, Villeurbanne, France
| | - Yves Queneau
- INSA Lyon, CNRS, Universite Claude Bernard Lyon 1, UMR 5246, ICBMS, Bât. E. Lederer, 1 rue Victor Grignard, F-69622, Villeurbanne, France.
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2
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Manson DE, Ananiev GE, Guo S, Ericksen SS, Santa EE, Blackwell HE. Abiotic Small Molecule Inhibitors and Activators of the LasR Quorum Sensing Receptor in Pseudomonas aeruginosa with Potencies Comparable or Surpassing N-Acyl Homoserine Lactones. ACS Infect Dis 2024; 10:1212-1221. [PMID: 38506163 PMCID: PMC11014758 DOI: 10.1021/acsinfecdis.3c00593] [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] [Indexed: 03/21/2024]
Abstract
The opportunistic pathogen Pseudomonas aeruginosa controls almost 10% of its genome, including myriad virulence genes, via a cell-to-cell chemical communication system called quorum sensing (QS). Small molecules that either inhibit or activate QS in P. aeruginosa represent useful research tools to study the role of this signaling pathway in infection and interrogate its viability as an antivirulence target. However, despite active research in this area over the past 20+ years, there are relatively few synthetic compounds known to strongly inhibit or activate QS in P. aeruginosa. Most reported QS modulators in this pathogen are of low potency or have structural liabilities that limit their application in biologically relevant environments such as mimics of the native N-acyl l-homoserine lactone (AHL) signals. Here, we report the results of a high-throughput screen for abiotic small molecules that target LasR, a key QS regulator in P. aeruginosa. We screened a 25,000-compound library and discovered four new structural classes of abiotic LasR modulators. These compounds include antagonists that surpass the potency of all known AHL-type compounds and mimetics thereof, along with an agonist with potency approaching that of LasR's native ligand. The novel structures of this compound set, along with their anticipated robust physicochemical profiles, underscore their potential value as probe molecules to interrogate the roles of QS in this formidable pathogen.
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Affiliation(s)
- Daniel E Manson
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
| | - Gene E Ananiev
- Small Molecule Screening Facility, University of Wisconsin Carbone Cancer Center, 600 Highland Ave., Madison, Wisconsin 53792, United States
| | - Song Guo
- Small Molecule Screening Facility, University of Wisconsin Carbone Cancer Center, 600 Highland Ave., Madison, Wisconsin 53792, United States
| | - Spencer S Ericksen
- Small Molecule Screening Facility, University of Wisconsin Carbone Cancer Center, 600 Highland Ave., Madison, Wisconsin 53792, United States
| | - Emma E Santa
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
| | - Helen E Blackwell
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
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3
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Alasiri A, Soltane R, Taha MN, Abd El-Aleam RH, Alshehri F, Sayed AM. Bakuchiol inhibits Pseudomonas aeruginosa's quorum sensing-dependent biofilm formation by selectively inhibiting its transcriptional activator protein LasR. Int J Biol Macromol 2024; 255:128025. [PMID: 37979739 DOI: 10.1016/j.ijbiomac.2023.128025] [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: 08/06/2023] [Revised: 10/26/2023] [Accepted: 11/09/2023] [Indexed: 11/20/2023]
Abstract
In the present study, we characterized Bakuchiol (Bak) as a new potent quorum sensing (QS) inhibitor against Pseudomonas aeruginosa biofilm formation. Upon extensive in vitro investigations, Bak was found to suppress the P. aeruginosa biofilm formation (75.5 % inhibition) and its associated virulence factor e.g., pyocyanin and rhamnolipids (% of inhibition = 71.5 % and 66.9 %, respectively). Upon LuxR-type receptors assay, Bak was found to selectively inhibit P. aeruginosa's LasR in a dose-dependent manner. Further in-depth molecular investigations (e.g., sedimentation velocity and thermal shift assays) revealed that Bak destabilized LasR upon binding and disrupted its functioning quaternary structure (i.e., the functioning dimeric form). The subsequent modeling and molecular dynamics (MD) simulations explained in more molecular detail how Bak interacts with LasR and how it can induce its dimeric form disruption. In conclusion, our study identified Bak as a potent and specific LasR antagonist that should be widely used as a chemical probe of QS in P. aeruginosa, offering new insights into LasR antagonism processes. The new findings shed light on the cryptic world of LuxR-type QS in this important opportunistic pathogen.
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Affiliation(s)
- Ahlam Alasiri
- Department of Biology, Adham University College, Umm Al-Qura University, Makkah 21955, Saudi Arabia.
| | - Raya Soltane
- Department of Biology, Adham University College, Umm Al-Qura University, Makkah 21955, Saudi Arabia.
| | - Mostafa N Taha
- Microbiology and Immunology Department, Faculty of Pharmacy, Nahda University, Beni-Suef, Egypt.
| | - Rehab H Abd El-Aleam
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Modern University for Technology and Information MTI, Cairo 11571, Egypt.
| | - Fatma Alshehri
- Department of Biology, College of Sciences, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia.
| | - Ahmed M Sayed
- Pharmacognosy Department, Faculty of Pharmacy, Nahda University, Beni Suef, Egypt; Department of Pharmacognosy, College of Pharmacy, Almaaqal University, 61014 Basra, Iraq.
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4
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Koh CMM, Ping LSY, Xuan CHH, Theng LB, San HS, Palombo EA, Wezen XC. A data-driven machine learning approach for discovering potent LasR inhibitors. Bioengineered 2023; 14:2243416. [PMID: 37552115 PMCID: PMC10411317 DOI: 10.1080/21655979.2023.2243416] [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: 03/10/2023] [Revised: 07/26/2023] [Accepted: 07/28/2023] [Indexed: 08/09/2023] Open
Abstract
The rampant spread of multidrug-resistant Pseudomonas aeruginosa strains severely threatens global health. This severity is compounded against the backdrop of a stagnating antibiotics development pipeline. Moreover, with many promising therapeutics falling short of expectations in clinical trials, targeting the las quorum sensing (QS) system remains an attractive therapeutic strategy to combat P. aeruginosa infection. Thus, our primary goal was to develop a drug prediction algorithm using machine learning to identify potent LasR inhibitors. In this work, we demonstrated using a Multilayer Perceptron (MLP) algorithm boosted with AdaBoostM1 to discriminate between active and inactive LasR inhibitors. The optimal model performance was evaluated using 5-fold cross-validation and test sets. Our best model achieved a 90.7% accuracy in distinguishing active from inactive LasR inhibitors, an area under the Receiver Operating Characteristic Curve value of 0.95, and a Matthews correlation coefficient value of 0.81 when evaluated using test sets. Subsequently, we deployed the model against the Enamine database. The top-ranked compounds were further evaluated for their target engagement activity using molecular docking studies, Molecular Dynamics simulations, MM-GBSA analysis, and Free Energy Landscape analysis. Our data indicate that several of our chosen top hits showed better ligand-binding affinities than naringenin, a competitive LasR inhibitor. Among the six top hits, five of these compounds were predicted to be LasR inhibitors that could be used to treat P. aeruginosa-associated infections. To our knowledge, this study provides the first assessment of using an MLP-based QSAR model for discovering potent LasR inhibitors to attenuate P. aeruginosa infections.
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Affiliation(s)
- Christabel Ming Ming Koh
- Faculty of Engineering, Computing, and Science, Swinburne University of Technology, Sarawak, Malaysia
| | - Lilian Siaw Yung Ping
- Faculty of Engineering, Computing, and Science, Swinburne University of Technology, Sarawak, Malaysia
| | - Christopher Ha Heng Xuan
- Faculty of Engineering, Computing, and Science, Swinburne University of Technology, Sarawak, Malaysia
| | - Lau Bee Theng
- Faculty of Engineering, Computing, and Science, Swinburne University of Technology, Sarawak, Malaysia
| | - Hwang Siaw San
- Faculty of Engineering, Computing, and Science, Swinburne University of Technology, Sarawak, Malaysia
| | - Enzo A. Palombo
- Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn, Victoria, Australia
| | - Xavier Chee Wezen
- Faculty of Engineering, Computing, and Science, Swinburne University of Technology, Sarawak, Malaysia
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5
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Hibbert TM, Whiteley M, Renshaw SA, Neill DR, Fothergill JL. Emerging strategies to target virulence in Pseudomonas aeruginosa respiratory infections. Crit Rev Microbiol 2023:1-16. [PMID: 37999716 DOI: 10.1080/1040841x.2023.2285995] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 11/08/2023] [Indexed: 11/25/2023]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that is responsible for infections in people living with chronic respiratory conditions, such as cystic fibrosis (CF) and non-CF bronchiectasis (NCFB). Traditionally, in people with chronic respiratory disorders, P. aeruginosa infection has been managed with a combination of inhaled and intravenous antibiotic therapies. However, due in part to the prolonged use of antibiotics in these people, the emergence of multi-drug resistant P. aeruginosa strains is a growing concern. The development of anti-virulence therapeutics may provide a new means of treating P. aeruginosa lung infections whilst also combatting the AMR crisis, as these agents are presumed to exert reduced pressure for the emergence of drug resistance as compared to antibiotics. However, the pipeline for developing anti-virulence therapeutics is poorly defined, and it is currently unclear as to whether in vivo and in vitro models effectively replicate the complex pulmonary environment sufficiently to enable development and testing of such therapies for future clinical use. Here, we discuss potential targets for P. aeruginosa anti-virulence therapeutics and the effectiveness of the current models used to study them. Focus is given to the difficulty of replicating the virulence gene expression patterns of P. aeruginosa in the CF and NCFB lung under laboratory conditions and to the challenges this poses for anti-virulence therapeutic development.
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Affiliation(s)
- Tegan M Hibbert
- Department of Clinical Infection, Microbiology and Immunology, University of Liverpool, Liverpool, UK
| | - Marvin Whiteley
- School of Biological Sciences, Georgia Institute of Technology, Centre for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Stephen A Renshaw
- The Bateson Centre and Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Sheffield, UK
| | - Daniel R Neill
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Joanne L Fothergill
- Department of Clinical Infection, Microbiology and Immunology, University of Liverpool, Liverpool, UK
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Soltane R, Alasiri A, Taha MN, Abd El-Aleam RH, Alghamdi KS, Ghareeb MA, Keshek DEG, Cardoso SM, Sayed AM. Norlobaridone Inhibits Quorum Sensing-Dependent Biofilm Formation and Some Virulence Factors in Pseudomonas aeruginosa by Disrupting Its Transcriptional Activator Protein LasR Dimerization. Biomolecules 2023; 13:1573. [PMID: 38002255 PMCID: PMC10669572 DOI: 10.3390/biom13111573] [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: 09/20/2023] [Revised: 10/11/2023] [Accepted: 10/12/2023] [Indexed: 11/26/2023] Open
Abstract
In the present study, norlobaridone (NBD) was isolated from Parmotrema and then evaluated as a new potent quorum sensing (QS) inhibitor against Pseudomonas aeruginosa biofilm development. This phenolic natural product was found to reduce P. aeruginosa biofilm formation (64.6% inhibition) and its related virulence factors, such as pyocyanin and rhamnolipids (% inhibition = 61.1% and 55%, respectively). In vitro assays inhibitory effects against a number of known LuxR-type receptors revealed that NBD was able to specifically block P. aeruginosa's LasR in a dose-dependent manner. Further molecular studies (e.g., sedimentation velocity and thermal shift assays) demonstrated that NBD destabilized LasR upon binding and damaged its functional quaternary structure (i.e., the functional dimeric form). The use of modelling and molecular dynamics (MD) simulations also allowed us to further understand its interaction with LasR, and how this can disrupt its dimeric form. Finally, our findings show that NBD is a powerful and specific LasR antagonist that should be widely employed as a chemical probe in QS of P. aeruginosa, providing new insights into LasR antagonism processes. The new discoveries shed light on the mysterious world of LuxR-type QS in this key opportunistic pathogen.
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Affiliation(s)
- Raya Soltane
- Department of Basic Sciences, Adham University College, Umm Al-Qura University, Makkah 21955, Saudi Arabia;
| | - Ahlam Alasiri
- Department of Basic Sciences, Adham University College, Umm Al-Qura University, Makkah 21955, Saudi Arabia;
| | - Mostafa N. Taha
- Microbiology and Immunology Department, Faculty of Pharmacy, Nahda University, Beni-Suef 62764, Egypt;
| | - Rehab H. Abd El-Aleam
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Modern University for Technology and Information (MTI), Cairo 11571, Egypt;
| | - Kawthar Saad Alghamdi
- Department of Biology, College of Science, University of Hafr Al Batin, Hafar Al Batin 39511, Saudi Arabia;
| | - Mosad A. Ghareeb
- Medicinal Chemistry Department, Theodor Bilharz Research Institute Kornaish El Nile, Warrak El-Hadar, Imbaba, P.O. Box 30, Giza 12411, Egypt;
| | - Doaa El-Ghareeb Keshek
- Department of Biology, Jumum College University, Umm Al-Qura University, Makkah 21955, Saudi Arabia;
- Agriculture Genetic Engineering Research Institute (AGERI), Agriculture Research Center, Giza 11571, Egypt
| | - Susana M. Cardoso
- LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal;
| | - Ahmed M. Sayed
- Pharmacognosy Department, Faculty of Pharmacy, Nahda University, Beni-Suef 62513, Egypt
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7
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Identification of 3-nitrophenol ester derivatives as novel quorum-sensing inhibitors of Pseudomonas aeruginosa. J Mol Struct 2023. [DOI: 10.1016/j.molstruc.2022.134284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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8
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Gajera G, Henriksen N, Cox B, Kothari V. Identification of anti-pathogenic activity among in silico predicted small-molecule inhibitors of Pseudomonas aeruginosa LasR or nitric oxide reductase (NOR). Drug Target Insights 2023; 17:101-109. [PMID: 37811195 PMCID: PMC10551673 DOI: 10.33393/dti.2023.2638] [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: 07/20/2023] [Accepted: 09/04/2023] [Indexed: 10/10/2023] Open
Abstract
Introduction Antibiotic-resistant Pseudomonas aeruginosa strains cause considerable morbidity and mortality globally. Identification of novel targets in this notorious pathogen is urgently warranted to facilitate discovery of new anti-pathogenic agents against it. This study attempted to identify small-molecule inhibitors of two important proteins LasR and nitric oxide reductase (NOR) in P. aeruginosa. 'Las' system can be said to be the 'master' regulator of quorum sensing in P. aeruginosa, whose receptor protein is LasR. Similarly, NOR is crucial to detoxification of reactive nitrogen species. Methods In silico identification of potential LasR or NOR inhibitors was attempted through a virtual screening platform AtomNet® to obtain a final subset of <100 top scoring compounds. These compounds were evaluated for their in vivo anti-pathogenic activity by challenging the model host Caenorhabditis elegans with P. aeruginosa in the presence or absence of test compounds. Survival of the worm population in 24-well assay plates was monitored over a period of 5 days microscopically. Results Of the 96 predicted LasR inhibitors, 11 exhibited anti-Pseudomonas activity (23%-96% inhibition of bacterial virulence as per third-day end-point) at 25-50 µg/mL. Of the 85 predicted NOR inhibitors, 8 exhibited anti-Pseudomonas activity (40%-85% inhibition of bacterial virulence as per second-day end-point) at 25-50 µg/mL. Conclusion Further investigation on molecular mode of action of compounds found active in this study is warranted. Virtual screening can be said to be a useful tool in narrowing down the list of compounds requiring actual wet-lab screening, saving considerable time and efforts for drug discovery.
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Affiliation(s)
- Gemini Gajera
- Institute of Science, Nirma University, Ahmedabad - India
| | | | - Bryan Cox
- Atomwise Inc, San Francisco, CA - USA
| | - Vijay Kothari
- Institute of Science, Nirma University, Ahmedabad - India
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Yin R, Cheng J, Wang J, Li P, Lin J. Treatment of Pseudomonas aeruginosa infectious biofilms: Challenges and strategies. Front Microbiol 2022; 13:955286. [PMID: 36090087 PMCID: PMC9459144 DOI: 10.3389/fmicb.2022.955286] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 08/09/2022] [Indexed: 01/10/2023] Open
Abstract
Pseudomonas aeruginosa, a Gram-negative bacterium, is one of the major pathogens implicated in human opportunistic infection and a common cause of clinically persistent infections such as cystic fibrosis, urinary tract infections, and burn infections. The main reason for the persistence of P. aeruginosa infections is due to the ability of P. aeruginosa to secrete extracellular polymeric substances such as exopolysaccharides, matrix proteins, and extracellular DNA during invasion. These substances adhere to and wrap around bacterial cells to form a biofilm. Biofilm formation leads to multiple antibiotic resistance in P. aeruginosa, posing a significant challenge to conventional single antibiotic therapeutic approaches. It has therefore become particularly important to develop anti-biofilm drugs. In recent years, a number of new alternative drugs have been developed to treat P. aeruginosa infectious biofilms, including antimicrobial peptides, quorum-sensing inhibitors, bacteriophage therapy, and antimicrobial photodynamic therapy. This article briefly introduces the process and regulation of P. aeruginosa biofilm formation and reviews several developed anti-biofilm treatment technologies to provide new directions for the treatment of P. aeruginosa biofilm infection.
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The Molecular Architecture of Pseudomonas aeruginosa Quorum-Sensing Inhibitors. Mar Drugs 2022; 20:md20080488. [PMID: 36005489 PMCID: PMC9409833 DOI: 10.3390/md20080488] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 07/24/2022] [Accepted: 07/25/2022] [Indexed: 02/04/2023] Open
Abstract
The survival selection pressure caused by antibiotic-mediated bactericidal and bacteriostatic activity is one of the important inducements for bacteria to develop drug resistance. Bacteria gain drug resistance through spontaneous mutation so as to achieve the goals of survival and reproduction. Quorum sensing (QS) is an intercellular communication system based on cell density that can regulate bacterial virulence and biofilm formation. The secretion of more than 30 virulence factors of P. aeruginosa is controlled by QS, and the formation and diffusion of biofilm is an important mechanism causing the multidrug resistance of P. aeruginosa, which is also closely related to the QS system. There are three main QS systems in P. aeruginosa: las system, rhl system, and pqs system. Quorum-sensing inhibitors (QSIs) can reduce the toxicity of bacteria without affecting the growth and enhance the sensitivity of bacterial biofilms to antibiotic treatment. These characteristics make QSIs a popular topic for research and development in the field of anti-infection. This paper reviews the research progress of the P. aeruginosa quorum-sensing system and QSIs, targeting three QS systems, which will provide help for the future research and development of novel quorum-sensing inhibitors.
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Acetylation of CspC Controls the Las Quorum-Sensing System through Translational Regulation of rsaL in Pseudomonas aeruginosa. mBio 2022; 13:e0054722. [PMID: 35467416 PMCID: PMC9239060 DOI: 10.1128/mbio.00547-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa is a ubiquitous pathogenic bacterium that can adapt to a variety environments. The ability to effectively sense and respond to host local nutrients is critical for the infection of P. aeruginosa. However, the mechanisms employed by the bacterium to respond to nutrients remain to be explored. CspA family proteins are RNA binding proteins that are involved in gene regulation. We previously demonstrated that the P. aeruginosa CspA family protein CspC regulates the type III secretion system in response to temperature shift. In this study, we found that CspC regulates the quorum-sensing (QS) systems by repressing the translation of a QS negative regulatory gene, rsaL. Through RNA immunoprecipitation coupled with real-time quantitative reverse transcription-PCR (RIP-qRT-PCR) and electrophoretic mobility shift assays (EMSAs), we found that CspC binds to the 5′ untranslated region of the rsaL mRNA. Unlike glucose, itaconate (a metabolite generated by macrophages during infection) reduces the acetylation of CspC, which increases the affinity between CspC and the rsaL mRNA, leading to upregulation of the QS systems. Our results revealed a novel regulatory mechanism of the QS systems in response to a host-generated metabolite.
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Vetrivel A, Ramasamy J, Natchimuthu S, Senthil K, Ramasamy M, Murugesan R. Combined machine learning and pharmacophore based virtual screening approaches to screen for antibiofilm inhibitors targeting LasR of Pseudomonas aeruginosa. J Biomol Struct Dyn 2022; 41:4124-4142. [PMID: 35451916 DOI: 10.1080/07391102.2022.2064331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Pseudomonas aeruginosa, a virulent pathogen affects patients with cystic fibrosis and nosocomial infections. Quorum sensing (QS) mechanism plays a crucial role in causing these ailments by mediating biofilm formation and expressing virulent genes. A novel approach to circumvent this bacterial infection is by hindering its QS network. Targeting LasR of las system serves beneficial as it holds the top position in QS system cascade. Here, we have integrated machine learning, pharmacophore based virtual screening, molecular docking and simulation studies to look for new leads as inhibitors for LasR. Support vector machine (SVM) learning algorithm was used to generate QSAR models from 66 antagonist dataset. The top three models resulted in correlation coefficient (R2) values of 0.67, 0.86, and 0.91, respectively. The correlation coefficient (R2test) values on external test set were found to be 0.62, 0.57, and 0.55, respectively. A four-point pharmacophore model was developed. The pharmacophore hypothesis AAAD_1 was used to screen for potential leads against MolPort database in ZincPharmer. The leads which showed predicted pIC50 value of >8.00 by SVM models were subjected to docking analysis that reranked the compounds based on docking scores. Four top leads namely ZINC3851967 N-[3,5-bis(trifluoromethyl)phenyl]-5-tert-butyl-6-chloropyrazine-2-carboxamide, ZINC4024175 4-Amino-1-[(2R,3S,4S,5S)-3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl]-2-oxopyrimidine-5-carbonitrile, ZINC2125703 N-[(5-Methoxy-4,7-dimethyl-2-oxo-2H-chromen-3-yl)acetyl]-beta-alanine, and ZINC3851966 N-[3,5-Bis(trifluoromethyl)phenyl]5-tert-butylpyrazine-2-carboxamide were selected. These compounds were checked for its stability by performing a molecular dynamics simulation for a period of 100 ns. The ADME properties of the leads were also determined. Hence, the compounds identified in this study can be used as possible leads for developing a novel inhibitor for LasR.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Aishwarya Vetrivel
- Department of Biochemistry, Biotechnology and Bioinformatics, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore, Tamil Nadu, India
| | - Janani Ramasamy
- Department of Biochemistry, Biotechnology and Bioinformatics, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore, Tamil Nadu, India
| | - Santhi Natchimuthu
- Department of Biochemistry, Biotechnology and Bioinformatics, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore, Tamil Nadu, India
| | - Kalaiselvi Senthil
- Department of Biochemistry, Biotechnology and Bioinformatics, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore, Tamil Nadu, India
| | - Monica Ramasamy
- Department of Biochemistry, Biotechnology and Bioinformatics, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore, Tamil Nadu, India
| | - Rajeswari Murugesan
- Department of Biochemistry, Biotechnology and Bioinformatics, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore, Tamil Nadu, India
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Sulforaphane and Its Bifunctional Analogs: Synthesis and Biological Activity. Molecules 2022; 27:molecules27051750. [PMID: 35268851 PMCID: PMC8911885 DOI: 10.3390/molecules27051750] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/04/2022] [Accepted: 03/05/2022] [Indexed: 12/27/2022] Open
Abstract
For decades, various plants have been studied as sources of biologically active compounds. Compounds with anticancer and antimicrobial properties are the most frequently desired. Cruciferous plants, including Brussels sprouts, broccoli, and wasabi, have a special role in the research studies. Studies have shown that consumption of these plants reduce the risk of lung, breast, and prostate cancers. The high chemopreventive and anticancer potential of cruciferous plants results from the presence of a large amount of glucosinolates, which, under the influence of myrosinase, undergo an enzymatic transformation to biologically active isothiocyanates (ITCs). Natural isothiocyanates, such as benzyl isothiocyanate, phenethyl isothiocyanate, or the best-tested sulforaphane, possess anticancer activity at all stages of the carcinogenesis process, show antibacterial activity, and are used in organic synthesis. Methods of synthesis of sulforaphane, as well as its natural or synthetic bifunctional analogues with sulfinyl, sulfanyl, sulfonyl, phosphonate, phosphinate, phosphine oxide, carbonyl, ester, carboxamide, ether, or additional isothiocyanate functional groups, and with the unbranched alkyl chain containing 2-6 carbon atoms, are discussed in this review. The biological activity of these compounds are also reported. In the first section, glucosinolates, isothiocyanates, and mercapturic acids (their metabolites) are briefly characterized. Additionally, the most studied anticancer and antibacterial mechanisms of ITC actions are discussed.
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Bhukta S, Samal SK, Vasudevan S, Sarveswari HB, Shanmugam K, Princy SA, Dandela R. A Prospective Diversity of Antibacterial Small Peptidomimetic and Quorum Sensing Mediated Drug: A Review. ChemistrySelect 2022. [DOI: 10.1002/slct.202102743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Swadhapriya Bhukta
- Institute of Chemical Technology-Indian Oil Odisha Campus Department of Industrial and Engineering Chemistry Bhubaneswar 751013 Odisha India
| | - Sangram Keshari Samal
- Laboratory of Biomaterials and Regenerative Medicine for Advanced Therapies Indian Council of Medical Research-Regional Medical Research Center Bhubaneswar 751013 Odisha India
| | - Sahana Vasudevan
- Quorum Sensing Laboratory Centre for Research in Infectious Diseases (CRID) School of Chemical and Biotechnology SASTRA University Thanjavur 613401 Tamil Nadu India
| | - Hema Bhagavathi Sarveswari
- Quorum Sensing Laboratory Centre for Research in Infectious Diseases (CRID) School of Chemical and Biotechnology SASTRA University Thanjavur 613401 Tamil Nadu India
| | - Karthi Shanmugam
- Quorum Sensing Laboratory Centre for Research in Infectious Diseases (CRID) School of Chemical and Biotechnology SASTRA University Thanjavur 613401 Tamil Nadu India
| | - S. Adline Princy
- Quorum Sensing Laboratory Centre for Research in Infectious Diseases (CRID) School of Chemical and Biotechnology SASTRA University Thanjavur 613401 Tamil Nadu India
| | - Rambabu Dandela
- Institute of Chemical Technology-Indian Oil Odisha Campus Department of Industrial and Engineering Chemistry Bhubaneswar 751013 Odisha India
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15
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Recent Advance in Small Molecules Targeting RhlR of Pseudomonas aeruginosa. Antibiotics (Basel) 2022; 11:antibiotics11020274. [PMID: 35203876 PMCID: PMC8868144 DOI: 10.3390/antibiotics11020274] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 12/02/2022] Open
Abstract
Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic gram-negative pathogen that can cause various infections, particularly in patients with compromised host defenses. P. aeruginosa forms biofilms and produces virulence factors through quorum sensing (QS) network, resulting in resistance to antibiotics. RhlI/RhlR, one of key QS systems in P. aeruginosa, is considered an attractive target for inhibiting biofilm formation and attenuating virulence factors. Several recent studies examined small molecules targeting the RhlI/RhlR system and their in vitro and in vivo biological activities. In this review, RhlR-targeted modulators, including agonists and antagonists, are discussed with particular focus on structure-activity relationship studies and outlook for next-generation anti-biofilm agents.
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16
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Aflakian F, Rad M, Hashemitabar G, Lagzian M, Ramezani M. Design and assessment of novel synthetic peptides to inhibit quorum sensing-dependent biofilm formation in Pseudomonas aeruginosa. BIOFOULING 2022; 38:131-146. [PMID: 35067121 DOI: 10.1080/08927014.2022.2028280] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 01/01/2022] [Accepted: 01/07/2022] [Indexed: 06/14/2023]
Abstract
Pseudomonas aeruginosa is one of the most common biofilm-producing bacteria, often leading to long-term and chronic infections. The LasR regulator protein acts as the central regulator of the quorum sensing (QS) system and coordinates the expression of some virulence and biofilm genes. In this study, novel peptides (WSF, FASK, YDVD) were designed for binding to the domain of the transcriptional activator of the LasR protein and interfere with LasR in the QS system of P. aeruginosa. The effects of these peptides on biofilm production, expression of biofilm-related genes (AlgC, PslA, PelA), and growth of planktonic P. aeruginosa were investigated. All three peptides inhibited the growth of P. aeruginosa planktonic cells at 1600 µg ml-1 and exhibited anti-biofilm effects at sub-inhibitory concentrations (800 µg ml-1). Measurements of the mRNA levels of biofilm-related genes at sub-inhibitory concentrations of the designed peptides showed a significant decrease.
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Affiliation(s)
- Fatemeh Aflakian
- Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Mehrnaz Rad
- Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Gholamreza Hashemitabar
- Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Milad Lagzian
- Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran
| | - Mohammad Ramezani
- Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
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17
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Miranda SW, Asfahl KL, Dandekar AA, Greenberg EP. Pseudomonas aeruginosa Quorum Sensing. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1386:95-115. [PMID: 36258070 PMCID: PMC9942581 DOI: 10.1007/978-3-031-08491-1_4] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Pseudomonas aeruginosa, like many bacteria, uses chemical signals to communicate between cells in a process called quorum sensing (QS). QS allows groups of bacteria to sense population density and, in response to changing cell densities, to coordinate behaviors. The P. aeruginosa QS system consists of two complete circuits that involve acyl-homoserine lactone signals and a third system that uses quinolone signals. Together, these three QS circuits regulate the expression of hundreds of genes, many of which code for virulence factors. P. aeruginosa has become a model for studying the molecular biology of QS and the ecology and evolution of group behaviors in bacteria. In this chapter, we recount the history of discovery of QS systems in P. aeruginosa, discuss how QS relates to virulence and the ecology of this bacterium, and explore strategies to inhibit QS. Finally, we discuss future directions for research in P. aeruginosa QS.
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Affiliation(s)
| | - Kyle L Asfahl
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA, USA
| | - Ajai A Dandekar
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA, USA
- Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
| | - E P Greenberg
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA, USA.
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18
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Chadha J, Harjai K, Chhibber S. Revisiting the virulence hallmarks of Pseudomonas aeruginosa: a chronicle through the perspective of quorum sensing. Environ Microbiol 2021; 24:2630-2656. [PMID: 34559444 DOI: 10.1111/1462-2920.15784] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 09/16/2021] [Accepted: 09/17/2021] [Indexed: 12/15/2022]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen and the leading cause of mortality among immunocompromised patients in clinical setups. The hallmarks of virulence in P. aeruginosa encompass six biologically competent attributes that cumulatively drive disease progression in a multistep manner. These multifaceted hallmarks lay the principal foundation for rationalizing the complexities of pseudomonal infections. They include factors for host colonization and bacterial motility, biofilm formation, production of destructive enzymes, toxic secondary metabolites, iron-chelating siderophores and toxins. This arsenal of virulence hallmarks is fostered and stringently regulated by the bacterial signalling system called quorum sensing (QS). The central regulatory functions of QS in controlling the timely expression of these virulence hallmarks for adaptation and survival drive the disease outcome. This review describes the intricate mechanisms of QS in P. aeruginosa and its role in shaping bacterial responses, boosting bacterial fitness. We summarize the virulence hallmarks of P. aeruginosa, relating them with the QS circuitry in clinical infections. We also examine the role of QS in the development of drug resistance and propose a novel antivirulence therapy to combat P. aeruginosa infections. This can prove to be a next-generation therapy that may eventually become refractory to the use of conventional antimicrobial treatments.
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Affiliation(s)
- Jatin Chadha
- Department of Microbiology, Panjab University, Chandigarh, India
| | - Kusum Harjai
- Department of Microbiology, Panjab University, Chandigarh, India
| | - Sanjay Chhibber
- Department of Microbiology, Panjab University, Chandigarh, India
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19
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Vetrivel A, Natchimuthu S, Subramanian V, Murugesan R. High-Throughput Virtual Screening for a New Class of Antagonist Targeting LasR of Pseudomonas aeruginosa. ACS OMEGA 2021; 6:18314-18324. [PMID: 34308062 PMCID: PMC8296597 DOI: 10.1021/acsomega.1c02191] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 06/16/2021] [Indexed: 05/28/2023]
Abstract
Pseudomonas aeruginosa, an opportunistic human pathogen, causes fatal effects in patients with cystic fibrosis and immunocompromised individuals and leads to around 1000 deaths annually. The quorum sensing mechanism of P. aeruginosa plays a major role in promoting biofilm formation and expression of virulent genes. Hence, quorum sensing inhibition is a promising novel approach to treat these bacterial infections as these organisms show a wide range of antibiotic resistance. Among the interconnected quorum sensing network of P. aeruginosa, targeting the las system is of increased interest as its principal receptor protein LasR is the earliest activated gene. It is also shown to be involved in the regulation of other virulence-associated genes. In this study, we have applied high-throughput virtual screening, an in silico computational method to identify a new class of LasR inhibitors that could serve as potent antagonists to treat P. aeruginosa-associated infections. Three-tire structure-based virtual screening was performed on the Schrödinger small molecule database, which resulted in 12 top hit compounds with docking scores lesser than -11.0 kcal/mol. Three of these best-scored compounds CACPD2011a-0001928786 (C1), CACPD2011a-0001927437 (C2), and CACPD2011a-0000896051 (C3) were further analyzed. The binding free energies of these compounds in complex with the target protein LasR (3IX4) were evaluated, and the pharmacokinetic properties were determined. The stability of the docked complexes was assessed by running a molecular dynamics simulation for 100 ns. Molecular dynamics simulation analysis revealed that all three compounds were found to be in stable contact with the protein over the entire simulation period. The antagonistic effect of these compounds was validated using the LasR reporter gene assay in the presence of acyl homoserine lactone. Significant reduction in the β-galactosidase enzyme activity was achieved at 100 nM concentration for all three compounds pursued. Hence, the present study provides strong evidence that these three compounds could serve as quorum sensing inhibitors of P. aeruginosa LasR protein and can be a probable candidate to treat Pseudomonas-associated infections.
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Affiliation(s)
- Aishwarya Vetrivel
- Department
of Biochemistry, Biotechnology and Bioinformatics, Avinashilingam Institute for Home Science and Higher Education for
Women, Coimbatore 641043, Tamil Nadu, India
| | - Santhi Natchimuthu
- Department
of Biochemistry, Biotechnology and Bioinformatics, Avinashilingam Institute for Home Science and Higher Education for
Women, Coimbatore 641043, Tamil Nadu, India
| | | | - Rajeswari Murugesan
- Department
of Biochemistry, Biotechnology and Bioinformatics, Avinashilingam Institute for Home Science and Higher Education for
Women, Coimbatore 641043, Tamil Nadu, India
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20
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Hitchner MA, Necelis MR, Shirley D, Caputo GA. Effect of Non-natural Hydrophobic Amino Acids on the Efficacy and Properties of the Antimicrobial Peptide C18G. Probiotics Antimicrob Proteins 2021; 13:527-541. [PMID: 32889698 PMCID: PMC7933317 DOI: 10.1007/s12602-020-09701-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Antimicrobial peptides (AMPs) have been an area of great interest, due to the high selectivity of these molecules toward bacterial targets over host cells and the limited development of bacterial resistance to these molecules through evolution. The peptides are known to selectively bind to bacterial cell surfaces through electrostatic interactions, and subsequently, the peptides insert into the cell membrane and cause local disruptions of membrane integrity leading to cell death. Previous experiments showed that replacing the Leu residues in the AMP C18G with other naturally occurring hydrophobic residues resulted in side-chain-dependent activities. This work extends the investigation to non-natural hydrophobic amino acids and the effect on peptide activity. Minimal inhibitory concentration (MIC) results demonstrated that amino acid substitutions containing long flexible carbon chains maintained or increased antimicrobial activity compared to natural analogues. In solution, the peptide showed aggregation only with the most hydrophobic non-natural amino acid substitutions. Binding assays using Trp fluorescence confirm a binding preference for anionic lipids while quenching experiments demonstrated that the more hydrophobic peptides are more deeply buried in the anionic lipid bilayers compared to the zwitterionic bilayers. The most effective peptides at killing bacteria were also those which showed some level of disruption of bacterial membranes; however, one peptide sequence exhibited very strong activity and very low levels of red blood cell hemolysis, yielding a promising target for future development.
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Affiliation(s)
- Morgan A Hitchner
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ, 08028, USA
| | - Matthew R Necelis
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ, 08028, USA
| | - Devanie Shirley
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ, 08028, USA
| | - Gregory A Caputo
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ, 08028, USA.
- Department of Molecular and Cellular Biosciences, Rowan University, 201 Mullica Hill Road, Glassboro, NJ, 08028, USA.
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21
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The Rhl Quorum-Sensing System Is at the Top of the Regulatory Hierarchy under Phosphate-Limiting Conditions in Pseudomonas aeruginosa PAO1. J Bacteriol 2021; 203:JB.00475-20. [PMID: 33288622 DOI: 10.1128/jb.00475-20] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 12/02/2020] [Indexed: 12/13/2022] Open
Abstract
Pseudomonas aeruginosa is a major nosocomial pathogen that presents high-level resistance to antibiotics. Its ability to cause infections relies on the production of multiple virulence factors. Quorum sensing (QS) regulates the expression of many of these virulence factors through three QS systems: Las, Rhl, and PQS. The Las system positively regulates the other two systems, so it is at the top of a hierarchized regulation. Nevertheless, clinical and environmental strains that lack a functional Las system have been isolated, and, surprisingly, some of them still have the ability to produce virulence factors and infect animal models, so it has been suggested that the hierarchy is flexible under some conditions or with atypical strains. Here, we analyze the PAO1 type strain and its ΔlasR-derived mutant and report, for the first time, a growth condition (phosphate limitation) where LasR absence has no effect either on virulence factor production or on the gene expression profile, in contrast to a condition of phosphate repletion where the LasR hierarchy is maintained. This work provides evidence on how the QS hierarchy can change from being a strictly LasR-dependent to a LasR-independent RhlR-based hierarchy under phosphate limitation even in the PAO1 type strain.IMPORTANCE Pseudomonas aeruginosa is an important pathogen, considered a priority for the development of new therapeutic strategies. An important approach to fight its infections relies on blocking quorum sensing. The Las system is the main regulator of the quorum-sensing response, so many research efforts aim to block this system to suppress the entire response. In this work, we show that LasR is dispensable in a phosphate-limited environment in the PAO1 type strain, which has been used to define the quorum-sensing response hierarchy, and that under this condition RhlR is at the top of the regulation hierarchy. These results are highly significant, since phosphate limitation represents a similar environment to the one that P. aeruginosa faces when establishing infections.
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22
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Sun H, Pulakat L, Anderson DW. Challenges and New Therapeutic Approaches in the Management of Chronic Wounds. Curr Drug Targets 2020; 21:1264-1275. [PMID: 32576127 DOI: 10.2174/1389450121666200623131200] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 05/10/2020] [Accepted: 05/20/2020] [Indexed: 02/07/2023]
Abstract
Chronic non-healing wounds are estimated to cost the US healthcare $28-$31 billion per year. Diabetic ulcers, arterial and venous ulcers, and pressure ulcers are some of the most common types of chronic wounds. The burden of chronic wounds continues to rise due to the current epidemic of obesity and diabetes and the increase in elderly adults in the population who are more vulnerable to chronic wounds than younger individuals. This patient population is also highly vulnerable to debilitating infections caused by opportunistic and multi-drug resistant pathogens. Reduced microcirculation, decreased availability of cytokines and growth factors that promote wound closure and healing, and infections by multi-drug resistant and biofilm forming microbes are some of the critical factors that contribute to the development of chronic non-healing wounds. This review discusses novel approaches to understand chronic wound pathology and methods to improve chronic wound care, particularly when chronic wounds are infected by multi-drug resistant, biofilm forming microbes.
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Affiliation(s)
- Hongmin Sun
- Division of Cardiovascular Medicine, Department of Medicine, University of Missouri, Columbia, Missouri 65212, United States
| | - Lakshmi Pulakat
- Division of Cardiovascular Medicine, Department of Medicine, University of Missouri, Columbia, Missouri 65212, United States
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23
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Shao X, Xie Y, Zhang Y, Liu J, Ding Y, Wu M, Wang X, Deng X. Novel therapeutic strategies for treating Pseudomonas aeruginosa infection. Expert Opin Drug Discov 2020; 15:1403-1423. [PMID: 32880507 DOI: 10.1080/17460441.2020.1803274] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Persistent infections caused by the superbug Pseudomonas aeruginosa and its resistance to multiple antimicrobial agents are huge threats to patients with cystic fibrosis as well as those with compromised immune systems. Multidrug-resistant P. aeruginosa has posed a major challenge to conventional antibiotics and therapeutic approaches, which show limited efficacy and cause serious side effects. The public demand for new antibiotics is enormous; yet, drug development pipelines have started to run dry with limited targets available for inventing new antibacterial drugs. Consequently, it is important to uncover potential therapeutic targets. AREAS COVERED The authors review the current state of drug development strategies that are promising in terms of the development of novel and potent drugs to treat P. aeruginosa infection. EXPERT OPINION The prevention of P. aeruginosa infection is increasingly challenging. Furthermore, targeting key virulence regulators has great potential for developing novel anti-P. aeruginosa drugs. Additional promising strategies include bacteriophage therapy, immunotherapies, and antimicrobial peptides. Additionally, the authors believe that in the coming years, the overall network of molecular regulatory mechanism of P. aeruginosa virulence will be fully elucidated, which will provide more novel and promising drug targets for treating P. aeruginosa infections.
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Affiliation(s)
- Xiaolong Shao
- Department of Biomedical Sciences, City University of Hong Kong , Hong Kong SAR, China
| | - Yingpeng Xie
- Department of Biomedical Sciences, City University of Hong Kong , Hong Kong SAR, China
| | - Yingchao Zhang
- Department of Biomedical Sciences, City University of Hong Kong , Hong Kong SAR, China
| | - Jingui Liu
- Department of Biomedical Sciences, City University of Hong Kong , Hong Kong SAR, China
| | - Yiqing Ding
- Department of Biomedical Sciences, City University of Hong Kong , Hong Kong SAR, China
| | - Min Wu
- Department of Biomedical Sciences, University of North Dakota , Grand Forks, North Dakota, USA
| | - Xin Wang
- Department of Biomedical Sciences, City University of Hong Kong , Hong Kong SAR, China
| | - Xin Deng
- Department of Biomedical Sciences, City University of Hong Kong , Hong Kong SAR, China.,Shenzhen Research Institute, City University of Hong Kong , Shenzhen, China
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24
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Virtual Screening of FDA-Approved Drugs against LasR of Pseudomonas aeruginosa for Antibiofilm Potential. Molecules 2020; 25:molecules25163723. [PMID: 32824118 PMCID: PMC7466078 DOI: 10.3390/molecules25163723] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 06/29/2020] [Accepted: 06/30/2020] [Indexed: 12/12/2022] Open
Abstract
Pseudomonas aeruginosa is a Gram-negative pathogenic bacterium that is present commonly in soil and water and is responsible for causing septic shock, pneumonia, urinary tract and gastrointestinal infections, etc. The multi-drug resistance (MDR) phenomenon has increased dramatically in past years and is now considered a major threat globally, so there is an urgent need to develop new strategies to overcome drug resistance by P. aeruginosa. In P. aeruginosa, a major factor of drug resistance is associated to the formation of biofilms by the LasR enzyme, which regulates quorum sensing and has been reported as a new therapeutic target for designing novel antibacterial molecules. In this study, virtual screening and molecular docking were performed against the ligand binding domain (LBD) of LasR by employing a pharmacophore hypothesis for the screening of 2373 FDA-approved compounds to filter top-scoring hit compounds. Six inhibitors out of 2373 compounds were found to have binding affinities close to that of known LasR inhibitors. The binding modes of these compounds to the binding site in LasR-LBD were analyzed to identify the key interactions that contribute to the inhibition of LasR activity. Then, 50 ns simulations of top hit compounds were performed to elucidate the stability of their binding conformations with the LasR-LBD. This study, thus concluded that sulfamerazine showed the highest binding affinity for the LasR-LBD binding pocket exhibiting strong inhibitory binding interactions during molecular dynamics (MD) simulation.
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25
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Inhibitory effects of novel 1,4-disubstituted 1,2,3-triazole compounds on quorum-sensing of P. aeruginosa PAO1. Eur J Clin Microbiol Infect Dis 2020; 40:373-379. [PMID: 32767176 DOI: 10.1007/s10096-020-03998-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/27/2020] [Indexed: 01/29/2023]
Abstract
Quorum sensing (QS) inhibition is an essential strategy to combat bacterial infection. Previously, we have synthesized a series of thymidine derivatives bearing isoxazole and 1,2,3-triazole rings (TITL). Herein, the inhibitory effects of TITL on QS of Pseudomonas aeruginosa PAO1 were evaluated. In vitro results demonstrated that TITL effectively inhibited biofilm formation and reduced the virulence factors of P. aeruginosa PAO1. In combination with antibiotics, our TITL compounds significantly prolonged the lifespans of Caenorhabditis elegans N2 nematodes that were infected with P. aeruginosa PAO1 in vivo. In conclusion, TITL compounds are promising candidates for the treatment of antibiotic-resistant P. aeruginosa PAO1.
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26
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Nam S, Ham SY, Kwon H, Kim HS, Moon S, Lee JH, Lim T, Son SH, Park HD, Byun Y. Discovery and Characterization of Pure RhlR Antagonists against Pseudomonas aeruginosa Infections. J Med Chem 2020; 63:8388-8407. [PMID: 32696644 DOI: 10.1021/acs.jmedchem.0c00630] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic human pathogen that forms biofilms and produces virulence factors via quorum sensing (QS). Blocking the QS system in P. aeruginosa is an excellent strategy to reduce biofilm formation and the production of virulence factors. RhlR plays an essential role in the QS system of P. aeruginosa. We synthesized 55 analogues based on the chemical structure of 4-gingerol and evaluated their RhlR inhibitory activities using the cell-based reporter strain assay. Comprehensive structure-activity relationship studies identified the alkynyl ketone 30 as the most potent RhlR antagonist. This compound displayed selective RhlR antagonism over LasR and PqsR, strong inhibition of biofilm formation, and reduced production of virulence factors in P. aeruginosa. Furthermore, the survival rate of Tenebrio molitor larvae treated with 30 in vivo greatly improved. Therefore, compound 30, a pure RhlR antagonist, can be utilized for developing QS-modulating molecules in the control of P. aeruginosa infections.
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Affiliation(s)
- SangJin Nam
- College of Pharmacy, Korea University, 2511 Sejong-ro, Jochiwon-eup, Sejong 30019, Republic of Korea
| | - So-Young Ham
- School of Civil, Environmental and Architectural Engineering, Korea University, 145 Anam-ro, Seongbuk-Gu, Seoul 02841, Republic of Korea
| | - Hongmok Kwon
- College of Pharmacy, Korea University, 2511 Sejong-ro, Jochiwon-eup, Sejong 30019, Republic of Korea
| | - Han-Shin Kim
- Korean Peninsula Infrastructure Cooperation Team, Korea Institute of Civil Engineering and Building Technology (KICT), Goyang-si, Gyeonggi-do 10223, Republic of Korea
| | - Suhyun Moon
- College of Pharmacy, Korea University, 2511 Sejong-ro, Jochiwon-eup, Sejong 30019, Republic of Korea
| | - Jeong-Hoon Lee
- School of Civil, Environmental and Architectural Engineering, Korea University, 145 Anam-ro, Seongbuk-Gu, Seoul 02841, Republic of Korea
| | - Taehyeong Lim
- College of Pharmacy, Korea University, 2511 Sejong-ro, Jochiwon-eup, Sejong 30019, Republic of Korea
| | - Sang-Hyun Son
- College of Pharmacy, Korea University, 2511 Sejong-ro, Jochiwon-eup, Sejong 30019, Republic of Korea
| | - Hee-Deung Park
- School of Civil, Environmental and Architectural Engineering, Korea University, 145 Anam-ro, Seongbuk-Gu, Seoul 02841, Republic of Korea.,KU-KIST Graduate School of Converging Science and Technology, Korea University, 145 Anam-ro, Seongbuk-Gu, Seoul 02841, Republic of Korea
| | - Youngjoo Byun
- College of Pharmacy, Korea University, 2511 Sejong-ro, Jochiwon-eup, Sejong 30019, Republic of Korea.,Biomedical Research Center, Korea University Guro Hospital, 148 Gurodong-ro, Guro-gu, Seoul 08308, Republic of Korea
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27
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Zheng AQ, Hao YN, Guo TT, Shu Y, Wang JH. A fluorescence imaging protocol for correlating intracellular free cationic copper to the total uptaken copper by live cells. Talanta 2020; 220:121355. [PMID: 32928391 DOI: 10.1016/j.talanta.2020.121355] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/22/2020] [Accepted: 06/24/2020] [Indexed: 01/26/2023]
Abstract
A variety of fluorescence probes have been developed for fluorescence imaging of metals in biological cells. However, accurate quantification of metals with fluorescent approaches is challenging due to the difficulty in establishing a standard calibration curve in living cells. Herein, a fluorescence imaging protocol is developed for imaging intracellular Cu2+ and its correlation with the cellular uptake of copper. The total amount of intracellular Cu is detected by inductively coupled plasma mass spectrometry (ICP-MS) in parallel. Fluorescence imaging of Cu2+ is accomplished with Rhodamine B derivative modified carbon dots (CDs-Rbh) based on fluorescence resonance energy transfer (FRET) from CDs to rhodamine. Intracellular Cu2+ is correlated with fluorescence ratio at λem 500-600 nm (rhodamine) to λem 425-475 nm (CDs) with excitation at λex 405 nm. It is found that Cu2+ is linearly correlated with the total intracellular uptaken copper content, with a linear correlation between the relative fluorescence ratio in fluorescence imaging and intracellular Cu derived from ICP-MS, including both Cu(I) and Cu(II) species. The linear calibration equation is lg(F2/F1) = 0.00148 m[Cu]-0.3622. This approach facilitates further investigation and elucidation of copper transition in live cells and the evaluation of their cytotoxicity.
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Affiliation(s)
- An-Qi Zheng
- Research Center for Analytical Sciences, Department of Chemistry, College of Sciences, Northeastern University, Shenyang 110819, China
| | - Ya-Nan Hao
- Research Center for Analytical Sciences, Department of Chemistry, College of Sciences, Northeastern University, Shenyang 110819, China
| | - Ting-Ting Guo
- Research Center for Analytical Sciences, Department of Chemistry, College of Sciences, Northeastern University, Shenyang 110819, China
| | - Yang Shu
- Research Center for Analytical Sciences, Department of Chemistry, College of Sciences, Northeastern University, Shenyang 110819, China.
| | - Jian-Hua Wang
- Research Center for Analytical Sciences, Department of Chemistry, College of Sciences, Northeastern University, Shenyang 110819, China.
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28
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Ni S, Li B, Xu Y, Mao F, Li X, Lan L, Zhu J, Li J. Targeting virulence factors as an antimicrobial approach: Pigment inhibitors. Med Res Rev 2019; 40:293-338. [PMID: 31267561 DOI: 10.1002/med.21621] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 05/30/2019] [Accepted: 06/13/2019] [Indexed: 12/19/2022]
Abstract
The fascinating and dangerous colored pathogens contain unique chemically pigmented molecules, which give varied and efficient assistance as virulence factors to the crucial reproduction and growth of microbes. Therefore, multiple novel strategies and inhibitors have been developed in recent years that target virulence factor pigments. However, despite the importance and significance of this topic, it has not yet been comprehensively reviewed. Moreover, research groups around the world have made successful progress against antibacterial infections by targeting pigment production, including our serial works on the discovery of CrtN inhibitors against staphyloxanthin production in Staphylococcus aureus. On the basis of the previous achievements and recent progress of our group in this field, this article will be the first comprehensive review of pigment inhibitors against colored pathogens, especially S. aureus infections, and this article includes design strategies, representative case studies, advantages, limitations, and perspectives to guide future research.
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Affiliation(s)
- Shuaishuai Ni
- Cancer Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Baoli Li
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Yixiang Xu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Fei Mao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Xiaokang Li
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Lefu Lan
- State Key Laboratory of Drug Research, Shanghai Institute of Material Medical, Chinese Academy of Sciences, Shanghai, China
| | - Jin Zhu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Jian Li
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.,Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, Shanghai, China
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Flockton TR, Schnorbus L, Araujo A, Adams J, Hammel M, Perez LJ. Inhibition of Pseudomonas aeruginosa Biofilm Formation with Surface Modified Polymeric Nanoparticles. Pathogens 2019; 8:pathogens8020055. [PMID: 31022836 PMCID: PMC6631850 DOI: 10.3390/pathogens8020055] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/09/2019] [Accepted: 04/17/2019] [Indexed: 01/02/2023] Open
Abstract
The gram-negative bacterial pathogen Pseudomonas aeruginosa represents a prominent clinical concern. Due to the observed high levels of antibiotic resistance, copious biofilm formation, and wide array of virulence factors produced by these bacteria, new treatment technologies are required. Here, we present the development of a series of P. aeruginosa LecA-targeted polymeric nanoparticles and demonstrate the anti-adhesion and biofilm inhibitory properties of these constructs.
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Affiliation(s)
- Tyler R Flockton
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, USA.
| | - Logan Schnorbus
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, USA.
| | - Agustin Araujo
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, USA.
| | - Jill Adams
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, USA.
| | - Maryjane Hammel
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, USA.
| | - Lark J Perez
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, USA.
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Quorum Sensing as Antivirulence Target in Cystic Fibrosis Pathogens. Int J Mol Sci 2019; 20:ijms20081838. [PMID: 31013936 PMCID: PMC6515091 DOI: 10.3390/ijms20081838] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 04/11/2019] [Accepted: 04/11/2019] [Indexed: 12/17/2022] Open
Abstract
Cystic fibrosis (CF) is an autosomal recessive genetic disorder which leads to the secretion of a viscous mucus layer on the respiratory epithelium that facilitates colonization by various bacterial pathogens. The problem of drug resistance has been reported for all the species able to colonize the lung of CF patients, so alternative treatments are urgently needed. In this context, a valid approach is to investigate new natural and synthetic molecules for their ability to counteract alternative pathways, such as virulence regulating quorum sensing (QS). In this review we describe the pathogens most commonly associated with CF lung infections: Staphylococcus aureus, Pseudomonas aeruginosa, species of the Burkholderia cepacia complex and the emerging pathogens Stenotrophomonas maltophilia, Haemophilus influenzae and non-tuberculous Mycobacteria. For each bacterium, the QS system(s) and the molecules targeting the different components of this pathway are described. The amount of investigations published in the last five years clearly indicate the interest and the expectations on antivirulence therapy as an alternative to classical antibiotics.
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Soto-Aceves MP, Cocotl-Yañez M, Merino E, Castillo-Juárez I, Cortés-López H, González-Pedrajo B, Díaz-Guerrero M, Servín-González L, Soberón-Chávez G. Inactivation of the quorum-sensing transcriptional regulators LasR or RhlR does not suppress the expression of virulence factors and the virulence of Pseudomonas aeruginosa PAO1. MICROBIOLOGY-SGM 2019; 165:425-432. [PMID: 30707095 DOI: 10.1099/mic.0.000778] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Pseudomonas aeruginosa is an environmental bacterium but is also an opportunistic pathogen. The aim of this work is to evaluate the contribution of P. aeruginosa LasR and RhlR transcriptional regulators of the quorum-sensing response (QSR) to the production of virulence factors, and to its virulence in a mouse abscess model. The QSR is a complex regulatory network that modulates the expression of several virulence factors, including elastase, pyocyanin and rhamnolipids. LasR, when complexed with the auto-inducer 3-oxo-dodecanoyl lactone (3O-C12-HSL), produced by LasI, is at the top of the QSR regulatory cascade since it activates transcription of some genes encoding virulence factors (such as the gene coding for elastase, lasB) and also transcription of both rhlR and rhlI, encoding the synthase of the auto-inducer butanoyl-homoserine lactone (C4-HSL). In turn RhlR, coupled with C4-HSL, activates the transcription of genes encoding for the enzymes involved in pyocyanin and rhamnolipid production. Several efforts have been made to obtain inhibitors of LasR activity that would suppress the QSR. However, these attempts have used chemical compounds that might not be specific for LasR inactivation. In this work we show that individual inactivation of either lasR or rhlR did not block the QSR, nor did it impair P. aeruginosa virulence, and that even a lasR rhlR double mutant still presented residual virulence, even lacking the production of virulence factors. These results show that the inhibition of either lasR or rhlR is not a straightforward approach to blocking P. aeruginosa virulence, due to the great complexity of the QSR.
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Affiliation(s)
- Martín P Soto-Aceves
- 1Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México Apdo, Postal 70228, Ciudad Universitaria, 04510, CDMX, México
| | - Miguel Cocotl-Yañez
- 2Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, CDMX, México
| | - Enrique Merino
- 3Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca Mor, México
| | | | | | - Bertha González-Pedrajo
- 5Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510, CDMX, México
| | - Miguel Díaz-Guerrero
- 5Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510, CDMX, México
| | - Luis Servín-González
- 1Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México Apdo, Postal 70228, Ciudad Universitaria, 04510, CDMX, México
| | - Gloria Soberón-Chávez
- 1Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México Apdo, Postal 70228, Ciudad Universitaria, 04510, CDMX, México
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Espinosa-Valdés MP, Borbolla-Alvarez S, Delgado-Espinosa AE, Sánchez-Tejeda JF, Cerón-Nava A, Quintana-Romero OJ, Ariza-Castolo A, García-Del Río DF, Loza-Mejía MA. Synthesis, In Silico, and In Vitro Evaluation of Long Chain Alkyl Amides from 2-Amino-4-Quinolone Derivatives as Biofilm Inhibitors. Molecules 2019; 24:molecules24020327. [PMID: 30658415 PMCID: PMC6359591 DOI: 10.3390/molecules24020327] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 01/10/2019] [Accepted: 01/16/2019] [Indexed: 01/29/2023] Open
Abstract
Infection from multidrug resistant bacteria has become a growing health concern worldwide, increasing the need for developing new antibacterial agents. Among the strategies that have been studied, biofilm inhibitors have acquired relevance as a potential source of drugs that could act as a complement for current and new antibacterial therapies. Based on the structure of 2-alkyl-3-hydroxy-4-quinolone and N-acylhomoserine lactone, molecules that act as mediators of quorum sensing and biofilm formation in Pseudomonas aeruginosa, we designed, prepared, and evaluated the biofilm inhibition properties of long chain amide derivatives of 2-amino-4-quinolone in Staphylococcus aureus and P. aeruginosa. All compounds had higher biofilm inhibition activity in P. aeruginosa than in S. aureus. Particularly, compounds with an alkyl chain of 12 carbons exhibited the highest inhibition of biofilm formation. Docking scores and molecular dynamics simulations of the complexes of the tested compounds within the active sites of proteins related to quorum sensing had good correlation with the experimental results, suggesting the diminution of biofilm formation induced by these compounds could be related to the inhibition of these proteins.
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Affiliation(s)
- Mariana Paola Espinosa-Valdés
- Facultad de Ciencias Químicas, Universidad La Salle-México. Av. Benjamin Franklin 45, Cuauhtémoc, Mexico City 06140, Mexico.
| | - Sara Borbolla-Alvarez
- Facultad de Ciencias Químicas, Universidad La Salle-México. Av. Benjamin Franklin 45, Cuauhtémoc, Mexico City 06140, Mexico.
| | - Ana Elena Delgado-Espinosa
- Facultad de Ciencias Químicas, Universidad La Salle-México. Av. Benjamin Franklin 45, Cuauhtémoc, Mexico City 06140, Mexico.
| | - Juan Francisco Sánchez-Tejeda
- Facultad de Ciencias Químicas, Universidad La Salle-México. Av. Benjamin Franklin 45, Cuauhtémoc, Mexico City 06140, Mexico.
| | - Anabelle Cerón-Nava
- Facultad de Ciencias Químicas, Universidad La Salle-México. Av. Benjamin Franklin 45, Cuauhtémoc, Mexico City 06140, Mexico.
| | - Osvaldo Javier Quintana-Romero
- Departamento de Química Orgánica, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Av. Instituto Politécnico Nacional 2508, Mexico City 07360, Mexico.
| | - Armando Ariza-Castolo
- Departamento de Química Orgánica, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Av. Instituto Politécnico Nacional 2508, Mexico City 07360, Mexico.
| | - Diego Fernando García-Del Río
- Facultad de Ciencias Químicas, Universidad La Salle-México. Av. Benjamin Franklin 45, Cuauhtémoc, Mexico City 06140, Mexico.
| | - Marco A Loza-Mejía
- Facultad de Ciencias Químicas, Universidad La Salle-México. Av. Benjamin Franklin 45, Cuauhtémoc, Mexico City 06140, Mexico.
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Janczewski Ł, Burchacka E, Psurski M, Ciekot J, Gajda A, Gajda T. New diaryl ω-(isothiocyanato)alkylphosphonates and their mercapturic acids as potential antibacterial agents. Life Sci 2019; 219:264-271. [PMID: 30658100 DOI: 10.1016/j.lfs.2019.01.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 01/14/2019] [Accepted: 01/14/2019] [Indexed: 11/17/2022]
Abstract
Thirty-four novel, diaryl ω-(isothiocyanato)alkylphosphonates with chlorine atom and methoxy, dimethoxy, methylsulfanyl, or methoxycarbonyl groups at ortho, meta, or para positions of the phenyl ring, and with an unbranched alkyl chain (n = 2-6) were designed and synthesized in a one-pot reaction in 11-76% yields. All isothiocyanates thus generated were evaluated for the first time for antibacterial activity on Pseudomonas aeruginosa and Staphylococcus aureus bacterial strains, and had satisfactory antibacterial activity in most cases. The highest activity, similar to that of reference gentamicin activity against S. aureus, was seen in compounds 9 and 13 (1.5 ± 0.1 and 2.5 ± 0.2 μM, respectively), whereas for P. aeruginosa more than half of tested compounds proved to be more effective than gentamicin. Additionally, selected isothiocyanates (9, 13, 18, and 23) were transformed in 52-73% yields into mercapturic acids 42-45, which also exhibited satisfactory antibacterial effect against S. aureus strain.
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Affiliation(s)
- Łukasz Janczewski
- Institute of Organic Chemistry, Faculty of Chemistry, Lodz University of Technology, 116 Żeromskiego St., 90-924 Łódź, Poland
| | - Ewa Burchacka
- Department of Medicinal Chemistry and Microbiology, Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
| | - Mateusz Psurski
- Department of Experimental Oncology, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 12 Rudolfa Weigla St., 53-144 Wrocław, Poland
| | - Jarosław Ciekot
- Department of Experimental Oncology, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 12 Rudolfa Weigla St., 53-144 Wrocław, Poland
| | - Anna Gajda
- Institute of Organic Chemistry, Faculty of Chemistry, Lodz University of Technology, 116 Żeromskiego St., 90-924 Łódź, Poland
| | - Tadeusz Gajda
- Institute of Organic Chemistry, Faculty of Chemistry, Lodz University of Technology, 116 Żeromskiego St., 90-924 Łódź, Poland
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Sarkar R, Mittal N, Sorensen J, Sen T. A Comparison of the Bioactivity of Usnic Acid versus Methylphloroacetophenone. Nat Prod Commun 2018. [DOI: 10.1177/1934578x1801301224] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The identification of natural products that disrupt biofilm formation has become an area of recently expanded interest in combating antibiotic resistance. The formation of biofilms has been correlated with increased pathogenesis in many strains of Gram-negative bacteria. Molecules that disrupt the formation of biofilms therefore represent a potentially novel way to combat pathogenesis. Lichen natural products are an underexplored source of biofilm disrupting natural products. We have investigated the biofilm disrupting activity of the lichen natural product usnic acid (UA) in comparison to the biosynthetic precursor methylphloroacetophenone (MPA). We have observed in our assays that UA is more bioactive than MPA, suggesting a rationale for the biosynthesis of UA in a wide variety of lichen species. These results suggest that lichen natural products may prove to be a rich source of biofilm inhibitors.
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Affiliation(s)
- Ratul Sarkar
- Department of Pharmaceutical Technology, Jadavpur University, Kolkata-700032, India
| | - Navriti Mittal
- Department of Chemistry, University of Manitoba, Winnipeg, R3T2N2, Canada
| | - John Sorensen
- Department of Chemistry, University of Manitoba, Winnipeg, R3T2N2, Canada
| | - Tuhinadri Sen
- Department of Pharmaceutical Technology, Jadavpur University, Kolkata-700032, India
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35
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Matilla MA, Krell T. The effect of bacterial chemotaxis on host infection and pathogenicity. FEMS Microbiol Rev 2018; 42:4563582. [PMID: 29069367 DOI: 10.1093/femsre/fux052] [Citation(s) in RCA: 152] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 10/19/2017] [Indexed: 12/26/2022] Open
Abstract
Chemotaxis enables microorganisms to move according to chemical gradients. Although this process requires substantial cellular energy, it also affords key physiological benefits, including enhanced access to growth substrates. Another important implication of chemotaxis is that it also plays an important role in infection and disease, as chemotaxis signalling pathways are broadly distributed across a variety of pathogenic bacteria. Furthermore, current research indicates that chemotaxis is essential for the initial stages of infection in different human, animal and plant pathogens. This review focuses on recent findings that have identified specific bacterial chemoreceptors and corresponding chemoeffectors associated with pathogenicity. Pathogenicity-related chemoeffectors are either host and niche-specific signals or intermediates of the host general metabolism. Plant pathogens were found to contain an elevated number of chemotaxis signalling genes and functional studies demonstrate that these genes are critical for their ability to enter the host. The expanding body of knowledge of the mechanisms underlying chemotaxis in pathogens provides a foundation for the development of new therapeutic strategies capable of blocking infection and preventing disease by interfering with chemotactic signalling pathways.
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Affiliation(s)
- Miguel A Matilla
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain
| | - Tino Krell
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain
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36
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Soukarieh F, Williams P, Stocks MJ, Cámara M. Pseudomonas aeruginosa Quorum Sensing Systems as Drug Discovery Targets: Current Position and Future Perspectives. J Med Chem 2018; 61:10385-10402. [PMID: 29999316 DOI: 10.1021/acs.jmedchem.8b00540] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Antimicrobial resistance (AMR) is a serious threat to public health globally, manifested by the frequent emergence of multidrug resistant pathogens that render current chemotherapy inadequate. Health organizations worldwide have recognized the severity of this crisis and implemented action plans to contain its adverse consequences and prolong the utility of conventional antibiotics. Hence, there is a pressing need for new classes of antibacterial agents with novel modes of action. Quorum sensing (QS), a communication system employed by bacterial populations to coordinate virulence gene expression, is a potential target that has been intensively investigated over the past decade. This Perspective will focus on recent advances in targeting the three main quorum sensing systems ( las, rhl, and pqs) of a major opportunistic human pathogen, Pseudomonas aeruginosa, and will specifically evaluate the medicinal chemistry strategies devised to develop QS inhibitors from a drug discovery perspective.
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Affiliation(s)
- Fadi Soukarieh
- School of Life Sciences, Centre for Biomolecular Sciences , University of Nottingham , Nottingham , NG7 2RD , U.K
| | - Paul Williams
- School of Life Sciences, Centre for Biomolecular Sciences , University of Nottingham , Nottingham , NG7 2RD , U.K
| | - Michael J Stocks
- School of Pharmacy, Centre for Biomolecular Sciences , University of Nottingham , Nottingham , NG7 2RD , U.K
| | - Miguel Cámara
- School of Life Sciences, Centre for Biomolecular Sciences , University of Nottingham , Nottingham , NG7 2RD , U.K
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37
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O'Reilly MC, Dong SH, Rossi FM, Karlen KM, Kumar RS, Nair SK, Blackwell HE. Structural and Biochemical Studies of Non-native Agonists of the LasR Quorum-Sensing Receptor Reveal an L3 Loop "Out" Conformation for LasR. Cell Chem Biol 2018; 25:1128-1139.e3. [PMID: 30033130 DOI: 10.1016/j.chembiol.2018.06.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 02/27/2018] [Accepted: 06/20/2018] [Indexed: 02/06/2023]
Abstract
Chemical strategies to block quorum sensing (QS) could provide a route to attenuate virulence in bacterial pathogens. Considerable research has focused on this approach in Pseudomonas aeruginosa, which uses the LuxR-type receptor LasR to regulate much of its QS network. Non-native ligands that antagonize LasR have been developed, yet we have little understanding of the mode by which these compounds interact with LasR and alter its function, as the receptor is unstable in their presence. Herein, we report an approach to circumvent this challenge through the study of a series of synthetic LasR agonists with varying levels of potency. Structural investigations of these ligands with the LasR ligand-binding domain reveal that certain agonists can enforce a conformation that deviates from that observed for other, often more potent agonists. These results, when combined with cell-based and biophysical analyses, suggest a functional model for LasR that could guide future ligand design.
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Affiliation(s)
- Matthew C O'Reilly
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Shi-Hui Dong
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, IL 61801, USA
| | - Francis M Rossi
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Kaleigh M Karlen
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Rohan S Kumar
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Satish K Nair
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, IL 61801, USA.
| | - Helen E Blackwell
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA.
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38
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Morales E, González-Valdez A, Servín-González L, Soberón-Chávez G. Pseudomonas aeruginosa quorum-sensing response in the absence of functional LasR and LasI proteins: the case of strain 148, a virulent dolphin isolate. FEMS Microbiol Lett 2018; 364:3861964. [PMID: 28591849 DOI: 10.1093/femsle/fnx119] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 06/06/2017] [Indexed: 02/06/2023] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that presents a complex regulatory network called 'quorum-sensing', which is responsible for the transcription of genes coding for several traits implicated in its pathogenicity. Strain 148 is a dolphin isolate that has been shown to produce quorum-sensing-regulated virulence traits and to be virulent in a mouse model, despite the fact that it contains a 20-kbp deletion that eliminates from the chromosome the lasR gene and the lasI promoter. LasR is a key quorum-sensing transcriptional regulator that, when coupled with the autoinducer 3-oxo-dodecanoyl homoserine lactone (3O-C12-HSL) produced by LasI, activates transcription of genes coding for some virulence-associated traits such as elastase, lasI, rhlI and rhlR. RhlR is also a key quorum-sensing transcriptional regulator that, when interacting with the autoinducer butanoyl homoserine lactone (C4-HSL) that is produced by the synthase RhlI, activates the genes involved in the synthesis of some virulence-associated traits, as rhamnolipids and pyocyanin. We describe that in P. aeruginosa 148, the LasR/3O-C12-HSL-independent rhlR transcriptional activation is due to the release of the negative effect of Vfr (a CRP-ortholog) caused by the insertion of an IS element in vfr, and that rhlI transcription is driven from the rhlR promoter, forming the rhlR-I operon.
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Affiliation(s)
- Estefanía Morales
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510, México, D. F. México
| | - Abigail González-Valdez
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510, México, D. F. México
| | - Luis Servín-González
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510, México, D. F. México
| | - Gloria Soberón-Chávez
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510, México, D. F. México
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39
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Nizalapur S, Kimyon O, Yee E, Bhadbhade MM, Manefield M, Willcox M, Black DS, Kumar N. Synthesis and biological evaluation of novel acyclic and cyclic glyoxamide based derivatives as bacterial quorum sensing and biofilm inhibitors. Org Biomol Chem 2017; 15:5743-5755. [PMID: 28654117 DOI: 10.1039/c7ob01011g] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Bacteria regulate the expression of various virulence factors and processes such as biofilm formation through a chemically-mediated communication mechanism called quorum sensing. Bacterial biofilms contribute to antimicrobial resistance as they can protect bacteria embedded in their matrix from the effects of antibiotics. Thus, developing novel quorum sensing inhibitors, which can inhibit biofilm formation, is a viable strategy to combat antimicrobial resistance. We report herein the synthesis of novel acyclic and cyclic glyoxamide derivatives via ring-opening reactions of N-acylisatins. These compounds were evaluated for their quorum sensing inhibition activity against P. aeruginosa MH602 and E. coli MT102. Compounds 20, 21 and 30 displayed the greatest quorum sensing inhibition activity against P. aeruginosa MH602, with 71.5%, 71.5%, and 74% inhibition, respectively, at 250 μM. Compounds 18, 20 and 21 exhibited the greatest QSI activity against E. coli MT102, with 71.5%, 72.1% and 73.5% quorum sensing inhibition activity, respectively. In addition, the biofilm inhibition activity was also investigated against P. aeruginosa and E. coli at 250 μM. The glyoxamide compounds 16, 18 and 19 exhibited 71.2%, 66.9%, and 66.5% inhibition of P. aeruginosa biofilms, respectively; whereas compounds 12, 20, and 22 showed the greatest inhibitory activity against E. coli biofilms with 87.9%, 90.8% and 89.5%, respectively. Finally, the determination of the in vitro toxicity against human MRC-5 lung fibroblast cells revealed that these novel glyoxamide compounds are non-toxic to human cells.
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Affiliation(s)
| | - Onder Kimyon
- School of Civil and Environmental Engineering, UNSW Australia, Sydney, NSW 2052, Australia
| | - Eugene Yee
- School of Chemistry, UNSW Sydney, NSW 2052, Australia.
| | - Mohan M Bhadbhade
- Solid State & Elemental Analysis Unit, Mark Wainwright Analytical Centre, Division of Research, UNSW Australia, NSW 2052, Australia
| | - Mike Manefield
- School of Civil and Environmental Engineering, UNSW Australia, Sydney, NSW 2052, Australia
| | - Mark Willcox
- School of Optometry and Vision Science, UNSW Australia, Sydney, NSW 2052, Australia
| | | | - Naresh Kumar
- School of Chemistry, UNSW Sydney, NSW 2052, Australia.
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40
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Zhang DW, Zhang YM, Li J, Zhao TQ, Gu Q, Lin F. Ultrasonic-assisted synthesis of 1,4-disubstituted 1,2,3-triazoles via various terminal acetylenes and azide and their quorum sensing inhibition. ULTRASONICS SONOCHEMISTRY 2017; 36:343-353. [PMID: 28069219 DOI: 10.1016/j.ultsonch.2016.12.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 12/07/2016] [Accepted: 12/08/2016] [Indexed: 05/28/2023]
Abstract
An efficient synthesis of 1,4-disubstituted 1,2,3-triazole derivatives was studied. 1,4-Disubstituted 1,2,3-triazoles containing isoxazole and thymidine structures were synthesized in 84-96% yields starting from various terminal isoxazole ether alkynes and β-thymidine azide derivatives via a 1,3-dispolar cycloaddition using copper acetate, sodium ascorbate as the catalyst under ultrasonic assisted condition. All the target compounds were characterized by HRMS, FT-IR, 1H NMR and 13C NMR spectroscopy. Furthermore, the quorum sensing inhibitory activities of synthesized compounds were evaluated with Chromobacterium violaceum (C. Violaceum CV026) based on their inhibition of violacein production, with compound C10-HSL as a positive control. The compounds 8a, 8c and 8f exhibited considerable levels of inhibitory activity against violacein production, and IC50 values were 217±19, 223±20 and 42.8±4.5μM, respectively, which highlighted the potential of these compounds as lead structures for further research towards the development of novel QS inhibitors.
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Affiliation(s)
- Da-Wei Zhang
- College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China
| | - Yu-Min Zhang
- College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China
| | - Jing Li
- College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China
| | - Tian-Qi Zhao
- College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China
| | - Qiang Gu
- College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China.
| | - Feng Lin
- College of Life Sciences, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China.
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41
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Suneby EG, Herndon LR, Schneider TL. Pseudomonas aeruginosa LasR·DNA Binding Is Directly Inhibited by Quorum Sensing Antagonists. ACS Infect Dis 2017; 3:183-189. [PMID: 28075113 DOI: 10.1021/acsinfecdis.6b00163] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Inhibition of quorum sensing in Pseudomonas aeruginosa is of interest as a possible antivirulence strategy for this pathogenic bacterium. The LasR regulator protein is important in coordinating gene expression in response to quorum sensing signaling molecules. One predominant strategy for LasR inhibition is the development of small-molecule antagonists that mimic the native autoinducer, though the mechanism by which they inactivate LasR is not known. This work reveals that multiple antagonists function by binding to and stabilizing LasR in a conformation that renders it unable to bind DNA. Further analysis of purified LasR complexed with known antagonists indicates that DNA binding can be recovered with the addition of native autoinducer, providing insights into the reversibility of ligand binding for this transcription factor. This in vitro assay could be used to assess future promising antagonists and complements existing cell-based reporter assays.
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Affiliation(s)
- Emma G. Suneby
- Department of Chemistry, Connecticut College, New London, Connecticut 06320, United States
| | - Leslie R. Herndon
- Department
of Chemistry, Smith College, Northampton, Massachusetts 01063, United States
| | - Tanya L. Schneider
- Department of Chemistry, Connecticut College, New London, Connecticut 06320, United States
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42
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Biswas NN, Yu TT, Kimyon Ö, Nizalapur S, Gardner CR, Manefield M, Griffith R, Black DS, Kumar N. Synthesis of antimicrobial glucosamides as bacterial quorum sensing mechanism inhibitors. Bioorg Med Chem 2017; 25:1183-1194. [DOI: 10.1016/j.bmc.2016.12.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 12/12/2016] [Accepted: 12/19/2016] [Indexed: 10/25/2022]
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43
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Capilato JN, Philippi SV, Reardon T, McConnell A, Oliver DC, Warren A, Adams JS, Wu C, Perez LJ. Development of a novel series of non-natural triaryl agonists and antagonists of the Pseudomonas aeruginosa LasR quorum sensing receptor. Bioorg Med Chem 2016; 25:153-165. [PMID: 27825554 DOI: 10.1016/j.bmc.2016.10.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 10/13/2016] [Accepted: 10/17/2016] [Indexed: 10/20/2022]
Abstract
Bacterial chemical communication, through a process called quorum sensing (QS), plays a central role in infection in numerous bacterial pathogens. Quorum sensing in Pseudomonas aeruginosa employs a series of small molecule receptors including the master QS regulator, LasR. In this study we investigate a non-natural triaryl series of LasR ligands using a combination of structure activity relationship studies and computational modeling. These studies have enabled the identification of key structural requirements for ligand binding and have revealed a new strategy for inducing the therapeutically relevant antagonism of LasR.
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Affiliation(s)
- Joseph N Capilato
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, United States
| | - Shane V Philippi
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, United States
| | - Thomas Reardon
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, United States
| | - Ashleigh McConnell
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, United States
| | - Dylan C Oliver
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, United States
| | - Amy Warren
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, United States
| | - Jill S Adams
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, United States
| | - Chun Wu
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, United States
| | - Lark J Perez
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, United States
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44
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Thomann A, Brengel C, Börger C, Kail D, Steinbach A, Empting M, Hartmann RW. Structure-Activity Relationships of 2-Sufonylpyrimidines as Quorum-Sensing Inhibitors to Tackle Biofilm Formation and eDNA Release ofPseudomonas aeruginosa. ChemMedChem 2016; 11:2522-2533. [DOI: 10.1002/cmdc.201600419] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 09/27/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Andreas Thomann
- Helmholtz Institute for Pharmaceutical Research Saarland; Department of Drug Design and Optimization; Campus E 8.1 66123 Saarbrücken Germany
| | - Christian Brengel
- Helmholtz Institute for Pharmaceutical Research Saarland; Department of Drug Design and Optimization; Campus E 8.1 66123 Saarbrücken Germany
| | - Carsten Börger
- PharmBioTec GmbH; Science Park 1 66123 Saarbrücken Germany
| | - Dagmar Kail
- PharmBioTec GmbH; Science Park 1 66123 Saarbrücken Germany
| | - Anke Steinbach
- Helmholtz Institute for Pharmaceutical Research Saarland; Department of Drug Design and Optimization; Campus E 8.1 66123 Saarbrücken Germany
| | - Martin Empting
- Helmholtz Institute for Pharmaceutical Research Saarland; Department of Drug Design and Optimization; Campus E 8.1 66123 Saarbrücken Germany
| | - Rolf W. Hartmann
- Helmholtz Institute for Pharmaceutical Research Saarland; Department of Drug Design and Optimization; Campus E 8.1 66123 Saarbrücken Germany
- Saarland University; Department of Pharmacy, Pharmaceutical and Medicinal Chemistry; Campus C 2.3 66123 Saarbrücken Germany
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45
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Welsh MA, Blackwell HE. Chemical probes of quorum sensing: from compound development to biological discovery. FEMS Microbiol Rev 2016; 40:774-94. [PMID: 27268906 DOI: 10.1093/femsre/fuw009] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/06/2016] [Indexed: 01/20/2023] Open
Abstract
Bacteria can utilize chemical signals to coordinate the expression of group-beneficial behaviors in a method of cell-cell communication called quorum sensing (QS). The discovery that QS controls the production of virulence factors and biofilm formation in many common pathogens has driven an explosion of research aimed at both deepening our fundamental understanding of these regulatory networks and developing chemical agents that can attenuate QS signaling. The inherently chemical nature of QS makes studying these pathways with small molecule tools a complementary approach to traditional microbiology techniques. Indeed, chemical tools are beginning to yield new insights into QS regulation and provide novel strategies to inhibit QS. Here, we review the most recent advances in the development of chemical probes of QS systems in Gram-negative bacteria, with an emphasis on the opportunistic pathogen Pseudomonas aeruginosa We first describe reports of novel small molecule modulators of QS receptors and QS signal synthases. Next, in several case studies, we showcase how chemical tools have been deployed to reveal new knowledge of QS biology and outline lessons for how researchers might best target QS to combat bacterial virulence. To close, we detail the outstanding challenges in the field and suggest strategies to overcome these issues.
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Affiliation(s)
- Michael A Welsh
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI 53706, USA
| | - Helen E Blackwell
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI 53706, USA
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46
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Kafle P, Amoh AN, Reaves JM, Suneby EG, Tutunjian KA, Tyson RL, Schneider TL. Molecular Insights into the Impact of Oxidative Stress on the Quorum-Sensing Regulator Protein LasR. J Biol Chem 2016; 291:11776-86. [PMID: 27053110 DOI: 10.1074/jbc.m116.719351] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Indexed: 01/05/2023] Open
Abstract
The LasR regulator protein functions at the top of the Pseudomonas aeruginosa quorum-sensing hierarchy and is implicated in promoting bacterial virulence. Of note is recent evidence that this transcription factor may also respond to oxidative stress. Here, all cysteines in LasR were inspected to deduce their redox sensitivity and to probe the connection between stress response and LasR activity using purified LasR and individual LasR domains. Cys(79) in the ligand binding domain of LasR appears to be important for ligand recognition and folding of this domain to potentiate DNA binding but does not seem to be sensitive to oxidative stress when bound to its native ligand. Two cysteines in the DNA binding domain of LasR do form a disulfide bond when treated with hydrogen peroxide, and formation of this Cys(201)-Cys(203) disulfide bond appears to disrupt the DNA binding activity of the transcription factor. Mutagenesis of either of these cysteines leads to expression of a protein that no longer binds DNA. A cell-based reporter assay linking LasR function with β-galactosidase activity gave results consistent with those obtained with purified LasR. This work provides a possible mechanism for oxidative stress response by LasR and indicates that multiple cysteines within the protein may prove to be useful targets for disabling its activity.
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Affiliation(s)
- Prapti Kafle
- From the Department of Chemistry, Connecticut College, New London, Connecticut 06320
| | - Amanda N Amoh
- From the Department of Chemistry, Connecticut College, New London, Connecticut 06320
| | - Jocelyn M Reaves
- From the Department of Chemistry, Connecticut College, New London, Connecticut 06320
| | - Emma G Suneby
- From the Department of Chemistry, Connecticut College, New London, Connecticut 06320
| | - Kathryn A Tutunjian
- From the Department of Chemistry, Connecticut College, New London, Connecticut 06320
| | - Reed L Tyson
- From the Department of Chemistry, Connecticut College, New London, Connecticut 06320
| | - Tanya L Schneider
- From the Department of Chemistry, Connecticut College, New London, Connecticut 06320
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47
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Wu B, Capilato J, Pham MP, Walker J, Spur B, Rodriguez A, Perez LJ, Yin K. Lipoxin A4 augments host defense in sepsis and reduces Pseudomonas aeruginosa virulence through quorum sensing inhibition. FASEB J 2016; 30:2400-10. [PMID: 26965685 DOI: 10.1096/fj.201500029r] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 02/29/2016] [Indexed: 12/13/2022]
Abstract
Bacterial infections can quickly turn into sepsis, with its attendant clinical sequelae of inflammation, tissue injury, and organ failure. Paradoxically, sustained inflammation in sepsis may lead to immune suppression, because of which the host is unable to clear the existing infection. Use of agents that suppress the inflammatory response may accelerate host immune suppression, whereas use of traditional antibiotics does not significantly affect inflammation. In this study, we investigated whether lipoxin A4 (LXA4), a specialized, proresolution lipid mediator, could increase neutrophil phagocytic activity as well as reduce bacterial virulence. Using the mouse cecal ligation and puncture (CLP) model of sepsis, the administration of LXA4 (7 μg/kg i.v.) 1 h after surgery increased neutrophil phagocytic ability and Fcγ receptor I (CD64) expression. Ex vivo studies have confirmed that the direct addition of LXA4 to CLP neutrophils increased phagocytic ability but not CD64 expression. LXA4 did not affect neutrophils taken from control mice in which CD64 expression was minimal. Taken together with in vivo data, these results suggest that LXA4 directly augments CD64-mediated neutrophil phagocytic ability but does not directly increase neutrophil CD64 expression. Bacterial communication and virulence is regulated by quorum sensing inducers. In Pseudomonas aeruginosa, virulence is induced with release of various virulence factors, by N-3-oxododecanolyl homoserine lactone binding to the quorum sensing receptor, LasR. We show that LXA4 is an inhibitor of LasR in P. aeruginosa and that it decreases the release of pyocyanin exotoxin. These results suggest that LXA4 has the novel dual properties of increasing host defense and decreasing pathogen virulence by inhibiting quorum sensing.-Wu, B., Capilato, J., Pham, M. P., Walker, J., Spur, B., Rodriguez, A., Perez, L. J., Yin, K. Lipoxin A4 augments host defense in sepsis and reduces Pseudomonas aeruginosa virulence through quorum sensing inhibition.
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Affiliation(s)
- Benedict Wu
- Department of Cell Biology, Rowan University School of Osteopathic Medicine, Stratford, New Jersey, USA; and
| | - Joseph Capilato
- Department of Chemistry and Biochemistry, Rowan University, Glassboro, New Jersey, USA
| | - Michelle P Pham
- Department of Chemistry and Biochemistry, Rowan University, Glassboro, New Jersey, USA
| | - Jean Walker
- Department of Cell Biology, Rowan University School of Osteopathic Medicine, Stratford, New Jersey, USA; and
| | - Bernd Spur
- Department of Cell Biology, Rowan University School of Osteopathic Medicine, Stratford, New Jersey, USA; and
| | - Ana Rodriguez
- Department of Cell Biology, Rowan University School of Osteopathic Medicine, Stratford, New Jersey, USA; and
| | - Lark J Perez
- Department of Chemistry and Biochemistry, Rowan University, Glassboro, New Jersey, USA
| | - Kingsley Yin
- Department of Cell Biology, Rowan University School of Osteopathic Medicine, Stratford, New Jersey, USA; and
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48
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O’Reilly MC, Blackwell HE. Structure-Based Design and Biological Evaluation of Triphenyl Scaffold-Based Hybrid Compounds as Hydrolytically Stable Modulators of a LuxR-Type Quorum Sensing Receptor. ACS Infect Dis 2016; 2:32-38. [PMID: 26807436 PMCID: PMC4709822 DOI: 10.1021/acsinfecdis.5b00112] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Indexed: 12/28/2022]
Abstract
![]()
Many
common bacterial pathogens utilize quorum sensing to coordinate group
behaviors and initiate virulence at high cell densities. The use of
small molecules to block quorum sensing provides a means of abrogating
pathogenic phenotypes, but many known quorum sensing modulators have
limitations, including hydrolytic instability and displaying non-monotonic
dose curves (indicative of additional targets and/or modes of action).
To address these issues, we undertook a structure-based scaffold-hopping
approach to develop new chemical modulators of the LasR quorum sensing
receptor in Pseudomonas aeruginosa.
We combined components from a triphenyl derivative known to strongly
agonize LasR with chemical moieties known for LasR antagonism and
generated potent LasR antagonists that are hydrolytically stable across
a range of pH values. Additionally, many of these antagonists do not
exhibit non-monotonic dose effects, delivering probes that inhibit
LasR across a wider range of assay conditions relative to known lactone-based
ligands.
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Affiliation(s)
- Matthew C. O’Reilly
- Department of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Helen E. Blackwell
- Department of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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49
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Nizalapur S, Kimyon Ö, Biswas NN, Gardner CR, Griffith R, Rice SA, Manefield M, Willcox M, Black DS, Kumar N. Design, synthesis and evaluation of N-aryl-glyoxamide derivatives as structurally novel bacterial quorum sensing inhibitors. Org Biomol Chem 2016; 14:680-693. [DOI: 10.1039/c5ob01973g] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Bacteria cooperatively regulate the expression of many phenotypes through a mechanism called quorum sensing (QS).
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Affiliation(s)
| | - Önder Kimyon
- School of Biotechnology and Biomolecular Sciences (BABS)
- UNSW Australia
- Sydney
- Australia
| | | | | | | | - Scott A. Rice
- Centre for Marine Biology
- School of Biological
- Earth and Environmental Sciences
- UNSW Australia
- Sydney
| | - Mike Manefield
- School of Biotechnology and Biomolecular Sciences (BABS)
- UNSW Australia
- Sydney
- Australia
| | - Mark Willcox
- School of Optometry and Vision Science
- UNSW Australia
- Sydney
- Australia
| | | | - Naresh Kumar
- School of Chemistry
- UNSW Australia
- Sydney
- Australia
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50
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Moore JD, Rossi FM, Welsh MA, Nyffeler KE, Blackwell HE. A Comparative Analysis of Synthetic Quorum Sensing Modulators in Pseudomonas aeruginosa: New Insights into Mechanism, Active Efflux Susceptibility, Phenotypic Response, and Next-Generation Ligand Design. J Am Chem Soc 2015; 137:14626-39. [PMID: 26491787 PMCID: PMC4665086 DOI: 10.1021/jacs.5b06728] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Quorum sensing (QS) is a chemical signaling mechanism that allows bacterial populations to coordinate gene expression in response to social and environmental cues. Many bacterial pathogens use QS to initiate infection at high cell densities. Over the past two decades, chemical antagonists of QS in pathogenic bacteria have attracted substantial interest for use both as tools to further elucidate QS mechanisms and, with further development, potential anti-infective agents. Considerable recent research has been devoted to the design of small molecules capable of modulating the LasR QS receptor in the opportunistic pathogen Pseudomonas aeruginosa. These molecules hold significant promise in a range of contexts; however, as most compounds have been developed independently, comparative activity data for these compounds are scarce. Moreover, the mechanisms by which the bulk of these compounds act are largely unknown. This paucity of data has stalled the choice of an optimal chemical scaffold for further advancement. Herein, we submit the best-characterized LasR modulators to standardized cell-based reporter and QS phenotypic assays in P. aeruginosa, and we report the first comprehensive set of comparative LasR activity data for these compounds. Our experiments uncovered multiple interesting mechanistic phenomena (including a potential alternative QS-modulatory ligand binding site/partner) that provide new, and unexpected, insights into the modes by which many of these LasR ligands act. The lead compounds, data trends, and mechanistic insights reported here will significantly aid the design of new small molecule QS inhibitors and activators in P. aeruginosa, and in other bacteria, with enhanced potencies and defined modes of action.
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Affiliation(s)
- Joseph D Moore
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Francis M Rossi
- Department of Chemistry, SUNY Cortland , Cortland, New York 13045, United States
| | - Michael A Welsh
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Kayleigh E Nyffeler
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Helen E Blackwell
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
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